JP2010180393A - Acrylic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition of which heat resistance is excellent and also transparency change depending on temperature is small and which is suitable for use as a molding material used for applications in which surface temperature change is large and transparency is required, for example, an interior material for an automobile and an exterior material for a motorcycle. <P>SOLUTION: The acrylic resin composition contains (A) a methacrylic acid ester-based polymer, (B) a rubber component, and (C) at least one modifier selected from the group consisting of an aromatic dicarboxylic acid ester, an aliphatic dicarboxylic acid ester, and a phosphoric acid ester. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an acrylic resin composition. More specifically, the present invention relates to an acrylic resin composition that can be suitably used as, for example, a molding material used in applications having a large change in surface temperature, such as an automobile interior material and a motorcycle exterior material. The motorcycle referred to in the present specification is a concept including a so-called motorized bicycle.

  Acrylic resin is excellent in transparency, but has poor impact resistance. Therefore, an acrylic resin composition in which an impact modifier containing a diene-based graft copolymer as a main component is added to acrylic resin is proposed. (For example, refer to Patent Document 1). However, this acrylic resin composition has transparency at normal temperature and good impact resistance, but the acrylic resin and the diene-based graft copolymer have different linear expansion coefficients. There are disadvantages in that the difference in refractive index from the graft copolymer increases, and the temperature change of transparency and glossiness increases.

  Moreover, as a composition excellent in heat resistance, impact resistance, transparency, etc., an acrylic block copolymer containing a methacrylic ester polymer block and an acrylate ester block, a diene polymer, etc. A thermoplastic resin composition containing a rubber is proposed (for example, see Patent Document 2). However, since this thermoplastic resin composition requires a special acrylic resin called a block copolymer containing a methacrylic ester polymer block and an acrylate ester block, from the viewpoint of industrial productivity. It cannot be said that it is preferable.

  Therefore, in recent years, it is a resin composition in which a commonly used methacrylate polymer and a rubber component are used in combination, and the temperature change of transparency and gloss is small, and the room temperature is high as in summer. Development of a resin composition that can be suitably used for automobile interior materials is desired.

JP 2002-309056 A International Publication No. 2002/081561 Pamphlet

  The present invention has been made in view of the above prior art, and provides an acrylic resin composition having good transparency and heat resistance that is practically satisfactory, and having a small temperature change in transparency and gloss. This is the issue.

The present invention
(1) (A) Methacrylate ester polymer, (B) rubber component, and (C) at least one modification selected from the group consisting of aromatic dicarboxylic acid ester, aliphatic dicarboxylic acid ester and phosphoric acid ester An acrylic resin composition comprising a quality agent,
(2) The present invention relates to an automotive interior material molded using the acrylic resin composition as a raw material, and (3) a motorcycle exterior material molded using the acrylic resin composition as a raw material.

  The acrylic resin composition of the present invention has an excellent effect that it has good transparency and heat resistance that is practically satisfactory, and the temperature change of transparency and gloss is small.

FIG. 1 is a schematic explanatory diagram of a light transmittance measuring device used in Examples 1 to 11 and Comparative Example 1.

  The inventors of the present invention have a resin composition in which a methacrylic acid ester polymer and a rubber component are used in combination, and since the rubber component is used, the resin composition is excellent in impact resistance. As a result of intensive studies focusing on the technical problem that transparency and glossiness are impaired as the linear expansion coefficient changes from room temperature to high temperature, a specific modifier is blended into this resin composition. In this case, this resin composition was found to have excellent impact resistance since it contains a rubber component, and surprisingly, the temperature change of transparency was small and it had good transparency. The present invention has been completed based on such findings.

  The acrylic resin composition of the present invention is selected from the group consisting of (A) methacrylic acid ester polymer, (B) rubber component, and (C) aromatic dicarboxylic acid ester, aliphatic dicarboxylic acid ester, and phosphoric acid ester. At least one modifier.

  Suitable methacrylic acid ester polymers include polymers having methacrylic acid esters as the main component. Here, “mainly containing a methacrylic ester” in the present specification means that the content of the methacrylic ester in the raw material monomer of the methacrylic ester polymer is 50% by mass or more. From the viewpoint of improving the heat resistance and transparency of the methacrylate ester polymer, the content of the methacrylate ester in the raw material monomer of the methacrylate ester polymer is preferably 80% by mass or more, more preferably 85% by mass or more. More preferably, it is 90 mass% or more.

  Typical examples of a polymer having a methacrylic acid ester as a main component include a methacrylic acid ester homopolymer, and a raw material monomer having a methacrylic ester as a main component, containing a methacrylic acid ester and another monomer. And a methacrylic acid ester copolymer obtained by this.

  Suitable methacrylic acid esters include, for example, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, from the viewpoint of increasing fluidity during heat-melting, heat decomposability, and compatibility with rubber components. Esters such as isobutyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, stearyl methacrylate Examples include methacrylic acid alkyl esters having 1 to 18 carbon atoms in the alkyl group, cyclohexyl methacrylate, phenyl methacrylate, and the like. Combined and can be used. These methacrylic acid esters are excellent in fluidity during heat melting, heat decomposability and compatibility with rubber components.

  Among the methacrylic acid esters, since they are easily available, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, methacrylic acid Isobornyl acid, cyclohexyl methacrylate, tridecyl methacrylate and stearyl methacrylate are preferred. Moreover, from a heat resistant viewpoint, the methacrylic acid alkylester whose carbon number of the alkyl group in an ester part is 1-4 is more preferable, and methyl methacrylate is further more preferable.

  In the methacrylic acid ester homopolymer, one kind of the methacrylic acid esters is used as the raw material monomer. When two or more kinds of methacrylic acid esters are used as the raw material monomer, the methacrylic acid ester polymer is a methacrylic acid ester copolymer.

  As a methacrylic acid ester copolymer obtained by polymerizing a raw material monomer containing a methacrylic acid ester and other monomers and having methacrylic acid ester as a main component, one or more of the methacrylic acid esters are used. And other monomers, and a copolymer obtained by polymerizing a raw material monomer mainly composed of a methacrylic acid ester. The methacrylic acid ester copolymer may be a random copolymer or a block copolymer. A methacrylic acid ester copolymer obtained by polymerizing a raw material monomer mainly composed of a methacrylic acid ester is usually a random copolymer, and this random copolymer can be easily obtained on the market. Can do.

  Examples of the other monomer include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, and acrylic acid 2 -Acrylic acid alkyl esters such as ethylhexyl, nonyl acrylate, decyl acrylate, dodecyl acrylate and stearyl acrylate; hydroxyl-containing acrylics such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and 4-hydroxybutyl acrylate Acid alkyl ester; cyclohexyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, trifluoromethyl acrylate, trifluoroethyl acrylate, pentafluoroethyl acrylate Other acrylic esters such as glycidyl acrylate, allyl acrylate, phenyl acrylate, toluyl acrylate, benzyl acrylate, isobornyl acrylate, 3-dimethylaminoethyl acrylate; unsaturated monocarboxylic acids such as methacrylic acid and acrylic acid Acid; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, divinylbenzene, vinylnaphthalene; maleic anhydride, maleic acid, Unsaturated dicarboxylic acid compounds such as maleic acid monoester, maleic acid diester, fumaric acid, fumaric acid monoester, fumaric acid diester or derivatives thereof; maleimide, methylmaleimide, ethylmaleimide, propylmer Maleimide compounds such as reimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclohexylmaleimide; conjugated diene compounds such as butadiene, isoprene; vinyl chloride, vinylidene chloride, tetrafluoroethylene, hexafluoropropylene Halogen-containing unsaturated compounds such as vinylidene fluoride and chloroprene; silicon-containing unsaturated compounds such as vinyltrimethoxysilane and vinyltriethoxysilane, and the like, but the present invention is not limited to such examples. . These other monomers can be used alone or in admixture of two or more.

  Among the other monomers, from the viewpoint of heat resistance, an alkyl acrylate ester and a vinyl cyanide compound are preferable, and an alkyl acrylate ester, acrylonitrile and methacrylonitrile in which the ester group has an alkyl group having 1 to 4 carbon atoms. Is more preferable.

  The content of the other monomer in the raw material monomer of the methacrylic ester polymer is 50% by mass or less, preferably 20% by mass or less, from the viewpoint of enhancing the heat resistance and transparency of the methacrylic ester copolymer. Preferably it is 15 mass% or less, More preferably, it is 10 mass% or less.

  In the present invention, a methacrylic ester polymer having methyl methacrylate as a main component as a raw material monomer is preferred from the viewpoints of heat resistance and transparency.

  The polymerization method of the raw material monomer of the methacrylic acid ester polymer is not particularly limited, but examples of the method include suspension polymerization method, bulk polymerization method, solution polymerization method and the like.

  The melt flow rate (230 ° C., 37.3 N) of the methacrylic ester polymer is not particularly limited, but is preferably 5 g / 10 min or more from the viewpoint of improving the fluidity at the time of heating and melting the methacrylic ester polymer. More preferably, it is 15 g / 10 min or more, and preferably 30 g / 10 min or less, more preferably 25 g / 10 min or less, from the viewpoint of increasing the mechanical strength of the methacrylate polymer. The melt flow rate of the methacrylic acid ester polymer can be easily adjusted by adjusting the polymerization temperature, the type and amount of the polymerization initiator and the chain transfer agent.

  The methacrylic acid ester polymer may contain other polymers as long as the object of the present invention is not impaired.

The rubber component is used for imparting impact resistance to the acrylic resin composition of the present invention.
Specific examples of the rubber component include, for example, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-styrene copolymer, methyl methacrylate- Butadiene-styrene copolymer, methyl methacrylate-butadiene-acrylonitrile-styrene copolymer, acrylic rubber, butyl rubber, ethylene-propylene-diene copolymer, styrene-butadiene copolymer, isobutylene polymer, ethylene-acetic acid Vinyl copolymers, isoprene rubbers, butadiene rubbers, chloroprene rubbers, nitrile rubbers and the like can be mentioned, but the present invention is not limited to such examples. These rubber components can be used alone or in admixture of two or more.

  From the viewpoint of enhancing impact resistance and improving the transparency and gloss of the acrylic resin composition of the present invention, the rubber component has a refractive index difference (absolute value) from that of the methacrylate polymer at 25 ° C. , Preferably 0.03 or less, more preferably 0.01 or less. Examples of such a rubber component include acrylic rubber and ethylene-vinyl acetate copolymer having a vinyl acetate content of 20 to 32% by mass.

  The acrylic rubber means a rubber mainly composed of an acrylic monomer such as acrylic acid, methacrylic acid, and derivatives thereof. The acrylic rubber may be composed only of an acrylic monomer, or may be composed of the acrylic monomer and another monomer. Here, “having the acrylic monomer as the main component” means that the content of the acrylic monomer in the raw material monomer constituting the acrylic rubber is 50% by mass or more. Examples of other monomers include aromatics such as styrene, α-methylstyrene, 2-methylstyrene, 4-methylstyrene, 2,4-diethylstyrene, 4-butoxystyrene, and N, N-dimethylaminostyrene. Vinyl compounds; α, β-ethylenically unsaturated nitrile compounds such as acrylonitrile, methacrylonitrile and vinylidene cyanide; Vinyl ester compounds such as vinyl acetate and vinyl propionate; Vinyl ether compounds such as ethyl vinyl ether, cetyl vinyl ether and hydroxybutyl vinyl ether However, the present invention is not limited to such examples. These other monomers can be used alone or in admixture of two or more.

  The acrylic rubber may be, for example, an acrylic rubber latex or a core-shell type acrylic rubber. As the core-shell type acrylic rubber, for example, a core-shell in which the core is formed of a rubbery polymer made of an acrylic polymer and the shell is formed of a glassy polymer having a glass transition point of 60 ° C. or higher. Examples include acrylic rubbers of the type.

  Examples of the acrylic rubber include core-shell type acrylic rubber such as trade name: Staphyloid IM-701, which is commercially available from Gantz Kasei Co., Ltd. Examples of the ethylene-vinyl acetate copolymer include trade names commercially available from Tosoh Corporation: Ultrasen 637, Ultrasen 750, and the like. Among these, from the viewpoint of enhancing transparency, an acrylic rubber is preferable, and a core-shell type acrylic rubber is more preferable.

  The rubber component may be crosslinked using a crosslinking agent. Examples of the crosslinking agent include sulfur; organic peroxides such as 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, and di-tert-butylperoxydiisopropylbenzene; tetramethylthiuram monosulfide, tetramethylthiuram disulfide, and the like. Organic sulfur compounds; oxime compounds such as p-quinonedioxime and p, p′-dibenzoylquinonedioxime; polyamines such as hexamethylenediamine carbamate and the like, but the present invention is limited to such examples only is not. Moreover, when using a crosslinking agent, you may use vulcanization accelerators, such as diphenyl guanidine, zinc dimethyldithiocarbamate, 2-mercaptobenzothiazole, dibenzothiazyl sulfide, if necessary.

  The amount of the rubber component is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and further preferably 25 parts by mass from the viewpoint of improving transparency and impact resistance per 100 parts by mass of the methacrylic ester polymer. From the viewpoint of improving heat resistance, it is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, and further preferably 50 parts by mass or less.

  The modifier is at least one selected from the group consisting of aromatic dicarboxylic acid esters, aliphatic dicarboxylic acid esters, and phosphoric acid esters.

  The present invention has one major feature in that a specific modifier is used together with a methacrylic ester polymer and a rubber component. The acrylic resin composition of the present invention is excellent in heat resistance because a specific modifier is used, and the linear expansion coefficient of the methacrylic ester polymer and the rubber component is greatly different. Therefore, the acrylic resin composition of the present invention is imparted with the excellent property that the temperature change of the transparency of the acrylic resin composition of the present invention is small.

  Among the modifiers, an aromatic dicarboxylic acid ester and a phosphoric acid ester are preferable, and an aromatic dicarboxylic acid ester is more preferable from the viewpoint of increasing the transparency of the acrylic resin composition of the present invention at a high temperature. Further, from the viewpoint of reducing the temperature change of the transparency of the acrylic resin composition of the present invention, aliphatic dicarboxylic acid esters and phosphoric acid esters are preferable, and aliphatic dicarboxylic acid esters are more preferable.

  Examples of the aromatic dicarboxylic acid ester include dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, ditridecyl phthalate, and phthalic acid Examples thereof include butylbenzyl, dicyclohexyl phthalate, and tetrahydrophthalic acid diester, but the present invention is not limited to such examples. These aromatic dicarboxylic acid esters can be used alone or in admixture of two or more. Among these aromatic dicarboxylic acid esters, dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, diheptyl phthalate, phthalate from the viewpoint of enhancing the transparency of the acrylic resin composition of the present invention at high temperatures. Di-2-ethylhexyl acid, diisononyl phthalate, diisodecyl phthalate and ditridecyl phthalate are preferred, and di-2-ethylhexyl phthalate is more preferred.

  Examples of the aliphatic dicarboxylic acid ester include adipic acid diesters such as dimethyl adipate, diethyl adipate, di-n-butyl adipate, diheptyl adipate, di-2-ethylhexyl adipate, diisononyl adipate, and diisodecyl adipate; Examples thereof include sebacic acid diesters such as dibutyl acid and di-2-ethylhexyl sebacate; maleic acid diesters such as dibutyl maleate and di2-ethylhexyl maleate; and fumaric acid diesters such as dibutyl fumarate. It is not limited to illustration only. These aliphatic dicarboxylic acid esters can be used alone or in admixture of two or more. Among these aliphatic dicarboxylic acid esters, adipic acid diesters are preferred from the viewpoint of enhancing the transparency of the acrylic resin composition of the present invention at high temperatures, and dimethyl adipate, diethyl adipate, di-n-butyl adipate , Diheptyl adipate, di-2-ethylhexyl adipate, diisononyl adipate and diisodecyl adipate are more preferred, and di-2-ethylhexyl adipate is more preferred.

  Examples of phosphate esters include tricresyl phosphate, triethyl phosphate, tributyl phosphate, tris phosphate (2-ethylhexyl), tris phosphate (2-chloroethyl), tris phosphate (dichloropropyl), and tributoxy phosphate. Examples include ethyl, tris phosphate (β-chloropropyl), triphenyl phosphate, octyl diphenyl phosphate, tris phosphate (isopropylphenyl), cresyl diphenyl phosphate, and the like, but the present invention is limited to such examples only. Is not to be done. These phosphate esters can be used alone or in admixture of two or more. Among these phosphate esters, from the viewpoint of enhancing the transparency of the acrylic resin composition of the present invention at high temperatures, tricresyl phosphate, triethyl phosphate, tributyl phosphate, tris phosphate (2-ethylhexyl), phosphorus Tris (2-chloroethyl) acid, tris (dichloropropyl) phosphate, tributoxyethyl phosphate, and tris (β-chloropropyl) phosphate are preferred, and tricresyl phosphate is more preferred.

  The amount of the modifier is preferably 3 parts by mass or more, more preferably 5 parts by mass, from the viewpoint of reducing the temperature change in transparency of the acrylic resin composition of the present invention per 100 parts by mass of the methacrylic ester polymer. Part or more, more preferably 10 parts by weight or more, and from the viewpoint of increasing the heat resistance and mechanical strength of the acrylic resin composition of the present invention, it is preferably 40 parts by weight or less, more preferably 35 parts by weight or less. Is 30 parts by mass or less, more preferably 25 parts by mass or less.

  Since the acrylic resin composition of the present invention itself has good transparency, it can be suitably used as it is, for example, as a molding material for a resin molded body.

  In general, a colorant is blended in the resin molding to give a desired color. Also in the acrylic resin composition of the present invention, a colorant such as a pigment can be further contained in order to impart a desired color. The acrylic resin composition of the present invention has a small change in transparency due to a temperature change. Accordingly, when a resin molded body having a predetermined shape is molded using an acrylic resin composition containing a colorant in the acrylic resin composition of the present invention as a molding material, a molded body having a small color temperature change is obtained. Can do.

  Examples of the colorant include pigments and dyes. The colorant can be appropriately selected and used according to the color required for a molded article molded using the acrylic resin composition of the present invention. Among the colorants, pigments are preferable from the viewpoint of light resistance. The pigment may be, for example, an inorganic pigment such as carbon black or an organic pigment.

  Since the amount of the colorant varies depending on the use of the acrylic resin composition of the present invention, the type of the colorant, and the like, it cannot be determined unconditionally. Usually, from the viewpoint of preventing the acrylic resin composition of the present invention from becoming hard, the amount of the colorant is preferably 30 parts by mass or less, more preferably 20 masses per 100 parts by mass of the acrylic resin composition of the present invention. Part or less, more preferably 10 parts by weight or less. In addition, since the color of the acrylic resin composition of the present invention may be colored and transparent in some cases, the lower limit of the amount of the colorant is preferably determined as appropriate depending on the application.

  In the acrylic resin composition of the present invention, for example, additives such as a stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a foaming agent, a lubricant, and a filler are not hindered if necessary. You may add within the range.

  The acrylic resin composition of the present invention includes, for example, a methacrylic ester polymer, a rubber component, a modifier, and, if necessary, a batch mixer, a tumbler, a Henschel mixer, a Banbury mixer, a roll, a single screw extruder, It can be easily prepared by heat-melt kneading by means such as a twin screw extruder.

  The temperature at which the methacrylic acid ester polymer, the rubber component, the modifier, and optionally the additive is heated and melt-kneaded is preferably 100 ° C. or higher, more preferably 150 ° C., from the viewpoint of uniformly dispersing each component. From the viewpoint of preventing deterioration of each component, it is preferably 250 ° C. or lower, more preferably 230 ° C. or lower, and further preferably 210 ° C. or lower.

  As described above, the acrylic resin composition of the present invention is obtained by heat-melting and kneading the methacrylic ester polymer, the rubber component, the modifier, and, if necessary, the additive and uniformly dispersing each component. can get.

  The acrylic resin composition of the present invention is processed into a molded product having a desired shape by, for example, injection molding, extrusion molding, blow molding, compression molding, calendar molding, thermoforming, rotational molding, sheet molding, film molding, etc. can do.

  Examples of the molded article in which the acrylic resin composition of the present invention is used include, for example, commonly used molded articles such as plates, sheets, films, etc., and the acrylic resin composition of the present invention has good transparency. Because the temperature change of the transparency is small, parts (parts) that make up automotive interior panels such as automotive instrument panels, door trims, etc. that become hot due to direct sunlight in summer, motorcycle windshields, It can be suitably used for a motorcycle exterior material made of resin such as mudguard.

  Furthermore, the acrylic resin composition of the present invention can be used in addition to the molded body, for example, bottles, pipes, packings, joints, pillars, wall materials, flooring materials, containers, electrical equipment cases, electrical circuit boards, etc. It can be used for various molded products.

  Next, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples.

Examples 1-11
Polymethyl methacrylate as a methacrylic acid ester polymer (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumipex LG21, melt flow rate (230 ° C., 37.3 N): 21 g / 10 min), and acrylic rubber as a rubber component [Gantz Kasei] Product name: Staphyloid IM-701], a compound shown in Table 1 as a modifier, was mixed so as to have the composition shown in Table 1, and the resulting mixture was mixed with a batch mixer [(stock) ) Manufactured by Toyo Seiki Seisakusho, trade name: Labo Plast Mill], and melted and kneaded at 180 ° C. and 30 rpm for 3 minutes to obtain 40 g of an acrylic resin composition.

The details of the modifier are as follows.
[Details of modifier]
・ Modifier A: Di-2-ethylhexyl adipate ・ Modifier B: tricresyl phosphate ・ Modifier C: Di-2-ethylhexyl phthalate

Comparative Example 1
A methacrylic acid ester polymer and a rubber component are mixed so as to have a ratio shown in Table 1, and the obtained mixture is put in a batch mixer [trade name: Labo Plast Mill, manufactured by Toyo Seiki Seisakusho], 180 40 g of an acrylic resin composition was obtained by heating and melt-kneading for 3 minutes at 30 ° C. and a rotation speed of 30 ° C.

Experimental Example Using a desktop test press machine (trade name: Table Type Test Press SA-303-IS, manufactured by Tester Sangyo Co., Ltd.), each of the acrylic resin compositions obtained in each Example and Comparative Example 1 was 200 ° C. After being melt-pressed at a pressure of 10 MPa, the film was cooled to 20 ° C. to produce a film having a thickness of about 1 mm and about 300 μm. As physical properties of the obtained film, light transmittance (1), light transmittance (2), breaking strength and heat resistance were measured based on the following measuring methods. Table 2 shows the measurement results of the light transmittance (1), breaking strength and heat resistance, and Table 3 shows the measurement results of the light transmittance (2).

[Light transmittance (1)]
FIG. 1 shows an outline of a light transmittance measuring apparatus used in measuring the light transmittance (1) having a thickness of about 1 mm obtained in each Example and Comparative Example 1. FIG. 1 is a schematic explanatory diagram of a light transmittance measuring apparatus.

  In FIG. 1, incident light 2 from a He—Ne laser irradiation device (manufactured by MELLES GRIO, product number: 05-LHP-121, wavelength: 633 nm) 1 is incident light of a light transmittance measuring device 3. 2 enters the light transmittance measuring device 3 through the irradiation hole 2 and irradiates the incident light 2 onto the film 4 having a thickness of about 1 mm. The transmitted light 5 transmitted through the film 4 is taken out from the transmitted light extraction hole 6 with a diameter of 10 mm provided in the light transmission measuring device 3 at a position 127 mm away from the film 4 and arranged at a position about 500 mm away from the film 4. The transmitted light intensity of the transmitted light 5 is measured with the detector 7 (a square having a side length of about 15 mm).

  First, the transmitted light intensity of the film 4 having a thickness of about 1 mm obtained in each Example and Comparative Example 1 is measured at room temperature (25 ° C.) using the light transmittance measuring device 3. Thereafter, when the film 4 is heated and reaches 40 ° C., 60 ° C. and 80 ° C., the transmitted light intensity is measured in the same manner as described above, and after cooling to 28 ° C., the transmitted light of the film 4 is again measured. Measure strength.

  The transmitted light 5 means light transmitted through the film 4. The transmitted light 5 is transmitted through the incident light 2 from the laser irradiation device 1 that has passed through the film 4 and is not refracted by the film 4. The concept includes both light and scattered light refracted by the film 4 and passed through the transmitted light extraction hole 6.

The light transmittance is the formula:
(Light transmittance)
= [Intensity of transmitted light 5 detected by detector 7] ÷ [Intensity of incident light 2 from laser irradiation apparatus 1]
Ask based on.

  Further, the difference between the light transmittance at room temperature (25 ° C.) and the light transmittance at 80 ° C. (“difference between 25 ° C. and 80 ° C.” in Table 2) (absolute value) is obtained.

[Light transmittance (2)]
In the measurement of the light transmittance (2) of the film obtained in each Example and Comparative Example 1, the light transmittance measuring device 3 shown in FIG. 1 is used as in the method of measuring the light transmittance (1).

  In the light transmittance (2), in the method of measuring the light transmittance (1), a detector 7 is disposed so as to cover the transmitted light extraction hole 6 of the light transmittance measuring device 3, and from the film 4 to the detector 7. The measurement is performed in the same manner as the measurement method of the light transmittance (1) except that the distance is changed to about 130 mm.

〔Breaking strength〕
A film having a thickness of about 300 μm is held with both hands, and when the film surfaces are bent until they form a corner of 100 degrees, it is examined whether or not breakage occurs, and the breaking strength is evaluated based on the following evaluation criteria.
(Evaluation criteria)
○: No break ×: With break

〔Heat-resistant〕
The glass transition point (Tg) of the film having a thickness of about 1 mm obtained in each Example and Comparative Example 1 was measured using a dynamic viscoelasticity measuring apparatus [trade name: Rhegel-E4000-DVE, manufactured by UBM Co., Ltd.]. To measure.

  From the results shown in Table 2 and Table 3, the acrylic resin composition obtained in each example uses a modifier, so the temperature change of the light transmittance is small and the transparency is low. It turns out that it is excellent in. Furthermore, when the amount of the modifier per 100 parts by mass of the methacrylic acid ester polymer is about 10 parts by mass or more, it can be seen that the temperature change of the light transmittance of the acrylic resin composition is further reduced. . On the other hand, since the modifier based on the acrylic resin composition obtained in Comparative Example 1 is not used, it can be seen that the temperature change of the light transmittance is large.

  Moreover, from the results shown in Table 2, it can be seen that the acrylic resin compositions obtained in each Example are excellent in breaking strength because the modifier is used. On the other hand, since the modifier based on the acrylic resin composition obtained in Comparative Example 1 is not used, it can be seen that the acrylic resin composition is inferior in breaking strength.

  Furthermore, from the results shown in Table 2, the glass transition point of the methacrylic ester polymer used in each Example and Comparative Example 1 is 104 ° C., whereas the acrylic resin obtained in each Example The glass-based resin composition has a glass transition point lower than the glass transition point of the methacrylic ester polymer, but has a glass transition point of 50 ° C. or higher, and thus has heat resistance that can be satisfied in practice.

  From the above, the acrylic resin composition of the present invention is excellent in mechanical strength, has a small change in transparency temperature, and has good transparency. Therefore, the acrylic resin composition should be suitably used for applications requiring transparency. You can see that Moreover, since the acrylic resin composition of this invention has a small temperature change of transparency, even if it contains a coloring agent, it turns out that the color is hard to change with a temperature change.

  Therefore, the acrylic resin composition of the present invention is suitably used as a molding material used in applications requiring a large change in surface temperature such as automotive interior materials and motorcycle exterior materials and requiring transparency. You can see that you can.

  The acrylic resin composition of the present invention is suitably used as a molding material used in applications requiring a large change in surface temperature, such as automotive interior materials and motorcycle exterior materials, where transparency is required. Can do.

DESCRIPTION OF SYMBOLS 1 He-Ne laser irradiation apparatus 2 Incident light 3 Light transmittance measuring apparatus 4 Film 5 Transmitted light 6 Transmitted light extraction hole 7 Detector

Claims (7)

  (A) a methacrylic ester polymer, (B) a rubber component, and (C) at least one modifier selected from the group consisting of an aromatic dicarboxylic acid ester, an aliphatic dicarboxylic acid ester, and a phosphoric acid ester. An acrylic resin composition comprising the same.   2. The acrylic resin composition according to claim 1, wherein the methacrylic ester polymer is a polymer mainly composed of methacrylic ester.   The acrylic resin composition according to claim 1 or 2, wherein the amount of the rubber component per 100 parts by mass of the methacrylic ester polymer is 10 to 100 parts by mass.   The acrylic resin composition according to any one of claims 1 to 3, wherein the amount of the modifying agent per 100 parts by mass of the methacrylic acid ester polymer is 3 to 40 parts by mass.   Furthermore, the acrylic resin composition in any one of Claims 1-4 formed by containing a coloring agent.   The interior material for motor vehicles formed using the acrylic resin composition in any one of Claims 1-5 as a raw material.   The exterior material for motorcycles shape | molded using the acrylic resin composition in any one of Claims 1-5 as a raw material.