Methacrylic resin composition and molded article thereof

Abstract

The present invention provides a methacrylic resin composition and a molded article thereof that maintain high transparency or excellent color tone and weather resistance, while also possessing excellent solvent resistance and high fluidity. [Solution] A methacrylic resin composition comprising a methacrylic resin (A) with a weight-average molecular weight of 50,000 to 200,000, an acrylic rubber polymer (B), and a modifier (C), wherein the modifier (C) contains a fatty acid derivative (C-1) which mainly consists of an unsaturated fatty acid amide and one or more fatty acid amides and their derivatives, and a phosphorus compound (C-2).

Description

[Technical Field]

[0001] The present invention relates to a methacrylic resin composition and a molded article thereof. More specifically, the present invention relates to a methacrylic resin composition and a molded article thereof that exhibit excellent fluidity during heat molding and excellent solvent resistance. [Background technology]

[0002] Methacrylic resins, such as polymethyl methacrylate (PMMA), exhibit higher transparency and weather resistance than other transparent resins, and also have relatively good moldability. For these reasons, they have been used in a wide range of applications, including vehicle components, lighting fixtures, optical materials, and building materials. In recent years, their excellent transparency and weather resistance have led to increased use in building materials and other applications as decorative components.

[0003] In recent years, with the establishment of new insulation ratings for residential equipment, there has been a strong demand for the efficient use of energy from an environmental protection perspective. Therefore, there is a strong need for building materials using resins that offer superior insulation performance compared to metals, which have been conventionally used as molding materials. Furthermore, with increased awareness of infectious disease prevention, there has been a growing need to disinfect hands with alcohol-based disinfectants before touching molded objects, or to spray alcohol-based disinfectants on the molded objects themselves and wipe them down. This necessitates a very high level of resistance to alcohol and other chemicals. Additionally, from a weight reduction perspective, there is a demand for relatively thin resin components, requiring the resin material constituting the molded object to have high fluidity for easy molding. Moreover, there is a demand for multilayer molding with dissimilar resins, requiring fluidity that facilitates multilayer molding with dissimilar resin materials that have relatively low recommended molding temperatures. The development of methacrylic resin compositions that combine these properties at a high level while maintaining the excellent transparency and weather resistance of methacrylic resins is particularly strongly demanded in the field of building materials.

[0004] The (meth)acrylic resin composition described in Patent Document 1 contains acrylic rubber particles within a specific range, and by setting the complex viscosity (melt viscosity) in the low shear rate region within a specific range, it is possible to obtain a film that ensures long-term continuous productivity and improves toughness. However, there is no description regarding solvent resistance, and there is a risk of problems such as the molded article cracking when it comes into contact with various solvents.

[0005] Furthermore, the acrylic resin film described in Patent Document 2 contains a thermoplastic resin with a reduced viscosity within a specific range and two types of rubber-containing polymers with different average particle sizes, thereby enabling the production of an acrylic resin film with excellent film-forming properties and a laminate of an acrylic resin film and ABS resin with excellent ethanol resistance. On the other hand, in this patent, the laminate is obtained by injection molding ABS resin onto a film formed at a cylinder temperature of 200-240°C and a T-die temperature of 250°C. As a result, the molding process is laborious, and there is room for improvement in moldability when performing co-extrusion multilayer molding with different resins. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 7328989 [Patent Document 2] Japanese Patent Publication No. 2002-309059 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the present invention aims to solve the problems of the above-mentioned prior art and to provide a methacrylic resin composition and its molded article that, when not containing dyes and pigments, maintains high transparency and weather resistance while having excellent solvent resistance and high fluidity, and when containing dyes and pigments, maintains excellent color tone and weather resistance while having excellent solvent resistance and high fluidity. [Means for solving the problem]

[0008] As a result of diligent research to solve the above problems, the inventors of the present invention have found that by incorporating an acrylic rubber polymer and a specific modifier into a methacrylic resin, a methacrylic resin with excellent solvent resistance and fluidity can be obtained, thus completing the present invention.

[0009] In other words, the present invention is as follows. [1] It contains a methacrylic resin (A) with a weight-average molecular weight of 50,000 to 200,000, an acrylic rubber polymer (B), and a modifier (C). A methacrylic resin composition wherein the modifier (C) contains a fatty acid derivative (C-1) which mainly consists of an unsaturated fatty acid amide and one or more of its derivatives, and a phosphorus compound (C-2). [2] The modifier (C) has the following ranges for each term of the Hansen solubility parameter calculated based on the JKU HSP method: The molecular weight distribution Mw / Mn of the methacrylic resin (A) is 1.3 or more and 2.0 or less. [1] The methacrylic resin composition described above. δd: 16 or more and 21 or less δp: 1.8 or more and 3.0 or less δh: 3.0 or more and 6.0 or less [3] The methacrylic resin composition according to [1] or [2], wherein, with respect to 100 parts by mass of the total of the methacrylic resin (A) and the acrylic rubber polymer (B), the content of the methacrylic resin (A) is 40 to 70 parts by mass, and the content of the acrylic rubber polymer (B) is 30 to 60 parts by mass. [4] The content of the fatty acid derivative (C-1), which contains one or more fatty acid amides and derivatives of the aforementioned unsaturated fatty acid amide as the main component, is 0.5 parts by mass or more and 3 parts by mass or less. The content of phosphorus-based compounds (C-2) is 0.1 parts by mass or more and 1 part by mass or less. The methacrylic resin composition according to any one of [1] to [3], characterized by satisfying the following formulas (1) and (2). 1 part by mass ≤ (C-1) + (C-2) ≤ 3 parts by mass ··· (1) 0.04 ≤ (C-2) / (C-1) ≤ 1 ··· (2) [5] The methacrylic resin composition according to any one of [1] to [4], wherein the methacrylic resin (A) is composed of 85 to 99.9 parts by mass of a repeating unit derived from a methacrylic ester and 0.1 to 15 parts by mass of a repeating unit derived from an acrylic ester. [6] The acrylic rubber polymer (B) contains either or both of a large particle size rubber polymer (B-1) having an average particle size of 150 nm or more and 350 nm or less and a small particle size rubber polymer (B-2) having an average particle size of 80 nm or more and less than 150 nm, The methacrylic resin composition according to any one of [1] to [5], characterized in that the content of the large particle size rubber polymer (B-1) having an average particle size of 150 nm or more and 350 nm or less and the content of the small particle size rubber polymer (B-2) having an average particle size of 80 nm or more and less than 150 nm with respect to 100 parts by mass of the methacrylic resin composition satisfy the following formulas (3) and (4). 0 ≤ (B-2) / (B-1) ≤ 0.65 ··· (3) 30 (parts by mass) ≤ (B-1) + (B-2) ≤ 60 (parts by mass) ··· (4) [7] The methacrylic resin composition according to any one of [1] to [6], containing 0.01 part or more and 4 parts or less of an iron composite oxide with respect to 100 parts by mass of the methacrylic resin composition. [8] A molded article, characterized by including the methacrylic resin composition according to any one of [1] to [7].

Advantages of the Invention

[0010] According to the present invention, it is possible to provide a methacrylic resin composition and a molded article thereof that are excellent in solvent resistance and fluidity while maintaining the transparency and weather resistance that are characteristics of methacrylic resins. [Modes for carrying out the invention]

[0011] The following describes in detail embodiments for carrying out the present invention (hereinafter referred to as "this embodiment"), but the present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist.

[0012] In this specification, the monomer component before polymerization is referred to as "~monomer," and the term "monomer" may be omitted. Also, the constituent units of a polymer are referred to as "~monomer units" and / or "~structural units," and may simply be written as "~units."

[0013] <Methacrylic resin composition> The methacrylic resin composition of this embodiment contains a methacrylic resin (A) with a weight-average molecular weight of 50,000 to 200,000 (hereinafter sometimes simply referred to as "component (A)"), an acrylic rubber polymer (B) (hereinafter sometimes simply referred to as "acrylic rubber (B)" or "component (B)"), and a modifier (C) (hereinafter sometimes simply referred to as "component (C)"), wherein the modifier (C) contains a fatty acid derivative (C-1) which contains one or more fatty acid amides and their derivatives, with unsaturated fatty acid amides as the main component, and a phosphorus compound (C-2). The components constituting the methacrylic resin composition of this embodiment will be described below.

[0014] <Methacrylic resin (A)> The methacrylic resin (A) contained in the methacrylic resin composition of this embodiment is preferably a polymer containing methacrylic acid ester monomer units, more preferably containing methacrylic acid ester monomer units and other vinyl monomer units copolymerizable to the methacrylic acid ester monomers, and even more preferably containing 80 to 99.9 parts by mass of methacrylic acid ester monomer units and 0.1 to 20 parts by mass of other vinyl monomer units copolymerizable to the methacrylic acid ester monomers. That is, the methacrylic resin (A) is preferably a copolymer of monomer components containing 80 to 99.9 parts by mass of methacrylic acid ester monomers and 0.1 to 20 parts by mass of other vinyl monomers copolymerizable to the methacrylic acid ester monomers. The methacrylic resin (A) may be a single methacrylic resin or a combination of two or more methacrylic resins.

[0015] When two or more methacrylic resins are used in combination, and the content and composition of each methacrylic resin are known, the content of methacrylic acid ester monomer units can be calculated by the following method.

[0016] Multiply the number of methacrylic acid ester monomer units contained in each methacrylic resin by the proportion of that resin, with methacrylic resin (A) set to 1. Calculate the above for all methacrylic resins and accumulate the results to determine the methacrylic acid ester monomer content in methacrylic resin (A). Calculate the number of vinyl monomer units contained in methacrylic resin (A) in the same manner.

[0017] When two or more methacrylic resins are used in combination, and the content and composition of each methacrylic resin are unknown, the following method can be used to calculate the amount.

[0018] The methacrylic resin composition is analyzed using the method described in <Analysis of Structural Units of Methacrylic Resin (A)>, and the content of the obtained methacrylic ester monomer units is defined as the content of methacrylic ester monomer units in methacrylic resin (A).

[0019] <Methacrylic acid ester monomer> The methacrylic acid ester monomers constituting the methacrylic acid ester monomer units contained in the methacrylic resin (A) are not limited to the following, but examples include butyl methacrylate, ethyl methacrylate, methyl methacrylate, propyl methacrylate, isopropyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, 2-ethylhexyl methacrylate, t-butylcyclohexyl methacrylate, benzyl methacrylate, and 2,2,2-trifluoroethyl methacrylate. From the viewpoint of availability and price, methyl methacrylate and ethyl methacrylate are preferred. The methacrylic acid ester monomers may be used individually or in combination of two or more.

[0020] The content of methacrylic acid ester monomer units is preferably 80 parts by mass or more, more preferably 82 parts by mass or more, even more preferably 84 parts by mass or more, particularly preferably 86 parts by mass or more, preferably 99.9 parts by mass or less, more preferably 99.8 parts by mass or less, even more preferably 99.5 parts by mass or less, and particularly preferably 95 parts by mass or less, relative to the methacrylic resin (A). By having a methacrylic acid ester monomer unit content of 99.9 parts by mass or less, decomposition of the resin during molding can be prevented, and the generation of volatile components such as methacrylic acid ester monomers and molding defects called silver can be effectively prevented. Furthermore, by having 80 parts by mass or more of methacrylic acid ester monomer units, the heat resistance generally required for molded products can be ensured. Having sufficient heat resistance ensures rigidity and the strength generally required for molded products can be ensured.

[0021] <Other vinyl monomers copolymerizable with methacrylate monomers> Other vinyl monomers copolymerizable with methacrylic acid ester monomers in methacrylic resin (A) include, but are not limited to, acrylic acid ester monomers having one acrylate group, such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, and 2-ethylhexyl acrylate. Other examples of acrylic acid ester monomers include those having two or more (meth)acrylate groups, such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate, in which the hydroxyl groups at both ends of ethylene glycol or its oligomers are esterified with acrylic acid or methacrylic acid; those having two alcohol hydroxyl groups, such as neopentyl glycol di(meth)acrylate and di(meth)acrylate, in which the hydroxyl groups of two alcohols are esterified with acrylic acid or methacrylic acid; and those having polyhydric alcohol derivatives, such as trimethylolpropane and pentaerythritol, esterified with acrylic acid or methacrylic acid.

[0022] In particular, methyl acrylate, ethyl acrylate, and n-butyl acrylate are preferred, and methyl acrylate and ethyl acrylate are even more preferred due to their availability. These can be used individually or in combination of two or more types.

[0023] The content of vinyl monomer units, which consist of vinyl monomers copolymerizable with methacrylic acid ester monomers, is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 18 parts by mass, even more preferably 0.5 to 16 parts by mass, and particularly preferably 5 parts by mass or more and 14 parts by mass or less, relative to the methacrylic resin (A). A content of 0.1 parts by mass or more prevents decomposition of the resin during molding, effectively preventing the generation of volatile components such as methacrylic acid ester monomers and molding defects known as silver. Furthermore, a vinyl monomer content of 20 parts by mass or less ensures the heat resistance generally required for molded products. Furthermore, regarding the content of vinyl monomer units, it is preferable to use an amount greater than 0 parts by mass and less than or equal to 0.4 parts by mass per 100 parts by mass of methacrylic resin (A), particularly when using monomers having two (meth)acrylate groups, when using monomers having three (meth)acrylate groups, it is preferable to use an amount greater than 0 parts by mass and less than or equal to 0.25 parts by mass, and when using monomers having four or more (meth)acrylate groups, it is preferable to use an amount greater than 0 parts by mass and less than or equal to 0.15 parts by mass, from the viewpoint of ensuring fluidity during melt molding and maintaining transparency.

[0024] Furthermore, other vinyl monomers besides acrylic acid monomers that can copolymerize with the methacrylic acid monomer include, but are not limited to, α,β-unsaturated acids such as acrylic acid and methacrylic acid; divalent carboxylic acids containing unsaturated groups such as maleic acid, fumaric acid, itaconic acid, and cinnamic acid, and their alkyl esters; styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, o-ethylstyrene, p-tert-butylstyrene, isopropenylbencene (α-methylstyrene); and 1-vinylnaphthalene. Examples include aromatic vinyl compounds such as 2-vinylnaphthalene, 1,1-diphenylethylene, isopropenyltoluene, isopropenylethylbenzene, isopropenylpropylbenzene, isopropenylbutylbenzene, isopropenylpentylbenzene, isopropenylhexylbenzene, and isopropenyloctylbenzene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride; maleimides and N-substituted maleimides such as N-methylmaleimide, N-ethylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide; amides such as acrylamide and methacrylamide; and polyfunctional monomers such as divinylbenzene.

[0025] In addition, for the methacrylic resin (A), vinyl monomers other than the vinyl monomers exemplified above may be appropriately added and copolymerized to improve properties such as heat resistance and moldability. Acrylic acid ester monomers copolymerizable with the above methacrylic acid ester monomer, or vinyl monomers other than the acrylic acid ester monomers exemplified above, may be used individually or in combination of two or more. The above methacrylic resin (A) refers to a resin with a degree of crosslinking (%) of 0.5 or less. The degree of crosslinking is the value measured by adding 29 g of N,N-dimethylformamide and 1 g of the sample to a glass container, shaking for 24 hours to obtain a swollen liquid, removing the supernatant liquid by centrifugation, evaporating the gel to dryness in a vacuum dryer at 130°C, and measuring the weight of the remaining material, using the same method as ASTM D6725.

[0026] <Weight-average molecular weight of methacrylic resin (A)> The weight-average molecular weight (Mw) of the methacrylic resin (A) contained in the methacrylic resin composition of this embodiment will be described. The weight-average molecular weight (Mw) of the methacrylic resin (A), as measured by GPC (gel permeation chromatography), is 50,000 to 200,000, from the viewpoint of combining good solvent resistance and fluidity. By having the weight-average molecular weight (Mw) of the methacrylic resin (A) in the range of 50,000 to 200,000, a balance can be achieved between fluidity, mechanical strength, and solvent resistance, and good moldability is maintained.

[0027] In this case, from the viewpoint of obtaining excellent solvent resistance, the lower limit of the weight-average molecular weight (Mw) of the methacrylic resin (A) is preferably 56,000 or more, more preferably 61,000 or more, and particularly preferably 62,000 or more. On the other hand, from the viewpoint of ensuring good fluidity, the upper limit of the weight-average molecular weight (Mw) of the methacrylic resin (A) is preferably 160,000 or less, more preferably 120,000 or less, even more preferably 96,000 or less, and particularly preferably 80,000 or less. Even when two or more types of methacrylic resins are used in combination, the molecular weight measured by GPC (gel permeation chromatography) is considered to be the weight-average molecular weight (Mw) of the methacrylic resin (A) contained in the methacrylic resin composition.

[0028] Furthermore, the molecular weight distribution (Mw / Mn) of the methacrylic resin (A) contained in the methacrylic resin composition of this embodiment is preferably 1.0 to 6.0, more preferably 1.0 to 5.0, even more preferably 1.0 to 4.0, even more preferably 1.0 to 2.5, and particularly preferably 1.5 to 1.7. A molecular weight distribution (Mw / Mn) of the methacrylic resin (A) of 1.0 to 6.0 ensures stable physical properties. Here, Mw represents the weight-average molecular weight, and Mn represents the number-average molecular weight. The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the methacrylic resin (A) can be measured by GPC, specifically by the method described in the [Examples] section below. Specifically, a calibration curve is created using a standard methacrylic resin with a known monodisperse weight-average molecular weight that is readily available as a reagent, and an analytical gel column that elutes high molecular weight components first, based on the elution time and weight-average molecular weight. Subsequently, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the methacrylic resin (A) to be measured can be determined from the obtained calibration curve, and the molecular weight distribution (Mw / Mn) can be calculated from these values. The number-average molecular weight (Mn) is the average molecular weight per single molecule and is defined as the total weight of the system divided by the number of molecules in the system. The weight-average molecular weight (Mw) is defined as the average molecular weight by weight fraction. In this invention, the molecular weight used is the molecular weight converted to PMMA.

[0029] <Content of methacrylic resin (A)> The content of methacrylic resin (A) is preferably 40 parts by mass or more, more preferably 42 parts by mass or more, particularly preferably 47 parts by mass or more, preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and particularly preferably 60 parts by mass or less, from the viewpoint of maintaining excellent transparency and weather resistance and exhibiting excellent solvent resistance and fluidity, per 100 parts by mass of the methacrylic resin composition.

[0030] <Methacrylic resin (A) manufacturing method> The methacrylic resin (A) contained in the methacrylic resin composition of this embodiment can be produced by solution polymerization, bulk polymerization, cast polymerization, or suspension polymerization, but is not limited to these methods. Preferably, bulk polymerization, solution polymerization, or suspension polymerization is used, and from the viewpoint of productivity, solution polymerization or suspension polymerization is more preferable.

[0031] The polymerization temperature should be appropriately selected according to the polymerization method, but it is preferably 50°C to 180°C, and more preferably 60°C to 160°C.

[0032] When manufacturing methacrylic resin (A), polymerization initiators may be used. Polymerization initiators are not limited to the following, but when radical polymerization is performed, for example, di-t-butyl peroxide, lauroyl peroxide, stearyl peroxide, benzoyl peroxide, t-butyl peroxyneodecanate, t-butyl peroxypivalate, dilauroyl peroxide, dicumyl peroxide, t-butyl peroxy-2-ethylhexanoate, 1,1-bis(t-butylperoxy)-3,3,5-trimethyl peroxide. Examples of common azo radical polymerization initiators include organic peroxides such as tylcyclohexane and 1,1-bis(t-butylperoxy)cyclohexane, and azobisisobutyronitrile, azobisisovaleronitrile, 1,1-azobis(1-cyclohexanecarbonitride), 2,2'-azobis-4-methoxy-2,4-azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, and 2,2'-azobis-2-methylbutyronitrile. These may be used individually or in combination of two or more. These radical polymerization initiators may also be used in combination with a suitable reducing agent as redox initiators. These radical polymerization initiators and / or redox initiators are generally used in an amount of 0 to 1 part by mass per 100 parts by mass of the total amount of monomers used in the polymerization of the methacrylic resin (A), and can be appropriately selected considering the polymerization temperature and the half-life of the polymerization initiator.

[0033] When selecting a polymerization method for methacrylic resin (A) such as bulk polymerization, cast polymerization, or suspension polymerization, it is preferable to use a peroxide-based polymerization initiator to prevent discoloration of the methacrylic resin (A). The peroxide-based polymerization initiator is not limited to the following, but examples include lauroyl peroxide, decanoyl peroxide, and t-butyl peroxy-2-ethylhexanoate, with lauroyl peroxide being more preferred.

[0034] Furthermore, when polymerizing a methacrylic resin (A) by solution polymerization at a high temperature of 90°C or higher, it is preferable to use a peroxide, azobis initiator, etc., as a polymerization initiator, which has a 10-hour half-life temperature of 80°C or higher and is soluble in the organic solvent used. The peroxide, azobis initiator, etc., are not limited to the following, but examples include 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, cyclohexane peroxide, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 1,1-azobis(1-cyclohexanecarbonilate), 2-(carbamoylazo)isobutyronitrile, etc.

[0035] When producing the methacrylic resin (A), the molecular weight of the methacrylic resin (A) may be controlled to the extent that it does not impair the objectives of the present invention. Methods for controlling the molecular weight of the methacrylic resin (A) are not limited to the following, but include, for example, using chain transfer agents such as alkyl mercaptans, dimethylacetamide, dimethylformamide, and triethylamine, or inifators such as dithiocarbamates, triphenylmethylazobenzene, and tetraphenylethane derivatives to control the molecular weight. It is also possible to adjust the molecular weight by adjusting the content of these substances. From the viewpoint of handling and stability, alkyl mercaptans are preferred as the chain transfer agent, and while the alkyl mercaptans are not limited to the following, examples include n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, 2-ethylhexyl thioglycolate, ethylene glycol dithioglycolate, trimethylolpropanetris (thioglycolate), pentaerythritol tetrakis (thioglycolate), and the like.

[0036] These can be added as appropriate depending on the molecular weight of the target methacrylic resin, but generally, they are used in the range of 0.001 parts by mass to 5 parts by mass per 100 parts by mass of the total amount of monomers used during polymerization of the methacrylic resin. Other methods for controlling molecular weight include changing the polymerization method, adjusting the amount of polymerization initiator, the chain transfer agent and initiator mentioned above, and changing various polymerization conditions such as polymerization temperature. These molecular weight control methods may be used individually or in combination of two or more methods.

[0037] <Acrylic rubber polymer (B)> The methacrylic resin composition of this embodiment must contain an acrylic rubber polymer (B). By using an acrylic rubber polymer having a refractive index close to that of the methacrylic resin, high transparency can be maintained. In this case, it is preferable to use acrylic rubber copolymer particles having a multilayer structure, such as those shown as "(meth)acrylic crosslinked rubber particles" in Japanese Patent No. 7328989, as the acrylic rubber polymer (B).

[0038] Examples of materials contained in the acrylic rubber polymer (B) include rubber polymers or crosslinked polymers thereof containing structural units derived from alkyl acrylates (alkyl acrylate units), and rubber polymers containing structural units derived from methacrylic acid esters (methacrylic acid units) and other copolymerizable structural units other than alkyl acrylate units.

[0039] The acrylic rubber polymer (B) is preferably in particulate form. When the acrylic rubber polymer (B) is in particulate form, its structure can be a single polymer particle or a multilayer particle composed of different types of polymers. Examples of multilayer particles include two-layer particles, three-layer particles, four-layer particles, and five or more-layer particles. The multilayer structure may be formed from a core-shell type graft copolymer. Examples of two-layer particles include two-layer polymer particles where the core (inner layer) is a cross-linked rubber polymer (I) and the outer shell (outermost layer) is a thermoplastic polymer (II). Examples of three-layer particles include three-layer polymer particles where the core (inner layer) is a polymer (III), the inner shell (inner layer) is a cross-linked rubber polymer (I), and the outer shell (outermost layer) is a thermoplastic polymer (II). Examples of four-layer structured particles include four-layer polymer particles in which the core (inner layer) is a cross-linked rubber polymer (I), the first inner shell (inner layer) is a polymer (III), the second inner shell (inner layer) is a cross-linked rubber polymer (I), and the outer shell (outermost layer) is a thermoplastic polymer (II).

[0040] The crosslinked rubber polymer (I) preferably contains 70 to 98% by mass of structural units derived from alkyl acrylate esters having 1 to 8 carbon atoms in the alkyl group, more preferably 75 to 90% by mass, and even more preferably 80 to 85% by mass, relative to the mass of the crosslinked rubber polymer (I). This content allows for a flexible rubber material with impact resistance. Furthermore, the crosslinked rubber polymer (I) preferably contains 2 to 30% by mass of structural units derived from aromatic vinyl monomers, more preferably 10 to 25% by mass, and even more preferably 15 to 20% by mass, relative to the mass of the crosslinked rubber polymer (I). This content allows for adjustment of the refractive index of the crosslinked rubber polymer (I) to match that of the (meth)acrylic resin (A), resulting in a highly transparent (meth)acrylic resin composition. Furthermore, the crosslinked rubber polymer (I) preferably contains 1 to 5% by mass of structural units derived from crosslinkable monomers, and more preferably 1 to 3% by mass, relative to the mass of the crosslinked rubber polymer (I). This content results in an appropriate crosslinking density, leading to good behavior as a rubber material.

[0041] The thermoplastic polymer (II) preferably contains 80 to 100% by mass of methyl methacrylate units, more preferably 85 to 97% by mass, and even more preferably 90 to 96% by mass, based on the mass of the thermoplastic polymer (II). The above content improves compatibility with the (meth)acrylic resin (A). Furthermore, the thermoplastic polymer (II) preferably contains 0 to 20% by mass of structural units derived from alkyl acrylate esters having 1 to 8 carbon atoms in the alkyl group, more preferably 3 to 15% by mass, and even more preferably 4 to 10% by mass, relative to the mass of the thermoplastic polymer (II). The above content levels improve compatibility with the (meth)acrylic resin (A).

[0042] Polymer (III) preferably contains 80 to 99.95% by mass of methyl methacrylate units, more preferably 85 to 98% by mass, and even more preferably 90 to 96% by mass, based on the mass of polymer (III). The above content levels result in good hardness, which is preferable. Polymer (III) preferably contains 0 to 19.95% by mass of structural units derived from alkyl acrylate esters having 1 to 8 carbon atoms in the alkyl group, and 0.05 to 2% by mass of crosslinkable monomers, relative to the mass of polymer (III); more preferably contains 2 to 15% by mass of structural units derived from alkyl acrylate esters having 1 to 8 carbon atoms in the alkyl group, and 0.05 to 1.5% by mass of structural units derived from crosslinkable monomers; and even more preferably contains 4 to 10% by mass of structural units derived from alkyl acrylate monomers having 1 to 8 carbon atoms in the alkyl group, and 0.1 to 1% by mass of structural units derived from crosslinkable monomers. The above content levels result in good hardness.

[0043] Specific examples of acrylic rubber polymers (B) include IR-441 (an acrylic rubber polymer manufactured by Mitsubishi Chemical Corporation with a multilayer structure and an average particle size of 200 nm), M-230 (an acrylic rubber polymer manufactured by Kaneka Corporation with a multilayer structure and an average particle size of 100 nm), M-210 (an acrylic rubber polymer manufactured by Kaneka Corporation with a multilayer structure and an average particle size of 200 nm), Clarity LA3320 (an acrylic block copolymer manufactured by Kuraray), and combinations thereof.

[0044] Furthermore, in order to exhibit a good solvent resistance improvement effect, the content of the acrylic rubber polymer (B) is preferably 20 parts by mass or more, more preferably 31 parts by mass or more, and particularly preferably 36 parts by mass or more, per 100 parts by mass of the methacrylic resin composition. On the other hand, from the viewpoint of ensuring good fluidity during melt molding, the content of the acrylic rubber polymer (B) is preferably 60 parts by mass or less, more preferably 56 parts by mass or less, and even more preferably 53 parts by mass or less, per 100 parts by mass of the methacrylic resin composition. Furthermore, if the acrylic rubber polymer (B) is in particulate form, the average particle size of the acrylic rubber polymer (B) is preferably 30 nm or more, more preferably 50 nm or more, even more preferably 80 nm or more, particularly preferably 100 nm or more, preferably 3000 nm or less, more preferably 1700 nm or less, even more preferably 1400 nm or less, and particularly preferably 400 nm or less, from the viewpoint of imparting impact strength and surface smoothness.

[0045] When the average particle size of the acrylic rubber polymer is 30 nm or larger, good weather resistance and sufficient impact strength tend to be obtained, and when it is 3000 nm or smaller, good transparency and good color tone can be ensured when heat-molded and colored using dyes and pigments.

[0046] The acrylic rubber polymer (B) preferably contains either or both of a large-particle rubber polymer (B-1) with an average particle size of 150 nm or more and 350 nm or less, and a small-particle rubber polymer (B-2) with an average particle size of 80 nm or more and less than 150 nm, and more preferably consists of either or both of the large-particle rubber polymer (B-1) and the small-particle rubber polymer (B-2). In this case, it is preferable that the content of the large-particle rubber polymer (B-1) with an average particle size of 150 nm or more and 350 nm or less, and the content of the small-particle rubber polymer (B-2) with an average particle size of 80 nm or more and less than 150 nm, satisfy the following formulas (3) and (4). 0≦(B-2) / (B-1)≦0.65 (3) 30≦(B-1)+(B-2)≦60...(4)

[0047] In this case, from the viewpoint of improving solvent resistance, the lower limit of formula (4) is more preferably 31 ≤ (B-1) + (B-2), and even more preferably 36 ≤ (B-1) + (B-2).

[0048] On the other hand, from the viewpoint of ensuring the weather resistance and fluidity of the molded article, the upper limit of equation (3) is more preferably (B-2) / (B-1) ≤ 0.50, and even more preferably (B-2) / (B-1) ≤ 0.35.

[0049] Furthermore, as an upper limit for equation (4), (B-1)+(B-2)≦60 is more preferable, (B-1)+(B-2)≦58 is even more preferable, and (B-1)+(B-2)≦53 is particularly preferable.

[0050] The average particle size of the acrylic rubber polymer (B) can be measured using conventionally known methods, such as the following:

[0051] Sections of a methacrylic resin composition at any multiple points (e.g., 5 points) are obtained using a microtome, and then ultrathin sectioning samples for observation are prepared using a dye (e.g., RuO4 (ruthenic acid)) staining method. The stained cross-sections of the acrylic rubber polymer are then imaged using a transmission electron microscope.

[0052] The particle sizes of all acrylic rubber polymers contained in images of section samples at any multiple points are measured, and the average of these particle sizes is taken as the average particle size of acrylic rubber polymer (B). If acrylic rubber polymer (B) contains either or both of large-particle rubber polymers (B-1) with an average particle size of 150 nm to 350 nm and small-particle rubber polymers (B-2) with an average particle size of 80 nm to less than 150 nm, the content of large-particle rubber polymers (B-1) and small-particle rubber polymers (B-2) can be determined, for example, as follows: The average particle size of acrylic rubber polymers with a particle size of 150 nm to 350 nm is taken as the average particle size (r1) of large-particle rubber polymers (B-1), and the average particle size of acrylic rubber polymers with a particle size of 80 nm to less than 150 nm is taken as the average particle size (r2) of small-particle rubber polymers (B-2). In this case, if multiple rubber particles exist in an aggregated form, one particle of the aggregate is treated as such, and the longest side is taken as the particle size of that particle. Furthermore, when observed at a magnification of 100,000 times, the total number of large-grained rubber polymer particles and small-grained rubber polymer particles was at least 100. Within an arbitrary range, the number of large-grained rubber polymer particles was denoted as n1, and the number of small-grained rubber polymer particles as n2. The content of large-grained rubber polymer (B-1) and small-grained rubber polymer (B-2) was derived using the following formulas with the particle size and number of particles measured by the above method. (B-1) content = 4 / 3 × π × (r1 / 2) 3 ×n1×[(B-1) mass per unit volume] (B-2) content = 4 / 3 × π × (r² / 2) 3 ×n²×[(B-2) mass per unit volume] Equation (3) was derived using the particle size and number of particles measured by the above method, as shown below. (B-2) / (B-1)=(r2) 3 ×n² × [(B-1) mass per unit volume] / (r1) 3 ×n1×[(B-2) mass per unit volume]

[0053] <Modifier (C)> The methacrylic resin composition of this embodiment must contain a modifier (C). The modifier (C) contains a fatty acid derivative (C-1) and a phosphorus compound (C-2).

[0054] Examples of fatty acid derivatives (C-1) include one or more fatty acid amides and their derivatives, which mainly consist of unsaturated fatty acid amides (hereinafter, these are collectively referred to as "fatty acid amide compounds").

[0055] Examples of unsaturated fatty acid amides include, but are not limited to, monounsaturated fatty acids such as myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, and nervonic acid; diunsaturated fatty acids such as linoleic acid, eicosadienoic acid, and docosadienoic acid; omega-3 fatty acids such as alpha-linolenic acid, stearidonic acid, eicosatetraenoic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid; omega-6 fatty acids such as linoleic acid, gamma-linolenic acid, dihomo-gamma-linolenic acid, arachidonic acid, docosatetraenoic acid, and docosapentaenoic acid; palmitoleic acid, Examples include unsaturated fatty acid amide compounds (monounsaturated fatty acid amide compounds) formed by amide bonding of ω-7 fatty acids such as vaccenic acid and pauric acid, ω-9 fatty acids such as oleic acid, elaidic acid, erucic acid, and nervonic acid, and ω-10 fatty acids such as sapienic acid with monoamine compounds such as ammonia, methylamine, ethylamine, propylamine, methylolamine, etylolamine, dimethylamine, and methylethylamine; and bisounsaturated fatty acid amide compounds formed by amide bonding of two molecules of the above fatty acids with diamine compounds such as methylenediamine, ethylenediamine, propanediamine, putrescine, cadaverine, and hexamethylenediamine.

[0056] Derivatives of unsaturated fatty acid amides are compounds in which a hydrogen atom, or part or all of the side chain of a chain-like hydrocarbon compound, is replaced with another organic group. Examples of organic groups include polyether groups, polyalkyl groups, aralkyl groups, and polyester groups, which may be used individually or in combination of two or more. Furthermore, derivatives of unsaturated fatty acid amides can be appropriately selected and used from a variety of compounds, such as monoamides and bisamides, depending on the situation.

[0057] These fatty acid derivatives (C-1) may be used individually or in combination of two or more.

[0058] The lower limit of the melting point of the fatty acid derivative (C-1) is not particularly limited, but from the viewpoint of facilitating handling during melt mixing and melt molding, and effectively preventing defects that lead to compositional unevenness such as slipping, it is preferably 50°C or higher, more preferably 60°C or higher, even more preferably 65°C or higher, and particularly preferably 70°C or higher. The melting point of the fatty acid derivative (C-1) moves to the vicinity of the surface in an appropriate proportion during melt mixing, and in order to have good solvent resistance, it is preferably 130°C or lower, more preferably 105°C or lower, and even more preferably 95°C or lower.

[0059] The upper limit of the 10% weight loss temperature of the fatty acid derivative (C-1) is not particularly limited, but from the viewpoint of obtaining better solvent resistance and scratch resistance of the resulting molded product, 350°C or lower is preferred. The reason for this is not entirely clear, but it is presumed that the fatty acid derivative (C-1) contained in the methacrylic resin composition volatilizes in the mold during injection molding, and the lower the 10% weight loss temperature, the easier it is for the fatty acid derivative (C-1) contained in the methacrylic resin composition to diffuse and move within the molded body during melt molding. As a result, the fatty acid derivative (C-1) is present in a high proportion on and near the surface of the final molded product. The 10% weight loss temperature of the fatty acid derivative (C-1) is more preferably 300°C or lower, and even more preferably 260°C or lower. On the other hand, the lower limit of the 10% weight loss temperature of the fatty acid derivative (C-1) is not particularly limited, but from the viewpoint of obtaining better scratch resistance of the resulting molded product, 140°C or higher is preferred. Although the reason is not entirely clear, it is presumed that if the 10% weight loss temperature is 140°C or higher, the fatty acid derivative (C-1) does not undergo excessive thermal decomposition during melt molding, allowing the effect of the fatty acid derivative (C-1) to be fully expressed. The 10% weight loss temperature of the fatty acid compound (C) is more preferably 160°C or higher, and even more preferably 180°C or higher. The upper and lower limits of the 10% weight loss temperature of the fatty acid derivative (C-1) can be arbitrarily combined.

[0060] As the fatty acid amide compound, for example, a compound represented by the following general formula (i) (hereinafter also referred to as "compound (i)") can be used. Compound (i) is preferred from the viewpoint that even with a small amount added, the resulting molded product has excellent scratch resistance and does not impair the inherent performance of the thermoplastic resin. R-CONH2(i) (In general formula (i), R is a hydrocarbon group having 10 to 25 carbon atoms, which may have substituents.)

[0061] The lower limit of the number of carbon atoms in R in formula (i) of the fatty acid amide compound is preferably 10 or more, more preferably 15 or more, and even more preferably 17 or more, from the viewpoint of excellent compatibility with methacrylic resins and excellent scratch resistance of the resulting molded article. The upper limit of the number of carbon atoms in R in formula (i) of the fatty acid amide compound is preferably 25 or less, more preferably 24 or less, and even more preferably 23 or less, from the viewpoint of good dispersibility of the fatty acid compound (C) in the methacrylic resin composition and good maintenance of scratch resistance of the resulting molded article. The above preferred upper and lower limits can be arbitrarily combined. Fatty acid amide compounds may be used individually or in combination of two or more.

[0062] Examples of unsaturated fatty acid amides include erucic acid amide, oleic acid amide, brassic acid amide, and elaidic acid amide. These unsaturated fatty acid amide compounds may be used individually or in combination of two or more. Among these unsaturated fatty acid amide compounds, erucic acid amide and oleic acid amide are more preferred because the resulting molded articles exhibit excellent solvent resistance and scratch resistance.

[0063] Examples of bisunsaturated fatty acid amide compounds include bis-fatty acid amides such as methylenebisoleamide and ethylenebisoleamide, and oleyl palmitamide. These bisunsaturated fatty acid amide compounds may be used individually or in combination of two or more.

[0064] The unsaturated fatty acid amide more preferably contains either oleic acid amide or erucic acid amide as a main component, where "contained as a main component" means that the mass is 65 parts by mass or more per 100 parts by mass of the total mass of the fatty acid amide compound. The content of the unsaturated fatty acid amide is preferably 50 parts by mass or more, more preferably 55 parts by mass or more, even more preferably 60 parts by mass or more, even more preferably 65 parts by mass or more, and particularly preferably 70 parts by mass or more, relative to the total amount of the fatty acid derivative (C-1). In order to improve the mechanical properties and scratch resistance of the methacrylic resin composition, the unsaturated fatty acid amide content is preferably 99.8 parts by mass or less, more preferably 99.5 parts by mass or less, even more preferably 95 parts by mass or less, and particularly preferably 91 parts by mass or less.

[0065] Furthermore, in order to exhibit a good solvent resistance improvement effect, the content of the fatty acid derivative (C-1) is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 0.8 parts by mass or more, and particularly preferably 1.2 parts by mass or more, per 100 parts by mass of the methacrylic resin composition. On the other hand, in order to effectively prevent bleed-out during molding and long-term use, it is preferably 5 parts by mass or less, more preferably 3.5 parts by mass or less, even more preferably 2.2 parts by mass or less, and particularly preferably 1.8 parts by mass or less.

[0066] These may be used individually or in combination of two or more.

[0067] The modifier to be used is preferably one with a decomposition temperature of 200°C to 400°C. The decomposition initiation temperature can be determined by the 1% weight loss temperature when the temperature is increased by 20°C / min using a thermogravimetric balance.

[0068] Furthermore, while not limited to the following, examples of phosphorus compounds (C-2) include CAS No. 31570-04-4, 3806-34-6, 26741-53-7, 119345-01-6, 203255-81-6, 145650-60-8, 52664-24-1, 80693-00-1, 126050-54-2, 80410-33-9, and 154862-43-8. In this embodiment, it is preferable to use a phosphorus compound (C-2) that has two or more aromatic rings. Specific product names of such phosphorus compounds (C-2) are not limited to the following, but examples include Adeka Stab 2112 and Adeka Stab HP-10 from Adeka, Sumitomo Chemical's Sumirizer GP, and BASF's Irgaphos 168 and Irgaphos 126. By using such a phosphorus-based compound (C-2), the solvent resistance of the methacrylic resin composition can be improved.

[0069] The melting point (Tm) of the phosphoric acid-based antioxidant is preferably 50°C or higher, more preferably 93°C or higher, even more preferably 96°C or higher, and even more preferably 100°C or higher, from the viewpoint of achieving good dispersibility. Furthermore, in order to disperse well in the molded article and act effectively, the melting point is preferably 200°C or lower, more preferably 185°C or lower, even more preferably 150°C or lower, and particularly preferably 135°C or lower.

[0070] <Content of phosphorus compounds (C-2)> The content of the phosphorus compound (C-2) is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.18 parts by mass or more, and particularly preferably 0.4 parts by mass or more, per 100 parts by mass of the methacrylic resin, in order to improve the solvent resistance of the methacrylic resin composition. Furthermore, in order to prevent contamination of molds and metal rolls due to bleed-out and to prevent the formation of precipitates called "eye resin" during extrusion molding, the content of the phosphorus compound is preferably 3.5 parts by mass or less, more preferably 2 parts by mass or less, even more preferably 1.8 parts by mass or less, and particularly preferably 1.2 parts by mass or less, per 100 parts by mass of the methacrylic resin. Furthermore, it is preferable that the content of (C-1) and (C-2) above satisfies the following formula. 1 part by mass ≦(C-1)+(C-2)≦3 parts by mass...(1) 0.04≦(C-2) / (C-1)≦1···(2) In this case, from the viewpoint of solvent resistance, the lower limit of equation (1) is preferably 1.04 parts by mass ≤ (C-1) + (C-2), and more preferably 1.08 parts by mass ≤ (C-1) + (C-2). On the other hand, from the viewpoint of preventing contamination of the mold and metal rolls during molding, the upper limit of equation (1) is more preferably (C-1) + (C-2) ≤ 2.6 parts by mass, even more preferably (C-1) + (C-2) ≤ 2.3 parts by mass, and particularly preferably (C-1) + (C-2) ≤ 2.1 parts by mass. Furthermore, from the viewpoint of balancing solvent resistance, fluidity, and moldability, the lower limit of equation (2) is preferably 0.06 ≤ (C-2) / (C-1), more preferably 0.08 ≤ (C-2) / (C-1), even more preferably 0.09 ≤ (C-2) / (C-1), and particularly preferably 0.2 ≤ (C-2) / (C-1). (2) The upper limit of equation (C-2) is preferably (C-2) / (C-1) ≤ 0.8, and more preferably (C-2) / (C-1) ≤ 0.7.

[0071] The modifier (C) may contain components other than those described above (C-1) and (C-2). The modifier (C) is preferably an organic compound in order to ensure good dispersion in the methacrylic resin composition. The modifier (C) ((C-1), (C-2)) is preferably such that the Hansen solubility parameters using the so-called JKU-HSP method described in the Hansen solubility index estimation method of Japanese Patent Application Publication No. 2018-173336 satisfy the following: δd: 16 to 21, δp: 1.8 to 3.0, and δh: 3.0 to 6.0. Satisfying the above range of Hansen solubility parameters can improve the solvent resistance exhibited when the resin composition of the present invention is molded.

[0072] In this case, in order to achieve both fluidity and solvent resistance, the fatty acid derivative (C-1) preferably satisfies δd: 16.1 or higher, more preferably 16.2 or higher, particularly preferably 16.3 or higher, preferably 19.0 or lower, more preferably 17.0 or lower, particularly preferably 16.5 or lower; δp preferably satisfies 1.88 or higher, more preferably 2.30 or higher, particularly preferably 2.40 or higher, preferably 2.90 or lower, more preferably 2.85 or lower, particularly preferably 2.82 or lower; δh preferably satisfies 3.80 or higher, more preferably 4.70 or higher, particularly preferably 5.20 or higher, preferably 5.90 or lower, more preferably 5.86 or lower, and particularly preferably 5.82 or lower. To improve solvent resistance, the phosphorus compound (C-2) preferably satisfies δd: 19.0 or higher, more preferably 19.1 or higher, particularly preferably 19.2 or higher, preferably 20.8 or lower, more preferably 20.6 or lower, particularly preferably 20.5 or lower; δp preferably satisfies 1.80 or higher, more preferably 1.85 or higher, particularly preferably 1.87 or higher, preferably 2.60 or lower, more preferably 2.30 or lower, particularly preferably 2.10 or lower; δh preferably satisfies 3.10 or higher, more preferably 3.20 or higher, particularly preferably 3.28 or higher, preferably 5.60 or lower, more preferably 5.10 or lower, and particularly preferably 4.60 or lower.

[0073] When components other than (C-1) and (C-2) are used as components of modifier (C), the content of the components of modifier (C) other than (C-1) and (C-2) is preferably 0.02 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.07 parts by mass or more, per 100 parts by mass of the methacrylic resin composition, from the viewpoint of fully exhibiting the effect of the modifier. Furthermore, from the viewpoint of fully exhibiting the modifying effect of (C-1) and (C-2), it is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 7.6 parts by mass or less.

[0074] <Dyes and Pigments> In this embodiment, the methacrylic resin composition preferably contains substantially no carbon-based compounds such as carbon black, fullerene, carbon nanotubes, or graphene (0 parts by mass per 100 parts by mass of the methacrylic resin composition) in order to prevent deformation due to heat accumulation. In this case, dyes and pigments other than carbon-based compounds may be mixed in.

[0075] Examples of dyes include nitroso dyes, nitro dyes, azo dyes, stilbene azo dyes, ketoimine dyes, triphenylmethane dyes, xanthene dyes, acridine dyes, quinoline dyes, methine / polymethine dyes, thiazole dyes, indamine / indophenol dyes, azine dyes, oxazine dyes, thiazine dyes, sulfur dyes, aminoketone / oxyketone dyes, anthraquinone dyes, indigoid dyes, and phthalocyanine dyes.

[0076] Examples of pigments include inorganic pigments such as titanium dioxide, titanium yellow, iron composite oxide, ultramarine, cobalt blue, chromium oxide, spinel green, lead chromate pigments, and cadmium pigments; azo pigments such as azo lake pigments, benzimidazolone pigments, diarylide pigments, and condensed azo pigments; phthalocyanine pigments such as phthalicyanine blue and phthalocyanine green; organic pigments such as isoindolinone pigments, quinophthalone pigments, quinacridone pigments, perylene pigments, anthraquinone pigments, perinone pigments, and condensed polycyclic pigments such as dioxazine violet; metallic pigments made from flake-shaped aluminum; spherical aluminum pigments used to improve weld appearance; mica powder for pearlescent metallic pigments; and metallic pigments made by coating polyhedral particles of inorganic materials such as glass with metal plating or sputtering. Among these, iron composite oxides are preferred from the viewpoint of good opacity and color development. Iron composite oxides are not limited to the following, but examples include CAS No. 68187-51-9, 68186-88-9, 68186-94-7, 68186-97-0, 68186-91-4, and 12737-27-8, and refer to oxides formed by combining iron with one or more other metal species.

[0077] In the methacrylic resin composition of this embodiment, if a dye pigment is included, the amount of dye pigment is preferably 0.01 to 25 parts by mass, more preferably 0.01 to 23 parts by mass, and even more preferably 0.02 to 21 parts by mass per 100 parts by mass of the methacrylic resin composition, in order to prevent molding defects such as bleed-out. In particular, it is preferable to include 0.01 to 4 parts by mass of iron composite oxide, more preferably 0.2 to 3.8 parts by mass, even more preferably 0.8 to 3.7 parts by mass, even more preferably 1.6 to 3.6 parts by mass, and especially preferably 1.9 to 3.5 parts by mass, in order to exhibit good shielding properties as a coloring agent.

[0078] <Other additives> The methacrylic resin composition of this embodiment may contain certain additives to impart various properties such as rigidity and dimensional stability.

[0079] Additives include, but are not limited to, various stabilizers such as UV absorbers and light stabilizers; plasticizers (paraffinic process oils, naphthenic process oils, aromatic process oils, paraffin, organic polysiloxanes, mineral oils); flame retardants (e.g., phosphorus-based, halogen-based, silica-based, silicone-based, etc., such as organophosphorus compounds, red phosphorus, and inorganic phosphates); flame retardant aids (e.g., antimony oxides, metal hydroxides, etc.); curing agents (diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, diethylaminopropylamine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, mensendiamine, isophoronediamine, N-aminoethylpiper Amines such as radins, m-xylenediamine, m-phenylenediamine, diaminophenylmethane, diaminodiphenylsulfone, dicyandiamide, and dihydrazide adipic acid; phenolic resins such as phenol novolac resin and cresol novolac resin; polymers such as liquid polymers and polysulfides; phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, methylcyclohexenetetracarboxylic anhydride, dodecyl succinic anhydride, trimellitic anhydride, chlorendicic anhydride, benzophenonetetracarboxylic anhydride, and acid anhydrides such as ethylene glycol bis(anhydrotrimate);Curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, and 2-phenyl-4-methylimidazole; organophosphines such as triphenylphosphine and tributylphosphine; benzyldimethylamine, 2-dimethylaminomethyl)phenol, 2,4,6-tris(diaminomethyl)phenol, and tertiary ammonium compounds such as tetramethylhexanediamine. Amines, boron salts such as triphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, and triethylamine tetraphenylborate, quinoid compounds such as 1,4-benzoquinone, 1,4-naphthoquinone, 2,3-dimethyl-1,4-benzoquinone, 2,6-dimethylbenzoquinone, and 2,3-dimethoxy-1,4-benzoquinone; antistatic agents (e.g., polyamide elastomers, quaternary ammonium salts, pyridine derivatives, aliphatic sulfonates, aromatic sulfonates); Examples of materials include: honates, aromatic sulfonates copolymers, sulfate esters, polyhydric alcohol partial esters, alkyldiethanolamines, alkyldiethanolamides, polyalkylene glycol derivatives, betaines, imidazoline derivatives, etc.); conductivity imparters; stress relaxants; release agents (alcohols, esters of alcohols and fatty acids, esters of alcohols and dicarboxylic acids, silicone oils, etc.); crystallization accelerators; hydrolysis inhibitors; sliding properties improvers (hydrocarbons such as low molecular weight polyethylene, higher alcohols, polyhydric alcohols, polyglycols, polyglycerols, silicones, fluororesins, etc.); compatibilizers; nucleating agents; reinforcing agents such as fillers; flow regulators; sensitizers; thickeners; anti-settling agents; anti-sagging agents; fillers (fibrous reinforcing agents such as glass fibers and carbon fibers, as well as glass beads, calcium carbonate, talc, clay, etc.); defoaming agents (silicone-based defoamers, surfactants, polyethers, higher alcohols, and other organic defoaming agents); coupling agents; light-diffusing fine particles; rust inhibitors; antibacterial and antifungal agents; antifouling agents; conductive polymers, etc. ;

[0080] In order to obtain the molded article made from the methacrylic resin composition of this embodiment, the content of the above-mentioned other additives in the methacrylic resin composition is preferably 0 to 20 parts by mass, more preferably 0.01 to 18 parts by mass, and even more preferably 0.02 to 15 parts by mass per 100 parts by mass of the methacrylic resin composition, in order to maintain the transparency of the methacrylic resin composition and prevent molding defects such as bleed-out.

[0081] In particular, to improve the weather resistance of the methacrylic resin composition of the present invention, it is preferable to include an ultraviolet absorber and / or a light stabilizer. Examples of ultraviolet absorbers are not limited to the following, but include benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, oxanilide-based ultraviolet absorbers, benzoate-based ultraviolet absorbers, etc., and benzotriazole-based ultraviolet absorbers are preferred from the viewpoint of exhibiting a stable ultraviolet absorption effect over a long period of time. From the viewpoint of improving the ultraviolet absorption effect, the content of the ultraviolet absorber is preferably 0.02 parts by mass or more, more preferably 0.06 parts by mass or more, and even more preferably 0.09 parts by mass or more, per 100 parts by mass of the methacrylic resin composition. Furthermore, from the viewpoint of preventing contamination of molds and metal rolls during molding, it is preferably 0.7 parts by mass or less, more preferably 0.37 parts by mass or less, and even more preferably 0.28 parts by mass or less.

[0082] The light stabilizer preferably contains a hindered amine-based light stabilizer, and from the viewpoint of good weather resistance, the content is preferably 0.03 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.08 parts by mass or more, per 100 parts by mass of the methacrylic resin composition. Furthermore, from the viewpoint of preventing contamination of molds and metal rolls during molding, the content is preferably 0.7 parts by mass or less, more preferably 0.35 parts by mass or less, and even more preferably 0.26 parts by mass or less.

[0083] From the viewpoint of improving weather resistance, the total content of UV absorbers and light stabilizers is preferably 0.05 parts by mass or more, more preferably 0.11 parts by mass or more, and even more preferably 0.17 parts by mass or more, per 100 parts by mass of the methacrylic resin composition. From the viewpoint of preventing contamination of molds and metal rolls during molding, the total content is preferably 1.4 parts by mass or less, more preferably 0.8 parts by mass or less, and even more preferably 0.54 parts by mass or less, per 100 parts by mass of the methacrylic resin composition. At this time, the ratio of light stabilizers to UV absorbers, and the UV absorber content / light stabilizer content are preferably 0.1 to 1.5, more preferably 0.2 to 1.1, and even more preferably 0.3 to 0.7, in order to maintain good weather resistance over a longer period of time.

[0084] The melting point of the UV absorber and light stabilizer is preferably 60°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher, in order to ensure good handling during extrusion. On the other hand, in order to disperse well during melt mixing and efficiently exert their effects, the melting point is preferably 230°C or lower, more preferably 210°C or lower, and even more preferably 150°C or lower.

[0085] <Methacrylic resin composition manufacturing method> The methacrylic resin composition of this embodiment can be produced by kneading the aforementioned methacrylic resin, modifier, rubbery polymer, and optionally selected additives, and is preferably produced by melt kneading in order to properly disperse each component.

[0086] Methods for producing methacrylic resin compositions include, for example, mixing using a mixing machine such as an extruder, heated roll, kneader, roller mixer, or Banbury mixer. Among these, melt mixing using an extruder is preferred in terms of productivity. The melt mixing temperature should follow the preferred processing temperature of the polymer constituting the methacrylic resin, and as a guideline, it is in the range of 140 to 300°C. To melt the resin, additives, and modifiers and ensure good production efficiency, a temperature of 180°C or higher is preferred, and 190°C or higher is more preferred. Furthermore, from the viewpoint of preventing resin degradation and volatilization of additives and modifiers, the upper limit of the processing temperature is preferably 280°C, and more preferably in the range of 265°C. In addition, it is preferable to provide a vent port in the extruder and connect a vacuum line to reduce the pressure in order to reduce volatile components remaining in the composition.

[0087] <Weight-average molecular weight of methacrylic resin composition> The weight-average molecular weight (Mw) of the methacrylic resin composition of this embodiment will be described. The weight-average molecular weight (Mw) of the methacrylic resin composition, as measured by GPC (gel permeation chromatography), is preferably 50,000 to 200,000, from the viewpoint of combining good solvent resistance and fluidity. By having the weight-average molecular weight (Mw) of the methacrylic resin composition in the range of 50,000 to 200,000, a balance can be achieved between fluidity, mechanical strength, and solvent resistance, and good moldability can be maintained.

[0088] In this case, from the viewpoint of obtaining excellent solvent resistance, the lower limit of the weight-average molecular weight (Mw) of the methacrylic resin composition is preferably 56,000 or more, more preferably 61,000 or more, and particularly preferably 62,000 or more. On the other hand, from the viewpoint of ensuring good fluidity, the upper limit of the weight-average molecular weight (Mw) of the methacrylic resin composition is preferably 160,000 or less, more preferably 120,000 or less, even more preferably 96,000 or less, and particularly preferably 80,000 or less.

[0089] Furthermore, the molecular weight distribution (Mw / Mn) of the methacrylic resin composition of this embodiment is preferably 1.0 to 6.0, more preferably 1.3 to 2.5, even more preferably 1.3 to 2.0, even more preferably 1.3 to 1.8, and particularly preferably 1.4 to 1.7. A molecular weight distribution (Mw / Mn) of 1.0 to 6.0 of the methacrylic resin composition stabilizes the various physical properties exhibited by the methacrylic resin composition. Here, Mw represents the weight-average molecular weight, and Mn represents the number-average molecular weight. The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the methacrylic resin composition can be measured by GPC, specifically by the method described in the [Examples] below. Specifically, a calibration curve is prepared using a standard methacrylic resin with a known monodisperse weight-average molecular weight that is available as a reagent, and an analytical gel column that elutes high molecular weight components first, based on the elution time and weight-average molecular weight. Subsequently, based on the obtained calibration curve, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the methacrylic resin composition to be measured can be determined, and the molecular weight distribution (Mw / Mn) can be calculated from these values. The number-average molecular weight (Mn) is the average molecular weight per single molecule and is defined as the total weight of the system divided by the number of molecules in the system. The weight-average molecular weight (Mw) is defined as the average molecular weight by weight fraction. In this invention, the molecular weight used is the molecular weight converted to PMMA.

[0090] <Molded body> The molded article of this embodiment is characterized by containing the above-described methacrylic resin composition.

[0091] The thickness of the molded article is not particularly limited, but from the viewpoint of maintaining excellent weather resistance, exhibiting high opacity when coloring agents are included, and reducing the amount of raw materials required for molding, a thickness of 0.01 to 5.0 mm is preferred, 0.05 to 2.6 mm is more preferred, 0.05 to 2.3 mm is even more preferred, 0.12 to 1.6 mm is even more preferred, and 0.15 mm to 0.8 mm is particularly preferred.

[0092] In this case, the thickness of the molded body is defined as the smallest value when classifying the length, width, and thickness of the molded body made of the methacrylic resin composition of the present invention. The thickness of the molded body of the present invention refers to the thickest part within that thickness. In the case of a laminated body such as a two-color molded body, the thickness of the individual molded body made of the methacrylic resin composition can be determined by cutting a cross-section of the molded body, observing it with a microscope, and using the microscope's length-measuring function. Furthermore, in the case of a three-dimensional laminated molded body rather than a simple plate-like laminated structure, the thickness of the methacrylic resin is defined as the distance between the surface layer of the acrylic resin composition layer and the other layer, and the thickness of the molded body of the present invention refers to the thickest part within that thickness.

[0093] <Method for manufacturing molded articles> The molded article of this embodiment can be manufactured by known molding methods. Known molding methods are not limited to the following, but include, for example, injection molding, extrusion molding, blow (hollow) molding, vacuum molding, compression molding, calendering, and inflation molding. Extrusion molding is particularly preferred from the viewpoint of productivity. Furthermore, the manufacturing method of the molded article may be single-color molding or two-color molding, and two-color molding is preferred from the viewpoint of enabling flexible design.

[0094] From the viewpoint of productivity, the molding temperature is preferably 170°C or higher, more preferably 190°C or higher, and even more preferably 200°C or higher. Furthermore, from the viewpoint of volatilization of the methacrylic resin (A), rubbery polymer (C), and various additives, it is preferably 290°C or lower, more preferably 280°C or lower, even more preferably 270°C or lower, and particularly preferably 230°C or lower. In this case, the molding temperature refers to the set temperature of the equipment used for molding, and in the case of equipment with multiple set temperatures, it refers to the maximum value.

[0095] <Characteristics of the molded product> When the molded article made from the methacrylic resin composition of this embodiment does not contain dyes or pigments, it is preferable that the total light transmittance at a thickness of 2 mm be 85% or more, more preferably 87% or more, and even more preferably 90% or more. The total light transmittance, excluding the thickness of the molded article, is measured in accordance with JIS K7361.

[0096] On the other hand, when a dye or pigment is included, regardless of the thickness of the molded body, the solar reflectance is preferably 10% or more, more preferably 15% or more, and even more preferably 17% or more. The solar reflectance is measured in accordance with JIS R3106. When a dye or pigment is included, the present invention provides good solar shielding even when the thickness of the molded body is thin, and can suppress heat accumulation in the molded body due to solar absorption and the resulting thermal deformation.

[0097] <Applications of molded products> The molded articles containing the methacrylic resin composition of this embodiment have good fluidity and solvent resistance, and also exhibit excellent long-term stability in outdoor environments exposed to ultraviolet light, long-term heat resistance, and long-term moist heat stability. Therefore, they can be suitably used for building components, vehicle components, electrical and electronic components, lighting components, and the like. Because it exhibits particularly excellent solvent resistance, enabling the long-term maintenance of molded products, it is especially preferable to use it as a building component. [Examples]

[0098] The embodiment will be described in detail below with reference to examples, but this embodiment is not limited to the examples described later.

[0099] [Raw materials used in the examples and comparative examples] <Methacrylic resin (A) raw materials> The raw materials for the methacrylic resin (A) used in the production of the methacrylic resin composition are as follows: • Methyl methacrylate (MMA): Manufactured by Asahi Kasei (contains 2,4-dimethyl-6-t-butylphenol manufactured by Chugai Trading Co., Ltd. at a concentration of 2.5 ppm as a polymerization inhibitor). • Methyl acrylate (MA): Manufactured by Mitsubishi Chemical (contains 14 ppm of 4-methoxyphenol (4-methoxyphenol) manufactured by Kawaguchi Chemical Industries as a polymerization inhibitor). • Ethyl acrylate (EA): Manufactured by Mitsubishi Chemical Corporation n-Octylmercaptan: Made by Arkema • 2-Ethylhexylthioglycolate: Made by Arkema • Lauroyl peroxide: Manufactured by Nippon Oil & Fats Co., Ltd. • Tricalcium phosphate: Manufactured by Nippon Chemical Industrial Co., Ltd., used as a suspending agent. • Calcium carbonate: Manufactured by Shiraishi Industries, used as a suspension agent. • Sodium lauryl sulfate: Manufactured by Wako Pure Chemical Industries, used as a suspension aid.

[0100] For the methacrylic resin (A), the methacrylic resins (A-1) to (A-7) were used according to the following manufacturing examples A1 to A7.

[0101] <Manufacturing Example A1 (Manufacturing of Methacrylic Resin (A-1))> In a container equipped with a stirrer, 2 kg of deionized water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were added to obtain a mixture (a). Next, 26 kg of deionized water was added to a 60 L reactor and the temperature was raised to 80°C. Mixture (a), 23.2 kg of methyl methacrylate, 1.5 kg of methyl acrylate, 27 g of lauroyl peroxide, and 75 g of n-octyl mercaptan were then added. Subsequently, suspension polymerization was carried out while maintaining a temperature of approximately 80°C. After observing the exothermic peak, the temperature was increased to 92°C at a rate of 1°C / min, and the mixture was aged for 60 minutes, effectively completing the polymerization reaction. Next, after cooling to 50°C, 20 parts by mass of sulfuric acid were added to dissolve and remove the suspension agent. The polymerization reaction solution was then sieved through a 1.68 mm mesh to remove aggregates, and the resulting bead-shaped polymer was washed, dehydrated, and dried to obtain polymer fine particles. The obtained polymer fine particles were melt-kneaded in a φ30 mm twin-screw extruder set to 240°C, and the strands were cooled and cut to obtain resin pellets [methacrylic resin (A-1)]. The weight-average molecular weight of the obtained resin pellets was 63,000, and the structural unit was MMA / MA = 94 / 6 parts by mass.

[0102] <Manufacturing Example A2 (Manufacturing of Methacrylic Resin (A-2))> In a container equipped with a stirrer, 2 kg of deionized water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were added to obtain a mixture (a). Next, 26 kg of deionized water was added to a 60 L reactor and the temperature was raised to 80°C. Mixture (a), 21.3 kg of methyl methacrylate, 3.4 kg of methyl acrylate, 27 g of lauroyl peroxide, and 75 g of n-octyl mercaptan were then added. Subsequently, suspension polymerization was carried out while maintaining a temperature of approximately 80°C. After observing the exothermic peak, the temperature was increased to 92°C at a rate of 1°C / min, and the mixture was aged for 60 minutes, effectively completing the polymerization reaction. Next, after cooling to 50°C, 20 parts by mass of sulfuric acid were added to dissolve and remove the suspension agent. The polymerization reaction solution was then sieved through a 1.68 mm mesh to remove aggregates, and the resulting bead-shaped polymer was washed, dehydrated, and dried to obtain polymer fine particles. The obtained polymer fine particles were melt-kneaded in a φ30 mm twin-screw extruder set to 240°C, and the strands were cooled and cut to obtain resin pellets [methacrylic resin (A-2)]. The weight-average molecular weight of the obtained resin pellets was 95,500, and the structural units were MMA / MA = 86 / 14 parts by mass.

[0103] <Manufacturing Example A3 (Manufacturing of Methacrylic Resin (A-3))> In a container equipped with a stirrer, 2 kg of deionized water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were added to obtain a mixture (a). Next, 26 kg of deionized water was added to a 60 L reactor and the temperature was raised to 80°C. Mixture (a), 23.2 kg of methyl methacrylate, 1.5 kg of methyl acrylate, 27 g of lauroyl peroxide, and 33 g of n-octyl mercaptan were then added. Subsequently, suspension polymerization was carried out while maintaining a temperature of approximately 80°C. After observing the exothermic peak, the temperature was increased to 92°C at a rate of 1°C / min, and the mixture was aged for 60 minutes, effectively completing the polymerization reaction. Next, after cooling to 50°C, 20 parts by mass of sulfuric acid were added to dissolve and remove the suspension agent. The polymerization reaction solution was then sieved through a 1.68 mm mesh to remove aggregates, and the resulting bead-shaped polymer was washed, dehydrated, and dried to obtain polymer fine particles. The obtained polymer fine particles were melt-kneaded in a φ30 mm twin-screw extruder set to 240°C, and the strands were cooled and cut to obtain resin pellets [methacrylic resin (A-3)]. The weight-average molecular weight of the obtained resin pellets was 180,000, and the structural unit was MMA / MA = 94 / 6 parts by mass.

[0104] <Manufacturing Example A4 (Manufacturing of Methacrylic Resin (A-4))> In a container equipped with a stirrer, 2 kg of deionized water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were added to obtain a mixture (a). Next, 26 kg of deionized water was added to a 60 L reactor and the temperature was raised to 80°C. Mixture (a), 23.4 kg of methyl methacrylate, 1.3 kg of methyl acrylate, 27 g of lauroyl peroxide, and 75 g of n-octyl mercaptan were then added. Subsequently, suspension polymerization was carried out while maintaining a temperature of approximately 80°C. After observing the exothermic peak, the temperature was increased to 92°C at a rate of 1°C / min, and the mixture was aged for 60 minutes, effectively completing the polymerization reaction. Next, after cooling to 50°C, 20 parts by mass of sulfuric acid were added to dissolve and remove the suspension agent. The polymerization reaction solution was then sieved through a 1.68 mm mesh to remove aggregates, and the resulting bead-shaped polymer was washed, dehydrated, and dried to obtain polymer fine particles. The obtained polymer fine particles were melt-kneaded in a φ30 mm twin-screw extruder set to 240°C, and the strands were cooled and cut to obtain resin pellets [methacrylic resin (A-4)]. The weight-average molecular weight of the obtained resin pellets was 59,500, and the structural unit was MMA / MA = 94 / 5 parts by mass.

[0105] <Manufacturing Example A5 (Manufacturing of Methacrylic Resin (A-5))> In a container equipped with a stirrer, 2 kg of deionized water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were added to obtain a mixture (a). Next, 26 kg of deionized water was added to a 60 L reactor and the temperature was raised to 80°C. Mixture (a), 24.3 kg of methyl methacrylate, 0.5 kg of methyl acrylate, 27 g of lauroyl peroxide, and 50 g of n-octyl mercaptan were then added. Subsequently, suspension polymerization was carried out while maintaining a temperature of approximately 80°C. After observing the exothermic peak, the temperature was increased to 92°C at a rate of 1°C / min, and the mixture was aged for 60 minutes, effectively completing the polymerization reaction. Next, after cooling to 50°C, 20 parts by mass of sulfuric acid were added to dissolve and remove the suspension agent. The polymerization reaction solution was then sieved through a 1.68 mm mesh to remove aggregates, and the resulting bead-shaped polymer was washed, dehydrated, and dried to obtain polymer fine particles. The obtained polymer fine particles were melt-kneaded in a φ30 mm twin-screw extruder set to 240°C, and the strands were cooled and cut to obtain resin pellets [methacrylic resin (A-5)]. The weight-average molecular weight of the obtained resin pellets was 100,000, and the structural unit was MMA / MA = 98 / 2 parts by mass.

[0106] <Manufacturing Example A6 (Manufacturing of Methacrylic Resin (A-6))> In a container equipped with a stirrer, 2 kg of deionized water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were added to obtain a mixture (a). Next, 26 kg of deionized water was added to a 60 L reactor and the temperature was raised to 80°C. Mixture (a), 21.2 kg of methyl methacrylate, 0.43 kg of methyl acrylate, 27 g of lauroyl peroxide, and 80 g of n-octyl mercaptan were then added. Subsequently, suspension polymerization was carried out while maintaining a temperature of approximately 80°C. After observing the exothermic peak, the temperature was increased to 92°C at a rate of 1°C / min, and the mixture was aged for 60 minutes, effectively completing the polymerization reaction. Next, after cooling to 50°C, 20 parts by mass of sulfuric acid were added to dissolve and remove the suspension agent. The polymerization reaction solution was then sieved through a 1.68 mm mesh to remove aggregates, and the resulting bead-shaped polymer was washed, dehydrated, and dried to obtain polymer fine particles. The obtained polymer fine particles were melt-kneaded in a φ30 mm twin-screw extruder set to 220°C, and the strands were cooled and cut to obtain resin pellets [methacrylic resin (A-6)]. The weight-average molecular weight of the obtained resin pellets was 35,000, and the structural unit was MMA / MA = 95 / 5 parts by mass.

[0107] <Manufacturing Example A7 (Manufacturing of Methacrylic Resin (A-7))> In a container equipped with a stirrer, 2 kg of deionized water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were added to obtain a mixture (a). Next, 26 kg of deionized water was added to a 60 L reactor and the temperature was raised to 80°C. Mixture (a), 21.2 kg of methyl methacrylate, 0.43 kg of methyl acrylate, 27 g of lauroyl peroxide, and 25 g of n-octyl mercaptan were then added. Subsequently, suspension polymerization was carried out while maintaining a temperature of approximately 80°C. After observing the exothermic peak, the temperature was increased to 92°C at a rate of 1°C / min, and the mixture was aged for 60 minutes, effectively completing the polymerization reaction. Next, after cooling to 50°C, 20 parts by mass of sulfuric acid were added to dissolve and remove the suspension agent. The polymerization reaction solution was then sieved through a 1.68 mm mesh to remove aggregates, and the resulting bead-shaped polymer was washed, dehydrated, and dried to obtain polymer fine particles. The obtained polymer fine particles were melt-kneaded in a φ30 mm twin-screw extruder set to 270°C, and the strands were cooled and cut to obtain resin pellets [methacrylic resin (A-7)]. The weight-average molecular weight of the obtained resin pellets was 250,000, and the structural unit was MMA / MA = 95 / 5 parts by mass.

[0108] <Acrylic rubber polymer (B)> • B-1 IR-441: An acrylic rubber polymer manufactured by Mitsubishi Chemical, with a multilayer structure and an average particle size of 200 nm. • B-2 M-230 Kaneka-made acrylic rubber polymer with a multilayer structure having an average particle size of 100 nm.

[0109] <Modifier (C)> <<Fatty acid derivative C-1>> • C-1-1 Neutron (Aliphatic monocarboxylic acid amide (C6-C24) oleic acid amide 70% or more): Manufactured by Nippon Seika Co., Ltd. ·C-1-2 BNT-22H (Aliphatic monocarboxylic acid amide (C6-C24) Beheninamide 80% or more): Manufactured by Nippon Seika Co., Ltd. • C-1-3 Alflow S-10 (Industrial Monostearamide (C17)): Manufactured by NOF Corporation • C-1-4 Zinc stearate: Manufactured by Kanto Chemical Co., Ltd. <<Phosphorus compound C-2>> ·C-2-1 ADEKA Stab HP-10 (2,2'-Methylenebis(4,6-di-tert-butylphenyl)2-ethylhexyl phosphite): Manufactured by ADEKA ·C-2-2 JP-650(tris-(2,4-di-tert-butylphenyl)phosphite): Manufactured by Johoku Chemical The values ​​for each term of the Hansen solubility parameter for the above modifier (C) are shown in Table 1.

[0110] [Table 1]

[0111] <Dyes and Pigments> • Iron composite oxide Chromium iron oxide CAS.12737-27-8: Manufactured by TOMATEC Titanium(IV) oxide CAS.13463-67-7: Manufactured by Ishihara Sangyo Co., Ltd.

[0112] [Measurement method] <Methacrylic resin (A) molecular weight and molecular weight distribution measurement method> The weight-average molecular weight and molecular weight distribution of methacrylic resin (A) were measured using the following equipment and under the following conditions. Measurement device: Tosoh Corporation gel permeation chromatography (HLC-8320GPC) Columns: 1 TSKgel SuperH2500, 2 TSKgel SuperHM-M, 1 TSKguardcolumn SuperH-H, connected in series. In this column, high molecular weight molecules elute quickly, while low molecular weight molecules elute more slowly. Detector: RI (Differential Refraction) Detector Detection sensitivity: 3.0mV / min Column temperature: 40℃ Sample: 0.02 g of methacrylic resin in a 10 mL solution of tetrahydrofuran. Injection volume: 10μL Developing solvent: tetrahydrofuran, flow rate: 0.6 mL / min Since the polymethyl methacrylate samples used as standard samples for the calibration curve each exhibited a single peak, (Mp) was denoted as the peak molecular weight, distinguishing it from the "peak-top molecular weight" notation used when there are multiple peaks. Peak molecular weight (Mp) Standard sample 1: 1,916,000 Standard sample 2 625,500 Standard sample 3: 298,900 Standard sample 4 138,600 Standard sample 5 60,150 Standard sample 6 27,600 Standard sample 7 10,290 Standard sample 8 5,000 Standard sample 9 2,810 Standard sample 10 850 Under the above conditions, the RI detection intensity was measured in relation to the elution time of the methacrylic resin. Based on the area of ​​the GPC elution curve and the calibration curve of the 7th order approximation formula, the weight-average molecular weight (Mw), molecular weight distribution (Mw / Mn), and GPC peak molecular weight (Mp) of the methacrylic resin (A) were determined.

[0113] <Analysis of structural units of methacrylic resin (A)> 1 The structural units were identified by 1H-NMR measurements, and their abundance (parts by mass) was calculated. 1 The measurement conditions for H-NMR are as follows: Equipment: JEOL-ECA500 Solvent: CDCl3-D1 (deuterated chloroform) Sample: 15 mg of component (A) was dissolved in 10.75 mL of CDCl3-d to prepare the sample for measurement.

[0114] <Measurement of average particle size of acrylic rubber polymer (B), and content of large-particle rubber polymer (B-1) and small-particle rubber polymer (B-2)> Sections of the methacrylic resin compositions of the examples and comparative examples were cut at any five points using a microtome, and then observational section samples were prepared using the RuO4 (ruthenic acid) staining ultrathin sectioning method. The stained acrylic rubber polymer cross-sections were observed and photographed at a magnification of 100,000x using a transmission electron microscope (model: HT7700) manufactured by Hitachi High-Technologics Co., Ltd.

[0115] When the particle sizes of all acrylic rubber polymers contained in images of section samples at any five points were measured, the average particle size of acrylic rubber polymers with a particle size of 150-300 nm was defined as the average particle size (r1) of large-particle rubber polymers (B-1), and the average particle size of acrylic rubber polymers with a particle size of 50-149 nm was defined as the average particle size (r2) of small-particle rubber polymers (B-2). In cases where multiple rubber particles existed in an aggregated form, one particle of the aggregate was considered, and the longest side was defined as the particle size of that particle. Furthermore, when observed at a magnification of 100,000x, the total number of large-particle rubber polymers and small-particle rubber polymers within an arbitrary range was at least 100. The number of large-particle rubber polymers and the number of small-particle rubber polymers were defined as n1 and n2, respectively, and the content of large-particle rubber polymers (B-1) and small-particle rubber polymers (B-2) was derived using the following formulas based on the particle sizes and number of particles measured by the above method. (B-1) content = 4 / 3 × π × (r1 / 2) 3×n1×1.17 (Content of (B-2) = 4 / 3×π×(r2 / 2)) 3 ×n2×1.10 Equation (3) was derived by the following equation using the particle size and the number of particles measured by the above method. (B-2) / (B-1)=(r2) 3 ×n2×1.10 / (r1) 3 ×n1×1.17

[0116] [Measurement of Physical Properties of Methacrylic Resin Composition] [Measurement Method and Evaluation Method of Fluidity] As an evaluation of the molding processability, the fluidity was evaluated by measuring the value (a) of the melt mass flow rate in accordance with JIS K7210-1 under the conditions of 230 °C and 3.8 kgf. It can be said that a sample with a larger value (a) of the melt mass flow rate has better high fluidity. As the measurement sample, the thermoplastic resin compositions produced in the examples and comparative examples described below were used. As the evaluation criteria, the following evaluation from 0 points (poor) to 5 points (most excellent) was performed for the fluidity (g / 10 min). 0 points: Unmeasurable 1 point: 0.1~0.9 2 points: 1.0~1.4 3 points: 1.5~2.4 4 points: 2.5~3.0 or 16 or more 5 points: 3.1~15

[0117] [Solvent Resistance of Methacrylic Resin Composition] The evaluation of the solvent resistance was performed by the critical strain ε (%) measured by the 1 / 4 ellipse method when the resin compositions produced in the examples and comparative examples described below were made into a flat plate with a thickness of 2.0 mm using a 37t compression molding machine manufactured by Toho Machinery Co., Ltd. set at 230 °C. At this time, the critical strain ε (%) is calculated by the following equation. Critical strain ε (%) = bt{1-(1 / a 2 -b 2 / a 4 )h 2} -3 / 2 / 2a2 ×100 The average value obtained from five of the above measurements will be used as the test value. a: elliptical diameter b: minor axis of the ellipse h: Distance to the crack location t: Thickness of the molded body The greater the critical strain value, the higher the solvent resistance. As a criterion for evaluation, the critical strain ε(%) was evaluated on a scale from 0 points (poor) to 5 points (best). 0 points: Calculation impossible due to lower limit of measurement. 1 point: 0.24~0.60 2 points: 0.61~1.0 3 points: 1.1~1.5 4 points: 1.6~2.5 5 points: 2.6~

[0118] [Total light transmittance] The total light transmittance was evaluated in accordance with JIS K7361 when the resin compositions produced in the examples and comparative examples described later were formed into 2.0 mm thick flat plates using a 37t compression molding machine manufactured by Toho Machinery Co., Ltd., set to 230°C. When the resin compositions do not contain dyes or pigments and are used in applications where transparency is required, the following evaluation criteria were used from the perspective of visibility. 0 points (Fail): Less than 85% 1 point (acceptable): 85% or more but less than 87% 2 points (Good): 87% to less than 90% 3 points (best): 90% or higher In this case, a higher total light transmittance is preferable.

[0119] [Solar reflectance] The solar reflectance was evaluated using acrylic resin compositions produced in the examples and comparative examples described later, which contain dyes and pigments. A two-color molded body with a methacrylic resin layer thickness of 0.3 mm was prepared by co-extrusion molding of a vinyl chloride resin composition and the methacrylic resin composition of the present invention, and measured in accordance with JIS R3106 using a Shimadzu Corporation UV-3600iPlus ultraviolet-visible-near-infrared spectrophotometer. The vinyl chloride resin composition was measured using a Konica Minolta, Inc. CM-700d spectrophotometer / color difference system, by D65 light source 10-degree field of view SCI method reflectance measurement. * =93.6, a * = -0.68, b * A polyvinyl chloride resin composition with a solar reflectance of 3.35 was used. The two-color molded product of the polyvinyl chloride resin composition and the methacrylic resin composition was obtained by extruding the polyvinyl chloride resin composition alone at a set temperature of 190°C and the methacrylic resin composition alone at a set temperature of 210°C, and then joining them at 195°C. A higher solar reflectance is preferable, but if it is 10% or more, there is no risk of the molded product accumulating heat and deforming due to solar absorption, and the opacity is also good, so it can be used in environments exposed to sunlight. If the solar reflectance is less than 10%, the opacity is poor, and there is a risk of the molded product accumulating heat and deforming due to solar absorption, so it cannot be used. Solar reflectance was evaluated according to the following criteria. 0 points (Fail): Less than 10% 1 point (acceptable): 10% or more but less than 12% 2 points (Good): 12% to less than 14% 3 points (best): 14% or more

[0120] 〔comprehensive evaluation〕 An overall evaluation was conducted using the total score from the fluidity evaluation and critical strain evaluation, and the total light transmittance if no dyes or pigments were included, or the solar reflectance if dyes or pigments were included, with the evaluation criteria being "- (Poor)", "+ (Sufficient for practical use)", "++ (Good)", "+++ (Excellent)", and "++++ (Very Excellent)". The criteria for judgment are as follows: -: Total score of 4 points or less, or a score of 0 in at least one of the following items: fluidity evaluation, critical strain evaluation, or total light transmittance (solar reflectance if dyes and pigments are included). +: At least one item must be worth 1 point, or the total score must be between 5 and 8 points. ++: Total score between 9 and 11 points, and either the liquidity assessment or critical strain assessment score of 2 points. +++: Total score between 9 and 11 points, and both liquidity assessment and critical strain score of 3 points or higher. ++++: Total score is 12 points +++++: Total score: 13 points

[0121] <Examples 1-11>, <Comparative Examples 1-10> (A mixture of methacrylic resin (A), acrylic rubber (B), fatty acid derivative (C-1), and phosphorus compound (C-2)) To a total of 100 parts by mass of methacrylic resin (A) and acrylic rubber (B), a fatty acid derivative (C-1) and a phosphorus compound (C-2) were hand-blended according to the blending ratio shown in Table 1. The mixture was then melt-kneaded at a discharge rate of 10 kg / hour and a rotation speed of 150 rpm in a Toshiba Machine Co., Ltd. TEM-26SS twin-screw extruder with three vents (L / D=48, using a 4-hole die, hopper-side barrel set temperature 230°C), and the strands were cooled and cut to obtain pellets of the methacrylic resin composition. In Comparative Example 2, extrusion molding was also performed with the hopper-side barrel set temperature set to 270°C to 295°C.

[0122] The types and amounts (in parts by mass) of methacrylic resin (A), acrylic rubber (B), fatty acid derivative (C-1), and phosphorus compound (C-2) in each methacrylic resin composition, along with the evaluation results, are shown in Table 1 below.

[0123] The methacrylic resin compositions of Examples 1 to 11 exhibited sufficient fluidity and solvent resistance for practical use. Of these, Example 8 showed sufficient fluidity and solvent resistance for practical use, but it had a high content of fatty acid derivative (C-1), resulting in the generation of volatile components during extrusion molding compared to the other examples, and thus inferior moldability. Furthermore, among Examples 9 to 12, which contain dyes and pigments, Example 12 exhibited sufficient fluidity and solvent resistance for practical use, but it had a higher dye and pigment content than Examples 9 to 11, resulting in slightly inferior dispersibility of the dyes and pigments.

[0124] On the other hand, in Comparative Example 1, the weight-average molecular weight of the methacrylic resin (A) was less than 50,000, resulting in poor dispersibility with the acrylic rubber (B), making extrusion molding impossible.

[0125] In Comparative Example 2, the methacrylic resin (A) had a weight-average molecular weight of over 200,000, resulting in very high viscosity. Although extrusion molding was attempted with the hopper-side barrel temperature set to 270°C, it was impossible. Furthermore, when extrusion molding was attempted with the hopper-side barrel temperature set to 295°C, a very large amount of volatile components were generated, causing vent-up and making stable extrusion molding impossible.

[0126] In Comparative Example 3, since it did not contain acrylic rubber (B), the solvent resistance could not be calculated at the lower limit of measurement, making it unsuitable for practical use.

[0127] In Comparative Example 4, the solvent resistance was insufficient because it did not contain a phosphorus-based compound (C-2). In Comparative Example 5, since neither the fatty acid derivative (C-1) nor the phosphorus compound (C-2) was contained as the lipid modifier (C), both the fluidity and solvent resistance were reduced compared to Examples 1-3.

[0128] In Comparative Examples 6-8, the fatty acid derivative (C-1) mainly composed of unsaturated fatty acid amides was not included, and instead saturated fatty acid amides or saturated fatty acid salts were included, resulting in reduced fluidity and / or solvent resistance compared to Example 6.

[0129] In the table, the units for the amounts of each compound are parts by mass. Note that the amounts for modifier (C) and composite oxide are calculated using parts by mass when the total mass of methacrylic resin (A) and acrylic rubber (B) is set to 100.

[0130] [Table 2] [Industrial applicability]

[0131] According to the present invention, when no dyes or pigments are included, a methacrylic resin composition, a molded article made from the methacrylic resin composition, and a method for producing the same are provided, which have sufficient transparency for practical use and excellent weather resistance, solvent resistance, and fluidity. When dyes or pigments are included, a methacrylic resin composition, a molded article made from the methacrylic resin composition containing the same, and a method for producing the same are provided, which have excellent color tone and excellent weather resistance, solvent resistance, and fluidity.

[0132] This invention has industrial potential applications in furniture, household goods, storage and storage supplies, building materials such as walls, roofs, window frames and gutters, toys and play equipment, hobby applications such as pachinko machine faces, medical and welfare products, office automation equipment, AV equipment, lighting equipment, vehicle parts, sanitary ware substitutes, and the like.

Claims

1. It contains a methacrylic resin (A) with a weight-average molecular weight of 50,000 to 200,000, an acrylic rubber polymer (B), and a modifier (C). A methacrylic resin composition wherein the modifier (C) contains a fatty acid derivative (C-1) which mainly consists of an unsaturated fatty acid amide and one or more fatty acid amides and their derivatives, and a phosphorus compound (C-2).

2. The modifier (C) is such that each term of the Hansen solubility parameter calculated based on the JKU HSP method is expressed within the following ranges: The molecular weight distribution Mw / Mn of the methacrylic resin (A) is 1.3 or more and 2.0 or less. The methacrylic resin composition according to claim 1. δd: 16 or more and 21 or less δp: 1.8 or more and 3.0 or less δh: 3.0 or more and 6.0 or less

3. The content of the fatty acid derivative (C-1), which contains one or more fatty acid amides and derivatives of the aforementioned unsaturated fatty acid amide as the main component, is 0.5 parts by mass or more and 3 parts by mass or less. The content of phosphorus-based compounds (C-2) is 0.1 parts by mass or more and 1 part by mass or less. The methacrylic resin composition according to claim 1, characterized in that it satisfies the following formulas (1) and (2). 1 part by mass ≦ ​​(C-1) + (C-2) ≦ 3 parts by mass... (1) 0.04≦(C-2) / (C-1)≦1...(2)

4. The methacrylic resin composition according to claim 1, wherein, with respect to 100 parts by mass of the total of the methacrylic resin (A) and the acrylic rubber polymer (B), the content of the methacrylic resin (A) is 40 to 70 parts by mass, and the content of the acrylic rubber polymer (B) is 30 to 60 parts by mass.

5. The methacrylic resin composition according to claim 1, wherein the methacrylic resin (A) is composed of 85 to 99.9 parts by mass of repeating units derived from methacrylic acid ester and 0.1 to 15 parts by mass of repeating units derived from acrylic acid ester.

6. The acrylic rubber polymer (B) contains either or both of the following: a large-particle rubber polymer (B-1) with an average particle size of 150 nm or more and 350 nm or less, and a small-particle rubber polymer (B-2) with an average particle size of 80 nm or more and less than 150 nm. The methacrylic resin composition according to claim 1, characterized in that the content of a large-particle rubber polymer (B-1) having an average particle size of 150 nm or more and 350 nm or less, and the content of a small-particle rubber polymer (B-2) having an average particle size of 80 nm or more and less than 150 nm, per 100 parts by mass of the methacrylic resin composition, satisfy the following formulas (3) and (4). 0≦(B-2) / (B-1)≦0.65...(3) 30 (parts by mass)≦(B-1)+(B-2)≦60 (parts by mass)...(4)

7. The methacrylic resin composition according to claim 1, comprising 0.01 parts or more and 4 parts or less of iron composite oxide per 100 parts by mass of the methacrylic resin composition.

8. A molded article characterized by comprising the methacrylic resin composition described in any one of claims 1 to 7.

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