JPWO2008026554A1 - Resin composition and molded body thereof - Google Patents

Abstract

Provided are a resin composition excellent in the strength of a thin-walled portion and having an excellent balance of heat resistance, impact resistance and molding processability, and a molded product thereof. The resin composition containing (A) component 5-40 mass% shown below, (B) component 30-75 mass%, and (C) component 10-50 mass%. Component (A): Maleimide having an weight average molecular weight of 90,000 to 130,000 containing an aromatic vinyl monomer residue, an unsaturated dicarboxylic acid imide derivative residue, and an unsaturated dicarboxylic acid anhydride monomer residue Copolymer, (B) component: vinyl copolymer containing aromatic vinyl monomer residue and vinyl cyanide monomer residue having a weight average molecular weight of 100,000 to 160,000, (C ) Component: A graft copolymer obtained by graft-polymerizing a rubber-like polymer with a monomer mixture containing an aromatic vinyl monomer and a vinyl cyanide monomer.

Description

  The present invention relates to a resin composition containing a maleimide copolymer and a molded product thereof.

Conventionally, a resin composition comprising a maleimide copolymer, a vinyl aromatic copolymer, and a graft copolymer is known as a resin composition excellent in heat resistance, impact resistance, and moldability (Patent Document 1). ).
However, when the resin composition is highly required to have high strength at the thin wall portion, the strength is insufficient and measures such as devising the molded product design may be necessary.

JP-A-8-183890

  This invention made it the subject to provide the resin composition excellent in the thin part strength, and the balance of heat resistance, impact resistance, and moldability, and its molded article.

The gist of the present invention is as follows.
(1) The resin composition characterized by containing (A) component 5-40 mass% shown below, (B) component 30-75 mass%, and (C) component 10-50 mass%.
(A) component: 40-80 mass% of aromatic vinyl monomer residues, 10-60 mass% of unsaturated dicarboxylic imide derivative residues, and less than 2 mass% of unsaturated dicarboxylic anhydride monomer residues ( However, a maleimide copolymer having a weight average molecular weight of 90,000 to 130,000.
Component (B): a vinyl copolymer having a weight average molecular weight of 100,000 to 160,000 containing 67 to 78% by mass of aromatic vinyl monomer residues and 22 to 33% by mass of vinyl cyanide monomer residues. Polymer.
Component (C): 30 to 70% by mass of a rubber-like polymer, and 30 to 70% of a monomer mixture containing 50 to 80% by mass of an aromatic vinyl monomer and 20 to 40% by mass of a vinyl cyanide monomer. Graft copolymer obtained by graft polymerization of mass%.
(2) The resin composition as described in said (1) containing 10-30 mass% of said (A) component, 40-65 mass% of said (B) component, and 20-40 mass% of said (C) component.
(3) In the component (A), the aromatic vinyl monomer is styrene, the unsaturated dicarboxylic imide derivative is N-phenylmaleimide, and the unsaturated dicarboxylic anhydride monomer is maleic anhydride. The resin composition according to (1) or (2).
(4) The resin according to any one of (1) to (3), wherein the aromatic vinyl monomer in the component (B) is styrene and the vinyl cyanide monomer is acrylonitrile. Composition.
(5) The resin composition according to any one of (1) to (4), wherein the rubbery polymer in the component (C) is a butadiene polymer and / or a butadiene-styrene copolymer.
(6) The resin according to any one of (1) to (5), wherein the aromatic vinyl monomer in the component (C) is styrene and the vinyl cyanide monomer is acrylonitrile. Composition.
(7) Resin of any one of said (1)-(6) in which said (A) component contains 0.1-1.5 mass% of unsaturated dicarboxylic anhydride monomer residues. Composition.
(8) The vinyl monomer residue that is copolymerizable with the aromatic vinyl monomer, the unsaturated dicarboxylic acid imide derivative, and the unsaturated dicarboxylic acid anhydride monomer. The resin composition according to any one of (1) to (7), wherein the resin composition is a maleimide copolymer containing 18% by mass or less.
(9) The component (B) is a vinyl copolymer further containing 10% by mass or less of the aromatic vinyl monomer and a vinyl monomer copolymerizable with the vinyl cyanide monomer. The resin composition according to any one of (1) to (8).
(10) In the component (C), the monomer mixture to be graft-polymerized contains 20 masses of vinyl monomer residues copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer. % Of the resin composition according to any one of (1) to (9).
(11) A molded article containing the resin composition according to any one of (1) to (10).
(12) The molded body according to (11), wherein the molded body is an injection molded body.

  According to the present invention, by blending a specific component at a specific ratio, a resin composition excellent in thin portion strength and having a good balance of heat resistance, impact resistance, and moldability can be obtained, and the resin The molded body using the composition can be suitably used for automobile parts, electrical / electronic machine parts, precision machine parts, office equipment parts, heat appliances and the like due to these excellent features.

The maleimide copolymer (A) will be described. In the present invention, a residue means a corresponding repeating unit in a polymer obtained by polymerizing a monomer or a derivative.
The component (A) contains an aromatic vinyl monomer residue, an unsaturated dicarboxylic imide derivative residue, and an unsaturated dicarboxylic anhydride monomer residue, and has a weight average molecular weight of 90,000 to 130,000. It is a certain maleimide copolymer.
(A) As a manufacturing method of component, as a first manufacturing method, a method of copolymerizing a monomer mixture of an aromatic vinyl monomer, an unsaturated dicarboxylic acid imide derivative, and an unsaturated dicarboxylic acid anhydride monomer, As a second production method, a monomer mixture of an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride monomer is copolymerized, and then an unsaturated dicarboxylic acid anhydride monomer in the copolymer. Examples include a method in which a unit residue is reacted with ammonia and / or a primary amine (imidation reaction) to be converted into an unsaturated dicarboxylic imide derivative unit. The maleimide copolymer of component (A) can be obtained by any method.

  The aromatic vinyl monomer constituting the component (A) is not particularly limited. For example, styrene monomers such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, and chlorostyrene are used. Can be mentioned. These monomers can be used alone or in combination of two or more. Particularly preferred is styrene.

  The unsaturated dicarboxylic acid imide derivative constituting the component (A) is not particularly limited. For example, maleimide, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-naphthyl Maleimide, glutarimide and the like can be mentioned. Particularly preferred is N-phenylmaleimide.

  (A) Although the unsaturated dicarboxylic acid anhydride monomer which comprises a component is not specifically limited, For example, each anhydride of maleic acid, itaconic acid, citraconic acid, and aconitic acid is mentioned. These monomers can be used alone or in combination of two or more. Particularly preferred is maleic anhydride.

  The maleimide copolymer of the component (A) further includes a vinyl monomer copolymerizable with the aromatic vinyl monomer, the unsaturated dicarboxylic acid imide derivative, and the unsaturated dicarboxylic acid anhydride monomer. It can also contain residues. Such copolymerizable vinyl monomers are not particularly limited, and examples thereof include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, methyl acrylate esters, ethyl acrylate esters, butyl acrylate esters, and the like. Acrylic acid esters, methacrylic acid ester monomers such as methyl methacrylic acid ester, ethyl methacrylic acid ester, vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid, acrylic acid amide, methacrylic acid amide, N-vinylcarbazole Etc. These monomers can be used alone or in combination of two or more. Preferred are methyl acrylate, acrylic acid and methacrylic acid. The unsaturated dicarboxylic acid anhydride monomer is also exemplified as a copolymerizable vinyl monomer in the first production method, and the unsaturated dicarboxylic acid anhydride group remaining in the second production method without being converted to an imide group is also included. It can be introduced into the copolymer.

  In the case of the first production method, bulk-suspension polymerization, solution polymerization and bulk polymerization are used. In the case of the second production method, known polymerization methods such as suspension polymerization, emulsion polymerization, solution polymerization and bulk polymerization are used. Can be used.

  In the second production method, ammonia and primary amine used for the imidization reaction may be in an anhydrous state or an aqueous solution state. The primary amine is not limited, and examples thereof include alkylamines such as methylamine, ethylamine, and cyclohexylamine, and aromatic amines such as aniline, toluidine, and naphthylamine. These monomers can be used alone or in combination of two or more. Particularly preferred is aniline.

  When the imidation reaction is performed in a solution state or a suspension state, it is preferable to use a normal reaction vessel, for example, an autoclave, and when it is performed in a bulk molten state, an extruder equipped with a devolatilizer can be used. .

  The temperature of the imidization reaction is about 80 to 350 ° C, preferably 100 to 300 ° C. When the temperature is lower than 80 ° C., the reaction rate is slow, and the reaction takes a long time and is not practical. On the other hand, when it exceeds 350 ° C., physical properties are deteriorated due to thermal decomposition of the polymer. A catalyst may be used during the imidation reaction, and a tertiary amine such as triethylamine is preferably used as the catalyst.

  (A) The weight average molecular weight of a component is 90,000-130,000, Preferably it is 100,000-120,000. If it is less than 90,000, the impact strength of the resulting resin composition is reduced, and if it exceeds 130,000, the strength of the thin portion of the obtained resin composition is not sufficiently improved.

The aromatic vinyl monomer residue used for the component (A) is preferably 40 to 80% by mass or less, and more preferably 40 to 60% by mass. If it is less than 40% by mass, the moldability is lowered, and if it exceeds 80% by mass, the heat resistance is lowered.
Moreover, unsaturated dicarboxylic imide derivative residue is 10-60 mass%, More preferably, it is 10-59 mass%, More preferably, it is 35-55 mass%. If it is less than 10% by mass, the heat resistance is not sufficiently improved, and if it exceeds 60% by mass, the impact strength of the resin composition is greatly reduced.
The unsaturated dicarboxylic acid anhydride monomer residue is less than 2% by mass (however, 0% by mass is not included), preferably 0.1 to 1.9% by mass, particularly preferably 0.3 to 1.1% by mass. When the unsaturated dicarboxylic acid anhydride monomer residue is 2% by mass or more or not contained, the strength of the thin portion is not significantly improved.
Furthermore, the vinyl monomer residue copolymerizable with these is preferably contained in an amount of 18% by mass or less, more preferably 10% by mass or less. When the copolymerizable vinyl monomer residue exceeds 18% by mass, compatibility with other components is lowered, impact resistance is likely to be lowered, and delamination occurs when formed into a molded body. It becomes easy to do.

The vinyl copolymer as the component (B) will be described.
The component (B) is a vinyl copolymer having an aromatic vinyl monomer residue and a vinyl cyanide monomer residue and having a weight average molecular weight of 100,000 to 160,000.
Although the aromatic vinyl monomer used for (B) component is not specifically limited, what was described as an aromatic vinyl monomer used for (A) component can be used, and it is used for (A) component. It can be the same or different. Styrene is preferred.
Although it does not specifically limit as a vinyl cyanide monomer, For example, an acrylonitrile, methacrylonitrile, (alpha) -chloro acrylonitrile is mentioned. These monomers can be used alone or in combination of two or more. Acrylonitrile is preferred.
The component (B) can further contain a vinyl monomer copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer. The copolymerizable vinyl monomer is not particularly limited, but those described as the copolymerizable vinyl monomer used for component (A) can be used, and those used for component (A) May be the same or different.

(B) The preferable aromatic vinyl monomer residue in a component is 67-78 mass%, More preferably, it is 69-76 mass%. If it is less than 67% by mass, the moldability is lowered, and if it exceeds 78% by mass, the heat resistance is lowered.
Moreover, a preferable vinyl cyanide monomer residue is 22-33 mass%, More preferably, it is 24-31 mass%. If it is less than 22% by mass or exceeds 33% by mass, the compatibility with the component (A) is lowered, and when the obtained resin composition is formed into a molded body, poor appearance such as delamination is likely to occur, and impact strength is also increased. It also causes a decrease.
The vinyl monomer residue copolymerizable with these is preferably 10% by mass or less, more preferably 5% by mass or less. When the content of the copolymerizable vinyl monomer residue exceeds 10% by mass, the compatibility with the component (A) and the component (C) decreases, and the resulting resin composition is made into a molded body. Occasionally, an appearance defect phenomenon of delamination is likely to occur, and it also causes a reduction in impact strength.

The component (B) can be produced by an ordinary polymerization method. Examples of the production method include suspension polymerization, solution polymerization, and emulsion polymerization.
The weight average molecular weight of the component (B) is 100,000 to 160,000, preferably 120,000 to 150,000. If it is less than 100,000, the impact strength and thin part strength of the resulting resin composition will be reduced, and if it exceeds 160,000, the moldability of the resulting resin composition will be reduced and the strength of the thin part will be reduced.

The graft copolymer (C) will be described.
The component (C) is a graft copolymer obtained by graft-polymerizing a rubber-like polymer with a monomer mixture containing an aromatic vinyl monomer and a vinyl cyanide monomer.
The rubbery polymer used for the component (C) is not particularly limited as long as it is a graft-polymerizable rubber. For example, it can be copolymerized with butadiene such as a butadiene polymer or a butadiene-styrene copolymer. And a copolymer with a vinyl monomer, an ethylene-propylene copolymer, an ethylene-propylene-diene copolymer, an acrylic rubber, and the like. These may be used alone or in combination of two or more. In the case of a butadiene-styrene copolymer, the butadiene monomer is preferably 60% by mass or more.

The aromatic vinyl monomer used for the component (C) is not particularly limited, but those described as the precursor of the aromatic vinyl monomer residue used for the component (A) can be used. It may be the same as or different from those used for component A) or component (B). Styrene is preferred.
The aromatic vinyl monomer in a preferable (C) component monomer mixture is 50-80 mass%, More preferably, it is 60-80 mass%. If the aromatic vinyl monomer content is less than 50% by mass, the molding processability decreases, and if it exceeds 80% by mass, impact resistance decreases.

The vinyl cyanide monomer used for the component (C) is not particularly limited, but those described as the precursor of the vinyl cyanide monomer residue used for the component (B) can be used. ) It may be the same as or different from that used for the component. Acrylonitrile is preferred.
The vinyl cyanide monomer in the component monomer mixture (C) is preferably 20 to 40% by mass, more preferably 24 to 31% by mass. When the vinyl cyanide monomer is less than 20% by mass or exceeds 40% by mass, the compatibility of the component (C) with the component (A) is reduced, and the layer obtained when the resulting resin composition is formed into a molded body. The appearance defect phenomenon of peeling is likely to occur and also causes a reduction in impact strength.

The copolymerizable vinyl monomer used for the component (C) is not particularly limited, but what is described as a precursor of the copolymerizable vinyl monomer residue used for the component (A). It can be used and may be the same as or different from those used for the component (A) and the component (B). Preferred are methyl acrylate, acrylic acid and methacrylic acid.
(C) 20 mass% or less of the copolymerizable vinyl monomer in a component monomer mixture is preferable, Most preferably, it is 10 mass% or less. When the copolymerizable vinyl monomer exceeds 20% by mass, the compatibility with other components is lowered, and particularly the impact resistance is liable to be lowered. Also, when the obtained resin composition is molded, delamination occurs. Appearance defects are likely to occur.

  In the production of the graft polymer as component (C), any known polymerization technique can be used. For example, aqueous heterogeneous polymerization such as suspension polymerization and emulsion polymerization, bulk polymerization, solution polymerization, and poor production polymer. Precipitation heterogeneous polymerization in a solvent, etc., and combinations thereof.

  The graft rubber particle diameter, the graft ratio, and the weight average molecular weight of the ungrafted copolymer in the component (C) are not particularly limited, but the graft rubber particle diameter is preferably 0.1 to 0.8 μm, particularly preferably 0.2. A range of ˜0.6 μm is preferable from the viewpoint of impact resistance. The graft ratio is 20 to 80%, particularly preferably 30 to 70%. If the graft ratio is less than 20%, the rubbery polymer tends to aggregate, so that appearance defects are likely to occur, resulting in a reduction in impact resistance. The weight average molecular weight of the ungrafted copolymer is preferably in the range of 50,000 to 200,000, particularly preferably in the range of 60,000 to 140,000, since the balance between impact resistance and moldability is good.

  (C) component mixes said aromatic vinyl monomer, vinyl cyanide monomer monomer, and vinyl monomer which can be copolymerized as needed, and the mixture 30-70 mass % Is graft-polymerized to 30 to 70% by mass of a rubbery polymer, and particularly preferably 40 to 60% by mass of the mixture is graft-polymerized to 40 to 60% by mass of a rubbery polymer. is there. If the rubber-like polymer is less than 30% by mass, the impact resistance of the resin composition is lowered, and if it exceeds 70% by mass, the molding processability is lowered, and the resulting resin composition is liable to cause an appearance defect phenomenon.

  In the graft polymerization, it is usually difficult for the whole amount of the monomer to be grafted onto the rubber-like polymer, and a non-grafted copolymer is by-produced. In the present invention, not only a true graft copolymer in which an ungrafted copolymer is positively separated and removed, but also a graft polymerization containing a non-grafted copolymer may be used. It can be handled.

The compounding ratio of the (A) component, the (B) component, and the (C) component of the resin composition in the present invention is such that the (A) component is 5 to 40% by mass, the (B) component is 30 to 75% by mass, ( C) A component is 10-50 mass%. Especially, (A) component, (B) component, and the compounding ratio of (C) component, (A) component is 10-30 mass%, (B) component is 40-65 mass%, (C) component is 20-40 mass% is preferable.
When the component (A) is less than 5% by mass, the heat resistance of the resulting resin composition is significantly reduced, and when it exceeds 40% by mass, the strength of the thin portion is significantly reduced.
If the component (B) is less than 30% by mass, the fluidity or thin part strength of the resulting resin composition is significantly reduced, and if it exceeds 75% by mass, the thin part strength is reduced.
When the component (C) is less than 10% by mass, the strength of the thin portion of the resin composition obtained is lowered, and when it exceeds 50% by mass, the heat resistance and fluidity are lowered.

  The resin composition of the present invention can be obtained by using an ordinary melt-kneading apparatus. Examples of a melt-kneading apparatus that can be suitably used include a single-screw extruder, a meshing-type rotating in the same direction, or a meshing-type rotating in a different direction. Examples include an extruder, a screw extruder such as a non- or incompletely meshing twin screw extruder, a Banbury mixer, a kneader, and a mixing roll.

  In the resin composition, a stabilizer, a plasticizer, a lubricant, an antioxidant, an ultraviolet absorber, a light stabilizer, glass fiber, carbon fiber, an inorganic filler, a colorant and the like are blended within a range not impairing the effects of the present invention. Can do.

  The present invention will be further described below with reference to examples and comparative examples, but these are only illustrative and do not limit the contents of the present invention. In the examples and comparative examples, “part” and “%” are based on mass unless otherwise specified.

Manufacture of Maleimide Copolymer (A) Component Into an autoclave equipped with a stirrer, 60 parts of styrene, 0.3 part of α-methylstyrene dimer and 100 parts of methyl ethyl ketone were charged, and the system was replaced with nitrogen gas. The temperature was raised to 0 ° C., and a solution prepared by dissolving 40 parts of maleic anhydride and 0.15 part of benzoyl peroxide in 200 parts of methyl ethyl ketone was continuously added in 8 hours. The temperature was kept at 85 ° C. for an additional 3 hours after the addition. To the copolymer solution thus obtained, 38 parts of aniline and 0.6 part of triethylamine were added and reacted at 140 ° C. for 7 hours. The reaction solution was supplied to a twin screw extruder with a vent and devolatilized to obtain a maleimide copolymer. From the C-13 NMR analysis, the conversion of acid anhydride groups to imide groups was 94 mol%. This maleimide copolymer is a copolymer containing 51.1% of N-phenylmaleimide units as unsaturated dicarboxylic imide derivatives, 47.0% of styrene units, and 1.9% of maleic anhydride units. It was set as copolymer A-1.
For other maleimide copolymers A-2 to A-10, the conversion rate of maleic anhydride to an imide group is adjusted by adjusting the addition amount of aniline, and the addition amount of α-methylstyrene dimer is adjusted. It was produced by the same method as A-1, except that the weight average molecular weight was adjusted by the above method. The component composition and weight average molecular weight are shown in Table 1.

  In an autoclave equipped with a stirrer, 47 parts of styrene, 0.6 part of α-methylstyrene dimer and 100 parts of methyl ethyl ketone were charged, and the system was purged with nitrogen gas. The temperature was raised to 90 ° C., and N-phenylmaleimide 53 And a solution prepared by dissolving 0.15 part of benzoyl peroxide in 200 parts of methyl ethyl ketone were continuously added over 6 hours. The temperature was kept at 90 ° C. for an additional 3 hours after the addition. The reaction solution was supplied to a twin screw extruder with a vent and devolatilized to obtain a maleimide copolymer. This maleimide copolymer is a copolymer containing 53.0% of N-phenylmaleimide units and 47.0% of styrene units as an unsaturated dicarboxylic imide derivative, and this was designated as copolymer A-11. . The component composition and weight average molecular weight are shown in Table 1.

Production of vinyl copolymer (B) component In a reaction vessel equipped with a stirrer, 71.5 parts of styrene, 28.5 parts of acrylonitrile, 2.5 parts of tricalcium phosphate, 0.33 parts of t-dodecyl mercaptan, t- 0.2 parts of butyl peroxyacetate and 250 parts of water were charged, and the temperature was raised to 70 ° C. to initiate polymerization. Seven hours after the start of polymerization, the temperature was raised to 75 ° C. and maintained for 3 hours to complete the polymerization. The polymerization rate reached 97%. 200 parts of a 5% aqueous hydrochloric acid solution was added to the obtained reaction solution for precipitation, and after dehydration and drying, a white bead copolymer was obtained. The composition of this copolymer was 72.0% styrene, 28.0% acrylonitrile, and the weight average molecular weight was 1330,000. This was designated as copolymer B-1.
The other vinyl copolymers B-2 to B-5 were prepared by adjusting the amount of styrene and acrylonitrile by adjusting the amount of styrene and acrylonitrile, and by adjusting the amount of t-dodecyl mercaptan. It was manufactured by the same method as B-1 except that was adjusted. The component composition and the weight average molecular weight are shown in Table 2.

Production of graft copolymer (C) component In a reaction vessel equipped with a stirrer, 126 parts of polybutadiene latex (solid content 35%, average particle size 0.3 μm, gel content 90%), styrene-butadiene latex 17 parts (solid) Min 67%, average particle size 0.5 μm, gel content 15%), sodium stearate 1 part, sodium formaldehyde sulfoxylate 0.2 part, tetrasodium ethylenediamine tetraacetic acid 0.01 part, sulfuric acid Ferrous iron (0.005 parts) and pure water (150 parts) were charged, and the temperature was heated to 50 ° C., to which 45 parts of a monomer mixture composed of 75% styrene and 25% acrylonitrile, 1.0 part of t-dodecyl mercaptan, 0.15 part of cumene hydroperoxide was continuously added in 6 hours, and after addition, the temperature was raised to 65 ° C. and polymerization was performed for 2 hours. The polymerization rate reached 97%. After 0.3 parts of an antioxidant (Ciba Specialty Chemical Co., Ltd., Irganox 1076) was added to the obtained latex, 300 parts of a 5% calcium chloride aqueous solution was added, solidified, washed with water, dried and then grafted as a white powder. A polymer was obtained. This was designated as copolymer C-1.

Next, in order to measure the graft ratio of C-1 and the molecular weight of the ungrafted copolymer, 3 g of C-1 was taken, swollen in a methyl ethyl ketone solution, and centrifuged in a supernatant solution of ungrafted styrene-acrylonitrile copolymer. When the molecular weight of the coalescence was measured by gel permeation chromatography, the weight average molecular weight was 105,000. The composition of the gel fraction (graft copolymer and rubbery polymer) precipitated by centrifugation was analyzed by Kjeldahl nitrogen quantitative analysis and pyrolysis gas chromatography, and the weight of the graft copolymer was measured from the amounts of styrene and acrylonitrile. The polybutadiene rubber was analyzed by bromine addition method to determine the weight of the rubbery polymer. From the weight of the graft copolymer thus obtained and the weight of the rubber-like polymer, the graft ratio was determined by the following formula, and the graft ratio was 47%.
Graft ratio = (weight of graft copolymer / weight of rubbery polymer) × 100 (%)

Examples 1-13
A maleimide copolymer (A) component, a vinyl copolymer (B) component, and a graft copolymer (C) component were blended so as to have the composition shown in Tables 3 and 4, and this blend was 35 mm. The resin composition was obtained by extruding at 280 ° C. with a unidirectional rotating twin screw extruder (L / D = 32) with a devolatilizer and pelletizing. In addition, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant with respect to 100 parts by weight of the blend of component (A), component (B) and component (C) (Ciba Specialty Chemicals Co., Ltd., IRGANOX1076) 0.5 part by weight was contained. Using the obtained pellets, test pieces for measuring physical properties were prepared by an injection molding machine, and various physical properties were measured. The results are shown in Tables 3 and 4.

Comparative Examples 1 to 21
Same as Example except blending maleimide copolymer (A) component, vinyl copolymer (B) component and graft copolymer (C) component so as to have the composition shown in Table 5 and Table 6. A resin composition was prepared by the method described above and evaluated in the same manner as in the examples. The results are shown in Tables 5 and 6.

In addition, the evaluation measuring method of various physical properties is as follows.
(1) MFR (Melt Mass Flow Rate): Measured according to JIS K 7210 under 220 ° C. and 98N load condition or 265 ° C. and 98N load condition.
(2) Charpy impact strength: Measured according to JIS K 7111 using a notched test piece.
(3) Vicat softening temperature: Measured according to JIS K 7206 under 50N load.
(4) Strength of the thin falling weight surface: 120 mm long and 40 mm wide obtained by injection molding, the gate is installed at the center of the lateral side surface, the portion from 0 to 40 mm in the vertical direction from the gate side is 3 mm in thickness, 40 to 80 mm A three-stage plate having a thickness of 2 mm and a thickness of 80 to 120 mm of 1 mm was used as a test piece. The height at which the test piece breaks 50% by naturally dropping a 100 g weight with a 10.8 mm diameter hemisphere at the tip of the drop vertically from various heights onto the center of the 1 mm thickness of the test piece.
(5) Weight average molecular weight: The weight average molecular weights of the components (A) and (B) were calculated by GPC (gel permeation chromatography) measurement. The conditions are shown below.
Apparatus: “SYSTEM-21” manufactured by Shodex
Column: PLgel MIXED-B
Temperature: 40 ° C
Solvent: Tetrahydrofuran Detection: RI
Concentration: 0.2%
Injection volume: 100 μl
Calibration curve: Standard polystyrene (manufactured by Polymer Laboratories) was used, and the relationship between elution time and elution amount was converted to molecular weight to obtain various average molecular weights.
(6) Component composition: The component composition ratio was measured using pyrolysis gas chromatography.
Thermal decomposition apparatus: JPS-220 manufactured by Nippon Analytical Industries
Thermal decomposition temperature: 590 ° C
Gas chromatography: 5890SERIESII manufactured by Hewlett-Packard Company
Column: Micropolar column DB-5
Carrier gas: He pressure 2 psi
Temperature condition: held at 50 ° C. for 5 minutes, then heated to 250 ° C. at 18 ° C./minute, held at 250 ° C. for 7 minutes Detection: FID
0.3 mg is weighed and measured. The peak area ratio of the detected three components was taken.
(7) Average particle diameter: Graft rubber particle diameter of component (C) was measured using N4 type manufactured by Coulter. The measurement conditions were a sample viscosity of 0.01 poise, a refractive index of 1.17, and a temperature of 20 ° C. The solvent used is dimethylformamide.

As is apparent from the results shown in Tables 3 to 6, when Example 2 and Example 3 having different weight average molecular weights of component (A) are compared with Comparative Example 1, the weight average molecular weight of component (A) is less than 90,000. Then, the strength of the thin part is inferior.
Moreover, when Example 1 and Example 6 and Comparative Example 4 are compared, and Example 2 and Example 3 and Comparative Example 2 are compared, if the weight average molecular weight of the component (A) exceeds 130,000, the strength of the thin portion is inferior.
Similarly, Example 3 and Comparative Example 4, Example 7 and Comparative Example 9, Example 8 and Comparative Example 10, Example 9 and Comparative Example 11, Example 10 and Comparative Example 12, Example 11 and Comparative Example 13, When Example 12 and Comparative Example 14, and Example 13 and Comparative Example 15 are compared with each other, if the weight average molecular weight of the component (A) exceeds 130,000, the moldability (MFR) is lowered and the strength of the thin portion is inferior.
Moreover, when Example 3 in which the weight average molecular weight of the component (B) is different from Comparative Example 5 and Comparative Example 6 are compared, if the weight average molecular weight of the component (B) is less than 100,000, the strength of the thin portion is inferior, and if it exceeds 160,000, molding is performed. Processability is reduced and the strength of the thin-walled portion is inferior.
Comparing Example 3 with Comparative Example 7 and Comparative Example 8 in which the amount of the aromatic vinyl monomer residue of component (B) and the amount of vinyl cyanide monomer residue are different, the amount of aromatic vinyl monomer of component (B) When the residual amount exceeds 78 mass% and the vinyl cyanide monomer residue is less than 22 mass%, the strength of the thin-walled portion is inferior, and the aromatic vinyl monomer residue content is less than 67 mass%. If it exceeds 33% by mass, the fluidity is lowered and the strength of the thin portion is inferior.
Comparing Example 3 and Comparative Example 3, Example 3, Example 4 and Comparative Example 22 in which the amount of the unsaturated dicarboxylic acid anhydride monomer residue of the component (A) is compared, the unsaturation of the component (A) If the dicarboxylic acid anhydride monomer residue is 2% by mass or more or 0% by mass, the strength of the thin portion is inferior.
As shown in Comparative Examples 16 and 17, when the component (A) is less than 5% by mass, the heat resistance is low, and when it exceeds 40% by mass, the Charpy impact strength and the thin-walled portion strength are low. Further, as shown in Comparative Examples 18 and 19, when the component (B) is less than 30% by mass, the strength of the thin portion is low, and when it exceeds 75% by mass, the Charpy impact strength and the strength of the thin portion are low. Further, as shown in Comparative Example 20 and Comparative Example 21, when the component (C) is less than 10% by mass, the Charpy impact strength and the thin portion strength are low, and when it exceeds 50% by mass, the heat resistance is low.
As described above, a resin composition excellent in the balance of heat resistance, impact resistance, and molding processability, in which the strength of the thin-walled portion is remarkably improved, can be obtained by blending specific components at a specific ratio.

The resin composition of the present invention is excellent in the strength of the thin-walled portion and excellent in the balance of heat resistance, impact resistance and molding processability. Further, the molded body using the resin composition has these excellent characteristics. Applications are expected to be suitable for automobile parts, electrical / electronic machine parts, precision machine parts, office equipment parts, heat appliances, etc.

The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2006-230001 filed on Aug. 28, 2006 are incorporated herein as the disclosure of the specification of the present invention. It is.

Claims (10)

A resin composition comprising 5 to 40% by mass of component (A), 30 to 75% by mass of component (B), and 10 to 50% by mass of component (C) shown below.
(A) component: 40-80 mass% of aromatic vinyl monomer residues, 10-60 mass% of unsaturated dicarboxylic imide derivative residues, and less than 2 mass% of unsaturated dicarboxylic anhydride monomer residues ( However, a maleimide copolymer having a weight average molecular weight of 90,000 to 130,000.
Component (B): a vinyl copolymer having a weight average molecular weight of 100,000 to 160,000 containing 67 to 78% by mass of aromatic vinyl monomer residues and 22 to 33% by mass of vinyl cyanide monomer residues. Polymer.
Component (C): 30 to 70% by mass of a rubber-like polymer, and 30 to 70% of a monomer mixture containing 50 to 80% by mass of an aromatic vinyl monomer and 20 to 40% by mass of a vinyl cyanide monomer. Graft copolymer obtained by graft polymerization of mass%.   In the component (A), the aromatic vinyl monomer is styrene, the unsaturated dicarboxylic imide derivative is N-phenylmaleimide, and the unsaturated dicarboxylic anhydride monomer is maleic anhydride. Item 2. The resin composition according to Item 1.   The resin composition according to claim 1 or 2, wherein the aromatic vinyl monomer in component (B) is styrene and the vinyl cyanide monomer is acrylonitrile.   The resin composition according to any one of claims 1 to 3, wherein the rubbery polymer in the component (C) is a butadiene polymer and / or a butadiene-styrene copolymer.   The resin composition according to any one of claims 1 to 4, wherein the aromatic vinyl monomer in component (C) is styrene and the vinyl cyanide monomer is acrylonitrile.   The component (A) further contains 18 masses of a vinyl monomer residue copolymerizable with the aromatic vinyl monomer, the unsaturated dicarboxylic imide derivative, and the unsaturated dicarboxylic anhydride monomer. The resin composition according to any one of claims 1 to 5, wherein the resin composition is a maleimide copolymer contained in an amount of 1% or less.   The component (B) is a vinyl copolymer further containing 10% by mass or less of the vinyl monomer residue copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer. The resin composition of any one of Claims 1-6.   In the component (C), the monomer mixture polymerized with the graph contains 20% by mass or less of the vinyl monomer residue copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer. The resin composition according to any one of claims 1 to 7, which is contained.   The molded object containing the resin composition of any one of Claims 1-8.   The molded body according to claim 9, wherein the molded body is an injection molded body.