Resin composition, molded body, decomposition and recovery method of resin composition and production method of recycled material

Abstract

To provide: a molded body excellent in shock resistance, heat resistance and transparency; a resin composition capable of producing the molded body; a decomposition and recovery method for the resin composition; and a production method of a recycled material using the molded body.SOLUTION: A resin composition comprises a methacrylic resin A, an acrylic block copolymer B, and crosslinked rubber particles C, where the methacrylic resin A is a random copolymer of a methacrylate ester and a vinyl monomer; the copolymer B is a block copolymer containing a butyl acrylate polymer block and a methacrylate ester polymer block; a content x of the butyl acrylate polymer block in the copolymer B and a content y of a butyl acrylate monomer unit in the copolymer B based on the total amount of the methacrylic resin A and the copolymer B exist in a range which satisfies a specific formula; and a content of the crosslinked rubber particles C is 0.1 pt.mass or more. Also provides are: a decomposition and recovery method for the resin composition; a molded body; and a production method of a recycled material using the molded body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin composition and a molded article containing the same, and further to a method for decomposing and recovering the resin composition and a method for producing a recycled material. [Background technology]

[0002] (Meth)acrylic resins have excellent properties such as weather resistance, transparency, and moldability, and are easily colorable, so they are attracting attention as materials for a variety of applications, such as office automation equipment, automobile parts, building materials (interior materials), lighting materials, and housings for electrical appliances. However, (meth)acrylic resins are prone to scratches and cracking, so it is important to improve their impact resistance and rigidity when expanding their uses or applying them to other applications.

[0003] For example, as one technique for improving the brittleness of (meth)acrylic resin and its molded articles, a resin composition using a methacrylic resin in combination with a specific triblock copolymer is proposed in Patent Document 1. According to Patent Document 1, the following resin composition proposed in Patent Document 1 is capable of improving the surface hardness, impact resistance, etc. when made into a film. The resin composition proposed in Patent Document 1 is as follows. "Comprising 65 to 99 parts by mass of a methacrylic resin (A) having 80% by mass or more of structural units derived from methyl methacrylate and having a melt viscosity η(A) of 1500 to 3500 Pa·s at 220°C and a shear rate of 122 / sec, and 1 to 35 parts by mass of a triblock copolymer (B) in which a methacrylic acid ester polymer block (b2) is bonded to each of both ends of an acrylic acid ester polymer block (b1), The triblock copolymer (B) contains 30 to 60 mass% of an acrylic acid ester polymer block (b1) and 40 to 70 mass% of a methacrylic acid ester polymer block (b2), and the triblock copolymer (B) has a melt viscosity η(B) of 75 to 1500 Pa s at 220°C and a shear rate of 122 / sec; Furthermore, a resin composition in which the ratio η(A) / η(B) of the melt viscosity η(A) to the melt viscosity η(B) is 1 to 20. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 139950 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in recent years, the development and practical application of electric vehicles have progressed rapidly, and the use of (meth)acrylic resins for exterior parts of electric vehicles, such as front grilles, bumpers, fenders, and spoilers, is being considered. For such vehicle exterior parts, design is also important, and high transparency is required for the materials used. Furthermore, since vehicle exterior parts are exposed to outdoor environments and are likely to be hit by flying stones, etc., it is also important that they have excellent heat resistance and impact resistance. In particular, since various vehicles, such as automobiles, are used in cold regions, vehicle exterior parts are required to exhibit high impact resistance not only in room temperature environments but also in low-temperature environments.

[0006] The present invention aims to provide a molded article having excellent impact resistance, heat resistance, and transparency, and a resin composition from which the molded article can be produced. It also aims to provide a method for decomposing and recovering the resin composition, and a method for producing recycled materials using the molded article. [Means for solving the problem]

[0007] That is, the object of the present invention has been achieved by the following means. <1> A resin composition comprising a methacrylic resin (A), an acrylic block copolymer (B), and crosslinked rubber particles (C), the methacrylic resin (A) is a random copolymer of a methacrylic acid ester and a vinyl monomer copolymerizable with the methacrylic acid ester, the acrylic block copolymer (B) is a block copolymer containing a butyl acrylate polymer block and a methacrylic acid ester polymer block, wherein when the content of the butyl acrylate polymer block is x% by mass relative to 100% by mass of the acrylic block copolymer (B), and the content of the monomer unit derived from butyl acrylate in the acrylic block copolymer (B) is y% by mass relative to 100% by mass of the total content of the methacrylic resin (A) and the acrylic block copolymer (B), x and y are within a region satisfying the following formulas 1 to 3: A resin composition, wherein the content of the crosslinked rubber particles (C) is 0.1 parts by mass or more per 100 parts by mass of the resin composition. Formula 1:y≧-0.43x+36.8 Formula 2:y≦19.4 Formula 3: x≦67 <2> Relative to 100 parts by mass of the resin composition, The content of the methacrylic resin (A) is 10 parts by mass or more and 84 parts by mass or less, the content of the acrylic block copolymer (B) is 15 parts by mass or more and 50 parts by mass or less, The content of the crosslinked rubber particles (C) is 1 part by mass or more and 40 parts by mass or less. <1> The resin composition according to claim 1. <3> The methacrylic resin (A) is, relative to 100% by mass of the random copolymer, The content of the monomer units derived from the methacrylic acid ester is 85.0% by mass or more and less than 99.0% by mass, The content of the monomer units derived from the vinyl monomer is more than 1.0% by mass and 15.0% by mass or less. <1> or <2> The resin composition according to claim 1. <4> The methacrylic acid ester contains an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms. <3> The resin composition according to claim 1. <5> The alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms includes methyl methacrylate. <4> The resin composition according to claim 1. <6> the above <1> ~ <5> A molded article comprising the resin composition according to any one of claims 1 to 4. <7> Used as exterior parts for vehicles, <6> The molded article according to claim 1. <8> the above <1> ~ <5> a decomposition step of decomposing the resin composition according to any one of the above items at a temperature of 380°C or higher; a separation step of separating the volatile components and solid matter generated by the decomposition step; A method for decomposing and recovering a resin composition, comprising: a recovery step of recovering a methacrylic acid ester from the volatile components. <9> The vehicle exterior material is a front grille. <7> A method for producing a recycled material using the molded body described in A step of melting and kneading a raw material containing crushed material obtained by crushing the molded body, A method for producing recycled materials, wherein the content of the crushed material is 0.01 parts by mass or more and 99.99 parts by mass or less per 100 parts by mass of the raw material. [Effects of the Invention]

[0008] The present invention provides a molded article having excellent impact resistance, heat resistance, and transparency, and a resin composition from which the molded article can be produced. The present invention also provides a method for decomposing and recovering the resin composition, and a method for producing a recycled material using the molded article. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the regions satisfying formulas 1 to 3 defined in the present invention, as well as x and y in examples and comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the present invention and this specification, the term "(meth)acrylic resin" refers to either or both of an acrylic resin and a methacrylic resin. The same applies to "(meth)acrylic acid ester" and "(meth)acrylic acid." In the present invention and this specification, the bonding mode (arrangement of structural units) of two or more structural units (also referred to as monomer units or constituent components) in a copolymer that becomes a resin or elastomer is not particularly limited, and unless otherwise specified, may be any bonding mode, such as random bonding (random copolymer), block bonding (block copolymer), alternating bonding (alternating copolymer), or graft bonding (graft copolymer).

[0011] In the present invention and this specification, when describing the physical properties and the like of Formulas 1 to 3, which will be described further below, by indicating numerical ranges, if the upper and lower limits of the numerical ranges are described separately, any of the upper and lower limits can be appropriately combined to form a specific numerical range. On the other hand, when describing multiple numerical ranges expressed using "to", the upper and lower limits forming the numerical ranges are not limited to the specific combinations written before and after "to" as specific numerical ranges, but can be a numerical range obtained by appropriately combining the upper and lower limits of each numerical range. Note that in the present invention and this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the upper and lower limits.

[0012] [[Resin composition]] The resin composition of the present invention (also referred to as a (meth)acrylic resin composition) contains a methacrylic resin (A) and an acrylic block copolymer (B), and further contains 0.1 parts by mass or more of crosslinked rubber particles (C) per 100 parts by mass of the resin composition. Details of the methacrylic resin (A), the acrylic block copolymer (B), and the crosslinked rubber particles (C) will be described later. In the resin composition of the present invention containing the above three components, the content x (mass%) of the butyl acrylate polymer block of the acrylic block copolymer (B) and the content y (mass%) of the monomer units derived from butyl acrylate that constitute this butyl acrylate polymer block fall within a range that satisfies the following formulas 1 to 3. In the resin composition of the present invention, since the resin composition contains the above three components and x and y for the acrylic block copolymer (B) are within a specific range, it is possible to improve impact resistance, particularly impact resistance in a low-temperature environment (hereinafter sometimes referred to as "low-temperature impact resistance"), while maintaining excellent heat resistance and transparency, and to realize a molded article that exhibits a good balance of heat resistance, transparency, and impact resistance. In the resin composition of the present invention, the methacrylic resin (A) and the acrylic block copolymer (B) are preferably contained as a base resin, where "as a base resin" refers to a component that forms the basis (matrix) of a molded article formed from the resin composition.

[0013] First, the conditions (formulas 1 to 3) that the resin composition of the present invention, particularly the acrylic block copolymer (B) must satisfy will be explained. The details of each component contained in the resin composition of the present invention will be described later, but the acrylic block copolymer (B) contains a butyl acrylate polymer block and a methacrylic acid ester polymer block. When the content of the butyl acrylate polymer block in 100% by mass of the acrylic block copolymer (B) is x% by mass, and the content of the butyl acrylate-derived monomer units constituting the butyl acrylate polymer block in 100% by mass of the total content of the methacrylic resin (A) and the acrylic block copolymer (B) is y% by mass, x and y exist within a region (including the vertices and boundaries defining the region) that satisfies the following formulas 1 to 3: The region satisfying formulas 1 to 3 is synonymous with the region surrounded by formulas 1 to 3, and further with the region surrounded by triangles whose vertices are the intersection of formulas 1 and 2, the intersection of formulas 2 and 3, and the intersection of formulas 1 and 3.

[0014] The resin composition of the present invention contains a methacrylic resin (A), an acrylic block copolymer (B), and a specific amount of crosslinked rubber particles (C), and x and y are within the range satisfying the following formulas 1 to 3. This is thought to change the morphology when molded into a product, resulting in a balance of impact resistance, heat resistance, and transparency. Formula 1:y≧-0.43x+36.8 Formula 2:y≦19.4 Formula 3: x≦67

[0015] Formula 3 is a relational expression that defines the range of x, and was determined empirically in the examples described below as a range in which transparency can be improved while exhibiting excellent impact resistance and heat resistance. When the content x of the butyl acrylate polymer block in 100% by mass of the acrylic block copolymer (B) is 67% by mass or less, the transparency of the resin composition becomes good. In terms of achieving a balance between impact resistance, transparency, and heat resistance at a higher level, Formula 3 is preferably Formula 3A below, more preferably Formula 3B, and even more preferably Formula 3C. Formula 3A: x≦65 Formula 3B: x≦62 Formula 3C: x≦58 The lower limit of x in formula 3 is not particularly limited, and is usually 1 or more, preferably 5 or more, more preferably 10 or more, and even more preferably 30 or more. The content x of the butyl acrylate polymer block in the acrylic block copolymer (B) is, for example, when synthesizing the acrylic block copolymer (B), 1 It can be determined by measurement such as H-NMR, but when a commercially available acrylic block copolymer (B) is used, the catalog value is used.

[0016] Formula 2 is a relational expression that defines the range of y, and was determined empirically in the examples described below as a range in which heat resistance can be improved while maintaining excellent impact resistance and transparency. When the content y of monomer units derived from butyl acrylate in the acrylic block copolymer (B) is 19.4% by mass or less, relative to the total content of the methacrylic resin (A) and the acrylic block copolymer (B) (100% by mass), the resin composition exhibits good heat resistance. In terms of achieving a balance between impact resistance, transparency, and heat resistance at a higher level, Formula 2 is preferably Formula 2A below, and more preferably Formula 2B below. Formula 2A:y≦18.9 Formula 2B:y≦18.4 The lower limit of y in formula 2 is not particularly limited, and is usually 1 or more, preferably 2 or more, more preferably 3 or more, and particularly preferably 4 or more. The content y of the monomer units derived from butyl acrylate in the total content of the methacrylic resin (A) and the acrylic block copolymer (B) (100% by mass) can be calculated from the contents of the methacrylic resin (A) and the acrylic block copolymer (B) in the resin composition of the present invention and the content x.

[0017] Formula 1 is a formula showing the relationship between x and y, and in the examples described below, it was determined as an empirical formula showing the range in which impact resistance, particularly low-temperature impact resistance, can be improved without impairing heat resistance and transparency. That is, as is clear from FIG. 1 and Table 2, a line connecting the midpoint between Example 1 and Comparative Example 4 (x = 50, y = 15.3) and the midpoint between Example 6 and Comparative Example 7 (x = 60, y = 11.0) was set as the boundary where the impact resistance improvement effect was obtained, and the region above this line (the + direction of the Y axis) (presumably the region where the morphology of the molded body changes) was found to be the region in which impact resistance can be improved without impairing heat resistance and transparency, and the relationship represented by Formula 1 was set. In this way, by setting x and y within the above range (x and y satisfy Formula 1), in combination with Formula 2 and Formula 3, impact resistance, heat resistance, and transparency can be balanced.

[0018] In terms of further improving impact resistance, it is preferable that the boundary of the above formula 1 is the straight line connecting Example 1 and Example 6, and specifically, it is preferable that x and y satisfy formula 1A. In terms of a high effect of improving impact resistance, it is more preferable that the boundary is the straight line connecting Example 3 and Example 6, and specifically, it is more preferable that x and y satisfy formula 1B. Formula 1A:y≧-0.32x+31.6 Formula 1B:y≧-0.49x+41.8

[0019] In the present invention, a preferred embodiment of Formula 1 and Formula 1A is a formula corresponding to a straight line obtained by translating the straight line represented by each formula in the y-axis direction until it passes through Example 3. In this preferred embodiment, each formula is represented by the following formula. Formula 1-1:y≧-0.43x+38.8 Formula 1A-1:y≧-0.32x+33.3

[0020] In the resin composition of the present invention, the region that x and y should satisfy is the region that satisfies the above formulas 1 to 3, and within this region, at least one of formulas 1 to 3 can be set to a region to which the above-mentioned preferred embodiment is applied, in that impact resistance, heat resistance, and transparency can be balanced at a high level.

[0021] When the resin composition of the present invention contains multiple acrylic block copolymers (B), x and y in the conditions (including preferred conditions and ranges) that the acrylic block copolymers (B) must satisfy are the sum of the products of the mass fractions of each acrylic block copolymer (B) and x and y. For example, when the resin composition of the present invention contains two acrylic block copolymers (B1) having an x ​​of 50% by mass and an acrylic block copolymer (B2) having an x ​​of 60% by mass in a mass ratio of 40:60, x of the entire acrylic block copolymer (B) is 56% by mass (50 × 0.4 + 60 × 0.6).

[0022] Next, the components contained in the resin composition of the present invention will be described.

[0023] [Methacrylic resin (A)] The methacrylic resin (A) contained in the resin composition of the present invention is a random copolymer of a methacrylic acid ester and a vinyl monomer copolymerizable with the methacrylic acid ester, and has monomer units derived from the methacrylic acid ester and monomer units derived from the vinyl monomer.

[0024] <Methacrylic acid ester> The methacrylic acid ester from which the methacrylic acid ester-derived monomer unit is derived is not particularly limited, and examples thereof include alkyl methacrylate (ester), aralkyl methacrylate (ester), and aryl methacrylate (ester), with alkyl methacrylate being preferred. The number of carbon atoms in the alkyl group constituting the alkyl methacrylate is not particularly limited, but is preferably 1 to 8, and more preferably 1 to 4, in terms of excellent impact resistance, heat resistance, and transparency. Examples of alkyl methacrylates include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, and lauryl methacrylate. Examples of aralkyl methacrylates include benzyl methacrylate, and examples of aryl methacrylates include phenyl methacrylate. The methacrylic acid ester preferably includes an alkyl methacrylate having an alkyl group having 1 to 8 carbon atoms, such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, sec-butyl methacrylate, or iso-butyl methacrylate, more preferably includes an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms, even more preferably includes methyl methacrylate, and particularly preferably includes methyl methacrylate. The methacrylic acid ester may have a substituent. The methacrylic resin (A) may contain one or more types of monomer units derived from the above methacrylic acid esters.

[0025] <Vinyl monomer> The vinyl monomer from which the vinyl monomer-derived monomer unit is derived is not particularly limited as long as it is a monomer copolymerizable with a methacrylic acid ester and has a vinyl group, and examples thereof include an acrylic acid ester and a monofunctional monomer having one polymerizable carbon-carbon double bond in the molecule. (acrylic ester) The acrylic acid ester is not particularly limited, and examples thereof include alkyl acrylate (esters), aralkyl acrylate (esters), and aryl acrylate (esters), with alkyl acrylate being preferred. The number of carbon atoms in the alkyl group constituting the alkyl acrylate is not particularly limited, but is preferably 1 to 8, and more preferably 1 to 4, in terms of excellent impact resistance, heat resistance, and transparency. Examples of alkyl acrylates include methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, tert-butyl acrylate, sec-butyl acrylate, iso-butyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and lauryl acrylate. Examples of aralkyl acrylates include benzyl acrylate. Examples of aryl acrylates include phenyl acrylate. The acrylic acid ester preferably includes an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, such as methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, tert-butyl acrylate, sec-butyl acrylate, or iso-butyl acrylate, more preferably an alkyl acrylate having an alkyl group having 1 to 4 carbon atoms, even more preferably methyl acrylate, and particularly preferably methyl acrylate. The acrylic acid ester may have a substituent. The methacrylic resin (A) may contain one or more types of monomer units derived from the above acrylic acid esters.

[0026] (monofunctional monomer) The monofunctional monomer is not particularly limited, and examples thereof include styrene-based monomers such as styrene, α-methylstyrene, and vinyltoluene (aromatic vinyl compounds described below); alkenyl cyanides such as acrylonitrile and methacrylonitrile; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and maleic anhydride; amides such as acrylamide and methacrylamide; N-substituted maleimides such as phenylmaleimide, cyclohexylmaleimide, and methylmaleimide; vinyl acetate, vinylpyridine, vinyl ketone, vinyl chloride, vinylidene chloride, vinylidene fluoride, olefins described below, and conjugated diene compounds described below. A lactone ring structure, a glutaric anhydride structure, or a glutarimide structure may be introduced into the main chain (main skeleton) of the methacrylic resin (A) to improve heat resistance. The monofunctional monomer may have a substituent. The methacrylic resin (A) may contain one or more types of monomer units derived from the above monofunctional monomers.

[0027] <Other polymerizable compounds> The methacrylic resin (A) may have a monomer unit derived from a polymerizable compound other than a methacrylic acid ester and other than the above-mentioned vinyl monomer (sometimes referred to as "other polymerizable compound"). The other polymerizable compound is not particularly limited as long as it is a polymerizable compound copolymerizable with a methacrylic acid ester and / or the above-mentioned vinyl monomer. The other polymerizable compound is preferably a monomer having one polymerizable carbon-carbon double bond in the molecule, but a polyfunctional monomer having two or more polymerizable carbon-carbon double bonds in the molecule can also be used as a crosslinkable monomer. Examples of such polyfunctional monomers include polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, and trimethylolpropane triacrylate; alkenyl esters of unsaturated carboxylic acids such as allyl acrylate, allyl methacrylate, and allyl cinnamate; polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, and triallyl isocyanurate; and aromatic polyalkenyl compounds such as divinylbenzene. The methacrylic resin (A) may contain one or more types of monomer units derived from the above-mentioned other polymerizable compounds.

[0028] As the methacrylic resin (A), a methacrylic resin consisting of a random copolymer of at least one methacrylic acid ester and at least one acrylic acid ester is preferred in terms of excellent impact resistance, heat resistance, and transparency; a methacrylic resin consisting of a random copolymer of a methacrylic acid ester containing an alkyl methacrylate having an alkyl group of 1 to 8 carbon atoms and an acrylic acid ester containing an alkyl acrylate having an alkyl group of 1 to 8 carbon atoms is more preferred; a methacrylic resin consisting of a random copolymer of a methacrylic acid ester containing an alkyl methacrylate having an alkyl group of 1 to 4 carbon atoms and an acrylic acid ester containing an alkyl acrylate having an alkyl group of 1 to 4 carbon atoms is even more preferred; a methacrylic resin consisting of a random copolymer of a methacrylic acid ester containing methyl methacrylate and an acrylic acid ester containing methyl acrylate is particularly preferred; and a methacrylic resin consisting of a random copolymer of methyl methacrylate and methyl acrylate is most preferred. In the present invention, the methacrylic resin refers to a resin containing a higher content of monomer units derived from methacrylic monomers such as methacrylic acid esters than monomer units derived from acrylic monomers such as acrylic acid esters.

[0029] The total mass of the methacrylic resin (A) (random copolymer), i.e., the content of each monomer unit in the total of all monomer units constituting the methacrylic resin (A), which is 100% by mass, is set appropriately, but is preferably set within the following range. The content of monomer units derived from methacrylic acid esters in 100% by mass of the total mass of the methacrylic resin (A) is not particularly limited, but is preferably 85.0% by mass or more and less than 99.0% by mass, more preferably 90.0% by mass or more and 98.9% by mass or less, and even more preferably 92.0% by mass or more and 98.8% by mass or less. The content of the monomer units derived from vinyl monomers in 100% by mass of the total mass of the methacrylic resin (A) is not particularly limited, but is preferably more than 1.0% by mass and 15.0% by mass or less, more preferably 1.1% by mass or more and 10.0% by mass or less, and even more preferably 1.2% by mass or more and 8.0% by mass or less. The content of the monomer units derived from other polymerizable compounds in the total mass of the methacrylic resin (A) (100% by mass) is not particularly limited and can be determined appropriately. For example, it is preferably 1.0% by mass or less, more preferably 0.1% by mass or less. By setting the content of each monomer unit in the methacrylic resin (A) used in combination with the acrylic block copolymer (B) and crosslinked rubber particles (C) described below within the above range, it is possible to impart excellent impact resistance, heat resistance, and transparency to a molded article of the resin composition of the present invention.

[0030] The content of each monomer unit can be calculated from the amount of compound used to become each monomer unit to be subjected to polymerization, or can be measured by a known method. When the methacrylic resin (A) contains two or more types of each monomer unit, the above content of each monomer unit refers to the total content of the two or more types of monomer units.

[0031] The characteristics and physical properties of the methacrylic resin (A) are not particularly limited and are determined appropriately depending on the application, the characteristics of the molded article (for example, impact resistance, rigidity), and the like. For example, the melt flow rate (MFR) of the methacrylic resin (A) is usually 0.1 to 30 g / 10 min, but is not particularly limited. From the viewpoint of moldability, the MFR is preferably 0.2 to 20 g / 10 min, and more preferably 0.5 to 15 g / 10 min. The MFR of the methacrylic resin (A) is a value measured according to a method in accordance with JIS K 7210 under conditions of a load of 3.8 kg and a test temperature of 230°C. The weight-average molecular weight of the methacrylic resin (A) is not particularly limited and is, for example, preferably 30,000 to 300,000, more preferably 40,000 to 250,000, and even more preferably 50,000 to 200,000. In the present invention, the weight-average molecular weight is a weight-average molecular weight measured by gel permeation chromatography (GPC) and converted into standard polystyrene. The methacrylic resin (A) has thermoplastic properties. The methacrylic resin (A) may have a crosslinked structure, but is preferably a resin not having a crosslinked structure. In the present invention, the term "a resin (polymer) not having a crosslinked structure" refers to a resin (polymer) that does not actively form a crosslinked structure, for example, a resin (polymer) that does not copolymerize a polyfunctional monomer as a polymerizable compound.

[0032] The methacrylic resin (A) may be a commercially available product or may be a synthetic product prepared as appropriate. The methacrylic resin (A) can be prepared (synthesized) by polymerizing a methacrylic acid ester, a vinyl monomer, and optionally other polymerizable compounds using a conventionally known method, such as bulk polymerization, suspension polymerization, emulsion polymerization, or solution polymerization. In the production method of the methacrylic resin (A), additives such as a polymerization initiator, a chain transfer agent, and a suspension stabilizer may be used. In particular, the use of a chain transfer agent can adjust the properties of the methacrylic resin (A), such as the MFR and weight-average molecular weight. The amount of the chain transfer agent added can be determined as appropriate depending on the type and ratio of the selected monomers and the desired properties. The polymerization temperature is not particularly limited and can be, for example, 50 to 190°C.

[0033] [Acrylic block copolymer (B)] The acrylic block copolymer (B) contained in the resin composition of the present invention is a block copolymer containing a butyl acrylate polymer block (hereinafter sometimes referred to as an "AB block" or "block (b1)") and a methacrylate ester polymer block (hereinafter sometimes referred to as an "ME block" or "block (b2)"), and may optionally contain a block (b3) other than block (b1) and block (b2). This copolymer (B) may contain one or more of each of block (b1) and block (b2). The upper limit of the number of each block that the copolymer (B) may contain is not particularly limited, but may be, for example, 5. The number of block (b3) that the copolymer (B) may contain is not particularly limited, but may be, for example, 1 or 2. The total number of blocks constituting the copolymer (B) may be 2 or more, for example, 2 to 5, and preferably 2 or 3.

[0034] In the acrylic block copolymer (B), the bonding mode of each block is not particularly limited, and block (b1), block (b2), and block (b3) can be bonded appropriately. Examples of bonding modes between block (b1) and block (b2) include a diblock copolymer having a structure represented by the formula (b1)-(b2), in which one end of block (b2) is bonded to one end of block (b1), a triblock copolymer having a structure represented by the formula (b2)-(b1)-(b2), and a triblock copolymer having a structure represented by the formula (b1)-(b2)-(b1), in which one end of polymer block (b1) is bonded to each end of block (b2). In addition to the above, examples of the bonding mode of each block include a block copolymer in which a plurality of structures represented by "(b1)-(b2)" are bonded together in a radial pattern (a structure represented by [(b1)-(b2)-]nX (n is an integer of 2 or more, and X is a residue of a coupling agent used; the same applies below)), a block copolymer in which a plurality of structures represented by "(b2)-(b1)" are bonded together in a radial pattern (a structure represented by [(b2)-(b1)-]nX), a block copolymer in which a plurality of structures represented by "(b1)-(b2)-(b1)" are bonded together in a radial pattern (a structure represented by [(b1)-(b2)-(b1)-]nX), a star-shaped block copolymer such as a block copolymer in which a plurality of structures represented by "(b2)-(b1)-(b2)" are bonded together in a radial pattern (a structure represented by [(b2)-(b1)-(b2)-]nX), and a block copolymer having a branched structure. The block (b3) may be incorporated into the copolymer (B), for example, at the end of each of the above bonding patterns or between adjacent blocks.

[0035] In the present invention, the acrylic block copolymer (B) is preferably a block copolymer composed of block (b1) and block (b2), more preferably the diblock copolymer or triblock copolymer, and even more preferably a diblock copolymer having a structure represented by the formula (b1)-(b2) or a triblock copolymer having a structure represented by the formula (b2)-(b1)-(b2).

[0036] The content of block (b1) in 100% by mass of the acrylic block copolymer (B) (corresponding to "x" in formulas 1 and 3) is set to a range that satisfies the above formulas 1 and 3 in consideration of impact resistance, heat resistance, and transparency. In order to improve impact resistance and transparency and achieve a balance between impact resistance, heat resistance, and transparency, the content of block (b1) in 100% by mass of the acrylic block copolymer (B) (corresponding to "x" in formula 3) is 67% by mass or less, and a preferred range is the same as the preferred range for "x" in formula 3. The content of block (b2) in 100% by mass of the acrylic block copolymer (B) is not particularly limited, but is 33% by mass or more, preferably 35 to 95% by mass, and more preferably 38 to 90% by mass, in order to achieve a good balance between impact resistance, heat resistance, and transparency. The content of the block (b3) in 100% by mass of the acrylic block copolymer (B) is not particularly limited, and can be, for example, 0 to 10% by mass. When the acrylic block copolymer (B) has a plurality of each block, the above content of each block refers to the total amount of the plurality of blocks.

[0037] The weight average molecular weight of the acrylic block copolymer (B) is not particularly limited, and is preferably, for example, 10,000 to 400,000.

[0038] (Butyl acrylate polymer block (b1)) The butyl acrylate polymer block (b1) in the acrylic block copolymer (B) is a block containing monomer units derived from n-butyl acrylate (simply referred to as "butyl acrylate" in the block (b1)), and may contain one or more types of monomer units other than the monomer units derived from butyl acrylate. The other monomer units are not particularly limited and include monomer units derived from compounds copolymerizable with butyl acrylate. Examples include monomer units derived from acrylic esters other than butyl acrylate, monomer units derived from methacrylic esters, monomer units derived from vinyl monomers, and monomer units derived from other polymerizable compounds. Monomer units derived from acrylic esters other than butyl acrylate are preferred, and monomer units derived from alkyl acrylates having 1 to 8 carbon atoms (excluding n-butyl groups), monomer units derived from aralkyl acrylates (preferably benzyl acrylate), and monomer units derived from aryl acrylates (preferably phenyl acrylate) are more preferred. Acrylic esters other than butyl acrylate, methacrylic esters, vinyl monomers, and other polymerizable compounds are as described above for the methacrylic resin (A). When block (b1) has monomer units derived from butyl acrylate and other monomer units, the bonding pattern of each monomer unit is not particularly limited, as described above.

[0039] The block (b1) is more preferably a block consisting of monomer units derived from butyl acrylate, a block consisting of monomer units derived from butyl acrylate and monomer units derived from 2-ethylhexyl acrylate, or a block consisting of monomer units derived from butyl acrylate and monomer units derived from benzyl acrylate.

[0040] The content of monomer units derived from butyl acrylate in 100% by mass of block (b1) is not particularly limited, and is, for example, preferably 45% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, particularly preferably 90% by mass or more, and most preferably 90% by mass or more, and can be 100% by mass. The content of other monomer units in 100% by mass of block (b1) is not particularly limited, and is, for example, preferably 55% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 10% by mass or less.

[0041] (Methacrylate polymer block (b2)) The methacrylic acid ester polymer block (b2) in the acrylic block copolymer (B) is a block containing a monomer unit derived from a methacrylic acid ester, and may contain a monomer unit other than the monomer unit derived from a methacrylic acid ester.

[0042] The methacrylic acid ester constituting the methacrylic acid ester copolymer block is not particularly limited, and examples thereof include alkyl methacrylate (ester), aralkyl methacrylate (ester), aryl methacrylate (ester), etc., with alkyl methacrylate being preferred. The number of carbon atoms in the alkyl group constituting the alkyl methacrylate is not particularly limited, but is preferably 1 to 18, more preferably 1 to 8, and even more preferably 1 to 4. Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, glycidyl methacrylate, and allyl methacrylate. Among these, from the viewpoint of improving transparency and further heat resistance, alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, and isobornyl methacrylate are preferred, with methyl methacrylate being more preferred. Block (b2) may contain one or more types of monomer units derived from these methacrylic acid esters.

[0043] The compound that becomes the other monomer unit is not particularly limited, and examples thereof include compounds copolymerizable with methacrylic acid esters, such as acrylic acid esters, vinyl monomers, and other polymerizable compounds. The acrylic acid esters, vinyl monomers, and other polymerizable compounds are as described above for the methacrylic resin (A). Block (b2) can contain one or more types of other monomer units. When block (b2) has a monomer unit derived from a methacrylic acid ester and another monomer unit, the bonding mode of each monomer unit is not particularly limited, as described above.

[0044] The block (b2) is more preferably a block consisting of monomer units derived from a methacrylic acid ester, and even more preferably a block consisting of monomer units derived from methyl methacrylate.

[0045] The content of monomer units derived from methacrylic acid esters in 100% by mass of block (b2) is not particularly limited, and is, for example, preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 98% by mass or more, and can also be 100% by mass. The content of other monomer units in 100% by mass of block (b2) is not particularly limited, and is, for example, preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 2% by mass or less.

[0046] (Block (b3)) The block (b3) that may be contained in the acrylic block copolymer (B) may be any block that does not correspond to the block (b1) or the block (b2). The compound that serves as the monomer unit constituting the block (b3) is not particularly limited, and examples thereof include olefins such as ethylene, propylene, 1-butene, isobutylene, and 1-octene; conjugated diene compounds such as 1,3-butadiene, isoprene, and myrcene; aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, and m-methylstyrene; vinyl acetate, vinylpyridine, acrylonitrile, methacrylonitrile, vinyl ketone, vinyl chloride, vinylidene chloride, vinylidene fluoride, acrylamide, methacrylamide, ε-caprolactone, and valerolactone. When the acrylic block copolymer (B) contains a plurality of blocks (b3), the types, composition ratios, weight-average molecular weights, and contents in the acrylic block copolymer (B) of the monomer units (monomers) constituting the blocks (b3) may be the same or different.

[0047] The acrylic block copolymer (B) may have a functional group such as a hydroxyl group, a carboxyl group, an acid anhydride group, or an amino group in the molecular chain or at the molecular chain terminal, as appropriate. The acrylic block copolymer (B) may have a crosslinked structure, but is preferably a polymer that does not have a crosslinked structure.

[0048] The method for producing the acrylic block copolymer (B) is not particularly limited, and any suitable conventionally known production method can be employed. Examples of methods for producing the acrylic block copolymer (B) include the living polymerization of the monomers capable of constituting the various polymer blocks described above (living polymerization method). Examples of such living polymerization methods include anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of a mineral acid salt such as an alkali metal or alkaline earth metal salt, anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organoaluminum compound, polymerization using an organic rare earth metal complex as a polymerization initiator, and radical polymerization using an α-halogenated ester compound as an initiator in the presence of a copper compound. Other examples include a method for producing a mixture containing an acrylic block copolymer by polymerizing the monomers constituting each block using a polyvalent radical polymerization initiator or a polyvalent radical chain transfer agent. Among these methods for producing an acrylic block copolymer, it is particularly preferable to employ a method in which an anionic polymerization is carried out in the presence of an organoaluminum compound using an organic alkali metal compound as a polymerization initiator, because this method allows the production of a highly pure acrylic block copolymer, facilitates control of the molecular weight and composition ratio, and is economical. In the present invention, commercially available acrylic block copolymers (B) can also be used. Examples of commercially available acrylic block copolymers (B) that can be suitably used in the present invention include the LA series and LK series of Kuraty (registered trademark) manufactured by Kuraray Co., Ltd., and NANOSTRENGTH (registered trademark) manufactured by ARKEMA.

[0049] [Crosslinked rubber particles (C)] The crosslinked rubber particles (C) contained in the resin composition of the present invention may be any rubber particles having a crosslinked structure, and are preferably spherical (meth)acrylic rubber particles having a three-layer structure consisting of an inner layer made of a hard polymer mainly composed of alkyl methacrylate, an intermediate layer made of an elastic copolymer mainly composed of alkyl acrylate, and an outer layer made of a hard polymer mainly composed of alkyl methacrylate. This three-layer structure spherical (meth)acrylic rubber particle has a so-called core-shell structure.

[0050] In order to suppress blocking, the crosslinked rubber particles (C) are preferably used as a mixture with the above-mentioned methacrylic resin (A). In this case, the amount of the methacrylic resin (A) mixed with the crosslinked rubber particles (C) is not particularly limited and can be appropriately determined taking into consideration the suppression of blocking. The amount of the methacrylic resin (A) mixed with the crosslinked rubber particles (C) is included in the content of the methacrylic resin (A) in the resin composition of the present invention.

[0051] In the crosslinked rubber particles (C), the inner layer is a hard polymer mainly composed of alkyl methacrylate. This hard polymer layer is preferably a polymer of a monomer consisting of 70 to 100 mass% of alkyl methacrylate and 0 to 30 mass% of another vinyl monomer copolymerizable therewith. As the alkyl methacrylate, an ester having an alkyl group having about 1 to 4 carbon atoms, particularly methyl methacrylate, is advantageous. Examples of other vinyl monomers that may be used include acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and cyclohexyl acrylate, aromatic vinyl compounds such as styrene, and vinyl cyan compounds such as acrylonitrile.

[0052] It is also effective to use a copolymerizable crosslinking monomer as one of the other vinyl monomers. The crosslinking monomer may be any one having at least two polymerizable carbon-carbon double bonds in one molecule, and examples thereof include the polyfunctional monomers described above for the methacrylic resin (A). Among these, alkenyl esters of unsaturated carboxylic acids and polyalkenyl esters of polybasic acids are preferred. These crosslinking monomers can be used alone or in combination of two or more types as needed.

[0053] The intermediate layer of the crosslinked rubber particles (C) is composed of an elastic copolymer primarily composed of alkyl acrylate. Specifically, it is preferably an elastic copolymer layer obtained by polymerizing a monomer mixture consisting of 50 to 99.9% by mass of alkyl acrylate, 0 to 49.9% by mass of another vinyl monomer copolymerizable therewith, and 0.1 to 10% by mass of a copolymerizable crosslinking monomer. The intermediate layer can be formed by polymerizing a monomer mixture having the composition shown here in the presence of the hard polymer that constitutes the inner layer. Two or more of the alkyl acrylate, other vinyl monomer, and crosslinking monomer may be used within the respective definitions, as long as the composition falls within the above-mentioned ranges.

[0054] The alkyl acrylate used here may be, for example, one in which the alkyl group has 1 to 8 carbon atoms. Of these, one in which the alkyl group has 4 to 8 carbon atoms, such as butyl acrylate or 2-ethylhexyl acrylate, is preferred.

[0055] The other vinyl monomer copolymerizable with alkyl acrylate, which is used as desired to form the elastic copolymer, is a monofunctional compound having one polymerizable carbon-carbon double bond in one molecule. Specific examples of suitable monomers include methacrylic acid esters such as methyl methacrylate, butyl methacrylate, and cyclohexyl methacrylate, aromatic vinyl compounds such as styrene, and vinyl cyan compounds such as acrylonitrile.

[0056] The copolymerizable cross-linkable monomer used to form the elastic copolymer may be any monomer having at least two polymerizable carbon-carbon double bonds in one molecule, and may be the same as those exemplified above as optional components forming the hard polymer layer of the inner layer. For the elastic copolymer of the intermediate layer, an alkenyl ester of an unsaturated carboxylic acid or a polyalkenyl ester of a polybasic acid is also preferably used.

[0057] The crosslinked rubber particles (C) have a layer of a hard polymer mainly composed of alkyl methacrylate outside the intermediate layer composed of the elastic copolymer. This outer layer is preferably formed by polymerizing, in the presence of the polymers formed as the inner and intermediate layers, a monomer mixture consisting of 50 to 100% by mass of alkyl methacrylate, 0 to 50% by mass of an acrylic acid ester, and 0 to 49% by mass of at least one other vinyl monomer copolymerizable therewith. This results in at least one polymer layer composed of the monomers listed here being bonded to the surface of the elastic copolymer constituting the intermediate layer.

[0058] The alkyl methacrylate that is the main component of the outer layer is preferably an ester having an alkyl group having about 1 to 8 carbon atoms, such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, etc. Examples of the acrylic acid ester that may be used include alkyl esters of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, and cyclohexyl acrylate. Examples of other vinyl monomers that may be used and are copolymerizable with the alkyl methacrylate and / or acrylic acid ester include aromatic vinyl compounds such as styrene, and vinyl cyan compounds such as acrylonitrile.

[0059] For the three-layer structure (meth)acrylic rubber particles as described above, the contents of JP-B-55-27576 can be appropriately referred to, and the contents of the same are incorporated herein as is. In particular, the composition described in Example 3 of JP-B-55-27576 is one of the preferred compositions.

[0060] In the crosslinked rubber particles (C), the mass ratio of the inner layer / intermediate layer / outer layer is not particularly limited and can be set appropriately, but is preferably, for example, 30 to 40 / 40 to 50 / 10 to 30. By setting the mass ratio of the inner layer / intermediate layer / outer layer within the above range, the impact resistance of a molded article formed from the resin composition of the present invention can be increased without decreasing the heat resistance and transparency.

[0061] The crosslinked rubber particles (C) can be produced, for example, by first polymerizing the monomer that will form the inner layer by emulsion polymerization or the like, polymerizing the monomer that will form the middle layer in the presence of the resulting polymer particles, and then polymerizing the monomer that will form the outer layer in the presence of the polymer particles that have formed up to the middle layer. In this process, the particle size of the crosslinked rubber particles (C) can be adjusted by adjusting the amount of emulsifier added and the amount of monomer charged.

[0062] The particle size of the crosslinked rubber particles (C) is not particularly limited and can be determined appropriately. In order to maintain the excellent effects of the methacrylic resin (A) and the acrylic block copolymer (B), the particle size of the crosslinked rubber particles (C) is preferably, for example, in the weight average particle size up to the intermediate layer in the range of 0.05 to 0.30 μm.

[0063] [Other ingredients] The resin composition of the present invention may contain components other than the above-mentioned components (hereinafter, sometimes referred to as "other components"). The other components are not particularly limited and include components commonly used in resin compositions, such as other (co)polymers that do not correspond to either the methacrylic resin (A) or the acrylic block copolymer (B), release agents, anti-sticking agents, UV absorbers, lubricants, antioxidants, plasticizers, antistatic agents, dyes (pigments), neutralizing agents, nucleating agents, adhesives, anti-fogging agents, anti-blocking agents, melt flow rate modifiers, fillers, solvents, silica particles, silica composite oxide particles, alumina particles, titania particles, etc. The resin composition of the present invention may contain one or more of the other components. In the present invention, the other components may be mixed with the methacrylic resin (A) during the preparation of the resin composition, or may be premixed with the methacrylic resin (A) prior to the preparation of the resin composition.

[0064] In a preferred embodiment of the resin composition of the present invention, the resin composition does not contain a glycerin fatty acid ester. In other words, the resin composition of the present invention does not have antiviral properties. The glycerin fatty acid ester may be any glycerin fatty acid ester that does not have antiviral properties, and examples thereof include glycerin fatty acid esters having an HLB value of 5 to 12, such as glycerin monolaurate (LBH value 5.4) and diglycerin monolaurate (LBH value 9.4). The HLB value is a value calculated by the Griffin method, but values ​​disclosed in known literature can also be used. In the present invention, the term "a resin composition that does not contain a glycerin fatty acid ester" does not exclude embodiments in which the resin composition inevitably contains a glycerin fatty acid ester, but also encompasses embodiments in which the resin composition contains less than 0.5% by mass of a glycerin fatty acid ester when the total of the methacrylic resin (A), the acrylic block copolymer (B), the crosslinked rubber particles (C), and the glycerin fatty acid ester is 100% by mass.

[0065] [Composition of Resin Composition] The resin composition of the present invention may contain the above-mentioned methacrylic resin (A), acrylic block copolymer (B), and crosslinked rubber particles (C). The content of each component (composition of the composition) is not particularly limited and is determined appropriately depending on the application, properties of the molded product (e.g., impact resistance, rigidity), etc., and is preferably set, for example, within the following ranges: The content of the methacrylic resin (A) in 100 parts by mass of the resin composition of the present invention (total of the methacrylic resin (A), the acrylic block copolymer (B), and the crosslinked rubber particles (C)) is preferably 10 to 84 parts by mass in terms of impact resistance, heat resistance, and transparency, more preferably 30 to 82 parts by mass, and even more preferably 50 to 80 parts by mass in terms of achieving a balance between impact resistance, heat resistance, and transparency at an even higher level. The content of the acrylic block copolymer (B) in 100 parts by mass of the resin composition of the present invention is preferably 15 to 50 parts by mass in terms of impact resistance, heat resistance, and transparency, more preferably 17 to 45 parts by mass, and even more preferably 19 to 40 parts by mass, in terms of achieving a balance between impact resistance, heat resistance, and transparency at even higher levels. The content of the crosslinked rubber particles (C) in 100 parts by mass of the resin composition of the present invention may be 0.1 parts by mass or more in terms of impact resistance, heat resistance, and transparency, and is preferably 1 to 40 parts by mass. In order to achieve a balance between impact resistance, heat resistance, and transparency at an even higher level, the content is more preferably 3 to 39 parts by mass, and even more preferably 5 to 38 parts by mass.

[0066] The content of other components in 100 parts by mass of the resin composition of the present invention is appropriately determined within a range that does not impair the effects of the present invention, and can be, for example, 0.5 parts by mass or less.

[0067] [Preparation of Resin Composition] The resin composition of the present invention can be produced by a known method, and can usually be prepared by mixing or kneading the methacrylic resin (A), the acrylic block copolymer (B), the crosslinked rubber particles (C), and optionally other components. The mixing and kneading methods are not particularly limited, and any suitable conventionally known method, such as a melt-kneading method, can be used. Conventional known mixers and kneaders can be used as equipment for mixing and kneading, including single-screw kneaders, twin-screw kneaders, multi-screw extruders, Henschel mixers, Banbury mixers, kneaders, and roll mills. Furthermore, when a higher rotation speed is required in the kneading method, a high-shear processing device can also be used. The kneading temperature is not particularly limited, and can be appropriately set taking into account the selected components, their amounts, properties, etc., and can be, for example, 200 to 280°C.

[0068] [[Molded body]] The molded article of the present invention is a molded article containing the resin composition of the present invention described above, and is usually a molded article obtained by molding the resin composition of the present invention by a known molding method. The molded article of the present invention has excellent impact resistance, heat resistance, and transparency, and also has the excellent characteristics of being able to recover the methacrylic acid ester in the resin composition (chemical recycling) and to recover it as a recycled material (material recycling). Therefore, the molded article of the present invention can be used for various purposes and is molded into a form, shape, and size suitable for each purpose. Examples of shapes include a sheet (including a film, a strip, and a plate, and may be long or short (leaf)), a block, and various three-dimensional shapes. By utilizing the above-mentioned excellent characteristics, the molded article of the present invention can be used in various applications, for example, in addition to the above-mentioned applications of conventional (meth)acrylic resins, for outdoor applications, and applications requiring impact resistance, heat resistance, and transparency, etc. For example, it can be suitably used as exterior vehicle parts such as front grilles, bumpers, fenders, and spoilers, and is particularly suitably used as front grilles requiring excellent impact resistance, heat resistance, and transparency.

[0069] The molded article of the present invention may be a molded article consisting solely of a molded article made of the resin composition of the present invention, or may be a molded article consisting of a molded article and other components. Examples of other components include a surface layer (coating layer), a colored layer, etc. Furthermore, the molded article of the present invention may be subjected to a surface treatment such as a hard coat or a water-repellent treatment, as necessary.

[0070] [Method of manufacturing molded body] The method for producing the molded article of the present invention is not particularly limited, and known molding methods can be applied, such as press molding, extrusion molding, injection molding, etc. The molding conditions for each molding method are not particularly limited as long as the resin composition of the present invention can be molded in a molten state, and can be set appropriately depending on the composition and physical properties of the resin composition of the present invention, and the kneading method and kneading conditions (kneading temperature) used in preparing the resin composition of the present invention can be preferably applied.

[0071] [[Method for decomposing and recovering a resin composition]] The resin composition of the present invention may be discarded or incinerated, but from the viewpoints of reducing the environmental load (environmental protection) and building a recycling-oriented society (sustainable society), it is desirable to recycle it. Through further investigations, the present inventors have found that methacrylic acid esters, and in some cases acrylic acid esters, can be recovered and recycled from the resin composition of the present invention by the following method. This decomposition and recovery method can also be applied to the molded article of the present invention. For example, similar to the resin composition of the present invention, methacrylic acid esters and the like can be recovered and recycled from the molded article of the present invention (including off-spec products, production intermediates, production waste, or used recovered products thereof) by the following method.

[0072] The method for decomposing and recovering a resin composition of the present invention comprises the steps of decomposing the resin composition of the present invention at a temperature of 380°C or higher, separating the volatile components and solid matter generated in this step, and recovering the methacrylic acid ester from the volatile components. By using this decomposition and recovery method of the present invention, it is possible to chemically recycle the methacrylic resin (A) contained in the resin composition, as well as the methacrylic acid ester and, in some cases, the acrylic acid ester constituting the acrylic block copolymer (B) and / or crosslinked rubber particles (C).

[0073] [Disassembly process] The heating temperature (decomposition temperature) of the resin composition of the present invention in the decomposition step may be 380°C or higher, and is appropriately determined depending on the types (boiling point, decomposition temperature, etc.) of the methacrylic resin (A), acrylic block copolymer (B), crosslinked rubber particles (C), etc. contained in the resin composition. For example, the temperature at which the methacrylic resin (A) or the like is decomposed and the resulting methacrylic acid ester or the like becomes gaseous is preferred. Specifically, the temperature is preferably 385°C or higher, more preferably 390°C or higher. The upper limit of the heating temperature is not particularly limited, and is, for example, preferably 500°C or lower, more preferably 460°C or lower. The heating time is not particularly limited and can be appropriately determined depending on the degree of decomposition of the methacrylic resin (A) or the like. For example, it can be 5 to 20 minutes. In this way, the methacrylic resin (A) or the like forming the resin composition of the present invention can be thermally decomposed into methacrylic acid esters and then acrylic acid esters.

[0074] [Separation process] In the separation step, the volatile components and solid matter generated in the decomposition step are separated. Although various known separation methods can be applied to this separation, it is preferable to separate the methacrylic acid ester and other volatile components into a gaseous state at the decomposition temperature and the other components into solid matter, thereby performing gas-solid separation.

[0075] [Recovery process] In the decomposition and recovery method of the present invention, a gaseous methacrylic acid ester or the like is captured and recovered. The method is not particularly limited, and various known recovery methods can be applied.

[0076] [Other processes] The decomposition and recovery method of the present invention may also include other steps in addition to the steps described above, such as a step of purifying the recovered (meth)acrylic acid ester and a step of cutting the resin composition of the present invention (strands or pellets).

[0077] The decomposition and recovery method of the present invention can decompose and recover the resin composition of the present invention and the molded article of the present invention through the simple steps of the decomposition step, separation step, and recovery step described above. Specifically, it can separate and recover a methacrylic acid ester, and in some cases an acrylic acid ester, from the resin composition of the present invention and the molded article of the present invention.

[0078] [[Method of manufacturing recycled materials]] The molded article of the present invention may be discarded or incinerated, but from the viewpoint of reducing the environmental load (environmental protection) and building a recycling-oriented society (sustainable society), it is desirable to recover and manufacture the resin composition as a recycled material. As a result of further investigations, the present inventors have found that the resin composition can be recovered and recycled as a recycled material from the molded article of the present invention by the method described below. This method for manufacturing recycled materials can also be applied to the resin composition of the present invention. For example, as with the molded article of the present invention, the resin composition can also be recovered and recycled as a recycled material from the resin composition of the present invention (including its non-standard products, manufacturing waste, recovered products, etc.) by the method described below. The resin composition recovered and produced by the method for producing recycled materials of the present invention is usually a composition containing the methacrylic resin (A), the acrylic block copolymer (B), and the crosslinked rubber particles (C), and is preferably the composition of the resin composition of the present invention, but it may also be a composition that does not contain any of the components or a composition that contains only a small amount of any of the components. In this case, the resin composition of the present invention can be obtained by adding the component that is not contained or that is contained in a small amount.

[0079] The method for producing a recycled material of the present invention includes a step of melting and kneading a raw material containing crushed material obtained by crushing a molded body. In this step, the content of the crushed material in 100 parts by mass of the raw material is 0.01 to 99.99 parts by mass. By using such a method for producing a recycled material of the present invention, the resin composition of the present invention forming the molded body can be recycled as a recycled material, preferably while maintaining its composition.

[0080] The method for crushing the compact is not particularly limited, and various known methods for crushing, disintegrating, pulverizing, etc. can be applied. The shape, size, etc. of the crushed material (crushed material, pulverized material, disintegrated material) are appropriately determined taking into consideration the handleability, the melt-kneaded state, etc. The raw material used for melt-kneading may contain the crushed material obtained in this manner, and other components may be added or unnecessary components may be removed, taking into consideration the composition of the molded article of the present invention, the recovery process, etc. However, the content of crushed material per 100 parts by mass of raw material can usually be 0.01 to 99.99 parts by mass, and is preferably 0.1 to 99.9 parts by mass, more preferably 1 to 99 parts by mass, and even more preferably 10 to 90 parts by mass, in order to enable the resin composition of the present invention to be recycled while maintaining its composition. The melt-kneading method and conditions are not particularly limited, but the kneading method and kneading conditions (kneading temperature) used in preparing the resin composition of the present invention can be preferably applied.

[0081] The method for producing a recycled material of the present invention may also include other steps in addition to the steps described above, such as a step of adjusting the composition of the recovered resin composition (a step of adding a component that is insufficiently contained to the recovered resin composition, a step of removing a component that is excessively contained from the recovered resin composition), and a step of purifying the recovered resin composition.

[0082] The method for producing a recycled material of the present invention can recover and produce a resin composition as a recycled material from the molded article of the present invention by the above-mentioned simple steps, and the resin composition of the present invention can be material recycled (horizontal recycling, cascade recycling). In a preferred embodiment of the method for producing a recycled material of the present invention, the resin composition of the present invention can be recovered and produced while maintaining the composition of the resin composition of the present invention, and horizontal recycling is also possible. [Example]

[0083] Examples of the present invention will be shown below, but the present invention is not limited to these examples.

[0084] [Production of methacrylic resin (A)] <Production of methacrylic resin (A1)> A mixture of 97.5 parts by mass of methyl methacrylate and 2.5 parts by mass of methyl acrylate, 0.016 parts by mass of 1,1-di(tert-butylperoxy)cyclohexane, and 0.16 parts by mass of n-octyl mercaptan were continuously fed into a polymerization reactor equipped with a stirrer, and a polymerization reaction was carried out at 175°C with an average residence time of 43 minutes. Next, the reaction liquid (partial polymer) discharged from the polymerization reactor was preheated, and then the reaction liquid was supplied to a devolatilizing extruder, where the unreacted monomer components were vaporized and recovered, and a pellet-shaped methacrylic resin (A1) was obtained. The obtained methacrylic resin (A1) was a random copolymer containing 97.5% by mass of monomer units derived from methyl methacrylate and 2.5% by mass of monomer units derived from methyl acrylate, and had a melt flow rate (MFR (230°C, 3.8 kg)) of 2 g / 10 min measured in accordance with JIS K 7210.

[0085] <Production of methacrylic resin (A2)> Pellet-shaped methacrylic resin (A2) was obtained in the same manner as for methacrylic resin (A1), except that a mixture of 96.0 parts by mass of methyl methacrylate and 4.0 parts by mass of methyl acrylate, 0.016 parts by mass of 1,1-di(tert-butylperoxy)cyclohexane, and 0.20 parts by mass of n-octyl mercaptan were continuously fed into a polymerization reactor equipped with a stirrer. The obtained methacrylic resin (A2) was a random copolymer containing 96.0% by mass of monomer units derived from methyl methacrylate and 4.0% by mass of monomer units derived from methyl acrylate, and had a melt flow rate (MFR (230°C, 3.8 kg)) of 5 g / 10 min measured in accordance with JIS K 7210.

[0086] <Production of methacrylic resin (A3)> Pellet-shaped methacrylic resin (A3) was obtained in the same manner as for methacrylic resin (A1), except that a mixture of 99.2 parts by mass of methyl methacrylate and 0.8 parts by mass of methyl acrylate, 0.016 parts by mass of 1,1-di(tert-butylperoxy)cyclohexane, and 0.17 parts by mass of n-octyl mercaptan were continuously fed into a polymerization reactor equipped with a stirrer. The obtained methacrylic resin (A3) was a random copolymer containing 99.2% by mass of monomer units derived from methyl methacrylate and 0.8% by mass of monomer units derived from methyl acrylate, and had a melt flow rate (MFR (230°C, 3.8 kg)) of 2 g / 10 min measured in accordance with JIS K 7210.

[0087] [Preparation of acrylic block copolymer (B)] A commercially available product was used as the acrylic block copolymer (B) used in the examples and comparative examples, the details of which are shown in Table 1. Unless otherwise specified below, butyl acrylate refers to n-butyl acrylate. [Table 1] In the "Block Structure" column of Table 1, "MMA" represents a methyl methacrylate polymer block, and "BA" represents a butyl acrylate polymer block. Furthermore, the "Butyl acrylate polymer block content (x)" in Table 1 is the content of the butyl acrylate polymer block relative to 100% by mass of the acrylic block copolymer (B), and is a catalog value.

[0088] [Production of Mixture (C'1) of Crosslinked Rubber Particles (C) and Methacrylic Resin] Crosslinked rubber particles (C) were produced by emulsion polymerization according to the method described in Japanese Patent Publication No. 55-27576. Specifically, the innermost layer was a hard copolymer obtained by polymerizing methyl methacrylate, methyl acrylate, and allyl methacrylate in proportions of 94.0 mass%, 5.8 mass%, and 0.2 mass%, respectively; the middle layer was an elastic copolymer obtained by polymerizing n-butyl acrylate, styrene, and allyl methacrylate in proportions of 81.5 mass%, 16.5 mass%, and 2.0 mass%, respectively; and the outermost layer was a hard copolymer obtained by polymerizing methyl methacrylate and methyl acrylate in proportions of 94.5 mass% and 5.5 mass%, respectively. Crosslinked rubber particles (C1) (spherical (meth)acrylic rubber particles with a three-layer structure) were produced. The weight average particle diameter of the elastic polymer constituting the middle layer was 0.23 μm. Next, in order to prevent blocking of the crosslinked rubber particles (C1), 67% by mass of the crosslinked rubber particles (C1) were mixed in latex form with 33% by mass of a methacrylic resin (A4) consisting of a random copolymer obtained by polymerizing methyl methacrylate and methyl acrylate in ratios of 90% by mass and 10% by mass, followed by salting out to produce a mixture (C'1) of the crosslinked rubber particles (C1) and the methacrylic resin (A4).

[0089] [Example 1] <Production of Resin Composition (Melting and Kneading)> 25 parts by mass of methacrylic resin (A1), 20 parts by mass of methacrylic resin (A2), 25 parts by mass of LA4285, and 30 parts by mass of a mixture of crosslinked rubber particles (C1) and methacrylic resin (A4) (C'1) were melt-kneaded using a twin-screw extruder (model: TEX30SS-30AW-2V, manufactured by Japan Steel Works, Ltd.) under the following kneading conditions, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped resin composition. (Mixing conditions in melt mixing) The temperatures of the extruder were set at 200°C, 200°C, 210°C, 220°C, 230°C, 240°C, 240°C, and 250°C from the raw material inlet side for eight heaters arranged at a distance from one another between the raw material inlet and the outlet. The screw rotation speed was set at 200 rpm. The raw material methacrylic resin (A1) and LA4285 were mixed and then fed from the pellet feeder at a feeding rate of 14.0 kg / hour.

[0090] <Production of molded products (injection molding)> The obtained pellet-like resin composition was molded into a flat plate-shaped molded product having a length of 50 mm, a width of 50 mm, and a thickness of 3.0 mm using an injection molding machine (EC130SXII-4A, manufactured by Toshiba Machine Co., Ltd.) under the following injection molding conditions. (Injection molding conditions) The temperatures inside the cylinder were set at 60°C, 230°C, 240°C, 250°C, and 250°C from the raw material inlet side, using five heaters spaced apart from each other between the inlet and the outlet. Other molding conditions were as follows: Injection speed: 50mm / sec Maximum injection pressure: 200MPa Holding pressure: 120MPa Mold temperature: 60℃ Cooling time: 40 seconds

[0091] [Examples 2 to 7 and Comparative Examples 1 to 10] In the production of the resin composition of Example 1, except that the composition (type and amount (content) of each component) was changed to that shown in Table 2, a resin composition was produced in the same manner as in the production of the resin composition of Example 1, and then a molded body was produced.

[0092] [Table 2]

[0093] [evaluation] The produced molded articles were evaluated for transparency, heat resistance, and low-temperature impact resistance. The results are shown in Table 3. <Evaluation of Transparency of Molded Products> The transparency of the molded article was evaluated by the total light transmittance (Tt) (unit: %) measured at 23°C in accordance with JIS K 7361-1. In this evaluation, a larger Tt indicates better transparency, and in the present invention, a Tt of 70% or more can be said to be good transparency.

[0094] <Evaluation of heat resistance of molded products> The heat resistance of the molded body was evaluated by the Vicat softening temperature (VST) (unit: °C) measured according to the B50 method of JIS K 7206. In this evaluation, a higher VST indicates better heat resistance, and in the present invention, a VST of 88.0 °C or higher can be said to have good heat resistance.

[0095] <Evaluation of low-temperature impact resistance of molded products> The low-temperature impact resistance of the molded articles was evaluated using a DuPont-type apparatus as specified in JIS K 5600-5-3. Specifically, a 12.7 mm radius punch and a cradle were used, along with a 300 g weight. The weight height was adjusted to 10 cm, 15 cm, 20 cm, 50 cm, or 100 cm. The test began by cooling the sample to -30°C, gradually raising the weight height, and recording the lowest weight height at which the test piece broke (first crack height) (unit: cm). In this evaluation, a higher first crack height indicates better low-temperature impact resistance; in the present invention, a first crack height of greater than 15 cm is considered to indicate good low-temperature impact resistance.

[0096] [Table 3]

[0097] <Evaluation of thermal decomposition> Thermal decomposition was evaluated by the temperature at which a pellet-shaped sample loses 5% of its mass when heated at 2°C / min in a nitrogen atmosphere (the mass of the sample before heating is considered to be 100%). In this evaluation, the higher the 5% mass loss temperature, the more difficult the sample is to thermally decompose. The 5% mass loss temperature of the pellets of the resin composition prepared in Example 2 was 316.1°C. On the other hand, pellets of Comparative Example 11 were produced in the same manner as in Example 2, except that the methacrylic resin (A1) in Example 2 was changed to the methacrylic resin (A3). The content of methyl acrylate monomer in the methacrylic resin (A) contained in these pellets was 0.8% by mass. The 5% mass loss temperature of these pellets was 314.6°C.

[0098] As is clear from the results shown in Tables 1 to 3 and Figure 1, the comparative resin compositions that do not contain the methacrylic resin (A), the acrylic block copolymer (B), and the crosslinked rubber particles (C), as well as the comparative resin compositions that contain the above three components but in which x and y do not fall within the range satisfying Formulas 1 to 3, are unable to balance low-temperature impact resistance, heat resistance, and transparency. In contrast, the resin compositions of the examples that contain the methacrylic resin (A), the acrylic block copolymer (B), and a specific amount of crosslinked rubber particles (C) and in which x and y fall within the range satisfying Formulas 1 to 3, are able to balance low-temperature impact resistance, heat resistance, and transparency.

[0099] Furthermore, as is clear from the results of the thermal decomposition evaluation, when the content of monomer units derived from vinyl monomers in the methacrylic resin (A) is more than 1.0 mass% and not more than 15.0 mass%, the methacrylic resin (A) is less susceptible to thermal decomposition, and a desirable effect of suppressing appearance defects such as silver streaks caused by thermal decomposition gas during injection molding or extrusion molding can be obtained. However, although the above-mentioned methacrylic resin (A) is less susceptible to thermal decomposition, it can be applied to the method for recovering a resin composition and the method for producing a recycled material of the present invention.

Claims

1. A resin composition comprising a methacrylic resin (A), an acrylic block copolymer (B), and crosslinked rubber particles (C), the methacrylic resin (A) is a random copolymer of a methacrylic acid ester and a vinyl monomer copolymerizable with the methacrylic acid ester, the acrylic block copolymer (B) is a block copolymer containing a butyl acrylate polymer block and a methacrylic acid ester polymer block, wherein when the content of the butyl acrylate polymer block is x% by mass relative to 100% by mass of the acrylic block copolymer (B), and the content of the monomer unit derived from butyl acrylate in the acrylic block copolymer (B) is y% by mass relative to 100% by mass of the total content of the methacrylic resin (A) and the acrylic block copolymer (B), x and y are within a region satisfying the following formulas 1 to 3: The resin composition, wherein the content of the crosslinked rubber particles (C) is 0.1 parts by mass or more per 100 parts by mass of the resin composition. Formula 1: y≧-0.43x+36.8 Formula 2: y≦19.4 Formula 3: x≦67

2. Relative to 100 parts by mass of the resin composition, The content of the methacrylic resin (A) is 10 parts by mass or more and 84 parts by mass or less, the content of the acrylic block copolymer (B) is 15 parts by mass or more and 50 parts by mass or less, The resin composition according to claim 1, wherein the content of the crosslinked rubber particles (C) is 1 part by mass or more and 40 parts by mass or less.

3. The methacrylic resin (A) is With respect to 100% by mass of the random copolymer, The content of the monomer units derived from the methacrylic acid ester is 85.0% by mass or more and less than 99.0% by mass, The resin composition according to claim 1, wherein the content of the monomer units derived from the vinyl monomer is more than 1.0 mass % and not more than 15.0 mass %.

4. The resin composition according to claim 3, wherein the methacrylic acid ester comprises an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms.

5. The resin composition according to claim 4, wherein the alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms comprises methyl methacrylate.

6. A molded article comprising the resin composition according to any one of claims 1 to 5.

7. The molded article according to claim 6, which is used as an exterior part for a vehicle.

8. A decomposition step of decomposing the resin composition according to any one of claims 1 to 5 at a temperature of 380 ° C. or higher; a separation step of separating the volatile components and solid matter generated by the decomposition step; A method for decomposing and recovering a resin composition, comprising: a recovery step of recovering a methacrylic acid ester from the volatile components.

9. 8. A method for producing a recycled material using the molded article according to claim 7, wherein the vehicle exterior material is a front grille, A step of melting and kneading a raw material containing crushed material obtained by crushing the molded body, A method for producing recycled materials, wherein the content of the crushed material is 0.01 parts by mass or more and 99.99 parts by mass or less per 100 parts by mass of the raw material.

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