JP2000159959A - Thermoplastic resin composition and sheet formed product comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition having excellent chemical resistance and extrusion moldability. SOLUTION: This thermoplastic resin composition comprises 100 pts.wt. of a resin composition, (C) 0.1-10 pts.wt. of a methyl methacrylate-based copolymer having a weight-average mol.wt. of >=2,000,000, (D) 0.5-10 pts.wt. of an ethylene/(meth)acrylic ester/carbon monoxide copolymer and (E) 0.05-5 pts.wt. of an α-olefin oligomer and/or an ethylene-α-olefin cooligomer. The resin composition comprises (A) 10-50 pts.wt. of a rubber-reinforced stylenic resin and (B) 50-90 pts.wt. of a vinyl cyanide-based copolymer obtained by copolymerizing a mixture comprising (1) 85-45 wt.% of an aromatic vinyl-based monomer, (2) 15-55 wt.% of a vinyl cyanide-based monomer and (3) 0-40 wt.% of another vinylic monomer capable of being copolymerized with the monomers.

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 for extrusion molding having excellent chemical resistance, extrudability, vacuum moldability and impact resistance.

[0002]

2. Description of the Related Art Acrylonitrile is added to a diene rubber component.
A so-called ABS resin containing a graft copolymer obtained by copolymerizing a cyanide compound such as methacrylonitrile and an aromatic vinyl compound component such as styrene and α-methylstyrene has a high impact resistance, a high mechanical strength and a good molding property. OA equipment, home appliances, automotive parts,
Widely used in application fields such as general goods. As described above, the ABS resin is used in various applications. In particular, in the field of home electric appliances, the ABS resin is often used for the inner box of the refrigerator in the electric refrigerator application.

[0003] However, the foaming agent remaining in the expanded polystyrene used as a heat insulating material may attack the ABS resin as the inner box and cause environmental stress deterioration.

In addition, it has been pointed out that a stable extrusion molded product cannot be obtained with a general-purpose ABS resin, or the thickness of a molded product obtained by vacuum forming is uneven, resulting in uneven dimensions.

Techniques for improving the above-mentioned properties of rubber-reinforced styrene resins represented by ABS resins and the like include ABS
A method of improving the chemical resistance by using another resin as a laminated material (Japanese Patent Application Laid-Open Nos. 5-42588, 6-47)
867 and JP-A-6-263958), but there are problems such as a difference in the heat expansion / contraction ratio and an increase in cost due to the use of another resin. In addition, a method of blending an acrylic rubber having a specific structure with an ABS resin to improve chemical resistance (JP-A-4-170460, JP-A-6-2874)
No. 03, JP-A-7-195599). Although the effect of improving the chemical resistance is recognized by this technique, the use of acrylic rubber reduces the impact value.

[0006] Japanese Patent Publication No. 55-50063 discloses a technique of blending a terpolymer of ethylene / (meth) acrylate / carbon monoxide with a thermoplastic resin to obtain an effect as a plasticizer, and a technique for improving the resistance to plasticizer. A technique for improving impact properties is disclosed. However, the ethylene / (meth) acrylate /
There is no technique disclosed in which a terpolymer of carbon monoxide is blended to improve chemical resistance without impairing fluidity.

[0007] Japanese Patent Application Laid-Open No. 9-324103 discloses that a high molecular weight acrylic copolymer is blended with a thermoplastic resin,
Although a technique for improving vacuum formability is disclosed, there is no technique for reducing unevenness in thickness during vacuum forming, that is, dimensional unevenness, and at the same time, reducing gas during extrusion and eliminating roll contamination. .

Further, in the method of manufacturing the inner box of the electric refrigerator, a sheet is formed by extrusion molding, and the sheet is vacuum-formed to obtain a product.
Extrusion moldability, vacuum moldability and impact resistance cannot be sufficiently satisfied.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned disadvantages of the prior art, and to improve the chemical resistance, extrudability, and the like.
It is an object of the present invention to provide a thermoplastic resin composition for extrusion molding having excellent balance of various properties such as vacuum moldability and impact resistance, and a sheet molded product comprising the same.

[0010]

Means for Solving the Problems As a means for solving the problems, as a result of intensive studies on a polymer component to be blended with the rubber-reinforced styrenic resin, a methacrylic acid having an average molecular weight of 2,000,000 or more was added to the rubber-reinforced styrene resin. By blending a methyl copolymer, an ethylene / (meth) acrylate / carbon monoxide terpolymer and an α-olefin oligomer and / or a copolymer of ethylene and an α-olefin, the above object can be achieved. The present invention has been found to be achieved efficiently, and has reached the present invention.

That is, the present invention relates to a method for producing a rubber-reinforced styrene resin comprising 10 to 50 parts by weight of an aromatic vinyl monomer (a).
85 to 45% by weight and vinyl cyanide monomer (b) 15
Vinyl cyanide-based copolymer (B) 50-90 obtained by copolymerizing a mixture comprising -55% by weight and 0-40% by weight of another vinyl monomer (c) copolymerizable therewith.
0.1 to 10 parts by weight of a methyl methacrylate-based copolymer (C) having a weight average molecular weight of 2,000,000 or more, based on 100 parts by weight of the resin composition consisting of parts by weight, ethylene / (meth)
0.5 to 10 parts by weight of an acrylate / carbon monoxide copolymer (D) and 0.05 to 5 parts by weight of an α-olefin oligomer and / or a co-oligomer of ethylene and an α-olefin (E) A thermoplastic resin composition, more preferably a rubbery polymer (A-1) 20 having a weight average particle diameter of 0.1 to 1.5 μm.
Aromatic vinyl monomer (a) 1 in the presence of ８０80 parts by weight
0 to 90% by weight, vinyl cyanide monomer (b) 0 to 5
0% by weight and 0-90% by weight of another vinyl monomer (c) copolymerizable therewith (A-
2) 10 to 50 parts by weight of a graft copolymer (A) obtained by graft polymerization of 80 to 20 parts by weight, 85 to 45% by weight of an aromatic vinyl monomer (A), and a vinyl cyanide monomer (B) A vinyl cyanide copolymer (B) obtained by copolymerizing a mixture of 15 to 55% by weight and another vinyl monomer copolymerizable therewith (c) 0 to 40% by weight.
A methyl methacrylate-based copolymer (C) having a content of methyl methacrylate of 30% by weight or more and a weight average molecular weight of 2,000,000 or more based on 100 parts by weight of a resin composition comprising 50 to 90 parts by weight. 0.1 to 10 parts by weight, copolymer of ethylene / (meth) acrylate / carbon monoxide (D) 0.5 to 10 parts by weight and α-olefin oligomer and / or ethylene and α-olefin co-oligomer 0.05 to 5 parts by weight of (E), and the intrinsic viscosity [η] of the acetone-soluble component of (A) + (B) + (C) + (D) + (E) is 0 .4 to 1.2 dl
/ G of a thermoplastic resin composition for extrusion molding, and a sheet molded product comprising the thermoplastic resin composition and suitable for an electric refrigerator inner box.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The rubber-reinforced styrene resin (A) in the present invention is not particularly limited,
The rubbery polymer (A-1) is converted from an aromatic vinyl monomer (a), a vinyl cyanide monomer (b), and another vinyl monomer (c) copolymerizable therewith. A monomer mixture comprising at least one or more selected monomers (A
-2) is a graft copolymer obtained by graft polymerization. Examples of the rubbery polymer (A-1) include, in addition to polybutadiene, a styrene-butadiene copolymer, an acrylonitrile-butadiene copolymer, and styrene- Examples thereof include a butadiene block copolymer, a butyl acrylate-butadiene copolymer, and a polyisoprene rubber. Among them, polybutadiene and a styrene-butadiene copolymer rubber are preferable.

The aromatic vinyl monomer (A) of the monomer mixture (A-2) 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.
The content of the aromatic vinyl monomer (a) is 10 to 90 parts with respect to the monomer mixture (A-2) in the presence of 20 to 80 parts by weight of the rubbery polymer (A-1). % By weight is preferred.
Within this range, the mechanical strength is excellent.

As the vinyl cyanide monomer (b),
Acrylonitrile, methacrylonitrile, ethacrylonitrile and the like can be mentioned, and acrylonitrile is particularly preferable. The content of the vinyl cyanide monomer (b) is 0 to 50% by weight based on the monomer mixture (A-2) in the presence of 20 to 80 parts by weight of the rubbery polymer (A-1). Is preferred. Within this range, the mechanical strength is excellent.

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 weight average particle size of the rubbery polymer (A-1) is determined from the viewpoints of impact resistance, moldability, especially fluidity and appearance of the molded article of the thermoplastic resin composition obtained.
It is preferably from 0.1 to 1.5 μm, more preferably from 0.2 to 1.2 μm.

The content of the rubbery polymer (A-1) is determined based on 100 parts by weight of the graft copolymer (A) in view of the impact resistance, fluidity, heat resistance and rigidity of the obtained resin composition. 20 to 80 parts by weight, more preferably 35 to 80 parts by weight.
７０70 parts by weight.

The graft ratio of the graft copolymer (A) is from 15 to 150 in view of mechanical strength and moldability.
%, More preferably 20 to 70%.
%. If the graft ratio is less than 15%, the impact resistance of the resulting thermoplastic resin composition for chemical resistance extrusion molding may not be sufficient, and if it exceeds 150%, moldability, especially fluidity, is reduced. Sometimes.

The content of the graft copolymer (A) is as follows:
Graft copolymer (A) and vinyl copolymer (B)
It is 10 to 50 parts by weight in 100 parts by weight. The content of the graft copolymer (A) is preferably from 18 to 40 parts by weight from the viewpoint of the balance among impact resistance, rigidity, heat resistance and fluidity. If the content is less than 10 parts by weight, the resulting thermoplastic resin composition for extrusion molding will have insufficient impact resistance, and if it exceeds 50 parts by weight, fluidity, heat resistance and rigidity will decrease. .

The vinyl cyanide copolymer (B) in the present invention is an aromatic vinyl monomer (a) exemplified as the rubber-reinforced styrene resin (A), and a vinyl cyanide monomer (b). And a copolymer obtained by copolymerizing a monomer mixture (B-1) composed of at least two kinds of monomers selected from other vinyl monomers (c) copolymerizable therewith, Each of these components is an aromatic vinyl monomer (a) /
The ratio of the vinyl cyanide monomer (b) / the other vinyl monomer copolymerizable with these (c) is 85 to 45% by weight / 55.
-15% by weight / 0-40% by weight. 80 to 50% by weight / from the viewpoint of extrusion moldability, chemical resistance and vacuum moldability
It is preferably 50 to 20% by weight / 0 to 30% by weight, more preferably 70 to 50% by weight / 40 to 30% by weight / 0 to 2%.
0% by weight. 15 vinyl cyanide monomers (b)
%, The chemical resistance of the obtained resin composition is not sufficient, and if it exceeds 55% by weight, the color tone stability at the time of melting in extrusion molding and vacuum molding may decrease.

The intrinsic viscosity [η] of the acetone-soluble component of the vinyl copolymer (B) is preferably 0.4 to 1.2 dl / g, more preferably 0.5 to 0.8 dl / g.
g, and less than 0.4 dl / g, the extrusion moldability and vacuum moldability are insufficient, and if it exceeds 1.2 dl / g, the fluidity decreases.

The content of the vinyl cyanide-based copolymer (B) is determined based on the balance of impact resistance, chemical resistance, rigidity, heat resistance and fluidity, from the viewpoint of the balance between the graft copolymer (A) and the vinyl copolymer. 90 to 50 in 100 parts by weight of the copolymer (B)
It must be parts by weight. If the content exceeds 90 parts by weight, the resulting thermoplastic resin composition for extrusion molding will have insufficient impact resistance. If the content is less than 50 parts by weight, the fluidity, heat resistance and rigidity will decrease.

The method for producing the copolymers (A) and (B) 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 methyl methacrylate copolymer (C) in the present invention is a copolymer of methyl methacrylate with another vinyl monomer copolymerizable with methyl methacrylate. And copolymers of unsaturated carboxylic acid esters and methyl methacrylate, and the like. Among them, preferred are methyl methacrylate / n-butyl acrylate copolymer and methyl methacrylate / 2-ethylhexyl acrylate copolymer Used.

Methyl methacrylate copolymer (C)
From the viewpoint of vacuum moldability of the obtained resin composition for extrusion molding, the content of methyl methacrylate is preferably 30% by weight or more. Further, the methyl methacrylate-based copolymer (C) needs to have a weight average molecular weight of 2,000,000 or more. If the amount is less than 2,000,000, the vacuum moldability of the obtained resin composition for extrusion molding is significantly reduced, which is not preferable. Among them, those having a weight average molecular weight of 3,000,000 or more are particularly preferable.

In the present invention, the content of the methyl methacrylate-based copolymer (C) is from 0.1 to 100 parts by weight of the graft copolymer (A) and the vinyl-based copolymer (B) from the viewpoint of vacuum moldability. It needs to be 1 to 10 parts by weight. When the content exceeds 10 parts by weight, the fluidity of the obtained thermoplastic resin composition decreases, and when the content is less than 0.1 part by weight,
It is not preferable because the amount of gas at the time of extrusion molding of the obtained thermoplastic resin composition is reduced and the dimensional stability of the vacuum molded product is significantly reduced.

The copolymer (D) is a terpolymer of ethylene / (meth) acrylate / carbon monoxide,
The acrylic group of the (meth) acrylic acid ester has a linear or branched ester moiety and has 1 carbon atom.
To 18, preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a sec-butyl group, a t-butyl group,
Examples thereof include an isobutyl group, a hexyl group, a 2-ethylhexyl group, and an octyl group, and those having 2 to 8 carbon atoms are more preferable. The copolymer (D) preferably has a composition ratio of 10 to 87% by weight of ethylene, more preferably 40 to 8%.
0% by weight, preferably 10 to 50% by weight of (meth) acrylic acid ester, more preferably 15 to 40% by weight, and preferably 5 to 40% by weight of carbon monoxide, more preferably 5 to 20% by weight. If necessary, it can be copolymerized with another copolymerizable monomer.

The content of the copolymer (D) is 0.5 to 10 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the graft copolymer (A) and the vinyl copolymer (B). 7
Parts by weight. When the content of the copolymer (D) is less than 0.5 part by weight, the obtained chemical-resistant thermoplastic resin composition for extrusion molding has insufficient chemical resistance and impact resistance. When the amount exceeds the weight part, heat resistance and rigidity are reduced, and further, delamination occurs.

The monomers also used for the α-olefin oligomer used in the present invention and / or the co-oligomer of ethylene and α-olefin (E) include ethylene and α-olefins having 3 to 20 carbon atoms, for example, Propylene, 1-butene, 1-hexene 4-methyl-1-pentene, 1-octene, 1-decene, 1-tetradecene,
Examples thereof include 1-hexesezecene, 1-octazecene, and 1-eicosene.

The α-olefin oligomer and / or the co-oligomer of ethylene and α-olefin (E) used in the present invention have a kinematic viscosity at 100 ° C. of 5 to 500 cS.
It is preferably t.

The α-olefin oligomer and / or the co-oligomer of ethylene and α-olefin (E) used in the present invention are 100 parts by weight of the graft copolymer (A) and the vinyl copolymer (B). Against 0.05
To 5 parts by weight, preferably 0.1 to 4 parts by weight. When the content is within this range, the chemical resistance of the thermoplastic resin composition for extrusion molding is improved, and the extrusion moldability, particularly, the reduction of deposits on the die and the screw current value during extrusion are stable, and the discharge unevenness is improved. Is eliminated. If the amount is less than 0.05 part by weight, the resulting chemical-resistant thermoplastic resin composition for extrusion molding has insufficient chemical resistance and the above-mentioned extrusion characteristics.
When the amount is more than 10 parts by weight, the mechanical properties of the obtained thermoplastic resin composition for extruding chemical resistance are deteriorated.

In addition, the thermoplastic resin composition of the present invention can be obtained from the viewpoints of extrusion moldability, vacuum moldability, and fluidity.
The intrinsic viscosity [η] of the acetone-soluble component (A) + (B) + (C) + (D) + (E) is preferably 0.4 to 1.2 dl / g.

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. If necessary, hindered phenols, sulfur-containing organic compounds, antioxidants such as phosphorus-containing organic compounds, phenols, heat stabilizers such as acrylates, benzotriazoles, benzophenones, salicylates, 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.

With respect to 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 employed.

The thermoplastic resin composition of the present invention is suitable for known extrusion molding, and is particularly excellent in sheet extrusion moldability.
In addition, the sheet is excellent in vacuum formability using the sheet as a secondary processing. In addition, injection molding, blow molding,
It can be formed by a known method currently used for forming a thermoplastic resin such as compression molding and gas assist molding. A sheet product extruded using the thermoplastic resin composition of the present invention is suitable for appearance and a vacuum formed product using the sheet product, and a product excellent in uneven thickness can be obtained. Particularly when the average thickness is 3.0 mm or less, a remarkable effect can be obtained.

The thermoplastic resin composition of the present invention has excellent chemical resistance and is suitable for box products in electric refrigerators.

The present invention will be described more specifically with reference to examples and comparative examples, but 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 properties of the thermoplastic resin composition for chemical extrusion molding 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 Size “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 the mixture was refluxed for 3 hours. p. m. (1000
After centrifugation at 0 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. Here, L is the rubber content of the graft copolymer. Graft rate (%) = ｛[(n) − (m) × L] /
[(M) × L]｝ × 100

(3) Intrinsic viscosity [η] 200 ml of acetone was added to 1 g of the sample, and the mixture was refluxed for 3 hours. p. m. (10000G)
After centrifugation at for 40 minutes, the insoluble matter is filtered. The filtrate was concentrated with a rotary evaporator, and the precipitate (acetone-soluble matter) was dried under reduced pressure at 60 ° C. for 5 hours. Then, using an Ubbelohde viscometer, a methyl ethyl ketone solution was used.
c was measured, and intrinsic viscosity [η] was calculated.

(4) Chemical resistance: A press-formed test piece (127 × 12.7 × 1.5 mm) was subjected to 1/4 as shown in FIG.
After fixing along the elliptical jig, CFC 141b 250ml
The jig was put into the desiccator with a diameter of 300 mm.
After standing for 24 hours in an environment of 23 ° C., the presence or absence of cracks and cracks is checked, and the critical strain (%) is calculated by the equation (1). Those with 1.0% were rated as △, those with 1.0% to 2.0% as ○, and those with more than 2.0% were rated as ◎.

[0042]

(Equation 1)

(5) Measurement of volatile matter: After drying the pellet to an equilibrium moisture content (80 ° C./3 hours or more), 3 g of a sample is weighed on an aluminum dish. Thereafter, a treatment at 180 ° C. for 3 hours is performed to calculate and obtain a loss on volatilization.

(6) Measurement of bleed amount: After the pellet was dried to an equilibrium moisture content (80 ° C./3 hours or more), FIG.
15 g of sample pellets are laid flat on a lower mold set at 270 ° C. as shown in (1) and left for 10 minutes. After the treatment, the bleed material trapped in the upper mold is weighed to obtain the bleed-out amount.

(7) Vacuum formability: dimension 500 mm × 50
Using a sheet having a thickness of 0 to 1.5 mm and a thickness of 1.5 to 3.0 mm, vacuum molding is performed with a plug-assist type vacuum molding machine, and the thickness of 10 molded products is measured. ,
It was determined as follows. ◎: 0.1 mm or less ○: More than 0.1 mm and 0.3 mm or less △: More than 0.3 mm and 1 mm or less ×: More than 1 mm

(8) Flexural modulus: ASTM D790
(23 ° C)

(9) Izod impact strength: ASTM D
256 (23 ° C, with V notch)

(10) MFR (melt flow rate): ISO 113
3 (220 ° C, 98N load)

(11) Kinematic viscosity: JIS K2283 (10
0 ℃)

(Reference Example) (A) Graft copolymer A1: 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 was charged, and the temperature in the reactor was raised to 65 ° C. while stirring. When the internal temperature reached 65 ° C., polymerization was started, and a predetermined amount of a mixture of monomers and t-dodecyl mercaptan shown in Table 1 was continuously added over 5 hours. At the same time, an aqueous solution comprising cumene hydroperoxide and potassium oleate shown in Table 1 was continuously added over 7 hours to complete the reaction.

To the obtained latex was added 1 part by weight of 2,2′-methylenebis (4-methyl-6-t-butylphenol) 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. The graft ratio of this graft copolymer was 45%. A2 to A6: In the same manner as in A1, a graft copolymer was obtained at the composition ratio shown in Table 1.

(B) Vinyl Copolymer B1: A monomer mixture consisting of 70% by weight of styrene and 30% by weight of acrylonitrile was subjected to bulk polymerization to obtain a pellet-shaped copolymer. The intrinsic viscosity [η] of the copolymer is 0.70 d
1 / g. B2: A monomer mixture consisting of 50% by weight of styrene and 50% by weight of acrylonitrile was subjected to suspension polymerization to obtain a bead-like copolymer. The intrinsic viscosity [η] of the copolymer is 0.65 dl.
/ G. B3: A monomer mixture consisting of 45% by weight of styrene, 30% by weight of acrylonitrile, and 25% by weight of N-phenylmaleimide was emulsion-polymerized to obtain a powdery copolymer. The intrinsic viscosity [η] of the copolymer was 0.65 dl / g.
B4: Emulsion polymerization of a monomer mixture consisting of 45% by weight of styrene, 30% by weight of acrylonitrile, and 25% by weight of α-methylstyrene, followed by powdering.
A copolymer was obtained. The intrinsic viscosity [η] of the copolymer was 0.85 dl / g. B5: A monomer mixture consisting of 80% by weight of styrene and 20% by weight of acrylonitrile was subjected to bulk polymerization to obtain a pellet-like copolymer. The intrinsic viscosity [η] of the copolymer is 0.28 d.
1 / g. B6: A monomer mixture consisting of 40% by weight of styrene and 60% by weight of acrylonitrile was subjected to bulk polymerization to obtain a pellet-shaped copolymer. The intrinsic viscosity [η] of the copolymer is 1.50.
dl / g.

(C) Methyl methacrylate copolymer C1: "METABLEN" P-530A manufactured by Mitsubishi Rayon Co.
Weight average molecular weight: 310 × 10 ⁴ C2: “METABLEN” L-1000 manufactured by Mitsubishi Rayon Co., Ltd.
Weight average molecular weight: 27 × 10 ⁴

(D) Ethylene / (meth) acrylate / carbon monoxide copolymer D1: "Elvaloy" manufactured by DuPont-Mitsui Polychemicals
EP4051 D2: "Elvaloy" manufactured by DuPont-Mitsui Polychemicals
HP553

(E) α-olefin oligomer and / or
Or ethylene and α-olefin colooligomer E1: “Lucant” HC10 manufactured by Mitsui Chemicals, Inc. 100 ° C.
Viscosity at room temperature: 10 cSt E2: "Lucant" HC20 manufactured by Mitsui Chemicals, Inc. 100 ° C
Viscosity at room temperature: 20 cSt E3: "Lucant" HC600 100 manufactured by Mitsui Chemicals, Inc.
Kinematic viscosity at 600C: 600 cSt

[0056]

EXAMPLES Examples 1 to 13 and Comparative Examples 1 to 6 (A) Graft copolymer, (B) vinyl copolymer, (C) methyl methacrylate copolymer described in Reference Examples,
(D) Ethylene / (meth) acrylate / carbon monoxide copolymer, (E) α-olefin oligomer and / or ethylene and α-olefin coloolomer in the proportions shown in Tables 2 and 3 And melt-kneaded with a 40 mmφ single screw extruder to obtain a pellet-shaped resin.

Test pieces were molded from the obtained pellets using an injection molding machine IS-50A manufactured by Toshiba Machine Co., Ltd., and various characteristics were evaluated. The results are shown in Tables 4 to 6.

According to Examples 1 to 13, the chemical resistance, extrusion characteristics, vacuum moldability, impact resistance and moldability of the thermoplastic resin composition for extrusion molding having the compounding ratio described in the claims of the present invention. It turns out that it is excellent. As described above, the resin composition of the present invention is excellent in vacuum moldability and chemical resistance, and thus is suitably used as a refrigerator inner box.

However, the comparative examples were methyl methacrylate-based copolymer, ethylene / (meth) acrylate / carbon monoxide copolymer, α-olefin oligomer and / or
Alternatively, any of the oligomers of ethylene and α-olefin is out of the range of the present invention, so that the chemical resistance, extrusion moldability and vacuum moldability are insufficient.

[0060]

[Table 1]

[0061]

[Table 2]

[0062]

[Table 3]

[0063]

[Table 4]

[0064]

[Table 5]

[0065]

[Table 6]

[0066]

The thermoplastic resin composition of the present invention is excellent in extrusion characteristics and vacuum moldability, and has good chemical resistance, so that a good vacuum molded product can be obtained, and the cost and production of the material can be reduced. Performance can be improved.

[Brief description of the drawings]

FIG. 1: 1/4 used for chemical resistance test of the composition of the present invention
It is a schematic diagram of an elliptical jig.

FIG. 2 is a schematic configuration diagram of an apparatus for measuring a bleed amount of the composition of the present invention.

[Explanation of symbols]

 1 Test piece 2 Upper mold 3 Spacer 4 Spacer 5 Pellet 6 Lower mold

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 BB035 BB054 BB074 BB125 BB154 BC061 BD045 BG063 BN142 BN152 CF055 CF065 CF075 CG005 CJ004 CL015 CL035 FA040 FD010 FD020 FD040 FD050 FD060 FD070 FD090 GFD130 FD130

Claims (8)

[Claims] 1. A rubber-reinforced styrene resin of 10 to 50 parts by weight, an aromatic vinyl monomer (a) of 85 to 45% by weight, a vinyl cyanide monomer (b) of 15 to 55% by weight and Other vinyl monomers (c) copolymerizable with
Methyl methacrylate having a weight average molecular weight of 2,000,000 or more with respect to 100 parts by weight of a resin composition comprising 50 to 90 parts by weight of a vinyl cyanide copolymer (B) obtained by copolymerizing a mixture consisting of 2% by weight. -Based copolymer (C) 0.1-
10 parts by weight, ethylene / (meth) acrylate /
0.5 to 10 parts by weight of a copolymer (D) composed of carbon monoxide and an α-olefin oligomer and / or a co-oligomer of ethylene and α-olefin (E) 0.05 to 5
A thermoplastic resin composition containing parts by weight. 2. An aromatic vinyl-based monomer (i) in the presence of 20 to 80 parts by weight of a rubbery polymer (A-1) having a weight-average particle diameter of 0.1 to 1.5 μm. % Of a vinyl cyanide-based monomer (b), and 0 to 90% by weight of another vinyl-based monomer (c) copolymerizable therewith (A- 2) Graft copolymer (A) 10 to 5 obtained by graft polymerization of 80 to 20 parts by weight
0 parts by weight, 85 to 45% by weight of an aromatic vinyl monomer (a) and 15 to 55% by weight of a vinyl cyanide monomer (b)
And other vinyl monomers copolymerizable therewith (c)
The content of methyl methacrylate is 30% based on 100 parts by weight of a resin composition comprising 50 to 90 parts by weight of a vinyl cyanide copolymer (B) obtained by copolymerizing a mixture comprising 0 to 40% by weight. 0.1 to 10 parts by weight of a methyl methacrylate-based copolymer (C) having a weight average molecular weight of 2,000,000 or more and a copolymer comprising ethylene / (meth) acrylate / carbon monoxide ( D) 0.
5 to 10 parts by weight and an α-olefin oligomer and / or a co-oligomer of ethylene and α-olefin
(E) 0.05 to 5 parts by weight of (A)
A thermoplastic resin composition for extrusion molding, wherein the intrinsic viscosity [η] of the acetone-soluble component of + (B) + (C) + (D) + (E) is 0.4 to 1.2 dl / g. 3. The methyl methacrylate copolymer (C)
Is methyl methacrylate having a weight average molecular weight of 3,000,000 or more /
3. An n-butyl acrylate copolymer.
The thermoplastic resin composition according to the above. 4. A copolymer (D) comprising 10 to 87% by weight of an ethylene polymer repeating unit, 10 to 50% by weight of a (meth) acrylate polymer repeating unit and 3
The thermoplastic resin composition according to any one of claims 1 to 3, comprising a polymer repeating unit of carbon monoxide at -40% by weight. 5. An α-olefin oligomer and / or a co-oligomer of ethylene and α-olefin (E) is 10
The kinematic viscosity at 0 ° C is 5 to 100 cSt.
The thermoplastic resin composition according to the above. 6. The thermoplastic resin composition for extrusion molding according to any one of claims 1 to 5. 7. A sheet molded product obtained by extruding the thermoplastic resin composition according to claim 1. 8. A sheet molded product for an electric refrigerator inner box, which is obtained by extruding the thermoplastic resin composition according to claim 1.