JP3044276B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a resin obtained by blending a specific polyolefin graft polymer and a specific terpolymer with a rubber-reinforced styrenic resin and having excellent chemical resistance and impact strength after coating. Composition.

[0002]

BACKGROUND OF THE INVENTION Problems to be Solved by the Invention
Resin, AES resin, AAS (ASA) resin and AC
BACKGROUND ART Rubber-reinforced styrene resins called S resins are widely used in a wide range of fields such as vehicles, light electric appliances, and miscellaneous goods because of their excellent mechanical properties such as impact resistance and workability, and excellent surface gloss. However, it has poor chemical resistance as compared with other engineering plastics, and has a problem that cracks are easily generated when it comes into contact with gasoline, brake fluid, grease or the like.

[0003] It has been known that the chemical resistance is improved by increasing the amount of vinyl cyanide (acrylonitrile) in the resin. However, as the amount of acrylonitrile increases, the impact resistance decreases and the initial coloring ( Yellowing) occurs. In addition, the present inventor has found improvement in chemical resistance by blending a terpolymer composed of olefin-unsaturated dicarboxylic anhydride-unsaturated carboxylic acid alkyl ester. With the development of functions, there has been a demand for the development of a composition having more excellent chemical resistance.

[0004] On the other hand, these resins are coated for the purpose of decoration or improvement of weather resistance. In recent years, molded articles provided for coating have been diversified, and molded articles having more complicated shapes have been used. Painting is required. Therefore, depending on the shape of the molded product, the impact strength after painting is remarkably inferior to that of the unpainted product, which may cause a problem as a product. In particular,
In exterior applications for vehicles, it is needless to say that this remarkable decrease in impact strength is a fatal defect.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on the above problems and found that a specific polyolefin graft polymer and a specific epoxy group-containing olefin copolymer were added to a rubber-reinforced styrene resin. It has been found that by blending the compound, a resin composition can be obtained in which the chemical resistance and the impact strength after coating are not significantly reduced are obtained.

That is, the present invention relates to a rubbery polymer (a-
1) and 50 to 90% by weight of an aromatic vinyl monomer, 50 to 10% by weight of a vinyl cyanide monomer and / or an unsaturated alkyl carboxylate monomer, and other copolymerizable vinyl monomers The crystalline polyolefin (b-1) and the aromatic vinyl monomer 50 to 100 parts by weight of the rubber-reinforced styrene resin (A) obtained by polymerizing 0 to 40% by weight of the monomer (a-2) are used. A polyolefin graft polymer obtained by polymerizing 100% by weight of a monomer (b-2) composed of 0 to 50% by weight of a vinyl cyanide monomer and / or an unsaturated carboxylic acid alkyl ester monomer. B) and a terpolymer (C) comprising an olefin, an unsaturated dicarboxylic anhydride and an unsaturated carboxylic acid alkyl ester monomer in a total amount of 0.1 to 40 parts by weight. What is provided is a thermoplastic resin composition characterized by being blended such that the weight ratio of the ft polymer (B) / terpolymer (C) is 5/95 to 95/5 by weight. It is.

Hereinafter, the present invention will be described in detail.

The rubber-reinforced styrenic resin (A) refers to a rubbery polymer (a-1) and an aromatic vinyl monomer 50 to 90.
% By weight, 50 to 10% by weight of a vinyl cyanide monomer and / or an unsaturated carboxylic acid alkyl ester monomer
And 0 to 40% by weight of another copolymerizable vinyl monomer
Is a resin obtained by polymerizing a monomer (a-2) consisting of: a graft weight obtained by polymerizing the monomer (a-2) in the presence of the rubbery polymer (a-1) described above. It is a mixture of a copolymer or a copolymer obtained by polymerizing the graft polymer and the monomer (a-2).

As the rubbery polymer (a-1), diene polymers having a glass transition temperature of 0 ° C. or lower, such as polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, and ethylene-propylene copolymer Examples thereof include an ethylene-propylene-based copolymer such as a copolymer, an ethylene-propylene-non-conjugated diene-based copolymer, an acrylate ester-based copolymer, and chlorinated polyethylene, and one or more kinds thereof can be used.

These rubbery polymers are produced by emulsion polymerization, solution polymerization, suspension polymerization, bulk polymerization and the like. The gel content of the rubbery polymer in the case of production by emulsion polymerization is not particularly limited, but is preferably from 0 to 95%.

As the aromatic vinyl monomer, styrene,
α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene,
Examples thereof include α-methylvinyltoluene, dimethylstyrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene, vinylnaphthalene, and the like, and one or more kinds can be used. Particularly, styrene is preferred.

Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonyl, fumaronitrile and the like, and one or more kinds thereof can be used. Acrylonitrile is particularly preferred.

The unsaturated carboxylic acid alkyl ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
-Ethylhexyl (meth) acrylate and the like,
One or two or more can be used. Particularly, methyl methacrylate is preferred.

Other copolymerizable vinyl monomers which can constitute the rubber-reinforced styrene resin (A) together with the above-mentioned monomers include acrylic acid, methacrylic acid, maleic acid and maleic anhydride. Maleimide compounds such as unsaturated carboxylic acids or unsaturated dicarboxylic anhydrides such as citraconic anhydride, maleimide, methylmaleimide, ethylmaleimide, N-phenylmaleimide, and O-chloro-N-phenylmaleimide. One or two or more can be used.

Aromatic vinyl monomer (i), vinyl cyanide monomer and / or unsaturated carboxylic acid alkyl ester monomer (ii) in monomer (a-2) and copolymerizable The composition ratio of the other vinyl monomer (iii) is (i) 50 to 90% by weight, (ii) 50 to 10% by weight.
And (iii) 0 to 40% by weight. Outside this range, heat resistance and workability are poor, which is not preferred. Preferably, (i) 50 to 80% by weight, (ii) 50 to 20% by weight
And (iii) 0 to 30% by weight, and in particular, a monomer (a-2) using a vinyl cyanide-based monomer as (ii) is preferable.

The rubbery polymer (a-1) and the monomer (a-
Although there is no particular limitation on the composition ratio with 2), rubbery polymers (a-1) 5 to 8 are preferred in view of heat resistance, impact resistance and workability.
It is preferably 0% by weight and 95 to 20% by weight of the monomer (a-2).

Particularly, a resin comprising a graft polymer having a graft ratio of 20 to 100% and a weight average particle size of 0.05 to 5 μm and a copolymer is preferred.

The method for producing the rubber-reinforced styrenic resin (A) (graft polymer and copolymer) is not particularly limited, and may be a known emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization or a combination thereof. A method is used.

The polyolefin graft polymer (B) refers to a crystalline polyolefin (b-1), 50 to 100% by weight of an aromatic vinyl monomer, a vinyl cyanide monomer and / or an unsaturated carboxylic acid. It is a polymer obtained by polymerizing a monomer (b-2) comprising 50 to 0% by weight of an alkyl ester monomer.

The crystalline polyolefins (b-1) are polyethylene and polypropylene, especially acrylonitrile / styrene mixed monomer (25/75 weight ratio).
Crystalline polyolefins having a swelling degree of 2 to 80% by weight (70 ° C., 1 hour immersion), particularly 2 to 60% by weight, are preferred.

Examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene. Polypropylene includes not only homopolymers but also random polymers with ethylene and α-olefins. Block polymers can be used, and one or more kinds can be used. The object of the present invention cannot be achieved with an amorphous ethylene-propylene copolymer.

Examples of the aromatic vinyl monomer and vinyl cyanide monomer include the monomers mentioned in the section of rubber-reinforced styrene resin (A). Examples of the unsaturated carboxylic acid alkyl ester-based monomer include the monomers listed in the section of the rubber-reinforced styrene-based resin (A), and glycidyl acrylate and glycidyl methacrylate.

Styrene as an aromatic vinyl monomer,
Acrylonitrile is preferred as the vinyl cyanide monomer, and glycidyl methacrylate and methyl methacrylate are preferred as the unsaturated carboxylic acid alkyl ester monomer.

The composition ratio of the aromatic vinyl monomer (i) to the vinyl cyanide monomer and / or the unsaturated carboxylic acid alkyl ester monomer (ii) in the monomer (b-2) is as follows: , (I) 50-100% by weight, (ii) 50-0%
% By weight. Outside this range, the chemical resistance is inferior and is not preferred.

Although the composition ratio of the crystalline polyolefin (b-1) and the monomer (b-2) is not particularly limited, the crystalline polyolefin (b) is preferred in view of chemical resistance, paintability and impact resistance. -1) 100 parts by weight of monomer (b-2) 20
To 200 parts by weight are preferred, and in particular, the monomer (b-2) 20
-100 parts by weight are preferred.

The method for producing the polyolefin graft polymer (B) is also not particularly limited, and known emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization, or a combination thereof can be used.

The terpolymer (C) comprises an olefin, an unsaturated dicarboxylic anhydride and an unsaturated carboxylic acid alkyl ester monomer.

Examples of the olefin include ethylene, propylene, butene-1, 4-methylpentene-1, and the like, with ethylene and propylene being particularly preferred. Examples of the unsaturated dicarboxylic anhydride include maleic anhydride, citraconic anhydride, aconitic anhydride, and the like, with maleic anhydride being particularly preferred. Examples of the unsaturated carboxylic acid alkyl ester-based monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and hydroxymethyl (meth) acrylate, and particularly ethyl acrylate. Butyl acrylate is preferred.

From the viewpoints of chemical resistance and impact resistance, 50 to 98.5% by weight, especially 55 to 96% by weight of olefin, 0.5 to 10% by weight of unsaturated dicarboxylic anhydride, especially 1 to 8% by weight of unsaturated carboxylic acid Acid alkyl ester monomer 1
A terpolymer of from 40 to 40% by weight, especially from 3 to 37% by weight, is preferred.

The terpolymer (C) can be produced by various methods. For example, olefin is supplied to a first zone of a cylindrical autoclave equipped with a blade-type stirrer, and then olefin is supplied to a second zone, an unsaturated dicarboxylic anhydride,
An unsaturated carboxylic acid alkyl ester-based monomer mixture is supplied, and a radical initiator such as t-butyl 2-ethyl-perhexanoate dissolved in a hydrocarbon fraction is injected into the third zone at 1000 to 2000 atm. Polymerization under pressure.

The resin composition of the present invention comprises a total of the polyolefin graft copolymer (B) and the terpolymer (C) per 100 parts by weight of the rubber-reinforced styrene resin (A).
0.1 to 40 parts by weight, and the polyolefin graft copolymer (B) and the terpolymer (C) are blended in a weight ratio of 5/95 to 95/5. It is a resin composition.

If the total of (B) and (C) is less than 0.1 part by weight per 100 parts by weight of (A), the improvement of the chemical resistance and the impact strength of paintability is not sufficient, and if it exceeds 40 parts by weight. It is not preferable because it tends to cause delamination. From the physical property balance of the final composition, the total of (B) and (C) is 0.1 to 30.
It is preferred to be blended by weight.

If the ratio of (B) to (C) is out of the above range, the balance between chemical resistance and impact strength after coating is unfavorably poor. Particularly, the range of 10/90 to 90/10 is preferable.

The order of mixing the rubber-reinforced styrene resin (A), the polyolefin graft copolymer (B) and the terpolymer (C) and the state thereof are not limited.
Depending on the state of pellets, beads, powder, etc. (A),
(B) and (C) a simultaneous simultaneous mixing of the three components, and a method of mixing the components remaining after the specific components are preliminarily mixed. As a mixing method, a known method such as a Banbury mixer, a roll, or an extruder can be adopted.

When mixing, if necessary, an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a lubricant, a dye, a pigment, a plasticizer, a flame retardant, a release material, a glass fiber, a metal fiber,
Additives such as carbon fibers and metal flakes, reinforcing agents and fillers can be added. In addition, a thermoplastic resin such as polyamide, polyacetal, polyester, polyphenylene oxide, polymethyl methacrylate, or polyvinyl chloride can be appropriately compounded.

Next, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited by these. In addition, the number of parts and the percentage are all shown on a weight basis.

Various resins used in Examples and Comparative Examples are as follows.

Rubber-reinforced styrene resin (A) ABS: polybutadiene rubber latex (particle size 0.35
50 parts (solid content), 35 parts of styrene and 15 parts of acrylonitrile were polymerized by a known emulsion polymerization method. On the other hand, in another reactor, 55 parts of styrene, 30 parts of acrylonitrile and 15 parts of N-phenylmaleimide were polymerized by a known emulsion polymerization method. Thereafter, after mixing the obtained polymer latex, salting out, dehydration, and drying were performed, and the rubber content of the graft polymer having a graft ratio of 55% was 25%.
% Resin was obtained.

AES: 50 parts of ethylene-propylene-ethylidene norbornene rubber (propylene content 41%, iodine value 15, Mooney viscosity 65), 35 parts of styrene and 15 parts of acrylonitrile are polymerized by a known suspension polymerization method. Dehydrated and dried. On the other hand, in another reactor, 70 parts of styrene and 30 parts of acrylonitrile were polymerized based on a known emulsion polymerization method, and subjected to salting out and drying. Both were mixed to obtain an AES resin having a rubber content of 25%.

Polyolefin graft polymer (B) B-1: polyethylene (high-pressure polyethylene, density 0.9
18g / cm ³ , melt flow rate 7g / 10min, swelling degree 2
(3%) 100 parts, styrene 30 parts and acrylonitrile 15 parts were polymerized based on a known suspension polymerization method, dehydrated and dried to obtain a graft polymer.

B-2: polypropylene (density 0.89 g / c
m ³ , melt flow rate 1.2 g / 10 min, swelling degree 27
%) 40 parts of styrene and 15 parts of acrylonitrile are polymerized based on a known suspension polymerization method,
After drying, a graft polymer was obtained.

Terpolymer (C) C-1: Ethylene-maleic anhydride-ethyl acrylate Terpolymer dissolved in a hydrocarbon fraction using a cylindrical autoclave equipped with a blade-type stirrer. 185 ° C, 1-butyl 2-ethylperhexanoate
The monomer mixture was polymerized at 600 atm to obtain a terpolymer D-2 containing 92% by weight of ethylene, 1.5% by weight of maleic anhydride and 6.5% by weight of ethyl acrylate.

C-2: Terpolymer of ethylene-maleic anhydride-butyl acrylate Terpolymer of 70% by weight of ethylene, 4% by weight of maleic anhydride and 26% by weight of butyl acrylate was prepared in the same manner as in C-1. A polymer was obtained.

The rubber-reinforced styrenic resin, polyolefin graft polymer, terpolymer and polypropylene were mixed in the composition shown in Table 1, mixed and mixed using a 40 mm twin-screw extruder and granulated. .

The physical properties of the obtained various compositions were measured by the following methods, and the results are shown in Table 1.

Chemical resistance: An ASTM1 dumbbell (1/8 inch thick, 217 mm in total length) injection-molded is fixed on an arc-shaped jig having stoppers at both ends (surface distortion of the test piece based on the curvature of the jig). 1% or 1.5%). Kerosene is applied to the surface of the test piece and left at 60 ° C. for 24 hours. After that, the test piece is checked for breakage and cracks on the test piece surface. ○ No crack △ Cracked × Bent

Impact test of unpainted product: Injection molded 60
After leaving a flat plate of × 60 × 2 mm in a low-temperature bath adjusted to -15 ° C. for one hour or more, the flat plate is taken out and immediately subjected to an impact test.

Impact test of painted product: injection molded 60 ×
One side of a 60 × 2 mm flat plate is coated with a urethane-based paint (Hi Urethane # 6500, manufactured by NOF Corporation) at 80 ° C.
Bake for 0 minutes. After adjusting the coated flat plate to −15 ° C. in the same manner as an unpainted product, the uncoated surface is set to be hit, and an impact test is performed.

The above impact test is carried out as follows.
Use a load of 2 kg for unpainted products and a load of 1 kg for painted products. Drop the load perpendicular to the test piece.
The impact test was performed 0 times to find the highest height with a destruction rate of 50% or less. For unpainted products, height (cm) x load (2 kg), for painted products, height (cm) x Load (1Kg)
To determine the impact energy (Kg-cm).

Delamination property: After the test piece shown in the figure was prepared, it was bent at the film gate part, and it was confirmed whether or not delamination had occurred at the molded part when the sprue part was removed.

[0051]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a plan view of a test piece used to evaluate the presence or absence of delamination.

FIG. 2 is a sectional view of a test piece.

[Explanation of symbols] Gate Film gate Molded product Sprue part A Bending direction

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C08L 55/02 C08L 55/02 (56) References JP-A-1-306457 (JP, A) JP-A-1-113452 (JP) JP-A-61-268748 (JP, A) JP-A-63-137947 (JP, A) JP-A-64-48847 (JP, A) JP-A-1-31159 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 51/04 C08L 23/00 C08L 33/06 C08L 35/00 C08L 51/06 C08L 55/02 WPI (DIALOG)

Claims (1)

(57) [Claims] 1. A rubbery polymer (a-1) and 50 to 90% by weight of an aromatic vinyl monomer, 50 to 90% by weight of a vinyl cyanide monomer and / or an unsaturated carboxylic acid alkyl ester monomer. 10% by weight and 0 to 40% by weight of another copolymerizable vinyl monomer (a-2) are polymerized with 100 parts by weight of a rubber-reinforced styrene resin (A), and the crystalline polyolefin (b- 1) and aromatic vinyl monomer 50-1
A polyolefin graft polymer obtained by polymerizing 00% by weight of a monomer (b-2) comprising 0 to 50% by weight of a vinyl cyanide-based monomer and / or an unsaturated carboxylic acid alkyl ester-based monomer (b-2) B) and a terpolymer (C) comprising an olefin, an unsaturated dicarboxylic anhydride and an unsaturated carboxylic acid alkyl ester monomer in total.
0.1 to 40 parts by weight and the ratio of polyolefin graft polymer (B) / terpolymer (C) is 5/95 to 95/5 by weight. Characteristic thermoplastic resin composition.