KR930004621B1 - Process for preparation of polyarylene sulfide polymer - Google Patents

Abstract

The arylene sulfide polymer is prepared by (1) reacting an alkali metal sulfide and polyhalogenated aromatic compound in an organic amide solvent, (2) dehydrating the reactant by distillation, (3) filtering the dehydrated and washing with methanol and hot water, and (4) drying. The absorbent packed into the aborbing tower is phosphorus pentoxide, zeolite, magnesium perchlorate, gamma-alumina, manganese dioxide, silica gel, sulfuric acid or their mixture. The polymer is useful for electronic and electric components and molded articles such as films, sheets and fibers.

Description

Process for preparing arylene sulfide polymer

The present invention relates to a method for preparing an arylene sulfide polymer, wherein by removing the crystal water liberated from alkali metal sulfides as the polymerization reaction proceeds in the preparation of the arylene sulfide, the polymerization rate of the resulting polymer The present invention relates to a method for preparing an arylene sulfide polymer capable of increasing molecular weight.

Arylene sulfide polymers have been used in the fields of electricity, electronics, automobiles, etc. due to the excellent heat resistance of the polymers since the invention of the USP3354129 by Philips Petroleum Company in 1967, and in 1975, high molecular weight polymer synthesis was invented. (USP3919177) After being used, it is a polymer material that is also used for heat-resistant films and fibers. The polymerization method currently widely used is a method for preparing arylene sulfide polymers by condensation polymerization of paradichlorobenzene and alkali metal sulfides in an organic amide solvent.

In addition to these methods, the use of other sulfur compounds such as alkali metal disulfides (USP3869433) instead of alkali metal sulfides has also been published, and the use of other aromatic chlorides such as dichloronaphthalene in place of paradichlorobenzene has also been disclosed.

Recently, research has been conducted to develop a synthetic method of increasing the molecular weight of a polymer rather than a change of raw materials.A method of increasing the molecular weight is a method of introducing a crosslinking bond by adding a small amount of trichloroaromatic compound having three polymerization functional groups ( USP3354129) and a method of using a catalytic material such as alkali metal carboxylic acid, alkali metal hydroxide, lithium carbonate (USP3919177) are disclosed.

The present invention relates to a method for increasing the molecular weight of an arylene sulfide polymer, while the conventional method increases the molecular weight of a polymer by adding a catalyst or a reactant in a reaction mixture, while the present invention uses the same reaction raw material. It is characterized by increasing the molecular weight of the polymer by only introducing a dehydration process during the polymerization reaction.

Hereinafter, the present invention will be described in detail. Currently widely used polymerization methods use paradichlorobenzene as a dihalo substituted aromatic compound, sodium sulfide as an alkali metal compound, and N-methyl-2-pyridone as a solvent. Sodium sulfate usually contains 6-9 molecules of crystallized water per molecule. After removing the crystallized water, the polymerization reaction starts. As a method of removing crystalline water, a method of dissolving sodium sulfide in an organic amide solvent and then distilling (USP3354129) is used.

However, the crystallized water of sodium sulfide is not completely removed even after distillation, and depending on the distillation conditions, 0.5-2.5 molecules of crystallized water remain as a complex compound with sodium sulfide and an organic amide solvent.

When the complex compound and paradichlorobenzene are put into a reactor and polymerized, as the polymerization proceeds, the water of the complex compound is released and is present in the reactant. This liberated water inhibits the increase in molecular weight of the polymer. Accordingly, the present invention relates to a polymerization method for increasing the molecular weight of a polymer by enhancing the reaction rate as well as enhancing the solubility of the polymer in an organic solvent by effectively removing the liberated water from the polymerization reaction system.

In the present invention, a method of removing water is to install a distillation column in a reactor to continuously distill the reactant to separate water while the reaction is in progress. Absorption column filled with an absorbent such as zeolite is installed in the reactor and the reaction solvent is contacted with the absorbent in gas or liquid state to remove free water from the reaction solvent, or the reaction mixture is directly contacted with the absorbent to remove water. Method is used.

An embodiment of the present invention will be described as follows.

Example 1

A distillation column was installed in a 1ι four-necked flask, and 126 g of sodium sulfide (46.5%), 0.5 g of sodium hydroxide, and 250 g of N-methyl-2-pyrrolidone were heated under nitrogen stream, and distilled until the temperature of the mixture reached 206 ° C. Water was removed.

The amount of water removed is 50 g. The dehydrated mixture prepared by the above method was cooled to 150 ° C, and then 112.5 g of p-dichlorobenzene and 50 g of N-methyl-2-pyrrolidone were added thereto, refluxed at a boiling point, and water liberated during the polymerization process. The polymerization was carried out for 5 hours while distilling off.

The resulting polymer mixture was filtered, washed with methanol and hot water, and dried overnight in a vacuum dryer at 80 ° C. to obtain 45 g of a white arylene sulfide polymer having an intrinsic viscosity of 0.24 dl / g.

Comparative Example 1

On the other hand, a mixture of the same composition as in Example 1 was added, and polymerization was performed for 6 hours in the same manner as in Example 1 except that the water liberated in the polymerization process was not removed by distillation, and thus white arylene having an intrinsic viscosity of 0.10 dl / g was used. A sulfide polymer was obtained.

Example 2

A dehydrated mixture prepared in the same manner as in Example 1, 112.5 g of p-dichlorobenzene and 50 g of N-methyl-2-pyrrolidone were placed in a high pressure reactor equipped with a distillation column while removing water liberated during polymerization (distillation). The amount of water removed by 15.5 g) was polymerized at 700 kpa 260 ° C. for 3 hours 30 minutes. Thereafter, washing and drying were performed in the same manner as in Example 1 to obtain 74 g of a white arylene sulfide polymer having an intrinsic viscosity of 0.25 dl / g.

Comparative Example 2

Meanwhile, a mixture of the same composition as in Example 2 was added, except that water freed during the polymerization process was not removed by distillation, and then polymerized for 4 hours in the same manner as in Example 2, with a white arylene having an intrinsic viscosity of 0.18 dl / g A sulfide polymer was obtained.

Example 3

In a high pressure reactor equipped with a distillation column, 126 g of sodium sulfide (46.5%), 0.5 g of sodium hydroxide, and 76.5 g of lithium acetate, 250 g of N-methyl-2-pyrrolidone were heated under nitrogen stream, and the mixture became 200 ° C. Distilled to remove 78 g of water. 112.5 g of p-dichlorobenzene and 50 g of N-methyl-2-pyrrolidone were added to the dehydrated mixture prepared in this manner, and the water liberated during the polymerization was removed (the amount of water removed by distillation was 15.5 g). After polymerization at 260 ° C. for 3 hours 30 minutes, washing and drying were carried out in the same manner as in Example 1 to obtain 77 g of a white arylene sulfide polymer having an intrinsic viscosity of 0.49 dl / g.

Comparative Example 3

Meanwhile, a mixture of the same composition as in Example 3 was added, except that the water liberated in the polymerization process was not removed by distillation. The polymerization was carried out for 4 hours in the same manner as in Example 3 to give a white arylene sulfide having an intrinsic viscosity of 0.34 dl / g. A polymer was obtained.

Example 4

In a high pressure reactor equipped with a distillation column, 126 g of sodium sulfide (46.5%), 0.5 g of sodium hydroxide, 76.5 g of lithium acetate, and 250 g of N-methyl-2-pyrrolidone were heated under a nitrogen stream, and the mixture was heated at 206 ° C. Distilled to remove 71 g of water. 100 g of p-dichlorobenzene, 11 g of m-dichlorobenzene, 1.0 g of trichlorobenzene, and 50 g of N-methyl-2-pyrrolidone were charged, and the zeolite (molecular 4A) was charged into a distillation column installed in a high pressure reactor to polymerize. 76 g of a white arylene sulfide polymer having an intrinsic viscosity of 0.4 dl / g was polymerized by polymerization in 260 ° C. for 3 hours and 30 minutes while absorbing and removing water liberated in the process. Got it.

[Comparative Example 4]

On the other hand, a mixture of the same composition as in Example 4 was added, except that the water liberated in the polymerization process was not absorbed and removed from the zeolite for 4 hours in the same manner as in Example 4 to give a white arylene having an intrinsic viscosity of 0.3 dl / g. A sulfide polymer was obtained.

Example 5

In a high pressure reactor equipped with a distillation column, 126 g of sodium sulfide (46.5%), 0.5 g of sodium hydroxide, 76.5 g of lithium acetate, and 250 g of N-methyl-2-pyrrolidone were heated under a nitrogen stream. Distilled to remove 71 g of water. 224 g of bis p-chlorophenylsulfone and 50 g of N-methyl-2-pyrrolidone were added thereto, and polymerization was performed at 200 ° C. for 3 hours and 30 minutes while removing water liberated in the polymerization process in the same manner as in Example 4. Thereafter, the resultant was washed and dried in the same manner as in Example 1 to obtain 167 g of a white arylene sulfide polymer having an intrinsic viscosity of 0.45 dl / g.

[Comparative Example 5]

Meanwhile, except that the mixture having the same composition as in Example 5 and not removing water liberated in the polymerization process was polymerized for 4 hours in the same manner as in Example 4 to obtain a white arylene sulfide polymer having an intrinsic viscosity of 0.37 dl / g. .

When the polymerization is carried out by removing the water liberated in the polymerization process from the reaction system as in the present invention from the above examples and comparative examples, the intrinsic viscosity of the product than the comparative example that all the reaction conditions are the same and does not remove the free water in the polymerization reaction Since the increase of about 30%, the degree of polymerization increases accordingly, and it can be seen that the polymerization time is also reduced by about 10%.

Claims (3)

A method of obtaining an arylene sulfide polymer by reacting an alkali metal sulfide with a polyhalo substituted aromatic compound in an organic amide solvent, wherein the water liberated from the alkali metal sulfide is removed from the reaction system as the polymerization reaction proceeds. Method of Making Polymers. The method for producing an arylene sulfide polymer according to claim 1, wherein the method of removing water is distillation. The method for producing arylene sulfide polymer according to claim 1, wherein the method for removing water is using pentoxide, zeolite, magnesium perchlorate, gamma alumina, manganese oxide, silica gel, calcium chloride or sulfuric acid alone or in combination.