Transparent thermoplastic resin composition, molded article obtained therefrom, and method for producing the transparent thermoplastic resin composition

Abstract

One object of the present invention is to provide a transparent thermoplastic resin composition having excellent impact resistance and fluidity while maintaining high transparency, and a molded product thereof. The gist of the present invention for achieving the above object is to provide a transparent thermoplastic resin composition comprising: a graft copolymer (A) obtained by graft copolymerizing a monomer mixture (a) containing at least an aromatic vinyl monomer (a1) and a (meth) acrylic acid ester monomer (a2) in the presence of a rubbery polymer (r); a vinyl copolymer (B) obtained by copolymerizing a monomer mixture (b) containing at least an aromatic vinyl monomer (b1), a (meth) acrylic acid ester monomer (b2) and a vinyl cyanide monomer (b3); the following ester compound (C); and the following Ester compound (D); wherein the ester compound (C) is a hydrogenated product of a triglyceride of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid, and 85% by mass or more of the acid constituting the triglyceride is a hydrogenated product of ricinoleic acid; and wherein the ester compound (D) is an ester of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid and a polyol (provided that the ester contains at least one ester bond with an unsaturated carboxylic acid), and 85% by mass or more of the acid constituting the ester is ricinoleic acid.

Description

Technical Field

[0001] The present invention relates to a transparent thermoplastic resin composition and a molded article thereof. Background Art

[0002] Transparent ABS (acrylonitrile butadiene styrene) resins containing graft copolymers obtained by copolymerization of a rubbery polymer such as a diene rubber with an aromatic vinyl compound such as styrene or α-methylstyrene, a vinyl cyanide compound such as acrylonitrile or methacrylonitrile, and an unsaturated carboxylic acid alkyl ester compound such as methyl methacrylate or methyl acrylate are widely used in applications such as consumer electronics, communication-related equipment, daily commodities, and medical equipment because they are excellent in transparency, balance between mechanical strength such as impact resistance and rigidity, molding processability due to fluidity, cost performance, etc. Attempts to further improve the impact resistance and fluidity of such resins are also continuing.

[0003] The following documents are known to disclose resin compositions containing hydrogenated castor oil. For example, Patent Document 1 discloses a thermoplastic resin composition comprising a rubber-modified styrene resin composition, which contains: (I) a continuous phase of 60 to 80% by mass of a styrene-(meth)acrylic acid ester-based copolymer, which is a copolymer of a styrene monomer, a (meth)acrylic acid ester monomer, and a vinyl monomer that can be copolymerized with these monomers and used as needed; and (II) a dispersed phase of a grafted copolymer obtained by grafting a styrene-(meth)acrylic acid ester copolymer onto a rubbery elastomer, which is a copolymer of a styrene monomer, a (meth)acrylic acid ester monomer, and a vinyl monomer that can be copolymerized with these monomers and used as needed, wherein the dispersed phase has a volume average particle size of 0.3 to 0.6 μm. size), and satisfies a specific range calculated by a specific formula defining the relationship between the weight average molecular weight (Mw) of the continuous phase, the amount of (meth)acrylate monomer units, and the amount of styrene monomer units. In addition, the rubber-modified styrene resin composition contains 0.005 to 0.05 parts by mass of an organopolysiloxane relative to 100 parts by mass of the resin composition, and 0.1 to 2.5 parts by mass of an ester-based lubricant relative to 100 parts by mass of the rubber-modified styrene resin composition, wherein the ester-based lubricant is hydrogenated castor oil.

[0004] In addition, the following documents are known to disclose resin compositions containing hydrogenated castor oil and fatty acid esters. For example, Patent Document 2 proposes a transparent thermoplastic resin composition comprising: a graft copolymer (A) obtained by graft copolymerizing a monomer mixture (a) containing at least an aromatic vinyl monomer (a1) and a (meth) acrylic acid ester monomer (a2) in the presence of a rubbery polymer (r); a vinyl copolymer (B) obtained by copolymerizing a monomer mixture (b) containing at least an aromatic vinyl monomer (b1), a (meth) acrylic acid ester monomer (b2) and a vinyl cyanide monomer (b3); an ester wax (C) which is hydrogenated castor oil; and an ester wax (D) which is a fatty acid ester composed of a linear saturated monocarboxylic acid having 12 to 30 carbon atoms and at least one alcohol selected from a linear saturated monohydric alcohol having 14 to 30 carbon atoms and a dihydric to hexahydric alcohol having 2 to 30 carbon atoms.

[0005] Citation List

[0006] Patent Literature

[0007] Patent Document 1: WO 2003 / 102076

[0008] Patent Document 2: JP 2020-139054 A SUMMARY OF THE INVENTION

[0010] Technical issues

[0011] However, conventional thermoplastic resin compositions cannot achieve high levels of transparency, impact resistance, and fluidity, and further improvements are required.

[0012] An object of the present invention is to solve the above-mentioned problems in the prior art and to provide: a transparent thermoplastic resin composition having both transparency, impact resistance and fluidity, that is, a transparent thermoplastic resin composition having excellent impact resistance and fluidity while maintaining particularly high transparency; and a molded article thereof.

[0013] Solutions to the Problem

[0014] As a result of intensive studies to achieve the above-mentioned purpose, the present inventors have found that a resin composition can achieve excellent impact resistance and fluidity while maintaining high transparency, thereby achieving the present invention, the resin composition containing: a vinyl copolymer obtained by copolymerizing a vinyl monomer mixture; a graft copolymer containing a rubbery polymer; and two types of specific additives.

[0015] Specifically, the present invention is characterized by the following (1) to (9).

[0016] (1) A transparent thermoplastic resin composition comprising:

[0017] a graft copolymer (A) obtained by graft-copolymerizing a monomer mixture (a) containing at least an aromatic vinyl monomer (a1) and a (meth)acrylate monomer (a2) in the presence of a rubbery polymer (r);

[0018] A vinyl copolymer (B) obtained by copolymerizing a monomer mixture (b) containing at least an aromatic vinyl monomer (b1), a (meth)acrylate monomer (b2) and a vinyl cyanide monomer (b3);

[0019] The following ester compound (C); and

[0020] The following ester compounds (D);

[0021] wherein the ester compound (C) is a hydrogenated product of a triglyceride of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid, and 85% by mass or more of the acid constituting the triglyceride is a hydrogenated product of ricinoleic acid; and

[0022] wherein the ester compound (D) is an ester of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid and a polyol (provided that the ester contains at least one ester bond with an unsaturated carboxylic acid), and 85% by mass or more of the acid constituting the ester is ricinoleic acid.

[0023] (2) The transparent thermoplastic resin composition according to (1) above, wherein the ester compound (D) has a hydroxyl value of 170 to 350 mg KOH / g.

[0024] (3) The transparent thermoplastic resin composition according to (1) or (2)

[0025] in:

[0026] The content of the ester compound (C) is 0.4 to 0.8 parts by mass relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B);

[0027] The content of the ester compound (D) is 0.6 to 2.4 parts by mass based on 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B); and

[0028] The mass ratio of the ester compound (C) to the ester compound (D) ((C):(D)) is 25:75 to 40:60.

[0029] (4) The transparent thermoplastic resin composition according to any one of (1) to (3), wherein an acetone-soluble component contained in the transparent thermoplastic resin composition has a weight average molecular weight of 100,000 to 120,000.

[0030] (5) The transparent thermoplastic resin composition according to any one of (1) to (4), wherein in the acetone-soluble component contained in the transparent thermoplastic resin composition, the content of the structural unit derived from the (meth)acrylate monomer is 50 to 82% by mass, the content of the structural unit derived from the aromatic vinyl monomer is 10 to 30% by mass, and the content of the structural unit derived from the vinyl cyanide monomer is 8 to 15% by mass, relative to the total amount of the structural unit derived from the (meth)acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer and the structural unit derived from other vinyl monomers as 100% by mass.

[0031] (6) The transparent thermoplastic resin composition according to any one of (1) to (5), wherein when the weight average molecular weight of the acetone soluble component contained in the transparent thermoplastic resin composition is defined as Mw1 and the content (mass %) of the structural unit derived from the vinyl cyanide monomer contained in the acetone soluble component relative to 100 mass % of the mass of the acetone soluble component is defined as W1, a value obtained by dividing Mw1 by W1 is 11,000 or more.

[0032] (7) The transparent thermoplastic resin composition according to any one of (1) to (6), wherein the transparent thermoplastic resin composition further comprises polydimethylsiloxane gum (E).

[0033] (8) A method for producing a transparent thermoplastic resin composition, the method comprising the steps of:

[0034] A graft copolymer (A) is obtained by graft-copolymerizing a monomer mixture (a) containing at least an aromatic vinyl monomer (a1) and a (meth)acrylate monomer (a2) in the presence of a rubbery polymer (r);

[0035] A vinyl copolymer (B) is obtained by copolymerizing a monomer mixture (b) containing at least an aromatic vinyl monomer (b1), a (meth)acrylate monomer (b2), and a vinyl cyanide monomer (b3); and

[0036] The graft copolymer (A), the vinyl copolymer (B), the following ester compound (C) and the following ester compound (D) are mixed,

[0037] wherein the ester compound (C) is a hydrogenated product of a triglyceride of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid, and 85% by mass or more of the acid constituting the triglyceride is hydrogenated ricinoleic acid; and

[0038] wherein the ester compound (D) is an ester of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid and a polyol (provided that the ester contains at least one ester bond with an unsaturated carboxylic acid), and 85% by mass or more of the acid constituting the ester is ricinoleic acid.

[0039] (9) A molded article formed using the transparent thermoplastic resin composition according to any one of (1) to (7).

[0040] (10) A molded article formed using the transparent thermoplastic resin composition produced by the method according to (8).

[0041] Advantageous Effects of the Invention

[0042] According to the present invention, it is possible to obtain a transparent thermoplastic resin composition having excellent impact resistance and fluidity while maintaining particularly high transparency. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a schematic diagram showing one embodiment of a production apparatus for producing a transparent thermoplastic resin composition according to the present invention.

[0044] Figure 2 is a diagram illustrating a molded product and an evaluation method for evaluating releasability.

[0045] Description of the implementation plan

[0046] The present invention will now be described. However, the following description is an example of an ideal embodiment, and the present invention is not limited to the contents of the description.

[0047] In the present specification, the term "(meth)acrylic acid" refers to acrylic acid and methacrylic acid. For example, the definition of methyl (meth)acrylate includes methyl acrylate and methyl methacrylate.

[0048] The transparent thermoplastic resin composition according to the present invention contains a graft copolymer (A), a vinyl copolymer (B) and two types of specific additives (ester compound (C) and ester compound (D)), which will be described later. The addition of the graft copolymer (A) can improve the formability of the transparent thermoplastic resin composition and improve the impact resistance and transparency of the resulting molded article. The addition of the vinyl copolymer (B) can improve the fluidity of the transparent thermoplastic resin composition and improve the transparency of the molded article. In addition, the addition of the two types of specific additives can not only improve the impact resistance of the molded article without causing a decrease in the transparency of the molded article, but also improve the fluidity of the transparent thermoplastic resin composition to obtain favorable formability.

[0049] (Graft copolymer (A))

[0050] The graft copolymer (A) contained in the transparent thermoplastic resin composition according to the present invention is a graft copolymer obtained by graft copolymerizing a monomer mixture (a) containing at least an aromatic vinyl monomer (a1) and a (meth) acrylic acid ester monomer (a2) in the presence of a rubbery polymer (r). The monomer mixture (a) may further contain other monomers (a3) ​​copolymerizable with the monomers (a1) and (a2).

[0051] Examples of rubbery polymers (r) include polybutadiene, poly(butadiene-styrene) (SBR), poly(butadiene-acrylonitrile) (NBR), poly(butadiene-butyl acrylate), poly(butadiene-methyl methacrylate), poly(butyl acrylate-methyl methacrylate), poly(butadiene-ethyl acrylate) and natural rubber. These polymers can be used alone or in combination of two or more thereof. Among them, polybutadiene, SBR, NBR or natural rubber are preferred from the viewpoint of further improving the impact resistance and transparency of the resulting molded article, and polybutadiene is more preferred.

[0052] The rubbery polymer (r) preferably has a mass average particle size of 0.15 to 0.4 μm, more preferably 0.20 to 0.35 μm, and even more preferably 0.25 to 0.35 μm. When the mass average particle size of the rubbery polymer (r) is less than 0.15 μm, the impact resistance of the molded article may be reduced. On the other hand, when the mass average particle size of the rubbery polymer (r) is greater than 0.4 μm, the transparency of the molded article may be reduced.

[0053] The mass average particle size of the rubbery polymer (r) can be determined as follows: diluting the latex of the rubbery polymer (r) in an aqueous medium to disperse it therein; measuring the particle size distribution using a laser diffraction / scattering particle size distribution measuring device (e.g., "LS13 320" (manufactured by Beckman Coulter Inc.); and calculating the mass average particle size from the particle size distribution.

[0054] The total amount of the rubbery polymer (r) and the monomer mixture (a) constituting the graft copolymer (A) is 100 mass %, and the content of the rubbery polymer (r) is preferably 20 to 80 mass %. When the content of the rubbery polymer (r) is 20 mass % or more (or more), the impact resistance and transparency of the molded article can be further improved. The content of the rubbery polymer (r) is more preferably 35 mass % or more. In addition, when the content of the rubbery polymer (r) is 80 mass % or lower, the flowability of the transparent thermoplastic resin composition and the impact resistance of the molded article can be further improved. The content of the rubbery polymer (r) is more preferably 60 mass % or lower.

[0055] Examples of the aromatic vinyl monomer (a1) include styrene monomers such as styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, o-methylstyrene, vinyltoluene and tert-butylstyrene. These monomers can be used alone or in combination of two or more thereof. Among them, styrene is preferred from the perspective of further improving the fluidity of the transparent thermoplastic resin composition and the transparency and rigidity of the molded article.

[0056] From the viewpoint of further improving the fluidity of the transparent thermoplastic resin composition and the transparency and rigidity of the molded article, the content of the aromatic vinyl monomer (a1) in the monomer mixture (a) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, relative to 100% by mass of the mass of the monomer mixture (a). On the other hand, from the viewpoint of improving the impact resistance and transparency of the molded article, the content of the aromatic vinyl monomer (a1) in the monomer mixture (a) is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. When the content of the aromatic vinyl monomer (a1) is within the above range, it is possible to easily produce a transparent thermoplastic resin composition in which the content of the structural unit derived from the aromatic vinyl monomer is 10 to 30% by mass relative to the total amount of the structural unit derived from the (meth) acrylic acid ester monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers contained in the acetone-soluble component in the transparent thermoplastic resin composition to be described later as 100% by mass.

[0057] The (meth) acrylic acid ester monomer (a2) in the monomer mixture (a) is preferably, for example, an ester of an alcohol having 1 to 6 carbon atoms and acrylic acid or methacrylic acid. The ester of an alcohol having 1 to 6 carbon atoms and acrylic acid or methacrylic acid may further contain a substituent, such as a hydroxyl group or a halogen group. Examples of esters of alcohol having 1 to 6 carbon atoms and acrylic acid or methacrylic acid include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate and 2,3,4,5-tetrahydroxypentyl (meth) acrylate. These esters may be used alone, or two or more thereof may be used in combination. Among them, methyl (meth) acrylate is preferred from the perspective of improving the transparency of the molded article.

[0058] From the viewpoint of improving the transparency of the molded article, the content of the (meth)acrylate monomer (a2) in the monomer mixture (a) is preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, based on 100% by mass of the total amount of the monomer mixture (a). On the other hand, from the viewpoint of improving the transparency of the molded article, the content of the (meth)acrylate monomer (a2) in the monomer mixture (a) is preferably 82% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, based on 100% by mass of the total amount of the monomer mixture (a). When the content of the (meth)acrylate monomer (a2) is within the range, it is possible to easily produce a transparent thermoplastic resin composition in which the content of the structural unit derived from the (meth)acrylate monomer is 50 to 82 mass % relative to 100 mass % of the total amount of the structural unit derived from the (meth)acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer and the structural unit derived from other vinyl monomers contained in the acetone-soluble component in the transparent thermoplastic resin composition to be described later.

[0059] The other monomer (a3) ​​copolymerizable with the aromatic vinyl monomer (a1) and the (meth)acrylate monomer (a2) is not particularly limited as long as it is a vinyl monomer different from the above-mentioned aromatic vinyl monomer (a1) and (meth)acrylate monomer (a2) and does not impair the effects of the present invention.

[0060] The other monomer (a3) ​​may specifically be, for example, a vinyl cyanide monomer, an unsaturated fatty acid, an acrylamide monomer or a maleimide monomer. These monomers may be used alone or in combination of two or more thereof.

[0061] Examples of vinyl cyanide monomers include acrylonitrile, methacrylonitrile and ethacrylonitrile. These monomers can be used alone or in combination of two or more thereof. Among them, acrylonitrile is preferred from the viewpoint of further improving the impact resistance of the molded article.

[0062] Examples of unsaturated fatty acids include itaconic acid, maleic acid, fumaric acid, crotonic acid, acrylic acid, and methacrylic acid.

[0063] Examples of the acrylamide monomer include acrylamide, methacrylamide, and N-methylacrylamide.

[0064] Examples of the maleimide monomer include N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N-octylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide.

[0065] From the viewpoint of improving the impact resistance of the molded article, the content of the other monomer (a3) ​​in the monomer mixture (a) is preferably 2% by mass or more relative to 100% by mass of the mass of the monomer mixture (a). On the other hand, from the viewpoint of improving the color of the molded article, the content of the other monomer (a3) ​​is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 5% by mass or less.

[0066] As other monomers (a3), vinyl cyanide monomers can be preferably used. Relative to the mass of monomer mixture (a) is 100% by mass, and the content of vinyl cyanide monomers in monomer mixture (a) is preferably 2% by mass or more. On the other hand, from the perspective of improving the color of the molded product, the content of vinyl cyanide monomers is preferably 30% by mass or less, more preferably 20% by mass or less, and more preferably 5% by mass or less. When the content of vinyl cyanide monomers is within the above range, it is possible to easily produce a transparent thermoplastic resin composition, wherein relative to the total amount of structural units derived from (meth) acrylate monomers, structural units derived from aromatic vinyl monomers, structural units derived from vinyl cyanide monomers, and structural units derived from other vinyl monomers contained in the acetone-soluble components in the transparent thermoplastic resin composition to be described later is 100% by mass, and the content of structural units derived from vinyl cyanide monomers is 8 to 15% by mass.

[0067] A portion of the graft copolymer (A) is soluble in acetone. The acetone soluble component preferably has a weight average molecular weight of 50,000 or more, more preferably 60,000 or more, but is not particularly limited thereto. When the weight average molecular weight of the acetone soluble component of the graft copolymer (A) is 50,000 or more, the impact resistance of the molded article can be further improved. On the other hand, the weight average molecular weight of the acetone soluble component of the graft copolymer (A) is preferably 100,000 or less, more preferably 90,000 or less. When the weight average molecular weight of the acetone soluble component of the graft copolymer (A) is 100,000 or less, the fluidity of the transparent thermoplastic resin composition can be further improved. Furthermore, when the weight average molecular weight of the acetone soluble component is within the range of 50,000 to 100,000, it is possible to easily produce a transparent thermoplastic resin composition in which the weight average molecular weight of the acetone soluble component in the transparent thermoplastic resin composition to be described later is 100,000 to 120,000.

[0068] In the present invention, "weight average molecular weight" refers to the molecular weight with respect to polymethyl methacrylate. In order to eliminate the influence of low molecular weight components, the weight average molecular weight is defined as a value obtained for components having a molecular weight of 3,000 or more.

[0069] In order to measure the weight average molecular weight of the acetone soluble component of the graft copolymer (A), the graft copolymer (A) is introduced into acetone to dissolve the soluble component, and the filtrate obtained by filtering the acetone insoluble component from the graft copolymer (A) is concentrated by a rotary evaporator to collect the acetone soluble component. About 0.03 grams of the collected acetone soluble component is dissolved in about 15 grams of tetrahydrofuran to prepare a solution of about 0.2 mass %. The weight average molecular weight of the acetone soluble component can be measured by calculating the GPC chromatogram obtained by measuring the solution prepared by using polymethyl methacrylate as a reference material. The GPC measurement can be carried out under the following conditions:

[0070] Measuring device: Waters 2695

[0071] Column temperature: 40°C

[0072] Detector: RI 2414 (differential refractometer)

[0073] Carrier eluent flow rate: 0.3 ml / min (solvent: tetrahydrofuran)

[0074] Column: TSkgel Super HZM-M (6.0 mm ID×15 cm), TSkgel Super HZM-N (6.0 mm ID×15 cm) (both manufactured by Tosoh Corporation) arranged in series

[0075] The graft ratio of the graft copolymer (A) is not particularly limited, but is preferably 10 to 100% from the viewpoint of improving the impact resistance of the molded article.

[0076] The grafting rate of the graft copolymer (A) can be determined by the following method. First, 80 ml of acetone is added to about 1 gram (m: sample mass) of the graft copolymer (A), and the mixture is refluxed in a hot water bath at 70°C for 3 hours. After the resulting solution is centrifuged at 8,000rpm (10,000G) for 40 minutes, the insoluble component is filtered to obtain the acetone insoluble component. The resulting acetone insoluble component is dried at 80°C for 5 hours under reduced pressure, its mass (n) is measured, and the grafting rate is calculated by the following equation. In the following equation, X represents the content (%) of the rubbery polymer in the graft copolymer (A).

[0077] Grafting rate (%) = {[(n)-((m)×X / 100)] / [(m)×X / 100]}×100

[0078] The difference in refractive index between the graft component (acetone insoluble component) of the graft copolymer (A) and the rubbery polymer (r) is preferably 0.03 or less, more preferably 0.01 or less. By reducing the difference in refractive index between the graft component (acetone insoluble component) of the graft copolymer (A) and the rubbery polymer (r) to 0.03 or less, the transparency of the molded article can be improved.

[0079] Since the refractive index of the graft component of the graft copolymer (A) mainly varies with the composition of the vinyl monomer as one of the components of the raw material, the refractive index can be controlled within a desired range by appropriately selecting the type and composition ratio of the vinyl monomer. In particular, when the conversion rate to the high molecular weight form is adjusted to 95% or more by emulsion polymerization, the composition of the graft component is approximately the same as that of the vinyl monomer mixture (a).

[0080] The refractive index of the graft component of the graft copolymer (A) can be estimated from the refractive index and content of the vinyl monomer. For example, in the case of a copolymer of styrene, methyl methacrylate and acrylonitrile, the refractive index of the graft component of the graft copolymer (A) can be estimated by the following equation: nD(G) = (1.595 × MS / 100) + (1.490 × MM / 100) + (1.510 × MA / 100)

[0081] In this equation, nD(G) represents the refractive index of the graft component of the graft copolymer (A), MS represents the content (mass %) of styrene, MM represents the content (mass %) of methyl methacrylate, and MA represents the content (mass %) of acrylonitrile. 1.595 represents the refractive index of polystyrene, 1.490 represents the refractive index of polymethyl methacrylate, and 1.510 represents the refractive index of polyacrylonitrile. The refractive indices of polystyrene, polymethyl methacrylate, and polyacrylonitrile can be measured by an Abbe refractometer.

[0082] In the present invention, the graft copolymer (A) is more preferably produced by emulsion polymerization because the mass average particle size of the rubbery polymer (r) can be easily adjusted to a desired range and polymerization stability can be easily controlled by removing heat during polymerization.

[0083] In the case of producing the graft copolymer (A) by emulsion polymerization, the method of introducing the rubbery polymer (r) and the monomer mixture (a) is not particularly limited. For example, all of these can be introduced at once. Alternatively, in order to control the distribution of the copolymer composition, a part of the monomer mixture (a) can be continuously introduced, or a part or all of the monomer mixture (a) can be introduced in portions. The expression "a part of the introduction of the monomer mixture (a)" used herein refers to a part of the monomer mixture (a) that is initially introduced, and the remainder of the mixture is continuously introduced over time. In addition, the expression "a part or all of the monomer mixture (a) is introduced in portions" refers to a part or all of the monomer mixture (a) that is introduced at one or more time points after the initial introduction.

[0084] In the case of producing the graft copolymer (A) by emulsion polymerization, various surfactants may be added as emulsifiers. It is particularly preferred to use anionic surfactants such as carboxylates, sulfates or sulfonates as such surfactants. These surfactants may be used alone or in combination of two or more thereof. Examples of "salts" used herein include: alkali metal salts such as sodium salts, lithium salts and potassium salts; and ammonium salts.

[0085] Examples of emulsifiers in the form of carboxylates include caprylate, caprate, laurate, myristate, palmitate, stearate, oleate, linoleate, linolenate, rosinate and behenate, dialkyl sulfosuccinates.

[0086] Examples of the emulsifier in the form of sulfate ester salts include sulfate ester salts of castor oil, sulfate ester salts of lauryl alcohol, polyoxyethylene lauryl sulfate, polyoxyethylene alkyl ether sulfate, and polyoxyethylene alkylphenyl ether sulfate.

[0087] Examples of the emulsifier in the form of sulfonate include dodecylbenzenesulfonate, alkylnaphthalenesulfonate, alkyldiphenylether disulfonate and naphthalenesulfonate condensate.

[0088] In the case of producing the graft copolymer (A) by emulsion polymerization, an initiator may be added as required. The initiator may be, for example, a peroxide, an azo-based compound or a water-soluble potassium persulfate. These initiators may be used alone or in combination of two or more thereof. A redox polymerization initiator may also be used as an initiator.

[0089] Examples of peroxides include benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, diisopropylbenzene hydroperoxide, tert-butyl hydroperoxide, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl carbonate, di-tert-butyl peroxide, tert-butyl peroxyoctanoate, 1,1-di(tert-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, and tert-butyl peroxy-2-ethylhexanoate. Among them, cumene hydroperoxide, 1,1-bis(tert-butylperoxy)3,3,5-trimethylcyclohexane, or 1,1-bis(tert-butylperoxy)cyclohexane are particularly preferably used.

[0090] Examples of azo compounds include azobisdimethylvaleronitrile, azobis(2,4-dimethyl)valeronitrile, 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2-cyano-2-propylazocarbonamide, 1,1'-azobiscyclohexane-1-carbonitrile, azobis(4-methoxy-2,4-dimethyl)valeronitrile, 2,2'-azobisisobutyric acid dimethyl ester, 1-tert-butylazo-2-cyanobutane, and 2-tert-butylazo-2-cyano-4-methoxy-4-methylpentane. Among them, 1,1'-azobiscyclohexane-1-carbonitrile is particularly preferably used.

[0091] The amount of the initiator added to produce the graft copolymer (A) is not particularly limited. However, from the perspective of the productivity of the graft copolymer (A), the amount of the initiator added is preferably 0.1 to 0.5 parts by mass relative to 100 parts by mass of the total amount of the rubbery polymer (r) and the monomer mixture (a).

[0092] In the case of producing the graft copolymer (A) by emulsion polymerization, a chain transfer agent can be used. The use of a chain transfer agent makes it possible to easily control the grafting rate of the graft copolymer (A) to a desired range. Examples of chain transfer agents include: mercaptans such as n-octyl mercaptan, tert-dodecyl mercaptan, n-dodecyl mercaptan, n-tetradecyl mercaptan and n-octadecyl mercaptan; and terpenes such as terpinolene. These chain transfer agents can be used alone, or two or more thereof are used in combination. Among them, n-octyl mercaptan and tert-dodecyl mercaptan are preferably used.

[0093] The amount of the chain transfer agent added for producing the graft copolymer (A) is not particularly limited. However, the amount of the chain transfer agent added is preferably 0.2 to 0.7 parts by mass relative to 100 parts by mass of the total amount of the rubbery polymer (r) and the monomer mixture (a), because the grafting rate of the graft copolymer (A) can be more easily controlled. The lower limit of the amount added is more preferably 0.4 parts by mass or more, and the upper limit is more preferably 0.6 parts by mass or less.

[0094] In the case of producing the graft copolymer (A) by emulsion polymerization, the polymerization temperature is not particularly limited. However, from the viewpoint of emulsification stability, the polymerization temperature is preferably 40 to 70°C.

[0095] In the case of producing the graft copolymer (A) by emulsion polymerization, a coagulant is usually added to the latex of the graft copolymer to collect the graft copolymer (A). An acid or a water-soluble salt is preferably used as the coagulant.

[0096] Examples of acids include sulfuric acid, hydrochloric acid, phosphoric acid and acetic acid. Examples of water-soluble salts include calcium chloride, magnesium chloride, barium chloride, aluminum chloride, magnesium sulfate, aluminum sulfate, ammonium aluminum sulfate, potassium aluminum sulfate and sodium aluminum sulfate. These can be used alone or in combination of two or more thereof. From the viewpoint of improving the color of the molded article, it is preferred to prevent the emulsifier from remaining in the thermoplastic resin composition and use an alkali metal fatty acid salt as an emulsifier to cause acid coagulation. In this case, it is preferred to subsequently remove the emulsifier by neutralization with an alkali such as sodium hydroxide.

[0097] (vinyl copolymer (B))

[0098] The vinyl copolymer (B) included in the transparent thermoplastic resin composition according to the present invention is a vinyl copolymer obtained by copolymerizing a monomer mixture (b) containing at least an aromatic vinyl monomer (b1), a (meth)acrylate monomer (b2) and a vinyl cyanide monomer (b3). The monomer mixture (b) may further contain other monomers (b4) copolymerizable with the monomers (b1) to (b3).

[0099] Examples of the aromatic vinyl monomer (b1) include those exemplified in the section of the aromatic vinyl monomer (a1). Among them, styrene is preferred.

[0100] From the perspective of further improving the fluidity of the transparent thermoplastic resin composition and the transparency and rigidity of the molded product, the content of the aromatic vinyl monomer (b1) in the monomer mixture (b) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, relative to the mass of the monomer mixture (b) as 100% by mass. In addition, from the perspective of improving the impact resistance and transparency of the molded product, the content of the aromatic vinyl monomer (b1) in the monomer mixture (b) is preferably 30% by mass or less, more preferably 27% by mass or less, and even more preferably 25% by mass or less. When the content of the aromatic vinyl monomer (b1) is within the above range, it is possible to easily produce a transparent thermoplastic resin composition, wherein the content of the structural unit derived from the aromatic vinyl monomer is 10 to 30% by mass relative to the total amount of the structural unit derived from the (meth) acrylic acid ester monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers contained in the acetone-soluble component in the transparent thermoplastic resin composition to be described later as 100% by mass.

[0101] Examples of the (meth)acrylate monomer (b2) include those exemplified in the section of the (meth)acrylate monomer (a2), and methyl (meth)acrylate is preferably used.

[0102] From the perspective of improving the transparency of the molded article, the content of the (meth) acrylate monomer (b2) in the monomer mixture (b) is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more, relative to the mass of the monomer mixture (b) as 100% by mass. In addition, from the perspective of further improving the transparency of the molded article, the content of the (meth) acrylate monomer (b2) in the monomer mixture (b) is preferably 82% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less. When the content of the (meth) acrylate monomer (b2) is within the range, it is possible to easily produce a transparent thermoplastic resin composition, wherein the content of the structural unit derived from the (meth) acrylate monomer is 50 to 82% by mass relative to the total amount of the structural unit derived from the (meth) acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers contained in the acetone-soluble component in the transparent thermoplastic resin composition to be described later as 100% by mass.

[0103] Examples of the vinyl cyanide monomer (b3) include acrylonitrile, methacrylonitrile and ethacrylonitrile. These monomers can be used alone or in combination of two or more thereof. Among them, acrylonitrile is preferred from the viewpoint of further improving the impact resistance of the molded article.

[0104] From the perspective of further improving the impact resistance of the molded article, the content of the vinyl cyanide monomer (b3) in the monomer mixture (b) is preferably 4% by mass or more, more preferably 8% by mass or more, and even more preferably 9% by mass or more, relative to the mass of the monomer mixture (b) as 100% by mass. In addition, from the perspective of improving the color of the molded article, the content of the vinyl cyanide monomer (b3) in the monomer mixture (b) is preferably 15% by mass or less, more preferably 13% by mass or less, and even more preferably 12% by mass or less. In particular, when the content of the vinyl cyanide monomer (b3) is in the range of 8 to 15% by mass, it is possible to easily produce a transparent thermoplastic resin composition, wherein the content of the structural unit derived from the vinyl cyanide monomer is 8 to 15% by mass relative to the total amount of the structural unit derived from the (meth) acrylic acid ester monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers contained in the acetone-soluble component in the transparent thermoplastic resin composition to be described later as 100% by mass.

[0105] Other monomers (b4) copolymerizable with these monomers are not particularly limited as long as they are vinyl monomers different from the above-mentioned aromatic vinyl monomers (b1), (meth)acrylate monomers (b2) and vinyl cyanide monomers (b3), copolymerizable with these monomers and not impairing the effects of the present invention.

[0106] The other monomer (b4) may specifically be, for example, an unsaturated fatty acid, an acrylamide monomer or a maleimide monomer. These monomers may be used alone or in combination of two or more thereof.

[0107] Examples of unsaturated fatty acids include itaconic acid, maleic acid, fumaric acid, crotonic acid, acrylic acid, and methacrylic acid.

[0108] Examples of the acrylamide monomer include acrylamide, methacrylamide, and N-methylacrylamide.

[0109] Examples of the maleimide monomer include N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N-octylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide.

[0110] From the viewpoint of improving the fluidity of the transparent thermoplastic resin composition and the impact resistance and transparency of the molded article, the content of other monomers (b4) in the monomer mixture (b) is preferably 20 mass % or less, more preferably 10 mass % or less, relative to the mass of the monomer mixture (b) as 100 mass %.

[0111] The vinyl copolymer (B) preferably has a weight average molecular weight of more than 100,000, more preferably more than 110,000. When the weight average molecular weight of the vinyl copolymer (B) is adjusted to more than 100,000, the impact resistance of the molded article can be further improved. In addition, the weight average molecular weight of the vinyl copolymer (B) is preferably 130,000 or less, more preferably 120,000 or less. When the weight average molecular weight of the vinyl copolymer (B) is adjusted to 130,000 or less, the fluidity of the transparent thermoplastic resin composition can be further improved. In addition, when the weight average molecular weight of the vinyl copolymer (B) is in the range of 100,000 to 130,000, it is possible to easily produce a transparent thermoplastic resin composition, wherein the weight average molecular weight of the acetone soluble component in the transparent thermoplastic resin composition described later is 100,000 to 120,000.

[0112] In order to eliminate the influence of low molecular weight components, the weight average molecular weight in the present invention refers to a value obtained for components having a molecular weight of 3,000 or more in terms of polymethyl methacrylate.

[0113] Here, the weight average molecular weight of the vinyl copolymer (B) can be determined by calculation using a GPC chromatogram obtained by measuring a 0.2 mass % solution of about 0.03 g of the vinyl copolymer (B) dissolved in about 15 g of tetrahydrofuran, with polymethyl methacrylate as a reference material. The GPC measurement can be performed under the following conditions:

[0114] Measuring device: Waters 2695

[0115] Column temperature: 40°C

[0116] Detector: RI 2414 (differential refractometer)

[0117] Carrier eluent flow rate: 0.3 ml / min (solvent: tetrahydrofuran)

[0118] Column: TSkgel Super HZM-M (6.0 mm ID×15 cm), TSkgel Super HZM-N (6.0 mm ID×15 cm) (both manufactured by Tosoh Corporation) arranged in series

[0119] The difference between the refractive index of the vinyl copolymer (B) and the refractive index of the rubber-like polymer (r) contained in the above-mentioned graft copolymer (A) is preferably 0.03 or less, more preferably 0.01 or less. By reducing the difference between the refractive index of the vinyl copolymer (B) and the refractive index of the rubber-like polymer (r) to 0.03 or less, the transparency of the molded article can be improved.

[0120] Since the refractive index of the vinyl copolymer (B) varies with the composition of the vinyl monomer as the main raw material, the refractive index can be controlled within a desired range by selecting the type and composition ratio of the vinyl monomer as appropriate. The refractive index of the vinyl copolymer (B) can be estimated by the refractive index and content of the vinyl monomer. For example, in the case of a copolymer of styrene, methyl methacrylate and acrylonitrile, the refractive index of the vinyl copolymer (B) can be estimated by the following equation:

[0121] nD(B)=(1.595×MS / 100)+(1.490×MM / 100)+(1.510×MA / 100)

[0122] In this equation, nD(B) represents the refractive index of the vinyl copolymer (B), MS represents the content (mass %) of styrene, MM represents the content (mass %) of methyl methacrylate, and MA represents the content (mass %) of acrylonitrile. 1.595 represents the refractive index of polystyrene, 1.490 represents the refractive index of polymethyl methacrylate, and 1.510 represents the refractive index of polyacrylonitrile. The refractive indices of polystyrene, polymethyl methacrylate, and polyacrylonitrile can each be measured by an Abbe refractometer.

[0123] The refractive index of the vinyl copolymer (B) can also be measured by an Abbe refractometer.

[0124] In the present invention, the method for producing the vinyl copolymer (B) is not particularly limited. However, from the viewpoint of improving the fluidity of the resulting transparent thermoplastic resin composition and the transparency and color of the resulting molded article, it is preferably used a continuous bulk polymerization method or a continuous solution polymerization method.

[0125] For producing the vinyl copolymer (B) by continuous bulk polymerization or continuous solution polymerization, any conventionally known method may be used, for example, a method in which the monomer mixture (b) is polymerized in a polymerization vessel and then stripped of monomers (desolventization / devolatilization).

[0126] As the polymerization reactor, it is possible to use, for example, a mixing type polymerization reactor having a stirring blade such as a paddle blade, a turbine blade, a propeller blade, a bull-margin blade, a multi-stage blade, an anchor blade, a Max Blend blade or a double helical blade, various types of tower reactors, etc. In addition, a multitubular reactor, a kneading reactor, a twin-screw extruder, etc. can also be used as a polymerization reactor (see, for example, Assessment of Polymer Production Process 10 "Assessment of Impact Resistant Polystyrene", the Society of Polymer Science, Japan, published on January 26, 1989).

[0127] Two or more of these polymerization kettles or polymerization reactors may be used, or, as required, two or more polymerization kettles or polymerization reactors may be used in combination. From the viewpoint of reducing the dispersion of the vinyl copolymer (B), it is preferred to use no more than two polymerization kettles or polymerization reactors, and more preferably a single-pot, completely mixed type polymerization kettle.

[0128] Typically, the reaction mixture obtained by polymerization using any of these polymerization kettles or polymerization reactors is then subjected to a stripper step to remove monomers and solvents and other volatile components. Examples of stripper methods include: a method of removing volatile components through a vent while heating in a single-screw or twin-screw extruder with a vent under normal pressure or reduced pressure; a method of removing volatile components using an evaporator such as a centrifugal evaporator containing a plate-fin heater in a drum; a method of removing volatile components using a thin film evaporator such as a centrifugal thin film evaporator; and a method of removing volatile components by preheating, foaming, and flashing into a vacuum tank using a multi-tube heat exchanger. Among them, a method of removing volatile components using a single-screw or twin-screw extruder with a vent is particularly preferred.

[0129] In the case of producing the vinyl copolymer (B), an initiator and / or a chain transfer agent may be used as required. Examples of the initiator and the chain transfer agent include the initiators and chain transfer agents exemplified in the method for producing the graft copolymer (A). A redox initiator is also used as the initiator.

[0130] The amount of the initiator added to produce the vinyl copolymer (B) is not particularly limited. However, the amount of the initiator added is preferably 0.01 to 0.10 parts by mass relative to 100 parts by mass of the total amount of the vinyl monomer mixture (b), because the weight average molecular weight of the vinyl copolymer (B) can be more easily adjusted to the above range.

[0131] The amount of the chain transfer agent added to produce the vinyl copolymer (B) is not particularly limited. However, the amount of the chain transfer agent added is preferably 0.10 to 0.40 parts by mass relative to 100 parts by mass of the total amount of the vinyl monomer mixture (b), because the weight average molecular weight of the vinyl copolymer (B) can be more easily adjusted to the above range. The lower limit of the amount added is more preferably 0.20 parts by mass or more, and the upper limit is more preferably 0.30 parts by mass or less.

[0132] In the case of producing the vinyl copolymer (B) by continuous bulk polymerization or continuous solution polymerization, the polymerization temperature is not particularly limited. However, the polymerization temperature is preferably 120° C. to 140° C. because the weight average molecular weight of the vinyl copolymer (B) can be more easily adjusted to the above range.

[0133] In the case of producing the vinyl copolymer (B) by continuous solution polymerization, the amount of solvent in the polymerization solution is preferably 30% by mass or less, more preferably 20% by mass or less from the viewpoint of productivity. From the viewpoint of polymerization stability, the solvent used is preferably ethylbenzene or methyl ethyl ketone, more preferably ethylbenzene.

[0134] (Transparent thermoplastic resin composition)

[0135] The transparent thermoplastic resin composition according to the present invention preferably contains 10 to 60 parts by mass of the graft copolymer (A) and 40 to 90 parts by mass of the vinyl copolymer (B), relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B). On the other hand, when the content of the graft copolymer (A) is less than 10 parts by mass and the content of the vinyl copolymer (B) is greater than 90 parts by mass, the impact resistance of the resulting molded article may be reduced. The transparent thermoplastic resin composition more preferably contains 20 parts by mass or more of the graft copolymer (A) and 80 parts by mass or less of the vinyl copolymer (B), relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B). On the other hand, when the content of the graft copolymer (A) is greater than 60 parts by mass and the content of the vinyl copolymer (B) is less than 40 parts by mass, the melt viscosity of the transparent thermoplastic resin composition may increase so that the fluidity is reduced, and the transparency of the resulting molded article may also be reduced. The transparent thermoplastic resin composition more preferably contains 50 parts by mass or less of the graft copolymer (A) and 50 parts by mass or more of the vinyl copolymer (B) relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B).

[0136] The acetone soluble component contained in the transparent thermoplastic resin composition according to the present invention preferably has a weight average molecular weight of 100,000 to 120,000. When the weight average molecular weight of the acetone soluble component contained in the transparent thermoplastic resin composition is adjusted to 100,000 or more, the impact resistance of the molded article can be further improved. When the weight average molecular weight of the acetone soluble component contained in the transparent thermoplastic resin composition is adjusted to 120,000 or less, the fluidity of the transparent thermoplastic resin composition can be further improved.

[0137] As used herein, the weight average molecular weight of the acetone soluble components contained in the transparent thermoplastic resin composition may be measured according to the same procedure as described in the section of the graft copolymer (A) after introducing the transparent thermoplastic resin composition into acetone to dissolve the soluble components.

[0138] In the acetone-soluble component contained in the transparent thermoplastic resin composition according to the present invention, from the viewpoint of improving the transparency of the molded article, the content of the structural unit derived from the (meth)acrylate monomer is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more, relative to the total amount of the structural unit derived from the (meth)acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers as 100% by mass. On the other hand, from the viewpoint of further improving the transparency of the molded article, the content of the structural unit derived from the (meth)acrylate monomer is preferably 82% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less.

[0139] In the acetone-soluble component contained in the transparent thermoplastic resin composition according to the present invention, from the viewpoint of further improving the fluidity of the transparent thermoplastic resin composition and the transparency and rigidity of the molded article, the content of the structural unit derived from the aromatic vinyl monomer is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, relative to the total amount of the structural unit derived from the (meth)acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers as 100% by mass. On the other hand, from the viewpoint of further improving the impact resistance and transparency of the molded article, the content of the structural unit derived from the aromatic vinyl monomer is preferably 30% by mass or less, more preferably 27% by mass or less, and even more preferably 25% by mass or less.

[0140] In the acetone-soluble component contained in the transparent thermoplastic resin composition according to the present invention, the content of the structural unit derived from the vinyl cyanide monomer is preferably 8% by mass or more, more preferably 9% by mass or more, relative to the total amount of the structural unit derived from the (meth)acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers as 100% by mass, from the viewpoint of further improving the impact resistance of the molded article. On the other hand, from the viewpoint of further improving the color of the molded article, the content of the structural unit derived from the vinyl cyanide monomer is preferably 15% by mass or less, more preferably 13% by mass or less, and still more preferably 11% by mass or less.

[0141] When a polymer is formed by polymerization of a number of monomers, the term "structural unit" as used herein refers to a repeating unit representing or corresponding to each monomer used in the structural formula of the polymer. For example, in polystyrene, the structural unit derived from styrene is [-CH2-CH(C6H5)-].

[0142] From the viewpoint of the balance between the fluidity of the transparent thermoplastic resin composition and the impact resistance of the molded article, the content of the rubbery polymer (r) contained in the transparent thermoplastic resin composition according to the present invention is preferably 12 to 22% by mass, relative to the total amount of the rubbery polymer (r), the structural unit derived from the (meth)acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers as 100% by mass. The content of the rubbery polymer (r) is more preferably 15% by mass or more and 20% by mass or less.

[0143] The content of the structural unit derived from the (meth)acrylate monomer, the content of the structural unit derived from the aromatic vinyl monomer, and the content of the structural unit derived from the vinyl cyanide monomer, relative to 100% by mass of the total amount of the structural unit derived from the (meth)acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers in the acetone-soluble component contained in the transparent thermoplastic resin composition, can be obtained by the following method.

[0144] Specifically, the transparent thermoplastic resin composition is introduced into acetone to dissolve the soluble components, and the filtrate obtained by filtering the acetone insoluble components from the transparent thermoplastic resin composition is concentrated and dried by a rotary evaporator to collect the acetone soluble components. The acetone soluble components thus obtained are formed into a film with a thickness of 30±5 μm by hot pressing, wherein the temperature is set to 230°C, and the film is subjected to FT-IR analysis. Based on a calibration curve prepared in advance by the intensity ratio of the following peaks appearing in the obtained FT-IR spectrum, the content of the structural unit derived from each monomer can be quantified. The relationship between the structural unit derived from each monomer and the corresponding peak is described below.

[0145] Structural units derived from (meth)acrylate monomers: at 3460 cm -1 The peak at 1730 cm-1 is attributable to the C=O stretching vibration of the carbonyl group of the ester. -1 The overtone peak of the peak at .

[0146] Structural units derived from aromatic vinyl monomers: 1605 cm-1 due to the vibration of the benzene nucleus -1 The peak

[0147] Structural units derived from vinyl cyanide monomers: 2240 cm-1 due to C≡N stretching -1 The peak

[0148] In addition, relative to the total amount of the rubbery polymer (r), the structural unit derived from the (meth) acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer, and the structural unit derived from other vinyl monomers as 100% by mass, the content of the rubbery polymer (r) can be quantified as follows. Specifically, the transparent thermoplastic resin composition is formed into a film having a thickness of 30±5 μm by hot pressing, wherein the temperature is set to 230° C., and the film is subjected to FT-IR analysis. Based on a calibration curve prepared in advance from the intensity ratio of the peaks of the structural units derived from the respective monomers and the rubbery polymer (r) appearing in the obtained FT-IR spectrum, the content of the rubbery polymer (r) can be quantified. The relationship between the rubbery polymer (r) and the corresponding peaks is described below.

[0149] Rubbery polymer (r): attributed to C=C at 960 cm -1 The peak

[0150] In the transparent thermoplastic resin composition according to the present invention, when the weight average molecular weight of the acetone soluble component contained in the transparent thermoplastic resin composition is defined as Mw1 and the content (mass %) of the structural unit derived from the vinyl cyanide monomer contained in the acetone soluble component relative to the mass of the acetone soluble component as 100 mass % is defined as W1, the value obtained by dividing Mw1 by W1 is preferably 11,000 or more. For example, when the weight average molecular weight of the acetone soluble component contained in the transparent thermoplastic resin composition is 500,000 and the content of the structural unit derived from the vinyl cyanide monomer contained in the acetone soluble component is 5% relative to the mass of the acetone soluble component as 100 mass %, the value obtained by dividing Mw1 by W1 is 100,000. When the value obtained by dividing Mw1 by W1 is less than 11,000, there is a case where the effect of improving the impact resistance by the structural unit derived from the vinyl cyanide monomer contained in the vinyl copolymer (B) becomes insufficient, which may result in a decrease in the impact resistance of the molded article, and is therefore not preferred.

[0151] The transparent thermoplastic resin composition according to the present invention contains an ester compound (C) and an ester compound (D) in addition to the graft copolymer (A) and the vinyl copolymer (B).

[0152] The ester compound (C) is a hydrogenated product of a triglyceride of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid, and 85% by mass or more of the acid constituting the triglyceride is a hydrogenated product of ricinoleic acid, i.e., 12-hydroxystearic acid.

[0153] Therefore, the main component of the ester compound (C) is an ester obtained from 12-hydroxystearic acid and glycerin.

[0154] Compounds synthesized by esterifying the above acid with glycerol can be used as the ester compound (C). However, since hydrogenated castor oil of natural origin is known as such a compound, it is economically advantageous in the present invention to use hydrogenated castor oil to obtain the transparent thermoplastic resin composition according to the present invention.

[0155] In the case of using hydrogenated castor oil as the ester compound (C), the hydrogenated castor oil preferably has an iodine value of 5 or less, more preferably 3 or less, from the viewpoint of improving the color of the resulting molded article, but is not particularly limited thereto. When the iodine value of the hydrogenated castor oil is 5 or less, discoloration caused by thermal degradation during processing can be reduced. The iodine value is measured in accordance with JIS K0070:1992.

[0156] The content of the ester compound (C) is preferably 0.4 to 2.0 parts by mass, more preferably 0.4 to 0.8 parts by mass, relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B). When the content of the ester compound (C) is 0.4 parts by mass or more relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B), it is possible to improve the impact resistance of the molded article and the fluidity of the transparent thermoplastic resin composition. In addition, when the content of the ester compound (C) is 2.0 parts by mass or less relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B), it is possible to improve the impact resistance of the molded article without impairing the transparency of the molded article, and further improve the fluidity of the transparent thermoplastic resin composition. In particular, when the content of the ester compound (C) is in the range of 0.4 to 0.8 parts by mass relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B), it is possible not only to improve the impact resistance of the molded article, the fluidity of the transparent thermoplastic resin composition and the releasability during the molding process, but also to reduce the amount of gas generated during the molding process and further reduce mold scaling.

[0157] The ester compound (D) is an ester of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid and a polyol (provided that the ester contains at least one ester bond with an unsaturated carboxylic acid), and 85% by mass or more of the acid constituting the ester is ricinoleic acid.

[0158] Polyol refers to a compound containing two or more hydroxyl groups in one molecule. Polyol is not particularly limited as long as it is a compound containing two or more hydroxyl groups. However, it is preferred to use diols to hexaols having 2 to 30 carbon atoms.

[0159] Examples of the diol among the above diols to hexaols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, 1,20-eicosandiol, 1,30-triacontandiol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, spiroglycol, 1,4-benzenediol, bisphenol A and hydrogenated bisphenol A. Examples of trihydric alcohols include 1,2,4-butanetriol, 1,2,5-pentanetriol, 2-methyl-1,2,4-butanetriol, glycerol, 2-methylpropanetriol, trimethylolethane, triethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene. Examples of tetrahydric alcohols include 1,2,3,6-hexanetetraol and pentaerythritol; examples of pentahydric alcohols include glucose; examples of hexahydric alcohols include dipentaerythritol.

[0160] Compounds synthesized by esterifying the above-mentioned acids with polyols can be used as ester compounds (D). However, it is economically advantageous to obtain compound (D) from natural fats or oils or processed products of natural fats or oils. In particular, it is easy to use modified compounds obtained using castor oil (castor oil-based polyester polyols) or derivatives thereof as starting materials, and castor oil is a type of vegetable oil obtained by extracting oil from the seeds of castor oil plants (scientific name: Ricinus communis L.). The composition of castor oil fatty acids included in castor oil is known to consist of 87 to 91% of ricinoleic acid, 4 to 5% of linoleic acid, 2.5 to 4% of oleic acid, 0.5 to 1.5% of palmitic acid, 0.5 to 1.5% of stearic acid, 0.5 to 1.5% of linolenic acid and 0.5 to 1.5% of dihydroxystearic acid.

[0161] In the case of using castor oil-based polyester polyol as the ester compound (D), examples thereof include polyester polyols made from castor oil or castor oil fatty acids. Examples of castor oil-based polyester polyols further include transesterification products of castor oil with other natural fats and oils, reaction products of castor oil with polyols, and esterification products of castor oil fatty acids with polyols. These polyester polyols can be used alone or as a mixture of two or more thereof.

[0162] As the ester compound (D), an ester compound having a hydroxyl value of 170 mg KOH / g or more, more preferably 200 mg KOH / g or more is preferably used. The use of an ester compound (D) having a hydroxyl value of 170 mg KOH / g or more can improve the fluidity of the transparent thermoplastic resin composition and further improve the transparency of the molded article. The upper limit of the hydroxyl value is preferably 350 mg KOH / g or less.

[0163] In addition, the ester compound (D) preferably has an acid value of 15 mg KOH / g or less. The acid value of the ester compound (D) is more preferably 10 mg KOH / g or less, still more preferably 8 mg KOH / g or less, and particularly preferably 2 mg KOH / g or less. When the acid value is 15 mg KOH / g or less, the ester compound (D) has high heat resistance, and in addition to reducing the amount of gas generated by unreacted residual fatty acids as low molecular weight components during molding and reducing mold fouling, it is also possible to improve the color of the molded product.

[0164] The acid value and the hydroxyl value were measured according to JIS K0070:1992.

[0165] In addition, the ester compound (D) preferably has a viscosity at 25°C of 200 to 1,500 mPa·s, more preferably 200 to 750 mPa·s, and even more preferably 200 to 500 mPa·s. When the above viscosity is 200 mPa·s or more, it is possible to reduce the amount of gas generated by the ester compound (D) during molding and reduce mold fouling. In addition, when the above viscosity is 1,500 mPa·s or less, the fluidity of the transparent thermoplastic resin composition can be further improved. The viscosity value is measured according to JIS Z8803:2011.

[0166] When castor oil or a polyester polyol based on castor oil is used as the ester compound (D) used in the present invention, castor oil or a polyester polyol based on castor oil can be produced according to a known production method, or a commercially available product thereof can be used. Examples of commercially available products of castor oil or a polyester polyol based on castor oil include URIC H series (H-30, H-31, H-52, H-57, H-62, H-73X, H-81, H-854, H-870, H-1823, H-1824, and HF-1300), URIC Y series (Y-403 and Y-406), URIC AC series (AC-005, AC-006, and AC-009), URIC PH series (PH-5001), and URICF series (F-40, F-60, and F-97), all manufactured by Itoh Oil Chemicals Co., Ltd. Among them, H-30, H-62 or H-73X is preferably used from the viewpoint of transparency and impact resistance of a molded article and fluidity of the transparent thermoplastic resin composition.

[0167] In the present invention, the content of the ester compound (D) in the transparent thermoplastic resin composition is preferably 0.4 to 3.0 parts by mass, more preferably 0.6 to 2.4 parts by mass, relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B). The upper limit of this content is more preferably 1.5 parts by mass or less. When the content of the ester compound (D) is 0.4 parts by mass or more relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B), it is possible to improve the fluidity of the transparent thermoplastic resin composition and improve the demoldability of the molded article. In addition, when the content of the ester compound (D) is 3.0 parts by mass or less relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B), the fluidity of the transparent thermoplastic resin composition can be further improved without damaging the transparency and impact resistance of the molded article. In particular, when the content of the ester compound (D) is in the range of 0.6 to 2.4 parts by mass relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B), it is possible not only to improve the impact resistance of the molded article, the fluidity of the transparent thermoplastic resin composition and the demoldability during the molding process, but also to reduce the amount of gas generated during the molding process and reduce mold scaling.

[0168] Since the ester compound (C) contributes greatly to the improvement of the impact resistance of the molded article in particular, the compound is considered to be unevenly distributed around the rubber polymer (r) in the transparent thermoplastic resin composition. As a result, it is possible to reduce the elastic modulus around the rubber polymer (r) to alleviate the huge difference in elastic modulus that occurs between the rubber phase and the matrix phase, and to alleviate the stress concentration at the interface. In addition, the presence of the ester compound (C) unevenly distributed around the rubber polymer (r) can improve the anti-impact sliding characteristics (slip characteristics) of the rubber polymer (r) and enhance the impact absorption capacity of the rubber polymer (r). On the other hand, excessive incorporation of the ester compound (C) is not preferred because the effect of improving the impact resistance of the molded article tends to be stable, which may lead to a decrease in demouldability and an increase in the amount of gas generated during the molding process, and cause mold fouling. Since the ester compound (D) contributes greatly to the improvement of the fluidity of the transparent thermoplastic resin composition in particular, the compound is considered to be well dispersed in the matrix phase of the transparent thermoplastic resin composition. In addition, the ester compound (D) makes it possible to maintain transparency. On the other hand, excessive incorporation of the ester compound (D) is not preferred because it may result in reduced impact resistance of the molded article and increased amount of gas generated during molding and may cause mold scaling.

[0169] Based on the above reasons, from the perspective of improving the impact resistance of the molded article, the fluidity of the transparent thermoplastic resin composition and the releasability during the molding process, and reducing the amount of gas generated during the molding process, the transparent thermoplastic resin composition according to the present invention preferably contains the ester compound (C) and the ester compound (D) in a mass ratio of 25:75 to 40:60. When the amount of the ester compound (D) is greater than 75% by mass and the amount of the ester compound (C) is less than 25% by mass, the impact resistance of the molded article may not be sufficiently obtained, and thus it is not preferred. On the other hand, when the amount of the ester compound (D) is less than 60% by mass and the amount of the ester compound (C) is greater than 40% by mass, the fluidity of the transparent thermoplastic resin composition may not be sufficiently obtained, which may result in reduced releasability, and thus it is not preferred.

[0170] The transparent thermoplastic resin composition according to the present invention may contain a carboxylic acid ester of a polyol which does not correspond to the ester compound (C) or the ester compound (D) as long as the object of the present invention is not impaired.

[0171] The transparent thermoplastic resin composition according to the present invention may further contain polydimethylsiloxane gum (E). The polydimethylsiloxane gum (E) used herein refers to a polydimethylsiloxane in the form of a gum and having a weight average molecular weight of more than 300,000. The polydimethylsiloxane having a weight average molecular weight of more than 300,000 is in the form of a gum rather than a liquid. The value of the weight average molecular weight of the polydimethylsiloxane gum (E) is measured in the same manner as described for the acetone soluble component of the graft copolymer (A) or for the vinyl copolymer (B), but calculated with polystyrene as a reference material.

[0172] The content of the polydimethylsiloxane gum (E) is not particularly limited. However, from the viewpoint of further improving the impact resistance without impairing the transparency and the releasability, the content of the polydimethylsiloxane gum (E) is preferably 15 to 100 ppm (i.e., 15×10 -6 Up to 100×10 -6 parts by mass), more preferably 30 to 80 ppm.

[0173] The transparent thermoplastic resin composition according to the present invention may further contain various kinds of antioxidants.

[0174] Examples of phenolic antioxidants include: reaction products of p-cresol·dicyclopentadiene·isobutylene; 2,4,5- and 2,4,6-3 phenols such as 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,6-di-tert-butyl-4-methylphenol, triethylene glycol-bis-[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], n-octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)acrylate, )-4-methylphenyl ester, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)]-4,6-di-tert-pentylphenyl acrylate (548.9, one), 3,9-bis[2-{3-(tert-butyl-4-hydroxy-5-methylphenyl)propoxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxa[5,5]undecane, 1,3,5-tris(3',5')-di-tert-butyl-4'-hydroxybenzyl-s-triazine-2,4,6(1H,2H,3H)-trione, 1,1,4-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane and 4,4'-butylenebis(3-methyl-6-tert-butylphenol); and the reaction product of p-cresol·dicyclopentadiene·isobutylene.

[0175] Examples of phosphorus-based antioxidants include pentaerythritol-type diphosphite compounds such as tris(2,4-di-tert-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)-pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)-pentaerythritol diphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, and dinonylphenyl pentaerythritol diphosphite.

[0176] Examples of the sulfur-based antioxidant include distearyl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, dilauryl thiodipropionate, laurylstearyl thiodipropionate, and pentaerythritol tetrakis(3-laurylthiopropionate).

[0177] If necessary, the transparent thermoplastic resin composition according to the present invention may further contain any of the following to the extent that the purpose of the present invention is not impaired: inorganic fillers such as glass fiber, glass powder, glass beads, glass flakes, alumina, alumina fiber, carbon fiber, graphite fiber, stainless steel fiber, whisker, potassium titanate fiber, wollastonite, asbestos, hard clay, calcined clay, talc, kaolin, mica, calcium carbonate, magnesium carbonate, aluminum oxide and minerals; heat stabilizers such as hindered phenol stabilizers and acrylate-based stabilizers; ultraviolet absorbers such as benzotriazole-based, benzophenone-based and UV absorbers of salicylic acid esters; hindered amine light stabilizers; lubricants and plasticizers, such as higher fatty acids, acid esters, acid amide compounds and higher alcohols; mold release agents, such as montanic acid, its salts, its esters and its half esters, stearyl alcohol, stearamide and ethylene wax; various types of flame retardants; auxiliary flame retardants; coloring inhibitors, such as phosphites and hypophosphites; neutralizers, such as phosphoric acid, sodium dihydrogen phosphate, maleic anhydride and succinic anhydride; nucleating agents; antistatic agents, such as amine-based, sulfonic acid-based, polyether-based antistatic agents; and colorants such as carbon black, pigments and dyes.

[0178] In the present invention, "transparent" means that a rectangular plate-shaped molded product (length: 50 mm, width: 40 mm, thickness: 3 mm) has a total light transmittance measured using a direct-reading haze meter manufactured by Toyo Seiki Co., Ltd. of 80% or more.

[0179] In one embodiment of the transparent thermoplastic resin composition according to the present invention, it is possible to obtain a transparent thermoplastic resin composition wherein a rectangular plate-shaped molded article thereof (length: 50 mm, width: 40 mm, thickness: 3 mm) has a total light transmittance of 87% or more and a haze (as an index of transparency) of 3 or less and a thermal conductivity of 14 kJ / m 2 The present invention relates to a transparent thermoplastic resin composition having a total light transmittance of 88% or more, a haze of 2 or less, a Charpy impact strength of 15 kJ / m2 or more, and a Charpy impact strength of 15 kJ / m2 or more. The present invention relates to a transparent thermoplastic resin composition having a total light transmittance of 88% or more, a haze of 2 or less, and a Charpy impact strength of 15 kJ / m2 or more. The present invention relates to a transparent thermoplastic resin composition having a total light transmittance of 88% or more, a haze of 2 or less, and a Charpy impact strength of 15 kJ / m2 or more. 2 The above, MFR (220 ℃, 98N) is 22g / 10min or more and when filled under the pressure of the lower limit pressure in the molding process + 60MPa, the number of white marks (including ejector marks) is 8 or less, and it has good mass production capability.

[0180] (Method for producing transparent thermoplastic resin composition)

[0181] Next, a method for producing a transparent thermoplastic resin composition according to the present invention will be described. The transparent thermoplastic resin composition according to the present invention can be obtained, for example, by mixing the above-mentioned graft copolymer (A), vinyl copolymer (B), ester compound (C) and ester compound (D) and, if necessary, one or more other components, such as the above-mentioned polydimethylsiloxane gum (E), and then melt-kneading. More preferred is a method in which the vinyl copolymer (B) is produced by continuous bulk polymerization, and further, the graft copolymer (A), ester compound (C), ester compound (D) and, if necessary, one or more other components, such as polydimethylsiloxane gum (E) are continuously melt-kneaded therewith. By continuously carrying out the production of the vinyl copolymer (B) to the production of the transparent thermoplastic resin composition as the final product, the thermal history can be reduced to improve the color of the transparent thermoplastic resin composition.

[0182] Figure 1 A schematic diagram showing one embodiment of an apparatus for producing a transparent thermoplastic resin composition preferably used in the present invention. Figure 1 The apparatus for producing a transparent thermoplastic resin composition shown in comprises: a complete mixing type polymerization kettle 1 for producing a vinyl copolymer (B); a single screw extruder type preheater 2 for heating the obtained vinyl copolymer (B) to a predetermined temperature; and a twin screw extruder type monomer stripping device 3; and these are connected in this order. In addition, a twin screw extruder type feeder 5 for supplying a graft copolymer (A), an ester compound (C), an ester compound (D) and, if necessary, another one or more components such as polydimethylsiloxane gum (E) by side feeding is connected to the twin screw extruder type monomer stripping device 3. The complete mixing type polymerization kettle 1 includes an agitator (ribbon blade) 7, and the twin screw extruder type monomer stripping device 3 includes a vent 8 for removing volatile components such as unreacted monomers.

[0183] The reaction product (vinyl copolymer (B)) continuously supplied from the complete mixing type polymerization kettle 1 is heated to a predetermined temperature in the single screw extruder type preheater 2 and then supplied to the twin screw extruder type monomer removal device 3. In the twin screw extruder type monomer removal device 3, volatile components such as unreacted monomers are removed from the system from the exhaust port 8, usually at a temperature of about 150 to 280° C. under normal pressure or reduced pressure. Usually, the removal of the volatile components is performed until the amount of the volatile components is reduced to a predetermined amount, for example, 10% by mass or less, more preferably 5% by mass or less. In addition, it is preferred that the removed volatile components are supplied again to the complete mixing type polymerization kettle 1.

[0184] The graft copolymer (A), the ester compound (C) and the polydimethylsiloxane gum (E) (if necessary) are supplied from the twin screw extruder type feeder 5 via an opening provided at a position closer to the downstream side thereof in the twin screw extruder type monomer removal device 3. In addition, the ester compound (D) is supplied to the twin screw extruder type feeder 5 using a liquid additive adding pump via a liquid additive adding nozzle 11 located at a position corresponding to 2 / 3 of the total length of the twin screw extruder type feeder 5 from the downstream side end of the twin screw extruder type feeder 5 (the position where the twin screw extruder type feeder 5 is connected to the twin screw extruder type monomer removal device 3). The twin screw extruder type feeder 5 preferably includes a heating device. The mixing state can be improved by supplying the graft copolymer (A) to the twin screw extruder type monomer removal device 3 in a molten or semi-molten state. The graft copolymer (A) is usually heated at a heating temperature of 100 to 220°C. The twin-screw extruder type feeder 5 may be, for example, a twin-screw extruder type feeder composed of a screw, a barrel, and a screw driving unit, and in which the barrel has heating and cooling functions.

[0185] At the position where the twin-screw extruder type monomer removal device 3 is connected to the twin-screw extruder type feeder 5, the content of unreacted monomers is preferably reduced to 10% by mass or less, more preferably to 5% by mass or less, in order to reduce thermal degradation of the rubber component caused by the subsequent operation of removing the unreacted monomers.

[0186] The vinyl copolymer (B), the graft copolymer (A), the ester compound (C), the ester compound (D) and, if necessary, the polydimethylsiloxane gum (E) are melt-kneaded in the melt-kneading zone 4 which is a region downstream of the position where the twin-screw extruder type monomer removal device 3 is connected to the twin-screw extruder type feeder 5, and the resulting transparent thermoplastic resin composition is discharged from the system from the discharge port 6. It is preferred that the melt-kneading zone 4 is provided with a water injection port 9, and a predetermined amount of water is added therethrough. The injected water and volatile components such as unreacted monomers are removed from the system from the final exhaust port 10 provided further downstream.

[0187] Since a small amount of polydimethylsiloxane gum (E) is added, it is preferred to prepare a resin diluted product of polydimethylsiloxane gum in advance according to the method disclosed in WO 2021 / 014736, and add polydimethylsiloxane gum as a resin diluted product of polydimethylsiloxane gum (wherein the content of polydimethylsiloxane gum (E) is approximately 10 mass %).

[0188] The transparent thermoplastic resin composition according to the present invention can be molded by any molding method. Examples of molding methods include injection molding, extrusion molding, inflation molding, blow molding, vacuum molding, compression molding, and gas-assisted molding. Among them, injection molding is preferably used. Injection molding is preferably carried out at a barrel temperature of 210 to 320°C, and preferably at a mold temperature of 30 to 80°C.

[0189] The transparent thermoplastic resin composition according to the present invention can be widely used as molded products of any shape. Examples of molded products include films, sheets, fibers, fabrics, nonwoven fabrics, injection molded products, extrusion molded products, vacuum pressure molded products, blow molded products, and composite materials with other materials.

[0190] The transparent thermoplastic resin composition according to the present invention can be used in applications such as consumer electronics, communication-related equipment, daily commodities, and medical equipment because the composition can have excellent impact resistance and flowability while maintaining particularly high transparency and good color. Example

[0191] The present invention will now be described in more detail with reference to Examples. However, the present invention is not to be construed as being limited to these Examples. First, the evaluation method is described.

[0192] <Evaluation Method of Transparent Thermoplastic Resin Composition>

[0193] (1) Transparency (haze)

[0194] The sample pellets of the resin composition were dried in a hot air dryer at 80° C. for 3 hours, and then filled into a molding machine SE-50DU manufactured by Sumitomo Heavy Industries, Ltd., which had been set to a barrel temperature of 230° C., and immediately molded into a rectangular plate-shaped molded article having a thickness of 3 mm. The haze (%) of each of five resulting rectangular plate-shaped molded articles was measured by a method according to ISO 14782 using a direct-reading haze meter manufactured by Toyo Seiki Co., Ltd., and the average of the measured values ​​was calculated.

[0195] (2) Transparency (total light transmittance)

[0196] The sample pellets of the resin composition were dried in a hot air dryer at 80° C. for 3 hours, and then filled into a molding machine SE-50DU manufactured by Sumitomo Heavy Industries, Ltd., which had been set to a barrel temperature of 230° C., and immediately molded into a rectangular plate-shaped molded article having a thickness of 3 mm. The total light transmittance (%) of each of five obtained rectangular plate-shaped molded articles was measured by a method according to ISO 13468 using a direct-reading haze meter manufactured by Toyo Seiki Co., Ltd., and the average value of the measured values ​​was calculated.

[0197] (3) Impact resistance (Charpy impact strength)

[0198] The sample pellets of the resin composition were dried in a hot air dryer at 80° C. for 3 hours, then filled into a molding machine SE-50DU manufactured by Sumitomo Heavy Industries, Ltd., which had been set to a barrel temperature of 230° C., and immediately molded into a dumbbell-shaped test piece having a thickness of 4 mm. The Charpy impact strength of each of five obtained dumbbell-shaped test pieces was measured by a method according to ISO 179, and the average value of the measured values ​​was calculated.

[0199] (4) Flowability (Melt Flow Rate (MFR))

[0200] The sample pellets of the resin composition were dried in a hot air dryer at 80° C. for 3 hours, and then the MFR was measured by a method according to ISO 1133 under the conditions of a measuring temperature of 220° C. and a load of 98N.

[0201] (5) Demolding

[0202] The sample pellets of the resin composition were dried in a hot air dryer at 80° C. for 3 hours and then filled into a molding machine PS60 manufactured by Nissei Plastic Industrial Co., Ltd., which had been set to a barrel temperature of 230° C., a mold temperature of 60° C., and a cooling time of 20 seconds. The mode of the molding machine was switched to a pressure control mode at the gate position to determine the pressure that could be filled into the resin. Figure 2 The lower limit pressure in the molded product shape shown in . Subsequently, for each of five molded products molded under the condition of lower limit pressure + 60 MPa, the number of white marks (including ejection marks) was counted by visual observation, and the average value thereof was calculated.

[0203] (6) Large-scale production capability

[0204] According to the procedure described in each of Examples and Comparative Examples, the production of pellets of the resin composition was performed for 2 hours, and then the used screen (#150 mesh) was observed to confirm the presence or absence of a gelled product (clogging material) on the screen.

[0205] Good: No gelled product (plugging material) was observed.

[0206] Poor: Some gelled product (plugging material) was observed.

[0207] <Production of Transparent Thermoplastic Resin Composition>

[0208] (Production Example 1) Graft copolymer (A)

[0209] Graft copolymer (A-1): Place the mixture in a 25 m 3 Into a reaction vessel were introduced 50 parts by mass (in terms of solid content) of polybutadiene latex (mass average particle size of rubber: 0.30 μm, refractive index: 1.516), 130 parts by mass of pure water, 0.4 parts by mass of sodium laurate, 0.2 parts by mass of glucose, 0.2 parts by mass of sodium pyrophosphate and 0.01 parts by mass of ferrous sulfate. After replacing the air in the vessel with nitrogen, the temperature was controlled to 60° C., and a monomer mixture consisting of 3.4 parts by mass of styrene, 1.4 parts by mass of acrylonitrile, 10.2 parts by mass of methyl methacrylate and 0.12 parts by mass of tert-dodecyl mercaptan was added as an initial charge over 45 minutes under stirring.

[0210] Subsequently, the initiator mixture consisting of 0.3 mass parts of cumene hydroperoxide, 1.6 mass parts of sodium laurate as emulsifier and 25 mass parts of pure water was continuously dripped over 5 hours. Meanwhile, the monomer mixture consisting of 2.8 mass parts of styrene, 0.6 mass parts of acrylonitrile, 8.3 mass parts of methyl methacrylate and 0.13 mass parts of tert-dodecyl mercaptan (t-dodecyl mercaptan) was continuously dripped over 1 hour in addition. After this, the monomer mixture consisting of 5.8 mass parts of styrene, 17.5 mass parts of methyl methacrylate and 0.27 mass parts of tert-dodecyl mercaptan was continuously dripped over 2 hours in addition. After the monomer mixture was dripped, polymerization was maintained while continuously adding the initiator mixture separately for 2 hours, and after this, no material was added in the next 1 hour, and then polymerization was terminated. After the completion of the polymerization, an emulsified dispersion of a reaction product of p-cresol·dicyclopentadiene·isobutylene was added thereto in an amount of 0.4 parts by mass based on the solid content of the reaction product of p-cresol·dicyclopentadiene·isobutylene relative to 100 parts by mass of the graft copolymer (A-1). The resulting latex of the graft copolymer was coagulated with 1.5% by mass sulfuric acid and then neutralized with sodium hydroxide, followed by washing, centrifugation and drying to obtain a graft copolymer (A-1) in the form of a powder (the ratio of the monomer-derived structural units being 24% by mass of structural units derived from styrene, 4% by mass of structural units derived from acrylonitrile and 72% by mass of structural units derived from methyl methacrylate) which had been mixed with the reaction product of p-cresol·dicyclopentadiene·isobutylene. The refractive index of the acetone-insoluble component of the obtained graft copolymer (A-1) was 1.516, and the difference in refractive index with the rubbery polymer (r) was 0.000. The grafting rate of the graft copolymer was 47%. Furthermore, the weight average molecular weight of the acetone soluble component was 72,000.

[0211] (Production Example 2) Vinyl copolymer (B)

[0212] Vinyl copolymer (B-1'): Production of styrene / acrylonitrile / methyl methacrylate copolymer was carried out by the same method as described in Example 1, except that the respective materials were supplied from a complete mixing type polymerization kettle, rather than from a twin screw extruder type feeder as in Example 1, to obtain a styrene / acrylonitrile / methyl methacrylate copolymer (ratio of monomer-derived structural units = structural units derived from styrene: 22.9 mass %; structural units derived from acrylonitrile: 10 mass %; structural units derived from methyl methacrylate: 67.1 mass %). The refractive index of the obtained styrene / acrylonitrile / methyl methacrylate copolymer was 1.516, and the difference from the refractive index of the rubbery polymer (r) was 0.000. In addition, the weight average molecular weight of the copolymer was 110,000.

[0213] Vinyl copolymer (B-2'): Production of styrene / acrylonitrile / methyl methacrylate copolymer was carried out by the same method as described in Example 23, except that the respective materials were supplied from a complete mixing type polymerization kettle, rather than from a twin screw extruder type feeder as in Example 23, to obtain a styrene / acrylonitrile / methyl methacrylate copolymer (ratio of monomer-derived structural units = structural units derived from styrene: 22.9 mass %; structural units derived from acrylonitrile: 10 mass %; structural units derived from methyl methacrylate: 67.1 mass %). The refractive index of the obtained styrene / acrylonitrile / methyl methacrylate copolymer was 1.516, and the difference from the refractive index of the rubbery polymer (r) was 0.000. In addition, the weight average molecular weight of the copolymer was 98,500.

[0214] Vinyl copolymer (B-3'): Production of styrene / acrylonitrile / methyl methacrylate copolymer was carried out by the same method as described in Example 24, except that the respective materials were supplied from a complete mixing type polymerization kettle, rather than from a twin screw extruder type feeder as in Example 24, to obtain a styrene / acrylonitrile / methyl methacrylate copolymer (ratio of monomer-derived structural units = structural units derived from styrene: 22.4 mass %; structural units derived from acrylonitrile: 12.6 mass %; structural units derived from methyl methacrylate: 65 mass %). The refractive index of the obtained styrene / acrylonitrile / methyl methacrylate copolymer was 1.516, and the difference from the refractive index of the rubbery polymer (r) was 0.000. In addition, the weight average molecular weight of the copolymer was 116,000.

[0215] Vinyl copolymer (B-4'): Production of styrene / acrylonitrile / methyl methacrylate copolymer was carried out by the same method as described in Example 25, except that the respective materials were supplied from a complete mixing type polymerization kettle, rather than from a twin screw extruder type feeder as in Example 25, to obtain a styrene / acrylonitrile / methyl methacrylate copolymer (ratio of monomer-derived structural units = structural units derived from styrene: 23.4 mass %; structural units derived from acrylonitrile: 7 mass %; structural units derived from methyl methacrylate: 69.6 mass %). The refractive index of the obtained styrene / acrylonitrile / methyl methacrylate copolymer was 1.516, and the difference from the refractive index of the rubbery polymer (r) was 0.000. In addition, the weight average molecular weight of the copolymer was 110,000.

[0216] (Production Example 3) Ester compound (C)

[0217] Ester compound (C-1): hydrogenated castor oil, manufactured by Itoh Oil Chemicals Co., Ltd. (iodine value: 5 or less)

[0218] (Production Example 4) Ester compound (D)

[0219] Ester compound (D-1): castor oil, URIC H-30, manufactured by Itoh Oil Chemicals Co., Ltd. (hydroxyl value: 155 to 165 mg KOH / g, viscosity: 660 to 720 mPa·s / 25°C)

[0220] Ester compound (D-2): castor oil-based polyester polyol, URIC H-62, manufactured by Itoh Oil Chemicals Co., Ltd. (hydroxyl value: 245 to 275 mg KOH / g, viscosity: 240 to 290 mPa·s / 25° C.)

[0221] Ester compound (D-3): castor oil-based polyester polyol, URIC H-73X, manufactured by Itoh Oil Chemicals Co., Ltd. (hydroxyl value: 260 to 280 mg KOH / g, viscosity: 800 to 1200 mPa·s / 25° C.)

[0222] (Production Example 5) Compounds other than the ester compound (C) and the ester compound (D) (other compounds (F))

[0223] Other compounds (F-1): Glyceryl monostearate, RIKEMAL S-100, manufactured by Riken Vitamin Co., Ltd.

[0224] Other compounds (F-2): Glyceryl mono / distearate, RIKEMAL S-200, manufactured by Riken Vitamin Co., Ltd.

[0225] Other compounds (F-3): Glyceryl mono-12-hydroxystearate, RIKEMAL HC-100, manufactured by Riken Vitamin Co., Ltd.

[0226] Other compounds (F-4): polyol ester, LOXIOL G24, manufactured by Emery Oleochemicals (hydroxyl value: 30 mg KOH / g or less)

[0227] Other compounds (F-5): partial fatty acid esters of polyols, LOXIOL VPA1726, manufactured by Emery Oleochemicals (hydroxyl value: 430 to 500 mg KOH / g, viscosity: 600 to 800 mPa·s / 25°C)

[0228] Other compound (F-6): partial fatty acid ester of glycerol, LOXIOL P1141, manufactured by Emery Oleochemicals (viscosity: 60 to 110 mPa·s / 25°C)

[0229] Other compounds (F-7): Pentaerythritol monostearate, EXCEPAL PE-MS, manufactured by Kao Corporation (Production Example 6) Polydimethylsiloxane (E)

[0230] E-1: GENIOPLAST GUM, Wacker Asahikasei silicone Co., Ltd. Preparation of resin diluted product of polydimethylsiloxane gum (E-1)

[0231] 30 kg (60 parts by mass) of graft copolymer (A-1), 15 kg (30 parts by mass) of vinyl copolymer (B-1') and 5 kg (10 parts by mass) of polydimethylsiloxane gum (E-1) were introduced into a double-arm pressure kneading machine (model: DS55-100MWH-H) manufactured by Moriyama Manufacturing Co., Ltd. The mixture was mixed at a stirring speed of 60 rpm for 5 minutes under a pressure of 1 MPa, and then the pressure was released, followed by mixing at normal pressure for 3 minutes. Thereafter, the mixture was stirred and mixed again at a pressure of 1 MPa for 5 minutes to obtain a resin diluted product (E-1') of polydimethylsiloxane gum, wherein the polydimethylsiloxane gum (E-1) was attached to the solid surfaces of the graft copolymer (A-1) and the vinyl copolymer (B-1'). The processing temperature was 58°C or lower.

[0232] Specific examples and comparative examples will be described below.

[0233] In each embodiment and comparative example, Figure 1 The continuous bulk polymerization device of the basic structure shown in the figure is used to produce the thermoplastic resin composition. The continuous bulk polymerization device comprises: a capacity of 2m 3A complete mixing type polymerization kettle 1 equipped with a condenser (not shown) and a spiral blade for evaporating and dry distilling monomer vapor; a single screw extruder type preheater 2; a twin screw extruder type monomer removal device 3; and a twin screw extruder type feeder 5, which is connected to the barrel portion of the monomer removal device at a position corresponding to 1 / 3 of the longitudinal direction from the downstream (exit) side end of the device for side feeding. The specific details are as described in the respective examples and comparative examples. It is noted that the vinyl copolymer (B) is produced in this system (in the table, the vinyl copolymer (B) produced in each of Examples 1 to 22 and Example 26 and Comparative Examples 1 to 10 is marked as "vinyl copolymer (B-1)", the vinyl copolymer (B) produced in Example 23 is marked as "vinyl copolymer (B-2)", the vinyl copolymer (B) produced in Example 24 is marked as "vinyl copolymer (B-3)", and the vinyl copolymer (B) produced in Example 24 is marked as "vinyl copolymer (B-4)").

[0234] [Example 1]

[0235] A monomer mixture (b) consisting of 22.9 parts by mass of styrene, 10 parts by mass of acrylonitrile, 67.1 parts by mass of methyl methacrylate, 0.21 parts by mass of n-octyl mercaptan and 0.015 parts by mass of 1,1-bis(tert-butylperoxy)cyclohexane was continuously supplied to a complete mixing type polymerization reactor at a rate of 150 kg / hour, and continuous bulk polymerization was carried out while maintaining a polymerization temperature of 130° C. and an internal pressure of 0.08 MPa. The polymerization rate of the polymerization reaction mixture at the outlet of the complete mixing type polymerization reactor was controlled to be 70±5%.

[0236] Subsequently, the polymerization reaction mixture is preheated by a single screw extruder type preheater and then supplied to a twin screw extruder type monomer stripping device, and unreacted monomers are collected from the exhaust port of the twin screw extruder type monomer stripping device by reduced pressure evaporation. The collected unreacted monomers are continuously refluxed into the complete mixing type polymerization kettle. At a position corresponding to 1 / 3 of the total length of the twin-screw extruder type monomer stripping device from its downstream side end, 2,2'-methylenebis(4-methyl-6-tert-butylphenol) as a phenolic stabilizer was supplied at 0.132 kg / hour, 3,3'-distearyl thiodipropionate as a sulfur-based stabilizer was supplied at 0.288 kg / hour, ester compound (C-1) was supplied at 0.484 kg / hour (0.2 parts by mass), and a semi-molten product of the graft copolymer (A-1) was supplied at 91.9 kg / hour (38 parts by mass) from a twin-screw extruder type feeder into the above-mentioned styrene / acrylonitrile / methyl methacrylate copolymer having an apparent polymerization rate of 99% or more. In addition, the ester compound (D-2) is supplied to the twin-screw extruder type feeder at 0.968 kg / hour (0.4 parts by mass) using a liquid addition pump via a liquid additive addition nozzle located at a position corresponding to 2 / 3 of the total length of the twin-screw extruder type feeder from the downstream side end of the twin-screw extruder type feeder (the position where the twin-screw extruder type feeder is connected to the twin-screw extruder type monomer stripping device), and melt-kneaded with the styrene / acrylonitrile / methyl methacrylate copolymer in the twin-screw extruder type monomer stripping device. During the above-mentioned melt-kneading step, water is supplied at 2 kg / hour at a position 1 / 6 of the total length of the twin-screw extruder type monomer stripping device relative to its downstream side end. Water and other volatile components are removed from the exhaust port further downstream in the twin-screw extruder type monomer stripping device by reduced pressure evaporation. Thereafter, the melt-kneaded product is discharged in the form of strands and cut with a cutter to obtain pellets of a transparent thermoplastic resin composition.

[0237] [Example 2]

[0238] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (D-2) was changed to 1.935 kg / hour (0.8 parts by mass).

[0239] [Example 3]

[0240] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (D-2) was changed to 2.903 kg / hour (1.2 parts by mass).

[0241] [Example 4]

[0242] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (D-2) was changed to 4.838 kg / hour (2 parts by mass).

[0243] [Example 5]

[0244] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (D-2) was changed to 6.289 kg / hour (2.6 parts by mass).

[0245] [Example 6]

[0246] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.210 kg / hour (0.5 parts by mass).

[0247] [Example 7]

[0248] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.210 kg / hour (0.5 parts by mass), and the feed rate of the ester compound (D-2) was changed to 1.935 kg / hour (0.8 parts by mass).

[0249] [Example 8]

[0250] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.210 kg / hour (0.5 parts by mass), and the feed rate of the ester compound (D-2) was changed to 2.903 kg / hour (1.2 parts by mass).

[0251] [Example 9]

[0252] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.210 kg / hour (0.5 parts by mass), and the feed rate of the ester compound (D-2) was changed to 4.838 kg / hour (2 parts by mass).

[0253] [Example 10]

[0254] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.210 kg / hour (0.5 parts by mass), and the feed rate of the ester compound (D-2) was changed to 6.289 kg / hour (2.6 parts by mass).

[0255] [Example 11]

[0256] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the feed rate of the ester compound (D-2) was changed to 0.968 kg / hour (0.4 parts by mass).

[0257] [Example 12]

[0258] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the feed rate of the ester compound (D-2) was changed to 1.935 kg / hour (0.8 parts by mass).

[0259] [Example 13]

[0260] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the feed rate of the ester compound (D-2) was changed to 2.903 kg / hour (1.2 parts by mass).

[0261] [Example 14]

[0262] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the feed rate of the ester compound (D-2) was changed to 4.838 kg / hour (2 parts by mass).

[0263] [Example 15]

[0264] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the feed rate of the ester compound (D-2) was changed to 6.289 kg / hour (2.6 parts by mass).

[0265] [Example 16]

[0266] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 2.903 kg / hour (1.2 parts by mass), and the feed rate of the ester compound (D-2) was changed to 0.968 kg / hour (0.4 parts by mass).

[0267] [Example 17]

[0268] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 2.903 kg / hour (1.2 parts by mass), and the feed rate of the ester compound (D-2) was changed to 1.935 kg / hour (0.8 parts by mass).

[0269] [Example 18]

[0270] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 2.903 kg / hour (1.2 parts by mass), and the feed rate of the ester compound (D-2) was changed to 2.903 kg / hour (1.2 parts by mass).

[0271] [Example 19]

[0272] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 2.903 kg / hour (1.2 parts by mass), and the feed rate of the ester compound (D-2) was changed to 4.838 kg / hour (2 parts by mass).

[0273] [Example 20]

[0274] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 2.903 kg / hour (1.2 parts by mass), and the feed rate of the ester compound (D-2) was changed to 6.289 kg / hour (2.6 parts by mass).

[0275] [Example 21]

[0276] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the ester compound (D-1) was used instead of the ester compound (D-2), and its feed rate was set to 2.903 kg / hour (1.2 parts by mass).

[0277] [Example 22]

[0278] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the ester compound (D-3) was used instead of the ester compound (D-2), and its feed rate was set to 2.903 kg / hour (1.2 parts by mass).

[0279] [Example 23]

[0280] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the composition of the monomer mixture (b) was changed to 22.9 parts by mass of styrene, 10 parts by mass of acrylonitrile, 67.1 parts by mass of methyl methacrylate, 0.265 parts by mass of n-octyl mercaptan and 0.015 parts by mass of 1,1-bis(tert-butylperoxy)cyclohexane, and the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the feed rate of the ester compound (D-2) was changed to 2.903 kg / hour (1.2 parts by mass).

[0281] [Example 24]

[0282] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the composition of the monomer mixture (b) was changed to 22.4 parts by mass of styrene, 12.6 parts by mass of acrylonitrile, 65 parts by mass of methyl methacrylate, 0.235 parts by mass of n-octyl mercaptan and 0.015 parts by mass of 1,1-bis(tert-butylperoxy)cyclohexane, and the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the feed rate of the ester compound (D-2) was changed to 2.903 kg / hour (1.2 parts by mass).

[0283] [Example 25]

[0284] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the composition of the monomer mixture (b) was changed to 23.4 parts by mass of styrene, 7 parts by mass of acrylonitrile, 69.6 parts by mass of methyl methacrylate, 0.225 parts by mass of n-octyl mercaptan and 0.015 parts by mass of 1,1-bis(tert-butylperoxy)cyclohexane, and the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the feed rate of the ester compound (D-2) was changed to 2.903 kg / hour (1.2 parts by mass).

[0285] [Example 26]

[0286] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), the feed rate of the ester compound (D-2) was changed to 2.903 kg / hour (1.2 parts by mass), and a resin diluted product of polydimethylsiloxane gum (E-1') was further supplied and its feed rate was set to 0.145 kg / hour (0.06 parts by mass).

[0287] [Comparative Example 1]

[0288] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the ester compound (C-1) was not supplied and the feed rate of the ester compound (D-2) was changed to 2.903 kg / hour (1.2 parts by mass).

[0289] [Comparative Example 2]

[0290] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the feed rate of the ester compound (C-1) was changed to 1.693 kg / hour (0.7 parts by mass), and the ester compound (D-2) was not supplied.

[0291] [Comparative Example 3]

[0292] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the ester compound (C-1) was not supplied, and the ester compound (D-2) was not supplied.

[0293] [Comparative Example 4]

[0294] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the ester compound (D-2) was not supplied, the other compound (F-1) was newly supplied, and the feed rate thereof was set to 2.903 kg / hour (1.2 parts by mass).

[0295] [Comparative Example 5]

[0296] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the ester compound (D-2) was not supplied, the other compound (F-2) was newly supplied, and the feed rate thereof was set to 2.903 kg / hour (1.2 parts by mass).

[0297] [Comparative Example 6]

[0298] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the ester compound (D-2) was not supplied, other compound (F-3) was newly supplied, and the feed rate thereof was set to 2.903 kg / hour (1.2 parts by mass).

[0299] [Comparative Example 7]

[0300] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the ester compound (D-2) was not supplied, other compound (F-4) was newly supplied, and the feed rate thereof was set to 2.903 kg / hour (1.2 parts by mass).

[0301] [Comparative Example 8]

[0302] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the ester compound (D-2) was not supplied, other compound (F-5) was newly supplied, and the feed rate thereof was set to 2.903 kg / hour (1.2 parts by mass).

[0303] [Comparative Example 9]

[0304] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the ester compound (D-2) was not supplied, other compound (F-6) was newly supplied, and the feed rate thereof was set to 2.903 kg / hour (1.2 parts by mass).

[0305] [Comparative Example 10]

[0306] Pellets of a transparent thermoplastic resin composition were obtained in the same manner as in Example 1, except that the ester compound (D-2) was not supplied, other compound (F-7) was newly supplied, and the feed rate thereof was set to 2.903 kg / hour (1.2 parts by mass).

[0307] The results are summarized in Tables 1 to 4.

[0308]

[0309]

[0310]

[0311]

[0312]

[0313]

[0314]

[0315]

[0316] As shown in the evaluation results of Examples 1 to 26, it has been revealed that the transparent thermoplastic resin composition of the present embodiment has both excellent impact resistance and fluidity while maintaining particularly high transparency.

[0317] Furthermore, as shown in Examples 7, 8, 13, 14 and 22, by adjusting the content of the ester compound (C) to be in the range of 0.4 to 0.8 parts by mass relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B), adjusting the content of the ester compound (D) to be in the range of 0.8 to 2.4 parts by mass relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B), adjusting the mass ratio of the ester compound (C) to the ester compound (D) to be in the range of 25:75 to 40:60 and using the ester compound (D) having a hydroxyl value of 170 to 350 mg KOH / g, the transparent thermoplastic resin compositions of these Examples are particularly excellent in the balance among transparency, impact resistance, fluidity, releasability and mass productivity.

[0318] Since the ester compound (C) was not added, the transparent thermoplastic resin composition of Comparative Example 1 exhibited poor impact resistance. Since the ester compound (D) was not added, the transparent thermoplastic resin composition of Comparative Example 2 exhibited poor fluidity and demoldability. Since the ester compound (C) and the ester compound (D) were not added, the transparent thermoplastic resin composition of Comparative Example 3 exhibited poor impact resistance and fluidity. Comparative Examples 4 to 10 are examples in which the ester compound (C) and the ester compound (D) are not used in combination and a compound different from these compounds, i.e., other compound (F), is used. A large amount of gel generation was observed in these comparative examples, indicating poor large-scale production capabilities.

[0319] Industrial Applicability

[0320] The transparent thermoplastic resin composition and the molded article according to the present embodiment can be widely used in applications such as consumer electronic products, communication-related equipment, daily commodities, and medical equipment.

[0321] List of Reference Numerals

[0322] 1 Completely mixed polymerization reactor

[0323] 2 Single screw extruder type preheater

[0324] 3 Twin-screw extruder type monomer removal device

[0325] 4 Melt kneading zone

[0326] 5 Twin screw extruder type feeder

[0327] 6 Discharge port

[0328] 7. Agitator (ribbon blade)

[0329] 8 Exhaust port

[0330] 9 Water injection port

[0331] 10 Final exhaust port

[0332] 11 Liquid additive adding nozzle

Claims

1. A transparent thermoplastic resin composition comprising: a graft copolymer (A) obtained by graft-copolymerizing a monomer mixture (a) containing at least an aromatic vinyl monomer (a1) and a (meth)acrylate monomer (a2) in the presence of a rubbery polymer (r); A vinyl copolymer (B) obtained by copolymerizing a monomer mixture (b) containing at least an aromatic vinyl monomer (b1), a (meth)acrylate monomer (b2) and a vinyl cyanide monomer (b3); The following ester compound (C); and The following ester compounds (D); wherein the ester compound (C) is a hydrogenated product of a triglyceride of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid, and 85% by mass or more of the acid constituting the triglyceride is a hydrogenated product of ricinoleic acid; and wherein the ester compound (D) is an ester of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid and a polyol, provided that the ester contains at least one ester bond with an unsaturated carboxylic acid and that 85% by mass or more of the acid constituting the ester is ricinoleic acid, wherein the ester compound (D) has a hydroxyl value of 170 to 350 mg KOH / g, and, in: The content of the ester compound (C) is 0.4 to 0.8 parts by mass relative to 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B); The content of the ester compound (D) is 0.6 to 2.4 parts by mass based on 100 parts by mass of the total amount of the graft copolymer (A) and the vinyl copolymer (B); and The mass ratio of the ester compound (C) to the ester compound (D) ((C):(D)) is 25:75 to 40:

60. 2 . The transparent thermoplastic resin composition according to claim 1 , wherein the acetone-soluble component contained in the transparent thermoplastic resin composition has a weight average molecular weight of 100,000 to 120,000.

3. The transparent thermoplastic resin composition according to claim 1 or 2, wherein in the acetone-soluble component contained in the transparent thermoplastic resin composition, the content of the structural unit derived from the (meth)acrylate monomer is 50 to 82% by mass, the content of the structural unit derived from the aromatic vinyl monomer is 10 to 30% by mass, and the content of the structural unit derived from the vinyl cyanide monomer is 8 to 15% by mass, relative to the total amount of the structural unit derived from the (meth)acrylate monomer, the structural unit derived from the aromatic vinyl monomer, the structural unit derived from the vinyl cyanide monomer and the structural unit derived from other vinyl monomers being 100% by mass.

4. The transparent thermoplastic resin composition according to claim 1 or 2, wherein when the weight average molecular weight of the acetone soluble component contained in the transparent thermoplastic resin composition is defined as Mw1 and the content (mass %) of the structural unit derived from the vinyl cyanide monomer contained in the acetone soluble component relative to 100 mass % of the mass of the acetone soluble component is defined as W1, a value obtained by dividing Mw1 by W1 is 11,000 or more. 5 . The transparent thermoplastic resin composition according to claim 1 , wherein the transparent thermoplastic resin composition further comprises polydimethylsiloxane gum (E).

6. A method for producing a transparent thermoplastic resin composition, the method comprising the steps of: A graft copolymer (A) is obtained by graft-copolymerizing a monomer mixture (a) containing at least an aromatic vinyl monomer (a1) and a (meth)acrylate monomer (a2) in the presence of a rubbery polymer (r); A vinyl copolymer (B) is obtained by copolymerizing a monomer mixture (b) containing at least an aromatic vinyl monomer (b1), a (meth)acrylate monomer (b2), and a vinyl cyanide monomer (b3); and The graft copolymer (A), the vinyl copolymer (B), the following ester compound (C) and the following ester compound (D) are mixed, wherein the ester compound (C) is a hydrogenated product of a triglyceride of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid, and 85% by mass or more of the acid constituting the triglyceride is a hydrogenated product of ricinoleic acid; and wherein the ester compound (D) is an ester of an acid selected from palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid and dihydroxystearic acid and a polyol, provided that the ester contains at least one ester bond with an unsaturated carboxylic acid and that 85% by mass or more of the acid constituting the ester is ricinoleic acid.

7. A molded article formed using the transparent thermoplastic resin composition according to any one of claims 1 to 5.

8. A molded article formed using the transparent thermoplastic resin composition produced by the method according to claim 6.

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