JP7062931B2 - Graft copolymer, thermoplastic resin composition and articles thereof - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention comprises a graft copolymer that provides a thermoplastic resin composition having an excellent molded appearance and impact resistance, a small dependence on the injection rate of the molded appearance, and excellent fluidity, and a thermoplastic containing the graft copolymer. The present invention relates to a resin composition and a molded product thereof.

Improving the impact resistance of a resin material has extremely high industrial usefulness, such as not only expanding the use of the resin material but also making it possible to cope with thinning and increasing the size of molded products. Various methods have been proposed for improving the impact resistance of resin materials. Of these, a method of improving impact resistance while maintaining the characteristics of the hard resin material by combining the rubber polymer and the hard resin material has already been industrialized. Examples of such a material include acrylonitrile-butadiene-styrene (ABS) resin.

However, although ABS resin is excellent in impact resistance and molded appearance, it is difficult to use it without painting or decoration such as a film because the weather resistance of polybudazien, which is a rubber component, is low.

In order to solve such a problem of ABS resin, acrylonitrile-styrene-acrylic acid ester (ASA) resin using acrylic rubber as a rubber component has been developed and industrialized.

For example, Patent Document 1 discloses a method in which an acrylonitrile-styrene (AS) resin is used as a hard resin material and an ASA resin is added thereto.
However, since the ASA resin has a large difference in refractive index between the acrylonitrile-styrene (AS) resin, which is a hard resin component, and the acrylic rubber, the molding appearance at the time of molding at a low injection speed is poor. Further, there is a problem that the molding appearance is further deteriorated at the time of molding at a high injection speed.

Patent Document 2 and Patent Document 3 disclose a method of adding a polybutadiene / acrylic rubber composite having a structure in which the outside of polybutadiene particles is covered with acrylic rubber to an AS resin.
In this method, the difference in refractive index between the rubber component and the AS resin is reduced by compounding polybutadiene, and the molded appearance is improved. However, there is a problem that the weather resistance is lowered due to the composite of polybutadiene.

Patent Document 4 discloses a method of increasing the refractive index of acrylic rubber by copolymerizing butyl acrylate and styrene.
However, with the method described in Patent Document 4, the impact resistance is significantly lowered. Further, although the molding appearance at the time of molding at a low injection speed is good, there is a problem that the molding appearance at the time of molding at a high injection speed is deteriorated, that is, the molding appearance is largely dependent on the injection speed. From the viewpoint of productivity, the appearance of molding at a high injection speed is important, but it is also extremely important in practice that the appearance of molding is less dependent on the injection speed. That is, for example, in a molded product such as a vehicle part, the injection speed differs depending on the part part, so that a resin having a large injection speed dependence causes an appearance defect depending on the part part at the time of molding, resulting in impairing the product value. Will be.

Japanese Unexamined Patent Publication No. 2017-71660 Japanese Unexamined Patent Publication No. 2007-204763 Japanese Unexamined Patent Publication No. 2009-242595 JP-A-2017-88774

INDUSTRIAL APPLICABILITY The present invention comprises a graft copolymer that provides a thermoplastic resin composition having excellent molded appearance and impact resistance, little dependence on the injection rate of the molded appearance, and excellent fluidity, and a thermoplastic containing the graft copolymer. An object of the present invention is to provide a resin composition and a molded product thereof.

As a result of repeated studies to solve the above problems, the present inventor has obtained a copolymer of a (meth) acrylic acid alkyl ester (Aa) and a (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group. By using the graft copolymer (B) obtained by graft-polymerizing the vinyl-based monomer mixture (m1) in the presence of (A), the molded appearance and impact resistance are excellent, and the injection speed of the molded appearance is excellent. It has been found that a thermoplastic resin composition having a small dependence and excellent fluidity can be obtained.
That is, the gist of the present invention is as follows.

[1] A vinyl-based monomer mixture (m1) in a copolymer (A) of a (meth) acrylic acid alkyl ester (Aa) and a (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group. A graft copolymer (B) obtained by graft-polymerizing the above.

[2] (Meta) in a total of 100% by mass of the (meth) acrylic acid alkyl ester (Aa) unit in the copolymer (A) and the (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group. The content of the acrylic acid alkyl ester (Aa) unit is 30 to 95% by mass, and the content of the (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group is 5 to 70% by mass. 1] The graft copolymer (B) according to.

[3] The copolymer (A) has a (meth) acrylic acid alkyl ester (Aa) unit, a (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group, a unit derived from a cross-linking agent, and a unit. / Or the graft copolymer (B) according to [1] or [2], which comprises a unit derived from a graft cross-linking agent.

[4] The proportion of units derived from the cross-linking agent and / or the graft cross-linking agent in the copolymer (A) has (meth) acrylic acid alkyl ester (Aa) units and an aromatic hydrocarbon group (meth). The graft according to [3], which is 0.1 to 3% by mass in a total of 100% by mass of the acrylic acid ester (Ab) unit and the unit derived from the cross-linking agent and / or the unit derived from the graft copolymer. Copolymer (B).

[5] The copolymer (A) contains a (meth) acrylic acid alkyl ester (Aa), a (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group, a cross-linking agent and / or a graft crossing agent. The graft copolymer (B) according to [3] or [4], which is a miniemulsion polymer of a mixture of a hydrophobic substance and an initiator.

[6] The graft copolymer (B) according to any one of [1] to [5], wherein the copolymer (A) has a volume average particle size of 50 to 800 nm and a swelling degree of 2 to 15 times. ..

[7] The vinyl-based monomer mixture (m1) contains an aromatic vinyl-based monomer and a cyanide vinyl-based monomer, and the aromatic vinyl-based monomer contained in the vinyl-based monomer mixture (m1). The graft copolymer (B) according to any one of [1] to [6], wherein the content of the graft copolymer is 40 to 90% by mass and the content of the vinyl cyanide-based monomer is 10 to 60% by mass. ..

[8] The ratio of the copolymer (A) to 100% by mass of the total of the copolymer (A) and the vinyl-based monomer mixture (m1) is 50 to 80% by mass, and the vinyl-based monomer mixture (m1). The graft copolymer (B) according to any one of [1] to [7], wherein the ratio of) is 20 to 50% by mass and the graft ratio is 25 to 100%.

[9] The thermoplastic resin composition containing the graft copolymer (B) according to any one of [1] to [8].

[10] The thermoplastic resin composition according to [9], which comprises a graft copolymer (B) and a copolymer (C) which is a polymerization reaction product of a vinyl-based monomer mixture (m2).

[11] The vinyl-based monomer mixture (m1) contains an aromatic vinyl-based monomer and a cyanide vinyl-based monomer, and the vinyl-based monomer mixture (m2) is a vinyl-based monomer mixture (m1). Aromatic vinyl-based monomer having the same structure as the aromatic vinyl-based monomer contained in, and a vinyl cyanide-based monomer having the same structure as the cyanide vinyl-based monomer contained in the vinyl-based monomer mixture (m1). The thermoplastic resin composition according to [10], which comprises a monomer.

[12] In a total of 100% by mass of the graft copolymer (B) and the copolymer (C), 10 to 40% by mass of the graft copolymer (B) and 60 to 90% by mass of the copolymer (C). %, The thermoplastic resin composition according to [10] or [11].

[13] A molded product obtained by molding the thermoplastic resin composition according to any one of [9] to [12].

According to the present invention, there is provided a thermoplastic resin composition and a molded product thereof, which are excellent in molded appearance and impact resistance, have a small dependence on the injection speed of the molded appearance, and are also excellent in fluidity.

Hereinafter, embodiments of the present invention will be described in detail.
In the present invention, "(meth) acrylic acid" means one or both of "acrylic acid" and "methacrylic acid", and the same applies to "(meth) acrylate".
Further, the "unit" means a structural portion derived from a compound (monomer, that is, a monomer) before polymerization contained in the polymer, and for example, "(meth) acrylic acid alkyl ester (Aa) unit". "" Means "a structural portion derived from (meth) acrylic acid alkyl ester (Aa) and contained in the copolymer (A)". The content ratio of each monomer unit of the polymer corresponds to the content ratio of the monomer in the monomer mixture used for producing the polymer.

[Graft copolymer (B)]
The graft copolymer (B) of the present invention is a copolymer (A) of a (meth) acrylic acid alkyl ester (Aa) and a (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group (hereinafter referred to as). , It may be referred to as "copolymer (A) of the present invention"), and is obtained by graft-polymerizing a vinyl-based monomer mixture (m1).

<Copolymer (A)>
The copolymer (A) of the present invention is a copolymer of a (meth) acrylic acid alkyl ester (Aa) and a (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group.

As the (meth) acrylic acid alkyl ester (Aa), a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 12 carbon atoms is preferable. Of these, n-butyl acrylate, 2-ethylhexyl acrylate, and ethyl acrylate are particularly preferable because the thermoplastic resin composition containing the obtained graft copolymer (B) has excellent impact resistance. The (meth) acrylic acid alkyl ester (Aa) can be used alone or in combination of two or more.

The (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group may be any (meth) acrylic acid ester having an aromatic hydrocarbon group, for example, (meth) acrylic acid aryl ester or (meth) acrylic. Examples of the substituent of the acid aryloxy ester and the alkyl ester moiety include, but are not limited to, an aryl group such as a phenyl group and a (meth) acrylic acid alkyl ester having an aryloxy group such as a phenoxy group. As the (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group, benzyl acrylate is excellent in impact resistance of the thermoplastic resin composition containing the obtained graft copolymer (B). , 2-Phenoxyethyl acrylate is particularly preferred. The (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group can be used alone or in combination of two or more.

The content of the (meth) acrylic acid alkyl ester (Aa) unit in the copolymer (A) and the content of the (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group are the obtained graft co-weights. The (meth) acrylic acid alkyl ester (Aa) unit and the unit of (meth) acrylic acid alkyl ester (Aa) can be used because the thermoplastic resin composition containing the coalescence (B) has excellent molding appearance and impact resistance, and in particular, the dependence of the molding appearance on the injection rate can be reduced. The (meth) acrylic acid alkyl ester (Aa) unit is 30 to 95% by mass in a total of 100% by mass of the (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group, and has an aromatic hydrocarbon group. The (meth) acrylic acid ester (Ab) unit is preferably 5 to 70% by mass, the (meth) acrylic acid alkyl ester (Aa) unit is 50 to 90% by mass, and has an aromatic hydrocarbon group (meth). ) Acrylic acid ester (Ab) unit is more preferably 10 to 50% by mass.

The content of the (meth) acrylic acid ester (Ab) unit and the (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group in the copolymer (A) is the same as that of the copolymer (A) and the graft. After decomposing the thermoplastic resin composition containing the polymer (B) or the graft copolymer (B) and the copolymer (C) described later and the molded product thereof into monomer units by heating at 600 ° C. , Can be calculated by component analysis with a GC-MS apparatus, but as described above, the (meth) acrylic acid alkyl ester (Aa) and the aromatic hydrocarbon group used in the production of the copolymer (A) are used. The content ratios of the (meth) acrylic acid alkyl ester (Aa) and the (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group in the total with the (meth) acrylic acid ester (Ab) having each are, respectively. , Corresponds to the content of the (meth) acrylic acid alkyl ester (Aa) unit and the (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group in the copolymer (A).

In addition to the (meth) acrylic acid alkyl ester (Aa) and the (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group, the copolymer (A) of the present invention contains units and grafts derived from a cross-linking agent. It is preferable that the copolymer has one or both of the units derived from the crossing agent, and when the copolymer (A) contains the units derived from the graft crossing agent and / or the cross-linking agent, the obtained graft is obtained. The effect of further improving the molded appearance and impact resistance of the thermoplastic resin composition containing the copolymer (B) is exhibited.

Examples of the graft crossover include allyl compounds, specifically, allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, and the like. Only one of these may be used, or two or more thereof may be mixed and used.
Examples of the cross-linking agent include dimethacrylate compounds, and specific examples thereof include ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, and 1,4-butylene glycol dimethacrylate. Only one of these may be used, or two or more thereof may be mixed and used.

When a cross-linking agent and / or a graft cross-linking agent is used, the proportion of the unit derived from the cross-linking agent and / or the graft cross-linking agent in the copolymer (A) is made by blending the obtained graft copolymer (B). Since the thermoplastic resin composition is excellent in molding appearance and impact resistance, it is crosslinked with a (meth) acrylic acid alkyl ester (Aa) unit and a (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group. Of the total 100% by mass of the unit derived from the agent and / or the unit derived from the graft cross-linking agent, 0.1 to 3% by mass is preferable, and 0.2 to 2% by mass is more preferable.

The copolymer (A) is a (meth) acrylic acid alkyl ester (Aa) unit, a (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group, as long as the object of the present invention is not impaired. It may contain other monomeric units other than the units derived from the cross-linking agent and / or the graft-crossing agent used as needed. Other monomer units that may be contained in the copolymer (A) include (meth) acrylic acid alkyl ester (Aa) contained in the vinyl-based monomer mixture (m1) described later and aromatic carbonization. One or more vinyl-based monomers other than the (meth) acrylic acid ester (Ab) having a hydrogen group can be mentioned, but these other vinyl-based monomers can be used to effectively obtain the effects of the present invention. The content of the polymer unit is preferably 20% by mass or less, particularly preferably 10% by mass or less, based on 100% by mass of the copolymer (A).

The method for producing the copolymer (A) is not particularly limited, but is limited to a (meth) acrylic acid alkyl ester (Aa), a (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group, a cross-linking agent and /. Alternatively, a method of emulsion polymerization or miniemulsion polymerization of a mixture containing a graft crossing agent is preferable, and a method of miniemulsion polymerization is a method because the physical properties of the resin composition containing the obtained graft copolymer (B) are excellent. Especially preferable.

As a method for producing the copolymer (A) by the emulsion polymerization method, a radical initiator, a (meth) acrylic acid alkyl ester (Aa), and a (meth) acrylic acid ester having an aromatic hydrocarbon group in an aqueous solvent (meth) acrylic acid ester (meth) Examples thereof include a method of adding a cross-linking agent and / or a graft crossing agent to Ab) and copolymerizing in the presence of an emulsifier.
The method of adding the radical initiator, the (meth) acrylic acid alkyl ester (Aa), the (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group, and the cross-linking agent and / or the graft crossover agent are collectively described. It may be divided or continuous.

The miniemulsion polymerization for producing the copolymer (A) is not limited to, for example, a (meth) acrylic acid alkyl ester (Aa) and a (meth) acrylic acid having an aromatic hydrocarbon group. The ester (Ab), the cross-linking agent and / or the graft crossover agent, the hydrophobic substance, and the initiator are mixed, and water and an emulsifier are added to the obtained mixture to impart a shearing force to the preemulsion (Ab). It can include a step of making a miniemulsion) and a step of heating the mixture to the polymerization initiation temperature to polymerize it.

In the miniemulsion step, for example, by carrying out a shearing step by ultrasonic irradiation, the monomer is torn off by the shearing force, and monomer micro oil droplets covered with an emulsifier are formed. Then, by heating to the polymerization initiation temperature of the initiator, the monomer fine oil droplets are polymerized as they are, and polymer fine particles are obtained. Any known method can be used as a method for applying a shearing force for forming the miniemulsion, and the high shearing device capable of forming the miniemulsion is not limited to these, but for example, a high pressure pump and a high pressure pump. There is an emulsification device consisting of an interaction chamber, a device for forming a miniemulsion by ultrasonic energy or high frequency, and the like. Examples of the emulsifying device including a high-pressure pump and an interaction chamber include a "pressure homogenizer" manufactured by SPX Corporation APV and a "microfluidizer" manufactured by Paulek Co., Ltd., and a miniemulsion is formed by ultrasonic energy or high frequency. Examples of the device for forming include, but are not limited to, "Sonic Dismulsioner" manufactured by Fisher Scientific and "ULTRASONIC HOMOGENIZER" manufactured by Nissei Tokyo Office.

From the viewpoint of workability, stability, manufacturability, etc., the amount of water solvent used in the miniemulsion should be such that the solid content concentration of the reaction system after polymerization is about 5 to 50% by mass. It is preferably about 100 to 500 parts by mass with respect to 100 parts by mass of the mixture other than the above.

When the copolymer (A) is produced by mini-emulsion polymerization, it is preferable to use a hydrophobic substance in a predetermined ratio. When a hydrophobic substance is added when forming a pre-emulsion, the production stability of the mini-emulsion polymerization tends to be further improved, and the copolymer (A) suitable for the present invention can be produced.

Examples of the hydrophobic substance include hydrocarbons having 10 or more carbon atoms, alcohols having 10 or more carbon atoms, hydrophobic polymers having a mass average molecular weight (Mw) of less than 10,000, and hydrophobic monomers, for example, alcohols having 10 to 30 carbon atoms. Vinyl ester, vinyl ether of alcohol having 12 to 30 carbon atoms, alkyl (meth) acrylate having 12 to 30 carbon atoms, vinyl acid vinyl ester having 10 to 30 carbon atoms (preferably 10 to 22 carbon atoms), p-alkylstyrene. , Hydrophobic chain transfer agents, hydrophobic peroxides and the like. These may be used alone or in admixture of two or more.

More specifically, the hydrophobic substance includes hexadecane, octadecane, icosan, liquid paraffin, liquid isoparaffin, paraffin wax, polyethylene wax, olive oil, cetyl alcohol, stearyl acrylate, lauryl acrylate, stearyl acrylate, and lauryl methacrylate. , Stearyl methacrylate, polystyrene having a number average molecular weight (Mn) of 500 to 10000, poly (meth) acrylic acid ester and the like.

The hydrophobic substance is based on 100 parts by mass of the (meth) acrylic acid alkyl ester (Aa), the (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group, and the cross-linking agent and / or the graft crossing agent. It is preferable to use 0.1 to 10 parts by mass, more preferably 1 to 3 parts by mass, from the viewpoint of controlling the particle size of the copolymer (A).

Examples of the emulsifier used in producing the copolymer (A) of the present invention include oleic acid, palmitic acid, stearic acid, alkali metal salts of loginic acid, alkali metal salts of alkenyl succinic acid, and the like. Use known emulsifiers alone or in combination of two or more, such as anionic emulsifiers selected from emulsifiers, alkyl sulfate esters, sodium alkylbenzene sulfonates, sodium alkylsulfosuccinates, sodium polyoxyethylene nonylphenyl ether sulfates, etc. can do.

The amount of the emulsifier added is 100 parts by mass in total of the (meth) acrylic acid alkyl ester (Aa), the (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group, and the cross-linking agent and / or the graft crossing agent. On the other hand, 0.01 to 1.0 part by mass is preferable, and more preferably 0.05 to 0.5 part by mass is preferable from the viewpoint of controlling the particle size of the copolymer (A).

The initiator used in the production of the copolymer (A) is a radical polymerization initiator for radical polymerization, and the type thereof is not particularly limited. For example, an azo polymerization initiator, a photopolymerization initiator, and an inorganic peroxide are used. Examples thereof include organic peroxides, redox-based initiators in which organic radicals, transition metals and reducing agents are combined. Of these, azo polymerization initiators, inorganic peroxides, organic peroxides, and redox-based initiators that can initiate polymerization by heating are preferable. These may be used alone or in combination of two or more.

Examples of the azo polymerization initiator include 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), and 2,2'-. Azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl) Azo] form amide, 4,4'-azobis (4-cyanovaleric acid), dimethyl 2,2'-azobis (2-methylpropionate), dimethyl 1,1'-azobis (1-sikuhexanecarboxylate) ), 2,2'-Azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2'-azobis (N-butyl-2-methylpropionamide), 2,2'-azobis ( N-cyclohexyl-2-methylpropionamide), 2,2'-azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis (2,4,4-trimethylpentane), etc. Can be mentioned.

Examples of the inorganic peroxide include potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide and the like.

Examples of the organic peroxide include peroxyester compounds, and specific examples thereof include α, α'-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3. 3-Tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 1- Cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy2-hexylhexanoate, t-butylperoxy2-hexylhexanoate, t-butylperoxyisobutyrate, t-hexylperoxyisopropyl Monocarbonate, t-butylperoxymaleic acid, t-butylperoxy 3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-bis (m-toluoleperoxy) ) Hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy2-ethylhexylmonocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyacetate, t-butylperoxy-m-toluole peroxide benzoate, t-butylperoxybenzoate, bis (t-butylperoxy) isophthalate, 1,1-bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane, 1,1 -Bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t) -Butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) butane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (4,4-di-t- Butylperoxycyclohexyl) propane, α, α'-bis (t-butyl peroxide) diisopropylbenzene, dicumyl peroxide, 2,5 -Dimethyl-2,5-bis (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, cumenhydroperoxide, diisopropylbenzenehydroperoxide, dilauroyl peroxide, diisononanoyl peroxide, t -Butyl hydroperoxide, benzoyl peroxide, lauroyl peroxide, dimethylbis (t-butylperoxy) -3-hexine, bis (t-butylperoxyisopropyl) benzene, bis (t-butylperoxy) trimethylcyclohexane, butyl-bis (t- Butylperoxy) Valerate, t-butyl 2-ethylhexaneperoxyate, dibenzoyl peroxide, paramentan hydroperoxide, t-butylperoxybenzoate and the like can be mentioned.

As the redox-based initiator, a combination of an organic peroxide, ferrous sulfate, a chelating agent and a reducing agent is preferable. For example, cumene hydroperoxide, ferrous sulfate, sodium pyrophosphate, and dextrose, or a combination of t-butyl hydroperoxide, sodium formaldehyde sulfoxylate (longalit), ferrous sulfate, and disodium ethylenediaminetetraacetate. And so on.

Of these, redox-based initiators and organic peroxides are preferable, and organic peroxides are particularly preferable.

The amount of the initiator added is 100 mass in total of the (meth) acrylic acid alkyl ester (Aa), the (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group, and the cross-linking agent and / or the graft crossing agent. It is usually 5 parts by mass or less, preferably 3 parts by mass or less, for example 0.001 to 3 parts by mass.

The step of preparing the above preemulsion is usually carried out at room temperature (about 10 to 50 ° C.), and the step of miniemulsion polymerization is carried out at 40 to 100 ° C. for about 30 to 600 minutes.

The average particle size of the copolymer (A) of the present invention dispersed in the aqueous dispersion is excellent in the physical characteristics of a molded product made of a thermoplastic resin composition containing the obtained graft copolymer (B). Therefore, 50 to 800 nm is preferable, 100 to 600 nm is more preferable, and 250 to 450 nm is further preferable.
The method for controlling the average particle size of the copolymer (A) is not particularly limited, and examples thereof include a method for adjusting the type or amount of the emulsifier used.
Here, the average particle size of the copolymer (A) is a volume average particle size measured by the method described in the section of Examples described later.

Further, the swelling degree of the copolymer (A) of the present invention is excellent in impact resistance and molded appearance of the thermoplastic resin composition containing the obtained graft copolymer (B), and in particular, injection of the molded appearance. Since the speed dependence can be reduced, it is preferably 2 to 15 times, more preferably 4 to 10 times.
The degree of swelling of the copolymer (A) is measured by the method described in the section of Examples described later.

<Graft copolymer (B)>
The graft copolymer (B) of the present invention is obtained by graft-polymerizing a vinyl-based monomer mixture (m1) in the presence of the copolymer (A).

Since the vinyl-based monomer mixture (m1) has excellent physical properties of the thermoplastic resin composition obtained by blending the obtained graft copolymer (B), the aromatic vinyl-based monomer and the vinyl cyanide-based simple substance are used. It is preferable to include a monomer.

Examples of the aromatic vinyl-based monomer contained in the vinyl-based monomer mixture (m1) include styrene, α-methylstyrene, o-, m- or p-methylstyrene, vinylxylene, and pt-butyl. Examples thereof include styrene and ethylstyrene, which can be used alone or in combination of two or more. The structure of the aromatic vinyl-based monomer is not particularly limited, but the thermoplastic resin composition has the same structure as the aromatic vinyl-based monomer contained in the vinyl-based monomer mixture (m2) described later. It is preferable in terms of impact resistance and molded appearance of the molded product.

The content of the aromatic vinyl-based monomer contained in the vinyl-based monomer mixture (m1) is 40 to 90% by mass, which is a thermoplastic resin containing the obtained graft copolymer (B). The composition and its molded product are preferable in terms of impact resistance and molded appearance, and more preferably 60 to 80% by mass.

Examples of the vinyl cyanide-based monomer contained in the vinyl-based monomer mixture (m1) include acrylonitrile and methacrylonitrile, and one or more of these can be used. The structure of the vinyl cyanide-based monomer is not particularly limited, but the obtained thermoplastic resin has the same structure as the vinyl cyanide-based monomer contained in the vinyl-based monomer mixture (m2) described later. It is preferable in terms of impact resistance and molded appearance of the composition and its molded product.

The content of the vinyl cyanide-based monomer contained in the vinyl-based monomer mixture (m1) is 10 to 60% by mass, which is a thermoplastic resin containing the obtained graft copolymer (B). It is preferable in terms of impact resistance and molded appearance of the composition and its molded product, and more preferably 20 to 40% by mass.

The vinyl-based monomer mixture (m1) may contain the above-mentioned aromatic vinyl-based monomer and cyanide vinyl-based monomer, and other vinyl-based monomers copolymerizable with these.
The content of the other copolymerizable vinyl-based monomer in the vinyl-based monomer mixture (m1) is preferably 20% by mass or less, particularly preferably 10% by mass or less.
Examples of other vinyl-based monomers include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, and t-butyl methacrylate. Amyl methacrylate, isoamyl methacrylate, octyl methacrylate, -2-ethylhexyl methacrylate, decyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate and other methacrylic esters, N-methylmaleimide, N-Cycloalkyl such as N-ethylmaleimide, Nn-propylmaleimide, Ni-propylmaleimide, Nn-butylmaleimide, Ni-butylmaleimide, N-tert-butylmaleimide, N-cyclohexylmaleimide, etc. N-arylmaleimide such as maleimide, N-phenylmaleimide, N-alkyl substituted phenylmaleimide, N-chlorophenylmaleimide, maleimide compounds such as N-aralkylmaleimide, methyl acrylate, ethyl acrylate, propyl acrylate, acrylic acid. Examples thereof include acrylic acid esters such as butyl. Only one of these may be used, or two or more thereof may be mixed and used.

In the graft copolymer (B), a vinyl-based monomer mixture (m1) is graft-polymerized on the copolymer (A).
The thermoplastic resin composition containing the obtained graft copolymer (B) is excellent in impact resistance and molded appearance, and in particular, the injection speed dependence of the molded appearance can be reduced, so that the graft copolymer (B) can be used. The copolymer (A) and the vinyl-based monomer mixture (m1) used for production are 100% by mass of the graft copolymer (B), 50 to 80% by mass of the copolymer (A), and a vinyl-based single amount. The polymer mixture (m1) is preferably 20 to 50% by mass.

Further, since the graft copolymer (B) is excellent in impact resistance and molded appearance of the thermoplastic resin composition containing the obtained graft copolymer (B), the graft ratio is 25 to 100%. It is preferable to have. The graft ratio of the graft copolymer (B) is measured by the method described in the section of Examples described later.

The graft copolymer (B) is produced by a known method such as a bulk polymerization method, a solution polymerization method, a bulk suspension polymerization method, a suspension polymerization method, and an emulsion polymerization method, and the obtained graft copolymer (B) is obtained. ) Is good in impact resistance of the thermoplastic resin composition, so that the emulsion polymerization method is preferable.

As a method of emulsion graft polymerization, a method of radically polymerizing by adding a vinyl-based monomer mixture (m1) collectively, continuously or intermittently in the presence of an emulsion of the copolymer (A) is used. Can be mentioned. Further, in the case of graft polymerization, a chain transfer agent is used for the purpose of adjusting the molecular weight of the graft polymer (B) and the graft ratio, and an inorganic electrolyte known for the purpose of adjusting the viscosity and pH of the latex, etc. May be used. Further, in the emulsified graft polymerization, various emulsifiers and radical initiators can be used as needed.
The type and amount of emulsifier and radical initiator added are not particularly limited. In addition, examples of the emulsifier and the radical initiator include the emulsifier and the radical initiator exemplified above in the description of the copolymer (A).

As a method for recovering the graft copolymer (B) from the aqueous dispersion of the graft copolymer (B), (i) the aqueous dispersion of the graft copolymer (B) in hot water in which a coagulant is dissolved. A method of collecting the body by charging it into a slurry state (wet method), (ii) semi-directly by spraying the aqueous dispersion of the graft copolymer (B) into a heated atmosphere. Examples thereof include a method of recovering the graft copolymer (B) (spray dry method).

Examples of the coagulant include inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid and nitric acid, and metal salts such as calcium chloride, calcium acetate and aluminum sulfate. The coagulant is selected according to the emulsifier used in the polymerization. That is, when only carboxylic acid soap such as fatty acid soap and rosin acid soap is used, any coagulant may be used. When an emulsifier that exhibits stable emulsifying power even in an acidic region such as sodium dodecylbenzene sulfonate is contained, it is necessary to use a metal salt.

As a method for obtaining the graft copolymer (B) in a dry state from the graft copolymer (B) in a slurry state, (i) washing is performed to elute the emulsifier residue remaining in the slurry into water, and then the slurry is used. Examples thereof include a method of dehydrating with a centrifugal dehydrator or a press dehydrator and further drying with an air flow dryer or the like, (ii) a method of simultaneously performing dehydration and drying with a squeezing dehydrator, an extruder or the like. After drying, the graft copolymer (B) is obtained in the form of powder or particles. Further, the graft copolymer (B) discharged from the squeezing dehydrator or extruder can be directly sent to an extruder or molding machine for producing a thermoplastic resin composition.

[Copolymer (C)]
The copolymer (C) is obtained by polymerizing a vinyl-based monomer mixture (m2).

The vinyl-based monomer mixture (m2) has the same composition as the above-mentioned vinyl-based monomer mixture (m1) because the thermoplastic resin composition obtained by blending the copolymer (C) has excellent physical properties. It is preferable that the aromatic vinyl-based monomer and the cyanide vinyl-based monomer are contained.

Examples of the aromatic vinyl-based monomer contained in the vinyl-based monomer mixture (m2) include styrene, α-methylstyrene, o-, m- or p-methylstyrene, vinylxylene, and pt-butyl. Examples thereof include styrene and ethylstyrene, which can be used alone or in combination of two or more. The structure of the aromatic vinyl-based monomer is not particularly limited, but the obtained thermoplastic resin has the same structure as the aromatic vinyl-based monomer contained in the above-mentioned vinyl-based monomer mixture (m1). It is preferable in terms of impact resistance and molded appearance of the composition and its molded product.

The content of the aromatic vinyl-based monomer contained in the vinyl-based monomer mixture (m2) is 40 to 90% by mass, that is, the impact resistance and molding of the obtained thermoplastic resin composition and its molded product. It is preferable in terms of appearance, and more preferably 60 to 80% by mass.

Examples of the vinyl cyanide-based monomer contained in the vinyl-based monomer mixture (m2) include acrylonitrile and methacrylonitrile, and one or more of these can be used. The structure of the vinyl cyanide-based monomer is not particularly limited, but the obtained thermoplastic resin has the same structure as the vinyl cyanide-based monomer contained in the vinyl-based monomer mixture (m1) described above. It is preferable in terms of impact resistance and molded appearance of the composition and its molded product.

The content of the vinyl cyanide-based monomer contained in the vinyl-based monomer mixture (m2) is 10 to 60% by mass, that is, the impact resistance and molding of the obtained thermoplastic resin composition and its molded product. It is preferable in terms of appearance, and more preferably 20 to 40% by mass.

The vinyl-based monomer mixture (m2) may contain the above-mentioned aromatic vinyl-based monomer and cyanide vinyl-based monomer, and other vinyl-based monomers copolymerizable with these.
The content of the other copolymerizable vinyl-based monomer in the vinyl-based monomer mixture (m2) is preferably 20% by mass or less, particularly preferably 10% by mass or less.
Examples of other vinyl-based monomers include those exemplified as other vinyl-based monomers that may be contained in the vinyl-based monomer mixture (m1), and these other vinyl-based monomers are One type can be used alone or two or more types can be used in combination.

The mass average molecular weight of the copolymer (C) is not particularly limited, but is preferably in the range of 10,000 to 300,000, and particularly preferably in the range of 50,000 to 200,000. When the mass average molecular weight of the copolymer (C) is within the above range, the obtained thermoplastic resin composition has excellent fluidity and impact resistance, and further, the dependence of the molded appearance on the injection rate can be reduced.
The mass average molecular weight of the copolymer (C) is measured by the method described in the section of Examples described later.

The method for producing the copolymer (C) is not particularly limited, and examples thereof include known methods such as emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization. Suspension polymerization and bulk polymerization are preferable from the viewpoint of heat resistance of the obtained thermoplastic resin composition.

The polymerization initiator used in the production of the copolymer (C) is not particularly limited, and examples thereof include organic peroxides.

A chain transfer agent can be used to adjust the molecular weight of the copolymer (C) during the production of the copolymer (C). The chain transfer agent is not particularly limited, and examples thereof include mercaptans, α-methylstyrene dimers, and terpenes.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention contains the above-mentioned graft copolymer (B) of the present invention, and preferably the above-mentioned graft copolymer (B) and the above-mentioned copolymer (C) of the present invention. And include.

The content of the graft polymer (B) of the present invention in the thermoplastic resin composition of the present invention is 10 to 10 when the total of the graft copolymer (B) and the copolymer (C) is 100% by mass. It is preferably 40% by mass, and the content of the copolymer (C) is preferably 60 to 90% by mass. When the contents of the graft polymer (B) and the copolymer (C) are in the above range, the thermoplastic resin composition and its molded product have excellent impact resistance and molded appearance, and further, the molded appearance is improved. The injection speed dependence can be reduced.

The thermoplastic resin composition of the present invention may contain other thermoplastic resins, if necessary. The other thermoplastic resin is not particularly limited, and for example, polycarbonate resin, polybutylene terephthalate (PBT resin), polyethylene terephthalate (PET resin), polyvinyl chloride, polystyrene, polyacetal resin, modified polyphenylene ether (modified PPE resin), and the like. Examples thereof include ethylene-vinyl acetate copolymers, polyarylates, liquid crystal polyester resins, polyethylene resins, polypropylene resins, fluororesins and polyamide resins (nylon). Only one of these may be used, or two or more thereof may be mixed and used.

The thermoplastic resin composition of the present invention includes other conventional additives during the production (mixing) and molding of the thermoplastic resin composition as long as the physical properties of the thermoplastic resin composition and the molded product thereof are not impaired. For example, lubricants, pigments, dyes, fillers (carbon black, silica, titanium oxide, etc.), heat resistant agents, oxidative deterioration inhibitors, weather resistant agents, mold release agents, plastics, antistatic agents, etc. can be blended. ..

The thermoplastic resin composition of the present invention can be produced by a known method using a known device. For example, there is a melt mixing method as a general method, and examples of the apparatus used in this method include an extruder, a Banbury mixer, a roller, a kneader, and the like. Either a batch type or a continuous type may be adopted for mixing. Further, the mixing order of each component is not particularly limited, and all the components may be uniformly mixed.

[Molding]
The molded product of the present invention is a molded product of the thermoplastic resin composition of the present invention. Examples of the molding method include an injection molding method, an injection compression molding machine method, an extrusion method, a blow molding method, a vacuum molding method, a pneumatic molding method, a calendar molding method, an inflation molding method and the like. Among these, an injection molding method and an injection compression molding method are preferable because they are excellent in mass productivity and can obtain a molded product with high dimensional accuracy.

[Use]
The use of the thermoplastic resin composition of the present invention and its molded product is not particularly limited, but the thermoplastic resin composition of the present invention and its molded product are excellent in impact resistance, molded appearance and fluidity. Since the injection speed dependence of the molded appearance is small, it is useful in a wide range of fields such as OA / home appliances, vehicles / ships, housing-related fields such as furniture / building materials, sanitary fields, miscellaneous goods, stationery / toys, and sporting goods fields. Is.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded.
In the following, "part" means "part by mass" and "%" means "% by mass".

Various measurement and evaluation methods in the following examples and comparative examples are as follows.

<Volume average particle size of copolymer (A)>
The volume average particle size of the copolymer (A) dispersed in the aqueous dispersion was measured using Microtrac (“Nanotrack 150” manufactured by Nikkiso Co., Ltd.) and ion-exchanged water as a measurement solvent.

<Degree of swelling of copolymer (A)>
The copolymer (A) was dried at 80 ° C. for 24 hours and then vacuum dried at 80 ° C. for 24 hours to prepare a dried product of the copolymer (A) in the form of a film. The weight of the obtained dried product is W1. The dried product was immersed in acetone at room temperature for 12 hours, then filtered through a 200 mesh wire mesh and the residue was weighed. Let the weight of the residual be W2. Then, the residual was vacuum dried at room temperature for 24 hours. The weight of the residual dried product after vacuum drying is defined as W3. The degree of swelling of the copolymer (A) is calculated by the following formula (1).
Swelling degree (%) = (W2 / W3) × 100… (1)

<Graft ratio of graft copolymer (B)>
1 g of the graft copolymer (B) was added to 80 mL of acetone, heated and refluxed at 65 to 70 ° C. for 3 hours, and the obtained suspended acetone solution was placed in a centrifuge (“CR21E” manufactured by Hitachi Koki Co., Ltd.). Then, the mixture was centrifuged at 14,000 rpm for 30 minutes to separate a precipitate component (acetone insoluble component) and an acetone solution (acetone soluble component). Then, the precipitate component (acetone insoluble component) was dried, its mass (Y (g)) was measured, and the graft ratio was calculated by the following formula (2). In the formula (2), Y is the mass (g) of the acetone-insoluble component of the graft copolymer (B), and X is the total mass (g) of the graft copolymer (B) used in determining Y. The rubber content is the solid content concentration of the copolymer (A) used in the production of the graft copolymer (B) in the aqueous dispersion.
Graft ratio (mass%) = {(YX x rubber fraction) / X x rubber fraction}
× 100… (2)

<Mass average molecular weight of copolymer (C)>
The mass average molecular weight of the copolymer (C) was determined by dissolving it in tetrahydrofuran (THF) using gel permeation chromatography (GPC) in terms of standard polystyrene (PS).

[Manufacturing of copolymer (A)]
<Manufacturing of copolymer (A-1)>
The copolymer (A-1) was produced by the following formulation.
[Mixing]
N-Butyl acrylate 54 parts 2-Phenoxyethyl acrylate 6 parts Allyl methacrylate 0.24 parts 1,3-butylene glycol dimethacrylate 0.12 parts Liquid paraffin (LP) 0.6 parts Dipotassium alkenyl succinate (ASK) 0.20 parts Gilauroyl peroxide 0.6 parts Ion exchanged water 406 parts

Reactor equipped with reagent injection container, cooling tube, jacket heater and stirrer, n-butyl acrylate, 2-phenoxyethyl acrylate, liquid paraffin, allyl methacrylate, dilauroyl peroxide, ion-exchanged water, alkenyl succin A preemulsion was obtained by charging dipotassium acid and ultrasonically treating it at room temperature with ULTRASONIC HOMOGENIZER US-600 manufactured by Nissei Tokyo Office at an amplitude of 35 μm for 20 minutes. The volume average particle size of the obtained latex was 350 nm.
The preemulsion was heated to 60 ° C. to initiate radical polymerization. Due to the polymerization, the liquid temperature rose to 78 ° C. The polymer was maintained at 75 ° C. for 30 minutes to complete the polymerization, and a copolymer (A-1) dispersed in an aqueous dispersion having a volume average particle diameter of 300 nm was obtained.

<Manufacturing of copolymers (A-2) to (A-7)>
Disperse in the aqueous dispersion in the same manner as the copolymer (A-1), except that the amounts of n-butyl acrylate, 2-phenoxyethyl acrylate, and dipotassium alkenyl succinate were changed as shown in Table 1A. The copolymers (A-2) to (A-7) were obtained.

<Manufacturing of copolymer (A-8)>
A copolymer (A-8) dispersed in an aqueous dispersion was obtained in the same manner as the copolymer (A-1) except that benzyl acrylate was used instead of 2-phenoxyethyl acrylate. rice field.

<Manufacturing of copolymer (A-9)>
Dipotassium alkenyl succinate 0.27 parts, ion exchange water 175 parts, n-butyl acrylate 48 parts, 2-phenoxyethyl acrylate 12 parts, allyl methacrylate 0.24 parts, 1,3-butylene glycol dimethacrylate 0. A mixture of 12 parts and 0.1 part of t-butylhydroperoxide was charged into the reactor. By passing a nitrogen stream through the reactor, the inside of the reactor was replaced with nitrogen, and the temperature was raised to 60 ° C. When the internal temperature reached 50 ° C., an aqueous solution consisting of 0.00015 parts of ferrous sulfate, 0.00045 parts of ethylenediaminetetraacetic acid disodium salt, 0.24 parts of longalit, and 5 parts of ion-exchanged water was added. The polymerization was started and the internal temperature was raised to 75 ° C. Further, this state was maintained for 1 hour to obtain a rubber-like polymer (A-9) dispersed in an aqueous dispersion having a volume average particle diameter of 0.30 μm.

<Manufacturing of copolymers (A-10) to (A-12)>
An aqueous dispersion similar to the copolymer (A-1) except that 2-butyl acrylate and dipotassium alkenyl succinate were not used and the amounts of n-butyl acrylate and dipotassium alkenyl succinate were as shown in Table 1B. The copolymers (A-10) to (A-12) dispersed in the above were obtained.

<Manufacturing of copolymer (A-13)>
A copolymer (A-13) dispersed in an aqueous dispersion was obtained in the same manner as the copolymer (A-1) except that styrene was used instead of 2-phenoxyethyl acrylate.

<Manufacturing of copolymer (A-14)>
In a stainless steel autoclave (hereinafter abbreviated as SUS autoclave), 145 parts of ion-exchanged water (hereinafter, simply abbreviated as water), 1.0 part of potassium loginate, 1.0 part of potassium oleate, sodium hydroxide After charging 0.06 part, 0.4 part of sodium sulfate and 0.3 part of t-dodecyl mercaptan and substituting with nitrogen, 125 parts of 1,3-butadiene was charged and the temperature was raised to 60 ° C.
Then, an aqueous solution prepared by dissolving 0.3 part of potassium persulfate in 5 parts of water was press-fitted to initiate polymerization. During the polymerization, the polymerization temperature was adjusted to 65 ° C., and when the internal pressure reached 4.5 kg / cm ² (gauge pressure) after 12 hours, unreacted 1,3-butadiene was recovered. Then, the internal temperature was kept at 80 ° C. for 1 hour to obtain a butadiene rubber latex having a volume average particle diameter of 250 nm and a solid content of 41%.

20 parts of butadiene rubber latex in terms of solid content was charged in a 5 liter glass reactor, then 1.0 part of dipotassium alkenylsuccinate and 150 parts of water were added to perform nitrogen substitution, and the internal temperature was raised to 70 ° C. It was warm. To this, an aqueous solution prepared by dissolving 0.12 parts of potassium persulfate in 10 parts of water was added, and 79.5 parts of n-butyl acrylate and 0.33 parts of allyl methacrylate, 1,3 were subsequently substituted with nitrogen in advance. -A monomer mixture consisting of 0.17 parts of butylene glycol dimethacrylate was continuously added dropwise over 2 hours. After completion of the dropping, the internal temperature was raised to 80 ° C. and held for 1 hour to obtain a copolymer (A-) dispersed in an aqueous dispersion having a volume average particle diameter of 300 nm composed of butadiene rubber and acrylic rubber. 14) was obtained.

The swelling degree and volume average particle size of the copolymers (A-1) to (A-14) are shown in Tables 1A and 1B.

[Manufacturing of graft copolymer (B)]
<Manufacturing of graft copolymer (B-1)>
After producing the copolymer (A-1), the ferrous sulfate 0. An aqueous solution consisting of 001 parts, disodium ethylenediamine tetraacetic acid salt 0.003 parts, longalit 0.3 parts, and ion-exchanged water 5 parts was added, followed by 0.65 parts of dipotassium alkenyl succinate and 10 parts of ion-exchanged water. An aqueous solution consisting of was added. Then, a mixed solution consisting of 13.6 parts of acrylonitrile and 26.4 parts of styrene and 0.18 parts of t-butyl hydroperoxide as a vinyl-based monomer mixture (m1) was added dropwise over 1 hour and 30 minutes for graft polymerization. I let you.
After the dropping is completed, the internal temperature is maintained at 75 ° C. for 10 minutes and then cooled. When the internal temperature reaches 60 ° C., 0.2 part of an antioxidant (manufactured by Yoshitomi Pharmaceutical Co., Ltd., Antage W500) and alkenyl succinic acid An aqueous solution prepared by dissolving 0.2 parts of dipotassium acid in 5 parts of ion-exchanged water was added. Then, the aqueous dispersion of the reaction product was coagulated with an aqueous sulfuric acid solution, washed with water, and then dried to obtain a graft copolymer (B-1). The graft ratio of the graft copolymer (B-1) was 40%.

<Manufacturing of graft copolymers (B-2) to (B-14)>
The graft copolymers (B-2) to (B-14) are the same as the graft copolymer (B-1) except that the type of the copolymer (A) used is changed as shown in Table 2. ) Was obtained.

The graft ratios of the graft copolymers (B-2) to (B-14) were as shown in Table 2.

[Manufacturing of copolymer (C)]
<Manufacturing of copolymer (C-1)>
150 parts of ion-exchanged water in a pressure-resistant reaction vessel, 34 parts of acrylonitrile and 66 parts of styrene as a vinyl-based monomer mixture (m2), 0.2 parts of 2,2'-azobis (isobutyronitrile), n -0.45 parts of octyl mercaptan, 0.47 parts of calcium hydroxyapatite and 0.003 parts of potassium alkenyl succinate were charged, the internal temperature was raised to 75 ° C., and the reaction was carried out for 3 hours. Then, the temperature was raised to 90 ° C. and held for 60 minutes to complete the reaction. The contents were washed with a centrifugal dehydrator and dehydrated repeatedly, and dried to obtain a copolymer (C-1) having a mass average molecular weight of 100,000.

[Examples 1 to 9, Comparative Examples 1 to 7]
Each component is mixed according to the composition (mass part) shown in Table 3, and 0.8 part of carbon black is further mixed there. 240 using a twin-screw extruder with a 30 mmφ vacuum vent (“PCM30” manufactured by Ikegai Corp.) The mixture was melt-kneaded at ° C to obtain a pellet-shaped thermoplastic resin composition. The melt volume rate of the obtained thermoplastic resin composition was evaluated by the following method. Further, the molded product obtained by injection molding the obtained thermoplastic resin composition was evaluated for its molding appearance and impact resistance by the following methods.
The evaluation results are shown in Table 3.

[Each evaluation method]
<Measurement of melt volume rate (MVR)>
The thermoplastic resin composition was measured at 220 ° C. according to ISO 1133 standard. The MVR is a measure of the fluidity of the thermoplastic resin composition.

<Injection molding 1>
Pellets of thermoplastic resin composition obtained by melt-kneading are injected by an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machinery Co., Ltd.) at a cylinder temperature of 200 to 270 ° C, a mold temperature of 60 ° C, and an injection rate of 25 g / sec. Under the above conditions, a molded product having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm was molded and used as a molded product for a Charpy impact test (molded product (Ma1)).

<Injection molding 2>
Pellets of thermoplastic resin composition obtained by melt-kneading are injected by an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machinery Co., Ltd.) at a cylinder temperature of 200 to 270 ° C, a mold temperature of 60 ° C, and an injection rate of 7 g / sec. Under the above conditions, a molded product having a length of 100 mm, a width of 100 mm, and a thickness of 3 mm was molded and used as a molded product for appearance evaluation (molded product (Ma2)).

<Injection molding 3>
Pellets of thermoplastic resin composition obtained by melt-kneading are injected by an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machinery Co., Ltd.) at a cylinder temperature of 200 to 270 ° C, a mold temperature of 60 ° C, and an injection rate of 128 g / sec. Under the above conditions, a molded product having a length of 100 mm, a width of 100 mm, and a thickness of 3 mm was molded and used as a high-speed injection molded product (high-speed injection molded product (Ma3)) for appearance evaluation.

<Appearance evaluation I>
For the molded product (Ma2), the brightness L ^* was measured by the SCE method using a spectrocolorimeter (“CM-3500d” manufactured by Konica Minolta Optips). Let the measured L ^* be "L ^* (ma)". The lower the L ^* , the blacker the color and the better the appearance.

<Appearance evaluation II>
For the high-speed injection molded product (Ma3), the brightness L ^* was measured by the SCE method using a spectrocolorimeter (“CM-3500d” manufactured by Konica Minolta Optips). Let the measured L ^* be "L ^* (mb)". The lower the L ^* , the blacker the color and the better the appearance.
When molding is performed under conditions of high injection speed, the rubber components in the resin are oriented, causing whitening and bronze phenomena, and L ^* becomes large. Therefore, the molding appearance under the condition that the injection speed is high is important.

<Appearance evaluation III (evaluation of appearance depending on injection speed)>
ΔL ^* = (L ^* (mb) -L ^* (ma)) ΔL ^* was calculated from the equation of ² . The smaller ΔL ^* , the smaller the dependence of the appearance on the injection speed. Generally, in a molded product such as a vehicle part, the injection speed differs depending on the part location. Therefore, in the case of a resin having a large dependence on the injection speed, poor appearance such as color unevenness on the surface of the component during molding occurs.

<Evaluation of impact resistance: Charpy impact test>
The molded product (Ma1) was subjected to a Charpy impact test (with a notch) under the condition of 23 ° C. according to ISO 179 standard, and the Charpy impact strength was measured.

As shown in Examples 1 to 9 in Table 3, according to each example, a thermoplastic resin composition and a molded product having excellent impact resistance, fluidity, and molded appearance were obtained. Moreover, the thermoplastic resin compositions of Examples 1 to 9 have a small dependence on the injection speed of the molded appearance.
On the other hand, the thermoplastic resin compositions and molded products obtained in Comparative Examples 1 to 7 were remarkably inferior in impact resistance, fluidity, and appearance, and the injection speed dependence of the molded appearance was also large.

Claims (12)

A vinyl-based monomer mixture (m1) is graft-polymerized on a copolymer (A) of a (meth) acrylic acid alkyl ester (Aa) and a (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group. It is a graft copolymer (B) made of acrylic acid.
The copolymer (A) contains a (meth) acrylic acid alkyl ester (Aa) unit, a (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group, a unit derived from a cross-linking agent, and / or. Contains units derived from graft cross-linkers
The graft copolymer (B) in which the vinyl-based monomer mixture (m1) contains an aromatic vinyl-based monomer and a cyanide vinyl-based monomer. (Meta) acrylic acid in a total of 100% by mass of the (meth) acrylic acid alkyl ester (Aa) unit in the copolymer (A) and the (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group. The content of the alkyl ester (Aa) unit is 30 to 95% by mass, and the content of the (meth) acrylic acid ester (Ab) unit having an aromatic hydrocarbon group is 5 to 70% by mass, according to claim 1. The graft copolymer (B) according to the above. The proportion of units derived from the cross-linking agent and / or the graft cross-linking agent in the copolymer (A) is the (meth) acrylic acid alkyl ester (Aa) unit and the (meth) acrylic acid ester having an aromatic hydrocarbon group. The graft according to claim 1 or 2, which is 0.1 to 3% by mass in a total of 100% by mass of the unit (Ab) and the unit derived from the cross-linking agent and / or the unit derived from the graft cross-linking agent. Polymer (B). The copolymer (A) is hydrophobic with a (meth) acrylic acid alkyl ester (Aa), a (meth) acrylic acid ester (Ab) having an aromatic hydrocarbon group, a cross-linking agent and / or a graft crossing agent. The graft copolymer (B) according to any one of claims 1 to 3, which is a miniemulsion polymer of a mixture of the substance and the initiator. The graft copolymer (B) according to any one of claims 1 to 4, wherein the copolymer (A) has a volume average particle size of 50 to 800 nm and a swelling degree of 2 to 15 times. Claimed that the content of the aromatic vinyl-based monomer contained in the vinyl-based monomer mixture (m1) is 40 to 90% by mass, and the content of the cyanide vinyl-based monomer is 10 to 60% by mass. Item 2. The graft copolymer (B) according to any one of Items 1 to 5. The ratio of the copolymer (A) to 100% by mass of the total of the copolymer (A) and the vinyl-based monomer mixture (m1) is 50 to 80% by mass, and the ratio of the vinyl-based monomer mixture (m1). The graft copolymer (B) according to any one of claims 1 to 6, wherein the amount is 20 to 50% by mass and the graft ratio is 25 to 100%. The thermoplastic resin composition containing the graft copolymer (B) according to any one of claims 1 to 7. The thermoplastic resin composition according to claim 8, which comprises the graft copolymer (B) and the copolymer (C) which is a polymerization reaction product of the vinyl-based monomer mixture (m2). The vinyl-based monomer mixture (m1) contains an aromatic vinyl-based monomer and a cyanide vinyl-based monomer, and the vinyl-based monomer mixture (m2) is contained in the vinyl-based monomer mixture (m1). An aromatic vinyl-based monomer having the same structure as the aromatic vinyl-based monomer and a cyanide vinyl-based monomer having the same structure as the cyanide vinyl-based monomer contained in the vinyl-based monomer mixture (m1). The thermoplastic resin composition according to claim 9. The total 100% by mass of the graft copolymer (B) and the copolymer (C) contains 10 to 40% by mass of the graft copolymer (B) and 60 to 90% by mass of the copolymer (C). The thermoplastic resin composition according to claim 9 or 10. A molded product obtained by molding the thermoplastic resin composition according to any one of claims 8 to 11.