JPH0578488A - Production of high-molecular weight polyphenylene sulfide - Google Patents

Abstract

PURPOSE:To obtain the subject moderately branched polyphenylene sulfide by reacting under heating, an alkali metal sulfide with dihalobenzene using a specific branching agent in the presence of an organic amide solvent. CONSTITUTION:In the presence of an organic amide solvent such as N,N- dimethylacetamide, (A) an alkali metal sulfide such as sodium sulfide is reacted under heating with (B) a dihalobenzene such as p-dichlorobenzene using (C), a compound of the formula (R is 3-23C organic group; X is halogen; A is glycidyl ether residue or vinyl group; (m) is 0-2; (n) is 1-6; (m+n)>=3), e.g. 2,4- dibromophenyl glycidyl ether as branching agent, thus obtaining the objective polyphenylene sulfide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyphenylene sulfide, and more particularly to a method for producing high molecular weight polyphenylene sulfide.

Polyphenylene sulfide (hereinafter abbreviated as PPS) has been attracting attention as a member for electric / electronic equipment and a member for automobile equipment by taking advantage of its excellent heat resistance and chemical resistance. In addition, various molded parts such as injection molding, extrusion molding,
Can be formed into films, sheets, fibers, etc.
Widely used in fields where chemical resistance is required.

[0003]

As a method for producing PPS, a method of reacting a dihaloaromatic compound with a sulfur source such as sodium sulfide in an organic amide solvent such as N-methylpyrrolidone is disclosed in Japanese Patent Publication No. 45-3368. ing.

However, since the polymer obtained by this method has a low molecular weight, it cannot be used as it is for applications such as injection molding. The low molecular weight polymer is heated and oxidized in air to be crosslinked to have a high molecular weight. Although it has been used for applications, even this high-molecular weight polymer has poor extrusion processability due to high degree of crosslinking and branching, and it has been difficult to form a film or fiber.

Therefore, a method of obtaining a high molecular weight PPS by a polymerization reaction has been proposed. As a typical example, as disclosed in JP-B-52-12240, R-COOM (R is a hydrocarbyl group, M is an alkali metal) is used as a polymerization aid, and the polymerization reaction is carried out in the presence thereof. Is the way. The high molecular weight polymer thus obtained is
It is considered to have excellent extrusion processability and applicability to films, fibers, etc.

However, in the above method, the polymerization aid used is required to have an approximately equimolar amount to sodium sulfide, and lithium acetate, which has a large effect in increasing the molecular weight, is expensive, resulting in high production cost, which is industrially disadvantageous. is there. Also,
Another problem of this method is that since a large amount of water-soluble organic acid salt is allowed to coexist in the polymerization system for polymerization, a large amount of organic acid salt is mixed into the treated wastewater after polymerization, which is a pollution problem. Is likely to occur, and it is very expensive to exclude it.

Further, US Pat. No. 4,038,263 discloses the use of lithium halide as a polymerization aid. If lithium halide is used as a polymerization aid, the above pollution problems and wastewater treatment problems are solved, but lithium halide is less effective in increasing the molecular weight than lithium acetate and the like, and thus a high molecular weight polymer is obtained. It is essential to add a cross-linking agent such as a polyhaloaromatic compound containing 3 or more halogens per molecule as disclosed in JP-B-54-8719, and lithium halide is expensive, so that The manufacturing operation becomes complicated, such as the need for recovery. Another problem is that when lithium halide is used as a polymerization aid, the polymer is often attached to the reaction vessel.

Further, there is a method in which the polymerization is carried out in two stages, a former stage and a latter stage, in which the polymerization temperature and the water content in the system are changed in the former stage and the latter stage to make PPS into a linearly high molecular weight. -7332, JP-A-62-149725
It is disclosed in the publication. However, this method has a drawback that the polymerization time becomes long because the high-molecular weight is not achieved unless the first-stage polymerization is carried out at a relatively low temperature for a long time, resulting in a decrease in productivity.

On the other hand, without using the above-mentioned polymerization aid, 3
A method for obtaining a branched PPS having a high molecular weight by allowing a compound having one or more halogens to exist in a reaction system is disclosed in JP-A-53-53.
It is disclosed in JP-A-136100 and JP-A-59-197430. However, the PPS obtained by this method has a defect that it is easily gelled and its thermal stability is poor.

[0010]

DISCLOSURE OF THE INVENTION The present invention is based on the above-mentioned conventional P
It is intended to provide a method for producing a high molecular weight PPS that solves the drawbacks of the PS production method.

[0011]

Means for Solving the Problems That is, according to the present invention, when PPS is produced by heating and reacting an alkali metal sulfide with dihalobenzene in the presence of an organic amide solvent, the general formula (I)
Compound (X) _m -R- (A) _n (I) (wherein R is an organic group having 3 to 32 carbon atoms, X is a halogen, A is a glycidyl ether residue or a vinyl group, , M is an integer of 0 to 2, n is an integer of 1 to 6,
m + n ≧ 3) in the presence of heat and reaction in the coexistence thereof, and will be described in detail below.

The branching agent used for the purpose of imparting branching to the PPS in the present invention is a compound represented by the general formula (I). Here, R is an organic group having 3 to 32 carbon atoms, and the organic group is mainly a hydrocarbon group and is inert during polymerization of phenoxy, alkoxy, amino, amide, ether, ketone, sulfone and the like. It means that even if it has a substituent, it does not matter.

Some examples of the branching agent represented by the general formula (I) used in the present invention are 2,4-dibromophenylglycidyl ether, dibromoneopentyl glycol diglycidyl ether, sorbitol polyglycidyl ether, Sorbitan polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2
-Hydroxyethyl) isocyanurate, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, dibromoneopentyl glycol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, trimethylol Propane trimethacrylate, tetramethylol methane triacrylate, tetramethylol methane triacrylate,
Tetramethylolmethane tetraacrylate, 2,6-
Included are dichlorostyrene and mixtures thereof.
Further, the addition amount of these branching agents is appropriately 0.0005 to 0.1 mol per mol of dihalobenzene, and the addition timing may be added together with dihalobenzene at once.
It may be added to the system after the polymerization of the alkali metal sulfide and dihalobenzene has started.

Alkali metal sulfides used in the present invention include lithium sulfide, sodium sulfide, potassium sulfide,
Included are rubidium sulfide, cesium sulfide and mixtures thereof, which may be used in the hydrate form. These alkali metal sulfides can be obtained by reacting an alkali metal hydrosulfide with an alkali metal base or hydrogen sulfide with an alkali metal base, but they may be prepared in situ prior to the addition of dihalobenzene into the polymerization system. Also, it does not matter if a product prepared outside the system is used. Preferred of the above alkali metal sulfides for use in the present invention is sodium sulfide.

Before adding dihalobenzene to carry out the polymerization, it is preferable to remove water in the system by distillation or the like to keep the amount of water to about 4 mol or less per mol of the alkali metal sulfide.
It is also possible to change the amount of water in the system during the polymerization.

The dihalobenzenes used in the present invention include p-dichlorobenzene, p-dibromobenzene, p-diiodobenzene, m-dichlorobenzene, m-dibromobenzene, m-diiodobenzene and 1-chloro-4. -Bromobenzene and the like can be mentioned, but preferred examples include p-dihalobenzene such as p-dichlorobenzene. If it is less than 30 mol% with respect to p-dihalobenzene, m-dihalobenzene such as m-dichlorobenzene or o-dihalobenzene such as o-dichlorobenzene and dichloronaphthalene, dibromonaphthalene, dichlorodiphenyl sulfone, dichloro. Copolymerization of dihaloaromatic compounds such as benzophenone, dichlorodiphenyl ether, dichlorodiphenyl sulfide, dichlorodiphenyl, dibromodiphenyl and dichlorodiphenyl sulfoxide may be used.

The polymerization solvent used in the present invention is preferably a polar solvent, particularly preferably an aprotic organic amide which is stable to alkali at high temperature. Some examples of the organic amide used in the present invention include N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoramide, N-methyl-ε-caprolactam and N.
-Ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone and the like and mixtures thereof.

The polymerization is carried out at 200 to 300 ° C., preferably 22
0.5 to 30 hours at 0 to 280 ° C, preferably 1 to 1
It is carried out under stirring for 5 hours.

The amounts of the alkali metal sulfide and dihalobenzene used in the present invention are molar ratios of (alkali metal sulfide) :( dihalobenzene) = 1.00:
0.95 to 1.10, preferably 1.00: 0.98 to
The range is 1.05.

The amount of the organic amide used is 3 to 60% by weight, preferably 7 to 60% by weight of the polymer produced by the polymerization.
It can be used in the range of up to 40% by weight.

It is also possible to add a known polymerization aid such as an alkali metal carboxylic acid salt or a lithium halide when the PPS of the present invention is produced and polymerize it.

Recovery of PPS from the reaction mixture thus obtained may be carried out by a conventional ordinary technique. For example, a method of recovering the polymer by washing with water after recovering the solvent by distillation, flushing or the like, or Examples include a method in which the reaction mixture is filtered to recover the solvent, and then the polymer is washed with water and recovered.

The PPS of the present invention has as its structural unit

[0024]

[Chemical 1] Must be contained in an amount of 70 mol% or more. If it is less than 30 mol% of the structural unit, m-phenylene sulfide unit

[0025]

[Chemical 2] o-phenylene sulfide unit

[0026]

[Chemical 3] Phenylene sulfide sulfone unit

[0027]

[Chemical 4] Phenylene sulfide ketone unit

[0028]

[Chemical 5] Phenylene sulfide ether unit

[0029]

[Chemical 6] Diphenylene sulfide unit

[0030]

[Chemical 7] It does not matter even if it contains one or more copolymerized units such as.

The PPS obtained as described above is a high molecular weight PPS having an appropriate branching, and therefore it is suitable not only for injection molding but also for extrusion molding of fibers, films, sheets, pipes and the like. ..

If necessary, glass fiber, carbon fiber,
Reinforcing fillers such as ceramic fibers such as alumina fibers, aramid fibers, wholly aromatic polyester fibers, metal fibers, potassium titanate whiskers, calcium carbonate, mica, talc, silica, barium sulfate, calcium sulfate,
Kaolin, clay, pyroferrite, bentonite,
Neserisite, Zeolite, Neferincinite, Attapulgite, Wollastonite, Ferrite, Calcium silicate, Magnesium carbonate, Dolomite, Antimony trioxide, Zinc oxide, Titanium oxide, Magnesium oxide,
It is also possible to mix inorganic fillers such as iron oxide, molybdenum disulfide, graphite, gypsum, glass beads, glass powder, glass balloons, quartz, quartz glass, and organic and inorganic pigments.

Further, a release agent such as wax, a silane-based or titanate-based coupling agent, a lubricant, a heat resistance stabilizer, a weather resistance stabilizer, a crystal nucleating agent, a foaming agent, a rust preventive, an ion trap agent, a flame retardant. A flame retardant auxiliary agent may be added if necessary.

Further, if necessary, polyethylene, polypropylene, polybutadiene, polyisoprene, polychloroprene, polystyrene, polybutene, poly α-methylstyrene, polyvinyl acetate, polyvinyl chloride, polyacrylic acid ester, polymethacrylic acid ester, polyacrylonitrile. , Nylon 6, nylon 66, nylon 6
Polyamide such as 10, nylon 12, nylon 11, nylon 46 and the like, polyester such as polyethylene terephthalate, polybutylene terephthalate and polyarylate,
Polyurethane, polyacetal, polycarbonate, polyphenylene oxide, polysulfone, polyether sulfone, polyallyl sulfone, polyphenylene sulfide sulfone, polyether ketone, polyether ether ketone, polyphenylene sulfide ketone, polyimide, polyamideimide, silicone resin, phenoxy resin, fluororesin, etc. It is also possible to use a mixture of one or more of the above homopolymers, random or block polymers, and graft polymers.

[0035]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

The melt viscosity of PPS produced in the following Examples and Comparative Examples was measured with a Koka type flow tester (die; φ = 0.5 mm, L = 2 mm).
It was measured at 0 ° C. and a load of 10 kg.

Example 1 A 500 ml autoclave was loaded with Na ₂ S.2.9H.
₂ O 0.60 mol, N-methyl-2-pyrrolidone 15
0 ml was added, the mixture was stirred under a nitrogen stream, heated to 200 ° C., and 22.0 g of a distillate mainly composed of water was distilled off. After that, it was cooled to 150 ° C., and p-dichlorobenzene (p-
(DCB) 0.594 mol and NMP 50 ml were added, the system was sealed in a nitrogen stream, the temperature was raised and polymerization was carried out at 225 ° C. for 5 hours, and then 0.003 mol 2,4-dibromophenylglycidyl ether was dissolved in 20 ml NMP. The mixture was pressed into an autoclave and further polymerized at 230 ° C. for 3 hours.
After the completion of the polymerization, the slurry cooled to room temperature was poured into a large amount of water to precipitate the polymer, which was filtered, washed with pure water, and then heated and vacuum dried overnight. The melt viscosity of the obtained polymer was 2330 poise (see Table 1).

Examples 2 to 5 Polymerization was performed in the same manner as in Example 1, except that the amount of branching agent added, the type of branching agent, and the timing of addition of branching agent were changed as shown in Table 1. The results are summarized in Table 1.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that the branching agent 2,4-dibromophenylglycidyl ether was not added. The melt viscosity of the obtained PPS is 23.
It was 0 poise and had a low viscosity as compared with the examples (see Table 1).

Comparative Example 2 Polymerization was carried out in the same manner as in Example 2 except that 1,2,4-trichlorobenzene was used instead of 2,4-dibromophenylglycidyl ether. The obtained polymer gelled in the flow tester, and the melt viscosity could not be measured (see Table 1).

[0041]

[Table 1]

[0042]

As is apparent from the above description, according to the present invention, a PPS having a high molecular weight and moderate branching can be obtained without the problems of the conventional method, and the P thus obtained can be obtained.
PS is suitable not only for injection molding but also for extrusion molding of films, fibers and the like.

Claims (1)

[Claims] 1. When a polyphenylene sulfide is produced by heating and reacting an alkali metal sulfide with dihalobenzene in the presence of an organic amide solvent, a compound (X) _m -R- (A) represented by the general formula (I) is produced. _n (I) (wherein R is an organic group having 3 to 32 carbon atoms, X is a halogen, A is a glycidyl ether residue or a vinyl group, m is an integer of 0 to 2, and n is 1 to 6). An integer, m
+ N ≧ 3), the method of producing a high-molecular-weight polyphenylene sulfide, which comprises heating and reacting under the coexistence.