Method for the production of improved pulp

Abstract

Compositions and method for improving properties of pulp produced or reducing the digester cycle time in alkaline chemical pulping processes in which an effective amount of at least one selected phosphonate or carboxylate compound or mixtures thereof is admixed with the alkaline aqueous mixture in the digester of the chemical pulping process. The compositions and method are especially well suited for use in the Kraft pulping process.

Description

BACKGROUND OF THE INVENTION

[0002] This invention relates to compositions and methods for the production of enhanced pulp in chemical pulping processes. More particularly, this invention relates to compositions and methods for producing enhanced pulp in the Kraft pulp process. This invention further relates to compositions and methods for improving the pulp production rate in chemical pulping processes.

[0003] Worldwide, pulp making is carried out on a large scale. Accordingly, it is highly desirable that such pulp making operations be carried out in a cost effective, efficient operation with minimum equipment downtime and with minimum periods of reduced process equipment operating efficiency. It is further desired to produce wood pulp of high strength, quality and high yield.

[0004] The basic steps in industrial pulp making are to convert plant fiber into chips, convert chips into pulp, (optionally) bleach the pulp, wash the pulp, and transform the pulp into suitable paper which can be used in paper products such as writing paper, newsprint and paper for documents.

[0005] Typically, several chemical pulping processes are used in industrial pulp making operations. Well known industrial alkaline chemical pulping processes include the Kraft (or sulfate), soda and alkaline sulfite processes. The Kraft process makes the strongest fibers of any pulp making process and is the most commonly used pulp making process in part due to its efficient recovery process for the cooking chemicals. Nevertheless some degree of degradation of the cellulose fibers occurs under conditions of the Kraft cook leading to shorter fibers and higher amounts of dissolved cellulose.

[0006] While the present invention has applicability to any of the above alkaline chemical pulping processes, it is particularly useful with the Kraft process and, as such, the Kraft process is described in more detail below.

[0007] Initially, suitable trees are harvested, debarked and then chipped into suitable size flakes or chips. These wood chips are sorted with the small and the large chips being removed. The remaining suitable wood chips are then charged to a digester (which is a vessel or tank for holding the chips and an aqueous digesting composition and which can be operated in either a batch or continuous mode as desired).

[0008] Illustratively, in a batch type digester, wood chips and a mixture of “weak black liquor,” the spent liquor from a previous digester cook, and “white liquor,” a solution of sodium hydroxide and sodium sulfide, that is either fresh or from the chemical recovery plant, is pumped into the digester. In the cooking process, lignin, which binds the wood fiber together, is dissolved in the white liquor forming pulp and black liquor.

[0009] The digester is sealed and the digester composition is heated to a suitable cook temperature, e.g. temperatures up to about 180° C., under high pressure. After an allotted cooking time at a particular temperature and pressure (H-factor) in the digester, the digester contents (pulp and black liquor) are transferred to a holding tank. The pulp in the holding tank is transferred to the brown stock washers while the liquid (black liquor formed in the digester) is sent to the black liquor recovery area. The black liquor is evaporated to a high solids content, usually 60-80% solids. Most commercial paper mills use multiple effect evaporators (MEE) as the black liquor evaporators. These evaporators generally range from four to eight effects in length.

[0010] The Kraft cook is highly alkaline, usually having a pH of 10 to 14, more particularly 12 to 14. The digester composition contains a large amount of sodium sulfide, which is used as an accelerant to increase the delignification rate of the cook. This works to release most of the lignin in the wood chips and thus the cellulose and part of the hemicellulose become available as pulp.

[0011] In practice, the pulping process and subsequent bleaching processes are separate operations. There are several bleaching sequences that are used commercially. Chlorine, chlorine dioxide, sodium hypochlorite, hydrogen peroxide, oxygen, ozone and mixtures thereof are employed in many bleaching processes. In one typical bleaching process, pulp recovered from the digester process is treated with the following steps: (a) chlorine dioxide, (b) caustic extraction, (c) chlorine dioxide, (d) caustic extraction, and (e) chlorine dioxide to reach the final pulp brightness. It is highly desirable to generate pulps, including Kraft pulps, with lower overall lignin content as these pulps require less bleaching chemical and thus generate less pollutant, especially absorbable organic halide (AOX) levels.

[0012] One approach to generate Kraft pulps with low lignin content is by using an extended delignification process. Extended delignification processes require extensive equipment changes (additional cooking vessels) and may result in higher facility energy requirements. Additionally, a major concern with extended delignification is to achieve decreased lignin content while minimizing cellulose damage. Cellulose damage is reflected in lower pulp viscosity and lower pulp strength.

[0013] Thus, preparation of pulp having decreased lignin content, i.e. lower Kappa number, with lower bleaching chemical requirements in the overall pulping operation is highly desired. Furthermore, preparation of pulp having improved strength properties is also highly desired. In addition, obtaining higher yields in the pulping process is highly desired as this could increase production and/or lower pulp production costs. Alternatively, preparation of pulp at an accelerated rate, e.g. reducing the digester cycle time in a batch digester, is desired even if the pulp properties remained constant. Compositions for use in chemical pulping processes and an improved chemical pulping process that can achieve one or more of the above improvements would be extremely valuable to the industry.

[0014] Compositions for use in chemical pulping processes and an improved chemical pulping process have now been discovered that achieve one or more of the desired pulp property or process throughput improvements.

SUMMARY OF THE INVENTION

[0015] It is an object of the invention to provide an improved chemical pulping process for the production of wood pulps. It is another object of this invention to provide an improved chemical pulping process for achieving increased lignin removal during the digester cycle for preparing pulp with improved physical properties. It is yet another object of the invention to reduce the amount of pulping chemicals required during the digester cook. It is yet another object of the invention to reduce the amount of chemicals required during bleaching of digested pulp to achieve bleached pulp of the desired brightness, etc. It is yet another object of this invention to provide an improved chemical pulping process that increases the pulp production rate while producing pulp with the required physical properties. It is yet another object of the invention to obtain higher yields in the pulping process. One or more of these objects as well as other objects are achieved in the invention which is described hereinafter in more non-limiting detail.

[0016] According to the invention, an aqueous composition for improving properties of pulp produced, reducing the digester cycle time, or reducing the pulping or bleaching chemicals required in alkaline chemical pulping processes is provided wherein the composition is added to the digester of the chemical pulping process, the composition comprising an effective amount of at least one compound selected from phosphonates having the formula:

X2NCH2PO3M2  (I),

[0017] phosphonates having the formula: 1

[0018] compounds having the formula:

(MOOC—CH2)2—N(CH2)2—N(CH2COOM)—(CH2)2N—(CH2COOM)2  (III),

[0019] phosphonates having the formula: 2

[0020] amine oxides of the phosphonates of formula (I), or mixtures thereof; wherein M is independently selected from hydrogen, alkali metal, alkaline earth metal or ammonium, X is independently selected from H, R, —CH2PO3M2 wherein R is an alkyl group or —NX2 substituted alkyl group having 2 to 6 carbon atoms, R′ is an alkyl group having 1 to 17 carbon atoms and R′ is optionally branched, optionally unsaturated, and optionally substituted with —SO3M, Y is selected from —PO3M2, H or R′, and Z is selected from —OH or —NR1R2 wherein R1 and R2 are independently selected from hydrogen or alkyl having 1 to 2 carbon atoms.

[0021] Further according to the invention, a method for improving properties of pulp produced or reducing the digester cycle time in alkaline chemical pulping processes is provided comprising adding an effective amount of at least one compound to the alkaline aqueous mixture in the digester of the chemical pulping process, wherein the at least one compound is as described above.

DETAILED DESCRIPTION OF THE DRAWINGS

[0022] NOT APPLICABLE.

DETAILED DESCRIPTION OF THE INVENTION

[0023] The wood chips that can be processed into pulp using the composition and chemical pulping process of the invention can be either hardwoods, softwoods or mixtures thereof. Suitable hardwoods include, but are not limited to, aspen, birch, cottonwood, poplar, maple, and the like, and mixtures thereof. Suitable softwoods include, but are not limited to, pine (e.g. red pine, jack pine, and Southern yellow pine), spruce, balsam fir, Douglas fir, and the like, and mixtures thereof.

[0024] A first embodiment of the invention relates to an aqueous composition for improving properties of pulp produced, reducing the digester cycle time, or reducing the pulping or bleaching chemicals required in alkaline chemical pulping processes wherein the composition is added to the digester of the chemical pulping process, the composition comprising an effective amount of at least one compound selected from phosphonates having the formula:

X2NCH2PO3M2  (I),

[0025] phosphonates having the formula: 3

[0026] compounds having the formula:

(MOOC—CH2)2—N(CH2)2—N(CH2COOM)—(CH2)2N—(CH2COOM)2 (III), phosphonates having the formula: 4

[0027] amine oxides of the phosphonates of formula (I), or mixtures thereof; wherein M is independently selected from hydrogen, alkali metal, alkaline earth metal or ammonium, X is independently selected from H, R, —CH2PO3M2 wherein R is an alkyl group or —NX2 substituted alkyl group having 2 to 6 carbon atoms, R′ is an alkyl group having 1 to 17 carbon atoms, preferably 1 to 11 carbon atoms, more preferably 11 to 5 carbon atoms, and most preferably methyl, and R′ is optionally branched, optionally unsaturated, and optionally substituted with —SO3M, Y is selected from —PO3M2, H or R′, and Z is selected from —OH or —NR1R2 wherein R1 and R2 are independently selected from hydrogen or alkyl having 1 to 2 carbon atoms.

[0028] In the phosphonates of the invention, M is preferably hydrogen or alkali metal, and the alkali metal is preferably sodium or potassium, X is preferably R or —CH2PO3M2, Y is preferably —PO3M2, and R′ is preferably an alkyl group having 1 to 11 carbon atoms, more preferably 1 to 5 carbon atoms, and most preferably methyl.

[0029] Examples of suitable phosphonates include, but are not limited to, the phosphonates in Table 1 below. Table 1 below provides formulas for representative phosphonates of formulas (I) and (II). The phosphonates in Table 1 are available from Solutia Inc., 575 Maryville Centre Drive, St. Louis, Mo. under the trademark Dequest® phosphonates and are identified by their Dequest® phosphonate product number. The preferred compound of formula (III) is diethylenetriamine pentaacetic acid (DTPA), or salts thereof.

[0030] Phosphonates of formula (II) wherein R′ is substituted with —SO3M can be prepared according to the procedures in German patent publication DE 198 57 251 A1 (Jun. 15, 2000) and U.S. Pat. No. 5,221,487, which are herein incorporated by reference. Suitable sulfonated phosphonates of formula (II) include, but are not limited to, 1-hydroxy-3-sulfonopropan-1,1-diphosphonic acid, 2-sulfo-1-hydroxyethylidene-1,1-diphosphonic acid, 2-sulfo-1-aminoethylidene-1,1-diphosphonic acid, and salts thereof.

[0031] Phosphonates of formula (II) wherein Z is —NR1R2 can be prepared according to the procedures in U.S. Pat. No. 3,979,385 and U.S. Pat. No. 4,006,182, which are herein incorporated by reference. Suitable phosphonates of formula (II) wherein Z is —NR1R2 include, but are not limited to, 1-aminoethylidene-1,1-disphosphonic acid and salts thereof.

TABLE 1
Dequest
Product
No.	Formula	X (or Y)	R (or R′)	N	X′ (or Z)	M
2000	I	2 —CH2PO3M2	—	—	—	6	H
2006	I	2 —CH2PO3M2	—	—	—	5	Na,
						1	H
2010	II	—PO3M2	—CH3	—	—OH	4	H
2016	II	—PO3M2	—CH3	—	—OH	4	Na
2041	I	1R, 1 —CH2PO3M2	—(CH2)nNX′2	2	2-CH2PO3M2	8	H
2046	I	1R, 1 —CH2PO3M2	—(CH2)nNX′2	2	2-CH2PO3M2	5	Na,
						3	H
2054	I	1R, 1 —CH2PO3M2	—(CH2)nNX′2	6	2-CH2PO3M2	6	K,
						2	H
2060	I	2R	—(CH2)nNX′2	2, 2	4-CH2PO3M2	10	H
2066	I	2R	—(CH2)nNX′2	2, 2	4-CH2PO3M2	7	Na,
						3	H
6004	Amine	2 —CH2PO3M2	—	—	—	5	K,
	oxide of I					1	H
7000	IV	—	—	—	—	5	H
2090	I	2R	—(CH2)nNX′2	6, 6	4-CH2PO3M2	10	H

[0032] The formulas and corresponding names of the Dequest phosphonates listed in Table 1 are shown below.

[0033] Dequest 2000—Amino-tri(methylenephosphonic Acid)

N(CH2PO3H2)3

[0034] Dequest 2006—Sodium Salt of Amino-tri(methylenephosphonic Acid)

Na5H[N(CH2PO3)3]

[0035] Dequest 2010—1-Hydroxyethylidene (1,1-diphosphonic Acid)

CH3C(OH)(PO3H2)2

[0036] Dequest 2016—Sodium Salt of 1-Hydroxyethylidene (1,1-Diphosphonic Acid)

Na4[CH3C(OH)(PO3)2]

[0037] Dequest 2041—Ethylenediamine tetra(methylenephosphonic Acid)

H8[(O3PCH2)2NCH2CH2N(CH2PO3)2]

[0038] Dequest 2046—Ethylenediamine tetra(methylenephosphonic Acid), Pentasodium Salt

Na5H3[(O3PCH2)2NCH2CH2N(CH2PO3)2]

[0039] Dequest 2054—Hexamethylenediamine tetra(methylenephosphonic Acid), Hexapotassium Salt

K6H2[(O3PCH2)2N(CH2)6N(CH2PO3)2]

[0040] Dequest 2060—Diethylenetriamine-penta(methylenephosphonic Acid)

(H2O3PCH2)2NCH2CH2N(CH2PO3H2)CH2CH2N(CH2PO3H2)2

[0041] Dequest 2066—Sodium Salt of Diethylenetriamine-penta(methylenephosphonic Acid)

Na7H3[(O3PCH2)2NCH2CH2N(CH2PO3)CH2CH2N(CH2PO3)2]

[0042] Dequest 6004—Nitrilotris(methylene)triphosphonic Acid N-Oxide, Potassium Salt

− O←+N—(CH2PO3K2)3

[0043] Dequest 7000—2-phosphonobutane-1,2,4-tricarboxylic Acid 5

[0044] Dequest 2090—Di(hexamethylene)triamine-penta(methylenephosphonic Acid) or Sodium Salt Thereof

(H2O3PCH2)2N(CH2)6N(CH2PO3H2)(CH2)6N(CH2PO3H2)2

[0045] Another preferred phosphonate of formula (I) is the compound N,N′-bis(3-aminopropyl)ethylenediamine-hexa(methylenephosphonic acid), or a salt thereof wherein the salt is sodium, potassium, ammonium and the like. When the compound is the sodium salt, the compound has the formula NaxHy[(O3PCH2)2NCH2CH2CH2N(CH2PO3)CH2CH2N(CH2PO3)CH2CH2CH2N—(CH2PO3)2]; wherein x+y is 12, and is designated herein as 4NHMP. This compound can be prepared according to the procedure in Example 1 of U.S. Pat. No. 5,261,491, which is herein incorporated by reference.

[0046] One preferred phosphonate of formula (I) is a phosphonate wherein at least one of X is R and R is —(CH2)nNX′2, wherein n is an integer from 2 to 6, preferably 2 to 4, and X′ is independently selected from R or —CH2PO3M2. Another preferred phosphonate of formula (I) is a phosphonate wherein each X is R and R is —(CH2)nNX′2, wherein n is an integer from 2 to 6, preferably 2 to 4, and X′ is independently selected from R or —CH2PO3M2. Another preferred phosphonate of formula I is a phosphonate wherein each X is —CH2PO3M2.

[0047] A preferred phosphonate of formula (II) is a phosphonate wherein Y is —PO3M2 and R′ is alkyl of 1 to 11 carbons, more preferably 1 to 5 carbon atoms. A more preferred phosphonate of formula (II) is a phosphonate wherein Y is —PO3M2 and R′ is methyl.

[0048] A preferred amine oxide of the phosphonate of formula (I) is −O←+N—(CH2PO3K2)3.

[0049] The preferred phosphonate of formula (IV) is 2-phosphonobutane-1,2,4-tricarboxylic acid.

[0050] The preferred aqueous compositions of the invention and the effective concentration of the phosphonates or polycarboxylates of the invention will depend on many factors including, but not limited to, the type of wood, the pulping conditions in the digester, whether the pulp is to be bleached or not, and the desired pulp properties.

[0051] In the aspect of the invention where an aqueous composition is added to the digester of the chemical pulping process for improving properties of pulp produced in alkaline chemical pulping processes, the composition comprises an effective property improving amount of at least one compound described above.

[0052] In another aspect of the invention where an aqueous composition is added to the digester of the chemical pulping process for reducing the digester cycle time in alkaline chemical pulping processes, the composition comprises an amount of at least one compound described above effective to permit reduction of the cycle time and production of pulp with comparable physical properties.

[0053] When the pulp is produced from hardwood wood chips, the currently preferred phosphonates of the invention are as follows:

[0054] CH3C(OH)(PO3M2)2,

[0055] (M2O3PCH2)2N(CH2)3N(CH2PO3M2)(CH2)2N(CH2PO3M2)(CH2)3N(CH2PO3M2)2,

[0056] (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, N(CH2PO3M2)3,

[0057] − O←+N—(CH2PO3M2)3,

[0058] (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2,

[0059] (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, and 6

[0060] more preferably CH3C(OH)(PO3M2)2,

[0061] (M2O3PCH2)2N(CH2)3N(CH2PO3M2)(CH2)2N(CH2PO3M2)(CH2)3N(CH2PO3M2)2,

[0062] (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2,

[0063] N(CH2PO3M2)3,

[0064] − O+N—(CH2PO3M2)3, and

[0065] (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, and

[0066] most preferably CH3C(OH)(PO3M2)2, and

[0067] (M2O3PCH2)2N(CH2)3N(CH2PO3M2)(CH2)2N(CH2PO3M2)(CH2)3N(CH2PO3M2)2.

[0068] When the pulp is produced from softwood wood chips, the currently preferred phosphonates of the invention are as follows:

[0069] N(CH2PO3M2)3,

[0070] (M2O3PCH2)2N(CH2)3N(CH2PO3M2)(CH2)2N(CH2PO3M2)(CH2)3N(CH2PO3M2)2,

[0071] CH3C(OH)(PO3M2)2,

[0072] − O←+N—(CH2PO3M2)3, 7

[0073] (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, and

[0074] (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, and

[0075] more preferably N(CH2PO3M2)3,

[0076] (M2O3PCH2)2N(CH2)3N(CH2PO3M2)(CH2)2N(CH2PO3M2)(CH2)3N(CH2PO3M2)2, and

[0077] CH3C(OH)(PO3M2)2.

[0078] Blends of at least two compounds independently selected from the phosphonates of formulas (I), (II) and (IV), the polycarboxylate of formula (III), and the amine oxides of the phosphonates of formula (I) may be used according to the invention. It is currently preferred to use a blend of two phosphonates, with a blend of a phosphonate of formula (I) with either a phosphonate of formula (I) or formula (II) being more preferred, and a blend of a phosphonate of formula (I) with a phosphonate of formula (II) being most preferred. The composition of the blends can vary over a wide range with the percentage of each component ranging broadly from 1 to 99 wt. %, provided each phosphonate is present in an amount of at least about 1 wt. %. Preferably, each phosphonate is present in an amount of at least about 10 wt. %. In the case of a two component blend, each phosphonate is present preferably in an amount of about 10 to about 90 wt. %, and more preferably in an amount of about 20 to about 80 wt. %.

[0079] A series of blends of phosphonates which may be used according to the invention were prepared for testing. The blends were prepared as concentrates having 30% total active acid content and were then diluted to the desired concentration for use. These blends (as described below) were tested in a simulated Kraft cook according to the procedure described in the Examples. The weight ratios of these various blends are shown in Table 2 below.

TABLE 2
		WEIGHT RATIO OF
		RESPECTIVE
BLEND NO. - BLEND OF	BLEND OF	PHOSPHONATES IN
PHOSPHONATES	PHOSPHONATES	BLEND
78	D2006/D2066	50/50
79	D2000/D2054	50/50
80	D2006/4NHMP	50/50
81	D2010/D2066A	50/50
82	D2010/D2054	50/50
83A	D2016/4NHMP	70/301
83B	D2016/4NHMP	25/751
84	D2054/4NHMP	50/50
85	D2010/D2000	50/50
86	4NHMP/D2066A	50/50
87	D2054/D2066A	50/50
94	D2046/D2006	50/50
95	D2046/D2016	60/40
96	D2046/D2054	60/40
97	D2046/D2066A	50/50
98	D2046/4NHMP	60/40

[0080] 1 A 50/50 blend concentrate having 30% total active acid content does not remain homogeneous.

[0081] The preferred blends for use in the invention are blends of a phosphonate selected from 1-hydroxyethylidene (1,1-diphosphonic acid) or salts thereof with a phosphonate selected from the phosphonates of formulas (I). More preferred are blends of phosphonates selected from 1-hydroxyethylidene (1,1-diphosphonic acid) or salts thereof with amino-tris(methylenephosphonic acid), N,N′-bis(3-aminopropyl)ethylenediamine-hexa(methylenephosphonic acid), hexamethylenediamine tetra(methylenephosphonic acid), diethylenetriamine-penta(methylenephosphonic acid) or salts thereof.

[0082] An effective amount of the compositions of the invention, i.e. the phosphonates, carboxylates, or mixtures thereof, is employed in the digester of a chemical pulping process to improve the properties of pulp produced or reduce the digester cycle time in alkaline chemical pulping processes. That effective amount depends on the particular phosphonate(s) employed in practicing this invention and other factors including, but not limited to, wood type, the digester composition, the operating conditions (i.e. H-factor) of the digester, the mode of addition of the compounds of the invention, the composition and operating conditions in the brown stock washing area, and bleaching area, as well as other factors and conditions known to those of ordinary skill in the art. Selection of the effective amount of phosphonate or carboxylate will be readily apparent to one of ordinary skill in the art after reading this specification.

[0083] The aqueous compositions of the invention for improving the properties of pulp produced or reducing the digester cycle time in alkaline chemical pulping processes include, but are not limited to, at least one phosphonate of formula (I), at least one phosphonate of formula (II), at least one compound of formula (III), at least one phosphonate of formula (IV), amine oxides of the phosphonates of formula (I), and mixtures of the above. Such mixtures, for example, may comprise a mixture of at least two phosphonates of formula (I), a mixture of at least one phosphonate of formula (I) and at least one phosphonate of formula (II), or a mixture of at least two phosphonates of formula (II). Preferably, the aqueous composition of the invention is at least one phosphonate of formula (I), at least one phosphonate of formula (II), a mixture of at least two phosphonates of formula (I), or a mixture of at least one phosphonate of formula (I) and at least one phosphonate of formula (II).

[0084] When the aqueous composition of the invention is at least one phosphonate of formula (I), the phosphonate(s) and the effective amount of each is as follows.

[0085] When the phosphonate is N(CH2PO3M2)3, the effective amount of phosphonate on an active acid basis is about 0.05 to about 1 wt. %, preferably about 0.1 to about 0.5 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0086] When the phosphonate is (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, the effective amount of the phosphonate on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.2 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0087] When the phosphonate is (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, the effective amount of the phosphonate on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.1 to about 0.5 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0088] When the phosphonate is (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, the effective amount of phosphonate on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.5 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0089] When the phosphonate is (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, the effective amount of phosphonate on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.5 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0090] When the aqueous composition of the invention is at least one phosphonate of formula (II), the effective amount of phosphonate on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.5 wt. %, based on the weight of wood chips (dry basis) charged to the digester. The preferred phosphonate of formula (II) is CH3C(OH)(PO3M2)2.

[0091] When the aqueous composition of the invention is at least one compound of formula (III), the effective amount of amino carboxylate on an active acid basis is about 0.05 to about 1 wt. %, preferably about 0.1 to about 0.5 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0092] When the aqueous composition of the invention is at least one phosphonate of formula (IV), the effective amount of phosphonate on an active acid basis is about 0.05 to about 1 wt. %, preferably about 0.1 to about 0.5 wt. %, based on the weight of wood chips (dry basis) charged to the digester. The preferred phosphonate of formula (IV) is 2-phosphonobutane-1,2,4-tricarboxylic acid.

[0093] When the aqueous composition of the invention is at least one amine oxide of the phosphonates of formula (I), the effective amount of amine oxide on an active acid basis is an amount similar to the effective amount of the corresponding phosphonate. Generally, the effective amount of amine oxide on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.1 to about 0.5 wt. %, based on the weight of wood chips (dry basis) charged to the digester. The preferred amine oxide of a phosphonate of formula (I) is −O←+N—(CH2PO3K2)3.

[0094] When the aqueous composition of the invention is a mixture of at least two phosphonates of formula (I), the phosphonate(s) and the effective amount of each mixture is as follows:

[0095] When the first phosphonate is (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, the second phosphonate is preferably selected from N(CH2PO3M2)3, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2. When the second phosphonate is N(CH2PO3M2)3, the amount of the mixture on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.2 wt. %, based on the weight of wood chips (dry basis) charged to the digester. When the second phosphonate is selected from (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, the amount of the mixture on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.2 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0096] When the first phosphonate is (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, the second phosphonate is preferably selected from (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, or N(CH2PO3M2)3, and the amount of the mixture on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.2 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0097] When the first phosphonate is (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, and the second phosphonate is (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2 or N(CH2PO3M2)3, the amount of the mixture on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.2 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0098] When the first phosphonate is (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, and the second phosphonate is N(CH2PO3M2)3, the amount of the mixture on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.2 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0099] The preferred blends of at least two phosphonates of formula (I) are blends of (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)—CH2CH2CH2N(CH2PO3M2)2 with N(CH2PO3M2)3, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2.

[0100] When the aqueous composition of the invention is a mixture of at least one phosphonate of formula (I) and at least one phosphonate of formula (II), the phosphonate(s) and the effective amount of each is as follows:

[0101] Preferred blends are mixtures of a first phosphonate selected from N(CH2PO3M2)3, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, or (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, and a second phosphonate selected from CH3C(OH)(PO3M2)2.

[0102] When the first phosphonate is selected from (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, the amount of the mixture on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.2 wt. %, based on the weight of wood chips (dry basis) charged to the digester. When the first phosphonate is N(CH2PO3M2)3, the amount of the mixture on an active acid basis is about 0.03 to about 1 wt. %, preferably about 0.05 to about 0.2 wt. %, based on the weight of wood chips (dry basis) charged to the digester.

[0103] The most preferred blends of at least one phosphonate of formula (I) and at least one phosphonate of formula (II) are blends of (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2 or N(CH2PO3M2)3, with CH3C(OH)(PO3M2)2.

[0104] A second embodiment of the invention relates to a method for improving properties of pulp produced, reducing the digester cycle time, or reducing the pulping or bleaching chemicals required in alkaline chemical pulping processes comprising adding an effective amount of at least one compound to the alkaline aqueous mixture in the digester of the chemical pulping process, wherein the at least one compound is as described above.

[0105] Optionally, other additives can be added with the compounds of the invention to the alkaline aqueous mixture in the digester. Typical additives include, but are not limited to, conventional additives known for use in the digester of a chemical pulping process. An example of a suitable additive that can be optionally added is anthroquinone.

[0106] In the practice of the method of this invention in a chemical pulping process, e.g. a Kraft process, the aqueous composition of the invention is admixed with an alkaline, aqueous composition in the digester. The aqueous composition of the invention can be added to the digester using any conventional means known to those of ordinary skill in the art. In addition, the aqueous composition of the invention can be added directly to the digester composition or it can be introduced into one of the aqueous feed compositions being charged to the digester prior to charging of that aqueous feed composition. The pH in the digester of an alkaline chemical pulping process is at least 9. In the case of a Kraft process, the pH in the digester is preferably about 10 to about 14, and more preferably about 12 to about 14. The temperature in the digester is typically in the range of about 110° C. to about 180° C., preferably about 150° C. to about 175° C. The aqueous composition of the invention can be added in a batch digester in any conventional manner known to one of ordinary skill in the art. For example, in a batch digester operation, the addition of the aqueous composition of the invention can be a bulk addition at the beginning of the digester cook cycle or during the digester cook cycle, or it can be added in multiple charges throughout the digestion cycle or continuously throughout the digester cook cycle. It is currently preferred to add the aqueous composition of the invention as a bulk charge at or near the beginning of the digester cook cycle. In the case of a continuous digester operation, the addition of the aqueous composition of the invention will typically be added continuously to maintain the effective concentration of the compounds of the invention.

[0107] The pulp that is recovered from the digester and washed can optionally be bleached using any conventional bleaching sequence depending on the desired end use of the pulp. Several bleaching sequences are used commercially in conjunction with chemical pulping processes. When bleaching is used, a majority of pulp mills use a 5-stage bleaching sequence. A common such bleaching sequence is the DEDED sequence. However, with the trend to reduce chlorine containing bleach steps, some pulp mills have moved to a bleaching sequence similar to DEopPD or DEopP. A less common bleaching sequence is the OPD sequence. The definitions for the letters used in the bleaching sequences are:

[0108] D=chlorine dioxide (ClO2)

[0109] C=chlorine (Cl2)

[0110] O=oxygen (O2)

[0111] P=hydrogen peroxide (H2O2)

[0112] E=alkaline extraction

[0113] Eop=alkaline extraction reinforced with oxygen and hydrogen peroxide

[0114] H=sodium hypochlorite (NaOCl)

[0115] Z=ozone (O3)

[0116] Bleaching processes are well known in the art and one of ordinary skill in the art will be able to practice any conventional bleaching sequence using pulp prepared using the process of the invention.

[0117] The use of the compounds of the invention in the process of the invention enable production of pulp with brightness comparable to pulp produced without use of the compounds of the invention but with a reduction in the amount of bleaching chemicals used or reduction in the number of bleaching steps. In the alternative, the use of the compounds of the invention in the process of the invention enable production of pulp with improved brightness compared to pulp produced without use of the compounds of the invention.

[0118] Viscosity is a measurement which relates viscosity of dissolved pulp to its strength properties. Mills use it as a way to test pulp properties quickly. Viscosity is related to the degree of cellulose polymerization and amount of lignin and hemicellulose attached to the fiber. Generally, as cellulose chains are broken and the lignin is removed, the viscosity decreases. The amount of damage to the fiber during the Kraft cook can be seen in the viscosity test. The compounds of the invention have been demonstrated in the examples herein to be good protectors of fiber strength during the Kraft cook. The benefits of achieving a higher viscosity at a given kappa number include the ability to cook a pulp longer and maintain a similar strength property or the ability to use more severe bleaching conditions to get a brighter pulp or use a process that is less expensive in chemical cost such as oxygen bleaching.

[0119] A small increase in yield of the pulp can result in a huge savings to the pulp mill. A yield increase means more pulp for the same amount of wood chips. This would also have the impact of lowering solids in the black liquor recovery area. Since many pulp mills are bottlenecked in the black liquor recovery area, this would allow some pulp mills to raise production without spending capital for additional equipment.

[0120] The use of the compounds of the invention generally result in decreasing the kappa number, so the pulp mill would have the ability to decrease the cook time or cook temperature (i.e. H-factor). Decreasing the Kraft cook temperature would result in less carbohydrate degradation. This would typically increase strength properties, viscosity and yield. Decreasing the cook time would allow a pulp mill to increase the number of Kraft cooks done in a day, i.e. increase the pulp production rate.

[0121] A third embodiment of the invention relates to the improved bleached and unbleached pulps prepared by the process of the invention.

[0122] One of ordinary skill in the art using this invention will be able to readily select an appropriate compound of the invention and concentration for addition to the digester to achieve the desired pulp property improvement or reduction in digester cycle time based on the disclosure of this specification. It will be apparent to those of skill in the art after reading this specification that many factors, including those of the type which have been mentioned herein, will determine the amount of the compounds of the invention needed to achieve the desired results. The determination of these amounts is within the ordinary skill of the artisan in this field without undue experimentation considering the direction provided herein.

[0123] The invention is further described in the following Examples which are not intended to limit or restrict the invention. Unless otherwise indicated all quantities are expressed by weight.

EXAMPLES

[0124] A Kraft cook test was employed in the following examples and illustrates the use of the process of this invention to determine the effect of the compositions of this invention as a pulp modifier in a Kraft cook. The general procedure described below was followed. Additionally, the tests were generally carried out at various concentrations as active acid based on the amount of wood chips (oven-dry basis) charged to the digester, for each inventive compound tested, and also with no added compound present.

[0125] As used herein, the active acid level is that amount of free acid which is equimolar to the amount of phosphonate or carboxylate that was actually added to the digester. Unless otherwise specified, use of “%” is on a weight basis.

Kraft Cook Test

[0126] The Kraft Cook Test used herein was developed to gauge the performance of the compositions of this invention in a simulated Kraft digester composition. The test was a standard Kraft cook in a model MK 610 Systems Inc. minimill laboratory digester. The digester aqueous composition temperature was ramped from ambient temperature to 170° C. in about 45 minutes and then maintained at 170° C. for the remainder of the test. Aspen or red pine wood chips were obtained from a pulp mill in the Upper Midwestern United States. Pulping conditions were: a 4:1 liquor to wood ratio, 16-20% AA (active alkali) and 25% sulfidity. The H-factor (length of cook) was varied in the cooks. The amount of phosphonate or carboxylate used was also varied.

Drying of Wood Chips

[0127] Aspen or pine wood chips that remained on a {fraction (1/4)}-inch round-holed mesh screen were utilized in the test, while removing knots and oversize chips.

[0128] Some of the wood chips were air dried overnight by laying them out on a counter. Wood chips not air dried were stored in a cold room at 13° C. and used before they began to show signs of decay.

Preparation of White Liquor/Charge of Digester

[0129] A liquor to wood ratio of 4:1 was prepared with 16-20% active alkali, having a 25% sulfidity.

[0130] The charge of phosphonate or carboxylate employed was based upon the weight of wood chips (oven-dry basis) charged to the digester to give the desired equivalent wt. % of active acid in the digester.

[0131] White liquor was prepared according to the following procedure (for most runs), although some Kraft cooks used different AA. For an 18% AA, 25% sulfidity: 62 g caustic and 61 g sodium sulfide nonahydrate were added to 500 mL water. After all chemicals were dissolved, the final dilution was added, which depended on the moisture content of the wood chips.

[0132] 350 grams (OD weight) of wood chips, prepared as described above, were added to the wood chip holder. White liquor (1L) and wood chips were transferred to the digester and the initial temperature and time recorded.

[0133] Each Kraft cook test example below was carried out according to the general procedure recited above. In most examples, the phosphonates and/or carboxylates were tested at various concentration levels. All levels are given in weight percent phosphonate or carboxylate on an active acid basis per weight wood chips (oven-dry basis).

[0134] The phosphonates used individually and in blends in the examples were obtained from Solutia Inc. (St. Louis, Mo.). DTPA was obtained from Dow Chemical (Versenex 80™), caustic, sulfuric acid and hydrogen peroxide were from Mallinckrodt, sodium sulfide nonahydrate from EM Science, potassium chlorate and oxalic acid from Fisher Scientific, sodium thiosulfate from J. T. Baker, and the oxygen cylinders from Twin City Oxygen.

Pulp Property Testing

[0135] The pulp properties of most interest in the industry are the kappa number (related to lignin content in the pulp), pulp brightness, screened yield, reject amount, and pulp strength properties.

Test Procedures

[0136] Kappa number (TAPPI test method T236)

[0137] Screened yield (amount of oven dried (“OD”) wood pulp passing through a 0.015 inch screen/total amount of OD starting pulp)

[0138] Reject rate (amount of OD wood pulp retained on a 0.015 inch screen/total amount of OD starting pulp)

[0139] ISO brightness (TAPPI test method T525)

[0140] Viscosity (TAPPI test method T230)

[0141] Tensile strength (TAPPI test method T494)

[0142] Burst strength (TAPPI test method T403)

[0143] Tear strength (TAPPI test method T414)

[0144] Handsheet making (TAPPI test method T220)

Pulp Bleaching

[0145] Several bleaching sequences were conducted to determine the bleaching response with the pulp treated according to the process of the invention compared to pulps prepared with no added compounds of the invention. The conditions used in the various bleach sequences were common for the paper industry.

Bleach Procedures

[0146] Pulp was prepared using the procedures described in the Kraft Cook Test section above. The pulp was thoroughly washed, so no carryover of the black liquor and/or compounds of the invention occurred.

[0147] The following bleach sequences were tested.

[0148] DEDED—Most pulp mills use a 5-stage bleaching sequence, a common one being the DEDED sequence. Pulp (30 g, OD wt. basis) was bleached in doubled plastic bags at 10% consistency at 70° C. using a hot water bath. Chemical dosage was varied depending on the stage. Bleaching times for D0, E1, D1, E2, and D2 were 150, 60, 90, 60 and 90 minutes, respectively. Residual chlorine dioxide was tested after each D stage. The pH exiting each bleach stage was also measured.

[0149] DEopPD—With the trend to reduce chlorine-containing bleaches, some mills have moved to a bleaching sequence similar to DEopD. Pulp (60 g, OD wt. basis) was bleached in plastic bags for the D stages and used a Mark IV Quantum mixer or LS1200 Chemineer reactor for the Eop stage. The D stages were bleached at 70° C., whereas the Eop stage was at 90° C. The consistency was 10% for all three stages. The D stages had different amounts of chemical charge. The Eop stage used 1% peroxide, 3% caustic, 0.1% magnesium sulfate, and 30, 40 or 100 psi oxygen gas. The pulp in the Eop stage was mixed for 4 seconds every 12 seconds. End pH, residuals and brightness were taken after every stage.

[0150] DEopP—The D, Eop, and P stages used 60, 240, and 30 g pulp (OD wt. basis), respectively. The bleaching times were 90, 60 and 120 minutes, respectively. The bleaching temperatures were 70, 90 and 85-87° C., respectively. The D stage used 1% chlorine dioxide on pulp. The Eop stage used 1% peroxide, 3% caustic, 0.1% magnesium sulfate, and 30, 40 or 100 psi oxygen gas. This stage used both a Mark IV Quantum mixer and LS1200 Chemineer reactor for the bleaching. The P stage used 1% peroxide, 2% caustic, 0.1% magnesium sulfate, and 1.5% sodium silicate based on OD pulp. Residuals, end pH, and brightness were determined after each stage.

[0151] OPD—The O, P and D stages all used 60 g pulp (OD wt. basis). The O stage used 2.5% caustic, 0.1% magnesium oxide, 90 psi oxygen gas, 10 or 15% consistency, 45 minute retention time, and 90° C. in a Mark IV Quantum mixer. The P stage used 2% caustic, 0.1% magnesium sulfate, 1.5% sodium silicate, 1.2% peroxide, 10% consistency, and 120 minutes at 85-88° C. The D stage used 0.8% chlorine dioxide, 0.3% caustic per 1% chlorine dioxide, and 90 minutes at 70° C. Residuals, end pH, and brightness were determined after each stage.

Bleached Pulp Property Testing

[0152] In addition to the pulp tests described above, chlorine dioxide and hydrogen peroxide residual levels were determined by iodine back titration.

Example 1

[0153] A series of Kraft cooks were performed on air dried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or various phosphonates at various concentrations. The pulp was recovered and tested and the results presented in Table 3.

[0154] The data in Table 3 demonstrates that the phosphonates of the invention produce pulp with lower kappa number, higher brightness and/or equivalent or improved strength properties.

Example 2

[0155] A series of Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using inventive compounds Dequest 2066 or DTPA at various concentrations. The pulp was recovered and tested and the results presented in Table 4.

[0156] The data in Table 4 demonstrates that Dequest 2066 and DTPA at effective concentrations produce pulp with lower kappa number, higher brightness and equivalent or improved strength properties.

TABLE 3
Screening Cooking Experiments on Hardwood (Aspen)
Sample/		Kappa	Freeness,	Basic Weight,	Bulk,	Brightness,	Tensile Index,	Burst Index	Tear Index,
Conc.	Yield, %	No.	mL	g/m2	cm2/g	%	N-m/g	KPa-m2/g	MN-m2/g
Control
#1	51.6	19.9	675	60.3	2.07	27.8	30.4	2.51	5.07
#2	53.5	19.5	701	61	2.22	28.2	29.2	2.01	5.15
#3	53.1	21.6	706	59.9	2.2	26.5	26.9	1.98	5.34
Avg.	52.7	20.3	694	60.4	2.16	27.5	28.8	2.17	5.19
D2006	0.03%	51.4	21.2	701	61.3	2.2	26.7	25.7	1.75	5.25
	0.20%	51.5	18.1	691	61.2	2.23	30.3	29.8	2.04	5.29
	0.50%	49.6	16.4	691	60.5	2.19	32	30.6	2.03	5.45
D2016	0.03%	52.3	21.6	703	60	2.19	27.1	26.7	1.83	4.97
	0.20%	51.6	16.2	688	60.8	2.12	32.6	30.7	2.23	5.37
	0.50%	51.7	15.2	688	60.4	2.13	33.9	28.3	1.95	5.85
D2066	0.03%	51.7	19.4	691	60.9	2.12	28.9	29.2	2.05	5.36
	0.20%	50.4	17.8	691	60.7	2.11	30.4	29.9	2.09	5.11
	0.50%	49.3	15	686	60.9	2.15	33.8	30.7	2.15	5.21
4NHMP	0.03%	52.9	19.8	690	60.5	2.2	27	24.8	1.71	5.45
	0.20%	53.3	16.9	686	61.1	2.22	29.6	31.1	2.14	5.91
	0.50%	54.3	15.8	683	60.6	2.22	32.4	31.3	2.15	5.75
D2054	0.03%	53.9	21.3	688	60.9	2.07	25.5	28	1.89	4.95
	0.20%	54.4	20.4	686	61.8	2.32	27.7	28.3	1.89	5.84
	0.50%	53	17.2	679	62	2.19	30.3	31.4	2.16	6.77
D6004	0.03%	54.1	20.2	685	61.5	2.25	27.3	27.6	1.8	5.38
	0.20%	54.6	18	681	61.6	2.24	29.8	27.7	1.81	5.41
	0.50%	54.6	16.8	682	61.4	2.13	31	26	2.31	5.57
D2060S	0.03%	53.2	19.6	691	62	2.18	27.5	27.7	2.28	5.44
	0.20%	53.3	17.9	691	62.4	2.12	29.1	27.8	2.31	5.68
	0.50%	53.1	16.5	692	62.5	2.24	32.3	29.5	1.95	6.03
D7000	0.03%	54	21.7	707	61.1	2.13	25.1	29	1.58	4.57
	0.20%	54.3	21.3	707	61.2	2.13	25.7	29.2	1.7	4.81
	0.50%	53.9	19.8	692	61.4	2.12	26.8	28.1	1.92	5.11
1 Conditions: AA = 18%, H-factor-1000, Sulfidity = 25%, Max. temperature = 170° C., Air dried wood chips.
2 Concentration of samples used (active acid basis) is based on the weight of wood chips (dry basis) charged to digester.

[0157]

TABLE 4
Cooking Experiments on Hardwood (Aspen)1
	Control	2066%2	2066A%2	DTPA2
	1	2	Avg.	0.05	0.10	0.20	0.30	0.40	0.50	0.03	0.20	0.50	0.20	0.50
Property
Yield %	50.9	51.2	51	49.8	51.5	50.8	51.4	50.2	50.6	51	51.4	50.2	51	50.7
Kappa No.	16.4	17.5	16.9	16.12	16.07	13.8	13.6	13.43	12.8	16	14	13.3	16.3	14
Freeness,	664	669	666	679	675	669	670	672	674				658	664
ml @ 20C
Basic Weight,	61.1	61.12	61.1	60.75	60.9	61	61	60.4	61.37	61	61.2	61.4	60.62	61.2
g/m{circumflex over ( )}2
Bulk,	1.93	1.853	1.89	1.913	1.935	1.915	1.901	1.896	1.908	1.921	1.937	1.913	1.86	1.891
cm{circumflex over ( )}3/g
Brightness	31.2	29.2	30.2	30.7	31.4	35.1	35.5	35.2	36	31.1	35.1	36.9	30.1	33.6
Tensile Index,	31.04	32.51	31.77	32.54	33	33.73	33.74	33.87	33.9	32.9	32.07	31.36	32.62	32.83
N*m/g
Burst index,	1.807	2.3	2.05	2.257	2.195	2.294	2.186	2.156	2.103	2.13	2.132	2.201	2.387	2.513
kPa*m{circumflex over ( )}2/g
Tear index,	4.52	4.789	4.65	4.754	5.103	5.27	5.321	5.15	4.988	5.334	5.591	5.174	4.492	4.74
mN*m{circumflex over ( )}2/g
Classi-
fication
of fiber
lengths
(%)*
R14	0	0	0	0	0	0	0	0	0				0	0
R28	2.71	2.89	2.8	2.92	3.98	7.79	10.85	11.21	11.48				6.11	7.81
R48	60.02	62.53	61.27	61.35	61.85	62.78	63.93	63.71	63.22				65.12	64.04
R100	29.08	25.35	27.22	27.1	25.75	22.66	18.97	18.58	18.15				21.33	19.9
P100	8.19	8.13	8.16	8.63	8.42	6.77	6.25	6.5	7.15				7.44	8.25
1 Conditions: AA = 18%, H-factor = 1000, Sulfidity = 25%, Max. temperature = 170° C., undried wood chips.
2 Concentration of samples used (active acid basis) is based on the weight of wood chips (dry basis) charged to digester.
3 Bauer-McNett fiber classification method (TAPPI test method T233cm-95)

Example 3

[0158] A series of Kraft cooks were performed on undried softwood (pine) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using inventive compounds Dequest 2066 or DTPA at various concentrations. The pulp was recovered and tested and the results presented in Table 5.

[0159] The data in Table 5 demonstrates that DTPA and selected phosphonates of the invention produce pulp from softwood with lower kappa number, higher brightness or improved burst index. Generally, DTPA and all of the phosphonates tested produced pulp having higher burst index. Dequest products 2006, 2016, 2060S, 6004 and 7000 produced pulp having higher brightness, and Dequest products 2006, 2016, 2060S, 6004 and 7000, and compound 4NHMP produced pulp with lower kappa number.

TABLE 5
Screening Cooking Experiments on Softwood (Pine)1
			Basic			Tensile		Tear
	Yield,	Kappa	Weight,	Bulk,	Brightness	Index,	Burst Index	Index,
Sample2	%	No.	g/m2	cm2/g	%	N-m/g	kPa-m2/g	MN-m2/g
Control
#1	41.8	24	61.2	2.32	29.2	47.06	4.313	21.54
#2	43.03	24.1	59.8	2.314	28.6	46.92	4.268	22.78
Avg.	42.4	24.05	60.5	2.317	28.9	46.99	4.29	22.16
2066A
0.05%	42.8	25.5	60.5	2.3	28.9	46.57	4.693	23.76
0.20%	43	24.9	61.2	2.32	28	48.61	4.785	23.08
0.50%	42.9	24.4	60.8	2.372	28.5	49.2	4.871	21.43
2060S
0.05%	42.6	25.1	60.8	2.338	28.6	47.2	4.47	23.1
0.20%	41.7	23.2	62.4	2.27	29.14	48.55	4.453	24.87
0.50%	42.1	23.6	61.1	2.316	28.7	48.65	4.721	24.54
2066
0.05%	42.8	25.86	60.8	2.332	28.6	47.12	4.35	23.16
0.20%	43	25.8	61.67	2.354	28.4	47.76	4.38	22.92
0.50%	43.1	24.9	61.9	2.31	27.7	48.72	4.53	22.25
2054
0.05%	42.3	24.7	61	2.32	29	46.94	4.4	22.9
0.20%	42.6	22.7	60.9	2.317	29	46.82	4.38	22.87
0.50%	42.1	25	61.1	2.327	27.7	47.54	4.58	23.7
4NHMP
0.05%	42.2	23.7	60.5	2.31	28.9	47.41	4.5	23.5
0.20%	41.9	22.9	61.29	2.26	28.56	47.81	4.521	22.82
0.50%	43.2	24.5	62.14	2.243	28.48	46.48	4.217	23.11
2006
0.05%	41.7	23.6	61.2	2.327	29.5	47.91	4.34	22.9
0.20%	41.8	20.8	60.78	2.3	29.7	48.76	4.36	22.48
0.50%	42.2	20.3	59.65	2.313	29.8	49.82	4.4	21.74
2016
0.05%	42.8	24	59.9	2.29	28.9	46.3	4.51	24.36
0.20%	42.5	22.5	60.93	2.281	28.5	46.92	4.756	24.47
0.50%	41.6	20.7	60.71	2.26	29.1	48.9	4.681	25.59
6004
0.05%	40.9	24.7	62.15	2.32	28.9	47.13	4.29	21.9
0.20%	41.8	23.76	61.74	2.268	27.6	46.83	4.385	22.63
0.50%	42.3	23.4	60.95	2.25	30.14	46.57	4.805	23.18
7000
0.05%	41.5	24.5	61.8	2.317	29.3	47.75	4.37	23.1
0.20%	43.09	22.54	61.04	2.32	29.5	47.71	4.413	22.96
0.50%	42.36	23.4	60.15	2.328	29.2	48.63	4.642	22.61
DPTA
0.20%	42.86	24.91	59	2.31	29	44.44	4.342	21.76
0.50%	42.7	24.6	60	2.207	28.3	47	4.778	22.64
1Conditions: AA = 20%, H-factor = 1700, Sulfidiry = 25%, Max. termperature = 170° C., unairdried wood chips
2Concentration if samples used (active acid basis) is based on the weight of wood chips (dry basis) charged to digester.

Example 4

[0160] A series of Kraft cooks were performed on undried softwood (pine) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using inventive compounds Dequest products 2006 and 2054 at various concentrations. The pulp was recovered and tested and the results presented in Table 6.

[0161] The data in Table 6 demonstrates that selected phosphonates of the invention produce pulp from softwood with lower kappa number and/or improved strength. Dequest product 2006 generally produced pulp having lower kappa number and improved strength, and Dequest product 2054 generally produced pulp with improved strength.

Example 5

[0162] Kraft cooks were performed on undried hardwood (aspen) and softwood (pine) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using inventive compound Dequest 2066 or 2006 at 0.2 wt. % (as active acid based on the weight of wood chips (dry basis) charged to the digester). The pulp was recovered and tested and the results presented in Table 7.

[0163] The data in Table 7 demonstrates that (at constant H-factor) a reduced amount of white liquor, i.e. alkali, can be used to achieve the same level of cook when using the phosphonate of the invention.

TABLE 6
Cooking experiments on Softwood (Pine)1
	Dosage Level %2
	Control	2054	2006
	0	0.05	0.1	0.2	0.3	0.4	0.5	0	.05	0.1	0.2	0.3	0.4	0.5
Yield %	42.4	42.3	43.2	42.75	42.17	42.81	42.1	42.4	41.7	42.2	41.8	42.7	41.2	42.2
Kappa no.	24.05	24.7	22.91	24.4	25.29	23.29	25	24.05	23.6	20.86	20.8	24.71	21.44	20.3
Basic Weight, g/m{circumflex over ( )}2	60.5	61	61.5	61.58	61	61.8	61.1	60.5	61.2	60.5	60.78	62.08	59.5	59.65
Bulk, cm{circumflex over ( )}3/g	2.317	2.32	2.249	2.33	2.221	2.02	2.327	2.317	2.327	2.305	2.3	2.39	2.119	2.313
Brightness %	28.9	29	29.69	27.6	29.23	28.67	27.7	28.9	29.5	30.1	29.7	27.87	26.8	29.8
Tensile Index, N*m/g	46.99	46.94	47.27	49.16	48.6	51.7	47.54	46.99	47.91	48.56	48.76	50.22	48.02	49.82
Burst index, kPa*m{circumflex over ( )}2/g	4.29	4.4	4.47	4.67	4.493	4.98	4.58	4.29	4.34	4.54	4.36	4.58	4.36	4.4
Tear index, mN{circumflex over ( )}m2/g	22.16	22.9	22.85	23.12	22.9	23.42	23.7	22.16	22.9	22.43	22.48	23.43	22.16	21.74
1Conditions: AA = 20%, H-factor-1700, Sulfidity = 25%, Max. temperature = 170° C., unairdried pine chips
2Concentration of samples used (active acid basis) is based on the weight of wood chips (dry basis) charged to digester.

[0164]

TABLE 7
Residual Alkali
	Hardwood
	(Aspen)1	Softwood (Pine)2
Property	Control	2066 (0.2%)	Control	2006 (0.2%)
Kappa No.	15.2	13.9	23.9	23.8
Black Liquor:
pH	13.3	13.61	13.38	13.53
Residual Alkali (RA)	22	24.8	13.8	13.95
Pulp reject, %	0.6	0.82	0.91	1.15
on screened pulp
1 Conditions: AA = 18%, HF 1000, Sulfidity = 25%, Temperature = 170° C., unairdried wood chips
2 Conditions: AA = 20%, HF 1700, Sulfidity = 25%, Temperature = 170° C., unairdried wood chips

Example 6

[0165] A series of Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using inventive compounds Dequest 2016 or 2066, or DTPA at various concentrations to test the effect of H-factor. The pulp was recovered and tested and the results presented in Table 8.

[0166] The data in Table 8 demonstrates that Dequest 2016 and 2066, and DTPA at effective concentrations produce pulp with lower kappa number and higher brightness. Dequest 2016 and 2066 generally produce pulp with higher viscosity, with the effect with Dequest 2066 being more pronounced. As H-factor is reduced, e.g. at H-factors F705 and HF558, the % reject is significantly less for pulps produced using Dequest 2016 and 2066, and DTPA.

Example 7

[0167] The pulps from the series of Kraft cooks performed in Example 6 were tested for pulp strength and the results presented in Table 9.

[0168] The data in Table 9 demonstrates that Dequest 2016 and 2066 produce pulp with better overall strength properties, while DTPA produces pulp with comparable strength properties. These results are in addition to the improvement in pulp, properties shown in Table 9.

TABLE 8
Hardwood (Aspen) Kraft Cooks H-Factor Effect
					Viscosity,
Sample	H-Factor1	Kappa number	Yield, %	Reject, %	cP	Brightness, %
Control:	HF1000	20.7	52.9	0.54	32.4	30.6
	HF853	22.5	52.7	1.75	39.4	29.2
	HF705	24.5	51.2	4.1	43.7	28.2
	HF558	28	45.6	15.85	48.3	28
2016 (0.05%)	HF705	19.1	52.8	1.89	42.2	32.4
2016 (0.1%)	HF705	18.12	53.7	0.8	42.7	33.1
2016 (0.2%)	HF1000	14.94	53.9	0.54	33.8	35.5
	HF853	16.02	53.5	1.07	39.6	34.4
	HF705	17.06	53.9	2.12	43.1	35.2
	HF558	18.3	52.1	3.73	51.9	35.1
2016 (0.3%)	HF705	15.67	53.14	2.04	43.3	36.2
2016 (0.4%)	HF705	14.75	53.24	2.42	43	37.1
2016 (0.1%)	HF1000	16.49	52.9	0.81	33.7	31.4
	HF853	16.92	51.43	1.57	38.1	32
	HF705	18.3	51.7	2.84	—	—
	HF558	21.44	49.4	5.27	51.2	31.5
2066 (0.2%)	HF1000	16.12	50.22	1.87	34.8	33.1
	HR853	16.6	51.2	1.88	38.5	33.8
	HR705	18.57	50.17	3.87	45.4	33.7
	HF558	20.08	48.6	6.18	52	33.5
DTPA (0.2%)	HF1000	18.69	51.65	1.05	—	—
	HF853	19.2	52.55	1.52	—	—
	HF705	18.95	52.86	3.24	40.2	31.5
	HF558	24.53	50.63	7.56	—	—
1Total Cooking Time
HF1000 = 105 min. (45 min. heat up, 60 min. at 170° C.);
HF853 = 95 min. (45 min. heat up, 50 min. hold at 170° C.);
HF705 = 85 min. (45 min. heat up, 40 min. hold at 170° C.);
HF558 = 75 min. (45 min. heat up, 30 min. hold at 170° C.).
2Concentration of samples used (active acid basis) is based on the weight of wood chips (dry basis) charged to digester.
3—: not determined.

[0169]

TABLE 9
Hardwood (Aspen) Strength
	Control	2016 (0.2%)
	HF1000	HF853	HF705	HF558	HF1000	HF853	HF705	HF558
B.W. g/m{circumflex over ( )}2	61.65	61.89	62.15	61.68	61.14	62.15	62.26	61.65
Bulk, cm{circumflex over ( )}3/g	1.95	1.984	2.05	2.03	1.937	1.951	1.963	1.962
Brightness, %	30.6	29.2	28.2	28	35.5	34.4	35.2	35.1
Tensile, N*m/g	23	22.23	22.2	21.17	26.24	24.4	23.77	22.13
Burst, kPa*m{circumflex over ( )}2/g	1.07	0.88	0.89	0.84	1.04	1	0.98	0.83
Tear, mN*m{circumflex over ( )}w/g	4.38	3.867	3.4	3.34	4.72	3.867	3.813	3.755
	2016 series, HF705		DTPA (0.2%)
	0.05%	0.10%	0.20%	0.30%	0.40%		HF705
B.W. g/m{circumflex over ( )}2	61.6	61.82	62.26	61.75	61.76		61.53
Bulk, cm{circumflex over ( )}3/g	2.032	2.028	1.963	1.972	1.97		2.043
Brightness, %	32.4	33.1	35.2	36.2	37.1		31.5
Tensile, N*m/g	21.28	22.6	23.77	23.55	22.83		20.75
Burst, kPa*m{circumflex over ( )}2/g	0.877	0.882	0.98	0.878	0.834		0.803
Tear, mN*m{circumflex over ( )}w/g	3.98	3.78	3.813	3.74	3.97		3.72
	2066 (0.2%)	2016 (0.1%)
	HF1000	HF853	HF705	HF558	HF1000	HF853	HF705	HF558
B.W. g/m{circumflex over ( )}2	61.45	60.93	60.8	61.16	60.79	61.26	61.82	61.2
Bulk, cm{circumflex over ( )}3/g	2.005	1.978	1.975	1.954	2.019	2.023	2.028	1.999
Brightness, %	33.1	33.8	33.7	33.5	31.4	32	33.1	31.5
Tensile, N*m/g	28.08	26.67	25.96	25	26.51	24.65	22.6	23.03
Burst, kPa*m{circumflex over ( )}2/g	1.05	0.97	0.97	0.95	0.94	0.87	0.88	0.85
Tear, mN*m{circumflex over ( )}w/g	4.23	4.1	4.04	3.93	4.29	4.02	3.78	3.79

Example 8

[0170] The pulps from the series of Kraft cooks performed in Example 6 were tested for pulp fiber classification using both the Bauer-McNett and Kajaani methods and the results presented in Tables 10 and 11, respectively.

[0171] In the Bauer-McNett method, the larger the number, the smaller the mesh opening and the reported values is the % of fibers that are retained at that screen size. For example, R14 means that the mesh has 14 openings per square inch. P100 means the amount of fibers passing through the R100 mesh screen. The data indicate that the pulps prepared according to the invention have slightly lower percentages of the fibers as medium and long fibers. This suggests that increased yield maintains shorter fibers in the recovered product.

[0172] The data in Tables 10 and 11 demonstrate the impact of treating the pulp with these products in the digester. As can be seen after final pulp bleaching, the fiber length was not negatively impacted by treatment with the compounds of the invention in the digester. The W weighted average fiber length data in Table 11 is more useful for fiber length when making this comparison. As Dequest 2010 charge is increased, both fiber length and coarseness decrease slightly compared to the control, indicating more intense cooking of the fiber or more of the material attached to the fiber is being removed.

Example 9

[0173] A series of Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using inventive phosphonate blends at various concentrations. The pulp was recovered and tested and the results presented in Table 12.

[0174] The data in Table 12 demonstrates that the Dequest blends all produced pulps with lower kappa number and higher brightness. The Dequest blends also produced pulp with comparable or higher yields. In addition, the Dequest blends generally had lower % reject than the control.

TABLE 10
Hardwood (Aspen) Kraft Pulp Classifications by Bauer-McNett1
		R14	R28	R48	R100
Sample %	H-Factor	Mesh	mesh	mesh	mesh	R24 + R48	P100
Control:	HF1000	0	14.2	62.6	18.4	76.8	4.8
	HF853	0	14.9	63.4	18	78.3	3.7
	HF705	0	18.5	62	17.2	80.5	2.3
	HF558	0	22.5	58.2	16.4	80.7	2.9
2066 (0.2%)	HF1000	0	2.6	63.6	27.3	66.2	6.5
	HF853	0	6.5	64.5	23.5	71	5.5
	HF705	0	11.4	62.8	20.7	74.2	5.1
	HF558	0	12.83	63.1	19.85	75.93	4.22
2016 (0.2%)	HF1000	0	9.1	61.2	23.6	70.3	6.1
	HF853	0	11	61.9	21.8	72.9	5.3
	HF705	0	12.1	62	21.9	74.1	4
	HF558	0	13.8	62.7	19.7	76.5	3.8
HF705:	2016 (0.05%)	0	3.6	64.6	27.2	68.2	4.6
	2016 (0.1%)	0	10.3	62.2	23.4	72.5	4.1
	2016 (0.2%)	0	12.1	62	21.9	74.1	4
	2016 (0.3%)	0	13.5	60.9	21.4	74.4	4.2
	2016 (0.4%)	0	12.8	62	21.64	74.8	3.56
1TAPPI test method T233cm-95

[0175]

TABLE 11
Hardwood (Aspen) Kraft Pulp Fiber Lengths By Kajaani FS-2001
	Arithmetic ave,	L weighted ave,	W weighted ave,	Coarseness,
	mm	mm	mm	mg/m
Control	HF1000	0.68	0.87	1	0.112
	HF853	0.69	0.89	1.01	0.114
	HF705	0.71	0.92	1.04	0.123
	HF558	0.75	0.97	1.12	0.147
2016 (0.2%):	HF1000	0.66	0.85	0.98	0.106
	HF853	0.67	0.86	0.98	0.104
	HF705	0.66	0.87	0.99	0.108
	HF558	0.68	0.86	0.98	0.113
2016 (0.1%):	HF1000	0.66	0.86	0.99	0.103
	HF853	0.69	0.88	1	0.101
	HF705	0.66	0.86	0.99	0.108
	HF558	0.69	0.89	1.01	0.113
2066 (0.2%):	HF1000	0.65	0.86	0.99	0.101
	HF853	0.68	0.87	1	0.104
	HF705	0.67	0.88	1.01	0.107
	HF558	0.69	0.88	1	0.109
DTPA (0.2%):	HF1000	0.67	0.85	0.98	0.109
	HF853	0.69	0.86	0.98	0.107
	HF705	0.66	0.85	0.97	0.112
Control:	HF558	0.7	0.9	1.04	0.122
2016 (0.00%):	HF705	0.71	0.92	1.04	0.123
2016 (0.05%):	HF705	0.69	0.87	0.99	0.108
2016 (0.1%):	HF705	0.66	0.86	0.99	0.108
2016 (0.2%):	HF705	0.66	0.87	0.99	0.108
2016 (0.3%):	HF705	0.68	0.85	0.97	0.108
2016 (0.4%):	HF705	0.68	0.85	0.97	0.107
1 TAPPI test method T271pm-91.

[0176]

TABLE 12
Hardwood (Aspen) Kraft Pulp Cooks Using Blends.
Blend	H-factor	Kappa num.	Yield, %	Reject, %	Brightness, %
#78 (0.2%);	853	18.17	53.3	2.2	31.4
2006 + 2066	705	18.6	52.72	3.04	31.8
#79 (0.2%):	853	17.67	50.3	4.15	30.76
2000 + 2054	705	17.7	52.5	3.3	30.8
#80 (0.1%):	853	20	52.95	2.32	30.93
2006 + 4NHMP	705	21.3	52.63	2.63	31
#81 (0.1%):	853	18.2	54.18	1.48	32.9
2010 + 2066A	705	20.5	53	2.48	31.5
#82 (0.1%):	853	18.2	53.3	1.72	32.7
2010 + 2054	705	18.3	50.86	3.31	33.3
#83A (0.2%):	853	15.3	54.07	1.48	33.7
2016 + 4NHMP (2:1)	705	17.6	52.7	2.17	33.5
#83B (0.2%):	853	16.68	52.5	2.61	35.15
2016 + 4NHMP (1:2)	705	17.6	51.26	4.68	35.9
#84 (0.2%):	853	16.7	52.7	1.57	31.4
2054 + 4NHMP	705	17.87	52.5	2.5	31.1
#85 (0.2%);	853	14.96	52.7	2.01	35.2
2010 + 2000	705	16.8	52.6	2.72	34.4
#86 (0.1%):	853	18.8	52.4	1.63	29.9
4NHMP + 2066A	705	20.3	50.2	3.75	29.3
#87 (0.1%):	853	19.06	53.1	1.5	32.1
2054 + 2066A	705	19.9	50.4	7.08	33.5
#94 (0.2%):	853	16.46	51.4	4.45	—
2046 + 2006	705	19.85	52.37	4.64	—
#95 (0.2%):	853	15.89	52.02	2.42	—
2046 + 2016	705	17.16	52.28	4.75	—
#96 (0.2%):	853*	15.75	51.06	4.92	—
2046 + 2054	705*	17.28	49.14	9.19	—
#97 (0.2%):	853*	16.81	48.82	8.37	—
2046 + 2066A	705*	18.15	48.32	10.41	—
#98 (0.2%):	853	15.1	49.4	2.98	—
2046 + 4NHMP	705	17.04	50.1	3.85	—
Control:	853	23.87	52.45	3.7	28.7
	705	25.2	49.84	5.5	28.3
*airdried chips were used instead of undried chips; other conditions the same.

Example 10

[0177] A series of Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2046 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 13.

[0178] The data in Table 13 demonstrates that Dequest 2046 produced pulps with lower kappa number and higher brightness. Dequest 2046 also produced pulp with comparable or higher yield depending on the H-factor used. In addition, Dequest 2046 had lower % reject than the control.

Example 11

[0179] A series of Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using compound 4NHMP or Blend 83B at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 14.

[0180] The data in Table 14 demonstrates that compound 4NHMP and Blend 83B produced pulps with higher brightness. Compound 4NHMP and Blend 83B also produced pulp with comparable or higher tensile strength depending on the H-factor used.

TABLE 13
Hardwood (Aspen) Kraft Pulp Cooks Using Dequest 2046
		Kappa
	H-factor	num.	Yield, %	Reject, %	Brightness, %
D2046	853	18.7	52.4	3.27	29.8
(0.2%):	705	18.8	51.86	4.2	30.2
Control:	853	23.87	52.45	3.7	28.7
	705	25.2	49.84	5.5	28.3

[0181]

TABLE 14
Hardwood (Aspen) Physical Property Testing
	Control	Blend 83B (0.2%)	4NHMP (0.2%)
H-factor	853	705	853	705	853	705
Basic weight,	61.51	61.65	61.67	62.15	61.14	61.27
g/m{circumflex over ( )}2
Bulk,	2.015	1.96	2.107	2.064	2.121	2.046
cm{circumflex over ( )}3/g
Brightness, %	28.2	27.5	34.5	34.8	34.3	34.3
Tensile index,	23.97	23.14	23.95	23.77	23.33	25.08
Nm/g
Burst index,	0.905	0.901	0.855	0.919	0.858	0.82
Pa.m{circumflex over ( )}2/g
Tear index,	4.64	4.95	4.62	5.08	4.95	4.73
nM.m{circumflex over ( )}2/g

Example 12

[0182] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2066 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 15. The pulp was then bleached using a DEDED sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 15. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 15.

[0183] The data in Table 15 demonstrates that Dequest 2066 produced pulps with higher initial brightness and lower kappa number. Dequest 2066 also produced final bleached pulp with higher viscosity and comparable final brightness (Series #1 v. Series #2).

Example 13

[0184] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2066 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 16. The pulp was then bleached using a DEopD sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 16. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 16.

[0185] The data in Table 16 demonstrates that Dequest 2066 produced pulps with higher initial brightness and lower kappa number. Dequest 2066 produced bleached pulp with higher viscosity and higher brightness after the DEop stage (Series #3 v. Series #6). Dequest 2066 also produced final bleached pulp with higher viscosity, higher yield and higher brightness (Series #4 v. Series #7).

TABLE 15
Hardwood (Aspen) DEDED Bleaching
	HW-Control		HW-2066 (0.2%)
Initial Kappa number		15.2		13.9
Initial Brightness, %		31.4		33.9
Initial Freeness @20° C., ml		665		670
General conditions	Consistency		10%
		Temperature		70° C.
D1	C102, % on OD pulp		1		1
	Time, min		150		150
	pH: Initially		3.4		3.5
	End		2.69		2.52
	Residual C102, g/l		ND		ND
	Brightness D		—		—
E	pH: Initially		12.44		12.47
	End		12.2		12.24
	Brightness DE		—		—
D2	C102, % on OD pulp		1		1
	Time, min		90		90
	End pH		2.48		2.46
	Residual C102, g/l		<0.02		<0.02
	Brightness DED		—		—
E	pH: Initially		12.42		12.48
	End		12.2		12.17
	Brightness DEDE		—		—
D3	C102, % on OD pulp		0.5		0.5
	Time, min		90		90
	End pH		4.04		4.08
	Residual C102, g/l		0.067		0.078
Yield, %/Series #		96.8	(#1)	96	(#2)
Final brightness, %		91.2		91.5
Freeness @20° C., ml		667		685
Viscosity, cP		20.3		21.1
1. Each experiment was conducted on a 30-g-OD-pulp scale
2. E stages: 2% NaOH, Time 60 min
3. ND: Not detectable
4. —: Not determined

[0186]

TABLE 16
Hardwood (Aspen) DEopD
	HW-Control		HW-2066 (0.2%)
Initial Kappa number			15.2		14.2
Initial Brightness, %			31.4		32.1
Initial Freeness @20° C., ml			665		663
General Conditions	Consistency			10%
		Temperature			D:70° C.; Eop:88° C.
D1	C102, % on OD pulp			1		1
	Time, min			90		90
	End pH			2.78		2.5
	Residual C102, g/l			0.014		0.01
	Brightness D			—		—
Eop	Conditions		NaOH:3%; MgS04:0.1%; H2O2:1%; 02
			pressure: 100 psi; Time 60 min
	pH: Initially			11.8		12.1
	End			11.6		11.5
	Residual H202, g/l			0.03		0.05
Brightness DEop., %		(Series #3)	81.8	(Series #6)	83.5
Kappa no			2.5		2.35
Viscosity, cP			13.6		14.3
Yield, %			96.2		95.9
D2	C102, % on OD pulp			0.6		0.6
	Time, min			90		90
	End pH			3.52		3.36
	Residual C102, g/l			<0.015		0.06
Total yield, %/Series #		(#4)	94.6	(#7)	95.4
Final brightness, %			92.2		92.77
Freeness @20° C., ml			645		645
Viscosity, cP			13.4		14
1. D stages were conducted on a 60 g -OD-pulp scale; Eop on a 240 g scale
2. —: Not determined

Example 14

[0187] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2066 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 17. The pulp was then bleached using a DEopP sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 17. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 17.

[0188] The data in Table 17 demonstrates that Dequest 2066 produced pulps with higher initial brightness and lower kappa number. Dequest 2066 produced bleached pulp with higher viscosity and higher brightness after the DEop stage (Series #3 v. Series #6). Dequest 2066 also produced final bleached pulp with higher viscosity and higher brightness (Series #5 v. Series #8).

Example 15

[0189] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2066 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 18. The pulp was then bleached using a DED and DEDED sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 18. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 18.

[0190] The data in Table 18 demonstrates that Dequest 2066 produced pulps with higher initial brightness and lower kappa number. Dequest 2066 produced bleached pulp with higher viscosity and higher brightness after the DED stage (Series #9 v. Series #10). Dequest 2066 also produced final bleached pulp with higher viscosity, higher yield and higher brightness (Series #11 v. Series #12).

TABLE 17
Hardwood (Aspen) DEopP Bleaching
	HW-Control		HW-2066 (0.2%)
Initial Kappa number		15.2		14.2
Initial Brightness, %		31.4		32.1
Initial Freeness @20° C., ml		665		663
General Conditions	Consistency		10%
		Temperature		D:70° C.; Eop:88° C.
D1	C102, % on OD pulp		1		1
	Time, min		90		90
	End pH		2.78		2.5
	Residual C102, g/l		0.014		0.01
	Brightness D		—		—
Eop	Conditions		NaOH:3%; MgS04:0.1%; H2O2:1%; 02
			pressure: 100 psi; Time 60 min
	pH: Initially		11.8		12.1
	End		11.6		11.5
	Residual H202, g/l		0.03		0.05
Brightness DEop., %/Series #		81.8	(#3)	83.5	(#6)
Kappa no		2.5		2.35
Viscosity, cP		13.6		14.3
Yield, %		96.2		95.9
P	Conditions		NaOH:2%; MgS04:0.1%; Na2Si03:1.5%;
			Temperature:86°—87° C.; Time:120 min
	H202, % on OD pulp		1		1
	pH: Initially		11.98		12.71
	End		11.34		12.25
	Residual H202, g/l		0.05		0.37
Total yield, %/Series #		96.1	(#5)	95.5	(#8)
Final brightness, %		87.3		88.71
Freeness @20° C., ml		640		630
Viscosity, cP		10.9		12
1. D stage was conducted on a 60 g -OD-pulp scale; Eop on a 240 g scale; and P stage on a 30 g-OD- pulp scale
2. —:Not determined.

[0191]

TABLE 18
Hardwood (Aspen) DEDED Bleaching
	HW-Control		HW-2066 (0.2%)
Sequence	Initial Kappa Number		15.2		14.2
	Initial Brightness, %		31.4		32.1
	Initial Freeness @20° C., ml		665		663
	General conditions	Consistency		10%
			Temperature		70° C.
	D1	C102, 2% on OD pulp		1		1
		Time, min.		150		150
		End pH		279		2.53
		Residual C102, g/l		0.004		0.004
		Brightness D		—		—
	E	End pH		12.25		12.23
		Brightness DE		—		—
DED	D2	C102, 2% on OD pulp		1		1
		Time, min.		90		90
		End pH		2.47		2.61
		Residual C102, g/l		0.027		0.03
		Yield, %		97.7		98.4
		Freeness, ml		670		668
		Brightness DED., %/Series #		85.2	(#9)	85.7	(#10)
		Viscosity, cP		21.1		22.2
DEDED	E	End pH		12.32		12.43
		Brightness DEDE		—		—
	D3	C102, % on OD pulp		0.25		0.25
		Time, min.		—		90
		End pH		4.78		4.73
		Residual C102, g/l		0.04		0.054
	Yield %/Series #		96.9	(#11)	97.4
	Final Brightness, %		90.3		91.7
	Freeness @20° C., ml		680		670
	Viscosity, cP		20		20.8
Note:
1. Each experiment was conducted on a 30-g-OD-pulp scale
2. E stages: 2% NaOH, Time 60 min
3. —: Not determined.

Example 16

[0192] Kraft cooks were performed on undried softwood (pine) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2006 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 19. The pulp was then bleached using a DEDED sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 19. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 19.

[0193] The data in Table 19 demonstrates that Dequest 2006 produced bleached pulp with higher viscosity, higher yield and higher brightness (Series #13 v. Series #14) even though the initial brightness and kappa numbers prior to bleaching were only slightly improved.

Example 17

[0194] Handsheets were prepared from the bleached pulps of Examples 12, 13, 15 and 16 and strength properties were determined. The results are presented in Table 20. In addition to the improvements in brightness and viscosity obtained from the bleached pulp of the invention, the overall strength of the handsheets produced from bleached pulp of the invention are improved compared to the control bleached pulp.

Example 18

[0195] The fiber length of the bleached pulps of Examples 12-16 was determined using the Kajaani fiber length method and the results are presented in Table 21.

TABLE 19
Softwood (Pine) DEDED Bleaching
	SW-Control		SW-2006 (0.2%)
Initial Kappa number		23.9		23.8
Initial Brightness, %		28.8		29.5
Initial Freeness @20° C., ml		695		680
General Conditions	Consistency		10%
		Temperature		70°—72° C.
D1	C102, % on OD pulp		1.5		1.5
	Time, min		90		90
	End pH		2.24		2.2
	Residual C102, g/l		0.004		0.0067
	Brightness D
E	End pH		12.29		12.11
	Brightness DE		—		—
D2	C102, % on OD pulp		1		1
	Time, min		90		90
	End pH		2.37		2.41
	Residual C102, g/l		0.007		0.013
E	End pH		12.05		12.26
	Brightness DEDE		—		—
D3	C102, % on OD pulp		0.5		0.5
	Time, min		120		120
	End pH		3.27		3.34
	Residual C102, g/l		0.034		0.047
Yield, %/Series #		96.2	(#13)	96.7	(#14)
Final brightness, %		89.6		90.7
Freeness @20° C., ml		700		700
Viscosity, cP		17		17.6
Note:
1. Each experiment was conducted on a 30-g-OD-pulp scale
2. E stages: 2% NaOH, Time 60 min
3. —: Not Determined.

[0196]

TABLE 20
Handsheet Strength Data For Bleached Pulps Without Beating
	Hardwood	Hardwood	Hardwood	Hardwood
	Sequences
	DEDED	DEop	DEopD	DED
	Series no.
	#1	#2	#3	#6	#4	#7	#9	#10
	Pulp type
	Control	2066 (0.2%)	Control	2066 (0.2%)	Control	2066 (0.2%)	Control	2066 (0.2%)
Ini. Kappa no.	15.2	13.9	15.2	14.2	15.2	14.2	15.2	14.2
Ini. Brightness, %	31.4	33.9	31.4	32.1	31.4	32.1	31.4	32.1
Ini. Viscosity, cP	25.8	26.4	25.8	26.9	25.8	26.9	25.8	26.9
Basic weight, g/m{circumflex over ( )}2	62.72	61.12	60.33	60.44	61.98	61.61	61.35	61.68
Bulk, cm{circumflex over ( )}3/g	2	2	2.11	1.98	2.18	2.01	2.286	2.281
Tensile Index, N*m/g	18.6	21	18.7	21.63	17	19.27	15.08	15.21
Burst Index, kPa*m{circumflex over ( )}2/g	0.66	0.73	0.67	0.7	<0.56	0.663	0.4	0.5
Tear Index, mN*m{circumflex over ( )}2/g	4.13	4.37	4.07	4.41	3.59	4.23	3.07	3.58
Brightness, %	91.2	91.5	81.8	83.5	92.2	92.77	85.2	85.7
Final Viscosity, cP	20.3	21.1	13.6	14.3	13.4	14	21.1	22.2
	Hardwood	Softwood	Hardwood
	Sequences
	DEDED	DEDED	DEopP
	Series no.
	#11	#12	#13	#14	#5	#8
	Pulp type
	Control	2066 (0.2%)	Control	2066 (0.2%)	Control	2066 (0.2%)
	Ini. Kappa no.	15.2	14.2	23.9	23.8	15.2	14.2
	Ini. Brightness, %	31.4	32.1	28.8	29.5	31.4	32.1
	Ini. Viscosity, cP	25.8	26.9	20.8	21.1	25.8	26.9
	Basic weight, g/m{circumflex over ( )}2	61.36	60.83	61.25	60.84	60.26	62.02
	Bulk, cm{circumflex over ( )}3/g	2.229	2.231	2.221	2.184	2.108	1.981
	Tensile Index, N*m/g	14.32	15.04	28.37	29.5	17.77	21.01
	Burst Index, kPa*m{circumflex over ( )}2/g	0.5	0.56	1.85	1.97	0.652	0.74
	Tear Index, mN*m{circumflex over ( )}2/g	3.48	3.86	20.37	20.62	3.85	4.47
	Brightness, %	90.3	91.7	89.6	90.7	84.7	85.4
	Final Viscosity, cP	20	20.8	17	17.6	10.9	12

[0197]

TABLE 21
Kajaani Fiber Length Testing On Bleached Pulps
	Arith-			Coarse-
	metic	L weighted	W weighted	ness	Series
	mm	mm	mm	mg/m	no.
HW-DEDED (1%-1%-0.5%):
Control	0.57	0.78	0.92	0.114	#1
2066 (0.2%)	0.63	0.81	0.94	0.114	#2
HW-DEop (1%-P1%):
Control	0.54	0.74	0.88	0.113	#3
2066 (0.2%)	0.55	0.76	0.92	0.114	#6
HW-DEopD (1%-P1%-0.6%):
Control	0.54	0.74	0.88	0.115	#4
2066 (0.2%)	0.54	0.75	0.89	0.117	#7
HW-DEopP (1%-P1%-P1%):
Control	0.54	0.74	0.88	0.122	#5
2066 (0.2%)	0.54	0.74	0.87	0.117	#8
HW-DED (1%-1%)
Control	0.59	0.79	0.92	0.108	#9
2066 (0.2%)	0.59	0.79	0.93	0.108	#10
HW-DEDED (1%-1%-0.25%):
Control	0.58	0.77	0.9	0.109	#11
2066 (0.2%)	0.58	0.77	0.91	0.109	#12
SW-DEDED (1%-1%-0.5%)
Control	1.42	2.23	2.7	0.194	#13
2006 (0.2%)	1.48	2.24	2.71	0.192	#14
HW—hardwood (aspen)
SW—softwood (red pine)

Example 19

[0198] Kraft cooks were performed on undried softwood (pine) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2006 or Blend 78 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 22. The pulp was then bleached using a DEDED sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 22. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 22.

[0199] The data in Table 22 demonstrates that Dequest 2006 and Blend 78 produced pulps with higher initial brightness, and Blend 78 produced pulp with higher initial viscosity and lower kappa number. Dequest 2006 and Blend 78 produced bleached pulp after the DED and DEDE stages that exhibited higher brightness. Dequest 2006 and Blend 78 also produced final bleached pulp with higher viscosity and final brightness.

Example 20

[0200] Kraft cooks were performed on undried softwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2006 or Blend 78 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 23. The pulp was then bleached using a DEopD and DEopP sequences as described in the Bleaching Description section of the Examples using the conditions set forth in Table 22. The bleached pulp was tested after the DEop stage and at the end of the DEopD and DEopP bleaching sequences and the results presented in Table 23.

[0201] The data in Table 23 demonstrates that Dequest 2006 and Blend 78 produced pulps with higher initial brightness, and Blend 78 produced pulp with lower kappa number. Dequest 2006 and Blend 78 produced bleached pulp with higher brightness after the DEop stage. Dequest 2006 and Blend 78 produced final bleached pulp with higher yield and higher brightness after both the DEopD and DEopP bleaching sequences.

Example 21

[0202] The bleached pulps of Example 19 were tested for Kajaani fiber length and physical properties and the results are presented in Table 24.

[0203] The data in Table 24 demonstrates that Dequest 2006 and Blend 78 produced pulps with higher final brightness and improved strength properties.

TABLE 22
Softwood (Pine) DEDED Bleach Sequences
I. Conditions:
	Stage	D1	E1	D2	E2	D3
	Time, min	90	60	90	60	120
	Temp., ° C.	70	70	70	70	70
	Consistency, %	10	10	10	10	10
II. Results:
	Non-adjusted pH
	Control	2006 (0.2%)	Blend 78 (0.2%)
Ini. Kappa number	24.5	24.3	24.05
Ini. Viscosity, cP	21.96	21.02	22.27
Ini. Brightness, %	29.3	30.4	30.6
D1:	C102 applied, %	1.5	1.5	1.5
	NaOH applied, %	0	0	0
	C102 residual, g/l	ND	ND	ND
	End pH	1.45	1.47	1.48
E1:	NaOH applied, %	2	2	2
	End pH	11.96	11.91	11.82
D2:	C102 applied, %	0.8	0.8	0.8
	NaOH applied, %	0	0	0
	C102 residual, g/l	˜0.006	0.006	0.006
	End pH	2.2	2.19	2.17
DED:	Yield, %	98.2	98.7	98.3
	Brightness, %	62.6	64.5	66.8
E2:	NaOH applied, %	2	2	2
	End pH	12.04	12.03	12.02
DEDE:	Yield, %	96.3	96	96.2
	Brightness, %	67.1	67.7	70.3
D3:	C102 applied, %	0.4	0.4	0.4
	NaOH applied, %	0	0	0
	C102 residual, g/l	0.006	˜0.009	0.009
	End pH	2.96	2.89	2.78
DEDE:	Yield, %	94.6	95.3	95
	Brightness, %	87.4	88.4	88.6

[0204]

TABLE 23
Softwood (Pine)-DEopD/DEopP Bleaching
I. Conditions
Stage	D1	*Eop	D2/**P
Time, min	90	50 at 80-90° C.	120/150
Temp., ° C.	70	90	85-87
Cons., %	10	10	10
Note:
*O2 pressure 40 psi MgSO4-0.1%; **Na2SiO3-1.59%, MgSO4-
0.1%, NaOH-2%
II. Results
			Blend 78
	Control	2006 (0.2%)	(0.2%)
Initial Kappa No.	24.5	24.3	24.05
Initial Brightness, %	29.3	30.4	30.6
D1:	C102, %	1.5	1.5	1.5
	Residual, g/l	0.003	0.003	0.003
	End pH	1.91	1.88	1.81
Eop:	NaOH, %	3	3	3
	H2O2, %	0.5	0.5	0.5
	Residual, g/l	0.031	0.046	0.107
	End pH	11.91	11.92	11.98
DEop:	Brightness, %	61.8	63.9	64.55
D2:	C10, %	0.8	0.8	0.8
	Residual, g/l	ND	0.003	0.003
	Yield, %	94.7	96.3	95.6
	End pH	2.09	2.1	2.04
DEop D:	Brightness, %	81.4	82.8	83.5
P:	H2O2, %	1	1	1
	Residual, g/l	0.042	0.092	0.046
	End pH	11.76	11.76	11.62
	Yield, %	94.3	94.7	95.8
DEop P:	Brightness, %	74.5	76.9	79.1

[0205]

TABLE 24
Kajaani Fiber Lengths and Physical Properties - Softwood (Pine) DEDED Bleaching
	Control:	2006 (0.2%)	Blend 78 (0.2%)
	Original:	DEDED:	Original:	DEDED:	Original:	DEDED:
Fiber Lengths:
Arithmetic Ave, mm	1.62	1.55	1.62	1.55	1.63	1.52
L weighted Ave, mm	2.35	2.28	2.32	2.23	2.32	2.21
W weighted Ave, mm	2.8	2.74	2.77	2.67	2.77	2.66
Coarseness, mg/m	0.19	0.183	0.191	0.188	0.193	0.188
Physical lengths:
Basic Weight, g/m2	61.1	61.46	60.84	61.26	60.75	61.07
Bulk, cm3/g	2.46	2.29	2.3	2.28	2.28	2.19
Brightness, %	29.3	82.6	30.4	83.1	30.6	83.3
Tensile index, Nm/g	23.36	25.87	26.82	26.74	34.65	29.41
Burst index, kPa.m2/g	1.128	1.638	1.539	1.93	1.7	2.12
Tear index, mN.m2/g	16.05	16.98	18.06	20.05	18.34	19.3

Example 22

[0206] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2016 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 25. The pulp was then bleached using a DEDED sequence (pH not adjusted) as described in the Bleaching Description section of the Examples using the conditions set forth in Table 25. In particular, the Dequest 2016 pulp was bleached with less ClO2 during both the D1 and D2 stages. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 25.

[0207] The data in Table 25 demonstrates that Dequest 2016 produced pulps with higher initial brightness and lower kappa number. Dequest 2016 also produced bleached pulp with higher brightness after the D1, E1, D2 and E2 stages and comparable final brightness. It is significant that the final brightness of the Dequest 2016 bleached pulp is slightly better than the control while less C102 was used because use of less bleaching chemicals has commercial advantages, including lower AOX, biological oxygen demand (BOD), and chemical oxygen demand (COD) in the discharge from the bleach unit of the pulp mill.

TABLE 25
Hardwood (Aspen)-DEDED Bleaching (pH NOT adjusted)
I. Conditions
	Stage	D1	E1	D2	E2	D3
	Time, min	90	60	90	60	90
	Temp., ° C.	70	70	70	70	70
	Cons., %	10	10	10	10	10
II. Results
	H-Factor:
	HF846		Control	2016 (0.2%)
	Initial Kappa No.	22.5	16
	Initial Brightness, %	29.2	34.4
	D1:	C102, %	1.3	1
		Residual, g/l	0.006	0.0091
		End pH	2.2	2.44
		Brightness, %	43.98	51.44
	E1:	NaOH, %	2	2
		End pH	11.82	11.79
		Brightness, %	57.9	61.78
	D2:	C102, %	0.5	0.4
		Residual, g/l	0.006	0.004
		End pH	3	3.35
		Brightness, %	82.85	83.36
	E2	NaOH, %	2	2
		End pH	11.78	11.74
		Brightness, %	82.25	83.06
	D3:	C102, %	0.2	0.2
		Residual, g/l	0.036	0.036
		End pH	4.48	4.45
		Brightness, %	91.12	91.56

Example 23

[0208] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2016 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 26. The pulp was then bleached using a DEDED sequence (pH adjusted) as described in the Bleaching Description section of the Examples using the conditions set forth in Table 26. In particular, the Dequest 2016 pulp was bleached with less ClO2 during both the D1 and D2 stages. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 26.

[0209] The data in Table 26 demonstrates that Dequest 2016 produced pulps with higher initial brightness and lower kappa number. Dequest 2016 also produced bleached pulp with higher brightness after the D1, E1, D2 and E2 stages and comparable final brightness. It is significant that the final brightness of the Dequest 2016 bleached pulp is slightly better than the control while less ClO2 was used because use of less bleaching chemicals has commercial advantages, including lower AOX, BOD, and COD in the discharge from the bleach unit of the pulp mill.

TABLE 26
Hardwood-DEDED Bleaching (pH adjusted)
I. Conditions
	Stage	D1	E1	D2	E2	D3
	Time, min	90	60	90	60	90
	Temp., ° C.	70	70	70	70	70
	NaOH added,	0.2		0.2		0.2
	0.2% per % C102
	Cons., %	10	10	10	10	10
II. Results
	H-Factor: HF846		Control	2016 (0.2%)
	Initial Kappa No.	22.5	16
	Initial Brightness, %	29.2	34.4
	D1:	C102, %	1.3	1
		Residual, g/l	0.006	0.006
		End pH	2.95	3.21
		Brightness, %	44.75	53.66
	E1:	NaOH, %	2	2
		End pH	11.84	11.8
		Brightness, %	57.74	61.98
	D2:	C102, %	0.5	0.4
		Residual, g/l	0.067	0.085
		End pH	3.93	4.21
		Brightness,%	83.27	84.1
	E2	NaOH, %	2	2
		End pH	11.8	11.78
		Brightness, %	82.63	83.38
	D3:	C102, %	0.2	0.2
		Residual, g/l	0.07	0.073
		End pH	5.17	5.38
		Brightness, %	90.53	90.59

Example 24

[0210] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2016 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 27. The pulp was then bleached using a OPD sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 27. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 27.

[0211] The data in Table 27 demonstrates that Dequest 2016 produced pulps with higher initial brightness and lower kappa number. Dequest 2016 also produced bleached pulp with higher brightness after the O, P and D stages.

Example 25

[0212] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2016 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 28. The pulp was then bleached using a DEopD sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 28. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 28.

[0213] The data in Table 28 demonstrates that Dequest 2016 produced pulps with higher initial brightness and lower kappa number. Dequest 2016 also produced bleached pulp with significantly higher brightness after the D1, Eop, and D2 stages. It is particularly significant that the final brightness of the invention is 4.1% higher than the control as a brightness of 88.7 may enable elimination of additional bleaching steps to achieve an acceptable final brightness.

TABLE 27
Hardwood (Aspen)-OPD Bleaching
Stage	*O	**P	D
Time, min	45@90° C.	120	90
Temp., ° C.	90	85-87	70
NaOH added, %	2.5	2	0.3% per % C102
Cons., %	15	10	10
Note:
*O2 pressure-90 psi, MgSO4-0.1%;
**MgSO4-0.1%, Na2SiO3-1.5%
	H-Factor: HF693		Control	2016 (0.2%)
	Initial Kappa No.	24.5	17.06
	Initial Brightness, %	28.3	35.2
	O:	End pH	11.74	11.83
		Kappa no.	15.1	12.2
		Brightness, %	39.93	46.83
	P:	H2O2 applied, %	1.2	1.2
		Residual, g/l	0.0077	0.015
		Kappa no.	10.8	8.9
		End pH	11.65	11.64
		Brightness, %	54.62	59.6
	D:	C102, %	0.8	0.8
		Residual, g/l	0.012	0.079
		End pH	4.75	4.42
		Brightness, %	81.28	83.12

[0214]

TABLE 28
Hardwood (Aspen)-DEopD Bleaching
I. Conditions
	Stage	D1	*Eop	D2
	Time, min	90	50@80-90° C.	90
	Temp., ° C.	70	90	70
	Cons., %		10
	Note:
	*MgSO4-0.1%
II. Results
	H Factor: HF693		Control	2016 (0.2%)
	Initial Kappa No	24.5	17.06
	Initial Brightness	28.3	35.2
	**D1:	C102, %	1	1
		Residual, g/l	0.003	0.003
		End pH	3.72	3.53
		Brightness, %	38.4	53.81
	Eop:	NaOH, %	3	3
		H2O2, %	0.5	0.5
		Oxygen, psi	30	30
		Kappa number	5.6	4.5
		Residual, g/l	0.046	0.118
		End pH	11.75	11.83
		Brightness, %	71.22	79.23
	D2:	C102, %	0.3	0.3
		Residual, g/l	0.006	0.006
		End pH	4.2	4.21
		Brightness, %	84.6	88.7+TZ,1/32
	Note:
	**pH adjusted with NaOH of 0.4% per % C102

Example 26

[0215] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2016 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 29. The pulp was then bleached using a DEopP sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 29. The bleached pulp was tested during and at the end of the bleaching sequence and the results presented in Table 29.

[0216] The data in Table 29 demonstrates that Dequest 2016 produced pulps with higher initial brightness and lower kappa number. Dequest 2016 also produced bleached pulp with significantly higher brightness after the D1, Eop, and P stages.

Example 27

[0217] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no phosphonate (control) or using Dequest 2016 at 0.2 wt. % concentration at H-factors of 1000, 846, 693 and 539. The pulp was recovered and tested and the results presented in Table 30. Pulp from the H-factor 846 and 693 runs were then bleached using various bleaching sequences as described in the Bleaching Description section of the Examples using the conditions set forth in Tables 25-29. The viscosity of the bleached pulp was determined at the end of the bleaching sequence and the results presented in Table 30.

[0218] The data in Table 30 demonstrates that Dequest 2016 produced pulps with higher initial brightness, lower kappa number, lower reject, higher yield, and higher viscosity. Dequest 2016 also produced bleached pulp with higher viscosity after the bleach stages of DEDED, DEDED (pH adjusted), DEop, DEopD, DEopP, 0, OP, and OPD for the H-factors tested. As such, the use of Dequest 2016 improved the pulps' response to bleaching sequences with respect to viscosity. 0.59

TABLE 29
Hardwood (Aspen)-DEopP Bleaching
	I. Conditions	Stage	D	*Eop	**P
		Time, min	90	50@80-90° C.	120
		Temp., ° C.	70	90	85-87
		Cons., %	10	10	10
II. Results	H Factor: HF693		Control	2016(0.2%)
	Initial Kappa No.		24.5	17.06
	Initial Brightness, %	28.3	35.2
	***D:	ClO2, %	1	1
		Residual, g/l	0.003	0.003
		End pH	3.72	3.53
		Brightness, %	38.4	53.81
	Eop:	NaOH, %	3	3
		O2 pressure,	30	30
		psi
		H2O2, %	0.5	0.5
		Residual, g/l	0.046	0.118
		Kappa no.	5.6	4.5
		End pH	11.75	11.83
		Brightness, %	71.22	79.23
	P:	H2O2, %	0.6	0.6
		Residual, g/l	0.007	0.011
		End pH	11.66	11.71
		Brightness, %	79.5	83.43
Note:
*MgSO4-0.1%;
**Na2SiO3-1.5%, MgSO4-0.1%, NaOH-2%
***pH adjusted with NaOH of 0.3% per % of ClO2

[0219]

TABLE 30
Hardwood Kraft Pulping (Aspen)
	H-factor:
	HW-control	HW-2016 (0.2%)
	1000	846	693	539	1000	846	693	539
Kappa no.	20.7	22.5	24.51	28	15.02	16.02	17.06	18.28
Yield, %	52.8	52.7	51.2	45.61	53.62	53.5	53.9	52.1
Reject, %	0.84	1.75	4.1	15.85	0.78	1.07	2.12	3.73
Brightness, %	30.6	29.2	28.2	28	35.5	34.4	35.2	35.1
Viscosity:	33.6	39.4	43.1	48.3	34.8	39.6	43.7	50.4
DEDED		29.8				30.6
DEDED (pH)		27.7				29.5
Deop			26.2				28.4
DeopD			25.7				26.8
DeopP			23.4				24.7
O			34.3				35.2
OP			28.1				29.1
OPD			26.7				27.8
Note:
1. See Tables 24-28 for bleaching sequences.
2. Other cooking conditions: AA18%, Sulfidity 25%, Highest temp. 170° C., Woodchip350 g OD/cook, Liquor: Woodchip ratio = 4:1.

Example 28

[0220] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either Dequest 2016 at 0.1 wt. % concentration or using Dequest 2066 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 31. The pulp was then bleached using a DEDED sequence (pH adjusted) as described in the Bleaching Description section of the Examples using the conditions set forth in Table 31. The bleached pulps were tested during and at the end of the bleaching sequence and the results presented in Table 31.

[0221] The data in Table 31 demonstrates that Dequest 2016 and 2066 produced pulps with higher initial brightness and lower Kappa number. Dequest 2016 and 2066 also produced bleached pulp with higher brightness after the D1, E1, D2 and E2 stages and comparable final brightness. It is significant that the final brightness is comparable while less ClO2 was used because use of less bleaching chemical has the aforementioned commercial advantages. Comparing Table 31 with Table 26, it is also shown that 0.2% Dequest 2016 produces brighter pulp than 0.1% Dequest 2016.

Example 29

[0222] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either Dequest 2016 at 0.1 wt. % concentration or using Dequest 2066 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 32. The pulp was then bleached using a DEopD sequence as described in the Bleaching Description section of the Examples using the conditions set forth in Table 32. The bleached pulps were tested during and at the end of the bleaching sequence and the results presented in Table 32.

[0223] The data in Table 32 demonstrates that Dequest 2016 and 2066 produced pulps with higher initial brightness and lower Kappa number. Dequest 2016 and 2066 also produced bleached pulp with significantly higher brightness after each stage. It is significant that the final brightness of the invention is 3.9-4.1% higher than the control as a brightness of 88.5-88.7 may enable elimination of additional bleaching steps to achieve an acceptable final brightness. Comparing Table 32 with Table 28, it is also shown that 0.1% and 0.2% Dequest 2016 produce equivalent brightness.

TABLE 31
Hardwood (Aspen)-DEDED Bleaching (pH adjusted)
I. Conditions
Stage	D1	E1	D2	E2	D3
Time, min	90	60	90	60	90
Temp., ° C.	70	70	70	70	70
NaOH added,	0.3 per % C102	2	0.3 per % C102	2	0
Cons., %	10	10	10	10	10
II. Results
	2016 (0.1%)	2066 (0.2%)	Control
Initial Kappa No.	18.1	18.57	22.5
Initial Brightness, %	33.1	33.7	29.2
D1:	C102, %	1	1	1.3
	Residual, g/l	0.003	0.006	0.006
	End pH	3.61	3.73	2.95
	Brightness, %	51.25	53.7	44.75
E1:	End pH	11.87	11.87	11.84
	Brightness, %	60.2	62.2	57.74
D2:	C102, %	0.5	0.5	0.5
	Residual, g/l	0.006	0.006	0.067
	End pH	4.21	4.22	3.93
	Brightness, %	83.7	84.8	83.27
E2:	End pH	11.72	11.74	11.8
	Brightness, %	83.8	84.46	82.63
D3:	C102, %	0.2	0.2	0.2
	Residual, g/l	0.036	0.03	0.07
	End pH	4.42	4.32	5.17
	Brightness, %	89.9	90.7	90.53

[0224]

TABLE 32
Hardwood (Aspen)-DEopD Bleaching
	I. Conditions	Stage	D1	*Eop	D2
		Time, min	90	50@80-90° C.	90
		Temp., ° C.	70	90	70
		Cons., %	10	10	10
II. Results			2016(0.1%)	2066(0.2%)	Control
	Initial		18.1	18.57	24.5
	Kappa No.
	Initial		33.1	33.7	28.3
	Bright-
	ness, %
	**D1:	ClO2, %	1	1	1
		Residual,	0.003	0.006	0.003
		g/l
		End pH	3.61	3.73	3.72
		Bright-	51.25	53.7	38.4
		ness, %
	Eop:	NaOH,%	3	3	3
		O2	30	30	30
		pressure,
		psi
		H2O2, %	0.5	0.5	0.5
		Residual,	0.122	0.18	0.046
		g/l
		Kappa no.	—	—	5.6
		End pH	11.69	11.66	11.75
		Bright-	78.8	79.15	71.22
		ness, %
	D2:	ClO2, %	0.3	0.3	0.3
		Residual,	0.006	0.009	0.006
		g/l
		End Ph	4.21	4.12	4.2
		Bright-	88.5	88.7	84.6
		ness, %
Note:
*MgSO4-0.1%
**pH adjusted with NaOH of 0.3% per %ClO2

Example 30

[0225] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either Dequest 2016 at 0.1 wt. % concentration or using Dequest 2066 at 0.2 wt. % concentration. The pulp was recovered and tested and the results presented in Table 33. The pulp was then bleached using a DEopP sequence (pH adjusted) as described in the Bleaching Description section of the Examples using the conditions set forth in Table 33. Tne bleached pulps were tested during and at the end of the bleaching sequence and the results presented in Table 33.

[0226] The data in Table 33 demonstrates that Dequest 2016 and 2066 produced pulps with higher initial brightness and lower Kappa number. Dequest 2016 and 2066 also produced bleached pulp with significantly higher brightness after each stage. It is significant that the final brightness of the invention is 5.2-6.15% higher than the control.

Example 31

[0227] Kraft cooks were performed on undried hardwood (aspen) wood chips according to the procedure described in the Pulping Description section of the Examples using either no added compound of the invention (control) or compound 4NHMP, DTPA, Blend 83A, and Blend 84 at 0.2 wt. % concentration or Blend 86 at 0.1 wt. % concentration. The pulp was recovered and tested and the results presented in Table 34. The pulp was then bleached using a DEDED sequence (pH adjusted) as described in the Bleaching Description section of the Examples using the conditions set forth in Table 34. The bleached pulps were tested during and at the end of the bleaching sequence and the results presented in Table 34.

[0228] The data in Table 34 demonstrates that compounds of the invention tested produced pulps with higher initial brightness and lower kappa number. The compounds of the invention tested also produced bleached pulp with higher brightness after the D1, E1, D2, E2 and D3 stages. The improvement in final brightness is significant. The data in Table 34 further demonstrates that the most significant improvement in final brightness is achieved with compound 4NHMP or the blend of compound 4NHMP and Dequest 2016 (Blend 83A).

TABLE 33
Hardwood (Aspen)-DEopP Bleaching
	I. Conditions	Stage	D	*Eop	**P
		Time, min	90	50@80-90° C.	120
		Temp., ° C.	70	90	85-87
		Cons., %	10	10	10
II. Results			2016(0.1%)	2066(0.2%)	Control
	Initial		18.1	18.57	24.5
	Kappa No.
	Initial		33.1	33.7	28.3
	Bright-
	ness, %
	***D:	ClO2, %	1	1	1
		Residual,	0.003	0.006	0.003
		g/l
		End pH	3.61	3.73	3.72
		Bright-	51.25	53.7	38.4
		ness,
	Eop:	NaOH, %	3	3	3
		O2	30	30	30
		pressure,
		psi
		H2O2, %	0.5	0.5	0.5
		Residual,	0.122	0.18	0.046
		g/l
		Kappa no.	—	—	5.6
		End pH	11.69	11.66	11.75
		Bright-	78.8	79.15	71.22
		ness,
	P:	H2O2, %	0.6	0.6	0.6
		Residual,	0.08	0.24	0.007
		g/l
		End pH	11.67	11.62	11.66
		Bright-	84.7	85.65	79.5
		ness, %
Note:
*MgSO4-0.1%;
**Na2SiO3-1.5%, MgSO4-0.1%, NaOH-2%
**pH adjusted with NaOH of 0.3% per % ClO2

[0229]

TABLE 34
Hardwood (Aspen) DEDED Bleaching (pH adjusted)
	I. Conditions:	Stage	D1	E1	D2	D2	E2	D3
		Time, min	90	60	90	90	60	90
		Temp., C.			70	70
		NaOH, %	0.3%/%	2	0.3%/%	0.3%/%	2	0
			ClO2		ClO2	ClO2
		Consistency			10
					Blend	Blend	Blend
				DTPA	83A	84	86	4NHMP
II. Results:		Control	(0.2%)	(0.2%)	(0.2%)	(0.1%)	(0.2%)
	Cooking	853	853	853	853	853	853
	H-Factor:
	Ini.	23.87	19.2	15.3	16.7	18.8	16.35
	Kappa no.
	Ini.	28.7	29.9	33.7	31.4	29.9	35.1
	Bright-
	ness, %
	D1:	ClO2, %	1	1	1	1	1	1
		Residual,	˜1.006	˜1.006	˜1.006	˜1.006	˜1.006	0.009
		g/l
		End pH	3.22	2.96	3.88	3.8	4.04	3.05
		Bright-	41.5	47.55	56.2	52.9	49.2	53.7
		ness, %
	E1:	End pH	11.94	11.95	11.93	11.94	11.89	12.04
		Bright-	54.3	58.5	64.28	61.8	59.7	64.8
		ness, %
	D2:	ClO2, %	0.5	0.5	0.032	0.5	0.5	0.5
		Residual,	0.0096	0.019	0.019	0.032	0.0096	0.016
		g/l
		End pH	4.21	—	4.57	4.62	4.49	4.11
		Bright-	79.5	82.5	86.3	84.6	84.1	86.2
		ness, %
	E2:	End pH	11.94	11.97	11.98	11.94	11.89	12.13
		Bright-	79.8	82.1	85.3	84.1	83.4	85.5
		ness, %
	D3:	ClO2, %	0.2	0.2	0.2	0.2	0.2	0.2
		Residual,	0.013	0.022	0.032	0.026	0.026	0.026
		g/l
		End pH	4.4	4.4	3.98	4.42	4.15	4.31
		Bright-	88.72	90	91.9	90.5	90.3	91.5
		ness, %

Example 32

[0230] Multiple Kraft cooks were performed in a custom-made laboratory-scale multiple digester equipment and the results presented in Table 35. The digester equipment consisted of seven Parr bomb reactors (approx. 1 L) in a carousel that were rotated through a temperature-controlled oil bath. Aspen wood chips and white liquor used in the Kraft cooks were obtained from a commercial pulp mill located in the Upper Midwestern United States. The wood chips used were hand picked to reduce variability. Pulping conditions were: liquor:wood weight ratio of 4:1, 16% active alkali and 26.7% sulfidity. The digester temperature was ramped from ambient temperature to 170° C. in approximately 72 minutes. The H-factor was varied in the cooks conducted.

[0231] Yield was determined as follows. Pulps were completely transferred from the Parr bomb reactors to individual containers. The pulps were disintegrated for one minute and filtered to remove liquid, followed by air drying in a ventilated hood in aluminum trays overnight. Total yield of solids from the above air-dried pulps was determined by the formula: Total Yield=(total solid weight of air-dried pulp recovered*100)/(weight of OD wood chip used).

[0232] Reject was determined as follows. Pulps were screened using a vibrating screener with a 200 mesh screen, and the total material retained on the screen was weighed after drying in an oven overnight. Reject % was determined by the formula:

Reject %=(weight OD retained material*100)/(weight of OD wood chip used).

[0233] The data in Table 35 demonstrate that the use of Dequest 2016 and Dequest 2066 in the Kraft cooks resulted in increased yields compared to the control without phosphonate.

[0234] The preceding description is for illustration and should not be taken as limiting. Various modifications and alterations will be readily suggested to persons skilled in the art. It is intended, therefore, that the foregoing be considered as exemplary only and that the scope of the invention be ascertained from the following claims.

TABLE 35
Aspen Kraft Cook Experiments Using Commercial Mill White Liquor
		Kappa
	H-Factor	number	% Total Yield	% Reject
Control:	600	14.09	58.4	1.25
	800	12.92	54.05	0.2
	1000	11.77	54.05	0.003
	1200	11.58	55.17	0.001
2016 (0.2 wt. %)	600	16.1	59.73	0.53
	800	13.44	58.57	0.28
	1000	11.94	56.83	2.07
	1200	12.68	56.43	1.25
2066 (0.2 wt. %)	600	16.15	57.33	0.8
	800	13.64	57.44	0.06
	1000	12.83	56.53	0.48
	1200	12.92	56.55	0.25
Repeated Trials:
Control:	600	15.12	56.74	—
	800	12.4	54	—
	1000	11.4	54.24	—
	1200	11.73	56.46	—
2016 (0.2 wt. %)	800	12.42	55.2	—
	1000	11.78	56.86	—

Claims

1. An aqueous composition for improving properties of pulp produced, reducing the digester cycle time, or reducing the pulping or bleaching chemicals required in alkaline chemical pulping processes, wherein said composition is added to the digester of said chemical pulping process, said composition comprising an effective amount of at least one compound selected from phosphonates having the formula:

2. The composition of claim 1 wherein M is independently selected from hydrogen or an alkali metal.

3. The composition of claim 2 wherein M is sodium or potassium when M is an alkali metal.

4. The composition of claim 1 wherein X is independently selected from —CH2PO3M2 or R.

5. The composition of claim 4 wherein at least one of X is R and R is —(CH12)nNX′2, wherein n is an integer from 2 to 6 and X′ is independently selected from R or —CH2PO3M2.

6. The composition of claim 4 wherein each X is R and R is —(CH2)nNX′2, wherein n is an integer from 2 to 6 and X′ is independently selected from R or —CH2PO3M2.

7. The composition of claim 1 wherein Y is —PO3M2.

8. The composition of claim 7 wherein Z is —OH.

9. The composition of claim 7 wherein R′ is an alkyl group having 1 to 11 carbon atoms.

10. The composition of claim 7 wherein R′ is substituted with —SO3M.

11. The composition of claim 7 wherein Z is —NR1R2.

12. The composition of claim 1 wherein R′ is an alkyl group having 1 to 11 carbon atoms.

13. The composition of claim 12 wherein R′ is an alkyl group having 1 to 5 carbon atoms.

14. The composition of claim 1 wherein said compound is at least one phosphonate of formula (1).

15. The composition of claim 1 wherein said compound is at least one phosphonate of formula (II).

16. The composition of claim 1 wherein said compound is at least one compound of formula (III).

17. The composition of claim 1 wherein said compound is at least one compound of formula (IV).

18. The composition of claim 1 wherein said compound is a mixture of at least two phosphonates of formula (I).

19. The composition of claim 1 wherein said compound is a mixture of at least one phosphonate of formula (I) and at least one phosphonate of formula (II).

20. The composition of claim 1 wherein said compound is a mixture of at least two phosphonates of formula (II).

21. The composition of claim 1 wherein said compound is a mixture of at least one compound of formula (III) or formula (IV) with at least one compound selected from the phosphonates of formula (I) or formula (II).

22. The composition of claim 1 wherein said compound is an amine oxide of the phosphonates of formula (I).

23. The composition of claim 22 wherein said amine oxide is −O←+N—(CH2PO3M2)3.

24. The composition of claim 14 wherein said phosphonate is N(CH2PO3M2)3 and the amount of said phosphonate on an active acid basis is about 0.05 to about 1 wt. % based on the weight of wood chips charged to said digester.

25. The composition of claim 15 wherein said phosphonate is CH3C(OH)(PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

26. The composition of claim 14 wherein said phosphonate is (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

27. The composition of claim 14 wherein said phosphonate is (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

28. The composition of claim 14 wherein said phosphonate is (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

29. The composition of claim 14 wherein said phosphonate is (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

30. The composition of claim 22 wherein the amount of said amine oxide of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

31. The composition of claim 16 wherein the amount of said compound on an active acid basis is about 0.05 to about 1 wt. % based on the weight of wood chips charged to said digester.

32. The composition of claim 17 wherein the amount of said compound on an active acid basis is about 0.05 to about 1 wt. % based on the weight of wood chips charged to said digester.

33. The composition of claim 18 wherein said phosphonate is a mixture of: (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2—N(CH2PO3M2)2, and a second phosphonate selected from N(CH2PO3M2)3, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2.

34. The composition of claim 33 wherein said second phosphonate is N(CH2PO3M2)3, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

35. The composition of claim 33 wherein said second phosphonate is selected from (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

36. The composition of claim 18 wherein said phosphonate is a mixture of (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2 and a second phosphonate selected from (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2 or N(CH2PO3M2)3, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester

37. The composition of claim 18 wherein said phosphonate is a mixture of (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2 and N(CH2PO3M2)3, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

38. The composition of claim 18 wherein said phosphonate is a mixture of (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2 and a second phosphonate selected from (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, or N(CH2PO3M2)3, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

39. The composition of claim 19 wherein said phosphonate is a mixture of a first phosphonate selected from N(CH2PO3M2)3, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, and a second phosphonate selected from CH3C(OH)(PO3M2)2.

40. The composition of claim 39 wherein where said first phosphonate is selected from (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

41. The composition of claim 39 wherein said first phosphonate is N(CH2PO3M2)3 and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

42. The composition of claim 1 wherein the pH of said alkaline aqueous mixture is at least 9.

43. The composition of claim 42 wherein the pH of said alkaline aqueous mixture is about 12 to 14.

44. The composition of claim 1 further comprising anthroquinone.

45. An aqueous composition for improving properties of pulp produced in alkaline chemical pulping processes, wherein said composition is added to the digester of said chemical pulping process, said composition comprising an effective property improving amount of at least one compound selected from phosphonates having the formula:

46. An aqueous composition for reducing the digester cycle time or reducing the pulping or bleaching chemicals required in alkaline chemical pulping processes, wherein said composition is added to the digester of said chemical pulping process, said composition comprising an effective amount of at least one compound selected from phosphonates having the formula:

47. A method for improving properties of pulp produced, reducing the digester cycle time, or reducing the pulping or bleaching chemicals required in alkaline chemical pulping processes comprising adding an effective amount of at least one compound to the alkaline aqueous mixture in the digester of said chemical pulping process, wherein said at least one compound is selected from phosphonates having the formula:

48. The method of claim 47 wherein M is independently selected from hydrogen or an alkali metal.

49. The method of claim 48 wherein M is sodium or potassium when M is an alkali metal.

50. The method of claim 47 wherein X is independently selected from —CH2PO3M2 or R.

51. The method of claim 50 wherein at least one of X is R and R is —(CH2)nNX′2, wherein n is an integer from 2 to 6 and X′ is independently selected from R or —CH2PO3M2.

52. The method of claim 50 wherein each X is R and R is —(CH2)nNX′2, wherein n is an integer from 2 to 6 and X′ is independently selected from R or —CH2PO3M2.

53. The method of claim 47 wherein Y is —PO3M2.

54. The method of claim 53 wherein Z is —OH.

55. The method of claim 53 wherein R′ is an alkyl group having 1 to 11 carbon atoms.

56. The method of claim 53 wherein R′ is substituted with —SO3M.

57. The method of claim 53 wherein Z is —NR1R2.

58. The method of claim 47 wherein R′ is an alkyl group having 1 to 11 carbon atoms.

59. The method of claim 55 wherein R′ is an alkyl group having 1 to 5 carbon atoms.

60. The method of claim 47 wherein said phosphonate is at least one phosphonate of formula (I).

61. The method of claim 47 wherein said phosphonate is at least one phosphonate of formula (II).

62. The method of claim 47 wherein said phosphonate is at least one phosphonate of formula (III).

63. The method of claim 47 wherein said compound is at least one compound of formula (IV).

64. The method of claim 47 wherein said phosphonate is a mixture of at least two phosphonates of formula (I).

65. The method of claim 47 wherein said phosphonate is a mixture of at least one phosphonate of formula (I) and at least one phosphonate of formula (II).

66. The method of claim 47 wherein said phosphonate is a mixture of at least two phosphonates of formula (II).

67. The method of claim 47 wherein said compound is a mixture of at least one compound of formula (III) or formula (IV) with at least one compound selected from the phosphonates of formula (I) or formula (II).

68. The method of claim 47 wherein said compound is an amine oxide of the phosphonates of formula (I).

69. The method of claim 68 wherein said amine oxide is −O←+N—(CH2PO3M2)3.

70. The method of claim 60 wherein said phosphonate is N(CH2PO3M2)3 and the amount of said phosphonate on an active acid basis is about 0.05 to about 1 wt. % based on the weight of wood chips charged to said digester.

71. The method of claim 61 wherein said phosphonate is CH3C(OH)(PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

72. The method of claim 60 wherein said phosphonate is (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

73. The method of claim 60 wherein said phosphonate is (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

74. The method of claim 60 wherein said phosphonate is (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

75. The method of claim 60 wherein said phosphonate is (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2 and the amount of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

76. The method of claim 68 wherein the amount of said amine oxide of said phosphonate on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

77. The method of claim 62 wherein the amount of said compound on an active acid basis is about 0.05 to about 1 wt. % based on the weight of wood chips charged to said digester.

78. The method of claim 63 wherein the amount of said compound on an active acid basis is about 0.05 to about 1 wt. % based on the weight of wood chips charged to said digester.

79. The method of claim 64 wherein said phosphonate is a mixture of: (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, and a second phosphonate selected from N(CH2PO3M2)3, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2.

80. The method of claim 79 wherein said second phosphonate is N(CH2PO3M2)3, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

81. The method of claim 79 wherein said second phosphonate is selected from (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

82. The method of claim 64 wherein said phosphonate is a mixture of (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2 and a second phosphonate selected from (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2 or N(CH2PO3M2)3, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

83. The method of claim 64 wherein said phosphonate is a mixture of (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2 and N(CH2PO3M2)3, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

84. The method of claim 64 wherein said phosphonate is a mixture of (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2 and a second phosphonate selected from (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, or N(CH2PO3M2)3 and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

85. The method of claim 65 wherein said phosphonate is a mixture of a first phosphonate selected from N(CH2PO3M2)3, (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2Po3M2)2, (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)2, and a second phosphonate selected from CH3C(OH)(PO3M2)2.

86. The method of claim 85 wherein where said first phosphonate is selected from (M2O3PCH2)2N(CH2)6N(CH2PO3M2)2, (M2O3PCH2)2NCH2CH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)CH2CH2CH2N—(CH2PO3M2)2, or (M2O3PCH2)2NCH2CH2N(CH2PO3M2)CH2CH2N(CH2PO3M2)2, and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

87. The method of claim 85 wherein said first phosphonate is N(CH2PO3M2)3 and the amount of said mixture on an active acid basis is about 0.03 to about 1 wt. % based on the weight of wood chips charged to said digester.

88. The method of claim 47 wherein said chemical pulping process is a Kraft process.

89. The method of claim 47 wherein the pulp from said digester is recovered, washed and subsequently bleached.

90. The method of claim 89 wherein said washed pulp is bleached using a bleaching process selected from DED, DEDED, DEopD, DEopP, ODED, OZEP, DEDP or CEH.

91. The method of claim 47 wherein the pH of said alkaline aqueous mixture is at least 9.

92. The method of claim 91 wherein the pH of said alkaline aqueous mixture is about 12 to 14.

93. The method of claim 47 wherein said alkaline aqueous mixture further comprises anthroquinone.

94. A method for improving properties of pulp produced in alkaline chemical pulping processes comprising adding an effective property improving amount of at least one compound to the alkaline aqueous mixture in the digester of said chemical pulping process, wherein said at least one compound is selected from phosphonates having the formula:

95. A method for reducing the digester cycle time or reducing the pulping or bleaching chemicals required in alkaline chemical pulping processes comprising adding an effective amount of at least one compound to the alkaline aqueous mixture in the digester of said chemical pulping process, wherein said at least one compound is selected from phosphonates having the formula:

96. A pulp prepared according to the process of claim 47.

97. A pulp prepared according to the process of claim 89.