Patent Application
20140363761
The present embodiments relate to methods of making a toner composition, for example, high gloss toner composition. More specifically, the present embodiments relate to methods of including a functional material into a toner composition. In particular, the present embodiments pertain to an improved method of making a toner composition for use with an electrophotographic imaging member comprising an overcoat layer protecting the imaging member surface and a contact type charging device, such as a “bias charge roll” (BCR).
U.S. patents describing emulsion aggregation toners include, for example, U.S. Pat. Nos. 5,370,963, 5,418,108, 5,290,654, 5,278,020, 5,308,734, 5,344,738, 5,403,693, 5,364,729, 5,346,797, 5,348,832, 5,405,728, 5,366,841, 5,496,676, 5,527,658, 5,585,215, 5,650,255, 5,650,256, 5,501,935, 5,723,253, 5,744,520, 5,763,133, 5,766,818, 5,747,215, 5,827,633, 5,853,944, 5,804,349, 5,840,462, and 5,869,215, the entire disclosures of which are incorporated herein by reference.
In electrophotography or electrophotographic printing, the charge retentive surface, typically known as a photoreceptor, is electrostatically charged, and then exposed to a light pattern of an original image to selectively discharge the surface in accordance therewith. The resulting pattern of charged and discharged areas on the photoreceptor form an electrostatic charge pattern, known as a latent image, conforming to the original image. The latent image is developed by contacting it with a finely divided electrostatically attractable powder known as toner. Toner is held on the image areas by the electrostatic charge on the photoreceptor surface. Thus, a toner image is produced in conformity with a light image of the original being reproduced or printed. The toner image may then be transferred to a substrate or support member (e.g., paper) directly or through the use of an intermediate transfer member, and the image affixed thereto to form a permanent record of the image to be reproduced or printed. Subsequent to development, excess toner left on the charge retentive surface is cleaned from the surface. The process is useful for light lens copying from an original or printing electronically generated or stored originals such as with a raster output scanner (ROS), where a charged surface may be imagewise discharged in a variety of ways.
To charge the surface of a photoreceptor, a contact type charging device has been used, such as disclosed in U.S. Pat. No. 4,387,980 and U.S. Pat. No. 7,580,655, which are incorporated herein by reference. The contact type charging device, also termed “bias charge roll” (BCR) includes a conductive member which is supplied a voltage from a power source with a D.C. voltage superimposed with an A.C. voltage of no less than twice the level of the D.C. voltage. The charging device contacts the image bearing member (photoreceptor) surface, which is a member to be charged. The outer surface of the image bearing member is charged at the contact area. The contact type charging device charges the image bearing member to a predetermined potential.
A long life photoreceptor enables significant cost reduction. Generally photoreceptor life extension is achieved with a wear-resistant overcoat. However, wear resistant overcoats are associated with an increase in A-zone deletion (a printing defect that occurs at high humidity). Most organic photoreceptor materials require a minimal wear rate of 2 nm/Kcycle (scorotron charging system) or from about 5 nm/Kcycle to about 10 nm/Kcycle (BCR charging system) in order to suppress A-zone deletion. In addition, wear-resistant overcoats cause torque system failures in BCR charging systems, resulting in motor failure and blade damage (which results in streaking of toner in prints.)
One solution is to include a functional material to a toner. A functional material may be defined both in the conventional sense of a material that is able to fix or repair damage to the photoreceptor and also a material that provides maintenance of desired photoreceptor function. However, direct addition of a functional material into a toner through blending with the intention of preparing a functional material liquid coating on toner is challenging, due to the agglomeration of the toner and impacting its transferring and charging performance. The agglomerate of toner can also cause severe clogging which can damage other xerographic components, such as the developer housing, the toner filling hopper, the waste toner transmission, etc.
As a result, use of a low wear overcoat with BCR charging systems is still a challenge, and there is a need to find a way to achieve the life target with overcoat technology in such systems.
According to embodiments illustrated herein, there is provided a process for preparing a toner composition, comprising (a) providing toner particles containing a toner resin, an optional colorant, and an optional release agent; (b) blending one or more additives to the toner particles to obtain a toner mixture; and (c) adding a capsule comprises a core and a polymeric shell to the toner mixture, wherein the core comprises a functional material.
The disclosure also provides a toner composition of the present embodiments for electrostatic image development, comprising toner particles comprising at least one resin, in combination with an optional colorant, and an optional release agent; and a capsule comprises a core and a polymer shell, wherein the core comprises a functional material selected from the group consisting of a lubricant material, a hydrophobic compound, a hydrophobic polymer, an amphiphilic compound, an amphiphilic polymer and mixtures thereof.
The disclosure further provides an image forming apparatus, comprising a) an imaging member having a charge retentive surface for developing an electrostatic latent image, wherein the imaging member comprises: a substrate; a photoconductive layer disposed on the substrate; and a protective layer disposed on the photoconductive layer; b) a bias charging unit; c) a latent image forming unit; d) a toner developing unit; e) a transfer unit; f) a cleaning unit in contact with the imaging member; g) a toner comprising toner particles comprising at least one resin, in combination with an optional colorant, and an optional release agent; and a capsule comprises a core and a polymer shell, wherein the core comprises a functional material.
For a better understanding of the present embodiments, reference may be made to the accompanying figures.
In the following description, it is understood that other embodiments may be utilized and structural and operational changes may be made without departure from the scope of the present embodiments disclosed herein.
The present embodiments are directed generally to improved methods of making a toner composition, for example, a high gloss toner composition. Particularly, the present embodiments relate to methods of including a capsule into a toner composition. In embodiments, the capsule contains a functional material in the core and a polymeric coating. In embodiments, the method including adding the capsule into a toner allows the functional material to be effectively applied onto the surface of an overcoated photoreceptor under BCR charging.
As used herein, “functional material” is a material that provides maintenance of desired photoreceptor function. For example, the functional material may be one that is continuously applied onto the photoreceptor surface through direct contact transfer and which can maintain the desired function(s) of the photoreceptor by providing continued lubrication and surface protection. Lubrication of the photoreceptor surface improves interaction with other components in a xerographic system, such as for example, the blade cleaner to reduce torque and blade damage. By maintaining a thin layer of surface material on the photoreceptor, the functional material also provides surface protection to prevent image deletion in, for example, a humid environment such as A-zone. Generally, the functions of the functional material include providing lubricity, and/or hydrophobicity.
Certain embodiments of the disclosure provide methods of including an encapsulated functional material into a toner composition by blending the encapsulated functional material with the toner, such blending step does not cause breakage of the polymeric shell of the capsule that leads to undesired leaking of the functional material. Typically, the functional material is in liquid form.
Subsequently, the photoreceptor 2 is substantially uniformly charged by the bias charge roller 4 to initiate the electrophotographic reproduction process. The charged photoreceptor is then exposed to a light image to create an electrostatic latent image on the photoreceptive member (not shown). This latent image is subsequently developed into a visible image by a toner developer 3. Thereafter, the developed toner image is transferred from the photoreceptive member may through a record medium to a copy sheet or some other image support substrate to which the image may be permanently affixed for producing a reproduction of the original document (not shown). The photoreceptor surface is generally then cleaned with a cleaner 5 to remove any residual developing material therefrom, in preparation for successive imaging cycles.
The capsule of the present embodiments has an average particle size from about 10 nm to about 15 μm, from about 50 nm to about 5 μm, or from about 150 nm to about 0.5 μm.
In embodiments, the functional material may comprise a material, being a compound or a polymer, capable of imparting desired surface functions to the photoreceptor. The functional materials may comprise, in particular embodiments, a hydrophobic, oleophobic, or amphiphilic material. For example, functional material may be selected from the group consisting of a lubricant material, a hydrophobic compound, a hydrophobic polymer, an oleophobic compound, an oleophobic polymer, an amphiphilic compound, an amphiphilic polymer and mixtures thereof. Illustrative examples of functional materials may include, for example, hydrophobic materials such as hydrocarbon compounds or polymers, oleophobic materials such as fluorinated hydrocarbon compounds or polymers, amphiphilic materials such as surfactants or copolymers, and the likes. The functional materials may further contain a functional group that facilitates adsorption of the functional materials on the photoreceptor surface, and optionally a reactive group that can chemically modify the photoreceptor surface. For examples, the functional material may comprise alkanes, fluoroalkanes, alkyl silanes, fluoroalkyl silanes alkoxy-silanes, siloxanes, glycols or polyglycols, mineral oil, synthetic oil, natural oil, or mixtures thereof. In embodiments, the functional material comprises a paraffin oil (also known as kerosene). In embodiments, the functional material may be in a form of liquid.
In embodiments, the functional material is present in an amount of from about 0.01 weight percent to about 10 weight percent, from about 0.1 weight percent to about 5 weight percent, or from about 0.5 weight percent to about 2 weight percent based on the total weight of the toner composition.
In embodiments, the thickness of the polymeric shell may be in a range between about 10 nm to about 1 um, between about 50 nm to about 0.5 um, or between about 100 nm to about 500 nm. Suitable examples of polymeric shell include, but are not limited to, melamine, urethane, and mixtures thereof. In one embodiment, the polymeric shell comprises methoxy methyl methylol melamine (MMM). In one embodiment, the polymeric shell comprises polyoxymethylene urea (PMU).
A variety of processes known in the art can be used to make the capsules herein. Examples of processes for making capsules are described in U.S. Pat. Nos. 2,800,458; 3,159,585; 3,516,846; 3,516,941; 3,533,958; 3,697,437; 3,778,383; 3,888,689; 3,965,033; 3,996,156; 4,010,038; 4,016,098; 4,087,376; 4,089,802; 4,100,103; 4,251,386; 4,269,729; 4,303,548; 4,460,722; and 4,610,927; UK Patent Nos. 2,006,709 and 2,062,570; and Benita, Simon (ed.), MICROENCAPSULATION: METHODS AND INDUSTRIAL APPLICATIONS (Marcel Dekker, Inc. 1996). Preferably the capsules are prepared by a precipitation method whereby polymers in solution are precipitated around a hydrophobic core material, resulting in a clear, non-pigmented shell surrounding a single droplet or particle of core material. Said capsules are available from Lipo technologies Inc.
In embodiments, the present disclosure provides a method including adding a capsule containing a functional material into a toner. In embodiments, the adding of the capsule into a toner may be carried out in a separate step, for example, the adding of the capsule may be performed at a different time than the adding of the additives. In embodiments, the adding of the functional material into a toner may be performed after the blending or mixing of the additives.
In one embodiment, the capsules may be added into a toner without an additional mixing step.
In another embodiment, The capsules may be blended or mixed with the toner mixture. The blending or mixing may be achieved by using, for example, a Henschel blender, a Nara Hybridiser, Cyclomix blender, or a V-cone mixer. A small lab scale mixer sold by Kyoritsu Co. product designation Sample Mill Model SK-M10 was used for the working examples.
Certain embodiments are based on the use of two blending steps that can be carried out separately: the first one blends the toner particles containing a toner resin, an optional colorant, an optional release agent, and one or more additives. The second blending step can be carried out to mix the capsule to the resulting toner mixture obtained from the first blending step. These mixing steps can be carried out at different conditions.
The first blending step that mixes the toner particles and the one or more additives can be carried out at a higher rotation rate (RPM) or mixing rate than the second blending step.
Typically, the blending and mixing of the additives with the toner particles are performed at a more vigorous blending process, for example, at a higher rotating speed and for longer time period. If the capsule is added together with the additives and mixed in with the toner through the same blending process, breakage of the capsules may occur. It is a critical feature of this method of including a capsule to the toner composition to be performed at a carefully selected speed and time period of the present embodiments, for example at a milder blending process, such as, at a lower rotating speed and, may be, for a shorter time period.
In embodiments, suitable toner resin includes, but is not limited to, thermoset resins, curable resins, thermoplastic resins and mixtures thereof, although other suitable resins can also be used. The resin composition may comprise one or more resins, such as two or more resins. The total amount of resin in the resin composition can be from about 1% to 99%, such as from about 10% to about 95%, or from about 20% to 90% by weight of the resin composition.
A resin used in the method disclosed herein may be any latex resin utilized in forming Emulsion Aggregation (EA) toners. Such resins, in turn, may be made of any suitable monomer. Any monomer employed may be selected depending upon the particular polymer to be used. Two main types of EA methods for making toners are known. First is an EA process that forms acrylate based, e.g., styrene acrylate, toner particles. See, for example, U.S. Pat. No. 6,120,967, incorporated herein by reference in its entirety, as one example of such a process. Second is an EA process that forms polyester, e.g., sodio sulfonated polyester. See, for example, U.S. Pat. No. 5,916,725, incorporated herein by reference in its entirety, as one example of such a process.
Illustrative examples of latex resins or polymers selected for the non crosslinked resin and crosslinked resin or gel include, but are not limited to, styrene acrylates, styrene methacrylates, butadienes, isoprene, acrylonitrile, acrylic acid, methacrylic acid, beta-carboxy ethyl arylate, polyesters, known polymers such as poly(styrene-butadiene), poly(methyl styrene-butadiene), poly(methyl methacrylate-butadiene), poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene), poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene), poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene), poly(butyl acrylate-butadiene), poly(styrene-isoprene), poly(methyl styrene-isoprene), poly(methyl methacrylate-isoprene), poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene), poly(butyl methacrylate-isoprene), poly(methyl acrylate-isoprene), poly(ethyl acrylate-isoprene), poly(propyl acrylate-isoprene), poly(butyl acrylate-isoprene); poly(styrene-propyl acrylate), poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid), poly(styrene-butadiene-methacrylic acid), poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid), poly(styrene-butyl acrylate-acrylonitrile), poly(styrene-butyl acrylate-acrylonitrile-acrylic acid), and the like, and mixtures thereof. The resin or polymer can be a styrene/butyl acrylate/carboxylic acid terpolymer. At least one of the resin substantially free of crosslinking and the cross linked resin can comprise carboxylic acid in an amount of from about 0.05 to about 10 weight percent based upon the total weight of the resin substantially free of cross linking or cross linked resin.
The monomers used in making the selected polymer are not limited, and the monomers utilized may include any one or more of, for example, styrene, acrylates such as methacrylates, butylacrylates, β-carboxy ethyl acrylate (β-CEA), etc., butadiene, isoprene, acrylic acid, methacrylic acid, itaconic acid, acrylonitrile, benzenes such as divinylbenzene, etc., and the like. Known chain transfer agents, for example dodecanethiol or carbon tetrabromide, can be utilized to control the molecular weight properties of the polymer. Any suitable method for forming the latex polymer from the monomers may be used without restriction.
The resin that is substantially free of cross linking (also referred to herein as a non crosslinked resin) can comprise a resin having less than about 0.1 percent cross linking. For example, the non-cross linked latex can comprise styrene, butylacrylate, and beta-carboxy ethyl acrylate (beta-CEA) monomers, although not limited to these monomers, termed herein as monomers A, B, and C, prepared, for example, by emulsion polymerization in the presence of an initiator, a chain transfer agent (CTA), and surfactant.
The resin substantially free of cross linking can comprise styrene:butylacrylate:beta-carboxy ethyl acrylate wherein, for example, the non cross linked resin monomers can be present in an amount of about 70 percent to about 90 percent styrene, about 10 percent to about 30 percent butylacrylate, and about 0.05 parts per hundred to about 10 parts per hundred beta-CEA, or about 3 parts per hundred beta-CEA, by weight based upon the total weight of the monomers, although not limited. For example, the carboxylic acid can be selected, for example, from the group comprised of, but not limited to, acrylic acid, methacrylic acid, itaconic acid, beta carboxy ethyl acrylate (beta CEA), fumaric acid, maleic acid, and cinnamic acid.
In a feature herein, the non-cross linked resin can comprise about 73 percent to about 85 percent styrene, about 27 percent to about 15 percent butylacrylate, and about 1.0 part per hundred to about 5 parts per hundred beta-CEA, by weight based upon the total weight of the monomers although the compositions and processes are not limited to these particular types of monomers or ranges. In another feature, the non-cross linked resin can comprise about 81.7 percent styrene, about 18.3 percent butylacrylate and about 3.0 parts per hundred beta-CEA by weight based upon the total weight of the monomers.
The initiator can be, for example, but is not limited to, sodium, potassium or ammonium persulfate and can be present in the range of, for example, about 0.5 to about 3.0 percent based upon the weight of the monomers, although not limited. The CTA can be present in an amount of from about 0.5 to about 5.0 percent by weight based upon the combined weight of the monomers A and B, although not limited. The surfactant can be an anionic surfactant present in the range of from about 0.7 to about 5.0 percent by weight based upon the weight of the aqueous phase, although not limited to this type or range.
The resin can be a polyester resin such as an amorphous polyester resin, a crystalline polyester resin, and/or a combination thereof. The polymer used to form the resin can be a polyester resin described in U.S. Pat. Nos. 6,593,049 and 6,756,176, the disclosures of each of which are hereby incorporated by reference in their entirety. Suitable resins also include a mixture of an amorphous polyester resin and a crystalline polyester resin as described in U.S. Pat. No. 6,830,860, the disclosure of which is hereby incorporated by reference in its entirety.
The resin can be a polyester resin formed by reacting a diol with a diacid in the presence of an optional catalyst. For forming a crystalline polyester, suitable organic diols include aliphatic diols with from about 2 to about 36 carbon atoms, such as 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol and the like; alkali sulfo-aliphatic diols such as sodio 2-sulfo-1,2-ethanediol, lithio 2-sulfo-1,2-ethanediol, potassio 2-sulfo-1,2-ethanediol, sodio 2-sulfo-1,3-propanediol, lithio 2-sulfo-1,3-propanediol, potassio 2-sulfo-1,3-propanediol, mixture thereof, and the like. The aliphatic diol may be, for example, selected in an amount of from about 40 to about 60 mole percent, such as from about 42 to about 55 mole percent, or from about 45 to about 53 mole percent (although amounts outside of these ranges can be used), and the alkali sulfo-aliphatic diol can be selected in an amount of from about 0 to about 10 mole percent, such as from about 1 to about 4 mole percent of the resin (although amounts outside of these ranges can be used).
Examples of organic diacids or diesters including vinyl diacids or vinyl diesters selected for the preparation of the crystalline resins include oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, dimethyl fumarate, dimethyl itaconate, cis, 1,4-diacetoxy-2-butene, diethyl fumarate, diethyl maleate, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexane dicarboxylic acid, malonic acid and mesaconic acid, a diester or anhydride thereof; and an alkali sulfo-organic diacid such as the sodio, lithio or potassio salt of dimethyl-5-sulfo-isophthalate, dialkyl-5-sulfo-isophthalate-4-sulfo-1,8-naphthalic anhydride, 4-sulfo-phthalic acid, dimethyl-4-sulfo-phthalate, dialkyl-4-sulfo-phthalate, 4-sulfophenyl-3,5-dicarbomethoxybenzene, 6-sulfo-2-naphthyl-3,5-dicarbomethoxybenzene, sulfo-terephthalic acid, dimethyl-sulfo-terephthalate, 5-sulfo-isophthalic acid, dialkyl-sulfo-terephthalate, sulfoethanediol, 2-sulfopropanediol, 2-sulfobutanediol, 3-sulfopentanediol, 2-sulfohexanediol, 3-sulfo-2-methylpentanediol, 2-sulfo-3,3-dimethylpentanediol, sulfo-p-hydroxybenzoic acid, N,N-bis(2-hydroxyethyl)-2-amino ethane sulfonate, or mixtures thereof. The organic diacid may be selected in an amount of, for example, from about 40 to about 60 mole percent, in embodiments from about 42 to about 52 mole percent, such as from about 45 to about 50 mole percent (although amounts outside of these ranges can be used), and the alkali sulfo-aliphatic diacid can be selected in an amount of from about 1 to about 10 mole percent of the resin (although amounts outside of these ranges can be used).
Examples of crystalline resins include polyesters, polyamides, polyimides, polyolefins, polyethylene, polybutylene, polyisobutyrate, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, polypropylene, mixtures thereof, and the like. Specific crystalline resins may be polyester based, such as poly(ethylene-adipate), poly(propylene-adipate), poly(butylene-adipate), poly(pentylene-adipate), poly(hexylene-adipate), poly(octylene-adipate), poly(ethylene-succinate), poly(propylene-succinate), poly(butylene-succinate), poly(pentylene-succinate), poly(hexylene-succinate), poly(octylene-succinate), poly(ethylene-sebacate), poly(propylene-sebacate), poly(butylene-sebacate), poly(pentylene-sebacate), poly(hexylene-sebacate), poly(octylene-sebacate), poly(decylene-sebacate), poly(decylene-decanoate), poly(ethylene-decanoate), poly(ethylene dodecanoate), poly(nonylene-sebacate), poly(nonylene-decanoate), copoly(ethylene-fumarate)-copoly(ethylene-sebacate), copoly(ethylene-fumarate)-copoly(ethylene-decanoate), copoly(ethylene-fumarate)-copoly(ethylene-dodecanoate), alkali copoly(5-sulfoisophthaloyl)-copoly(ethylene-adipate), alkali copoly(5-sulfoisophthaloyl)-copoly(propylene-adipate), alkali copoly(5-sulfoisophthaloyl)-copoly(butylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(octylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(propylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(butylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(octylene-adipate), alkali copoly(5-sulfoisophthaloyl)-copoly(ethylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(propylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(butylenes-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(pentylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(hexylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(octylene-succinate), alkali copoly(5-sulfo-isophthaloyl)-copoly(ethylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(propylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(butylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(octylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(propylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(butylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), poly(octylene-adipate), wherein alkali is a metal like sodium, lithium or potassium. Examples of polyamides include poly(ethylene-adipamide), poly(propylene-adipamide), poly(butylenes-adipamide), poly(pentylene-adipamide), poly(hexylene-adipamide), poly(octylene-adipamide), poly(ethylene-succinimide), and poly(propylene-sebecamide). Examples of polyimides include poly(ethylene-adipimide), poly(propylene-adipimide), poly(butylene-adipimide), poly(pentylene-adipimide), poly(hexylene-adipimide), poly(octylene-adipimide), poly(ethylene-succinimide), poly(propylene-succinimide), and poly(butylene-succinimide).
The crystalline resin can be present, for example, in an amount of from about 5 to about 50 percent by weight of the toner components, such as from about 10 to about 35 percent by weight of the toner components (although amounts outside of these ranges can be used). The crystalline resin can possess various melting points of, for example, from about 30° C. to about 120° C., in embodiments from about 50° C. to about 90° C. (although melting points outside of these ranges can be obtained). The crystalline resin can have a number average molecular weight (Mn), as measured by gel permeation chromatography (GPC) of, for example, from about 1,000 to about 50,000, such as from about 2,000 to about 25,000 (although number average molecular weights outside of these ranges can be obtained), and a weight average molecular weight (Mw) of, for example, from about 2,000 to about 100,000, such as from about 3,000 to about 80,000 (although weight average molecular weights outside of these ranges can be obtained), as determined by Gel Permeation Chromatography using polystyrene standards. The molecular weight distribution (Mw/Mn) of the crystalline resin can be, for example, from about 2 to about 6, in embodiments from about 3 to about 4 (although molecular weight distributions outside of these ranges can be obtained).
Examples of diacids or diesters including vinyl diacids or vinyl diesters used for the preparation of amorphous polyesters include dicarboxylic acids or diesters such as terephthalic acid, phthalic acid, isophthalic acid, fumaric acid, dimethyl fumarate, dimethyl itaconate, cis, 1,4-diacetoxy-2-butene, diethyl fumarate, diethyl maleate, maleic acid, succinic acid, itaconic acid, succinic acid, succinic anhydride, dodecylsuccinic acid, dodecylsuccinic anhydride, glutaric acid, glutaric anhydride, adipic acid, pimelic acid, suberic acid, azelaic acid, dodecane diacid, dimethyl terephthalate, diethyl terephthalate, dimethylisophthalate, diethylisophthalate, dimethylphthalate, phthalic anhydride, diethylphthalate, dimethylsuccinate, dimethylfumarate, dimethylmaleate, dimethylglutarate, dimethyladipate, dimethyl dodecylsuccinate, and combinations thereof. The organic diacid or diester can be present, for example, in an amount from about 40 to about 60 mole percent of the resin, such as from about 42 to about 52 mole percent of the resin, or from about 45 to about 50 mole percent of the resin (although amounts outside of these ranges can be used).
Examples of diols that can be used in generating the amorphous polyester include 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, pentanediol, hexanediol, 2,2-dimethylpropanediol, 2,2,3-trimethylhexanediol, heptanediol, dodecanediol, bis(hydroxyethyl)-bisphenol A, bis(2-hydroxypropyl)-bisphenol A, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, xylenedimethanol, cyclohexanediol, diethylene glycol, bis(2-hydroxyethyl)oxide, dipropylene glycol, dibutylene, and combinations thereof. The amount of organic diol selected can vary, and can be present, for example, in an amount from about 40 to about 60 mole percent of the resin, such as from about 42 to about 55 mole percent of the resin, or from about 45 to about 53 mole percent of the resin (although amounts outside of these ranges can be used).
Polycondensation catalysts which may be used in forming either the crystalline or amorphous polyesters include tetraalkyl titanates, dialkyltin oxides such as dibutyltin oxide, tetraalkyltins such as dibutyltin dilaurate, and dialkyltin oxide hydroxides such as butyltin oxide hydroxide, aluminum alkoxides, alkyl zinc, dialkyl zinc, zinc oxide, stannous oxide, or combinations thereof. Such catalysts may be used in amounts of, for example, from about 0.01 mole percent to about 5 mole percent based on the starting diacid or diester used to generate the polyester resin (although amounts outside of this range can be used).
Suitable amorphous resins include polyesters, polyamides, polyimides, polyolefins, polyethylene, polybutylene, polyisobutyrate, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, polypropylene, combinations thereof, and the like. Examples of amorphous resins which may be used include alkali sulfonated-polyester resins, branched alkali sulfonated-polyester resins, alkali sulfonated-polyimide resins, and branched alkali sulfonated-polyimide resins. Alkali sulfonated polyester resins may be useful in embodiments, such as the metal or alkali salts of copoly(ethylene-terephthalate)-copoly(ethylene-5-sulfo-isophthalate), copoly(propylene-terephthalate)-copoly(propylene-5-sulfo-isophthalate), copoly(diethylene-terephthalate)-copoly(diethylene-5-sulfo-isophthalate), copoly(propylene-diethylene-terephthalate)-copoly(propylene-diethylene-5-sulfoisophthalate), copoly(propylene-butylene-terephthalate)-copoly(propylene-butylene-5-sulfoisophthalate), copoly propoxylated bisphenol-A-fumarate)-copoly(propoxylated bisphenol A-5-sulfo-isophthalate), copoly(ethoxylated bisphenol-A-fumarate)-copoly(ethoxylated bisphenol-A-5-sulfo-isophthalate), and copoly(ethoxylated bisphenol-A-maleate)-copoly(ethoxylated bisphenol-A-5-sulfo-isophthalate), wherein the alkali metal is, for example, a sodium, lithium or potassium ion.
An unsaturated amorphous polyester resin can be used as a latex resin. Examples of such resins include those disclosed in U.S. Pat. No. 6,063,827, the disclosure of which is hereby incorporated by reference in its entirety. Exemplary unsaturated amorphous polyester resins include, but are not limited to, poly(propoxylated bisphenol co-fumarate), poly(ethoxylated bisphenol co-fumarate), poly(butyloxylated bisphenol co-fumarate), poly(co-propoxylated bisphenol co-ethoxylated bisphenol co-fumarate), poly(1,2-propylene fumarate), poly(propoxylated bisphenol co-maleate), poly(ethoxylated bisphenol co-maleate), poly(butyloxylated bisphenol co-maleate), poly(co-propoxylated bisphenol co-ethoxylated bisphenol co-maleate), poly(1,2-propylene maleate), poly(propoxylated bisphenol co-itaconate), poly(ethoxylated bisphenol co-itaconate), poly(butyloxylated bisphenol co-itaconate), poly(co-propoxylated bisphenol co-ethoxylated bisphenol co-itaconate), poly(1,2-propylene itaconate), and combinations thereof. A suitable polyester resin can be a polyalkoxylated bisphenol A-co-terephthalic acid/dodecenylsuccinic acid/trimellitic acid resin, or a polyalkoxylated bisphenol A-co-terephthalic acid/fumaric acid/dodecenylsuccinic acid resin, or a combination thereof.
Such amorphous resins can have a weight average molecular weight (Mw) of from about 10,000 to about 100,000, such as from about 15,000 to about 80,000.
An example of a linear propoxylated bisphenol a fumarate resin that can be used as a latex resin is available under the trade name SPARII from Resana S/A Industrias Quimicas, Sao Paulo Brazil. Other propoxylated bisphenol a fumarate resins that can be used and are commercially available include GTUF and FPESL-2 from Kao Corporation, Japan, and EM181635 from Reichhold, Research Triangle Park, N.C., and the like.
Suitable crystalline resins that can be used, optionally in combination with an amorphous resin as described above, include those disclosed in U.S. Patent Application Publication No. 2006/0222991, the disclosure of which is hereby incorporated by reference in its entirety. In embodiments, a suitable crystalline resin can include a resin formed of dodecanedioic acid and 1,9-nonanediol.
Such crystalline resins can have a weight average molecular weight (Mw) of from about 10,000 to about 100,000, such as from about 14,000 to about 30,000.
For example, a polyalkoxylated bisphenol A-co-terephthalic acid/dodecenylsuccinic acid/trimellitic acid resin, or a polyalkoxylated bisphenol A-co-terephthalic acid/fumaric acid/dodecenylsuccinic acid resin, or a combination thereof, can be combined with a polydodecanedioic acid-co-1,9-nonanediol crystalline polyester resin.
The resins can have a glass transition temperature of from about 30° C. to about 80° C., such as from about 35° C. to about 70° C. The resins can have a melt viscosity of from about 10 to about 1,000,000 Pa*S at about 130° C., such as from about 20 to about 100,000 Pa*S. One, two, or more toner resins may be used. Where two or more toner resins are used, the toner resins can be in any suitable ratio (e.g., weight ratio) such as, for instance, about 10 percent (first resin)/90 percent (second resin) to about 90 percent (first resin)/10 percent (second resin). The resin can be formed by emulsion polymerization methods.
The resin can be formed at elevated temperatures of from about 30° C. to about 200° C., such as from about 50° C. to about 150° C., or from about 70° C. to about 100° C. However, the resin can also be formed at room temperature.
Stirring may be used to enhance formation of the resin. Any suitable stirring device may be used. In embodiments, the stirring speed can be from about 10 revolutions per minute (rpm) to about 5,000 rpm, such as from about 20 rpm to about 2,000 rpm, or from about 50 rpm to about 1,000 rpm. The stirring speed can be constant or the stirring speed can be varied. For example, as the temperature becomes more uniform throughout the mixture, the stirring speed can be increased. However, no mechanical or magnetic agitation is necessary in the method disclosed herein.
A wax can be combined with the latex or emulsion, colorant, and the like in forming toner particles. When included, the wax can be present in an amount of, for example, from about 1 weight percent to about 25 weight percent of the toner particles, such as from about 5 weight percent to about 20 weight percent of the toner particles, although amounts outside these ranges can be used.
Suitable waxes include waxes having, for example, a weight average molecular weight of from about 500 to about 20,000, such as from about 1,000 to about 10,000, although molecular weights outside these ranges may be utilized. Suitable waxes include, for example, polyolefins such as polyethylene, polypropylene, and polybutene waxes such as commercially available from Allied Chemical and Petrolite Corporation, for example POLYWAX™ polyethylene waxes from Baker Petrolite, wax emulsions available from Michaelman, Inc. and the Daniels Products Company, EPOLENE N-15™ commercially available from Eastman Chemical Products, Inc., and VISCOL 550-P™, a low weight average molecular weight polypropylene available from Sanyo Kasei K. K.; plant-based waxes, such as carnauba wax, rice wax, candelilla wax, sumacs wax, and jojoba oil; animal-based waxes, such as beeswax; mineral-based waxes and petroleum-based waxes, such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, and Fischer-Tropsch wax; ester waxes obtained from higher fatty acid and higher alcohol, such as stearyl stearate and behenyl behenate; ester waxes obtained from higher fatty acid and monovalent or multivalent lower alcohol, such as butyl stearate, propyl oleate, glyceride monostearate, glyceride distearate, and pentaerythritol tetra behenate; ester waxes obtained from higher fatty acid and multivalent alcohol multimers, such as diethyleneglycol monostearate, dipropyleneglycol distearate, diglyceryl distearate, and triglyceryl tetrastearate; sorbitan higher fatty acid ester waxes, such as sorbitan monostearate, and cholesterol higher fatty acid ester waxes, such as cholesteryl stearate. Examples of functionalized waxes that can be used include, for example, amines, amides, for example AQUA SUPERSLIP 6550™, SUPERSLIP 6530™ available from Micro Powder Inc., fluorinated waxes, for example POLYFLUO 190™, POLYFLUO 200™, POLYSILK 19™, POLYSILK 14™ available from Micro Powder Inc., mixed fluorinated, amide waxes, for example MICROSPERSION 19™ also available from Micro Powder Inc., imides, esters, quaternary amines, carboxylic acids or acrylic polymer emulsion, for example JONCRYL 74™, 89™, 130™, 537™, and 538™, all available from SC Johnson Wax, and chlorinated polypropylenes and polyethylenes available from Allied Chemical and Petrolite Corporation and SC Johnson wax. Mixtures and combinations of the foregoing waxes can be used. Waxes can be included as, for example, fuser roll release agents.
The toner particles described herein can further include colorant. Colorant includes pigments, dyes, mixtures of dyes, mixtures of pigments, mixtures of dyes and pigments, and the like.
When present, the colorant can be added in an effective amount of, for example, from about 1 to about 25 percent by weight of the particle, such as from about 2 to about 12 weight percent. Suitable colorants include, for example, carbon black like REGAL 330® magnetites, such as Mobay magnetites M08029™, M08060 ™; Columbian magnetites; MAPICO BLACKS™ and surface treated magnetites; Pfizer magnetites CB4799 ™, CB5300 ™, CB5600™, MCX6369 ™; Bayer magnetites, BAYFERROX 8600™, 8610™; Northern Pigments magnetites, NP-604™, NP-608™; Magnox magnetites TMB-100™, or TMB-104™; and the like. As colored pigments, there may be selected cyan, magenta, yellow, red, green, brown, blue or mixtures thereof. Specific examples of pigments include phthalocyanine HELIOGEN BLUE L6900™, D6840™, D7080™, D7020™, PYLAM OIL BLUE™, PYLAM OIL YELLOW™, PIGMENT BLUE 1™ available from Paul Uhlich & Company, Inc., PIGMENT VIOLET 1™, PIGMENT RED 48™, LEMON CHROME YELLOW DCC 1026™, E.D. TOLUIDINE RED™ and BON RED C™ available from Dominion Color Corporation, Ltd., Toronto, Ontario, NOVAPERM YELLOW FGL™, HOSTAPERM PINK E™ from Hoechst, and CINQUASIA MAGENTA™ available from E.I. DuPont de Nemours & Company, and the like. Generally, colorants that can be selected are black, cyan, magenta, or yellow, and mixtures thereof. Examples of magentas are 2,9-dimethyl-substituted quinacridone and anthraquinone dye identified in the Color Index as CI-60710, CI Dispersed Red 15, diazo dye identified in the Color Index as CI-26050, CI Solvent Red 19, and the like. Illustrative examples of cyans include copper tetra(octadecyl sulfonamido) phthalocyanine, x-copper phthalocyanine pigment listed in the Color Index as CI-74160, CI Pigment Blue, and Anthrathrene Blue, identified in the Color Index as CI-69810, Special Blue X-2137, and the like; while illustrative examples of yellows are diarylide yellow 3,3-dichlorobenzidene acetoacetanilides, a monoazo pigment identified in the Color Index as CI-12700, CI Solvent Yellow 16, a nitrophenyl amine sulfonamide identified in the Color Index as Foron Yellow SE/GLN, CI Dispersed Yellow 33 2,5-dimethoxy-4-sulfonanilide phenylazo-4′-chloro-2,5-dimethoxy acetoacetanilide, and Permanent Yellow FGL. Colored magnetites, such as mixtures of MAP ICO BLACK™, and cyan components can also be selected as colorants. Other known colorants may be selected, such as Levanyl Black A-SF (Miles, Bayer) and Sunsperse Carbon Black LHD 9303 (Sun Chemicals), and colored dyes such as Neopen Blue (BASF), Sudan Blue OS (BASF), PV Fast Blue B2G01 (American Hoechst), Sunsperse Blue BHD 6000 (Sun Chemicals), Irgalite Blue BCA (Ciba-Geigy), Paliogen Blue 6470 (BASF), Sudan III (Matheson, Coleman, Bell), Sudan II (Matheson, Coleman, Bell), Sudan IV (Matheson, Coleman, Bell), Sudan Orange G (Aldrich), Sudan Orange 220 (BASF), Paliogen Orange 3040 (BASF), Ortho Orange OR 2673 (Paul Uhlich), Paliogen Yellow 152, 1560 (BASF), Lithol Fast Yellow 0991K (BASF), Paliotol Yellow 1840 (BASF), Neopen Yellow (BASF), Novoperm Yellow FG 1 (Hoechst), Permanent Yellow YE 0305 (Paul Uhlich), Lumogen Yellow D0790 (BASF), Sunsperse Yellow YHD 6001 (Sun Chemicals), Suco-Gelb L1250 (BASF), Suco-Yellow D1355 (BASF), Hostaperm Pink E (American Hoechst), Fanal Pink D4830 (BASF), Cinquasia Magenta (DuPont), Lithol Scarlet D3700 (BASF), Toluidine Red (Aldrich), Scarlet for Thermoplast NSD PS PA (Ugine Kuhlmann of Canada), E.D. Toluidine Red (Aldrich), Lithol Rubine Toner (Paul Uhlich), Lithol Scarlet 4440 (BASF), Bon Red C (Dominion Color Company), Royal Brilliant Red RD-8192 (Paul Uhlich), Oracet Pink RF (Ciba-Geigy), Paliogen Red 3871K (BASF), Paliogen Red 3340 (BASF), and Lithol Fast Scarlet L4300 (BASF).
The toner particles can contain other optional additives, as desired or required. For example, the toner can include positive or negative charge control agents, for example, in an amount of from about 0.1 to about 10 percent by weight of the toner, such as from about 1 to about 3 percent by weight of the toner (although amounts outside of these ranges may be used). Examples of suitable charge control agents include quaternary ammonium compounds inclusive of alkyl pyridinium halides; bisulfates; alkyl pyridinium compounds, including those disclosed in U.S. Pat. No. 4,298,672, the disclosure of which is hereby incorporated by reference in its entirety; organic sulfate and sulfonate compositions, including those disclosed in U.S. Pat. No. 4,338,390, the disclosure of which is hereby incorporated by reference in its entirety; cetyl pyridinium tetrafluoroborates; distearyl dimethyl ammonium methyl sulfate; aluminum salts such as BONTRON E84™ or E88™ (Orient Chemical Industries, Ltd.); combinations thereof, and the like. Such charge control agents can be applied simultaneously with the shell resin described above or after application of the shell resin.
External additive particles can be blended with the toner particles after formation including flow aid additives, which additives can be present on the surface of the toner particles. Examples of these additives include metal oxides such as titanium oxide, silicon oxide, aluminum oxides, cerium oxides, tin oxide, mixtures thereof, and the like; colloidal and amorphous silicas, such as AEROSILR™, metal salts and metal salts of fatty acids inclusive of zinc stearate, calcium stearate, or long chain alcohols such as UNILIN 700, and mixtures thereof.
In general, silica can be applied to the toner surface for toner flow, tribo enhancement, admix control, improved development and transfer stability, and higher toner blocking temperature. TiO2 may be applied for improved relative humidity (RH) stability, tribo control and improved development and transfer stability. Zinc stearate, calcium stearate and/or magnesium stearate can be used as an external additive for providing lubricating properties, developer conductivity, tribo enhancement, enabling higher toner charge and charge stability by increasing the number of contacts between toner and carrier particles. A commercially available zinc stearate known as Zinc Stearate L, obtained from Ferro Corporation, can be used. The external surface additives can be used with or without a coating.
Each of these external additives can be present in an amount of from about 0.1 percent by weight to about 5 percent by weight of the toner, such as from about 0.25 percent by weight to about 3 percent by weight of the toner, although the amount of additives can be outside of these ranges. The toners may include, for example, from about 0.1 weight percent to about 5 weight percent titanium dioxide, such as from about 0.1 weight percent to about 8 weight percent silica, or from about 0.1 weight percent to about 4 weight percent zinc stearate (although amounts outside of these ranges may be used). Suitable additives include those disclosed in U.S. Pat. Nos. 3,590,000, 3,800,588, and 6,214,507, the disclosures of each of which are hereby incorporated by reference in their entirety. Again, these additives can be applied simultaneously with the shell resin described above or after application of the shell resin.
The toner particles can have a weight average molecular weight (Mw) in the range of from about 17,000 to about 80,000 daltons, a number average molecular weight (Mn) of from about 3,000 to about 10,000 daltons, and a MWD (a ratio of the Mw to Mn of the toner particles, a measure of the polydispersity, or width, of the polymer) of from about 2.1 to about 10 (although values outside of these ranges can be obtained).
Any resin may be utilized in forming a toner core of the present disclosure. In the event that the core resin is to be crosslinked, any crosslinkable resin may be utilized. Such resins, in turn, may be made of any suitable monomer. Suitable monomers useful in forming the resin include, but are not limited to, styrenes, acrylates, methacrylates, butadienes, isoprenes, acrylic acids, methacrylic acids, acrylonitriles, diol, diacid, diamine, diester, mixtures thereof, and the like. Any monomer employed may be selected depending upon the particular polymer to be utilized.
In embodiments, the core resins may be an amorphous resin, a crystalline resin, and a combination. In further embodiments, the polymer utilized to form the resin core may be a polyester resin, including the resins described in U.S. Pat. Nos. 6,593,049 and 6,756,176, the disclosures of each of which are hereby incorporated by reference in their entirety. Suitable resins may also include a mixture of an amorphous polyester resin and a crystalline polyester resin as described in U.S. Pat. No. 6,830,860, the disclosure of which is hereby incorporated by reference in its entirety.
In embodiments, the resin may be a polyester resin formed by reacting a diol with a diacid in the presence of an optional catalyst. For forming a crystalline polyester, suitable organic diols include aliphatic diols with from about 2 to about 36 carbon atoms, such as 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol and the like; alkali sulfo-aliphatic diols such as sodio 2-sulfo-1,2-ethanediol, lithio 2-sulfo-1,2-ethanediol, potassio 2-sulfo-1,2-ethanediol, sodio 2-sulfo-1,3-propanediol, lithio 2-sulfo-1,3-propanediol, potassio 2-sulfo-1,3-propanediol, mixture thereof, and the like. The aliphatic diol may be, for example, selected in an amount of from about 40 to about 60 mole percent, in embodiments from about 42 to about 55 mole percent, in embodiments from about 45 to about 53 mole percent, and the alkali sulfo-aliphatic diol can be selected in an amount of from about 0 to about 10 mole percent, in embodiments from about 1 to about 4 mole percent of the resin.
Examples of organic diacids or diesters including vinyl diacids or vinyl diesters selected for the preparation of the crystalline resins include oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, dimethyl fumarate, dimethyl itaconate, cis, 1,4-diacetoxy-2-butene, diethyl fumarate, diethyl maleate, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexane dicarboxylic acid, malonic acid and mesaconic acid, a diester or anhydride thereof; and an alkali sulfo-organic diacid such as the sodio, lithio or potassio salt of dimethyl-5-sulfo-isophthalate, dialkyl-5-sulfo-isophthalate-4-sulfo-1,8-naphthalic anhydride, 4-sulfo-phthalic acid, dimethyl-4-sulfo-phthalate, dialkyl-4-sulfo-phthalate, 4-sulfophenyl-3,5-dicarbomethoxybenzene, 6-sulfo-2-naphthyl-3,5-dicarbomethoxybenzene, sulfo-terephthalic acid, dimethyl-sulfo-terephthalate, 5-sulfo-isophthalic acid, dialkyl-sulfo-terephthalate, sulfoethanediol, 2-sulfopropanediol, 2-sulfobutanediol, 3-sulfopentanediol, 2-sulfohexanediol, 3-sulfo-2-methylpentanediol, 2-sulfo-3,3-dimethylpentanediol, sulfo-p-hydroxybenzoic acid, N,N-bis(2-hydroxyethyl)-2-amino ethane sulfonate, or mixtures thereof. The organic diacid may be selected in an amount of for example, in embodiments from about 40 to about 60 mole percent, in embodiments from about 42 to about 52 mole percent, in embodiments from about 45 to about 50 mole percent, and the alkali sulfo-aliphatic diacid can be selected in an amount of from about 1 to about 10 mole percent of the resin.
Examples of crystalline resins include polyesters, polyamides, polyimides, polyolefins, polyethylene, polybutylene, polyisobutyrate, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, polypropylene, mixtures thereof, and the like. Specific crystalline resins may be polyester based, such as poly(ethylene-adipate), poly(propylene-adipate), poly(butylene-adipate), poly(pentylene-adipate), poly(hexylene-adipate), poly(octylene-adipate), poly(ethylene-succinate), poly(propylene-succinate), poly(butylene-succinate), poly(pentylene-succinate), poly(hexylene-succinate), poly(octylene-succinate), poly(ethylene-sebacate), poly(propylene-sebacate), poly(butylene-sebacate), poly(pentylene-sebacate), poly(hexylene-sebacate), poly(octylene-sebacate), alkali copoly(5-sulfoisophthaloyl)-copoly(ethylene-adipate), alkali copoly(5-sulfoisophthaloyl)-copoly(propylene-adipate), alkali copoly(5-sulfoisophthaloyl)-copoly(butylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), alkali copoly(5-sulfa-isophthaloyl)-copoly(octylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(propylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(butylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(octylene-adipate), alkali copoly(5-sulfoisophthaloyl)-copoly(ethylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(propylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(butylenes-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(pentylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(hexylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(octylene-succinate), alkali copoly(5-sulfo-isophthaloyl)-copoly(ethylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(propylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(butylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(octylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(propylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(butylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), poly(octylene-adipate), wherein alkali is a metal like sodium, lithium or potassium. Examples of polyamides include poly(ethylene-adipamide), poly(propylene-adipamide), poly(butylenes-adipamide), poly(pentylene-adipamide), poly(hexylene-adipamide), poly(octylene-adipamide), poly(ethylene-succinamide), and poly(propylene-sebacamide). Examples of polyimides include poly(ethylene-adipimide), poly(propylene-adipimide), polybutylene-adipimide), poly(pentylene-adipimide), poly(hexylene-adipimide), poly(octylene-adipimide), poly(ethylene-succinimide), poly(propylene-succinimide), and poly(butylene-succinimide).
The crystalline resin may be present, for example, in an amount of from about 5 to about 50 percent by weight of the toner components, in embodiments from about 5 to about 35 percent by weight of the toner components. The crystalline resin can possess various melting points of, for example, from about 30° C. to about 120° C., in embodiments from about 50° C. to about 90° C. The crystalline resin may have a number average molecular weight (Mn), as measured by gel permeation chromatography (GPC) of, for example, from about 1,000 to about 50,000, in embodiments from about 2,000 to about 25,000, and a weight average molecular weight (Mw) of for example, from about 2,000 to about 100,000, in embodiments from about 3,000 to about 80,000, as determined by Gel Permeation Chromatography using polystyrene standards. The molecular weight distribution (Mw/Mn) of the crystalline resin may be, for example, from about 2 to about 6, in embodiments from about 2 to about 4.
Examples of diacid or diesters including vinyl diacids or vinyl diesters selected for the preparation of amorphous polyesters include dicarboxylic acids or diesters such as terephthalic acid, phthalic acid, isophthalic acid, fumaric acid, dimethyl fumarate, dimethyl itaconate, cis, 1,4-diacetoxy-2-butene, diethyl fumarate, diethyl maleate, maleic acid, succinic acid, itaconic acid, succinic acid, succinic anhydride, dodecylsuccinic acid, dodecylsuccinic anhydride, glutaric acid, glutaric anhydride, adipic acid, pimelic acid, suberic acid, azelaic acid, dodecanediacid, dimethyl terephthalate, diethyl terephthalate, dimethylisophthalate, diethylisophthalate, dimethylphthalate, phthalic anhydride, diethylphthalate, dimethyl succinate, dimethyl fumarate, dimethylmalcate, dimethylglutarate, dimethyladipate, dimethyl dodecylsuccinate, and combinations thereof. The organic diacid or diester may be present, for example, in an amount from about 40 to about 60 mole percent of the resin, in embodiments from about 42 to about 52 mole percent of the resin, in embodiments from about 45 to about 50 mole percent of the resin.
Examples of diols utilized in generating the amorphous polyester include 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, pentanediol, hexanediol, 2,2-dimethylpropanediol, 2,2,3-trimethylhexanediol, heptanediol, dodecanediol, bis(hydroxyethyl)-bisphenol A, bis(2-hydroxypropyl)-bisphenol A, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, xylenedimethanol, cyclohexanediol, diethylene glycol, bis(2-hydroxyethyl) oxide, dipropylene glycol, dibutylene, and combinations thereof. The amount of organic diol selected can vary, and may be present, for example, in an amount from about 40 to about 60 mole percent of the resin, in embodiments from about 42 to about 55 mole percent of the resin, in embodiments from about 45 to about 53 mole percent of the resin.
Polycondensation catalysts which may be utilized for either the crystalline or amorphous polyesters include tetraalkyl titanates, dialkyltin oxides such as dibutyltin oxide, tetraalkyltins such as dibutyltin dilaurate, and dialkyltin oxide hydroxides such as butyltin oxide hydroxide, aluminum alkoxides, alkyl zinc, dialkyl zinc, zinc oxide, stannous oxide, or combinations thereof. Such catalysts may be utilized in amounts of, for example, from about 0.01 mole percent to about 5 mole percent based on the starting diacid or diester used to generate the polyester resin.
In embodiments, suitable amorphous resins include polyesters, polyamides, polyimides, polyolefins, polyethylene, polybutylene, polyisobutyrate, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, polypropylene, combinations thereof, and the like. Examples of amorphous resins which may be utilized include poly(styrene-acrylate) resins, crosslinked, for example, from about 10 percent to about 70 percent, poly(styrene-acrylate) resins, poly(styrene-methacrylate) resins, crosslinked poly(styrene-methacrylate) resins, poly(styrene-butadiene) resins, crosslinked poly(styrene-butadiene) resins, alkali sulfonated-polyester resins, branched alkali sulfonated-polyester resins, alkali sulfonated-polyimide resins, branched alkali sulfonated-polyimide resins, alkali sulfonated poly(styrene-acrylate) resins, crosslinked alkali sulfonated poly(styrene-acrylate) resins, poly(styrene-methacrylate) resins, crosslinked alkali sulfonated-poly(styrene-methacrylate) resins, alkali sulfonated-poly(styrene-butadiene) resins, and crosslinked alkali sulfonated polystyrene-butadiene) resins. Alkali sulfonated polyester resins may be useful in embodiments, such as the metal or alkali salts of copoly(ethylene-terephthalate)-copoly(ethylene-5-sulfo-isophthalate), copoly(propylene-terephthalate)-copoly(propylene-5-sulfo-isophthalate), copoly(diethylene-terephthalate)-copoly(diethylene-5-sulfo-isophthalate), copoly(propylene-diethylene-terephthalate)-copoly(propylene-diethylene-5-sulfoisophthalate), copoly(propylene-butylene-terephthalate)-copoly(propylene-butylene-5-sulfo-isophthalate), copoly(propoxylated bisphenol-A-fumarate)-copoly(propoxylated bisphenol A-5-sulfo-isophthalate), copoly(ethoxylated bisphenol-A-fumarate)-copoly(ethoxylated bisphenol-A-5-sulfo-isophthalate), and copoly(ethoxylated bisphenol-A-maleate)-copoly(ethoxylated bisphenol-A-5-sulfo-isophthalate), and wherein the alkali metal is, for example, a sodium, lithium or potassium ion.
Examples of other suitable resins or polymers which may be utilized include, but are not limited to, poly(styrene-butadiene), poly(methylstyrene-butadiene), poly(methyl methacrylate-butadiene), poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene), poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene), poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene), poly(butyl acrylate-butadiene), poly(styrene-isoprene), poly(methylstyrene-isoprene), poly(methyl methacrylate-isoprene), poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene), poly(butyl methacrylate-isoprene), poly(methyl acrylate-isoprene), poly(ethyl acrylate-isoprene), poly(propyl acrylate-isoprene), poly(butyl acrylate-isoprene); poly(styrene-propyl acrylate), poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid), poly(styrene-butadiene-methacrylic acid), poly(styrene-butadiene-acrylonitrile-acrylic acid), poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid), poly(styrene-butyl acrylate-acrylonitrile), and poly(styrene-butyl acrylate-acrylonitrile-acrylic acid), and combinations thereof. The polymer may be block, random, or alternating copolymers.
In embodiments, the core resin is a crosslinkable resin. A crosslinkable resin is a resin comprising crosslinkable group or groups such as C═C bond. The resin can be crosslinked for example through a free radical polymerization with an initiator. In embodiments, an unsaturated polyester resin may be utilized as a latex resin. Examples of such resins include those disclosed in U.S. Pat. No. 6,063,827, the disclosure of which is hereby incorporated by reference in its entirety. Exemplary unsaturated polyester resins include, but are not limited to, poly(propoxylated bisphenol co-fumarate), poly(ethoxylated bisphenol co-fumarate), poly(butyloxylated bisphenol co-fumarate), poly(co-propoxylated bisphenol co-ethoxylated bisphenol co-fumarate), poly(1,2-propylene fumarate), poly(propoxylated bisphenol co-maleate), poly(ethoxylated bisphenol co-maleate), poly(butyloxylated bisphenol co-maleate), poly(co-propoxylated bisphenol co-ethoxylated bisphenol co-maleate), poly(1,2-propylene maleate), poly(propoxylated bisphenol co-itaconate), poly(ethoxylated bisphenol co-itaconate), poly(butyloxylated bisphenol co-itaconate), poly(co-propoxylated bisphenol co-ethoxylated bisphenol co-itaconate), poly(1,2-propylene itaconate), and combinations thereof.
As discussed above, the latex emulsion produced according to the method disclosed herein can be used to form a toner, such as an EA toner. The latex emulsion can be added to a pre-toner mixture, such as before particle aggregation in the EA coalescence process. The latex or emulsion, as well as a binder resin, a wax such as a wax dispersion, a colorant, and any other desired or required additives such as surfactants, may form the pre-toner mixture.
The pre-toner mixture can be prepared, and the pH of the resulting mixture can be adjusted, by an acid such as, for example, acetic acid, nitric acid or the like. The pH of the mixture can be adjusted to be from about 4 to about 5, although a pH outside this range can be used. Additionally, the mixture can be homogenized. If the mixture is homogenized, homogenization can be accomplished by mixing at a mixing speed of from about 600 to about 4,000 revolutions per minute, although speeds outside this range can be used. Homogenization can be accomplished by any suitable means, including, for example, an IKA ULTRA TURRAX T50 probe homogenizer.
Following the preparation of the above mixture, including the addition or incorporation into the pre-toner mixture of the latex emulsion produced by the methods disclosed herein, an aggregating agent can be added to the mixture. Any suitable aggregating agent can be used to form a toner. Suitable aggregating agents include, for example, aqueous solutions of a divalent cation or a multivalent cation material. The aggregating agent can be, for example, polyaluminum halides such as polyaluminum chloride (PAC), or the corresponding bromide, fluoride, or iodide, polyaluminum silicates such as polyaluminum sulfosilicate (PASS), and water soluble metal salts including aluminum chloride, aluminum nitrite, aluminum sulfate, potassium aluminum sulfate, calcium acetate, calcium chloride, calcium nitrite, calcium oxylate, calcium sulfate, magnesium acetate, magnesium nitrate, magnesium sulfate, zinc acetate, zinc nitrate, zinc sulfate, zinc chloride, zinc bromide, magnesium bromide, copper chloride, copper sulfate, and combinations thereof. The aggregating agent can be added to the mixture at a temperature that is below the glass transition temperature (Tg) of the resin.
The aggregating agent can be added to the mixture used to form a toner in an amount of, for example, from about 0.01 percent to about 8 percent by weight, such as from about 0.1 percent to about 1 percent by weight, or from about 0.15 percent to about 0.8 percent by weight, of the resin in the mixture, although amounts outside these ranges can be used. The above can provide a sufficient amount of agent for aggregation.
To control aggregation and subsequent coalescence of the particles, the aggregating agent can be metered into the mixture over time. For example, the agent can be metered into the mixture over a period of from about 5 to about 240 minutes, such as from about 30 to about 200 minutes, although more or less time can be used as desired or required. The addition of the agent can occur while the mixture is maintained under stirred conditions, such as from about 50 revolutions per minute to about 1,000 revolutions per minute, or from about 100 revolutions per minute to about 500 revolutions per minute, although speeds outside these ranges can be used. The addition of the agent can also occur while the mixture is maintained at a temperature that is below the glass transition temperature of the resin discussed above, such as from about 30° C. to about 90° C., or from about 35° C. to about 70° C., although temperatures outside these ranges can be used.
The particles can be permitted to aggregate until a predetermined desired particle size is obtained. A predetermined desired size refers to the desired particle size to be obtained as determined prior to formation, and the particle size being monitored during the growth process until such particle size is reached. Samples can be taken during the growth process and analyzed, for example with a Coulter Counter, for average particle size. The aggregation thus can proceed by maintaining the elevated temperature, or slowly raising the temperature to, for example, from about 30° C. to about 99° C., and holding the mixture at this temperature for a time from about 0.5 hours to about 10 hours, such as from about hour 1 to about 5 hours (although times outside these ranges may be utilized), while maintaining stirring, to provide the aggregated particles. Once the predetermined desired particle size is reached, then the growth process is halted. The predetermined desired particle size can be within the desired size of the final toner particles.
The growth and shaping of the particles following addition of the aggregation agent can be accomplished under any suitable conditions. For example, the growth and shaping can be conducted under conditions in which aggregation occurs separate from coalescence. For separate aggregation and coalescence stages, the aggregation process can be conducted under shearing conditions at an elevated temperature, for example, of from about 40° C. to about 90° C., such as from about 45° C. to about 80° C. (although temperatures outside these ranges may be utilized), which can be below the glass transition temperature of the resin as discussed above.
Once the desired final size of the toner particles is achieved, the pH of the mixture can be adjusted with a base to a value of from about 3 to about 10, such as from about 5 to about 9, although a pH outside these ranges may be used.
The adjustment of the pH can be used to freeze, that is to stop, toner growth. The base utilized to stop toner growth can include any suitable base such as, for example, alkali metal hydroxides such as, for example, sodium hydroxide, potassium hydroxide, ammonium hydroxide, combinations thereof, and the like. In embodiments, ethylene diamine tetraacetic acid (EDTA) may be added to help adjust the pH to the desired values noted above.
After aggregation, but prior to coalescence, a resin coating can be applied to the aggregated particles to form a shell thereover. Any resin described above as suitable for forming the toner resin can be used as the shell.
Other resins that can be used as shell material are vinyl types of polymer latexes such as styrene-acrylate latexes.
The shell resin can be applied to the aggregated particles by any method within the purview of those skilled in the art. The resins utilized to form the shell can be in an emulsion including any surfactant described above. The emulsion possessing the resins can be combined with the aggregated particles described above so that the shell forms over the aggregated particles. In embodiments, the shell may have a thickness of up to about 5 microns, such as from about 0.1 to about 2 microns, or from about 0.3 to about 0.8 microns, over the formed aggregates, although thicknesses outside of these ranges may be obtained.
The formation of the shell over the aggregated particles can occur while heating to a temperature of from about 30° C. to about 80° C. in embodiments from about 35° C. to about 70° C., although temperatures outside of these ranges can be utilized. The formation of the shell can take place for a period of time of from about 5 minutes to about 10 hours, such as from about 10 minutes to about 5 hours, although times outside these ranges may be used.
For example, the toner process can include forming a toner particle by mixing the polymer latexes, in the presence of a wax dispersion and a colorant with an optional coagulant while blending at high speeds. The resulting mixture having a pH of, for example, of from about 2 to about 3, can be aggregated by heating to a temperature below the polymer resin Tg to provide toner size aggregates. Optionally, additional latex can be added to the formed aggregates providing a shell over the formed aggregates. The pH of the mixture can be changed, for example, by the addition of a sodium hydroxide solution, until a pH of about 7 may be achieved.
Following aggregation to the desired particle size and application of any optional shell, the particles can be coalesced to the desired final shape. The coalescence can be achieved by, for example, heating the mixture to a temperature of from about 45° C. to about 100° C., such as from about 55° C. to about 99° C. (although temperatures outside of these ranges may be used), which can be at or above the glass transition temperature of the resins used to form the toner particles, and/or reducing the stirring, for example, to a stirring speed of from about 100 revolutions per minute to about 1,000 revolutions per minute, such as from about 200 revolutions per minute to about 800 revolutions per minute (although speeds outside of these ranges may be used). The fused particles can be measured for shape factor or circularity, such as with a Sysmex FPIA 2100 analyzer, until the desired shape is achieved.
Higher or lower temperatures can be used, it being understood that the temperature is a function of the resins used for the binder. Coalescence may be accomplished over a period of from about 0.01 hours to about 9 hours, such as from about 0.1 hours to about 4 hours (although times outside of these ranges can be used).
After aggregation and/or coalescence, the mixture can be cooled to room temperature, such as from about 20° C. to about 25° C. The cooling can be rapid or slow, as desired. Suitable cooling methods include introducing cold water to a jacket around the reactor. After cooling, the toner particles can be washed with water, and then dried. Drying can be accomplished by any suitable method for drying including, for example, freeze-drying.
Certain embodiments of the present disclosure provides a toner for electrostatic image development, comprising toner particles comprising at least one resin, in combination with an optional colorant, and an optional release agent; and a capsule comprises a core and a polymer shell, wherein the core comprises a functional material. Certain embodiments of the present disclosure provides a toner for electrostatic image development, comprising toner particles comprising at least one resin, in combination with an optional colorant, and an optional release agent; and a capsule comprises a core containing a paraffin oil and a polymer shell.
Certain embodiments of the present disclosure provides an image forming apparatus, comprising a) an imaging member having a charge retentive surface for developing an electrostatic latent image, wherein the imaging member comprises: a substrate; a photoconductive layer disposed on the substrate; and a protective layer disposed on the photoconductive layer; b) a bias charging unit; c) a latent image forming unit; d) a toner developing unit; e) a transfer unit; f) a cleaning unit in contact with the imaging member; g) a toner comprising toner particles comprising at least one resin, in combination with an optional colorant, and an optional release agent; and a capsule comprises a core and a polymer shell, wherein the core comprises a functional material.
In embodiments, the capsule breaks at contact position between the transfer unit and the imaging member.
In embodiments, the capsule breaks at the contact position between the cleaning unit and the imaging member.
As used herein, the singular forms “a”, “and,” and “the” include plural referents unless the context clearly indicates otherwise.
As used herein, numerical values are often presented in a range format throughout this document. The use of a range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the use of a range expressly includes all possible subranges, all individual numerical values within that range, and all numerical values or numerical ranges including integers within such ranges and fractions of the values or the integers within ranges unless the context clearly indicates otherwise. This construction applies regardless of the breadth of the range and in all contexts throughout this document. Thus, for example, reference to a range of 100-1000 RPM includes 200-1000 RPM, 300-900 RPM, 450-700 RPM, 500-950 RPM, 650-800 RPM, 100-230 RPM, 150-560 RPM, and so forth.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, and are also intended to be encompassed by the following claims.
While the description above refers to particular embodiments, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of embodiments herein.
The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of embodiments being indicated by the appended claims rather than the foregoing description. All changes that come within the meaning of and range of equivalency of the claims are intended to be embraced therein.
The examples set forth herein below and are illustrative of different compositions and conditions that can be used in practicing the present embodiments. All proportions are by weight unless otherwise indicated. It will be apparent, however, that the present embodiments can be practiced with many types of compositions and can have many different uses in accordance with the disclosure above and as pointed out hereinafter.
Capsules containing paraffin oil were supplied by Lipo technologies, Inc. The capsules contain a thin polymer layer i) a methoxy methyl methylol melamine (MMM) polymeric coating, or ii) a polyoxymethylene urea (PMU) coating. The sizes of the capsules were averaged about 5 μm, about 12 μm, or about 14 μm.
70 grams of an control toner includes additives including 1.71% RY50-silica (Nippon Aerosil Co., Ltd), 0.88% JMT2000-titania (Tayca Corp.), 1.73% X24 silica (Shin-Etsu Chemical Co., Ltd.), 0.55% E10-cerium oxide (Mitsui Mining & Smelting Co., Ltd.), 0.2% ZnSt-zinc stearate (Asahi Denka Kogyo Co., Ltd.) were blended in a blender sold by Kyoritsu Co. product designation Sample Mill Model SK-M1 Oat 13500 RPM for 30 seconds.
Blending of Toner with Lipocapsules 70 grams of the same toner parent particles and the same surface additives as described in Example 2, were all blended in a blender at 13500 RPM for 30 seconds. 3.5 grams Lipocapsules as described in Example 1 were then added to the resulting mixture and further blended at 500 RPM for 15 seconds.
Toner charging performances were tested on the control toner from Example 2 and the toner obtained from Example 4. Developer samples were prepared with 0.5 g of the toner sample and 10 g of the carrier. A duplicate developer sample pair was prepared. One developer of the pair was conditioned overnight in A-zone (28° C./85% RH), and the other was conditioned overnight in the J-zone environmental chamber (21° C./10% RH). The next day, the developer samples were sealed and agitated for 1 hour using a Turbula mixer. After 1 hour of mixing, the toner charge was measured using a charge spectrograph using a 100 V/cm field. The toner charge (q/d) was measured visually as the midpoint of the toner charge distribution. The charge is being reported in millimeters of displacement from the zero line.
An overcoated photoreceptor was installed into one of the CRU in XEROX® DocuColor 250 (DC250) used for print test. The printing test was carried in a humid environment with temperature 29° C. and humidity: 85%.
The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others. Unless specifically recited in a claim, steps or components of claims should not be implied or imported from the specification or any other claims as to any particular order, number, position, size, shape, angle, color, or material.
All the patents and applications referred to herein are hereby specifically, and totally incorporated herein by reference in their entirety in the instant specification.
