Polysiloxane-containing graft copolymer, resin composition using the same, and molded article comprising the same

Abstract

To provide a polyorganosiloane-containing graft copolymer which has improved impact resistance while maintaining its inherent rigidity as a thermoplastic resin, and which exhibits, in a molded product obtained from a thermoplastic resin, a high color developing property to provide a molded product having excellent appearance, and to provide a thermoplastic resin composition having such properties as mentioned above and a molded product.SOLUTION: Provided is a polyorganosiloane-containing graft copolymer obtained by graft polymerizing a vinyl monomer (b) to a rubber (A) comprising a polyorganosiloxane (A1) and a vinyl polymer (A2), where a refractive index is 1.47-1.60, a weight average particle diameter is more than 50 nm and less than 300 nm, and the rubber (A) contains an aromatic vinyl monomer unit in an amount of more than 30 mass% and 90 mass% or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polyorganosiloxane-containing graft copolymer that maintains the original rigidity of a thermoplastic resin, improves impact resistance, exhibits high color developability in a molded article obtained from the thermoplastic resin, and provides a molded article with excellent appearance.

Background Art

[0002] Thermoplastic resins such as aromatic polycarbonate resins are excellent as general-purpose engineering plastics in terms of transparency, impact resistance, heat resistance, dimensional stability, etc. Due to their excellent properties, they are widely used industrially as materials in the automotive, OA equipment, electrical and electronic fields, etc. In recent years, a method of adding a polyester resin or the like to an aromatic polycarbonate resin has been used for the purpose of improving chemical resistance and fluidity, but in many cases, the impact resistance is insufficient. In order to improve the impact resistance, a method of further adding an impact modifier is used.

[0003] Molded articles obtained from the above resins are being thinned year by year for the purpose of miniaturization, weight reduction, high functionality, etc., and further improvement in impact resistance characteristics and maintenance of rigidity are required. In recent years, for applications such as electrical and electronic equipment casings and household appliances, in order to reduce the cost of products, they may be used without painting, and it is required that the resin itself be colored to develop a desired color tone and that the molded appearance be excellent.

[0004] For example, Patent Document 1 proposes a silicone / acrylic composite rubber-based graft copolymer obtained by graft-polymerizing one or more vinyl monomers onto a composite rubber containing a polyorganosiloxane rubber and a polyalkyl (meth)acrylate rubber, wherein the content of the polyorganosiloxane is 15 to 70% by mass, the content of the composite rubber is 75 to 90% by mass, and the charged amount of iron is 0.0001 to 2 ppm in the graft copolymer latex. However, the graft copolymer described in Patent Document 1 lacks sufficient color-developing property and rigidity.

[0005] Patent Document 2 proposes a polyorganosiloxane-containing graft copolymer obtained by polymerizing one or more vinyl monomers (b) for grafting in the presence of a rubber (A) containing a polyorganosiloxane and a vinyl polymer, wherein the refractive index of the rubber (A) is in the range of 1.47 to 1.56 and the volume average particle diameter is in the range of 300 to 2000 nm. However, since the volume average particle diameter of the graft copolymer described in Patent Document 2 is 300 nm or more, the appearance of the molded product obtained by injection molding is not sufficient.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a polyorganosiloxane-containing graft copolymer that can impart impact resistance while maintaining the original rigidity of a thermoplastic resin, and can obtain a molded product having excellent color-developing property and molding appearance. Another object of the present invention is to provide a thermoplastic resin composition and a molded body having such performance.

Means for Solving the Problems

[0008] The present invention has the following aspects. [1] A polyorganosiloxane-containing graft copolymer obtained by graft polymerizing a vinyl monomer (b) onto a rubber (A) containing a polyorganosiloxane (A1) and a vinyl polymer (A2), having a refractive index of 1.47 to 1.60, a weight average particle diameter of greater than 50 nm and less than 300 nm, and containing an aromatic vinyl unit in the rubber (A) in an amount of more than 30% by mass and 90% by mass or less based on 100% by mass in total of the rubber (A). [2] The polyorganosiloxane-containing graft copolymer according to [1], wherein the rubber (A) contains an alkyl (meth)acrylate unit. [3] The polyorganosiloxane-containing graft copolymer according to any one of [1] or [2], wherein the rubber (A) contains an alkyl (meth)acrylate unit in an amount of more than 0% by mass and 30% by mass or less based on 100% by mass in total of the rubber (A). [4] The polyorganosiloxane-containing graft copolymer according to any one of [1] to [3], wherein the content of the polyorganosiloxane (A1) in the polyorganosiloxane-containing graft copolymer is 1 to 50% by mass. [5] The polyorganosiloxane-containing graft copolymer according to any one of [1] to [4], containing a vinyl polymerizable group-containing silane compound in an amount of more than 0.5% by mass and 10% by mass or less with respect to the polyorganosiloxane (A1). [6] The polyorganosiloxane-containing graft copolymer according to any one of [1] to [5], containing (meth)acrylate in an amount of 50 to 100% by mass with respect to the vinyl monomer (b). [7] A resin composition containing the polyorganosiloxane-containing graft copolymer according to any one of [1] to [6]. [8] The resin composition according to [7], containing a polycarbonate resin and a polyester resin. [9] The resin composition according to [8], wherein the polycarbonate resin is an aromatic polycarbonate resin.

[10] The resin composition according to [8] or [9], wherein the polyester resin is an aromatic polyester resin.

[11] A molded article comprising the thermoplastic resin composition according to any one of [7] to

[10] .

Advantages of the Invention

[0009] According to the present invention, it is possible to provide a polyorganosiloxane-containing graft copolymer capable of providing a resin composition and a molded article that are excellent in impact resistance, color developability, and molding appearance while maintaining the original rigidity of the thermoplastic resin. Further, according to the present invention, it is possible to provide a resin composition and a molded article having such performance.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in detail. In the present invention, “(meth)acrylate” means at least one of “acrylate” and “methacrylate”. In the present invention, the polyorganosiloxane-containing graft copolymer may be simply referred to as “graft copolymer”.

[0011] 〔Polyorganosiloxane-containing graft copolymer〕 The polyorganosiloxane-containing graft copolymer (which may be simply referred to as “graft copolymer”) of the present invention is a polyorganosiloxane-containing graft copolymer obtained by graft-polymerizing a vinyl monomer (b) to a rubber (A) containing a polyorganosiloxane (A1) and a vinyl polymer (A2), having a refractive index of 1.47 to 1.60, a weight average particle diameter of more than 50 nm and less than 300 nm, and containing more than 30% by mass and 90% by mass or less of the aromatic vinyl monomer unit in the rubber (A) based on 100% by mass in total of the rubber (A).

[0012] "Measurement of refractive index" The thin-film polyorganosiloxane-containing graft copolymer is measured at 23°C using an Abbe refractometer in accordance with JIS K 7142 Method A by compression molding.

[0013] The graft copolymer of the present invention preferably has a refractive index of 1.47 to 1.60. By setting it to 1.47 or more, a thermoplastic resin composition excellent in color developability can be obtained, and by setting it to 1.60 or less, a resin composition excellent in low-temperature impact strength can be obtained, which is preferable. The refractive index of the graft copolymer of the present invention can be adjusted to a desired refractive index by adjusting the content of polyorganosiloxane (A1), the vinyl polymer (A2), and the types and amounts of vinyl monomers (b).

[0014] This is because the refractive index of the graft copolymer of the present invention can be predicted as a value calculated using the following formula (Formula 1) described in POLYMER HANDBOOK 4th Edition (Wiley Interscience).

[0015] [[Formula 1]] n = v1n1 + v2n2 + v3n3 + ··· In the formula, "n1, n2, n3, ···" represent the refractive indices of the homopolymers of the respective monomers at 20°C, and the values described in POLYMER HANDBOOK 4th Edition can be used. In the formula, "v1, v2, v3, ···" represent the volume fractions of the respective monomers.

[0016] The weight-average particle diameter of the graft copolymer of the present invention needs to be greater than 50 nm and less than 300 nm. When it is greater than 50 nm, the effect of imparting impact resistance when added to the resin is excellent, and when it is less than 300 nm, it is less likely to cause a decrease in rigidity when added to the resin, and a molded product with an excellent molded appearance without flow marks can be obtained. Also, the preferable range is greater than 50 nm and 250 nm or less, more preferably 100 to 250 nm, and even more preferably 100 to 200 nm.

[0017] As the value of the weight average particle diameter, the value measured by the following method can be adopted. Using a latex of the graft copolymer diluted to a concentration of about 3% with deionized water as a sample, the particle diameter is measured using a CHDF2000 type particle size distribution meter manufactured by MATEC, USA. The median diameter is used as the average particle diameter for the particle diameter.

[0018] The measurement can be carried out under the following standard conditions recommended by MATEC. Cartridge: Dedicated capillary type cartridge for particle separation (product name; C-202) Carrier liquid: Dedicated carrier liquid (product name; 2XGR500) Liquid property of the carrier liquid: Almost neutral Flow rate of the carrier liquid: 1.4 ml / min Pressure of the carrier liquid: Approximately 4,000 psi (2,600 kPa) Measurement temperature: 35 °C Sample usage amount: 0.1 ml Also, as the standard particle diameter substance, 12 types of particles within the particle diameter range of 40 to 800 nm of monodisperse polystyrene with a known particle diameter manufactured by DUKE, USA are used.

[0019] 〔Polyorganosiloxane (A1)〕 Polyorganosiloxane (A1) is a polymer containing organosiloxane units in which at least one organic group is bonded to a silicon atom as a constituent unit. Polyorganosiloxane (A1) can be obtained by polymerizing an organosiloxane or an "organosiloxane mixture" containing one or more components used as necessary, such as an organosiloxane. Components used as necessary include siloxane-based crosslinking agents, siloxane-based graft crosslinking agents, and siloxane oligomers having end-capping groups.

[0020] As the organosiloxane, any of linear organosiloxane, alkoxysilane compound, and cyclic organosiloxane can be used. Among them, alkoxysilane compound and cyclic organosiloxane are preferable, and cyclic organosiloxane is more preferable because of its high polymerization stability and high polymerization rate.

[0021] As the alkoxysilane compound, a bifunctional alkoxysilane compound is preferable, and examples thereof include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, dimethyldipropoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, and the like.

[0022] As the cyclic organosiloxane, those having a 3- to 7-membered ring are preferable, and examples thereof include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, and octaphenylcyclotetrasiloxane. These can be used alone or in combination of two or more. Among these, since the particle size distribution is easy to control, it is preferable that the main component is octamethylcyclotetrasiloxane.

[0023] As the organosiloxane, since a graft copolymer having higher low-temperature impact resistance can be obtained, it is preferable to use an organosiloxane which is cyclic dimethylsiloxane and / or a bifunctional dialkylsilane compound.

[0024] Cyclic dimethylsiloxane is a cyclic siloxane having two methyl groups on a silicon atom, and examples thereof include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane.

[0025] In addition, the bifunctional dialkylsilane compound is a compound having two alkyl groups among the above bifunctional alkoxysilane compounds, and examples thereof include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, and dimethyldipropoxysilane. These can be used alone or in combination of two or more.

[0026] As the siloxane-based crosslinking agent, those having a siloxy group are preferred. By using a siloxane-based crosslinking agent, a polyorganosiloxane having a crosslinked structure can be obtained. Examples of the siloxane-based crosslinking agent include trifunctional or tetrafunctional silane-based crosslinking agents such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetrabutoxysilane. Among them, a tetrafunctional crosslinking agent is preferred, and tetraethoxysilane is more preferred. The content of the siloxane-based crosslinking agent is preferably 0 to 30% by mass, more preferably 0 to 15% by mass, and still more preferably 0 to 5% by mass in 100% by mass of the organosiloxane mixture. By setting the content of the siloxane-based crosslinking agent to 0 to 30% by mass, a graft copolymer having good low-temperature impact resistance can be obtained.

[0027] The vinyl polymerizable group-containing silane compound is a siloxane-based graft crosslinking agent, which has a siloxy group and a functional group polymerizable with a vinyl monomer. By using the vinyl polymerizable group-containing silane compound, a polyorganosiloxane having a functional group polymerizable with a vinyl monomer can be obtained. Since the polyorganosiloxane has a functional group polymerizable with a vinyl monomer, the polyorganosiloxane and the vinyl polymer (A2) described later can have a chemical bond, and the vinyl monomer (b) can be grafted by radical polymerization. Therefore, a graft copolymer excellent in dispersibility and impact strength when added to a resin can be obtained.

[0028] Examples of the vinyl group-containing polymerizable silane compound include siloxanes represented by formula (I). RSiR1n(OR2)(3-n) (I) In formula (I), R1 represents a methyl group, an ethyl group, a propyl group, or a phenyl group. R2 represents an organic group in an alkoxy group, and examples thereof include a methyl group, an ethyl group, a propyl group, or a phenyl group. n represents 0, 1, or 2. R represents any group represented by formulas (I-1) to (I-4).

[0029] CH2=C(R3)-COO-(CH2) p - (I-1) CH2=C(R4)-C6H4- (I-2) CH2=CH- (I-3) HS-(CH2) p - (I-4) In these formulas, R3 and R4 each represent hydrogen or a methyl group, and p represents an integer of 1 to 6.

[0030] Examples of the functional group represented by formula (I-1) include a methacryloyloxyalkyl group. Examples of the siloxane having this group include β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethylsilane, γ-methacryloyloxypropyldiethoxymethylsilane, δ-methacryloyloxybutyldiethoxymethylsilane, and the like.

[0031] These vinyl polymerizable group-containing silane compounds can be used alone or in combination of two or more. The content of the vinyl polymerizable group-containing silane compound is preferably more than 0.5% and 10% by mass or less, more preferably more than 1.0% and 8.0% by mass or less, and even more preferably more than 2.0% and 8.0% by mass or less with respect to 100% by mass of the organosiloxane mixture. By containing the vinyl polymerizable group-containing silane compound in an amount of more than 0.5% and 10% by mass or less, a graft copolymer capable of providing a resin composition having a sufficient proportion of chemical bonds with polyorganosiloxane and a good balance between impact resistance and color development can be obtained.

[0032] The siloxane oligomer having a terminal blocking group refers to a siloxane oligomer having an alkyl group or the like at the terminal of the organosiloxane oligomer and stopping the polymerization of the polyorganosiloxane.

[0033] Examples of the siloxane oligomer having a terminal blocking group include hexamethyldisiloxane, 1,3-bis(3-glycidoxypropyl)tetramethyldisiloxane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, and a siloxane oligomer having a trimethylsilyl group as the terminal blocking group.

[0034] [Method for Producing Polyorganosiloxane (A1)] The production method of the polyorganosiloxane (A1) is not particularly limited. For example, the following production methods can be adopted. First, an organosiloxane mixture containing an organosiloxane, a vinyl group-containing polymerizable silane compound, a siloxane crosslinking agent as required, and a siloxane oligomer having a terminal blocking group as required is emulsified with an emulsifier and water to prepare an emulsion. Then, the mixture is polymerized at a high temperature using an acid catalyst, and then the acid is neutralized with an alkaline substance to obtain a latex of the polyorganosiloxane. In the following description of the production method, the case where an "organosiloxane mixture" is used as the raw material for polymerization will be described, but the same production process can also be applied to the case where "organosiloxane" is used alone.

[0035] In this production method, examples of the method for preparing the emulsion include a method using a homomixer that atomizes with a shearing force by high-speed rotation, a method using a homogenizer that atomizes with a jet output by a high-pressure generator and mixing by high-speed stirring, etc. Among these, the method using a homogenizer is a preferable method because the particle size distribution of the latex of the polyorganosiloxane becomes narrow.

[0036] Examples of the method for mixing the acid catalyst during polymerization include: (1) a method of adding and mixing the acid catalyst all at once together with the organosiloxane mixture, the emulsifier, and water; (2) a method of adding the acid catalyst aqueous solution all at once into the emulsion of the organosiloxane mixture; (3) a method of dropping the emulsion of the organosiloxane mixture into the hot acid catalyst aqueous solution at a constant rate and mixing, etc. Since it is easy to control the particle size of the polyorganosiloxane, a method of maintaining the emulsion of the organosiloxane mixture at a high temperature and then adding the acid catalyst aqueous solution all at once into it is preferable.

[0037] The polymerization temperature is preferably 50 °C or higher, more preferably 70 °C or higher. Also, when the acid catalyst aqueous solution is added all at once to the emulsion of the organosiloxane mixture for polymerization, the polymerization time is usually 2 hours or more, preferably 5 hours or more.

[0038] Furthermore, since the crosslinking reaction between silanols proceeds at a temperature of 30°C or lower, in order to increase the crosslinking density of the polyorganosiloxane, after polymerization at a high temperature of 50°C or higher, the resulting latex can also be held at a temperature of 30°C or lower for about 5 to 100 hours.

[0039] The polymerization reaction of the organosiloxane mixture can be terminated by neutralizing the reaction system containing the latex to pH 6 - 8 with an alkaline substance such as sodium hydroxide, potassium hydroxide, or aqueous ammonia.

[0040] The emulsifier used in the above production method is not particularly limited as long as it can emulsify the organosiloxane mixture, but an anionic emulsifier or a nonionic emulsifier is preferred. Examples of the anionic emulsifier include sodium alkylbenzene sulfonate, sodium alkyl diphenyl ether disulfonate, sodium alkyl sulfate, sodium polyoxyethylene alkyl sulfate, and sodium polyoxyethylene nonylphenyl ether sulfate. Examples of the nonionic emulsifier include the following: polyoxyethylene alkyl ether, polyoxyethylene alkylene alkyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene tribenzyl phenyl ether, polyoxyethylene polyoxypropylene glycol, etc. These emulsifiers can be used alone or in combination of two or more.

[0041] The amount of the emulsifier used is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the organosiloxane mixture. By adjusting the amount of the emulsifier used, the particle diameter of the polyorganosiloxane latex can be adjusted to a desired value. If the amount of the emulsifier used is 0.05 parts by mass or more, the emulsion stability of the organosiloxane mixture emulsion is sufficient. If the amount of the emulsifier is 10 parts by mass or less, the amount of the emulsifier remaining in the powder of the graft copolymer can be sufficiently reduced, so that the heat resistance to decomposition and the deterioration of the surface appearance of the resin composition containing the graft copolymer and the resin can be suppressed.

[0042] Examples of the acid catalyst used in the polymerization of the organosiloxane mixture include sulfonic acids such as aliphatic sulfonic acids, aliphatic-substituted benzenesulfonic acids, and aliphatic-substituted naphthalenesulfonic acids, and mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid. These acid catalysts can be used alone or in combination of two or more. Among these, when using mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid, the particle size distribution of the polyorganosiloxane latex can be narrowed, and further, a reduction in the heat resistance to decomposition of the molded product due to the emulsifier component in the polyorganosiloxane latex and a reduction in the appearance defect can be achieved.

[0043] The amount of the acid catalyst used is preferably 0.005 to 5 parts by mass per 100 parts by mass of the organosiloxane. If the amount of the acid catalyst used is 0.005 parts by mass or more, the polyorganosiloxane can be polymerized in a short time. If the amount of the acid catalyst used is 5 parts by mass or less, a molded product having good heat resistance to decomposition and appearance can be obtained.

[0044] In addition, since the amount of the acid catalyst used is a factor that determines the particle diameter of the polyorganosiloxane, in order to obtain the polyorganosiloxane having the particle diameter described later, it is more preferable that the amount of the acid catalyst used is 0.005 to 1.5 parts by mass.

[0045] The weight average particle diameter of the polyorganosiloxane in the latex is not particularly limited, but is preferably in the range of 250 to 1000 nm. By setting the weight average particle diameter of the polyorganosiloxane within the range of 250 to 1000 nm, it is possible to adjust the weight average particle diameter of the rubber (A) within the range of 300 to 2000 nm.

[0046] The "weight average particle diameter / number average particle diameter (Dw / Dn)" of the polyorganosiloxane in the latex is preferably in the range of 1.0 to 1.7. By setting Dw / Dn within the range of 1.0 to 1.7, a graft copolymer with high transparency can be obtained when added to the resin.

[0047] As the values of these Dw and Dn, the values measured by the following method can be adopted. Using a sample obtained by diluting the latex of polyorganosiloxane with deionized water to a concentration of about 3%, the particle diameter is measured using a CHDF2000 particle size distribution analyzer manufactured by MATEC, USA. The median diameter is used as the average particle diameter for the particle diameter.

[0048] The measurement can be carried out under the following standard conditions recommended by MATEC. Cartridge: Special capillary cartridge for particle separation (product name; C-202) Carrier liquid: Special carrier liquid (product name; 2XGR500) Liquid property of the carrier liquid: Almost neutral Flow rate of the carrier liquid: 1.4 ml / min Pressure of the carrier liquid: About 4,000 psi (2,600 kPa) Measurement temperature: 35 °C Sample usage amount: 0.1 ml Also, as the standard particle diameter substances, 12 types of particles within the particle diameter range of 40 to 800 nm of monodisperse polystyrene with a known particle diameter manufactured by DUKE, USA, are used.

[0049] In the latex of the polyorganosiloxane obtained by the above method, an emulsifier may be added as necessary for the purpose of improving mechanical stability. As the emulsifier, an anionic emulsifier and a nonionic emulsifier similar to those exemplified above are preferable.

[0050] [Vinyl polymer (A2)] The vinyl polymer (A2) of the present invention includes a polymer obtained by polymerizing an aromatic vinyl monomer for rubber (a1) and other monomer components for rubber (a2), wherein the rubber (A) contains an aromatic vinyl unit in an amount of more than 30% by mass and 90% by mass or less based on 100% by mass in total of the rubber (A).

[0051] [Aromatic vinyl monomer for rubber (a1)] Examples of the aromatic vinyl monomer for rubber (a1) include styrene, α-methylstyrene, o-, m- or p-methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, fluorostyrene, p-tert-butylstyrene, ethylstyrene, vinylnaphthalene, etc. These can be used alone or in combination of two or more.

[0052] Among these, based on 100% by mass in total of the rubber (A), it is necessary to contain an aromatic vinyl unit in an amount of more than 30% by mass and 90% by mass or less. Preferably it is more than 40% by mass and 85% by mass or less, more preferably more than 60% by mass and 80% by mass. By containing an aromatic vinyl unit in an amount of more than 30% by mass, it is excellent in color developability and rigidity when added to the resin, and by containing it in an amount of 90% by mass or less, it is excellent in impact strength and molding appearance.

[0053] [Other monomer components for rubber (a2)] Examples of the other monomer components for rubber (a2) include the following monomers. Methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, i-butyl methacrylate etc. alkyl methacrylate; ethyl acrylate, n-propyl acrylate, n-butyl acrylate, i-butyl acrylate, 2-ethylhexyl acrylate etc. alkyl acrylate; allyl (meth) acrylate; aryl (meth)acrylate in which the ester group is a phenyl group or a substituted phenyl group, such as phenyl (meth)acrylate, 4-t-butylphenyl (meth)acrylate, bromophenyl (meth)acrylate, dibromophenyl (meth)acrylate, 2,4,6-tribromophenyl (meth)acrylate, monochlorophenyl (meth)acrylate, dichlorophenyl (meth)acrylate, trichlorophenyl (meth)acrylate; polyfunctional vinyl monomers such as triallyl cyanurate, triallyl isocyanurate, divinylbenzene, ethylene glycol dimethacrylate diester, propylene glycol dimethacrylate diester, 1,3-butylene glycol dimethacrylate diester, 1,4-butylene glycol dimethacrylate diester, 1,6-hexanediol diacrylate ester, triallyl trimellitate; vinyl cyanide monomers such as acrylonitrile, methacrylonitrile, etc. These can be used alone or in combination of two or more kinds.

[0054] Among these, based on 100% by mass of the total of the rubber (A), it is preferable to contain alkyl (meth)acrylate units and one or more selected from allyl (meth) acrylate units in an amount of more than 0% by mass and 30% by mass or less. By containing alkyl (meth)acrylate units and one or more selected from allyl (meth) acrylate units in an amount of more than 0% by mass, it is excellent in impact strength when added to the resin, and by containing them in an amount of 30% by mass or less, it is excellent in color developability and rigidity when added to the resin.

[0055] The method for producing the vinyl polymer (A2) is not particularly limited, and for example, it can be produced by an emulsion polymerization method, a suspension polymerization method, or a fine suspension polymerization method, but it is preferable to use the emulsion polymerization method.

[0056] As the radical polymerization initiator used for the polymerization of the aromatic vinyl monomer (a1) for rubber and / or other monomer components (a2) for rubber, an azo initiator, a peroxide, and a redox initiator combining a peroxide and a reducing agent are used. These can be used alone or in combination of two or more. Among these, azo initiators and redox initiators are preferred.

[0057] Examples of the azo initiator include the following. Oil-soluble azo initiators such as 2,2'-azobisisobutyronitrile, dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-butyronitrile); water-soluble azo initiators such as 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis[N-(2-carboxymethyl)-2-methylpropionamidine] hydrate, 2,2'-azobis-(N,N'-dimethylenebisobutylamidine) dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, etc. These can be used alone or in combination of two or more.

[0058] Examples of the peroxide include the following. Inorganic peroxides such as hydrogen peroxide, potassium persulfate, ammonium persulfate; organic peroxides such as diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, succinic acid peroxide, t-butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, etc. These can be used alone or in combination of two or more.

[0059] When a peroxide is combined with a reducing agent to form a redox initiator, it is preferable to use the above peroxide in combination with a reducing agent such as sodium formaldehyde sulfoxylate, L-ascorbic acid, fructose, dextrose, sorbose, inositol, etc., and ferrous sulfate disodium ethylenediaminetetraacetate. These reducing agents can be used singly or in combination of two or more.

[0060] The radical polymerization initiator used for the polymerization of the aromatic vinyl monomer (a1) for rubber and other monomer components (a2) for rubber preferably has a solubility in water at 20 °C of 5% by mass or less, more preferably 2% by mass or less. By polymerizing using this radical polymerization initiator, a graft copolymer excellent in low-temperature impact resistance can be obtained.

[0061] Examples of the radical polymerization initiator having a solubility in water at 20 °C of 5% by mass or less include the following. Cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, t-butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, 2,2'-azobisisobutyronitrile, dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-butyronitrile), etc. These can be used singly or in combination of two or more.

[0062] The solubility of the radical polymerization initiator in water at 20 °C can be known from the catalogs of various radical polymerization initiators, etc.

[0063] When using an azo initiator, the amount of the radical polymerization initiator used is preferably 0.01 to 1 part by mass with respect to 100 parts by mass in total of the monomers. In the case of a redox initiator, the amount of the peroxide used is preferably 0.01 to 1 part by mass with respect to 100 parts by mass in total of the monomers. From the viewpoint of outgas resistance, the amount of the reducing agent used is preferably 0.01 to 1 part by mass with respect to 100 parts by mass in total of the monomers.

[0064] 〔Rubber (A)〕 Rubber (A) contains polyorganosiloxane (A1) and vinyl polymer (A2). Examples of rubber (A) include rubbers having the following structures (1) to (5). (1) A rubber having a multilayer structure in which the core of polyorganosiloxane (A1) is coated with the shell of vinyl polymer (A2). (2) A rubber having a multilayer structure in which the core of vinyl polymer (A2) is coated with the shell of polyorganosiloxane (A1). (3) A composite rubber having a structure in which polyorganosiloxane (A1) and vinyl polymer (A2) are interposed with each other. (4) A composite rubber having a sea-island structure in which polyorganosiloxane (A1) is an island and vinyl polymer (A2) is a sea. (5) A composite rubber having a sea-island structure in which polyorganosiloxane (A1) is a sea and vinyl polymer (A2) is an island. Among these, the rubber having the structure of (5) is preferable, and it is particularly excellent in impact strength and rigidity when a graft copolymer is added to a resin.

[0065] The content of polyorganosiloxane (A1) is preferably 1 to 50% by mass, preferably 5 to 35% by mass, more preferably 10 to 30% by mass with respect to 100% by mass of the polyorganosiloxane-containing graft copolymer. By setting it to 1% by mass or more, the impact strength is excellent when the graft copolymer is added to a resin, and by setting it to 50% by mass or less, the color developability, rigidity, and molding appearance are excellent.

[0066] The method for producing the rubber (A) is not particularly limited. For example, it can be produced by an emulsion polymerization method, a suspension polymerization method, or a mini-suspension polymerization method, but it is preferable to use the emulsion polymerization method. Among them, the rubber (A) preferably has the structure of the above-mentioned (5). As a method for obtaining a rubber having the structure of (5), a method of polymerizing (a1) and / or (a2) in the presence of a polyorganosiloxane rubber can be mentioned. Specifically, first, (a1) and / or (a2) are added to the latex of the polyorganosiloxane rubber and impregnated into the polyorganosiloxane, and then polymerization is carried out using a known radical polymerization initiator. In this method, as a method for adding (a1) and / or (a2), a method of adding the entire amount thereof at once to the polyorganosiloxane latex, a method of adding it dropwise at a constant rate in portions, or a method of adding a part of it at once and adding the rest dropwise at a constant rate can be mentioned. Among these, a method of adding a part of (a1) and / or (a2) at once and adding the rest dropwise at a constant rate is preferable because a graft copolymer excellent in the ease of controlling polymerization and the impact strength when added to a resin can be obtained.

[0067] When producing the latex of the rubber (A), an emulsifier can be added to stabilize the latex and control the particle diameter of the rubber (A). Examples of the emulsifier include the same ones as the above-mentioned emulsifiers used when producing the latex of the polyorganosiloxane, and anionic emulsifiers and nonionic emulsifiers are preferable.

[0068] The weight average particle diameter (Dw) of the rubber (A) is not particularly limited, but it is preferably 10 nm to 290 nm. If the weight average particle diameter of the rubber (A) is 10 nm or more, it is excellent in impact strength when added to a resin, and if it is 290 nm or less, it is preferable because it is excellent in rigidity and molding appearance.

[0069] [Vinyl monomer (b)] By polymerizing the vinyl monomer (b) in the presence of the above-mentioned rubber (A) to form a graft portion composed of a vinyl polymer on the rubber (A), a polyorganosiloxane-containing graft copolymer can be obtained.

[0070] Examples of the vinyl monomer (b) include the following. Aromatic vinyl monomers such as styrene, α-methylstyrene, and vinyltoluene; alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and i-butyl methacrylate; alkyl acrylates such as ethyl acrylate, n-butyl acrylate, and methyl acrylate; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; aryl (meth)acrylates in which the ester group is a phenyl group or a substituted phenyl group, such as phenyl (meth)acrylate, 4-t-butylphenyl (meth)acrylate, bromophenyl (meth)acrylate, dibromophenyl (meth)acrylate, 2,4,6-tribromophenyl (meth)acrylate, monochlorophenyl (meth)acrylate, dichlorophenyl (meth)acrylate, and trichlorophenyl (meth)acrylate. These can be used alone or in combination of two or more. Among these, (meth)acrylate is preferable, alkyl methacrylate is more preferable, and methyl methacrylate is even more preferable. When (meth)acrylate is used as the vinyl monomer (b), it has excellent compatibility with the resin and excellent impact strength and molding appearance when added to the resin.

[0071] When (meth)acrylate is used as the vinyl monomer (b), its content is preferably 50 to 100% by mass, more preferably 75 to 100% by mass, based on (b). When the content of (meth)acrylate is 50% by mass or more based on (b), it is preferable because it has even better compatibility with the resin and excellent impact strength and molding appearance when added to the resin.

[0072] The vinyl monomer (b) may contain a crosslinkable monomer. In that case, the amount of the crosslinkable monomer used in 100% by mass of the vinyl monomer (b) is preferably 0.005% by mass or less.

[0073] The content of rubber (A) in the graft copolymer is preferably 10 to 99% by mass based on 100% by mass of the graft copolymer. If the content of rubber (A) is 10% by mass or more, the impact strength of the resin composition will be sufficient. If it is 99% by mass or less, it is preferable because it has excellent dispersibility in the resin and good molding appearance.

[0074] Examples of the graft copolymerization method include a method in which vinyl monomer (b) is added to the latex of rubber (A) and polymerized in one or multiple stages. In the case of multi-stage polymerization, in the presence of the latex of rubber (A), it is preferable to divide the total amount of vinyl monomer (b) used and add it sequentially or continuously for polymerization. Such a polymerization method has good polymerization stability and can stably obtain a latex having a desired particle size and particle size distribution.

[0075] During the polymerization of the graft portion, an emulsifier can be added as needed. Examples of the emulsifier used for the polymerization of the graft portion include the same ones as the aforementioned emulsifier used in the production of rubber (A), and anionic emulsifiers and nonionic emulsifiers are preferable.

[0076] When recovering the powder of the graft copolymer from the latex of the graft copolymer, either a spray drying method or a coagulation method can be used.

[0077] The spray drying method is a method of spraying the latex of the graft copolymer in the form of fine droplets into a dryer and drying it by applying a heating gas for drying thereto. Examples of the method for generating the fine droplets include a rotary disk type, a pressure nozzle type, a two-fluid nozzle type, and a pressurized two-fluid nozzle type. The capacity of the dryer may be either a small scale such as used in a laboratory or a large scale such as used industrially. The temperature of the heating gas for drying is preferably 200°C or lower, more preferably 120 to 180°C. Latices of two or more kinds of graft copolymers produced separately can also be spray-dried together. Further, in order to improve powder properties such as blocking and bulk specific gravity during spray drying, an optional component such as silica can be added to the latex of the graft copolymer and then spray-dried.

[0078] The coagulation method is a method of coagulating the latex of the graft copolymer, separating, recovering, and drying the graft copolymer. First, the latex of the graft copolymer is put into hot water in which a coagulant is dissolved, salting out and coagulating to separate the graft copolymer. Next, the separated wet graft copolymer is recovered by dehydration or the like to obtain a graft copolymer with a reduced water content. The recovered graft copolymer is dried using a squeeze dehydrator or a hot air dryer.

[0079] Examples of the coagulant include inorganic salts such as aluminum chloride, aluminum sulfate, sodium sulfate, magnesium sulfate, sodium nitrate, calcium acetate, and acids such as sulfuric acid, and calcium acetate is particularly preferred. These coagulants can be used alone or in combination of two or more kinds, but when using two or more kinds, it is necessary to select a combination that does not form a water-insoluble salt. For example, using calcium acetate in combination with sulfuric acid or its sodium salt is not preferred because it forms a water-insoluble calcium salt.

[0080] The above-mentioned coagulant is usually used as an aqueous solution. From the viewpoint of stably coagulating and recovering the graft copolymer, the concentration of the coagulant aqueous solution is preferably 0.1% by mass or more, particularly preferably 1% by mass or more. Further, from the viewpoint of reducing the amount of the coagulant remaining in the recovered graft copolymer and preventing deterioration of the molding appearance of the molded article, the concentration of the coagulant aqueous solution is preferably 20% by mass or less, particularly preferably 15% by mass or less. The amount of the coagulant aqueous solution is not particularly limited, but is preferably 10 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the latex.

[0081] The method of bringing the latex into contact with the coagulant aqueous solution is not particularly limited, but usually the following methods can be mentioned. (1) A method of continuously adding the latex into the coagulant aqueous solution while stirring and holding it for a certain period of time, (2) A method of continuously injecting the coagulant aqueous solution and the latex into a container equipped with a stirrer at a certain ratio while bringing them into contact, and continuously extracting a mixture containing the coagulated polymer and water from the container. The temperature when bringing the latex into contact with the coagulant aqueous solution is not particularly limited, but is preferably 30°C or higher and 100°C or lower. The contact time is not particularly limited.

[0082] The coagulated graft copolymer is washed with about 1 to 100 times by mass of water and the filtered wet graft copolymer is dried using a fluid dryer, a squeezing dehydrator, or the like. The drying temperature and drying time may be appropriately determined depending on the obtained graft copolymer. It is also possible to directly send the graft copolymer discharged from the squeezing dehydrator or the extruder to an extruder or a molding machine for producing a resin composition without recovering it, and mix it with a thermoplastic resin to obtain a molded article.

[0083] In the present invention, from the viewpoint of the thermal decomposition resistance of the resin composition obtained by mixing the graft copolymer with a thermoplastic resin, it is preferable to recover the graft copolymer using a coagulation method.

[0084] 〔Thermoplastic resin composition〕 The "graft copolymer" used in the thermoplastic resin composition of the present invention can be mixed with a thermoplastic resin and used as a thermoplastic resin composition. In the following description, the polyorganosiloxane-containing graft copolymer may sometimes be simply referred to as the "graft copolymer".

[0085] The thermoplastic resin that can be used in the present invention is not particularly limited, and examples thereof include one or more resins selected from thermoplastic resins and thermoplastic elastomers.

[0086] 〔Thermoplastic resin〕 Examples of the thermoplastic resin include the following. Olefin resins such as polypropylene (PP) and polyethylene (PE); Styrene (St)-based resins such as polystyrene (PS), high-impact polystyrene (HIPS), (meth)acrylate-styrene copolymer (MS), styrene-acrylonitrile copolymer (SAN), styrene-maleic anhydride copolymer (SMA), acrylonitrile-butadiene-styrene copolymer (ABS), acrylate ester-styrene-acrylonitrile copolymer (ASA), acrylonitrile-ethylene-propylene rubber-styrene copolymer (AES); Acrylic (Ac) resins such as polymethyl methacrylate (PMMA); Polycarbonate (PC) resin; Polyamide (PA) resin; Polyester (PEs) resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); Engineering plastics such as (modified) polyphenylene ether ((m-)PPE) resin, polyoxymethylene (POM) resin, polysulfone (PSO) resin, polyarylate (PAr) resin, polyphenylene sulfide (PPS) resin; Thermoplastic polyurethane (PU) resin; Vinyl chloride (PVC)-based resins such as rigid vinyl chloride resin, semi-rigid vinyl chloride resin, and flexible vinyl chloride resin; Alloys of PC resin and St-based resin such as PC / ABS; Alloys of PVC-based resin and St-based resin such as PVC / ABS; Alloys of PA resin and St-based resin such as PA / ABS; Alloys of PA resin and thermoplastic elastomer (TPE); Alloys of PA resin and polyolefin resin such as PA / PP; Alloys of PC resin and PEs resin such as PC / PBT; Alloys of olefin resins such as PP / TPE and PP / PE; Alloys of PPE-based resin and other resins such as PPE / HIPS, PPE / PBT, and PPE / PA; Alloys of PVC-based resin and acrylic resin such as PVC / PMMA, etc.

[0087] Examples of the thermoplastic elastomer include, for example, the following: styrenic elastomers, olefinic elastomers, vinyl chloride elastomers, urethane elastomers, polyester elastomers, polyamide elastomers, fluorine elastomers, 1,2-polybutadiene, trans 1,4-polyisoprene, etc. Among these, urethane elastomers, polyester elastomers, and polyamide elastomers are preferred.

[0088] Among the above-mentioned thermoplastic resins, the following are preferred: St resins, PC resins, PA resins, PET resins, PBT resins, (m-)PPE resins, POM resins, PU resins, alloys of PC resins such as PC / ABS and St resins, alloys of PA resins such as PA / ABS and St resins, alloys of PA resins and TPEs, alloys of PA resins such as PA / PP and polyolefin resins, alloys of PC resins such as PC / PBT and PEs resins, alloys of PPE resins such as PPE / PBT and PPE / PA and other resins, etc.

[0089] Furthermore, among the above-mentioned resins, resins containing polycarbonate resins and polyester resins are preferred because the effects of the present invention can be significantly exhibited.

[0090] As for the polycarbonate resin, aromatic polycarbonate resins are preferred from the viewpoints of heat resistance and impact resistance. The aromatic polycarbonate resin is a thermoplastic aromatic polycarbonate polymer or copolymer which may be branched and obtained by reacting an aromatic hydroxy compound or a small amount of polyhydroxy compound thereof with phosgene or a diester of carbonic acid. The production method of the aromatic polycarbonate resin is not particularly limited, and known methods, that is, the phosgene method (interfacial polymerization method), the melting method (ester exchange method), etc. are adopted. In the present invention, an aromatic polycarbonate resin produced by the melting method and having the amount of terminal OH groups adjusted can also be used.

[0091] Examples of the aromatic polycarbonate resin include the following: Iupilon (registered trademark) S-1000, S-2000, S-3000, H-3000 or H-4000 (manufactured by Mitsubishi Engineering-Plastics Corporation), or Panlite (registered trademark) L1250, L1225 or K1300 (manufactured by Teijin Chemicals Ltd.), etc.

[0092] Further, the polyester resin is preferably an aromatic polyester resin, more preferably a polybutylene terephthalate resin because it is excellent in the balance of heat resistance, fluidity, and chemical resistance. Examples of the polybutylene terephthalate resin include those commercially available under trade names such as "Trecon" manufactured by Toray Industries, Inc.; "Novaduran" manufactured by Mitsubishi Engineering-Plastics Corporation; "Durabex" manufactured by Polyplastics Co., Ltd., etc. In addition, the polybutylene terephthalate resin can be obtained by polymerization by a known method, for example, by subjecting terephthalic acid or its alkyl diester and 1,4-butanediol to dehydration condensation by a known method.

[0093] The content of the graft copolymer in a total of 100% by mass of the thermoplastic resin and the graft copolymer is preferably 0.5 to 50% by mass, more preferably 1 to 20% by mass. If the content of the graft copolymer is 0.5% by mass or more, a resin composition excellent in impact resistance can be obtained, and if it is 50% by mass or less, a resin composition excellent in color development property, molding appearance, and rigidity can be obtained.

[0094] [Additives] The thermoplastic resin composition can contain various additives as long as it does not deviate from the object of the present invention. Examples of the additives include stabilizers such as phenolic stabilizers, phosphorus stabilizers, ultraviolet absorbers, amine-based light stabilizers; flame retardants such as phosphorus-based, bromine-based, silicone-based, and organic metal salt-based flame retardants; modifiers for imparting various physical properties such as hydrolysis resistance; fillers such as titanium oxide and talc; dyes and pigments; and plasticizers.

[0095] Examples of additives that can be used include the following: flame retardants, anti-drip agents (e.g., fluorinated polyolefins, silicones, and aramid fibers), lubricants, mold release agents (e.g., pentaerythritol tetrastearate), nucleating agents, antistatic agents, stabilizers, fillers, reinforcing agents (e.g., glass fibers, carbon fibers, mica, kaolin, talc, CaCO3, and glass flakes), dyes, and pigments. Examples of inorganic pigments include iron oxide, ultramarine, titanium oxide, carbon black, etc. Examples of organic pigments include phthalocyanine-based and anthraquinone-based blue pigments, perylene-based and quinacridone-based red pigments, isoindolinone-based yellow pigments, etc. Special pigments include fluorescent pigments, metallic powder pigments, pearl pigments, etc. Examples of dyes include nigrosine-based, perinone-based, and anthraquinone-based dyes, and various grades corresponding to the required colors are commercially available and can be used. These can be used alone or in combination of two or more.

[0096] [Method for Preparing Resin Composition] The method for preparing the thermoplastic resin composition of the present invention is not particularly limited. However, the graft copolymer, the thermoplastic resin, and various additives used as needed are mixed and dispersed using a V-type blender, Henschel mixer, or the like, and this mixture is melt-kneaded using an extruder or a kneader such as a Banbury mixer, a pressure kneader, or a roll. The mixing of these components can be carried out batchwise or continuously, and the mixing order of the components is not particularly limited. The melt-kneaded product can be made into pellets and used for various moldings.

[0097] [Molded Article] The molded article according to the present invention is formed by molding the above thermoplastic resin composition. Examples of the molding method of the thermoplastic resin composition include, for example, a method of molding the thermoplastic resin composition or a mixture of the graft copolymer powder and the thermoplastic resin using an injection molding machine.

[0098] The use of the molded article is not particularly limited, and it can be widely used industrially as a material in the fields of automobiles, OA equipment, electrical and electronics, etc.

Examples

[0099] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. Prior to the Examples, various evaluation methods and Production Examples 1 to 2 of the latex of polyorganosiloxane will be described. Examples 1 to 2 and Comparative Examples 1 to 3 are examples related to the production and evaluation of graft copolymers, and Examples 3 to 4 and Comparative Examples 4 to 7 are examples related to the production and evaluation of thermoplastic resin compositions. In the Production Examples, Examples, etc., "parts" and "%" mean "parts by mass" and "mass%" unless otherwise specified.

[0100] 〔Evaluation Method〕 (1) Solids content A latex of polyorganosiloxane with a mass w1 is dried in a hot air dryer at 180 °C for 30 minutes, and the mass w2 of the residue after drying is measured. The solids content [%] is calculated by the following formula. Solids content [%] = w2 / w1 × 100

[0101] (2) Mass average particle diameter (Dw) A sample obtained by diluting "rubber latex" or "graft copolymer latex" with deionized water to a solids concentration of about 3% is used, and the particle diameter is measured using the above-mentioned CHDF2000 type particle size distribution meter manufactured by MATEC, USA, under the above-mentioned conditions, and the mass average particle diameter Dw is measured.

[0102] (3) Charpy impact strength In accordance with JIS K 7111-1 / 1eA, at temperatures of 23 °C and -30 °C, a V-notch is made on a test piece 1 (length 80.0 mm × width 10.0 mm × thickness 4 mm) obtained by injection molding, and the Charpy impact strength is measured using a 4J hammer.

[0103] (4) Color developability (pigment colorability) The test piece 2 (length: 100.0 mm, width: 50.0 mm, thickness: 2.0 mm) obtained by injection molding was measured in accordance with JIS Z 8729 (Method for expressing object color by L*a*b* color system), and the measurement was carried out using SE-4000 (trade name) manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with JIS Z 8722. The object color was measured according to the following "Measurement Condition 2", and L* was used as an index of color development property. The lower the L*, the better the blackness, indicating excellent color development property when pigments are added. "Measurement Condition 2" Apparatus: Spectrophotometric color difference meter SE-4000 (manufactured by Nippon Denshoku Industries Co., Ltd., 0-45° rear spectrophotometric method), Measurement range: 380 - 780 nm, Measurement light source: C light (2° field of view) Measurement method: Reflectance method

[0104] (5) Molding appearance The test piece 2 was produced according to the following "Molding Conditions", and the flow marks (patterns seen in a striped shape near the gate of the molded body) appearing near the gate of the test piece 2 were visually observed. "Molding Conditions" Cylinder temperature: 260 °C, Mold temperature: 60 °C, Injection speed: 80 mm / s "Judgment method" Visually judge the appearance of the gate part. (○: Flow marks are not prominent, ×: Flow marks are prominent)

[0105] (6) Bending properties (rigidity) In accordance with JIS K 7171, using a test piece (length: 80.0 mm × width: 10.0 mm × thickness: 4 mm), the measurement was carried out at a temperature of 23 °C and a test speed of 2 mm / min. The higher the flexural modulus and the maximum point strength, the better the rigidity.

[0106] [Production Example 1] 2 parts of tetraethoxysilane (TEOS), 2 parts of γ-methacryloyloxypropyl dimethoxymethylsilane (DSMA), and 96 parts of a cyclic organosiloxane mixture (manufactured by Shin-Etsu Silicone Co., Ltd., product name: DMC, a mixture of cyclic organosiloxanes with 3 to 6 members in the ring) were mixed to obtain 100 parts of an organosiloxane mixture. An aqueous solution prepared by dissolving 0.67 part of sodium dodecylbenzenesulfonate (DBSNa) and 0.67 part of dodecylbenzenesulfonic acid (DBSH) in 200 parts of deionized water was added to the mixture, and after stirring at 10,000 rpm for 5 minutes with a homomixer, it was passed twice through a homogenizer at a pressure of 20 MPa to obtain a stable premixed emulsion.

[0107] Next, the above emulsion was charged into a 5-liter separable flask equipped with a cooling condenser, the aqueous solution was heated to a temperature of 80°C and held for 5 hours to cause a polymerization reaction, then cooled to room temperature (25°C) and held for 12 hours, and then a 5% aqueous sodium hydroxide solution was added to neutralize the reaction solution to pH 7.0 to obtain a polyorganosiloxane latex (S-1).

[0108] The solid content of the polyorganosiloxane latex (AS-1) was 29.2% by mass. Also, the number average particle diameter (Dn) of this latex measured by a capillary particle size distribution meter was 98 nm, the weight average particle diameter (Dw) was 204 nm, and Dw / Dn was 2.1.

[0109] [Production Example 2] 2 parts of tetraethoxysilane (TEOS), 2 parts of γ-methacryloyloxypropyl dimethoxymethylsilane (DSMA), and 96 parts of octamethylcyclotetrasiloxane (manufactured by Momentive Performance Materials Japan Co., Ltd., product name: TSF404) were mixed to obtain 100 parts of an organosiloxane mixture. An aqueous solution prepared by dissolving 1 part of sodium dodecylbenzenesulfonate (DBSNa) in 150 parts of deionized water was added to the mixture, and after stirring at 10,000 rpm for 5 minutes with a homomixer, it was passed twice through a homogenizer at a pressure of 20 MPa to obtain a stable premixed emulsion.

[0110] Next, the above emulsion was placed in a 5-liter separable flask equipped with a cooling condenser, and then the emulsion was heated to a temperature of 80°C. Subsequently, a mixture of 0.20 part of sulfuric acid and 49.8 parts of distilled water was continuously added over 3 minutes. After maintaining the state of heating at 80°C for 7 hours to cause a polymerization reaction, it was cooled to room temperature (25°C), and the resulting reaction product was held at room temperature (25°C) for 6 hours. Thereafter, a 5% aqueous sodium hydroxide solution was added to neutralize the reaction solution to pH 7.0, obtaining a polyorganosiloxane latex (AS-2).

[0111] The solid content of the polyorganosiloxane latex (AS-2) was 29.8% by mass. Also, the number average particle diameter (Dn) of this latex measured by a capillary particle size distribution meter was 384 nm, the weight average particle diameter (Dw) was 403 nm, and Dw / Dn was 1.1.

[0112] [Example 1] 102.74 parts (30.0 parts in terms of polymer) of the polyorganosiloxane latex (AS-1) obtained in Production Example 1 was taken into a 5-liter separable flask, and 160 parts of deionized water was added and mixed. Subsequently, a mixture of 14.75 parts of styrene (St), 0.25 part of allyl methacrylate (AMA), and 0.07 part of cumene hydroperoxide (CHP) (1 / 4 amount of the mixture used for rubber polymerization) was added to this separable flask, and stirring was continued at 25°C for 1 hour to impregnate the polyorganosiloxane.

[0113] By passing a nitrogen stream through this separable flask, the atmosphere in the flask was replaced with nitrogen, and the liquid temperature was raised to 70 °C. When the liquid temperature reached 70 °C, an aqueous solution prepared by dissolving 0.001 part of ferrous sulfate (Fe), 0.003 part of disodium ethylenediaminetetraacetate (EDTA), and 0.24 part of sodium formaldehyde sulfoxylate (SFS) in 10 parts of deionized water was added to initiate radical polymerization. After maintaining the state for 30 minutes from the start of radical polymerization, a solution prepared by mixing 44.25 parts of styrene (St), 0.75 part of allyl methacrylate (AMA), and 0.21 part of cumene hydroperoxide (CHP) was added dropwise over 120 minutes.

[0114] To complete the polymerization of the vinyl monomer component, the state at 70 °C was maintained for 1 hour after the completion of the dropwise addition, and a latex of rubber containing polyorganosiloxane and styrene was obtained.

[0115] With the liquid temperature of this latex at 70 °C, a mixed solution of 9.5 parts of methyl methacrylate (MMA), 0.5 part of butyl acrylate (BA), and 0.05 part of t-butyl hydroperoxide (t-BH) was added dropwise into this latex over 1 hour to initiate and continue the graft polymerization reaction. After the completion of the dropwise addition, the temperature was maintained at 70 °C for 1 hour and then cooled to 25 °C to obtain a latex of a graft copolymer (G-1) containing polyorganosiloxane.

[0116] Next, 500 parts of an aqueous solution with a calcium acetate concentration of 1% by mass was heated to 85 °C, and while stirring, 340 parts of the latex of the graft copolymer (G-1) was gradually added dropwise and coagulated in this aqueous solution. After the obtained graft copolymer (G-1) was filtered, washed, dehydrated, and then dried, a powder of the graft copolymer (G-1) was obtained. The polymerization rate and weight average particle diameter of the graft copolymer (G-1) are shown in Table 1. Incidentally, this polymerization rate is the polymerization rate of the monomer components used in all steps from the production of the composite rubber to the graft polymerization.

[0117] [Example 2, Comparative Examples 1 and 2] A polyorganosiloxane-containing graft copolymer (G-2, G'-1, and 2) was produced in the same manner as in Example 1, except that the types and amounts of each raw material used in Example 1 were changed to the conditions shown in Table 1, and further, a powder of the graft copolymer was obtained. The polymerization rate and mass average particle diameter of each obtained graft copolymer are shown in Table 1. Also shown in Table 1 is the peak temperature of tanδ measured under Measurement Condition 1. The numerical values in parentheses in the columns of the monofunctional vinyl monomer (a1) and polyfunctional vinyl monomer (a2) in Table 1 indicate the composition ratio (mass %) in 100% by mass of the vinyl polymer (A2). The refractive index measured by an Abbe refractometer is also shown in Table 1.

[0118] [Comparative Example 3] 106.16 parts (31.0 parts in terms of polymer) of the polyorganosiloxane latex (AS-1) obtained in Production Example 1 was taken into a separable flask with a capacity of 5 liters, and 160 parts of deionized water was added and mixed. Next, a mixture of 56.6 parts of butyl acrylate (BA), 1.4 parts of allyl methacrylate (AMA), and 0.05 part of t-butyl hydroperoxide (t-BH) was added into this separable flask, and stirring was continued at 25 °C for 1 hour to impregnate the polyorganosiloxane.

[0119] The atmosphere in the separable flask was replaced with nitrogen by passing a nitrogen stream through the flask, and the liquid temperature was raised to 45 °C. When the liquid temperature reached 45 °C, an aqueous solution prepared by dissolving 0.001 part of ferrous sulfate (Fe), 0.003 part of disodium ethylenediaminetetraacetate (EDTA), and 0.24 part of sodium formaldehyde sulfoxylate (SFS) in 10 parts of deionized water was added to initiate radical polymerization. After the initiation of radical polymerization, in order to complete the polymerization of the vinyl monomer component, the temperature was maintained at 60 °C for 60 minutes from the time when the liquid temperature reached 60 °C, and a latex of rubber containing polyorganosiloxane and butyl acrylate was obtained.

[0120] With the latex at a liquid temperature of 60°C, a mixed solution of 10.5 parts of methyl methacrylate (MMA), 0.5 part of butyl acrylate (BA), and 0.05 part of t-butyl hydroperoxide (t-BH) was dropped into this latex over 1 hour to initiate and continue the graft polymerization reaction. After the dropping was completed, the state at a temperature of 60°C was maintained for 1 hour and then cooled to 25°C to obtain a latex of a polyorganosiloxane-containing graft copolymer (G’-3).

[0121] Next, 500 parts of an aqueous solution with a calcium acetate concentration of 1% by mass was heated to 40°C, and while stirring, 340 parts of the latex of the graft copolymer (G’-3) was gradually dropped into this aqueous solution for coagulation. After the obtained graft copolymer (G’-3) was filtered, washed, dehydrated, and then dried, a powder of the graft copolymer (G’-3) was obtained. The polymerization rate and weight average particle diameter of the graft copolymer (G’-3) are shown in Table 1. Note that this polymerization rate is the polymerization rate of the monomer components used in all steps from the production of the composite rubber to the graft polymerization.

[0122]

Table 1

[0123] The abbreviations in Table 1 are as follows. St: Styrene BA: n-Butyl acrylate AMA: Allyl methacrylate MMA: Methyl methacrylate

[0124] [Examples 3 and 4 , Comparative Examples 4 ~ 7 Each polyorganosiloxane-containing graft copolymer (G-1) to (G-2), (G’-1) to (G’- 3 ​Powder of [[ID=]], polybutylene terephthalate resin (manufactured by Mitsubishi Engineering-Plastics Corporation, trade name: Novaduran 5010R5), and carbon black (manufactured by Mitsubishi Chemical Corporation, trade name: Carbon Black #960B) were blended and mixed at the ratios shown in Table 2. After drying the blend at 120 °C for 12 hours, it was fed into a 30 mm Φ twin-screw extruder (L / D = 30), melt-mixed and extruded at a cylinder temperature of 260 °C and a screw rotation speed of 150 rpm to obtain pellets of thermoplastic resin compositions (H-1) to (H-7).

[0125] After drying the obtained pellets at 120 °C for 12 hours, they were fed into a 100 t injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., trade name: SE-100DU), and injection molding was performed at a cylinder temperature of 260 °C and a mold temperature of 60 °C to obtain each "test piece 1" (length 80 mm, width 10 mm, thickness 4 mm) and each "test piece 2" (length 100 mm, width 50 mm, thickness 2 mm). For test piece 1, for the Charpy impact test, a V-notch was cut with a notching machine in accordance with JIS K 7111-1A. Subsequently, using each test piece, the Charpy impact strength, color developability, molding appearance, and flexural properties were measured. The evaluation results are shown in Table 2.

[0126] [Table 2]

[0127] [Performance Comparison of Resin Compositions] In Examples 3 and 4, the balance of impact strength, color developability, and flexural properties was excellent, and the molding appearance was good.

[0128] Comparative Example 4、5 Since the weight average particle diameter of the graft copolymer was 300 nm or more, it was inferior in rigidity. Also, the flow marks were prominent and the molding appearance was inferior.

[0129] Comparative Example 6 Since the graft copolymer had a low refractive index and did not contain 30 mass% or more of aromatic vinyl units, it was inferior in rigidity and particularly in color developability.

[0130] Comparative Example 7 Since it did not contain a graft copolymer, its impact strength was inferior.

Claims

1. A polyorganosiloxane-containing graft copolymer obtained by graft-polymerizing a vinyl monomer (b) onto a rubber (A) containing a polyorganosiloxane (A1) and a vinyl polymer (A2), having a refractive index of 1.52 to 1.60, a weight-average particle diameter greater than 50 nm and less than 300 nm, containing more than 60% by mass and 80% by mass or less of an aromatic vinyl unit in the rubber (A) based on 100% by mass in total of the rubber (A), and containing 75 to 100% by mass of (meth)acrylate with respect to the vinyl monomer (b).

2. The polyorganosiloxane-containing graft copolymer according to claim 1, wherein the rubber (A) contains at least one selected from an alkyl (meth)acrylate unit and an allyl (meth)acrylate unit.

3. The polyorganosiloxane-containing graft copolymer according to any one of claims 1 or 2, wherein the rubber (A) contains more than 0% by mass and 30% by mass or less of at least one selected from an alkyl (meth)acrylate unit and an allyl (meth)acrylate unit based on 100% by mass in total of the rubber (A).

4. The polyorganosiloxane-containing graft copolymer according to any one of claims 1 to 3, wherein the content of the polyorganosiloxane (A1) in the polyorganosiloxane-containing graft copolymer is 5 to 35% by mass.

5. The polyorganosiloxane-containing graft copolymer according to any one of claims 1 to 4, containing more than 0.5% by mass and 10% by mass or less of a structural unit derived from a vinyl polymerizable group-containing silane compound with respect to the polyorganosiloxane (A1).

6. A resin composition containing the polyorganosiloxane-containing graft copolymer according to any one of claims 1 to 5.

7. The resin composition according to claim 6, containing a polycarbonate resin and a polyester resin.

8. The resin composition according to claim 7, wherein the polycarbonate resin is an aromatic polycarbonate resin.

9. The resin composition according to claim 7 or 8, wherein the polyester resin is an aromatic polyester resin.

10. A molded article made of the thermoplastic resin composition according to any one of claims 7 to 9.

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