JPH04337328A - Production of phosphazene polymer - Google Patents

Abstract

PURPOSE:To obtain a phosphazene polymer under a relatively mild reaction condition in a short time and in high yield without causing a problem of remaining chlorine. CONSTITUTION:An organophosphine-imine [e.g. N-trimethylsilyl-tris(2,2,2- trifluoroethoxy)posphineimine] shown by formula I (R<1> is substituted or nonsubstituted monofunctional hydrocarbon; R'' is H or monofunctional organic group) is subjected to polycondensation by using an ionic compound shown by formula II {R<3> is substituted or nonsubstituted monofunctional hydrocarbon; X<-> is R<4>3SiF2<-> or HF2<-> (R<4> is H or monofunctional organic group)] as a polycondensation catalyst.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing phosphazene polymers having excellent properties such as heat resistance, cold resistance and oil resistance.

0002

[Prior Art and Problems to be Solved by the Invention] Phosphazene polymers are polymeric compounds having a P=N skeleton, and have excellent retardancy and low smoke generation properties, as well as organic groups bonded to phosphorus atoms. Various properties can be imparted depending on the type, and it is attracting attention as a highly functional material.

Conventionally, the method for producing this phosphazene polymer has been to subject hexachlorocyclotriphosphazene to ring-opening polymerization to form a dichlorophosphazene polymer;
A method of substituting the chlorine atom in this compound with various organic groups is known (US Pat. No. 3,370,020). Furthermore, as a method for producing phosphazene polymers by polycondensation reaction, a method of polycondensing N-(dichlorophosphoryl)trichlorophosphazene has also been proposed (Patent Publication No. 62
-501144 publication).

However, in the method of ring-opening polymerization of hexachlorocyclotriphosphazene, when the polymer yield reaches around 60%, a crosslinking reaction occurs and gelation occurs. The process must be stopped at a certain point, and it takes time and effort to replace the chlorine atoms in the polymer with various organic groups after polymerization, making the resulting polymer extremely expensive. Furthermore, even in the above substitution reaction, it is difficult to completely replace chlorine atoms, and there is a problem that trace amounts of residual chlorine may affect the performance of the polymer. Further, in the method of polycondensing N-(dichlorophosphoryl)trichlorophosphazene, although the polymer yield is improved, the problem regarding residual chlorine is not solved.

[0005] Therefore, as a method for producing phosphazene polymers without causing the problem of residual chlorine, a method has been proposed in which N-trimethylsilylphosphazene, which is an organophosphazene monomer, is polycondensed (US Pat. No. 4, No. 412,053).

However, although this production method improves the problems of polymer yield and residual chlorine, it has the problems of a high reaction temperature of 190° C. or higher and a reaction time of 40 hours or more. are doing.

The present invention was developed in view of the above circumstances, and it is possible to produce a phosphazene polymer in a short time and in high yield under relatively mild reaction conditions without causing the problem of residual chlorine. The purpose of the present invention is to provide a method for producing a novel phosphazene polymer.

[0008]

[Means and Effects for Solving the Problems] As a result of intensive studies to achieve the above object, the present inventors have discovered that phosphazene is produced by thermal polycondensation of organophosphine-imine represented by the following general formula (1). When obtaining a polymer, polycondensation is carried out using an ionic compound represented by the following general formula (2) as a polycondensation catalyst to efficiently promote the polycondensation reaction and achieve a relatively low temperature of 50 to 180°C. So 3
It is possible to produce a phosphazene polymer in high yield in a short period of time, such as ~30 hours, and in this case, since neither the starting material nor the catalyst contains chlorine atoms, the polymer can be produced without causing the problem of residual chlorine mentioned above. They discovered that it could be manufactured and completed the present invention.

[0009]

[Case 2]

Therefore, the present invention provides a method for polycondensing an organophosphine-imine represented by the above general formula (1) using an ionic compound represented by the above general formula (2) as a polycondensation catalyst. The present invention provides a method for producing a phosphazene polymer characterized by the following.

[0011] The present invention will be explained in more detail below. In the production method of the present invention, the phosphazene monomer used as a starting material is an organophosphine-imine represented by the following general formula (1) as described above. .

0012

[Chemical formula 3]

Here, R1 in the general formula (1) is an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group,
Monovalent hydrocarbon group such as an aralkyl group, preferably having 1 carbon number
~8 Monovalent hydrocarbon groups in which part or all of the hydrogen atoms are replaced with fluorine atoms, specifically methyl group, ethyl group, isopropyl group, phenyl group, tolyl group, 2
, 2,2-trifluoroethyl group, 1-trifluoromethyl-2,2,2-trifluoroethyl group, 2,2,3
, 3,3-pentafluoropropyl group, 2,2,3,3
-tetrafluoropropyl group, among others, phenyl group, 2,2,2-trifluoroethyl group, and 2,2,3,3-tetrafluoropropyl group are particularly preferred. Moreover, R2 in general formula (1) is
It is a hydrogen atom or a monovalent organic group, preferably having 1 to 10 carbon atoms. Specifically, hydrogen atoms, alkyl groups such as methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, and isobutyl groups, aryl groups such as phenyl groups, alkenyl groups such as vinyl groups, methoxy groups,
Examples include alkoxy groups such as ethoxy groups, aryloxy groups such as phenoxy groups, substituted monovalent hydrocarbon groups such as 3,3,3-trifluoropropyl groups, chloromethyl groups, and 3-chloropropyl groups. , generally referred to as a methyl group.

Specifically, the organophosphine-imine represented by the general formula (1) includes N-trimethylsilyl-tris(2,2,2-trifluoroethoxy)phosphineimine, N-trimethylsilyl-bis(2, 2,
2-trifluoroethoxy)ethoxyphosphinimine, N-trimethylsilyl-bis(2,2,2-trifluoroethoxy)phenoxyphosphinimine, N-trimethylsilyl-bis(2,2-dimethylpropyloxy)2,2,2- Trifluoroethoxyphosphinimine, N-trimethylsilyl-bis(1-trifluoromethyl-2,2,2-trifluoroethyloxy)2,2,
2-trifluoroethoxyethoxyphosphinimine,
N-trimethylsilyl-tris(1-trifluoromethyl-2,2,2-trifluoroethyloxy)phosphinimine, N-trimethylsilyl-tris(2,2,3
, 3-tetrafluoropropyloxy)phosphinimine and the like. Note that these organophosphine-imines can be obtained by reacting the corresponding phosphine with silyl azide.

Further, the ionic compound containing a sulfur atom used as a polycondensation catalyst in the production method of the present invention is represented by the following general formula (2).
R3 is a substituted or unsubstituted monovalent hydrocarbon group, specifically an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an aryl group such as a phenyl group, an aralkyl group such as a benzyl group, etc. are mentioned, but it is usually a methyl group or an ethyl group. Furthermore, X- is represented by the following formula (3) or (
4), in formula (3), R4 represents a hydrogen atom or a monovalent organic group, and examples thereof include the same groups as R2 above.

[0016]

[C4]

[0017] Specific examples of this sulfur-containing ionic compound include the following compounds. In the following formula, Me represents a methyl group, Et represents an ethyl group, and Ph represents a phenyl group.

[0018]

[C5]

In the production method of the present invention, the above-mentioned starting material monomer organophosphine-imine is heated and polycondensed using the above-mentioned ionic compound as a polycondensation catalyst. The amount of the ionic compound used can be a catalytic amount, and the molar ratio is usually 1/1 to the phosphazene monomer as the starting material.
It is said to be about 0 to 1/106. In addition, the method of adding the ionic compound described above is such that even if it is added as it is to the reaction system,
It may be added after being dissolved in an appropriate solvent, and in this case diglyme, N,N-dimethylformamide, etc. can be used as the solvent.

This polycondensation reaction is carried out using organophosphine-imine [(R1O)3P=NSiR
[R1O] group bonded to the phosphorus atom and [SiR2 3] bonded to the nitrogen atom in [R1OSiR2 3]
], and the main chain of the polymer is lengthened.
In this case, the reaction may be carried out without a solvent or in a suitable organic solvent. Examples of reaction solvents include diglyme, triglyme, tetraglyme, N,N-dimethylformamide, N,N-dimethylacetamide, N- Methylpyrrolidone and the like can be used. Moreover, this polycondensation reaction is preferably carried out under an inert gas atmosphere such as nitrogen gas or argon gas. Furthermore, the reaction conditions are 50~
It is preferable to react at a reaction temperature of 180°C, especially 80 to 130°C, for 3 hours or more, especially 5 to 20 hours, and it is preferable to carry out the reaction while distilling volatile condensates from the reaction system. . In addition, in the case of bulk polymerization, the generated phosphazene polymer can be directly subjected to the next processing step, or in the case of solution polymerization using a solvent, it can be subjected to a conventional separation method, for example, using a non-solvent such as methanol. It can be easily separated and purified by methods such as reprecipitation.

In the production method of the present invention, the above-mentioned polycondensation reaction proceeds almost quantitatively, making it possible to produce a phosphazene polymer in an extremely high yield, and furthermore, the temperature of the reaction system is returned to room temperature to carry out the reaction. After stopping the polymerization reaction, it is possible to restart the polymerization reaction by adding the starting material phosphazene monomer and heating it to return the reaction system to the temperature of the polymerization conditions. The degree of polymerization of the coalescence can be increased.

[0022]

[Examples] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to the following Examples. In the following examples, the molecular weight of the polymer was measured using a GPC molecular weight measuring device (HLC-8020 manufactured by Toso).

[Example 1] N-trimethylsilyl-tris (
2,2,2-trifluoroethoxy)phosphinimine (2,2,2-trifluoroethoxy) phosphinimine (20.7 g) was stored, and tris(diethylamino)
Sulfonium trimethyl difluorosilicate 75mg
was added and stirred at 100°C for 20 hours under a nitrogen atmosphere to perform a polycondensation reaction, and then the reaction mixture was heated at 140°C/2 m
The volatile matter was removed by standing under mHg for 5 hours to obtain 11.4 g of phosphazene polymer.

The number average molecular weight of the obtained phosphazene polymer was 80,000, and the weight average molecular weight was 98,000.

[Example 2] 22.0 g of N-trimethylsilyl-tris(2,2,2-trifluoroethoxy)phosphinimine was placed in a flask similar to that used in Example 1, and tris(dimethyl Add 58 mg of amino)sulfonium trimethyldifluorosilicate and heat at 120°C under nitrogen atmosphere.
After stirring for 20 hours to perform a polycondensation reaction, the reaction mixture was washed with 100 ml of methanol, and the solid content was dried under reduced pressure to obtain 9.9 g of a phosphazene polymer.

The number average molecular weight of the obtained phosphazene polymer was 94,000, and the weight average molecular weight was 113,000.

[Example 3] 21.8 g of N-phenyldimethylsilyl-tris(2,2,2-trifluoroethoxy)phosphinimine was placed in a flask similar to that used in Example 1, and tris was added to the flask. Add 52 mg of (diethylamino)sulfonium hydrogen difluoride, and add 12 mg of (diethylamino)sulfonium hydrogen difluoride to the
After stirring at 0° C. for 20 hours to perform a polycondensation reaction, the reaction mixture was washed with 100 ml of methanol, and the solid content was dried under reduced pressure to obtain 10.7 g of a phosphazene polymer.

The number average molecular weight of the obtained phosphazene polymer was 110,000, and the weight average molecular weight was 132,000.

[Example 4] In a flask similar to that used in Example 1, N-trimethylsilyl-bis(1-trifluoromethyl-2,2,2
-Trifluoroethyloxy)2,2,2-trifluoroethoxyethoxyphosphinimine (28.3 g) was placed therein, and 79 mg of tris(diethylamino)sulfonium trimethyldifluorosilicate was added thereto, followed by stirring at 120°C for 25 hours under a nitrogen atmosphere. After carrying out the polycondensation reaction, the reaction mixture was washed with 100 ml of methanol,
The solid content was dried under reduced pressure to obtain phosphazene polymer 11.7
I got g.

The number average molecular weight of the obtained phosphazene polymer was 101,000, and the weight average molecular weight was 127,000.

[Example 5] 23.5 g of N-phenyldimethylsilyl-tris(2,2,2-trifluoroethoxy)phosphinimine was placed in a flask similar to that used in Example 1, and tris was added to the flask. Add 66 mg of (diethylamino)sulfonium trimethyldifluorosilicate and add 1
After stirring at 20° C. for 20 hours to perform a polycondensation reaction, the reaction mixture was washed with 100 ml of methanol, and the solid content was dried under reduced pressure to obtain 10.0 g of a phosphazene polymer.

The number average molecular weight of the obtained phosphazene polymer was 92,000, and the weight average molecular weight was 107,000.

[0033]

Effects of the Invention As explained above, according to the method for producing a phosphazene polymer of the present invention, the polymerization temperature is 5 to 180°C.
, a phosphazene polymer containing no chlorine atoms can be produced easily and in high yield under relatively mild reaction conditions with a reaction time of 3 hours or more, and therefore unreacted monomers, which are essential in conventional production methods, are The polymer separation step and substitution can omit post-treatment steps such as reaction steps, and the phosphazene polymer can be industrially produced very advantageously.

Claims (1)

[Claims] Claim 1: Organophosphine-imine represented by the following general formula (1) is used as a polycondensation catalyst by the following general formula (
A method for producing a phosphazene polymer, comprising polycondensation using an ionic compound represented by 2). [Chemical formula 1]