Resin composition and molded article

Abstract

The present invention provides a resin composition which enables the achievement of a molded body that exhibits excellent flame retardancy without significantly deteriorating the impact resistance characteristics. A resin composition according to the present invention contains a thermoplastic resin and a polyorganosiloxane-containing polymer, while satisfying formula (1).　(1): Y - X ≥ 20°C (In formula (1), X represents the temperature at which the residual amount of the polyorganosiloxane-containing polymer reaches 1 part by mass if 100 parts by mass of the polyorganosiloxane-containing polymer is heated up to 550°C at a heating rate of 10°C / minute at a nitrogen flow rate of 200 mL / minute; and Y represents the temperature at which the residual amount of the thermoplastic resin reaches 90 parts by mass if 100 parts by mass of the thermoplastic resin is heated up to 550°C at a heating rate of 10°C / minute at a nitrogen flow rate of 200 mL / minute.)

Description

[Technical Field]

[0001] The present invention relates to a resin composition and a molded article. This application claims priority based on Japanese Patent Application No. 2021-056874, filed on March 30, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] Rubber-containing polymers, in which vinyl monomers are polymerized onto rubbery polymers, can be dispersed in a wide variety of resins while maintaining a predetermined rubber particle size and rubber structure, and are therefore suitable for use in resins that require impact strength.

[0003] Among these, silicone rubbers are less susceptible to hardening and discoloration due to heat or ultraviolet light than butadiene rubbers, and have excellent durability, making them suitable for use in applications requiring long-term maintenance of mechanical properties, such as building materials and automotive components. Polyorganosiloxanes, typified by polydimethylsiloxane, are used as silicone rubbers, and various graft copolymers using rubbers containing such polyorganosiloxanes are known.

[0004] Patent Document 1 describes a polyorganosiloxane-containing graft copolymer having a specific glass transition temperature (Tg), which is obtained by graft polymerizing a monofunctional vinyl monomer and a polyfunctional vinyl monomer in a specific ratio onto a rubber containing polyorganosiloxane. Patent Document 2 describes a polyorganosiloxane-containing graft copolymer having a volume average particle size of 300 to 2000 nm and a polyorganosiloxane content of 70 to 98 mass %. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2018 / 225582 [Patent Document 2] International Publication No. 2013 / 162080 Summary of the Invention [Problem to be solved by the invention]

[0006] When the polyorganosiloxane-containing polymer described in Patent Document 1 or 2 is added to a resin, the resulting molded article may have a problem with flame retardancy. Also, when a flame retardant such as a metal salt is added to a thermoplastic resin in addition to the polyorganosiloxane-containing polymer in order to improve flame retardancy, impact resistance may be significantly reduced. An object of the present invention is to provide a resin composition that can give a molded article exhibiting excellent flame retardancy without significantly reducing impact resistance. [Means for solving the problem]

[0007] The present invention has the following aspects. [1] A thermoplastic resin and a polyorganosiloxane-containing polymer, A resin composition that satisfies the following formula (1): YX≧20℃ (1) (In formula (1), X means the temperature at which the residual amount of the polyorganosiloxane-containing polymer becomes 1 part by mass when 100 parts by mass of the polyorganosiloxane-containing polymer is heated to 550°C at 10°C / min under conditions of a nitrogen flow rate of 200 mL / min, and Y means the temperature at which the residual amount of the thermoplastic resin becomes 90 parts by mass when 100 parts by mass of the thermoplastic resin is heated to 550°C at 10°C / min under conditions of a nitrogen flow rate of 200 mL / min.) [2] The resin composition of [1], which satisfies the following formula (2): XZ≦40℃ (2) (In formula (2), X has the same meaning as X in formula (1), and Z means the temperature at which the remaining amount of the polyorganosiloxane-containing polymer becomes 70 parts by mass when 100 parts by mass of the polyorganosiloxane-containing polymer is heated to 550°C at a rate of 10°C / min under the condition of a nitrogen flow rate of 200 mL / min.) [3] The polyorganosiloxane-containing polymer is a polymer having a composite and a graft portion, The composite includes a polyorganosiloxane and a first vinyl polymer; The resin composition according to [1] or [2], wherein the graft portion contains a second vinyl polymer. [4] The resin composition according to [3], wherein the proportion of the polyorganosiloxane in 100% by mass of the polyorganosiloxane-containing polymer is 70% by mass or more and 98% by mass or less. [5] The resin composition according to [3] or [4], wherein the first vinyl polymer contains a structural unit derived from a (meth)acrylate monomer. [6] The resin composition according to any one of [3] to [5], wherein the polyorganosiloxane contains structural units derived from a siloxane-based crosslinking agent, and the proportion of the structural units derived from the siloxane-based crosslinking agent in 100% by mass of the polyorganosiloxane is 3% by mass or less. [7] A molded article containing the resin composition of any one of [1] to [6]. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a resin composition that can give a molded article that exhibits excellent flame retardancy without significantly reducing impact resistance. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the embodiments of the present invention will be described in detail, but the present invention is not limited to these descriptions, and modifications other than those exemplified below can be made as appropriate within the scope that does not detract from the spirit of the present invention. In the present invention, the vinyl monomer means a compound having a polymerizable double bond. In the present invention, (meth)acrylic means one or both of acrylic and methacrylic, and (meth)acrylic acid ester means one or both of acrylic acid ester and methacrylic acid ester. In this specification, the symbol "to" is used to mean that the numerical values before and after it are included as the lower and upper limits. That is, a numerical value expressed as "A to B" means A or more and B or less.

[0010] The resin composition according to this embodiment contains a thermoplastic resin and a polyorganosiloxane-containing polymer, and satisfies the following formula (1). YX≧20℃ (1)

[0011] In formula (1), X means the temperature at which the residual amount of polyorganosiloxane-containing polymer becomes 1 part by mass when 100 parts by mass of polyorganosiloxane-containing polymer is heated to 550°C at 10°C / min under conditions of a nitrogen flow rate of 200 mL / min, and Y means the temperature at which the residual amount of thermoplastic resin becomes 90 parts by mass when 100 parts by mass of thermoplastic resin is heated to 550°C at 10°C / min under conditions of a nitrogen flow rate of 200 mL / min.

[0012] <Polyorganosiloxane-containing polymer> A polyorganosiloxane-containing polymer according to one embodiment of the present invention (hereinafter also referred to as "polymer (C)") comprises a polymer (A) and a second vinyl polymer (B) (hereinafter also referred to as "vinyl polymer (B)"). The polymer (A) is preferably a composite containing at least a polyorganosiloxane (A1) and further containing a first vinyl polymer (A2) (hereinafter also referred to as "vinyl polymer (A2)"). The polyorganosiloxane (A1) and the vinyl polymer (B) are preferably at least partially crosslinked. The polyorganosiloxane-containing polymer is preferably a graft copolymer having a composite (composite rubbery polymer) of the polyorganosiloxane (A1) and the vinyl polymer (A2) and a graft portion containing the vinyl polymer (B1).

[0013] The polymer (C) is a polyorganosiloxane-containing polymer that satisfies formula (1) relative to the thermoplastic resin contained in the resin composition. As a result, when blended with a resin to produce a molded article, it is possible to provide a molded article that has high impact resistance, high flame retardancy, and excellent appearance.

[0014] By decomposing the polymer (C) at a temperature lower than the temperature at which the thermoplastic resin begins to decompose, the silicone component of the polyorganosiloxane-containing polymer can form a carbonized layer on the surface of the molded article before the thermoplastic resin decomposes. This carbonized layer reduces heat transfer to the inside of the molded article, thereby suppressing the decomposition of the thermoplastic resin and further preventing the outflow of combustible gases generated inside the molded article into the air, which is thought to improve the flame retardancy of the molded article.

[0015] The value of "YX" in formula (1) is 20°C or higher, preferably 25°C or higher, more preferably 30°C or higher, even more preferably 35°C or higher, and particularly preferably 40°C or higher. If the values of Y and X are smaller than a certain value, the silicone component is likely to form a carbonized layer, improving flame retardancy. Therefore, the value of "YX" in formula (1) is preferably 60°C or lower, more preferably 50°C or lower. The above upper and lower limits can be combined arbitrarily. For example, the value of "YX" in formula (1) is preferably 20 to 60°C, more preferably 25 to 60°C or higher, even more preferably 30 to 60°C or higher, even more preferably 35 to 50°C or higher, and particularly preferably 40 to 50°C or higher.

[0016] The resin composition according to this embodiment preferably satisfies the following formula (2) because the silicone component of the polyorganosiloxane-containing polymer has a fast decomposition rate, which facilitates the formation of a carbonized layer and improves flame retardancy. XZ≦40℃ (2)

[0017] In formula (2), X has the same meaning as X in formula (1), and Z means the temperature at which the residual amount of the polyorganosiloxane-containing polymer becomes 70 parts by mass when 100 parts by mass of the polyorganosiloxane-containing polymer is heated to 550°C at a rate of 10°C / min under the condition of a nitrogen flow rate of 200 mL / min.

[0018] The value of "XZ" in formula (2) is preferably 39°C or less, and more preferably 30°C or less. From the viewpoint of improving impact strength, the value of "XZ" in formula (2) is preferably 1°C or more, and more preferably 10°C or more. The above upper and lower limits can be combined arbitrarily. For example, the value of "XZ" in formula (2) is preferably 1 to 40°C, more preferably 1 to 39°C, and even more preferably 10 to 30°C.

[0019] There are no particular limitations on the method for adjusting the temperatures X and Z in the formulas (1) and (2), and examples thereof include a method for adjusting the amount of alkali metal in the polymer (C) and a method for adjusting the particle size of the polymer (C).

[0020] Increasing the alkali metal content of polymer (C) tends to decrease X and Z. Polymer (C) powder can be obtained by drying polymer (C) obtained by the method described below, and then treating it with an alkali metal salt solution can increase the amount of alkali metal atoms in the polymer (C) powder, thereby decreasing X and Z. Specifically, deionized water is added to the polymer (C) powder and stirred, and then an alkali metal salt aqueous solution is added and stirred, followed by filtration, washing, dehydration, and drying, thereby obtaining a polymer (C) powder containing more alkali metal atoms. Increasing the alkali metal salt concentration of the alkali metal salt solution tends to increase the amount of alkali metal atoms contained in the polymer (C) powder, and X and Z tend to decrease.

[0021] The amount of alkali metal atoms contained in the polyorganosiloxane-containing polymer is 100 ppm by mass or more, preferably 150 ppm by mass or more, and more preferably 200 ppm by mass or more, in order to improve flame retardancy and moist heat resistance. The amount of alkali metal atoms contained in the polyorganosiloxane-containing polymer is preferably 1000 ppm by mass or less, more preferably 800 ppm by mass or less, even more preferably 600 ppm by mass or less, and particularly preferably 400 ppm by mass or less, in order to improve impact resistance. The above upper and lower limits can be arbitrarily combined. For example, 100 to 1000 ppm by mass is preferred, 100 to 800 ppm by mass is more preferred, 150 to 600 ppm by mass is even more preferred, and 200 to 400 ppm by mass is particularly preferred.

[0022] The alkali metal is not particularly limited, and examples thereof include lithium, sodium, potassium, rubidium, and cesium atoms. The polyorganosiloxane-containing polymer may contain one type of alkali metal atom, or may contain two or more types of alkali metal atoms. When the polyorganosiloxane-containing polymer contains two or more types of alkali metal atoms, the amount of alkali metal atoms contained in the polyorganosiloxane-containing polymer refers to the total mass of the alkali metal atoms. The alkali metal atom is preferably a lithium atom, a sodium atom, or a potassium atom, and particularly preferably a sodium atom.

[0023] The alkali metal atomic weight can be measured by weighing out approximately 0.25 g of sample, adding 8 mL of nitric acid and 2 mL of hydrogen fluoride water, decomposing using microwaves (wet decomposition), and then diluting the solution to 50 mL with distilled water. This is the test solution, and can be measured using an ICP optical emission spectrometer (Thermo iCAP7400 Duo).

[0024] Increasing the particle size of the polymer (C) tends to decrease X and Z. Specifically, for example, reducing the amount of emulsifier used in producing the polyorganosiloxane (A) tends to increase the particle size of the polyorganosiloxane-containing polymer (polymer (C)), and X and Z can be reduced.

[0025] The mass average particle diameter Dw of the polyorganosiloxane-containing polymer is not particularly limited, but is preferably 350 nm or more, more preferably 375 nm or more, and even more preferably 400 nm or more, from the viewpoint of improving appearance and moist heat resistance. From the viewpoint of improving productivity, the mass average particle diameter Dw of the polyorganosiloxane-containing polymer is preferably 1000 nm or less, more preferably 800 nm or less, even more preferably 600 nm or less, and particularly preferably 500 nm or less. The above upper and lower limits can be arbitrarily combined. For example, 350 to 1000 nm is preferred, 350 to 800 nm is more preferred, 375 to 600 nm is more preferred, and 400 to 500 nm is particularly preferred.

[0026] Polyorganosiloxane-containing polymers may contain alkaline earth metals and aluminum due to the production method. Since alkaline earth metals and aluminum are impurities, it is preferable that the alkaline earth metal and aluminum content in the polyorganosiloxane-containing polymer is low, but the alkaline earth metal and aluminum content has little effect on the present invention. On the other hand, since attempting to remove alkaline earth metals and aluminum from the polyorganosiloxane-containing polymer can complicate the process, the alkaline earth metal and aluminum content in the polyorganosiloxane-containing polymer may be 150 ppm or more, 100 ppm or more, 50 ppm or more, 0 ppm or more, or even 0 ppm, respectively, from the viewpoint of improving productivity.

[0027] (Polyorganosiloxane (A1)) The polyorganosiloxane (A1) is a polymer containing an organosiloxane unit. The organosiloxane unit means an Si-O unit to which an organic group is bonded. The polyorganosiloxane has a structure represented by the following formula (1).

[0028] [ka]

[0029] In formula (1), R 1 and R 2 each independently represents a hydrogen atom, a halogen atom, or a monovalent organic group; R 1 and R 2 At least one of the groups is a monovalent organic group, and n represents an integer of 2 or more.

[0030] The polyorganosiloxane (A1) can be obtained by polymerizing an organosiloxane mixture containing an organosiloxane. The organosiloxane mixture may further contain components that are used as needed. Examples of optional components include a siloxane crosslinking agent, a siloxane crosslinking agent, and a siloxane oligomer having a terminal blocking group.

[0031] Examples of organosiloxanes include linear organosiloxanes, alkoxysilane compounds, and cyclic organosiloxanes. Alkoxysilane compounds and cyclic organosiloxanes are preferred, and cyclic organosiloxanes are more preferred due to their high polymerization stability and high polymerization rate.

[0032] The alkoxysilane compound is preferably a bifunctional alkoxysilane compound. Examples include dimethyldimethoxysilane, dimethyldiethoxysilane, diethoxydiethylsilane, dipropoxydimethylsilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, and methylphenyldiethoxysilane. The alkoxysilane compounds can be used alone or in combination of two or more.

[0033] The cyclic organosiloxane is preferably a 3- to 7-membered cyclic organosiloxane. Examples include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, and octaphenylcyclotetrasiloxane. The cyclic organosiloxane can be used alone or in combination of two or more. Octamethylcyclotetrasiloxane is preferred because it is easy to control the particle size distribution.

[0034] As the organosiloxane, at least one selected from the group consisting of cyclic dimethylsiloxanes and bifunctional dialkylsilane compounds is preferred in order to obtain a polymer (C) capable of increasing the impact strength of a molded article.

[0035] Cyclic dimethylsiloxane is a cyclic siloxane having two methyl groups on a silicon atom. Examples include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. The cyclic dimethylsiloxane can be used alone or in combination of two or more.

[0036] A bifunctional dialkylsilane compound is a silane compound having two alkoxy groups and two alkyl groups on a silicon atom. Examples include dimethyldimethoxysilane, dimethyldiethoxysilane, diethoxydiethylsilane, and dipropoxydimethylsilane. The bifunctional dialkylsilane compound can be used alone or in combination of two or more.

[0037] The siloxane crosslinking agent is preferably one having a siloxy group. Examples of the siloxane crosslinking agent include trifunctional or tetrafunctional silane crosslinking agents such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetrabutoxysilane. A tetrafunctional crosslinking agent is preferred, and tetraethoxysilane is more preferred.

[0038] The proportion of the siloxane crosslinking agent in 100% by mass of the organosiloxane mixture, i.e., the proportion of structural units derived from the siloxane crosslinking agent in 100% by mass of the polyorganosiloxane, is not particularly limited, and in order to improve flame retardancy, it is preferably 10% by mass or less, more preferably 3% by mass or less, even more preferably 0.5% by mass or less, and may even be 0% by mass. If the proportion of the siloxane crosslinking agent is not more than the upper limit, it is easy to improve the impact strength of the resulting molded article.

[0039] The siloxane crosslinking agent has a siloxy group (—Si—O—) and a functional group polymerizable with a vinyl monomer. Examples of the siloxane crosslinking agent include siloxanes represented by the following formula (I): R-Si(R 1 ) n (OR 2 ) (3-n) (I) In formula (I), R 1 represents a methyl group, an ethyl group, a propyl group, or a phenyl group. 2 represents an organic group such as a hydrocarbon group, and is preferably, for example, a methyl group, an ethyl group, a propyl group, or a phenyl group. n represents 0, 1, or 2. R represents a functional group represented by any of the following formulas (I-1) to (I-4). 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 independently represents a hydrogen atom or a methyl group, and p represents an integer of 1 to 6.

[0040] The functional group represented by formula (I-1) can be exemplified by a methacryloyloxyalkyl group.The siloxane having the group represented by formula (I-1) can be exemplified by β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethylsilane, γ-methacryloyloxypropyldiethoxymethylsilane, δ-methacryloyloxybutyldiethoxymethylsilane. An example of the functional group represented by formula (I-2) is a vinylphenyl group. An example of the siloxane having a group represented by formula (I-2) is vinylphenylethyldimethoxysilane. Examples of siloxanes having a functional group represented by formula (I-3) include vinyltrimethoxysilane and vinyltriethoxysilane. The functional group represented by formula (I-4) can be a mercaptoalkyl group. Examples of siloxanes having a group represented by formula (I-4) include γ-mercaptopropyldimethoxymethylsilane, γ-mercaptopropylmethoxydimethylsilane, γ-mercaptopropyldiethoxymethylsilane, γ-mercaptopropylethoxydimethylsilane, and γ-mercaptopropyltrimethoxysilane.

[0041] The siloxane crosslinking agent can be used alone or in combination of two or more. As the siloxane crosslinking agent, γ-methacryloyloxypropylmethyldimethoxysilane is preferred because it is easy to form an island-sea structure when the polyorganosiloxane (A1) and the vinyl polymer (A2) are composited.

[0042] When the organosiloxane mixture contains a siloxane crossing agent, the proportion of the siloxane crossing agent in 100% by mass of the organosiloxane mixture is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more. The proportion of the siloxane crossing agent in 100% by mass of the organosiloxane mixture is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, the proportion is preferably 0.05 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.5 to 5% by mass. When the proportion of the siloxane graft crossing agent is within the above upper and lower limits, sufficient covalent bonds can be formed between the polyorganosiloxane (A1) and the vinyl polymer (A2), resulting in a polymer (C) with good impact strength.

[0043] The mass average particle diameter of the polyorganosiloxane (A1) is preferably 100 nm or more, more preferably 200 nm or more, and even more preferably 300 nm or more. The mass average particle diameter of the polyorganosiloxane (A1) is preferably 1000 nm or less, more preferably 800 nm or less, and even more preferably 600 nm or less. The above upper and lower limits can be arbitrarily combined. For example, it is preferably 100 to 1000 nm, more preferably 200 to 800 nm, and even more preferably 300 to 600 nm. When the mass average particle diameter of the polyorganosiloxane (A1) is within the above upper and lower limit ranges, it is easy to adjust the mass average particle diameter of the polymer (C) to be within the above preferred upper and lower limit ranges.

[0044] <Method for producing polyorganosiloxane (A1)> The method for producing the polyorganosiloxane (A1) is not particularly limited, and for example, a production method (M) can be used in which an organosiloxane mixture containing an organosiloxane, optionally a siloxane-based crosslinking agent, optionally a siloxane-based crosslinking agent, and optionally a siloxane oligomer having a terminal blocking group is emulsified with an emulsifier and water to prepare an emulsion, the organosiloxane mixture is polymerized in this emulsion at high temperature in the presence of an acid catalyst, and then the acid catalyst is neutralized with an alkaline substance to obtain a polyorganosiloxane latex. In the following explanation, the case where an "organosiloxane mixture" is used as the raw material for polymerization will be described. The same manufacturing process can also be applied when an "organosiloxane" is used as the raw material for polymerization.

[0045] In the production method (M), the emulsion preparation method can be, for example, by using a homomixer to atomize by shearing force due to high speed rotation; or by using a high pressure generator to atomize by jetting force, for example, by using a homogenizer to mix by high speed stirring; The method using a homogenizer is preferred because it can easily narrow the particle size distribution of the polyorganosiloxane latex.

[0046] Examples of methods for mixing the acid catalyst during polymerization include adding the acid catalyst all at once with the organosiloxane mixture, emulsifier, and water and mixing them (Method 1), adding the acid catalyst aqueous solution all at once to an emulsion of the organosiloxane mixture (Method 2), and adding the organosiloxane mixture emulsion dropwise at a constant rate to a hot aqueous acid catalyst solution and mixing them (Method 3).Method 3 is preferred because it is easy to control the particle size of the polyorganosiloxane.

[0047] The polymerization temperature is preferably 50° C. or higher, more preferably 70° C. or higher. The upper limit of the polymerization temperature is, for example, 100° C. When polymerization is carried out using Method 3, the polymerization time is usually 2 hours or more, preferably 5 hours or more.

[0048] At temperatures below 30°C, the crosslinking reaction between silanols proceeds. Therefore, in order to increase the crosslink density of the polyorganosiloxane, the resulting latex can be maintained at a temperature below 30°C for about 5 to 100 hours after polymerization at a high temperature of 50°C or higher.

[0049] 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 aqueous ammonia.

[0050] The emulsifier is not particularly limited as long as it can emulsify the organosiloxane mixture, and anionic emulsifiers or nonionic emulsifiers are preferred. Examples of anionic emulsifiers include sodium alkylbenzenesulfonate, sodium alkyldiphenyl ether disulfonate, sodium alkyl sulfate, sodium polyoxyethylene alkyl sulfate, and sodium polyoxyethylene nonylphenyl ether sulfate. Examples of nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkylene alkyl ethers, polyoxyethylene distyrenated phenyl ethers, polyoxyethylene tribenzyl phenyl ethers, and polyoxyethylene polyoxypropylene glycols. The emulsifiers can be used alone or in combination of two or more.

[0051] The amount of emulsifier used is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, per 100 parts by mass of the organosiloxane mixture. The amount of emulsifier used is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, per 100 parts by mass of the organosiloxane mixture. The above upper and lower limits can be arbitrarily combined. For example, 0.05 to 20 parts by mass is preferred, and 0.1 to 10 parts by mass is more preferred. The particle size of the polyorganosiloxane latex can be adjusted to a desired value by adjusting the amount of emulsifier used. Increasing the amount of emulsifier reduces the particle size, while decreasing the amount of emulsifier increases the particle size. When the amount of emulsifier used is equal to or greater than the lower limit, the emulsion stability of the organosiloxane mixture emulsion can be improved. When the amount of emulsifier used is equal to or less than the upper limit, the molded product has excellent heat discoloration resistance and surface appearance.

[0052] Examples of acid catalysts used in the polymerization of organosiloxane mixtures 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. The acid catalysts can be used alone or in combination of two or more. The use of mineral acids makes it easier to narrow the particle size distribution of the polyorganosiloxane latex and also helps to prevent problems (such as reduced thermal decomposition resistance and poor appearance of the molded product) caused by the emulsifier components in the polyorganosiloxane latex.

[0053] The amount of acid catalyst used is preferably 0.005 to 40 parts by mass per 100 parts by mass of organosiloxane. When the amount of acid catalyst used is 0.005 parts by mass or more, the organosiloxane mixture can be polymerized in a short time. When the amount of acid catalyst used is 40 parts by mass or less, the molded article has excellent heat discoloration resistance and surface appearance.

[0054] Since the amount of acid catalyst used is a factor that determines the particle size of polyorganosiloxane (A1), in order to obtain polyorganosiloxane (A1) with a particle size described below, it is more preferable to use an amount of acid catalyst of 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of organosiloxane. Note that if the amount of acid catalyst used is small, the particle size tends to be large.

[0055] To improve the mechanical stability of the polyorganosiloxane latex obtained by production method (M), an emulsifier may be added as needed. As the emulsifier, the same anionic emulsifiers and nonionic emulsifiers as those exemplified above are preferred.

[0056] (Vinyl polymer (A2)) The polymer (A) may contain a vinyl polymer (A2). When the polymer (A) contains the vinyl polymer (A2), the polymer (A) may be a polymer in which the vinyl polymer (A2) and the polyorganosiloxane (A1) are crosslinked, or may be a composite polymer in which the polyorganosiloxane (A1) and the vinyl polymer (A2) are not crosslinked, and it is preferable that the vinyl polymer (A2) and the polyorganosiloxane (A1) are crosslinked.

[0057] The vinyl polymer (A2) is a polymer obtained by polymerizing the vinyl monomer component (a2), i.e., the vinyl polymer (A2) contains vinyl monomer units derived from the vinyl monomer component (a2). The vinyl monomer component (a2) constituting the first vinyl polymer (A2) may be one type of vinyl monomer or two or more types of vinyl monomers.

[0058] From the viewpoint of the impact strength of the molded article, the vinyl monomer component (a2) preferably contains a (meth)acrylate monomer (hereinafter also referred to as "monomer (a2-1)").

[0059] The monomer (a2-1) is not particularly limited, and preferably includes (meth)acrylates in which the alkyl group has 1 to 20 carbon atoms. Examples include alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate; and alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, tridecyl methacrylate, and stearyl methacrylate.

[0060] The (meth)acrylate is preferably an alkyl acrylate having 1 to 20 carbon atoms. In order to improve the impact strength of the molded article, the number of carbon atoms in the alkyl group of the alkyl acrylate is preferably 2 or more, more preferably 3 or more, even more preferably 4 or more, and is preferably 16 or less, more preferably 12 or less, and even more preferably 8 or less. n-Butyl acrylate is particularly preferred. The monomer (a2-1) can be used alone or in combination of two or more.

[0061] When the vinyl monomer component (a2) contains the monomer (a2-1), it may contain other monomers. Examples of other monomers include polyfunctional monomers copolymerizable with the monomer (a2-1) (hereinafter also referred to as "monomer (a2-2)"). From the viewpoint of the impact strength of the molded article, the vinyl monomer component (a2) preferably contains the monomer (a2-1) and the monomer (a2-2).

[0062] The monomer (a2-2) is not particularly limited, and examples thereof include (meth)acrylates and cyanurates. Examples of (meth)acrylates include ethylene glycol dimethacrylate, propylene glycol dimethacrylate, ethylene glycol diacrylate, propylene glycol diacrylate, and allyl methacrylate. Examples of cyanurates include triallyl cyanurate and triallyl isocyanurate.

[0063] Allyl methacrylate, triallyl cyanurate, and triallyl isocyanurate are preferred, and allyl methacrylate is more preferred, as these will result in better impact strength of the molded article. The monomer (a2-2) can be used alone or in combination of two or more.

[0064] The proportion of the monomer (a2-1) in 100% by mass of the vinyl monomer component (a2) is not particularly limited, and from the viewpoint of improving the impact strength of the molded article, it is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. The proportion of the monomer (a2-1) in 100% by mass of the vinyl monomer component (a2) is 100% by mass or less, preferably 99.9% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, it is preferably 60 to 100% by mass, more preferably 70 to 100% by mass, even more preferably 80 to 99.9% by mass, and particularly preferably 90 to 99.9% by mass.

[0065] The proportion of the monomer (a2-2) in 100% by mass of the vinyl monomer component (a2) is not particularly limited, but is preferably 0.1% by mass or more, and more preferably 2% by mass or less, in order to improve impact strength.

[0066] The vinyl monomer component (a2) may contain another monomer (a2-3) in addition to the monomers (a2-1) and (a2-2). The other monomer (a2-3) is not particularly limited, and examples thereof include aromatic vinyl monomers, vinyl cyanide monomers, and (meth)acrylic group-modified silicones.

[0067] The aromatic vinyl monomer is not particularly limited, and examples thereof include styrene and α-methylstyrene. The vinyl cyanide monomer is not particularly limited, and examples thereof include acrylonitrile and methacrylonitrile. The other monomers (a2-3) can be used alone or in combination of two or more.

[0068] (Polymer (A)) The polymer (A) contains a polyorganosiloxane (A1) and a vinyl polymer (A2). The polymer (A) preferably functions as a composite rubber of the polyorganosiloxane (A1) and the vinyl polymer (A2). To function as a composite rubber, the glass transition temperatures (hereinafter sometimes referred to as Tg) of the polyorganosiloxane (A1) and the vinyl polymer (A2) are preferably each 0°C or lower.

[0069] In the polymer (A), the mass ratio of polyorganosiloxane (A1) / vinyl polymer (A2) is preferably 50 / 50 or more, more preferably 70 / 98 or more, and is preferably 99 / 1 or less, more preferably 95 / 5 or less, from the viewpoint of impact strength and flame retardancy of the molded article. The above upper and lower limits can be arbitrarily combined. For example, a ratio of 50 / 50 to 99 / 1 is preferred, and 70 / 98 to 95 / 5 is more preferred.

[0070] <Method for producing polymer (A)> The method for producing the polymer (A) is not particularly limited, but a method in which a vinyl monomer component (a2) constituting the vinyl polymer (A2) is polymerized in the presence of a latex containing polyorganosiloxane (A1) is preferred because the impact strength of the molded product is excellent.

[0071] The method for polymerizing the vinyl monomer component (a2) in the presence of a latex containing polyorganosiloxane (A1) is not particularly limited, and examples thereof include: a method of adding the vinyl monomer component (a2) dropwise to the latex containing polyorganosiloxane (A1) and polymerizing (method i); a method of adding a part of the vinyl monomer component (a2) to the latex containing polyorganosiloxane (A1) under conditions that do not initiate polymerization, impregnating the particles of polyorganosiloxane (A1), and then initiating polymerization, and then adding the remaining part of the vinyl monomer component (a2) dropwise or all at once and polymerizing (method ii); a method of adding the entire amount of the vinyl monomer component (a2) to the latex containing polyorganosiloxane (A1) under conditions that do not initiate polymerization, impregnating the particles of polyorganosiloxane (A1), and then polymerizing (method iii); Method iii is preferred because it provides a molded product with excellent impact strength.

[0072] The method for producing the vinyl polymer (A2) is not particularly limited, and examples thereof include emulsion polymerization, suspension polymerization, and fine suspension polymerization, in which the vinyl monomer (a2) is polymerized, with emulsion polymerization being preferred.

[0073] The radical polymerization initiator used in the polymerization of the vinyl monomer (a2) may be an azo initiator, a peroxide, or a redox initiator that combines a peroxide and a reducing agent. The radical polymerization initiator may be used alone or in combination of two or more. Azo initiators and redox initiators are preferred.

[0074] Examples of azo initiators include oil-soluble azo initiators such as 2,2'-azobisisobutyronitrile, dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(2-butyronitrile); and 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 can be used alone or in combination of two or more.

[0075] Examples of peroxides include 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 peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, and t-butylperoxy-2-ethylhexanoate. One type of peroxide can be used alone, or two or more types can be used in combination.

[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, and ferrous sulfate·ethylenediaminetetraacetic acid disodium salt. The redox initiators can be used alone or in combination of two or more.

[0077] The radical polymerization initiator used for polymerizing the vinyl monomer (a2) is preferably a radical polymerization initiator having a solubility in water at 20°C of 5% by mass or less, more preferably 2% by mass or less, since this makes it easier to obtain a graft copolymer having excellent impact resistance.

[0078] Examples of radical polymerization initiators having a solubility of 5% by mass or less in water at 20°C include cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, t-butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, 2,2'-azobisisobutyronitrile, dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(2-butyronitrile). Radical polymerization initiators having a solubility of 5% by mass or less in water at 20°C can be used alone or in combination of two or more.

[0079] The solubility of a radical polymerization initiator in water at 20°C can be found from catalogs of various radical polymerization initiators.

[0080] When an azo-based initiator is used as the radical polymerization initiator, the amount of the azo-based initiator used is preferably 0.01 to 1 part by mass per 100 parts by mass of the total of the monomers. When a redox initiator is used as the radical polymerization initiator, the amount of peroxide used is preferably 0.01 to 1 part by mass per 100 parts by mass of the total monomers.When a redox initiator is used as the radical polymerization initiator, the amount of reducing agent used is preferably 0.01 to 1 part by mass per 100 parts by mass of the total monomers.

[0081] (Vinyl polymer (B)) The vinyl polymer (B) is a polymer obtained by polymerizing the vinyl monomer component (b), and is a polymer containing structural units derived from the vinyl monomer. The vinyl monomer component (b) constituting the vinyl polymer (B) may be one or more kinds of vinyl monomers.

[0082] The vinyl monomer constituting the vinyl monomer component (b) is not particularly limited, but a (meth)acrylate monomer is preferred.

[0083] The (meth)acrylate monomer is not particularly limited, and examples thereof include alkyl (meth)acrylates. When one or more vinyl monomers contain alkyl (meth)acrylates such as methyl (meth)acrylate, the resulting graft copolymer tends to have excellent compatibility and dispersibility in thermoplastic resins such as polycarbonate resins. Examples of alkyl (meth)acrylates include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and i-butyl methacrylate; methyl acrylate, ethyl acrylate, and n-butyl acrylate. The (meth)acrylate monomer may be used alone or in combination of two or more. The number of carbon atoms in the alkyl group of the alkyl (meth)acrylate is not particularly limited, and is preferably 1 or more, and preferably 12 or less, more preferably 6 or less, and even more preferably 4 or less. The above upper and lower limits can be combined arbitrarily. For example, 1 to 12 is preferred, 1 to 6 is more preferred, and 1 to 4 is even more preferred. Methyl methacrylate is particularly preferred.

[0084] The vinyl monomer component (b) may further include one or more monomers selected from the group consisting of polyfunctional vinyl monomers, aromatic vinyl monomers, and vinyl cyanide monomers.

[0085] Examples of the polyfunctional vinyl monomer include allyl (meth)acrylate, triallyl cyanurate, divinylbenzene, diallyl phthalate, and ethylene glycol di(meth)acrylate. One type of polyfunctional vinyl monomer may be used alone, or two or more types may be used in combination.

[0086] The aromatic vinyl monomer is not particularly limited, and examples thereof include styrene and α-methylstyrene. The aromatic vinyl monomers may be used alone or in combination of two or more.

[0087] The vinyl cyanide monomer is not particularly limited, and examples thereof include acrylonitrile and methacrylonitrile. One type of vinyl cyanide monomer may be used alone, or two or more types may be used in combination.

[0088] The proportion of the (meth)acrylate monomer in 100% by mass of the vinyl polymer (B) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and may be 100% by mass.

[0089] The Tg of the vinyl polymer (B) is preferably 70°C or higher, more preferably 80°C or higher, even more preferably 90°C or higher, and preferably 105°C or lower. The above upper and lower limits can be combined arbitrarily. For example, 70 to 105°C is preferred, 80 to 105°C is more preferred, and 90 to 105°C is even more preferred. When the Tg of the vinyl polymer (B) is at least the above lower limit, the fluidity of the resulting polymer (C) powder is improved. The Tg of the vinyl polymer (B) can be adjusted by the types and ratio of the vinyl monomers constituting the vinyl monomer component (b).

[0090] The Tg of the vinyl polymer (B) can be determined by the FOX formula. In this case, the Tg of the homopolymer of the vinyl monomer constituting the vinyl monomer component (b) can be, for example, the value described in "POLYMER HANDBOOK" (Wiley Interscience, 1999). The Tg of the homopolymer of the vinyl monomer not described in this document can be calculated using Bicerano's method, "Prediction of Polymer Properties" (Marcel Dekker, 2002).

[0091] (Method for producing polymer (C)) The polymer (C) can be produced, for example, by polymerizing (graft polymerizing) the vinyl monomer component (b) in the presence of the polymer (A), thereby obtaining a polymer in which a part or all of the vinyl polymer (B) is grafted onto the polymer (A).

[0092] The method for producing the polymer (C) is not particularly limited, but a method in which a vinyl monomer component (b) is added to a latex of the polymer (A) and the vinyl monomer component (b) is polymerized in the latex is preferred. The latex of the polymer (A) is preferably produced by polymerizing the vinyl monomer component (a2) in the presence of a latex containing the polyorganosiloxane (A1).

[0093] The conditions for polymerizing the vinyl monomer component (b) are not particularly limited, and conventional conditions can be applied, such as conditions of 45 to 95° C. and 0.1 to 10 hours.

[0094] The method of adding the vinyl monomer component (b) to the latex of the polymer (A) is not particularly limited, but dropwise addition is preferred because it can prevent the generation of cullets. The entire amount of the vinyl monomer component (b) may be added dropwise continuously, or the vinyl monomer component (b) may be added dropwise in multiple portions with a holding time during which it is not added dropwise.

[0095] After polymerizing the vinyl monomer component (b), it is preferable to recover the polymer (C) as a powder (or a group of powders, or a group of powders containing impurities) from the resulting latex of the polymer (C). When recovering the polymer (C) as a powder, a direct drying method such as spray drying or a coagulation method can be used. The direct drying method allows the auxiliary agents added during polymerization to remain in the resulting powder. The coagulation method allows the amount of residual polymerization auxiliary agents, such as the emulsifier and its coagulation salt used during polymerization, and the initiator, contained in the resulting powder to be reduced in the washing step after coagulation. The powder recovery method can be appropriately selected so that the desired remaining state is achieved when the polymer (C) is added to a thermoplastic resin.

[0096] Spray drying, a direct drying method, involves spraying the latex of polymer (C) into a dryer in the form of fine droplets and then drying them by applying a heated drying gas. Methods for generating fine droplets include, for example, 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 range from a small-scale capacity for laboratory use to a large-scale capacity for industrial use. The temperature of the heated drying gas is preferably 200°C or less, more preferably 120 to 180°C. Two or more graft copolymer latexes produced separately can also be spray-dried together. To improve powder properties such as blocking during spray drying and bulk density, optional components such as silica can be added to the latex of polymer (C) before spray drying.

[0097] The coagulation method is a method in which the latex of polymer (C) is coagulated, and the polymer (C) is separated, recovered, and dried. The latex of polymer (C) is poured into hot water in which a coagulant has been dissolved, and the polymer (C) is separated by salting out and coagulation. The separated wet polymer (C) is then dehydrated, etc., and the polymer (C) with a reduced water content is recovered. The recovered polymer (C) is dried using a compression dehydrator or a hot air dryer.

[0098] Examples of the coagulant include inorganic salts such as aluminum chloride, aluminum sulfate, sodium sulfate, magnesium sulfate, sodium nitrate, and calcium acetate; acids such as sulfuric acid; and calcium acetate is preferred. The coagulants can be used alone or in combination of two or more.

[0099] When the coagulant is used as an aqueous solution, the concentration of the aqueous coagulant solution is preferably 0.1% by mass or more, more preferably 1% by mass or more, from the viewpoint of stably coagulating and recovering the polymer (C). The concentration of the aqueous coagulant solution is preferably 20% by mass or less, more preferably 15% by mass or less, from the viewpoint of reducing the amount of coagulant remaining in the recovered polymer (C) and preventing deterioration of the molded appearance of the molded article. The above upper and lower limits can be arbitrarily combined. For example, 0.1 to 20% by mass is preferred, and 1 to 15% by mass is more preferred. 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 per 100 parts by mass of the latex of polymer (C).

[0100] The method for contacting the latex of polymer (C) with the aqueous coagulant solution is not particularly limited, and the following methods can be mentioned. (1) A method in which latex is continuously added to an aqueous coagulant solution while stirring it and the solution is maintained for a certain period of time. (2) A method in which an aqueous coagulant solution and latex are continuously poured into a vessel equipped with a stirrer at a constant ratio to bring them into contact with each other, and the 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 30° C. or higher and 100° C. or lower. The contact time is not particularly limited.

[0101] The coagulated polymer (C) is washed with water in an amount of about 1 to 100 times by mass of the polymer (C) and then filtered. The wet polymer (C) filtered off is dried using a fluidized bed dryer, a compression dehydrator, or the like. The drying temperature and drying time may be appropriately determined depending on the polymer (C) to be obtained. The polymer (C) discharged from the squeeze dehydrator or extruder may be sent directly to an extruder or molding machine for producing a resin composition without being recovered, and mixed with a thermoplastic resin to obtain a molded product.

[0102] The resulting polymer (C) can be dried to obtain a powder of polymer (C), but the amount of alkali metal atoms in the powder of polymer (C) can be increased by treating it with an alkali metal salt solution. Specifically, deionized water is added to the powder of polymer (C) and stirred, and then an aqueous alkali metal salt solution is added and stirred, followed by filtration, washing, dehydration, and drying to obtain a powder of polymer (C) containing more alkali metal atoms. Increasing the alkali metal salt concentration of the alkali metal salt solution tends to increase the amount of alkali metal atoms contained in the powder of polymer (C).

[0103] The proportion of polyorganosiloxane (A1) in 100 mass% of polymer (C) is preferably less than 100 mass%, more preferably 98 mass% or less. The proportion of polyorganosiloxane (A1) in 100 mass% of polymer (C) is preferably 50 mass% or more, more preferably 70 mass% or more, even more preferably 90 mass% or more, and particularly preferably 95 mass% or more. The above upper and lower limits can be arbitrarily combined. For example, 50 mass% or more but less than 100 mass% is preferred, 70 mass% or more but less than 100 mass% is more preferred, 70 to 98 mass% is more preferred, 90 to 98 mass% or more is particularly preferred, and 95 to 98 mass% or more is particularly preferred. When the proportion of polyorganosiloxane (A1) is equal to or greater than the lower limit, the impact strength of the molded article is excellent. When the proportion is equal to or less than the upper limit, the colored appearance of the molded article is excellent.

[0104] The proportion of polymer (A) in 100% by mass of polymer (C) is preferably 60% by mass or more, more preferably 70% by mass or more. The proportion of polymer (A) in 100% by mass of polymer (C) is preferably 95% by mass or less, more preferably 90% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, 60 to 95% by mass is preferred, and 70 to 90% by mass is more preferred. When the content of polymer (A) is at least the lower limit, the impact strength and flame retardancy of the molded article are excellent. When the content is at most the upper limit, the dispersibility of polymer (C) in the thermoplastic resin is excellent, and the appearance of the obtained molded article is excellent.

[0105] The proportion of graft moieties in 100% by mass of polymer (C) is preferably 5% by mass or more, more preferably 7.5% by mass or more, and even more preferably 10% by mass or more. The proportion of graft moieties in 100% by mass of polymer (C) is preferably 20% by mass or less, more preferably 17.5% by mass or less, and even more preferably 15% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, it is preferably 5 to 20% by mass, more preferably 7.5 to 17.5% by mass, and even more preferably 10 to 15% by mass. When the content of graft moieties is equal to or greater than the lower limit, the dispersibility of polymer (C) in the thermoplastic resin is excellent, and the appearance of the resulting molded article is excellent. When it is equal to or less than the upper limit, the impact strength of the molded article is excellent.

[0106] The proportion of the vinyl polymer (B) in 100% by mass of the polymer (C) is preferably 5% by mass or more, more preferably 10% by mass or more. The proportion of the vinyl polymer (B) in 100% by mass of the polymer (C) is preferably 40% by mass or less, more preferably 35% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, 5 to 40% by mass is preferred, and 10 to 35% by mass is more preferred. When the content of the vinyl polymer (B) is equal to or greater than the lower limit, the dispersibility of the polymer (C) in the thermoplastic resin is excellent, and the appearance of the obtained molded article is excellent. When the content is equal to or less than the upper limit, the impact strength of the molded article is excellent.

[0107] <Resin composition> A resin composition according to one embodiment of the present invention (hereinafter also referred to as "the resin composition") contains a thermoplastic resin (hereinafter also referred to as "thermoplastic resin (D)") and a polyorganosiloxane-containing polymer. The polyorganosiloxane-containing polymer contained in the resin composition is preferably polymer (C).

[0108] The thermoplastic resin (D) is not particularly limited, and examples thereof include engineering plastics (such as aromatic polycarbonates), styrene-based resins, polyester resins, olefin-based resins (such as polyethylene), thermoplastic elastomers, biodegradable resins, halogen-based resins (such as vinyl chloride resins), and acrylic resins.

[0109] As the engineering plastic, various known thermoplastic engineering plastics can be used without any particular limitation. Examples of engineering plastics include polyphenylene ether, polycarbonate, polyester polymers (polyethylene terephthalate, polybutylene terephthalate, etc.), syndiotactic polystyrene, nylon polymers (6-nylon, 6,6-nylon, etc.), polyarylate, polyphenylene sulfide, polyether ketone, polyether ether ketone, polysulfone, polyether sulfone, polyamide imide, polyether imide, and polyacetal.

[0110] For example, special styrene-based resins such as heat-resistant ABS and heat-resistant acrylic resins that require excellent heat resistance and melt fluidity are also included as engineering plastics in the present invention. When greater strength development is required, aromatic polycarbonate and polybutylene terephthalate are more preferred. Examples of aromatic polycarbonates include 4,4'-dioxydiarylalkane polycarbonates such as 4,4'-dihydroxydiphenyl-2,2-propane (bisphenol A) polycarbonates.

[0111] Examples of olefin resins include high-density polyethylene; medium-density polyethylene; low-density polyethylene; copolymers of ethylene and other α-olefins; polypropylene; copolymers of propylene and other α-olefins; polybutene; and poly-4-methylpentene-1.

[0112] Examples of thermoplastic elastomers include styrene-based elastomers, urethane-based elastomers, polyolefin-based elastomers, polyamide-based elastomers, fluorine-based elastomers, chlorinated PE-based elastomers, and acrylic-based elastomers.

[0113] Examples of styrene-based elastomers include styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-ethylene-butene copolymer (SEB), styrene-ethylene-propylene copolymer (SEP), styrene-ethylene-butene-styrene copolymer (SEBS), styrene-ethylene-propylene-styrene copolymer (SEPS), styrene-ethylene-propylene-styrene copolymer (SEEPS), styrene-butadiene-butylene-styrene copolymer (SBBS), partially hydrogenated SIS copolymer, and partially hydrogenated styrene-isoprene-butadiene-styrene copolymer. A "-" indicates that the monomers forming the unit connected by the "-" are copolymerized, and a "·" indicates that the unit is randomly modified by hydrogenation or other methods after copolymerization.

[0114] Examples of urethane elastomers include reaction products of polymeric diols, organic diisocyanates, and chain extenders. Examples of the polymer diol include polyester diol, polyether diol, polyester ether diol, polycarbonate diol, and polyester polycarbonate diol. Examples of organic diisocyanates include 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate (4,4'-dicyclohexylmethane diisocyanate), isophorone diisocyanate, and hexamethylene diisocyanate, with 4,4'-diphenylmethane diisocyanate being preferred. Examples of chain extenders include ethylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,3-propanediol, 1,6-hexanediol, neopentyl glycol, 1,9-nonanediol, cyclohexanediol, and 1,4-bis(β-hydroxyethoxy)benzene.

[0115] Examples of polyolefin elastomers include ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-vinyl acetate copolymer, butyl rubber, butadiene rubber, propylene-butene copolymer, and ethylene-acrylic acid ester copolymer.

[0116] Examples of styrene-based resins include polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-styrene-α-methylstyrene copolymer, acrylonitrile-methyl methacrylate-styrene-α-methylstyrene copolymer, ABS resin, AS resin, MABS resin, MBS resin, AAS resin, AES resin, acrylonitrile-butadiene-styrene-α-methylstyrene copolymer, acrylonitrile-methyl methacrylate-butadiene-styrene-α-methylstyrene copolymer, styrene-maleic anhydride copolymer, styrene-maleimide copolymer, styrene-N-substituted maleimide copolymer, acrylonitrile-styrene-N-substituted maleimide copolymer, acrylonitrile-butadiene-styrene-β-isopropenylnaphthalene copolymer, and acrylonitrile-methyl methacrylate-butadiene-styrene-α-methylstyrene-maleimide copolymer.

[0117] The polyester resin is a polymer of a polybasic acid and a polyhydric alcohol, and is not particularly limited as long as it has thermoplastic properties. Examples of polybasic acids include terephthalic acid, naphthalic dicarboxylic acid, cyclohexyl dicarboxylic acid, and their esters. Examples of polyhydric alcohols include ethylene glycol, propylene glycol, butanediol, pentanediol, neopentyl glycol, hexanediol, octanediol, decanediol, cyclohexanedimethanol, hydroquinone, bisphenol A, 2,2-bis(4-hydroxyethoxyphenyl)propane, 1,4-dimethyloltetrabromobenzene, and tetrabromobisphenol A bis(2-hydroxyethyl)ether (TBA-EO). The polyester resin may be a homopolymer, a copolymer, or a blend of two or more thereof. As the polyester resin, a commercially available product such as "PETG" manufactured by Eastman Chemical Company may be used.

[0118] Examples of biodegradable resins include microbial polymers, chemically synthesized polymers, and natural product polymers. Examples of microbial polymers include biopolyesters such as polyhydroxybutyrate / valerate (PHB / V), bacterial cellulose, and microbial polysaccharides (pullulan, curdlan, etc.). Examples of chemically synthesized polymers include aliphatic polyesters (such as polycaprolactone, polybutylene succinate, polyethylene succinate, polyglycolic acid, and polylactic acid), polyvinyl alcohol, and polyamino acids (such as PMLG). Examples of natural polymers include chitosan, cellulose, starch, and cellulose acetate.

[0119] Examples of halogen-based resins include vinyl chloride resins such as vinyl chloride homopolymers, copolymers containing 80% or more by mass of vinyl chloride, and highly chlorinated polyvinyl chloride. In addition to vinyl chloride, copolymer components include monovinylidene compounds such as ethylene, vinyl acetate, methyl methacrylate, and butyl acrylate. The proportion of structural units derived from these compounds in the copolymer may be 20% by mass or less. Examples of halogen-based resins include vinyl chloride resins, as well as fluorinated polymers, brominated polymers, and iodinated polymers.

[0120] Examples of acrylic resins include copolymers of methyl methacrylate and copolymerizable vinyl monomers, such as alkyl acrylates (e.g., methyl acrylate, ethyl acrylate, i-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate), alkyl methacrylates (e.g., ethyl methacrylate, propyl methacrylate, n-butyl methacrylate), and aromatic vinyl compounds (e.g., styrene, α-methylstyrene, vinyltoluene).

[0121] Polymer alloys of engineering plastics such as polyester resins such as polyphenylene ether, polycarbonate, polyethylene terephthalate, and polybutylene terephthalate, polyamide resins such as syndiotactic polystyrene, 6-nylon, and 6,6-nylon, polyarylate, polyphenylene sulfide, polyether ketone, polyether ether ketone, polysulfone, polyether sulfone, polyamide imide, polyether imide, and polyacetal with other thermoplastic resins are also included in the scope of the thermoplastic resin (D).

[0122] The thermoplastic resin (D) can be used alone or in combination of two or more. The thermoplastic resin (D) preferably contains at least one selected from the group consisting of aromatic polycarbonate, polymethyl methacrylate, styrene-acrylonitrile copolymer, polyethylene terephthalate, polybutylene terephthalate, polyvinyl chloride, polyphenylene sulfide, and polyacetal, and more preferably contains at least one selected from the group consisting of polymethyl methacrylate and styrene-acrylonitrile copolymer, because these resins are industrially readily available and have an excellent balance between impact strength and colorability of the molded article.

[0123] In addition to the above, the present resin composition may contain various well-known additives within the scope of the present invention. Examples of additives include flame retardants (e.g., phosphorus-based, bromine-based, silicone-based, and organometallic salt-based), anti-drip agents (e.g., fluorinated polyolefins, silicones, and aramid fibers), lubricants (e.g., long-chain fatty acid metal salts such as magnesium stearate), release agents (e.g., pentaerythritol tetrastearate), nucleating agents, antistatic agents, stabilizers (e.g., phenolic stabilizers, phosphorus-based stabilizers, ultraviolet absorbers, and amine-based light stabilizers), fillers (e.g., titanium oxide, talc, mica, kaolin, calcium carbonate, and glass flakes), plasticizers, reinforcing agents (e.g., glass fiber and carbon fiber), colorants, and pigments. In the present invention, the presence of the polymer (C) tends to improve the flame retardancy of the resin composition, so high flame retardancy can be obtained without adding a flame retardant or even with the addition of a small amount of a flame retardant.

[0124] Examples of inorganic pigments include iron oxide, ultramarine, titanium oxide, and carbon black. Examples of organic pigments include phthalocyanine-based and anthraquinone-based blue pigments, perylene-based and quinacridone-based red pigments, and isoindolinone-based yellow pigments. Examples of specialty pigments include fluorescent pigments, metal powder pigments, and pearl pigments. Examples of dyes include nigrosine-based, perinone-based, and anthraquinone-based dyes. Various grades of dyes and pigments are commercially available depending on the required color, and these can be used, either alone or in combination of two or more.

[0125] The proportion of polymer (C) in 100% by mass of the resin composition is not particularly limited, but is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more. The proportion of polymer (C) in 100% by mass of the resin composition is preferably 30% by mass or less, more preferably 20% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, 0.5 to 30% by mass is preferred, 1 to 30% by mass is more preferred, and 2 to 20% by mass is even more preferred. When the proportion of polymer (C) is at least the lower limit, the impact strength of the resulting molded article is excellent. When it is at most the upper limit, a decrease in the fluidity and heat distortion temperature of the resin composition can be suppressed.

[0126] The proportion of thermoplastic resin (D) in 100% by mass of the resin composition is not particularly limited, but is preferably 40% by mass or more, and more preferably 50% by mass or more. The proportion of thermoplastic resin (D) in 100% by mass of the resin composition is preferably 99.5% by mass or less, more preferably 99% by mass or less, and even more preferably 98% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, 40 to 99.5% by mass is preferred, 40 to 99% by mass is more preferred, and 50 to 98% by mass is even more preferred. When the proportion of thermoplastic resin (D) is equal to or greater than the lower limit, a decrease in the fluidity and heat distortion temperature of the resin composition can be suppressed. When the proportion is equal to or less than the upper limit, the impact strength of the resulting molded article is excellent.

[0127] (Method of producing resin composition) The resin composition can be produced by mixing a polyorganosiloxane-containing polymer, preferably a polymer (C), a thermoplastic resin (D), and, if necessary, additives. The method for mixing the materials is not particularly limited and includes known blending methods, such as mixing and kneading methods using a tumbler, V-type blender, super mixer, Nauta mixer, Banbury mixer, kneading roll, extruder, etc. An example of a method for producing the resin composition of the present invention is a method in which the polymer (C), the thermoplastic resin (D) in pellet form, and, if necessary, additives are mixed using an extruder, extruded into a strand shape, and cut into pellets using a rotary cutter, etc. By this method, a resin composition in pellet form can be obtained.

[0128] <Molded body> A molded article according to one embodiment of the present invention (hereinafter also referred to as "the molded article") contains the resin composition. That is, the molded article preferably contains a polymer (C) and a thermoplastic resin (D). The molded article may further contain other components, such as known components.

[0129] The present molded article can be produced, for example, by molding the present resin composition. Examples of the molding method include molding methods used for molding thermoplastic resin compositions, such as injection molding, extrusion molding, blow molding, and calendar molding.

[0130] The molded article can be widely used industrially as various materials in the fields of, for example, automobiles, office automation equipment, home appliances, electrical and electronic equipment, construction, lifestyle and cosmetics, and medical products. More specifically, it can be used as, for example, housings for electronic devices, various parts, coating materials, automotive structural members, automotive interior parts, light reflectors, building structural members, and fittings. Even more specifically, it can be used as, for example, interior and exterior members for personal computer housings, mobile phone housings, personal digital assistant housings, portable game console housings, printers, copiers, and the like, conductive coating materials, automotive interior and exterior members, building exterior members, resin window frame members, flooring materials, and piping members. [Example]

[0131] 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 1-1 to 1-6 will be described. Examples 1-1 to 1-6 and comparative examples 1-1 to 1-7 are examples relating to the production and evaluation of graft copolymers, and Examples 2-1 to 2-9 and comparative examples 2-1 to 2-8 are examples relating to the production and evaluation of thermoplastic resin compositions. In the production examples and examples, "parts," "%," and "ppm" mean "parts by mass," "% by mass," and "ppm by mass," respectively, unless otherwise specified.

[0132] <Solid content> A mass w1 of polyorganosiloxane latex is dried in a hot air dryer at 180°C for 30 minutes, and 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

[0133] <Particle size> The "polyorganosiloxane (A1) latex" or the "polymer (C) latex" was diluted with deionized water to a solid content concentration of about 3% and used as a sample. The number average particle diameter Dn and the mass average particle diameter Dw were measured using a particle size distribution analyzer CHDF2000 manufactured by MATEC Corporation, USA, under the following conditions. Cartridge: Dedicated capillary cartridge for particle separation (product name: C-202), Carrier liquid: Dedicated carrier liquid (product name: 2XGR500), Carrier liquid pH: Neutral, Carrier liquid flow rate: 1.4 mL / min Carrier fluid pressure: 4,000 psi (2,600 kPa), Measurement temperature: 35℃, Sample volume: 0.1 mL.

[0134] <Thermal decomposition> The graft copolymer was subjected to thermogravimetric analysis using TG / DTA6200 (manufactured by Seiko Instruments Inc.), and the thermal decomposition property was evaluated by the following method. Under conditions of a nitrogen flow rate of 200 mL / min, 100 parts by mass of polyorganosiloxane-containing polymer was heated to 550°C at 10°C / min. The temperature at which the remaining amount of polyorganosiloxane-containing polymer was 1 part by mass was defined as X, and the temperature at which the remaining amount of polyorganosiloxane-containing polymer was 70 parts by mass was defined as Z. Samples with a remaining amount of 1% or less at the end of the test were rated as thermally decomposable A, and those with a remaining amount of 1% or less were rated as thermally decomposable B. For samples with a thermal decomposition rate of A, the thermal decomposition rate was calculated using "XZ." The smaller the "XZ" value, the shorter the time required from the start to the end of thermal decomposition, and the better the thermal decomposition rate.

[0135] <y-x> When 100 parts by mass of thermoplastic resin was heated to 550°C at a rate of 10°C / min under conditions of a nitrogen flow rate of 200 mL / min, the temperature at which the residual amount of thermoplastic resin became 90 parts by mass was defined as Y, and the X used in the thermal decomposition evaluation was used as X. For samples where the temperature at which X was confirmed was determined, the thermal decomposition was calculated using "YX". If the "YX" value was 20 or higher, the polyorganosiloxane-containing polymer was excellent in contributing to the formation of a charred layer, and therefore the flame retardancy was excellent. For samples where the temperature at which X was confirmed was not confirmed, the rating was B. If the rating was B, it was difficult for the polyorganosiloxane-containing polymer to form a charred layer, and the effect on flame retardancy was poor.

[0136] (Polymer manufacturing method) [Production Example 1-1: Production of Polyorganosiloxane Latex (S-1)] Two parts of gamma-methacryloyloxypropyldimethoxymethylsilane (DSMA) and 98 parts of octamethylcyclotetrasiloxane (TSF404, manufactured by Momentive Performance Materials Japan, Inc.) were mixed to obtain 100 parts of an organosiloxane mixture. An aqueous solution of one part of sodium dodecylbenzenesulfonate (DBSNa) dissolved in 150 parts of deionized water was added to the organosiloxane mixture, and the mixture was stirred at 10,000 rpm for five minutes using a homomixer. The mixture was then passed through a homogenizer twice at a pressure of 20 MPa to obtain a stable premixed emulsion.

[0137] The resulting emulsion was placed in a 5-liter separable flask equipped with a cooling condenser, heated to 80°C, and a mixture of 0.20 parts sulfuric acid and 49.8 parts distilled water was continuously added over 3 minutes. The mixture was maintained at 80°C for 7 hours to allow the polymerization reaction to proceed, after which it was cooled to room temperature (25°C), and the resulting reaction mixture was maintained at room temperature for 6 hours. A 5% aqueous solution of sodium hydroxide was added to the resulting reaction mixture to neutralize the reaction solution to pH 7.0, yielding polyorganosiloxane latex (S-1).

[0138] The polyorganosiloxane latex (S-1) had a solid content of 30.2% by mass, a number average particle diameter (Dn) of 384 nm, a mass average particle diameter (Dw) of 403 nm, and a Dw / Dn ratio of 1.05.

[0139] [Production Example 1-2: Production of Polyorganosiloxane Latex (S-2)] A polyorganosiloxane latex (S-2) was obtained in the same manner as in Production Example 1-1, except that the composition of the organosiloxane mixture was changed to the composition shown in Table 1. The polyorganosiloxane latex (S-2) had a solid content of 30.4% by mass, a number average particle diameter (Dn) of 384 nm, a mass average particle diameter (Dw) of 403 nm, and a Dw / Dn ratio of 1.05.

[0140] [Production Example 1-3: Production of Polyorganosiloxane Latex (S-3)] A polyorganosiloxane latex (S-3) was obtained in the same manner as in Production Example 1-1, except that the composition of the organosiloxane mixture was changed to the composition shown in Table 1. The polyorganosiloxane latex (S-3) had a solids content of 30.6% by mass, a number average particle diameter (Dn) of 384 nm, a mass average particle diameter (Dw) of 403 nm, and a Dw / Dn ratio of 1.05.

[0141] [Production Example 1-4: Production of Polyorganosiloxane Latex (S-4)] A polyorganosiloxane latex (S-4) was obtained in the same manner as in Production Example 1-1, except that the composition of the organosiloxane mixture was changed to the composition shown in Table 1. The polyorganosiloxane latex (S-4) had a solid content of 30.8% by mass, a number average particle diameter (Dn) of 384 nm, a mass average particle diameter (Dw) of 403 nm, and a Dw / Dn ratio of 1.05.

[0142] [Production Example 1-5: Production of Polyorganosiloxane Latex (S-5)] 0.5 parts of γ-methacryloyloxypropyldimethoxymethylsilane (DSMA), 2 parts of tetraethoxysilane (TEOS), and 97.5 parts of octamethylcyclotetrasiloxane (Shin-Etsu Silicones, product name: DMC, a mixture of 3- to 6-membered cyclic organosiloxanes) were mixed to obtain 100 parts of an organosiloxane mixture. An aqueous solution of 0.68 parts of sodium dodecylbenzenesulfonate (DBSNa) and 0.68 parts of dodecylbenzenesulfonic acid (DBSH) dissolved in 150 parts of deionized water was added to the organosiloxane mixture, and the mixture was stirred at 10,000 rpm in a homomixer for 5 minutes. The mixture was then passed through a homogenizer twice at a pressure of 20 MPa to obtain a stable premixed emulsion.

[0143] The resulting emulsion was placed in a 5-liter separable flask equipped with a cooling condenser, heated to 80°C, and maintained at this temperature for 5 hours to allow the polymerization reaction to proceed. The emulsion was then cooled to room temperature (25°C), and the resulting reaction mixture was maintained at room temperature for 6 hours. A 5% aqueous solution of sodium hydroxide was added to the resulting reaction mixture to neutralize the reaction solution to pH 7.0, yielding a polyorganosiloxane latex (S-5).

[0144] The polyorganosiloxane latex (S-5) had a solids content of 33.0% by mass, a number average particle diameter (Dn) of 64 nm, a mass average particle diameter (Dw) of 248 nm, and a Dw / Dn ratio of 3.88.

[0145] [Production Example 1-6: Production of Polyorganosiloxane Latex (S-6)] A polyorganosiloxane latex (S-6) was obtained by the same procedure as in Production Example 1-1, except that the composition of the organosiloxane mixture was changed to the composition shown in Table 1 and the amount of sodium dodecylbenzenesulfonate (DBSNa) was increased to 1.5 parts.

[0146] The polyorganosiloxane latex (S-6) had a solid content of 30.8% by mass, a number average particle diameter (Dn) of 38 nm, a mass average particle diameter (Dw) of 276 nm, and a Dw / Dn ratio of 7.26.

[0147] The ingredients of Production Examples 1-1 to 1-6 are shown in Table 1. The abbreviations in Table 1 are as follows: TSF404: Octamethylcyclotetrasiloxane DMC: A mixture of cyclic organosiloxanes with 3 to 6 ring members DSMA: γ-methacryloyloxypropyldimethoxymethylsilane TEOS: Tetraethoxysilane

[0148] [Table 1]

[0149] [Example 1-1] 80 parts of the polyorganosiloxane latex (S-1) obtained in Production Example 1-1 (10.0 parts in terms of polymer) was placed in a 5-liter separable flask, and a mixture of 8.82 parts of butyl acrylate (BA), 0.18 parts of allyl methacrylate (AMA), and 0.16 parts of cumene hydroperoxide (CB) was added. Stirring was continued at room temperature for 1 hour to impregnate the polyorganosiloxane.

[0150] The atmosphere in the flask was replaced with nitrogen by passing a nitrogen stream, 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 ethylenediaminetetraacetic acid disodium salt (EDTA), and 0.24 parts of sodium formaldehyde sulfoxylate (SFS) dissolved in 10 parts of deionized water was added to initiate radical polymerization. After the dropwise addition was completed, the liquid temperature was maintained at 65°C for 1 hour to complete the polymerization of the acrylate component, yielding a composite rubber latex of polyorganosiloxane and poly(n-butyl acrylate).

[0151] The liquid temperature of the obtained composite rubber latex was set to 65°C, and a mixture of 11.0 parts of methyl methacrylate (MMA) and 0.24 parts of cumene hydroperoxide (CB) was added dropwise to the latex over 1 hour to initiate the graft polymerization reaction. After the dropwise addition was completed, the temperature was maintained at 65°C for 1 hour, and then cooled to room temperature to obtain a latex of polyorganosiloxane-containing graft copolymer (G-1).

[0152] 500 parts of an aqueous solution containing calcium acetate at a concentration of 1% by mass was heated to 85°C, and 340 parts of the latex of graft copolymer (G-1) was gradually added dropwise with stirring to coagulate the mixture. The resulting graft copolymer (G-1) was filtered, washed, dehydrated, and then dried to obtain graft copolymer (G-1).

[0153] 10 parts of the obtained graft copolymer (G-1) was added to 141 parts of deionized water and stirred for 3 minutes, and then 10 parts of a 10% by mass aqueous sodium chloride solution was added and stirred for 3 minutes. The graft copolymer (A-1) was filtered, washed, dehydrated, and then dried to obtain a sodium-containing graft copolymer powder (A-1). The mass average particle size and thermal decomposition property of the obtained graft copolymer powder (A-1) were measured by the above-mentioned methods. The results are shown in Table 2.

[0154] [Examples 1-2 to 1-4] Polyorganosiloxane-containing graft copolymers (G-2 to G-4) were produced in the same manner as in Example 1-1, except that the raw material compositions used in Example 1-1 were changed to the conditions shown in Table 2. Graft copolymer powders (A-2 to A-4) were also obtained and subjected to the same measurements. The results are shown in Table 2.

[0155] [Examples 1-5] In the same manner as in Example 1-1, polyorganosiloxane-containing graft copolymer (G-1) was produced, and the amount of the aqueous solution with a sodium chloride concentration of 10% by mass was changed to 20 parts, and the graft copolymer powder (A-5) was obtained in the same manner as in Example 1-1, and the same measurements were carried out. The results obtained are shown in Table 2.

[0156] [Examples 1-6] In the same manner as in Example 1-1, polyorganosiloxane-containing graft copolymer (G-1) was produced, and the amount of the aqueous solution with a sodium chloride concentration of 10% by mass was changed to 50 parts, and the graft copolymer powder (A-6) was obtained in the same manner as in Example 1-1, and the same measurements were carried out. The results obtained are shown in Table 2.

[0157] [Comparative Example 1-1] After obtaining polyorganosiloxane-containing graft copolymer (G-1), the treatment with sodium chloride solution was not carried out, and polyorganosiloxane-containing graft copolymer powder (A-7) was obtained in the same manner as in Example 1-1, and the same measurements were carried out. The results obtained are shown in Table 2.

[0158] [Comparative Example 1-2] After obtaining polyorganosiloxane-containing graft copolymer (G-2), the treatment with sodium chloride solution was not carried out, and polyorganosiloxane-containing graft copolymer powder (A-8) was obtained in the same manner as in Example 1-2, and the same measurements were carried out. The results obtained are shown in Table 2.

[0159] [Comparative Example 1-3] The polyorganosiloxane-containing graft copolymer powder (A-9) was obtained in the same manner as in Example 1-3, except that the polyorganosiloxane-containing graft copolymer (G-3) was not treated with sodium chloride solution after the preparation, and the same measurements were carried out. The results are shown in Table 2.

[0160] [Comparative Example 1-4] The polyorganosiloxane-containing graft copolymer powder (A-10) was obtained in the same manner as in Example 1-4, except that the polyorganosiloxane-containing graft copolymer (G-4) was not treated with sodium chloride solution after the preparation, and the same measurements were carried out. The results are shown in Table 2.

[0161] [Comparative Example 1-5] A polyorganosiloxane-containing graft copolymer (G-5) was produced in the same manner as in Example 1-1, except that the raw material compositions used in Example 1-1 were changed to the conditions shown in Table 2. A graft copolymer powder (A-11) was also obtained and the same measurements were carried out. The results are shown in Table 2.

[0162] [Comparative Examples 1-6] After obtaining polyorganosiloxane-containing graft copolymer (G-5) by the method described in Comparative Example 1-5, add 10 parts of obtained graft copolymer (G-5) into 141 parts of deionized water, stir for 3 minutes, then add 10 parts of aqueous solution of sodium chloride concentration of 10 mass%, stir for 3 minutes, filter, wash, dehydrate, then dry to obtain the powder (A-12) of graft copolymer containing sodium, and carry out the same measurement.The obtained results are shown in Table 2.

[0163] [Comparative Example 1-7] In the same manner as in Example 1-1, except that the raw material composition used in Example 1-1 was changed to the conditions shown in Table 2, polyorganosiloxane-containing graft copolymer (G-6) was obtained, and then 10 parts of the obtained graft copolymer (G-6) was added to 141 parts of deionized water and stirred for 3 minutes, and then 10 parts of an aqueous solution of sodium chloride with a concentration of 10% by mass was added and stirred for 3 minutes, and then filtered, washed, dehydrated, and then dried to obtain a powder of graft copolymer (A-13) containing sodium, and the same measurement was carried out. The obtained results are shown in Table 2.

[0164] [Table 2]

[0165] The abbreviations in Table 2 are as follows: nBA: n-butyl acrylate AMA: Allyl methacrylate MMA: Methyl methacrylate Na: Sodium K: Potassium

[0166] Compared with the graft copolymers according to Comparative Examples 1-1 to 1-7, the graft polymers according to Examples 1-1 to 1-6 had improved thermal decomposition properties.

[0167] [Examples 2-1 to 2-9, Comparative Examples 2-1 to 2-8] A mixture was obtained by blending the polyorganosiloxane-containing polymer powder, additives, and thermoplastic resin in the ratios shown in Table 3. This mixture was fed into a devolatilizing twin-screw extruder (manufactured by Ikegai Corporation, PCM-30 (trade name)) and kneaded to produce pellets of each resin composition.

[0168] The following thermoplastic resins were used: PC: Polycarbonate resin (Iupilon S-2000F, manufactured by Mitsubishi Engineering Plastics Corporation, viscosity average molecular weight 24,000). When the thermal decomposition of PC was measured, the temperature at which 90% of the PC remained was 506°C.

[0169] The following additives were used: A-3750: Acrylic-modified PTFE (Metablen A-3750, manufactured by Mitsubishi Chemical Corporation).

[0170] Pellets of the resin composition were injection molded using an injection molding machine (SE100DU (trade name), manufactured by Sumitomo Heavy Industries, Ltd.) to prepare test pieces for evaluation. Specimen specifications: Test piece A: length 80 mm x width 10 mm x thickness 4 mm Test piece B: length 100 mm x width 50 mm x thickness 2 mm Test piece C: length 125 mm x width 13 mm x thickness 1.6 mm The extrusion conditions and injection molding conditions are as follows: Extrusion barrel temperature 280℃, Injection cylinder temperature: 280℃, Mold temperature: 60℃.

[0171] Test piece A was notched with a Type A notch in accordance with ISO 179-1 and the Charpy impact strength was measured. The higher the Charpy impact strength value, the higher the impact resistance. The results are shown in Table 3.

[0172] Test piece B is visually inspected for flow marks (striped patterns seen near the gate of the molded article) that appear near the gate of test piece B. "Evaluation method" The appearance of the gate was visually evaluated (A: flow marks were not noticeable, B: flow marks were noticeable). The evaluation results are shown in Table 3.

[0173] Using test piece C, the total burning time and the presence or absence of dripping upon ignition of five test pieces were measured using a vertical burning test method conforming to the UL94V test. The shorter the total burning time, the higher the flame retardancy, and the less dripping is preferred. The evaluation results are shown in Table 3.

[0174] [Table 3]

[0175] The resin composition according to Comparative Example 2-1 did not contain a graft copolymer, and therefore had low low-temperature impact strength and flame retardancy. The molded articles of Examples 2-1 to 2-9, in which the temperature at which the thermoplastic resin remaining amount was 90% and the value of the polyorganosiloxane-containing polymer remaining amount were specific values, had better flame retardancy than the molded articles of Comparative Examples 2-1 to 2-8. If the graft copolymer (A) does not decompose, the effect of improving flame retardancy cannot be obtained. If the decomposition temperature of the graft copolymer (A) is too close to that of the matrix resin, the matrix resin decomposes before the graft copolymer forms a carbonized layer, and therefore the effect of improving flame retardancy cannot be obtained. Compared with the graft copolymers according to Examples 2-1 to 2-9, the graft copolymers according to Comparative Examples 2-6 and 2-7 were inferior in appearance.

Claims

1. The thermoplastic resin and the polyorganosiloxane-containing polymer are included, The polyorganosiloxane-containing polymer has a mass average particle diameter Dw of 375 nm or more, A resin composition satisfying the following formula (1): Y-X≧20℃...(1) (In formula (1), X means the temperature at which the residual amount of the polyorganosiloxane-containing polymer becomes 1 part by mass when 100 parts by mass of the polyorganosiloxane-containing polymer is heated to 550°C at 10°C / min under the condition of a nitrogen flow rate of 200 mL / min, and Y means the temperature at which the residual amount of the thermoplastic resin becomes 90 parts by mass when 100 parts by mass of the thermoplastic resin is heated to 550°C at 10°C / min under the condition of a nitrogen flow rate of 200 mL / min.)

2. The resin composition according to claim 1, which satisfies the following formula (2): X-Z≦40℃...(2) (In formula (2), X has the same meaning as X in formula (1), and Z means the temperature at which the remaining amount of the polyorganosiloxane-containing polymer becomes 70 parts by mass when 100 parts by mass of the polyorganosiloxane-containing polymer is heated to 550°C at a rate of 10°C / min under the condition of a nitrogen flow rate of 200 mL / min.)

3. The polyorganosiloxane-containing polymer is a polymer having a composite and a graft portion, the composite includes a polyorganosiloxane and a first vinyl polymer; The resin composition according to claim 1 or 2, wherein the graft portion comprises a second vinyl polymer.

4. The resin composition according to claim 3, wherein the proportion of the polyorganosiloxane in 100% by mass of the polyorganosiloxane-containing polymer is 70% by mass or more and 98% by mass or less.

5. The resin composition according to claim 3 or 4, wherein the first vinyl polymer contains a structural unit derived from a (meth)acrylate monomer.

6. The polyorganosiloxane contains a constituent unit derived from a siloxane-based crosslinking agent, and the proportion of the constituent unit derived from the siloxane-based crosslinking agent in 100% by mass of the polyorganosiloxane is 3% by mass or less. The resin composition according to any one of claims 3 to 5.

7. A molded article comprising the resin composition according to any one of claims 1 to 6.

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