JPH01167334A - Production of poly (p-phenylene sulfide) - Google Patents

Abstract

PURPOSE:To obtain the title high-molecular weight polymer suitable for films, yarn, etc., by dehydrating an alkali metallic sulfide under heating through addition of sodium salt of a specific pyridinedicarboxylic acid and then reacting the resultant dehydrated composition with a dihalobenzene. CONSTITUTION:(A) Sodium salt of a pyridinedicarboxylic acid (e.g., sodium nicotinate) shown by formula (R is 1-20C organic group) n is 0-4) is dissolved in (B) a polar aprotic solvent (e.g., N, N-dimethylacetamide) and dehydrated with (C) an alkali metallic sulfide such as lithium sulfide and (D) 5-40 mols based on 1 mol component C of water under heating to give a dehydrated composition. This composition is reacted with (E) p-dihalobenzene (e.g., p- dichlorobenzene) at 200-300 deg.C to give the aimed polymer.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a method for producing poly(P-phenylene sulfide), and more specifically, to a method for producing poly(P-phenylene sulfide), and more specifically to a method for producing poly(P-phenylene sulfide).
-) unilene sulfide).

Poly(p-phenylene sulfide) is attracting attention as a material for electrical and electronic equipment and automobile equipment due to its excellent heat resistance and chemical resistance.

We also manufacture various molded parts using injection molding, extrusion molding, etc.

Can be formed into films, sheets, fibers, etc., and has heat resistance,
Widely used in fields that require chemical resistance.

[Prior art] As a method for producing poly(p-)unilene sulfide), N
- A method of reacting a dihaloaromatic compound with an alkali gold aK compound such as sodium sulfide in a polar aprotic solvent such as methylpyrrolidone is disclosed in Japanese Patent Publication No. 3368/1983.

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, so this low molecular weight polymer is heated and oxidized in air to increase its molecular weight and used for molding processing. However, even this high-molecular-weight polymer had poor extrusion processability, probably due to the high degree of crosslinking and monobranching, and it was difficult to mold it into films and fibers.

Therefore, a method of obtaining high molecular weight poly(P-)unilene sulfide by a polymerization reaction has been proposed.

Typical examples include a method in which R-COOM (R is a hydrocarbyl group, 9M is an alkali metal) is used as a polymerization aid and the polymerization reaction is carried out in the presence of R-COOM, as disclosed in Japanese Patent Publication No. 12240/1983; , a method of carrying out a polymerization reaction in the presence of an alkali metal salt of pyridinecarboxylic acid represented by an integer) as a polymerization aid, as shown in Japanese Patent Application No. 61-303655 previously filed by the present inventor. can be mentioned. The high molecular weight polymer thus obtained has excellent extrusion processability and has applicability to films, fibers, etc.

However, in the above method, only the expensive lithium salt exhibits a remarkable effect on increasing the molecular weight, resulting in high production costs and is industrially disadvantageous. On the other hand, since cheap sodium salts do not have sufficient molecular weight, it is necessary to add a crosslinking agent such as a polyhaloaromatic compound containing three or more halogens per molecule, which only complicates the manufacturing process. However, there are problems such as the resulting polymer tends to gel.

[Problems to be Solved by the Invention] The present invention provides a high molecular weight poly(p-phenylene) which solves the above-mentioned drawbacks by significantly increasing the polymerization effect of the sodium salt of pyridinecarboxylic acid and making it equivalent to or higher than that of the lithium salt. sulfide).

[Means for solving the problem] When an alkali metal sulfide is heated and dehydrated in a polar aprotic solvent in the presence of a sodium salt of pyridinecarboxylic acid represented by an integer from 0 to 4, water is converted into an alkali. A dehydrated composition is formed by adding 5 to 40 moles per mole of metal sulfide and then dehydrating, followed by mixing the dehydrated composition with p-
Poly(
The present invention relates to a method for producing P-phenylene sulfide). The details will be explained below.

The polymerization aid used in the present invention is a sodium salt of a dicarboxylic acid of the general formula. Here, the maximum R is an organic group having a carbon number of C to C2o, which is a ketone that is inactive during polymerization.

Some examples of sodium salts of pyridinecarboxylic acid used in the present invention include:
Sodium nicotinate, sodium 2-methylnicotinate, sodium 4-methylnicotinate, sodium 5-methylnicotinate, sodium 6-methylnicotinate,
Sodium 2,4-dimethylnicotinate, 2,5-
Mention may be made of sodium dimethylnicotinate, sodium 2,6-dimethylnicotinate, sodium 4,6-dimethylnicotinate, sodium 5,6-dimethylnicotinate and mixtures thereof. Moreover, these salts can be used regardless of whether they are anhydrous salts or hydrated salts.

Also, the amount of sodium pyridinecarboxylate added is p
- 0.05 to 4 mol, preferably 0.1 to 2 mol per mol of dihalobenzene is suitable. If the amount added is too small, the effect of increasing the molecular weight will not be sufficient, while if it is too large, it will become difficult to stir the reaction vessel, which is undesirable. Furthermore, the sodium pyridinecarboxylate should be added to the system prior to dehydration of the alkali metal sulfide.

In the present invention, the water added to the system when dehydrating alkali metal sulfides refers to free water, which is different from crystal water of alkali metal sulfides, pyridine carboxylates, etc. It is important for the present invention to exhibit the effects of the present invention that 5 to 40 moles of such free water, which does not contain crystal water, etc., are added per mole of alkali metal sulfide to the system before dehydration. . If the amount of added water is less than 5 moles, it is not sufficient to enhance the high molecular weight effect of sodium pyridinecarboxylate, while if it is more than 40 moles, the amount of energy used during dehydration increases, which is economically disadvantageous.

In addition, in order to increase the polymerization effect of sodium pyridine carboxylate, it is necessary to simultaneously add the alkali metal sulfide, polar aprotic solvent, sodium pyridine carboxylate, and the above specified amount of water to the system before dehydrating the alkali metal sulfide. It is important that these components be present, and the object of the present invention can be achieved by allowing the above four components to coexist and then dehydrating them.

The alkali metal sulfides used in the present invention include lithium sulfide, sodium sulfide, and potassium sulfide.

These alkali metal sulfides include rubidium sulfide, cesium sulfide and mixtures thereof, which may also be used in the form of hydrates. However, it may be prepared on the spot prior to adding p-dihalobenzene into the polymerization system, or it may be prepared outside the system. Among the alkali metal sulfides mentioned above, sodium sulfide is preferred for use in the present invention.

Before polymerization by adding p-dihalobenzene, it is preferable to remove the water in the system by distillation or the like to reduce the amount to about 4 mol or less per 1 mol of alkali metal sulfide. It is also possible to vary the amount of.

Examples of p-dihalobenzene used in the present invention include p-dichlorobenzene and p-dibromobenzene.

Mention may be made of p-shortbenzene and mixtures thereof, with p-dichlorobenzene being preferred.

In addition, if it is less than 30 mol% based on ρ-dihalobenzene, m-dihalobenzene such as m-dichlorobenzene or 0-
0-dihalobenzenes such as dichlorobenzene and dichloronaphthalene, dibromonaphthalene, dichlorodiphenyl sulfone, dichlorobenzophenone, dichlordiphenyl ether.

dichlordiphenyl sulfide, dichlordiphenyl,
Polyhaloaromatics that can be copolymerized with dihaloaromatic compounds such as dibromodiphenyl and dichlorodiphenyl sulfoxide, and further contain a small amount of 3 or more halogens per molecule as long as the linearity of the polymer is not affected. compounds such as trichlorobenzene, tribromobenzene.

Triiodobenzene, tetrachlorobenzene, trichloronaphthalene, tetrachloronaphthalene, etc. can also be used in combination.

The polymerization solvent used in the present invention is preferably a polar solvent, and particularly preferably a solvent that is aprotic and stable against alkalis at high temperatures. For example, N,N-dimethylacetamide,
N,N-dimethylformamide, hexamethylphosphoramide, N-methyl-ε-caglolactam, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, 1.
Examples include 3-dimethylimidazolidinone, dimethylsulfoxide, sulfolane, tetramethylurea, and mixtures thereof.

Polymerization at 200-300°C, preferably 220-280°C
It is preferably carried out under stirring for 0.5 to 30 hours, and preferably for 1 to 15 hours. Further, the amounts of the alkali metal sulfide and p-dihalobenzene used in the present invention are expressed in a molar ratio of (alkali metal sulfide)=(p-dihalobenzene)=1. OO
: The range of 0.90 to 1.10 is preferable, and the amount of polar aprotic solvent used is such that the amount of polymer produced by polymerization is 3 to 60% by weight, preferably 7 to 40% by weight. can.

Poly(P-7) from the reaction mixture thus obtained
(22lene sulfide) can be recovered using conventional techniques, such as distillation of the solvent.

After recovery by flushing etc., the polymer is washed with water and recovered, or after the reaction mixture is filtered and the solvent is recovered,
Examples include a method of washing the polymer with water and recovering it. However, in order to prevent coloring of the polymer, formation of gel, etc., it is preferable to use a method that does not impart thermal history to the polymer as much as possible, that is, a method in which the reaction mixture is filtered, the solvent is recovered, and then the polymer is washed with water and recovered.

The poly(p-)unilene sulfide of the present invention must contain 70 mol% or more of F-s% as its constituent unit. If it is less than 30 mol% of the #4 component,
m-phenylene sulfide unit ゛g(〕's71
, o-phenylene sulfide sulfide ketone unit -+
o-co-@-sq phenylene sulfide ether unit.

There is no problem even if it contains copolymerized units such as 4o-@-sh and diphenylene sulfide units mγ°.

The poly(p-phenylene sulfide) obtained in the above manner has a linear and high molecular weight, and is therefore suitable for use not only in injection molding but also in extrusion molded products such as fibers, films, and pipes. be.

In addition, if necessary, reinforcing fillers such as glass fibers, carbon fibers, ceramic fibers such as alumina fibers, aramid fibers, wholly aromatic polyester fibers, metal fibers, potassium titanate whiskers, calcium carbonate, mica, talc, silica, etc. Barium sulfate.

Calcium sulfate, kaolin, clay, pyroferrite, bentonite, sericite, zeolite.

Nephelinsinite, attalpulgite, wollastonite, PMF, ferrite, calcium gaoxide, magnesium carbonate, dolomite, antimony trioxide, zinc oxide, titanium oxide, magnesium oxide, iron vi oxide, molybdenum disulfide, graphite 9 gypsum, Inorganic and organic materials such as glass beads, glass powder, glass balloons, quartz glass, etc.

Inorganic pigments can also be blended.

In addition, plasticizers and mold release agents such as aromatic hydroxy derivatives,
Silane-based and titanate-based coupling agents, lubricants, heat-resistant stabilizers, weather-resistant stabilizers, crystal nucleating agents.

Foaming agents, rust preventives, ion trapping agents, flame retardants, H combustion aids, etc. may be added as necessary.

Furthermore, polyethylene, polybutadiene,
Polyisoprene, polychloroprene, polystyrene, polybutene, polyα-methylstyrene, polyvinyl acetate, polyvinyl chloride, polyacrylate, polymethacrylate, polyacrylonitrile, nylon 6, nylon 66°, nylon 610. nylon 12
．． Polyamides such as nylon 11° and nylon 46, polyethylene terephthalate, polybutylene terephthalate,
Polyesters such as polyarylates, polyurethanes, polyacetals, polycarbonates, polyphenylene oxides, polysulfones, polyethersulfones, polyallylsulfones, polyester getones.

Polyetheretherketone, polyimide, polyamideimide, silicone resin, phenoxy resin.

It is also possible to use a mixture of one or more types of homopolymers such as fluorocarbon resins, random or block copolymers, and graft copolymers.

[Examples] The present invention will be specifically described below with reference to Examples, but the present invention is not limited only to these Examples.

In addition, poly(p) produced in the following Examples and Comparative Examples
-phenylene sulfide) was measured using a Koka type flow tester (dice; φ=0, 5 lIm,
L = 2 Ilm), 300℃, 101qr
Measured by load.

Example 1 Sodium sulfide N was added to a 500 ml autoclave.
a S ・2.9H200.5 mol, N-methyl-2
- Add pyrrolidone (hereinafter abbreviated as NMP) 125a+I, 0.15 mol of sodium nicotinate, and 9.5 mol of distilled water, stir under a nitrogen stream, and raise the temperature to 200°C.
86.2 g of water and 11.9 g of NMP were distilled off. After cooling the system to 170°C, 0.50 mol of p-dichlorobenzene (hereinafter abbreviated as p-DCB) was added to NMP.
42 ml and encapsulated the system under nitrogen flow.
The temperature was raised to 245° C. for 10 hours. After the polymerization is completed, the system is cooled, the contents are poured into water, and washed with about 5 fl of warm water. After repeating the filtration, it was washed once with methanol and dried under vacuum overnight to obtain white, small granular poly(p-phenylene sulfide). Polymer yield was 93%,
The melt viscosity was 211 Pa.s. (See Table 1) Examples 2 to 5 Addition amount (added water/N a 2
S molar ratio), type and amount of sodium pyridinecarboxylate (sodium pyridinecarboxylate/Na
2 S molar ratio) 1 Polymerization temperature 9 Polymerization was carried out by changing the polymerization time. The results are shown in Table 1.

Comparative Example 1 No additive water was added and the polymerization was carried out at 230°C.
Polymerization was carried out in the same manner as in Example 1, except that the polymerization was carried out at 265° C. for 2 hours. The obtained polymer was in the form of granules with a yield of 96% and a melt viscosity of 110 Pa.s, indicating that a single sodium nicotinate system without added water had a poor polymerization effect. (See Table 1) Comparative Example 2 Polymerization was carried out in the same manner as in Example 1, except that water was added in a molar amount three times that of sodium sulfide. The obtained polymer was in the form of small granules with a yield of 94%.

The melt viscosity was 119 Pa.s, indicating that the effect of increasing the molecular weight was not sufficiently enhanced if the amount of added water was small. (See Table 1) Comparative Example 3 Polymerization was carried out in the same manner as in Example 1, except that nonahydrate was used as sodium sulfide, no added water was added, and the polymerization time was 5 hours.

The obtained polymer was in the form of small granules with a yield of 92% and a melt viscosity of 8.
8 Pa, s, indicating that when water present in the polymerization system exists in the form of crystal water, it contributes little to the effect of increasing the molecular weight. (See Table 1) Comparative Example 4 In the absence of NMP, sodium sulfide, sodium nicotinate, and added water were heated and dehydrated to 200°C, and then NMP
was added and heated to 200℃ again.

Polymerization was carried out in the same manner as in Example 1 except for dehydration. The obtained polymer was in powder form with a yield of 94% and a melt viscosity of 30 Pa.s, which was lower than that of the examples. (See Table 1) Comparative Example 5 After heating water and sodium nicotinate in an amount twice the mole of sodium sulfide in NMP and dehydrating it to 200°C,
Polymerization was carried out in the same manner as in Example 1, except that sodium sulfide and water were added in an amount 3 times the mole of sodium sulfide, heated to 200° C. again, and dehydrated. The obtained polymer was in the form of small granules with a yield of 94% and a melt viscosity of 97 Pa, s.
The melt viscosity was lower than that of the examples. (See Table 1) Comparative Example 6 After dehydrating sodium nicotinate, ρ-DCB, NM
Polymerization was carried out in the same manner as in Example 1 except that P was added together with P. The obtained polymer was in the form of small granules with a yield of 9.
2%, and the melt viscosity was 85 Pa.s, which was lower than that of the example.

(See Table 1) As can be seen from these examples (Comparative Examples 1 to 6), if NMP, sodium [chloride], sodium pyridinecarboxylate, and a specific amount of added water do not coexist during dehydration, the effect of increasing the molecular weight will be reduced. This shows that the effects of the present invention can only be exerted by dehydrating the system in which the four components coexist.

[Effects of the Invention] As is clear from the above explanation, according to the present invention, high molecular weight poly(P-phenylene sulfide) can be obtained even when sodium salt of pyridinecarboxylic acid is used as a polymerization aid. The obtained poly(p-)unilene sulfide) is suitable not only for injection molding applications but also for extrusion molding applications such as films and fibers.

Claims (1)

[Claims] 1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (R is an organic group having a carbon number of C_1 to C_2_0, n
is an integer of 0 to 4), when heating and dehydrating an alkali metal sulfide in a polar aprotic solvent, the amount of water is 5 to 40% per mole of alkali metal sulfide. molar addition followed by dehydration to form a dehydrated composition, followed by addition of the dehydrated composition and p
- A method for producing poly(p-phenylene sulfide), which comprises reacting with dihalobenzene.