JP3133784B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition comprising polyvinylidene fluoride and polyarylene sulfide, which is useful as an industrial material, particularly an industrial material requiring heat resistance and chemical resistance.

[0002]

2. Description of the Related Art Polyvinylidene fluoride is widely used in fields where chemical resistance is required because of its excellent chemical resistance. However, its melting point is as low as about 170 ° C. and under high temperature conditions exceeding about 150 ° C. Since the strength is greatly reduced, it has not been put to practical use in a field where heat resistance is required.

On the other hand, polyarylene sulfide resins represented by polyphenylene sulfide resins have excellent heat resistance. The melting point of polyphenylene sulfide resin is about 28
It is as high as 0 ° C. and has sufficiently practical mechanical properties even at a high temperature of 150 ° C. or more. Polyarylene sulfide resin is a crystalline polymer and relatively excellent in chemical resistance, but is inferior in chemical resistance as compared with polyvinylidene fluoride, and is particularly weak to solvents such as halogenated hydrocarbons and nitric acid. Further, polyarylene sulfide resin has low melt viscosity and thus has poor extrusion moldability, and is not a preferable resin material for obtaining pipes and other extruded products.

The present inventors have studied a blend of polyvinylidene fluoride and polyarylene sulfide in order to provide an industrial material having excellent heat resistance and chemical resistance, but these two resins are compatible. Therefore, a molded product having good mechanical strength could not be obtained.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin composition useful as an industrial material having excellent heat resistance and chemical resistance. More specifically, the present invention relates to polyvinylidene fluoride and polyarylene. In a resin composition based on a sulfide resin, thermoplasticity that is not only superior in heat resistance and chemical resistance by increasing the compatibility of both resins but also suitable for forming a molded article having good mechanical strength An object of the present invention is to provide a resin composition.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to provide a resin mixture consisting of 100 to 95% by weight of a polyarylene sulfide resin and 95 to 5% by weight of polyvinylidene fluoride, a methyl methacrylate polymer and α, β. -A resin composition comprising 1 to 50 parts by weight of a copolymer obtained by graft copolymerization with a polymer of a glycidyl ester of an unsaturated acid, wherein the branch component of the graft copolymer has an epoxy group. And the methyl methacrylate polymer as a trunk component is represented by the following formula

Embedded image (Wherein R is hydrogen, a methyl group or an ethyl group), characterized in that it is a graft copolymer obtained by melt-kneading a polymer of an α, β-unsaturated glycidyl ester represented by the formula: This is achieved by a resin composition that:

[0007] The polyarylene sulfide resin (hereinafter referred to as PAS resin) used in the present invention is a polymer substantially consisting of repeating units -RS- (R: arylene group). Preferably, the following formula

Embedded image And a random copolymer and a block copolymer containing at least 70 mol%, more preferably at least 90 mol%, of these repeating units. Examples of the small-quantity copolymerization component in the copolymer include an arylene sulfide unit represented by the following formula.

[0008]

Embedded image

[0009] PAS resins generally include Japanese Patent Publication No. 45-3
No. 368, a polymer having a relatively small molecular weight, which is obtained by polymerization, is heated in an oxygen atmosphere after polymerization, or is heated by adding a crosslinking agent such as peroxide to form a polymer having a high molecular weight. So-called thermal crosslinking type P
AS resin and a linear high molecular weight polymer obtained by a production method represented by JP-B-52-12240, JP-B-54-8719, and JP-A-61-7332, so-called linear Although there is a type PAS resin and the like, any of them can be used in the present invention.

The melt viscosity of the PAS resin used in the present invention is not particularly limited as long as a molded product can be obtained by a usual method such as injection molding or extrusion molding.
A resin having an apparent melt viscosity of approximately 100 poise to 5,000 poise at a temperature of 10 ° C. and a shear rate of 10 ¹ to 10 ⁴ sec ⁻¹ is preferable from the viewpoint of resin properties and moldability. Polyvinylidene fluoride used in the present invention is not particularly limited as long as a molded product having mechanical strength that does not hinder practical use is obtained by injection molding or extrusion molding in the same manner as the PAS resin. 10,000 ~
1,500,000, preferably 20,000 to 1,000
000 is used.

The graft copolymer acting as a compatibilizer for both the PAS resin and the polyvinyldene fluoride resin is a graft copolymer of a methyl methacrylate polymer and a glycidyl ester polymer of an α, β-unsaturated acid. It is a copolymer obtained by polymerization. This graft copolymerization can be prepared as described below by the method described in Jpn. Polymers, Vol. 44, No. 2, pp. 89-95 (February 1987). That is, first, methyl methacrylate and a monomer having a peroxide bond are copolymerized to prepare a block copolymer or a random copolymer having a peroxide bond in a side chain. Next, a polymer of a glycidyl ester of an α, β-unsaturated acid is graft-copolymerized with the copolymer. The copolymerization of the methyl methacrylate and the monomer having a peroxide bond is emulsion polymerization,
It can be obtained by radical polymerization by any of suspension polymerization, bulk polymerization, and solution polymerization, or by living anionic polymerization. As the monomer having a peroxide bond, for example, the following formula

Embedded image The compound represented by these is mentioned. The proportion of the peroxide bond-containing monomer unit in the obtained copolymer is usually from 0.1 to
10% by weight, preferably 1 to 5% by weight, and the molecular weight of the copolymer is 3,000 to 1,000,000.
0, preferably 10,000 to 500,000.
Upon copolymerization of methyl methacrylate and the above-mentioned peroxide-containing monomer, other monomers, for example, methyl acrylate, styrene, vinyl acetate, etc., may be copolymerized as long as the effects of the present invention are not impaired. Can be. A polymer of α, β-unsaturated glycidyl ester can also be prepared by the same radical polymerization as described above. As the α, β-unsaturated acid glycidyl ester, the following formula

Embedded image The compound represented by is used. R in the above formula is hydrogen, a methyl group or an ethyl group, and specific examples of the glycidyl ester include glycidyl methacrylate, glycidyl acrylate, and glycidyl ethyl acrylate. Of these, glycidyl methacrylate is most preferred. The glycidyl ester of an α, β-unsaturated acid may be polymerized alone or may be copolymerized with ethylene, vinyl acetate, styrene, methyl methacrylate and the like. Among them, an ethylene / glycidyl methacrylate copolymer is preferable, and an ethylene / glycidyl methacrylate copolymer having a glycidyl methacrylate content of 3 to 30% by weight, particularly 10 to 20% by weight is most preferable. The molecular weight of the polymer of the glycidyl ester of an α, β-unsaturated acid is not particularly limited, but is generally from 10,000 to
1,000,000, preferably 20,000-50
Those having a range of 000 are used. The above-mentioned polymer of methyl methacrylate and the polymer of α, β-unsaturated glycidyl ester are mixed at a predetermined ratio by using an extruder, a kneader or the like at a high temperature, preferably 180 to 250 ° C, more preferably 200 to 230 ° C. By melt-kneading at a temperature of ° C., a graft copolymer of a methyl methacrylate polymer and an α, β-unsaturated glycidyl ester is obtained. The copolymerization ratio of the polymer of methyl methacrylate to the polymer of glycidyl ester of α, β-unsaturated acid is preferably 95.
/ 5 to 5/95 (weight ratio), more preferably 90/10
-10/90 (weight ratio).

The copolymerization ratio (molar ratio) of methyl methacrylate to glycidyl ester is preferably selected from the range of 98/2 to 20/80, particularly 90/10 to 40/60. In consideration of the mechanical strength, heat resistance, and moldability of the resin molded product, the molecular weight of the copolymer is determined to have a weight average molecular weight of 2,0.
It is preferably in the range of 00 to 1,000,000.

In the resin composition of the present invention, the ratio of PAS resin to polyvinylidene fluoride is 95/5 to 5/95.
(Weight ratio), preferably 90/10 to 10/90 (weight ratio). When the proportion of the PAS resin exceeds 95% by weight, the resistance to solvents such as halogenated hydrocarbons and nitric acid is considerably reduced, and when the proportion of the PAS resin is less than 5% by weight, heat resistance and mechanical properties are reduced.

The amount of the graft copolymer of the methyl methacrylate polymer as a compatibilizer and the polymer of glycidyl ester of α, β-unsaturated acid is 100 parts by weight in total of polyvinylidene fluoride and PAS resin. 1 to 50 parts by weight, preferably 3 to 20 parts by weight. If the amount of the copolymer is less than 1 part by weight, no effect of improving the compatibility is observed, and the resin composition is inferior in mechanical properties and chemical resistance. Conversely, if the blending amount of the copolymer exceeds 50 parts by weight, the thermal and mechanical properties of the resin composition deteriorate.

In the resin composition of the present invention, reinforcing fibers and / or inorganic fillers can be blended in order to improve strength, heat resistance, rigidity and dimensional stability. Examples of the reinforcing fibers include glass fibers, carbon fibers such as polyacrylonitrile and pitch, inorganic fibers such as graphite fibers, potassium titanate fibers, silicon carbide fibers, asbestos fibers, ceramic fibers, and stainless steel fibers, and aromatic polyamides (aramids). And organic fibers such as fibers. As the inorganic filler, kaolin, clay, bentonite, zeolite, mica, mica, talc, wollastonite, ferrite, calcium silicate, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, molybdenum dioxide, graphite, gypsum, glass , Beads, glass balloons and the like. If necessary, the surface of these reinforcing fibers and the inorganic filler can be pretreated with a silane-based, titanate-based or aluminate-based coupling agent before use. The blending amounts of the reinforcing fibers and the inorganic filler are preferably 100 parts by weight or less and 80 parts by weight or less, respectively, based on 100 parts by weight of a resin mixture composed of a PAS resin, polyvinylidene fluoride, and a compatibilizer.

The resin composition of the present invention contains a heat stabilizer, an ultraviolet absorber, a foaming agent, a flame retardant, a colorant, a release agent, a gas adsorbent and the like as long as the object of the present invention is not hindered. I can do it.

The resin composition of the present invention is generally in the form of pellets, and is mainly used as a raw material for injection molding and extrusion molding. The means for producing the pellets is not particularly limited, but after PAS resin, polyvinylidene fluoride, and a compatibilizer are dry-blended using a tumbler mixer, a ribbon blender, a Henschel mixer, a V blender, and the like, a kneader, a Banbury mixer, The mixture is melt-kneaded using a single-screw or twin-screw extruder, extruded and cut into pellets. For melt-kneading, single-screw and twin-screw extruders having particularly large kneading power are preferred. The melt-kneading temperature in this case is a temperature equal to or higher than the melting point of the PAS resin, that is, 280 to 350 ° C, preferably 290 to 330 ° C.
° C.

[0018]

The graft copolymer of the methyl methacrylate polymer and the glycidyl ester polymer of an α, β-unsaturated acid used in the present invention has a glycidyl ester moiety at the molecular terminal of the PAS resin. Reacts with SH groups,
In addition, the methyl methacrylate moiety in the copolymer shows great compatibility with polyvinylidene fluoride. Therefore, the PAS resin and the polyvinylidene fluoride in the resin composition of the present invention are compatible with each other to form an alloy. As a result, the molded article formed from the resin of the present invention has both the excellent chemical resistance and solvent resistance inherent in polyvinylidene fluoride and the excellent mechanical properties and heat resistance inherent in PAS resin. Note that merely mixing the PAS resin and polyvinylidene fluoride does not exhibit the excellent mechanical properties inherent in the PAS resin. Accordingly, the resin composition of the present invention is particularly useful as a molding material for equipment requiring heat resistance and chemical resistance, for example, a pipe for a chemical plant.

[0019]

EXAMPLES The resin composition of the present invention will be specifically described below with reference to examples. Polyphenylene sulfide (PPS), resin powder / toprene “T” as PAS resin
-4 "(manufactured by Toprene, melt viscosity: 2,000 poise at 300C), and" Solief 1010 "(manufactured by Solvay) as polyvinylidene fluoride (PVDF). Examples of the graft copolymer with a glycidyl ester polymer include a graft copolymer of 30% by weight of poly (methyl methacrylate) and 70% by weight of an ethylene / glycidyl methacrylate copolymer (“MODIPA A4200” manufactured by NOF CORPORATION, 230 0.7 g / min, d = 0.
993 g / cm ³ ).

The respective components were dry-blended and melt-kneaded at 290 ° C. using a 45 mmφ twin screw extruder to form pellets. The pellets were injection molded at 300 ° C. and a mold temperature of 140 ° C. to prepare test pieces, and the physical properties were evaluated according to the following criteria. The results are shown in Table 1. Melt flow rate (MFR): JIS K-675
8,300 ° C, load 2.16 kg Flexural modulus and bending strength: JIS K-7203 Tensile strength: JIS K-7113 Heat distortion temperature (HDT): JIS K-7207, load 1
8.6 kg Chemical resistance: 40 ° C. in dichloroethane (CH ₂ Cl ₂ )
For 10 days and in 20% nitric acid at 100 ° C. for 10 days,
Each was immersed, the change in weight was determined, and the change was expressed as a reduction rate (%).

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 81/00-81/02 C08L 27/12-27/16 C08L 51/06

Claims (1)

(57) [Claims] 1. A polyarylene sulfide resin 5 to 9
100% by weight of a resin mixture consisting of 5% by weight and 95 to 5% by weight of polyvinylidene fluoride and a copolymer obtained by graft copolymerization of a methyl methacrylate polymer and a polymer of a glycidyl ester of an α, β-unsaturated acid. Polymers 1 to 5
A resin composition comprising 0 parts by weight, wherein the graft component has an epoxy group, and a methyl methacrylate polymer as a trunk component has the following formula: (Wherein R is hydrogen, a methyl group or an ethyl group), characterized in that it is a graft copolymer obtained by melt-kneading a polymer of an α, β-unsaturated glycidyl ester represented by the formula: Resin composition.