JP3186121B2 - 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 having excellent impact resistance.

[0002]

2. Description of the Related Art Rubber-reinforced aromatic vinyl resins such as A
BS resins and AES resins are widely used as molding materials for various molded products because of their excellent impact resistance, excellent moldability and excellent balance of various performances. For example, in order to improve heat resistance, Japanese Patent Application Laid-Open No. 58938/1983 describes a resin composition comprising polyvinyl chloride, ABS resin, and flaky graphite. No. 222135 discloses a resin composition comprising a polystyrene resin, carbon black and graphite. In recent years, it has been used as a housing material for home video cameras.

[0003]

However, the invention disclosed in the above-mentioned publications is a resin composition which improves the respective properties of heat resistance and conductivity. Further, when used as a housing material for a home video camera, a weld is generated due to its complicated shape. Welds are currently painted to make the appearance of the product worse and reduce the value of the product, but this has led to an increase in the cost of the product. An object of the present invention is to provide a thermoplastic resin composition having excellent weld appearance and impact resistance.

[0004]

Means for Solving the Problems In order to achieve the above object, the present inventors have developed a rubber-reinforced aromatic vinyl copolymer,
As a result of examining various inorganic fillers, it was found that by blending graphite and / or molybdenum disulfide with a specific composition in a specific rubber-reinforced aromatic vinyl copolymer, a thermoplastic material with excellent weld appearance and impact resistance was obtained. Solved by the resin composition.

The present invention relates to (A) the following (A1) + (A2)
100 parts by weight of a component, and the rubbery polymer content is 5 to 5.
50% by weight of rubber-reinforced aromatic vinyl copolymer 85
(A1) In the presence of a rubbery polymer content of 28 to 80% by weight
Aromatic vinyl compound and vinyl cyanide compound, or aromatic
Aromatic vinyl compound and vinyl cyanide compound and other copolymerizable
Graft copolymers 100 to 1 obtained by copolymerizing various monomers
0 parts by weight (A2) 0 to 90 parts by weight of a copolymer obtained by copolymerizing an aromatic vinyl compound or an aromatic vinyl compound and another copolymerizable monomer; and (B) graphite and / or disulfide Molybdenum 0.5-1
5% by weight of a thermoplastic resin composition,
The rubbery polymer content of the above (A1) is 32 to 70 weight
% Of the thermoplastic resin composition.

As the rubber-reinforced aromatic vinyl copolymer which is the component (A) of the present invention, the component (A) is 5 to 50% by weight, preferably 10 to 35% by weight, more preferably 10 to 35% by weight of a rubbery polymer. Contains 10-25% by weight. If it is less than 5% by weight, the weld appearance and impact resistance are inferior, and 50% by weight.
When it exceeds, the weld appearance is inferior. The amount of the component (A) used in the thermoplastic resin composition of the present invention is from 85 to 99.5.
%, Preferably 90 to 99.5% by weight, more preferably 95 to 99.5% by weight. If it is less than 85% by weight, weld appearance and impact resistance are poor, and 99.5%
If the content is more than 10% by weight, the weld appearance is inferior. The component (A)
It comprises 100 to 10 parts by weight of the following component (A1) and 0 to 90% by weight of (A2). Particularly preferably, (A
1) 90 to 10 parts by weight of component and 10 to 9 of component (A2)
When the component (A) consisting of 0 parts by weight is used, the more excellent effect intended by the present invention can be obtained.

The component (A1) is an aromatic vinyl compound or a graft copolymer obtained by copolymerizing an aromatic vinyl compound and a vinyl compound copolymerizable with the aromatic vinyl compound in the presence of a rubbery polymer. Yes, as the rubbery polymer used here, polybutadiene, styrene butadiene copolymer, styrene-isoprene copolymer, acrylonitrile butadiene copolymer, ethylene-α-olefin-polyene copolymer, acrylic rubber, silicone Rubber, polyisoprene, butyl rubber, styrene butadiene block copolymer, styrene-isoprene block copolymer, hydrogenated styrene butadiene block copolymer, hydrogenated butadiene polymer, hydrogenated styrene butadiene copolymer, etc. , Styrene-butadiene block copolymer and polystyrene The-isoprene block copolymers, AB type, ABA type, ABA tapered, include such those having a structure of radial teleblock-type, which are used alone or in combination.

[0008] The rubbery polymer in the component (A1) is 28 to
It is 80% by weight, preferably 30 to 70% by weight, particularly preferably 32 to 70% by weight . If it is less than 28% by weight, the impact resistance and weld appearance are inferior, and if it exceeds 80% by weight, the weld appearance is inferior, which is not preferable. As the aromatic vinyl compound in the component (A1), styrene, α-methylstyrene, methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, p-tert-butylstyrene, ethylstyrene , Vinyl naphthalene, etc.
Seeds or two or more can be used. Particularly preferred is styrene.

The vinyl compound copolymerizable with the aromatic vinyl compound in the component (A1) includes acrylonitrile,
Vinyl cyanide compounds such as methacrylonitrile; alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate; methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate and 2-ethylhexyl methacrylate; maleimide; N-phenyl Maleimide compounds such as maleimide and N-cyclohexylmaleimide, unsaturated acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid and cinnamic acid, maleic anhydride, itaconic anhydride, chloromaleic anhydride and citraconic anhydride , Butenyl succinic anhydride,
Unsaturated carboxylic anhydrides such as tetrahydrophthalic anhydride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, 2-methylallyl glycidyl ether, styrene-p-glycidyl ether,
3,4-epoxybutene, 3,4-epoxy-1-pentene, 3,4-epoxy-3-methylpentene, 5,6
-Epoxy-1-hexene, vinylcyclohexene monoxide, epoxy group-containing unsaturated compounds such as p-glycidylstyrene, allylamine, amino group-containing unsaturated compounds such as aminoethyl methacrylate, aminopropyl methacrylate and aminostyrene, 3-hydroxy-1-propene, 4-hydroxy-1butene, cis-4-hydroxy-2butene, trans-4-hydroxy-2
Butene, 3-hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-5-hydroxy-2-pentene, cis-1,4-hydroxy-2-butene, trans-1,4-hydroxy-2
Butene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 2-hydroxyethyl crotonate,
Examples include hydroxyl group-containing unsaturated compounds such as 2,3,4,5,6-pentahydroxyhexyl methacrylate, 2,3,4,5-tetrahydroxypentyl acrylate, and 2,3,4,5-tetrahydroxypentyl methacrylate. And one or more of them are used.

In the graft copolymer (A1), the ratio (graft ratio) of the vinyl copolymer directly grafted to the rubbery polymer to the rubbery polymer is as follows:
Measured by solvent fractionation with acetone,
When the content is 50%, the balance between impact resistance and weld appearance is excellent, which is preferable. The graft ratio is more preferably from 40 to 130%, particularly preferably from 45 to 120%. Preferred components (A1) include butadiene rubber-styrene copolymer, butadiene rubber-styrene-acrylonitrile copolymer, ethylene-propylene rubber-styrene-acrylonitrile copolymer, hydrogenated styrene-butadiene rubber-styrene-acrylonitrile. Copolymers and silicone rubber-styrene-acrylonitrile copolymers may be mentioned, and these may be used alone or in combination of two or more.

The component (A2) is an aromatic vinyl compound or a copolymer composed of a vinyl compound copolymerizable with an aromatic vinyl compound, and is used together with the aromatic vinyl compound and the aromatic vinyl compound used herein. Examples of the polymerizable vinyl compound include all compounds used in the above (A1).
Preferred components (A2) include polystyrene, styrene-acrylonitrile copolymer and styrene-methyl methacrylate- (acrylonitrile) copolymer,
These are used alone or in combination of two or more. Also,
MEA solution 30 of a methyl ethyl ketone (MEK) soluble component of a rubber-reinforced aromatic vinyl copolymer as the component (A) 30
Intrinsic viscosity ([η] 30 ° C MEK, unit dl) measured at ℃
/ G) is preferably from 0.2 to 1.2, and more preferably from 0.3 to 1.0.
Is more preferred. The components (A1) and (A2) can be produced by known polymerization methods such as emulsion polymerization, suspension polymerization, bulk polymerization and solution polymerization.

(2) Examples of the graphite and molybdenum disulfide as component (B) of the present invention, ie, graphite as component (B), include natural graphite, artificial graphite, and flaky graphite, and have an average particle diameter of 100 μm or less. Is excellent in weld appearance and impact resistance, preferably 1 to 50 μm, and more preferably 5 to 4 μm.
0 μm is more preferred. As the component (B), molybdenum disulfide having an average particle diameter of 50 μm or less is excellent in weld appearance and impact resistance, and preferably 0.1 to 3 μm.
0 μm, more preferably 0.5 to 20 μm. The amount of the component (B) used in the thermoplastic resin composition of the present invention is 15 to 0.5% by weight, preferably 10 to 0.5% by weight.
It is 0.5% by weight, more preferably 8 to 0.5% by weight. If it exceeds 15% by weight, the weld appearance and impact resistance are inferior. If it is less than 0.5% by weight, the weld appearance is inferior, which is not preferable.

In the production of the thermoplastic resin composition of the present invention, known ultraviolet absorbers, flame retardants, antioxidants, plasticizers, coloring agents, lubricants, inorganic fillers such as talc and glass fibers, carbon fibers and the like can be used. Additives can be added for use. Further depending on the required performance, other polymers, for example, polyamide, polybutylene terephthalate, polyethylene terephthalate, polyamide elastomer, polyester elastomer, polypropylene, polyethylene, polycarbonate, polysulfone, polyethersulfone, PPS, polyetheretherketone, Polyimide, vinylidene fluoride polymer, liquid crystal polymer, ethylene-glycidyl methacrylate copolymer, or an AS-graft of ethylene-glycidyl methacrylate copolymer can be blended. In producing the thermoplastic resin composition of the present invention, a known kneading apparatus can be used. For example, there are a roll, a kneader, a Banbury mixer, a continuous kneader, an extruder, a single-screw extruder, and a twin-screw extruder. When kneading, (A)
The component and the component (B) may be mixed at once, or may be divided and obtained by kneading two or more stages.

The thermoplastic resin composition obtained according to the present invention can be molded into various molded articles by injection molding, sheet extrusion molding, vacuum molding, heterogeneous molding, foam molding and the like. Various molded products obtained by the above molding method,
Utilizing its excellent properties, it can be used as a housing for home video cameras, automobile interior parts, housing for home electric appliances, various parts related to electronics and electricity, and the like.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples and Production Examples, but these are all illustrative and do not limit the content of the present invention. In the following examples, parts and% indicate parts by weight and% by weight, respectively. 1. Component (A1) in component (A); A1-1 to A1-4 A1-1 : ABS resin comprising 30% of polybutadiene, 10% of styrene butadiene copolymer, 30% of styrene, and 10% of acrylonitrile, graft ratio 50 %, Intrinsic viscosity [η] (30 ° C, in methyl ethyl ketone, the same applies hereinafter)
= 0.43 A1-2: EPDM30 containing ethylidene norbornene
%, Styrene 49%, acrylonitrile 21%, AES resin, graft ratio 45%, intrinsic viscosity [η] = 0.
42 A1-3: ABS resin comprising 25% polybutadiene, 65% styrene, 20% acrylonitrile, graft ratio 40%, intrinsic viscosity [η] = 0.40 A1-4: 90% polybutadiene, 7% styrene, 3% acrylonitrile ABS resin, graft ratio 5
%, Intrinsic viscosity [η] = 0.3

[0016] 2. Component (A2) in component (A): A2-
1 A2-1: styrene 75%, AS resin intrinsic viscosity consisting of acrylonitrile 25% [η] = 0.61 3 . (B) Graphite and molybdenum disulfide B-1 in component B: graphite is artificial graphite fine powder UF manufactured by Showa Denko KK
G30 (average particle diameter 30 μm) was used. B-2: 2 Molybdenum sulfide used was Molypowder PB (average particle diameter 10 μm) manufactured by Sumiko Lubrication Co., Ltd. B-3: Ketjen Black (average particle size: 30 μm) manufactured by EC Japan Co., Ltd. was used . Other components (C) C-1: polyamide elastomer (P made by ATOCHEM
EBAX5537SN00) With the compounding recipe shown in Table 1, each component was kneaded at a time using a 50 mmφ single screw extruder to obtain a pellet-like thermoplastic resin composition. Weld appearance and impact resistance were evaluated using test samples obtained by injection molding of pelletized thermoplastic resin.

Evaluation method Impact resistance Using a molded product with a notch and a thickness of 1/4 ", ASTM
Izod impact strength at 23 ° C. was measured according to D256. Weld appearance A donut-shaped molded product having a thickness of about 2 mm was formed, and the appearance of the weld was visually evaluated. ◎: Very good 〇: Good ×: Poor

[0018]

[Table 1]

Examples 1 to 5 are the thermoplastic resin compositions of the present invention, which are the objects of the present invention. Comparative Example 1 is not preferable because the component (B) is less than the range of the present invention, so that the weld appearance is inferior. Comparative Example 2 is not preferable because the component (B) exceeds the range of the present invention, so that the weld appearance and impact resistance are poor. In Comparative Example 3, since the rubbery polymer of the graft copolymer as the component (A1) was less than the range of the present invention, the weld appearance and impact resistance were poor, which was not preferable. Comparative Example 4 is not preferable because the rubbery polymer of the fluff copolymer, which is the component (A1), exceeds the range of the present invention, so that the weld appearance is inferior. In Comparative Example 5, since the graft copolymer as the component (A1) in the component (A) is less than the range of the present invention, the weld appearance and the impact resistance are poor, which is not preferable.

[0020]

Industrial Applicability The thermoplastic resin composition of the present invention is a resin having a well-balanced weld appearance and impact resistance. Therefore, the thermoplastic resin composition of the present invention can be used for various electric / electronic parts requiring weld appearance and impact resistance, for example, housings for home video cameras, automobile interior parts, and the like. .

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-64-62344 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 51/04 C08K 3/04 C08K 3 / 30 C08L 25/00-25/18 C08L 55/02

Claims (2)

(57) [Claims] (A) The following component (A1) + (A2) component 10
Rubber-reinforced aromatic vinyl copolymer having a rubbery polymer content of 5 to 50% by weight.
5% by weight (A1) In the presence of a rubbery polymer content of 28 to 80% by weight
Aromatic vinyl compound and vinyl cyanide compound, or aromatic
Aromatic vinyl compound and vinyl cyanide compound and other copolymerizable
Graft copolymers 100 to 1 obtained by copolymerizing various monomers
0 parts by weight (A2) 0 to 90 parts by weight of a copolymer obtained by copolymerizing an aromatic vinyl compound or an aromatic vinyl compound and another copolymerizable monomer; and (B) graphite and / or disulfide Molybdenum 0.5-1
A thermoplastic resin composition comprising 5% by weight. 2. The rubbery polymer content of (A1) is from 32 to
The thermoplastic resin composition according to claim 1, which is 70% by weight.