(METH)acrylic resin composition, molded body thereof, method for producing molded body, method for decomposing and recovering (METH)acrylic resin composition, method for recycling (METH)acrylic resin composition, and recycled (METH)acrylic resin composition

Abstract

The purpose of the present invention is to provide: a molded body which exhibits excellent scattering prevention properties while increasing impact resistance and rigidity; a (meth)acrylic resin composition able to produce this molded body; a method for recycling the (meth)acrylic resin composition; a recycled (meth)acrylic resin composition; a method for producing the molded body; and a method for decomposing and recovering the (meth)acrylic resin composition. Provided are: a (meth)acrylic resin composition that contains a fibrous glass filler and a (meth)acrylic resin in which the content of a structural unit derived from a (meth)acrylic acid ester is 90-99.985 mol% and the content of a structural unit derived from (meth)acrylic acid is 0.015-9.0 mol%, each relative to a total of 100 mol% of all structural units; a method for recycling the (meth)acrylic resin composition; a recycled (meth)acrylic resin composition; a molded body of the (meth)acrylic resin composition; a method for producing the molded body; and a method for decomposing and recovering the (meth)acrylic resin composition.

Description

(Meth)acrylic resin composition, molded article thereof, method for producing molded article, method for decomposing and recovering (meth)acrylic resin composition and method for recycling (meth)acrylic resin composition, and recycled (meth)acrylic resin composition

[0001] The present invention relates to a (meth)acrylic resin composition, a molded article such as a car body using the (meth)acrylic resin composition, and a method for producing the molded article. The present invention also relates to a method for decomposing and recovering the (meth)acrylic resin composition. Furthermore, the present invention relates to a method for recycling the (meth)acrylic resin composition and a recycled (meth)acrylic resin composition.

[0002] (Meth)acrylic resins are used in a variety of applications due to their excellent weather resistance, moldability, and ease of coloring. In particular, in recent years, due to their excellent transparency and recyclability, technologies for applying (meth)acrylic resins to applications where other resins have previously been used have been explored. For example, due to their excellent balance of mechanical properties such as rigidity, strength, and impact resistance, (meth)acrylic resins have attracted attention as alternative materials to hard resins such as acrylonitrile-butadiene-styrene copolymers (ABS resins), which are used in office automation equipment, automotive parts, building materials (interior materials), and housings for electrical appliances. However, whether (meth)acrylic resins are used in conventional applications or as alternative materials, in practice, (meth)acrylic resins and molded articles thereof lack sufficient impact resistance and rigidity, limiting their applications. Therefore, as the applications of (meth)acrylic resins expand, technologies for improving impact resistance and rigidity have been explored.

[0003] One technique for enhancing the impact resistance and rigidity of (meth)acrylic resins and molded articles thereof is the incorporation of glass fibers. Various glass fiber-reinforced (meth)acrylic resin compositions and molded articles thereof have been proposed. For example, Patent Document 1 describes a surface-hardened glass fiber-reinforced acrylic resin sheet used as a surface-hardened acrylic resin sheet for automobile sunroofs. Patent Document 2 describes a method for producing a transparent glass fiber-reinforced thermoplastic resin composition by blending, in a molten state, a transparent resin component comprising a uniform mixture of (A) 10 to 80 wt % (resin basis) of an acrylic resin primarily composed of methyl methacrylate, with 84 wt % or more of methyl methacrylate, and (B) 90 to 20 wt % (resin basis) of a copolymer essentially consisting of 88 to 73 wt % styrene and 12 to 27 wt % acrylonitrile, with 5 to 60 wt % (total composition basis) of glass fibers. The refractive indexes of the resin component and the glass fiber are substantially the same, resulting in a transparent glass fiber-reinforced thermoplastic resin composition. Patent Document 3 describes a glass fiber-reinforced acrylic resin composition containing a methacrylic resin having a ring structure in its main chain and a fibrous glass filler.

[0004] Publication No. 03-034327, Publication No. 05-331335, Publication No. 2022-158606

[0005] However, resin molded articles used for various applications such as those described above may break or shatter upon impact, causing fragments to fly, which may result in secondary damage to personnel or property. Therefore, resin molded articles are required to have excellent properties such as impact resistance and rigidity, as well as the ability to withstand impact and not to cause fragments to fly even if they do break or shatter (hereinafter, simply referred to as "shatterproof properties"). However, Patent Documents 1 to 3 do not consider shatterproof properties upon impact.

[0006] Furthermore, with the recent rise in resource prices and growing awareness of environmental issues, the practical application of technologies for recovering and recycling molded articles used for various applications as described above has been promoted. Examples of (meth)acrylic resin recycling methods include material recycling, in which recovered molded articles are remolded to produce new molded articles; chemical recycling, in which (meth)acrylic acid esters constituting the (meth)acrylic resin are recovered from the recovered molded articles and polymerized to obtain the (meth)acrylic resin; and thermal recycling, in which recovered molded articles are used as fuel. Among these, material recycling offers significant benefits in reducing environmental impact and building a recycling-oriented society, as it reuses the recovered (meth)acrylic resin as is. However, recovered ordinary (glass fiber-free) (meth)acrylic resins typically have inferior physical properties and characteristics compared to virgin (meth)acrylic resins, and recovered glass fiber-reinforced (meth)acrylic resins in particular tend to have inferior physical properties and characteristics. Therefore, it is not easy to realize material recycling of recovered (meth)acrylic resins, and currently they are recycled chemically or thermally.

[0007] An object of the present invention is to provide a molded article that has improved impact resistance and rigidity while also having excellent shatterproof properties, and a (meth)acrylic resin composition from which this molded article can be produced. Another object of the present invention is to provide a method for producing the molded article, and a method for decomposing and recovering the (meth)acrylic resin composition. A further object of the present invention is to provide a recycling method for recovering the (meth)acrylic resin composition from a (meth)acrylic resin composition or a molded article thereof, and a recycled (meth)acrylic resin composition using the recovered (meth)acrylic resin composition.

[0008] That is, the objects of the present invention have been achieved by the following means. <1> A (meth)acrylic resin composition comprising a (meth)acrylic resin in which the content of structural units derived from a (meth)acrylic acid ester is 90 to 99.985 mol % and the content of structural units derived from (meth)acrylic acid is 0.015 to 9.0 mol %, relative to 100 mol % of the total content of all structural units, and a fibrous glass filler. <2> The (meth)acrylic resin composition according to <1>, in which the content of structural units derived from a (meth)acrylic acid ester is 90 to 99.0 mol %, and the content of structural units derived from (meth)acrylic acid is 0.1 to 9.0 mol %. <3> The (meth)acrylic resin composition according to <1> or <2>, in which the content of the fibrous glass filler is 1 to 40 parts by mass per 100 parts by mass of the (meth)acrylic resin composition. <4> The (meth)acrylic resin composition according to any one of <1> to <3>, wherein the fibrous glass filler has a fiber diameter of 3 to 25 μm and a fiber length of 0.1 to 10 mm. <5> The (meth)acrylic resin composition according to any one of <1> to <3>, wherein the fibrous glass filler has a fiber diameter of 3 to 25 μm and a fiber length of 0.5 to 10 mm. <6> The (meth)acrylic resin composition according to any one of <1> to <5>, wherein the fibrous glass filler comprises a glass filler having a flat cross-sectional shape in which the ratio of the major axis to the minor axis in the cross section [major axis / minor axis] is 2.0 or more. <7> The (meth)acrylic resin composition according to any one of <1> to <6>, wherein the (meth)acrylic resin contains a ring structure consisting of glutaric anhydride in its main chain, and the content of structural units containing the ring structure is 1.0 mol % or less, relative to 100 mol % of the total of all structural units of the (meth)acrylic resin. <8> The (meth)acrylic resin composition according to any one of <1> to <7>, wherein the (meth)acrylic acid ester is at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, isobutyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.<9> The (meth)acrylic resin composition according to any one of <1> to <8>, further comprising a styrene copolymer, wherein the styrene copolymer is a styrene-acrylonitrile copolymer or a styrene-acrylonitrile-phenylmaleimide copolymer. <10> The (meth)acrylic resin composition according to any one of <1> to <9>, further comprising (meth)acrylic rubber particles, wherein the (meth)acrylic rubber particles are spherical (meth)acrylic rubber particles having a three-layer structure consisting of an inner layer made of a hard polymer mainly composed of an alkyl methacrylate, a middle layer made of an elastic copolymer mainly composed of an alkyl acrylate, and an outer layer made of a hard polymer mainly composed of an alkyl methacrylate. <11> A molded article made of the (meth)acrylic resin composition according to any one of <1> to <10> above. <12> A car body made of the (meth)acrylic resin composition according to any one of <1> to <10> above. <13> A method for producing a molded product by injection molding the (meth)acrylic resin composition according to any one of the above <1> to <10>, wherein a rapid heating and cooling mold is used, and the injection step is carried out when the mold cavity surface temperature is 110°C or higher, and the mold opening step is carried out when the mold cavity surface temperature is 80°C or lower. <14> A method for producing a molded product by extrusion molding the (meth)acrylic resin composition according to any one of the above <1> to <10>, comprising the steps of discharging a melt of the (meth)acrylic resin composition from a die and cooling the discharged melt to obtain a molded product. <15> A method for decomposing and recovering a (meth)acrylic resin composition, comprising decomposing the (meth)acrylic resin composition according to any one of the above <1> to <10> at a temperature of 380°C or higher, and separating a volatile component from a solid matter, thereby recovering a (meth)acrylic acid ester.

[0009] <16> A recycled (meth)acrylic resin composition comprising the (meth)acrylic resin composition according to any one of the above <1> to <10> or a molded product thereof, or a (meth)acrylic resin composition recovered from the following recycled (meth)acrylic resin composition or a molded product thereof, a virgin (meth)acrylic resin, and a virgin fibrous glass filler. (Recycled (meth)acrylic resin composition) A recycled (meth)acrylic resin composition comprising the (meth)acrylic resin composition according to any one of the above <1> to <10> or a (meth)acrylic resin composition recovered from a molded product thereof, a virgin (meth)acrylic resin, and a virgin fibrous glass filler. The recycled (meth)acrylic resin composition includes the recycled (meth)acrylic resin compositions according to the below <17> to <19>.

[0010] <17> The recycled (meth)acrylic resin composition according to <16>, wherein the virgin (meth)acrylic resin contained in the recycled (meth)acrylic resin composition contains a (meth)acrylic resin having a content of structural units derived from (meth)acrylic acid esters of 90 to 99.985 mol% and a content of structural units derived from (meth)acrylic acid of 0.015 to 9.0 mol%, relative to 100 mol% of the total content of all structural units. <18> The recycled (meth)acrylic resin composition according to <16> or <17>, wherein the content of the fibrous glass filler contained in the recovered (meth)acrylic resin composition per 100 parts by mass of the recovered (meth)acrylic resin composition is the same as the content of the virgin fibrous glass filler per 100 parts by mass of the total of the virgin (meth)acrylic resin and the virgin fibrous glass filler in the recycled (meth)acrylic resin composition. <19> The recycled (meth)acrylic resin composition according to any one of <16> to <18>, wherein the content of the virgin fibrous glass filler in the recycled (meth)acrylic resin composition is 1 to 40 parts by mass based on a total of 100 parts by mass of the virgin (meth)acrylic resin and the virgin fibrous glass filler. <20> The recycled (meth)acrylic resin composition according to any one of <16> to <19>, wherein, based on 100% by mass of the recycled (meth)acrylic resin composition, the content of the recovered (meth)acrylic resin composition is 1 to 99% by mass, and the total content of the virgin (meth)acrylic resin and the virgin fibrous glass filler is 1 to 99% by mass.

[0011] <21> A method for recycling a (meth)acrylic resin composition or a (meth)acrylic resin composition that has formed a molded article, comprising recovering a (meth)acrylic resin composition from the (meth)acrylic resin composition or its molded article according to any one of the above <1> to <10>, or the recycled (meth)acrylic resin composition or its molded article according to any one of the above <16> to <19>, and mixing the recovered (meth)acrylic resin composition with a virgin (meth)acrylic resin and a virgin fibrous glass filler.

[0012] One embodiment of the method for recycling the (meth)acrylic resin composition according to the above item <21> includes the following recycling method. That is, a method for recycling a (meth)acrylic resin composition or a (meth)acrylic resin composition that has formed a molded article, comprising recovering the (meth)acrylic resin composition from the (meth)acrylic resin composition according to any one of the above items <1> to <10> or a molded article thereof, or the following recycled (meth)acrylic resin composition or a molded article thereof, and mixing the recovered (meth)acrylic resin composition with a virgin (meth)acrylic resin and a virgin fibrous glass filler. (Recycled (meth)acrylic resin composition) A recycled (meth)acrylic resin composition comprising the (meth)acrylic resin composition according to any one of the above items <1> to <10> or a (meth)acrylic resin composition recovered from a molded article thereof, a virgin (meth)acrylic resin, and a virgin fibrous glass filler.

[0013] The present invention can provide a molded article that has improved impact resistance and rigidity while also having excellent shatterproof properties, and a (meth)acrylic resin composition from which the molded article can be produced. The present invention also can provide a method for producing the molded article, and a method for decomposing and recovering the (meth)acrylic resin composition. Furthermore, the present invention can provide a recycling method for recovering the (meth)acrylic resin composition from a (meth)acrylic resin composition or a molded article thereof, and a recycled (meth)acrylic resin composition using the recovered (meth)acrylic resin composition.

[0014] 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." Furthermore, in the present invention and this specification, the bonding mode (arrangement of the structural units) of two or more structural units in a copolymer that becomes a resin or elastomer is not particularly limited, and includes, for example, random bonding (random copolymer), block bonding (block copolymer), alternating bonding (alternating copolymer), and graft bonding (graft copolymer). In the present invention and this specification, when describing content, physical properties, etc., by indicating a numerical range, if the upper and lower limits of the numerical range 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 represented by "to" (...), the upper and lower limits forming the numerical range are not limited to the specific combinations written before and after "to" as a specific numerical range, and can be any numerical range obtained by appropriately combining the upper and lower limits of each numerical range. 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 lower and upper limits.

[0015] In the present invention and this specification, "unused (meth)acrylic resin" refers to a (meth)acrylic resin that has not been used in the preparation of a (meth)acrylic resin composition or the production (molding) of a molded body. Examples include (meth)acrylic resin obtained by polymerization or its isolated and purified form, and commercially available (meth)acrylic resin. "Recycled (meth)acrylic resin" refers to a (meth)acrylic resin recovered from waste materials such as residues generated in the preparation of a (meth)acrylic resin composition (including recycled (meth)acrylic resin compositions), waste materials such as fragments, defective products, and residues generated in the production of molded bodies (including recycled molded bodies), and even molded bodies discarded by consumers (including recycled molded bodies). On the other hand, "recycled (meth)acrylic resin" refers to a (regenerated) (meth)acrylic resin that contains recovered (meth)acrylic resin and can be reused, for example, in the preparation of a new (meth)acrylic resin composition. This also applies to each component used in the preparation of the (meth)acrylic resin composition of the present invention.

[0016] Furthermore, the term "virgin (meth)acrylic resin composition" refers to a (meth)acrylic resin composition that has not been molded into a molded product or the like, and includes, for example, a (meth)acrylic resin composition obtained by preparation. The term "recycled (meth)acrylic resin composition" refers to a recovered (meth)acrylic resin composition that has been regenerated from waste generated during the preparation of a (meth)acrylic resin composition (including a recycled (meth)acrylic resin composition), waste generated during the production of a molded product (including a recycled molded product), or even from molded products discarded by consumers (including recycled molded products) using conventional methods and conditions, preferably the recovery step of the recycling method of the present invention. Meanwhile, the term "recycled (meth)acrylic resin composition" refers to a (meth)acrylic resin composition that contains the recovered (meth)acrylic resin composition and can be reused for the production of new molded products, etc. In the present invention, the recovered waste and molded products include those containing a recovered (meth)acrylic resin composition that has already been recovered at least once. Therefore, in the present invention, the recycled (meth)acrylic resin encompasses both a recovered (meth)acrylic resin that has been recovered once and a recovered (meth)acrylic resin that has been recovered two or more times. Similarly, the recycled (meth)acrylic resin composition of the present invention encompasses both a resin composition containing a recycled (meth)acrylic resin composition that has been recovered once and a resin composition containing a recycled (meth)acrylic resin composition that has been recovered two or more times. Regarding a resin composition containing a recycled (meth)acrylic resin composition that has been recovered two or more times, in order to distinguish it from a recycled (meth)acrylic resin composition to be prepared, a resin composition that is used in the preparation of this resin composition and contains an already regenerated (previous generation) recycled (meth)acrylic resin composition may be referred to as a "recycled (meth)acrylic resin composition."

[0017] Furthermore, the term "unused molded body" refers to a molded body that has been molded but has not been used as a resin component such as a finished product or semi-finished product. The term "recycled molded body" refers to a molded body that has been collected as waste generated during the manufacture of a molded body, or a molded body that has been discarded by a consumer and then collected. On the other hand, the term "recycled molded body" refers to a molded body obtained by molding a recycled (meth)acrylic resin composition.

[0018] In the present invention and this specification, the term "(meth)acrylic resin" can include "virgin (meth)acrylic resin," "recycled (meth)acrylic resin," and "recycled (meth)acrylic resin," but unless otherwise specified, "(meth)acrylic resin" is used as the term meaning "virgin (meth)acrylic resin." Similarly, the term "(meth)acrylic resin composition" can include "virgin (meth)acrylic resin composition," "recycled (meth)acrylic resin composition," and "recycled (meth)acrylic resin composition," but unless otherwise specified, "(meth)acrylic resin composition" is used as the term meaning "virgin (meth)acrylic resin composition." However, when the term "(meth)acrylic resin composition" refers to a recycled (meth)acrylic resin composition, the content of the recovered (meth)acrylic resin composition in 100% by mass of the recycled (meth)acrylic resin composition is, for example, less than 1% by mass. Furthermore, "molded body" can include "unused molded body", "recovered molded body", and "recycled molded body", but unless otherwise specified, "molded body" is used as a term meaning "unused molded body".

[0019] [(Meth)acrylic Resin Composition] The (meth)acrylic resin composition of the present invention (hereinafter sometimes referred to as the "resin composition of the present invention") contains a (meth)acrylic resin and a fibrous glass filler, which will be described later. In the resin composition of the present invention, by using a (meth)acrylic resin having a predetermined content of structural units derived from (meth)acrylic acid in addition to structural units derived from a (meth)acrylic acid ester in combination with the fibrous glass filler, it is believed that the interfacial strength between the fibrous glass filler and the (meth)acrylic resin is strengthened, and excellent shatterproof properties can be achieved while improving impact resistance and rigidity. First, the components contained in the resin composition of the present invention will be described. Each component contained in the resin composition of the present invention may be one type or two or more types.

[0020] [(Meth)acrylic Resin] The (meth)acrylic resin contained in the resin composition of the present invention has structural units derived from (meth)acrylic acid esters and structural units derived from (meth)acrylic acid, and may further have structural units containing a ring structure, as described below, and structural units other than these (hereinafter, sometimes referred to as "other structural units"). This (meth)acrylic resin has a content of structural units derived from (meth)acrylic acid esters of 90 to 99.985 mol % and a content of structural units derived from (meth)acrylic acid of 0.015 to 9.0 mol %, relative to 100 mol % of the total content of all structural units forming the (meth)acrylic resin. When used in combination with a fibrous glass filler, as described above, a (meth)acrylic resin having this composition can exhibit excellent impact resistance, rigidity, and shatterproof properties in a molded article of the (meth)acrylic resin.

[0021] <Structural Units Derived from (Meth)acrylic Acid Esters> The (meth)acrylic acid esters from which the structural units derived from (meth)acrylic acid esters are derived are not particularly limited, and examples thereof include (meth)acrylic acid alkyl esters and (meth)acrylic acid aryl esters, with (meth)acrylic acid alkyl esters being preferred. The alkyl group constituting the (meth)acrylic acid alkyl ester is not particularly limited, and an alkyl group having 1 to 8 carbon atoms is preferred. Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl methacrylate, lauryl methacrylate, and benzyl methacrylate. The (meth)acrylic acid ester preferably contains methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, iso-butyl (meth)acrylate, or 2-ethylhexyl (meth)acrylate, more preferably methyl (meth)acrylate, and even more preferably methyl methacrylate. The (meth)acrylic acid ester may have a substituent. The (meth)acrylic resin may contain one or more structural units derived from the above (meth)acrylic acid ester.

[0022] <Structural units derived from (meth)acrylic acid> The (meth)acrylic acid from which the structural units derived from (meth)acrylic acid are derived is not particularly limited, and examples thereof include acrylic acid and methacrylic acid, with methacrylic acid being preferred. The (meth)acrylic acid may have a substituent. The (meth)acrylic resin may contain one or more structural units derived from the above (meth)acrylic acid.

[0023] <Structural Unit Containing a Ring Structure> The (meth)acrylic resin can contain a ring structure in its main chain. In the present invention, containing (incorporating) a ring structure in the main chain of the (meth)acrylic resin means that a partial structure bonded to a carbon atom constituting the carbon chain that forms the main chain of the (meth)acrylic resin forms a ring structure together with this carbon atom. It is preferable that this ring structure is incorporated into the main chain of the (meth)acrylic resin by having a structural unit containing a ring structure. The structural unit containing a ring structure affects the impact resistance and rigidity of the (meth)acrylic resin, so it can be contained or not contained in consideration of the desired impact resistance and rigidity, as well as the balance between them. When a structural unit containing a ring structure is contained in the (meth)acrylic resin in consideration of the balance between impact resistance and rigidity, the structural unit containing a ring structure is preferably one or more structural units containing a ring structure made of a cyclic anhydride compound, among the structural units containing a ring structure described below, in terms of achieving a good balance between impact resistance and rigidity while also achieving excellent shatterproof properties, and more preferably a structural unit containing a ring structure made of a glutaric anhydride compound. On the other hand, when the (meth)acrylic resin does not contain a structural unit containing a ring structure in consideration of the balance between impact resistance and rigidity, the structural unit containing a ring structure that is not to be contained is preferably a structural unit containing a ring structure made of a glutaric anhydride compound, more preferably a structural unit containing a ring structure made of a cyclic anhydride compound, and even more preferably a structural unit containing a ring structure as described below, among the structural units containing a ring structure described below.

[0024] The ring structure is not particularly limited, and examples thereof include ring structures formed from cyclic imides such as maleimide and glutarimide; ring structures formed from cyclic acid anhydrides such as maleic anhydride and glutaric anhydride; ring structures formed from cyclic amides (e.g., lactam ring structures); and cyclic ester ring structures such as ring structures formed from lactones. Examples of cyclic acid anhydrides include acid anhydrides of unsaturated carboxylic acids, and preferred examples include maleic anhydride and itaconic anhydride. Examples of maleimides include N-substituted maleimides such as phenylmaleimide, cyclohexylmaleimide, and methylmaleimide. Each compound forming the ring structure may have an appropriate substituent. The ring structure (structural unit containing a ring structure) of the (meth)acrylic resin may be one type or two or more types.

[0025] Examples of the structural unit having a ring structure made of glutarimide and the structural unit having a ring structure made of glutaric anhydride include structural units represented by the following formula (A).

[0026] In formula (A), R １ and R ２ each independently represents a hydrogen atom or an alkyl group, and R ３ represents a hydrogen atom or a substituent. １ represents an oxygen atom or a nitrogen atom, and X １ is an oxygen atom, n is 0, and X １ When R is a nitrogen atom, n is 1. １ and R ２ alkyl groups that can be ３ The substituents that can be taken as the ring structure represented by formula (A) are not particularly limited, and for example, the content of formula (1) described in Patent Document 3 can be appropriately referred to, and the content thereof is incorporated as it is into the present specification as a part of the description. １ is a methyl group, and two R ２ is a hydrogen atom, and X １ is preferably a structural unit having a ring structure made of glutaric anhydride in which R is an oxygen atom.

[0027] Examples of the structural unit having a ring structure made of maleimide and the structural unit having a ring structure made of maleic anhydride include a structural unit represented by the following formula (B).

[0028] In formula (B), R ４ and R ５ each independently represents a hydrogen atom or a methyl group, R ６ is a hydrogen atom or a substituent, and X ２ is an oxygen atom or a nitrogen atom. ２ is an oxygen atom, n is 0, and X ２ When R is a nitrogen atom, n is 1. ６ The substituents that can be taken as R are not particularly limited, and for example, the content of formula (2) described in Patent Document 3 can be appropriately referred to, and the content thereof is incorporated as it is into the present specification as a part of the description. ４ and R ５ are all hydrogen atoms, and X ２ is preferably a structural unit having a ring structure consisting of maleic anhydride in which R is an oxygen atom.

[0029] The ring structure consisting of lactone and the ring structure consisting of cyclic amide (pyrrolidinone) are not particularly limited, and for example, the lactone ring structure and pyrrolidinone ring structure described in Patent Document 3 can be referred to as appropriate, and the contents thereof are incorporated as is into this specification as part of their description.

[0030] The (meth)acrylic resin may contain one or more structural units containing the above ring structure. The ring structure contained in the main chain of the (meth)acrylic resin can be formed by an appropriate method, for example, by the various methods described in Patent Document 3, and the content of Patent Document 3 is incorporated herein by reference.

[0031] <Other Structural Units> The (meth)acrylic resin may contain other structural units. The compound (monomer) from which the other structural units are derived is not particularly limited as long as it is a compound copolymerizable with a (meth)acrylic acid ester and / or (meth)acrylic acid, and examples thereof include monofunctional monomers having one polymerizable carbon-carbon double bond in the molecule and polyfunctional monomers having two or more polymerizable carbon-carbon double bonds in the molecule. Examples of such monofunctional monomers include aromatic vinyl compounds such as styrene and α-methylstyrene; vinyl cyanide compounds such as (meth)acrylonitrile and (meth)acrylamide; and unsaturated carboxylic acids such as maleic acid and itaconic acid (excluding (meth)acrylic acid and anhydrides of unsaturated carboxylic acids). Examples of 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 (meth)acrylic resin may contain one or more of the above-mentioned other structural units.

[0032] As the (meth)acrylic resin, methacrylic resin is preferred in terms of excellent shatterproof properties, impact resistance, and rigidity, and a resin composed of a copolymer of at least one methacrylic acid ester and methacrylic acid is more preferred. The above-mentioned methacrylic resin and resin composed of a copolymer more preferably contain methyl methacrylate. In the present invention, the methacrylic resin refers to a resin that contains a higher content of structural units derived from methacrylic monomers such as methacrylic acid esters and methacrylic acid than structural units derived from acrylic monomers such as acrylic acid esters and acrylic acid.

[0033] The content of each structural unit in the total 100 mol % of all structural units constituting the (meth)acrylic resin can be set as appropriate, but is preferably set within the following range: In the total 100 mol % of all structural units constituting the (meth)acrylic resin, the content of structural units derived from (meth)acrylic acid esters is 90 to 99.985 mol %, preferably 90 to 99.8 mol %, more preferably 90 to 99.0 mol %, even more preferably 92 to 98.0 mol %, and particularly preferably 93.0 to 97.0 mol %, in order to achieve excellent shatterproof properties while maintaining excellent impact resistance and rigidity. In 100 mol% of the total content of all structural units constituting the (meth)acrylic resin, the content of structural units derived from (meth)acrylic acid has a strong tendency to contribute to improvement in impact resistance, particularly shatterproof properties, and is capable of realizing excellent shatterproof properties while maintaining excellent impact resistance and rigidity. Therefore, the content is 0.015 to 9.0 mol%, preferably 0.05 to 9.0 mol%, more preferably 0.1 to 9.0 mol%, even more preferably 0.2 to 8.0 mol%, and particularly preferably 0.3 to 5.0 mol%.

[0034] When the (meth)acrylic resin composition of the present invention contains a resin other than a (meth)acrylic resin, the content (% by mass) of structural units derived from (meth)acrylic acid in the total resin can be calculated by multiplying the content (% by mass) of the structural units derived from (meth)acrylic acid in the total resin by the content (% by mass) of the structural units derived from (meth)acrylic acid in the total resin. The content (% by mass) of structural units derived from (meth)acrylic acid in the total resin is not particularly limited, but can be, for example, 0.01 to 10% by mass, preferably 0.1 to 10.0% by mass, more preferably 0.2 to 8.0% by mass, and even more preferably 0.3 to 5.0% by mass, in order to achieve excellent shatterproof properties while maintaining excellent impact resistance and rigidity.

[0035] The content of structural units containing ring structures in the total 100 mol% content of all structural units constituting the (meth)acrylic resin is not particularly limited and is appropriately determined taking into consideration the balance between impact resistance and rigidity. For example, when the (meth)acrylic resin contains structural units containing ring structures, the content of structural units containing ring structures in the total 100 mol% content can be, for example, 10 to 80 mol%, and preferably 20 to 60 mol%. On the other hand, when the (meth)acrylic resin contains a small amount of structural units containing ring structures, the content of structural units containing ring structures in the total 100 mol% content is preferably 1.0 mol% or less, more preferably 0.7 mol% or less, and even more preferably 0.5 mol% or less, from the viewpoint of the balance between impact resistance and rigidity. The lower limit of the content of structural units containing ring structures may be greater than 0 mol%, and can be, for example, 0.001 mol% or more. The content of structural units having a ring structure composed of a glutaric anhydride compound among structural units having a ring structure is determined appropriately taking into consideration the presence or absence of other structural units having ring structures, the content of the structural units having the ring structure, etc., but is preferably within the above range. The content of other structural units in the total content of all structural units constituting the (meth)acrylic resin (100 mol %) is determined appropriately depending on the application, properties, etc., and is, for example, preferably 0.1 to 1.0 mol %, more preferably 0.2 to 0.8 mol %, and even more preferably 0.3 to 0.7 mol %.

[0036] The content of each component can be calculated from the amount of the compound used to derive each component to be subjected to polymerization, or can be measured by a known method. For example, the content of the component derived from (meth)acrylic acid can be determined by the nuclear magnetic resonance spectrum ( １３ It can be calculated by measuring C-NMR. When the (meth)acrylic resin contains two or more types of each constituent component, the above content of each constituent component is the total content of the two or more constituent components.

[0037] The characteristics and physical properties of the (meth)acrylic resin are not particularly limited and are determined appropriately depending on the application, the characteristics of the molded product (e.g., impact resistance, rigidity), etc. For example, the weight average molecular weight of the (meth)acrylic resin is not particularly limited, but is preferably 5×10 ４ ~2 x 10 ５ It can be said that:

[0038] The (meth)acrylic resin may be a commercially available product, or may be a synthetic product synthesized as appropriate. When synthesizing a (meth)acrylic resin, the resin may be produced by polymerizing a (meth)acrylic acid ester, (meth)acrylic acid, a compound that leads to a structural unit containing a ring structure, and optionally a compound that leads to other structural units, using a conventionally known method such as bulk polymerization, suspension polymerization, emulsion polymerization, or solution polymerization. In the method for producing a (meth)acrylic resin, additives such as a polymerization initiator, a chain transfer agent, or a suspension stabilizer may be used. The polymerization temperature is not particularly limited and may be, for example, 110 to 190°C.

[0039] [Fiberous Glass Filler] The fibrous glass filler contained in the composition of the present invention is not particularly limited and may be in any form, such as roving, chopped strand, middle fiber, glass beads, surfacing mat, chopped strand mat, satin weave, lattice weave, plain weave, open plain weave, twill weave, or net. The glass material forming the fibrous glass filler is not particularly limited and, for example, quartz glass, borosilicate glass, fluorosilicate glass, alkali-free glass, alkali-containing glass (e.g., soda glass), potassium lime glass, and lead glass are preferably used. As the fibrous glass filler, E-GF, S-GF, T-GF, and the like (alkali-free glass fibers), C-GF, and the like (alkali-containing glass fibers) are preferably used. When the glass material is surface-treated, the surface treatment agent is not particularly limited and includes various coupling agents, with silane-based coupling agents being preferred.

[0040] The shape of the fibrous glass filler is not particularly limited as long as it is fibrous, and examples of the cross-sectional shape include a circular, elliptical, and flat shape. One preferred embodiment of the fibrous glass filler includes a fibrous glass filler having a flat cross-sectional shape (sometimes referred to as a "flat fibrous glass filler" in the present invention). When a molded product is formed by injection molding or extrusion molding, this flat fibrous glass filler can reduce the difference in properties between the TD direction (transverse direction) and the MD direction (machine direction), such as the difference in rigidity (flexural modulus) and the difference in strength (Charpy impact strength), which are caused by the arrangement anisotropy of the fibrous glass filler.

[0041] The size of the fibrous glass filler is not particularly limited and can be set appropriately. For example, a preferred embodiment of the fiber length is 0.5 to 10 mm, and another preferred embodiment is 0.1 to 10 mm. A preferred fiber diameter is 3 to 25 μm. For a flat fibrous glass filler, in addition to or instead of the fiber diameter, the ratio of the major axis to the minor axis in the cross section [major axis / minor axis] can be specified. This ratio [major axis / minor axis] is not particularly limited, but is preferably 2.0 or more in view of the difference in properties between the TD and MD. In the present invention, the ratio of the major axis to the minor axis in a cross section [major axis / minor axis] refers to the ratio [major axis / minor axis] of the major axis (the maximum length in the longitudinal direction of the cross section, i.e., the maximum height of the cross section when the flat fibrous glass filler is arranged so that the major axis direction is vertical) to the minor axis (the maximum length in the short direction of the cross section, i.e., the maximum width of the cross section when the flat fibrous glass filler is arranged so that the major axis direction is horizontal) in a cross section intersecting the axis of the fibrous glass filler, usually a vertical cross section, and indicates the flatness ratio of the cross section of the flat fibrous glass filler. The closer this ratio [major axis / minor axis] is to 1.0, the more circular the cross section shape becomes. The ratio [major axis / minor axis] is more preferably 2.5 or more. On the other hand, the upper limit of the ratio [major axis / minor axis] is not particularly limited and can be 8.0 or less, preferably 5.0 or less, and more preferably 4.5 or less.

[0042] The ratio [long diameter / short diameter] of one flat fibrous glass filler can be determined by observing any flat cross section of the flat fibrous glass filler under a microscope, measuring its short diameter and long diameter, and dividing the long diameter by the short diameter.In the present invention, the ratio [long diameter / short diameter] of a flat fibrous glass filler is determined by measuring a plurality of, for example, 10, flat fibrous glass fillers, and calculating the arithmetic average of the ratios [long diameter / short diameter] of each flat fibrous glass filler.The shape of the flat cross section can be a shape obtained by squeezing a circular cross section in one diameter direction, such as a (near) rectangle, a (near) oval with chamfered corners of a rectangle, an ellipse, or a shape with a narrowed center (cocoon shape), and the like.A (near) rectangle or a (near) oval is preferred.In addition, in the present invention, the above-mentioned shapes such as a cocoon shape representing the cross section shape include not only geometrically accurate shapes, but also shapes with partial deformation as long as the above shape is maintained as a whole. The cross section of the flat fiber used to calculate the ratio [long diameter / short diameter] may be a cross section obtained by cutting the flat fiber (taken out from the molded body), or may be a cross section of the flat fiber appearing on the cut surface of the molded body. In the present invention, when a commercially available fibrous glass filler is used, the fiber length and fiber diameter of the fibrous glass filler can be the values ​​listed in the catalog, and the ratio [long diameter / short diameter] may be calculated as described above or the values ​​listed in the catalog may be used.

[0043] The fibrous glass filler may be silicon dioxide (SiO ２ ) 35 to 100 mass%, aluminum oxide (Al ２ O ３ ) 0 to 30 mass%, boron oxide (B ２ O ３ ) and 0 to 65% by mass of others (magnesium oxide, zinc oxide, barium oxide, etc.).

[0044] The flat fibrous glass filler can be produced, for example, by spinning using a nozzle having an appropriate hole shape, such as an oval, cocoon-shaped, elliptical, or rectangular slit-shaped, as a bushing used to discharge the molten material. It can also be produced by spinning the molten material from a plurality of nozzles having various cross-sectional shapes (including circular cross-sections) arranged closely together, and joining the spun molten filaments to form a single filament. For such production techniques, reference can be made, as appropriate, to the contents of, for example, Japanese Patent Laid-Open Nos. 7-291649 and 2000-344541, the contents of which are incorporated herein by reference.

[0045] [Styrene Copolymer] The resin composition of the present invention may contain a styrene copolymer (resin) as a resin component in addition to the above-mentioned (meth)acrylic resin. The styrene copolymer may be any copolymer having a structural unit derived from a styrene compound (excluding those corresponding to the above-mentioned (meth)acrylic resin). Examples of the styrene copolymer include a styrene-methyl methacrylate copolymer, a styrene-acrylonitrile copolymer, a styrene-acrylonitrile-phenylmaleimide copolymer, an acrylonitrile-butadiene-styrene block copolymer (ABS resin), and an acrylate-styrene-acrylonitrile copolymer (ASA resin). A styrene-acrylonitrile copolymer or a styrene-acrylonitrile-phenylmaleimide copolymer is preferred. The styrene-acrylonitrile copolymer or the styrene-acrylonitrile-phenylmaleimide copolymer preferably contains 65 to 90% by mass of styrene and 10 to 35% by mass of acrylonitrile, relative to 100% by mass of the total of styrene and acrylonitrile. More preferably, the styrene and acrylonitrile are 70 to 85% by mass and 15 to 30% by mass of acrylonitrile. In addition, with respect to the ABS resin, ASA resin, and styrene-acrylonitrile-phenylmaleimide copolymer, the contents of butadiene, acrylate, and phenylmaleimide are not particularly limited and may be determined appropriately.

[0046] [(Meth)acrylic Rubber Particles] The resin composition of the present invention may contain (meth)acrylic rubber particles. These (meth)acrylic rubber particles differ from the above-mentioned (meth)acrylic resin in that they do not contain structural units derived from (meth)acrylic acid. The (meth)acrylic rubber particles are not particularly limited, but are preferably spherical (meth)acrylic rubber particles having a three-layer structure composed 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. These spherical (meth)acrylic rubber particles having a three-layer structure (hereinafter sometimes referred to as "(meth)acrylic rubber particles (B)") have a so-called core-shell structure.

[0047] In the (meth)acrylic rubber particles (B), the inner layer is a hard polymer primarily composed of alkyl methacrylate. This hard polymer layer is preferably a polymer of a monomer consisting of 70 to 100% by mass of alkyl methacrylate and 0 to 30% by 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 optionally used include acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and cyclohexyl acrylate; aromatic vinyl compounds such as styrene; and vinyl cyanide compounds such as acrylonitrile.

[0048] It is also effective to use a copolymerizable cross-linking monomer as one of the other vinyl monomers. The cross-linking monomer may be any monomer having at least two polymerizable carbon-carbon double bonds in one molecule, and examples thereof include the polyfunctional monomers described above for the (meth)acrylic resin. Among these, alkenyl esters of unsaturated carboxylic acids and polyalkenyl esters of polybasic acids are preferred. These cross-linking monomers can be used alone or in combination of two or more types as needed.

[0049] The intermediate layer of the (meth)acrylic rubber particles (B) 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 cross-linking 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 types of alkyl acrylate, other vinyl monomer, and cross-linking monomer may be used within the respective definitions, as long as the composition falls within the above-mentioned ranges.

[0050] 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.

[0051] 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 cyanide compounds such as acrylonitrile.

[0052] The copolymerizable crosslinkable 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.

[0053] The (meth)acrylic rubber particles (B) 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 weight of alkyl methacrylate, 0 to 50% by weight of an acrylic acid ester, and 0 to 49% by weight 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.

[0054] 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 optionally include alkyl esters of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, etc. Furthermore, examples of other vinyl monomers that may be used optionally 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.

[0055] The three-layer structure (meth)acrylic rubber particles (B) as described above can be found, for example, in the content of Japanese Patent Publication No. 55-27576, the content of which is incorporated herein by reference. In particular, the composition described in Example 3 of Japanese Patent Publication No. 55-27576 is one of the preferred compositions.

[0056] In the (meth)acrylic rubber particles (B), the mass ratio of 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, and outer layer within the above range, the hardness and impact resistance of a molded article formed from the (meth)acrylic resin composition of the present invention can be increased.

[0057] The (meth)acrylic rubber particles (B) can be produced, for example, by first polymerizing a monomer for the inner layer by emulsion polymerization or the like, polymerizing a monomer for the intermediate layer in the presence of the resulting polymer particles, and then polymerizing a monomer for the outer layer in the presence of the polymer particles that have formed up to the intermediate layer. In this process, the particle size of the (meth)acrylic rubber particles (B) can be adjusted by adjusting the amount of emulsifier added, the amount of monomer charged, etc.

[0058] The particle size of the (meth)acrylic rubber particles (B) is not particularly limited and can be determined as appropriate. In order to maintain the excellent effects of the (meth)acrylic resin and the fibrous glass filler, it is preferable that the particle size of the (meth)acrylic rubber particles (B) be, for example, in the range of 0.2 to 0.30 μm in weight average up to the intermediate layer.

[0059] [Other Components] The (meth)acrylic 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 release agents, anti-sticking agents, UV absorbers, lubricants, antioxidants, plasticizers, antistatic agents, dyes (pigments), neutralizing agents, UV absorbers, lubricants, nucleating agents, adhesives, anti-fogging agents, anti-blocking agents, melt flow rate adjusters, and solvents. Examples of release agents include higher fatty acid esters, higher aliphatic alcohols, higher fatty acids, higher fatty acid amides, higher fatty acid metal salts, and fatty acid derivatives. Examples of UV absorbers include benzophenone UV absorbers, cyanoacrylate UV absorbers, benzotriazole UV absorbers, malonic acid ester UV absorbers, and oxalanilide UV absorbers. Examples of antioxidants include phenolic antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. Examples of lubricants include silicone oils and polysiloxane compounds. Examples of antistatic agents include conductive inorganic particles, tertiary amines, quaternary ammonium salts, cationic acrylic acid ester derivatives, and cationic vinyl ether derivatives. The (meth)acrylic resin composition may contain one or more of the other components. In the present invention, the other components may be mixed with the (meth)acrylic resin or the like during preparation of the (meth)acrylic resin composition, or may be mixed with the (meth)acrylic resin in advance of preparation of the (meth)acrylic resin composition.

[0060] [Composition of (meth)acrylic resin composition] The composition of the present invention only needs to contain the above-mentioned (meth)acrylic resin and the above-mentioned fibrous glass filler, and the content of each component (composition of the composition) is not particularly limited and is determined appropriately depending on the application, the properties of the molded product (e.g., impact resistance, rigidity), etc., and is preferably set, for example, within the following range: The content of the (meth)acrylic resin per 100 parts by mass of the composition of the present invention is preferably 10 to 90 parts by mass, in order to achieve excellent shatterproof properties while improving impact resistance and rigidity, and more preferably 60 to 85 parts by mass, and even more preferably 70 to 80 parts by mass, in order to achieve a balance between impact resistance, rigidity, and shatterproof properties at an even higher level. The content of the fibrous glass filler in 100 parts by mass of the composition of the present invention is preferably 1 to 40 parts by mass, in order to achieve excellent shatterproof properties while increasing impact resistance and rigidity, and more preferably 10 to 35 parts by mass, and even more preferably 15 to 30 parts by mass, in order to achieve a balance between impact resistance, rigidity, and shatterproof properties at an even higher level. In the composition of the present invention, the ratio of the content of the (meth)acrylic resin to the content of the fibrous glass filler [(meth)acrylic resin content / fibrous glass filler content] is appropriately determined taking into consideration the above-mentioned respective contents, and can be, for example, 65 / 35 to 90 / 10, and preferably 70 / 30 to 85 / 15.

[0061] The content of the styrene copolymer per 100 parts by mass of the composition of the present invention is preferably 80 parts by mass or less, more preferably 10 to 75 parts by mass, and even more preferably 15 to 70 parts by mass, in order to maintain the excellent effects of the (meth)acrylic resin and the fibrous glass filler. The contents of the styrene-acrylonitrile copolymer and the styrene-acrylonitrile-phenylmaleimide copolymer are each appropriately determined in consideration of the content of the styrene copolymer.

[0062] The content of the (meth)acrylic rubber particles in 100 parts by mass of the composition of the present invention is preferably 70 parts by mass or less, more preferably 5 to 65 parts by mass, and even more preferably 10 to 60 parts by mass, in order to maintain the excellent effects of the (meth)acrylic resin and the fibrous glass filler.

[0063] The content of other components in 100 parts by mass of the composition of the present invention may be appropriately determined within a range that does not impair the effects of the present invention, and may be, for example, 0.5 parts by mass or less.

[0064] [Preparation of (Meth)acrylic Resin Composition] The (meth)acrylic resin composition of the present invention can be produced by known methods and can typically be prepared by mixing or kneading the (meth)acrylic resin, fibrous glass filler, and other appropriate components. The mixing and kneading methods are not particularly limited, and any conventionally known method, such as melt kneading, can be used. Conventional 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 set appropriately taking into account the selected components, their amounts, properties, etc., and can be, for example, 200 to 280°C. In preparing the (meth)acrylic resin composition, recovered components (e.g., recovered (meth)acrylic resin) and recycled components (e.g., recycled (meth)acrylic resin) can be used as the respective components, but in the present invention, unused components are usually used.

[0065] [Molded Article] The molded article of the present invention is a molded article made from the (meth)acrylic resin composition of the present invention described above, and is typically a molded article obtained by molding the (meth)acrylic resin composition of the present invention using a known molding method. The molded article of the present invention has excellent impact resistance, rigidity, and shatterproof properties, and further has the excellent feature of enabling (material) recycling of the (meth)acrylic resin composition, and recovery and (chemical) recycling of the (meth)acrylic acid ester in the (meth)acrylic resin composition. Therefore, the molded article of the present invention can be used for various applications and is molded into a form, shape, and size suitable for each application. Examples of shapes include sheet-like shapes (including film-like, strip-like, and plate-like shapes, and may be long or short (leaf-like)), block-like shapes, and various three-dimensional shapes. By utilizing these excellent characteristics, the molded article of the present invention can be used for various applications, such as applications requiring impact resistance and rigidity in addition to conventional (meth)acrylic resin applications, outdoor applications, and even as a replacement for various resins such as ABS resin. Examples include car bodies (vehicle outer layer members, vehicle body members) such as tail lamp covers, head lamp covers, visors, and fenders; vehicle interior members such as meter panel covers; battery members such as battery casings; optical members such as lenses, display protection plates, optical films, and light guide plates; office automation equipment; cosmetic container members, building members (interior members); housings for electrical appliances; and members installed outdoors that require shatterproof properties (for example, signs, soundproof walls, resin exterior wall sheeting for agricultural greenhouses, roofing materials for carports and garages). The molded article of the present invention is preferably applied to car bodies, as its excellent characteristics can be effectively utilized.

[0066] The molded article of the present invention may be a molded article consisting solely of a molded article made of the (meth)acrylic resin composition of the present invention, or may be a molded article consisting of a molded article and other members. Examples of other members 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, a water-repellent treatment, a hydrophilic treatment, or a photocatalytic treatment, as necessary.

[0067] [Method for manufacturing molded article] The method for manufacturing the molded article of the present invention is not particularly limited, and known molding methods can be applied, such as press molding, extrusion molding, and injection molding. The molding conditions for each molding method are not particularly limited as long as the (meth)acrylic resin composition of the present invention can be molded in a molten state, and can be appropriately set depending on the composition and physical properties of the (meth)acrylic resin composition of the present invention. In the method for manufacturing the molded article, a recovered (meth)acrylic resin composition and a recycled (meth)acrylic resin composition can be used as the (meth)acrylic resin composition, but in the present invention, a virgin (meth)acrylic resin composition is usually used.

[0068] <Injection Molding Method (Heat and Cool Molding Method)> One preferred embodiment of the molded article of the present invention is produced by injection molding, and specifically, a preferred injection molding method (heat and cool molding method) is one in which a rapid heating and cooling mold is used, an injection step of the (meth)acrylic resin composition of the present invention is carried out when the mold cavity surface temperature is 110° C. or higher, and then a mold opening step is carried out when the mold cavity surface temperature is 80° C. or lower. When a resin composition containing a fibrous glass filler is molded, unevenness, roughness, etc. due to the fibrous glass filler usually occurs on the surface of the molded article, but when the (meth)acrylic resin composition of the present invention is molded by the above-mentioned heat and cool molding method, the surface of the obtained molded article becomes a mirror finish, resulting in a molded article with excellent appearance.

[0069] The rapid heating and cooling mold used in this heat-and-cool molding method can be any known mold having an internal space (cavity) that matches the shape and dimensions of the molded product to be molded, and is not particularly limited. In the injection step, the (meth)acrylic resin composition of the present invention is injected into a rapid heating and cooling mold whose cavity surface temperature has been heated to 110°C or higher. The cavity surface temperature during injection is determined depending on the composition and physical properties of the (meth)acrylic resin composition of the present invention, and is preferably 115°C or higher. The cavity surface temperature is not particularly limited and can be, for example, 140°C or lower, preferably 130°C or lower. In the injection step, injection conditions other than the cavity surface temperature, such as injection speed, injection pressure, and holding pressure, can be appropriately set depending on the composition and physical properties of the (meth)acrylic resin composition of the present invention. Examples include the injection conditions in the examples described below. In the mold opening step, the mold cavity surface temperature is cooled to 80°C or lower, and then the rapid heating and cooling mold is opened. The cavity surface temperature when the mold is opened is not particularly limited as long as it is 80° C. or less, and can be, for example, 75° C. or less, and is preferably 70° C. or less. In the mold opening step, conditions other than the cavity surface temperature are not particularly limited and can be set appropriately.

[0070] <Extrusion Molding Method> In view of excellent productivity, extrusion molding is one of the preferred embodiments for producing the molded article of the present invention. Specifically, a method including the steps of extruding a melt of the (meth)acrylic resin composition of the present invention from a die and cooling the extruding melt to obtain a molded article is preferred. The extruder used in the extrusion molding method may be a known extruder such as a single-screw extruder, twin-screw extruder, or multi-screw extruder. The extrusion conditions in the extruding step are not limited as long as they allow the (meth)acrylic resin composition of the present invention to be extruded from the die in a molten state, and are determined depending on the composition and physical properties of the (meth)acrylic resin composition of the present invention. For example, the heating temperature (extrusion temperature) of the (meth)acrylic resin composition of the present invention can be 200 to 290°C. The extrusion conditions other than the heating temperature, such as the extrusion rate (extrusion rate) and screw rotation speed, can be appropriately set depending on the composition and physical properties of the (meth)acrylic resin composition of the present invention. The cooling method in the step of obtaining a molded product is not particularly limited, and any known cooling method such as air cooling, water cooling, or forced cooling using a cooler can be applied. The cooling conditions at this time, such as the cooling rate and cooling temperature, can be appropriately set depending on the composition and physical properties of the (meth)acrylic resin composition of the present invention.

[0071] [Method for Decomposing and Recovering (Meth)acrylic Resin Composition] The (meth)acrylic resin composition of the present invention may be discarded or incinerated, but it is desirable to recycle it from the viewpoints of reducing the environmental load (environmental protection), building a recycling-oriented society (sustainable society), etc. As a result of further investigations, the present inventors have found that the (meth)acrylic acid ester can be recovered and recycled from the (meth)acrylic resin composition of the present invention by the following method.

[0072] In the method for decomposing and recovering a (meth)acrylic resin composition of the present invention, the (meth)acrylic resin composition of the present invention is decomposed at a temperature of 380°C or higher, and the resulting volatile components and solid matter are separated. This decomposition and recovery method of the present invention allows for chemical recycling of the (meth)acrylic acid ester contained in the poly(meth)acrylic resin composition. The heating temperature (decomposition temperature) of the (meth)acrylic resin composition of the present invention may be 380°C or higher, and is appropriately determined depending on the types (boiling point, decomposition temperature, etc.) of the (meth)acrylic resin, styrene copolymer, (meth)acrylic rubber particles, etc. contained in the (meth)acrylic resin composition. For example, the temperature at which the (meth)acrylic resin is decomposed and the resulting (meth)acrylic acid ester becomes gaseous is preferred, specifically, 385°C or higher is preferred, and 390°C or higher is more preferred. 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 (meth)acrylic resin, etc. For example, the time can be set to 5 to 20 minutes. In this manner, the (meth)acrylic resin constituting the (meth)acrylic resin composition of the present invention can be thermally decomposed into (meth)acrylic acid esters.

[0073] In the decomposition and recovery method of the present invention, the resulting volatile components and solid matter are separated during or after the thermal decomposition of the (meth)acrylic resin. While various known separation methods can be applied for this separation, it is preferable to separate the (meth)acrylic acid ester into a gaseous state as a volatile component and the other components into solid matter at the decomposition temperature.

[0074] The decomposition and recovery method of the present invention may also include other steps in addition to the decomposition and separation steps, such as a step of purifying the recovered (meth)acrylic acid ester and a step of cutting a molded article made of the (meth)acrylic resin composition of the present invention.

[0075] The decomposition and recovery method of the present invention can decompose and recover the (meth)acrylic resin composition of the present invention and the molded article of the present invention by the simple steps of decomposition and separation described above, and specifically can separate and recover the (meth)acrylic acid ester from the (meth)acrylic resin composition of the present invention and the molded article of the present invention.

[0076] The decomposition and recovery method of the present invention can also be applied to the molded article of the present invention. For example, similarly to the (meth)acrylic resin composition of the present invention, the (meth)acrylic acid ester can be recovered and recycled from the molded article of the present invention (including its off-spec products, production intermediates, production waste, or used recovered products) by the above-mentioned method. The decomposition and recovery method of the present invention can also be applied to the recovered (meth)acrylic resin composition and recycled (meth)acrylic resin composition described below, as well as recovered molded articles and recycled molded articles, instead of unused (meth)acrylic resin compositions. In this case, the (meth)acrylic acid ester can be recovered and recycled by the above-mentioned method, in which the target of application is the above-mentioned composition or molded article instead of the (meth)acrylic resin composition of the present invention.

[0077] [[Recycled (meth)acrylic resin composition]] The recycled (meth)acrylic resin composition of the present invention is a resin composition containing a recovered (meth)acrylic resin composition. This recovered (meth)acrylic resin composition includes one or more of the (meth)acrylic resin composition of the present invention (corresponding to the above-mentioned recycled (meth)acrylic resin composition) or a molded product thereof, as well as the recycled (meth)acrylic resin composition of the present invention or a recovered (meth)acrylic resin composition recovered from a recycled molded product thereof. That is, the recovered (meth)acrylic resin composition includes recovered (meth)acrylic resin compositions recovered from waste generated in the preparation of the (meth)acrylic resin composition of the present invention, waste generated in the production of a molded product of the present invention, and molded products of the present invention discarded by consumers, as well as recovered (meth)acrylic resin compositions recovered from waste generated in the preparation of recycled (meth)acrylic resin compositions that have already been recycled, waste generated in the production of recycled molded products, and recycled molded products discarded by consumers.

[0078] The recycled (meth)acrylic resin composition of the present invention is a resin composition containing the (meth)acrylic resin composition of the present invention or the molded article of the present invention, or the recycled (meth)acrylic resin composition of the present invention (corresponding to the above-mentioned recycled (meth)acrylic resin composition) or a (meth)acrylic resin composition recovered and recycled from a recycled molded article, etc., and unused (meth)acrylic resin and unused fibrous glass filler as virgin materials. Even though the recycled (meth)acrylic resin composition of the present invention contains a recovered (meth)acrylic resin composition, it satisfies the excellent levels of impact resistance, rigidity, and shatterproofness exhibited by the (meth)acrylic resin composition of the present invention, and therefore can achieve excellent shatterproofness while enhancing impact resistance and rigidity.

[0079] In the recycled (meth)acrylic resin composition of the present invention, the recovered (meth)acrylic resin composition may contain each of its components together (present or dispersed) or independently. The source of recovery or the number of times (recycle number) of the recovered (meth)acrylic resin composition contained in the recycled (meth)acrylic resin composition of the present invention is not particularly limited. For example, the number of times the recovered (meth)acrylic resin composition is recovered is preferably set within a range in which the recycled (meth)acrylic resin composition of the present invention satisfies the excellent levels of impact resistance, rigidity, and shatterproof properties exhibited by the (meth)acrylic resin composition of the present invention. The number of times the recovered (meth)acrylic resin composition is recovered depends on, for example, the composition and physical properties of the recycled (meth)acrylic resin composition, but, for example, from the viewpoints of impact resistance, rigidity, and shatterproof properties, it is preferably 2 to 10 times. When the recycled (meth)acrylic resin composition of the present invention contains recovered (meth)acrylic resin compositions that have been recovered multiple times, the recovered (meth)acrylic resin compositions contained in the recycled (meth)acrylic resin composition of the present invention may be recovered (meth)acrylic resin compositions that have been recovered the same number of times, or may be multiple types of recovered (meth)acrylic resin compositions that have been recovered different numbers of times.

[0080] The virgin (meth)acrylic resin contained in the recycled (meth)acrylic resin composition of the present invention is not particularly limited, and any appropriate (meth)acrylic resin can be used. However, in terms of impact resistance, rigidity, and shatterproof properties, it is preferable to use the (meth)acrylic resin of the present invention, i.e., a (meth)acrylic resin in which the content of structural units derived from (meth)acrylic acid esters is 90 to 99.985 mol % and the content of structural units derived from (meth)acrylic acid is 0.015 to 9.0 mol % relative to the total content of all structural units (100 mol %). Details of the (meth)acrylic resin of the present invention are as described above. Furthermore, the virgin fibrous glass filler contained in the recycled (meth)acrylic resin composition of the present invention is not particularly limited, but is preferably the fibrous glass filler described above. The recycled (meth)acrylic resin composition of the present invention may contain virgin styrene copolymer, virgin (meth)acrylic rubber particles, and virgin other components. Each of these virgin components is as described above. Each of the components contained in the recycled (meth)acrylic resin composition of the present invention may be one type or two or more types.

[0081] [Composition of Recycled (Meth)acrylic Resin Composition] The recycled (meth)acrylic resin composition of the present invention may contain the above-described recycled (meth)acrylic resin composition, a virgin (meth)acrylic resin, and a virgin fibrous glass filler, and its composition (components and amounts) can be determined appropriately depending on the intended use and the properties of the molded product (e.g., impact resistance, rigidity). The composition of the recycled (meth)acrylic resin composition of the present invention (which includes the composition of the recycled (meth)acrylic resin composition of the present invention, regardless of the number of times the contained recycled (meth)acrylic resin composition has been recovered; the same applies hereinafter) preferably satisfies the preferred ranges for excellent levels in the evaluations of shatterproofness, impact resistance, and rigidity in the examples described below. The composition of the recycled (meth)acrylic resin composition of the present invention more preferably satisfies the composition (components and amounts) within the ranges described above for the (virgin) (meth)acrylic resin composition of the present invention, and even more preferably has the same composition (components and amounts) as the (virgin) (meth)acrylic resin composition of the present invention. The composition of the (virgin) (meth)acrylic resin composition of the present invention is as described above.

[0082] In the present invention, the term "same composition" refers to the identity of both the (meth)acrylic resin and the fibrous glass filler, regardless of the identity of the styrene copolymer, (meth)acrylic rubber particles, and other components. In the present invention, it is preferable that the styrene copolymer and / or (meth)acrylic rubber particles, in addition to the (meth)acrylic resin and the fibrous glass filler, are also the same. While the (meth)acrylic resin and the fibrous glass filler may be altered by recycling the (meth)acrylic resin composition of the present invention, the identity of the components in the present invention is determined based on their identity in an unused state.

[0083] In the recycled (meth)acrylic resin composition of the present invention, in order to achieve excellent levels of impact resistance, rigidity, and shatterproof properties, it is preferable that the content of the fibrous glass filler derived from the recovered (meth)acrylic resin composition and the content of the virgin fibrous glass filler contained in the recycled (meth)acrylic resin composition are the same. That is, it is preferable that the content of the recovered fibrous glass filler contained in the recovered (meth)acrylic resin composition per 100 parts by mass of the recovered (meth)acrylic resin composition is the same as the content of the virgin fibrous glass filler per 100 parts by mass of the total of the virgin (meth)acrylic resin and the virgin fibrous glass filler contained in the recycled (meth)acrylic resin composition. In this case, the content of the recovered fibrous glass filler and the content of the virgin fibrous glass filler can each be in the same range as the content of the (virgin) fibrous glass filler in the (meth)acrylic resin composition of the present invention. For example, in the recycled (meth)acrylic resin composition of the present invention, in order to achieve a balance of impact resistance, rigidity, and shatterproof properties at excellent levels, the content of the virgin fibrous glass filler in a total of 100 parts by mass of the virgin (meth)acrylic resin and the virgin fibrous glass filler is preferably 1 to 40 parts by mass, with more preferred and even more preferred ranges being as described above.

[0084] In the recycled (meth)acrylic resin composition of the present invention, the contents of the recovered (meth)acrylic resin composition, the unused (meth)acrylic resin, and the unused fibrous glass filler are each not particularly limited and can be set appropriately. For example, in 100% by mass of the recycled (meth)acrylic resin composition, the content of the recovered (meth)acrylic resin composition is preferably 1 to 99% by mass, more preferably 3 to 90% by mass, even more preferably 5 to 80% by mass, and particularly preferably 10 to 70% by mass, in order to achieve a good balance of impact resistance, rigidity, and shatterproof properties. In this case, the contents of the recovered (meth)acrylic resin and the recovered fibrous glass filler in the recovered (meth)acrylic resin composition can be set appropriately, but are preferably the above-mentioned respective contents in the (meth)acrylic resin composition of the present invention. Furthermore, in 100% by mass of the recycled (meth)acrylic resin composition, the total content of the virgin (meth)acrylic resin and the virgin fibrous glass filler is preferably 1 to 99% by mass, more preferably 10 to 97% by mass, even more preferably 20 to 95%, and particularly preferably 30 to 90%, in order to achieve a good balance of impact resistance, rigidity, and shatterproof properties at an excellent level. In this case, the content of the virgin (meth)acrylic resin and the content of the virgin fibrous glass filler in the above total content can be set as appropriate, but it is preferable to set the respective contents as described above for the (meth)acrylic resin composition of the present invention.

[0085] When the recycled (meth)acrylic resin composition of the present invention contains at least one of a virgin styrene copolymer, a virgin (meth)acrylic rubber particle, and a virgin other component, the total content of the virgin (meth)acrylic resin, the virgin fibrous glass filler, the virgin styrene copolymer, the virgin (meth)acrylic rubber particle, and the virgin other component (i.e., the total content of components other than the recovered (meth)acrylic resin composition in the recycled (meth)acrylic resin composition of the present invention) is preferably set to the same range as the total content of the virgin (meth)acrylic resin and the virgin fibrous glass filler in 100% by mass of the recycled (meth)acrylic resin composition. The content of each unused component is not particularly limited and can be set appropriately. The content of each component in the recycled (meth)acrylic resin composition of the present invention is preferably set to the above-mentioned content when the total mass of components other than the recovered (meth)acrylic resin composition in the recycled (meth)acrylic resin composition of the present invention is taken as 100% by mass. The content of the recovered (meth)acrylic resin composition is as described above.

[0086] [Preparation of Recycled (Meth)acrylic Resin Composition] The recycled (meth)acrylic resin composition of the present invention can be prepared in the same manner as the preparation of the (meth)acrylic resin composition of the present invention, except that a recovered (meth)acrylic resin composition, a virgin (meth)acrylic resin, a virgin fibrous glass filler, and, optionally, a virgin styrene copolymer, a virgin (meth)acrylic rubber particle, a virgin other component, etc. are used. In the present invention, it is preferable to prepare the recycled (meth)acrylic resin composition by the recycling method of the present invention described below. Each of the above-mentioned virgin components used in preparing the recycled (meth)acrylic resin composition of the present invention may be mixed individually with the recovered (meth)acrylic resin composition, or two or more virgin components may be mixed in advance as a mixture.

[0087] [[Recycled Molded Article]] The recycled molded article of the present invention is a molded article made from the recycled (meth)acrylic resin composition of the present invention described above, and is usually a molded article obtained by molding the recycled (meth)acrylic resin composition of the present invention by a known molding method. The recycled molded article of the present invention has excellent impact resistance, rigidity, and shatterproof properties, and further has the excellent feature that the recycled (meth)acrylic resin composition can be (materially) recycled, and the (meth)acrylic acid ester in the (meth)acrylic resin composition can be recovered and (chemically) recycled again (multiple times). Therefore, the recycled molded article of the present invention can be used for various applications, just like the molded article of the present invention. The form, shape, and dimensions of the recycled molded article of the present invention are the same as those of the molded article of the present invention.

[0088] [Method for Producing Recycled Molded Article] The method for producing the recycled molded article of the present invention is not particularly limited, and is the same as the method for producing the molded article of the present invention, except that the recycled (meth)acrylic resin composition of the present invention is used.

[0089] [Recycling Method] The recycling method for a (meth)acrylic resin composition of the present invention (sometimes simply referred to as the "recycling method of the present invention") is a method for recycling a (meth)acrylic resin composition, or a (meth)acrylic resin composition forming a molded article, by (material) recycling the (meth)acrylic resin composition or the (meth)acrylic resin composition forming a molded article. The recycling method of the present invention was completed by finding that even if the (meth)acrylic resin composition of the present invention has been recycled once or multiple times, by using the (meth)acrylic resin composition in combination with a virgin (meth)acrylic resin composition and a virgin fibrous glass filler, a recycled molded article exhibiting desired impact resistance, rigidity, and shatterproof properties can be formed without significantly impairing the properties of the (meth)acrylic resin composition before recovery. In the recycling method of the present invention, a recycled (meth)acrylic resin composition or a recycled molded article that has already been recycled can be used as the processing target. In this case, the (meth)acrylic resin composition can be recycled multiple times. That is, the (meth)acrylic resin composition and molded article used in the recycling method of the present invention can be selected from one or more of the (meth)acrylic resin composition of the present invention or a molded article thereof, and further, the recycled (meth)acrylic resin composition of the present invention or a recycled molded article thereof. The number of recycling times (number of recovery times) of the recycled (meth)acrylic resin composition or recycled molded article used in the recycling method of the present invention is not particularly limited, and can be appropriately determined within a range in which a molded article formed using the obtained recycled (meth)acrylic resin composition exhibits excellent impact resistance, rigidity, and shatterproof properties. For example, it can be the same as the number of recovery times of the above-mentioned recovered (meth)acrylic resin composition.

[0090] [Recovery Step] In the recycling method of the present invention, first, the (meth)acrylic resin composition is recovered from at least one of the (meth)acrylic resin composition of the present invention or a molded article thereof, and the recycled (meth)acrylic resin composition of the present invention or a recycled molded article thereof. The recovery method and conditions are not particularly limited, and each resin composition or each molded article may be melt-mixed and recovered as a molten mixture (including strands, pellets, etc.). However, in order to prevent deterioration of properties, it is preferable to recover and collect each resin composition or each molded article in its original form. The source of recovery of each resin composition and each molded article is not particularly limited.

[0091] [Mixing Step] In the recycling method of the present invention, the recovered (meth)acrylic resin composition, unused (meth)acrylic resin, and unused fibrous glass filler are then mixed to prepare a recycled (meth)acrylic resin composition. The mixing method and mixing conditions are not particularly limited, but the mixing method and kneading method used in preparing the (meth)acrylic resin composition of the present invention can be suitably employed. In the above mixing, unused styrene copolymer, unused (meth)acrylic rubber particles, and unused other components can also be mixed, preferably in the amounts described above. Each of the components to be mixed may be one type or two or more types.

[0092] In the present invention, the recycled (meth)acrylic resin composition prepared as described above, or a recycled molded article made of this recycled (meth)acrylic resin composition, can be subjected again to the recovering step and the mixing step to prepare a recycled (meth)acrylic resin composition that has been recycled multiple times. That is, in the recycling method of the present invention, the recovering step and the mixing step can be repeated multiple times, appropriately interspersed with a molding step and a using step. The number of times that the composition is recycled can be appropriately determined within a range in which a molded article made of the recycled (meth)acrylic resin composition that has been recycled multiple times exhibits excellent impact resistance, rigidity, and shatterproof properties. For example, it can be the same as the number of times that the recovered (meth)acrylic resin composition was recovered.

[0093] The recycled (meth)acrylic resin composition can be prepared as described above. When molded into an article, the resulting recycled (meth)acrylic resin composition exhibits excellent impact resistance, rigidity, and shatterproof properties.

[0094] The recycling method of the present invention may include other steps in addition to the above-mentioned recovering step and mixing step. Examples of other steps include a step of washing the recovered (meth)acrylic resin composition or molded body, a step of pulverizing the recovered molded body, and a step of molding the prepared recycled (meth)acrylic resin composition. The molding step is not particularly limited, and is the same as the method for producing a molded body of the present invention, except that the recycled (meth)acrylic resin composition of the present invention is used.

[0095] Examples of the present invention will be shown below, but the present invention is not limited to these examples.

[0096] [Preparation, synthesis or preparation of (unused) (meth)acrylic resin] <Preparation of methacrylic resin PM1> As the methacrylic resin PM1, a commercially available product, ALTUGLAS HT121 (trade name, manufactured by ARKEMA), was used. Hereinafter, the methacrylic resin PM1 will be referred to as methacrylic resin HT121.

[0097] <Synthesis of Methacrylic Resin PM2> In a 5 L autoclave equipped with a stirrer, 1.3 parts by mass of methacrylic acid (hereinafter referred to as "MAA"; manufactured by Nippon Shokubai Co., Ltd.) and 98.7 parts by mass of methyl methacrylate (hereinafter referred to as "MMA"; manufactured by Sumitomo Chemical Co., Ltd.) were mixed to obtain a monomer mixture. To this monomer mixture, 0.4 parts by mass of lauryl peroxide (Laurox K (trade name), manufactured by Kayaku Akzo Co., Ltd.) as a polymerization initiator and 0.34 parts by mass of 1-dodecyl mercaptan as a chain transfer agent were added relative to 100 parts by mass of the total monomer mixture, and these were dissolved. Furthermore, 0.060 parts by mass of hydroxyethyl cellulose (SANHEC H (trade name), manufactured by Sansho Co., Ltd.) as a suspension stabilizer was dissolved in ion-exchanged water relative to 100 parts by mass of the total monomer mixture to form an aqueous phase for suspension polymerization. 150 parts by mass of the aqueous phase was then added relative to 100 parts by mass of the aforementioned monomer mixture, and suspension polymerization was carried out at 60°C. The resulting slurry-like reaction liquid was dehydrated using a dehydrator (Centrifuge H-122 (trade name), manufactured by Kokusan Co., Ltd.) and washed twice with 40 L of ion-exchanged water, and then dried to obtain a bead-like polymer composition. This bead-like polymer composition was blended with 0.05 parts by mass of a phosphorus-based antioxidant (Irgafos 168 (trade name), manufactured by BASF Japan Ltd.) per 100 parts by mass of the polymer composition, and the blend was melt-kneaded using a twin-screw extruder (model: TEX30SS-30AW-2V) manufactured by The Japan Steel Works, Ltd., under the following kneading conditions, extruded into a strand shape, water-cooled, and cut with a strand cutter to obtain pellet-like methacrylic resin PM2.

[0098] <Synthesis of Methacrylic Resin PM3> Methyl methacrylate and methyl acrylate were polymerized to synthesize the methacrylic resin PM3.

[0099] <Synthesis of Methacrylic Resin PM4> Methyl methacrylate and methyl acrylate were polymerized to synthesize the methacrylic resin PM4.

[0100] <Synthesis of methacrylic resin PM5> Methyl methacrylate and methyl acrylate were polymerized to synthesize methacrylic resin PM5.

[0101] <Preparation of Methacrylic Resin PM6> 20 parts by mass of the methacrylic resin PM4 and 50 parts by mass of the methacrylic resin PM5 were mixed together to obtain a mixture of methacrylic resin PM6.

[0102] <Synthesis of Methacrylic Resin PM7> Methyl methacrylate and methyl acrylate were polymerized to synthesize the methacrylic resin PM7.

[0103] The prepared, synthesized or prepared methacrylic resins PM1 to PM7 were measured for nuclear magnetic resonance spectrum ( １３ The molar ratio of each component was calculated by taking the integral value of each peak in the obtained NMR chart. Specifically, a nuclear magnetic resonance apparatus (Bruker: Avance 600 (trade name), (10 mm cryoprobe)) was used. １３ The C-NMR was measured. Deuterated chloroform was used as the measurement solvent, and the measurement was performed by the inverse gate proton decoupling method. The chemical shift value was based on chloroform. The MMA content was determined from the integrated value of the peak with a chemical shift of 173.0 to 180.4 ppm. The MAA content was determined from the integrated value of the peak with a chemical shift of 180.4 to 188.0 ppm. The content of glutaric anhydride structure formed by cyclocondensation of MMA and MAA was determined from the integrated value of the peak with a chemical shift of 170.0 to 173.0 ppm. The results are shown in Table 1. - Nuclear magnetic resonance spectrum measurement conditions - Resonance frequency: 400 MHz Measurement temperature: 27°C Pulse repetition time: 20 seconds Number of accumulations: 4000 Sample concentration: 300 mg / 2.5 mL Solvent: CDCl ３

[0104]

[0105] In Table 1, "MA" indicates the content (unit: mol%) of structural units derived from methyl acrylate, "MMA" indicates the content (unit: mol%) of structural units derived from methyl methacrylate, "MAA" indicates the content (unit: mol%) of structural units derived from methacrylic acid, and "ring structure" indicates the content (unit: mol%) of structural units containing a ring structure consisting of glutaric anhydride.

[0106] [Preparation of Fibrous Glass Filler] The following fibrous glass fillers were prepared as the fibrous glass fillers. <Fibrous Glass Filler (T-289)> ESC03T-289: trade name, chopped strand, fiber diameter 13 μm, fiber length 3.0 mm, circular cross section, manufactured by Nippon Electric Glass Co., Ltd. <Flat Fibrous Glass Filler (T-480-FGF)> ESC03T-480-FGF: trade name, chopped strand, fiber length 4.0 mm, major axis: 20 μm, minor axis: 5 μm, aspect ratio: 4.0, manufactured by Nippon Electric Glass Co., Ltd.

[0107] [Preparation of Styrene Copolymer] A styrene-acrylonitrile copolymer resin (hereinafter referred to as "SAN resin"; product name: Lytac A 120PCF, manufactured by Nippon A&L Co., Ltd.) was prepared as a styrene copolymer.

[0108] [(meth)acrylic rubber particle production] The spherical (meth)acrylic rubber particle of three-layer structure is produced by emulsion polymerization method.The (meth)acrylic rubber particle synthesized has the following structure: innermost layer is the hard polymer obtained by polymerizing the monomer composition of 93.8% by mass of methyl methacrylate, 6.0% by mass of methyl acrylate and 0.2% by mass of allyl methacrylate; middle layer is the elastic polymer obtained by polymerizing the monomer composition of 81% by mass of butyl acrylate, 17% by mass of styrene and 2% by mass of allyl methacrylate; outermost layer is the hard polymer obtained by polymerizing the monomer composition of 94% by mass of methyl methacrylate and 6% by mass of methyl acrylate; innermost layer / middle layer / outermost layer proportion is 35% by mass / 45% by mass / 20% by mass; and the weight average particle diameter of the elastic polymer layer that constitutes the middle layer is 0.22 μm.

[0109] [Examples 1 to 9 and Comparative Examples 1 to 8] A (virgin) (meth)acrylic resin composition was prepared using a virgin (meth)acrylic resin, and a (virgin) molded article (sheet) was produced using this (meth)acrylic resin composition, and these were evaluated.

[0110] Example 1 80 parts by mass of methacrylic resin PM1 and 20 parts by mass of fibrous glass filler (T-289) were melt-kneaded using a single-screw extruder (model: VS40, manufactured by Tanabe Plastics Co., Ltd.) under the following melt-kneading conditions, extruded into a strand, solidified by water cooling, and cut with a strand cutter to obtain a pellet-shaped methacrylic resin composition (1). Next, using the prepared methacrylic resin composition (1), injection molding (heat and cool molding) was performed under the following conditions to obtain a sheet-like molded product (1) having a thickness of 3 mm. - Melt-kneading conditions - The temperature of the extruder was set to 200 ° C, 220 ° C, 230 ° C, 250 ° C, and 260 ° C, respectively, from the raw material inlet side, for five heaters arranged spaced apart from each other between the raw material inlet and the outlet. Kneading was performed at a screw rotation speed of 70 rpm. - Injection molding conditions - Equipment: NADEM2800II-DM (manufactured by Meiki Seisakusho) Mold: 248mm x 198mm x 3mm Injection speed: 30mm / s Injection pressure: 200MPa Rotation speed: 100rpm Holding pressure: 100MPa Mold temperature (high temperature, during injection): 140°C Mold temperature (low temperature, during removal): 70°C

[0111] Examples 2 to 9 Pellet-shaped methacrylic resin compositions (2) to (9) were obtained in the same manner as in Example 1, except that the components (methacrylic resin, fibrous glass filler, SAN resin, and (meth)acrylic rubber particles) shown in Table 2-1 were mixed in the mass ratios shown in Table 2-1 in Example 1. Furthermore, each of the methacrylic resin compositions (2) to (9) was injection molded in the same manner as in Example 1 to obtain sheet-shaped molded products (2) to (9), respectively.

[0112] Comparative Examples 1 to 4 and 8 Pellet-shaped methacrylic resin compositions (C1) to (C4) and (C8) were obtained in the same manner as in Example 1, except that the components (methacrylic resin, fibrous glass filler, and SAN resin) shown in Table 2-2 were mixed in the mass ratios shown in Table 2-2 in Example 1. Furthermore, each of the methacrylic resin compositions (C1) to (C4) and (C8) was injection molded in the same manner as in Example 1 to obtain sheet-shaped molded products (C1) to (C4) and (C8), respectively.

[0113] Comparative Examples 5 to 7 Pellet-shaped methacrylic resin compositions (C5) to (C7) were obtained in the same manner as in Example 1, except that the components (methacrylic resin and (meth)acrylic rubber particles) shown in Table 2-2 were mixed in the mass ratios shown in Table 2-2 in Example 1. Furthermore, each of the methacrylic resin compositions (C5) to (C7) was injection molded in the same manner as in Example 1 to obtain sheet-shaped molded products (C5) to (C7), respectively.

[0114] [Examples 10 to 13 and Comparative Examples 9 and 10] A methacrylic resin composition prepared using unused methacrylic resin was collected and mixed with unused methacrylic resin and unused fibrous glass filler (T-289) to prepare a recycled methacrylic resin composition. This process was repeated a predetermined number of times to obtain a recycled methacrylic resin composition, which was then used to produce a recycled molded article (sheet). The prepared recycled methacrylic resin composition and the produced recycled molded article were evaluated.

[0115] Example 10 A methacrylic resin composition (10-1) prepared as follows was recovered. This methacrylic resin composition (10-1) was used as a recovered methacrylic resin composition and mixed with unused methacrylic resin and unused fibrous glass filler (T-289) to prepare a recycled methacrylic resin composition (10-2) having the same composition as the prepared methacrylic resin composition (10-1) and containing 50% by mass of the recovered methacrylic resin composition. Specifically, 4 parts by mass of methacrylic resin PM1, 76 parts by mass of methacrylic resin PM7, and 20 parts by mass of fibrous glass filler (T-289) were melt-kneaded using a single-screw extruder (model: VS40, manufactured by Tanabe Plastics Co., Ltd.) under the following melt-kneading conditions, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped methacrylic resin composition (10-1). Next, the prepared pellet-shaped methacrylic resin composition (10-1) was recovered, and 50 parts by mass of this recovered methacrylic resin composition (10-1), 2 parts by mass of methacrylic resin PM1, 38 parts by mass of methacrylic resin PM7, and 10 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the following melt-kneading conditions, extruded into a strand shape, solidified by water cooling, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (10-2).

[0116] Using the obtained recycled methacrylic resin composition (10-2), injection molding (heat and cool molding) was carried out under the following conditions to obtain a recycled sheet-shaped molded product (10) having a thickness of 3 mm. - Melt kneading conditions - The temperature of the extruder was set at 200°C, 220°C, 230°C, 250°C, and 260°C from the raw material inlet side for five heaters arranged at a distance from each other between the raw material inlet and the outlet. Kneading was performed at a screw rotation speed of 70 rpm. - Injection molding conditions - Apparatus: NADEM2800II-DM (manufactured by Meiki Seisakusho Co., Ltd.) Mold: 248 mm x 198 mm x 3 mm Injection speed: 30 mm / s Injection pressure: 200 MPa Rotation speed: 100 rpm Holding pressure: 100 MPa Mold temperature (high temperature, during injection): 140°C Mold temperature (low temperature, during removal): 70°C

[0117] Example 11 A methacrylic resin composition (11-1) prepared as follows was recovered. This methacrylic resin composition (11-1) was used as a recovered methacrylic resin composition and mixed with unused methacrylic resin and unused fibrous glass filler (T-289) to prepare a recycled methacrylic resin composition (11-2) having the same composition as the prepared methacrylic resin composition (11-1) and a 50% by mass content of the recovered methacrylic resin composition. This process was repeated four more times to prepare a recycled methacrylic resin composition (11-6) having the same composition as the methacrylic resin composition (11-1) and a 50% by mass content of the recovered methacrylic resin composition. In Example 11, the recycled methacrylic resin compositions (11-2) to (11-5) all correspond to recycled methacrylic resin compositions used in the next recycled methacrylic resin composition preparation process.

[0118] Specifically, 4 parts by mass of methacrylic resin PM1, 76 parts by mass of methacrylic resin PM7, and 20 parts by mass of fibrous glass filler (T-289) were melt-kneaded using a single-screw extruder (model: VS40, manufactured by Tanabe Plastics Co., Ltd.) under the melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped methacrylic resin composition (11-1). Next, the prepared pellet-shaped methacrylic resin composition (11-1) was recovered, and 50 parts by mass of this recovered methacrylic resin composition (11-1), 2 parts by mass of methacrylic resin PM1, 38 parts by mass of methacrylic resin PM7, and 10 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (11-2).

[0119] Furthermore, the prepared pellet-shaped recycled methacrylic resin composition (11-2) was recovered, and 50 parts by mass of this recovered methacrylic resin composition (11-2), 2 parts by mass of methacrylic resin PM1, 38 parts by mass of methacrylic resin PM7, and 10 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (11-3). Next, the prepared pellet-shaped recycled methacrylic resin composition (11-3) was recovered, and 50 parts by mass of this recovered methacrylic resin composition (11-3), 2 parts by mass of methacrylic resin PM1, 38 parts by mass of methacrylic resin PM7, and 10 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (11-4).

[0120] Furthermore, the prepared pellet-shaped recycled methacrylic resin composition (11-4) was recovered, and 50 parts by mass of this recovered methacrylic resin composition (11-4), 2 parts by mass of methacrylic resin PM1, 38 parts by mass of methacrylic resin PM7, and 10 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (11-5). Next, the prepared pellet-shaped recycled methacrylic resin composition (11-5) was recovered, and 50 parts by mass of this recovered methacrylic resin composition (11-5), 2 parts by mass of methacrylic resin PM1, 38 parts by mass of methacrylic resin PM7, and 10 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above single-screw extruder under the melt-kneading conditions shown in Example 10, extruded into a strand, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (11-6).

[0121] Using the obtained recycled methacrylic resin composition (11-6), injection molding (heat and cool molding) was carried out under the injection molding conditions shown in Example 10 to obtain a recycled sheet-shaped molded product (11) having a thickness of 3 mm.

[0122] Example 12 A methacrylic resin composition (12-1) prepared as follows was recovered. This methacrylic resin composition (12-1) was used as a recovered methacrylic resin composition and mixed with unused methacrylic resin and unused fibrous glass filler (T-289) to prepare a recycled methacrylic resin composition (12-2) having the same composition as the prepared methacrylic resin composition (12-1) and a recovered methacrylic resin composition content of 70% by mass. Specifically, 4 parts by mass of methacrylic resin PM1, 76 parts by mass of methacrylic resin PM7, and 20 parts by mass of fibrous glass filler (T-289) were melt-kneaded using a single-screw extruder (model: VS40, manufactured by Tanabe Plastics Co., Ltd.) under the melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped methacrylic resin composition (12-1). Next, the prepared pellet-shaped methacrylic resin composition (12-1) was recovered, and 70 parts by mass of this recovered methacrylic resin composition (12-1), 1.2 parts by mass of methacrylic resin PM1, 22.8 parts by mass of methacrylic resin PM7, and 6 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (12-2).

[0123] Using the obtained recycled methacrylic resin composition (12-2), injection molding (heat and cool molding) was carried out under the injection molding conditions shown in Example 10 to obtain a recycled sheet-shaped molded product (12) having a thickness of 3 mm.

[0124] Example 13 A methacrylic resin composition (13-1) prepared as follows was recovered. This methacrylic resin composition (13-1) was used as a recovered methacrylic resin composition and mixed with unused methacrylic resin and unused fibrous glass filler (T-289) to prepare a recycled methacrylic resin composition (13-2) having the same composition as the prepared methacrylic resin composition (13-1) and a recovered methacrylic resin composition content of 70% by mass. This process was repeated four more times to prepare a recycled methacrylic resin composition (13-6) having the same composition as the methacrylic resin composition (11-1) and a recovered methacrylic resin composition content of 70% by mass. In Example 13, the recycled methacrylic resin compositions (13-2) to (13-5) all correspond to recycled methacrylic resin compositions used in the next recycled methacrylic resin composition preparation process.

[0125] Specifically, 4 parts by mass of methacrylic resin PM1, 76 parts by mass of methacrylic resin PM7, and 20 parts by mass of fibrous glass filler (T-289) were melt-kneaded using a single-screw extruder (model: VS40, manufactured by Tanabe Plastics Co., Ltd.) under the melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped methacrylic resin composition (13-1). Next, the prepared pellet-shaped methacrylic resin composition (13-1) was recovered, and 70 parts by mass of this recovered methacrylic resin composition (13-1), 1.2 parts by mass of methacrylic resin PM1, 22.8 parts by mass of methacrylic resin PM7, and 6 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (13-2).

[0126] Furthermore, the prepared pellet-shaped recycled methacrylic resin composition (13-2) was recovered, and 70 parts by mass of this recovered methacrylic resin composition (13-2), 1.2 parts by mass of methacrylic resin PM1, 22.8 parts by mass of methacrylic resin PM7, and 6 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (13-3). Next, the prepared pellet-shaped recycled methacrylic resin composition (13-3) was recovered, and 70 parts by mass of this recovered methacrylic resin composition (13-3), 1.2 parts by mass of methacrylic resin PM1, 22.8 parts by mass of methacrylic resin PM7, and 6 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (13-4).

[0127] Furthermore, the prepared pellet-shaped recycled methacrylic resin composition (13-4) was recovered, and 70 parts by mass of this recovered methacrylic resin composition (13-4), 1.2 parts by mass of methacrylic resin PM1, 22.8 parts by mass of methacrylic resin PM7, and 6 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (13-5). Next, the prepared pellet-shaped recycled methacrylic resin composition (13-5) was recovered, and 70 parts by mass of this recovered methacrylic resin composition (13-5), 1.2 parts by mass of methacrylic resin PM1, 22.8 parts by mass of methacrylic resin PM7, and 6 parts by mass of fibrous glass filler (T-289) were melt-kneaded using the above-mentioned single-screw extruder under the above-mentioned melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (13-6).

[0128] Using the obtained recycled methacrylic resin composition (13-6), injection molding (heat and cool molding) was carried out under the injection molding conditions shown in Example 10 to obtain a recycled sheet-shaped molded product (13) having a thickness of 3 mm.

[0129] <Comparative Example 9> A methacrylic resin composition (C9-1) prepared as follows was recovered. This methacrylic resin composition (C9-1) was used as a recovered methacrylic resin composition as is, and a recycled methacrylic resin composition (C9-2) having the same composition as the prepared methacrylic resin composition (C9-1) and a content of recovered methacrylic resin composition of 100% by mass was prepared. Specifically, 4 parts by mass of methacrylic resin PM1, 76 parts by mass of methacrylic resin PM7, and 20 parts by mass of fibrous glass filler (T-289) were melt-kneaded using a single-screw extruder (model: VS40, manufactured by Tanabe Plastics Co., Ltd.) under the melt-kneading conditions shown in Example 10 and extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped methacrylic resin composition (C9-1). Next, the prepared pellet-shaped methacrylic resin composition (C9-1) was recovered, and this recovered methacrylic resin composition (C9-1) was again melt-kneaded using the single-screw extruder under the melt-kneading conditions shown in Example 10, extruded into a strand shape, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (C9-2).

[0130] Using the obtained recycled methacrylic resin composition (C9-2), injection molding (heat and cool molding) was carried out under the injection molding conditions shown in Example 10 to obtain a recycled sheet-shaped molded product (C9) having a thickness of 3 mm.

[0131] Comparative Example 10 A methacrylic resin composition (C10-1) prepared as follows was recovered. This methacrylic resin composition (C10-1) was used as a recovered methacrylic resin composition as is to prepare a recycled methacrylic resin composition (C10-2) having the same composition as the prepared methacrylic resin composition (10-1) and containing 100% by mass of the recovered methacrylic resin composition. This process was repeated four more times to prepare a recycled methacrylic resin composition (C10-6) having the same composition as the methacrylic resin composition (C10-1) and containing 100% by mass of the recovered methacrylic resin composition.

[0132] Specifically, 4 parts by mass of methacrylic resin PM1, 76 parts by mass of methacrylic resin PM7, and 20 parts by mass of fibrous glass filler (T-289), using a single-screw extruder (model: VS40, manufactured by Tanabe Plastics Co., Ltd.), melt-kneaded under the melt-kneading conditions shown in Example 10 and extruded into a strand, water-cooled and solidified, and cut with a strand cutter to obtain a pellet-shaped methacrylic resin composition (C10-1). Then, the prepared pellet-shaped methacrylic resin composition (C10-1) was recovered, and this recovered methacrylic resin composition (C10-1) was again recovered using the single-screw extruder, melt-kneaded under the melt-kneading conditions shown in Example 10, extruded into a strand, water-cooled and solidified, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (C10-2).

[0133] Furthermore, the prepared pellet-shaped recycled methacrylic resin composition (C10-2) was recovered, and this recovered methacrylic resin composition (C10-2) was again melt-kneaded using the single-screw extruder under the melt-kneading conditions shown in Example 10, extruded into a strand, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (C10-3). Next, the prepared pellet-shaped recycled methacrylic resin composition (C10-3) was recovered, and this recovered methacrylic resin composition (C10-3) was again melt-kneaded using the single-screw extruder under the melt-kneading conditions shown in Example 10, extruded into a strand, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (C10-4).

[0134] Furthermore, the prepared pellet-shaped recycled methacrylic resin composition (C10-4) was recovered, and this recovered methacrylic resin composition (C10-4) was again melt-kneaded using the single-screw extruder under the melt-kneading conditions shown in Example 10, extruded into a strand, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (C10-5). Next, the prepared pellet-shaped recycled methacrylic resin composition (C10-5) was recovered, and this recovered methacrylic resin composition (C10-5) was again melt-kneaded using the single-screw extruder under the melt-kneading conditions shown in Example 10, extruded into a strand, water-cooled to solidify, and cut with a strand cutter to obtain a pellet-shaped recycled methacrylic resin composition (C10-6).

[0135] Using the obtained recycled methacrylic resin composition (C10-6), injection molding (heat and cool molding) was carried out under the injection molding conditions shown in Example 10 to obtain a recycled sheet-shaped molded product (C10) having a thickness of 3 mm.

[0136] The prepared sheet-like molded articles were used to evaluate shatterproof properties, impact resistance, and rigidity. The prepared sheet-like molded articles were also used to decompose and recover the (meth)acrylic resin composition. The sheet-like molded articles of Examples 1 to 13 had smooth, mirror-finished surfaces.

[0137] [Evaluation of Shatterproof Properties] Each sheet-like molded product was used to conduct a shatterproof test using a DuPont drop weight test (1 kg load, 1 m height). Test pieces were cut into squares measuring 5 cm in the MD and 5 cm in the TD. Here, the MD direction is the direction parallel to the flow direction of the (meth)acrylic resin composition during injection molding, and the TD direction is the direction perpendicular to the flow direction of the (meth)acrylic resin composition during injection molding. The shatterproof properties were evaluated as "OK" (pass) if no large fragments were scattered, and as "NG" (fail) if large fragments were scattered. The results are shown in Table 2-1 and Table 2-2 (collectively referred to as "Table 2").

[0138] [Evaluation of Impact Resistance] After notching each sheet-form molding using a notching machine (manufactured by Ueshima Seisakusho), the Charpy impact strength (kJ / m) of each sheet-form molding was measured using a Charpy impact tester DG-CB (model, manufactured by Toyo Seiki Co., Ltd.) in accordance with JIS K 7111-1. ２ ) was measured. Specifically, an impact test was carried out parallel to the width direction of the edgewise test piece, and the following conditions were adopted: A notch as the notch shape, tip radius 0.25 mm ± 0.05 mm, and remaining width after notch 8 mm ± 0.2 mm. The cutting direction (longitudinal direction) of the test piece was the MD direction. The measured Charpy impact strength (kJ / m ２ ) was evaluated as the impact resistance (strength) of each sheet-like molding. In this evaluation, a higher Charpy impact strength indicates better impact resistance, and in the present invention, a value of 3.0 kJ / m ２ The results are shown in Table 2.

[0139] [Evaluation of Rigidity] The flexural modulus (MPa) of each sheet-like molded article was measured in accordance with JIS K 7171 using an automatic tensile / bending combined testing machine (manufactured by A&D Co., Ltd.). The measured flexural modulus (MPa) was evaluated as the rigidity of each sheet-like molded article. The test specimens were cut out in the MD direction. In this evaluation, a higher flexural modulus indicates better rigidity, and in the present invention, a flexural modulus of 4000 MPa or more is preferable. The results are shown in Table 2.

[0140] [Decomposition and Recovery] Each of the produced sheet-like moldings was decomposed and recovered to evaluate whether or not the methyl methacrylate (MMA) component could be recovered (chemical recyclability). Specifically, each sheet-like molding was thermally decomposed in a tubular furnace at 450°C for 10 minutes, and the resulting decomposition products were measured by GC-MS to qualitatively identify the detected components. During this thermal decomposition, volatile components were generated, and black solid matter remained on the combustion board inside the tubular furnace. As a result of measuring the volatile components by GC-MS, it was found that the main component recovered was the methyl methacrylate (MMA) component. Cases in which the MMA component could be separated from the fibrous glass filler were evaluated as "OK" (pass), and cases in which the MMA component could not be separated from the fibrous glass filler were evaluated as "NG" (fail). The results are shown in Table 2.

[0141]

[0142]

[0143] In Table 2, "content of structural units (mol %)" indicates the content (mol %) of each structural unit in all structural units of the methacrylic resin, "MA" indicates the content of structural units derived from methyl acrylate, "MMA" indicates the content of structural units derived from methyl methacrylate, "MAA" indicates the content of structural units derived from methacrylic acid, and "ring structure" indicates the content of structural units containing a ring structure consisting of glutaric anhydride. In Table 2, with respect to the components contained in the methacrylic resin composition, blank cells indicate that the content of the component in the composition is 0 mass %.

[0144] [Example 14] A (virgin) (meth)acrylic resin composition was prepared using virgin (meth)acrylic resin and virgin flat fibrous glass filler (T-480-FGF), and a (virgin) molded body (sheet) was produced using this (meth)acrylic resin composition, and these were evaluated. Specifically, a pellet-shaped methacrylic resin composition (14) was obtained in the same manner as in Example 1, except that the flat fibrous glass filler (T-480-FGF) was used instead of the fibrous glass filler (T-289) in Example 1. Next, the prepared methacrylic resin composition (14) was injection molded in the same manner as in Example 1 to obtain a sheet-shaped molded body (14). The surface of this sheet-shaped molded body (14) was smooth and mirror-finished.

[0145] The prepared sheet-like molded product (14) was evaluated for shatterproof properties, impact resistance, and rigidity in the same manner as in Example 1. The prepared sheet-like molded product (14) was also used to decompose and recover the (meth)acrylic resin composition. For the evaluation of impact resistance and rigidity, the test pieces were cut out in two directions, the MD direction and the TD direction, and two types of test pieces cut out in different directions were prepared. Here, the MD direction is the direction parallel to the flow direction of the (meth)acrylic resin composition during injection molding, and the TD direction is the direction perpendicular to the flow direction of the (meth)acrylic resin composition during injection molding. The results of each evaluation are shown in Table 3, along with the results of Example 1.

[0146]

[0147] In Table 3, the "TD" column in the "Charpy impact strength" and "flexural modulus" columns shows the measurement results of test pieces cut out in the TD direction, and the "MD" column shows the measurement results of test pieces cut out in the MD direction.

[0148] The results shown in Tables 1 to 3 reveal the following. Methacrylic resin compositions that do not contain a methacrylic resin having structural units derived from methacrylic acid and a fibrous glass filler are unable to balance impact resistance, rigidity, and shatterproof properties. That is, for methacrylic resin compositions containing a fibrous glass filler but in which the methacrylic resin does not have structural units derived from methacrylic acid (Comparative Examples 1 to 3), the sheet-shaped molded articles broke (cracked) in the DuPont drop weight test, scattering large pieces with sharp edges, and exhibiting poor shatterproof properties. Furthermore, a methacrylic resin composition containing a fibrous glass filler and a styrene copolymer but in which the methacrylic resin does not have structural units derived from methacrylic acid (Comparative Example 4) exhibited poor shatterproof properties. Furthermore, in a methacrylic resin composition (Comparative Example 8) containing too little structural units derived from methacrylic acid in the methacrylic resin, each sheet-shaped molding broke in the DuPont drop weight test, scattering large fragments with sharp edges, and the composition had poor shatterproof properties. On the other hand, in the methacrylic resin compositions (Comparative Examples 5 to 7) not containing a fibrous glass filler, even though the methacrylic resin contained structural units derived from methacrylic acid, each sheet-shaped molding broke (cracked) in the DuPont drop weight test, scattering large fragments with sharp edges, and the composition had poor impact resistance and / or rigidity.

[0149] In the recycled methacrylic resin compositions (Comparative Examples 9 and 10) prepared by recovering the prepared (unused) methacrylic resin composition and melt-mixing the recovered methacrylic resin composition without mixing it with unused components, each sheet-shaped molded body broke (cracked) in the DuPont drop weight test, scattering large pieces with sharp edges, regardless of the number of times it was recovered. Moreover, the recycled methacrylic resin composition (C10-6) of Comparative Example 10, in which the number of times it was recovered was set to 6, showed a large decrease in Charpy impact strength.

[0150] In contrast, methacrylic resin compositions (Examples 1 to 9) containing a methacrylic resin having structural units derived from methacrylic acid and a fibrous glass filler within the content range specified in the present invention were able to achieve a balance of impact resistance, rigidity, and shatterproof properties. Furthermore, recycled methacrylic resin compositions (Examples 10 to 13) prepared by recovering a prepared (virgin) methacrylic resin composition and mixing the recovered methacrylic resin composition with virgin components at a ratio of 50 or 70 mass% based on the total mass of the mixed components maintained excellent rigidity regardless of the number of times the resin was recovered, while preventing cracking of each sheet-shaped molded body in a DuPont drop weight test and suppressing a decrease in Charpy impact strength. As a result, they achieved a balance of impact resistance, rigidity, and shatterproof properties similar to those of a (virgin) methacrylic resin composition. In Examples 11 and 13, the measured values ​​of Charpy impact strength and flexural modulus did not decrease even when the number of times the resin was recovered was increased, showing almost the same values. Therefore, it was confirmed that the recycled methacrylic resin compositions (11-2) to (11-5) and (13-2) to (13-5) also achieved a balance of impact resistance, rigidity, and shatterproof properties. Furthermore, it was confirmed that Example 14, which used a flat fibrous glass filler (T-480-FGF), showed a smaller difference in properties between test pieces cut in the TD direction and those cut in the MD direction compared to Example 1, which used a fibrous glass filler (T-289) with a substantially circular cross-sectional shape. Furthermore, the methacrylic resin compositions (Examples 1 to 9, 14) and the recycled methacrylic resin compositions (Examples 10 to 13) could also be molded into molded articles, and by heating them to a predetermined temperature, the methacrylic acid esters that make up the methacrylic resin could be recovered.

[0151] From the above results, it can be seen that the methacrylic resin compositions of the present invention (virgin methacrylic resin compositions and recycled methacrylic resin compositions) can be suitably used in various applications and as a replacement for various resins by utilizing the above-mentioned excellent properties, and furthermore, material recycling and chemical recycling are also possible.

Claims

1. A (meth)acrylic resin composition comprising: a (meth)acrylic resin having a content of structural units derived from a (meth)acrylic acid ester of 90 to 99.985 mol % and a content of structural units derived from (meth)acrylic acid of 0.015 to 9.0 mol %, relative to 100 mol % of the total content of all structural units; and a fibrous glass filler.

2. The (meth)acrylic resin composition according to claim 1, wherein the content of structural units derived from the (meth)acrylic acid ester is 90 to 99.0 mol %, and the content of structural units derived from the (meth)acrylic acid is 0.1 to 9.0 mol %.

3. The (meth)acrylic resin composition according to claim 1, wherein the content of the fibrous glass filler is 1 to 40 parts by mass per 100 parts by mass of the (meth)acrylic resin composition.

4. The (meth)acrylic resin composition according to claim 1, wherein the fibrous glass filler has a fiber diameter of 3 to 25 μm and a fiber length of 0.1 to 10 mm.

5. The (meth)acrylic resin composition according to claim 1, wherein the fibrous glass filler has a fiber diameter of 3 to 25 μm and a fiber length of 0.5 to 10 mm.

6. The (meth)acrylic resin composition according to claim 1, wherein the fibrous glass filler comprises a glass filler having a flat cross-sectional shape with a ratio of the long axis to the short axis in the cross section [long axis / short axis] of 2.0 or more.

7. The (meth)acrylic resin composition according to claim 1, wherein the (meth)acrylic resin contains a ring structure consisting of glutaric anhydride in its main chain, and the content of structural units containing the ring structure is 1.0 mol % or less relative to 100 mol % in total of all structural units of the (meth)acrylic resin.

8. The (meth)acrylic resin composition according to claim 1, wherein the (meth)acrylic acid ester is at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, iso-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.

9. The (meth)acrylic resin composition according to claim 1, further comprising a styrene copolymer, said styrene copolymer being a styrene-acrylonitrile copolymer or a styrene-acrylonitrile-phenylmaleimide copolymer.

10. The (meth)acrylic resin composition according to claim 1, further comprising (meth)acrylic rubber particles, the (meth)acrylic rubber particles being spherical (meth)acrylic rubber particles having a three-layer structure consisting of an inner layer made of a hard polymer mainly made of an alkyl methacrylate, a middle layer made of an elastic copolymer mainly made of an alkyl acrylate, and an outer layer made of a hard polymer mainly made of an alkyl methacrylate.

11. A molded article made of the (meth)acrylic resin composition according to any one of claims 1 to 10.

12. A car body made of the (meth)acrylic resin composition according to any one of claims 1 to 10.

13. A method for producing a molded article by injection molding the (meth)acrylic resin composition according to any one of claims 1 to 10, comprising using a rapid heating and cooling mold, carrying out the injection step when the mold cavity surface temperature is 110°C or higher, and carrying out the mold opening step when the mold cavity surface temperature is 80°C or lower.

14. A method for producing a molded article by extruding the (meth)acrylic resin composition according to any one of claims 1 to 10, comprising the steps of discharging a melt of the (meth)acrylic resin composition from a die, and cooling the discharged melt to obtain a molded article.

15. A method for decomposing and recovering a (meth)acrylic resin composition, comprising decomposing the (meth)acrylic resin composition according to any one of claims 1 to 10 at a temperature of 380°C or higher, and separating the volatile components from solid matter to recover a (meth)acrylic acid ester.

16. A recycled (meth)acrylic resin composition comprising the (meth)acrylic resin composition according to any one of claims 1 to 10 or a molded product thereof, or a (meth)acrylic resin composition recovered from the following recycled (meth)acrylic resin composition or a molded product thereof, a virgin (meth)acrylic resin, and a virgin fibrous glass filler. <Recycled (meth)acrylic resin composition> A recycled (meth)acrylic resin composition comprising the (meth)acrylic resin composition according to any one of claims 1 to 10 or a (meth)acrylic resin composition recovered from a molded product thereof, a virgin (meth)acrylic resin, and a virgin fibrous glass filler.

17. The recycled (meth)acrylic resin composition according to claim 16, wherein the unused (meth)acrylic resin contained in the recycled (meth)acrylic resin composition contains a (meth)acrylic resin in which the content of structural units derived from (meth)acrylic acid esters is 90 to 99.985 mol % and the content of structural units derived from (meth)acrylic acid is 0.015 to 9.0 mol %, relative to 100 mol % of the total content of all structural units.

18. The recycled (meth)acrylic resin composition according to claim 16, wherein the content of the fibrous glass filler contained in the recovered (meth)acrylic resin composition in 100 parts by mass of the recovered (meth)acrylic resin composition is the same as the content of the unused fibrous glass filler in a total of 100 parts by mass of the unused (meth)acrylic resin and the unused fibrous glass filler in the recycled (meth)acrylic resin composition.

19. The recycled (meth)acrylic resin composition according to claim 16, wherein the content of the unused fibrous glass filler in the recycled (meth)acrylic resin composition is 1 to 40 parts by mass per 100 parts by mass of the unused (meth)acrylic resin and the unused fibrous glass filler combined.

20. The recycled (meth)acrylic resin composition according to claim 16, wherein, in 100% by mass of the recycled (meth)acrylic resin composition, a content of the recovered (meth)acrylic resin composition is 1 to 99% by mass, and a total content of the unused (meth)acrylic resin and the unused fibrous glass filler is 1 to 99% by mass.

21. A method for recycling a (meth)acrylic resin composition or a (meth)acrylic resin composition forming a molded article, comprising recovering a (meth)acrylic resin composition from the (meth)acrylic resin composition according to any one of claims 1 to 10 or a molded article thereof, or the following recycled (meth)acrylic resin composition or a molded article thereof, and mixing the recovered (meth)acrylic resin composition with a virgin (meth)acrylic resin and a virgin fibrous glass filler. <Recycled (meth)acrylic resin composition> A recycled (meth)acrylic resin composition comprising the (meth)acrylic resin composition according to any one of claims 1 to 10 or a (meth)acrylic resin composition recovered from a molded article thereof, a virgin (meth)acrylic resin, and a virgin fibrous glass filler.

Images