JP2019147868A - Thermoplastic resin composition and molded article thereof - Google Patents

Abstract

To provide a thermoplastic resin composition excellent in fluidity, heat resistance, impact resistance, color development, and scratch resistance.SOLUTION: The thermoplastic resin composition contains 28-48 mass% of a graft copolymer (A) and 52-72 mass% of a copolymer (B) based on 100 mass% of the total of the graft copolymer (A) and the copolymer (B). The graft copolymer (A) is obtained by polymerizing an aromatic vinyl monomer and a vinyl cyanide monomer onto a composite rubbery polymer (a) having a volume average particle diameter of 50 nm or more and less than 240 nm and comprising a polyorganosiloxane (a-1) and an alkyl (meth)acrylate polymer (a-2). The copolymer (B) is obtained by polymerizing an aromatic vinyl monomer, a (meth)acrylate monomer, and an unsaturated dicarboxylic acid anhydride monomer. The content of the aromatic vinyl monomer unit is 40-68 mass% in 100 mass% of the total of these monomer units.SELECTED DRAWING: Figure 1

Description

  The present invention is a thermoplastic resin composition capable of providing a molded article excellent in fluidity, heat resistance, impact resistance, color development, and scratch resistance, and is formed by molding this thermoplastic resin composition. It relates to molded products.

  By improving the impact resistance of the molded product, not only will the use of the resulting molded product be expanded, but it will also be industrially useful, such as being able to respond to thinner and larger molded products. Become very expensive. Therefore, various techniques have been proposed so far for improving the impact resistance of the obtained molded product. Among these methods, a method for increasing the impact resistance of a molded product by using a resin material in which a rubbery polymer and a hard resin are combined has already been industrialized. Examples of such resin materials include acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene-acrylic ester (ASA) resin, acrylonitrile-ethylene / propylene / non-conjugated diene copolymer-styrene (AES) resin, and the like. Can be mentioned.

  Moreover, when high designability is calculated | required by a molded article, the coating process is performed to the molded article obtained from these resin materials, and high appearance quality is obtained. However, the coating process has problems such as a large environmental load, complicated processes, and high manufacturing costs. Therefore, the coating treatment of the molded product may be omitted. In this case, in addition to mechanical properties such as impact resistance, the molded product is required to have scratch resistance that is not noticeable even when the scratch is attached.

  Furthermore, parts such as automobile grills are becoming larger and more complicated in shape, and high fluidity is required in order to improve moldability.

  Resin materials from which molded articles with good impact resistance can be obtained include copolymers of methyl methacrylate, maleic anhydride, styrene, alkyl acrylate, copolymers of vinyl cyanide and aromatic vinyl, and rubber A polymer using a graft copolymer obtained by graft polymerization of vinyl cyanide and aromatic vinyl is known (Patent Document 1).

  In addition, as a resin material capable of obtaining a molded article having good impact resistance and scratch resistance, a graft copolymer obtained by graft-polymerizing a specific monomer mixture to a crosslinked ethylene / α-olefin copolymer; , N-substituted maleimide or maleic anhydride, aromatic vinyl, and a methacrylic ester resin obtained by polymerizing a monomer mixture containing a methacrylic ester are known (Patent Document 2).

JP-A-2-272050 JP 2014-80525 A

However, since the thermoplastic resin composition described in Patent Document 1 uses butadiene rubber as the graft rubber component, the sliding property is low and the scratch resistance is poor.
The thermoplastic resin composition described in Patent Document 2 uses an ethylene / α-olefin copolymer as a graft rubber component, and thus has excellent slidability and scratch resistance. Low and moldability was poor.

  The present invention is a thermoplastic resin composition capable of providing a molded article excellent in fluidity, heat resistance, impact resistance, color development, and scratch resistance, and is formed by molding this thermoplastic resin composition. The object is to provide a molded product.

  The present invention solves the above problems and includes the following aspects.

[1] The following graft copolymer (A) and copolymer (B) are contained, and the graft copolymer is based on a total of 100% by mass of the graft copolymer (A) and the copolymer (B). A thermoplastic resin composition having a polymer (A) content of 28 to 48 mass% and a copolymer (B) content of 52 to 72 mass%.
Graft copolymer (A): Composite rubber polymer of polyorganosiloxane (a-1) and alkyl (meth) acrylate polymer (a-2) having a volume average particle size of 50 nm or more and less than 240 nm ( a) a graft copolymer (A) obtained by polymerizing a vinyl monomer mixture (m1) containing an aromatic vinyl monomer and a vinyl cyanide monomer to a)
Copolymer (B): A copolymer (B) obtained by polymerizing an aromatic vinyl monomer, a (meth) acrylic acid ester monomer and an unsaturated dicarboxylic acid anhydride monomer. , Based on a total of 100% by mass of the aromatic vinyl monomer unit, the (meth) acrylic acid ester monomer unit, and the unsaturated dicarboxylic anhydride monomer unit contained in the copolymer (B). And a copolymer (B) having an aromatic vinyl monomer unit content of 40 to 68% by mass.

[2] The polyorganosiloxane (a-1) has a vinyl polymerizable functional group-containing siloxane unit of 0.3 to 3 mol% and a dimethylsiloxane unit of 99.7 to 97 mol% (provided that the vinyl polymerizable functional group is contained). The total particle size of siloxane units and dimethylsiloxane units is 100 mol%.), And the alkyl (meth) acrylate in the (meth) acrylate polymer (a-2). The content of the monomeric monomer unit is 80 to 100% by mass with respect to the total mass of all monomeric units constituting the (meth) acrylate polymer (a-2), and the composite rubber polymer Polyorganosiloxane (a-1) in 100 mass% in total of polyorganosiloxane (a-1) and alkyl (meth) acrylate polymer (a-2) in (a) The proportion is 1% by mass or more and less than 25% by mass, and the content of the aromatic vinyl monomer in 100% by mass of the vinyl monomer mixture (m1) is 65 to 82% by mass. The monomer content is 18 to 35% by mass, and the mass ratio of the composite rubber polymer (a) and the vinyl monomer mixture (m1) in the graft copolymer (A) is composite rubber. 10 to 80% by mass of the polymer (a) and 20 to 90% by mass of the vinyl monomer mixture (m1) (however, the total of the composite rubber polymer (a) and the vinyl monomer mixture (m1) The thermoplastic resin composition according to [1], wherein the thermoplastic resin composition is 100% by mass.

[3] Total 100% by mass of the aromatic vinyl monomer unit, the (meth) acrylic acid ester monomer unit, and the unsaturated dicarboxylic anhydride monomer unit contained in the copolymer (B). In contrast, the content of the aromatic vinyl-based monomer unit is 40 to 68% by mass, the content of the (meth) acrylic acid ester-based monomer unit is 20 to 30% by mass, the unsaturated dicarboxylic acid anhydride unit The thermoplastic resin composition according to [1] or [2], wherein the content of the monomer unit is 8 to 20% by mass, and the mass average molecular weight (Mw) of the copolymer (B) is 100,000 to 200,000. object.

[4] A molded product obtained by molding the thermoplastic resin composition according to any one of [1] to [3].

The thermoplastic resin composition of the present invention is excellent in fluidity, and can provide a molded product excellent in heat resistance, impact resistance, color development and scratch resistance under good moldability.
For this reason, the thermoplastic resin composition and molded product thereof of the present invention are useful as vehicle interior / exterior parts, office equipment, home appliances, building materials and the like.

It is explanatory drawing of the evaluation method of scratch resistance in an Example.

  Hereinafter, embodiments of the present invention will be described in detail.

[Definition of terms]
The following definitions of terms apply throughout this specification and the claims.
“Molded product” means a product formed by molding a thermoplastic resin composition.
“Lightness (L ^* )” means a lightness value (L ^* ) among color values in the L ^* a ^* b ^* color system adopted in JIS Z 8729.
The “SCE method” means a method of measuring a color by using a spectrocolorimeter in accordance with JIS Z 8722 and removing specularly reflected light with an optical trap.
“Unit” refers to a structural portion derived from a monomer compound (monomer) before polymerization. For example, “acrylate monomer unit” refers to “acrylate monomer”. "Structural part".
“(Meth) acryl” refers to one or both of “acryl” and “methacryl”. The same applies to “(meth) acrylate”.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention comprises the following graft copolymer (A) and copolymer (B) with respect to a total of 100% by mass of the graft copolymer (A) and copolymer (B). The graft copolymer (A) is contained in an amount of 28 to 48% by mass and the copolymer (B) is contained in an amount of 52 to 72% by mass. This specific graft copolymer (A) and Since the copolymer (B) is contained at a specific ratio, a molded product having excellent fluidity and excellent heat resistance, impact resistance, color development, and scratch resistance can be obtained.
Graft copolymer (A): Composite rubber polymer of polyorganosiloxane (a-1) and alkyl (meth) acrylate polymer (a-2) having a volume average particle size of 50 nm or more and less than 240 nm ( a) and a graft copolymer (A) obtained by polymerizing a vinyl monomer mixture (m1) containing an aromatic vinyl monomer and a vinyl cyanide monomer (hereinafter referred to as “the present invention”). May be referred to as “graft copolymer (A)”.)
Copolymer (B): a copolymer (B) obtained by polymerizing an aromatic vinyl monomer, a (meth) acrylic acid ester monomer, and an unsaturated dicarboxylic acid anhydride monomer. And 100% by mass in total of the aromatic vinyl monomer unit, the (meth) acrylic acid ester monomer unit, and the unsaturated dicarboxylic anhydride monomer unit contained in the copolymer (B). The copolymer (B) having an aromatic vinyl monomer unit content of 40 to 68% by mass (hereinafter sometimes referred to as “copolymer (B) of the present invention”).

[Graft Copolymer (A)]
The graft copolymer (A) of the present invention is a composite rubber of a polyorganosiloxane (a-1) and an alkyl (meth) acrylate polymer (a-2) having a volume average particle diameter of 50 nm or more and less than 240 nm. Is a graft copolymer (A) obtained by polymerizing a vinyl monomer mixture (m1) containing an aromatic vinyl monomer and a vinyl cyanide monomer to a porous polymer (a). .

That is, the graft copolymer (A) of the present invention is obtained by graft polymerization of the vinyl monomer mixture (m1) in the presence of the specific composite rubbery polymer (a). In other words, it consists of a composite rubber polymer (a) portion and a vinyl copolymer portion which is a copolymer of the vinyl monomer mixture (m1).
In the graft copolymer (A), it is difficult to specify how the vinyl monomer mixture (m1) is polymerized in the presence of the composite rubber polymer (a). For example, the vinyl copolymer obtained by polymerizing the vinyl monomer mixture (m1) includes those bonded to the composite rubber polymer (a) and those not bonded to the composite rubber polymer (a). And exist. It is also difficult to specify the molecular weight of the vinyl copolymer bonded to the composite rubber polymer (a), the proportion of structural units, and the like. That is, there is a situation (impossible / unpractical situation) that the graft copolymer (A) cannot be directly specified by its structure or characteristics or is not practical. Accordingly, in the present invention, the graft copolymer (A) is defined as “obtained by polymerizing the vinyl monomer mixture (m1) in the presence of the composite rubbery polymer (a)”. Is more appropriate.

<Polyorganosiloxane (a-1)>
The polyorganosiloxane (a-1) constituting the composite rubber polymer (a) is not particularly limited, but a polyorganosiloxane containing a vinyl polymerizable functional group (vinyl polymerizable functional group-containing polyorganosiloxane) is preferable. Polyorganosiloxane having a vinyl polymerizable functional group-containing siloxane unit and a dimethylsiloxane unit is more preferable.

  Examples of the vinyl polymerizable functional group include a methacryloyl group, an acryloyl group, and a vinyl group.

  The vinyl polymerizable functional group-containing siloxane is not particularly limited as long as it contains a vinyl polymerizable functional group and can be bonded to dimethylsiloxane via a siloxane bond, but considering the reactivity with dimethylsiloxane. Various alkoxysilane compounds containing a vinyl polymerizable functional group are suitable. Specifically, β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethylsilane, methacryloyloxysiloxane such as γ-methacryloyloxypropyldiethoxymethylsilane, δ-methacryloyloxybutyldiethoxymethylsilane; vinylsiloxane such as tetramethyltetravinylcyclotetrasiloxane; p-vinylphenyldimethoxymethylsilane, γ-mercaptopropyldimethoxy And mercaptosiloxanes such as methylsilane and γ-mercaptopropyltrimethoxysilane. These vinyl polymerizable functional group-containing siloxanes may be used alone or in combination of two or more.

  As the dimethylsiloxane, a dimethylsiloxane-based cyclic body having 3 or more members is preferable, and a dimethylsiloxane-based ring having 3 to 7 members is more preferable. Specific examples include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. These dimethylsiloxanes may be used alone or in combination of two or more.

  The content of the vinyl polymerizable functional group-containing siloxane unit is preferably 0.3 to 3 mol% with respect to the total number of moles (100 mol%) of all units constituting the polyorganosiloxane. If the ratio of the vinyl polymerizable functional group-containing siloxane unit is within the above range, the polyorganosiloxane (a-1) and the alkyl (meth) acrylate polymer (a-2) are sufficiently complexed and obtained. It becomes difficult for the polyorganosiloxane (a-1) to bleed out on the surface of the product. Therefore, the color developability, in particular, the color developability of the molded product when colored black is improved, and the impact resistance of the obtained molded product is further improved.

  As the polyorganosiloxane (a-1), the color developability of the molded product when colored black is further improved, so that silicon atoms having three or more siloxane bonds are 0 relative to all silicon atoms in the polyorganosiloxane. It is preferably ˜1 mol%. As a preferable aspect of the polyorganosiloxane (a-1), 0.3 to 3 mol% of a vinyl polymerizable functional group-containing siloxane unit and 99.7 to 97 mol% of a dimethylsiloxane unit (provided that a vinyl polymerizable functional group is contained) The total of the siloxane units and the dimethylsiloxane units is 100 mol%.) And the number of silicon atoms having 3 or more siloxane bonds is 1 mol% or less with respect to the total silicon atoms in the polyorganosiloxane Is mentioned.

  The average particle diameter of the polyorganosiloxane (a-1) is not particularly limited, but is preferably 400 nm or less, more preferably 150 nm or less, because the color forming property of the obtained molded article is further improved. About a lower limit, 20 nm or more is preferable. Here, the average particle size of the polyorganosiloxane (A-1) is a value (volume average particle size) calculated from the particle size distribution obtained by measuring the volume-based particle size distribution using a particle size distribution analyzer. ).

  The polyorganosiloxane (a-1) can be obtained, for example, by polymerizing a siloxane mixture containing dimethylsiloxane and vinyl polymerizable functional group-containing siloxane. The polymerization method is not particularly limited, but emulsion polymerization is preferred.

The emulsion polymerization of the siloxane mixture is usually performed using an emulsifier, water, and an acid catalyst.
As the emulsifier, an anionic emulsifier is preferable. Specific examples include sodium alkylbenzene sulfonate, sodium lauryl sulfonate, sodium polyoxyethylene nonylphenyl ether sulfate, and the like. Among these, sulfonic acid-based emulsifiers such as sodium alkylbenzene sulfonate and sodium lauryl sulfonate are preferable. These emulsifiers may be used alone or in combination of two or more. The amount of the emulsifier used is preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the siloxane mixture. If the usage-amount of an emulsifier is 0.05 mass part or more, a dispersion state will be easy to be stabilized and it will become easy to hold | maintain the emulsification state of a fine particle diameter. On the other hand, if the usage-amount of an emulsifier is 5 mass parts or less, coloring of the molded article resulting from an emulsifier can be suppressed.

  Examples of the acid catalyst include organic acid catalysts such as sulfonic acids (eg, aliphatic sulfonic acid, aliphatic substituted benzene sulfonic acid, aliphatic substituted naphthalene sulfonic acid, etc.); inorganic acids such as mineral acids (eg, sulfuric acid, hydrochloric acid, nitric acid, etc.) A catalyst etc. are mentioned. These acid catalysts may be used alone or in combination of two or more. Among these, aliphatic substituted benzenesulfonic acid is preferable, and n-dodecylbenzenesulfonic acid is particularly preferable in that it is excellent in the stabilizing action of the latex of siloxane latex (La) described later. In addition, when n-dodecylbenzenesulfonic acid and a mineral acid such as sulfuric acid are used in combination, the influence of the color of the emulsifier used in the production of the polyorganosiloxane (a-1) on the color of the molded product can be reduced. Although the addition amount of an acid catalyst should just be determined suitably, it is about 0.1-20 mass parts normally with respect to 100 mass parts of siloxane mixtures.

  The mixing of the acid catalyst may be performed at the timing of mixing the siloxane mixture, the emulsifier and water, or the emulsifier and water are added to the siloxane mixture to emulsify to form a latex (siloxane latex (La)). It may be after Since it is easy to control the particle diameter of the resulting polyorganosiloxane (a-1), it is preferable to mix the siloxane latex (La) and the acid catalyst after making the siloxane latex (La) fine. In particular, it is preferable to drop the finely divided siloxane latex (La) dropwise into the acid catalyst aqueous solution at a constant rate. In addition, when mixing an acid catalyst at the timing which mixes a siloxane mixture, an emulsifier, and water, it is preferable to atomize after mixing these.

  The siloxane latex (La) can be finely divided by using, for example, a homomixer that makes fine particles by a shearing force by high-speed rotation, or a homogenizer that makes fine particles by jet output from a high-pressure generator. Examples of a method of mixing a siloxane mixture, an emulsifier, water, and an acid catalyst, and a method of mixing a finely divided siloxane latex (La) and an acid catalyst include mixing by high-speed stirring, mixing by a high-pressure emulsifier such as a homogenizer Is mentioned. Among these, a method using a homogenizer is preferable because the particle size distribution of the polyorganosiloxane (a-1) can be reduced.

The polymerization temperature is preferably 50 ° C. or higher, and preferably 80 ° C. or higher. In addition, when dripping the micronized siloxane latex (La) in the acid catalyst aqueous solution, the temperature of the acid catalyst aqueous solution is preferably 50 ° C. or higher, and preferably 80 ° C. or higher.
The polymerization time is preferably 2 hours or longer, and more preferably 5 hours or longer when the acid catalyst is mixed at the timing of mixing the siloxane mixture, the emulsifier and water. On the other hand, when the finely divided siloxane latex (La) and the acid catalyst are mixed, it is preferable that the finely divided siloxane latex (La) is dropped into the acid catalyst aqueous solution and held for about 1 hour.

  The polymerization is stopped by cooling the reaction solution and neutralizing the reaction solution with an alkaline substance such as sodium hydroxide, potassium hydroxide, sodium carbonate or the like so that the pH of the reaction solution at 25 ° C. is about 6-8. Can be done by.

  The average particle size of the polyorganosiloxane (a-1) can be controlled by adjusting the composition of the siloxane mixture, the amount of acid catalyst used (the content of the acid catalyst in the acid catalyst aqueous solution), the polymerization temperature, and the like. For example, the average particle size tends to increase as the amount of the acid catalyst used decreases, and the average particle size tends to decrease as the polymerization temperature increases.

<Alkyl (meth) acrylate polymer (a-2)>
The (meth) acrylate polymer (a-2) constituting the composite rubber polymer (a) is a single monomer containing at least one vinyl monomer essentially containing an alkyl (meth) acrylate monomer. It is obtained by polymerizing body components. The monomer component may contain a monomer (other monomer) other than the alkyl (meth) acrylate monomer.

  Examples of alkyl (meth) acrylate monomers include acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate; hexyl methacrylate, methacryl Examples include methacrylic acid alkyl esters such as 2-ethylhexyl acid and n-lauryl methacrylate. These alkyl (meth) acrylate monomers may be used alone or in combination of two or more. Among these, n-butyl acrylate is preferable because the impact resistance of the obtained molded product is further improved.

  In the (meth) acrylate polymer (a-2), the content of the alkyl (meth) acrylate monomer unit is that of all monomer units constituting the (meth) acrylate polymer (a-2). 80-100 mass% is preferable with respect to the total mass, and 90-100 mass% is more preferable.

  Other monomers constituting units other than the alkyl (meth) acrylate monomer units that may be included in the (meth) acrylate polymer (a-2) include alkyl (meth) acrylate monomers. Although it is not particularly limited as long as it can be copolymerized with a monomer, aromatic vinyl monomers (for example, styrene, α-methylstyrene, p-methylstyrene, etc.), vinyl cyanide monomers (for example, acrylonitrile, Methacrylonitrile, etc.). These other monomers may be used individually by 1 type, and may use 2 or more types together.

  The manufacturing method in particular of an alkyl (meth) acrylate type polymer (a-2) is not restrict | limited, It can carry out according to a well-known method.

<Composite rubbery polymer (a)>
The composite rubber polymer (a) constituting the graft copolymer (A) of the present invention is a composite in which a polyorganosiloxane (a-1) and an alkyl (meth) acrylate polymer (a-2) are combined. It is rubber.

  The content ratio of the polyorganosiloxane (a-1) to the alkyl (meth) acrylate polymer (a-2) in the composite rubber polymer (a) is as follows: polyorganosiloxane (a-1) and alkyl (meth) When the total with the acrylate polymer (a-2) is 100% by mass, the proportion of the polyorganosiloxane (a-1) is preferably 1% by mass or more and less than 25% by mass. Within this range, the molded article obtained has better scratch resistance, impact resistance, and color developability.

The volume average particle diameter of the composite rubber polymer (a) is 50 nm or more and less than 240 nm, and preferably 90 or more and less than 160 nm. When the volume average particle diameter is less than 50 nm, the impact resistance of the obtained molded article is lowered, and when the volume average particle diameter exceeds 240 nm, the color developability of the obtained molded article is lowered.
Here, the volume average particle size of the composite rubbery polymer (a) is a value calculated from a particle size distribution obtained by measuring a volume-based particle size distribution using a particle size distribution meter.

  The production method of the composite rubber polymer (a) is not particularly limited, but a plurality of latexes each containing a polyorganosiloxane (a-1) and an alkyl (meth) acrylate polymer (a-2) are heteroaggregated or co-polymerized. Method of enlargement: Monomer forming one polymer in the presence of latex containing either one of polyorganosiloxane (a-1) and alkyl (meth) acrylate polymer (a-2) Examples include a method of polymerizing components to form a composite. In particular, since the volume average particle diameter of the composite rubbery polymer (a) can be easily adjusted to be within the above-described range, the alkyl (meth) acrylate is present in the presence of the latex polyorganosiloxane (a-1). It is preferable to obtain a copolymer latex by radical polymerization of a monomer component containing at least one vinyl monomer having an essential monomer. Alternatively, in the presence of latex polyorganosiloxane (a-1), a monomer component containing one or more vinyl monomers essentially containing an alkyl (meth) acrylate monomer is radically polymerized. A method comprising a step of obtaining a polymer latex (radical polymerization step), and a step of enlarging the polymer latex by mixing the polymer latex and an acid group-containing copolymer latex (enlargement step). preferable. This method preferably further includes a step of adding a condensed acid salt to the polymer latex (a condensed acid salt adding step) after the radical polymerization step and before the enlargement step.

(Radical polymerization process)
In the radical polymerization step, a monomer component containing at least one vinyl monomer having an alkyl (meth) acrylate monomer in the presence of latex polyorganosiloxane (a-1) is radicalized. This is a process of polymerization. A monomer component containing at least one vinyl monomer having an alkyl (meth) acrylate monomer as an essential component may be added to the latex polyorganosiloxane (a-1) all at once. , May be added continuously or intermittently.

  When radically polymerizing a monomer component containing one or more vinyl monomers essentially containing an alkyl (meth) acrylate monomer, a graft crossing agent or a crosslinking agent may be used as necessary. . Examples of the graft crossing agent and the crosslinking agent include allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene, dimethacrylic acid ethylene glycol diester, dimethacrylic acid propylene glycol diester, dimethacrylic acid 1,3-butylene glycol diester. And 1,4-butylene glycol diester of dimethacrylic acid. These may be used individually by 1 type and may use 2 or more types together.

  In radical polymerization, a radical polymerization agent and an emulsifier are usually used. Examples of the radical polymerization initiator include peroxides, azo initiators, redox initiators in which an oxidizing agent and a reducing agent are combined. In these, a redox-type initiator is preferable and especially the sulfoxylate-type initiator which combined ferrous sulfate, ethylenediaminetetraacetic acid disodium salt, sodium formaldehyde sulfoxylate, and hydroperoxide is preferable.

  Although it does not restrict | limit especially as an emulsifier, since it is excellent in the stability of the latex at the time of radical polymerization and a polymerization rate can be raised, various carboxylic acids, such as sodium sarcosinate, fatty acid potassium, fatty acid sodium, alkenyl succinate dipotassium, rosin acid soap, etc. Salts are preferred. Of these, dipotassium alkenyl succinate is preferred because gas generation can be suppressed when the obtained graft copolymer (A) and the thermoplastic resin composition containing the graft copolymer are molded at high temperature. Specific examples of dipotassium alkenyl succinate include dipotassium octadecenyl succinate, dipotassium heptadecenyl succinate, dipotassium hexadecenyl succinate and the like. An emulsifier may be used individually by 1 type and may be used in combination of 2 or more type.

(Blowing process)
The enlargement step is a step of enlarging the copolymer latex by mixing the copolymer latex obtained in the radical polymerization step and the acid group-containing copolymer latex.
The acid group-containing copolymer latex used for enlargement is composed of an acid group-containing monomer, an alkyl (meth) acrylate monomer, and other monomers copolymerizable with these if necessary. It is a latex of an acid group-containing copolymer obtained by polymerizing a monomer component containing.

  As the acid group-containing monomer, an unsaturated compound having a carboxy group is preferable. Examples of the compound include (meth) acrylic acid, itaconic acid, crotonic acid and the like, and (meth) acrylic acid is particularly preferable. An acid group containing monomer may be used individually by 1 type, and may use 2 or more types together.

  Examples of the alkyl (meth) acrylate monomer include esters of acrylic acid and / or methacrylic acid and alcohol having a linear or branched alkyl group having 1 to 12 carbon atoms, such as methyl acrylate, Ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methacrylic acid Examples thereof include isobutyl, t-butyl methacrylate, 2-ethylhexyl methacrylate and the like, and alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms is particularly preferable. Alkyl (meth) acrylate monomers may be used alone or in combination of two or more.

  The other monomer is a monomer copolymerizable with an acid group-containing monomer and an alkyl (meth) acrylate monomer, and an acid group-containing monomer and an alkyl (meth) acrylate monomer It is a monomer other than the body. Other monomers include aromatic vinyl monomers (eg, styrene, α-methylstyrene, p-methylstyrene, etc.), vinyl cyanide monomers (eg, acrylonitrile, methacrylonitrile, etc.), Examples thereof include compounds having two or more polymerizable functional groups (for example, allyl methacrylate, polyethylene glycol ester dimethacrylate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitic acid, etc.). Another monomer may be used individually by 1 type and may use 2 or more types together.

  The amount of these monomers used is such that the proportion of the acid group-containing monomer unit is 5 to 40% by mass as the proportion in the solid content of 100% by mass of the acid group-containing copolymer latex, alkyl (meth) acrylate. An amount such that the system monomer unit is 60 to 95% by mass, an amount such that the other monomer unit is 0 to 48% by mass, and an acid group-containing monomer unit is 8 to 30% by mass, The amount that the alkyl (meth) acrylate monomer unit is 70 to 92% by mass and the amount that the other monomer unit is 0 to 30% by mass are more preferable. When the ratio of the acid group-containing monomer unit is 5% by mass or more and the ratio of the alkyl (meth) acrylate monomer unit is 95% by mass or less, sufficient enlargement ability can be obtained. Further, when the ratio of the acid group-containing monomer unit is 40% by mass or less and the ratio of the alkyl (meth) acrylate monomer unit is 60% by mass or more, a large amount is produced during the production of the acid group-containing copolymer latex. It is possible to suppress the formation of agglomerates. Moreover, if other monomer units are 48 mass% or less, the obtained acid group containing copolymer latex can have sufficient enlargement capability.

The acid group-containing copolymer latex used for enlargement can be produced by a general emulsion polymerization method.
Examples of emulsifiers used in emulsion polymerization include carboxylic acid-based emulsifiers exemplified by oleic acid, palmitic acid, stearic acid, alkali metal salts of rosin acid, alkali metal salts of alkenyl succinic acid, etc .; alkyl sulfate esters, alkylbenzene sulfones Known emulsifiers such as anionic emulsifiers selected from sodium acid, sodium alkylsulfosuccinate, sodium polyoxyethylene nonylphenyl ether sulfate and the like can be mentioned. These emulsifiers may be used alone or in combination of two or more.

  As a method of using the emulsifier, the whole amount may be added all at once in the initial stage of polymerization, or may be added continuously or intermittently. Depending on the amount of emulsifier and how it is used, the particle size of the acid group-containing copolymer latex may eventually affect the particle size of the composite rubber polymer (a) latex with an enlarged particle size. It is preferred to select the correct amount and method of use.

  As a polymerization initiator used for emulsion polymerization, a thermal decomposition initiator, a redox initiator, or the like can be used. Examples of the thermal decomposition type initiator include potassium persulfate, sodium persulfate, and ammonium persulfate. Examples of the redox type initiator include organic peroxides represented by cumene hydroperoxide-sodium formaldehyde sulfoxylate-iron. Combinations of salts and the like are exemplified. These polymerization initiators may be used alone or in combination of two or more.

  In the case of emulsion polymerization, a chain transfer agent such as mercaptans (for example, t-dodecyl mercaptan, n-octyl mercaptan, etc.), terpinolene, α-methylstyrene dimer or the like is used to adjust the molecular weight or the pH is adjusted. Therefore, an electrolyte can be added as an alkali, an acid, or a thickener.

  The addition amount of acid group-containing copolymer latex in the enlargement step (solid content conversion amount) may be adjusted so that the volume average particle diameter of the composite rubbery polymer (a) is within the above-described range. Usually, 0.1-5 mass parts is preferable with respect to 100 mass parts of solid content of the copolymer latex obtained at a radical polymerization process, and 0.3-3 mass parts is more preferable. If the addition amount of the acid group-containing copolymer latex is 0.1 parts by mass or more, the enlargement proceeds sufficiently. Moreover, it can suppress that agglomerates generate | occur | produce in large quantities. On the other hand, if the addition amount of the acid group-containing copolymer latex is 5 parts by mass or less, the pH of the enlarged latex can be suppressed from being lowered, and the latex is less likely to become unstable. The acid group-containing copolymer latex may be added all at once to the copolymer latex, or may be added continuously or intermittently by dropping.

  It is preferable to appropriately control stirring during enlargement. If the stirring is insufficient, the unexpanded rubbery polymer may remain due to local enlargement. On the other hand, if the stirring is performed excessively, the enlarged latex becomes unstable and a large amount of agglomerates may be generated. Although the temperature in particular when performing enlargement is not restrict | limited, 20-90 degreeC is preferable and 30-80 degreeC is more preferable. If the temperature is outside this range, the enlargement may not proceed sufficiently.

  In addition, the composite rubber polymer (a) is enlarged using an acid group-containing copolymer latex as described above, and then a vinyl monomer having an alkyl (meth) acrylate monomer as an essential component is used. You may manufacture by further adding and polymerizing the monomer component containing 1 or more types.

(Condensate addition process)
Prior to the enlargement step, it is more preferable to add a condensed acid salt to the copolymer latex. If a condensation salt is added to the copolymer latex before the acid group-containing copolymer latex is added, the addition of the acid group-containing copolymer latex can be reduced because the enlargement tends to proceed. It becomes possible, and it becomes easy to adjust the volume average particle diameter of the composite rubbery polymer (a) within the above-mentioned range.

  As the condensed acid salt, for example, a salt of a condensed acid such as phosphoric acid or silicic acid and an alkali metal and / or alkaline earth metal is used. Among these, pyrophosphoric acid and alkali metal salts which are condensed acids of phosphoric acid are preferable, and sodium pyrophosphate or potassium pyrophosphate is particularly preferable.

  The addition amount of the condensed acid salt may be adjusted so that the volume average particle diameter of the composite rubber polymer (a) is within the above-mentioned range. Usually, the copolymer latex obtained in the radical polymerization step is used. It is preferable to set it as 0.1-5 mass parts with respect to 100 mass parts of solid content, and 0.3-3 mass parts is more preferable. When the addition amount of the condensed acid salt is 0.1 parts by mass or more, the enlargement is sufficiently advanced, and when it is 5 parts by mass or less, the enlargement is sufficiently advanced, or the rubber latex is easily stabilized, and a large amount of aggregation is caused. The generation of lumps can be suppressed. The condensed acid salt is preferably added to the copolymer latex all at once.

  The pH of the mixture of copolymer latex and condensed acid salt at 25 ° C. is preferably 7 or more. If the pH is 7 or more, enlargement is likely to proceed sufficiently. In order to make pH 7 or more, general alkali compounds, such as sodium hydroxide and potassium hydroxide, can be used.

<Vinyl monomer mixture (m1)>
The vinyl monomer mixture (m1) is a monomer mixture containing at least an aromatic vinyl monomer and a vinyl cyanide monomer.

Examples of the aromatic vinyl monomer include styrene, α-methyl styrene, o-, m- or p-methyl styrene, vinyl xylene, pt-butyl styrene, ethyl styrene, etc. Styrene and α-methylstyrene are preferred from the viewpoint of the fluidity of the plastic resin composition, the color developability of the resulting molded product, and the impact resistance. An aromatic vinyl-type monomer may be used individually by 1 type, and may be used in combination of 2 or more type.
The content of the aromatic vinyl monomer is preferably 65 to 82% by mass, more preferably 73 to 80% by mass, and further preferably 75 to 80% by mass in 100% by mass of the vinyl monomer mixture (m1). . When the content of the aromatic vinyl monomer is within the above range, the resulting molded article is further excellent in impact resistance and color development.

  Examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile. A vinyl cyanide monomer may be used individually by 1 type, and may be used in combination of 2 or more type. The content of the vinyl cyanide monomer is preferably 18 to 35% by mass, more preferably 20 to 27% by mass, and further preferably 20 to 25% by mass in 100% by mass of the vinyl monomer mixture (m1). . When the content of the vinyl cyanide monomer is within the above range, the resulting molded article is further excellent in impact resistance and color development.

  In addition to the aromatic vinyl monomer and the vinyl cyanide monomer, the vinyl monomer mixture (m1) does not impair the effects of the present invention by using other monomers copolymerizable therewith. It may be included in the range. Other monomers include acrylic acid esters (methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, etc.), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, etc.) ), Maleimide compounds (N-cyclohexylmaleimide, N-phenylmaleimide, etc.) and the like. Another monomer may be used individually by 1 type and may be used in combination of 2 or more type.

<Graft copolymer (A)>
The graft copolymer (A) is a graft copolymer obtained by polymerizing the vinyl monomer mixture (m1) in the presence of the composite rubber polymer (a).

  The method for polymerizing the vinyl monomer mixture (m1) in the presence of the composite rubber polymer (a) is not particularly limited, but it is emulsified because the reaction can be controlled to proceed stably. Polymerization is preferred. Specifically, a method in which a vinyl-based monomer mixture (m1) is charged all at once into the composite rubber polymer (a) and then polymerized; a vinyl-based monomer mixture ( A method in which a part of m1) is first charged and the rest is dropped into the polymerization system while polymerizing as needed; the composite rubber-like polymer (a) is polymerized at any time while dropping the entire amount of the vinyl monomer mixture (m1). The method etc. are mentioned, These can be divided into 1 step | paragraph or 2 steps | paragraphs or more. It is also possible to change the kind and composition ratio of the vinyl monomer mixture (m1) in each stage.

  The mass ratio of the composite rubber polymer (a) and the vinyl monomer mixture (m1) is not particularly limited, but the balance between impact resistance and color developability of the obtained molded product becomes better. The composite rubber polymer (a) is preferably 10 to 80% by mass, the vinyl monomer mixture (m1) is preferably 20 to 90% by mass, and the composite rubber polymer (a) is preferably 30 to 70% by mass. %, And the vinyl monomer mixture (m1) is particularly preferably 30 to 70% by mass (however, the total of the composite rubbery polymer (a) and the vinyl monomer mixture (m1) is 100% by mass. And). When the graft polymerization is performed at such a mass ratio, the fluidity of the resulting thermoplastic resin composition, and the impact resistance and color developability of the molded product are further improved.

  In the graft polymerization, a radical polymerization initiator and an emulsifier are usually used. Examples of these radical polymerization initiators and emulsifiers include the radical polymerization initiators and emulsifiers exemplified above in the description of the method for producing the composite rubber polymer (a). Moreover, when performing radical polymerization, in order to control the molecular weight and graft ratio of the obtained graft copolymer (A), you may add various well-known chain transfer agents.

  The graft copolymer (A) is usually obtained in a latex state. As a method for recovering the graft copolymer (A) from the latex of the graft copolymer (A), for example, the latex of the graft copolymer (A) is poured into hot water in which a coagulant is dissolved. Examples thereof include a wet method of coagulating in a slurry state; a spray drying method of recovering the graft copolymer (A) semi-directly by spraying the latex of the graft copolymer (A) in a heated atmosphere.

  Examples of the coagulant used in the wet method include inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid; metal salts such as calcium chloride, calcium acetate, and aluminum sulfate, and are selected according to the emulsifier used in the polymerization. . For example, when only a carboxylic acid soap such as fatty acid soap or rosin acid soap is used as an emulsifier, one or more of the above-mentioned coagulants can be used. Further, when an emulsifier exhibiting a stable emulsifying power even in an acidic region such as sodium alkylbenzene sulfonate is used as the emulsifier, a metal salt is suitable as the coagulant.

  When a wet method is used, a slurry-like graft copolymer (A) is obtained. As a method for obtaining the dried graft copolymer (A) from the slurry graft copolymer (A), first, the remaining emulsifier residue is eluted and washed in water, and then the slurry is centrifuged or pressed. Examples include a method of dehydrating with a dehydrator or the like and then drying with an airflow dryer or the like; a method of simultaneously performing dehydration and drying with a press dehydrator or an extruder. By this method, a powder or particulate dry graft copolymer (A) is obtained.

  Although it does not restrict | limit especially as washing | cleaning conditions, It is preferable to wash | clean on the conditions from which the amount of emulsifier residues contained in 100 mass% of graft copolymers (A) after drying becomes the range of 0.3-2 mass%. If the emulsifier residue in the graft copolymer (A) is 0.3% by mass or more, the fluidity of the obtained graft copolymer (A) and the thermoplastic resin composition containing the graft copolymer tends to be further improved. . On the other hand, if the emulsifier residue in the graft copolymer (A) is 2% by mass or less, gas generation can be suppressed when the thermoplastic resin composition is molded at a high temperature. In addition, without recovering the graft copolymer (A) discharged from the press dehydrator or the extruder, it can be directly sent to an extruder or a molding machine for producing the resin composition to obtain a molded product.

[Copolymer (B)]
The copolymer (B) of the present invention is a copolymer obtained by polymerizing an aromatic vinyl monomer, a (meth) acrylic acid ester monomer, and an unsaturated dicarboxylic acid anhydride monomer ( B), a total of 100 aromatic vinyl monomer units, (meth) acrylic acid ester monomer units, and unsaturated dicarboxylic acid anhydride monomer units contained in the copolymer (B). The content of the aromatic vinyl monomer unit is 40 to 68 mass% with respect to mass%.

  Examples of the aromatic vinyl monomer unit contained in the copolymer (B) of the present invention include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, Examples include units derived from styrene monomers such as p-tert-butylstyrene, α-methylstyrene, and α-methyl-p-methylstyrene. Of these, styrene units are preferred. These aromatic vinyl monomer units may be one type or a combination of two or more types.

  (Meth) acrylic acid ester monomer units include methyl methacrylate monomers such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, dicyclopentanyl methacrylate, and isobornyl methacrylate. And units derived from each acrylate monomer such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, and the like. Among these, a methyl methacrylate unit is preferable. These (meth) acrylic acid ester-based monomer units may be one kind or a combination of two or more kinds.

  Examples of the unsaturated dicarboxylic acid anhydride monomer unit include units derived from respective anhydride monomers such as maleic acid anhydride, itaconic acid anhydride, citraconic acid anhydride, and aconitic acid anhydride. These unsaturated dicarboxylic acid anhydride monomer units may be one kind or a combination of two or more kinds. Among these, maleic anhydride monomer units are preferred.

  The copolymer (B) of the present invention contains aromatic vinyl in a total of 100% by mass of aromatic vinyl monomer units, (meth) acrylic acid ester units and unsaturated dicarboxylic acid anhydride monomer units. 40 to 68% by mass of monomer units, preferably 20 to 30% by mass of (meth) acrylic acid ester monomer units, and 8 to 20% by mass of unsaturated dicarboxylic acid anhydride monomer units. . More preferably, the aromatic vinyl monomer unit is 50 to 68% by mass, the (meth) acrylic acid ester monomer unit is 22 to 28% by mass, and the unsaturated dicarboxylic acid anhydride monomer unit is 10 to 18% by mass. is there.

  When the aromatic vinyl monomer unit is 68% by mass or less, the effect of imparting heat resistance to the thermoplastic resin composition is improved. When the (meth) acrylic acid ester monomer unit is 30% by mass or less, the thermal stability is improved and a molded article having a good appearance can be obtained. When the unsaturated dicarboxylic acid anhydride monomer unit is 20% by mass or less, the thermal stability is improved and a molded article having a good appearance can be obtained. On the other hand, if the aromatic vinyl monomer unit is 40% by mass or more, the heat resistance imparting effect of the thermoplastic resin composition is improved. When the (meth) acrylic acid ester monomer unit is 20% by mass or more, the thermal stability is improved, and a molded product having a good appearance can be obtained. If the unsaturated dicarboxylic acid anhydride monomer unit is 8% by mass or more, the thermal stability is improved, and a molded product having a good appearance can be obtained.

  The copolymer (B) of the present invention can be copolymerized other than aromatic vinyl monomer units, (meth) acrylic acid ester monomer units, and unsaturated dicarboxylic anhydride monomer units. Other vinyl monomer units may be included in the copolymer as long as the effects of the invention are not impaired. In that case, the content of the other vinyl monomer units that can be copolymerized is 100% of copolymer (B). Preferably in the mass%, it is 5 mass% or less. Other copolymerizable vinyl monomer units are derived from monomers such as vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, and vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid. The unit to do is mentioned. Two or more types of copolymerizable vinyl monomer units may be used.

The copolymer (B) of the present invention preferably has a mass average molecular weight (Mw) of 100,000 to 200,000, and more preferably a mass average molecular weight (Mw) of 120,000 to 180,000. If the mass average molecular weight (Mw) is too large, the moldability of the thermoplastic resin composition and the appearance of the resulting molded product may be inferior. If the mass average molecular weight (Mw) is too small, the moldability and the obtained The strength of the molded product may be inferior.
Here, the mass average molecular weight (Mw) of the copolymer (B) is a value in terms of polystyrene by gel permeation chromatography (GPC).

The manufacturing method of the copolymer (B) of this invention is demonstrated below.
There is no particular limitation on the polymerization mode for producing the copolymer (B) of the present invention, and it can be produced by a known method such as solution polymerization or bulk polymerization, but solution polymerization is more preferred. The solvent used in the solution polymerization is preferably non-polymerizable from the viewpoint that a by-product is difficult to produce and that there are few adverse effects. The type of solvent is not particularly limited. For example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and acetophenone, ethers such as tetrahydrofuran and 1,4-dioxane, toluene, ethylbenzene, xylene and chlorobenzene Aromatic hydrocarbons, etc. are mentioned, but methyl ethyl ketone and methyl isobutyl ketone are preferred from the viewpoint of the solubility of the monomer and copolymer and the ease of solvent recovery.

  10-100 mass parts is preferable with respect to 100 mass parts of copolymers (B) obtained, and, as for the addition amount of a solvent, More preferably, it is 30-80 mass parts. If the addition amount of the solvent is 10 parts by mass or more, it is suitable for controlling the reaction rate and the viscosity of the polymerization solution, and if it is 100 parts by mass or less, it is suitable for obtaining a desired mass average molecular weight (Mw). is there.

The polymerization method is not particularly limited, but is preferably a radical polymerization method from the viewpoint that it can be produced with high productivity by a simple process.
The polymerization initiator is not particularly limited. For example, dibenzoyl peroxide, t-butyl peroxybenzoate, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, t-butyl peroxy Known organic compounds such as isopropyl monocarbonate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyacetate, dicumyl peroxide, ethyl-3,3-di- (t-butylperoxy) butyrate Known azo compounds such as peroxides, azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile, azobismethylbutyronitrile, and the like can be used. Two or more of these polymerization initiators can be used in combination. Among these, it is preferable to use an organic peroxide having a 10-hour half-life temperature of 70 to 110 ° C.

  In the polymerization of the copolymer (B), it is preferable to perform polymerization so that the copolymer composition distribution becomes small. That is, since the aromatic vinyl monomer and the unsaturated dicarboxylic acid anhydride monomer have strong alternating copolymerization properties, the aromatic vinyl monomer and the (meth) acrylic acid ester monomer A method of continuously adding unsaturated dicarboxylic acid anhydride monomer so as to correspond to the polymerization rate is preferred. The control of the polymerization rate can be adjusted by the polymerization temperature, the polymerization time, and the addition amount of the polymerization initiator. It is preferable to continuously add a polymerization initiator because the polymerization rate can be more easily controlled. By reducing the copolymer composition distribution, a copolymer (B) excellent in the balance between heat resistance and strength and a molded product containing the same can be obtained.

  Moreover, in order to make the mass average molecular weight (Mw) of the copolymer (B) obtained into a preferable range of 100,000 to 200,000, in addition to the adjustment of the polymerization temperature, the polymerization time, and the addition amount of the polymerization initiator. And a method of adjusting the addition amount of the solvent and the addition amount of the chain transfer agent. Although it does not specifically limit as a chain transfer agent, For example, using well-known chain transfer agents, such as n-dodecyl mercaptan, t-dodecyl mercaptan, and 2, 4- diphenyl-4-methyl- 1-pentene. Can do.

  There is no limitation in particular about the method of collect | recovering the copolymer (B) of this invention from a polymerization reaction liquid, A well-known devolatilization technique can be used. For example, a method in which a polymerization reaction solution is continuously fed to a twin-screw devolatilizing extruder using a gear pump to devolatilize a polymerization solvent, unreacted monomers, and the like. The devolatilizing component including the polymerization solvent, unreacted monomer, etc. is condensed and recovered using a condenser, etc., and the polymerization solvent can be reused by purifying the condensate in a distillation tower. .

[Content Ratio of Graft Copolymer (A) and Copolymer (B)]
The thermoplastic resin composition of the present invention comprises 28 to 48 mass of the graft copolymer (A) with respect to 100 mass% in total of the graft copolymer (A) of the present invention and the copolymer (B) of the present invention. %, And the copolymer (B) is contained in an amount of 52 to 72% by mass. By including the graft copolymer (A) and the copolymer (B) within this limited range, a molded product having excellent fluidity, heat resistance, impact resistance, color development, and scratch resistance is provided. The thermoplastic resin composition can be made.
The thermoplastic resin composition of the present invention comprises 30 to 46 mass% of the graft copolymer (A) with respect to 100 mass% in total of the graft copolymer (A) of the present invention and the copolymer (B) of the present invention. %, And the copolymer (B) is preferably contained in an amount of 54 to 70% by mass.
The thermoplastic resin composition of the present invention may contain only one kind of the graft copolymer (A) of the present invention, and the composition, physical properties and copolymerization of the composite rubbery polymer (a). It may contain two or more of different components. Similarly, the copolymer (B) of the present invention may contain only one type, or may contain two or more types.

[Other thermoplastic resins]
The thermoplastic resin composition of the present invention may contain a thermoplastic resin other than the graft copolymer (A) and the copolymer (B) of the present invention.
Examples of other thermoplastic resins include polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyvinyl chloride, polystyrene, polyacetal, modified polyphenylene ether, ethylene-vinyl acetate copolymer, polyarylate, liquid crystal polyester, polyethylene, polypropylene, and fluorine. Examples thereof include resins and polyamides. Another thermoplastic resin may be used individually by 1 type, and may use 2 or more types together.

  When the thermoplastic resin composition of the present invention contains other thermoplastic resin, in order to effectively obtain the effect of containing the graft copolymer (A) and the copolymer (B) of the present invention, Others in 100% by mass of all resin components in the thermoplastic resin composition of the present invention (usually, the total of the graft copolymer (A) and copolymer (B) of the present invention and other thermoplastic resins) The thermoplastic resin is preferably contained in an amount of 80% by mass or less, particularly 50% by mass or less.

[Various additives]
The thermoplastic resin composition of the present invention may contain various additives as long as the object of the present invention is not impaired. Examples of various additives include antioxidants, lubricants, processing aids, pigments, dyes, fillers, silicone oils, paraffin oils, and the like. These additives may be used individually by 1 type, and may use 2 or more types together.

〔Molding〕
The molded article of the present invention can be obtained by molding the thermoplastic resin composition of the present invention by a known molding method.
Examples of the molding method include injection molding, press molding, extrusion molding, vacuum molding, and blow molding.
The use of the molded article includes vehicle interior / exterior parts, office equipment, home appliances, building materials, etc., and vehicle interior / exterior parts are preferable.
In particular, the thermoplastic resin composition of the present invention is effective for use in vehicle interior / exterior parts because of excellent fluidity and excellent heat resistance, impact resistance, color development, and scratch resistance of the resulting molded product. .

Hereinafter, an example is shown concretely. However, the present invention is not limited to these examples.
In the following, “%” means “mass%” and “part” means “part by mass”.

[Measurement and evaluation method]
Various measurements and evaluation methods in the following examples and comparative examples are as follows.

<Measurement method of mass average molecular weight (Mw)>
Mass average molecular weight in terms of polystyrene using GPC (GPC: “GPC / V2000” manufactured by Waters, column: “Shodex AT-G + AT-806MS” manufactured by Showa Denko KK) and o-dichlorobenzene (145 ° C.) as a solvent. (Mw) was measured.

<Volume average particle diameter>
The volume average particle diameter (MV) was measured using a microtrack (“Nanotrack 150” manufactured by Nikkiso Co., Ltd.) using pure water as a measurement solvent.

<Melting and kneading>
Graft copolymer (A) and copolymer (B) were mixed, and 0.8 parts of carbon black was mixed with 100 parts in total of graft copolymer (A) and copolymer (B). The thermoplastic resin composition was colored and melt kneaded at a cylinder temperature of 200 to 260 ° C. and a vacuum of 93.325 kPa using a twin screw extruder with a 28 mmφ vacuum vent (“TEX-28V” manufactured by Nippon Steel Works, Ltd.). Got. Further, after melt-kneading, pelletization was performed using a pelletizer (“SH type pelletizer” manufactured by Souken Co., Ltd.).

<Molding of molded product for physical property evaluation (Ma1)>
The thermoplastic resin composition was formed into a molded product (Ma1) of 100 × 100 mm (thickness 3 mm) by injection molding.

<Molding of molded product for physical property evaluation (Ma2)>
The thermoplastic resin composition was formed into a molded product (Ma2) having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm by injection molding.

<Fluidity>
For the thermoplastic resin composition, the melt volume rate (MVR) was measured under the condition of 230 ° C. in accordance with the ISO 1133 standard.

<Heat resistance>
With respect to the molded product (Ma1), the deflection temperature under load (° C.) was measured by the flatwise method in accordance with the ISO test method 75 standard, 1.83 MPa, 4 mm.

<Impact resistance>
The molded product (Ma2) was subjected to a Charpy impact test (notched) at 23 ° C. in accordance with ISO 179 standard, and the Charpy impact strength was measured.

<Color development>
For the molded product (Ma1), the lightness L ^* was measured by the SCE method using a spectrocolorimeter (“CM-3500d” manufactured by Konica Minolta Optips). The L ^* measured in this way is referred to as “L ^* (ma)”. The lower L ^* , the more black and the better the color developability.

<Scratch resistance>
As shown in FIG. 1, a rod-like jig 10 having a tip 11 formed in a hemispherical shape was prepared, and a car wash towel (Joiful Car Wash Towel 3p) 12 was placed on the tip 11. The tip part 11 covered with the car wash towel 12 is brought into contact with the surface of the molded product (Ma1) 13 so that the rod-shaped jig 10 is at a right angle, and the tip part 11 is brought into contact with the surface of the molded product (Ma1) 13. Were slid in the horizontal direction (arrow direction in the figure) and reciprocated 100 times. At that time, the applied load was 1 kg. After reciprocating 100 times, the lightness L ^* of the surface of the scratched molded article (Mc) was measured by the SCE method using a spectrocolorimeter. The L ^* measured in this way is referred to as “L ^* (mc)”.
(Determination of scratch resistance)
A determination index ΔL ^* of the degree of conspicuousness of scratches on the molded product (Mc) was calculated from the following formula. As the absolute value of ΔL ^* (mc−ma) is larger, scratches are more conspicuous.
ΔL ^* (mc−ma) = L ^* (mc) −L ^* (ma)

[Production of Graft Copolymer (A)]
<Production of polyorganosiloxane (a-1a)>
96 parts of octamethyltetracyclosiloxane, 2 parts of γ-methacryloxypropyldimethoxymethylsilane and 2 parts of ethyl orthosilicate were mixed to obtain 100 parts of a siloxane mixture. To this was added 300 parts of ion-exchanged water in which 10 parts of sodium dodecylbenzenesulfonate was dissolved, and the mixture was stirred at 10000 rpm for 2 minutes with a homomixer, and then passed once through a homogenizer at a pressure of 30 MPa to provide a stable premixed organosiloxane. Latex was obtained.

  Separately, 2 parts of dodecylbenzenesulfonic acid and 98 parts of ion-exchanged water were injected into a reactor equipped with a reagent injection container, a cooling tube, a jacket heater and a stirring device to prepare a 2% aqueous solution of dodecylbenzenesulfonic acid. . While this aqueous solution was heated to 85 ° C., a premixed organosiloxane latex was added dropwise over 4 hours, and the temperature was maintained for 1 hour after the completion of the addition, followed by cooling. The reaction solution was allowed to stand at room temperature for 48 hours and then neutralized with an aqueous sodium hydroxide solution to obtain a polyorganosiloxane (a-1a) latex. A part of the polyorganosiloxane (a-1a) latex was dried at 170 ° C. for 30 minutes to obtain a solid content concentration of 17.3%. The volume average particle diameter of the polyorganosiloxane (a-1a) dispersed in the latex was 30 nm.

<Production of graft copolymer (A-1)>
In a reactor equipped with a reagent injection container, a condenser tube, a jacket heater and a stirrer, 8.0 parts of polyorganosiloxane (a-1a) latex in terms of solid content, sodium polyoxyethylene alkylphenyl ether sulfate 0 .55 parts was charged, and 190 parts of ion-exchanged water was added and mixed. Thereafter, 42.0 parts of n-butyl acrylate, 0.14 part of allyl methacrylate, 0.075 part of 1,3-butylene glycol dimethacrylate and t as monomers constituting the methacrylate polymer (a-2) A mixture consisting of 0.088 parts of butyl hydroperoxide was added. The atmosphere was purged with nitrogen by passing a nitrogen stream through the reactor, and the temperature was raised to 60 ° C. When the temperature inside the reactor reached 60 ° C., 0.0001 part of ferrous sulfate, 0.0003 part of ethylenediaminetetraacetic acid disodium salt and 0.24 part of Rongalite were dissolved in 10 parts of ion-exchanged water. An aqueous solution was added to initiate radical polymerization. The liquid temperature rose to 78 ° C. by polymerization of the (meth) acrylic acid ester component. This state was maintained for 1 hour, and polymerization was continued until no polymerization exotherm was confirmed, thereby obtaining a latex of the composite rubber polymer (a1). The volume average particle diameter of the composite rubber polymer (a1) dispersed in the latex was 91 nm.

  After the liquid temperature inside the reactor dropped to 60 ° C., an aqueous solution in which 0.4 part of Rongalite was dissolved in 10 parts of ion-exchanged water was added. Next, a mixture of 7.5 parts of acrylonitrile, 22.5 parts of styrene and 0.1 part of t-butyl hydroperoxide was added dropwise over about 1 hour for polymerization. After holding for 1 hour after the completion of dropping, an aqueous solution in which 0.0002 part of ferrous sulfate, 0.0006 part of ethylenediaminetetraacetic acid disodium salt and 0.25 part of Rongalite were dissolved in 10 parts of ion-exchanged water was added. Subsequently, a mixed liquid of 5.0 parts of acrylonitrile, 15.0 parts of styrene, and 0.1 part of t-butyl hydroperoxide was dropped over about 40 minutes for polymerization. After the completion of dropping, the mixture was held for 1 hour and then cooled to obtain a latex of graft copolymer (A-1). Next, 150 parts of an aqueous solution in which calcium acetate was dissolved at a rate of 5% was heated to 60 ° C. and stirred. In the calcium acetate aqueous solution, 100 parts of the latex of the graft copolymer (A-1) was gradually dropped and solidified. The obtained solidified product was separated, washed, and dried to obtain a dry powder of the graft copolymer (A-1).

<Production of Graft Copolymers (A-2) to (A-5)>
As shown in Table 1, except that the mass ratio of polyorganosiloxane (a-1a) and n-butyl acrylate and the addition amount (parts) of sodium polyoxyethylene alkylphenyl ether sulfate were changed, the graft copolymer ( In the same manner as in A-1), graft copolymers (A-2) to (A-5) were obtained. Table 1 shows the volume average particle diameter of the composite rubber polymer dispersed in the latex (wherein the graft copolymer (A-8) is not a composite rubber polymer).

<Production of acid group-containing copolymer latex (I-1)>
In a reactor equipped with a reagent injection container, a condenser, a jacket heater and a stirrer, 200 parts of ion exchange water, 2 parts of potassium oleate, 4 parts of sodium dioctylsulfosuccinate, ferrous sulfate heptahydrate 0.003 Part, 0.009 part of ethylenediaminetetraacetic acid disodium salt and 0.3 part of sodium formaldehyde sulfoxylate were charged under a nitrogen stream, and the temperature was raised to 60 ° C. When the temperature reached 60 ° C., a mixture composed of 85 parts of n-butyl acrylate, 15 parts of methacrylic acid and 0.5 part of cumene hydroperoxide was continuously added dropwise over 120 minutes. After completion of the dropwise addition, ripening was further performed for 2 hours while maintaining the temperature at 60 ° C., the solid content was 33%, the polymerization conversion was 96%, and the acid group-containing copolymer had an acid group content of 120 nm. A copolymer latex (I-1) was obtained.

<Production of graft copolymer (A-6)>
In a reactor equipped with a reagent injection container, a condenser, a jacket heater and a stirrer, 4.0 parts of polyorganosiloxane (a-1a) latex in terms of solid content and 0.48 parts of dipotassium alkenyl succinate And 190 parts of ion exchange water were charged and mixed. Next, as a monomer constituting the alkyl (meth) acrylate polymer (a-2), 46 parts of n-butyl acrylate, 0.4 part of allyl methacrylate, 0.09 part of 1,3-butylene glycol dimethacrylate, A mixture consisting of 0.12 parts of t-butyl hydroperoxide was added. The atmosphere was purged with nitrogen by passing a nitrogen stream through the reactor, and the internal temperature was raised to 60 ° C. When the internal temperature reached 60 ° C., from 0.000075 part of ferrous sulfate heptahydrate, 0.00023 part of ethylenediaminetetraacetic acid disodium salt, 0.2 part of sodium formaldehyde sulfoxylate, 10 parts of ion-exchanged water The resulting aqueous solution was added to initiate radical polymerization. After the polymerization exotherm is confirmed, the jacket temperature is set to 75 ° C., and the polymerization is continued until the polymerization exotherm is not confirmed. (Radical polymerization step).
The obtained composite rubber had a volume average particle size of 100 nm.

  After the temperature of the liquid inside the reactor dropped to 70 ° C., 0.20 part of 5% sodium pyrophosphate aqueous solution was added as a solid content. After controlling the internal temperature at 70 ° C., 0.30 part of the acid group-containing copolymer latex (I-1) is added as a solid content, stirred for 30 minutes, enlarged, and the composite rubber polymer (a2) Latex was obtained (blowing process). The obtained latex-like composite rubbery polymer (a2) had a volume average particle diameter of 165 nm. Moreover, the ratio of the particle | grains whose particle diameter is 300-500 nm occupied in all the particles of a composite rubber-like polymer (a2) was 10 volume%. The measurement results are shown in Table 1.

  An aqueous solution comprising 0.001 part of ferrous sulfate heptahydrate, 0.003 part of ethylenediaminetetraacetic acid disodium salt, 0.3 part of Rongalite, and 10 parts of ion-exchanged water is added to the latex of the composite rubber polymer (a2). Was added. Subsequently, a mixed liquid composed of 10 parts of acrylonitrile, 30 parts of styrene, and 0.18 part of t-butyl hydroperoxide was dropped over 80 minutes for polymerization. After completion of dropping, the mixture is kept at a temperature of 75 ° C. for 30 minutes, and then a mixture comprising 2.5 parts of acrylonitrile, 7.5 parts of styrene, 0.05 part of t-butyl hydroperoxide, and 0.02 part of n-octyl mercaptan. Was added dropwise over 20 minutes to polymerize. After completion of the dropwise addition, the state at a temperature of 75 ° C. was maintained for 30 minutes, 0.05 parts of cumene hydroperoxide was added, and the state at a temperature of 75 ° C. was maintained for 30 minutes. In the presence of a2), a latex of a graft copolymer (A-6) obtained by polymerizing acrylonitrile and styrene was obtained. Subsequently, 150 parts of a 1% calcium acetate aqueous solution was heated to 60 ° C., and 100 parts of the latex of the graft copolymer (A-6) was gradually dropped into the solution to solidify. The precipitate was separated, dehydrated, washed and dried to obtain a graft copolymer (A-6).

<Production of Graft Copolymers (A-7) to (A-10)>
The amount of polyorganosiloxane (a-1a), dipotassium alkenyl succinate and n-butyl acrylate, the amount of sodium pyrophosphate used in the enlargement step, and the acid group-containing copolymer latex (I-1) Graft copolymers (A-7) to (A-10) were obtained in the same manner as the graft copolymer (A-6) except that the amount was changed as shown in Table 1. The volume average particle diameter of the composite rubber polymer constituting the graft copolymers (A-6) to (A-10) obtained in each example, and the particle diameter occupied in all the particles of the composite rubber polymer Table 1 shows the ratio of particles having a size of 300 to 500 nm.

[Obtaining or Manufacturing Copolymer (B)]
<Copolymer (B-1)>
As the copolymer (B-1), Density Co., Ltd. Resphi R-100 (65% by mass of styrene units, 25% by mass of methyl methacrylate units, 11% by mass of maleic anhydride units) was used.

<Copolymer (B-2)>
As a copolymer (B-2), Density Co., Ltd. Regisfi R-200 (styrene unit 58 mass%, methyl methacrylate unit 26 mass%, maleic anhydride unit 17 mass%) was used.

<Copolymer (B-3)>
As the copolymer (B-3), Resphi R-310 (Styrene unit 71 mass%, methyl methacrylate unit 10 mass%, maleic anhydride unit 19 mass%) manufactured by Denka Co., Ltd. was used.

<Production Example 4: Production of copolymer (B-4)>
20% maleic anhydride solution dissolved in methyl isobutyl ketone so that maleic anhydride has a concentration of 20% and methyl isobutyl so that t-butylperoxy-2-ethylhexanoate is 2% by mass. A 2% t-butylperoxy-2-ethylhexanoate solution diluted with ketone was prepared in advance and used for polymerization.
A 120 liter autoclave equipped with a stirrer was charged with 8 kg of 20% maleic anhydride solution, 0.8 kg of styrene, 17.6 kg of methyl methacrylate and 30 g of t-dodecyl mercaptan, and the gas phase was replaced with nitrogen gas. Then, the temperature was raised to 88 ° C. over 40 minutes with stirring. While maintaining 88 ° C. after the temperature rise, a 20% maleic anhydride solution was added at a rate of 2.5 kg / hour and a 2% t-butylperoxy-2-ethylhexanoate solution was added at a rate of 250 g / hour, respectively. The addition continued continuously over 6 hours. Thereafter, the addition of the 2% t-butylperoxy-2-ethylhexanoate solution was stopped, and 10 g of t-butylperoxyisopropyl monocarbonate was added. The 20% maleic anhydride solution was heated to 120 ° C. over 2 hours at a temperature increase rate of 16 ° C./hour while maintaining the addition rate of 2.5 kg / hour. The addition of the 20% maleic anhydride solution was stopped when the addition amount reached 20 kg. After the temperature increase, the polymerization was terminated by maintaining 120 ° C. for 1 hour. The polymerization solution was devolatilized from methyl isobutyl ketone and a small amount of unreacted monomer using a known method to obtain a pellet-shaped copolymer (B-4). When the composition of the obtained copolymer (B-4) was analyzed by ¹³ C-NMR method, it was 24% by mass of styrene units, 63% by mass of methyl methacrylate units, and 13% by mass of maleic anhydride units. .

<Production Example 5: Production of copolymer (B-5)>
In a pressure-resistant reaction vessel, 150 parts of distilled water, 20 parts of N-phenylmaleimide, 50 parts of styrene and 30 parts of methyl methacrylate, 0.2 part of 2,2′-azobis (isobutyronitrile), n-octyl Mercaptan (0.25 part) and polyvinyl alcohol (0.7 part) were charged, the internal temperature was raised to 75 ° C., and the reaction was performed for 3 hours. Then, it heated up to 90 degreeC and reaction was completed by hold | maintaining for 60 minutes. The content was washed with a centrifugal dehydrator, dehydrated repeatedly, and dried to obtain a copolymer (B-5).

[Example 1]
Graft copolymer (A-1) 36 parts, copolymer (B-1) 64 parts, carbon black 0.8 parts were mixed and a 28 mmφ vacuum vented twin screw extruder (manufactured by Nippon Steel Works, Ltd. “ TEX-28V ") was melt kneaded at a cylinder temperature of 200 to 260 ° C and a vacuum of 93.325 kPa to obtain a thermoplastic resin composition.
The thermoplastic resin composition was pelletized, and various molded products were molded to evaluate fluidity, impact resistance, color development, and heat resistance. The results are shown in Table 2.

[Examples 2 to 10]
A thermoplastic resin composition was prepared in the same manner as in Example 1 except that the formulation was changed to the formulation shown in Table 2.
The thermoplastic resin composition was pelletized, and various molded products were molded to evaluate fluidity, impact resistance, color development, and heat resistance. The results are shown in Table 2.

[Comparative Examples 1-8]
A thermoplastic resin composition was prepared in the same manner as in Example 1 except that the formulation was changed to the formulation shown in Table 3.
The thermoplastic resin composition was pelletized, and various molded products were molded to evaluate fluidity, impact resistance, color development, and heat resistance. The results are shown in Table 3.

From the above results, the following can be understood.
The thermoplastic resin compositions of Examples 1 to 10 were excellent in fluidity, and the obtained molded articles were excellent in impact resistance, color development, heat resistance, and scratch resistance.
Therefore, when the thermoplastic resin composition of the present invention is used, a molded product excellent in fluidity, impact resistance, color development, heat resistance, and scratch resistance can be obtained, and vehicle interior / exterior parts, office equipment, home appliances, building materials are obtained. It can be seen that the present invention can be applied to such uses.
On the other hand, from the results of Comparative Examples 1 to 8, any one other than the present invention had insufficient fluidity, impact resistance, color development, scratch resistance, or heat resistance.

  Molded articles using the thermoplastic resin composition of the present invention are useful as vehicle interior / exterior parts, office equipment, home appliances, building materials and the like.

10 Jig 11 Tip 12 Car Wash Towel 13 Molded Product (Ma1)

Claims (4)

The following graft copolymer (A) and copolymer (B) are contained, and the graft copolymer (A) and the copolymer (B) are 100% by mass in total with respect to the graft copolymer (A). A thermoplastic resin composition having a content of A) of 28 to 48 mass% and a content of the copolymer (B) of 52 to 72 mass%.
Graft copolymer (A): Composite rubber polymer of polyorganosiloxane (a-1) and alkyl (meth) acrylate polymer (a-2) having a volume average particle size of 50 nm or more and less than 240 nm ( a) a graft copolymer (A) obtained by polymerizing a vinyl monomer mixture (m1) containing an aromatic vinyl monomer and a vinyl cyanide monomer to a)
Copolymer (B): A copolymer (B) obtained by polymerizing an aromatic vinyl monomer, a (meth) acrylic acid ester monomer and an unsaturated dicarboxylic acid anhydride monomer. ,
With respect to a total of 100% by mass of the aromatic vinyl monomer unit, the (meth) acrylic acid ester monomer unit, and the unsaturated dicarboxylic anhydride monomer unit contained in the copolymer (B). A copolymer (B) having an aromatic vinyl monomer unit content of 40 to 68% by mass The polyorganosiloxane (a-1) has a vinyl polymerizable functional group-containing siloxane unit of 0.3 to 3 mol% and a dimethylsiloxane unit of 99.7 to 97 mol% (provided that the vinyl polymerizable functional group-containing siloxane unit and The total particle size of dimethylsiloxane units is 100 mol%.)
In the (meth) acrylate polymer (a-2), the content of alkyl (meth) acrylate monomer units is all monomer units constituting the (meth) acrylate polymer (a-2). 80 to 100% by mass relative to the total mass of
Ratio of polyorganosiloxane (a-1) in a total of 100% by mass of polyorganosiloxane (a-1) and alkyl (meth) acrylate polymer (a-2) in the composite rubber polymer (a) Is 1% by mass or more and less than 25% by mass,
The content of the aromatic vinyl monomer in 100% by mass of the vinyl monomer mixture (m1) is 65 to 82% by mass, and the content of the vinyl cyanide monomer is 18 to 35% by mass. Yes, the mass ratio of the composite rubber polymer (a) and the vinyl monomer mixture (m1) in the graft copolymer (A) is 10 to 80% by mass of the composite rubber polymer (a). The monomer mixture (m1) is 20 to 90% by mass (however, the total of the composite rubbery polymer (a) and the vinyl monomer mixture (m1) is 100% by mass). The thermoplastic resin composition according to claim 1.   With respect to a total of 100% by mass of the aromatic vinyl monomer unit, the (meth) acrylic acid ester monomer unit, and the unsaturated dicarboxylic acid anhydride monomer unit contained in the copolymer (B). The content of aromatic vinyl monomer units is 40 to 68% by mass, the content of (meth) acrylic acid ester monomer units is 20 to 30% by mass, unsaturated dicarboxylic anhydride monomer units. The thermoplastic resin composition according to claim 1 or 2, wherein the content of is 20 to 20% by mass, and the mass average molecular weight (Mw) of the copolymer (B) is 100,000 to 200,000.   A molded article obtained by molding the thermoplastic resin composition according to any one of claims 1 to 3.

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