JPH11269333A - Thermoplastic resin composition sheet forming, and formed product thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition well-balanced between resistance to impact and heat, capable of giving molded products of good appearance, and useful for, e.g., large-size, vacuum-molded members for automobiles by compounding a specific (meth)acrylate ester copolymer into a specific copolymer mixture in a specific ratio. SOLUTION: This composition is obtained by compounding 0.5 to 10 pts.wt. of a (meth)acrylate ester copolymer having a weight-average molecular weight of 1,000,000 to 6,000,000 in 100 pts.wt. of a mixture comprising (A) 10 to 50 pts.wt. of a rubber-containing graft copolymer obtained by graft-copolymerizing, in the presence of a rubbery polymer, (M1 ) a vinyl cyanide-based monomer and (M2 ) aromatic vinyl-based monomer or (M3 ) another monomer copolymerizable with the above, (B) 5 to 50 pts.wt. of a maleimide-based copolymer composed of 5 to 45 wt.% of the component M1 , 40 to 90 wt.% of the component M2 and (M4 ) 5 to 55 wt.% of a maleimide-based monomer (e.g. N-phenyl maleimide), and (C) 5 to 80 pts.wt. of vinyl cyanide-based copolymer composed of 10 to 45 wt.% of the component M1 and 90 to 55 wt.% of the component M2 .

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 forming a sheet having an excellent balance between impact resistance and heat resistance and excellent appearance of a molded article.

[0002]

2. Description of the Related Art Acrylonitrile-butadiene-styrene copolymer resin (ABS resin) has an excellent balance of impact resistance and is widely used as a resin for injection molding. recent years,
Attention has been paid to a technique for obtaining a large vacuum molded product by sheet molding, and a resin composition suitable for sheet molding has been developed for ABS resin.

[0003] In particular, a thermoplastic resin composition for blow molding containing a maleimide-based copolymer has been proposed to improve heat resistance (Japanese Patent Application Laid-Open No. 4-120157).
However, although the heat resistance is improved, the appearance of the sheet molded product is not sufficient.

[0004] The present invention relates to a thermoplastic resin composition for sheet molding excellent in such a balance between impact resistance and heat resistance and excellent in appearance of a molded article.

[0005]

[Problems to be solved by the invention]
The present inventors have conducted intensive studies in order to solve the above-described problems, and as a result, a rubber-containing graft copolymer, a maleimide copolymer, and a (meth) acrylate copolymer having a specific molecular weight at a specific ratio. By blending with a vinyl cyanide-based copolymer, a resin composition excellent in balance between impact resistance and heat resistance and excellent in appearance of a sheet molded product has been found, and the present invention has been achieved.

[0006]

That is, the present invention relates to a vinyl cyanide-based monomer (b), an aromatic vinyl-based monomer (c) and a copolymer thereof in the presence of a rubbery polymer (a). 10 to 50 parts by weight of a rubber-containing graft copolymer (I) obtained by grafting at least one monomer selected from other polymerizable vinyl monomers (d), vinyl cyanide monomer Maleimide copolymer (II) 5 consisting of 5 to 45% by weight of the compound (b), 40 to 90% by weight of the aromatic vinyl monomer (c) and 5 to 55% by weight of the maleimide monomer (e) To 50 parts by weight, and 10 to 45% by weight of a vinyl cyanide monomer (b) and 90 to 55% by weight of an aromatic vinyl monomer (c) (III). (I) + consisting of 5 to 80 parts by weight
(II) + (III) = 100 parts by weight, (meth) acrylate copolymer (IV) having a weight average molecular weight of 100 × 10 ⁴ to 600 × 10 ⁴ (0.5 to 10)
A thermoplastic resin composition for forming a sheet, wherein the thermoplastic resin composition contains parts by weight.

The rubbery polymer (a) used for the rubber-containing graft copolymer (I) in the present invention is a diene rubber, an acrylic rubber, an ethylene rubber or the like, and specific examples include polybutadiene, polybutadiene, and polybutadiene. (Butadiene-styrene), poly (butadiene-acrylonitrile), polyisoprene, poly (butadiene-butyl acrylate), poly (butadiene-methyl acrylate), poly (butadiene-methyl methacrylate), poly (butyl acrylate-methacrylic) Acid), poly (butadiene-
Ethyl acrylate), ethylene-propylene rubber, ethylene-propylene-diene rubber, poly (ethylene-
Isobutylene), poly (ethylene-methyl acrylate)
And the like. These rubbery polymers are used in one kind or in a mixture of two or more kinds. Among these rubbery polymers, polybutadiene, poly (butadiene-styrene), poly (butadiene-acrylonitrile) and ethylene-propylene rubber are particularly preferably used in view of impact resistance.

Specific examples of the vinyl cyanide monomer (b) used in the rubber-containing graft copolymer (I), maleimide copolymer (II) and vinyl cyanide copolymer (III) in the present invention Examples thereof include acrylonitrile and methacrylonitrile, and one or more kinds can be used. Among them, acrylonitrile is particularly preferable in terms of heat resistance.

Specific examples of the aromatic vinyl monomer (c) used in the rubber-containing graft copolymer (I), maleimide copolymer (II) and vinyl cyanide copolymer (III) in the present invention Are styrene, α-methylstyrene, orthomethylstyrene, paramethylstyrene,
Examples thereof include para-t-butylstyrene and halogenated styrene, and one or more kinds can be used. Of these, styrene and α-methylstyrene are particularly preferred in view of moldability, and styrene is more preferred.

Another copolymerizable vinyl monomer (d) used for the rubber-containing graft copolymer (I) in the present invention.
Specific examples of acrylic acid, unsaturated carboxylic acid such as methacrylic acid, (meth) acrylates such as methyl acrylate, methyl methacrylate, butyl acrylate, acrylamide, methacrylamide, N-methylacrylamide and the like (Meth) acrylamides, maleimides, maleimides such as N-methylmaleimide, and unsaturated carboxylic anhydrides such as maleic anhydride, citraconic anhydride, aconitic anhydride, and the like. Among them, methyl methacrylate, N-phenylmaleimide is preferred in terms of moldability.

In the present invention, the maleimide copolymer (I)
Specific examples of the maleimide-based monomer (e) used for I) include N-phenylmaleimide, N-cyclohexylmaleimide, N-methylmaleimide, and maleimide. Among them, N-phenylmaleimide is preferred in terms of moldability. Particularly preferably used.

The content of the rubbery polymer (a) in the rubber-containing graft copolymer (I) in the present invention is preferably from 10 to 80% by weight, more preferably from 40 to 70% by weight, from the viewpoint of impact resistance. . Further, the content of the vinyl cyanide monomer (b) in the rubber-containing graft copolymer (I) is preferably from 5 to 70% by weight in view of color stability, more preferably from 10 to 60% by weight. . Further, the content of the aromatic vinyl monomer (c) in the rubber-containing graft copolymer (I) is preferably from 10 to 80% by weight in terms of color stability, and more preferably from 20 to 70% by weight. .

The graft ratio is 10 to 80% by weight,
The reduced viscosity of the copolymer of the graft component is 0.2 to 0.8.
dl / g is preferred in terms of impact resistance.

In the present invention, the maleimide copolymer (I)
The structural unit of the monomer component of I) is 5 to 45% by weight of a vinyl cyanide monomer (b) and an aromatic vinyl monomer (c).
40 to 90% by weight and the maleimide monomer (e)
55% by weight.

Among them, vinyl cyanide monomer (b)
5 to 40% by weight, aromatic vinyl monomer (c) 30 to 5
Those in the range of 5% by weight and 30 to 55% by weight of the maleimide monomer (e) are preferred in terms of the balance between impact resistance and heat resistance.

If the amount of the vinyl cyanide monomer is less than 5% by weight, the impact resistance is poor, and if it exceeds 45% by weight, the color tone stability is reduced. When the content of the aromatic vinyl monomer (c) is less than 40%, the color tone stability of the thermoplastic resin composition for sheet molding at the time of melting is significantly reduced, and when it exceeds 90% by weight, heat resistance is poor. . When the amount of the maleimide-based monomer (e) is less than 5% by weight, heat resistance is not sufficient, and 55% by weight.
If it exceeds, impact resistance is inferior.

The glass transition temperature of the maleimide-based copolymer (II) in the present invention is 12 from the viewpoint of heat resistance.
0 ° C. or higher is preferable, and 210 ° C. or lower is preferable from the viewpoint of impact resistance. More preferably, it is 135 to 200 ° C.

The weight-average molecular weight / number-average molecular weight ratio of the maleimide-based copolymer (II) in the present invention is preferably 2.0 or more from the viewpoint of the appearance of the obtained sheet molded product.
It is preferably 3.0 or less from the viewpoint of impact resistance.
More preferably, the ratio of weight average molecular weight / number average molecular weight is 2.1 to 2.8.

In the present invention, the constituent units of the monomer component of the vinyl cyanide copolymer (III) are 10 to 45% by weight of the vinyl cyanide monomer (b), Body (c) is 90 to 55% by weight. Preferably,
It is 20 to 40% by weight of the vinyl cyanide monomer (b) and 80 to 60% by weight of the aromatic vinyl monomer (c).

If the content of the vinyl cyanide monomer (b) is less than 10% by weight and the content of the aromatic vinyl monomer (c) exceeds 90% by weight, the impact resistance is not sufficient. When the content of the vinyl cyanide-based monomer (b) exceeds 45% by weight and the content of the aromatic vinyl-based monomer (c) is less than 55% by weight, the color tone stability decreases.

The molecular weight of the vinyl copolymer (III) is not particularly limited, but the reduced copolymer has a reduced viscosity of 0.30 to 0.30.
Those having a range of 0.90 dl / g, particularly 0.35 to 0.85 dl / g are preferably used in view of impact resistance and fluidity. In the thermoplastic resin composition of the present invention, the rubber-containing graft copolymer (I) and the maleimide-based copolymer (I
The mixing ratio of I) and the vinyl cyanide-based copolymer (III) is 10 to 50 parts by weight of the rubber-containing graft copolymer (I), 5 to 50 parts by weight of the maleimide-based copolymer (II),
It is necessary that the amount of the vinyl cyanide copolymer (III) is 5 to 80 parts by weight. If the rubber-containing graft copolymer (I) is less than 10 parts by weight, the impact strength is not sufficient,
When the amount exceeds 50 parts by weight, heat resistance is poor. If the amount of the maleimide-based copolymer (II) is less than 5 parts by weight, the heat resistance is not sufficient, and if it exceeds 50 parts by weight, the appearance of the molded article is poor. If the amount of the vinyl cyanide copolymer (III) is less than 5 parts by weight, the heat resistance is not sufficient, and if it exceeds 80 parts by weight, the color tone stability is poor.

Specific examples of the (meth) acrylate copolymer (IV) in the present invention include methyl methacrylate, ethyl methacrylate, n-2 propyl methacrylate, and n-butyl methacrylate. Among them, methyl methacrylate is preferably used. These can be used alone or in combination of two or more.

In the present invention, the mixing ratio of the (meth) acrylate copolymer (IV) is (I) + (II) +
(III) The amount is 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight based on 100 parts by weight. If the amount of the (meth) acrylate copolymer (IV) is less than 0.5 part, the appearance of the sheet molded product is inferior, and if it exceeds 10 parts by weight, the heat resistance decreases.

The (meth) acrylate ester according to the present invention
The weight average molecular weight of the copolymer (IV) is 100 × 10
^Four~ 600 × 10^FourAnd preferably
150 × 10^Four~ 550 × 10^FourIt is. Weight average molecular weight
Is 100 × 10^FourIf it is less than this, the swell ratio is small and
And the appearance of the sheet molding is poor, and 600 × 10
^FourWhen the sheet exceeds the limit, bumps and craters
Poor appearance of shaped article. Thermoplastic resin for sheet molding of the present invention
The composition has excellent impact resistance, heat resistance, and appearance of molded products.
Suitable for large vacuum formed parts for automobiles and motorcycles
You. For example, specific examples of large vacuum formed parts for automobiles and motorcycles
Examples are bumpers, aero parts, scooter houses
It is suitable as a member such as a ring.

In the present invention, if necessary, 2,6-di-t-butyl-4-methylphenol, 4,
Phenolic antioxidants such as 4'-butylidene-bis (3-methyl-6-t-butylphenol); phosphorus-based oxidations such as tris (mixed, mono- and dinonylphenyl) phosphites and diphenyl isodecyl phosphite Antioxidants, sulfur-based antioxidants such as dilauryl thiodipropionate, dimyristyl thiodipropionate diasterial thiodipropionate, 2-hydroxy-4
-Octoxybenzophenone, 2- (2-hydroxy-
UV absorbers such as 5-methylphenyl) benzotriazole, bis (2,2,6,6, -tetramethyl-4-
Light stabilizers such as piperidinyl), antistatic agents such as hydroxylalkylamine and sulfonate, lubricants such as ethylenebisstearylamide and metal soap, glass fibers,
Inorganic filler such as carbon fiber, tetrabromobisphenol A, decabromodiphenyl oxide, TBA
It is also possible to add a flame retardant such as an epoxy oligomer, a TBA polycarbonate oligomer, antimony trioxide, a coloring agent, and the like.

Hereinafter, an example of a method for producing the thermoplastic resin composition for sheet molding of the present invention will be described.

The method for producing the rubber-containing graft copolymer (I), the maleimide copolymer (II) and the vinyl copolymer (III) in the present invention is not particularly limited.
It can be produced by emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization, or a combination thereof.

There is no particular limitation on the blending / melt extrusion of the thermoplastic resin composition for sheet molding of the present invention, and a generally known method can be employed. For example, kneading using a mixer such as a ribbon blender, a V-type blender, a Henschel mixer, an extruder such as a single screw extruder, a twin screw extruder, a Banbury mixer, a mixing roll, a pressure kneader, or the like can be employed. .

[0029]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples, but these examples do not limit the present invention. Parts and% in Reference Examples, Examples and Comparative Examples represent parts by weight and% by weight, respectively. In addition, each physical property value was calculated | required by the following test method.

The reduced viscosity (ηsp / c) was measured from a methyl ethyl ketone solution having a measuring temperature of 30 ° C. and a sample concentration of 0.4 g / dl using an Ubbelohde viscometer.

The graft ratio was determined by adding acetone to a predetermined amount (m) of the graft copolymer and refluxing for 3 hours. p. m. After centrifugation at (10000 G) for 40 minutes, the insoluble matter was filtered, the insoluble matter was dried under reduced pressure at 60 ° C. for 5 hours, and the weight (n) was measured and calculated by the following formula. Here, L is the rubber content of the graft copolymer.

Graft ratio (%) = [｛(n)-(m) ×
L｝ / {(m) × L｝] × 100 A vinyl cyanide monomer, an aromatic vinyl monomer in the maleimide copolymer (II) and the vinyl cyanide copolymer (III), and The content of the maleimide-based monomer was determined by FT-IR analysis of a film sample having a thickness of about 30 μm.

The glass transition temperature of the maleimide-based copolymer (II) is determined by the inflection of the calorific value when the temperature is increased at a rate of 20 ° C./min in a nitrogen gas flow using a Perkin-Elmer differential scanning calorimeter. It was determined from the point (middle point).

The weight-average molecular weight / number-average molecular weight ratio of the maleimide copolymer (II) and the weight-average molecular weight of the (meth) acrylate copolymer (IV) were determined by gel permeation chromatography as follows. The weight average molecular weight and the number average molecular weight were measured and determined under the following conditions.

Apparatus: GPC-244 made by WATERS Column: TSK gel Flow rate: THF solvent 0.1% solution 1.0 ml / min Temperature: 23 ° C. Detector: Differential refractive index detector Molecular weight calibration: Polystyrene

The Izod impact strength with a 12.7 mm notch was measured for an injection-molded thermoplastic resin composition for sheet molding according to ASTM D256.

The 6.4 mm load deflection temperature (DTL) of the thermoplastic resin composition for sheet molding is as follows:
The measurement was performed according to ASTM D648 (1.82 MPa / cm ² ).

The yellowing degree (YI) is measured by injection molding of a thermoplastic resin composition for sheet molding (square plate: 120 × 100 × 3 m).
m) according to JIS K7103 using a colorimeter (ND-100) manufactured by Nippon Denshoku Industries Co., Ltd.
The stimulus values X, Y and Z were measured and calculated.

The swell ratio is ISO1133 (240 ° C.
The ratio between the average strand diameter and the orifice diameter generated in the MFR measured according to 98 N load was determined.

The appearance of the molded product was determined by visually inspecting the occurrence of die lines, craters, and bumps. The die line was determined as ○ when the number was not determined by the number of sheets in the sheet, Δ when the number was one or two, and × when three or more were generated. Regarding the craters and butters, those having a good degree were evaluated as ○, those having a good degree were evaluated as Δ, and those having a poor degree were evaluated as ×.

Hereinafter, examples and comparative examples will be described.

Reference Example 1 Production of Rubber-Containing Graft Copolymer (I) In a reactor purged with nitrogen, 120 parts of pure water and 0.5 part of glucose were added.
Part, sodium pyrophosphate 0.5 part, ferrous sulfate 0.0
05 parts and polybutadiene latex (rubber particle diameter 0.3 μm, gel content 85%) 50 parts (solid content conversion)
And the temperature inside the reactor was raised to 65 ° C. while stirring. When the internal temperature reached 65 ° C., the polymerization was started, and a mixture consisting of a monomer (35 parts of styrene and 15 parts of acrylonitrile) and 0.3 part of t-dodecylmercaptan was added.
It was dripped continuously over time. At the same time, 0.25 parts of cumene hydroperoxide and potassium oleate.
An aqueous solution consisting of 5 parts and 25 parts of pure water was continuously dropped over 7 hours to complete the reaction. The obtained graft copolymer latex was coagulated with sulfuric acid, neutralized with caustic soda, washed, filtered and dried to obtain a rubber-containing graft copolymer (I). The graft ratio of this graft copolymer (I) is 45
%, Ηsp / c of the resin component was 0.68 dl / g. Reference Example 2 Production of Maleimide-Based Copolymer (II) A methyl methacrylate / acrylamide copolymer (Japanese Patent Publication No. 45-2415) was placed in a stainless steel autoclave having a capacity of 20 L and equipped with a baffle and a Faudra-type stirring blade.
A solution of 0.05 part in 165 parts of ion-exchanged water was stirred at 400 rpm, and the inside of the system was replaced with nitrogen gas. Next, acrylonitrile 10 parts styrene 50
, A mixed solution of 40 parts of N-phenylmaleimide, 0.46 part of t-dodecylmercaptan, and 0.15 part of 2,2′-azobisisobutylnitrile was added while stirring the reaction system, and the temperature was raised to 60 ° C. Then, polymerization was performed for 110 minutes. Thereafter, the temperature was raised to 100 ° C. over 50 minutes to complete the polymerization. Thereafter, the reaction system is cooled, the polymer is separated, washed and dried, and acrylonitrile 10% by weight and styrene 5
A maleimide-based copolymer (II) of 0% by weight and 40% by weight of N-phenylmaleimide was obtained. The glass transition temperature of this maleimide-based copolymer (II) was 167 ° C., and the ratio of weight average molecular weight / number average molecular weight was 2.4.

Reference Example 3 Vinyl cyanide copolymer (I
Production of II) In a stainless steel autoclave having a capacity of 20 L and equipped with a baffle and a Faudra type stirring blade, a methyl methacrylate / acrylamide copolymer (Japanese Patent Publication No. 45-2415)
A solution of 0.05 part in 165 parts of ion-exchanged water was stirred at 400 rpm, and the inside of the system was replaced with nitrogen gas. Next, 32 parts of acrylonitrile and styrene 4.
0 parts, t-dodecyl mercaptan 0.46 parts, 2,2 '
-Azobis (2,4-dimethylvaleronitrile) 0.3
9 parts, 2,2'-azobisisobutylnitrile 0.05
A part of the mixed solution was added while stirring the reaction system, and the temperature was raised to 58 ° C. to initiate polymerization. After a lapse of 15 minutes from the start of the polymerization, 64 parts of styrene from a feed pump provided at the top of the autoclave was added over 110 minutes. During this time, 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. Later,
Cooling of the reaction system, separation of the polymer,
After washing and drying, a vinyl cyanide copolymer (II) containing 10% by weight of acrylonitrile and 50% by weight of styrene was prepared.
I) was obtained. This vinyl cyanide copolymer (III)
Ηsp / c was 0.55 dl / g.

Reference Example 4 (Meth) acrylic acid ester copolymer (IV) A: "METABLEN" P530A (manufactured by Mitsubishi Rayon Co., Ltd.) Weight average molecular weight = 310 × 10 ⁴ B: "METABLEN" P501A (manufactured by Mitsubishi Rayon Co., Ltd.) Weight average molecular weight = 80 × 10 ⁴

Examples 1 to 5 and Comparative Examples 1 to 6 The rubber-containing graft copolymer (I), maleimide copolymer (II) and vinyl cyanide copolymer (I) described in Reference Examples
II) and (meth) acrylate copolymer (I)
V) was kneaded with a Henschel mixer at the mixing ratio shown in Table 1, and then extruded with a 40 mmφ extruder to obtain a thermoplastic resin composition for sheet molding. The swell ratio of the obtained composition was measured, and a test piece of the composition was prepared by injection molding, and the 12.7 mm Izod impact strength and yellowing degree (Y
I), a 6.4 mm load deflection temperature (DTL) was measured, and the measured values are shown in Table 2. Further, the sheet was formed, and the results of the formed appearance are also shown in Table 2.

From the Examples and Comparative Examples, the thermoplastic resin composition for sheet molding of the present invention is excellent in balance between impact resistance and heat resistance, and excellent in appearance of molded products. This is realized only by blending a specific additive in a specific ratio.

In Comparative Examples 1 and 2, the impact resistance was reduced when the proportion of the rubber-containing graft copolymer (I) was less than 10 parts by weight, and the heat resistance was reduced when the proportion was more than 50 parts by weight. For Comparative Examples 3 and 4, the maleimide-based copolymer (I
When the compounding ratio of I) is less than 5 parts by weight, heat resistance decreases,
If it exceeds 50 parts by weight, the appearance of the molded product is inferior. Comparative Example 5,
6, the (meth) acrylate copolymer (I)
In the case of V) having a low weight-average molecular weight (80 × 10 ⁴ ), the appearance of the molded article was inferior in both cases of blending and not adding.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

The thermoplastic resin composition for forming a sheet of the present invention is excellent in the balance between impact resistance and heat resistance and excellent in appearance of a sheet molded product by mixing a specific additive in a specific ratio. The obtained thermoplastic resin composition for sheet molding is obtained.

The thermoplastic resin composition for sheet forming of the present invention is used for sheet forming processing by utilizing these characteristics, and is particularly suitable as a resin material for large vacuum formed parts for automobiles and motorcycles.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 51/04 C08L 51/04 55/02 55/02

Claims (5)

[Claims] 1. A vinyl cyanide monomer (b), an aromatic vinyl monomer (c) and other vinyl monomers copolymerizable therewith in the presence of a rubbery polymer (a). 10 to 50 parts by weight of a rubber-containing graft copolymer (I) obtained by grafting at least one or more monomers selected from the group (d);
A maleimide-based copolymer comprising 5 to 45% by weight of a vinyl cyanide-based monomer (b), 40 to 90% by weight of an aromatic vinyl-based monomer (c) and 5 to 55% by weight of a maleimide-based monomer (e). 5 to 50 parts by weight of polymer (II) and 10 to 45% by weight of vinyl cyanide monomer (b) and 90 to 55% by weight of aromatic vinyl monomer (c) The weight average molecular weight is 100 × 10 ⁴ to 600 × 10 ⁴ based on 100 parts by weight of (I) + (II) + (III) consisting of 5 to 80 parts by weight of the copolymer (III) (meta ) Acrylate copolymer (IV)
A thermoplastic resin composition for forming a sheet, comprising 5 to 10 parts by weight. 2. The thermoplastic resin composition for sheet molding according to claim 1, wherein the maleimide monomer (e) in the maleimide copolymer (II) is N-phenylmaleimide. 3. The maleimide copolymer (II) has a glass transition temperature of 120 to 210 ° C. and a ratio of weight average molecular weight / number average molecular weight of 2.0 to 3.0. Thermoplastic resin composition for sheet molding. 4. The thermoplastic resin composition for sheet molding according to claim 1, which is used for large vacuum molded parts for automobiles or motorcycles. 5. A molded article obtained by molding the thermoplastic resin composition for sheet molding according to claim 1.