JPS63161045A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition useful in an automobile field, etc., having excellent impact resistance in TD direction (direction perpendicular to flow of resin in processing), by blending a thermoplastic resin composition consisting of a copolymer resin of an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride, etc., with an organopolysiloxane. CONSTITUTION:100pts.wt. sum of (A) 50-90pts.wt., preferably 60-85pts.wt. copolymer resin (e.g. styrene-maleic anhydride copolymer, etc.) of an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride and (B) 50-10 pts.wt., preferably 40-15pts.wt. copolymer resin obtained by copolymerizing two or more compounds selected from a group consisting of methacrylic ester, vinyl cyanide and an aromatic vinyl in the presence of rubber is blended with (C) 1.3-5pts.wt., preferably 1.5-4pts.wt. organopolysiloxane (e.g. dimethylpolysiloxane, etc.).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has excellent impact resistance, heat resistance, and gloss, and can be used as a material for molded products in the fields of home appliances, automobiles, food, medicine, miscellaneous goods, etc. Thermoplastic resin compositions useful as thermoplastic resin compositions.

Y Prior art J Copolymers of aromatic vinyl monomers and unsaturated dicarboxylic anhydrides, especially styrene-maleic anhydride copolymers (SM
Although A) has superior heat resistance compared to styrene resins, it has the disadvantage of poor mechanical properties, particularly impact resistance.

Therefore, as a method to improve the impact resistance of this material, a method is known in which styrene and maleic anhydride are copolymerized in the presence of rubber, but since adding rubber increases the viscosity of the polymerization system, it is difficult to control the polymerization. However, there are disadvantages in that heat resistance and gloss are reduced.

For this reason, attempts have been made to combine the conflicting properties of impact resistance and heat resistance in a composition system (Japanese Patent Application Laid-Open No. 54-50553). However, this set/paraboloid is S
It is a mixture of MA, 7crylonitrile-butadiene-styrene tM resin (^BS resin), etc., and polycarbonate, etc., but when polycarbonate is blended, high temperature kneading is required, so the rubber component may deteriorate due to heat when mixed. There is a drawback that impact resistance is not sufficiently improved.

In addition, in order to improve impact resistance without impairing the excellent heat resistance and gloss that SMA has in composition systems, we have developed systems such as SMA and He〇S resins, methyl methacrylate-butadiene-styrene resins (MBS resins), etc. A composition to which an organic polysiloxane is added has been proposed (Japanese Patent Application Laid-Open No. 61-241).
Publication No. 342).

However, this composition and the above-mentioned conventional compositions have poor impact strength in the direction parallel to the resin flow during processing (
Although it shows a considerably large value in the MD force direction (hereinafter referred to as the MD force direction), it is a low value in the direction perpendicular to the resin flow during processing (hereinafter referred to as the TD force direction), and in many cases, this lower value is Since it is a factor that controls the impact resistance strength of the product, it has the disadvantage of having low impact resistance overall.

[Problem to be Solved by the Invention 1] The present invention solves the problem by combining SMA, ^BS resin, and methyl methacrylate.
The object of the present invention is to provide a composition in which an organic polysiloxane is added to a butadiene-styrene resin (MBS resin) or the like, and the impact resistance in the TD force direction is improved.

[Means for Solving the Problems 1] As a result of various studies conducted by the present inventors regarding the above-mentioned resin M parabolic system, it was unexpectedly possible to increase the proportion of organic polysiloxane in the conventional composition to a certain limit. It was discovered that increasing the TD force increases the impact strength in the TD force direction and improves the abrasion resistance, and based on this knowledge, the present invention was completed.

That is, the present invention provides (A) a copolymer resin of an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride, (B) a methacrylic acid ester monomer, a vinyl cyanide monomer, and an aromatic resin in the presence of rubber. In a composition consisting of a thermoplastic resin obtained by copolymerizing two or more compounds selected from the group consisting of group vinyl monomers and (C) an organic polysiloxane, (
The total resin amount of A) and (B) is 100 parts by weight, (A
), 50 to 10 parts by weight of (B), and 1.3 to 5 parts by weight of (C).

In the present invention, a copolymer of an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride is used as component (A).

Here, as the aromatic vinyl monomer, styrene pond, a-
It includes styrene derivatives such as methylstyrene, 0-methylstyrene, 1m-methylstyrene, p-methylstyrene, 2,4-dichlorostyrene, 2,5-dichlorostyrene, and trimethylstyrene.

Additionally, some of these vinyl aromatic compounds can be replaced with other copolymerizable monomers such as methacrylic acid, methyl methacrylate, methyl acrylate, ethyl methacrylate, acrylonitrile, halogen-containing vinyl monomers, etc. You can also do it.

Further, as the unsaturated dicarboxylic acid anhydride, maleic anhydride is particularly useful, but anhydrides such as itaconic acid, citraconic acid, mesafonic acid, ethylmaleic acid, methylitafonic acid, and chlormaleic acid can also be used.

Component (A) of the present invention is obtained by copolymerizing the above-mentioned aromatic vinyl monomer and unsaturated dicarboxylic acid anhydride using a known method such as solution polymerization, bulk polymerization, or bulk-suspension polymerization. It is something. In producing this copolymer, rubber can also be blended and modified. Rubbers that can be used to modify the copolymer include various rubbers such as polybutadiene rubber, butyl rubber, styrene-butadiene rubber, acrylonitrile rubber, ethylene-propylene rubber, and natural rubber.

Specifically, styrene-maleic anhydride copolymer (SMA) is suitable as the component (A) as described above.

The SMA preferably has a maleic anhydride content of 1 to 30% by weight, particularly preferably 3 to 25% by weight. Here, if the maleic anhydride content of SM^ is less than % by weight, the heat resistance will be poor,
Moreover, if the maleic anhydride content exceeds 30% by weight, impact resistance decreases, which is not preferable.

This component (A) is used in a proportion of 50 to 90 parts by weight, preferably 60 to 85 parts by weight, based on the total resin amount of components (A) and (B) being 100 parts by weight.

Next, in the present invention, two or more compounds selected from the group consisting of methacrylic acid ester monomer, vinyl cyanide monomer, and aromatic vinyl monomer are combined in the presence of rubber as component (B). A thermoplastic resin obtained by polymerization is used.

There are various kinds of rubbers, such as diene rubber or a mixture of diene rubbers, such as butadiene rubber (13
R), imprene rubber (IR), chlorobutylene rubber (
OR), piperylene rubber, styrene-butadiene copolymer rubber, styrene-butadiene block copolymer rubber,
Acrylonitrile-butanoene copolymer rubber (NI3R
), ethylene-bu-a-pyrene rubber (BPR), terpolymer (EPT), which is a copolymerization of ethylene and propylene with a small amount of diene, and in-butylene-isobutylene rubber (
IIR), ethylene-vinyl acetate rubber, chlorinated polyethylene, epichlorohydrin rubber, ethylene-acrylic acid or a derivative thereof, rubber of acrylic acid or a derivative thereof, and the like.

Among these, butadiene rubber (BR) is particularly suitable.

Various methacrylic acid ester monomers can be mentioned, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, and methyl methacrylate is particularly preferred. .

Next, examples of vinyl cyanide monomers include acrylonitrile and 1-methyl methaacrylonide.

Further, as the aromatic vinyl monomer, there are those listed as the component (A) above, and specifically, for example, styrene,
A-methylstyrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, dimethylstyrene, chlorostyrene, etc. are used.

Component (B) in the present invention is a solution of two or more compounds selected from the group consisting of methacrylic acid ester monomers, vinyl cyanide monomers, and aromatic vinyl monomers in the presence of the rubber. It is a thermoplastic resin obtained by copolymerization using known methods such as polymerization, bulk polymerization, suspension polymerization, bulk-suspension polymerization, and emulsion polymerization. In particular, when producing a thermoplastic resin with a high rubber component content, it is preferable to produce it by emulsion graft polymerization. Specifically, for example, a methacrylic acid ester monomer and an aromatic vinyl monomer are emulsion graft-polymerized to a polybutadiene latex,
It can be produced by coagulating the obtained polybutadiene copolymer latex with an inorganic acid or an inorganic salt such as aluminum sulfate.

Among the components (B) obtained in this way, those obtained by copolymerizing styrene-methyl methacrylate or styrene-acrylonitrile in the presence of polybutadiene or a butanoene copolymer containing 30% by weight or more of butadiene. Thermoplastic resins are preferred. Note that the above styrene may be partially or entirely replaced with α-methylstyrene or the like. Specifically, methyl methacrylate-
Butadiene-styrene resins (MBS resins) and acrylonitrile-butadiene-styrene resins (^BS resins) can be mentioned as suitable ones, in particular those with a butadiene rubber content of 30 to 90% by weight and a methyl methacrylate or acrylonitrile content of 40% by weight. -2% by weight, and those with a styrene content of 40-2% by weight are preferred.

The amount of component (B) as described above is calculated by subtracting the parts by weight of the resin used in component (A) from 100 parts by weight, and the amount of resin used is 100 parts by weight.
50-10 parts by weight, preferably 40-1 parts by weight
It is used in a proportion of 5 parts by weight. (B) The blending ratio of the component is 50
When the amount exceeds 1 part by weight, heat resistance decreases, and when the proportion of component (B) is less than 10 parts by weight, impact resistance decreases.

Furthermore, in the present invention, organic polysiloxane is used as component (C). Here, the organic polysiloxane is a polymer having a repeating unit represented by the following general formula RI i O- (wherein R' and R2 represent an alkyl group, an aryl group, or an aralkyl group).

In the component (C) in the present invention, this repeating unit may be one type of homopolymer type aiso polysiloxane,
Further, it may be a random type, block type, or graph F type copolymerized isopolysiloxane consisting of a combination of two or more types of repeating units. Furthermore, in the present invention, some of the organic groups of these organic polysiloxanes may be substituted with hydroxyl groups, alkoxy groups, hydroxyalkyl groups, or polyhydroxyfulkylene groups. These organic polysiloxanes may be used not only as a single type but also as a mixture of two or more types.

Specific examples of component (C) as described above include dimethylpolysiloxane, methylphenylpolysiloxane, diphenylpolysiloxane, etc., with dimethylpolysiloxane being particularly preferred. This (C)
The viscosity of the organic polysiloxane component is not particularly limited, but is 10 to 100,000 cst (30°C), preferably 100 to 50,000 cst (30°C). If the viscosity at 30°C is less than 10cst, the volatility will be extremely high and the appearance will be poor when molded.If the viscosity is more than 100,000csL at 30°C, it will not be uniformly mixed into the composition. Not desirable as it is difficult.

The organic polysiloxane as component (C) is 1.3 to 5 parts by weight, preferably 1.5 parts by weight, based on the amount of resin in the composition.
It is used in a proportion of ~4 parts by weight. If the blending ratio of component (C) is less than 1.3 parts by weight, the effect of improving the impact resistance in the TD force direction will be insufficient, and the blending ratio of component (C) will be less than 5 parts by weight.
If it exceeds 1 part by weight, it is not preferable because the heat resistance decreases.

The present invention consists of the above three components (A) component, (B) component and (C) component, and if necessary, antioxidants such as hindered phenol type and phosphorus type, ultraviolet absorber,
Flame retardants, plasticizers, lubricants, lath fibers, black iso fillers such as silicate and titanium oxide, and thermoplastic resins such as polystyrene, polyethylene and polypropylene can be blended.

The thermoplastic resin composition of the present invention is not particularly limited in the kneading order, and may be produced by simultaneously kneading the three components (A), (B), and (C) by a conventional method, or (A) It is also possible to produce by adding component (C) in advance during the polymerization of component or component (B) and mixing the two together.

The kneading can be carried out using a known method such as a single-screw kneading extruder, a Banbury mixer, etc., at a temperature of 150 to 200°C.

[Effect of the invention 1゛The thermoplastic resin composition of the present invention has improved impact resistance in the TD force direction, has a well-balanced impact resistance in all directions, and has greatly improved overall strength. There is. Moreover,
The thermoplastic resin composition of the present invention also has excellent heat resistance and gloss.

Therefore, the thermoplastic resin composition of the present invention can be advantageously applied to a wide range of fields such as home appliances, automobiles, foods, medicine, and miscellaneous goods by extrusion molding, injection molding, etc.

〔Example〕

Next, the present invention will be explained by examples.

Examples 1 to 10 and Comparative Examples 1 to 6 (Styrene-maleic anhydride copolymer (SM^) as Ahr & min, 30 parts by weight of 7crylonitrile and 10 parts by weight of styrene in 60 parts by weight of polybutanoene as component (B)) Resin obtained by emulsion graft copolymerization (^BS) or resin obtained by emulsion graft copolymerization of 25 parts by weight of methyl methacrylate and 15 parts by weight of styrene on 60 parts by weight of polybutadiene (MBS), dimethylpolymer as component (C) Siloxane (silicon) was prepared and kneaded at 180° C. in a monopongee extrusion kettle at the blending ratio shown in the table to obtain a resin composition.

The evaluation results of the Fizot impact strength in MD force direction and TD force direction, heat distortion temperature, and gloss of the obtained resin composition are shown in the table.

These results show that the improvement in the Fizot impact strength in the TD force direction is remarkable and is well balanced with the MD force direction impact strength.

These tests were conducted using the following method.

Izot test is JIS K 6872 (with /mark)
Compliant.

The heat distortion temperature was based on JIS K 6872.

Sliding wear test As shown in Figures 1 and 2, two types of plates and hollow cylinders were tested.
A method of measuring the wear of a plastic test piece by touching the lower surface of a hollow cylindrical mating material of the same material to which a constant load is applied from above each plastic specimen, and rotating either the test piece or the mating material. It was carried out by

(1) The dimensions of the test piece are 130xz, 1i30zz, a square plate with a thickness of 2 to 5zz, a disc with a diameter of 40xx and a thickness of 2 to Sxx, or an outer diameter of 25.61JI, an inner diameter of 20yrx, and a length of 1.
Let it be a 5zz cylinder.

(2) The dimensions of the mating material are outer diameter 25.6zz and inner diameter 20mm.
Let it be a cylinder with length xx and length 15zz. The surface roughness of the sliding surface that comes into contact with the test piece is approximately 0.
It is set to 8 μmRa.

(3) In principle, the material of the mating material shall be JISC4005.
1 (carbon copper steel material for mechanical structures) shall be 545C as specified.

The hardness of the measurement surface of the mating material is 1IRc12 to 25 according to the definition of Rockwell C hardness.

The test load was 1.5Ag, and the rotational speed of the rotating shaft was the average sliding speed on the sliding surface of the test piece, which was 0.5±0.02.
5 m/s, measure the mass of the test piece after 30 minutes, and measure the amount of wear V ax from the amount of decrease. The specific wear amount was calculated as follows, where the test load at this time was P kg and the average sliding distance was L km.

The numerical values in the table are averaged data using five test pieces.

The following SM^ polymers and organic siloxanes were used in the table.

SMA1 Weight average molecular weight 200,000, maleic anhydride content 7 mol%.

SMA 2 weight average molecular weight 260,000, maleic anhydride content 14%.

Silicone 1 Viscosity 3000cst/30'C (Toregi's) Near 5H200, 30QOOCST).

Silicone 2 Viscosity 10000cst/30'C (Toshi Silicone 511200.10000cst).

Silicone 3 Viscosity 200 cst/30"C (East Silicone 5H 200, 200 cst).

[Brief explanation of the drawing]

@Figure 1 and Figure 2 are drawings for explaining the abrasion test method used in the examples, and the symbols in the figures are 1; test piece, 2.
; mating material; 3; sliding surface; 4; rotating shaft.

Claims (1)

[Scope of Claims] 1 (A) Copolymer resin of aromatic vinyl monomer and unsaturated dicarboxylic acid anhydride, (B) methacrylic acid ester monomer, vinyl cyanide monomer in the presence of rubber and a thermoplastic resin obtained by copolymerizing two or more compounds selected from the group consisting of aromatic vinyl monomers and (C) an organic polysiloxane, in which (A) and (B) When the total resin amount is 100 parts by weight, (A) is 50 to 90 parts by weight, (B) is 50 to 10 parts by weight, and (C) is 1.3 to 90 parts by weight.
A thermoplastic resin composition characterized in that it contains 5 parts by weight. 2. The composition according to claim 1, wherein the copolymer of aromatic vinyl monomer and unsaturated dicarboxylic anhydride is a styrene-maleic anhydride copolymer. 3 The organic polysiloxane is dimethylpolysiloxane,
The composition according to claim 1, which is one or more selected from the group consisting of methylphenylpolysiloxane and diphenylpolysiloxane.