WO2019009203A1 - Polymer, graft polymer, and thermoplastic resin composition - Google Patents

Abstract

The present invention provides: a polymer capable of giving a graft polymer which has a low degree of crosslinking and nevertheless has a high degree of grafting; a graft polymer with a high degree of grafting which is suitable for use as a material for a thermoplastic resin composition capable of giving molded articles that are excellent in terms of impact resistance, surface appearance, and thermal stability; and a thermoplastic resin composition capable of giving molded articles that are excellent in terms of impact resistance, surface appearance, and thermal stability. The polymer is obtained by polymerizing a mixture comprising the following (Aa) ingredient and (Ab) ingredient. (Aa) ingredient: an acrylic ester. (Ab) ingredient: a branched polyfunctional compound having two or more allyl groups, all the carbon-carbon double bonds contained in the polyfunctional compound being derived from the allyl groups.

Description

Polymer, graft polymer and thermoplastic resin composition

The present invention relates to polymers, graft polymers and thermoplastic resin compositions.
The present application claims priority based on Japanese Patent Application No. 2017-132989 filed in Japan on July 6, 2017, and Japanese Patent Application No. 2018-060726 filed on March 27, 2018, The contents are incorporated herein.

Thermoplastic resin compositions such as acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene-acrylate (ASA) resin, acrylonitrile-ethylene / propylene / nonconjugated diene copolymer-styrene (AES) resin are It is used in a wide range of fields because molded articles excellent in impact resistance, molding processability, secondary processability (plating, coating, etc.) and surface appearance can be obtained.
The thermoplastic resin composition contains a graft polymer and a thermoplastic resin other than the graft polymer (hereinafter, also referred to as "other thermoplastic resin"). The graft polymer is obtained by graft polymerization of a monomer such as a vinyl monomer which imparts compatibility with other thermoplastic resins to a rubbery polymer (hereinafter, also referred to as "rubbery polymer"). It is a polymer obtained by

Various rubber polymers are used as graft polymers, and, for example, olefin rubbers such as polybutadiene, polybutadiene-styrene copolymer, silicone rubber, acrylic rubber, ethylene-propylene-diene rubber (EPDM), etc. And composite combs and the like obtained by combining these are known. Among these, acrylic rubber obtained by polymerizing an acrylic ester is widely used because it is excellent in light resistance and chemical resistance of a molded article to be obtained and excellent in economical efficiency.

Since the degree of crosslinking of the rubbery polymer in the graft polymer greatly affects the impact resistance of the resulting molded article, it is important to control the degree of crosslinking of the rubbery polymer.
For example, it is known that molded articles having excellent impact resistance can be obtained from a thermoplastic resin composition containing a graft polymer using EPDM having a specific degree of crosslinking or an acrylic rubber as a rubbery polymer ( See, for example, Patent Documents 1 to 3).

In addition, as a method of adjusting the degree of crosslinking of acrylic rubber, when producing acrylic rubber, a polyfunctional compound having two or more (meth) acryloyl groups, vinyl groups, allyl groups and the like in the molecule is used as a crosslinking agent The method of copolymerizing the said crosslinking agent with an acrylic ester is known.

JP 2012-224670 A Unexamined-Japanese-Patent No. 2002-284823 JP 2012-214734 A

By the way, in the graft polymer, the graft ratio, which is a ratio of the rubber polymer covered with a polymer of a monomer such as a vinyl monomer, also greatly affects various physical properties of the molded article. Generally, the higher the graft ratio, the better the surface appearance and the thermal stability of the molded article. As a method of increasing the graft ratio, a method of increasing the amount of addition of the polyfunctional compound used when adjusting the degree of crosslinking of the rubbery polymer is generally used.
However, if it is attempted to increase the graft ratio by increasing the addition amount of the polyfunctional compound, the degree of crosslinking of the rubbery polymer tends to increase, and the impact resistance of the molded article tends to decrease.
As described above, it has been difficult to control the degree of crosslinking of the rubbery polymer and the degree of grafting of the graft polymer in a high degree, and to achieve both the impact resistance of the molded article, the surface appearance and the thermal stability.

An object of the present invention is to provide a polymer capable of obtaining a graft polymer having a high graft ratio while having a low degree of crosslinking.
Another object of the present invention is to provide a graft polymer having a high graft ratio, which is suitable as a material of a thermoplastic resin composition from which molded articles having excellent impact resistance, surface appearance and thermal stability can be obtained.
Another object of the present invention is to provide a thermoplastic resin composition from which a molded article excellent in impact resistance, surface appearance and thermal stability is obtained.

The present invention includes the following aspects.
[1] A polymer obtained by polymerizing a mixture containing the following (Aa) component and (Ab) component.
Component (Aa): acrylic ester.
(Ab) Component: A branched polyfunctional compound having two or more allyl groups, and all carbon-carbon double bonds contained in the polyfunctional compound are derived from the allyl group.
[2] The component (Ab) is at least one member selected from the group consisting of pentaerythritol tetraallyl ether, pentaerythritol triallyl ether, pentaerythritol diallyl ether, trimethylolpropane triallyl ether and trimethylolpropane diallyl ether , The polymer as described in [1].
[3] The polymer according to [1] or [2], which has a swelling degree of 4 to 20 times.
[4] The polymer according to any one of [1] to [3] is selected from the group consisting of aromatic vinyl, vinyl cyanide, (meth) acrylate, N-substituted maleimide and maleic acid Graft polymers obtained by graft polymerization of one or more monomers.
[5] The graft polymer according to [4], which has a graft density of 0.065 mol / nm ² or more.
[6] A thermoplastic resin composition comprising the graft polymer according to [4] or [5] 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 a low degree of crosslinking.
In addition, the graft polymer of the present invention is suitable as a material of a thermoplastic resin composition from which a molded article having a high graft ratio and excellent in impact resistance, surface appearance and thermal stability can be obtained.
Moreover, according to the thermoplastic resin composition of this invention, the molded article which is excellent in impact resistance, surface external appearance, and heat stability is obtained.

Hereinafter, the present invention will be described in detail.
The following definitions of terms apply throughout the present specification and claims.
"Molded article" means what is obtained by molding a thermoplastic resin composition.
"(Meth) acrylic" is a generic term for "acrylic" and "methacrylic".
"(Meth) acrylic acid ester" is a generic 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 component (Aa) and component (Ab) (hereinafter also referred to as “mixture (α)”): It is obtained by polymerization. That is, a polymer (A) is a polymer of at least (Aa) component and (Ab) component, and contains (Aa) component unit and (Ab) component unit. The polymer (A) obtained by polymerizing the mixture (α) tends to be rubbery. The mixture (α) is also referred to as a monomer other than the components (Aa) and (Ab) (hereinafter referred to as “other monomers”) according to the physical properties required for the molded article.
) May be included.
Component (Aa): acrylic ester.
(Ab) Component: A branched polyfunctional compound having two or more allyl groups, and all carbon-carbon double bonds contained in the polyfunctional compound are derived from the allyl group.

In the polymer (A), it is not always easy to specify how the (Aa) component and the (Ab) component are polymerized. That is, there are circumstances (impossible / not practical situations) in which it is impossible or almost impossible to directly identify the polymer (A) by its structure or properties. Therefore, in the present invention, it is more appropriate to define the polymer (A) as "obtained by polymerizing a mixture containing the (Aa) component and the (Ab) component".

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

The content of the component (Aa) is 80% by mass or more and 99.95% by mass or less based on the total (total mass) of the component (Aa), the component (Ab) and the other monomer in the mixture (α) Is preferable, and 90.1% by mass or more and 99.9% by mass or less are more preferable. When the content of the component (Aa) is in the above range, the resulting molded article is further excellent in impact resistance, surface appearance and thermal stability.

<(Ab) component>
The component (Ab) is a branched polyfunctional compound having two or more allyl groups. All carbon-carbon double bonds contained in the polyfunctional compound are derived from an allyl group.
The component (Ab) can be obtained, for example, by reacting a branched polyol with allyl alcohol. Examples of branched polyols include pentaerythritol, dipentaerythritol, trimethylol ethane and its dimer, trimethylol propane and its dimer, and triethylol propane and its dimer. Among these, pentaerythritol and trimethylolpropane are preferable.

More specifically, examples of the component (Ab) include pentaerythritol tetraallyl ether, pentaerythritol triallyl ether, pentaerythritol diallyl ether, trimethylolpropane triallyl ether, trimethylolpropane diallyl ether and the like. Among these, pentaerythritol triallyl ether and trimethylolpropane triallyl ether are 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% by mass or more and 5% by mass or less based on the total (total mass) of the component (Aa) in the mixture (α), the component (Ab) and the other monomers Is preferably 0.1% by mass or more and 3% by mass or less. When the content of the component (Ab) is within the above range, the degree of swelling of the polymer (A) is 4 to 20 times, and the graft density of the graft polymer (C) described later is 0.065 mol / nm ² or more It becomes easy to adjust to 0.5 mol / nm ² or less. As a result, the impact resistance, the surface appearance, the injection speed dependency of the molding appearance, and the thermal stability of the molded article obtained are further excellent.

<Other monomer>
When the mixture (α) contains other monomers, the polymer (A) contains (Aa) component units, (Ab) component units and other monomer units.
Other monomers are not particularly limited as long as they can be copolymerized with the (Aa) component and the (Ab) component, and examples thereof include aromatic vinyl, vinyl cyanide, methacrylic acid ester, N-substituted maleimide, and maleic acid. It can be mentioned. In addition, in order to adjust the degree of crosslinking of the polymer (A), the component (Ab) and another compound having two or more carbon-carbon double bonds other than aromatic vinyl, methacrylic acid ester, and N-substituted maleimide are used. You may use as a monomer.

Examples of the aromatic vinyl include styrene, α-methylstyrene, o-, m- or p-methylstyrene, vinylxylene, p-t-butylstyrene, ethylstyrene and the like.
Examples of vinyl cyanide include acrylonitrile and methacrylonitrile.
Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, amyl methacrylate, methacryl ester Isoamyl acid, octyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate and the like can be mentioned.
As the N-substituted maleimide, for example, N-cyclohexyl maleimide, N-phenyl maleimide and the like can be mentioned.
Examples of compounds having two or more carbon-carbon double bonds include allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate (1,3-butylene glycol dimethacrylate), Compounds having two carbon-carbon double bonds such as di- (meth) acrylates of diols such as 6-hexanediol diacrylate, 2-propenyl acrylate, divinylbenzene, etc .; triallyl isocyanurate having an aromatic ring And compounds having three or more carbon-carbon double bonds such as triallyl cyanurate, triallyl trimate and the like. Among these, allyl methacrylate, 2-propenyl acrylate, triallyl isocyanurate and triallyl cyanurate are preferable.
One of these other monomers may be used alone, or two or more thereof may be mixed and used.

When the mixture (α) contains one or more monomers selected from the group consisting of aromatic vinyl, vinyl cyanide, methacrylic acid ester, N-substituted maleimide and maleic acid as another monomer, the content thereof Is preferably more than 0% by mass and less than 19.95% by mass, and more than 0% by mass with respect to the total (total mass) of the component (Aa), the component (Ab) and the other monomers in the mixture (α) Less than 10% by mass is more preferable. If the content of the other monomer is within the above range, the original performance of the polymer (A) is likely to be exhibited.
When the mixture (α) contains a compound having two or more of the carbon-carbon double bonds as another monomer, the content thereof is the component (Aa), the component (Ab) and the other components in the mixture (α). More than 0 mass% and less than 3 mass% are preferable with respect to the total (total mass) of the monomer of these. If the content of the compound having two or more carbon-carbon double bonds is within the above range, the degree of swelling of the polymer (A) is 4 to 20 times, and grafting of a graft polymer (C) described later density easily adjusted to below 0.065 mol / nm ² or more 0.5 mol / nm ² a. As a result, the impact resistance of the resulting molded article, the molded appearance, and the injection speed dependency of the molded appearance are further excellent.

<Method of producing polymer (A)>
The polymer (A) is produced, for example, by a known method such as bulk polymerization, solution polymerization, bulk suspension polymerization, suspension polymerization, emulsion polymerization, miniemulsion polymerization and the like. Among these, the particle diameter of the polymer (A) can be easily controlled, and the graft polymer described later can also be easily manufactured. Therefore, the emulsion polymerization method and the miniemulsion polymerization are preferable.

The method for producing the polymer (A) by miniemulsion polymerization is not particularly limited. For example, an aqueous solvent and an emulsifier are added to the mixture (α), and if necessary, a hydrophobic compound, a radical initiator, a chain transfer agent, etc. In addition, a step of applying shear force to the obtained mixed liquid to prepare a pre-emulsion (mini-emulsion) (mini-emulsification step), a step of polymerizing the obtained mini-emulsion by heating to the polymerization initiation temperature (polymerization step )including.
In the mini-emulsification process, the shear force applied to the mixture tears the monomer away to form an emulsifier covered monomer micro oil droplet. Thereafter, by heating to the polymerization initiation temperature of the radical initiator in the polymerization step, the monomer fine oil droplets are polymerized as they are, and polymer fine particles are obtained.

Any known method can be used to apply shear force to the mixture to form a miniemulsion. The high shear device for applying a shear force to the mixed solution is not particularly limited, and examples thereof include an emulsification device comprising a high pressure pump and an interaction chamber, and a device for forming a miniemulsion by ultrasonic energy or high frequency.
As an emulsifying apparatus comprising a high pressure pump and an interaction chamber, for example, a "pressure type homogenizer" manufactured by SPX Corporation APV, a "high pressure homogenizer" manufactured by Sanmaru Kikai Co., Ltd., a "microfluidizer" manufactured by Powrex Co., Ltd., etc. Can be mentioned.
As an apparatus for forming a mini-emulsion by ultrasonic energy or high frequency, for example, "Sonic Dissembrator" manufactured by Fisher Scient, "ULTRASONIC HOMOGENIZER" manufactured by Nippon Seiki Co., Ltd., etc. may be mentioned.

From the viewpoint of workability, stability, manufacturability, etc., the amount of use of the aqueous solvent in the mini-emulsification step is such that the solid content concentration of the reaction solution after the polymerization step is about 5% by mass to 50% by mass, It is preferable to set it as about 100 mass parts or more and 500 mass parts or less with respect to a total of 100 mass parts of components other than the water-based solvent in a liquid mixture.

When the production of the polymer (A) is carried out by miniemulsion polymerization, it is preferable to use the hydrophobic compound in the proportion as described later. When forming a miniemulsion, the addition of a hydrophobic compound tends to further improve the production stability of miniemulsion polymerization, and a polymer (A) suitable for the present invention can be easily produced.

The hydrophobic compound includes, for example, a hydrocarbon having 10 or more carbon atoms, an alcohol having 10 or more carbon atoms, a hydrophobic polymer having a weight average molecular weight (Mw) of less than 10000, a hydrophobic monomer such as an alcohol 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 ester of carboxylic acid having 10 to 30 carbon atoms (preferably having 10 to 22 carbon atoms), p-alkylstyrene And hydrophobic chain transfer agents, hydrophobic peroxides and the like.
One of these hydrophobic compound agents may be used alone, or two or more thereof may be mixed and used.

More specifically, as the hydrophobic compound, hexadecane, octadecane, icosane, liquid paraffin, liquid isoparaffin, paraffin wax, polyethylene wax, polyethylene wax, olive oil, cetyl alcohol, stearyl acrylate, lauryl acrylate, stearyl acrylate, lauryl methacrylate Examples include stearyl methacrylate, polystyrene having a number average molecular weight (Mn) of 500 to 10,000, and poly (meth) acrylic acid ester.

The amount of the hydrophobic compound added is preferably 0.1 parts by mass to 10 parts by mass with respect to 100 parts by mass of the mixture (α), and more preferably 1 part by mass to 3 parts by mass. If the addition amount of the hydrophobic compound is within the above range, the particle size and particle size distribution of the polymer (A) can be easily controlled.

The mini-emulsification step is usually carried out at about 10 to 50 ° C., and the polymerization step is usually carried out at 40 to 100 ° C. for about 30 to 600 minutes.

In the emulsion polymerization method of polymer (A), a radical initiator, components (Aa) and (Ab) and, if necessary, other monomers are added to an aqueous solvent, in the presence of an emulsifier. And the method of making it copolymerize. The addition method of the radical initiator, the component (Aa), the component (Ab) and the other monomer may be batch, divided or continuous.

As an emulsifier used for emulsion polymerization or mini-emulsion polymerization, an anionic surfactant, nonionic surfactant, an amphoteric surfactant etc. are mentioned, for example.
As the emulsifier, more specifically, sulfuric acid ester of higher alcohol, alkyl benzene sulfonate, polyoxyethylene nonyl phenyl ether sulfate, fatty acid sulfonate (eg, alkali metal salt of alkyl sulfosuccinic acid, etc.), phosphoric acid Anionic interface such as salt type (eg, ammonium monoglyceride phosphate), fatty acid salt (eg, oleic acid, palmitic acid, stearic acid, alkali metal salt of rosin acid, alkali metal salt of alkenyl succinic acid, etc.), amino acid derivative salt, etc. Activators; nonionic surfactants such as alkyl ester type, alkyl ether type, alkyl phenyl ether type, etc. of common polyethylene glycol; having carboxylic acid salt, sulfuric acid ester salt, sulfonic acid salt, phosphoric acid ester salt etc in the anion part Amine salt in the cation part Amphoteric surface active agents having a quaternary ammonium salt and the like.
One of these emulsifying agents may be used alone, or two or more thereof may be mixed and used.

The addition amount of the emulsifier is preferably more than 0 parts by mass and 10 parts by mass or less, more preferably 0.005 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the mixture (α). From the point of being easier to control, 0.01 parts by mass or more and 5 parts by mass or less are more preferable.

As a radical initiator used in the emulsion polymerization method, known ones can be used. For example, azo polymerization initiator, photo polymerization initiator, inorganic peroxide, organic peroxide, organic peroxide, organic peroxide, transition metal and reducing agent And redox based initiators in combination. Among these, an azo polymerization initiator capable of initiating polymerization by heating, an inorganic peroxide, an organic peroxide, and a redox initiator are preferable.
One of these radical initiators may be used alone, or two or more thereof may be mixed and used.

As an azo polymerization initiator, for example, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 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-methyl propionate), dimethyl 1,1'-azobis (1-cyclohexane hexacarboxylate) 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) And 4-trimethylpentane).

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

Examples of the organic peroxide include peroxy ester 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-ethylhexa Noate, t-hexylperoxy 2-hexylhexanoate, t-butylperoxy 2-hexylhexanoate, t-butylperoxyisobutyrate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t- Butylperoxy 3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-bis (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t- Butylperoxy 2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyacetate, t-butylperoxy-m-toluoyl 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-butylperoxide) 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, dilauroyl peroxide, diisono Nanoyl peroxide, benzoyl peroxide, lauroyl peroxide, dimethylbis (t-butylperoxy) -3-hexyne, bis (t-butylperoxyisopropyl) benzene, bis (t-butylperoxy) trimethylcyclohexane, butyl- Bis (t-butylperoxy) valerate, t-butyl 2-ethylhexaneperoxyacid, dibenzoylperoxide, paramenthane hydroperoxide, t-butylperoxybenzoate and so on It is below.

The redox initiator is preferably a combination of an organic peroxide, ferrous sulfate, a chelating agent and a reducing agent. For example, those composed of cumene hydroperoxide, ferrous sulfate, sodium pyrophosphate and dextrose, t-butyl hydroperoxide, sodium formaldehyde sulfoxylate (long gallite), ferrous sulfate and disodium ethylenediaminetetraacetate And the like.

The addition amount of the radical initiator is preferably more than 0 parts by mass and 5 parts by mass or less with respect to 100 parts by mass of the mixture (α), more preferably more than 0 parts by mass and 3 parts by mass, and 0.001 to 3 parts by mass The following are more preferable.
It is preferable at the point which the impact resistance of the molded article obtained as the addition amount is in the said range, and the molding external appearance being excellent.

A chain transfer agent may be added as needed during the production of the polymer (A).
Chain transfer agents include mercaptans such as octyl mercaptan, n- or t-dodecyl mercaptan, n-hexadecyl mercaptan, n- or t-tetradecyl mercaptan; allyl sulfonic acid, methallyl sulfonic acid, sodium salts thereof, etc. Allyl compounds of the formula: α-methylstyrene dimer and the like. Among these, mercaptans are preferable from the viewpoint of easy adjustment of molecular weight.
One of these chain transfer agents may be used alone, or two or more thereof may be mixed and used.

The method of adding the chain transfer agent may be batchwise, split or continuous.
The addition amount of the chain transfer agent is preferably more than 0 parts by mass and 2 parts by mass or less, and more preferably 0.01 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the mixture (α).
It is preferable at the point which the impact resistance of the molded article obtained as the addition amount is in the said range, and the molding external appearance being excellent.

In addition, a polymer (A) can be used as composite rubber with the polymer (Hereafter, it is also called "the other rubbery polymer.") Which has rubbers other than a polymer (A).
Other rubbery polymers include, for example, ethylene-propylene rubber (EPR), ethylene-propylene-nonconjugated diene copolymer (EPDM), ethylene-α-olefin copolymer, diene-based rubber, polyorganosiloxane and the like Be
The composite rubber is obtained, for example, by a known method such as a method of polymerizing the mixture (α) in the presence of another rubbery polymer, a method of co-enlarging the polymer (A) and the other rubbery polymer, Be

<Physical properties>
The swelling degree of the polymer (A) is represented by an increase in the weight of the polymer (A) in which the acetone is not dissolved in acetone, and the higher the degree of swelling, the longer the distance between crosslinking points. It 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 4 to 20 times, more preferably 4 to 15 times, and still more preferably 6 to 11 times. If the degree of swelling of the polymer (A) is in the above range, the impact resistance, molded appearance, and injection speed dependency of molded appearance of the resulting molded article are further excellent.
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 to swell the polymer (A) with acetone until it becomes saturated. Thereafter, the mixture is centrifuged at 14000 rpm to separate into an acetone solution and an insoluble component swollen with acetone, and the mass of the insoluble component swollen with acetone is measured. Next, the insolubles swollen with acetone are vacuum dried, the mass of the dried insolubles is measured, and the degree of swelling of the polymer (A) is determined from the following formula (1).
Degree of swelling (fold) = mass of insoluble matter swollen with acetone (g) / mass of insoluble matter after drying (g) (1)

As a method of controlling the degree of swelling of the polymer (A), a method of adjusting the content of the compound (Ab) and the compound having two or more carbon-carbon double bonds contained in the mixture (α) can be mentioned .

The volume average particle diameter of the polymer (A) is preferably 50 nm to 800 nm, more preferably 80 nm to 700 nm, still more preferably 100 nm to 600 nm, and particularly preferably 250 nm to 450 nm. If the volume average particle diameter of the polymer (A) is in the above range, the impact resistance of the resulting molded article tends to be further excellent.
The volume average particle diameter of the polymer (A) can be calculated from the particle diameter distribution obtained by measuring the volume-based particle diameter distribution using a laser diffraction, particle size distribution measuring device of scattering method.

It does not specifically limit as a method to control the volume average particle diameter of a polymer (A), A well-known method can be used. For example, in the production of the polymer (A), a method of adjusting the addition amount of an emulsifier used at the time of emulsion polymerization or miniemulsion polymerization, a latex of the polymer (A) having a small particle diameter with an acid or acid group containing copolymer latex There is a method etc. to bloat.

The glass transition temperature of the polymer (A) is preferably -150 ° C. or more and 0 ° C. or less, and more preferably -80 ° C. or more and 0 ° C. or less. If the glass transition temperature of the polymer (A) is in the above range, the impact resistance of the resulting molded article tends to be further excellent.
The glass transition temperature of the polymer (A) is a value determined by dynamic viscoelasticity measurement (DMTA). Specifically, it is obtained when the temperature is raised from -100 ° C. to 5 ° C./min at a frequency of 1 Hz. The temperature at the time of the maximum peak of the tangent loss (tan δ) is defined as the glass transition temperature.

<Function effect>
The polymer (A) of the present invention described above is obtained by polymerizing a mixture (α) containing the (Aa) component and the (Ab) component. Therefore, the polymer (A) of the present invention can obtain a graft polymer having a high graft ratio while having a low degree of crosslinking. Although the reason is not clear, it is considered as follows.
The allyl group of the component (Ab) is low in the reactivity of the radical addition reaction, but it tends to cause hydrogen abstraction by radicals and tends to be the initiation point of polymerization. Therefore, when the (Aa) component and the (Ab) component are polymerized, the (Ab) component is likely to be the molecular terminal of the polymer of the (Aa) component (that is, a polyacrylic acid ester). As a result, since the distance between crosslinking points, which is the distance between two (Ab) components, becomes long, the degree of crosslinking of the polymer (A) tends to be low. Further, since the allyl group of the component (Ab) has low reactivity, it is difficult to consume the allyl group at the production of the polymer (A), and the pendant allyl group tends to remain in the polymer (A). Therefore, when using the polymer (A) of this invention for manufacture of a graft polymer, it exists in the tendency for graft polymerization to advance easily by using a pendant allyl group as a polymerization point. Therefore, the graft polymer obtained by using the polymer (A) of the present invention has a high graft ratio.

"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 comprises aromatic vinyl, vinyl cyanide, (meth) acrylate, N- It is obtained by graft polymerization of one or more 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 addition, in the graft polymer (C), it is difficult to specify how the monomer (B) is polymerized to the polymer (A). For example, as the polymer (B), those bonded to the polymer (A) and those not bonded to the polymer (A) exist. Moreover, it is also difficult to specify the molecular weight of the polymer (B) bonded to the polymer (A), the ratio of the structural units, and the like.
That is, there are circumstances (impossible / not practical situations) that it is impossible or almost impossible to directly identify the graft polymer (C) by its structure or properties.
Therefore, in the present invention, it is more appropriate to define the graft polymer (C) as “the one obtained by graft polymerization of the monomer (B) to the polymer (A)”.

<Polymer (A)>
Since the polymer (A) is the polymer (A) of the present invention described above, the description thereof is omitted.
A polymer (A) may be used individually by 1 type, and may mix and use 2 or more types.

<Monomer (B)>
The monomer (B) is at least one monomer selected from the group consisting of aromatic vinyl, vinyl cyanide, (meth) acrylic acid ester, N-substituted maleimide and maleic acid.
A monomer (B) can be selected according to the compatibility with the below-mentioned other thermoplastic resin (D), and the objective of a molded article. For example, when aromatic vinyl is used as the monomer (B), moldability tends to be good. If vinyl cyanide is used, the chemical resistance and impact resistance of the molded article, and the compatibility with other thermoplastic resins (D) having polarity can be improved. By using a methacrylic acid ester, the surface hardness and the surface appearance of the resulting molded article can be improved. The heat resistance can be improved by using an N-substituted maleimide.

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

<Method of producing graft polymer (C)>
The graft polymer (C) is obtained by graft polymerization of the monomer (B) to the polymer (A).
In the graft polymer (C), the polymer (A) is from 40% by mass to 75% by mass, and the monomer (B) is from 25% by mass to 60% by mass (however, the polymer (A) and the monomer (B)) The total of B) is preferably 100% by mass. The proportion of the polymer (A) is more preferably 45% by mass to 70% by mass, and the proportion of the monomer (B) is more preferably 30% by mass to 55% by mass. If the ratio of the polymer (A) to the monomer (B) is within the above range, the productivity of the thermoplastic resin composition obtained by blending the graft polymer (C) or the graft polymer (C) And the impact resistance, surface appearance and thermal stability of the resulting molded article tend to be further improved.

The method of graft polymerizing the monomer (B) to the polymer (A) is not particularly limited, but the method of polymer (A) production is preferably emulsion polymerization or mini-emulsion polymerization, so emulsion graft polymerization is preferable. Is preferred.
As a method of emulsion graft polymerization, a method of radically polymerizing the monomer (B) in a batch, continuously or intermittently in the presence of the emulsion of the polymer (A) can be mentioned. In addition, at the time of graft polymerization, a chain transfer agent is used for the purpose of controlling the molecular weight of the graft polymer (C) or controlling the grafting rate, or a known inorganic electrolyte or the like for controlling the viscosity or pH of the latex. You may use it. In the emulsion graft polymerization, various emulsifiers and radical initiators can be used as needed.
There are no particular restrictions on the type and amount of chain transfer agent, emulsifier, and radical initiator. Moreover, as a chain transfer agent, an emulsifier, and a radical initiator, the chain transfer agent, the emulsifier, and the radical initiator which were illustrated above in description of a polymer (A) are mentioned.

The graft polymer (C) obtained by emulsion graft polymerization is in the 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 precipitation agent is added to the aqueous dispersion, heated and stirred, and then the precipitation agent is separated and precipitated. The precipitation method which water-washes, dehydrates, and dries the graft polymer (C) is mentioned.
Examples of the precipitation agent include aqueous solutions of sulfuric acid, acetic acid, calcium chloride, magnesium sulfate and the like.
One of these precipitation agents may be used alone, or two or more thereof may be mixed and used.

<Physical properties>
The graft ratio of the graft polymer (C) is preferably 50% or more and 150% or less, and more preferably 60% or more and 120% or less. When the graft ratio of the graft polymer (C) is in the above range, the surface appearance and the thermal stability of the resulting molded article become further better.
The grafting ratio of the graft polymer (C) can be specifically measured as follows. That is, the graft polymer (C) is added to acetone, heated and refluxed at 65 ° C. to 70 ° C. for 3 hours, the obtained suspension acetone solution is centrifuged at 14000 rpm, and the acetone dissolved matter and the acetone insoluble matter Separated. Subsequently, the acetone insoluble matter is dried under vacuum, and the mass of the acetone insoluble matter after drying is measured, and the graft ratio of the graft polymer (C) is determined from the following formula (2). P in the formula (2) is the mass (g) of the acetone insolubles after drying, and Q is the mass (g) of the polymer (A) used in the production of the graft polymer (C) is there.
Graft ratio (%) = {(P−Q) / Q} × 100 (2)

Graft density of the graft polymer (C) is preferably from 0.065 mol / nm ² or more, 0.070 mol / nm ² or more is more preferable. When the graft density of the graft polymer (C) is in the above range, the impact resistance, molded appearance, and injection speed dependency of molded appearance of the resulting molded article are further excellent. The upper limit value of the graft density of the graft polymer (C) is not particularly limited, but 0.500 mol / nm ² is preferable, and 0.300 mol / nm ² is more preferable.
Specifically, the graft density of the graft polymer (C) can be measured as follows. That is, the number average molecular weight is measured using gel permeation chromatography (GPC) with respect to the acetone solution which has been centrifuged by the above method for measuring the graft ratio, and the number average molecular weight of the acetone solution is measured according to the following formula (3). , Graft ratio (%), specific gravity (g / cm ² ) of polymer (A), volume average particle diameter (nm) of polymer (A) dispersed in aqueous dispersion, graft density (mol) Calculate / nm ² ).
Graft density (mol / nm ² ) = 1/3 × (volume average particle diameter of polymer (A) (nm)) × 1⁄2 × specific gravity of polymer (A) (g / cm ³ ) × grafting ratio %) × (1 / (number-average molecular weight of acetone solution)) (3)

<Function effect>
The graft polymer (C) of the present invention described above is obtained by graft polymerization of the monomer (B) onto the above-described polymer (A) of the present invention, and the polymer (A) The part of) has a high degree of grafting while having a low degree of crosslinking. Therefore, the graft polymer (C) of the present invention is suitable as a material of a thermoplastic resin composition from which a molded article excellent in impact resistance, surface appearance and thermal stability is obtained.

"Thermoplastic resin composition"
The thermoplastic resin composition of the present invention comprises the graft polymer (C) of the present invention and a thermoplastic resin other than the graft polymer (C) (hereinafter also referred to as "other thermoplastic resin (D)"). including.
The thermoplastic resin composition of the present invention may contain optional components such as various additives, as needed, as long as the effects of the present invention are not impaired.

<Graft polymer (C)>
The graft polymer (C) contained in the thermoplastic resin composition is the above-described graft polymer (C) of the present invention, and thus the description thereof is 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)>
There is no particular limitation on the other thermoplastic resin (D), and for example, acrylic resin (PMMA), acrylonitrile-styrene copolymer (AS resin), polycarbonate resin, polybutylene terephthalate (PBT resin), methyl methacrylate-styrene copolymer 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, fluorine resin, and polyamide resin (nylon).
One of these other thermoplastic resins (D) may be used alone, or two or more thereof may be mixed and used.

<Optional component>
As various additives, for example, lubricants, pigments, dyes, fillers (carbon black, silica, titanium oxide etc.), heat resisting agents, oxidation deterioration inhibitors, weathering agents, mold release agents, plasticizers, antistatic agents, etc. It can be mentioned.

<Content of each component>
5 mass% or more and 70 mass% or less are preferable with respect to the total mass of a graft polymer (C) and another thermoplastic resin (D), and content of a graft polymer (C) is 10 mass% or more and 50 % Or less is more preferable. If content of a graft polymer (C) is more than the said lower limit, the impact resistance of the molded article obtained will be further excellent. On the other hand, when the content of the graft polymer (C) is equal to or less than the above upper limit value, the function originally possessed by the other thermoplastic resin (D) is likely to be sufficiently exhibited. For example, when an acrylic resin is used as the other thermoplastic resin (D), the hardness of the molded article tends to be high. When a polycarbonate resin is used as another thermoplastic resin (D), the heat resistance of the molded article tends to be high.

The content of the other thermoplastic resin (D) is preferably 30% by mass or more and 95% by mass or less, and 50% by mass, based on the total mass of the graft polymer (C) and the other thermoplastic resin (D). More than 90 mass% is more preferred. If content of another thermoplastic resin (D) is more than the said lower limit, the function which another thermoplastic resin (D) has originally will be fully exhibited easily. On the other hand, if content of other thermoplastic resin (D) is below the said upper limit, the impact resistance of the molded article obtained will be further excellent.

50 mass% or more and 100 mass% or less are preferable with respect to the total mass of a thermoplastic resin composition, and, as for the sum total of content of a graft polymer (C) and other thermoplastic resin (D), 80 mass% or more 100 mass% or less is more preferable.

<Method of producing thermoplastic resin composition>
The thermoplastic resin composition can be produced by a known method using a known apparatus, using the graft polymer (C), the other thermoplastic resin (D) and optionally, optional components. For example, a melt mixing method is mentioned as a general method, and an extruder, a Banbury mixer, a roller, a kneader etc. are mentioned as an apparatus used by this method. Either a batch system or a continuous system may be adopted for mixing. Moreover, there is no restriction | limiting in particular also in the order of mixing of each component, etc., and all the components should just be mixed uniformly.
In addition, you may add an arbitrary component, when shape | molding a thermoplastic resin composition.

<Function effect>
The thermoplastic resin composition of the present invention described above contains the above-described graft polymer (C) of the present invention and the other thermoplastic resin (D), so that it has impact resistance, surface appearance and heat stability. It is possible to obtain a molded article having excellent properties.

"Molding"
A molded article 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 pressure forming method, a calendar molding method, and an inflation molding method.
Among them, injection molding method and injection compression molding method are preferable because they are excellent in mass productivity and can obtain molded products with high dimensional accuracy.
The molded article obtained by the present invention is excellent in impact resistance, surface appearance and thermal stability.

Hereinafter, an Example is shown concretely. However, the present invention is not limited to these examples.
"%" Described below means "mass%", and "part" means "mass part".
The various measurement and evaluation methods in the following examples are as follows.

"Measurement and evaluation"
<Method of measuring volume average particle diameter>
The volume average particle diameter (MV) of the polymer (A) was measured using Microtrac (“Nanotrac 150” manufactured by Nikkiso Co., Ltd.) and pure water as the measurement solvent.

<Method of measuring swelling degree>
The latex of the polymer (A) was coagulated with methanol and sulfuric acid, washed with methanol and then vacuum dried. The dried polymer (A) was weighed and immersed in acetone for 20 hours to swell the polymer (A) with acetone until it became saturated. Thereafter, the mixture was centrifuged at 14000 rpm to separate into an acetone dissolved component and an insoluble component swollen with acetone, and the mass of the insoluble component swollen with acetone was measured. Next, the insolubles swollen with acetone were dried under vacuum, the mass of the insolubles 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 crosslinking.
Degree of swelling (fold) = mass of insoluble matter swollen with acetone (g) / mass of insoluble matter after drying (g) (1)

<Method of measuring graft rate>
The graft polymer (C) was washed with methanol, added to acetone, and heated under reflux at 65 ° C. for 3 hours. The obtained suspended acetone solution was centrifuged at 14000 rpm for 30 minutes in a centrifuge (manufactured by Hitachi Koki Co., Ltd., “CR21E”) to separate into an acetone-dissolved matter and an acetone-insoluble matter. Subsequently, the acetone insoluble matter was dried under vacuum, 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). P in the formula (2) is the mass (g) of the acetone insolubles after drying, and Q is the mass (g) of the polymer (A) used in the production of the graft polymer (C) is there.
Graft ratio (%) = {(P−Q) / Q} × 100 (2)

<Measurement method of graft density>
The number average molecular weight was measured using gel permeation chromatography (GPC) about the acetone solution which was centrifuged by the measuring method of the graft ratio mentioned above. Specifically, the acetone solution was diluted using tetrahydrofuran (THF) as a solvent and introduced into the GPC apparatus. Using a calibration curve previously obtained with a standard polystyrene having a known molecular weight, the polystyrene-equivalent molecular weight of the acetone-dissolved matter was measured to determine the number average molecular weight. And in the following formula (3), the number average molecular weight of the acetone-soluble matter, the grafting ratio (%), the specific gravity (g / cm ² ) of the polymer (A), the polymer (A) dispersed in the aqueous dispersion The grafting density (mol / nm ² ) was calculated by substituting the volume average particle size (nm) of
Graft density (mol / nm ² ) = 1/3 × (volume average particle diameter of polymer (A) (nm)) × 1⁄2 × specific gravity of polymer (A) (g / cm ³ ) × grafting ratio %) × (1 / (number-average molecular weight of acetone solution)) (3)

<Evaluation of impact resistance>
Pellets of the thermoplastic resin composition are molded by an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machine Co., Ltd.) at a cylinder temperature of 200 to 270 ° C., a mold temperature of 60 ° C., and an injection speed of 25 g / sec. A molded article (i) having a length of 80 mm, a width of 10 mm and a thickness of 4 mm was obtained.
The obtained molded product (i) was subjected to a Charpy impact test (with a V notch having a thickness of 4 mm) at 23 ° C. in accordance with the ISO 179 standard, and the Charpy impact strength was measured.

<Evaluation of surface appearance>
Pellets of the thermoplastic resin composition are injection molded with a cylinder temperature of 200 to 270 ° C., a mold temperature of 60 ° C., and an injection speed of 40 g / sec using an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machine Co., Ltd.) A molded article (ii) having a length of 100 mm, a width of 100 mm and a thickness of 2 mm was obtained.
About the obtained molded article (ii), the reflectance (%) of the surface of the molded article (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 holding pellets of the thermoplastic resin composition at 230 ° C. for 20 minutes in an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machine Co., Ltd.), cylinder temperature 200 to 270 ° C., mold temperature 60 ° C. A 100 mm long, 100 mm wide, 2 mm thick molded article was continuously injection molded at an injection speed of 40 g / sec, and a fifth shot was obtained as a molded article (iii).
About the obtained molded article (iii), the reflectance (%) of the surface of the molded article (iii) at an incident angle of 60 ° and a reflection angle of 60 ° is measured using a gloss meter, and the gloss is maintained from the following formula (4) The rate was determined. The higher the gloss retention, the better the thermal stability.
Gloss retention (%) = (reflectance of molded article (iii) / reflectance of molded article (ii)) × 100 (4)

<Measurement of fluidity (melt volume rate: MVR)>
The MVR of the thermoplastic resin composition at 220 ° C. was measured at a load of 98 N (10 kg) according to the ISO 1133: 1997 standard. In addition, MVR becomes a standard of the fluidity of the thermoplastic resin composition, and means that the larger the numerical value, the better the fluidity.

<Appearance evaluation of molding condition dependency>
(Appearance evaluation of molded articles (1))
Pellets of the thermoplastic resin composition are injection molded with a cylinder temperature of 200 to 270 ° C., a mold temperature of 60 ° C., and an injection speed of 7 g / sec using an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machine Co., Ltd.) A molded product (iv) having a length of 100 mm, a width of 100 mm and a thickness of 3 mm was obtained.
The lightness L ^* of the obtained molded product (iv) was measured by the SCE method using a spectrocolorimeter ("CM-3500d" manufactured by Konica Minolta Optips Co., Ltd.). Let L ^* thus measured be “L ^* (iv)”. The lower the L ^* , the blacker, which means that the appearance is good.

(Evaluation of appearance of molded product (2))
Pellets of the thermoplastic resin composition are injection molded with a cylinder temperature of 200 to 270 ° C., a mold temperature of 60 ° C., and an injection speed of 128 g / sec using an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machine Co., Ltd.) A molded product (v) having a length of 100 mm, a width of 100 mm and a thickness of 3 mm was obtained.
The lightness L ^* of the obtained molded product (v) was measured by the SCE method using a spectrocolorimeter ("CM-3500d" manufactured by Konica Minolta Optips Co., Ltd.). Let L ^* measured in this way be "L ^* (v)".
When molding is performed under conditions where the injection speed is high, the rubber component in the resin is oriented to cause whitening and bronzing, which tends to increase L ^* . Therefore, the molding appearance under the condition of high injection speed is important. The lower the L ^* , the blacker, which means that the appearance is good.

(Appearance evaluation of molded articles (3))
The difference (ΔL ^* = L ^* (v) −L ^* (iv)) between L ^* of the molded article (iv) and the molded article (v) was determined.
Generally, in molded articles such as vehicle parts, the injection speed varies depending on the part location. Therefore, in the case of a resin having a large injection speed dependency, appearance defects occur such as color unevenness occurring on the surface of the part during molding. As ΔL ^* is smaller, it is less likely to cause color unevenness caused by the shape of a molded product etc., and the molding condition dependency (injection velocity dependency) of the molding appearance is smaller.

"Example 1-1"
<Production of Polymer (A)>
In a reaction vessel equipped with a reagent injection vessel, a cooling pipe, a jacket heater and a stirrer, 300 parts of deionized water, 1 part of dipotassium alkenyl succinate, 0.2 parts of t-butyl hydroperoxide, and (Aa) component 99.7 parts of butyl acrylate and 0.3 parts of pentaerythritol triaryl ether as component (Ab) were added, and the inside of the reaction vessel was substituted with nitrogen for 1 hour, and then the temperature was raised to 55.degree.
Then, 0.3 parts of sodium formaldehyde sulfoxylate, 0.0001 parts of ferrous sulfate heptahydrate, 0.0003 parts of disodium ethylenediaminetetraacetate, and 10 parts of deionized water are added to a reaction vessel, The polymerization was started. After the heat of polymerization was confirmed, the jacket temperature was raised to 75 ° C., the polymerization was continued until the heat of polymerization was not confirmed, and the polymer was kept for 1 hour to obtain a latex of the polymer (A1).
The volume average particle diameter of the obtained polymer (A1) was 113 nm, and the degree of swelling was 18 times.

<Production of Graft Polymer (C)>
In a reaction vessel equipped with a reagent injection vessel, a cooling pipe, a jacket heater and a stirrer, 230 parts of deionized water, 50 parts of the latex of the polymer (A1) in terms of solid content, and 0.5% dipotassium alkenyl succinate Parts and 0.3 parts of sodium formaldehyde sulfoxylate were charged, the inside of the reaction vessel was replaced with nitrogen for 1 hour, and the temperature was raised to 70 ° C. while stirring. In addition, the mass of deionized water in the latex of the polymer (A1) is also included in the charged amount of deionized water.
Then, the temperature of the mixture was raised to 80 ° C. while a mixture consisting of 15 parts of acrylonitrile, 35 parts of styrene and 0.5 parts of t-butyl hydroperoxide was dropped into the reaction vessel over 100 minutes. After completion of the dropwise addition, the resultant was maintained at 80 ° C. and cooled to obtain a latex of a graft polymer (C1). Next, the latex of the graft polymer (C1) was coagulated 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 54%.

"Examples 1-2 to 1-4"
Polymers (A2) to (A4) were obtained in the same manner as in Example 1-1 except that the amounts of butyl acrylate and pentaerythritol triallyl ether were changed as shown in Table 1. The volume average particle size and the degree of swelling of the polymers (A2) to (A4) were measured. The results are shown in Table 1.
Graft polymers (C2) to (C4) were obtained in the same manner as in Example 1-1 except that the obtained polymers (A2) to (A4) were used. The grafting rate was measured for the graft polymers (C2) to (C4). The results are shown in Table 1.

"Examples 2-1 to 2-4, 3-1 to 3-4, 4-1 to 4-4"
Example 1-1 is the same as Example 1-1 except that the polyfunctional acrylates of the types shown in Tables 1 and 2 are used as the component (Ab) and the preparation amounts of butyl acrylate and polyfunctional compounds are changed as shown in Tables 1 and 2. The polymers (A5) to (A16) were obtained. The volume average particle size and the degree of swelling of the polymers (A5) to (A16) were measured. The results are shown in Tables 1 and 2.
Graft polymers (C5) to (C16) were obtained in the same manner as in Example 1-1 except that the obtained polymers (A5) to (A16) were used. The grafting rate was measured for the graft polymers (C5) to (C16). The results are shown in Tables 1 and 2.

"Comparative Examples 1-1 to 1-4, 2-1 to 2-4, 3-1 to 3-4, 4-1 to 4-4, 5-1 to 5-4"
Example 1-1 is the same as Example 1-1 except that the polyfunctional acrylates of the types shown in Tables 3 and 4 are used as the component (A2) and the preparation amounts of butyl acrylate and polyfunctional compounds are changed as shown in Tables 3 and 4 The polymers (A17) to (A36) were obtained. The volume average particle size and the degree of swelling of the polymers (A17) to (A36) were measured. The results are shown in Tables 3 and 4.
Graft polymers (C17) to (C36) were obtained in the same manner as in Example 1-1 except that the obtained polymers (A17) to (A36) were used. The graft ratio was measured for the graft polymers (C17) to (C36). The results are shown in Tables 3 and 4.

 

 

The abbreviations in Tables 1 to 4 are as follows.
Ab-1: Pentaerythritol triallyl ether Ab-2: trimethylolpropane triallyl ether Ab-3: pentaerythritol diallyl ether Ab-4: trimethylolpropane diallyl ether Ab-5: pentaerythritol triacryloyl Ab-6: trimethylolpropane triacryloyl Ab-7: allyl methacrylate Ab-8: triallyl isocyanurate Ab-9: triallyl cyanurate

As apparent from Tables 1 and 2, the polymers of the respective examples using branched polyfunctional compounds having two or more allyl groups and in which all carbon-carbon double bonds are derived from the allyl group (A) had a high degree of swelling, ie, a low degree of crosslinking. Moreover, the graft polymer (C) obtained using the polymer (A) of each Example had a high graft ratio.
Thus, according to the present invention, a polymer (A) which can achieve a high grafting rate when grafted while having a low crosslinking degree can be obtained.

On the other hand, as apparent from Tables 3 and 4, in the case of Comparative Examples 1-1 to 1-4 and 2-1 to 2-4 using a polyfunctional compound having no allyl group, the polymers (A) The degree of crosslinking was high, and the graft ratio of the graft polymer (C) was low.
In the case of Comparative Examples 3-1 to 3-4 using a polyfunctional compound having a carbon-carbon double bond derived from a methacroyl group in addition to a carbon-carbon double bond derived from an allyl group, crosslinking of the polymer (A) When the degree is low, the graft ratio of the graft polymer (C) is low, and when it is attempted to obtain a graft polymer (C) having a high graft ratio, the degree of crosslinking of the polymer (A) tends to be high.
In Comparative Examples 4-1 to 4-4 and 5-1 to 5-4 using a polyfunctional compound having a cyclic structure instead of a branched one having three allyl groups, the degree of crosslinking of the polymer (A) When the value of V is low, the graft ratio of the graft polymer (C) is low, and when it is attempted to obtain a graft polymer (C) having a high graft ratio, the degree of crosslinking of the polymer (A) tends to be high.

"Examples 5 to 13"
Using a polymer (A) of the type shown in Table 5, a graft polymer (C) of the type shown in Table 5 was obtained in the same manner as in Example 1-1.
40 parts of the obtained graft polymer (C) and 60 parts of an acrylonitrile-styrene copolymer ("GMS ABS Co., Ltd.," AXS resin 202N ") as another thermoplastic resin (D) are mixed, The mixture was melt-kneaded at 220 ° C. using a screw extruder (“TEX-28V” manufactured by Japan Steel Works, Ltd.) to obtain a pellet-like thermoplastic resin composition.
The impact resistance, the surface appearance and the thermal stability were evaluated for a molded article obtained by injection molding the obtained thermoplastic resin composition. The results are shown in Table 5.

"Comparative Examples 6 to 17"
Using a polymer (A) of the type shown in Table 6, a graft polymer (C) of the type shown in Table 6 was obtained in the same manner as Example 1-1.
40 parts of the obtained graft polymer (C) and 60 parts of an acrylonitrile-styrene copolymer ("GMS ABS Co., Ltd.," AXS resin 202N ") as another thermoplastic resin (D) in a twin-screw extruder The mixture was melt-kneaded at 220 ° C. using (manufactured by Japan Steel Works, Ltd., “TEX-28V”) to obtain a pellet-like thermoplastic resin composition.
The impact resistance, the surface appearance and the thermal stability were evaluated for a molded article obtained by injection molding the obtained thermoplastic resin composition. The results are shown in Table 6.

As apparent from Table 5, the molded articles obtained in the respective examples were excellent in impact resistance, surface appearance and thermal stability.
On the other hand, as is apparent from Table 6, in the case of each of the comparative examples, it is difficult to achieve both impact resistance and thermal stability, and the molded articles obtained in each of the comparative examples have impact resistance, surface appearance and thermal resistance. Not all of the stability was satisfied.

"Example 14-1"
<Production of Polymer (A)>
400 parts of deionized water, 99.0 parts of n-butyl acrylate as component (Aa), pentaerythritol as component (Ab) in a reactor equipped with a reagent injection container, a cooling pipe, a jacket heater and a stirrer 1.0 part of triallyl ether, 0.10 parts of 1,3-butylene glycol dimethacrylate as other monomers, 0.20 parts of allyl methacrylate, 0.33 parts of dipotassium alkenyl succinate, and a hydrophobic compound 0.6 parts of liquid paraffin and 0.6 parts of dilauroyl peroxide were charged as ultrasonic waves, and sonicated for 20 minutes at an amplitude of 35 μm using “ULTRONIC HOMOGENIZER US-600” manufactured by Nippon Seiki Co., Ltd. under normal temperature By doing this, a pre-emulsion was obtained (mini-emulsification step). The volume average particle diameter of the obtained latex was 350 nm.
The pre-emulsion was heated to 60 ° C. to initiate radical polymerization. The liquid temperature rose to 78 ° C. due to the polymerization. The polymerization was completed by maintaining the temperature at 75 ° C. for 30 minutes (polymerization step) to obtain a polymer (A37) dispersed in an aqueous dispersion having a volume average particle diameter of 300 nm and a degree of swelling of 5.1.

<Production of Graft Polymer (C)>
After producing the polymer (A37), 0.001 part of ferrous sulfate, ethylenediaminetetraacetic acid with respect to 60 parts (as solid content) of the polymer (A37) while keeping the internal temperature of the reactor at 75 ° C. An aqueous solution consisting of 0.003 parts of disodium salt, 0.3 parts of Rongalite and 5 parts of ion-exchanged water was added, followed by an aqueous solution consisting of 0.65 parts of dipotassium alkenyl succinate and 10 parts of ion-exchanged water . Thereafter, a mixture consisting of 13.6 parts of acrylonitrile, 26.4 parts of styrene, and 0.18 parts of t-butyl hydroperoxide was added dropwise over 1 hour and 30 minutes to effect graft polymerization.
After completion of the dropwise addition, 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 Kawaguchi Chemical Industry Co., Ltd., "Anthege W 500") An aqueous solution of 0.2 parts of dipotassium alkenyl succinate in 5 parts of ion-exchanged water was added to obtain an aqueous dispersion of the reaction product. Next, the aqueous dispersion of the reaction product was coagulated with an aqueous sulfuric acid solution, washed with water, and dried to obtain a graft polymer (C37). The graft ratio of the obtained graft polymer (C37) was 54%, and the graft density was 0.069 mol / nm ² .

"Examples 14-2 to 14-7"
Example 14- except that the preparation amounts of n-butyl acrylate, pentaerythritol triarylether, 1,3-butylene glycol dimethacrylate, allyl methacrylate and dipotassium alkenylsuccinate were changed as shown in Tables 7 and 8. In the same manner as in 1, the polymers (A38) to (A43) dispersed in the aqueous dispersion were obtained. The volume average particle size and the degree of swelling of the polymers (A38) to (A43) were measured. The results are shown in Tables 7 and 8.
Graft polymers (C38) to (C43) were obtained in the same manner as in Example 14-1 except that the obtained polymers (A38) to (A43) were used. The graft ratio and the graft density were measured for the graft polymers (C38) to (C43). The results are shown in Tables 7 and 8.

"Example 14-8"
0.33 parts of alkenyl potassium succinate, 175 parts of ion-exchanged water, 98.8 parts of n-butyl acrylate as the component (Aa), 1.2 parts of pentaerythritol triaryl ether as the component (Ab), and the like A mixture of 0.10 parts of 1,3-butylene glycol dimethacrylate and 0.1 parts of t-butyl hydroperoxide was charged to the reactor. After the inside of the reactor was purged with nitrogen by passing a nitrogen stream through the reactor, the temperature was raised to 60.degree. Thereafter, when the internal temperature of the reactor reaches 50 ° C., it comprises 0.00015 parts of ferrous sulfate, 0.00045 parts of ethylenediaminetetraacetic acid disodium salt, 0.24 parts of Rongalite, and 5 parts of ion-exchanged water The aqueous solution was added to initiate polymerization, and the internal temperature was raised to 75 ° C. Further, this state was maintained for 1 hour to obtain a polymer (A44) dispersed in an aqueous dispersion having a volume average particle diameter of 300 nm and a swelling degree of 7.3 times.
A graft polymer (C44) was obtained in the same manner as in Example 14-1 except that the obtained polymer (A44) was used. The graft ratio and graft density were measured for the graft polymer (C44). The results are shown in Table 8.

As apparent from Tables 7 and 8, the polymers (A) of Examples 14-1 to 14-7 subjected to mini-emulsion polymerization have a low degree of swelling, and their crosslinkability is higher than that of Examples 1-1 and the like. The degree of grafting tended to be slightly higher, but the grafting rate of the graft polymer (C) could be increased. The polymers (A) of Examples 14-1 to 14-7 were able to control the graft density of the graft polymer (C).
In Example 14-8, the volume average particle diameter of the polymer (A) is increased without using miniemulsion polymerization, but the swelling degree and graft weight equivalent to those of Examples 14-1 to 14-7 are obtained. The results of grafting rate and grafting density of coalesced (C) were obtained.

"Examples 15 to 22"
Using the polymer (A) of the type shown in Table 9, a graft polymer (C) of the type shown in Table 9 was obtained in the same manner as in Example 14-1.
28 parts of the obtained graft polymer (C), 72 parts of an acrylonitrile-styrene copolymer ("GMS ABS Co., Ltd.," AXS resin 202N ") as another thermoplastic resin (D), 0 parts of carbon black Eight parts were mixed and melt-kneaded at 220 ° C. using a twin-screw extruder (“TEX-28V” manufactured by Japan Steel Works, Ltd.) to obtain a pellet-like thermoplastic resin composition.
The fluidity of the obtained thermoplastic resin composition was evaluated. The results are shown in Table 9.
In addition to impact resistance, surface appearance and thermal stability, molded articles obtained by injection molding the obtained thermoplastic resin composition were evaluated for appearance evaluations (1) to (3) of the molded articles. The results are shown in Table 9.

As apparent from Table 9, the thermoplastic resin compositions obtained in Examples 15 to 22 were excellent in fluidity. In addition, molded articles obtained using these thermoplastic resin compositions were excellent in impact resistance, surface appearance and thermal stability. In addition, the molded product is whitened or bronzed also in the appearance evaluation (2) of the molded product which is excellent in the black appearance of the molded product in the appearance evaluation (1) of the molded product which lowers the injection speed and conversely increases the injection speed. The appearance tended to be less prone to defects. Furthermore, it was shown that the appearance was good also in the appearance evaluation (3) of the molded product, and appearance defects such as color unevenness due to the injection speed which is the molding condition were not easily generated.
Thus, by using the graft polymer of the present invention, a molded article excellent in impact resistance, surface appearance and thermal stability can be obtained. In addition, the thermoplastic resin composition of the present invention is an excellent molding material which is excellent in flowability and moreover, less dependent on molding conditions.

The polymer of the present invention can obtain a graft polymer having a high graft ratio while having a low degree of crosslinking. Therefore, the graft polymer obtained from the polymer of the present invention is suitable as a material of a thermoplastic resin composition from which a molded article excellent in impact resistance, surface appearance and thermal stability is obtained.
According to the thermoplastic resin composition of the present invention, a molded article excellent in impact resistance, surface appearance and thermal stability can be obtained.

Claims (6)

The polymer obtained by polymerizing the mixture containing the following (Aa) component and (Ab) component.
Component (Aa): acrylic ester.
(Ab) Component: A branched polyfunctional compound having two or more allyl groups, and all carbon-carbon double bonds contained in the polyfunctional compound are derived from the allyl group. The component (Ab) is at least one member selected from the group consisting of pentaerythritol tetraallyl ether, pentaerythritol triallyl ether, pentaerythritol diallyl ether, trimethylolpropane triallyl ether and trimethylolpropane diallyl ether. The polymer according to 1. The polymer according to claim 1 or 2, wherein the degree of swelling is 4 to 20 times. The polymer according to any one of claims 1 to 3 includes one or more selected from the group consisting of aromatic vinyl, vinyl cyanide, (meth) acrylic acid ester, N-substituted maleimide and maleic acid. Graft polymer obtained by graft polymerizing a monomer. The graft polymer according to claim 4, having a graft density of 0.065 mol / nm ² or more. A thermoplastic resin composition comprising the graft polymer according to claim 4 and a thermoplastic resin other than the graft polymer.