Thermoplastic resin composition

Abstract

Provided is a thermoplastic resin composition containing a (meth)acrylic resin, an acrylonitrile-styrene-acrylic acid ester resin, a coloring component containing two or more components, one of the two or more components being carbon black and the remaining components being one or more dyes and / or pigments, and silica particles, in which the blending amount of the (meth)acrylic resin is 50 to 90 mass parts, the blending amount of the acrylonitrile-styrene-acrylic acid ester resin is 10 to 50 mass parts, the blending amount of the carbon black is 0.0005 to 0.01 mass parts, the blending amount of the remaining components is 0.02 to 1.0 mass parts, the ratio (component Cb / component Ca) of the blending amount of the remaining components to the blending amount of the carbon black is 75 to 1000, and the blending amount of the silica particles is 0.3 to 5 mass parts.

Description

thermoplastic resin composition

[0001] The present invention relates to a thermoplastic resin composition, particularly to a thermoplastic resin composition containing a meth(acrylic) resin as a main component.

[0002] In recent years, unpainted plastic parts have been increasingly used in automobiles, due to trends in aesthetics and the need to reduce manufacturing costs. Therefore, a wider range of properties are being required of plastic parts in addition to the properties typically required. In particular, when plastic parts are used in an unpainted state, the plastic parts themselves are required to have aesthetics, scratch resistance, and other properties that have traditionally been provided by paint (paint layer and painted surface).

[0003] In particular, scratch resistance for automotive plastic parts is important because scratches can occur on the plastic parts while driving, washing the car, wiping off dirt or wax adhering to the surface, or even when the plastic parts are attached to the vehicle body, which can result in whitening starting from the scratched area or unevenness being generated, which can impair the color tone and deteriorate the aesthetic appearance. For this reason, unpainted plastic parts are particularly required to be scratch-resistant, and even if scratches do occur, the scratches are less noticeable.

[0004] BACKGROUND ART Conventionally, examples of thermoplastic resin compositions that can improve the color and appearance of resin parts include polycarbonate resin compositions and (meth)acrylic resin compositions.

[0005] However, resin parts molded from polycarbonate resin compositions tend to be particularly susceptible to scratches, and resin parts made using (meth)acrylic resin compositions, while highly resistant to scratches, tend to be susceptible to abrasions caused by friction with tools made of relatively soft materials, such as rags and work gloves, and also tend to have low impact resistance.

[0006] As an example of such a (meth)acrylic resin composition and a molded article thereof, there is known an "injection-molded article made from a (meth)acrylic resin composition containing a (meth)acrylic resin and an inorganic filler, and having a surface with an arithmetic mean roughness of 20 nm or more and 280 nm or less," which aims to "provide an injection-molded article that is excellent in scratch resistance and has high gloss even when colored, and an automotive part made from the injection-molded article" (see Patent Document 1 below).

[0007] International Publication No. 2017 / 20048

[0008] However, while the (meth)acrylic resin composition disclosed in Patent Document 1 can certainly produce an injection-molded article that is excellent in scratch resistance and has high gloss even when colored, it has been difficult to achieve satisfactory scratch resistance, impact resistance, and solvent resistance (good aesthetics) in a preform (molded article), which is a resin part that is used in an unpainted state.

[0009] The present inventors have conducted extensive research to solve the above problems, and have found that the above problems can be solved by adjusting the blending amounts (contents) of predetermined components, thereby completing the present invention.

[0010] That is, the present invention provides the following [1] to [7]. [1] A coloring component (component C) comprising a (meth)acrylic resin (component A), an acrylonitrile-styrene-acrylic ester resin (component B), and two or more components, one of which is carbon black (component Ca), and the remaining component (component Cb) is at least one of a dye and a pigment, and silica particles (component D), wherein, when the total amount of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic ester resin (component B) is 100 parts by mass, the amount of the (meth)acrylic resin (component A) is 50 to 90 parts by mass, and the amount of the acrylonitrile-styrene-acrylic ester resin (component B) is 10 to 50 parts by mass, and when the total amount of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic ester resin (component B) is 100 parts by mass, [2] A thermoplastic resin composition according to [1], wherein the amount of carbon black (component Ca) is 0.0005 to 0.01 parts by mass, the amount of the remaining component (component Cb) is 0.02 to 1.0 parts by mass, the ratio of the amount of the remaining component (component Cb) to the amount of carbon black (component Ca) (component Cb / component Ca) is 75 to 1000, and the amount of the silica particles (component D) is 0.3 to 5 parts by mass per 100 parts by mass of the total amount of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic acid ester resin (component B). [2] The thermoplastic resin composition according to [1], wherein the particle size (median diameter) of the silica particles (component D) is 100 nm to 1500 nm. [3] The thermoplastic resin composition according to [1] or [2], wherein the (meth)acrylic resin (component A) contains a polymer obtained by copolymerizing a methacrylic acid ester with a monomer other than the methacrylic acid ester that is copolymerizable with the methacrylic acid ester, and the content of structural units derived from the methacrylic acid ester in the polymer is 80% by mass to 99.9% by mass. [4] A formed material obtained by molding the thermoplastic resin composition according to [1] or [2]. [5] The formed material according to [4], which is a pillar member for an automobile.[6] A method for producing thermoplastic resin composition pellets, comprising a step of extruding the thermoplastic resin composition according to [1] or [2] using an extruder to obtain thermoplastic resin composition pellets. [7] A method for producing a shaped material according to [4], comprising a step of introducing the thermoplastic resin composition into an injection molding machine, setting a heater temperature to 220°C or more and 240°C or less, and extruding and molding the thermoplastic resin composition.

[0011] According to the present invention, it is possible to provide a thermoplastic resin composition that can provide satisfactory scratch resistance, impact resistance, and solvent resistance (good aesthetics), particularly in resin parts (formed and shaped materials) that are used in an unpainted state, and in particular a thermoplastic resin composition that contains a (meth)acrylic resin as a main component.

[0012] The following is a detailed description of an embodiment of the present invention. The present invention is not limited to the following description, and each component can be appropriately modified within the scope of the present invention.

[0013] 1. 1. Thermoplastic Resin Composition The thermoplastic resin composition of this embodiment comprises: a (meth)acrylic resin (component A); an acrylonitrile-styrene-acrylic ester resin (component B); a coloring component (component C) containing two or more components, one of which is carbon black (component Ca) and the remaining component (component Cb) is at least one of a dye and a pigment; and silica particles (component D), wherein, when the total amount of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic ester resin (component B) is 100 parts by mass, the amount of the (meth)acrylic resin (component A) is 50 to 90 parts by mass, and the amount of the acrylonitrile-styrene-acrylic ester resin (component B) is 10 to 50 parts by mass, and relative to 100 parts by mass of the total amount of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic ester resin (component B), the amount of carbon black (component Ca) is 0.0005 to 0.01 parts by mass, the amount of the remaining component (component Cb) is 0.02 to 1.0 parts by mass, the ratio of the amount of the remaining component (component Cb) to the amount of carbon black (component Ca) (component Cb / component Ca) is 75 to 1000, and the amount of the silica particles (component D) is 0.3 to 5 parts by mass per 100 parts by mass of the total of the amount of the (meth)acrylic resin (component A) and the amount of the acrylonitrile-styrene-acrylic acid ester resin (component B). The thermoplastic resin composition of this embodiment will now be described in detail.

[0014] <Component A: (meth)acrylic resin> The term "(meth)acrylic" in "(meth)acrylic resin" encompasses the meanings of both "acrylic" and "methacrylic".

[0015] As the (meth)acrylic resin (component A), it is preferable to use a methacrylic resin because it has excellent hardness, weather resistance, and transparency. The methacrylic resin is a polymer obtained by polymerizing a monomer containing a methacrylic acid ester, such as an alkyl methacrylate, as a main component.

[0016] Examples of the (meth)acrylic resin (component A) include homopolymers of methacrylic acid esters (polyalkyl methacrylates) which are monomers, copolymers of methacrylic acid esters, and copolymers of 50% by mass or more of methacrylic acid esters and 50% by mass or less of a monomer other than methacrylic acid esters that is copolymerizable with the methacrylic acid esters.

[0017] When the (meth)acrylic resin (component A) is a copolymer of a methacrylic acid ester and a monomer other than a methacrylic acid ester, it is preferable that, relative to 100% by mass of the total amount of monomers (structural units), the methacrylic acid ester (structural units derived therefrom) accounts for 80% by mass or more and the monomer (structural units) copolymerizable with methacrylic acid esters other than methacrylic acid esters accounts for 20% by mass or less; it is more preferable that the methacrylic acid ester (structural units derived therefrom) accounts for 90% by mass or more and the monomer (structural units derived therefrom) other than methacrylic acid esters accounts for 10% by mass or less; it is even more preferable that the methacrylic acid ester (structural units derived therefrom) accounts for 99% by mass or more and the monomer (structural units derived therefrom) copolymerizable with methacrylic acid esters other than methacrylic acid esters accounts for 1% by mass or less; and it is even more preferable that the methacrylic acid ester (structural units derived therefrom) accounts for 99.9% by mass or more and the monomer (structural units derived therefrom) copolymerizable with methacrylic acid esters other than methacrylic acid esters accounts for 0.1% by mass or less.

[0018] Examples of the monomer other than methacrylic acid ester include acrylic acid ester, a monofunctional monomer having one polymerizable carbon-carbon double bond in the molecule, and a monomer having a ring structure.

[0019] Examples of such monofunctional monomers include styrene-based monomers such as styrene, α-methylstyrene, and vinyltoluene; alkenyl cyanides such as acrylonitrile and methacrylonitrile; acrylic acid; methacrylic acid; maleic anhydride; and N-substituted maleimides such as phenylmaleimide, cyclohexylmaleimide, and methylmaleimide. A lactone ring structure, a glutaric anhydride structure, or a glutarimide structure may be introduced into the main chain (main skeleton) of the (meth)acrylic resin from the viewpoint of improving heat resistance.

[0020] More specifically, the (meth)acrylic resin is preferably a homopolymer (a1): a homopolymer of methyl methacrylate, or a copolymer (a2): a copolymer containing 50 to 99.9% by mass of structural units derived from methyl methacrylate and 0.1 to 50% by mass of at least one structural unit derived from a (meth)acrylic acid ester represented by the following formula (1):

[0021]

[0022] In the formula (1), R １ represents a hydrogen atom or a methyl group, R １ is a hydrogen atom, R ２ represents an alkyl group having 1 to 8 carbon atoms, and R １ When R is a methyl group, ２ represents an alkyl group having 2 to 8 carbon atoms.

[0023] In the copolymer (a2), the total amount of the structural unit derived from methyl methacrylate and at least one structural unit derived from the (meth)acrylic acid ester represented by the formula (1) is preferably 100% by mass.

[0024] In the formula (1), R １ is a hydrogen atom, R ２ Examples of the alkyl group having 1 to 8 carbon atoms represented by the formula (1) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. １ is a methyl group, R ２Examples of the alkyl group having 2 to 8 carbon atoms represented by the formula (I) include an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.

[0025] The (meth)acrylic acid ester represented by the formula (1) is preferably an acrylic acid ester, more preferably methyl acrylate or ethyl acrylate, and even more preferably methyl acrylate.

[0026] Examples of the "monomer having a ring structure", which is a monomer other than methacrylic acid ester that is copolymerizable with methacrylic acid ester, include maleic anhydride, itaconic anhydride, maleimide, and N-methylmaleimide.

[0027] In this embodiment, the "monomer having a ring structure" is preferably maleic anhydride, itaconic anhydride, maleimide, or N-methylmaleimide, more preferably maleimide or N-methylmaleimide, and even more preferably N-methylmaleimide.

[0028] In the present embodiment, the (meth)acrylic resin has a melt mass flow rate (MFR) at 230°C measured under a load of 3.8 kg in accordance with a method in accordance with JIS K 7210 of usually 0.1 to 30 g / 10 min. From the viewpoints of improving the strength of a shaped material, which is a molded article obtained by molding the (meth)acrylic resin composition, and also improving its moldability, the MFR is preferably 0.2 to 20 g / 10 min, and more preferably 0.5 to 15 g / 10 min.

[0029] The (meth)acrylic resin (component A) can be prepared (synthesized) by polymerizing the monomers already described by any suitable conventional method, such as suspension polymerization or bulk polymerization. During preparation, the molecular weight, properties, and the like required for the (meth)acrylic resin (component A) of this embodiment can be adjusted to preferred ranges by further adding, for example, any suitable conventional chain transfer agent. The amount of chain transfer agent added can be determined appropriately depending on the types and ratios of the selected monomers, as well as the required properties.

[0030] In this embodiment, the copolymer that is the (meth)acrylic resin (component A) excludes a copolymer that is the same as the acrylonitrile-styrene-acrylic acid ester resin (component B) described below.

[0031] <Component B: Acrylonitrile-Styrene-Acrylate Ester Resin (ASA Resin)> In the present embodiment, the acrylonitrile-styrene-acrylate ester resin (component B) is preferably a graft copolymer that contains an acrylic ester polymer (acrylic ester polymer) as a main chain and has branched chains that are polymers (acrylonitrile-styrene polymers) in which acrylonitrile and styrene are polymerized from the acrylic ester polymer, and are bonded to the acrylic ester polymer.

[0032] The acrylonitrile-styrene-acrylic acid ester resin (component B) is more preferably a graft polymer in which the acrylic acid ester polymer, which is the main chain, is particulate and rubbery, and the acrylonitrile-styrene polymer, which is the branched chain, protrudes from the particulate acrylic acid ester polymer and is arranged so as to cover the particulate acrylic acid ester polymer, so that the acrylonitrile-styrene-acrylic acid ester resin as a whole is also particulate.

[0033] Suitable examples of the acrylic acid ester, which is a monomer that can constitute the main chain of the acrylonitrile-styrene-acrylic acid ester resin, include methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-dimethylaminoethyl acrylate, and 2-hydroxyethyl acrylate.

[0034] The acrylonitrile-styrene-acrylic acid ester resin (component B), which is a graft polymer configured in such a particulate form, can be produced by any suitable conventionally known production method using any suitable conventionally known radical polymerization initiator, graft crossing agent, and further crosslinking agent.

[0035] In the acrylonitrile-styrene-acrylate resin (component B) of this embodiment, the mass ratio of the acrylic acid ester polymer that can form the main chain to the acrylonitrile-styrene polymer that can form the branched chain is not particularly limited. From the viewpoint of improving impact resistance, the mass ratio is preferably such that the amount of the acrylic acid ester polymer is 10 to 80 mass% and the amount of the acrylonitrile-styrene polymer is 20 to 90 mass%, and more preferably such that the amount of the acrylic acid ester is 20 to 70 mass% and the amount of the acrylonitrile-styrene polymer is 30 to 80 mass%, when the total amount of the acrylic acid ester polymer and the acrylonitrile-styrene polymer is 100 mass%.

[0036] Suitable examples of acrylate esters that can form the main chain include methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-dimethylaminoethyl acrylate, and 2-hydroxyethyl acrylate.

[0037] The acrylonitrile-styrene-acrylate resin (component B), which is a particulate graft polymer, may be a commercially available product. Examples of commercially available acrylonitrile-styrene-acrylate resins (component B) include "UA-1400" manufactured by Nippon A&L, Inc., "Techno ABS150" manufactured by Techno UMG, and "PW-978B" manufactured by CHIMEI Corporation.

[0038] In this embodiment, the acrylonitrile-styrene-acrylic acid ester resin (component B) excludes copolymers that are the same as the copolymers that are the (meth)acrylic resins (component A) already described.

[0039] In the thermoplastic resin composition of the present embodiment, the blending amounts of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic acid ester resin (component B) are preferably such that, when the total of the blending amounts of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic acid ester resin (component B) is taken as 100 parts by mass, the blending amount of the (meth)acrylic resin (component A) is 50 to 90 parts by mass and the blending amount of the acrylonitrile-styrene-acrylic acid ester resin (component B) is 10 to 50 parts by mass; and from the viewpoint of improving scratch resistance, the blending amount of the (meth)acrylic resin (component A) is more preferably 15 to 35 parts by mass and the blending amount of the acrylonitrile-styrene-acrylic acid ester resin (component B) is 15 to 25 parts by mass.

[0040] <Component C: Coloring Component> The thermoplastic resin composition of the present embodiment includes a coloring component (component C) containing two or more components, one of which is carbon black (component Ca), and the remaining component (component Cb) is at least one of a dye and / or a pigment.

[0041] The amount of the coloring component (component C) contained in the thermoplastic resin composition of the present embodiment is preferably such that, relative to 100 parts by mass of the total of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic acid ester resin (component B), the amount of carbon black (component Ca) is 0.0005 to 0.01 parts by mass and the amount of the remaining components (component Cb) is 0.02 to 1.0 parts by mass; from the viewpoint of improving solvent resistance, the amount of carbon black (component Ca) is more preferably 0.0005 to 0.0075 parts by mass and the amount of the remaining components (component Cb) is 0.1 to 0.95 parts by mass; and it is even more preferably 0.0005 to 0.005 parts by mass and the amount of the remaining components (component Cb) is 0.446 to 0.898 parts by mass.

[0042] In the coloring component (component C) contained in the thermoplastic resin composition of this embodiment, the ratio (component Cb / component Ca) of the blending amount of the remaining component (component Cb) to the blending amount of carbon black (component Ca) is preferably 75 to 1,000, and from the viewpoint of improving scratch resistance, impact resistance, and solvent resistance, particularly solvent resistance, and thereby improving the aesthetic appearance (and its maintenance), it is more preferably 85 to 950, and even more preferably 90 to 900.

[0043] The carbon black (component Ca) and the remaining components (component Cb) that can be contained in the coloring component (component C) will be specifically described below.

[0044] (i) Component Ca: Carbon Black Carbon black (component Ca), which is one of the components contained in the coloring component (component C) that can be contained in the thermoplastic resin composition of this embodiment, has the function of being able to color a molded body (base material) black in combination with the remaining component (component Cb) described below.

[0045] From the viewpoint of improving dispersibility in a thermoplastic resin composition and improving color development, the particle size of the carbon black (component Ca), i.e., the number average particle size of the primary particles measured based on observation using an electron microscope, is preferably 10 nm to 20 nm, and more preferably 10 nm to 15 nm.

[0046] In the present embodiment, examples of carbon black (component Ca) include channel black, furnace black, lamp black, thermal black, ketjen black, naphthalene black, etc. As carbon black (component Ca), not only one of these may be used, but also two or more may be used in combination.

[0047] As the carbon black (component Ca), it is also possible to use carbon black that has been subjected to a secondary treatment such as adding surface functional groups by oxidation treatment, graphitizing by heat treatment in an inert gas atmosphere, or activation treatment with water vapor or carbon dioxide gas.

[0048] As the carbon black (component Ca), commercially available products can also be used. Examples of commercially available carbon black (component Ca) include "HCF" and "MCF" manufactured by Mitsubishi Chemical Corporation and "Denka Black" manufactured by Denka Company Limited.

[0049] (ii) Component Cb: Remaining components (carbon black (component Ca) remaining components that may be contained in the coloring component (component C)) One of the two or more components that may be contained in the coloring component (component C) is carbon black (component Ca), and the remaining components (component Cb) are one or more of a dye and / or a pigment.

[0050] In the coloring component (component C) of the present embodiment, the dye and pigment that can be contained in the remaining component (component Cb) is preferably one or more types selected from the group consisting of inorganic pigments, organic pigments, oil-soluble dyes, acid dyes, and basic dyes.

[0051] The "dyes and pigments" that can constitute the remaining component (component Cb) do not include carbon black.

[0052] Suitable examples of inorganic pigments that are dyes and pigments that can be contained in the remaining component (component Cb) include titanium oxide and zinc oxide.

[0053] Suitable examples of organic pigments that are dyes and pigments that can be contained in the remaining component (component Cb) include quinacridone, polyazo yellow, anthraquinone yellow, polyazo red, azo lake yellow, perylene, phthalocyanine green, phthalocyanine blue, and isoindolinone yellow.

[0054] Suitable examples of oil-soluble dyes that are dyes and pigments contained in the remaining component (component Cb) include mono- and disazo oil-soluble dyes, metal complex salt-type monoazo oil-soluble dyes, anthraquinone oil-soluble dyes, phthalocyanine oil-soluble dyes, and triphenylmethane oil-soluble dyes.

[0055] Suitable examples of acid dyes, which are dyes and pigments that can be contained in the remaining component (component Cb), include azo acid dyes, anthraquinone acid dyes, and triphenylmethane acid dyes.

[0056] Suitable examples of basic dyes, which are dyes and pigments that can be contained in the remaining component (component Cb), include azo basic dyes, diphenyl basic dyes, triphenylmethane basic dyes, azine basic dyes, oxazine basic dyes, and thiazine basic dyes.

[0057] The remaining component (component Cb) may be a commercially available product. Examples of commercially available products that can be used as the remaining component (component Cb) include "Sumiplast Black HB" and "Sumiplast Black G-2" manufactured by Sumitomo Chemtex Co., Ltd.

[0058] In adjusting the composition of the coloring component (component C) in the thermoplastic resin composition of this embodiment, that is, the ratio (component Cb / component Ca) of the amount of the remaining component (component Cb) to the amount of carbon black (component Ca), the carbon black (component Ca) and the remaining component (component Cb) already described may be blended individually, or the carbon black (component Ca) and the remaining component (component Cb) may be mixed in advance to adjust the ratio (component Cb / component Ca) of the amount of the remaining component (component Cb) to the amount of carbon black (component Ca), One or more colorants containing black (containing carbon black (component Ca) and a component corresponding to the remaining component (component Cb)) (first colorant) may be mixed with one or more colorants not containing carbon black (containing a component corresponding only to the remaining component (component Cb)) (second colorant). Furthermore, two or more colorants containing carbon black (first colorants) may be mixed together to prepare a mixture, and the ratio of the amount of the remaining component (component Cb) to the amount of carbon black (component Ca) (component Cb / component Ca) may be adjusted, and the resulting mixture may be compounded.

[0059] The mixture in which carbon black (component Ca) and the remaining components (component Cb) are premixed may be a commercially available product. Examples of commercially available products that can be used as the coloring component (component C) in which carbon black (component Ca) and the remaining components (component Cb) are premixed include "Sumiplast Black HLG" and "Sumiplast Black H3B" manufactured by Sumitomo Chemtex Co., Ltd.

[0060] <Component D: Silica Particles> In this embodiment, the thermoplastic resin composition contains silica particles (component D). By containing the silica particles (component D) in the thermoplastic resin composition, scratch resistance can be further improved. As the silica particles, spherical silica is preferred.

[0061] From the viewpoint of improving scratch resistance, the particle size (median diameter) of the silica particles (component D) is preferably 100 nm to 1500 nm, more preferably 100 nm to 1000 nm, and even more preferably 100 nm to 500 nm.

[0062] As the silica particles (component D), commercially available products can be used, such as "Admafine S0-C2" manufactured by Admatechs Co., Ltd., "Snowtex O" manufactured by Nissan Chemical Industries, Ltd., and "Sunsphere NP-30" manufactured by AGC Si-Tech Co., Ltd.

[0063] The particle size (median diameter) of silica particles (component D) can be determined, for example, by a laser diffraction particle size distribution analyzer. The instrument used to measure the particle size is not particularly limited. Examples of instruments that can measure particle size include the "Microtrac" manufactured by Nikkiso Co., Ltd., the "LA" manufactured by Horiba, Ltd., the "CILAS" manufactured by CilaS Corporation, the "Mastersizer" manufactured by Malvern Instruments, and the "LS" manufactured by Beckman Coulter. The median diameter that can be measured by a measurement method using a laser diffraction particle size distribution analyzer is also called d50, and refers to a predetermined particle diameter at which, when a powder is divided in half, the volume of the side with a larger particle diameter is equal to the volume of the side with a smaller particle diameter.

[0064] From the viewpoint of improving scratch resistance, the amount of silica particles (component D) in the thermoplastic resin composition is preferably 0.3 parts by mass or more and 5 parts by mass or less, more preferably 0.7 parts by mass or more and 3 parts by mass or less, and even more preferably 1 part by mass or more and 2 parts by mass or less, relative to 100 parts by mass of the total amount of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic acid ester resin (component B).

[0065] <Other Components That May Be Included in the Thermoplastic Resin Composition> The thermoplastic resin composition of this embodiment may further contain other components as needed, in addition to the (meth)acrylic resin (component A), acrylonitrile-styrene-acrylate resin (component B), coloring component (component C), and silica particles (component D) already described. Examples of other components include an ultraviolet absorber, an antioxidant, a release agent, an antistatic agent, and a flame retardant.

[0066] Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, malonic acid ester-based ultraviolet absorbers, and oxalanilide-based ultraviolet absorbers.

[0067] Examples of antioxidants include phenolic antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants.

[0068] Examples of the release agent include higher fatty acid esters, higher fatty alcohols, higher fatty acids, higher fatty acid amides, higher fatty acid metal salts, and fatty acid derivatives.

[0069] Examples of antistatic agents include conductive inorganic particles, tertiary amines, quaternary ammonium salts, cationic acrylic acid ester derivatives, and cationic vinyl ether derivatives.

[0070] Examples of the flame retardant include cyclic nitrogen compounds, phosphorus-based flame retardants, silicon-based flame retardants, cage-type silsesquioxanes or partially cleaved structures thereof, and silica-based flame retardants.

[0071] 2. Method for Producing Thermoplastic Resin Composition The thermoplastic resin composition of the present embodiment can be produced (prepared) by carrying out a kneading step using any suitable conventionally known equipment and conditions to mix the (meth)acrylic resin (component A), the acrylonitrile-styrene-acrylate ester resin (component B), the coloring component (component C), and the silica particles (component D) already described above, as well as any other desired components.

[0072] In the method for producing a thermoplastic resin composition according to the present embodiment, the temperature conditions in the (melt) kneading step are not particularly limited. The temperature conditions can be any suitable conditions taking into consideration the selected components, their amounts, properties, etc. In the melt kneading step, for example, the temperature from the raw material inlet to the outlet of the extruder may be set to, for example, 180°C to 260°C.

[0073] Any suitable conventional mixer or kneader can be used in the kneading step. Specific examples of such equipment include a single-screw kneader, a twin-screw kneader, a multi-screw extruder, a Henschel mixer, a Banbury mixer, a kneader, and a roll mill. Furthermore, when a higher rotation speed is required in the kneading step, a high-shear processing device, for example, may be used.

[0074] 3. Thermoplastic Resin Composition Pellets and Method for Producing the Same In this embodiment, when producing a preform by, for example, injection molding, it is preferable to form the thermoplastic resin composition into thermoplastic resin composition pellets in advance, from the viewpoint of further improving the production efficiency of the target preform. The shape, size, etc. of the thermoplastic resin composition pellets can be set within any suitable range, taking into consideration, for example, the injection molding apparatus used to produce the preform and the conditions applied during production.

[0075] The thermoplastic resin composition pellets can be produced by a step of extruding the thermoplastic resin composition using any suitable conventionally known extruder to obtain the thermoplastic resin composition pellets.

[0076] Specifically, the thermoplastic resin composition pellets can be produced by taking up strands of the thermoplastic resin composition extruded from an extruder with a pelletizer and cutting them into individual pieces of a predetermined length.

[0077] In the present embodiment, when the thermoplastic resin composition is extruded using an extruder, it is preferable to extrude the composition at a cylinder temperature of, for example, 230°C or higher and 250°C or lower.

[0078] In this embodiment, if the thermoplastic resin composition is made into thermoplastic resin composition pellets, portability and storage stability can be further improved.

[0079] 4. Preform (Molded Article) The preform of this embodiment is a preform (molded article) obtained by molding the thermoplastic resin composition described above. Specifically, the preform refers to a component, member, or final product itself that has been given a predetermined shape by applying a predetermined heat and force to a material such as a resin composition, rubber, glass, or metal. That is, the preform obtained by molding the thermoplastic resin composition of this embodiment is a molded article that can be used for a predetermined purpose and fulfill a predetermined function, and is obtained by molding into a predetermined shape using any suitable conventional molding method. The shape, thickness, and other dimensions of the preform that can be produced in this embodiment are not particularly limited.

[0080] The base material of this embodiment can satisfy scratch resistance, impact resistance, and solvent resistance (good aesthetics), and is therefore particularly suitable for use in automotive exterior components such as pillar components, front grille components, and rear garnish components, which can be used in an unpainted state, as well as automotive interior components such as power window switch covers.

[0081] 5. Method for Producing Preform (Molded Article) A preform containing the thermoplastic resin composition can be produced by molding the thermoplastic resin composition described above.

[0082] In this embodiment, the preform can be produced by molding the thermoplastic resin composition described above using any suitable conventional molding method, such as extrusion molding or injection molding.

[0083] In this embodiment, the preform is preferably produced by a process in which the thermoplastic resin composition (pellets) described above is introduced into an injection molding machine and extruded at a heater temperature of 220° C. to 240° C., i.e., by injection molding. Hereinafter, the case in which the preform of this embodiment is produced by injection molding will be described as an example.

[0084] Specifically, the base material of this embodiment produced by injection molding can be produced by first moltenizing the thermoplastic resin composition described above, then injecting it into a cavity of a mold provided in an injection molding machine to fill and mold the cavity, and then cooling it, and then peeling the base material, which is a molded product formed from the thermoplastic resin composition, from the mold and removing it.

[0085] More specifically, the base material of this embodiment can be produced by loading thermoplastic resin composition pellets into the cylinder from a hopper provided in an injection molding machine, melting them while rotating the screw, and then retracting the screw to fill a predetermined amount of thermoplastic resin composition into the cylinder.While applying pressure by advancing the screw, the molten thermoplastic resin composition is injected into the cavity of a mold at a predetermined injection temperature and a predetermined injection speed to fill the cavity.The mold is then held under pressure for a certain period of time until it is sufficiently cooled, and finally the mold is opened and the resin is peeled off and removed from the mold.

[0086] In this embodiment, the conditions for the injection molding method when producing a preform (injection molding conditions) are not particularly limited. The conditions for producing a preform by injection molding can be set by adopting any suitable conditions known in the art. In this embodiment, for example, a molded product of a desired shape and size can be produced by injection molding under the following conditions: the temperature inside the cylinder of the injection molding machine (molding temperature) is about 200°C to 270°C, the dwell pressure is about 80 MPa, the mold temperature is about 60°C, and the cooling time is about 30 seconds.

[0087] In this embodiment, the temperature inside the cylinder of the injection molding machine is preferably 200°C to 270°C, and more preferably 220°C to 240°C.

[0088] In this embodiment, the holding pressure (MPa) in the injection molding machine is preferably 10 MPa to 100 MPa, and more preferably 20 MPa to 90 MPa.

[0089] In this embodiment, the mold temperature (°C) of the injection molding machine is preferably 30°C to 80°C, and more preferably 50°C to 70°C.

[0090] In this embodiment, the cooling time (seconds) is the time required for the molten methacrylic resin composition filled in the cavity of the mold to be cooled while being held under pressure in the mold. The cooling time is preferably 20 to 150 seconds (seconds), and more preferably 30 to 60 seconds.

[0091] 6. Evaluation Method <Charpy Impact Strength> The preform of this embodiment has excellent impact strength. Specifically, the preform of this embodiment has "Charpy impact strength (unit: kJ / m)" which is an index of the absorbed energy against an applied impact. ２ ) is excellent.

[0092] Specifically, the Charpy impact strength can be measured in accordance with JIS K7111-2 using a test piece produced by molding the thermoplastic resin composition (pellets) described above into a flat plate of a predetermined size (for example, length 200 mm × width 120 mm × thickness 3 mm).

[0093] In the thermoplastic resin composition of the present embodiment, the Charpy impact strength of a molded article obtained by molding the thermoplastic resin composition is preferably 2.8 or more, and more preferably 4.2 or more.

[0094] <Scratch Resistance> The preform of this embodiment has excellent scratch resistance. Specifically, the preform of this embodiment has excellent scratch resistance, as measured by a "felt scratch test" and the difference in the "gloss at a gloss measurement angle of 60°" before and after the "felt scratch test," i.e., the "difference in gloss values" calculated by the following formula: Formula: Difference in gloss values ​​(Gloss loss 60°) = Gloss before the felt scratch test (Gloss 60° (Before)) - Gloss after the felt scratch test (Gloss 60° (After))

[0095] In this embodiment, the "felt scratch test" can be performed using any suitable conventionally known measuring device. Specifically, the "felt scratch test" can be performed using a commercially available device, specifically, for example, the "Flat Abrasion Tester PA-2A" manufactured by Daiei Chemical Precision Machinery Co., Ltd.

[0096] In this embodiment, the "felt scratch test" can be performed using a flat test molded piece of a predetermined size (e.g., length 145 mm x width 60 mm x thickness 3 mm) under predetermined conditions, such as a friction stroke of 140 mm, test stand reciprocation speed of 60±2 times / min, number of test stand reciprocations: 100 reciprocations, test load: 2000 g, friction surface: 2 cm x 2 cm, and felt: Green Fel. The "felt scratch test" is preferably performed multiple times (preferably, for example, three times), and the average value obtained is used as the measured value.

[0097] In this embodiment, the "difference in gloss value" can be calculated by measuring the "gloss at a gloss measurement angle of 60°" in accordance with JIS Z8741 using any suitable conventionally known device capable of measuring gloss, for the test piece on which the "felt scratch test" has been performed as described above and the test piece before the "felt scratch test" has been performed.

[0098] In this embodiment, the measurement of the "glossiness at a glossiness measurement angle of 60°" can be performed using any suitable conventionally known measuring device. The "glossiness at a glossiness measurement angle of 60°" can be measured using a commercially available device, specifically, for example, the "Portable Glossmeter GM268Plus" manufactured by KONICA MINOLTA.

[0099] In the thermoplastic resin composition of this embodiment, the "difference in gloss value" calculated by the following formula before and after the "felt scratch test" for a molded article obtained by molding the thermoplastic resin composition is preferably 6.4 or less, and more preferably 4.2 or less. Formula: Gloss value difference (Gloss loss 60°) = Gloss before felt scratch test (Gloss 60° (before)) - Gloss after felt scratch test (Gloss 60° (after))

[0100] <Solvent Resistance> In this embodiment, the test for "solvent resistance" (solvent resistance test) can be carried out by measuring the color of a test molded piece produced by molding the thermoplastic resin composition (pellets) already described into a flat plate of a predetermined size (e.g., 200 mm long x 120 mm wide x 3 mm thick) and the test molded piece after the "solvent resistance test" using any suitable conventionally known device capable of measuring the color by the SCE (specular reflected light excluded) method at a gloss measurement angle of 60°, and further calculating and evaluating the L* value (a parameter related to the color at a gloss measurement angle of 60°) in accordance with JIS Z8781-4. Specifically, this can be carried out by, for example, performing the following steps: (Steps) Step 1: Prepare a test solvent (e.g., a mixed solution of 250 mL of pure water, 200 mL of ethanol, and 50 mL of normal propanol). Step 2: Immerse filter paper (e.g., Advantec's "No. 3," 125 mm) in the obtained test solvent for a predetermined time (e.g., 15 minutes). Step 3: After immersion, recover the filter paper and place it on an area including the center of the main surface of the test molded piece. Step 4: Leave the test molded piece with the filter paper placed in an oven (e.g., ESPEC's "SPH-300") set to 60°C for 4 hours. Step 5: After 4 hours, remove the test molded piece from the oven and cool it at room temperature for 1 hour. Step 6: Using a spectrophotometer (for example, "SD-7000" manufactured by Nippon Denshoku Industries Co., Ltd.), measure the color of the main surface of the test molded piece (the area where the filter paper is placed or was placed) at a gloss measurement angle of 60° in accordance with JIS Z8722 using the SCE (specular reflection excluded) method before and after the treatments in steps 1 to 5 above, and calculate the L* value in accordance with JIS Z8781-4. Step 7: Calculate and evaluate the magnitude of the change in the L* value of the test molded piece before and after the solvent resistance test in steps 1 to 5 above using the following formula. Formula: Delta L* (change in L* value) = L* (after test) - L* (before test)

[0101] In the thermoplastic resin composition of the present embodiment, the Delta L* value (amount of change in L* value) before and after a "solvent resistance test" on an article molded from the thermoplastic resin composition is preferably 2.3 or less, and more preferably 1.6 or less.

[0102] Examples Example 1 (1) Production of Thermoplastic Resin Composition Pellets A mixture of 65 parts by mass of a (meth)acrylic resin (component A: "SUMIPEX ME" manufactured by Sumitomo Chemical Co., Ltd.; a copolymer of methyl methacrylate and methacrylic acid), 35 parts by mass of an acrylonitrile-styrene-acrylic acid ester resin (component B: "UA-1400" manufactured by Nippon A&L Co., Ltd.), 1 part by mass of silica particles (component D: "Admafine S0-C2" manufactured by Admatechs Co., Ltd. (average particle size (median diameter): 0.5 μm)), and a first colorant containing an oil-soluble dye as the "dye or pigment" ("Sumiplast Black" manufactured by Sumitomo Chemtex Co., Ltd.) containing 2% by mass of carbon black was used. A mixture was obtained by placing 0.025 parts by mass of a first colorant HLG and 0.43 parts by mass of a second colorant (manufactured by Sumitomo Chemtex Co., Ltd., "Sumiplast Black HB") (referred to as "first colorant HLG") that does not contain carbon black and contains an oil-soluble dye as the "dye or pigment" (referred to as "second colorant HB") in a resin bag and hand-blending them.

[0103] As described above, the ratio (component C / component Ca) of the content of the coloring component (component C) to the content of carbon black (component Ca) was adjusted by adjusting the blending amount of the first colorant HLG and the blending amount of the second colorant HB. The blending amounts of the first colorant HLG and the second colorant HB are also shown in Table 1 below, and the blending amounts of each component are also shown in Table 3 below.

[0104] The resulting mixture was kneaded using a single-screw extruder (manufactured by Tanabe Plastic Machinery Co., Ltd.) with a screw diameter of 40 mm under the following kneading conditions, then extruded into a strand, water-cooled, and cut with a strand cutter to obtain pelletized (meth)acrylic resin compositions, i.e., thermoplastic resin composition pellets (also referred to as (meth)acrylic resin composition pellets). (Kneading Conditions) The cutter rotation speed of the single-screw extruder was 10 rpm, and the screw rotation speed of the single-screw extruder was 80 rpm. The heater temperatures from the side (C1) closest to the raw material inlet to the side (C5) closest to the outlet were set as follows: C1: 230°C, C2: 240°C, C3: 250°C, C4: 250°C, and C5: 250°C.

[0105] The obtained thermoplastic resin composition pellets were molded into a flat plate of 200 mm length x 120 mm width x 3 mm thickness using an injection molding machine (Toshiba Machine Co., Ltd. "IS-130F") under the following injection molding conditions to obtain a test molded piece. (Injection molding conditions) The molding temperature was heater 1: 240 ° C, heater 2: 240 ° C, heater 3: 230 ° C, heater 4: 220 ° C, and the inlet: 60 ° C. The mold temperature was 60 ° C, the injection speed was 10 mm / sec to 26 mm / sec, the dwell pressure switching position was 5 mm, the dwell time was 10 sec, and the dwell pressure speed was 26 mm / sec. The cooling time was 30 sec, the screw rotation speed during metering was 60 rpm, the back pressure was 15 MPa, the screw metering position was 68.5 mm, and the suckback amount was 3 mm.

[0106] Examples 2 to 8 Thermoplastic resin composition pellets were produced in the same manner as in Example 1, except that the blending amounts of the first colorant HLG and the second colorant HB were as shown in Table 1. Test molded specimens were then obtained by injection molding using the thermoplastic resin composition pellets. The blending amounts of each component are also shown in Table 3.

[0107] Examples 9 to 12 Thermoplastic resin composition pellets were produced in the same manner as in Example 1, except that the blending amounts of the first colorant HLG and the second colorant HB were as shown in Table 2 below, and then test molded specimens were obtained by injection molding using the thermoplastic resin composition pellets. The blending amounts of each component are also shown in Tables 3 and 4 below.

[0108] Comparative Examples 1 to 4 Thermoplastic resin composition pellets were produced in the same manner as in Example 1, except that the blending amounts of the first colorant HLG and the second colorant HB were as shown in Table 2 below, and then test molded specimens were obtained by injection molding using the thermoplastic resin composition pellets. The blending amounts of each component are also shown in Table 4 below.

[0109]

[0110]

[0111] (2) Evaluation (i) Charpy impact strength Using the test molded specimens obtained in the examples and comparative examples already described, the Charpy impact strength (kJ / m) was measured in accordance with JIS K7111-2. ２ ) was measured and evaluated. For the measurement, test molded specimens were used that had been notched (cut) in a conventional manner. Here, the higher the measured Charpy impact strength value, the better the impact resistance can be evaluated. When the measured Charpy impact strength was 2.8 or more, it was evaluated as "good", and when the Charpy impact strength was less than 2.8, it was evaluated as "unacceptable". The results are shown in Tables 5 and 6 below.

[0112] (ii) Scratch Resistance First, using the test molded pieces obtained in the examples and comparative examples already described, a "felt scratch test" was carried out under the following conditions using a "flat abrasion tester PA-2A" manufactured by Daiei Chemical Precision Machinery Co., Ltd. (Conditions) Friction stroke: 140 mm Test stand reciprocating speed: 60±2 times / min Number of reciprocating times on the test stand: 100 reciprocating times Test load: 2000 g Friction surface: 2 cm x 2 cm Felt: Green Felt Test location: A total of three tests were carried out using divided test molded pieces (length 145 mm x width 60 mm x thickness 3 mm) divided from the test molded piece (length 200 mm x width 120 mm x thickness 3 mm).

[0113] Next, for the split test molded pieces on which the "felt scratch test" was carried out as described above, the gloss at a gloss measurement angle of 60° (Gloss 60° (After)) was measured in accordance with JIS Z8741 using a "portable gloss meter GM268Plus" manufactured by KONICA MINOLTA. For comparison (evaluation), the gloss at a gloss measurement angle of 60° (Gloss 60° (Before)) was also measured in the same manner for the split test molded pieces before the "felt scratch test" was carried out. The smaller the "difference in gloss value" calculated by the following formula between the gloss before and after the "felt scratch test", the more excellent the scratch resistance it can be evaluated to have. Formula: Difference in gloss value (Gloss loss 60°) = Gloss before felt scratch test (Gloss 60° (before)) - Gloss after felt scratch test (Gloss 60° (after))

[0114] In the evaluation, if the "difference in gloss value" before and after the "felt scratch test" was 6.4 or less, it was evaluated as "good," and if the difference was more than 6.4, it was evaluated as "fail." The results are shown in Tables 5 and 6 below.

[0115] (iii) Solvent Resistance Using the test specimens obtained in the examples and comparative examples described above, solvent resistance tests were conducted to evaluate the test solvents according to the following steps. (Steps) Step 1: A mixed solution of 250 mL of pure water, 200 mL of ethanol, and 50 mL of normal propanol was prepared as the test solvent. Step 2: Filter paper (Advantec No. 3, 125 mm) was immersed in the obtained test solvent for 15 minutes. Step 3: The immersed filter paper was recovered and placed on the area including the center of the main surface of the test specimen. Step 4: The test specimen with the filter paper placed on it was placed in an oven (ESPEC SPH-300) set to 60°C for 4 hours. Step 5: After 4 hours, the test specimen was removed from the oven and cooled at room temperature for 1 hour. The solvent resistance test was completed through steps 1 to 5. Step 6: Using a spectrocolorimeter ("SD-7000" manufactured by Nippon Denshoku Industries Co., Ltd.), the color of the main surface of the test molded piece (the area where the filter paper is placed or had been placed) before and after the treatments in steps 1 to 5 above was measured by the SCE (specular reflection excluded) method at a gloss measurement angle of 60° in accordance with JIS Z8722, and the L* value was calculated in accordance with JIS Z8781-4. Step 7: The magnitude of change in the L* value of the test molded piece before and after the solvent resistance test in steps 1 to 5 above was calculated and evaluated based on the following formula. Formula: Delta L* (amount of change in L* value) = L* (after test) - L* (before test)

[0116] In the evaluation, the smaller the calculated Delta L* value, the better the solvent resistance. Here, when the calculated Delta L* value was 2.3 or less, it was evaluated as "good," and when the Delta L* value was more than 2.3, it was evaluated as "poor." The results are shown in Tables 5 and 6 below.

[0117]

[0118]

[0119]

[0120]

[0121] When Comparative Example 1 was compared with Examples 2, 5, 7, 11, and 12, the solvent resistance of Examples 2, 5, 7, 11, and 12 was clearly superior to that of Comparative Example 1. Furthermore, when Comparative Example 2 was compared with Examples 1, 3, 4, 6, 8, 9, and 10, the solvent resistance of Examples 1, 3, 4, 6, 8, 9, and 10 was clearly superior to that of Comparative Example 2. Furthermore, when Comparative Example 3 was compared with Examples 2, 5, 7, 11, and 12, the scratch resistance of Examples 2, 5, 7, 11, and 12 was clearly superior to that of Comparative Example 3. In addition, when Comparative Example 4 was compared with Examples 1, 3, 4, 6, 8, 9, and 10, the scratch resistance of Examples 1, 3, 4, 6, 8, 9, and 10 was clearly superior to that of Comparative Example 4.

[0122] As is clear from the above, with the thermoplastic resin compositions of Examples 1 to 12, molded articles (injection molded articles) obtained by molding the thermoplastic resin compositions that satisfy the predetermined requirements already described were able to satisfy all of the scratch resistance, impact resistance, and solvent resistance (good appearance before and after the test), and in particular, molded articles having an appearance with an excellent color tone, also known as piano black, could be produced.

Claims

1. A coloring component (component C) containing two or more components, one of which is carbon black (component Ca) and the remaining component (component Cb) is one or more of a dye and a pigment, and silica particles (component D), wherein, when the total amount of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic ester resin (component B) is 100 parts by mass, the amount of the (meth)acrylic resin (component A) is 50 to 90 parts by mass, the amount of the acrylonitrile-styrene-acrylic ester resin (component B) is 10 to 50 parts by mass, and relative to 100 parts by mass of the total amount of the (meth)acrylic resin (component A) and the acrylonitrile-styrene-acrylic ester resin (component B), a thermoplastic resin composition comprising: a carbon black (component Ca) in an amount of 0.0005 to 0.01 parts by mass; a remaining component (component Cb) in an amount of 0.02 to 1.0 parts by mass; a ratio of the amount of the remaining component (component Cb) to the amount of the carbon black (component Ca) (component Cb / component Ca) of 75 to 1000; and an amount of the silica particles (component D) in an amount of 0.3 to 5 parts by mass per 100 parts by mass of the total of the amount of the (meth)acrylic resin (component A) and the amount of the acrylonitrile-styrene-acrylic acid ester resin (component B).

2. The thermoplastic resin composition according to claim 1, wherein the silica particles (component D) have a particle size (median diameter) of 100 nm to 1,500 nm.

3. The thermoplastic resin composition according to claim 1 or 2, wherein the (meth)acrylic resin (component A) contains a polymer obtained by copolymerizing a methacrylic acid ester with a monomer other than the methacrylic acid ester that is copolymerizable with the methacrylic acid ester, and the content of structural units derived from the methacrylic acid ester in the polymer is 80% by mass to 99.9% by mass.

4. A base material molded from the thermoplastic resin composition according to claim 1 or 2.

5. The base material according to claim 4, which is a pillar member for an automobile.

6. A method for producing thermoplastic resin composition pellets, comprising the step of extruding the thermoplastic resin composition according to claim 1 or 2 using an extruder to obtain thermoplastic resin composition pellets.

7. A method for producing the preform according to claim 4, comprising the steps of introducing the thermoplastic resin composition into an injection molding machine, setting the heater temperature to 220°C or higher and 240°C or lower, and extruding and molding the composition.

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