JPH09202848A - Thermoplastic resin composition excellent in impact resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition improved in impact resistance, good in luster, containing small-sized rubber and medium-sized rubber in specified proportions each having specific graft segment and narrow in particle size distribution. SOLUTION: This thermoplastic resin composition comprises (A) a graft copolymer 10-70wt.% in graft rate composed of (i) a rubber polymer having 250-800nm volume-average particle diameter in <=50% standard deviation of particle size distribution and (ii) a grafted segment, (B) a second graft copolymer 20-80wt.% in graft rate composed of (iii) a rubber polymer having 60-160nm volume-average particle diameter in <=40% standard deviation of particle size distribution and (iv) a grafted segment, (C) a maleimide-based copolymer, and (D) an α-alkyl aromatic vinyl copolymer. In this composition, the volume ratio (i)/(i+iii) is 0.3-0.9, the components (i) and (iii) are e.g. diene rubber polymers, respectively, the weight ratio C/(C+D) is 0.1-0.9, the reduced viscosities of the MEK solubles of the components A to D are 0.3-1.2dL/g, respectively, and the contents of the components (i) and (iii) in the components A to D are 5-40wt.%, respectively.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention provides a molded article which is excellent in impact resistance, particularly surface impact strength, and is excellent in gloss, rigidity, workability, heat resistance (heat distortion temperature) and heat stability. It belongs to the technical field of producing and utilizing a thermoplastic resin composition.

[0002]

2. Description of the Related Art In recent years, for the purpose of improving the heat resistance of styrene resins, development of maleimide resins in which a maleimide monomer is copolymerized as a copolymerization component has been activated. The maleimide resin has a high heat distortion temperature and workability, but has a drawback that the impact resistance is not sufficient.

On the other hand, conventionally, for the purpose of improving the heat resistance of a styrene resin, an α-alkylstyrene resin obtained by copolymerizing α-methylstyrene as a copolymerization component is used in a large amount to improve the heat resistance. Since it is necessary to copolymerize α-alkylstyrene, there is a drawback that the thermal stability is not sufficient.

Various methods have been proposed to improve the impact resistance of maleimide resins and the thermal stability of α-alkylstyrene resins. For example, JP-A-60-2172
In Japanese Patent Publication No. 49, a combined use of a maleimide resin and an α-alkylstyrene resin obtained by copolymerizing α-alkylstyrene at a high content rate is proposed. The method of using a maleimide resin and an α-alkylstyrene resin in combination is an effective method from the viewpoint of heat resistance, impact resistance, thermal stability and balance with other properties.

However, although these conventionally proposed methods have the effect of improving the impact resistance of the maleimide resin, the improvement level is not sufficient.

That is, it is necessary to improve the compatibility of the maleimide resin and the α-alkylstyrene resin, which are the matrix, so as to be advantageous in impact resistance, but even if the compatibility is improved, the characteristics are not improved. It is only near the middle of both polymers used and no significant effect is seen.
In particular, the surface impact strength, which is a problem in terms of practical use, is inferior to the conventional styrene-based resin and α-alkylstyrene-based resin even when the method proposed above is used.

From recent studies, the mechanical properties of polymers,
It is said that it is most effective to find a rubber phase that matches the matrix phase in order to improve the impact resistance.

For example, in the case of styrenic resins, a method of using various rubber-like polymers has been proposed in order to develop impact resistance.

Among them, there are many examples in which an improvement method is proposed by paying attention to the rubber particle size distribution, for example, Japanese Patent Laid-Open No. 59-2.
No. 32138, a medium particle size rubber and a large particle size rubber of several microns are used in combination, and in JP-A-60-23438, a graft monomer is simultaneously polymerized in a mixture of a small particle size rubber and a medium particle size rubber. There is a method of using a graft polymer, and JP-A-62-199645 discloses a method of using a rubber having a low graft ratio and a small particle diameter rubber in combination with a medium particle diameter rubber.

[0010]

However, there are many proposals of effective rubber phases for each of the styrene resin, the maleimide resin, and the α-alkylstyrene resin, but the maleimide resin and the α-alkylstyrene resin are different from each other. Almost no effective rubber phase has been found that can effectively improve the impact resistance of the coexisting matrix. This is because the most advantageous rubber phase for the matrix in which the maleimide resin and the α-alkylstyrene resin coexist is the rubber phase of the styrene resin alone, the rubber phase of the maleimide resin alone, and the α-alkylstyrene resin. This is because it is considered to be different from the rubber phase alone. That is, it has been reported from the recent literature of Wu et al. That the entanglement density of the matrix and the optimum rubber particle size have a correlation, but the matrix in which the maleimide resin and the α-alkylstyrene resin coexist. The entanglement density of is considered to be different from the styrene resin alone, the maleimide resin alone, and the α-alkylstyrene resin alone, and even the optimum rubber particle diameter is different from those of these single resins. It is considered.

Also in the case of styrene resins, the proposed method does not have a sufficient effect of improving the surface impact strength, and a large particle size rubber is used. The method (1) and (2) increase the Izod impact strength, but have a problem that the surface impact strength, which is important for practical use, is low.

[0012]

[Means for Solving the Problems] The above-mentioned problems have hitherto been caused in order to produce a medium particle size rubber or a large particle size rubber by an emulsion polymerization method by aggregating small particle size rubbers by stirring shearing force during polymerization. However, it is considered that the conventional medium particle size rubber and large particle size rubber have an extremely wide particle size distribution.

The inventors of the present invention have high surface impact strength, which is important for practical use, in a system in which a maleimide resin and an α-alkylstyrene resin are used in combination, and have the above-mentioned problems found in styrene resins. As a result of extensive studies on not only matrix phase but also rubber phase in order to obtain a non-use system, it is possible to obtain a small particle diameter rubber and a medium particle diameter rubber having a specific graft portion and a narrow particle diameter distribution. When the species are present in a specific ratio, the surface impact strength can be improved, and particularly when the medium particle size rubber is an enlarged rubber, the effect is remarkable, and the gloss is also good, and the present invention is completed. I arrived.

That is, according to the present invention, the volume average particle diameter is 25.
Consisting of a rubber polymer (A) and a graft part (a) having a particle size distribution of 0 to 800 nm and a standard deviation of 50% or less,
Graft copolymer (I) having a graft ratio of 10 to 70% (weight%, the same applies hereinafter), and a volume average particle size of 60 to 160
nm, a graft copolymer (II) consisting of a rubber polymer (B) having a particle size distribution with a standard deviation of 40% or less and a graft part (b) and having a graft ratio of 20 to 80%, a vinyl cyanide compound. 10-40%, maleimide-based monomer 5-
Maleimide-based copolymer (III) obtained by polymerizing 50%, aromatic vinyl compound 10-85% and monomer copolymerizable with these, 0-30% (total 100%) and vinyl cyanide compound 10- 40%, an α-alkyl aromatic vinyl compound 30-75%, and a monomer copolymerizable with these 0-30% (total 100%), an α-alkyl aromatic vinyl copolymer (IV And a volume ratio of the rubber polymer (A) to the rubber polymer (A) and the rubber polymer (B) (A /
(A + B)) is 0.3 to 0.9, and the rubber polymers (A) and (B) are one or more of a diene rubber polymer, an olefin rubber polymer and an acrylic rubber polymer. And graft units of the graft copolymers (I) and (II) are both 15 to 60 mol% of vinyl cyanide compound unit, 85 to 40 mol% of aromatic vinyl compound unit, and a monomer which can be copolymerized with these. It is a polymer composed of 0 to 30 mol% of body units, and the weight ratio of the maleimide copolymer (III) to the maleimide copolymer (III) and the α-alkylaromatic vinyl copolymer (IV) ( III / (III + IV)) is 0.1 to 0.9, and the graft copolymers (I) and (I
I), maleimide-based copolymer (III) and α-alkyl aromatic vinyl-based copolymer (IV) have a reduced viscosity (30 ° C., in a N, N-dimethylformamide solution) of a methyl ethyl ketone soluble component of 0. Rubber weight of 3 to 1.2 dl / g and in the graft copolymers (I), (II), maleimide copolymer (III) and α-alkyl aromatic vinyl copolymer (IV). Thermoplastic resin composition having excellent content of impact resistance (claim 1), wherein the content of the coalesced (A) and (B) is 5 to 40%, the rubber polymer (A) is acrylic acid,
5 to 50% of at least one unsaturated acid (c) of methacrylic acid, itaconic acid and crotonic acid, having 1 carbon atom
An acid obtained by polymerizing 50 to 95% of (meth) alkyl acrylate (d) having an alkyl group of 1 to 12 and 0 to 40% of a monomer copolymerizable with the component (c) and the component (d). The thermoplastic resin composition (claim 2) and the rubber polymer (A) according to claim 1, which are rubber polymers (A-1) produced by a coagulation and enlargement method using a group-containing latex (S). 5-25% of at least one unsaturated acid (c) of acrylic acid, methacrylic acid, itaconic acid and crotonic acid, alkyl acrylate (d-1) 5-30 having an alkyl group having 1 to 12 carbon atoms %, An alkyl methacrylate having an alkyl group having 1 to 12 carbon atoms (d-2) 80 to 20% and a component (c), (d)
-1) component, at least one of aromatic vinyl monomer copolymerizable with component (d-2), monomer having two or more polymerizable functional groups in the molecule, and vinyl cyanide compound
The thermoplastic resin composition according to claim 2, which is a rubber polymer (A-2) produced by a coagulation and enlargement method using an acid group-containing latex (S-1) prepared by polymerizing 0 to 40% of a seed. (Claim 3) The thermoplastic resin composition according to claim 1, wherein the α-alkyl aromatic vinyl copolymer (IV) has an α-alkyl aromatic vinyl unit content of 50 mol% or less. Item 4. The thermoplastic resin according to claim 1, wherein the α-alkyl aromatic vinyl-based copolymer (IV) is an α-alkyl aromatic vinyl-based copolymer (IV) obtained by a suspension polymerization method. The composition (Claim 5) and the maleimide-based copolymer (III) contain 50 mol% of an aromatic vinyl compound unit.
The thermoplastic resin composition according to claim 1 containing the above (claim 6).

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic resin composition of the present invention comprises:
A graft copolymer (I) used for improving impact resistance,
(II), a maleimide-based copolymer used to give heat stability, fluidity, heat resistance and rigidity (III), an α-alkyl aromatic vinyl-based copolymer used to give heat resistance, rigidity and fluidity Consist of (IV).

The graft copolymer (I) is a rubber polymer (A) for improving impact resistance, a rubber polymer (A) and a maleimide copolymer (III), an α-alkyl aromatic vinyl copolymer. It comprises a graft part (a) for improving the adhesiveness with the polymer (IV).

The rubber polymer (A) in the graft copolymer (I) has a volume average particle size of 250 to 800 nm,
Preferably 300-700 nm, more preferably 35
0 to 650 nm, standard deviation is 50% or less, preferably 4
It is 5% or less, more preferably 40% or less. When the volume average particle diameter of the rubber polymer (A) exceeds 800 nm, the gloss decreases and sufficient surface impact strength cannot be obtained. On the other hand, if it is less than 250 nm, the impact resistance is lowered. Further, when the standard deviation exceeds 50%, the surface impact strength decreases. Generally, the lower limit of the standard deviation is about 10%.

Specific examples of the rubber polymer (A) include polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, butadiene-acrylic ester rubber, hydrogenated styrene-butadiene rubber and other diene rubber polymers, ethylene. Examples include olefin rubber polymers such as propylene rubber and ethylene-propylene-diene rubber, and acrylic rubber polymers such as polyacrylic acid ester rubber and ethylene-acrylic acid ester rubber. These may be used alone or in combination of two or more.

When a diene rubber polymer, particularly polybutadiene rubber or styrene-butadiene rubber is used as the rubber polymer (A), it is preferable from the viewpoint of impact resistance, and an olefin rubber polymer, particularly ethylene- When a propylene-diene rubber is used, it is preferable from the viewpoint of fluidity, and when an acrylic rubber polymer, particularly a polyacrylate rubber is used, it is preferable from the viewpoint of weather resistance.

As the rubber polymer (A), at least one unsaturated acid (c) of acrylic acid, methacrylic acid, itaconic acid or crotonic acid (c) is added to a rubber latex in an amount of 5 to 50.
%, Further 5 to 35%, (meth) alkyl acrylate (d) having an alkyl group having 1 to 12 carbon atoms 50 to 50%
95%, and further 65 to 95% and the component (c),
A rubber polymer produced by a coagulation and enlargement method using an acid group-containing latex (S) obtained by polymerizing 0 to 40%, further 0 to 20% of a monomer copolymerizable with the component (d). When (A-1) is used, it is preferable from the viewpoint that the impact resistance of the molded product obtained from the obtained thermoplastic resin composition is improved. In particular, the rubber polymer (A) is an unsaturated acid (c) of at least one kind of acrylic acid, methacrylic acid, itaconic acid, and crotonic acid (c) 5 to 25%, further 7 to 23%, and a carbon number of 1 Alkyl acrylate (d-1) having ˜12 alkyl groups (d-1) 5 to 30%, further 7 to 27%, alkyl methacrylate (d-2) 80 to 20% having alkyl groups having 1 to 12 carbon atoms, Is 75 to 30% and an aromatic vinyl monomer copolymerizable with the component (c), the component (d-1) and the component (d-2), and a monomer having two or more polymerizable functional groups in the molecule. At least one of a monomer and a vinyl cyanide compound
When the rubber polymer (A-2) produced by the coagulation and enlargement method using the acid group-containing latex (S-1) prepared by polymerizing 40%, and further 0 to 20% is used, It is preferable in that the surface impact strength of the molded article obtained from the obtained thermoplastic resin composition is particularly improved. The total amount of the (d-1) component and the (d-2) component is 75-
95%, and further 77 to 93%.

The amount of the acid group-containing latex used is 0.1 to 15 parts (solid content), more preferably 0.5 to 100 parts (weight part, the same applies hereinafter) (solid content) of the rubber latex. It is preferable to add 10 parts to cause coagulation and enlargement in terms of good production stability and improved impact resistance, particularly surface impact strength, of the molded product.

Specific examples of the (meth) alkyl acrylate (d) having an alkyl group having 1 to 12 carbon atoms include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate. , Stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate,
Octyl methacrylate, lauryl methacrylate, stearyl methacrylate, glycidyl methacrylate,
2-hydroxyethyl methacrylate and the like can be mentioned. These may be used alone or in combination of two or more.

Specific examples of the monomer copolymerizable with the above-mentioned components (c) and (d) include styrene,
Aromatic vinyl monomers such as α-methylstyrene, p-methylstyrene, vinylnaphthalene, chlorostyrene and bromstyrene, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, allyl methacrylate,
Examples thereof include monomers having two or more polymerizable functional groups in the molecule such as diallyl phthalate and triallyl cyanurate, acrylamide, methacrylamide, maleimide, phenylmaleimide, and cyclohexylmaleimide. These may be used alone or in combination of two or more.

Specific examples of the alkyl acrylate (d-1) having an alkyl group having 1 to 12 carbon atoms include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, 2- Examples thereof include ethylhexyl acrylate. These may be used alone or in combination of two or more. Of these, butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, and the like are preferable because it is easy to control the enlarged diameter.

Specific examples of the alkyl methacrylate (d-2) having an alkyl group having 1 to 12 carbon atoms include methyl methacrylate, ethyl methacrylate,
Examples include propyl methacrylate, butyl methacrylate, hexyl methacrylate, octyl methacrylate, lauryl methacrylate, stearyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate and the like. These may be used alone,
Two or more kinds may be used in combination. Of these, butyl methacrylate, 2-ethylhexyl methacrylate and the like are preferable because it is easy to control the enlarged diameter.

Further, an aromatic vinyl monomer copolymerizable with the above-mentioned component (c), component (d-1) and component (d-2), a monomer having two or more polymerizable functional groups in the molecule. Specific examples of the monomer and the vinyl cyanide compound include those listed as specific examples of the monomer copolymerizable with the components (c) and (d). These may be used alone or in combination of two or more.

The graft ratio of the graft portion (a) in the graft copolymer (I) is 10 to 70%, preferably 15.
˜65%, more preferably 20 to 60%. If the graft ratio is less than 10%, the impact resistance will decrease, and if it exceeds 70%, the workability will decrease.

The graft portion (a) has a vinyl cyanide compound unit content of 15 to 60 mol%, preferably 20 to 55 mol%, more preferably 30 to 52 mol%, and an aromatic vinyl compound unit of 85 to 40 mol%, preferably Is a polymer consisting of 80 to 45 mol%, more preferably 70 to 48 mol%, and 0 to 30 mol%, preferably 0 to 20 mol% of a monomer unit copolymerizable therewith. When the graft part (a) is out of the above range, that is, when the vinyl cyanide compound unit content is less than 15 mol%, the impact resistance of the molded article produced from the composition of the present invention is lowered, and the vinyl cyanide compound unit content is less. If it exceeds 60 mol%, the workability is deteriorated.

The vinyl cyanide compound unit in the graft part (a) is a unit such as acrylonitrile or methacrylonitrile, and the aromatic vinyl compound unit is styrene, α-methylstyrene, p-methylstyrene, chlorostyrene, or the like. Units such as bromostyrene and vinylnaphthalene, and the copolymerizable monomer units include (meth) acrylic acid and its methyl, ethyl, propyl, butyl, 2-hydroxyethyl, 2-ethylhexyl, glycidyl, etc. Examples thereof include units of (meth) acrylic acid ester-based monomers and units of maleimide-based monomers such as maleimide and N-phenylmaleimide. These may be used alone or in combination of two or more. Of these, an acrylonitrile unit is preferred as the vinyl cyanide compound unit and a styrene unit is preferred as the aromatic vinyl unit from the industrial viewpoint.

The graft copolymer (II) is a rubber polymer (B) for improving impact resistance, a rubber copolymer (B) and a maleimide copolymer (III), an α-alkyl aromatic vinyl. It comprises a graft part (b) for improving the adhesiveness with the system copolymer (IV).

The rubber polymer (B) in the graft copolymer (II) has a volume average particle size of 60 to 160 nm, preferably 70 to 140 nm, more preferably 80 to 1 nm.
30 nm, standard deviation is 40% or less, preferably 35% or less, and more preferably 30% or less. When the volume average particle diameter of the rubber polymer (B) is less than 60 nm, the impact resistance decreases, and when it exceeds 160 nm, sufficient surface impact strength cannot be obtained. Further, when the standard deviation exceeds 40%, the surface impact strength decreases. Generally, the lower limit of the standard deviation is about 10%.

Specific examples of the rubber polymer (B) include polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, butadiene-acrylic acid ester rubber, hydrogenated styrene-butadiene rubber and other diene rubber polymers, ethylene. Examples include olefin rubber polymers such as propylene rubber and ethylene-propylene-diene rubber, and acrylic rubber polymers such as polyacrylic acid ester rubber and ethylene-acrylic acid ester rubber. These may be used alone or in combination of two or more.

When a diene rubber polymer, especially polybutadiene rubber or styrene-butadiene rubber is used as the rubber polymer (B), it is preferable from the viewpoint of impact resistance, and an olefin rubber polymer, especially ethylene- When a propylene-diene rubber is used, it is preferable from the viewpoint of fluidity, and when an acrylic rubber polymer, particularly a polyacrylate rubber is used, it is preferable from the viewpoint of weather resistance.

The graft ratio of the graft part (b) in the graft copolymer (II) is 20 to 80%, preferably 25.
~ 75%, more preferably 40-65%. If the graft ratio is less than 20%, the impact resistance will decrease, and if it exceeds 80%, the workability will decrease.

The graft portion (b) has a vinyl cyanide compound unit content of 15 to 60 mol%, preferably 20 to 55 mol%, more preferably 35 to 55 mol%, and an aromatic vinyl compound unit of 85 to 40 mol%, preferably Is a polymer composed of 80 to 45 mol%, more preferably 65 to 45 mol%, and 0 to 30 mol%, preferably 0 to 20 mol% of a monomer unit copolymerizable therewith. When the graft part (b) is out of the above range, that is, when the vinyl cyanide compound unit content is less than 15 mol%, the impact resistance of the molded article produced from the composition of the present invention is lowered and the vinyl cyanide compound unit content is 60%. If it exceeds mol%, the workability tends to deteriorate.

The vinyl cyanide compound unit in the graft portion (b) is a unit such as acrylonitrile or methacrylonitrile, and the aromatic vinyl compound unit is styrene, α-methylstyrene, p-methylstyrene, chlorostyrene, or the like. Units such as bromostyrene and vinylnaphthalene, and the copolymerizable monomer units include (meth) acrylic acid and its methyl, ethyl, propyl, butyl, 2-hydroxyethyl, 2-ethylhexyl, glycidyl, etc. Examples thereof include units of (meth) acrylic acid ester-based monomers and units of maleimide-based monomers such as maleimide and N-phenylmaleimide. These may be used alone or in combination of two or more. Of these, an acrylonitrile unit is preferred as the vinyl cyanide compound unit and a styrene unit is preferred as the aromatic vinyl unit from the industrial viewpoint.

Next, the graft copolymers (I) and (II)
The production method will be described.

As long as the graft copolymers (I) and (II) used in the present invention can be obtained, they may be produced by any polymerization method, initiator, chain transfer agent, surfactant and the like. Absent.

For example, the polymerization method may be one produced by various known polymerization methods such as a suspension polymerization method, an emulsion polymerization method, an emulsion-suspension polymerization method, and an emulsion-bulk polymerization method. Of these, the emulsion polymerization method is preferable because the volume ratio of the graft portion to the rubber polymer can be easily controlled.

The initiator for producing the graft copolymers (I) and (II) is also a thermal decomposition type initiator such as potassium persulfate, and a redox type initiator such as Fe-reducing agent-organic peroxide. Known initiators can be used without limitation.

When a chain transfer agent is used, a known chain transfer agent such as t-dodecyl mercaptan, n-dodecyl mercaptan, α-methylstyrene dimer and terpinolene is used for the purpose of adjusting the volume ratio of the grafted portion to the rubber polymer. It may be used within a range that can be controlled within the range.

Regarding the charging method during polymerization, any method may be used as long as it is within the scope of the present invention. For example, in order to obtain the graft copolymers (I) and (II), the rubber polymers (A) and (B) may be simultaneously charged in the same polymerization machine to simultaneously polymerize the monomer mixture. ,
The graft copolymers (I) and (II) may be produced by different polymerization machines, but the latter method is preferable because the graft ratio can be easily controlled. Further, when the graft copolymers (I) and (II) are continuously polymerized by the same polymerization machine, the rubber polymer (A) is charged to convert the monomer mixture into the rubber polymer (A). A method in which after a certain amount of polymerization, the rubber polymer (B) is charged and the remaining amount of the monomer mixture is polymerized, an amount corresponding to the specific surface area of the rubber polymers (A) and (B) is polymerized. preferable.

The maleimide-based copolymer (III) is a vinyl cyanide compound in an amount of 10 to 40%, preferably 15 to 3
5%, more preferably 15 to 30%, maleimide monomer 5 to 50%, preferably 10 to 45%, more preferably 10 to 35%, aromatic vinyl compound 10 to 85
%, Preferably 20-75%, more preferably 50-
65% and 0 to 30% of a monomer copolymerizable therewith,
It is preferably a copolymer obtained by polymerizing 0 to 20% (total 100%).

In the maleimide copolymer (III), the impact resistance is obtained when the vinyl cyanide compound content is less than 10%, the processability is greater than 40%, and the maleimide monomer content is less than 5%. When the heat resistance exceeds 45%, the workability decreases, when the aromatic vinyl compound is less than 10%, the workability decreases, and when the heat resistance exceeds 85%, the impact resistance decreases.
In particular, when the content of the aromatic vinyl compound in the maleimide-based copolymer (III) is 50 mol% or more, it is preferable from the viewpoint that the thermal stability and the impact resistance are improved. Reduced viscosity (30
C, in N, N-dimethylformamide solution) 0.3-
1.2 dl / g, further 0.35-1.0 dl / g,
Particularly, 0.40 to 0.9 dl / g is preferable from the viewpoint of improving impact resistance and workability.

The vinyl cyanide compound forming the maleimide copolymer (III) is acrylonitrile or methacrylonitrile, and the aromatic vinyl compound is styrene, α-methylstyrene, p-methylstyrene or p-methylstyrene. Isopropyl styrene, chlorostyrene, bromostyrene, vinyl naphthalene, etc. are used as the maleimide-based monomer. Maleimide, N-methylmaleimide, N
-Ethylmaleimide, N-propylmaleimide, N-butylmaleimide, N-phenylmaleimide, N- (p-
Methylphenyl) maleimide and the like, and as a copolymerizable monomer, (meth) acrylic acid and its (meth) acryl such as methyl, ethyl, propyl, butyl, 2-hydroxyethyl, 2-ethylhexyl and glycidyl. Examples thereof include acid ester type monomers. These may be used alone or in combination of two or more. Of the vinyl cyanide compounds, acrylonitrile is impact resistant, N-phenylmaleimide is a maleimide monomer from the viewpoint of heat resistance, and aromatic vinyl compounds are styrene and α-methylstyrene. It is preferable in terms of workability and impact resistance.

The maleimide copolymer (III) is a known bulk polymerization method, solution polymerization method, bulk-suspension polymerization method, suspension polymerization method, emulsion polymerization method, emulsion-suspension polymerization method, emulsion-bulk polymerization method. It can be produced by a conventional method or a polymerization method thereof and a post-imidization method.

The α-alkyl aromatic vinyl copolymer (IV) contains 10 to 40%, preferably 15 to 35% of a vinyl cyanide compound, and an α-alkyl aromatic vinyl compound 3
0 to 75%, preferably 35 to 70% and a monomer residue copolymerizable therewith 0 to 30%, preferably 0 to 20%
% (Total 100%).

Α-Alkyl aromatic vinyl copolymer (I
In V), when the vinyl cyanide compound content is less than 10%, the impact resistance is deteriorated, and when it exceeds 40%, the workability is deteriorated.
When the content of the α-alkyl aromatic vinyl compound is less than 30%, the workability is deteriorated, and when it exceeds 75%, the stability during production is deteriorated and the thermal stability is also deteriorated. In particular, the content of the α-alkyl aromatic vinyl compound unit in the α-alkyl aromatic vinyl copolymer (IV) is 50 mol% or less,
From the viewpoint of thermal stability, the reduced viscosity (30 ° C., in N, N-dimethylformamide solution) of the methyl ethyl ketone soluble component is 0.3 to 1.2 dl from the viewpoint that the balance between impact resistance and processability is improved. / G, further 0.35
It is preferably 1.0 dl / g, particularly 0.4 to 0.9 dl / g.

Α-Alkyl aromatic vinyl copolymer (I
Examples of the vinyl cyanide compound forming V) include acrylonitrile and methacrylonitrile, and examples of the α-alkyl aromatic vinyl compound include α-methylstyrene and α-methylstyrene.
-Ethylstyrene and the like, and as a copolymerizable monomer, (meth) acrylic acid and its (meth) acrylic acid such as methyl, ethyl, propyl, butyl, 2-hydroxyethyl, 2-ethylhexyl and glycidyl. Examples thereof include ester monomers. These are 1
They may be used alone or in combination of two or more. Among the vinyl cyanide compounds, acrylonitrile is α-alkyl aromatic vinyl compounds in terms of impact resistance and polymerizability with α-alkyl aromatic vinyl compounds.
-Methylstyrene is preferable in terms of heat resistance and impact resistance.

Α-Alkyl aromatic vinyl copolymer (I
V) can be produced by a known bulk polymerization method, solution polymerization method, bulk-suspension polymerization method, suspension polymerization method, emulsion polymerization method, emulsion-suspension polymerization method, or emulsion-bulk polymerization method. Among these, the suspension polymerization method is preferable from the viewpoint of improving the thermal stability.

The weight ratio (III / (III + IV)) of the maleimide copolymer (III) to the maleimide copolymer (III) and the α-alkylaromatic vinyl polymer (IV) was 0.
1-0.9, more 0.2-0.8, especially 0.3
~ 0.7. If the weight ratio is less than 0.1, the workability decreases, and if it exceeds 0.9, the impact resistance decreases.

The graft copolymer (I) in the present invention,
(II), maleimide-based copolymer (III) and α-alkyl aromatic vinyl-based copolymer (IV) have a reduced viscosity (30 ° C., in N, N-dimethylformamide solution) of the methyl ethyl ketone soluble component of 0. 0.3-1.2 dl / g, preferably 0.35-1.0 dl / g, particularly preferably 0.40
0.9 dl / g. When the reduced viscosity, which is an index of molecular weight, is less than 0.3 dl / g, the impact resistance is 1.2 dl.
If it exceeds / g, the workability is deteriorated.

The thermoplastic resin composition of the present invention comprises two special graft copolymers (I) and (II) in which the particle size distribution and the graft portion of the rubber polymer are controlled and the maleimide copolymer ( III), α-alkyl aromatic vinyl copolymer (I
V), and the rubber polymer content in these four components is 5 to
It is 40%, preferably 10 to 30%. Outside this range, that is, when the rubber polymer content is less than 5%, the impact resistance decreases, and when the rubber polymer content exceeds 40%, the processability decreases. Further, in the rubber polymer, the volume ratio of the rubber polymer (A) to the rubber polymer (A) and the rubber polymer (B) (A /
(A + B)) is 0.3 to 0.9, and further 0.40
It is 0.85, and outside this range, sufficient impact resistance, particularly surface impact strength cannot be obtained.

The method of producing the composition of the present invention is also the method of producing the graft copolymers (I), (II), the maleimide copolymer (III) and the α-alkyl aromatic vinyl copolymer (IV). Although different, they can be produced, for example, by mixing them in various states such as latex, suspension, slurry, solution, powder, beads, pellets, or by mixing them in a state in which the above states are combined.

In the case of recovering the polymer powder from the copolymer latex, a usual method such as calcium chloride, magnesium chloride, a salt of an alkaline earth metal such as magnesium sulfate, sodium chloride or sodium sulfate can be used for the latex. Alkaline metal salts, hydrochloric acid, sulfuric acid,
The latex can be recovered by a method of coagulating the latex by adding an inorganic acid such as phosphoric acid or acetic acid or an organic acid, and then dehydrating and drying. Also, a spray drying method can be used.

The above mixture can be obtained by kneading with a known melt-kneading machine such as Banbury mixer, roll mill, single-screw extruder or twin-screw extruder.

The compositions of the present invention include the well known antioxidants, heat stabilizers, UV absorbers, pigments, antistatic agents,
Additives such as lubricants can be added as needed. In particular, hindered phenol-based, sulfur-based, phosphorus-based, hindered amine-based stabilizers used for styrene resins,
Interior of benzophenone-based and benzotriazole-based UV absorbers, organopolysiloxanes, aliphatic hydrocarbons, esters of higher fatty acids and higher alcohols, amides of higher fatty acids, bisamides and their modified products, oligoamides, metal salts of higher fatty acids, etc. By using a lubricant, an external lubricant, etc., the composition of the present invention can have higher performance as a molding resin composition.

Specific examples of the hindered phenol-based stabilizer include 1,1,3-tris (2-methyl-4-).
Hydroxy-5-tert-butylphenyl-butane,
n-octadecyl-3- (3 ', 5'-di-tert-
Butyl-4-hydroxyphenyl) propionate),
Tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, triethylene glycol-bis- [3- (3-te
rt-butyl-5-methyl-4-hydroxyphenyl)
Propionate], pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]), 2,6-di-ter
t-Butyl-4-methylphenol, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-te)
rt-butylphenol), tris- (3,5-di-t)
ert-butyl-4-hydroxybenzyl) -isocyanurate) and the like.

Specific examples of the sulfur-based stabilizer include:
3,3'-thiodipropionic acid, dialkyl-3,3 '
-Thiodipropionate, pentaerythritol-tetrakis (3-alkylthiopropionate), tetrakis [methylene-3- (alkylthio) propionate]
Methane, bis [2-methyl-4 (3-alkyl-thiopropionyloxy) -5-tert-butylphenyl]
Examples include sulfide.

Specific examples of the phosphorus-based stabilizer include stearylphenyl phosphite, tris (mono, di, nonylphenyl) phosphite, distearyl pentaerythritol diphosphite, and tris (2,4-di-te).
rt-Butylphenyl) phosphite, di (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, tetrakis (2,4-di-tert-butylphenyl) 4,4-diphenylenephosphite, bis Examples include (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite.

Specific examples of the hindered amine-based stabilizer include dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate of dimethyl succinate and poly [[ 6- (1,1,3,3
-Tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [[2,
2,6,6-Tetramethyl-4-piperidyl) imino]], 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,2
2,6,6-pentamethyl-4-piperidyl) and the like.

These stabilizers may be used alone.
More than one species may be used in combination.

Specific examples of the benzophenone-based and benzotriazole-based ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone and 2-. (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (3-t-butyl-
5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2)
-Hydroxyphenyl) -5-chlorobenzotriazole and the like.

Specific examples of the organopolysiloxane include polydimethylsiloxane, polydiethylsiloxane, polymethylphenylsiloxane and the like.

Specific examples of the aliphatic hydrocarbon include synthetic paraffin, polyethylene wax, polypropylene wax and the like.

Specific examples of the ester of higher fatty acid and higher alcohol include esters of montanic acid and stearyl alcohol, stearyl stearate, behener behenate and the like.

Specific examples of the amides, bisamides and modified products thereof and oligoamides of the higher fatty acids include stearic acid amide, ethylenebisstearic acid amide, higher fatty acids such as stearic acid and dicarboxylic acids such as succinic acid and ethylenediamine. Examples thereof include compounds having a melting point higher than that of bisamide, which are synthesized from such a diamine by a dehydration reaction.

Specific examples of the metal salts of higher fatty acids include higher aliphatic calcium salts such as lauric acid, myristic acid, palmitic acid, stearic acid and oleic acid, magnesium salts, aluminum salts and cadmium salts. To be

These lubricants may be used alone.
More than one species may be used in combination.

Further, the composition of the present invention may contain halogen-based or phosphite-based flame retardants, antimony compounds such as antimony trioxide, silicone compounds such as polydimethylsiloxane, alumina, etc., depending on the degree of flame retardancy required. You may mix and use the aluminum compound of these.

Further, the composition of the present invention contains reinforcing fibers such as glass fiber and carbon fiber, mica, talc, clay and glass beads in order to improve mechanical properties such as elastic modulus and heat resistance. Fillers may be added.

Preferred examples of the thermoplastic resin composition of the present invention as described above have a volume average particle size of 300 to 700.
nm, a graft polymer (I) consisting of a rubber polymer (A) having a particle size distribution with a standard deviation of 45% or less and a graft part (a) and having a graft ratio of 20 to 60%, and a volume average particle size of Graft copolymer (II) having a particle size distribution of 70 to 140 nm and a standard deviation of 35% or less, a rubber polymer (B) and a graft part (b), and having a graft ratio of 40 to 65%, and cyanation. Vinyl compound 15 to 30%, maleimide monomer 10 to 35%, aromatic vinyl compound 50
~ 65% and 0 to 20% of monomers copolymerizable therewith
Maleimide copolymer (III) obtained by polymerizing (100% in total) and vinyl cyanide compound 15 to 35%,
35-70% of α-alkyl aromatic vinyl compounds and 0-30% of monomers copolymerizable with them (total 100%)
A thermoplastic resin composition comprising an α-alkyl aromatic vinyl-based copolymer (IV) obtained by polymerizing a rubber polymer, the rubber polymer (A), the rubber polymer (A), and the rubber polymer in a rubber polymer. The volume ratio (A / (A + B)) to (B) is 0.
4 to 0.85, the rubber polymers (A) and (B) are one or more of a diene rubber polymer and an acrylic rubber polymer, and the graft copolymers (I) and (II). ) Is a polymer comprising 30 to 52 mol% of a vinyl cyanide compound unit, 70 to 48 mol% of an aromatic vinyl compound unit, and 0 to 20 mol% of a monomer unit copolymerizable therewith. Yes, the weight ratio of the maleimide-based copolymer (III) to the maleimide-based copolymer (III) and the α-alkyl aromatic vinyl-based copolymer (IV) (III / (III + I
V)) is 0.3 to 0.7, and in the graft copolymers (I), (II), the maleimide-based copolymer (III) and the α-alkyl aromatic vinyl-based copolymer (IV). Has a reduced viscosity (at 30 ° C. in an N, N-dimethylformamide solution) of 0.4 to 0.9 dl / g, and the graft copolymers (I), (II) and maleimide copolymers The content of the rubber polymers (A) and (B) in the polymer (III) and the α-alkyl aromatic vinyl copolymer (IV) is 10 to 30%, and the rubber polymer (A) is
5 to 25% of at least one unsaturated acid (c) of acrylic acid, methacrylic acid, itaconic acid, and crotonic acid, and at least one alkyl acrylate (d-1) having an alkyl group having 1 to 12 carbon atoms 5 to 30%, at least one kind of alkyl methacrylate having 1 to 12 carbon atoms (d-2) 80 to 20%, component (c), (d-1)
Component, an aromatic vinyl monomer copolymerizable with the component (d-2), a monomer having two or more polymerizable functional groups in the molecule, and at least one of vinyl cyanide compounds 0 to
The case is a rubber polymer (A-2) produced by a coagulation and enlargement method using an acid group-containing latex (S-1) prepared by polymerizing 40%.

The above range provides a composition which is excellent in impact resistance, particularly surface impact strength, which is the effect of the present invention, and which is excellent in gloss, rigidity, processability, heat resistance and thermal stability.

[0074]

EXAMPLES Hereinafter, the composition of the present invention will be described based on specific examples, but these examples do not limit the present invention.

The abbreviations used in the examples have the following meanings.

BMA: butyl methacrylate, BA: butyl acrylate, St: styrene, MAA: methacrylic acid, tDM: t-dodecyl mercaptan, CHP: cumene hydroperoxide, AN: acrylonitrile, PMI: N-phenylmaleimide, αS: α -Methylstyrene, HTP: di-t-butylperoxyhexahydroterephthalate.

The evaluation in the examples was carried out by the following methods.

[Volume Average Particle Size of Rubber Polymer, Standard Deviation of Particle Size Distribution] The volume average particle size and standard deviation of particle size distribution of each of the rubber polymers (A) and (B) are measured by the following method. did.

Taking the rubber polymer (A) as an example, the graft copolymer (I) and the maleimide copolymer (III) are mixed in a latex state at a ratio of 20% of the rubber polymer (A). Then, solidification and heat treatment were performed to obtain a powder containing the rubber polymer (A). The powder is pelletized and injection molded in the same manner as in the production of the thermoplastic resin described below, and the
I got a standard dumbbell molded product. The center of the dumbbell molded product in the thickness direction was cut out with a microtome so as to be parallel to the flow direction. Cutout piece (50-100 nm thickness)
Was stained with osmium tetroxide and observed with a transmission electron microscope. About the observation photograph (20,000 times) NIRECO
LUZEX IID manufactured by Co., Ltd. was used to obtain the rubber polymer (A).
Image analysis was performed to determine the volume average particle size of the rubber polymer (A) and the standard deviation of the particle size distribution.

The volume average particle size and the standard deviation of the particle size distribution of the rubber polymer (B) are the same as those of the rubber polymer (A) using the graft copolymer (II) and the maleimide copolymer (III). The same method was used.

[Graft ratio of graft copolymer] 1 g of the powder of the graft copolymer was added to 40 m of methyl ethyl ketone.
In addition to 1, the mixture was dissolved at 23 ° C. for 1 hour and then centrifuged to obtain the methyl ethyl ketone soluble and insoluble components of the graft copolymer. A large amount of methanol was added to the obtained methyl ethyl ketone soluble component to obtain an insoluble component of the methyl ethyl ketone-methanol solution. The graft ratio was measured from the ratio of the methyl ethyl ketone soluble component and the methyl ethyl ketone-methanol solution insoluble component and the methyl ethyl ketone insoluble component.

[Composition of Grafts (a) and (b), Composition of Copolymer] The composition was specified by the charging ratio of the monomer and the polymerization conversion ratio.

[Polymerization conversion rate] It was determined from the amount of liquid after polymerization and the solid content concentration.

[Rubber Polymer Content in Graft Copolymers (I), (II), Maleimide Copolymers (III) and α-Alkyl Aromatic Vinyl Copolymers (IV)] Rubber at the start of polymerization The amount and the amount of each component at the time of polymerization, the conversion rate, and the compounding ratio were determined.

[Volume ratio (A / (A + B))] Charge amount of the rubber polymers (A) and (B), graft copolymer (I)
It was calculated from the polymerization conversion rates in (2) and (II) and the graft copolymers (I) and (II).

[Reduced viscosity] Graft copolymer (I),
Powder 1 consisting of (II), maleimide-based copolymer (III) and α-alkyl aromatic vinyl-based copolymer (IV)
g to 40 ml of methyl ethyl ketone for 1 hour, 23
After dissolving at 0 ° C., centrifugation was performed to obtain a methyl ethyl ketone soluble component. The soluble component was taken out and 0.3 g / dl
As a concentrated N, N-dimethylformamide solution, 30
The reduced viscosity was measured at ° C.

[Characteristics of Thermoplastic Resin Composition] (Impact Resistance) The surface impact strength and the Izod impact strength were evaluated. The surface impact strength was evaluated by the falling weight strength of a 2 mm thick flat plate test piece of 100 mm × 150 mm at 23 ° C. The evaluation value is
Half fracture height × falling weight load = half fracture energy (unit:
kgfm). Izod impact strength is ASTM
2 by the method of D-256 standard (1/4 inch thickness)
It evaluated at 3 degreeC (unit: kgcm / cm).

It is excellent if the Izod impact strength is 25 kgcm / cm or more and the surface impact strength is 3.5 kgfm or more.

(Tensile Strength, Tensile Elongation) ASTM D63
Evaluation was carried out at 23 ° C. using No. 1 dumbbell by the method of 8 standards.

(Bending strength, flexural modulus) ASTM D7
Evaluation was performed at 23 ° C. according to the 90 standard method.

(Gloss) 2 mm of 100 mm × 150 mm
The thickness of the flat plate test piece was evaluated by the reflectance at 60 °.

(Heat Resistance (HDT)) ASTM D648
It was evaluated at the heat distortion temperature of the standard load of 18.6 kg / cm ² .

(Fluidity) Using a 100B injection molding machine manufactured by FANUC CO., LTD., At a cylinder temperature of 250 ° C. and an injection pressure of 1350 kg / cm ² , the flow length of resin in a 3 mm thick spiral mold ( The unit was mm).

(Thermal stability) 100B manufactured by FANUC CORPORATION
Using injection molding machine, cylinder temperature 290 ℃, retention 1
Dumbbell molded product after 0 minutes (ASTM standard No. 1 dumbbell)
And the degree of discoloration were visually evaluated by a 5-point method (5 points: no silver, no discoloration, 4 points: no silver, some discoloration, 3 points: some silver and discoloration, 2 points: There is a considerable amount of silver or discoloration, 1
Point: Silver or severe discoloration).

It is shown that the larger the numerical value of each of these, the better.

Examples 1 to 11 and Comparative Examples 1 to 11 (1) Production of Rubber Polymer (B) The following substances were charged in a 100 L polymerization machine.

Pure water 230 parts (15 kg) Potassium persulfate 0.2 part After removing air in the polymerization machine with a vacuum pump, the following substances were charged.

Sodium oleate 0.5 part Sodium rosinate 2 parts Butadiene 100 parts The temperature of the system was raised to 60 ° C. to initiate polymerization. The polymerization was completed in 20 hours, and the conversion rate was 96%. The obtained rubber polymer is called a rubber polymer (B ₁ ).

The obtained rubber polymer (B ₁ ) had a volume average particle diameter of 90 nm and a standard deviation of 22%.

300 parts of pure water, sodium oleate 0.
The rubber polymer (B ₂ ) was polymerized in the same manner as the rubber polymer (B ₁ ) with 2 parts and 1.8 parts of sodium rosinate. The volume average particle diameter of the rubber polymer (B ₂ ) is 120 nm,
The standard deviation was 23%.

(2) Production of rubber polymer (A) As the first step, the acid group-containing latex (S) used for enlarging the rubber polymer (B) into the rubber polymer (A) is as follows. Manufactured to.

The following substances were charged in a reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet, a monomer inlet and a thermometer.

Pure water 200 parts Dioctyl sodium sulfosuccinate 0.55 parts / S ₁
Amount used during polymerization 0.40 parts of sodium dioctyl sulfosuccinate /
Amount used during S ₂ and S ₃ polymerization Sodium formaldehyde sulfoxylate 0.5 parts / Amount used during S ₁ , S ₂ and S ₃ polymerization While stirring the contents, raise the temperature to 70 ° C. under a nitrogen stream. It was After reaching 70 ° C., the monomers shown in Table 1 were continuously added dropwise over 1.5 hours for the first step and 3.5 hours for the second step. After the dropwise addition was completed, stirring was continued at 70 ° C. for 1 hour to complete the polymerization.

[0104]

[Table 1]

Next, the latex of the acid group-containing latex (S ₁ ) to (S ₃ ) prepared in advance for the latex of the rubber polymer (B ₁ ).
Are added all at once at the temperature shown in Table 2 at 60 ° C., and then stirred for 1
The rubber polymer (A ₁ ) to (A ₃ ) latex was produced by continuously enlarging it for a period of time.

The volume average particle diameter and standard deviation of the obtained rubber polymers (A ₁ ) to (A ₃ ) latex were determined. Table 2 shows the results.

[0107]

[Table 2]

(3) Production of graft copolymer (I) Stirrer, reflux condenser, nitrogen inlet, monomer inlet,
The following substances were charged into a reactor equipped with a thermometer.

Pure water 280 parts Rubber polymer (solid content) Amount shown in Table 3 Sodium formaldehyde sulfoxylate 0.3 parts EDTA 0.01 parts Ferrous sulfate 0.0025 parts Nitrogen airflow while stirring the contents The temperature was raised to 60 ° C. below. After reaching 60 ° C., the graft monomer mixture shown in Table 3 was continuously added dropwise over 4 hours. After dropping, 60
Stirring was continued for 1 hour at 0 ° C. to complete the polymerization. The obtained graft copolymer is used as a graft copolymer (I-1) to (I-
6).

The obtained graft copolymer (I-1)-
The graft ratio of (I-6) is shown in Table 3 together with the volume average particle diameter and standard deviation of the rubber polymer.

[0111]

[Table 3]

(4) Preparation of Graft Copolymer (II) The same composition as that of the graft copolymer (I) was prepared according to the charging composition shown in Table 4. The obtained graft copolymers are referred to as graft copolymers (II-1) to (II-4).

The obtained graft copolymer (II-1)-
The graft ratio of (II-4) is shown in Table 4 together with the volume average particle diameter and standard deviation of the rubber polymer.

[0114]

[Table 4]

(5) Production of Maleimide Copolymer (III) Stirrer, reflux condenser, nitrogen inlet, monomer inlet,
The following substances were charged into a reactor equipped with a thermometer.

Sodium dioctyl sulfosuccinate 1.0 part Sodium formaldehyde sulfoxylate 0.5 part EDTA 0.01 part Ferrous sulfate 0.0025 part While stirring the content, raise the temperature to 65 ° C. under a nitrogen stream. It was After reaching 65 ° C., the monomer mixture shown in Table 5 was continuously added dropwise over 6 hours. In addition, 0.5 part of dioctyl sodium sulfosuccinate was added at 1 hour of polymerization time and 0.5 part at 3 hours of polymerization time. After completion of the dropping, stirring was continued at 65 ° C. for 1 hour to complete the polymerization. The obtained maleimide-based copolymer is used as a maleimide-based copolymer (III-1) to (III-
3).

[0117]

[Table 5]

(6) Production of α-alkyl aromatic vinyl copolymer (IV) α-alkyl aromatic vinyl copolymers (IV-1) to (IV
-2) was produced as follows.

110 parts of pure water was placed in an agitator-equipped autoclave equipped with a thermometer. After degassing, the following substances and the monomers shown in Table 6 were charged with stirring.

Pure water 110 parts Tricalcium phosphate 0.08 parts Sodium dodecyl sulfonate 0.03 parts Toluene 1.0 parts Di-t-butylperoxyhexahydroterephthalate 0.5 parts Raise to 95 ° C. while stirring the autoclave. After heating for 3 hours, 0.3 part of tricalcium phosphate was added as an additional dispersant, and the mixture was further stirred for 5 hours to terminate the polymerization. The obtained α-alkyl aromatic vinyl-based copolymers are referred to as α-alkyl aromatic vinyl-based copolymers (IV-1) to (IV-2).

Α-Alkyl aromatic vinyl copolymer (IV
-3) to (IV-4) were manufactured as follows.

The following substances were charged in a reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet, a monomer inlet and a thermometer.

Pure water 250 parts Sodium dioctyl sulfosuccinate 1.0 part Sodium formaldehyde sulfoxylate 0.5 parts EDTA 0.01 parts Ferrous sulfate 0.0025 parts While stirring the contents, under a nitrogen stream 65 ° C. The temperature was raised to. After reaching 65 ° C., the monomer mixture shown in Table 6 was continuously added dropwise over 6 hours. However, (IV-3) is 1
After the total amount of 75 parts of the second step was charged all at once, the second step was added dropwise over 6 hours. Further, 0.5 part of dioctyl sodium sulfosuccinate was added at 1 hour of the polymerization time and 0.
Added 5 copies. After completion of the dropping, stirring was continued at 65 ° C. for 1 hour to complete the polymerization. The obtained α-alkyl aromatic vinyl copolymers are referred to as α-alkyl aromatic vinyl copolymers (IV-3) to (IV-4).

[0124]

[Table 6]

(6) Production of thermoplastic resin composition Table 7 shows the graft copolymer latex produced in (3) and (4) and the copolymer slurry or latex produced in (5) and (6). After mixing at the ratios shown, add 0.5 parts of a phenolic stabilizer (BHT) and add calcium chloride 2
Parts were added to solidify. The solidified slurry was dehydrated and dried to obtain a resin powder. 100 parts of the obtained resin powder was mixed with 1 part of ethylenebisstearylamide, and 2 parts manufactured by Tabata Co., Ltd.
Blended evenly in a 0 L blender. Furthermore,
A 40 m / m uniaxial extruder manufactured by Tabata was melt-kneaded at a temperature of 270 ° C. to produce pellets of the thermoplastic resin composition.

The characteristics of the thermoplastic resin composition were investigated using the obtained pellets. Table 7 shows the results.

[0127]

[Table 7]

From the results shown in Table 7, the resin compositions of the present invention represented by Examples 1 to 11 are excellent in impact resistance, particularly surface impact strength, and have gloss, rigidity, heat resistance, fluidity and heat stability. It turns out that it is also good.

[0129]

When a molded product is produced using the thermoplastic resin composition of the present invention, impact resistance, especially surface impact strength is high, and gloss, rigidity, heat resistance, fluidity (workability), and thermal stability are high. A good molded product can be obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08L 35/00 LJW C08L 35/00 LJW 51/00 LKS 51/00 LKS 51/06 LLE 51/06 LLE

Claims (6)

[Claims] 1. A rubber polymer (A) having a volume average particle size of 250 to 800 nm and a standard deviation of 50% or less.
And a graft portion (a), and the graft ratio is 10 to
70% by weight of the graft copolymer (I), a volume average particle size of 60 to 160 nm, a rubber polymer (B) and a graft part (b) having a particle size distribution with a standard deviation of 40% or less. Graft copolymer (II) having a ratio of 20 to 80% by weight, vinyl cyanide compound 10 to 40% by weight, maleimide monomer 5 to 50% by weight, aromatic vinyl compound 10 to 85% by weight, and these Maleimide copolymer (III) obtained by polymerizing 0 to 30% by weight of copolymerizable monomer (total 100% by weight), 10 to 40% by weight of vinyl cyanide compound, and α-alkyl aromatic vinyl compound 30. To 75% by weight and 0 to 30% by weight (100% by weight in total) of monomers copolymerizable therewith, a thermoplastic resin composition comprising an α-alkyl aromatic vinyl copolymer (IV) And Te, and rubber polymer (A)
And the rubber polymer (A) and the rubber polymer (B) have a volume ratio (A / (A + B)) of 0.3 to 0.9, and the rubber polymers (A) and (B) are diene-based. One or more of a rubber polymer, an olefin rubber polymer and an acrylic rubber polymer, and the graft portion of each of the graft copolymers (I) and (II) is a vinyl cyanide compound unit of 15 to 60 mol. %, An aromatic vinyl compound unit of 85 to 40 mol% and a monomer unit of 0 to 30 mol% copolymerizable therewith, wherein the maleimide copolymer (III) and the maleimide copolymer ( III) and a weight ratio of α-alkyl aromatic vinyl copolymer (IV) (III / (III + IV))
Is 0.1 to 0.9, the graft copolymer (I),
(II), maleimide-based copolymer (III) and α-alkyl aromatic vinyl-based copolymer (IV) have reduced viscosity (30 ° C., in N, N-dimethylformamide solution) of reduced methyl ethyl ketone soluble component. Rubber of 3 to 1.2 dl / g and in the graft copolymers (I), (II), the maleimide copolymer (III) and the α-alkyl aromatic vinyl copolymer (IV). A thermoplastic resin composition containing 5 to 40% by weight of the polymers (A) and (B). 2. The rubber polymer (A) comprises 5 to 50% by weight of at least one unsaturated acid (c) of acrylic acid, methacrylic acid, itaconic acid and crotonic acid, and has 1 carbon atom.
50 to 95% by weight of (meth) alkyl acrylate (d) having 12 to 12 alkyl groups and component (c), (d)
A rubber polymer (A-1) produced by a coagulation and enlargement method using an acid group-containing latex (S) obtained by polymerizing 0 to 40% by weight of a monomer copolymerizable with a component. Item 2. The thermoplastic resin composition according to item 1. 3. The rubber polymer (A) comprises 5 to 25% by weight of at least one unsaturated acid (c) selected from acrylic acid, methacrylic acid, itaconic acid and crotonic acid, and has 1 carbon atom.
An alkyl acrylate (d having an alkyl group of 12 to 12
-1) 5 to 30% by weight, alkyl methacrylate (d-2) 80 to 20 having an alkyl group having 1 to 12 carbon atoms
% By weight and (c) component, (d-1) component, (d-
2) Polymerize at least 1 to 40% by weight of an aromatic vinyl monomer copolymerizable with the component, a monomer having two or more polymerizable functional groups in the molecule, and a vinyl cyanide compound. Acid group-containing latex (S
The thermoplastic resin composition according to claim 2, which is a rubber polymer (A-2) produced by a coagulation and enlargement method using -1). 4. The α-alkyl aromatic vinyl copolymer (IV) has an α-alkyl aromatic vinyl unit content of 5
The thermoplastic resin composition according to claim 1, which is 0 mol% or less. 5. The thermoplastic according to claim 1, wherein the α-alkyl aromatic vinyl-based copolymer (IV) is an α-alkyl aromatic vinyl-based copolymer (IV) obtained by a suspension polymerization method. Resin composition. 6. The maleimide-based copolymer (III) contains 50 mol% or more of an aromatic vinyl compound unit.
The thermoplastic resin composition according to the above.