Claims
- 1. A method for solidifying liquid organic compounds, which comprises adding polyhexamethylenimine having a number average molecular weight of 500 to 20,000 and having a structural unit of the general formula [(CH.sub.2).sub.6 NH] to a liquid organic compound in the presence of water, said liquid organic compound being selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, ester compounds and halogenated hydrocarbons.
- 2. A method according to claim 1, wherein said polyhexamethylenimine is substantially linear.
- 3. A method according to claim 1, wherein the amount of the polyhexamethylenimine is 0.1 to 20 parts by weight per 100 parts by weight of the organic compound.
- 4. A method according to claim 1 or 3, wherein the amount of water is 0.02 to 200 parts by weight per 100 parts by weight of the organic compound.
- 5. A method according to claim 1 wherein the liquid organic compounds are solidified at a temperature of 0.degree. to 200.degree. C.
- 6. A method according to claim 5 in which the solidifying temperature is between 10.degree. and 100.degree. C.
Priority Claims (4)
| Number |
Date |
Country |
Kind |
| 52-116149 |
Sep 1977 |
JPX |
|
| 53-29265 |
Mar 1978 |
JPX |
|
| 53-67617 |
Jun 1978 |
JPX |
|
| 53-68959 |
Jun 1978 |
JPX |
|
Parent Case Info
This is a division, of application Ser. No. 946,528, filed Sept. 26, 1978, now U.S. Pat. No. 4,216,307.
This invention relates to a process for preparing polyhexamethylenimine. More specifically, it relates to a process for preparing polyhexamethylenimine by condensing hexamethylenediamine in the presence of metallic palladium or a palladium compound.
The invention also relates to a novel use of polyhexamethylene as a gelling agent, and to a novel polyhexamethylenimine compound.
Polycondensation reaction between an alkylenediamine containing 2 to 6 carbon atoms and an alkylene dihalide containing 1 to 4 carbon atoms in the presence of a strong basic compound is known as a process for preparing a polyalkylenepolyamine (J. Polymer Sci. 45, 289, 1960). This method, however, has the defect that because the resulting reaction mixture contains the amine, water, alkaline solution, and salts, it is difficult to separate and recover the desired polyalkylene polyamine, and treatment of by-products such as the alkali metal halide requires huge cost. Furthermore, no report has been made about the synthesis of a polymer of hexamethylenimine by this method.
A method is also known to produce a polyalkylenimine by condensing ethylenediamine or 1,3-propanediamine with the aid of a compound of a transition metal of Group VIII of the periodic table as a catalyst. However, when ethylene diamine or 1,3-propanediamine is condensed, the resulting polyalkylenimine is a di- to tetra-mer of the starting amine, and a polyalkylenimine having a high molecular weight cannot be obtained (Japanese Laid-Open Patent Publications Nos. 41308/76 and 36608/77).
It is also known to produce polyhexamethylenimine by ring-opening polymerization of hexamethylenimine using an acid catalyst (German Patent No. 1037126). This method requires the use of the expensive hexamethylenimine as a raw material, and the reaction must be carried out at a temperature of as high as 200.degree. to 350.degree. C. Furthermore, separation of the polyhexamethylenimine from the catalyst is not always easy. The method also has the defect of not giving polyhexamethylenimine having a high degree of polymerization.
None of these prior art methods have come into commercial acceptance because of the various problems described.
It is an object of this invention therefore to provide a process which can easily afford polyhexamethylenimine of high commercial value in high yields from a cheap starting material without requiring a high reaction temperature.
Another object of the invention is to provide a process for preparing polyhexamethylenimine in which the separation and recovery of the resulting polyhexamethylenimine is very easy.
Still another object of this invention is to provide a process which can optionally afford either polyhexamethylenimines of low degrees of polymerization or those of high degrees of polymerization.
The present inventors made extensive investigations in order to achieve these objects, and found that when hexamethylenediamine is condensed using metallic palladium or a palladium compound at relatively low temperatures, polyhexamethylenimine having the desired degree of polymerization can be obtained in good yields, and the separation of the catalyst is easy.
Specifically, the present invention provides a process for producing polyhexamethylenimine which comprises condensing hexamethylenediamine at a temperature of from 50.degree. to 300.degree. C. in the presence of at least one palladium catalyst selected from the group consisting of metallic palladium and palladium compounds to form polyhexamethylenimine having an average degree of polymerization of at least 3, then separating the catalyst from the reaction mixture, and recovering the polyhexamethylenimine formed.
The catalyst used in this invention is metallic palladium or a palladium compound.
The metallic palladium denotes palladium black, or metallic palladium supported on a carrier. The carrier is, for example, carbon black, magnesium oxide, magnesium chloride, magnesium sulfate, barium sulfate, calcium carbonate, barium carbonate, alumina, silica, silica-alumina, or molecular sieves. Other carriers which do not hamper the reaction can also be used.
The palladium compound, as referred to in this invention, is a palladium complex compound having a valence of 0, 2 or 4. At least one such compound can be used. Specific examples of palladium compounds that can be used in this invention are listed below.
(1) Palladium complex compounds expressed by the general formula PdL.sup.1 L.sup.2 L.sup.3 or PdL.sup.1 L.sup.2 L.sup.3 L.sup.4 wherein L.sup.1, L.sup.2, L.sup.3 and L.sup.4 each represent a ligand of the formula ##STR1## M represents P, As or Sb; R.sup.1, R.sup.2 and R.sup.3 represent a halogen atom, the group NR.sub.2 (R being hydrogen or alkyl), a C.sub.1-16 alkyl, alkenyl, cycloalkyl, cycloalkenyl or aryl group, or derivatives of these; and R.sup.4, R.sup.5 and R.sup.6 represent a hydrogen atom, a C.sub.1-16 alkyl, alkenyl, cycloalkyl, cycloalkenyl or aryl group, or derivatives of these.
Specific examples of these compounds are as follows:
(2) Palladium complex compounds expressed by the general formula PdA.sup.1 A.sup.2 L.sup.1 L.sup.2 wherein A.sup.1 and A.sup.2 represent a hydrogen atom, a halogen atom, NO.sub.3, CNS, R.sup.4, R.sup.4 CO or R.sup.4 COO, and R.sup.4, L.sup.1 and L.sup.2 are as defined above.
Specific examples of compounds of this group are as follows:
(3) Palladium complex compounds expressed by the general formula PdL.sup.1 L.sup.2 Q wherein Q represents a dienophile such as maleic anhydride, maleic acid esters, fumaric acid esters, fumaronitrile, benzoquinone, naphthoquinone or acetylene dicarboxylic acid esters, and L.sup.1 and L.sup.2 are as defined hereinabove.
Specific examples are as follows: ##STR2##
L.sup.1 L.sup.2 in the palladium complex compounds (1) to (3) may be a bidentate ligand of the general formula ##STR3## wherein M represents P, As or Sb; R.sup.7, R.sup.8, R.sup.9 and R.sup.10 represent R.sup.1, R.sup.2, R.sup.3, OR.sup.4 OR.sup.5 or OR.sup.6 defined hereinabove; and R.sup.11 represents a divalent hydrocarbon group.
Specific examples of these bidentate ligands are as follows:
(4) Palladium complex compounds expressed by the general formula PdA.sup.1 YL.sup.1 wherein Y is a .pi.-allyl group of the general formula ##STR7## wherein R.sup.12, R.sup.13, R.sup.14, R.sup.15 and R.sup.16 represent a hydrogen or halogen atom, a C.sub.1-16 alkyl, alkenyl, cycloalkyl, cycloalkenyl or aryl group, or derivatives of these; and A.sup.1 and L.sup.1 are as defined hereinabove.
Specific examples of these compounds are as follows: ##STR8##
(5) Palladium complex compounds expressed by the general formula [PdX.sup.1 X.sup.2 Z].sub.2 wherein X.sup.1 and X.sup.2 represent a halogen atom, and Z represents an olefin having 1 to 20 carbon atoms. The olefin denotes a monolefin such as an .alpha.-olefin, iso-olefin or internal olefin, a diolefin, a polyolefin, a vinyl compound, or derivatives of these.
Specific examples of these palladium compounds are as follows: ##STR9##
(6) Palladium compounds expressed by the general formula PdX.sup.1 X.sup.2 D wherein D represents a diene such as butadiene, cyclopentadiene or cyclooctadiene, derivatives of these dienes, or carbon monoxide; and X.sup.1 and X.sup.2 represent a halogen atom.
Specific examples of these palladium compounds are as follows: ##STR10##
(7) Palladium complex compounds expressed by the general formula PdB.sup.1 B.sup.2 wherein B.sup.1 and B.sup.2 represent D or Y defined hereinabove.
Specific examples of these compounds are as follows: ##STR11##
(8) Palladium complex compounds expressed by the general formula [PdX.sup.1 Y].sub.2 wherein X.sup.1 and Y are as defined hereinabove.
Specific examples of these compounds are as follows: ##STR12##
(9) Palladium compounds expressed by the general formula ##STR13## wherein R.sup.4 is as defined above.
Specific examples of these compounds are Pd(OOCCH.sub.3).sub.2, Pd(OOCC.sub.3 H.sub.5).sub.2, Pd(OOCC.sub.3 H.sub.7).sub.2, and Pd(OOCC.sub.6 H.sub.5).sub.2.
(10) Palladium compounds expressed by the general formula Pd(OR.sup.4).sub.2 wherein R.sup.4 is as defined hereinabove.
Specific examples are Pd(OH).sub.2, Pd(OCH.sub.3).sub.2, Pd(OC.sub.2 H.sub.5).sub.2, Pd(O i-C.sub.3 H.sub.7).sub.2, Pd(O t-C.sub.4 H.sub.9), and Pd(OC.sub.6 H.sub.5).
(11) Palladium compounds expressed by the general formula Pd[OCR.sup.4 .dbd.CH-COR.sup.5 ].sub.2 wherein R.sup.4 and R.sup.5 are as defined above.
Specific examples of these compounds are Pd[OCH.dbd.CH-COCH.sub.3 ].sub.2, Pd[OC(CH.sub.3).dbd.CH-COCH.sub.3 ].sub.2, and Pd[OC(CH.sub.3).dbd.CH-COC.sub.2 H.sub.5 ].sub.2.
(12) Palladium compounds expressed by the general formula Pd(R.sup.17 NC).sub.4, PdX.sub.2 (R.sup.17 NC).sub.2, Pd(R.sup.17 NC).sub.2 or PdX.sub.2 (R.sup.17 CN).sub.2 wherein X represents a halogen atom, and R.sup.17 represents a C.sub.1-16 alkyl, alkenyl, cycloalkyl, cycloalkenyl or aryl group, or derivatives of these.
Specific examples of these compounds are Pd(para-CH.sub.3 C.sub.6 H.sub.4 NC).sub.4, Pd(CH.sub.3 NC).sub.2, Pd(para-OCH.sub.3 -C.sub.6 H.sub.4 NC).sub.4, PdCl.sub.2 -(C.sub.6 H.sub.5 NC).sub.2, and PdCl.sub.2 (C.sub.6 H.sub.5 CN).sub.2.
(13) Inorganic salts or oxide of palladium. Specific examples are PdI.sub.2, PdCl.sub.2, PdBr.sub.2, Pd(CN).sub.2, Pd(CNS).sub.2, Pd(NO.sub.3).sub.2, PdSO.sub.4, PdO, PdI.sub.4, PdCl.sub.4, PdBr.sub.4, PdS.sub.2 and PdSe.sub.2.
(14) Complexes of the palladium compounds (1) to (13) with amines or inorganic compounds.
Specific examples of these compounds are as follows: ##STR14## Pd(NO.sub.2).sub.2 (NH.sub.3).sub.2, Na.sub.2 PdCl.sub.4, K.sub.2 PdCl.sub.4, K.sub.2 PdBr.sub.4, K.sub.2 Pd(CN).sub.4, (NH.sub.4).sub.2 PdCl.sub.4, H.sub.2 (PdCl.sub.4).sub.2, H.sub.2 (PdCl.sub.6).sub.2, Na.sub.2 PdCl.sub.6, K.sub.2 PdCl.sub.6, (NH.sub.4).sub.2 PdCl.sub.6, PdCl.sub.4 (NH.sub.3).sub.2, and K.sub.2 Pd(CN).sub.4.
(15) Palladium compounds (1) to (14) above as supported on carriers. All carriers which are used to support metallic palladium can be applied.
The amount of the catalyst used in this invention is at least 0.0001 mole per mole of the starting amine. For commercial operations, amounts in the range of 0.0001 to 0.5 mole, preferably 0.001 to 0.2 mole, are suitable. If the amount of the catalyst is smaller than the lower limit, the reaction time is prolonged to cause commercial disadvantage. When the amount of the catalyst is too large, the molecular weight of the product is reduced, but there is no other appreciable adverse effect on the reaction. However, separation and recovery of the excessive catalyst requires more labor and time.
The reaction in accordance with this invention proceeds easily even in the absence of solvent. For convenience, a solvent may be used. Any compounds which act as solvent without hampering the reaction can be used in this invention as the solvent. Specific examples of the solvent are aromatic hydrocarbons such as benzene, toluene or xylene, aliphatic hydrocarbons such as n-pentane, n-hexane and n-heptane, alicyclic hydrocarbons such as cyclohexane, cyclooctane and methylcyclohexane, ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane and dimethoxyethane, and esters such as ethyl acetate, butyl acetate, ethyl propionate and ethyl butyrate.
The reaction in accordance with this invention can be performed at 50.degree. to 300.degree. C., preferably 120.degree. to 250.degree. C. Too low reaction temperature are commercially disadvantageous because the reaction time is prolonged, and too high reaction temperatures, on the other hand, will increase the formation of by-products. The reaction time is usually at least 5 minutes, preferably from 15 minutes to 100 hours. The reaction proceeds favorably by stirring or shaking, and the rate of reaction is considerably affected by the amount of the catalyst, the reaction temperature, the rate of stirring , etc. The reaction pressure may be atmospheric pressure. The reaction can also be performed under elevated pressures using ammonia or nitrogen.
The reaction in accordance with this invention can be performed either batchwise or continuously. Alternatively, a semi-batchwise method can be used in which hexamethylenediamine is added consecutively.
Since in the present invention by-products such as water and salts are not formed, the desired polyalkylenimine can be easily separated by simply separating the catalyst by filtration using a solvent, etc. The catalyst separated can be re-used repeatedly.
When the process of this invention described hereinabove is performed using a mixture of hexamethylenediamine and at least one amine of the general formula ##STR15## wherein m is an integer of 2 to 9, and n is an integer of 1 to 5 with the proviso that when m is 6, n is not 1, instead of the hexamethylenediamine alone, a copolymer (to be referred to hereinbelow as copolyalkylenimine) having a unit of the formula [(CH.sub.2).sub.6 NH] and a unit of the general formula ##STR16## (m and n are as defined above) can be obtained.
Examples of amines of the formula ##STR17## which can be co-condensed with hexamethylenediamine include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,9-diaminononane, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, and tripropylenetetramine.
The ratio of the amine of the general formula ##STR18## to hexamethylenediamine used in the co-condensation reaction can be varied according to the purpose. Suitably, it is from 1:100 to 100:1, preferably from 1:10 to 10:1.
The amount of the catalyst in the co-condensation method of this invention is at least 0.0001 mole, preferably 0.0001 to 0.5 mole, more preferably 0.001 to 0.2 mole, per mole of the amine.
When hexamethylenediamine is co-condensed with the amine of general formula (I) by a semi-batchwise method, one or both of these compounds are consecutively fed into the reaction system. Alternatively, a blocked copolymer may be prepared by first completing the condensation of one of the amines and adding the other amine after completion of the condensation of the first-named amine.
The use of the processes of this invention described hereinabove can afford either polyhexamethylenimines or copolyalkylenimines of high degrees of polymerization or those of low degrees of polymerization. Specifically, polyhexamethylenimines or copolyalkylenimines of low degrees of polymerization and high degrees of polymerization with an average degree of polymerization of at least 3 can be produced as desired by changing the reaction conditions such as the reaction temperature, the reaction time or the amount of the catalyst. Furthermore, the amounts of by-products such as hexamethylenimine are very small, and the desired polyhexamethylenimine or copolyalkylenimine can be produced with high selectivity and in high yields. For example, products of low degrees of polymerization can be obtained when the amount of the catalyst is increased, and products of high degree of polymerization can be obtained when the amount of the catalyst is decreased.
Some of the polyhexamethylenimines obtained by the process of the present invention contain a recurring unit of the formula
These novel polyhexamethylenimines of the invention are preferably linear polymers. The linear polymers, as referred to herein, mean polymers in which at least 70% of the entire amines in the polymer molecule consists of secondary amino groups (--NH--). In other words, they denote polymers in which at least 70% of the recurring units contained in the polymer molecule consists of the recurring unit of formula (II) given above.
The molecular weight of polymer is a number average molecular weight measured by using a vapor pressure osmometer.
Known hexamethylenimine polymers, for example polyhexamethylenimine obtained by ring-opening polymerization of a cyclic hexamethylenimine monomer (German Pat. No. 1037126), or an oligomer of hexamethylenimine formed as a by-product in the synthesis of hexamethylenimine monomer by hydrogenating .epsilon.-caprolactam with a cobalt catalyst (T. Ayusawa and T. Shimodaira, Ind. Eng. Chem. Prod. Res. Dev., 15, 295 (1976)), have a molecular weight of as low as less than 500. The polyhexamethylenimine obtained by the ring-opening polymerization of cyclic hexamethylenimine is a penta- to hexa-mer, and the oligomer of hexamethylenimine formed as a by-product in the catalytic hydrogenation reaction of .epsilon.-caprolactam is a tri- to tetra-mer. The polyhexamethylenimine obtained by the ring-opening polymerization of cyclic hexamethylenimine contains more tertiary amino groups than secondary ones in the polymer molecule, and is not a linear polymer.
The novel polyhexamethylenimine of this invention have a molecular weight of at least 1,000, which is far higher than those of the polymers or oligomers of hexamethylenimine described in the above-cited literature references. Elemental analysis, infrared absorption spectrum, .sup.1 H-NMR, and .sup.13 C-NMR have shown that the novel polyhexamethylenimines of the present invention are polyamines in which hexamethylenimine units [(CH.sub.2).sub.6 NH] are recurring in chain. It has also been found from the quantitative analysis of primary, secondary and tertiary amines and the measurement of molecular weight by a vapor pressure osmometer method that these polymers are polyamines which are substantially linear and little branched and have a molecular weight of at least 1,000, usually 1,000 to 20,000.
US Referenced Citations (2)
| Number |
Name |
Date |
Kind |
| 3516944 |
Litt et al. |
Jun 1970 |
|
| 4007128 |
Poklacki |
Feb 1977 |
|
Foreign Referenced Citations (1)
| Number |
Date |
Country |
| 546266 |
Feb 1974 |
CHX |
Divisions (1)
|
Number |
Date |
Country |
| Parent |
946528 |
Sep 1978 |
|
Patent Grant
4309324
