Polyorganosiloxane-containing graft copolymer powder, resin composition using same, and molded body made of same

Abstract

To provide polyorganosiloxane-containing graft copolymer powder which can provide an aromatic polyester resin composition excellent in the balance of color development and impact resistance and a molded product composed of the same.SOLUTION: Polyorganosiloxane-containing graft copolymer powder of the invention is powder of the polyorganosiloxane-containing graft copolymer made by graft polymerizing a mixture (B) of a vinyl monomer (b1) with an epoxy group and an another vinyl monomer (b2) to a polyorganosiloxane-containing rubber (A), in which a content of the polyorganosiloxane (A1) in the rubber (A) is 12-50 mass%, a weight average particle diameter of the polyorganosiloxane-containing graft copolymer is 300-2,000 nm, and an epoxy equivalent of the polyorganosiloxane-containing graft copolymer is 2,500-7,800 g / eq.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyorganosiloxane-containing graft copolymer powder, a resin composition containing the polyorganosiloxane-containing graft copolymer powder, and a molded article of the resin composition. [Background technology]

[0002] Resins such as aromatic polyester resins are general-purpose engineering plastics that excel in transparency, impact resistance, heat resistance, dimensional stability, etc., and due to their excellent properties, are widely used industrially as materials in the fields of automobiles, office automation equipment, electrical and electronics, etc. To improve the impact resistance of these resins, a method of adding impact modifiers is used.

[0003] In recent years, molded products obtained from the above resins are sometimes used without painting, mainly for applications such as housings for electric and electronic devices and home appliances, in order to reduce the cost of the products, and there is a demand for coloring the resin itself to produce a desired color tone.

[0004] For example, Patent Documents 1 and 2 disclose the use of a specific polyorganosiloxane-based graft copolymer as an impact strength modifier for polybutylene terephthalate resin and the like. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-277450 A [Patent Document 2] Japanese Patent Application Publication No. 9-3146 Summary of the Invention [Problem to be solved by the invention]

[0006] However, even the graft copolymers of Patent Documents 1 and 2 sometimes had an insufficient balance of color development, impact resistance, and other mechanical properties when added to a thermoplastic resin, particularly an aromatic polyester resin, and also had insufficient color development when added to an alloy of an aromatic polycarbonate resin and an aromatic polyester resin.

[0007] The object of the present invention is to provide a polyorganosiloxane-containing graft copolymer capable of providing a resin composition and a molded article having an excellent balance between color development and mechanical properties such as impact strength. Another object of the present invention is to provide a resin composition and a molded article having an excellent balance between color development and mechanical properties such as impact strength. [Means for solving the problem]

[0008] The present invention has the following aspects.

[0009] [1] A polyorganosiloxane-containing graft copolymer powder obtained by graft polymerizing a mixture (B) of a vinyl monomer (b1) having an epoxy group and other vinyl monomers (b2) onto a rubber (A) containing polyorganosiloxane, wherein the content of polyorganosiloxane (A1) contained in the rubber (A) is 12 to 50 mass%, the mass average particle size of the polyorganosiloxane-containing graft copolymer powder is 300 to 2000 nm, and the epoxy equivalent of the polyorganosiloxane-containing graft copolymer powder is 2500 to 7800 g / eq.

[0010] [2] The polyorganosiloxane-containing graft copolymer powder according to [1], wherein the graft portion of the polyorganosiloxane-containing graft copolymer powder has a single-layer structure containing an epoxy group, or a multilayer structure containing an epoxy group in at least the outermost layer.

[0011] [3] The polyorganosiloxane-containing graft copolymer powder according to [1] or [2], wherein the vinyl monomer mixture (B) contains the vinyl monomer (b1) in an amount of 0.1 to 20 mass %.

[0012] [4] The polyorganosiloxane-containing graft copolymer powder according to any one of [1] to [3], wherein the content of the rubber (A) in the polyorganosiloxane-containing graft copolymer powder is in the range of 10 to 90 mass %.

[0013] [5] A resin composition comprising the polyorganosiloxane-containing graft copolymer powder according to any one of [1] to [4] above.

[0014] [6] The resin composition according to [5], which contains a thermoplastic resin.

[0015] [7] The resin composition according to [6], wherein the thermoplastic resin is a polyester resin.

[0016] [8] The resin composition according to [7], wherein the polyester resin is an aromatic polyester resin.

[0017] [9] The resin composition according to [6], wherein the thermoplastic resin comprises a polyester resin and a polycarbonate resin.

[0018]

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

[0019]

[11] A molded article made of the resin composition according to any one of [5] to

[10] above. Effect of the Invention

[0020] 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 having an excellent balance between color development and mechanical properties such as impact strength. Also, according to the present invention, it is possible to provide a resin composition and a molded article having an excellent balance between color development and mechanical properties such as impact strength. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention will be described in detail below. 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".

[0022] <Polyorganosiloxane-containing graft copolymer> The powder of the polyorganosiloxane-containing graft copolymer (sometimes simply referred to as "graft copolymer") of the present invention is a polyorganosiloxane-containing graft copolymer powder obtained by graft polymerizing a mixture (B) of a vinyl monomer (b1) having an epoxy group and another vinyl monomer (b2) to a rubber (A) containing polyorganosiloxane, and the content of the polyorganosiloxane (A1) in the rubber (A) is 12-50 mass%, and the mass average particle size is 300-2000 nm. The epoxy equivalent of the polyorganosiloxane-containing graft copolymer powder is preferably 2500-7800 g / eq. The polyorganosiloxane-containing graft copolymer powder preferably contains an epoxy group at least in the outermost layer. The graft portion of the polyorganosiloxane-containing graft copolymer powder contains an epoxy group, and the graft portion may be a single-layer structure containing an epoxy group, or may be a multi-layer structure containing an epoxy group at least in the outermost layer.

[0023] [Rubber containing polyorganosiloxane (A)] The rubber (A) containing polyorganosiloxane is preferably a composite rubber containing polyorganosiloxane and polyalkyl(meth)acrylate.

[0024] [Polyorganosiloxane] Polyorganosiloxane is a polymer containing an organosiloxane unit in which at least one organic group is bonded to a silicon atom as a constituent unit. Polyorganosiloxane can be obtained by polymerizing an organosiloxane or an "organosiloxane mixture" containing an organosiloxane and one or more components used as needed. Examples of components used as needed include a siloxane-based crosslinking agent, a siloxane-based grafting agent, and a siloxane oligomer having a terminal blocking group.

[0025] As the organosiloxane, either a chain organosiloxane or a cyclic organosiloxane can be used. Cyclic organosiloxanes are preferred because they have high polymerization stability and a high polymerization rate. As the cyclic organosiloxane, 3- to 7-membered rings are preferred, and examples thereof include the following. Hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, etc. These may be used alone or in combination of two or more. Among these, it is preferred that 60 mass% or more of the organosiloxane is octamethylcyclotetrasiloxane, since it is easy to control the particle size distribution of the polyorganosiloxane rubber formed.

[0026] As the organosiloxane, any of linear organosiloxane, alkoxysilane compound, and cyclic organosiloxane can be used. Among them, alkoxysilane compound and cyclic organosiloxane are preferred, and cyclic organosiloxane is more preferred because of its high polymerization stability and high polymerization rate.

[0027] The alkoxysilane compound is preferably a bifunctional alkoxysilane compound, and examples thereof include dimethyldimethoxysilane, dimethyldiethoxysilane, diethoxydiethylsilane, dipropoxydimethylsilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, and methylphenyldiethoxysilane.

[0028] The cyclic organosiloxane is preferably one having a 3-7 membered ring, 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, it is preferable that the main component is octamethylcyclotetrasiloxane, since it is easy to control the particle size distribution of the polyorganosiloxane formed, and it is preferable that 60 mass% or more of the organosiloxane is octamethylcyclotetrasiloxane.

[0029] As the organosiloxane, it is preferable to use an organosiloxane that is a cyclic dimethylsiloxane and / or a difunctional dialkylsilane compound, since a graft copolymer having higher low-temperature impact resistance can be obtained.

[0030] Cyclic dimethylsiloxane is a cyclic siloxane having two methyl groups on a silicon atom, and examples thereof include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. These can be used alone or in combination of two or more. Examples of bifunctional dialkylsilane compounds include dimethyldimethoxysilane, dimethyldiethoxysilane, diethoxydiethylsilane, and dipropoxydimethylsilane. These can be used alone or in combination of two or more.

[0031] The siloxane crosslinking agent is preferably one having a siloxy group. By using the siloxane crosslinking agent, a polyorganosiloxane having a crosslinked structure can be obtained. Examples of the siloxane crosslinking agent include trifunctional or tetrafunctional silane crosslinking agents such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetrabutoxysilane. Among them, a tetrafunctional crosslinking agent is preferable, and tetraethoxysilane is more preferable. The content of the siloxane crosslinking agent is preferably 0 to 30 mass%, more preferably 0 to 15 mass%, and more preferably 0 to 5 mass% in 100 mass% of the organosiloxane mixture, and is preferably 0.05 mass% or more, and more preferably 0.1 mass% or more from the viewpoint of obtaining a sufficient effect of addition. By setting the content of the siloxane crosslinking agent to 0 to 30 mass%, a graft copolymer having good low-temperature impact resistance can be obtained.

[0032] The siloxane-based graft crosslinking agent has a siloxy group and a functional group polymerizable with a vinyl monomer. By using the siloxane-based graft crosslinking agent, 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 can be grafted with an alkyl (meth)acrylate component (a monomer component that forms a polyalkyl (meth)acrylate that constitutes the composite rubber together with the polyorganosiloxane) and a vinyl monomer mixture (B) by radical polymerization.

[0033] The siloxane-based grafting agent may be a siloxane represented by formula (I). RSiR 1 n (OR 2 ) (3-n) (I) In formula (I), R 1 R represents a methyl group, an ethyl group, a propyl group, or a phenyl group.2 represents an organic group in the 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 of the groups represented by formulae (I-1) to (I-4).

[0034] CH2=C(R 3 )-COO-(CH2)p- (I-1) CH2=C(R 4 )-C6H4- (I-2) CH2=CH- (I-3) HS-(CH2)p- (I-4) In these formulas, R 3 and R 4 each represents a hydrogen atom or a methyl group, and p represents an integer of 1 to 6.

[0035] The functional group represented by formula (I-1) can include methacryloyloxyalkyl group.The siloxane having this group can include, for example, β-methacryloyloxyethyl dimethoxymethylsilane, γ-methacryloyloxypropyl methoxydimethylsilane, γ-methacryloyloxypropyl dimethoxymethylsilane, γ-methacryloyloxypropyl trimethoxysilane, γ-methacryloyloxypropyl ethoxydiethylsilane, γ-methacryloyloxypropyl diethoxymethylsilane, δ-methacryloyloxybutyl diethoxymethylsilane, etc.

[0036] These siloxane-based graft crossing agents can be used alone or in combination of two or more. The content of the siloxane-based graft crossing agent is preferably 0 to 40 mass%, more preferably 0.05 to 40 mass%, and more preferably 0.05 to 20 mass%, based on 100 mass% of the organosiloxane mixture. In order to obtain a sufficient effect of addition, it is more preferably 0.1 mass% or more, and even more preferably 0.5 mass% or more. By setting the content of the siloxane-based graft crossing agent to 0 to 40 mass%, it is possible to obtain a graft copolymer that can provide a resin composition having a good balance between low-temperature impact resistance and color development.

[0037] The siloxane oligomer having a terminal blocking group refers to a siloxane oligomer that has an alkyl group or the like at the end of the organosiloxane oligomer and terminates the polymerization of polyorganosiloxane.

[0038] Examples of siloxane oligomers having terminal blocking groups include hexamethyldisiloxane, 1,3-bis(3-glycidoxypropyl)tetramethyldisiloxane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, and methoxytrimethylsilane.

[0039] [Method of producing polyorganosiloxane] There is no particular limitation on the method for producing polyorganosiloxane, and for example, the following production method can be adopted. First, an organosiloxane mixture containing an organosiloxane, a siloxane-based crosslinking agent if necessary, a siloxane-based grafting agent if necessary, and a siloxane oligomer having a terminal blocking group if necessary is emulsified with an emulsifier and water to prepare an emulsion. Thereafter, the mixture is polymerized at high temperature using an acid catalyst, and then the acid is neutralized with an alkaline substance to obtain a polyorganosiloxane latex. In the following description of the production method, the case where an "organosiloxane mixture" is used as a raw material for polymerization is described, but the same production process can also be applied when "organosiloxane" is used.

[0040] In this manufacturing method, the method of preparing emulsion can be, for example, the method of using a homomixer that uses the shearing force of high-speed rotation to make fine particles, the method of using a homogenizer that uses the ejection force of a high-pressure generator to make fine particles, etc., and mixing by high-speed stirring.Among these, the method of using a homogenizer is preferred because it narrows the particle size distribution of polyorganosiloxane latex.

[0041] The method of mixing the acid catalyst during polymerization includes (1) adding the acid catalyst together with the organosiloxane mixture, emulsifier and water all at once and mixing, (2) adding the acid catalyst aqueous solution all at once to the emulsion of the organosiloxane mixture, and (3) dropping the emulsion of the organosiloxane mixture into a high-temperature aqueous acid catalyst solution at a constant rate and mixing it, etc. The method of keeping the emulsion of the organosiloxane mixture at a high temperature and then adding the acid catalyst aqueous solution thereto all at once is preferred because it is easy to control the particle size of the polyorganosiloxane.

[0042] The polymerization temperature is preferably at least 50° C., and more preferably at least 70° C. The polymerization time is usually at least 2 hours, and preferably at least 5 hours, when the polymerization is carried out by adding the aqueous acid catalyst solution all at once to the emulsion of the organosiloxane mixture.

[0043] Furthermore, since the crosslinking reaction between silanols proceeds at temperatures of 30°C or lower, in order to increase the crosslinking density of the polyorganosiloxane, the latex formed after polymerization at a high temperature of 50°C or higher can be kept at a temperature of 30°C or lower for about 5 to 100 hours.

[0044] The polymerization reaction of the organosiloxane mixture can be terminated by neutralizing the reaction system containing the latex to a pH of 6 to 8 with an alkaline substance such as sodium hydroxide, potassium hydroxide, or an aqueous ammonia solution.

[0045] The emulsifier used in the above production method is not particularly limited as long as it is capable of emulsifying the organosiloxane mixture, but anionic emulsifiers or nonionic emulsifiers are preferred.

[0046] 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.

[0047] Examples of nonionic emulsifiers include the following: polyoxyethylene alkyl ethers, polyoxyethylene alkylene alkyl ethers, polyoxyethylene distyrenated phenyl ethers, polyoxyethylene tribenzyl phenyl ethers, polyoxyethylene polyoxypropylene glycols, and the like.

[0048] These emulsifiers can be used alone or in combination of two or more.

[0049] The amount of emulsifier used is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the organosiloxane mixture. The particle size of the polyorganosiloxane latex can be adjusted to a desired value by adjusting the amount of emulsifier used. If the amount of emulsifier used is 0.05 parts by mass or more, the emulsion stability of the organosiloxane mixture emulsion is sufficient. If the amount of emulsifier is 10 parts by mass or less, the amount of emulsifier remaining in the powder of the graft copolymer can be sufficiently reduced, so that the deterioration of the thermal decomposition resistance and surface appearance of the resin composition containing the graft copolymer and a resin can be suppressed.

[0050] Examples of the acid catalyst used in the polymerization of the organosiloxane mixture include sulfonic acids such as aliphatic sulfonic acid, aliphatic-substituted benzenesulfonic acid, and aliphatic-substituted naphthalenesulfonic acid, 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, the use of mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid can narrow the particle size distribution of the polyorganosiloxane latex, and can also reduce the deterioration of the thermal decomposition resistance and the appearance defects of the molded product caused by the emulsifier component in the polyorganosiloxane latex.

[0051] 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 thermal decomposition resistance and appearance can be obtained.

[0052] In addition, since the amount of the acid catalyst used is a factor that determines the particle size of the polyorganosiloxane, in order to obtain a polyorganosiloxane having a particle size described below, it is more preferable to use 0.005 to 1.5 parts by mass of the acid catalyst per 100 parts by mass of the organosiloxane.

[0053] The mass average particle diameter of the polyorganosiloxane latex is preferably within the range of 250 to 1000 nm. By adjusting the mass average particle diameter of the polyorganosiloxane latex within the range of 250 to 1000 nm, it is possible to adjust the mass average particle diameter of the polyorganosiloxane-containing rubber (A) within the range of 300 to 2000 nm.

[0054] The "mass average particle diameter Dw / number average particle diameter Dn (Dw / Dn)" of the polyorganosiloxane latex is preferably within a range of 1.0 to 1.7, more preferably within a range of 1.0 to 1.5. By making Dw / Dn within a range of 1.0 to 1.7, a graft copolymer having excellent color development properties can be obtained when added to a resin.

[0055] The values ​​of Dw and Dn can be measured by the following method. A polyorganosiloxane latex is diluted with deionized water to a concentration of about 3% by mass, and the particle size is measured using a particle size distribution analyzer CHDF2000 manufactured by MATEC Corporation, USA. The median size is used as the average particle size.

[0056] The measurements can be performed under the following standard conditions recommended by MATEC. Cartridge: Dedicated capillary cartridge for particle separation (product name: C-202), Carrier fluid: Dedicated carrier fluid (product name: 2XGR500), Carrier liquid: neutral, Carrier liquid flow rate: 1.4 ml / min; Carrier fluid pressure: Approximately 4,000 psi (2,600 kPa), Measurement temperature: 35℃, Sample volume used: 0.1ml. The standard particle size material is monodisperse polystyrene with known particle sizes manufactured by DUKE Corporation in the United States, and contains 12 types of particles within the particle size range of 40 to 800 nm.

[0057] To the polyorganosiloxane latex obtained by the above method, an emulsifier may be added as necessary for the purpose of improving mechanical stability. As the emulsifier, the same anionic emulsifiers and nonionic emulsifiers as those exemplified above are preferable.

[0058] [Composite rubber] In the present invention, a composite rubber containing polyorganosiloxane and polyalkyl(meth)acrylate (hereinafter, abbreviated as "composite rubber") can be used as the rubber (A) containing polyorganosiloxane. The composite rubber is preferably a rubber containing the polyorganosiloxane and a polyalkyl(meth)acrylate having a homopolymer glass transition temperature Tg of 0°C or less, and more preferably a rubber obtained by polymerizing an alkyl(meth)acrylate in the presence of a polyorganosiloxane rubber.

[0059] The polyalkyl(meth)acrylate (PA) constituting the composite rubber can be obtained by polymerizing an alkyl(meth)acrylate component (hereinafter, abbreviated as "(meth)acrylate component for composite rubber"). The (meth)acrylate component for composite rubber preferably contains an alkyl(meth)acrylate having a glass transition temperature Tg, represented by the following FOX formula, of 0°C or lower and -100°C or higher, and a crosslinkable monomer. 1 / (273+Tg)=Σ(wi / (273+Tgi)) However, each symbol indicates the following: Tg: glass transition temperature of the copolymer (℃), wi: mass fraction of monomer i, Tgi: Glass transition temperature (℃) of the homopolymer obtained by polymerizing monomer i. The value of Tgi is described in POLYMER HANDBOOK Volume 1 (WILEY-INTERSCIENCE).

[0060] Examples of (meth)acrylate components for composite rubber include the following: methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. These may be used alone or in combination of two or more.

[0061] In order to set the glass transition temperature of the polyalkyl (meth)acrylate (PA) to 0° C. or lower and -100° C. or higher, it is preferable to use 50% by mass or more, and more preferably 80% by mass or more, of an alkyl (meth)acrylate having a homopolymer glass transition temperature of 0° C. or lower and -100° C. or higher. However, this mass % is a value based on 100% by mass of the total amount of the (meth)acrylate components for the composite rubber to be subjected to polymerization.

[0062] Examples of alkyl (meth)acrylates having a homopolymer glass transition temperature of 0° C. or less include ethyl acrylate, n-propyl acrylate, n-butyl acrylate, i-butyl acrylate, and 2-ethylhexyl acrylate. These may be used alone or in combination of two or more. Among these, n-butyl acrylate is particularly preferred in consideration of the impact resistance of the thermoplastic resin composition and the gloss of the molded product.

[0063] Examples of the crosslinkable monomer include the following polyfunctional monomers: allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,6-hexanediol diacrylate, triallyl trimellitate, etc. These may be used alone or in combination of two or more.

[0064] In the production of the composite rubber of the present invention, the amount of the crosslinkable monomer used in 100% by mass of the polyalkyl (meth)acrylate component is preferably 0.1 to 20.0% by mass, and more preferably 0.3 to 10.0% by mass. By using the crosslinkable monomer in an amount of 0.1 to 20.0% by mass, a molded product having excellent impact strength can be obtained.

[0065] The content of polyorganosiloxane in 100% by mass of the composite rubber is preferably 12 to 50% by mass, more preferably 14 to 45% by mass, and even more preferably 15 to 40% by mass. If the content of polyorganosiloxane is 12% by mass or more, a resin composition having an excellent balance between impact strength and color development can be obtained. If the content is 50% by mass or less, a resin composition having excellent color development can be obtained.

[0066] [Manufacturing method of compound rubber] The method for producing the composite rubber in the present invention is not particularly limited, and can be produced by, for example, emulsion polymerization, suspension polymerization, or microsuspension polymerization, but it is preferable to use emulsion polymerization.Among them, the method of emulsion polymerization of the (meth)acrylate component for composite rubber in the presence of polyorganosiloxane rubber latex to obtain the composite rubber latex is particularly preferable.

[0067] A method for preparing a mixture of polyorganosiloxane rubber latex and (meth)acrylate component for composite rubber includes adding the above alkyl (meth)acrylate and crosslinkable monomer to polyorganosiloxane rubber latex. In this way, the (meth)acrylate component for composite rubber (and crosslinkable monomer) is impregnated into the particles of polyorganosiloxane rubber, and then polymerized by the action of a known radical polymerization initiator. In this manufacturing method, a method for adding the (meth)acrylate component for composite rubber to the latex of polyorganosiloxane rubber includes adding the entire amount at once and adding it dropwise at a constant speed.

[0068] When producing the latex of the composite rubber, an emulsifier can be added to stabilize the latex and control the particle size of the composite rubber. The emulsifier is not particularly limited, and anionic emulsifiers and nonionic emulsifiers are preferred.

[0069] Examples of anionic emulsifiers include sodium alkylbenzene sulfonate, sodium alkyl diphenyl ether disulfonate, sodium alkyl sulfate, sodium polyoxyethylene alkyl sulfate, sodium polyoxyethylene nonylphenyl ether sulfate, sodium sarcosinate, potassium fatty acid, sodium fatty acid, dipotassium alkenyl succinate, rosin acid soap, sodium polyoxyethylene alkyl phosphate, and calcium polyoxyethylene alkyl phosphate.

[0070] Examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene distyrenated phenyl ether, and polyoxyethylene tribenzyl phenyl ether.

[0071] These emulsifiers may be used alone or in combination of two or more kinds.

[0072] Examples of radical polymerization initiators used in the polymerization of the (meth)acrylate component for composite rubber include azo-based initiators, peroxides, and redox-based initiators that combine peroxides with reducing agents. These may be used alone or in combination of two or more. Among these, azo-based initiators and redox-based initiators are preferred from the viewpoint of suppressing outgassing of the resin composition (particularly the aromatic polycarbonate resin composition).

[0073] Examples of azo initiators include the following: oil-soluble azo initiators such as 2,2'-azobisisobutyronitrile and dimethyl 2,2'-azobis(2-methylpropionate); 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'-dimethyleneisobutylamidine)dihydrochloride and 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride. These may be used alone or in combination of two or more.

[0074] Examples of peroxides include the following: inorganic peroxides such as hydrogen peroxide, potassium persulfate, and ammonium persulfate, and organic peroxides such as diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, succinic acid peroxide, t-butyl peroxy neodecanoate, t-butyl peroxy neoheptanoate, t-butyl peroxy pivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, and t-butyl peroxy-2-ethylhexanoate. These peroxides may be used alone or in combination of two or more.

[0075] Among these peroxides, it is preferable to use an organic peroxide from the viewpoint of suppressing outgassing of the aromatic polycarbonate resin composition. Among these, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, and cumene hydroperoxide are more preferable from the viewpoint of chemical resistance.

[0076] 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, or the like, and ferrous sulfate·ethylenediaminetetraacetic acid disodium salt.

[0077] These reducing agents may be used alone or in combination of two or more. When sodium formaldehyde sulfoxylate is used as the reducing agent, it is preferable to reduce the amount used as much as possible from the viewpoint of suppressing outgassing of the resin composition.

[0078] When an azo-based radical polymerization initiator is used, the amount of the radical polymerization initiator is preferably 0.01 to 1 part by mass per 100 parts by mass of the composite rubber.

[0079] In the case of a redox initiator, the amount of peroxide used is preferably 0.01 to 1 part by mass per 100 parts by mass of the composite rubber, and the amount of reducing agent used is preferably 0.01 to 1 part by mass per 100 parts by mass of the composite rubber.

[0080] [Mixture (B)] A polyorganosiloxane-containing graft copolymer can be obtained by graft polymerizing a mixture (B) of a vinyl monomer (b1) having an epoxy group and another vinyl monomer (b2) in the presence of the above-mentioned rubber (A) to form a graft portion made of a vinyl polymer on the rubber (A).

[0081] [Epoxy group-containing vinyl monomer (b1)] When the mixture (B) contains a vinyl monomer (b1) having an epoxy group, a graft copolymer having excellent reactivity with thermoplastic resins such as polyester resins can be obtained, and a resin composition and a molded article thereof having excellent impact strength, color development, and tensile properties can be obtained. In the case of an alloy of an aromatic polyester resin and an aromatic carbonate resin, the graft portion is formed using the mixture (B) containing the vinyl monomer (b1) having an epoxy group, so that the graft copolymer is easily arranged in the aromatic polyester resin, and the color development is significantly improved.

[0082] Examples of the vinyl monomer (b1) having an epoxy group include glycidyl methacrylate, glycidyl acrylate, vinyl glycidyl ether, allyl glycidyl ether, glycidyl ether of hydroxyalkyl (meth)acrylate, glycidyl ether of polyalkylene glycol (meth)acrylate, and glycidyl itaconate. Among these, glycidyl methacrylate is more preferable. These may be used alone or in combination of two or more kinds.

[0083] [Other vinyl monomers (b2)] Other vinyl monomers (b2) can be used in combination with the vinyl monomer (b1). Examples of other vinyl monomers (b2) include aromatic vinyl monomers such as styrene, α-methylstyrene, and vinyl toluene; 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; cyanide vinyl monomers such as acrylonitrile and methacrylonitrile; aryl (meth)acrylates such as phenyl (meth)acrylates in which the organic group of the ester group is an aryl group such as a phenyl group or a substituted phenyl group; hydroxyl group-containing monomers such as 2-hydroxypropyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate (e.g., hydroxyl group-containing alkyl (meth)acrylates); acrylic acid, methacrylic acid, maleic acid, itaconic acid, and the like. Examples of the monomer include unsaturated carboxylic acids such as carboxylic acid, halogen-containing monomers such as monobromophenyl (meth)acrylate, dibromophenyl (meth)acrylate, 2,4,6-tribromophenyl (meth)acrylate, monochlorophenyl (meth)acrylate, dichlorophenyl (meth)acrylate, and trichlorophenyl (meth)acrylate (e.g., halogen-containing phenyl (meth)acrylate); thiol-containing monomers such as isopropylthiol methacrylate (e.g., thiol-containing alkyl (meth)acrylate), and amino-containing monomers such as dimethylaminoethyl methacrylate (e.g., amino-containing alkyl (meth)acrylate); unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride; and maleimide derivatives such as N-phenylmaleimide, N-cyclohexylmaleimide, and Nt-butylmaleimide. These may be used alone or in combination of two or more. Among these, aromatic vinyl monomers, alkyl (meth)acrylates, vinyl cyanide monomers, and aryl (meth)acrylates in which the organic group of the ester group is an aryl group such as a phenyl group or a substituted phenyl group are preferred from the viewpoint of compatibility with the resin and color development of the resin composition. These vinyl monomers (b2) can be used alone or in combination of two or more.

[0084] [Content of vinyl monomer (b1) in vinyl monomer mixture (B)] The content of the vinyl monomer (b1) having an epoxy group in the vinyl monomer mixture (B) is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 1 to 5% by mass. When the vinyl monomer (b1) is contained in the vinyl monomer mixture (B) at 0.1% by mass or more, the reactivity with thermoplastic resins such as aromatic polyester resins is improved, and the interfacial strength is improved, so that a resin composition and a molded article thereof having excellent impact resistance and color development can be obtained. In particular, in the case of an alloy of an aromatic polyester resin and an aromatic carbonate resin, when the vinyl monomer (b1) is contained in the vinyl monomer mixture (B) at 0.1% by mass or more, the graft copolymer is easily arranged in the aromatic polyester resin, and the color development is significantly improved. In addition, by setting the content of the vinyl monomer (b1) in the vinyl monomer mixture (B) to 20 mass % or less, the graft copolymer is dispersed in a thermoplastic resin such as an aromatic polyester resin without agglomeration, so that a resin composition and a molded article thereof having excellent impact resistance and color development can be obtained.

[0085] [Epoxy equivalent of graft copolymer] The polyorganosiloxane-containing graft copolymer of the present invention has an epoxy equivalent of 2500 to 7800 g / eq as measured by the following measurement method. The epoxy equivalent is preferably in the range of 3000 to 7600 g / eq, more preferably in the range of 4000 to 6000 g / eq. The epoxy equivalent represents the amount of epoxy groups contained in the polyorganosiloxane-containing graft copolymer, and the smaller the value, the greater the amount of epoxy groups in the polyorganosiloxane-containing graft copolymer. The epoxy group is deactivated during polymerization or powder recovery, and is different from the amount charged during polymerization. Therefore, in the present invention, it has been found that the arrangement of rubber in an alloy of polyester and polycarbonate resin is controlled by the epoxy equivalent of the polyorganosiloxane-containing graft copolymer. When the epoxy equivalent of the polyorganosiloxane-containing graft copolymer is 7800 g / eq or less, when the polyorganosiloxane-containing graft copolymer is added to an alloy of polyester and polycarbonate resin, the polyorganosiloxane-containing graft copolymer is arranged in the polyester phase, resulting in significantly excellent color development. In addition, when the epoxy equivalent is 2500 g / eq or more, aggregation of the polyorganosiloxane-containing graft copolymer is suppressed, resulting in excellent fluidity and color development.

[0086] (Measurement method 1) Add 50ml of acetone (special grade) to 2.0g of polyorganosiloxane-containing graft copolymer, stir, and then add 50ml of ethanol (special grade). Add 10ml of 0.2mol / l hydrochloric acid-dioxane solution (special grade) to it and stir at 70℃ for 20 minutes. Then, cool to 25℃ and titrate to the end point with 0.1mol / l potassium hydroxide-ethanol solution using phenolphthalein indicator, and the value obtained by titration is "T". In addition, titrate the 0.2mol / l hydrochloric acid-dioxane solution used for the measurement to the end point with 0.1mol / l potassium hydroxide-ethanol solution using phenolphthalein indicator, and the value obtained by titration is "B". Using these values, calculate the epoxy equivalent using the following formula. Epoxy equivalent (g / eq) = 2.0 x 1000 / (0.994 x 0.1 x (B + (A / 5.61 x 2.0) - T)) In addition, "A" is the acid value of the polyorganosiloxane-containing graft copolymer.

[0087] [Rubber (A) content in graft copolymer (powder)] The content of the rubber (A) in the graft copolymer (powder) is preferably 10.0 to 99.9% by mass relative to 100% by mass of the graft copolymer (powder). If the content of the rubber (A) is 10.0% by mass or more, the impact resistance of the resin composition and its molded article will be sufficient, and if it is 99.9% by mass or less, the surface appearance of the molded article will be good, which is preferable. From the viewpoint of improving the impact resistance of the resin composition and its molded article, the content of the rubber (A) is preferably 50.0% by mass or more, more preferably 60% by mass or more, and even more preferably 65.0% by mass or more relative to 100% by mass of the graft copolymer (powder). In addition, from the viewpoint of forming a sufficient amount of graft parts and improving the surface appearance (color development) and tensile properties of the resin composition and its molded article, the content of the rubber (A) in the graft copolymer (powder) is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less.

[0088] [Graft content in graft copolymer] From the viewpoint of obtaining a resin composition and a molded article thereof having excellent impact strength, color development, and tensile properties, the content of the graft portion in the graft copolymer is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, relative to 100% by mass of the graft copolymer. In addition, from the viewpoint of providing a sufficient amount of rubber (A) in the graft copolymer and improving the impact resistance of the resin composition and its molded article, the content of the graft portion in the graft copolymer is preferably 50 mass% or less, more preferably 40 mass% or less, and even more preferably 35 mass% or less, relative to 100 mass% of the graft copolymer.

[0089] [Mass average particle size of graft copolymer] The mass average particle diameter of the polyorganosiloxane-containing graft copolymer of the present invention is 300 to 2000 nm, more preferably 300 to 1000 nm, even more preferably 300 to 800 nm, and even more preferably 350 to 600 nm. When the mass average particle diameter of the polyorganosiloxane-containing graft copolymer is 300 nm or more, the impact resistance and color development when added to a resin are good, and when it is 2000 nm or less, the dispersibility when added to a resin is good, and the appearance of the molded product is good.

[0090] [Method for producing graft copolymer] As a method of graft copolymerization (method of forming a graft portion), for example, a method of adding a mixture (B) of a vinyl monomer (b1) and a vinyl monomer (b2) to a latex of a rubber (A) and polymerizing in one or multiple stages can be mentioned. In order to improve the reactivity of the obtained polyorganosiloxane-containing graft copolymer with a thermoplastic resin such as an aromatic polyester resin, it is preferable to polymerize in one stage, or to add the vinyl monomer (b1) only in the final stage in the case of polymerization in multiple stages, since a graft portion having a reactive group can be efficiently formed in the outermost layer.

[0091] When forming the graft portion (graft copolymerization), an emulsifier can be added as necessary. The emulsifier used in forming the graft portion (graft copolymerization) can be the same as the emulsifier used in producing the rubber (A), and anionic emulsifiers and nonionic emulsifiers are preferred.

[0092] When the powder of the graft copolymer is recovered from the latex of the graft copolymer, either a spray drying method or a coagulation method can be used.

[0093] The spray drying method is a method in which the latex of the graft copolymer is sprayed in the form of fine droplets in a dryer and dried by applying a heated gas for drying. Examples of methods for generating fine droplets include a rotating 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 any of a small capacity for laboratory use and a large capacity for industrial use. The temperature of the heating gas for drying is preferably 200°C or less, more preferably 120 to 180°C. Two or more types of graft copolymer latexes produced separately can be spray-dried together. Furthermore, in order to improve powder properties such as blocking during spray drying and bulk density, an optional component such as silica can be added to the latex of the graft copolymer and then spray-dried.

[0094] The coagulation method is a method in which the latex of the graft copolymer is coagulated, and the graft copolymer is separated, recovered, and dried. First, the latex of the graft copolymer is poured into hot water in which a coagulant is dissolved, and the graft copolymer is separated by salting out and coagulation. Next, the separated wet graft copolymer is recovered with a reduced water content by dehydration or the like. The recovered graft copolymer is dried using a squeeze dehydrator or a hot air dryer.

[0095] Examples of the coagulant include inorganic salts such as aluminum chloride, aluminum sulfate, sodium sulfate, magnesium sulfate, sodium nitrate, and calcium acetate, and acids such as sulfuric acid, with calcium acetate being particularly preferred. These coagulants can be used alone or in combination of two or more, but when using two or more, it is necessary to select a combination that does not form a water-insoluble salt. For example, the combined use of calcium acetate and sulfuric acid or its sodium salt is not preferred because it forms a water-insoluble calcium salt.

[0096] The coagulant is usually used as an aqueous solution. The concentration of the aqueous coagulant solution is preferably 0.1% by mass or more, particularly 1% by mass or more, from the viewpoint of stably coagulating and recovering the graft copolymer. In addition, from the viewpoint of reducing the amount of coagulant remaining in the recovered graft copolymer and preventing deterioration of the molded appearance of the molded product, the concentration of the aqueous coagulant solution is preferably 20% by mass or less, particularly 15% by mass or less. The amount of the aqueous coagulant solution is not particularly limited, but is preferably 10 parts by mass or more and 500 parts by mass or less relative to 100 parts by mass of the latex.

[0097] The method of contacting the latex with the aqueous coagulant solution is not particularly limited, but typically includes the following methods: (1) A method in which latex is continuously added to an aqueous coagulant solution while stirring the solution and the solution is maintained for a certain period of time, and (2) A method in which the aqueous coagulant solution and latex are continuously poured into a vessel equipped with a stirrer at a certain ratio while being contacted with each other, and a mixture containing the coagulated polymer and water is continuously withdrawn from the vessel. The temperature when the latex is brought into contact with the aqueous coagulant solution is not particularly limited, but is preferably from 30° C. to 100° C. The contact time when the latex is brought into contact with the aqueous coagulant solution is not particularly limited.

[0098] The coagulated graft copolymer is washed with about 1 to 100 times the mass of water, and the wet graft copolymer filtered is dried using a fluidized dryer, a squeeze dehydrator, or the like. The drying temperature and drying time may be appropriately determined depending on the graft copolymer obtained. It is also possible to directly send the graft copolymer discharged from the fluidized dryer, squeeze dehydrator, or extruder after drying or dehydration to an extruder or molding machine that produces a resin composition without recovering it, and mix it with a thermoplastic resin to obtain a molded product.

[0099] In the present invention, the graft copolymer is preferably recovered by a coagulation method from the viewpoint of the thermal decomposition resistance of the resin composition obtained by mixing the graft copolymer with the thermoplastic resin.

[0100] <Thermoplastic resin composition> The polyorganosiloxane-containing graft copolymer of the present invention can be mixed with a thermoplastic resin and used as a thermoplastic resin composition.

[0101] 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.

[0102] [Thermoplastic resin] Examples of thermoplastic resins include the following: olefin-based 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), acrylic acid ester-styrene-acrylonitrile copolymer (ASA), and acrylonitrile-ethylene-propylene rubber-styrene copolymer (AES); acrylic (Ac)-based resins such as polymethyl methacrylate (PMMA); polycarbonate (PC) resins; polyamide (PA) resins; polyester (PEs) resins such as polyethylene terephthalate (PET) resins and polybutylene terephthalate (PBT) resins; polyphenylene ether (PPE) resins and modified polyphenylene ether (m-PPE) resins. Engineering plastics such as PPE resin, polyoxymethylene (POM) resin, polysulfone (PSO) resin, polyarylate (PAr) resin, polyphenylene (PPS) resin, etc.; thermoplastic polyurethane (PU) resin; polyvinyl chloride (PVC) resin such as rigid polyvinyl chloride resin, semi-rigid polyvinyl chloride resin, soft polyvinyl chloride resin, etc.; alloys of PC resin and St-based resin such as PC / ABS; alloys of PVC 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 resin and other resins such as PPE / HIPS, PPE / PBT, PPE / PA; alloys of PVC resin and acrylic resin such as PVC / PMMA, etc.

[0103] Examples of thermoplastic elastomers include styrene-based elastomers, olefin-based elastomers, vinyl chloride-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, fluorine-based elastomers, 1,2-polybutadiene, trans-1,4-polyisoprene, etc. Among these, urethane-based elastomers, polyester-based elastomers, and polyamide-based elastomers are preferred.

[0104] Among the above-mentioned thermoplastic resins, the following are preferable: St-based resin, PC resin, PA resin, PET resin, PBT resin, PPE resin, m-PPE resin, POM resin, PU resin, alloys of PC resin and St-based resin such as PC / ABS, alloys of PA resin and St-based resin such as PA / ABS, alloys of PA resin and TPE, alloys of PA resin and polyolefin-based resin such as PA / PP, alloys of PC resin and PEs resin such as PC / PBT, alloys of PPE-based resin and other resin such as PPE / PBT and PPE / PA, etc.

[0105] Furthermore, among the above-mentioned resins, from the viewpoint of maximizing the effect of improving pigment colorability and impact resistance, polyester resins are preferred, aromatic polyesters are more preferred, alloys of polyester resins and polycarbonates are even more preferred, alloys of aromatic polyester resins and aromatic polycarbonates are particularly preferred, and among aromatic polyester resins, polybutylene terephthalate resins are highly preferred, and among aromatic carbonate resins, polycarbonate resins are extremely preferred.

[0106] Examples of polybutylene terephthalate resins (PBT resins) include commercially available products such as "Trecon" manufactured by Toray Industries, Inc., "NovaDuran" manufactured by Mitsubishi Engineering Plastics Corporation, and "Duranex" manufactured by Polyplastics Co., Ltd. Moreover, the polybutylene terephthalate resin can be obtained by polymerization using a known method, for example, by dehydration condensation of terephthalic acid or its alkyl diester with 1,4-butanediol using a known method.

[0107] Examples of aromatic polycarbonate resins include Iupilon (registered trademark) S-1000, S-2000, S-3000, H-3000, and H-4000 (manufactured by Mitsubishi Engineering Plastics Corporation), and Panlite (registered trademark) L1250, L1225, and K1300 (manufactured by Teijin Chemical Co., Ltd.).

[0108] The content of the polyorganosiloxane-containing graft copolymer in the total of 100% by mass of the thermoplastic resin and the polyorganosiloxane-containing graft copolymer is not particularly limited, but can be set in the range of 0.5 to 99.9% by mass, preferably 1 to 40% by mass, more preferably 1 to 30% by mass, and even 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 99.9% by mass or less, a resin composition excellent in surface appearance can be obtained. The content of the resin components (the graft copolymer and the thermoplastic resin) in the resin composition of the present invention is not particularly limited as long as it is within a range in which desired characteristics can be obtained, but can be set in the range of, for example, 80 to 100% by mass with respect to the resin composition, preferably 90% by mass or more, and more preferably 95% by mass or more. The components other than the resin components in the resin composition of the present invention include the following additives.

[0109] [Additives] The thermoplastic resin composition may contain various additives as long as they do not deviate from the object of the present invention. Examples of additives include stabilizers such as phenol-based stabilizers, phosphorus-based stabilizers, ultraviolet absorbers, and amine-based light stabilizers; flame retardants such as phosphorus-based, bromine-based, silicone-based, and organometallic salt-based; modifiers for imparting various physical properties such as hydrolysis resistance; fillers such as titanium oxide and talc; dyes and pigments; and plasticizers. The content of the additives is not particularly limited as long as it does not deviate from the object of the present invention, but can be set to a range of 20% by mass or less relative to the thermoplastic resin composition, preferably 10% by mass or less, more preferably 5% by mass or less, and from the viewpoint of obtaining a sufficient addition effect, preferably 0.1% by mass or more, more preferably 0.2% by mass or more.

[0110] When the thermoplastic resin is an aromatic polyester resin, the following can be used as additives: flame retardants, anti-drip agents (e.g., fluorinated polyolefins, silicones, and aramid fibers), lubricants, 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. These can be used alone or in combination of two or more.

[0111] [Method for preparing resin composition] The method for preparing the thermoplastic resin composition of the present invention is not particularly limited, but the composition can be prepared by mixing and dispersing the graft copolymer, the thermoplastic resin, and various additives used as necessary using a V-type blender, a Henschel mixer, or the like, and melt-kneading the mixture using an extruder or a kneader such as a Banbury mixer, a pressure kneader, or a roll. The mixing of each of these components can be carried out batchwise or continuously, and the mixing order of each component is not particularly limited. The melt-kneaded product can be made into pellets and used for various moldings.

[0112] [Molded body] The molded article according to the present invention is obtained by molding the above-mentioned thermoplastic resin composition. Examples of the method for molding the thermoplastic resin composition include a method for molding the thermoplastic resin composition or a mixture of the graft copolymer powder and a thermoplastic resin with an injection molding machine.

[0113] There are no particular limitations on the applications of the molded articles, and they can be widely used industrially as materials in the fields of automobiles, office automation equipment, and electrical and electronic equipment. EXAMPLES

[0114] The present invention will be specifically described below with reference to examples and comparative examples. Prior to the examples, various evaluation methods and polyorganosiloxane latex production examples 1 and 2 will be described. Examples 1 to 6 and comparative examples 1 to 8 are examples relating to the production and evaluation of graft copolymers, and Examples 7 to 13 and comparative examples 9 to 23 are examples relating to the production and evaluation of thermoplastic resin compositions. In the production examples and examples, "parts" and "%" mean "parts by mass" and "% by mass" unless otherwise specified.

[0115] <Evaluation method> (1) Solids A mass w1 of polyorganosiloxane latex is dried in a hot air dryer at 180°C for 30 minutes, the mass w2 of the residue after drying is measured, and the solid content [%] is calculated using the following formula. Solid content [%] = w2 / w1 × 100

[0116] (2) Mass average particle diameter (Dw) The rubber latex or graft copolymer latex is diluted with deionized water to a solid content concentration of about 3%, and the sample is used to measure the particle size and mass average particle size Dw using the above-mentioned CHDF2000 particle size distribution analyzer manufactured by MATEC Corporation, USA, under the above-mentioned conditions.

[0117] (3) Charpy impact strength In accordance with JIS K 7111, the Charpy impact strength of a test piece (length 80.0 mm x width 10.0 mm x thickness 4 mm, with a V-notch) is measured at temperatures of 23°C and -30°C.

[0118] (4) Charpy impact strength after wet heat test A test piece (length 80.0 mm x width 10.0 mm x thickness 4 mm, with a V-notch) is exposed to conditions of 120°C and 2 atm for 48 hours using a pressure cooker tester, and the Charpy impact strength at a temperature of 23°C is measured in accordance with JIS K 7111.

[0119] (5) Color development JIS Z 8729(L * a * b* The measurement was performed in accordance with JIS Z 8722, using SE-4000 manufactured by Nippon Denshoku Kogyo Co., Ltd., and the L of the test piece obtained by injection molding was * Measure the L * The lower the value, the better the color development.

[0120] (6) Liquidity The melt flow rate is measured in accordance with JIS K 7210 at a temperature of 250°C and a load of 2.16 kgf (21.18 N).

[0121] (7) Tensile properties In accordance with JIS K 7161, measurements are performed at a temperature of 23°C and a test speed of 50 mm / min using a multipurpose test piece shape specified in JIS-7139 molded using the one-point gate method.

[0122] (8) Bending properties In accordance with JIS K 7171, measurements are performed using test pieces (length 80.0 mm x width 10.0 mm x thickness 4 mm) at a temperature of 23°C and a test speed of 2 mm / min.

[0123] (9) Epoxy equivalent of polyorganosiloxane-containing graft copolymer The epoxy equivalent is measured according to the method described above (measurement method 1). Note that the acid value is set to 0 if the polymer composition does not contain an acid component such as acrylic acid.

[0124] [Production Example 1] 2 parts of tetraethoxysilane (TEOS), 2 parts of γ-methacryloyloxypropyldimethoxymethylsilane (DSMA), and 96 parts of octamethylcyclotetrasiloxane (product name: TSF404, manufactured by Momentive Performance Materials Japan, Inc.) were mixed to obtain 100 parts of an organosiloxane mixture. An aqueous solution of 1 part of sodium dodecylbenzenesulfonate (DBSNa) dissolved in 150 parts of deionized water was added to the mixture, and the mixture was stirred at 10,000 rpm for 5 minutes with a homomixer, and then passed through a homogenizer twice at a pressure of 20 MPa to obtain a stable premixed emulsion.

[0125] Next, the 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, and then a mixture of 0.20 parts of sulfuric acid and 49.8 parts of distilled water was continuously added over 3 minutes. The state of being heated to 80°C was maintained for 7 hours to cause a polymerization reaction, and then the reaction product was cooled to room temperature (25°C), and the reaction product obtained was kept at 25°C for 6 hours. Then, a 5% aqueous sodium hydroxide solution was added to neutralize the reaction liquid to pH 7.0, and polyorganosiloxane latex (A-1) was obtained.

[0126] The solid content of the polyorganosiloxane latex (A-1) was 29.8% by mass. The number average particle diameter (Dn) of this latex, measured by the above-mentioned method using a capillary particle size distribution analyzer, was 384 nm, the mass average particle diameter (Dw) was 403 nm, and Dw / Dn was 1.05.

[0127] [Production Example 2] 2 parts of γ-methacryloyloxypropyldimethoxymethylsilane (DSMA) and 98 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 membered rings) were mixed to obtain 100 parts of an organosiloxane mixture. An aqueous solution of 0.68 parts of sodium dodecylbenzenesulfonate (DBSNa) dissolved in 150 parts of deionized water was added to the mixture, and the mixture was stirred at 10,000 rpm for 5 minutes with a homomixer, and then passed through a homogenizer twice at a pressure of 20 MPa to obtain a stable premixed emulsion.

[0128] Next, an aqueous solution of 10 parts of dodecylbenzenesulfonic acid (DBSH) dissolved in 680 parts of deionized water was placed in a 5-liter separable flask equipped with a cooling condenser, and the aqueous solution was heated to a temperature of 80°C. Then, the above emulsion was continuously added over a period of 240 minutes to cause a polymerization reaction, and the mixture was cooled to room temperature (25°C), and a 5% aqueous sodium hydroxide solution was added to neutralize the reaction liquid to pH 7.0, thereby obtaining a polyorganosiloxane latex (A-2).

[0129] The solid content of the polyorganosiloxane latex (A-2) was 18.2% by mass. The number average particle diameter (Dn) of this latex, measured by the above-mentioned method using a capillary particle size distribution analyzer, was 67 nm, the mass average particle diameter (Dw) was 83 nm, and Dw / Dn was 1.24.

[0130] [Example 1] 29.8 parts of the polyorganosiloxane latex (A-1) obtained in Production Example 1 (10.0 parts in terms of polymer) was collected in a 5-liter separable flask, and 160 parts of deionized water was added and mixed. Next, a mixture of 59.1 parts of butyl acrylate (BA), 0.9 parts of allyl methacrylate (AMA), and 0.25 parts of t-butyl hydroperoxide (t-BH) was added to the separable flask, and stirring was continued for 1 hour at 25°C to impregnate the polyorganosiloxane.

[0131] The atmosphere in the separable flask was replaced with nitrogen by passing a nitrogen gas flow through the flask, and the liquid temperature was raised to 50°C. When the liquid temperature reached 50°C, an aqueous solution of 0.001 parts of ferrous sulfate (Fe), 0.003 parts of disodium ethylenediaminetetraacetate (EDTA), and 0.24 parts of sodium formaldehyde sulfoxylate (SFS) in 10 parts of deionized water was added to initiate radical polymerization. In order to complete the polymerization of the acrylate component, the liquid temperature was maintained at 65°C for 1 hour, and a latex of a composite rubber of polyorganosiloxane and poly-n-butyl acrylate was obtained.

[0132] The liquid temperature of this latex was set to 65°C, and a mixture of 25.5 parts of methyl methacrylate (MMA), 1.5 parts of butyl acrylate (BA), 3.0 parts of glycidyl methacrylate (GMA), and 0.03 parts of t-butyl hydroperoxide (t-BH) was dropped into this latex over one hour to initiate a graft polymerization reaction. After the dropwise addition was completed, the temperature was maintained at 65°C for one hour, and then cooled to 25°C to obtain a latex of polyorganosiloxane-containing graft copolymer (G-1).

[0133] Next, 500 parts of an aqueous solution with a calcium acetate concentration of 1% by mass was heated to 85° C., and 340 parts of the latex of the graft copolymer (G-1) was gradually dropped into the aqueous solution while stirring to coagulate it. The obtained graft copolymer (G-1) was filtered, washed, dehydrated, and then dried to obtain a powder of the graft copolymer (G-1). The polymerization rate, mass average particle size, and epoxy equivalent of the obtained graft copolymer (G-1) are shown in Table 1. The 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. The polymerization rate was calculated by measuring the mass of the solid content of the latex sampled at the end of the graft polymerization, and dividing this value by the mass of the solid content when it was assumed that all the monomer components used in all steps had become residues.

[0134] [Examples 2 to 6, Comparative Examples 1 to 8] Polyorganosiloxane-containing graft copolymers (G-2 to G-6, and G'-1 to G'-8) were 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, graft copolymer powders were obtained. The polymerization rate, mass average particle size, and epoxy equivalent of each of the obtained graft copolymers are shown in Table 1.

[0135] The abbreviations in Table 1 are as follows. BA: n-butyl acrylate AMA: Allyl methacrylate MMA: Methyl methacrylate GMA: glycidyl methacrylate HPMA: Hydroxypropyl methacrylate FM-1: Unsaturated fatty acid hydroxyalkyl ester modified ε-caprolactone (manufactured by Daicel Corporation, product name: Plaxel FM-1)

[0136] [Table 1]

[0137] [Example 7, Comparative Examples 9-16] Each of the polyorganosiloxane-containing graft copolymers (G-1), (G'-1) to (G'-7) powders, polybutylene terephthalate resin (manufactured by Mitsubishi Engineering Plastics Co., Ltd., product name: Novaduran 5010R5), and carbon black (manufactured by Mitsubishi Chemical Co., Ltd., product name: Carbon Black #960B) were blended and mixed in the ratios shown in Table 2. The blend was dried at 120°C for 12 hours, then fed to a 30mmΦ twin-screw extruder (L / D=30) and 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-9).

[0138] The pellets obtained were dried at 120°C for 12 hours, and then fed to a 100t injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., product name: SE-100DU) and injection molded at a cylinder temperature of 260°C and a mold temperature of 60°C to obtain "test piece 1" (length 80mm, width 10mm, thickness 4mm), "test piece 2" (length 100mm, width 50mm, thickness 2mm), and "test piece 3" (multipurpose test piece shape defined by JIS-7139 molded by one-point gate method). For test piece 1, a V-notch was cut using a notching machine for Charpy impact testing in accordance with JIS K 7111-1A. Next, the Charpy impact strength, Charpy impact strength after wet heat test, color development, fluidity, tensile properties, and bending properties were measured using each test piece. The evaluation results are shown in Table 2.

[0139] [Comparison of resin composition performance] Example 7 had an excellent balance of impact strength, color development, fluidity, tensile properties, and bending properties.

[0140] Comparative Example 9 did not contain a vinyl monomer having an epoxy group in the graft moiety, and therefore was inferior in impact strength and tensile properties (strength at breaking point and tensile modulus). Comparative Example 12 did not contain a vinyl monomer having an epoxy group in the graft portion, and the graft portion in the graft copolymer was relatively small (the rubber portion was relatively large), so the tensile properties (strength at break and tensile modulus) and color development were poor. Comparative Examples 14 and 15 were inferior in tensile properties (tensile modulus) since they did not contain a vinyl monomer having an epoxy group in the graft moiety. Comparative Example 16 did not contain a vinyl monomer having an epoxy group in the graft portion, and the graft portion in the graft copolymer was relatively small (the rubber portion was relatively large), so the tensile properties (tensile modulus) and color development were poor.

[0141] In Comparative Example 10, the Si content in the composite rubber was low, so the color development was poor. Also, the tensile properties were poor because the second layer (outermost layer) of the graft section did not contain a monomer having an epoxy group (resulting in a large epoxy equivalent).

[0142] In Comparative Example 11, the mass average particle diameter of the graft copolymer was small, and therefore the color development was poor.

[0143] Comparative Example 13, which did not contain a graft copolymer, had poor impact strength.

[0144] [Table 2]

[0145] [Examples 8-13, Comparative Examples 17-23] Each of the polyorganosiloxane-containing graft copolymers (G-1) to (G-6), (G'-1) to (G'-4), (G'-7), and (G'-8) powders, polybutylene terephthalate resin (manufactured by Mitsubishi Engineering Plastics Corporation, trade name; Novaduran 5010R5), polycarbonate resin (manufactured by Mitsubishi Engineering Plastics Corporation, trade name; Iupilon S-2000F, viscosity average molecular weight 24,000), carbon black (manufactured by Mitsubishi Chemical Corporation, trade name; Carbon Black #960B), and octadecyl phosphate as a phosphorus stabilizer (manufactured by ADEKA Corporation, trade name; Adeka STAB AX-71) were blended and mixed in the ratios shown in Table 3. The blend was dried at 120°C for 12 hours, and then fed into a 30 mmΦ twin-screw extruder (L / D=30) and 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-10) to (H-22).

[0146] The pellets obtained were dried at 120°C for 12 hours, and then fed to a 100t injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., product name: SE-100DU) and injection molded at a cylinder temperature of 260°C and a mold temperature of 60°C to obtain "test piece 1" (length 80mm, width 10mm, thickness 4mm), "test piece 2" (length 100mm, width 50mm, thickness 2mm), and "test piece 3" (multipurpose test piece shape defined by JIS-7139 molded by one-point gate method). For test piece 1, a V-notch was cut using a notching machine for Charpy impact testing in accordance with JIS K 7111-1A. Next, the Charpy impact strength, color development, fluidity, tensile properties, and bending properties were measured using each test piece. The evaluation results are shown in Table 3.

[0147] [Comparison of resin composition performance] Examples 8 to 13 were excellent in the balance of impact strength, color development, fluidity, tensile properties, and bending properties, and were particularly excellent in color development.

[0148] In Comparative Examples 17, 20, and 22, since the grafted portion did not contain a vinyl monomer having an epoxy group, the graft copolymer was not arranged in the PBT phase, and the color development was particularly poor.

[0149] In Comparative Example 18, since the Si content in the composite rubber was low and the epoxy equivalent of the graft copolymer exceeded the upper limit of the range of 2500 to 7800 g / eq, the graft copolymer was not arranged in the PBT phase, and the color development was poor.

[0150] In Comparative Example 19, the mass average particle diameter of the graft copolymer was small, and therefore the color development was poor.

[0151] Comparative Example 21 did not contain a graft copolymer and therefore had poor impact strength.

[0152] In Comparative Example 23, the epoxy equivalent of the graft copolymer was below the lower limit of the range of 2500 to 7800 g / eq (too many epoxy groups), so the graft copolymer aggregated and the color development and flowability were poor.

[0153] [Table 3] [Industrial Applicability]

[0154] The graft copolymer powder according to the present invention can be added to resins and is useful for improving the color development and mechanical properties of resin compositions and their molded articles. The resin compositions and their molded articles according to the present invention can be widely used as materials in the fields of automobiles, office automation equipment, home appliances, housings, and other electrical and electronic fields.

Claims

1. A polyorganosiloxane-containing graft copolymer powder obtained by graft polymerizing a mixture (B) of a vinyl monomer (b1) having an epoxy group and another vinyl monomer (b2) onto a rubber (A) containing polyorganosiloxane, The content of polyorganosiloxane (A1) contained in the rubber (A) is 12 to 50 mass %, The polyorganosiloxane-containing graft copolymer powder has a mass average particle size of 300 to 2000 nm; The epoxy equivalent of the polyorganosiloxane-containing graft copolymer powder is 2500 to 7800 g / eq; The vinyl monomer mixture (B) contains the vinyl monomer (b1) in an amount of 0.1 to 20 mass %, A polyorganosiloxane-containing graft copolymer powder, in which the content of graft portions formed from the vinyl monomer mixture (B) in the polyorganosiloxane-containing graft copolymer powder is 10 mass% or more.

2. The polyorganosiloxane-containing graft copolymer powder according to claim 1, wherein the graft portion of the polyorganosiloxane-containing graft copolymer powder has a single-layer structure containing an epoxy group, or a multi-layer structure containing an epoxy group in at least the outermost layer.

3. The polyorganosiloxane-containing graft copolymer powder according to claim 1 or 2, wherein the content of the graft portion in the polyorganosiloxane-containing graft copolymer powder is 20% by mass or more.

4. The polyorganosiloxane-containing graft copolymer powder according to claim 1 or 2, wherein the content of the graft portion in the polyorganosiloxane-containing graft copolymer powder is 30% by mass or more.

5. The polyorganosiloxane-containing graft copolymer powder according to any one of claims 1 to 4, wherein the content of the graft portion in the polyorganosiloxane-containing graft copolymer powder is 50 mass% or less.

6. The polyorganosiloxane-containing graft copolymer powder according to any one of claims 1 to 5, wherein the mass average particle diameter of the polyorganosiloxane-containing graft copolymer powder is 300 to 800 nm.

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

8. The resin composition according to claim 7, which comprises a thermoplastic resin.

9. The resin composition according to claim 8 , comprising a polyester resin as the thermoplastic resin.

10. The resin composition according to claim 9, wherein the polyester resin is an aromatic polyester resin.

11. The resin composition according to claim 8 , wherein the thermoplastic resin comprises a polyester resin and a polycarbonate resin.

12. The resin composition according to claim 11, wherein the polyester resin is an aromatic polyester resin, and the polycarbonate resin is an aromatic polycarbonate resin.

13. A molded article made of the resin composition according to any one of claims 7 to 12.

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