JP7011444B2 - Graft polymer and thermoplastic resin composition - Google Patents

Description

The present invention relates to polymers, graft polymers and thermoplastic resin compositions.

Thermoplastic resin compositions such as acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene-acrylic acid ester (ASA) resin, acrylonitrile-ethylene-propylene / non-conjugated diene copolymer-styrene (AES) resin are resistant. It is used in a wide range of fields because it can provide molded products with excellent impact resistance, molding processability, secondary processability (plating, coating, etc.), and surface appearance.
The thermoplastic resin composition contains a graft polymer and a thermoplastic resin other than the graft polymer (hereinafter, also referred to as “another thermoplastic resin”). The graft polymer is obtained by graft-polymerizing a rubbery polymer (hereinafter, also referred to as “rubbery polymer”) with a monomer such as a vinyl-based monomer that imparts compatibility with other thermoplastic resins. It is a polymer obtained by the above.

Various rubbery polymers are used for the graft polymer, and for example, olefin rubbers such as polybutadiene, polybutadiene-styrene copolymer, silicone rubber, acrylic rubber, and ethylene / propylene / diene rubber (EPDM). And composite com that combines these are known. Among these, acrylic rubber obtained by polymerizing an acrylic acid ester is widely used because it has excellent light resistance, chemical resistance, and economic efficiency of the obtained molded product.

Since the degree of cross-linking of the rubber polymer in the graft polymer has a great influence on the impact resistance of the obtained molded product, it is important to control the degree of cross-linking of the rubber polymer to obtain an appropriate degree of cross-linking. ..
For example, it is known that a molded product having excellent impact resistance can be obtained from a thermoplastic resin composition containing EPDM having a specific degree of cross-linking or a graft polymer using acrylic rubber as a rubber polymer. For example, see Patent Documents 1 to 3).

Further, as a method for adjusting the degree of cross-linking of acrylic rubber, a polyfunctional compound having two or more (meth) acryloyl groups, vinyl groups, allyl groups, etc. in the molecule is used as a cross-linking agent in the production of acrylic rubber. , A method of copolymerizing the cross-linking agent with an acrylic acid ester is known.

Japanese Unexamined Patent Publication No. 2012-224670 Japanese Unexamined Patent Publication No. 2002-284823 Japanese Unexamined Patent Publication No. 2012-214734

By the way, in the graft polymer, the graft ratio, which is the ratio of the rubbery polymer coated with the polymer of the monomer such as the vinyl-based monomer, also has a great influence on various physical properties of the molded product. Generally, the higher the graft ratio, the better the surface appearance and thermal stability of the molded product.
Further, when the thermoplastic resin composition is molded by injection molding or the like, a defect phenomenon such as deterioration of the molded appearance due to deformation of the rubbery polymer is likely to occur, particularly in a portion where shearing is likely to occur, such as in the vicinity of a gate. Therefore, in order to eliminate the defect phenomenon, the degree of cross-linking of the rubbery polymer may be increased to prevent deformation during molding, and the graft ratio of the graft polymer may be increased. As a method for increasing the graft ratio, a method for increasing the addition amount of the polyfunctional compound used when adjusting the degree of cross-linking of the rubbery polymer is common.

However, if the degree of cross-linking of the rubber polymer is increased or the graft ratio of the graft polymer is increased in order to improve the surface appearance, molded appearance, and thermal stability of the molded product, the impact resistance of the molded product is lowered. Tend to do. On the other hand, if the degree of cross-linking of the rubbery polymer is made appropriate in order to improve the impact resistance of the molded product, the graft ratio of the graft polymer is lowered, and the surface appearance, molded appearance and thermal stability of the molded product are improved. It tends to decrease.
In this way, it is difficult to highly control the degree of cross-linking of the rubber polymer and the graft ratio of the graft polymer, and to achieve both the impact resistance of the molded product, the surface appearance, the thermal stability and the molded appearance. there were.

An object of the present invention is to provide a polymer capable of obtaining a graft polymer having a high degree of cross-linking and a high graft ratio.
Another object of the present invention is to provide a graft polymer having a high graft ratio, which is suitable as a material for a thermoplastic resin composition capable of obtaining a molded product having excellent impact resistance, surface appearance, thermal stability and molded appearance. And.
Another object of the present invention is to provide a thermoplastic resin composition capable of obtaining a molded product having excellent impact resistance, surface appearance, thermal stability and molded appearance.

The present invention includes the following aspects.
[1] A polymer obtained by polymerizing a mixture containing the following component (Aa), component (Ab), and component (Ac).
(Aa) Ingredient: Acrylic acid ester.
Component (Ab): A branched allyl ether compound having a hydroxy group and two or more allyl groups, and all carbon-carbon double bonds contained in the allyl ether compound are derived from the allyl group.
(Ac) component: A reactive compound having a functional group capable of reacting with a hydroxy group and one or more functional groups selected from the group consisting of a (meth) acryloyl group, a vinyl group, and -CH = CH-.
[2] The polymer according to [1], wherein the component (Ab) is at least one selected from the group consisting of pentaerythritol triallyl ether, pentaerythritol diallyl ether, and trimethylolpropane diallyl ether.
[3] One or more singles selected from the group consisting of aromatic vinyl, vinyl cyanide, (meth) acrylic acid ester, N-substituted maleimide and maleic acid in the polymer according to [1] or [2]. A graft polymer obtained by graft-polymerizing a weight.
[4] A thermoplastic resin composition containing the graft polymer according to [3] and a thermoplastic resin other than the graft polymer.

The polymer of the present invention can obtain a graft polymer having a high graft ratio while having an appropriate degree of cross-linking.
Further, the graft polymer of the present invention is suitable as a material for a thermoplastic resin composition capable of obtaining a molded product having a high graft ratio and excellent impact resistance, surface appearance, thermal stability and molded appearance.
Further, according to the thermoplastic resin composition of the present invention, a molded product having excellent impact resistance, surface appearance, thermal stability and molded appearance can be obtained.

Hereinafter, the present invention will be described in detail.
The definitions of the following terms apply throughout the specification and claims.
The "molded article" means a product obtained by molding a thermoplastic resin composition.
"(Meta) acrylic" is a general term for "acrylic" and "methacrylic".
"(Meta) acrylic acid ester" is a general term for "acrylic acid ester" and "methacrylic acid ester".

"Polymer"
The polymer of the present invention (hereinafter, also referred to as “polymer (A)”) is a mixture containing the following (Aa) component, (Ab) component, and (Ac) component (hereinafter, “mixture (α)). It is also called.) It is obtained by polymerizing. That is, the polymer (A) is a polymer of at least the (Aa) component, the (Ab) component, and the (Ac) component, and the (Aa) component unit, the (Ab) component unit, and the (Ac) component unit are used. include. The polymer (A) obtained by polymerizing the mixture (α) tends to be rubbery. The mixture (α) is a monomer other than the component (Aa), the component (Ab) and the component (Ac) (hereinafter, also referred to as “other monomer”) depending on the physical characteristics required for the molded product. May include.
(Aa) Ingredient: Acrylic acid ester.
Component (Ab): A branched allyl ether compound having a hydroxy group and two or more allyl groups, and all carbon-carbon double bonds contained in the allyl ether compound are derived from the allyl group.
(Ac) component: A reactive compound having a functional group capable of reacting with a hydroxy group and one or more functional groups selected from the group consisting of a (meth) acryloyl group, a vinyl group, and -CH = CH-.

In the polymer (A), it is not always easy to specify how the component (Aa), the component (Ab), and the component (Ac) are polymerized. That is, there is a situation (impossible / impractical situation) in which the polymer (A) cannot be directly specified by its structure or property, or is almost impractical. Therefore, in the present invention, it is more appropriate to define the polymer (A) as "a product obtained by polymerizing a mixture containing the component (Aa), the component (Ab), and the component (Ac)". Will be done.

<(Aa) component>
The component (Aa) is an acrylic acid ester.
Examples of the component (Aa) include an acrylic acid alkyl ester having an alkyl group having 1 to 12 carbon atoms; an acrylic acid aryl ester having an aromatic hydrocarbon group such as a phenyl group and a benzyl group.
More specifically, the component (Aa) includes methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, and t-butyl acrylate. , Amil acrylate, Isoamyl acrylate, octyl acrylate, -2-ethylhexyl acrylate, decyl acrylate, lauryl acrylate, stearyl acrylate, cyclohexyl acrylate, pentyl acrylate, phenyl acrylate, benzyl acrylate and the like. Be done. Among these, n-butyl acrylate, 2-ethylhexyl acrylate, and ethyl acrylate are preferable because the polymer (A) tends to be rubbery.
One of these (Aa) components may be used alone, or two or more thereof may be mixed and used.

The content of the component (Aa) is 80 to 99.9 with respect to the total (total mass) of the component (Aa), the component (Ab), the component (Ac) and other monomers in the mixture (α). The mass% is preferable, and 90.1 to 99.8 mass% is more preferable. If the content of the component (Aa) is not less than the above lower limit value, the impact resistance of the obtained molded product is further improved, and if it is not more than the above upper limit value, the impact resistance, surface appearance, thermal stability of the molded product, The molded appearance is further improved.

<(Ab) component>
The component (Ab) is a branched-chain allyl ether compound having a hydroxy group and two or more allyl groups. All carbon-carbon double bonds contained in the allyl ether compound are derived from the allyl group.
The number of hydroxy groups may be one in one molecule or two or more.

The component (Ab) is obtained, for example, by reacting a branched-chain polyol with allyl alcohol. Examples of the branched-chain polyol include pentaerythritol, dipentaerythritol, trimethylolethane and its dimer, trimethylolpropane and its dimer, trimethylolpropane and its dimer, and the like. Of these, pentaerythritol and trimethylolpropane are preferable.

More specifically, the component (Ab) includes pentaerythritol triallyl ether, pentaerythritol diallyl ether, trimethylolpropane diallyl ether and the like. Among these, pentaerythritol triallyl ether is preferable.
One of these (Ab) components may be used alone, or two or more thereof may be mixed and used.

The content of the component (Ab) is 0.05 to 5 with respect to the total (total mass) of the component (Aa), the component (Ab), the component (Ac) and other monomers in the mixture (α). The mass% is preferable, and 0.1 to 2% by mass is more preferable. If the content of the component (Ab) is at least the above lower limit, the impact resistance, surface appearance, thermal stability, and molding appearance of the obtained molded product are further improved, and if it is at least the above upper limit, the resistance of the molded product is improved. Impact resistance is further improved.

<(Ac) component>
The component (Ac) is a reactive compound having a functional group capable of reacting with a hydroxy group and one or more functional groups selected from the group consisting of a (meth) acryloyl group, a vinyl group, and -CH = CH-. be.

Examples of the functional group capable of reacting with the hydroxy group include an isocyanate group, a thioisocyanate group, an oxylan group, an oxetane group, a carbodiimide group, a silanol group, an oxazoline group, an aziridine group, an epoxy group, a carboxy group and a dicarboxylic acid anhydride group. Can be mentioned. Among these, an isocyanate group, an epoxy group, and a dicarboxylic acid anhydride group are preferable from the viewpoint of excellent reactivity.
The number of functional groups that can react with the hydroxy group may be one in one molecule, two or more, and in the case of two or more, the types of functional groups may be the same or different.
Here, the "dicarboxylic acid anhydride group" is a functional group derived from a dicarboxylic acid anhydride, and is specifically represented by —CO—O—CO—.

The number of one or more functional groups selected from the group consisting of (meth) acryloyl group, vinyl group, and -CH = CH- may be one, two or more, or two or more in one molecule. In the case of, the types of functional groups may be the same or different.

More specifically, the component (Ac) includes 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, glycidyl acrylate, glycidyl methacrylate, maleic anhydride and the like. Among these, 2-acryloyloxyethyl isocyanate, glycidylmethacrylate, and maleic anhydride are preferable.
One of these (Ac) components may be used alone, or two or more thereof may be mixed and used.

The content of the component (Ac) is 0.05 to 5 with respect to the total (total mass) of the component (Aa), the component (Ab), the component (Ac) and other monomers in the mixture (α). The mass% is preferable, and 0.1 to 2% by mass is more preferable. If the content of the component (Ac) is at least the above lower limit value, the impact resistance and surface appearance of the obtained molded product are further improved, and if it is at least the above upper limit value, the impact resistance of the molded product is further improved.

<Other monomers>
When the mixture (α) contains other monomers, the polymer (A) contains (Aa) component units, (Ab) component units, (Ac) component units and other monomer units.
The other monomer is not particularly limited as long as it can be copolymerized with the component (Aa), the component (Ab) and the component (Ac), and is, for example, aromatic vinyl, vinyl cyanide, methacrylic acid ester, N-substituted. Maleimide and maleic acid can be mentioned.

Examples of the aromatic vinyl include styrene, α-methylstyrene, o-, m- or p-methylstyrene, vinylxylene, pt-butylstyrene, ethylstyrene and the like.
Examples of vinyl cyanide include acrylonitrile and methacrylonitrile.
Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, amyl methacrylate and methacrylic acid. Examples thereof include isoamyl acid acid, octyl methacrylate, -2-ethylhexyl methacrylate, decyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate and the like.
Examples of the N-substituted maleimide include N-cyclohexylmaleimide and N-phenylmaleimide.
One of these other monomers may be used alone, or two or more thereof may be mixed and used.

The content of the other monomers is 19.95 mass with respect to the total (total mass) of the (Aa) component, the (Ab) component, the (Ac) component and the other monomers in the mixture (α). % Is preferable, and less than 10% by mass is more preferable. When the content of the other monomer is within the above range, the original performance of the polymer (A) is likely to be exhibited.

<Method for producing polymer (A)>
The polymer (A) 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, an emulsion polymerization method, or a mini-emulsion polymerization method. Among these, emulsion polymerization and mini-emulsion polymerization are preferable because the particle size of the polymer (A) can be easily controlled and the graft polymer described later can be easily produced.

As a method for producing the polymer (A) by the emulsification polymerization method, a radical initiator, a component (Aa), a component (Ab), a component (Ac), and if necessary, another monomer are added to an aqueous solvent. , A method of copolymerizing in the presence of an emulsifier can be mentioned. The method for adding the radical initiator, the (Aa) component, the (Ab) component, the (Ac) component and other monomers may be batch, split or continuous.

Examples of the emulsifier used in the emulsification polymerization method include anionic surfactants, nonionic surfactants, amphoteric surfactants and the like.
More specifically, the emulsifier includes a sulfate ester of a higher alcohol, an alkylbenzene sulfonate, a fatty acid sulfonate, a phosphate type (for example, ammonium monoglyceride phosphate), a fatty acid salt (for example, dipotassium alkenyl succinate), and the like. Anionic surfactants such as amino acid derivative salts; Nonionic surfactants such as alkyl ester type, alkyl ether type and alkyl phenyl ether type of ordinary polyethylene glycol; , An amphoteric surfactant having a phosphoric acid ester salt or the like and having an amine salt, a quaternary ammonium salt or the like in the cation portion, and the like can be mentioned.
One of these emulsifiers may be used alone, or two or more of them may be mixed and used.

The amount of the emulsifier added is preferably 10 parts by mass or less, more preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the mixture (α).

Known radical initiators can be used in the emulsion polymerization method, and examples thereof include azo polymerization initiators, photopolymerization initiators, inorganic peroxides, organic peroxides, organic peroxides, transition metals, and reducing agents. Examples include a redox-based initiator that combines the above. Among these, an azo polymerization initiator, an inorganic peroxide, an organic peroxide, and a redox-based initiator that can initiate polymerization by heating are preferable.
These radical initiators 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'-azo. Bisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl) azo ] Formamide, 4,4'-azobis (4-cyanovaleric acid), dimethyl 2,2'-azobis (2-methylpropionate), dimethyl 1,1'-azobis (1-cycloxycarboxylate) , 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) and the like. ..

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) -Butyl peroxy) cyclododecane, 2,2-bis (t-butyl peroxy) butane, n-butyl 4,4-bis (t-butyl peroxy) 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, cumene hydroperoxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide 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, those composed of cumene hydroperoxide, ferrous sulfate, sodium pyrophosphate, and dextrose, those used in the examples described later, and the like can be mentioned.

The amount of the radical initiator added is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and further preferably 0.001 to 3 parts by mass with respect to 100 parts by mass of the mixture (α).

A chain transfer agent may be added as needed during the production of the polymer (A).
Examples of the chain transfer agent include octyl mercaptans, n- or t-dodecyl mercaptans, n-hexadecyl mercaptans, n- or t-tetradecyl mercaptans and other mercaptans; allyl sulphonic acid, methallyl sulphonic acid, sodium salts thereof and the like. Allyl compound; α-methylstyrene dimer and the like. Among these, mercaptans are preferable because the molecular weight can be easily adjusted.
These chain transfer agents may be used alone or in admixture of two or more.

The method for adding the chain transfer agent may be batch, split, or continuous.
The amount of the chain transfer agent added is preferably 2 parts by mass or less, more preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the mixture (α).

The polymer (A) can be used as a composite rubber with a polymer having a rubbery substance other than the polymer (A) (hereinafter, also referred to as “another rubbery polymer”).
Examples of other rubbery polymers include ethylene / propylene rubber (EPR), ethylene / propylene / non-conjugated diene copolymer (EPDM), ethylene-α-olefin copolymer, diene rubber, polyorganosiloxane and the like. Be done.
The composite rubber can be obtained by a known method such as a method of polymerizing a mixture (α) in the presence of another rubbery polymer, a method of co-enlargement of the polymer (A) and another rubbery polymer, and the like. Be done.

<Physical characteristics>
The degree of swelling of the polymer (A) is represented by an increase multiple of the mass of the insoluble acetone of the polymer (A) when immersed in an acetone solvent. The higher the degree of swelling, the longer the distance between the crosslinking points and the more the crosslinking. This means that the degree is low, and the polymer (A) tends to be a soft rubber. The degree of swelling of the polymer (A) is preferably 6 to 12 times, more preferably 7 to 10 times. When the degree of swelling of the polymer (A) is within the above range, the impact resistance of the obtained molded product tends to be high.
Specifically, the degree of swelling of the polymer (A) can be measured as follows. That is, first, the weighed polymer (A) is immersed in acetone for 20 hours, and the polymer (A) is swollen with acetone until it is saturated. Then, it is centrifuged at 14000 rpm, separated into an acetone-dissolved component and an acetone-swelled insoluble substance, and the mass of the acetone-swelled insoluble substance is measured. Next, the insoluble matter swollen with acetone is vacuum dried, the mass of the insoluble matter after drying is measured, and the degree of swelling of the polymer (A) is determined from the following formula (1).
Swelling degree (double) = mass of insoluble matter swollen with acetone (g) / mass of insoluble matter after drying (g) ... (1)

The degree of swelling of the polymer (A) can be controlled by adjusting the amount of the component (Ab) and the component (Ac) added in the production of the polymer (A). For example, if the amount of the component (Ab) and the component (Ac) added is increased, the degree of swelling becomes low. In particular, when the amount of the (Ac) component added is increased, the degree of swelling tends to decrease. The degree of swelling tends to decrease by increasing the amount of the component (Ab) added, but the effect is lower than that of the component (Ac). Rather, increasing the amount of the component (Ab) added causes the graft polymer (C) described later. ) Has a greater effect of improving the graft rate.

The volume average particle size of the polymer (A) is preferably 50 to 700 nm, more preferably 80 to 500 nm, and even more preferably 120 to 500 nm. If the volume average particle size of the polymer (A) is at least the above lower limit, the impact resistance and thermal stability of the obtained molded product are further improved, and if it is at least the above upper limit, the surface appearance and molding of the molded product are further improved. The appearance tends to be even better.
The volume average particle size of the polymer (A) can be calculated from the obtained particle size distribution by measuring the volume-based particle size distribution using a laser diffraction or scattering type particle size distribution measuring device.

The method for controlling the volume average particle size of the polymer (A) is not particularly limited, and a known method can be used. For example, in the production of the polymer (A), a method of adjusting the addition amount of an emulsifying agent used in emulsion polymerization or mini-emulsion polymerization, a latex of a polymer (A) having a small particle size is used as an acid or acid group-containing copolymer ( There is a method of enlarging with the latex of E).

In the case of bloating with the latex of the acid group-containing copolymer (E), for example, the latex of the acid group-containing copolymer (E) may be mixed with the latex of the polymer (A) having small particles. At this time, it is more preferable to add the condensing salt before mixing the latex of the acid group-containing copolymer (E).
By enlarging the polymer (A) in this way, the polymer (A) having a desired volume average particle size can be easily obtained. Further, by adding the condensate, the proportion of the polymer (A) of the small particles remaining without bloating can be reduced.

Examples of the condensing acid salt include salts of condensate acids such as phosphoric acid and silicic acid and at least one of an alkali metal and an alkaline earth metal. Among these, a salt of pyrophosphate, which is a condensing acid of phosphoric acid, and an alkali metal is preferable, and sodium pyrophosphate or potassium pyrophosphate is particularly preferable.
The amount of the condensate added is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 7 parts by mass with respect to 100 parts by mass of the solid content of the polymer (A) of the small particles. If the amount of the condensate added is within the above range, the hypertrophy will sufficiently proceed. In particular, when the amount of the condensate added is not more than the above upper limit, the stability of the latex is further enhanced and the generation of agglomerates can be suppressed.

The latex of the acid group-containing copolymer (E) includes an acid group-containing monomer, a (meth) acrylic acid alkyl ester-based monomer, and other monomers copolymerizable with these in water. It is obtained by polymerizing a monomer mixture containing.

Examples of the acid group-containing monomer include unsaturated compounds having a carboxy group, and specific examples thereof include (meth) acrylic acid, itaconic acid, and crotonic acid. Of these, (meth) acrylic acid is particularly preferred.
One of these acid group-containing monomers may be used alone, or two or more thereof may be mixed and used.

Examples of the (meth) acrylic acid alkyl ester-based monomer include esters of (meth) acrylic acid and an alcohol having a linear or branched alkyl group having 1 to 12 carbon atoms, and specific examples thereof include acrylic. Methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n methacrylate -Butyl, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate and the like can be mentioned. Among these, (meth) acrylic acid alkyl esters having an alkyl group having 1 to 8 carbon atoms are particularly preferable.
These (meth) acrylic acid alkyl ester-based monomers may be used alone or in combination of two or more.

The other monomer used for producing the latex of the acid group-containing copolymer (E) is a monomer copolymerizable with the acid group-containing monomer and the (meth) acrylic acid alkyl ester-based monomer. , And the monomer excluding the acid group-containing monomer and the (meth) acrylic acid alkyl ester-based monomer.
Examples of the other monomer include the other monomers described above in the description of the polymer (A).
One of these other monomers may be used alone, or two or more thereof may be mixed and used.

The ratio of each monomer unit to the total mass of all the monomer units constituting the acid group-containing copolymer (E) is as follows.
The ratio of the acid group-containing monomer unit is preferably 5 to 40% by mass, more preferably 8 to 30% by mass.
The ratio of the (meth) acrylic acid alkyl ester-based monomer unit is preferably 60 to 95% by mass, more preferably 70 to 92% by mass.
The ratio of the other monomer units is preferably 48% by mass or less, more preferably 30% by mass or less.
When the ratio of the acid group-containing monomer unit is equal to or more than the above lower limit value, the hypertrophy ability becomes better, and when the ratio is equal to or less than the above upper limit value, the latex of the acid group-containing copolymer (E) is produced. Agglomerates are less likely to occur.

The glass transition temperature of the polymer (A) is preferably 0 ° C. or lower, more preferably −80 to 0 ° C. When the glass transition temperature of the polymer (A) is within the above range, the impact resistance of the obtained molded product tends to be further excellent.
The glass transition temperature of the polymer (A) is a value obtained by dynamic viscoelasticity measurement (DMTA), and is specifically obtained when the temperature is raised from −100 ° C. to 5 ° C./min at a frequency of 1 Hz. The temperature at the maximum peak of the tangent loss (tan δ) to be obtained is defined as the glass transition temperature.

<Action effect>
The polymer (A) of the present invention described above is obtained by polymerizing a mixture (α) containing a component (Aa), a component (Ab), and a component (Ac). Therefore, the polymer (A) of the present invention can obtain a graft polymer having a high graft ratio while having an appropriate degree of cross-linking. The reason for this is not clear, but it is thought to be as follows.
Although the allyl group of the component (Ab) has low reactivity in the radical addition reaction, hydrogen abstraction by radicals is likely to occur, and it is likely to be a starting point of polymerization. Therefore, when the component (Aa) and the component (Ab) are polymerized, the component (Ab) tends to become the molecular terminal of the polymer of the component (Aa) (that is, the polyacrylic acid ester), and the hydroxy group of the component (Ab) becomes. It will be present at the end of the molecule. On the other hand, the component (Ac) is likely to undergo a radical addition reaction and is easily incorporated into the molecular chain of the polymer of the component (Aa). Then, the hydroxy group of the (Ab) component at the end of the molecule and the functional group of the (Ac) component incorporated in the molecular chain that can react with the hydroxy group react to form a crosslinked structure. Therefore, the proportion of the polymer of the component (Aa) that does not participate in the cross-linking structure is reduced, and the polymer (A) having an appropriate degree of cross-linking can be obtained.
Further, since the allyl group of the component (Ab) has low reactivity, the allyl group is less likely to be consumed during the production of the polymer (A), and the pendant allyl group tends to remain in the polymer (A). Therefore, when the polymer (A) of the present invention is used for producing a graft polymer, the graft polymerization tends to proceed easily with the pendant allyl group as the polymerization point. Therefore, the graft polymer obtained by using the polymer (A) of the present invention has a high graft ratio.
As described above, by using the component (Aa), the component (Ab), and the component (Ac) in combination, it is possible to obtain a structure having many graft points while maintaining an appropriate degree of cross-linking.

"Graft polymer"
The graft polymer of the present invention (hereinafter, also referred to as "graft polymer (C)") is a polymer (A) of the present invention, which is an aromatic vinyl, vinyl cyanide, (meth) acrylic acid ester, N-. It is obtained by graft-polymerizing one or more kinds of monomers (hereinafter, also referred to as "monomer (B)") selected from the group consisting of substituted maleimide and maleic acid. That is, the graft polymer (C) is composed of a polymer (A) portion and a polymer (B) portion obtained by polymerizing the monomer (B).

In the graft polymer (C), it is difficult to specify how the monomer (B) is polymerized with the polymer (A). For example, as the polymer (B), there are those bonded to the polymer (A) and those not bonded to the polymer (A). Further, it is also difficult to specify the molecular weight of the polymer (B) bound to the polymer (A), the ratio of the constituent units, and the like. That is, there is a situation (impossible / impractical situation) in which the graft polymer (C) cannot be directly specified by its structure or property, or is almost impractical. Therefore, in the present invention, it is more appropriate to define the graft polymer (C) as "a polymer (A) obtained by graft-polymerizing the monomer (B)".

<Polymer (A)>
Since the polymer (A) is the polymer (A) of the present invention described above, the description thereof will be omitted.
As the polymer (A), one type may be used alone, or two or more types may be mixed and used.

<Monomer (B)>
The monomer (B) is one or more monomers selected from the group consisting of aromatic vinyl, vinyl cyanide, (meth) acrylic acid ester, N-substituted maleimide and maleic acid.
The monomer (B) can be selected depending on the compatibility with the other thermoplastic resin (D) described later and the purpose of the molded product. For example, if aromatic vinyl is used as the monomer (B), the moldability tends to be good. When vinyl cyanide is used, it is possible to improve the chemical resistance, impact resistance, and compatibility with other thermoplastic resins (D) having polarity of the molded product. By using a methacrylic acid ester, the surface hardness and surface appearance of the obtained molded product can be improved. Heat resistance can be improved by using N-substituted maleimide.

Examples of the aromatic vinyl, vinyl cyanide, and N-substituted maleimide include aromatic vinyl, vinyl cyanide, and N-substituted maleimide among the other monomers exemplified above in the description of the polymer (A). Be done.
Examples of the (meth) acrylic acid ester include the component (Aa) exemplified above in the description of the polymer (A) and the methacrylic acid ester among other monomers.
One of these monomers (B) may be used alone, or two or more thereof may be mixed and used.

<Manufacturing method of graft polymer (C)>
The graft polymer (C) is obtained by graft-polymerizing the monomer (B) with the polymer (A).
The graft polymer (C) is 40 to 90% by mass of the polymer (A) and 10 to 60% by mass of the monomer (B) (however, the total of the polymer (A) and the monomer (B) is 100. It is preferably obtained by graft-polymerizing (% by mass). The proportion of the polymer (A) is more preferably 45 to 70% by mass, and the proportion of the monomer (B) is more preferably 30 to 55% by mass. When the ratio of the polymer (A) to the monomer (B) is within the above range, the productivity of the graft polymer (C) and the thermoplastic resin composition obtained by blending the graft polymer (C). The impact resistance, surface appearance, and thermal stability of the obtained molded product tend to be further improved.

The method of graft-polymerizing the monomer (B) to the polymer (A) is not particularly limited, but since the method for producing the polymer (A) is preferably emulsion polymerization or miniemulsion polymerization, emulsion graft polymerization is preferable. It is preferable to carry out with.
Examples of the emulsified graft polymerization method include a method of radically polymerizing the monomer (B) in the presence of an emulsion of the polymer (A) by adding the monomer (B) collectively, continuously or intermittently. Further, in the case of graft polymerization, a chain transfer agent is used for the purpose of adjusting the molecular weight and the graft ratio of the graft polymer (C), and a known inorganic electrolyte or the like is used for the purpose of adjusting the viscosity and pH of the latex. You may use it. Further, in the emulsified graft polymerization, various emulsifiers and radical initiators can be used as needed.
The type and amount of the chain transfer agent, emulsifier, and radical initiator are not particularly limited. Examples of the chain transfer agent, emulsifier, and radical initiator include the chain transfer agent, emulsifier, and radical initiator exemplified above in the description of the polymer (A).

The graft polymer (C) obtained by emulsified graft polymerization is in a state of being dispersed in an aqueous medium.
As a method for recovering the graft polymer (C) from the aqueous dispersion containing the graft polymer (C), for example, a precipitate is added to the aqueous dispersion, heated and stirred, and then the precipitate is separated and precipitated. Examples thereof include a precipitation method in which the graft polymer (C) is washed with water, dehydrated, and dried.
Examples of the precipitant include an aqueous solution of sulfuric acid, acetic acid, calcium chloride, magnesium sulfate and the like.
One of these precipitates may be used alone, or two or more thereof may be mixed and used.

<Physical characteristics>
The graft ratio of the graft polymer (C) is preferably 40 to 150%, more preferably 50 to 120%, still more preferably 60 to 100%. When the graft ratio of the graft polymer (C) is at least the above lower limit value, the surface appearance, thermal stability, and molded appearance of the obtained molded product are further improved. On the other hand, when the graft ratio of the graft polymer (C) is not more than the above upper limit value, the productivity of the thermoplastic resin can be maintained satisfactorily. In addition, when a certain amount of the polymer (A) is contained in the thermoplastic resin composition, it is necessary to increase the blending amount of the graft polymer (C), but the blending amount of the graft polymer (C) is high. Even if it increases, the original performance of the thermoplastic resin can be fully exhibited.
Specifically, the graft ratio of the graft polymer (C) can be measured as follows. That is, the graft polymer (C) was added to acetone, heated and refluxed at 65 to 70 ° C. for 3 hours, and the obtained suspended acetone solution was centrifuged at 14000 rpm to separate it into an acetone-dissolved component and an acetone-insoluble component. do. Next, the acetone-insoluble matter is vacuum-dried, the mass of the acetone-insoluble matter after drying is measured, and the graft ratio of the graft polymer (C) is obtained from the following formula (2). In the formula (2), P is the mass (g) of the acetone insoluble matter after drying, and Q is the mass (g) of the polymer (A) used for producing the graft polymer (C). be.
Graft rate (%) = {(PQ) / Q} x 100 ... (2)

The graft ratio of the graft polymer (C) can be controlled by adjusting the addition amount of the component (Ab) and the component (Ac) in the production of the polymer (A). For example, when the polymer (A) produced by increasing the addition amounts of the (Ab) component and the (Ac) component is used, the graft ratio of the graft polymer (C) tends to be high. In particular, when the amount of the component (Ab) added is increased, the graft rate tends to increase. The graft ratio tends to increase even if the amount of the component (Ac) added is increased, but the effect is lower than that of the component (Ab). Rather, increasing the amount of the component (Ac) added causes the polymer (A) to swell. The effect of lowering the degree is greater. If the amount of the component (Ac) added is excessively increased in order to increase the graft ratio of the graft polymer (C), the degree of swelling of the polymer (A) is too low, and the impact resistance of the obtained molded product is improved. May decrease.

<Action effect>
The graft polymer (C) of the present invention described above is obtained by graft-polymerizing the monomer (B) to the above-mentioned polymer (A) of the present invention, and is obtained by graft-polymerizing the polymer (A). ) Has a high degree of cross-linking, but has a high graft rate. Therefore, the graft polymer (C) of the present invention is suitable as a material for a thermoplastic resin composition capable of obtaining a molded product having excellent impact resistance, surface appearance, thermal stability and molded appearance.

"Thermoplastic resin composition"
The thermoplastic resin composition of the present invention includes the graft polymer (C) of the present invention and a thermoplastic resin other than the graft polymer (C) (hereinafter, also referred to as “another thermoplastic resin (D)”). including.
The thermoplastic resin composition of the present invention may contain arbitrary components such as various additives, if necessary, as long as the effects of the present invention are not impaired.

<Graft polymer (C)>
Since the graft polymer (C) contained in the thermoplastic resin composition is the graft polymer (C) of the present invention described above, the description thereof will be omitted.
As the graft polymer (C), one type may be used alone, or two or more types may be used in combination.

<Other thermoplastic resin (D)>
The other thermoplastic resin (D) is not particularly limited, and for example, acrylic resin (PMMA), acrylonitrile-styrene copolymer (AS resin), polycarbonate resin, polybutylene terephthalate (PBT resin), and methyl methacrylate-styrene are used together. Polymerized resin (MS resin), polyethylene terephthalate (PET resin), polyvinyl chloride, polystyrene, polyacetal resin, modified polyphenylene ether (modified PPE resin), ethylene-vinyl acetate copolymer, polyarylate, liquid crystal polyester resin, polyethylene resin, Examples thereof include polypropylene resin, fluororesin, and polyamide resin (nylon).
As these other thermoplastic resins (D), one type may be used alone, or two or more types may be mixed and used.

<Arbitrary ingredient>
Examples of various additives include lubricants, pigments, dyes, fillers (carbon black, silica, titanium oxide, etc.), heat resistant agents, oxidative deterioration inhibitors, weather resistant agents, mold release agents, plasticizers, antistatic agents, and the like. Can be mentioned.

<Contents of each component>
The content of the graft polymer (C) is preferably 5 to 70% by mass, more preferably 10 to 50% by mass, based on the total mass of the graft polymer (C) and the other thermoplastic resin (D). .. When the content of the graft polymer (C) is at least the above lower limit value, the impact resistance of the obtained molded product is further excellent. On the other hand, when the content of the graft polymer (C) is not more than the above upper limit value, the functions originally possessed by the other thermoplastic resin (D) are easily exhibited. For example, when an acrylic resin is used as the other thermoplastic resin (D), the hardness of the molded product tends to be high. When a polycarbonate resin is used as the other thermoplastic resin (D), the heat resistance of the molded product tends to be high.

The content of the other thermoplastic resin (D) is preferably 30 to 95% by mass, preferably 50 to 90% by mass, based on the total mass of the graft polymer (C) and the other thermoplastic resin (D). More preferred. When the content of the other thermoplastic resin (D) is at least the above lower limit value, the functions originally possessed by the other thermoplastic resin (D) can be sufficiently exhibited. On the other hand, when the content of the other thermoplastic resin (D) is not more than the above upper limit value, the impact resistance of the obtained molded product is further excellent.

The total content of the graft polymer (C) and the other thermoplastic resin (D) is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, based on the total mass of the thermoplastic resin composition. preferable.

<Manufacturing method of thermoplastic resin composition>
The thermoplastic resin composition can be produced by a known method using a known apparatus using the graft polymer (C), another thermoplastic resin (D), and if necessary, an optional component. For example, a melt mixing method is mentioned as a general method, and examples of the apparatus used in this method include an extruder, a Banbury mixer, a roller, and a kneader. 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.
The optional component may be added when molding the thermoplastic resin composition.

<Action effect>
Since the thermoplastic resin composition of the present invention described above contains the above-mentioned graft polymer (C) of the present invention and another thermoplastic resin (D), it has impact resistance, surface appearance, and thermal stability. A molded product having excellent properties and molded appearance can be obtained.

"Molding"
The molded product is obtained by molding the thermoplastic resin composition of the present invention by a known molding method.
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.
The molded product obtained by the present invention is excellent in impact resistance, surface appearance and thermal stability.

Hereinafter, examples will be specifically shown. However, the present invention is not limited to these examples.
In the following, "%" means "% by mass" and "parts" means "parts by mass".
Various measurement and evaluation methods in the following examples are as follows.

"Measurement / evaluation"
<Measuring method of volume average particle size>
For the polymer (A), the volume average particle size (MV) was measured using Microtrac (manufactured by Nikkiso Co., Ltd., “Nanotrack 150”) and pure water as a measurement solvent.

<Measurement method of swelling degree>
The latex of the polymer (A) was solidified with methanol and sulfuric acid, washed with methanol, and vacuum dried. The dried polymer (A) was weighed, immersed in acetone for 20 hours, and the polymer (A) was swollen with acetone until saturated. Then, it was centrifuged at 14000 rpm, separated into an acetone-dissolved component and an acetone-swelled insoluble matter, and the mass of the acetone-swelled insoluble matter was measured. Next, the insoluble matter swollen with acetone was vacuum dried, the mass of the insoluble matter after drying was measured, and the degree of swelling of the polymer (A) was determined from the following formula (1). The higher the degree of swelling, the lower the degree of cross-linking.
Swelling degree (double) = mass of insoluble matter swollen with acetone (g) / mass of insoluble matter after drying (g) ... (1)

<Measurement method of graft rate>
The graft polymer (C) was washed with methanol, added to acetone, and heated to reflux at 65 ° C. for 3 hours. The obtained suspended acetone solution was centrifuged at 14000 rpm and separated into an acetone-dissolved component and an acetone-insoluble component. Next, the acetone-insoluble matter was vacuum-dried, the mass of the acetone-insoluble matter after drying was measured, and the graft ratio of the graft polymer (C) was determined from the following formula (2). In the formula (2), P is the mass (g) of the acetone insoluble matter after drying, and Q is the mass (g) of the polymer (A) used for producing the graft polymer (C). be.
Graft rate (%) = {(PQ) / Q} x 100 ... (2)

<Evaluation of impact resistance>
Pellets of the thermoplastic resin composition were molded at 230 ° C. to obtain a molded product (i) having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm.
The obtained molded product (i) was subjected to a Charpy impact test (with a V notch having a thickness of 4 mm) under the condition of 23 ° C. in accordance with ISO 179 standard, and the Charpy impact strength was measured.

<Evaluation of surface appearance>
Pellets of the thermoplastic resin composition were injection molded at 230 ° C. and an injection speed of 40 g / sec to obtain a molded product (ii) having a length of 100 mm, a width of 100 mm and a thickness of 2 mm.
With respect to the obtained molded product (ii), the reflectance (%) of the surface of the molded product (ii) at an incident angle of 60 ° and a reflection angle of 60 ° was measured using a gloss meter. The higher the reflectance, the better the surface appearance.

<Evaluation of thermal stability>
After the pellet of the thermoplastic resin composition is allowed to stay at 230 ° C. for 20 minutes in an injection molding machine, a molded product having a length of 100 mm, a width of 100 mm and a thickness of 2 mm is continuously injection molded at 230 ° C. and an injection speed of 40 g / sec. The fifth shot was obtained as a molded product (iii).
With respect to the obtained molded product (iii), the reflectance (%) of the surface of the molded product (iii) at an incident angle of 60 ° and a reflection angle of 60 ° was measured using a gloss meter, and gloss was maintained by the following formula (3). I asked for the rate. The higher the gloss retention rate, the better the thermal stability.
Gloss retention rate (%) = (reflectance of molded product (iii) / reflectance of molded product (ii)) x 100 ... (3)

<Evaluation of molding appearance>
Injection molding was performed using pellets of the thermoplastic resin composition at 230 ° C. and an injection speed of 40 g / sec to obtain a molded product (iv) having a length of 100 mm, a width of 100 mm and a thickness of 2 mm.
Using a colorimeter (manufactured by Konica Minolta Japan Co., Ltd., "CM-508D"), the difference between the L ^* at the center of the obtained molded product (iv) and the L ^* at the center and the gate (ΔL ^* ). Was measured. From the difference (ΔL ^* ) from L ^* in the central part, the molding appearance was evaluated according to the following evaluation criteria. ◎ and ○ are passed.
⊚: L ^* ≤8 and 0≤ΔL ^* ≤0.5, and the molded product (iv) is uniformly black as a whole.
〇: L ^* ≤8 and 0.5 <ΔL ^* ≤1. The molded product (iv) is entirely black, but the gate portion is slightly white.
Δ: 8 <L ^* or 1 <ΔL ^* , and the molded product (iv) is entirely white or the gate portion is white.
X: 8 <L ^* and 1 <ΔL ^* , the molded product (iv) is white as a whole, and the gate portion is whiter.

"Example 1"
<Manufacturing of polymer (A)>
In a reaction vessel equipped with a reagent injection vessel, a cooling tube, a jacket heater and a stirrer, 300 parts of deionized water, 1 part of dipotassium alkenylsuccinate, 0.2 parts of t-butylhydroperoxide, and (Aa) component. 99.2 parts of butyl acrylate, 0.5 part of pentaerythritol triallyl ether as the component (Ab), and 0.3 part of 2-acryloyloxyethyl isocyanate as the component (Ac) were added, and the inside of the reaction vessel was filled with nitrogen. After 1 hour of replacement with, the temperature was raised to 55 ° C.
Next, 0.3 part of sodium formaldehyde sulfoxylate, 0.0001 part of ferrous sulfate heptahydrate, 0.0003 part of ethylenediaminetetraacetic acid disodium, and 10 parts of deionized water were added to the reaction vessel. Polymerization was started. After the heat generation of polymerization was confirmed, the jacket temperature was set to 75 ° C., the polymerization was continued until the heat generation of polymerization was no longer confirmed, and the mixture was held for another 1 hour to obtain a latex of the polymer (A1).
The volume average particle size of the obtained polymer (A1) was 112 nm, and the degree of swelling was 8 times.

<Manufacturing of graft polymer (C)>
230 parts of deionized water, 50 parts of polymer (A1) latex in terms of solid content, and 0.5 dipotassium alkenyl succinate in a reaction vessel equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer. A portion and 0.3 portion of sodium formaldehyde sulfoxylate were charged, the inside of the reaction vessel was replaced with nitrogen for 1 hour, and then the temperature was raised to 70 ° C. with stirring. The amount of deionized water charged includes the mass of deionized water in the latex of the polymer (A1).
Then, a mixed solution consisting of 15 parts of acrylonitrile, 35 parts of styrene and 0.5 part of t-butyl hydroperoxide was added dropwise to the reaction vessel over 100 minutes, and the temperature was raised to 80 ° C. After completion of the dropping, the mixture was kept at 80 ° C. and then cooled to obtain a latex of the graft polymer (C1). Next, the latex of the graft polymer (C1) was solidified with a 1.5% aqueous sulfuric acid solution, dehydrated, washed, and dried to obtain a powdery graft polymer (C1).
The graft ratio of the obtained graft polymer (C1) was 73%.

<Manufacturing of thermoplastic resin composition>
40 parts of graft polymer (C1), 60 parts of acrylonitrile-styrene copolymer (“SR31B” manufactured by MGBS Co., Ltd.) as another thermoplastic resin (D), 1 part of ethylene bisstearylamide, and carbon. 0.8 parts of black (manufactured by Mitsubishi Chemical Co., Ltd., "# 960") and 0.8 parts are melt-kneaded at 220 ° C. using a twin-screw extruder (manufactured by Japan Steel Works, Ltd., "TEX-28V") to form pellets. The thermoplastic resin composition of the above was obtained.
The impact resistance, surface appearance, thermal stability and molded appearance of the molded product obtained by injection molding the obtained thermoplastic resin composition were evaluated. The results are shown in Table 1.

"Example 2"
<Production of acid group-containing copolymer (E)>
In a reaction vessel equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer, 200 parts of deionized water, 2 parts of potassium oleate, 4 parts of sodium dioctylsulfosuccinate, and 0 ferrous sulfate heptahydrate are used. .003 parts, 0.009 parts of disodium ethylenediamine tetraacetate, and 0.3 parts of sodium formaldehyde sulfoxylate were charged under a nitrogen stream, and the temperature was raised to 60 ° C. At 60 ° C., a mixture consisting of 82 parts of butyl acrylate, 18 parts of methacrylic acid and 0.5 part of cumene hydroperoxide was continuously added dropwise over 120 minutes. The reaction was continued at 60 ° C. for 2 hours, and then cooled to obtain a latex of the acid group-containing copolymer (E). The volume average particle size of the obtained acid group-containing copolymer (E) was 150 nm.

<Manufacturing of polymer (A)>
(1st stage)
240 parts of deionized water, 1 part of dipotassium alkenyl succinate, 0.16 part of t-butyl hydroperoxide, and (Aa) component in a reaction vessel equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer. To add 79.36 parts of butyl acrylate, 0.4 part of pentaerythritol triallyl ether as the component (Ab), and 0.24 part of 2-acryloyloxyethyl isocyanate as the component (Ac), and nitrogen in the reaction vessel. After 1 hour of replacement with, the temperature was raised to 55 ° C.
Next, 0.3 part of sodium formaldehyde sulfoxylate, 0.0001 part of ferrous sulfate heptahydrate, 0.0003 part of ethylenediaminetetraacetic acid disodium, and 10 parts of deionized water were added to the reaction vessel. Polymerization was started. After the polymerization heat generation was confirmed, the jacket temperature was set to 75 ° C., the polymerization was continued until the polymerization heat generation was not confirmed, and the reaction was further carried out for 1 hour. To this, add 1 part of a 5% aqueous sodium pyrophosphate solution in solid content, add 2.5 parts of the latex of the acid group-containing copolymer (E) in solid content, and stir for 30 minutes (enlargement step). , Obtained latex.

(2nd stage)
To the obtained latex, 60 parts of deionized water, 0.03 part of sodium formaldehyde sulfoxylate, 0.002 part of ferrous sulfate heptahydrate, and 0.006 part of disodium ethylenediaminetetraacetate were added. .. Next, 19.84 parts of butyl acrylate as the (Aa) component, 0.1 part of pentaerythritol triallyl ether as the (Ab) component, 0.06 part of 2-acryloyloxyethyl isocyanate and t-butylhydro as the (Ac) component. A mixed solution consisting of 0.02 part of peroxide was added dropwise over 1 hour and reacted to obtain a latex of the polymer (A2).
The volume average particle size of the obtained polymer (A2) was 310 nm, and the degree of swelling was 8 times.

<Manufacturing of graft polymer (C)>
In a reaction vessel equipped with a reagent injection container, a cooling tube, a jacket heater and a stirrer, 230 parts of deionized water, 50 parts of polymer (A2) latex in terms of solid content, and 0.5 dipotassium alkenyl succinate. A portion and 0.3 portion of sodium formaldehyde sulfoxylate were charged, the inside of the reaction vessel was replaced with nitrogen for 1 hour, and then the temperature was raised to 70 ° C. with stirring. The amount of deionized water charged includes the mass of deionized water in the latex of the polymer (A2).
Then, a mixed solution consisting of 15 parts of acrylonitrile, 35 parts of styrene and 0.5 part of t-butyl hydroperoxide was added dropwise to the reaction vessel over 100 minutes, and the temperature was raised to 80 ° C. After completion of the dropping, the mixture was kept at 80 ° C. and then cooled to obtain a latex of the graft polymer (C2). Next, the latex of the graft polymer (C2) was solidified with a 1.5% aqueous sulfuric acid solution, dehydrated, washed, and dried to obtain a powdery graft polymer (C2).
The graft ratio of the obtained graft polymer (C2) was 68%.

<Manufacturing of thermoplastic resin composition>
40 parts of the graft polymer (C2), 60 parts of the acrylonitrile-styrene copolymer (“AXS Resin 202N” manufactured by UMG ABS Co., Ltd.) as another thermoplastic resin (D), and 1 part of ethylene bisstearylamide. , Carbon black (manufactured by Mitsubishi Chemical Co., Ltd., "# 960") and 0.8 parts are melt-kneaded at 220 ° C. using a twin-screw extruder (manufactured by Japan Steel Works, Ltd., "TEX-28V"). A pellet-shaped thermoplastic resin composition was obtained.
The impact resistance, surface appearance, thermal stability and molded appearance of the molded product obtained by injection molding the obtained thermoplastic resin composition were evaluated. The results are shown in Table 1.

"Example 3"
The polymer (A3) was obtained in the same manner as in Example 2 except that 3 parts of a 5% aqueous sodium pyrophosphate solution was used in terms of solid content and 3 parts of a latex of the acid group-containing copolymer (E) was used in terms of solid content. .. For the polymer (A3), the volume average particle size and the degree of swelling were measured. The results are shown in Table 1.
A graft polymer (C3) was obtained in the same manner as in Example 2 except that the obtained polymer (A3) was used. The graft ratio was measured for the graft polymer (C3). The results are shown in Table 1.
A thermoplastic resin composition was obtained in the same manner as in Example 2 except that the obtained graft polymer (C3) was used. The impact resistance, surface appearance, thermal stability and molded appearance of the molded product obtained by injection molding the obtained thermoplastic resin composition were evaluated. The results are shown in Table 1.

"Examples 4-6, 8-11"
The compounds shown in Tables 1 and 2 were used as the component (Ab) and the component (Ac), and the amounts of the component (Aa), the component (Ab) and the component (Ac) charged were changed as shown in Tables 1 and 2. Polymers (A4) to (A6) and (A8) to (A11) were obtained in the same manner as in Example 2 except for the above. The volume average particle size and the degree of swelling of the polymers (A4) to (A6) and (A8) to (A11) were measured. The results are shown in Tables 1 and 2.
Graft polymers (C4) to (C6), (C8) to (C11) in the same manner as in Example 2 except that the obtained polymers (A4) to (A6) and (A8) to (A11) were used. ) Was obtained. The graft ratios of the graft polymers (C4) to (C6) and (C8) to (C11) were measured. The results are shown in Tables 1 and 2.
A thermoplastic resin composition was obtained in the same manner as in Example 2 except that the obtained graft polymers (C4) to (C6) and (C8) to (C11) were used. The impact resistance, surface appearance, thermal stability and molded appearance of the molded product obtained by injection molding the obtained thermoplastic resin composition were evaluated. The results are shown in Tables 1 and 2.

"Example 7"
The weight was the same as in Example 1 except that 1 part of dipotassium alkenyl succinate was changed to 1.2 parts of sodium dodecylbenzene sulfonate and 2-acryloyloxyethyl isocyanate was changed to maleic anhydride as a component (Ac). A coalescence (A7) was obtained. For the polymer (A7), the volume average particle size and the degree of swelling were measured. The results are shown in Table 1.
Using the obtained polymer (A7), a graft polymer (C7) was obtained in the same manner as in Example 1 except that the 1.5% sulfuric acid aqueous solution was changed to a 5% calcium chloride aqueous solution. The graft ratio was measured for the graft polymer (C7). The results are shown in Table 1.
A thermoplastic resin composition was obtained in the same manner as in Example 1 except that the obtained graft polymer (C7) was used. The impact resistance, surface appearance, thermal stability and molded appearance of the molded product obtained by injection molding the obtained thermoplastic resin composition were evaluated. The results are shown in Table 1.

"Comparative Examples 1 to 7"
The compounds shown in Table 3 were used as the components (Ab) and (Ac), and the amounts of the components (Aa), (Ab) and (Ac) were changed as shown in Table 3. Polymers (A12) to (A18) were obtained in the same manner as in Example 2. For the polymers (A12) to (A18), the volume average particle size and the degree of swelling were measured. The results are shown in Table 3.
Graft polymers (C12) to (C18) were obtained in the same manner as in Example 2 except that the obtained polymers (A12) to (A18) were used. The graft ratio was measured for the graft polymers (C12) to (C18). The results are shown in Table 3.
A thermoplastic resin composition was obtained in the same manner as in Example 2 except that the obtained graft polymers (C12) to (C18) were used. The impact resistance, surface appearance, thermal stability and molded appearance of the molded product obtained by injection molding the obtained thermoplastic resin composition were evaluated. The results are shown in Table 3.

The abbreviations in Tables 1 to 3 are as follows.
Ab-1: Pentaerythritol Triallyl Ether-Ab-2: Trimethylol Propaneallyl Ether-Ab-3: Pentaerythritol Diallyl Ether-Ab-4: Trimethylol Propanetriallyl Ether-Ab-5: Pentaerythritol Triacrylate- Ab-6: Allyl Methacrylate ・ Ac-1: 2-acryloyloxyethyl isocyanate ・ Ac-2: Glycidyl methacrylate ・ Ac-3: Maleic anhydride ・ Ac-4: Butyl isocyanate ・ Ac-5: 2-Hydroxyethyl acrylate

As is clear from Tables 1 and 2, the polymer (A) obtained in each example had an appropriate degree of cross-linking. In addition, the graft polymer (C) obtained by using the polymer (A) of each example had a high graft ratio. Further, the molded product obtained in each example was excellent in impact resistance, surface appearance, thermal stability and molded appearance.
As described above, according to the present invention, a polymer (A) capable of achieving a high graft ratio when grafted can be obtained while having an appropriate crosslinked structure.

On the other hand, as is clear from Table 3, from the polymer (A) of Comparative Example 1 in which the component (Ac) was not used, the graft polymer (C) having a high graft ratio was obtained, but the polymer (A). ) Was low in degree of cross-linking. Further, the molded product obtained in Comparative Example 1 was inferior in impact resistance.
From the polymer (A) of Comparative Example 2 using a branched chain-like trimethylolpropanetriallyl ether having no hydroxy group as the component (Ab), a graft polymer (C) having a high graft ratio can be obtained. However, the degree of cross-linking of the polymer (A) was low. Further, the molded product obtained in Comparative Example 2 was inferior in impact resistance and molded appearance.
From the polymer (A) of Comparative Example 3 using the branched-chain pentaerythritol triacrylate having no allyl group and having an acryloyl group as the component (Ab), the graft polymer (C) having a high graft ratio is shown. Was not obtained. Further, the molded product obtained in Comparative Example 3 was inferior in impact resistance, thermal stability and surface appearance.
The polymer (A) of Comparative Example 4 using a butyl isocyanate having no functional group selected from the group consisting of a (meth) acryloyl group, a vinyl group, and −CH = CH— as a component (Ac). ), Although the graft polymer (C) having a high graft ratio was obtained, the degree of cross-linking of the polymer (A) was low. Further, the molded product obtained in Comparative Example 4 was inferior in impact resistance and molded appearance.
From the polymer (A) of Comparative Example 5 using 2-hydroxyethyl acrylate having no functional group capable of reacting with the hydroxy group as the component (Ac), the graft polymer (C) having a high graft ratio was obtained. However, the degree of cross-linking of the polymer (A) was low. Further, the molded product obtained in Comparative Example 5 was inferior in impact resistance and molded appearance.
As the component (Ab), the molded products obtained in Comparative Examples 6 and 7 using allyl methacrylate having no hydroxy group and one allyl group and not using the component (Ac) had impact resistance and heat resistance. It was not possible to achieve both stability.
As described above, in the case of each comparative example, it was difficult to increase the graft ratio of the graft polymer (C) while imparting an appropriate degree of cross-linking to the polymer (A).

The polymer of the present invention can obtain a graft polymer having a high graft ratio while having an appropriate degree of cross-linking. Therefore, the graft polymer obtained from the polymer of the present invention is suitable as a material for a thermoplastic resin composition capable of obtaining a molded product having excellent impact resistance, surface appearance, thermal stability and molded appearance. According to the thermoplastic resin composition of the present invention, a molded product having excellent impact resistance, surface appearance, thermal stability and molded appearance can be obtained.

Claims (3)

A polymer obtained by polymerizing a mixture containing the following (Aa) component, (Ab) component, and (Ac) component includes aromatic vinyl, vinyl cyanide, (meth) acrylic acid ester, and N-substituted maleimide. A graft polymer obtained by graft-polymerizing one or more monomers selected from the group consisting of and maleic acid.
(Aa) Component: One or more selected from the group consisting of an acrylic acid alkyl ester having an alkyl group having 1 to 12 carbon atoms and an acrylic acid aryl ester having an aromatic hydrocarbon group .
Component (Ab): A branched allyl ether compound having a hydroxy group and two or more allyl groups, and all carbon-carbon double bonds contained in the allyl ether compound are derived from the allyl group.
(Ac) component: A reactive compound having a functional group capable of reacting with a hydroxy group and one or more functional groups selected from the group consisting of a (meth) acryloyl group, a vinyl group, and -CH = CH-. The graft polymer according to claim 1, wherein the component (Ab) is at least one selected from the group consisting of pentaerythritol triallyl ether, pentaerythritol diallyl ether, and trimethylolpropane diallyl ether. A thermoplastic resin composition comprising the graft polymer according to claim 1 or 2 and a thermoplastic resin other than the graft polymer.