JPH02382B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyarylene sulfide resin composition that is well-balanced in heat resistance, impact resistance, extrusion stability, moldability, color tone, and appearance of molded products. Polyarylene sulfide resin, represented by polyphenylene sulfide, itself has excellent heat resistance, and molding materials reinforced with reinforcing agents such as gas fibers can be used for automobile parts, electronics-related parts, etc. It is being used as a metal substitute in the field of metals, and is attracting attention as a material with the potential to grow into large engineering plastics. However, unreinforced polyarylene sulfide resin has poor extrusion stability and moldability, and the molded products obtained are not only black and have poor appearance, but also have insufficient mechanical properties such as impact resistance. For,
The reality is that it is still not used as a molding material. Therefore, the present inventors conducted extensive studies with the aim of improving the impact resistance, extrusion stability, moldability, and appearance of molded products of polyarylene sulfide resin without using reinforcing agents such as glass fiber. By blending a specific amount of a specific olefin copolymer with polyarylene sulfide resin,
The present invention was achieved by discovering that the above-mentioned desired properties can be improved in a balanced manner while maintaining the excellent heat resistance of polyarylene sulfide resin, and even the color tone of molded products can be improved. That is, the present invention uses 70 to 99 weight % of α-olefin and 1 to 1 to 1 of glycidyl esters of α,β-unsaturated acids based on 100 parts by weight of polyarylene sulfide resin.
Olefin copolymer consisting of 30% by weight 0.5-50
The present invention provides a polyarylene sulfide resin composition characterized in that it contains parts by weight. The polyarylene sulfide resin used in the present invention is a polymer whose main constituent units are repeating units of the general formula [-Ar-S]-, where Ar in the above formula contains at least one 6-membered carbon ring. A specific example of a divalent aromatic residue is

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[Formula] etc. (X is F, Cl, Br or CH ₃ , m is 1 to 3). Among them, typical polyarylene sulfide resin has the general formula

It is a polyphenylene sulfide represented by the formula: For example, one commercially available from Phillips Petroleum Company of the United States under the trade name "Ryton" can be used. These polyarylene sulfide resins have a molecular weight of 10,000 or more, especially 20,000 to 50,000, and a melting point of 270.
~290°C is preferably used. The above-mentioned "Ryton" usually has a molecular weight of 20,000 or less, but for example, according to the method described in Japanese Patent Publication No. 12240/1983,
High molecular weight polyphenylene sulfide having a molecular weight of 20,000 or more can be easily obtained. The olefin copolymer used in the present invention is α-
It is a copolymer consisting of an olefin and a glycidyl ester of an α,β-unsaturated acid. Examples of the α-olefin here include ethylene, propylene, and butene-1, but ethylene is preferably used. In addition, glycidyl ester of α,β-unsaturated acid has the general formula

It is a compound represented by the formula (R represents a hydrogen atom or a lower alkyl group), and specific examples thereof include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, etc. Among them, glycidyl methacrylate is preferred. used. The amount of copolymerized glycidyl ester of α,β-unsaturated acid in the olefin copolymer is preferably 1 to 30% by weight, particularly 3 to 20% by weight, and if it is less than 1% by weight, the desired improvement effect cannot be obtained. If the amount exceeds 30% by weight, gelation occurs during melt-kneading with the polyarylene sulfide resin, further deteriorating extrusion stability, moldability, mechanical properties, etc., which is not preferable. In addition, the olefin copolymer may contain other copolymerizable unsaturated monomers, such as vinyl ether, vinyl acetate, vinyl propionate, and acrylic acid, as long as the amount is 40% by weight or less and does not impede the purpose of the present invention. Methyl, methyl methacrylate, acrylonitrile, styrene, etc. may be copolymerized. The blending amount of the above olefin copolymer is 0.5 to 50 parts by weight per 100 parts by weight of the polyarylene sulfide resin.
Parts by weight, especially 5 to 30 parts by weight, are preferred; if it is less than 0.5 parts by weight, the desired improvement effect cannot be obtained;
If the amount exceeds 1 part by weight, not only will the excellent heat resistance of the polyarylene sulfide resin itself deteriorate, but also gelation will occur during melt-kneading, resulting in poor mechanical properties, extrusion stability, moldability, etc., which is preferable. do not have. By blending the olefin copolymer with the above copolymerization composition into the polyarylene sulfide resin at the above blending ratio, the extrusion stability during melt extrusion and the moldability represented by the lower limit pressure for injection molding are significantly improved. A resin composition is obtained which gives a molded article with excellent balance in impact resistance, appearance and color tone. Such effects of the present invention are specifically obtained when the above glycidyl group-containing copolymer is used as the olefinic copolymer, and other well-known olefinic copolymers such as ethylene-vinyl acetate copolymers are used. Similar effects cannot be obtained when using ethylene-propylene copolymers or ethylene-propylene copolymers. Although the reason for this is not clear, it is probably because the glycidyl group in the olefin copolymer acts specifically with the polyphenylene sulfide resin in the composition of the present invention. The resin composition of the present invention may contain conventional additives such as antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, mold release agents, fillers, and fibrous or powdery additives within the range that does not impair the purpose of the present invention. A reinforcing agent, a coloring agent, a flame retardant, a flame retardant aid, an antistatic agent, a crystallization accelerator, and other thermoplastic or thermosetting resins can be further blended. There are no particular limitations on the means for preparing the resin composition of the present invention, but after melt-kneading the polyarylene sulfide resin and the olefin copolymer in an extruder at a temperature higher than the melting point of the polyarylene sulfide resin,
A typical method is pelletizing. Note that the melt-kneading temperature is preferably 280 to 320°C; if it is less than 280°C, the polyarylene sulfide resin will not be sufficiently melted, and if it exceeds 320°C, it will cause crosslinking reactions and thermal decomposition reactions of the olefin copolymer, so be careful. It takes. The resin composition of the present invention thus obtained can be easily molded by conventional methods such as injection molding and extrusion molding, and the resulting molded products and films exhibit excellent performance as described above. The effects of the present invention will be further explained below with reference to Examples. Reference Example 1 (Preparation of polyphenylene sulfide) 5 moles of sodium sulfide, 1.2 kg of N-methylpyrrolidone and lithium acetate dihydrate were charged in the number of moles shown in Table 1 into an autoclave equipped with a stirrer, and the distillate was collected. It was heated to 205°C in 2 hours while being removed. Then, 1,4-dichlorobenzene was added to this system.
After preparing 5.1 mol and raising the temperature to 245℃ for 20 minutes, further
The reaction was carried out at 245° C. and 5 to 8 kg/cm ² gauge pressure. The reaction products were washed several times with hot water and dried to obtain two types of high molecular weight polyphenylene sulfides A and B having the weight average molecular weights and melting points shown in Table 1. Table 1 also shows "Ryton V-1" (polyphenylene sulfide manufactured by Philips Petroleum) as Polymer No. C.

[Table] Example 1, Comparative Example 1 Various polyphenylene sulfides (A to C) shown in Table 1 and ethylene-glycidyl methacrylate (90/10 weight ratio) copolymer were mixed in the proportions shown in Table 2. After dry blending and melt mixing using a screw extruder set at 290 to 310°C, the mixture was extruded into guts and pelletized using a strand cutter. As a measure of the extrusion stability during gut extrusion, the ratio of pelletizable guts to the total guts was evaluated, and the pellet color tone was determined based on the L value. Each pellet was then placed in a 5 oz screw in-line injection molding machine set at 290-300°C.
Izotsu impact test piece under the condition of mold temperature 140℃,
A dumbbell test piece and a test piece for measuring heat distortion temperature were molded. At the time of molding dumbbell test pieces, the lower limit pressure for molding, which is a measure of moldability, was measured, and the mold releasability, degree of burrs, and appearance of the molded product (surface gloss) were evaluated. For each test piece obtained, ASTM D-256
Izot impact strength was measured according to . These results are shown in Table 2.

[Table] As is clear from the results in Table 2, the compositions of the present invention (Nos. 1 to 3) have significantly improved extrusion stability compared to polyphenylene sulfide alone (Nos. 4 to 6). This not only greatly improves pellet color tone (L value) and moldability, but also provides molded products with extremely excellent impact resistance and surface gloss. Furthermore, if the amount of ethylene-glycidyl methacrylate copolymer is less than 0.5 parts by weight (No. 7), the desired effect will hardly be obtained, and if it exceeds 50 parts by weight (No. 8), it will cause gelation in the extruder. oxidation occurs, making extrusion impossible. In addition, No. 1 heat distortion temperature (18.6Kg/cm ² under load)
It was found that the temperature was 114℃, which was not much lower than No. 4's 120.5℃. On the other hand, the tensile stress and elongation were determined according to ASTM D-638.
According to the measurement, No. 1 has 703Kg/cm ² , which is larger than No. 4's 677Kg/cm ² , and No. 1 has an elongation of 703Kg/cm 2 .
It was found that it was 8.2%, which was higher than No. 4's 2.9%. Comparative Example 2 100 parts by weight of polyphenylene sulfide (No. B) shown in Table 1 (Reference Example 1) and ethylene-vinyl acetate copolymer [copolymerization ratio 80:20 (weight ratio), DQDJ- manufactured by Nippon Unicar] 3868] 10 parts by weight was dry blended and then extruded in the same manner as in Example 1, and then molded, but the extrusion stability was rather poor and the pellet color tone and moldability were hardly improved.
The izot impact strength of the molded product (with notches) is 2.6
There was almost no improvement in Kg/cm/cm. Example 2 Various polyphenylene sulfides (A to C) shown in Table 1 and ethylene-glycidyl methacrylate (90/10 weight ratio) copolymer were dry blended in the proportions shown in Table 3, and Example 1 was prepared. Perform the same operation as
Pellets and test pieces were obtained. The obtained pellets and test pieces were evaluated in the same manner as in Example 1, and the results shown in Table 3 were obtained.

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Claims (1)

[Claims] 1 The main structural unit is a repeating unit of the general formula [-Ar-S]- (Ar in the formula represents a divalent aromatic residue containing at least one 6-membered carbon ring) For 100 parts by weight of polyarylene sulfide resin, α-
A polyarylene sulfide resin composition characterized by containing 0.5 to 50 parts by weight of an olefin copolymer consisting of 70 to 99% by weight of olefin and 1 to 30% by weight of glycidyl ester of α,β-unsaturated acid. thing.