JPH05295260A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject resin composition containing a polyarylene sulfide resin, a specific fluororesin and graft polymer of a polymethacrylic acid methyl ester and an unsaturated acid glycidyl ester polymer and having good heat resistance, chemical resistance and sliding characteristics. CONSTITUTION:The objective thermoplastic resin composition is obtained by blending (A) 100 pts.wt. resin mixture consisting of 95-5wt.% polyarylene sulfide resin (e.g. polyphenylene sulfide resin) and 95-5wt.% fluororesin composed of 5-95wt.% polyvinylidene fluoride and 95-5wt.% homopolymer or copolymer of tetrafluoroethylene with (B) 1-50 pts.wt. graft copolymer of methyl methacrylate polymer and an alpha,beta-unsaturated acid glycidyl ester, obtained by subjecting a copolymer having a peroxy bond at the side chain and prepared by copolymerizing methyl methacrylate with a monomer having the peroxy bond to graft copolymerization with an alpha,beta-unsaturated acid glycidyl ester (e.g. glycidyl methacrylate).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a fluororesin and a polyarylene sulfide as main components, which are useful as industrial materials, particularly industrial materials required to have heat resistance and chemical resistance and high sliding properties. It relates to a thermoplastic resin composition.

[0002]

2. Description of the Related Art Polyvinylidene fluoride has excellent chemical resistance and is therefore widely used in fields requiring 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 the field where heat resistance is required.

On the other hand, polyarylene sulfide resin (hereinafter referred to as PAS resin) represented by polyphenylene sulfide resin (hereinafter referred to as PPS resin) is excellent in heat resistance. The melting point of PPS resin is as high as about 280 ° C,
It has mechanical properties that are practically acceptable even at high temperatures of 150 ° C or higher. PAS resin is a crystalline polymer and is relatively excellent in chemical resistance, but it is inferior in chemical resistance to polyvinylidene fluoride and is particularly vulnerable to solvents such as halogenated hydrocarbons and nitric acid. Moreover, since the PAS resin has a low melt viscosity and thus has poor extrusion moldability, it cannot be said to be a preferable resin material for obtaining an extrusion molded product such as a pipe.

Even if polyvinylidene fluoride and a PAS resin are simply blended in order to obtain an industrial material having excellent heat resistance and chemical resistance, the two resins have poor compatibility with each other. The product was inferior in mechanical strength. Further, the molded product obtained from the blend of polyvinylidene fluoride and PAS resin is inferior in sliding properties and cannot be used as a sliding material.

An object of the present invention is a resin composition based on polyvinylidene fluoride and a PAS resin, in which the compatibility of both resins is further improved and not only the heat resistance and chemical resistance are excellent, It is an object to provide a thermoplastic resin composition suitable for forming a molded product having very excellent mechanical properties and sliding properties.

[0006]

The above-mentioned object is to provide 100 parts by weight of a resin mixture consisting of 5 to 95% by weight of PAS resin and 95 to 5% by weight of fluororesin, methyl methacrylate polymer and α, β-unsaturation. Graft copolymer with acid glycidyl ester polymer 1 to 50 parts by weight, wherein the fluororesin is polyvinylidene fluoride 5 to 95% by weight and tetrafluoroethylene homopolymer or copolymer 95 to 5 parts by weight %
It is achieved by a thermoplastic resin composition comprising:

The PAS resin used in the present invention is a polymer which is substantially composed of repeating units -RS- (R: arylene group). Preferably, the following formula

[Chemical 1] A polyparaphenylene sulfide resin having a repeating unit represented by, and a random copolymer and a block copolymer containing the repeating unit in an amount of 70 mol% or more, more preferably 90 mol% or more. Examples of the small amount copolymerization component in the copolymer include arylene sulfide units represented by the following formula.

[0008]

[Chemical 2]

PAS resins are generally used in Japanese Patent Publication No. 45-3.
Cross-linking and high molecular weight by heating a polymer having a relatively small molecular weight obtained by the production method represented by JP 368 So-called thermally crosslinked P
AS resins and linear and high molecular weight polymers obtained by the production methods represented by JP-B-52-12240, JP-B-54-8719, and JP-A-61-7332, so-called linear chains. Although there are type PAS resins 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, but the temperature is 300.
C., die orifice L / D = 10, apparent melt viscosity measured at a load of 20 kg is about 100 poise or more, 50,
Those having a porosity of 000 poise or less are preferable from the viewpoint of resin physical properties and moldability. The polyvinylidene fluoride used in the present invention is not particularly limited as long as it is possible to obtain a molded product having mechanical strength that does not hinder practical use by injection molding, extrusion molding, etc., like the PAS resin, but generally the number average molecular weight is The thing of 10,000-1,500,000 is used.

The polymer of ethylene tetrafluoride used in the present invention is a homopolymer or a main component of ethylene tetrafluoride and other fluorine-containing or non-containing monomer copolymerizable therewith as a poor component. And a copolymer. Generally, a copolymer is used for the purpose of improving the melt moldability of the obtained resin composition. Examples of the monomer copolymerized with tetrafluoroethylene include perfluoroalkyl vinyl ether, hexafluoropropylene, ethylene, chlorotrifluoroethylene, vinylidene fluoride and vinyl fluoride. The type and amount of these monomers may be appropriately set within a range that does not impair the sliding characteristics of the obtained resin composition.

A graft copolymer of a methyl methacrylate polymer acting as a compatibilizing agent for both PAS resin and fluororesin and a polymer of a glycidyl ester of an α, β-unsaturated acid is a polymer article. Vol. 44, No. 2, 89-95
It can be prepared as follows by the method described on page (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 as a side chain. Then, a copolymer of glycidyl ester of α, β-unsaturated acid is graft-copolymerized with this copolymer.

The copolymerization of the above-mentioned methyl methacrylate and the monomer containing a peroxide bond is carried out by emulsion polymerization, suspension polymerization, bulk polymerization,
It can be obtained by radical polymerization by any method of solution polymerization or living anion polymerization. As the monomer having a peroxide bond, for example, the following formula

[Chemical 3] The compound represented by The ratio of the peroxide bond-containing monomer unit in the obtained copolymer is usually 0.1 to 1
0% by weight, preferably 1 to 5% by weight, and the copolymer has a molecular weight of 3,000 to 1,000,000.
It is 0, preferably 10,000 to 500,000.
Upon copolymerization of methyl methacrylate and the above-mentioned peroxide bond-containing monomer, other monomers, for example, methyl acrylate, styrene, vinyl acetate, etc. are copolymerized within a range not impairing the effects of the present invention. You can

Polymers of glycidyl esters of α, β-unsaturated acids can also be prepared by radical polymerization similar to the above. The glycidyl ester of α, β-unsaturated acid has the following formula

[Chemical 4] The compound represented by R in the above formula is hydrogen or a lower alkyl 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 α, β-unsaturated acid may be polymerized alone or may be copolymerized with ethylene, vinyl acetate, styrene, methyl methacrylate and the like.
Among them, ethylene / glycidyl methacrylate copolymer is preferable, and particularly, the content of glycidyl methacrylate is 3 to.
Most preferred is an ethylene / glycidyl methacrylate copolymer of 30% by weight, especially 10-20% by weight. α, β
The molecular weight of the polymer of glycidyl ester of unsaturated acid is not particularly limited, but is generally 10,000 to 1,000,
000, preferably in the range of 20,000 to 500,000 is used.

The above-mentioned methyl methacrylate polymer and α, β
-Methyl methacrylate by melt-kneading with a polymer of a glycidyl ester of an unsaturated acid at a predetermined ratio at a high temperature using an extruder, a kneader or the like, preferably 180 to 250 ° C, more preferably 200 to 230 ° C. A graft copolymer of the above polymer with a glycidyl ester of an α, β-unsaturated acid is obtained. The copolymerization ratio of the polymer of methyl methacrylate and the polymer of glycidyl ester of α, β-unsaturated acid is preferably 95/5 to 5/95 (weight ratio), more preferably 80/20 to 20 /. 80 (weight ratio).

In the thermoplastic resin composition of the present invention, P
The ratio of AS resin and fluororesin is 95/5 to 5/95
(Weight ratio), preferably 90/10 to 10/90 (weight ratio), and this fluororesin is polyvinylidene fluoride 5
˜95% by weight, preferably 10 to 90% by weight and 95 to 5% by weight, preferably 90 to 10% by weight, from a homopolymer or copolymer of tetrafluoroethylene. When the relative proportions of the PAS resin, the polyvinylidene fluoride and the tetrafluoroethylene polymer in the thermoplastic resin composition of the present invention are smaller than the above range, the heat resistance, the chemical resistance and the sliding property are lower than the permissible levels. descend.

The compounding amount of the graft copolymer of the methyl methacrylate polymer as the compatibilizer and the polymer of the glycidyl ester of α, β-unsaturated acid is 100 parts by weight in total of the fluororesin and the PAS resin. It is 1 to 50 parts by weight, preferably 3 to 20 parts by weight. If the blending amount of this graft copolymer is less than 1 part by weight, the effect of improving compatibility is not recognized,
The resin composition is inferior in mechanical properties and chemical resistance. vice versa,
If the blending amount of the graft copolymer exceeds 50 parts by weight, the thermal properties and mechanical properties of the resin composition deteriorate.

In the resin composition of the present invention, reinforcing fibers and / or inorganic fillers may be added in order to improve strength, heat resistance, rigidity and dimensional stability. Examples of the reinforcing fiber include glass fiber, carbon fiber such as polyacrylonitrile-based and pitch-based, graphite fiber, potassium titanate fiber, silicon carbide fiber, asbestos fiber, ceramic fiber, stainless fiber and other inorganic metal fibers and aromatic polyamide (aramid). ) Examples include organic fibers such as fibers. As the inorganic filler, carion, clay, bentonite, zeolite, mica, mica, talc, wollastonite, ferrite, calcium silicate, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, molybdenum disulfide, graphite, gypsum, Examples include glass, beads, glass balloons and the like. If necessary, the surface of these reinforcing fibers and the inorganic filler can be pretreated with a coupling agent such as a silane type, titanate type or aluminate type before use. The blending amounts of the reinforcing fiber 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 the resin mixture consisting of the PAS resin, polyvinylidene fluoride and a polymer of tetrafluoroethylene.

The resin composition of the present invention contains a heat stabilizer, an ultraviolet absorber, a foaming agent, a flame retardant, a coloring agent, a release agent, a gas adsorbent, etc. within a range not hindering the achievement of the object of the present invention. It can be done.

The resin composition of the present invention is generally in the form of pellets and is mainly used as a molding raw material for injection molding and injection molding. The method for producing pellets is not particularly limited, but PAS resin, polyvinylidene fluoride, a polymer of tetrafluoroethylene, and a compatibilizing agent are dry blended using a tumbler mixer, a ribbon blender, a Henschel mixer, a V blender, or the like. After doing
It is melt-kneaded using a kneader, Banbury mixer, single-screw or twin-screw extruder, extruded, and cut into pellets. For melt-kneading, single-screw and twin-screw extruders having a particularly high kneading force are preferable. The melt-kneading temperature in this case is 280 ° C.
-350 degreeC, Preferably it is 290-330 degreeC.

[0021]

EXAMPLES Hereinafter, the resin composition of the present invention will be specifically described with reference to Examples. In the examples, the heat resistance and mechanical properties of molded articles obtained from the resin composition were measured on injection-molded test pieces according to the following methods. Flexural modulus JIS K7203 Tensile strength JIS K7113 Heat distortion temperature JIS K7207 (18.6kg)
load)

As the sliding characteristics, the wear amount W and the friction coefficient μ
And the PV limit value was evaluated. Each measuring method is as follows. 30mm x 30mm sheet-like molded product
Cut into a size of 3 mm, and the friction surface is polished and finished.
Prepare carbon steel for machine structure as mating material, inner diameter 20m
m, outer diameter 25.6 mm, height 15 mm, and cylindrical finish.

A load of 5 kg was applied at a friction speed of 60 cm / s using a cylindrical end face type friction / wear tester manufactured by Orientec.
The amount of wear W [weight loss of test piece (mg)] when changing from 30 kg to 30 kg was measured. Further, the frictional force F (kgf) was calculated by the following formula (1), and the friction coefficient μ was calculated from the measurement result of the frictional force F by the following formula (2). Friction force F = (Rf) / r (1) R: Distance between load cell center and rotation center (mm) f: Load just under load cell center (kgf) r: Radius (outer diameter) of mating material Friction coefficient μ = F / P (2) P: Load (kgf) Further, the limit PV value is the load when the friction surface melts and the friction coefficient starts to increase when the load is increased under the condition of the friction speed of 60 cm / s. Calculated from

The resins used are as follows. PAS resin: PPS made by Topren Co., Ltd. "Toprene T-
7 ”[300 ° C melt viscosity 7,000 poise (die orifice L
/ D = 10, measured with a load of 20 kg] Polyvinylidene fluoride (PVDF): Sobe made by Solvay
lef1010 Polytetrafluoroethylene: Daikin L-5 L-5 methyl methacrylate polymer 30% by weight and ethylene / glycidyl methacrylate 70% by weight graft copolymer (EGMA-g-PMMA): NOF Corporation Manufactured by Model A4200, melt flow rate at 230 ° C. 0.7 g / min, d = 0.993 g / cm ³

45 mmφ after dry blending each component
It was melt-kneaded at 300 ° C. using a twin-screw extruder to obtain pellets. The pellets were injection-molded at 300 ° C. and a mold temperature of 140 ° C. to prepare test pieces, and their characteristics were evaluated (Examples 1 to 7). The results are shown in Table 1. For comparison, a resin composition containing neither polytetrafluoroethylene nor EGMA-g-PMMA was similarly evaluated. The results are shown in Table 2 (Comparative Examples 1 to 3).

[0026]

FUNCTION AND EFFECT OF THE INVENTION The graft copolymer of the methyl methacrylate polymer used in the present invention and the polymer of glycidyl ester of α, β-unsaturated acid has a glycidyl ester moiety at the molecular end of PAS resin. Reacts with SH groups,
Further, the methyl methacrylate portion in the copolymer shows a great compatibility with the fluororesin, particularly polyvinylidene fluoride. Therefore, the PAS resin in the resin composition of the present invention and polyvinylidene fluoride are compatible with each other to form an alloy, and a molded article formed from this has a chemical resistance, a solvent resistance and a PAS which polyvinylidene fluoride originally has. It has excellent mechanical properties and heat resistance that the resin originally has. Moreover, by including a graft copolymer of a methyl methacrylate polymer and a polymer of a glycidyl ester of an α, β-unsaturated acid and a copolymer of tetrafluoroethylene, sliding properties and mechanical properties are improved. Is greatly improved. Therefore, the molded product obtained from the resin composition of the present invention is useful as a member such as a roller, a gear, and a bearing that is required to have low friction characteristics and low wear characteristics.

[Table 1]

Claims (1)

[Claims] 1. A polyarylene sulfide resin 5 to 95.
100 parts by weight of a resin mixture consisting of 100% by weight and a fluororesin of 95 to 5% by weight, a methyl methacrylate polymer and α,
A homopolymer or copolymer of 1 to 50 parts by weight of a graft copolymer with a polymer of glycidyl ester of β-unsaturated acid, wherein the fluororesin is 5 to 95% by weight of polyvinylidene fluoride and ethylene tetrafluoride. A thermoplastic resin composition comprising 95 to 5% by weight.