JP2000344995A - Thermoplastic resin composition and sheet molding - Google Patents

Abstract

(57) [Problem] To provide a thermoplastic resin composition excellent in extrusion moldability, vacuum moldability, color tone stability and surface appearance. A thermoplastic resin composition comprising a rubber-reinforced styrene resin having a specific structure, and a specific high molecular weight polymer and an α-olefin oligomer and / or a co-oligomer of ethylene and an α-olefin. .

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 excellent in extrusion moldability, vacuum moldability, color tone stability and surface appearance.

[0002]

2. Description of the Related Art Acrylonitrile is added to a diene rubber component.
The so-called ABS resin, which contains a graft copolymer obtained by copolymerizing a vinyl cyanide compound such as methacrylonitrile, and an aromatic vinyl compound component such as styrene and α-methylstyrene, has a balance of physical properties such as impact resistance and rigidity. ,
OA because of its excellent chemical resistance, molding processability, gloss, etc.
It is widely used as a resin for injection molding in application fields such as equipment, home appliances, automobile parts, and general goods. recent years,
In these applications, products are becoming larger and lighter, and thus a technique for obtaining a large-sized, thin-walled molded product by performing vacuum molding using an ABS resin has attracted attention.

[0003] In the production of large, thin-walled vacuum molded articles, a resin sheet is first formed by sheet molding, and then the sheet is subjected to vacuum (pneumatic) molding to obtain a desired shape. For this reason, the resin materials used for such applications include:
Good extrusion moldability (color tone stability during heating and melting, low roll stainability) and good vacuum moldability (thickness uniformity) are required. It is also imperative that the material have a good appearance in order to give the consumer a clean impression when implemented as a product.

Japanese Patent Application Laid-Open No. 9-324103 discloses that a high molecular weight acrylic copolymer is blended with a thermoplastic resin,
A technique for improving vacuum formability is disclosed, but a technique for reducing unevenness in thickness during vacuum forming, that is, reducing size unevenness, reducing gas during extrusion, and eliminating roll dirt is not disclosed. . Further, since the melt viscosity of the thermoplastic resin obtained by blending the high molecular weight compound increases, coloring due to shear heat generation during extrusion molding is problematic.

[0005] In general, in such applications, there has been a serious problem in extrusion molding that productivity is reduced due to poor appearance called white streaks due to deposits on a die.

In the production of vacuum molded articles, as described above, conventional ABS resins cannot sufficiently satisfy various properties such as extrusion moldability, vacuum moldability, color tone stability and surface appearance.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin composition which solves the above-mentioned drawbacks of the prior art and is excellent in extrusion moldability, vacuum moldability, color tone stability and surface appearance. It is in.

[0008]

As means for solving such problems, as a result of intensive studies on polymer components to be blended with the rubber-reinforced styrene-based resin, a specific structure of the rubber-reinforced styrene-based resin having a specific structure was determined. Methacrylic acid ester-based copolymers and α-olefin oligomers and / or ethylene and α-olefin col-oligomers
The present inventors have found that the above objects can be efficiently achieved by blending the compound of the present invention, and have reached the present invention.

That is, the present invention relates to a rubber-based polymer (R)
At least one selected from aromatic vinyl monomers (a), vinyl cyanide monomers (b), and other vinyl monomers copolymerizable therewith (c) in the presence of 10 to 80 parts by weight of a graft copolymer (A) obtained by graft polymerization of a monomer mixture (GM) composed of monomers, 75 to 45% by weight of an aromatic vinyl monomer (a), and cyanide A monomer mixture (MM) comprising 25 to 55% by weight of a vinyl-based monomer (b) and at least two or more monomers selected from other vinyl-based monomers (c) copolymerizable therewith.
And a vinyl copolymer (B) having an average vinyl cyanide content of ± 5% by weight and containing 80% by weight or more of the vinyl copolymer (B) in the composition distribution of vinyl cyanide ( B) 0.1 to 10 parts by weight of a high molecular weight polymer (C) having a weight average molecular weight of 1,000,000 or more per 100 parts by weight of a resin composition of 20 to 90 parts by weight and α
An olefin oligomer and / or ethylene and α-
A thermoplastic resin composition comprising 0.05 to 5 parts by weight of an olefin oligomer (D).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the rubbery polymer (R) in the present invention include, in addition to polybutadiene, styrene-
Butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block copolymer, butyl acrylate-butadiene copolymer, polyisoprene rubber, and the like, among which polybutadiene and styrene-butadiene copolymer rubber are preferable. .

The weight average particle diameter of the rubbery polymer (R) is from 0.1 to 1.5 μm from the viewpoint of impact resistance, moldability, flowability and appearance of the thermoplastic resin composition obtained. Preferably, it is more preferably 0.2 to 1.2 μm.

The aromatic vinyl monomer (a) of the monomer mixture (GM) in the present invention includes styrene, α-methylstyrene, p-methylstyrene, vinyltoluene,
Examples thereof include t-butylstyrene, o-ethylstyrene, o-chlorostyrene and o, p-dichlorostyrene, and styrene and α-methylstyrene are particularly preferable.
One or more of these can be used.

As the vinyl cyanide monomer (b),
Acrylonitrile, methacrylonitrile, ethacrylonitrile and the like can be mentioned, and acrylonitrile is particularly preferable.

Other copolymerizable vinyl monomers (c) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and (meth) acrylic acid. α, β such as n-butyl, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate and 2-chloroethyl (meth) acrylate -Unsaturated carboxylic acid esters, N-methylmaleimide, N-cyclohexylmaleimide, maleimide compounds such as N-phenylmaleimide, unsaturated dicarboxylic acids such as maleic acid, unsaturated dicarboxylic anhydrides such as maleic anhydride, and acrylamide. And unsaturated amides. Of these, methyl methacrylate, N-phenylmaleimide and And maleic anhydride are preferred.

The content of the rubbery polymer (R) used in the graft copolymer (A) in the present invention is not particularly limited, but is preferably 10 to 90% by weight in view of impact resistance, and more preferably 40 to 90% by weight. ~ 80% by weight is preferred. The content of the aromatic vinyl-based monomer (a) in the monomer mixture (GM) constituting the graft component is not particularly limited, but may be 10 to 10%.
80% by weight is preferable in terms of moldability, and more preferably 20%
~ 70% by weight is preferred. In addition, the monomer mixture (G
The content of the vinyl cyanide monomer (b) in M) is not particularly limited, but is preferably 5 to 70% by weight in view of moldability, and more preferably 10 to 60% by weight. The graft ratio and the reduced viscosity of the graft component copolymer are not particularly limited. The graft ratio is 10 to 80% by weight, and the reduced viscosity of the graft component copolymer is 0.2 to 1.0 dl.
/ G is preferred in terms of impact resistance.

The method for producing the graft copolymer (A) may be any of polymerization methods such as emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization, and is not particularly limited. There is also no particular limitation on the method of charging the monomer, and the initial batch charging, or while charging a part or all of the charged monomer continuously or divided to suppress the generation of the composition distribution of the copolymer. It may be polymerized.

The content of the graft copolymer (A) is as follows:
Graft copolymer (A) and vinyl copolymer (B)
It is 10 to 80 parts by weight in 100 parts by weight. The content of the graft copolymer (A) is preferably from 18 to 50 parts by weight from the viewpoint of the balance among impact resistance, rigidity, heat resistance and fluidity. When the content is less than 10 parts by weight, the resulting thermoplastic resin composition has insufficient impact resistance, and when it exceeds 80 parts by weight, the fluidity, heat resistance and rigidity decrease.

The vinyl copolymer (B) in the present invention
Is obtained by copolymerizing a monomer mixture (MM) containing 75 to 45% by weight of an aromatic vinyl monomer (A) and 25 to 55% by weight of a vinyl cyanide monomer (B). And
Other vinyl monomers (c) copolymerizable therewith may be used in combination.

The aromatic vinyl monomer (A) in the monomer mixture (MM) includes styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, t-butylstyrene, o-ethylstyrene, Examples thereof include o-chlorostyrene and o, p-dichlorostyrene, with styrene and α-methylstyrene being particularly preferred. These are 1
Species or two or more can be used.

As the vinyl cyanide monomer (b),
Acrylonitrile, methacrylonitrile, ethacrylonitrile and the like can be mentioned, and acrylonitrile is particularly preferable.

Other copolymerizable vinyl monomers (c) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and (meth) acrylic acid. α, β such as n-butyl, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate and 2-chloroethyl (meth) acrylate -Unsaturated carboxylic acid esters, N-methylmaleimide, N-cyclohexylmaleimide, maleimide compounds such as N-phenylmaleimide, unsaturated dicarboxylic acids such as maleic acid, unsaturated dicarboxylic anhydrides such as maleic anhydride, and acrylamide. And unsaturated amides. Of these, methyl methacrylate, N-phenylmaleimide and And maleic anhydride are preferred.

The monomer composition ratio is preferably (a) 75
~ 45 wt% / (b) 55-25 wt% / (c) 0-3
0% by weight. From the viewpoint of extrusion moldability and vacuum moldability, (a) 78 to 50% by weight / (b) 50 to 27% by weight
/ (C) 0-23% by weight is more preferable, and (A) 73-55% by weight / (b) 45-27% by weight is more preferable.
/ (C) 0 to 18% by weight. If the content of the vinyl cyanide-based monomer (b) is less than 25%, the excellent mechanical properties inherent to the ABS resin are undesirably deteriorated. Also, 55
Exceeding the weight percentage lowers the color stability during heating and melting in extrusion molding and vacuum molding.

The intrinsic viscosity [η] of the acetone-soluble component of the vinyl copolymer (B) is 0.4 to 0.4 in terms of the balance between vacuum moldability, impact resistance, sheet processability, and sheet color.
1.2 dl / g, preferably 0.5 to 0.9
dl / g is more preferable.

In the present invention, the vinyl copolymer (B)
In the composition distribution of vinyl cyanide, it is necessary that 80% by weight or more of the copolymer is contained within an average content of vinyl cyanide of ± 5% by weight. If the content is less than 80% by weight, the color tone stability at the time of heating and melting decreases, which is not preferable.
% By weight or more is preferred. The composition distribution of vinyl cyanide is
Cyclohexane is added to the methyl ethyl ketone solution of the vinyl copolymer (B), and the content of the vinyl cyanide monomer in the precipitated vinyl cyanide copolymer is sequentially analyzed with an infrared spectrophotometer. It is required by The average vinyl cyanide content of the vinyl copolymer (B) can be determined by analysis with an infrared spectrophotometer using the entire vinyl copolymer (B) sample.

The method for producing the vinyl copolymer (B) in the present invention is not particularly limited, and a known emulsion polymerization method,
A suspension polymerization method, a bulk polymerization method, a solution polymerization method, and a polymerization method in which these are appropriately combined are used. However, from the viewpoint of narrowing the composition distribution of the vinyl copolymer, a bulk polymerization method and a solution polymerization method are particularly preferably selected.

The high molecular weight polymer (C) in the present invention comprises:
It is necessary that the weight average molecular weight is 1,000,000 or more. If the amount is less than 1,000,000, the vacuum moldability of the obtained resin composition is unpreferably reduced. Among them, those having a weight average molecular weight of 2,000,000 or more are particularly preferable.

The high molecular weight polymer (C) is not particularly limited as long as it satisfies the above molecular weight range. However, from the viewpoint of compatibility with the vinyl copolymer (B), methacrylic acid ester copolymers are particularly preferred. Preferably, it is a combined (i) or aromatic vinyl copolymer (ii).

The methacrylic acid ester-based copolymer (i) in the present invention is a copolymer which essentially contains a methacrylic acid ester and may contain an acrylic acid ester as a copolymer component. The ester portion is preferably composed of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an allyl group and a substituted product thereof. Specific monomers include methyl (meth) acrylate, ethyl (meth) acrylate, (Meta)
N-propyl acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate,
Examples thereof include chloromethyl (meth) acrylate and 2-chloroethyl (meth) acrylate. Methyl methacrylate is preferably used as the methacrylate, and as specific copolymers, methyl methacrylate / n-butyl acrylate copolymer and methyl methacrylate / 2-ethylhexyl acrylate copolymer are preferably used. Can be

The methacrylate ester copolymer (i) preferably has a methacrylate content of 30% by weight or more from the viewpoint of vacuum moldability of the thermoplastic resin composition to be obtained.

Further, the aromatic vinyl copolymer (ii) is
90 to 45% by weight of an aromatic vinyl monomer (A), 10 to 55% by weight of a vinyl cyanide monomer (B), and 0 to 45% by weight of another monomer copolymerizable therewith (C) % Of a mixture obtained by copolymerizing a mixture consisting of From the viewpoint of compatibility with the vinyl copolymer (B), (A) 85-5
0% by weight / (b) 15 to 50% by weight / (c) 0 to 35% by weight, and (a) 80 to 55% by weight / (b) 20
-45 wt% / (c) 0-25 wt% is particularly preferred.

When the aromatic vinyl copolymer (ii) is used as the high molecular weight polymer (C), the weight average molecular weight is preferably 3,000,000 or more in the above-mentioned molecular weight range from the viewpoint of vacuum moldability. It is particularly preferably at least 5 million, and most preferably at least 5.5 million.

The content of the high molecular weight polymer (C) is determined based on the graft copolymer (A) and the vinyl copolymer (B).
It is necessary to be 0.1 to 10 parts by weight in parts by weight,
Preferably it is 0.3 to 8 parts by weight. If the amount is less than 0.1 part by weight, the resulting thermoplastic resin composition has poor extrusion moldability (roll stain) and vacuum moldability. If the amount exceeds 10 parts by weight, the fluidity is extremely deteriorated, so that the coloring during the sheet molding becomes large due to the heat generated by shearing.

The α-olefin oligomer according to the present invention
And / or monomers used for the ethylene-α-olefin coloolomer (D) include ethylene and α-olefins having 3 to 20 carbon atoms, for example, propylene;
1-butene, 1-hexene 4-methyl-1-pentene,
Examples thereof include 1-octene, 1-decene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene.

The α-olefin oligomer and / or the co-oligomer of ethylene and α-olefin (D) used in the present invention have a kinematic viscosity at 100 ° C. of 5 to 100 cS.
t is preferable from the viewpoint of extrudability.

The α-olefin oligomer and / or the co-oligomer of ethylene and α-olefin (D) used in the present invention are 100 parts by weight of the graft copolymer (A) and the vinyl copolymer (B). Against 0.05
The object of the present invention can be achieved in the range of from 5 to 5 parts by weight, preferably from 0.1 to 4 parts by weight. If the amount is less than 0.05 part by weight, the effect of improving the extrusion moldability of the obtained thermoplastic resin composition is not sufficient, which is not preferable. If the amount exceeds 5 parts by weight, the mechanical properties of the obtained thermoplastic resin composition will deteriorate.

In the present invention, by using an α-olefin oligomer and / or a co-oligomer of ethylene and an α-olefin (D), a substance adhered to a die at the time of extrusion-molding the obtained thermoplastic resin composition. Is reduced, and the appearance defect called white streaks on the surface of the molded article caused by the attached matter is improved, so that the extrudability can be greatly improved.

In the thermoplastic resin composition of the present invention, polyolefins such as vinyl chloride, polyethylene and polypropylene, polyamides such as nylon 6 and nylon 66, polyethylene terephthalate, and the like, as long as the object of the present invention is not impaired.
The performance as a molding resin can be improved by adding a polyester such as polybutylene terephthalate and polycyclohexanedimethyl terephthalate, a polycarbonate, and various elastomers. In addition, if necessary, an antioxidant such as a hindered phenol type, a sulfur-containing organic compound type, a phosphorus-containing organic compound type, a heat stabilizer such as a phenol type or an acrylate type, a benzotriazole type, a benzophenone type, a salicylate type, etc. Various stabilizers such as ultraviolet absorbers, light stabilizers such as organic nickel-based and hindered amine-based,
Lubricants such as metal salts of higher fatty acids, higher fatty acid amides,
Plasticizers such as phthalates and phosphates; halogen-containing compounds such as polybromodiphenyl ether, tetrabromobisphenol-A, brominated epoxy oligomers and brominated polycarbonate oligomers; phosphorus-based compounds; and difficulties such as antimony trioxide. Flame retardants / flame retardants, carbon black, titanium oxide, pigments, dyes, and the like can also be added. Further, reinforcing agents and fillers such as glass fibers, glass flakes, glass beads, carbon fibers, and metal fibers can also be added. Regarding the method for producing the thermoplastic resin composition of the present invention, various methods such as melt kneading with a Banbury mixer, a roll, and a single-screw or multi-screw extruder can be adopted.

The thermoplastic resin composition of the present invention is suitable for known extrusion molding, and is particularly excellent in sheet extrusion moldability.
In addition, it is excellent in vacuum formability using the sheet as a secondary processing. In addition, molding can be performed by a known method currently used for molding a thermoplastic resin, such as injection molding, blow molding, compression molding, and gas assist molding.

The thermoplastic resin composition for extrusion molding of the present invention is suitably used for box products in electric refrigerators.

The present invention will be described more specifically with reference to the following examples and comparative examples. However, these examples do not limit the present invention. Here, unless otherwise specified, "%" represents% by weight and "parts" represents parts by weight. A method for analyzing the resin characteristics of the thermoplastic resin composition will be described below. For general properties such as mechanical strength and heat resistance, test pieces were molded by injection molding and measured according to the following test methods. (1) Weight average rubber particle diameter “Rubber Age Vol.88 p.484-
490 (1960) by E.I. Schmidt, P .;
H. Sodium alginate method described in "Biddison" (using the fact that the particle size of polybutadiene to be creamed varies depending on the concentration of sodium alginate, the particles having a cumulative weight fraction of 50% based on the cumulative weight fraction of the creamed weight ratio and the sodium alginate concentration) Find the diameter). (2) Graft ratio Acetone was added to a predetermined amount (m) of the graft copolymer, and 70%.
Refluxed for 3 hours in a hot water bath at 8800 rpm. p.
m. After centrifugation at (10000 G) for 40 minutes, the insoluble matter was filtered, and the insoluble matter was dried under reduced pressure at 60 ° C. for 5 hours, and the weight (n) was measured. The graft ratio was calculated from the following equation. Graft rate (%) = ｛[(n) − (m) × L] /
[(M) × L]｝ × 100 where L is the rubber content of the graft copolymer. (3) Intrinsic viscosity [η] 200 ml of acetone was added to 1 g of the sample, and the mixture was refluxed in a 70 ° C. water bath for 3 hours. p. m.
After centrifugation at (10000 G) for 40 minutes, the insoluble matter is filtered. The filtrate is concentrated on a rotary evaporator,
The precipitate (acetone-soluble matter) was dried under reduced pressure at 60 ° C. for 5 hours, and the intrinsic viscosity [η] was calculated by measuring ηsp / c at 30 ° C. in a methyl ethyl ketone solution using an Ubbelohde viscometer. (4) Average content of vinyl cyanide monomer: 22
0 and in a heated press set at ℃ the thickness 30 ± 5 [mu] m in film form, which appeared in the chart obtained by analyzing with FT-IR, 2240 cm ^-1 attributed to -C≡N stretching
The content of vinyl cyanide monomer in the sample was determined from the peak area of. (5) Vinyl cyanide monomer composition distribution: 8 per 2 g of sample
0 ml of methyl ethyl ketone was added and left at room temperature for 24 hours to dissolve, cyclohexane was added little by little, and the weight of the precipitated vinyl copolymer was measured in sequence,
Using the precipitate as a sample, the content of the vinyl cyanide monomer was determined in the same manner as in (4). Then, the cumulative weight fraction of the precipitated vinyl copolymer and the vinyl cyanide monomer content with respect to the entire vinyl polymer used as the sample are plotted, and the average content of the vinyl cyanide monomer ± 5
The ratio (% by weight) of the vinyl copolymer contained within the range of% by weight was determined. (6) Measurement of volatile matter: After the pellet was dried to an equilibrium moisture content (80 ° C./3 hours or more), the sample was placed on an aluminum dish.
g. After that, a treatment at 180 ° C. for 3 hours is performed.
Calculate and determine the volatilization loss. (7) Measurement of bleed amount: After the pellets were dried to an equilibrium moisture content (80 ° C./3 hours or more), 270 shown in FIG.
15 g of the sample pellet (4) is laid flat on the lower mold (5) set at 0 ° C via the spacers (2) and (3), and left to stand for 10 minutes. After the treatment, the bleed material trapped in the upper mold (1) is weighed to obtain a bleed-out amount. (8) Vacuum formability: The sheet was formed at a forming temperature of 260 ° C. using a sheet forming machine equipped with a T-die and a drawing roll, to obtain a resin plate having a size of 600 mm × 600 mm and a thickness of 2 mm. This resin plate was vacuum-formed by a plug-assist type vacuum forming machine using a box-shaped mold having an opening of 450 mm × 450 m and a depth of 300 mm, and the unevenness in wall thickness (thickness uniformity) was visually evaluated. ◎: very good ○: good △: slightly uneven thickness ×: large uneven thickness or breakage occurred. (9) Flexural modulus: ASTM D790 (23 ° C.) (10) Izod impact strength: ASTM D256 (2
(3 ° C., with V notch) (11) Kinematic viscosity: JIS K2283 (100 ° C.) (12) Surface appearance (white streaks): Sheet molding obtained 30 minutes after the start of steady operation in sheet molding of (8) Determined visually using the product.

：: very good ：: good △: slightly poor ×: poor (13) Sheet color tone (YI value): JIS K71
03 compliant. The resin plate obtained in (8) is 100 mm × 100
A sample cut into mm was used as a sample. (14) Weight-average molecular weight: A standard polystyrene conversion value measured by gel permeation chromatography under the following conditions was used. Apparatus: gel permeation chromatograph, GPC-244 (WA
Column: TSK-gel-GMHXL, (7.8 m inner diameter)
m / length 30 cm) (2) (manufactured by Tosoh), number of theoretical plates;
15000th step Solvent: THF Flow rate: 1.0 ml / min Temperature: 23 ° C Sample concentration: 0.2% Solubility: complete dissolution Filtration: 0.5 μ-TOSOH-H
-13-5 (Tosoh) Injection amount: 200 µl Detector: 401-Differential refractometer (manufactured by WATERS) Standard sample: monodisperse polystyrene (manufactured by Tosoh) (Reference example) (A) Graft copolymer A1: Nitrogen-substituted 120 parts of pure water, 0.5 part of glucose, 0.5 part of sodium pyrophosphate, 0.005 part of ferrous sulfate and a predetermined amount of polybutadiene latex shown in Table 1 were charged into the reactor, and the reactor was stirred and stirred. Was raised to 65 ° C. The time when the internal temperature reached 65 ° C. was defined as the initiation of polymerization, and a predetermined amount of a mixture of monomer and t-dodecylmercaptan shown in Table 1 was continuously added over 4.5 hours. At the same time, an aqueous solution comprising cumene hydroperoxide and potassium oleate shown in Table 1 was added to 6
The reaction was completed by continuous addition over time.

To the obtained latex, 2,2′-methylenebis (4-methyl-6-t-butylphenol) was added in an amount of 1 part by weight based on 100 parts by weight of the solid content of the latex.
Subsequently, the latex was coagulated with sulfuric acid, neutralized with sodium hydroxide, washed, filtered, and dried to obtain a powdery graft copolymer. A2, A3: In the same manner as in A1, a graft copolymer was obtained at the composition ratio shown in Table 1. (B) Matrix resin (Tables 2 and 3) B1: A monomer mixture consisting of 67% by weight of styrene and 33% by weight of acrylonitrile was subjected to continuous bulk polymerization to obtain a pellet-shaped copolymer. B2: A monomer mixture consisting of 57% by weight of styrene and 43% by weight of acrylonitrile was subjected to continuous bulk polymerization to obtain a pellet-like copolymer. B3: A monomer mixture consisting of 57% by weight of styrene, 28% by weight of acrylonitrile and 15% by weight of N-phenylmaleimide was subjected to continuous bulk polymerization to obtain a pellet-shaped copolymer. B4: A monomer mixture consisting of 57% by weight of styrene, 28% by weight of acrylonitrile, and 15% by weight of α-methylstyrene was subjected to continuous bulk polymerization to obtain a pellet-shaped copolymer. B5: A monomer mixture consisting of 87% by weight of styrene and 13% by weight of acrylonitrile was subjected to continuous bulk polymerization to obtain a pellet-shaped copolymer. B6: A monomer mixture consisting of 32% by weight of styrene and 68% by weight of acrylonitrile was subjected to continuous bulk polymerization to obtain a pellet-like copolymer. B7: 0.05 part of a copolymer consisting of 20% by weight of methyl methacrylate and 80% by weight of acrylamide was dissolved in 165 parts of ion-exchanged water in a stainless steel autoclave having a capacity of 20 L and equipped with a baffle and a Fowler-type stirring blade. The solution was stirred at 400 rpm, and the inside of the system was replaced with nitrogen gas. Next, acrylonitrile 38 parts, styrene 62
Part, t-dodecyl mercaptan 0.45 part, 2,2'-
Azobis (2,4-dimethylvaleronitrile) 0.40
And a mixed solution of 2,2′-azobisisobutylnitrile was added while stirring the reaction system, and the temperature was raised to 58 ° C. to initiate polymerization. Thereafter, the polymerization reaction was carried out for 125 minutes, during which the reaction temperature was raised to 65 ° C. After the addition of styrene to the reaction system was completed, the temperature was raised to 100 ° C. over 50 minutes. Thereafter, the reaction system was cooled, the polymer was separated, washed, and dried according to a usual method to obtain a bead-like copolymer. (C) High molecular weight polymer (Ci) Methacrylate copolymer C1: "METABLEN" P-530A manufactured by Mitsubishi Rayon Co., Ltd.
Weight average molecular weight: 310 × 10 ⁴ C2: “METABLEN” L-1000 manufactured by Mitsubishi Rayon Co., Ltd.
Weight average molecular weight: 27 × 10 ⁴ (C-ii) Aromatic vinyl copolymer C3: 76 parts of styrene, 24 parts of acrylonitrile, 3.5 parts of potassium laurate, 240 parts of deionized water and 0.1 part of hydrosulfite Was charged into a flask and heated while stirring under a nitrogen stream. When the internal temperature reached 45 ° C., 0.12 parts of potassium persulfate was added as a 1% aqueous solution as an initiator to initiate polymerization. . The above monomer mixture was reacted for 4 hours while keeping the internal temperature at 53 ° C. The final polymerization rate of the obtained latex was 98%. The latex was coagulated using 2 parts of sulfuric acid, washed with water and dried to obtain a powdery polymer. The weight average molecular weight is 620 × 1
0 was ^4. (D) α-olefin oligomer and / or col-oligomer of ethylene and α-olefin D1: “Lucant” HC10 manufactured by Mitsui Chemicals, Inc.
Viscosity at room temperature: 10 cSt D2: "Lucant" HC20 manufactured by Mitsui Chemicals, Inc. 100 ° C
Viscosity at room temperature: 20 cSt D3: "Lucant" HC600 100 manufactured by Mitsui Chemicals, Inc.
Kinematic viscosity at 600C: 600 cSt

[0043]

EXAMPLES Examples 1 to 12 and Comparative Examples 1 to 8 (A) Graft copolymer, (B) vinyl copolymer, (C) high molecular weight polymer, (D) α- After blending an olefin oligomer and / or a co-oligomer of ethylene and an α-olefin in proportions shown in Tables 4 and 5,
40mmφ single screw extruder (Cylinder set temperature: 260
C.) to obtain a pellet-shaped resin.

The obtained pellets were subjected to an injection molding machine IS-50A manufactured by Toshiba Machine Co., Ltd. (cylinder set temperature: 260 ° C.).
The test pieces were molded by using, and various characteristics were evaluated. The results are shown in Tables 6 to 8.

According to Examples 1 to 12, the thermoplastic resin compositions having the compounding ratios described in the claims of the present invention are excellent in vacuum moldability, color tone stability and surface appearance, and cause volatilization which causes roll contamination in sheet molding. It can be seen that the minuteness and bleed amount are small and the extrudability is excellent.

However, in Comparative Examples 1 and 2, the monomer composition of the vinyl copolymer (B) did not satisfy the scope of the present invention.
It can be seen that either the mechanical properties or the color tone stability are inferior. In Comparative Example 3, since the ratio of the vinyl cyanide-based monomer in the vinyl-based copolymer (B) contained within the average content of the vinyl cyanide monomer ± 5% by weight did not satisfy the range of the present invention, Poor color stability during processing. Comparative Examples 4 to 7 were graft copolymers (A), vinyl copolymers (B), high molecular weight polymers (C), and α-olefin oligomers.
And / or the blending ratio of the copolymer of ethylene and α-olefin (D) is out of the range described in the claims of the present invention, so that the extrudability, vacuum moldability, impact resistance, rigidity, color stability and surface Inferior to any of the appearances. Comparative Example 8 is inferior in vacuum moldability because the weight average molecular weight of the high molecular weight polymer (C) is out of the range described in the claims of the present invention.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

[Table 4]

[0051]

[Table 5]

[0052]

[Table 6]

[0053]

[Table 7]

[0054]

[Table 8]

[0055]

The thermoplastic resin composition of the present invention is excellent in extrusion moldability, vacuum moldability, color stability and surface appearance, and is therefore suitably used for vacuum molding applications requiring the above properties.

[Brief description of the drawings]

FIG. 1 is a schematic view of a jig used for measuring a bleed amount in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper mold 2 Spacer 3 Spacer 4 Pellet 5 Lower mold

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08L 25/12 C08L 25/12 33/18 33/18 101/00 101/00 // B29K 33:04 101: 12 F Term (Reference) 4F071 AA02 AA15 AA20 AA21 AA22 AA31 AA33 AA77 AA88 AH12 BA01 BB06 BC01 4F207 AA13 AA21 AA45 AG01 KA01 4J002 AA013 BB034 BB054 BB124 BB154 BB174 BB194 BC07BC03BC07 BC07BC073 GQ00

Claims (6)

[Claims] 1. An aromatic vinyl monomer (a), a vinyl cyanide monomer (b) and another vinyl monomer copolymerizable therewith in the presence of a rubbery polymer (R). 10 to 80 parts by weight of a graft copolymer (A) obtained by graft polymerization of a monomer mixture (GM) comprising at least one or more monomers selected from the group (c), and an aromatic vinyl monomer (A) 75 to 45% by weight, vinyl cyanide monomer (b) 25 to 55% by weight and at least two or more kinds selected from other vinyl monomers (c) copolymerizable therewith. A monomer mixture (MM) composed of monomers is copolymerized, and in the vinyl cyanide composition distribution, the vinyl cyanide average content is within ± 5% by weight, and at least 80% by weight of the vinyl copolymer. -Containing vinyl copolymer (B) 2
0.1 to 10 parts by weight of a high molecular weight polymer (C) having a weight average molecular weight of 1,000,000 or more and α-olefin oligomer and / or ethylene with respect to 100 parts by weight of the resin composition comprising 0 to 90 parts by weight. A thermoplastic resin composition containing 0.05 to 5 parts by weight of an oligomer of an α-olefin (D). 2. The thermoplastic resin composition according to claim 1, wherein the high molecular weight polymer (C) is a methacrylate copolymer (i). 3. The high molecular weight polymer (C) is 90 to 45% by weight of an aromatic vinyl monomer (A), 10 to 55% by weight of a vinyl cyanide monomer (B), and is copolymerizable therewith. The thermoplastic resin composition according to claim 1, which is an aromatic vinyl copolymer (ii) obtained by copolymerizing a mixture comprising 0 to 45% by weight of another monomer (c). 4. The thermoplastic resin according to claim 1, wherein the intrinsic viscosity [η] of the acetone-soluble component of the vinyl copolymer (B) is 0.4 to 1.2 dl / g. Composition. 5. An α-olefin oligomer and / or a co-oligomer of ethylene and α-olefin (D) is 10
The kinematic viscosity at 0 ° C is 5 to 100 cSt.
The thermoplastic resin composition according to any one of the above. 6. A sheet molded product obtained by extruding the thermoplastic resin composition according to claim 1.