JPS59217727A - Production of polyphenylene sulfide - Google Patents

Abstract

PURPOSE:To obtain a polyphenylene sulfide having high molecular weight, stably, by reacting a mixture of anhydrous sodium sulfide and sodium sulfide with a polyhalogenated aromatic compound in an organic plar solvent controlling the amount of water in the system. CONSTITUTION:The objective polyphenylene sulfide can be prepared by reacting (A) a mixture of (i) 0.1-15wt% of anhydrous sodium sulfide and (ii) 99.9-85wt% of anhydrous sodium sulfide with (B) a polyhalogenated aromatic compound such as p-dichlorobenzene, in (C) an organic polar solvent such as N-methylpyrrolidone, controlling the water-content in the polymerization system to <=0.3mol per 1mol of sodium sulfide.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface preparation method for polyphenylene sulfide, and more particularly to a method for producing high molecular weight polyphenylene sulfide.

Polyphenylene sulfide is produced by a method as disclosed in Japanese Patent Publication No. 3368/1983. That is, N-
It is produced by a method in which P-dichlorobenzene and sodium sulfide are reacted in an acidic medium such as methylpyrrolidone. The polyphenylene sulfide obtained by this method has an extremely low degree of polymerization and is not suitable for use as it is.Industrially, this low degree of polymerization is heated in air to cause oxidative crosslinking.

Through three-dimensional crosslinking, it has a high molecular weight and is used for practical purposes such as injection molding. However, even this high molecular weight product has poor extrudability, and is used for applications such as fibers, films, pipes, and sheets. I couldn't.

Furthermore, a method for obtaining high molecular weight polyphenylene sulfide through a polymerization reaction is already known. That is, 1% Kaisho 53-
156.100. Japanese Patent Publication No. 51-144, 495. As shown in JP-A-51-144.497 and JP-A-55-28,217.

Prior to the polymerization step, the polymer is polymerized after removing water caused by polymerization aids such as alkali sulfide or its water salts from the system. For example, JP-A-53-13
According to No. 6,100, prior to one polymerization step, a mixture of IJ and N-methylpyrrolidone is heated and dehydrated to remove 1.0 ~2.4 mol 7).

At this time, various problems occur. First, N-methylpyrrolidone, an expensive common medium, evaporates with water.
The recovery rate decreases, causing an increase in costs. Second, there is a problem in that the dehydration process of valorized sodium, which is produced as a by-product from valorized sodium, may corrode if the dehydration process of valorized sodium is carried out in the same pot as the polymerization pot, which must be made of iron or stainless steel. , reducing the durability or safety of the pot.

Thirdly, because valorized sodium itself is not thermally stable enough, it decomposes or oxidizes during the dehydration process, causing water to deteriorate.
/・The equivalence balance with the aromatic compound is disrupted, and therefore the polymer 1iPPS cannot be stably produced.

As a result of extensive research, the present inventors have found that high molecular weight polyphenylene sulfide can be stably obtained by using substantially anhydrous sodium chloride and sodium bitite without delicate control of moisture content. They discovered this and arrived at the present invention.

That is, the present invention is substantially anhydrous and contains zero sodium sulfite.
．． 1-15 weight and value) IJum 999-8
Polyphenylene sulfide is produced by reacting a mixture consisting of 5% by weight of a polyhaloaromatic compound in an organic polar medium under conditions in which water present in the polymerization system is 0.6 mol or less per 1 mol of sodium sulfide. Provides a method for manufacturing.

The polyhaloaromatic compounds used in the method of the invention are norogenated aromatic compounds having two or more atoms directly bonded to an aromatic nucleus, specifically p-dichlorobenzene.

m-dichlorobenzene, 0-dichlorobenzene, trichlorobenzene, tetrachlorobenzene, dichloronaphthalene, trichloronaphthalene, dibromobenzene, tribromobenzene, dibromnaphthalene, shortbenzene, triiodobenzene, dichlorodiphenylsulfone, Examples thereof include dibromidiphenyl sulfone, dichlorobenzophenone, dibrombenzophenone, dichlordiphenyl ether, dibromidiphenyl ether, dichlordiphenyl sulfite, dibromidiphenyl sulfide, dichlorbiphenyl, dibrombiphenyl, and mixtures thereof. Usually dihaloaromatic compounds are used, preferably p-dichlorobenzene. Sho 1
In order to increase the viscosity of the polymer due to the branched structure, a polyhaloaromatic compound having three or more halogen substituents in one molecule may be used in combination with a small amount of a dihaloaromatic compound.

The sulfur source used in the present invention is a mixture of sodium sulfide and Wt oxide. '5 mole or less. Such mixtures with more than 0.3 mol of water cannot be used in the present invention. It should be noted that such a mixture preferably has 0.2 mol or less of water, more preferably 0.1 mol or less of water.

In addition, the above mixture consists of 0.1 to 15 tbw of sodium sulfite and 999 to 85 tb of sodium sulfite, and 0.5 to 7 tb of sodium sulfite and 995 to 93 tb of sodium sulfite. Preferably, it consists of heavy skin. Since this mixture contains sodium chloride 5MP11, an unexpected effect is exhibited in a polymerization system containing almost no water. In other words, in the polymerization system of the present invention, sulfite (IJ)
The base has a buffering effect and is present in the vicinity of the active end of one polymerization, thereby activating the polymerization reaction and synergistically exhibiting functions such as preventing decomposition of the polyphenylene sulfide poly ff - produced.

In the present invention, there are no particular limitations on the method of mixing anhydrous sodium and sodium sulfite as long as the composition ratio of the resulting mixture is within the range of the present invention. For example, it is sufficient to simply collect anhydrous sodium sulfide and sodium sulfate in a predetermined amount and mix the two together. Alternatively, fecal sodium may be partially oxidized with oxygen in the air to obtain a mixture as a result.

The organic polar solvent used in the process of the invention should practically be liquid at the reaction temperature and pressure used. Preferred polar and polar tormentants include formamide, acetamide, N-methylformamide%N, N-
Dimethylformamide, N,N-dimethylacetamide, 2-pyrrolidone, N-methyl-2-hyrrolidone, N-
Amides, ureas and lactams such as ethyl-2-pyrrolidone, ε-caprolactam, N-methyl-ε-caprolactam, hexamethylphosphoramide, tetramethylurinol, 1,3-dimethyl-2-imidazolidinone; sulfolane; Examples include sulfones such as dimethylsulfolane; nitriles such as benzonitrile; ketones such as methylphenylketone; and mixtures thereof. Among these solvents are amides.

It is particularly preferred to use aprotic organic polar solvents such as lactams or sulfones.

In the present invention or in the polymerization system, it is necessary that the amount of water present is at most 0.6 mol, preferably at most 0.2 mol, per mol of sodium sulfide. The moisture is the sum total of all moisture present in a polymerization system, and includes, for example, hydration water of sodium sulfide, hydration water of a polymerization aid, free water, and the like. If the water content exceeds 0.6 mol/1 mol of alkali sulfide, it is not preferable because not only is it impossible to convert polyphenylene sulfide into a polymer, but also corrosion of stainless steel, iron, etc. walls occurs.

In the production method of the present invention, it is preferable to use various polymerization aids together. The polymerization aid is selected depending on its ability to accelerate the polymerization reaction, its ability to prevent decomposition of the polymer during the post-treatment process, its ability to remove by-product common salt present in the polymer, and the like.

One polymerization aid that can be used in the present invention is lithium halides, including, for example, lithium chloride, lithium bromide, lithium iodide, and mixtures thereof.

One of the polymerization aids that can be used in the present invention is organic carboxylic acid 9-acid. The organic group other than the carboxyl group of the organic carboxylic acid metal salt usually has 1 to 50 carbon atoms,
It may also contain nitrogen, fR elements, halogen, silica, and sulfur, and is preferably an alkyl group, a cycloalkyl group, an aryl group, or an alkylaryl group. Also,
The metal atoms of organic carboxylic acid metal salts are lithium, sodium, and potassium.

Rubidium, cesium, magnesium, calcium, zinc.

It is selected from strontium, cadmium, and barium, with alkali metals being particularly preferred. Incidentally, the organic carboxylic acid metal salt is preferably anhydrous, but if necessary, it may be used in the polymerization system in the presence of an organic polar solvent such as N-methylpyrrolidone without adding sodium monochloride prior to the polymerization step. It can also be used after dehydration until the moisture content falls within the range of the present invention.

The carboxylic acid metal salts that can be used in the method of the present invention include lithium acetate, sodium acetate, potassium acetate,
Boo 10- Lithium ropionate, sodium globionate, lithium 2-methylpropionate, rubidium butyrate, lithium valerate, sodium valerate, cesium hexanoate, lithium heptanoate, lithium 2-methyloctoate, potassium dodecane, 4- rubidium ethyl ettradecanoate,
Sodium octadecanoate, sodium heneicosanoate, lithium cyclohexanecarboxylate, cesium cyclototicanecarboxylate, sodium 3-methylcyclopentanecarboxylate, potassium cyclohexyl acetate, potassium benzoate, lithium benzoate, sodium benzoate, m-)ruylic acid Potassium, lithium phenylacetate, 4
-Sodium phenylcyclohexanecarboxylate, p-
Potassium tolyl acetate, lithium 4-ethylcyclohexyl acetate, dilithium succinate, disodium succinate,
Dipotassium succinate, dilithium adipate, disodium adipate, dipotassium adipate, dilithium sebacate, disodium sebacate, dipotassium sepacate, dilithium decanedicarboxylate, disodium decanedicarboxylate, decanedicarboxylic acid Dipotassium, dilithium phthalate, disodium phthalate, dipotassium phthalate, dilithium inphthalate, disodium isophthalate, dipotassium isophthalate, dilithium terephthalate, disodium terephthalate, dipotassium terephthalate, trimellit trilithium acid, trisodium trimellitate, tripotassium trimellitate, tetralithium pyromellitate, tetrasodium pyromellitate, tetrapotassium pyromellitate, dilithium toluene dicarboxylate.

Disodium toluene dicarboxylate, dipotassium toluene dicarboxylate, dilithium naphthalene dicarboxylate,
Mention may be made of disodium naphthalene dicarboxylate, dipotassium naphthalene dicarboxylate, magnesium acetate, calcium acetate, calcium benzoate, and other similar salts and mixtures thereof.

One of the polymerization aids that can be used in the present invention is Compound A shown below.

Compound A: ao+cn, cn, o+n (wherein R is an alkyl group and/or an alkyl group having 8 to 60 carbon atoms, and is oxygen, sulfur, fluorine, or chlorine.

It may also contain atoms such as bromine. n is 0 or more and 500
Represents the following integer. ) R in the above formula has 8 to 60 carbon atoms. Preferred are 8-3o alkyl groups and/or aryl groups, including oxygen,
It may contain atoms such as sulfur, fluorine, chlorine, and bromine. Examples of R include octyl group, lauryl group,
Decyl group.

Straight chain alkyl groups such as tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, octadecyl group, tocosyl group; 1-methylhebutyl group, 2-ethylhexyl group,
Branched alkyl groups such as 1-methyl-4-ethylhexyl i, i-mer-4-ethyloctyl groups; ethylphenyl groups.

butylphenyl group, hexylphenyl group, dotecylphenyl group, nonylphenyl group, isooctylphenyl group,
Examples include alkylaryl groups such as tetrapropylene phenyl group and vinyl phenyl group: alcohol residues of sorbicun alkyl esters. These compounds can be used alone or in mixtures. In addition, the HLB of such a compound is preferably 0 to 195. Here, HLB is a numerical value indicating the balance between hydrophilicity and hydrophobicity, and is defined by a linear equation.

Molecular Weight of Compound A One of the polymerization aids that can be used in the present invention is Compound 14-B shown below.

Compound B: (wherein, R1 is an alkylene group having 2 to 4 carbon atoms, R1
is hydrogen or an alkyl group and/or aryl group having 1 to 30 carbon atoms, and a and m indicate the average degree of polymerization, and are 1 to 50 and 0 to 90, respectively. )7B'' as an example of 81 in the above formula or -CBICHI-, -Cl,
CH-.

and mixtures thereof. Also, as an example of R2.

Limescale, methyl group, ethyl group, butyl group, octyl group, nonyl group, dodecyl group, cetyl group, 1-methylheptyl,
Alkyl groups such as 2-ethylhexyl and 1-methyl-4-ethyloctylnato: alkylaryl groups such as ethylphenyl and dodecylphenyl; aryl groups such as phenyl and naphthyl groups; and the like. Specifically, the compound represented by the above formula B includes polyoxyethylene phenyl formaldehyde condensate, polyoxyethylene methylphenyl formaldehyde condensate, polyoxyethylene nonylphenyl formaldehyde condensate, polyoxyethylene cetyl phenyl formaldehyde condensate, Polyoxypropylene methylphenyl formaldehyde condensate, polyoxypropylene nonylphenyl formaldehyde condensate, polyoxybutylene phenyl formaldehyde condensate, polyoxybutylene nonylphenyl formaldehyde condensate, phenol formaldehyde condensate, nonylphenol formaldehyde condensate, etc., and mixtures thereof. Can be mentioned.

The amount of sodium sulfide used in the method of the present invention is
0 in the molar ratio to aromatic compounds ranging from 0.8 to 1.2.

Preferably it is in the range of 0.9 to 11. In addition, the amount of organic polar solvent used is 2 in molar ratio to the alkali metal sulfide.
．． In the range 5 to 20, preferably fL, < in the range 3 to 10.

The addition rate of the polymerization auxiliary agent that can be used in the method of the present invention varies depending on the type of compound used, but is usually 10.01 to 200 weight tS, preferably 0.5 to 100 weight tS, per monomer of the beaten aromatic compound. The weight range is t%.

In the present invention, it is preferred to carry out the polymerization in the presence of an alkali hydroxide. Examples of alkali hydroxides that can be used are lithium hydroxide, sodium hydroxide, and potassium hydroxide.

Mention may be made of rubidium hydroxide, cesium hydroxide and mixtures thereof. The amount of alkali hydroxide used is generally in the range of o, ooa to 8 mol, preferably 0.01517 to 0.6 mol, per 1 mol of sodium sulfide.

Furthermore, an alkali carbonate salt can be used in the present invention or as a substitute compound for the above-mentioned alkali hydroxide. The amount of alkali carbonate used is generally 0.004 to 0.9 mol, preferably 0.010 to 0.0, per 1 mol of sodium sulfide.
It is within the range of 4 moles.

(When carrying out the method of the present invention or prior to one polymerization step, water in the system is sulfurized in advance) 0 per mole of IJum
．． It is necessary to keep the amount within 6 moles. If the polymerization solvent or polymerization aid contains water or is a hydrated salt,
Before introducing IJum into the system, it is dehydrated within a predetermined time.

At this time, sulfidation occurs) When dehydration is performed in the presence of IJium,
In addition to making dehydration difficult, corrosion of the reaction vessel and decomposition of sodium sulfide occur, and even if treated materials are used for polymerization, polymer spears cannot be obtained.

18- The reaction temperature at which the polymerization is carried out in the present invention is generally from 170C to
330C=preferably 190-300C. The pressure should be in a range that maintains the polymerization bath medium and the polymerization monomer, the haloaromatic compound, substantially in the liquid phase, generally from normal pressure to 200 DA♂1, preferably from normal pressure to 20
Selected from the range A-. The reaction time varies depending on temperature and pressure, but generally ranges from 10 minutes to about 72 hours, preferably from 1 hour to 48 hours.

The method of the present invention is applied to polyhaloaromatic compounds, sulfurized) IJ
This can be carried out by mixing a mixture of sodium sulfite and sodium sulfite with a polymerization solvent and, if necessary, a polymerization aid, and heating the mixture preferably under an inert atmosphere. There is no particular restriction on the mixing order of each component, and the mixing may be carried out by adding the above components in small amounts or all at once during one polymerization step.

The polyphenylene sulfide produced by the process of the invention can be isolated and purified in conventional manner, for example by filtering the polymer and then washing with water, or by diluting the reaction mixture with water and then filtering and washing with water. be done. that time,
The polymerization bath medium can be recovered by distillation from the mixture prior to washing with water. It is also preferable to blow carbon dioxide during or at the end of the polymerization reaction to prevent decomposition of the polyphenylene sulfide. , which not only contributes to increasing the molecular weight of the produced polymer but also is effective in preventing the decomposition of N-methylpyrrolidone.

Polyphenylene sulfide produced by the method of the present invention has a significantly higher molecular weight than polyphenylene sulfide produced by conventional production methods, and has a liquid viscosity of approximately 0.19 or more without the need for crosslinking treatment such as heating in air. , 50
The melt index at 0C and a load of 5Kg is approximately 0.
The desired properties range from 1.9/10 minutes to about 10001710 minutes, preferably from 0.5.9/1Q minutes to 500.9/10 minutes. In other words, in the method for producing polyphenylene sulfide of the present invention, the crosslinking step, which was conventionally essential, is no longer necessary. In addition, the noise produced by the use of polymerization aids, which was conventionally necessary in the production of high molecular weight polyphenylene sulfide, can be reduced.

The polyphenylene sulfide produced according to the present invention can be used in injection molding or compression molding applications without particular crosslinking. Also, sheets, films, tubes,
It can also be used for extrusion molding, blow molding, and welding of tubes and the like. If necessary, it is also suitable to blend the polyphenylene sulfide of the present invention with fillers, pigments, a-fuel agents, stabilizers, and other polymers. For example 1
Glass fibers can also be blended to improve mechanical strength and heat resistance.

Hereinafter, the method of the present invention will be explained according to examples. Polymer 21 - The intrinsic viscosity value [η] of enylene sulfide is 0.4.9/
The polymer concentration was measured at 206 C in α-chlornaphthalene at a polymer concentration of 100 ml of ordinary liquid, and the value was calculated according to Equation 5. In addition, parts and parts in Example 1 are based on weight.Reference Example Water content was 0.1% (0,0086 mol/Na, 8
1 mole) was obtained. This substantially anhydrous sodium sulfide and anhydrous sodium sulfite were mixed to obtain mixtures having various compositions as shown in Table 1.

22- Table 1 (Reference example) -23- [Example 1] 1j N-methylpyrrolidone 350.9 in autoclave
゜Sodium sulfide mixture F6a, 6i<m obtained in reference example
62.4L (0.8 mol in terms of pure sodium hydroxide) and 0.419 L (0.01 mol) of sodium hydroxide were added, and then the water content was adjusted as shown in Table 2, and 117. <S10.80 mol) and N
- Add acid solution consisting of methylpyrrolidone 8011,
The reaction was carried out at 0C for 1 hour and then at 260C for 3 hours. The internal pressure at the end of polymerization was 4.0-/cIIL2.

As shown in Table 2, the yield and liquid viscosity of the obtained polymer are greatly affected by the water content in the polymerization system, and when the water content in one polymerization system is less than 0.6 mol 1 mol Na18 1 mol. A polymer capping polymer can be obtained.

24- [Comparative Example 1] 11 In an autoclave, 350 g of N-methylpyrrolidone and Sankyo Chemical Co., Ltd. 32 trisulfide) IJium (9 water 4) 192
．． 2.9 (0.80 mol) and sodium hydroxide 0.
4.9 (0.01 mol) was charged, and under a nitrogen atmosphere, 1
．． It took about 2 hours to reach 200C from SOC to "C1"! The temperature was raised while stirring, a mixture with N-methylpyrrolidone containing 21.6 mA of water was distilled out, and the mixture was cooled to 150C. After, p-dichlorobenzene 111610.80
mol] 1N-methylpyrrolidone 8011'.

The water content in the system immediately before polymerization was 2.7 mol per mol of sodium chloride. 1 hour at 260C, then 260C
The reaction was carried out for C5 hours. Internal pressure at the completion of polymerization is 6.5 Kf
／It was a male.

Table 3 shows the yield, intrinsic viscosity, and degree of corrosion of the inner wall of the autoclave of the polyphenylene sulfide prepared.

Also.

As shown in Table 6, the same procedure was carried out for various water-containing neck systems with different dehydration temperatures and dehydration times.

In addition, changing the dehydration conditions or changing the raw material value)
Polyphenylene sulfide was obtained by the same σ-) method except that IJium was replaced with pentahydrate. The results are also listed in Table 2.

[Example 2] Anhydrous sulfide obtained in the customary example) IJum A, B, C,
D.

Polyphenylene sulfitone was obtained in the same manner as in Example 1 except that E, G, H, and I were used as raw materials. The results are shown in Table 4.

From this example, high molecular weight polyphenylene sulfide can be obtained only when using a specific anhydrous sodium sulfide containing 0.1 to 15 weight of sodium nitrous acid [Example 3]. Polyphenylene sulfide was synthesized using the obtained sodium sulfide mixture F in the same manner as /I61 of Example 1 in the presence of the polymerization aid shown in Table 5. The results are also listed in the same table.

As can be seen from this example and Comparative Example 2 described below, it is clear that when anhydrous sodium sulfide within the scope of the present invention is used, high molecular weight polyphenylene sulfide can be obtained in high yield [Comparative Example 2] Table /46 of Comparative Example 1 except that the polymerization aid described in 6 was used.
Polyphenylene sulfide was synthesized in the same manner as in 1.

The results are also listed in the same table.

Claims (1)

[Claims] Virtually anhydrous VF acid? A mixture of IJum D, 1 to 15% by weight and 99.9 to 5% sodium chloride and a polyhaloaromatic compound are mixed in an organic polar solvent, and the water present in the polymerization system is reduced to sodium sulfide. 1
A method for creating polyphenylene sulfide, characterized in that the reaction is carried out under moxibustion conditions at a concentration of 0.6 mole per mole or less.