JPH0379376B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyphenylene sulfide, and its object is to provide a new and useful method for producing high molecular weight polyphenylene sulfide at low cost. There is something to do.

As a method for producing such polyphenylene sulfide (hereinafter abbreviated as PPS),
45-3368 has already proposed reacting an alkali metal sulfide with a polyhaloaromatic compound in an organic amide solvent such as N-methylpyrrolidone, but PPS produced by such a method is Due to its low molecular weight and therefore low melt viscosity, it has the disadvantage that it cannot be extruded into fibers, films, or extruded sheets.

On the other hand, as a method for obtaining high molecular weight PPS, Japanese Patent Publication No. 52-12240 discloses that an alkali metal carboxylate is added, and U.S. Patent No. 4,038,260 discloses that an alkali metal sulfonic acid Although it is described that the process is carried out by adding a salt, according to these inventions, the amount of the alkali metal carboxylate or sulfonate added must be close to equimolar to the alkali metal sulfide; In order to obtain a polymer with a higher molecular weight, it is necessary to use a large amount of particularly expensive lithium acetate and sodium benzoate among the alkali metal salts of the organic acid, and in the end, the resulting polymer Each had the disadvantage of being expensive.

However, as a result of intensive studies by the present inventors in order to eliminate the drawbacks of the various conventional techniques as described above, the present inventors found that a specific amount of an alkali metal salt of the organic acid, particularly for an organic acid dissolved in an organic amide solvent, was used. By using the product obtained by reacting the alkali metal hydroxide, alkali metal carbonate and/or alkali metal bicarbonate, it is possible to
Furthermore, the inventors discovered that high molecular weight PPS could be obtained and completed the present invention.

In other words, in the case of conventional methods, both
Although methods have been adopted that use alkali metal salts of organic acids, such as lithium acetate and sodium benzoate, which are synthesized in a reactor separate from the reaction reactor for producing PPS and purified, the present inventors discovered that According to the method, an alkali metal salt of the organic acid is synthesized in an organic amide solvent used as a reaction solvent during PPS preparation, and then the metal salt is directly synthesized without any purification. PPS can be obtained by charging a polyhaloaromatic compound and an alkali metal sulfide in the same pot used for the synthesis of PPS.This method can be called an extremely innovative method, and requires the use of separately purified and expensive PPS. Compared to conventional methods using alkali metal salts of organic acids, it is possible to obtain dispersed particles of the metal salts that are more finely powdered and have a larger surface area. The prevention effect is also great, and the result is that not only a higher molecular weight polymer can be obtained, but the production cost can be significantly reduced compared to the conventional method using a separately purified alkali metal salt of an organic acid. The present invention has been completed by discovering that there are merits, but the present invention is based on the general formula RY [ ] [wherein R is a monovalent aliphatic group] dissolved in an organic amide solvent. aromatic or alicyclic hydrocarbon group, Y is -COOH or -
Let it represent the group SO ₃ H. ] An organic acid obtained by adding 0.9 to 1.5 equivalents of one or more compounds selected from the group consisting of alkali metal hydroxide, alkali metal carbonate, and alkali metal bicarbonate to the organic acid represented by The present invention provides a method for producing polyphenylene sulfide, which comprises reacting an alkali metal oxide and a polyhaloaromatic compound in the organic amide solvent containing an alkali metal salt.

Here, the above-mentioned polyhaloaromatic compound refers to a halogenated aromatic compound having two or more halogen atoms directly bonded to an aromatic nucleus, and typical examples include p-dichlorobenzene, m -dichlorobenzene, o-dichlorobenzene, trichlorobenzene, tetrachlorobenzene, dichloronaphthalene, trichloronaphthalene, diprombenzene, triprombenzene, dipromnaphthalene, tripromnaphthalene, diiodobenzene, triiodobenzene, dichlorobenzene chlordiphenyl sulfone, dipromdiphenyl sulfone, dichlorobenzophenone, diprombenzophenone, diclodiphenyl ether, dibromidiphenyl ether, dichlordiphenyl sulfide or diphenyl sulfide, etc. These can also be used as a mixture of two or more types.

On the other hand, typical examples of the above-mentioned alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide, and two or more of these may be mixed together.
It may be used as a hydrate, an aqueous mixture, or an anhydride, and it goes without saying that the sulfide derived from alkali metal bisulfide and alkali metal hydroxide may be used. It is.

Further, typical organic amide solvents include N-methylpyrrolidone, N-ethylpyrrolidone, N,N-dimethylformamide, N,N-
-Dimethylacetamide, N-methylcaprolactam, tetramethylurea or 1,3-dimethyl-2-imidazolidine, etc., but two or more of these may be used in combination, and among these, N-methyl It is pyrrolidone.

Furthermore, typical organic acids mentioned above include acetic acid, propionic acid, 2-methylpropionic acid, butyric acid, valeric acid, hexanoic acid, cyclohexanecarboxylic acid, cyclohexylacetic acid, benzoic acid, toluic acid, phenylacetic acid, and naphthalenecarboxylic acid. Acids: Naphthenic acids; Methanesulfonic acid, ethanesulfonic acid, propylsulfonic acid, butylsulfonic acid, hexylsulfonic acid, cyclohexylsulfonic acid, phenylsulfonic acid, naphthalenesulfonic acid, dodecylbenzenesulfonic acid or toluenesulfonic acid, etc. Two or more of these can be used in combination.

On the other hand, typical examples of the above-mentioned alkali metal hydroxides include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide; Lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate or cesium carbonate, as well as lithium bicarbonate, sodium bicarbonate, potassium bicarbonate,
Examples include rubidium hydrogen carbonate and cesium hydrogen carbonate, which can be used in either an aqueous solution or powder form.

The amount of the alkali metal sulfide used is suitably in the range of 0.8 to 1.2, preferably in the range of 0.9 to 1.1, in molar ratio to the dihalogenated aromatic compound among the polyhaloaromatic compounds,
In particular, when a polyhaloaromatic compound having more than two halogen atoms per molecule is used for the purpose of obtaining a branched polyphenylene sulfide, the molar ratio converted to the dihalogenated aromatic compound is A range of 0.0002 to 0.015, preferably 0.001 to 0.01 is suitable.

In addition, the amount of the organic amide solvent used is the molar ratio to the alkali metal sulfide, and the amount is 2.5 to 2.5.
A range of 20, preferably 3 to 10, is suitable.

Further, the amount of the organic acid used is suitably within a range of 0.05 to 1.5 in terms of molar ratio to the alkali metal sulfide.

Furthermore, the appropriate amount of the alkali metal hydroxide and/or alkali metal (bi)carbonate used is a total equivalent ratio of 0.9 to 1.5, preferably 0.95 to 1.1, relative to the organic acid. .

When carrying out the method of the present invention, the organic acid is preferably heated under an inert gas atmosphere at room temperature to
The alkali metal hydroxide and/or alkali metal (heavy) carbonate are dissolved in the organic amide solvent in a temperature range of 180°C, and then the alkali metal hydroxide and/or alkali metal (heavy)carbonate in the form of a powder or aqueous solution is gradually added thereto while stirring. It is better to use this method. After that, the above-mentioned alkali metal sulfide was further added to give 150~
At a temperature of 230°C, preferably 170-210°C, most of the water in the system is expelled from the system under normal pressure. Next, the polyhaloaromatic compound is added to the reaction system under pressure at 210 to 290°C, preferably
The polymerization reaction is carried out at 230 to 280 DEG C. for 1 to 10 hours, and after the reaction is completed, the reaction mixture is separated, washed and dried in a conventional manner to obtain the desired polymer.

Thus, the polyphenylene sulfide obtained by the method of the present invention can be used as engineering plastics or formed into a film or sheet for various purposes.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples. In the following, unless otherwise specified, all percentages are by weight, and the intrinsic viscosity of the polymer to be measured is 0.4g/100
This was measured in α-chlornaphthalene at 206° C. using a solution with a concentration of 1 ml.

Example 1 350 g of N-methylpyrrolidone and 97.6 g (0.8 mol) of benzoic acid were placed in the autoclave of 1, and heated to 120°C under a nitrogen atmosphere to uniformly dissolve them. ℃ 80 g (0.8 mol) of NaOH aqueous solution was dropped over 30 minutes,
The mixture was stirred and reacted at 120 to 140°C for an additional 30 minutes to obtain a dispersion of N-methylpyrrolidone containing sodium benzoate.

After that, 105g of sodium sulfide/2.7 hydrate
After charging (0.8 mol), the temperature was raised to 200°C over 2 hours, and 80ml of water was distilled out. after that,
The reaction system was cooled to 170°C, 118g (0.8 mol) of p-dichlorobenzene and 80g of N-methylpyrrolidone were added, and the temperature was raised to 220°C for 30 minutes to give 2.
The reaction was carried out for an hour, and the polymerization reaction was further carried out at 250°C for 3 hours. After cooling, the reaction mixture was then washed three times with hot water, twice with acetone, and dried to give 79.5
g of granular polymer were obtained (yield=92%). The intrinsic viscosity of the obtained polymer was 0.32.

Comparative Example 1 The use of benzoic acid and 40% NaOH aqueous solution was completely omitted, and the same amounts of N-methylpyrrolidone and sodium sulfide 2.7 hydrate were immediately heated to 200°C over a period of 1.5 hours. The same operation as in Example 1 was repeated, except that 21 ml of water was distilled out, and 71 g of powdered polymer was obtained (yield = 82%). Note that the intrinsic viscosity of this polymer was 0.13.

Comparative Example 2 In the autoclave of 1, 350 g of N-methylpyrrolidone and 105 g of sodium sulfide 2.7 hydrate were added.
(0.8 mol) and 115 g (0.8 mol) of sodium benzoate (Kishida Chemical Co., Ltd. product, first class reagent) were charged and the temperature was gradually raised to 200°C over 1.5 hours to produce 20ml.
of water was distilled out.

Thereafter, the procedure was carried out in the same manner as in Comparative Example 1.
74.5 g of granular polymer was obtained (yield = 86%).
Note that the intrinsic viscosity of this polymer was 0.26.

Example 2 The same molar amount (192 g) of acetic acid was used instead of benzoic acid, and the same molar amount (192 g) was used instead of 40% NaOH aqueous solution.
The procedure was carried out in the same manner as in Example 1 except that 10% LiOH in g) was used, and the amount of distilled water in the dehydration step was
With 205 ml, the polymer yield and yield are 78 g, respectively.
It was 90%. Also, the intrinsic viscosity of this polymer is
It was 0.31.

Example 3 The same procedure as Example 1 was carried out except that the same molar amount (59 g) of propionic acid was used instead of benzoic acid. 76 g (yield = 88%) of polymer was obtained. The intrinsic viscosity of was 0.28.

Example 4 The same molar amount (138 g) of p-
Example 1 except that toluenesulfonic acid was used.
By repeating the same operation as above, 78 g (yield = 90%) of a polymer with an intrinsic viscosity of 0.26 was obtained.

Claims (1)

[Claims] 1 A compound of the general formula RY dissolved in an organic amide solvent [wherein R represents a monovalent aliphatic, aromatic or alicyclic hydrocarbon group, and Y represents - COOH or −
Let it represent the group SO ₃ H. ] An organic acid obtained by adding 0.9 to 1.5 equivalents of one or more compounds selected from the group consisting of alkali metal hydroxide, alkali metal carbonate, and alkali metal bicarbonate to the organic acid represented by A method for producing polyphenylene sulfide, which comprises reacting an alkali metal sulfide with a polyhaloaromatic compound in the organic amide solvent containing an alkali metal salt.