JPH03210365A - Manufacture of polyarylene sulfide resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition having excellent impact strength and surface appearance without any considerable detriment to heat resistance and mechanical strengths inherent in polyarylene sulfide resin by mixing a polyarylene sulfide resin with a liquid conjugated diene polymer or its solution and melt compounding the mixture. CONSTITUTION:A polyarylene sulfide resin (A) is mixed with a liquid conjugated diene polymer (B), optionally its solution, in a Henschel mixer, a kneader, etc. The solvent is removed from the mixture if necessary, and the mixture is melt compounded by, e.g. an extruder, thus giving a polyarylene sulfide rein composition. The weight ratio of A to B is (60 to 99.5):(40 to 0.5), preferably (75 to 90):(25 to 10).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing polyarylene sulfide resin having excellent impact strength and surface appearance.

(Prior art) As a polyarylene sulfide resin composition with improved impact strength, JP-A-56-118456 discloses a polyarylene sulfide resin composition blended with a specific conjugated diene block copolymer consisting of a vinyl aromatic compound and a conjugated diene compound. Arylene sulfide resin compositions have been proposed.

(Problems to be Solved by the Invention) However, this composition is insufficient in terms of improving impact strength without impairing the heat resistance and mechanical properties inherent to polyarylene sulfide. Furthermore, molded articles made of such compositions also have the problem of poor surface appearance.

Also, even if you try to improve the impact strength by simply mixing a conjugated diene polymer with a polyarylene sulfide resin using a conventional method (for example, by mixing powders in a Henschel mixer or the like and melt-mixing them in an extruder), this will not work. Since the compatibility between the two is poor, impact strength cannot be sufficiently improved, and the surface appearance of the molded product is also poor.

In view of this situation, the present inventors used a conjugated diene polymer to improve the heat resistance and mechanical strength of polyarylene sulfide resin without significantly reducing its inherent heat resistance and mechanical strength (improving impact strength and improving surface appearance). As a result of extensive research into a method for producing a polyarylene sulfide resin composition that can yield good molded products, the present invention has been achieved.

(Means for Solving the Problems) That is, the gist of the present invention is to add 40 to 99.5 parts by weight of a liquid conjugated diene polymer to 60 to 99.5 parts by weight of a polyarylene sulfide resin.
A method for producing a polyarylene sulfide resin composition includes a step of mixing 0.5 parts by weight, and a step of melt-mixing the mixed polyarylene sulfide resin and a conjugated diene polymer.

The polyarylene sulfide resin used in the present invention has the general formula -CO-
1-〇- or an alkylene group having 5 or less carbon atoms, and the alkylene group may be methylene or polymethylene,
methylene or polymethylene having up to two methyl side chains) having substituents consisting of 1 to 3 halogen or methyl groups on the aromatic ring of these formulas, or a mixture of two or more of these can be mentioned. Such polyarylene sulfide resin may have a linear structure or a branched structure.

Among such polyarylene sulfide resins, polyphenylene sulfide is preferably used.

The liquid conjugated diene polymer used in the present invention is one whose main constituent unit is a diolefin having a military double bond, and it is sufficient that it is liquid when mixed with the polyarylene sulfide resin. The conjugated diene polymer itself may be in liquid form (or it may be a so-called conjugated diene polymer solution in which a normally solid conjugated diene polymer is dissolved in an appropriate solvent.The structural unit of the conjugated diene polymer is 1.3
-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, chlorobrene, 1,3-pentadiene, 1,3-hexadiene, etc. , 3-butadiene,
Isoprene is a preferred example. The conjugated diene polymer used in the present invention may be a copolymer using two or more of the above structural units. The conjugated diene polymer may also contain a small amount of other copolymerizable vinyl monomers such as styrene, acrylonitrile, etc., as long as the object of the present invention is not impaired. In addition, conjugated diene polymers may be crosslinked or non-crosslinked as long as they are liquid or substantially soluble in the solvent. It can be produced by conventional methods such as polymerization.

When using the conjugated diene polymer dissolved in a solvent, the solvent may be an aliphatic hydrocarbon such as n-hexane or octane, an aromatic hydrocarbon such as benzene or toluene, an alicyclic hydrocarbon such as cyclohexane, or tetrahydrofuran. I can give an example.

In the present invention, the blending ratio of the polyarylene sulfide resin and the conjugated diene polymer is 60 to 99.5 parts by weight of the polyarylene sulfide resin and 40 to 0.5 parts by weight of the conjugated diene polymer in order to improve impact strength. Polyarylene sulfide resin 75
It is preferable that the amount of the conjugated diene polymer is 25 to 10 parts by weight relative to 90 M parts. Conjugated diene polymer is 0.5
If the amount is less than 40 parts by weight, the effect of improving the impact strength of the polyarylene sulfide resin is small, and if it exceeds 40 parts by weight, the strength, rigidity, and heat resistance of the molded product will be impaired, which is not preferable. The composition obtained by the production method of the present invention can further contain a filler.

The vine filler used here may be fibrous, granular, or both, including glass fiber, carbon fiber, potassium titanate, asbestos, silicon carbide, Ceramic fiber, metal fiber, silicon nitride, aramid fiber, PMF, barium sulfate, calcium sulfate, calcium silicate, calcium carbonate, magnesium carbonate, dolomite, antimony trioxide, zinc oxide, titanium oxide, magnesium oxide, iron oxide, molybdenum disulfide , mica, talc, kaolin, pyrophyllite, bentonite, sericite, zeolite, nephelinsinite, acpargite, wollastonite, clay,
Examples include ferrite, graphite, gypsum, glass beads, glass balloons, and quartz.

When such a filler is used, the amount added is a total of 10% of the polyarylene sulfide resin and conjugated diene polymer.
It is preferable to use 10 to 300 parts by weight relative to 0 parts by weight, and if it exceeds 300 parts by weight, the melt flowability of the composition deteriorates, which tends to impair the appearance of the molded product, which is not preferable.

An antioxidant can be added to the composition obtained by the production method of the present invention. An antioxidant suitable for adding is N.
, N'-diphenyl-p-phenylenediamine, N-isopropyl-No-phenyl-p-phenylenediamine, N-1,3-dimethylbutyl-N-phenyl-p-phenylenediamine, etc. , 6-nitoxy 2.2, dihydroquinoline derivatives such as 4-trimethyl-1,2-dihydroquinoline, 4,
4°-Butylidenebis(6-t-butyl-m-cresol), 2.2′-methylenebis(4-methyl-6-t-
butylphenol), 2.2°-methylenebis(4-ethyl-6-t-butylphenol), 4.4'-thiobis(6-t-butyl-m-cresol), 2.6-
Examples include phenol derivatives such as di-t-butyl-p-cresol, 2,5-di-t-amylhydroquinone, and 2,5-di-butylhydroquinone.

The composition obtained by the production method of the present invention may contain a mold release agent, a coloring agent, an ultraviolet absorber, a foaming agent, a rust preventive, a flame retardant, a flame retardant aid, etc., if necessary.

In the present invention, when the polyarylene sulfide resin and the liquid conjugated diene polymer are mixed, the two are mixed relatively uniformly. Any method that can mix the two can be used for this mixing.
The mixture can be mixed using a Henschel mixer or a Niegoo, or by putting both in a bag and kneading by hand.

If the conjugated diene polymer itself is liquid, it may be melted and kneaded as is, but if the conjugated diene polymer is dissolved in a solvent and used as a liquid, it may be mixed with polyarylene sulfide resin and then dried. to remove the solvent. In the present invention, the mixture of the polyarylene sulfide resin and the conjugated diene polymer thus obtained is melt-mixed. For this melt mixing method, any method may be used as long as the polyarylene sulfide resin is melted and the mixture can be further mixed and mixed. It is possible to suitably employ a method in which the material is extruded into a beveled material under extrusion conditions.

The above-mentioned antioxidants, other additives, and fillers may be added and mixed at any stage of the above process, but when adding fibrous fillers, it is preferable to add them immediately before melt mixing.

The polyarylene sulfide resin composition thus obtained does not undergo phase separation even after extrusion molding, injection molding, and other molding processes under normal conditions, and addition of these polymers to polyarylene sulfide resin Since the amount is appropriate, impact strength is improved without significantly impairing the excellent properties of polyarylene sulfide, resulting in a composition with excellent surface appearance of molded products.

(Example) The present invention will be further explained below with reference to Examples.

In the examples, I zod impact strength is ASTM D2
Heat distortion temperature was evaluated according to ASTM D648. The surface appearance of the molded product was visually evaluated for the presence or absence of burl luster, and those with no pearlescent luster were rated ○ and those with pearlescent luster were rated X.

Furthermore, in the examples, "parts" represent "parts by weight" unless otherwise specified.

Examples 1 to 3 Polyphenylene sulfide resin (pps) (manufactured by Toblen ■, Toblen T-4, average particle size 50 μm) and liquid polybutadiene (liquid PBd) (manufactured by Usso Kasei ■, B-3)
000, number average molecular weight 3080) and an antioxidant (manufactured by Yoro Kagaku Kogyo ■, W-400.2.2-methylenebis(4-methyl-6-t-butylphenol)) in the amounts listed in Table 1. An antioxidant dissolved in liquid polybutadiene was added to the polyphenylene sulfide resin, mixed using a Henschel mixer, and the resulting mixture was extruded using a twin screw extruder (Uniluna-30Φ, cylinder temperature 290°C). , turned into a beret. Using this pellet, a test piece for mechanical property evaluation was molded and evaluated using an injection molding machine (manufactured by Toshiba Machine ■, 1S-100) under conditions of a cylinder temperature of 290°C and a mold temperature of 80°C. The results are shown in Table 1.

Examples 4 to 6 Polyphenylene sulfide resin similar to that used in Example 1 and polybutadiene rubber (manufactured by Nippon Zeon ■, N1p)
ol 1220S) (P B d ) and the same antioxidant as used in Example 1 in the amounts listed in Table 1, polyphenylene sulfide resin was placed in a Henschel mixer and mixed with polybutadiene rubber while stirring. An oxidizing agent dissolved in 100 parts by weight of toluene was gradually added, and after the addition was finished, the mixture was further stirred and mixed, then dried to remove the toluene, and then melted in the same manner as in Example 1. The test pieces were mixed, pelletized, and injection molded, and the mechanical properties of the obtained test pieces were evaluated. The results are shown in Table 1.

Example 7 A mixture of 20 parts by weight of the same polybutadiene rubber used in Example 4 and 0.3 parts by weight of the same antioxidant as used in Example 1 dissolved in 100 parts by weight of toluene was prepared. 80 parts by weight of the same polyphenylene sulfide resin as used was mixed in a Nigu, dried to remove toluene, and 67 parts by weight of glass fiber was added thereto.
Extruded into pellets under the same conditions as above, and set the mold temperature to 14
A test piece for mechanical property evaluation was obtained by injection molding under the same conditions as in Example 1 except that the temperature was 0°C, and the properties were evaluated. The results are shown in Table 1.

Comparative Example 1 Using only 100 parts by weight of the same polyphenylene sulfide resin as used in Example 1, extrusion pelletization and injection molding were conducted under the same conditions as used in Example 1 without adding a conjugated diene polymer. A piece was obtained and evaluated. The results are shown in Table 1.

Comparative Example 2 A test piece obtained by blending 67 parts by weight of glass fiber with 100 parts by weight of the same polyphenylene sulfide resin used in Example 1 and extrusion pelletizing and injection molding under the same conditions as used in Example 7. The mechanical properties of the material were evaluated. The results are shown in Table 1.

Table 1 (Effects of the Invention) As described above, according to the method of the present invention, the conjugated diene polymer and the polyarylene sulfide resin are uniformly mixed, and the process of extrusion molding, injection molding, etc. The excellent properties of polyarylene sulfide are not significantly impaired because the composition is dispersed and mixed to such an extent that phase separation does not occur even after processes such as molding under these conditions, and the blending ratio of each component of the composition is appropriate. The result is a composition with excellent performance that provides excellent impact strength and molded product surface appearance without any damage.

Note that preferred embodiments of the present invention are as follows.

2) The method for producing a resin composition according to claim 1, wherein the polyarylene sulfide resin is a polyphenylene sulfide resin.

2) The method for producing a resin composition according to claim 1, wherein the conjugated diene polymer is polybutadiene, polyisoprene, or a copolymer of 1,3-butadiene and isoprene.

3) The method for producing a resin composition according to claim 1, wherein the liquid conjugated diene polymer is itself liquid.

4) The method for producing a resin composition according to claim 1, wherein the liquid conjugated diene polymer is a conjugated diene polymer dissolved in a solvent.

5) The blending ratio of polyarylene sulfide resin and conjugated diene polymer is 75 to 9 for polyarylene sulfide resin.
2. The method for producing a resin composition according to claim 1, wherein the amount of the conjugated diene polymer is 25 to 10 parts by weight relative to 0 parts by weight.

6) The method for producing a resin composition according to claim 1, further comprising an antioxidant.

Claims (1)

[Claims] 1) A step of mixing 60 to 99.5 parts by weight of polyarylene sulfide resin with 40 to 0.5 parts by weight of liquid conjugated diene polymer, and then melt-mixing the mixed polyarylene sulfide resin and conjugated diene polymer. A method for producing a polyarylene sulfide resin composition, comprising the step of: