Copolymer, resin composition and resin molded article

Abstract

To provide a copolymer that can yield a resin composition with a high elastic modulus and superior transparency and impact resistance when blended into a methacrylic polymer.SOLUTION: A copolymer includes a structural unit derived from a macromonomer (A) represented by the formula (1), and a structural unit derived from a comonomer (B) copolymerizable with the macromonomer (A). The copolymer has a molecular weight (Mw) of 200,000 or more, and the comonomer (B) includes an aromatic acrylate (B1).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a copolymer, a resin composition, and a resin molded article. [Background technology]

[0002] (Meth)acrylic polymers have excellent transparency, weather resistance, high elasticity, surface hardness, etc., and are therefore widely used in applications such as front panels for liquid crystal and organic electroluminescence (EL) displays, signage, lighting, home appliances, vehicle interior and exterior materials, industrial materials, construction materials, and optical films, lenses, light guide plates, and light collecting members used in liquid crystal and organic electroluminescence (EL) displays. However, (meth)acrylic polymers are brittle materials that are weak against impact, and depending on the application, it is required to improve the impact resistance while maintaining a high elastic modulus and excellent transparency.

[0003] As a technique for improving the impact resistance of (meth)acrylic polymers, for example, a resin composition in which a block copolymer or a graft copolymer having a poly(meth)acrylate chain (hereinafter also referred to as a "block / graft copolymer") is blended with a (meth)acrylic polymer is known. A block / graft copolymer has two or more polymer segments chemically linked to each other, and blending the block / graft copolymer with a (meth)acrylic polymer forms a nanometer-sized phase-separated structure known as a "microphase-separated structure." Therefore, this resin composition and a resin molded article obtained by molding the resin composition can exhibit the properties of both the (meth)acrylic polymer and the block / graft copolymer.

[0004] Patent Document 1 discloses a technique for improving impact resistance by producing a block / graft copolymer by copolymerizing a macromonomer, which is a (meth)acrylic polymer having a polymerizable functional group in its molecular structure, with other acrylate monomers and aromatic vinyl monomers using a suspension polymerization method, and then adding the resulting block / graft copolymer to a (meth)acrylic polymer.

[0005] Patent Document 2 discloses that a block / graft copolymer is produced by copolymerizing a macromonomer with an alkyl acrylate monomer and an aromatic acrylate monomer using a solution polymerization method, and that a resin composition in which the obtained block / graft copolymer is added to a (meth)acrylic polymer exhibits excellent thermal decomposition resistance and transparency. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2021 / 193613 [Patent Document 2] Japanese Patent Application Publication No. 2018-159010 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the method described in Patent Document 1, an aromatic vinyl monomer such as styrene is used as a comonomer to be copolymerized with the macromonomer, and therefore the Tg of the entire polymer segment consisting of the comonomer units becomes high and the mobility of the polymer segment consisting of the comonomer units decreases, resulting in insufficient impact resistance of the resulting resin composition and the resin molded product obtained by molding the resin composition.

[0008] In the resin composition described in Patent Document 2, the mass average molecular weight of the block / graft copolymer is low, and therefore the function of the block / graft copolymer is not fully exhibited, and the impact resistance of this resin composition and the resin molded article obtained by molding the resin composition is insufficient.

[0009] An object of the present invention is to provide a copolymer which, when blended with a (meth)acrylic polymer, gives a resin composition having a high elastic modulus and excellent transparency and impact resistance, a resin composition having a high elastic modulus and excellent transparency and impact resistance, and a resin molded article. [Means for solving the problem]

[0010] The present invention has the following aspects. [1] A copolymer comprising a structural unit derived from a macromonomer (A) represented by the following formula (1) and a structural unit derived from a comonomer (B) copolymerizable with the macromonomer (A), The copolymer has a mass average molecular weight (Mw) of 200,000 or more, A copolymer, wherein the comonomer (B) comprises an aromatic acrylate (B1). [ka] However, R and R 1 ~R n each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group; X 1 ~X n each independently represents a hydrogen atom or a methyl group, n represents a natural number of 2 to 10,000, and Z represents a terminal group. [2] The copolymer according to [1], wherein the proportion of structural units derived from the macromonomer (A) relative to the total mass of the copolymer is 45% by mass or more and 99% by mass or less. [3] The copolymer according to [1] or [2], wherein the polymer consisting only of structural units derived from the comonomer (B) has a glass transition temperature of −35° C. or lower. [4] containing a group derived from a non-metallic chain transfer agent, The copolymer according to any one of [1] to [3], wherein the proportion of the group derived from the non-metallic chain transfer agent relative to the total mass of the copolymer is 0.01 to 0.5% by mass. [5] The macromonomer (A) has a structural unit derived from methyl methacrylate, The copolymer according to any one of [1] to [4], wherein the proportion of the structural units derived from methyl methacrylate to the total mass of the macromonomer (A) is 90 mass % or more. [6] The copolymer according to any one of [1] to [5], wherein the aromatic acrylate (B1) is at least one selected from the group consisting of benzyl acrylate, phenoxyethyl acrylate, and phenyl acrylate. [7] The copolymer according to any one of [1] to [6], wherein the comonomer (B) includes an alkyl acrylate (B2). [8] The copolymer according to [7], wherein the alkyl acrylate (B2) is at least one selected from the group consisting of methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, tridecyl acrylate, and i-stearyl acrylate. [9] A resin composition comprising the copolymer according to any one of [1] to [8] and a (meth)acrylic polymer (Z).

[10] The (meth)acrylic polymer (Z) contains a structural unit derived from methyl methacrylate, The resin composition according to [9], wherein the proportion of the structural units derived from methyl methacrylate relative to the total mass of the (meth)acrylic polymer (Z) is 80 mass % or more.

[11] A resin molded product obtained by molding the resin composition according to [9] or

[10] . [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a copolymer which, when blended with a (meth)acrylic polymer, gives a resin composition having a high elastic modulus and excellent transparency and impact resistance, a resin composition having a high elastic modulus and excellent transparency and impact resistance, and a resin molded article. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the embodiments for carrying out the present invention will be described in detail, but the present invention is not limited to the following description and can be carried out in various modified forms within the scope of the gist thereof. In the present invention, "(meth)acrylic acid" refers to acrylic acid or methacrylic acid. "(meth)acrylate" refers to acrylate or methacrylate. "(meth)acryloyl" refers to acryloyl or methacryloyl. In the present invention, "monomer" means an unpolymerized compound, and "structural unit" means a unit constituting a polymer derived from a monomer formed by polymerization of the monomer. The "structural unit" may be a unit formed directly by a polymerization reaction, or may be a unit in which a part of the unit is converted into a different structure by treating the polymer. In the present invention, "% by mass" indicates the content of a specific component contained in a total amount of 100% by mass. In the present invention, unless otherwise specified, a numerical range expressed using "to" in this specification means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. For example, "A to B" means A or more and B or less.

[0013] [Copolymer] The copolymer of the present invention (hereinafter also referred to as "the copolymer") contains structural units derived from a macromonomer (A) represented by the following formula (1) (hereinafter also referred to as "macromonomer (A) units"), and structural units derived from a comonomer (B) copolymerizable with the macromonomer (A) (hereinafter also referred to as "comonomer (B) units").

[0014] [ka] However, R and R 1 ~R n each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group; X 1 ~X n each independently represents a hydrogen atom or a methyl group, n represents a natural number of 2 to 10,000, and Z represents a terminal group.

[0015] The copolymer contains macromonomer (A) units, which allows a resin composition containing the copolymer and the (meth)acrylic polymer (Z) and a resin molded article molded therefrom to have a high elastic modulus, transparency, and impact resistance. The copolymer contains comonomer (B) units, which allows the resin composition and the resin molded article to have even better impact resistance. The macromonomer (A) and the comonomer (B) will be described in detail below.

[0016] The content of macromonomer (A) units in the copolymer is preferably 45% by mass or more, more preferably 47% by mass or more, and even more preferably 50% by mass or more, based on the total mass of the copolymer, since this improves the handleability of the copolymer. On the other hand, the content of macromonomer (A) units is preferably 99% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less, based on the total mass of the copolymer, since this reduces the amount of the copolymer used and achieves a modifying effect with a small amount added. The above upper and lower limits can be combined in any combination. The content of macromonomer (A) units relative to the total mass of the copolymer can be, for example, 45% by mass or more and 99% by mass or less, further 47% by mass or more and 75% by mass or less, or even 50% by mass or more and 70% by mass or less.

[0017] The content of the comonomer (B) units in the copolymer is preferably 1% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more, based on the total mass of the copolymer, since this copolymer is more likely to have an effect of improving impact resistance. On the other hand, the content of the comonomer (B) units is preferably 55% by mass or less, more preferably 53% by mass or less, and even more preferably 50% by mass or less, since this copolymer when blended into a resin composition will have good transparency. The above upper and lower limits can be combined in any combination. The content of the comonomer (B) units relative to the total mass of the copolymer can be, for example, from 1% by mass to 55% by mass, further from 25% by mass to 53% by mass, or further from 30% by mass to 50% by mass.

[0018] In the present copolymer, the mass ratio of macromonomer (A) units:comonomer (B) units is preferably from 45:55 to 99:1, more preferably from 47:53 to 75:25, and even more preferably from 50:50 to 70:30.

[0019] The present copolymer can be obtained by polymerizing a polymerizable composition (X) containing a macromonomer (A) and a comonomer (B). The polymerizable composition (X) and the method for producing the present copolymer will be described in detail below. The present copolymer includes all copolymers obtained by polymerizing the polymerizable composition (X). The present copolymer may contain unreacted macromonomer (A) or a polymer consisting of comonomer (B) units.

[0020] From the viewpoint of improving the impact resistance of the resulting resin composition and resin molded article, the mass average molecular weight (Mw) of the copolymer is 200,000 or more, preferably 300,000 or more, and more preferably 400,000 or more. When Mw is 200,000 or more, the copolymer can be sufficiently miscible with the (meth)acrylic polymer (Z), thereby improving the impact resistance. On the other hand, the upper limit of Mw of the present copolymer is not particularly limited, but from the viewpoint of improving the handleability of the resin composition, it is preferably 3,500,000 or less, more preferably 3,000,000 or less, and even more preferably 2,000,000 or less. The above upper and lower limits can be combined in any desired manner. The Mw of the copolymer can be, for example, from 200,000 to 3,500,000, further from 300,000 to 3,000,000, or further from 400,000 to 2,000,000. There are no particular limitations on the method for controlling the Mw of the present copolymer to 200,000 or more. For example, the Mw can be controlled according to well-known techniques by adjusting the polymerization method, the type and amount of polymerization initiator, the amount of chain transfer agent, the polymerization temperature, etc.

[0021] [Polymerizable composition (X)] The polymerizable composition (X) is one of the raw materials for the present copolymer, and contains a macromonomer (A) and a comonomer (B). The polymerizable composition (X) typically contains a polymerization initiator. The polymerizable composition (X) may contain a non-metallic chain transfer agent, if necessary. The polymerization initiator and the non-metallic chain transfer agent will be described in detail below.

[0022] The content of macromonomer (A) in polymerizable composition (X) is preferably 45% by mass or more, more preferably 47% by mass or more, and even more preferably 50% by mass or more, based on the total mass of polymerizable composition (X), since this improves the handleability of the copolymer. On the other hand, the content of macromonomer (A) is preferably 99% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less, based on the total mass of polymerizable composition (X), since this reduces the amount of the copolymer used and achieves a modifying effect with a small amount added. The above upper and lower limits can be combined in any combination. The content of the macromonomer (A) relative to the total mass of the polymerizable composition (X) can be, for example, 45% by mass or more and 99% by mass or less, further 47% by mass or more and 75% by mass or less, or further 50% by mass or more and 70% by mass or less.

[0023] The content of the comonomer (B) in the polymerizable composition (X) is preferably 1% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more, based on the total mass of the polymerizable composition (X), since the copolymer is more likely to have an effect of improving impact resistance. On the other hand, the content of the comonomer (B) is preferably 55% by mass or less, more preferably 53% by mass or less, and even more preferably 50% by mass or less, since the copolymer is blended into a resin composition to improve transparency. The above upper and lower limits can be combined in any combination. The content of the comonomer (B) relative to the total mass of the polymerizable composition (X) can be, for example, 1 mass% or more and 55 mass% or less, further 25 mass% or more and 53 mass% or less, or further 30 mass% or more and 50 mass% or less.

[0024] In the polymerizable composition (X), the mass ratio of macromonomer (A):comonomer (B) is preferably from 45:55 to 99:1, more preferably from 47:53 to 75:25, and even more preferably from 50:50 to 70:30.

[0025] The content of the radical polymerization initiator in the polymerizable composition (X) can be appropriately selected by a person skilled in the art according to well-known techniques, and is, for example, 0.0001 to 10% by mass relative to the total mass of the polymerizable composition (X).

[0026] The content of the non-metallic chain transfer agent in the polymerizable composition (X) is preferably 0.01 to 0.5% by mass, more preferably 0.01 to 0.25% by mass, and particularly preferably 0.04 to 0.25% by mass, relative to the total mass of the polymerizable composition (X). When the content of the non-metallic chain transfer agent is 0.01% by mass or more, crosslinking of the resulting copolymer can be sufficiently prevented. When the amount of the non-metallic chain transfer agent is 0.5% by mass or less, the composition distribution of the resulting copolymer can be prevented from becoming broad, thereby improving the impact resistance of the resulting resin molded article.

[0027] When the polymerizable composition (X) contains a non-metallic chain transfer agent, the resulting copolymer contains groups derived from the non-metallic chain transfer agent. The proportion of the group derived from the non-metallic chain transfer agent relative to the total mass of the copolymer is preferably 0.01 to 0.5 mass%, more preferably 0.01 to 0.25 mass%, and particularly preferably 0.04 to 0.25 mass%, from the viewpoint of keeping the content of the non-metallic chain transfer agent in the polymerizable composition (X) within the above-mentioned preferred range.

[0028] [Macromonomer (A)] Macromonomer (A) is represented by the following formula (1), and has a radically polymerizable unsaturated double bond group at one end of the poly(meth)acrylate segment. The dotted line in formula (1) represents the repeating state of (meth)acrylate units.

[0029] [ka] However, R and R 1 ~R n each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group; X 1 ~X neach independently represents a hydrogen atom or a methyl group, n represents a natural number of 2 to 10,000, and Z represents a terminal group.

[0030] The inclusion of macromonomer (A) units in the copolymer improves the compatibility between the copolymer and the (meth)acrylic polymer (Z) described below when producing the resin composition of the present invention. As a result, the resulting resin composition and resin molded article have excellent impact resistance and transparency and a high elastic modulus. By designing the types of structural units constituting the macromonomer (A) and the (meth)acrylic polymer (Z) and the composition ratio of the structural units to be similar, the compatibility between the copolymer and the (meth)acrylic polymer (Z) can be improved.

[0031] In the formula (1), R and R 1 ~R n The alkyl group, cycloalkyl group, aryl group or heterocyclic group may have a substituent.

[0032] R and R 1 ~R n Examples of the alkyl group include branched or linear alkyl groups having 1 to 20 carbon atoms. Specific examples include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and icosyl groups. Among these, in terms of availability, methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, pentyl, hexyl, heptyl, and octyl groups are preferred, with methyl, ethyl, n-propyl, i-propyl, n-butyl, and t-butyl groups being more preferred, and methyl being particularly preferred.

[0033] R and R 1 ~R nExamples of the cycloalkyl group include cycloalkyl groups having 3 to 20 carbon atoms. Specific examples include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a t-butylcyclohexyl group, an isobornyl group, and an adamantyl group. In view of availability, a cyclopropyl group, a cyclobutyl group, and an adamantyl group are preferred.

[0034] R and R 1 ~R n The aryl group may be, for example, an aryl group having a carbon number of 6 to 18. Specific examples include a phenyl group, a benzyl group, and a naphthyl group.

[0035] R and R 1 ~R n Examples of the heterocyclic group include heterocyclic groups having 5 to 18 carbon atoms. Specific examples include a γ-lactone group, an ε-caprolactone group, and a morpholine group. Examples of heteroatoms contained in the heterocycle include an oxygen atom, a nitrogen atom, and a sulfur atom.

[0036] R or R 1 ~R n The substituents of each independently include a group or atom selected from the group consisting of an alkyl group, an aryl group, a carboxy group, an alkoxycarbonyl group (-COOR'), a carbamoyl group (-CONR'R''), a cyano group, a hydroxy group, an amino group, an amide group (-NR'R''), a halogen atom, an allyl group, an epoxy group, an alkoxy group (-OR'), and a group exhibiting hydrophilicity or ionicity. Examples of R' and R'' each independently include the same groups as R (excluding heterocyclic groups).

[0037] R or R 1 ~R n The alkoxycarbonyl group as the substituent of the formula (I) includes, for example, a methoxycarbonyl group. R or R 1 ~R nExamples of the carbamoyl group as a substituent of include an N-methylcarbamoyl group and an N,N-dimethylcarbamoyl group. R or R 1 ~R n The amide group as the substituent of the formula (I) includes, for example, a dimethylamide group. R or R 1 ~R n Examples of the halogen atom as a substituent of include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R or R 1 ~R n Examples of the alkoxy group as the substituent include an alkoxy group having 1 to 12 carbon atoms. A specific example is a methoxy group. R or R 1 ~R n Examples of the hydrophilic or ionic group as a substituent include an alkali salt of a carboxy group or an alkali salt of a sulfoxyl group, a poly(alkylene oxide) group such as a polyethylene oxide group or a polypropylene oxide group, and a cationic substituent such as a quaternary ammonium base.

[0038] R and R 1 ~R n is preferably at least one selected from an alkyl group and a cycloalkyl group, more preferably an alkyl group. The alkyl group is preferably a methyl group, an ethyl group, an n-propyl group, or an i-propyl group, and from the viewpoint of availability, a methyl group is more preferred.

[0039] In the formula (1), X 1 ~X n From the viewpoint of ease of synthesis of macromonomer (A), X 1 ~X n Preferably, 80 mol % or more of the total number of moles (100 mol %) of the groups are methyl groups.

[0040] It is preferable that n is a value such that the mass average molecular weight of the macromonomer (A) is 10,000 or more and 100,000 or less. A more preferable range of the weight average molecular weight of the macromonomer (A) is as described below.

[0041] In the formula (1), Z is a terminal group of the macromonomer (A). Examples of the terminal group of the macromonomer (A) include a hydrogen atom and a group derived from a radical polymerization initiator, similar to terminal groups of polymers obtained by known radical polymerization.

[0042] The macromonomer (A) preferably contains a structural unit derived from methyl methacrylate (hereinafter also referred to as an "MMA unit"). The content of MMA units in macromonomer (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on the total mass of macromonomer (A). When the content of MMA units is 80% by mass or more, the impact resistance and transparency of the resin composition and resin molded article become better, and the elastic modulus becomes higher. Meanwhile, the upper limit of the content of MMA units is not particularly limited, and may be 100% by mass or less, for example, 99% by mass or less, based on the total mass of macromonomer (A). The above upper and lower limits can be combined in any manner.

[0043] When the macromonomer (A) contains an MMA unit, the macromonomer (A) may further contain at least one selected from the group consisting of a structural unit derived from a methacrylate other than MMA (hereinafter also referred to as a "methacrylate unit") and a structural unit derived from an acrylate (hereinafter also referred to as an "acrylate unit"). The content of the acrylate units contained in the macromonomer (A) is preferably 0.5% by mass or more, more preferably 2% by mass or more, and even more preferably 4% by mass or more, relative to the total mass of the macromonomer (A), since this improves the thermal decomposition resistance of the copolymer. On the other hand, the content of the acrylate units is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to the total mass of the macromonomer (A), since this improves the thermal decomposition resistance of the resin composition. The above upper and lower limits can be combined in any manner.

[0044] The monomer forming the methacrylate unit or the acrylate unit is not particularly limited as long as it is a monomer copolymerizable with methyl methacrylate, and for example, the same monomers as those listed in the below-described "Comonomers forming the comonomer units of the (meth)acrylic polymer (Z)" can be used. These monomers can be used alone or in combination of two or more. Among the above, in terms of availability, the monomers constituting the methacrylate units are preferably n-butyl methacrylate, lauryl methacrylate, dodecyl methacrylate, stearyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, and 4-hydroxybutyl methacrylate, and more preferably n-butyl methacrylate and 2-ethylhexyl methacrylate.In terms of availability, the monomers constituting the acrylate units are preferably methyl acrylate, n-butyl acrylate, lauryl acrylate, dodecyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, and 4-hydroxybutyl acrylate, and more preferably methyl acrylate, ethyl acrylate, and n-butyl acrylate.

[0045] By adjusting the molecular weight of the polymer chains composed of macromonomer (A) units in the present copolymer, when the present copolymer and the (meth)acrylic polymer (Z) are mixed to produce the resin composition of the present invention, the polymer chains are appropriately entangled with the (meth)acrylic polymer (Z). This improves the interfacial strength between the present copolymer and the matrix phase formed by the (meth)acrylic polymer (Z), and improves the impact resistance and elastic modulus of the resulting resin composition and resin molded article.

[0046] Here, it is known that the molecular weight Me between entanglement points of polymethyl methacrylate is approximately 9,200 g / mol (Wu et al., Polymer Engineering and Science, June 1992, Vol. 32, No. 12, p. 823). Therefore, the mass average molecular weight (Mw) of the macromonomer (A) is preferably at least 10,000, more preferably at least 15,000, even more preferably at least 20,000, and particularly preferably at least 24,000. When the Mw of the macromonomer (A) is 10,000 or more, entanglement occurs between the polymer chains formed from macromonomer (A) units and the (meth)acrylic polymer (Z), improving the interfacial strength between the copolymer and the matrix phase formed by the (meth)acrylic polymer (Z), and improving the impact resistance of the resin composition and the resin molded article. On the other hand, the Mw of the macromonomer (A) is preferably 1,000,000 or less, more preferably 80,000 or less, even more preferably 60,000 or less, and particularly preferably 50,000 or less, because this improves the copolymerizability of the macromonomer (A) with the comonomer (B) and allows the resin composition and the resin molded article to maintain good impact resistance. The above upper and lower limits can be combined in any desired manner. The Mw of the macromonomer (A) can be, for example, 10,000 or more and 100,000 or less, further 15,000 or more and 80,000 or less, further 20,000 or more and 60,000 or less, or further 24,000 or more and 50,000 or less. In the present invention, Mw of the macromonomer (A) means the weight average molecular weight, which is the relative molecular weight determined by gel permeation chromatography (GPC) in terms of polymethyl methacrylate (PMMA).

[0047] The macromonomer (A) may be a mixture of two or more types of macromonomers. In that case, the Mw of the macromonomer (A) is calculated as the value for the entire macromonomer (A). When multiple types of macromonomers (A) with different Mw are used in combination, the macromonomer (A) with a lower Mw is thought to play a role in reducing the syrup viscosity and preventing the copolymer from crosslinking, while the macromonomer (A) with a higher Mw is thought to play a role in ensuring compatibility with the matrix resin when used as an additive.

[0048] The raw material monomers constituting the poly(meth)acrylate segment of the macromonomer (A) are composed of one or more (meth)acrylates. The raw material monomers preferably contain methyl methacrylate, and may further contain a (meth)acrylate other than methyl methacrylate. The (meth)acrylate other than methyl methacrylate is not particularly limited as long as it is a monomer copolymerizable with methyl methacrylate, and for example, the same monomers as those listed in the below-described "Comonomers forming the comonomer units of the (meth)acrylic polymer (Z)" can be used. These monomers can be used alone or in combination of two or more. Among the above, in terms of ease of availability, methyl acrylate, n-butyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate are preferred, and methyl acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are more preferred.

[0049] It is preferable that the raw material monomer contains an acrylate in part, since the copolymer as a product, the resin composition of the present invention containing the copolymer, and the resin molded article of the present invention molded using the resin composition have excellent thermal decomposition resistance. Examples of acrylates include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, and t-butyl acrylate. Among these, methyl acrylate, ethyl acrylate, and n-butyl acrylate are preferred in terms of availability.

[0050] [Method for producing macromonomer (A)] The macromonomer (A) can be produced by a known method. Examples of methods for producing the macromonomer (A) include a method of polymerizing raw material monomers using a cobalt chain transfer agent (U.S. Patent No. 4,680,352), a method of polymerizing raw material monomers using an α-substituted unsaturated compound such as α-bromomethylstyrene as a chain transfer agent (WO 88 / 04304), a method of chemically bonding a polymerizable group to one end of a poly(meth)acrylate segment (JP 60-133007 A, U.S. Patent No. 5,147,952 A), and a method using thermal decomposition (JP 11-240854 A). Among these, the method of polymerizing raw material monomers using a cobalt chain transfer agent is preferred because it requires fewer production steps and uses a catalyst with a high chain transfer constant.

[0051] Examples of methods for polymerizing raw material monomers using a cobalt chain transfer agent include bulk polymerization, solution polymerization, and aqueous dispersion polymerization methods such as suspension polymerization and emulsion polymerization. Among these, aqueous dispersion polymerization is preferred, and suspension polymerization is particularly preferred, from the viewpoint of simplifying the recovery process of macromonomer (A). Furthermore, after polymerization, it is also possible to obtain the copolymer by copolymerization by adding comonomer (B) and a radical polymerization initiator without recovering macromonomer (A).

[0052] As the cobalt chain transfer agent, a cobalt chain transfer agent represented by the following formula (2) can be used, and for example, those described in Japanese Patent No. 3587530, JP-A-6-23209, JP-A-7-35411, U.S. Pat. Nos. 45269945, 4694054, 4834326, 4886861, 5324879, WO 95 / 17435, and JP-T-9-510499 can be used.

[0053] [ka] Here, R1 to R4 each independently represent an alkyl group, a cycloalkyl group, or an aryl group, and X each independently represent an F atom, a Cl atom, a Br atom, an OH group, an alkoxy group, an aryloxy group, an alkyl group, or an aryl group.

[0054] [Comonomer (B)] The comonomer (B) is a monomer that copolymerizes with the macromonomer (A). The copolymer contains the comonomer (B) units, and thus the resin composition and the resin molded article have good impact resistance.

[0055] The comonomer (B) comprises an aromatic acrylate (B1). The comonomer (B) preferably further comprises an alkyl acrylate (B2). The comonomer (B) may contain other monomers (B3) as required.

[0056] [Aromatic acrylate (B1)] The refractive index of a polymer comprising aromatic acrylate (B1) units is higher than the refractive index of a polymer comprising alkyl acrylate (B2) units. Therefore, by including aromatic acrylate (B1) in the comonomer (B), the refractive index of the polymer chain containing comonomer (B) units can be adjusted to match the refractive index of the (meth)acrylic copolymer (Z) blended with this copolymer.

[0057] Examples of aromatic acrylates (B1) include benzyl acrylate, phenyl acrylate, phenoxyethyl acrylate, phenoxypolyethylene glycol acrylate, biphenyl acrylate, nonylphenyl acrylate, nonylphenoxyethyl acrylate, nonylphenoxypolyethylene glycol acrylate, cumylphenol acrylate, cumylphenoxyethyl acrylate, cumylphenoxypolyethylene glycol acrylate, o-phenylphenol acrylate, ethoxylated o-phenylphenol acrylate, tribromophenyl acrylate, and EO-modified tribromophenyl acrylate. One or more of these can be appropriately selected and used. Among these, benzyl acrylate, phenoxyethyl acrylate, and phenyl acrylate are preferred in terms of availability.

[0058] [Alkyl acrylate (B2)] When the comonomer (B) contains the acrylate (B2), the resulting resin composition and resin molded article have good transparency and impact resistance, and a high modulus of elasticity. The alkyl acrylate (B2) refers to an acrylate in which the ester group is an alkyl group. Examples of the alkyl group include a linear alkyl group, a branched alkyl group, and a cyclic alkyl group. Of these, a linear alkyl group or a branched alkyl group is preferred in that the polymer segment formed from the comonomer (B) unit has excellent flexibility. The alkyl group has, for example, 1 to 20 carbon atoms. The alkyl group may have a substituent such as an alkoxy group, a hydroxyl group, a carboxy group, an epoxy group, an amino group, an amide group, or a vinyl group.

[0059] The alkyl acrylate (B2) can provide the resulting resin composition and resin molded article with better impact resistance, so it is preferable that the glass transition temperature (Tg) of the polymer consisting only of alkyl acrylate (B2) units is lower than 0°C.

[0060] Examples of the alkyl acrylate (B2) include unsubstituted alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, tridecyl acrylate, n-stearyl acrylate, i-stearyl acrylate, cyclohexyl acrylate, and isobornyl acrylate; alkoxy group-containing acrylates such as 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate; hydroxyl group-containing acrylates such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, and glycerol acrylate; 2-acryloyloxyethyl hexahydrophthalic acid, 2-acryloyloxypropyl hexahydrophthalic acid, and 2-acryloyloxyethyl phthalic acid; Examples of suitable acrylates include carboxyl group-containing acrylates such as 2-acryloyloxypropyl phthalate, 2-acryloyloxyethyl maleate, 2-acryloyloxypropyl maleate, 2-acryloyloxyethyl succinate, and 2-acryloyloxypropyl succinate; epoxy group-containing acrylates such as glycidyl acrylate, glycidyl α-ethyl acrylate, and 3,4-epoxybutyl acrylate; amino group-containing acrylates such as dimethylaminoethyl acrylate and diethylaminoethyl acrylate; and polyfunctional acrylates such as ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,6-hexanediol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, allyl acrylate, and N,N'-methylenebisacrylamide. These may be used alone or in combination of two or more.

[0061] Among the above-mentioned monomers, in terms of availability, at least one selected from the group consisting of methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, tridecyl acrylate, and i-stearyl acrylate is preferred. Alternatively, since the Tg of a polymer consisting only of alkyl acrylate (B2) units is less than 0°C, at least one selected from the group consisting of 2-ethylhexyl acrylate, 4-hydroxybutyl acrylate, n-butyl acrylate, n-propyl acrylate, ethyl acrylate, and 2-hydroxyethyl acrylate is preferred. Alternatively, at least one selected from the group consisting of methyl acrylate, ethyl acrylate, and n-butyl acrylate is preferred, as this improves the compatibility between the macromonomer (A) and the comonomer (B), thereby improving the transparency and impact resistance of the resulting resin composition and resin molded article, and increasing the elastic modulus.

[0062] [Other Monomers (B3)] The other monomer (B3) may be any monomer that is copolymerizable with the macromonomer (A) and the aromatic acrylate (B1), and examples thereof include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, n-lauryl methacrylate, n-stearyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, and isobornyl methacrylate. methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, glycerol methacrylate, etc.; hydroxyl group-containing methacrylates such as 2-methacryloyloxyethyl hexahydrophthalic acid, 2-methacryloyloxypropyl hexahydrophthalic acid, 2-methacryloyloxyethyl phthalic acid, 2-methacryloyloxypropyl ... carboxyl group-containing methacrylates such as 2-methacryloyloxyethyl maleate, 2-methacryloyloxypropyl maleate, 2-methacryloyloxyethyl succinate, 2-methacryloyloxypropyl succinate; epoxy group-containing methacrylates such as glycidyl methacrylate and 3,4-epoxybutyl methacrylate; amino group-containing methacrylates such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; polyfunctional methacrylates such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate; aromatic vinyls such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, and pt-butylstyrene, vinylethylbenzene, vinyltoluene, vinylxylene, vinylnaphthalene, diphenylethylene, and divinylbenzene;Examples of suitable vinyl monomers include carboxyl group-containing vinyl monomers such as (meth)acrylic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, and monomethyl itaconate; acid anhydride group-containing vinyl monomers such as maleic anhydride and itaconic anhydride; amide group-containing vinyl monomers such as (meth)acrylamide, Nt-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetone acrylamide, maleic acid amide, and maleimide; and vinyl monomers such as (meth)acrylonitrile, vinyl chloride, vinyl acetate, and vinyl propionate. These may be used alone or in combination.

[0063] The content of the aromatic acrylate (B1) in the comonomer (B) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on the total mass of the comonomer (B). When the content of the aromatic acrylate (B1) is 5% by mass or more, it is easy to match the refractive index of the polymer chain containing the comonomer (B) unit with the refractive index of the (meth)acrylic copolymer (Z). On the other hand, the content of the aromatic acrylate (B1) is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on the total mass of the comonomer (B).

[0064] The content of the alkyl acrylate (B2) in the comonomer (B) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 65% ​​by mass or more, based on the total mass of the comonomer (B). When the content of the alkyl acrylate (B2) is 50% by mass or more, the impact resistance of the resulting resin composition and resin molded article can be improved. On the other hand, the content of the alkyl acrylate (B2) is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less, based on the total mass of the comonomer (B).

[0065] The content of the other monomer (B3) is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to the total mass of the comonomer (B), and may be 0% by mass.

[0066] The refractive index of the polymer comprising comonomer (B) units in the copolymer is not particularly limited, but for example, the refractive index at a wavelength of 589 nm is preferably 1.44 to 1.54, more preferably 1.47 to 1.51. In particular, from the viewpoint of transparency of the resin composition, the absolute value of the refractive index difference between the macromonomer (A) described above and the (meth)acrylic polymer (Z) described below is preferably 0.05 or less, more preferably 0.03 or less, and even more preferably 0.01 or less. The refractive index of the polymer comprising the comonomer (B) units in this copolymer can be considered to be the same as the refractive index of a polymer obtained by polymerizing only the comonomer (B) under the same conditions as those used to produce this copolymer.

[0067] The copolymerization reaction mechanism between the macromonomer (A) and the comonomer (B) is described in detail in a report by Yamada et al. (Prog. Polym. Sci. 31 (2006) pp. 835-877), etc. As the comonomer (B), a monomer having a double bond and having radical polymerizability can be used alone or in combination of two or more kinds.

[0068] The glass transition temperature (Tg) of the polymer comprising comonomer (B) units in this copolymer is preferably -35°C or lower, more preferably -37°C or lower, and even more preferably -40°C or lower, since this allows the resulting resin composition and resin molded product to have better impact resistance. To achieve good impact resistance, the polymer chain containing the comonomer (B) units must have sufficient mobility in a temperature range above the Tg. It is known that the lower the Tg, the better the mobility of the polymer chain under the same temperature environment. If the Tg of the polymer comprising comonomer (B) units is -35°C or lower, the polymer chain containing the comonomer (B) units will have sufficient mobility, resulting in good impact resistance. In the present invention, the Tg of the polymer comprising comonomer (B) units can be calculated using the Fox equation using values ​​described in known documents such as "Polymer Handbook, Fourth Edition, 2003." Alternatively, the dynamic viscoelasticity of the resulting resin molded product can be measured, and the value of tan δ can be used as the Tg.

[0069] [Polymerization initiator] When the polymerization reaction of the polymerizable composition (X) is carried out in the presence of a polymerization initiator, a radical polymerization initiator is typically used as the polymerization initiator. Examples of the radical polymerization initiator include known organic peroxides such as 2,4-dichlorobenzoyl peroxide and t-butyl peroxypivalate, and known azo compounds such as 2,2'-azobisisobutyronitrile and 2,2'-azobis(2,4-dimethylvaleronitrile).

[0070] [Non-metallic chain transfer agents] By carrying out the polymerization reaction of the polymerizable composition (X) in the presence of a non-metallic chain transfer agent, crosslinking of the resulting copolymer can be prevented. Conventionally, crosslinking of the copolymer was prevented by the chain transfer effect of the macromonomer (A), and a low-molecular-weight macromonomer (A) had to be used to increase the molar percentage of the macromonomer (A) used. It has now been discovered that the addition of a non-metallic chain transfer agent makes it possible to use a macromonomer (A) with a higher molecular weight, further improving impact resistance. Examples of non-metallic chain transfer agents include sulfur-containing chain transfer agents such as t-dodecyl mercaptan and n-octyl mercaptan, α-methylstyrene dimer, carbon tetrachloride, and terpenoids. Among these, sulfur-containing chain transfer agents are preferred from the viewpoints of easy availability and high chain transfer ability. One or more of these can be appropriately selected and used.

[0071] [Method of producing copolymer] The present copolymer can be produced, for example, by a production method including a step of polymerizing a polymerizable composition (X) containing a macromonomer (A) and a comonomer (B).

[0072] The polymerization reaction is preferably carried out using a radical polymerization method, such as bulk polymerization methods such as bulk polymerization and cast polymerization, or solution polymerization, and aqueous dispersion polymerization methods such as suspension polymerization and emulsion polymerization. Aqueous dispersion polymerization methods such as suspension polymerization and emulsion polymerization are preferred because they can simplify the recovery process of the produced copolymer, and suspension polymerization is more preferred because the resulting copolymer particles are easy to handle. In the suspension polymerization method, the copolymer is obtained as spherical particles having an average particle size of about 5 μm to 1 mm. The obtained spherical particles are easy to handle and there is little concern about dust scattering when used in processing operations such as extrusion and molding, and they are therefore suitable for use in resin compositions. Furthermore, suspension polymerization is also preferred because the resulting resin composition has good moldability. The reason for this is unclear, but it is presumed that trace amounts of abnormal polymers and residual emulsifiers produced in emulsion polymerization cause foreign matter and thickening, and as a result, suspension polymerization is superior to emulsion polymerization. In the method for producing the copolymer, the case where the polymerization reaction is carried out by suspension polymerization will be described in detail below.

[0073] [Production of copolymers by suspension polymerization] In the method for producing the present copolymer, when the present copolymer is produced by suspension polymerization, examples include a method including the following steps i) to v) in which the production of macromonomer (A) and the production of the present copolymer are carried out separately, and a method including the following steps I) to II) in place of the following steps i) to ii) of the following steps i) to v) in which the production of macromonomer (A) and the production of the present copolymer are carried out continuously.

[0074] i) Syrup preparation process A syrup is prepared by dissolving the bead-shaped macromonomer (A) produced by suspension polymerization in a solution containing the comonomer (B). When preparing the syrup, a mixture containing the macromonomer (A) and the comonomer (B) can be heated at a temperature equal to or lower than the boiling point of the comonomer (B) to promote dissolution of the macromonomer (A). The temperature at which the syrup is prepared is preferably in the range of 20°C to 100°C, more preferably in the range of 40°C to 80°C. If the polymerization initiator used does not react at the temperature at which the syrup is prepared, the polymerization initiator can be mixed with the syrup to obtain a polymerizable composition (X), and then the polymerizable composition (X) can be heated. When a non-metallic chain transfer agent is used, it is preferably added during the preparation of the syrup.

[0075] ii) Polymerization initiator dissolution step If the polymerization initiator used reacts at the temperature at which the syrup obtained in step i) is prepared, the syrup is cooled to room temperature or below, and then the polymerization initiator is added and dissolved uniformly. The temperature of the syrup when the polymerization initiator is added is preferably not more than 15°C below the 10-hour half-life temperature of the polymerization initiator.

[0076] iii) Preparation of aqueous solution The polymerizable composition (X) and the aqueous solution are mixed and then stirred to prepare a suspension in which droplets of the polymerizable composition (X) are dispersed in the aqueous solution. The aqueous solution is an aqueous solution for dispersing the polymerizable composition (X), and may contain a dispersant, an electrolyte, and other auxiliaries. By appropriately selecting the combination of the dispersant and the electrolyte, the dispersibility of droplets of the polymerizable composition (X) formed in the aqueous solution when the polymerizable composition (X) is dispersed in the aqueous solution can be controlled. The water used in the aqueous solution is preferably deionized water, since this improves the dispersibility of droplets of the polymerizable composition (X). Examples of dispersants include alkali metal salts of poly(meth)acrylic acid, copolymers of alkali metal salts of (meth)acrylic acid and (meth)acrylic acid esters, copolymers of alkali metal salts of (meth)acrylic acid sulfoalkyl and (meth)acrylic acid esters, alkali metal salts of polystyrene sulfonates, copolymers of alkali metal salts of styrene sulfonates and (meth)acrylic acid esters, or copolymers formed from combinations of these monomers; polyvinyl alcohol with a saponification degree of 70 to 100%, methyl cellulose, starch, and hydroxyapatite. These may be used alone or in combination of two or more. Among these, copolymers of alkali metal salts of (meth)acrylic acid sulfoalkyl and (meth)acrylic acid esters and copolymers of alkali metal salts of (meth)acrylic acid and (meth)acrylic acid esters are preferred, as they exhibit good dispersion stability during suspension polymerization. The dispersant is used, for example, in an amount of 0.0005 to 0.5 parts by mass per 100 parts by mass of the polymerizable composition (X). Examples of the electrolyte include sodium carbonate, sodium sulfate, manganese sulfate, etc. The electrolyte is used in an amount of, for example, 0.01 to 1.0 part by mass relative to 100 parts by mass of the polymerizable composition (X).

[0077] I) Syrup preparation process The syrup is prepared by adding a solution containing a comonomer (B) to a bead-like macromonomer (A) produced by suspension polymerization dispersed in an aqueous solution. The temperature at which the macromonomer (A) is dissolved in the solution containing the comonomer (B) is preferably in the range of 20°C to 100°C, more preferably in the range of 40°C to 90°C, and even more preferably in the range of 50°C to 80°C. When a non-metallic chain transfer agent is used, it is preferably added during the preparation of the syrup.

[0078] II) Polymerization initiator dissolution process When the polymerization initiator reacts at the temperature at which the syrup obtained in step I) is prepared, the syrup is cooled to room temperature or below, and then the polymerization initiator is added and dissolved uniformly to obtain the polymerizable composition (X). The temperature of the syrup when the polymerization initiator is added is preferably not more than the temperature obtained by subtracting 15°C from the 10-hour half-life temperature of the polymerization initiator.

[0079] iv) Polymerization reaction step The resulting suspension is then heated while stirring to initiate the polymerization reaction. It is preferable to remove dissolved oxygen from the polymerizable mixture and the aqueous solution before heating by subjecting them to vacuum degassing or nitrogen substitution. The polymerization temperature during the polymerization reaction is an important condition for obtaining the copolymer (block / graft copolymer) of the present invention in high yield. The polymerization temperature here refers to the temperature of the suspension. The polymerization temperature is preferably 50°C to 90°C, more preferably 55°C to 85°C, and even more preferably 60°C to 80°C. If the polymerization temperature is too low, the reaction may proceed slowly, resulting in a long polymerization time. On the other hand, if the polymerization temperature is too high, cleavage of the adduct radical, which is a reaction intermediate, takes precedence, tending to reduce the yield of the copolymer (block / graft polymer). In the latter stage of the polymerization reaction, the suspension can be heated to increase the reaction rate of the polymerizable composition (X) and eliminate unreacted radical polymerization initiator. The temperature to which the suspension is heated is preferably 80°C or higher, more preferably 85°C or higher. The temperature-raising time can be determined by calculating the time required for the radical polymerization initiator to disappear, and is, for example, about 30 minutes to 2 hours.

[0080] v) Recovery process After the above step, the suspension is cooled to room temperature or below, and the resulting copolymer in the form of beads is recovered by a known method such as filtration. If necessary, a washing step for removing impurities such as dispersants and electrolytes, a step for removing beads containing air bubbles, a drying step, etc. may be performed. The finally obtained copolymer in the form of beads (block / graft copolymer) is referred to as the present copolymer.

[0081] Alternatively, the polymerization reaction can be carried out using a bulk polymerization method, such as a mass polymerization method or a cast polymerization method, and can include the step of heating the polymerizable mixture to polymerize it.

[0082] [Resin composition] The resin composition of the present invention contains the present copolymer and a (meth)acrylic polymer (Z). The resin composition of the present invention may contain other components (Q) as needed, provided that the effects of the present invention are not impaired.

[0083] The content of the (meth)acrylic polymer (Z) in the resin composition of the present invention is preferably 10 to 99 mass%, more preferably 20 to 98 mass%, even more preferably 30 to 90 mass%, and particularly preferably 30 to 65 mass%, based on the total mass of the resin composition. When the content of the (meth)acrylic polymer (Z) is 10 mass% or more, the resin composition and a resin molded article obtained by molding the resin composition can well maintain the excellent properties inherent to acrylic resins (transparency, weather resistance, high elastic modulus, surface hardness, etc.). When the content of the (meth)acrylic polymer (Z) is 99 mass% or less, the resin composition and a resin molded article will have good properties such as impact resistance.

[0084] The content of the present copolymer in the resin composition of the present invention is preferably 1 to 90 mass %, more preferably 2 to 80 mass %, even more preferably 10 to 70 mass %, and particularly preferably 35 to 70 mass %, relative to the total mass of the resin composition. When the content of the present copolymer is 1 mass % or more, the properties of the resin composition and the resin molded article, such as impact resistance, are improved. When the content of the present copolymer is 90 mass % or less, the resin composition and the resin molded article can well maintain the excellent properties inherent to acrylic resins (transparency, weather resistance, high elastic modulus, surface hardness, etc.). The content of the copolymer can be optimized as appropriate depending on the elastic modulus and impact resistance required for the resin molded article.

[0085] The content of the other component (Q) is not particularly limited as long as it is within a range that does not impair the effects of the present invention, and is generally preferably 0 to 20 mass %, more preferably 0.1 to 5 mass %, relative to the total mass of the resin composition.

[0086] The resin composition of the present invention is suitable as a molding material used in known melt molding processes such as injection molding, extrusion molding, compression molding, blow molding, etc. In particular, the resin composition of the present invention is suitable as a molding material used in injection molding or extrusion molding.

[0087] [(Meth)acrylic polymer (Z)] The (meth)acrylic polymer (Z) preferably contains an MMA unit from the viewpoints of heat resistance, hardness, scratch resistance, weather resistance, transparency, and processability. The content of MMA units in the (meth)acrylic polymer (Z) is preferably 80% by mass or more, more preferably 90% by mass or more, based on the total mass of the (meth)acrylic polymer (Z). When the content of MMA units is 80% by mass or more, the heat resistance, hardness, scratch resistance, weather resistance, transparency, and processability of the (meth)acrylic polymer (Z) can be maintained at a good level. Meanwhile, the upper limit of the content of MMA units is not particularly limited, and the content of MMA units may be 100% by mass, i.e., the polymer may be composed solely of MMA units.

[0088] In addition to MMA units, the (meth)acrylic polymer (Z) may contain, for various purposes, structural units derived from other comonomers copolymerizable with MMA (hereinafter referred to as "comonomer units"). For example, when the (meth)acrylic polymer (Z) contains an acrylate unit as a comonomer unit, depolymerization of the (meth)acrylic polymer (Z) when exposed to high temperature conditions is suppressed, thereby improving thermal decomposition resistance. In addition, by adjusting the type and content of the comonomer unit, the glass transition temperature (Tg), processability, heat resistance, refractive index, weather resistance, releasability, and thermal decomposition resistance of the (meth)acrylic polymer (Z) can be controlled.

[0089] The content of the comonomer unit in the (meth)acrylic polymer (Z) is preferably 20 mass% or less, more preferably 10 mass% or less, based on the total mass of the (meth)acrylic polymer (Z), in order to favorably maintain the properties of the (meth)acrylic polymer, such as heat resistance, hardness, scratch resistance, weather resistance, transparency, processability, etc. On the other hand, the lower limit of the content of the comonomer unit is not particularly limited, and the polymer may not contain a comonomer unit, i.e., may be composed only of MMA units.

[0090] Examples of the comonomers that form the comonomer units of the (meth)acrylic polymer (Z) include the following a) to i). a) (Meth)acrylate monomers other than methyl methacrylate, such as methyl acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate, cyclohexyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and phenoxyethyl (meth)acrylate. b) Hydroxyl group-containing vinyl monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and glycerol (meth)acrylate. c) Carboxyl group-containing vinyl monomers such as (meth)acrylic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxypropyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxypropyl phthalic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxypropyl maleic acid, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, and monomethyl itaconate. d) Vinyl monomers containing an acid anhydride group, such as maleic anhydride and itaconic anhydride. e) Epoxy group-containing vinyl monomers such as glycidyl (meth)acrylate, glycidyl α-ethyl acrylate, and 3,4-epoxybutyl (meth)acrylate. f) Amino group-containing (meth)acrylate vinyl monomers such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate. g) Vinyl monomers containing an amide group, such as (meth)acrylamide, Nt-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetone acrylamide, maleic acid amide, and maleimide. h) Vinyl monomers such as styrene, α-methylstyrene, vinyltoluene, (meth)acrylonitrile, vinyl chloride, vinyl acetate, and vinyl propionate. i) Polyfunctional vinyl monomers such as divinylbenzene, ethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, allyl (meth)acrylate, and N,N'-methylenebis(meth)acrylamide.

[0091] These comonomers can be used alone or in combination of two or more. Among these, methyl acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred in terms of availability, with methyl acrylate being more preferred.

[0092] The mass average molecular weight (Mw) of the (meth)acrylic polymer (Z) is not particularly limited, but is preferably 30,000 to 1,000,000, more preferably 50,000 to 500,000, and even more preferably 80,000 to 200,000. If the (meth)acrylic polymer (Z) has an Mw of 30,000 or more, the (meth)acrylic polymer is more likely to exhibit its inherent properties, such as heat resistance, hardness, scratch resistance, weather resistance, and transparency. On the other hand, if the (meth)acrylic polymer (Z) has an Mw of 1,000,000 or less, the melt viscosity falls within an appropriate range, resulting in good melt-kneadability and processability.

[0093] [Other components (Q)] Other components (Q) are added to the resin composition as needed. Examples of other components (Q) include mold release agents, antioxidants, heat stabilizers, impact modifiers, flexibility modifiers, weather resistance modifiers, colorants, inorganic pigments, organic pigments, carbon black, ferrite, conductivity modifiers, ultraviolet absorbers, infrared absorbers, lubricants, inorganic fillers, reinforcing agents, plasticizers, antiplasticizers, neutralizing agents, crosslinking agents, flame retardants, preservatives, insect repellents, fragrances, radical scavengers, sound absorbing materials, and core-shell rubber.

[0094] The resin composition of the present invention can be obtained by mixing the present copolymer, the (meth)acrylic polymer (Z), and, if necessary, other components (Q) by a known physical mixing method using a Henschel mixer, a blender, or the like, or by kneading them by a known melt mixing method using an extruder, or the like. By obtaining the resin composition in the form of pellets, the workability when the resin composition is subsequently melt-molded to obtain a resin molded article is improved.

[0095] [Resin molding] The resin molded article of the present invention is obtained by molding the resin composition of the present invention. The resin molded article of the present invention can be obtained by molding pellets of the resin composition of the present invention by a known melt molding method such as extrusion molding, injection molding, compression molding, or blow molding. The shape of the resin molded product of the present invention is not particularly limited, and examples thereof include a film shape, a sheet shape, a plate shape, a substantially box shape, and a three-dimensional shape having curved surfaces.

[0096] The resin molded article of the present invention has excellent impact resistance and transparency and a high elastic modulus, and therefore can be suitably used for display front panels such as liquid crystal and organic electroluminescence (EL) displays, signage, lighting equipment, home appliances, vehicle interior and exterior materials, industrial materials, construction materials, lenses, light guide plates, light collecting members, optical films used in liquid crystal and organic electroluminescence (EL) displays, etc. [Example]

[0097] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. "Parts" means "parts by mass."

[0098] [raw materials] The abbreviations for the compounds used in the examples and comparative examples are as follows. MMA: methyl methacrylate (manufactured by Mitsubishi Chemical Corporation, trade name: Acryester (registered trademark) M) MA: Methyl acrylate (Mitsubishi Chemical Corporation) BA: n-butyl acrylate (Mitsubishi Chemical Corporation) St: Styrene (Fujifilm Wako Pure Chemical Industries, Ltd.) BzA: benzyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name: Viscoat #160) Chain transfer agent (2): n-octyl mercaptan (Fujifilm Wako Pure Chemical Industries, Ltd.) Polymerization initiator (1): 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate (manufactured by NOF Corporation, trade name: Perocta O) Polymerization initiator (2): 2,2'-azobis(2-methylbutyronitrile) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: V-59) (Meth)acrylic polymer (Z-1): acrylic resin containing 80% by mass or more of methyl methacrylate units, Mw 100,000, manufactured by Mitsubishi Chemical Corporation, trade name: ACRYPET (registered trademark) VH001

[0099] [Evaluation method] The evaluations in the examples and comparative examples were carried out by the following methods.

[0100] <Mass average molecular weight (Mw) and number average molecular weight (Mn) of macromonomer (A)> The mass average molecular weight (Mw) and number average molecular weight (Mn) of the macromonomer (A) were measured by gel permeation chromatography (GPC). 10 mg of macromonomer (A) was dissolved in 10 mL of tetrahydrofuran, and the solution was filtered through a 0.45 μm filter to prepare a sample for GPC measurement. A polymer measurement guard column (manufactured by Tosoh Corporation, product name: TSK-GUARD COLUMN SUPER HH) and two polymer measurement columns (manufactured by Tosoh Corporation, product name: TSK-GEL SUPER HM-H) were connected in series to a GPC measurement device (manufactured by Tosoh Corporation, model name: HLC-8320). A differential refractometer (RI) was used as the detector. Measurements were performed under the following conditions: separation column temperature: 40°C, mobile phase: tetrahydrofuran, mobile phase flow rate: 0.6 mL / min, and sample injection volume: 10 μL. A calibration curve was created using several types of polymethyl methacrylate with known molecular weights (Polymer Laboratories, peak molecular weight (Mp) 1,560 to 19,500,000) as standard polymers, and the Mw and Mn values ​​calculated as polymethyl methacrylate were determined.

[0101] <Mass average molecular weight (Mw) and number average molecular weight (Mn) of copolymer> The weight average molecular weight (Mw) and number average molecular weight (Mn) of the copolymer were measured by gel permeation chromatography (GPC). 10 mg of the copolymer was dissolved in 10 mL of tetrahydrofuran, and the solution was filtered through a 0.45 μm filter to prepare a sample for GPC measurement. A polymer measurement guard column (manufactured by Tosoh Corporation, product name: TSK-GUARD COLUMN SUPER HH) and one ultra-polymer measurement column (manufactured by Tosoh Corporation, product name: TSK-GEL GMHHR-H) were connected in series to a GPC measurement device (manufactured by Tosoh Corporation, model name: HLC-8320). A differential refractometer (RI) was used as the detector. Measurements were performed under the following conditions: separation column temperature: 40°C, mobile phase: tetrahydrofuran, mobile phase flow rate: 0.6 mL / min, and sample injection volume: 10 μL. A calibration curve was created using several types of polymethyl methacrylate with known molecular weights (Polymer Laboratories, peak molecular weight (Mp) 1,560 to 19,500,000) as standard polymers, and the Mw and Mn values ​​calculated as polymethyl methacrylate were determined.

[0102] <Glass transition temperature of polymers consisting of comonomer units of copolymers> The glass transition temperature (Tg) of the polymer consisting of the comonomer units of the copolymer was calculated from the Tg of the polymer consisting of each comonomer unit only using the Fox equation. The Tg values ​​of the polymer consisting of each comonomer unit only were taken from the literature values ​​listed in the Polymer Handbook (POLYMER HANDBOOK FOURTH EDITION 2003).

[0103] <Charpy impact test> Charpy impact strength (unit: kJ / m) is used as an index of impact resistance of resin molded products. 2 ) was measured. The Charpy impact strength was measured in accordance with JIS K 7111 using a Charpy impact tester (manufactured by Toyo Seiki Co., Ltd., product name: DG-CP) using a rod-shaped resin molding as a test piece (without a notch). Five pieces were tested using a 15J hammer, and the average value was calculated. A three-level evaluation was conducted according to the following criteria. AA: Charpy impact strength 35kJ / m 2 End A: Charpy impact strength is 25kJ / m 2 More than 35kJ / m 2 less than B: Charpy impact strength is 25kJ / m 2 less than

[0104] <Bending elasticity test> Using a rod-shaped resin molded body as a test piece, the flexural modulus (unit: MPa) of the test piece was determined using a Tensilon universal testing machine (manufactured by Orientec Co., Ltd., product name: RTC-1250A) in accordance with JIS K 7171. The flexural modulus was determined from a stress-strain curve obtained under conditions of room temperature of 23°C and a test speed of 2 mm / min. A three-level evaluation was conducted according to the following criteria. AA: Flexural modulus of elasticity of 2.0 GPa or more A: Flexural modulus is 1.5 GPa or more and less than 2.0 GPa B: Flexural modulus less than 1.5 GPa

[0105] <Total light transmittance evaluation> As an index of transparency of the resin molded article, total light transmittance (unit: %) was measured. The total light transmittance was measured in accordance with JIS K 7361-1 using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., device name: NDH4000) using a plate-shaped resin molded article as a test piece. A three-level evaluation was conducted according to the following criteria. AA: Total light transmittance is 90% or more A: Total light transmittance is 85% or more but less than 90% B: Total light transmittance is less than 85%

[0106] [Synthesis of dispersant (1)] A reactor equipped with a stirrer, a condenser, and a thermometer was charged with 61.6 parts of a 17% by mass aqueous potassium hydroxide solution, 19.1 parts of MMA, and 19.3 parts of deionized water. The liquid in the reactor was then stirred at room temperature, and after confirming the exothermic peak, the mixture was stirred for 4 hours. After this, the reaction liquid in the reactor was cooled to room temperature to obtain an aqueous potassium methacrylate solution. Next, 900 parts of deionized water, 70 parts of a 42% by weight aqueous solution of 2-sulfoethyl sodium methacrylate (manufactured by Mitsubishi Chemical Corporation, trade name: Acryester SEM-Na), 16 parts of the above potassium methacrylate aqueous solution, and 7 parts of MMA were added to a polymerization apparatus equipped with a stirrer, a condenser, and a thermometer, and the mixture was stirred. While the atmosphere inside the polymerization apparatus was replaced with nitrogen, the temperature of the liquid inside the polymerization apparatus was raised to 50°C. 0.053 parts of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: V-50) was added as a polymerization initiator, and the temperature of the liquid inside the polymerization apparatus was raised to 60°C. After adding the polymerization initiator, 1.4 parts of MMA were added in five instalments every 15 minutes (total amount of MMA: 7 parts). The liquid inside the polymerization apparatus was then stirred and maintained at 60°C for 6 hours, after which it was cooled to room temperature to obtain a transparent aqueous solution of dispersant (1) with a solids content of 8% by weight.

[0107] [Synthesis of chain transfer agent (1)] In a synthesis apparatus equipped with a stirrer, 2.00 g (8.03 mmol) of cobalt(II) acetate tetrahydrate (Fujifilm Wako Pure Chemical Industries, Ltd., Wako Special Grade), 3.86 g (16.1 mmol) of diphenylglyoxime (Tokyo Chemical Industry Co., Ltd., EP Grade), and 100 mL of diethyl ether previously deoxygenated by nitrogen bubbling were placed under a nitrogen atmosphere and stirred at room temperature for 2 hours. Next, 20 mL of boron trifluoride diethyl ether complex (Tokyo Chemical Industry Co., Ltd., EP Grade) was added and stirred for an additional 6 hours. The resulting mixture was filtered, the solid washed with diethyl ether, and dried at 100 MPa or less at 20 °C for 12 hours to obtain 5.02 g (7.93 mmol, 99% yield) of chain transfer agent (1) as a brown solid.

[0108] [Production Example 1: Synthesis of Macromonomer (A-1)] A polymerization apparatus equipped with a stirrer, condenser, and thermometer was charged with 145 parts of deionized water, 0.1 parts of sodium sulfate (NaSO), and 0.26 parts of dispersant (1) (solid content 8% by mass) and stirred to obtain a uniform aqueous solution. Next, 95 parts of MMA, 5.0 parts of MA, 0.0023 parts of chain transfer agent (1), and 0.25 parts of polymerization initiator (1) were added to obtain an aqueous dispersion. The atmosphere inside the polymerization apparatus was then thoroughly purged with nitrogen, and the aqueous dispersion was heated to 80°C and held there for 3 hours, then heated to 90°C and held there for 2 hours. The reaction solution was then cooled to 40°C to obtain an aqueous suspension of the macromonomer. This aqueous suspension was filtered through a filter cloth, and the filtrate was washed with deionized water and dried at 40°C for 16 hours to obtain macromonomer (A-1). The molecular weight (Mn, Mn) of the obtained macromonomer is shown in Table 1.

[0109] [Production Example 2: Synthesis of Macromonomer (A-2)] Macromonomer (A-2) was obtained in the same manner as in Production Example 1, except that the charging composition was changed as shown in Table 1. The molecular weights (Mn, Mn) of the obtained macromonomer are shown in Table 1.

[0110] [Production Example 3: Synthesis of Macromonomer (A-3)] Macromonomer (A-3) was obtained in the same manner as in Production Example 1, except that the charging composition was changed as shown in Table 1. The molecular weights (Mn, Mn) of the obtained macromonomer are shown in Table 1.

[0111] [Production Example 4: Synthesis of Copolymer (1)] In a polymerization apparatus equipped with a stirrer, a condenser, and a thermometer, 50 parts of the macromonomer (A-1) obtained in Production Example 1, 145 parts of deionized water, 0.26 parts of dispersant (1), and 0.3 parts of sodium sulfate were added and stirred to obtain an aqueous suspension. Next, the temperature inside the polymerization apparatus was raised to 70°C, and 38.5 parts of BA, 11.5 parts of BzA, and 0.07 parts of chain transfer agent (2) were slowly added. The mixture was then maintained at 70°C for 1 hour with stirring to dissolve the macromonomer (A-1) in the BA and BzA, obtaining a dispersion. The polymerization apparatus was then cooled to 40°C, and 0.3 parts of polymerization initiator (2) was added and stirred for 30 minutes to dissolve the mixture. The atmosphere inside the polymerization apparatus was then thoroughly purged with nitrogen, and the aqueous dispersion was heated to 72°C and maintained for 5 hours, then heated to 90°C and maintained for 1 hour. After cooling to below 40°C, the mixture was filtered through a filter cloth, and the filtrate was washed with deionized water. The filtered residue was then dried in a hot air circulation dryer at 40° C. for 12 hours to obtain a bead-like copolymer (1). Table 2 shows the charge composition and the Mw of the obtained bead-like copolymer. The Tg of a polymer consisting only of BzA units is 6°C, and the Tg of a polymer consisting only of BA units is -54°C (POLYMER HANDBOOK FOURTH EDITION 2003). The Tg of a polymer consisting of comonomer (B) units of copolymer (1) was calculated to be -42.8°C using the Fox equation.

[0112] [Production Examples 5 to 7: Synthesis of Copolymers (2) to (4)] Bead-like copolymers (2) to (4) were obtained in the same manner as in Example 1, except that the feed composition was changed as shown in Table 2. Table 2 shows the feed composition, Mw of the obtained bead-like copolymer, and Tg of the polymer composed of comonomer (B) units.

[0113] [Production Example 8: Synthesis of copolymer (5)] In a polymerization apparatus equipped with a stirrer, a condenser, and a thermometer, 60 parts of the macromonomer (A-1) obtained in Production Example 1, 150 parts of deionized water, 0.26 parts of dispersant (1), and 0.3 parts of sodium sulfate were added and stirred to obtain an aqueous suspension. Next, the temperature inside the polymerization apparatus was raised to 70°C, and 33.2 parts of BA and 6.8 parts of Stabilizer were slowly added. The mixture was then stirred and maintained at 70°C for 1 hour to dissolve the macromonomer (A-1) in the BA and Stabilizer, obtaining a dispersion. The polymerization apparatus was then cooled to 40°C, and 0.5 parts of polymerization initiator (2) was added and stirred for 30 minutes to dissolve the mixture. The atmosphere inside the polymerization apparatus was then thoroughly purged with nitrogen, and the aqueous dispersion was heated to 82°C and maintained for 4 hours, then heated to 90°C and maintained for 1 hour. After cooling to below 40°C, the mixture was filtered through a filter cloth, and the filtrate was washed with deionized water. The filtrate was then dried in a hot air circulation dryer at 40°C for 12 hours to obtain a bead-like copolymer (5). Table 2 shows the charged composition, Mw of the resulting copolymer in the form of beads, and Tg of the polymer composed of comonomer (B) units.

[0114] [Production Example 9: Synthesis of copolymer (6)] In this example, the copolymer (6) was produced by solution polymerization. A separable flask equipped with a stirrer, a condenser, and a thermometer was charged with 100 parts of toluene and 50 parts of the macromonomer (A-2) obtained in Production Example 2, and the mixture was stirred at 50°C for 1 hour to obtain a homogeneous solution. After cooling to room temperature, 35 parts of BA, 15 parts of BzA, and 0.3 parts of polymerization initiator (2) were added and stirred to obtain a homogeneous solution. Nitrogen bubbling was then performed for 30 minutes while stirring to replace the atmosphere in the separable flask with nitrogen. The temperature was then raised to 69°C to initiate polymerization, and the mixture was maintained for 5 hours. The mixture was then cooled to room temperature to obtain a polymer solution containing copolymer (6). Next, reprecipitation of copolymer (6) obtained by solution polymerization was performed. First, 200 parts of toluene were added to 100 parts of the polymerization reaction solution to obtain 300 parts of a diluted solution. The diluted solution was then poured into 3,000 parts of methanol to generate a precipitate, which was then filtered to obtain a solid recovered product. The recovered product was dried under reduced pressure to obtain copolymer (6). Table 2 shows the charged composition, Mw of the resulting copolymer in the form of beads, and Tg of the polymer composed of comonomer (B) units.

[0115] [Example 1] 60 parts of the (meth)acrylic polymer (Z-1) and 40 parts of the copolymer (1) were melt-kneaded using a twin-screw extruder (TEM-26SX, manufactured by Toshiba Machine Co., Ltd.) under conditions of a cylinder temperature of 200 to 240°C and a die temperature of 240°C to obtain a pellet-shaped resin composition. The resin composition was then injection molded using an injection molding machine (SE100EV-A, manufactured by Sumitomo Heavy Industries, Ltd.) under conditions of a cylinder temperature of 250°C, a mold temperature of 80°C, and a molding time of 20 seconds to obtain a plate-shaped resin molded product (width 50 mm, length 100 mm, thickness 3 mm) and a rod-shaped resin molded product (width 10 mm, length 80 mm, thickness 4 mm). The evaluation results of the obtained resin molded products are shown in Table 3.

[0116] [Examples 2 to 5, Comparative Examples 1 and 2] Plate-shaped resin molded products and rod-shaped resin molded products were obtained in the same manner as in Example 1, except that the types of copolymers blended with the (meth)acrylic polymer (Z-1) and their blending ratios were changed as shown in Table 3. The evaluation results of the obtained resin molded products are shown in Table 3.

[0117] [Reference example 1] Except for using only the (meth)acrylic polymer (Z-1) without blending the copolymer, a plate-shaped resin molded product and a rod-shaped resin molded product were obtained in the same manner as in Example 1. The evaluation results of the obtained resin molded products are shown in Table 3.

[0118] [Table 1]

[0119] [Table 2]

[0120] [Table 3]

[0121] The resin molded articles obtained in Examples 1 to 5 had good transparency, a high elastic modulus, and excellent impact resistance. The resin molded article obtained in Comparative Example 1 had insufficient impact resistance because the comonomer (B) of the copolymer did not contain the aromatic acrylate (B1). The resin molded article obtained in Comparative Example 2 had insufficient impact resistance because the mass average molecular weight of the copolymer was less than 200,000. The resin molded product obtained in Reference Example 1 did not contain a copolymer, and therefore, compared with Examples 1 to 6, the impact resistance was insufficient.

[0122] As shown in Examples 1 to 5, the resin composition of the present invention has a total light transmittance of 90% or more and a light transmittance of 35 kJ / m 2 The resin molded article can have the above Charpy impact test (unnotched) and a flexural modulus of 2000 MPa or more. Generally, the impact resistance of a resin molded article tends to decrease as the modulus of elasticity increases, which is a so-called trade-off relationship. In other words, the resin molded article of the present invention has the remarkable property of achieving both impact resistance and modulus of elasticity, which are contradictory properties.

Claims

1. A copolymer comprising a structural unit derived from a macromonomer (A) represented by the following formula (1) and a structural unit derived from a comonomer (B) copolymerizable with the macromonomer (A), The copolymer has a mass average molecular weight (Mw) of 200,000 or more, the macromonomer (A) has a structural unit derived from methyl methacrylate, a ratio of the structural units derived from methyl methacrylate to the total mass of the macromonomer (A) is 90 mass% or more, A copolymer, wherein the comonomer (B) comprises an aromatic acrylate (B1). 【Chemistry 1】 However, R and R １ ~R ｎ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group; X １ ~X ｎ each independently represents a hydrogen atom or a methyl group, n represents a natural number of 2 to 10,000, and Z represents a terminal group.

2. A copolymer comprising a structural unit derived from a macromonomer (A) represented by the following formula (1) and a structural unit derived from a comonomer (B) copolymerizable with the macromonomer (A), The copolymer has a mass average molecular weight (Mw) of 200,000 or more, the comonomer (B) comprises an aromatic acrylate (B1); A copolymer comprising only structural units derived from the comonomer (B) has a glass transition temperature of −35° C. or lower. 【Chemistry 2】 However, R and R １ ~R ｎ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group; X １ ~X ｎ each independently represents a hydrogen atom or a methyl group, n represents a natural number of 2 to 10,000, and Z represents a terminal group.

3. 2. The copolymer according to claim 1, wherein the polymer consisting only of structural units derived from the comonomer (B) has a glass transition temperature of −35° C. or lower.

4. The copolymer according to any one of claims 1 to 3, wherein a proportion of structural units derived from the macromonomer (A) relative to the total mass of the copolymer is 45 mass% or more and 99 mass% or less.

5. containing a group derived from a non-metallic chain transfer agent, The copolymer according to any one of claims 1 to 4, wherein the proportion of the group derived from the non-metallic chain transfer agent relative to the total mass of the copolymer is 0.01 to 0.5 mass%.

6. The copolymer according to any one of claims 1 to 5, wherein the aromatic acrylate (B1) is at least one selected from the group consisting of benzyl acrylate, phenoxyethyl acrylate, and phenyl acrylate.

7. The copolymer according to any one of claims 1 to 6, wherein the comonomer (B) comprises an alkyl acrylate (B2).

8. The copolymer according to claim 7, wherein the alkyl acrylate (B2) is at least one selected from the group consisting of methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, tridecyl acrylate, and i-stearyl acrylate.

9. A resin composition comprising the copolymer according to any one of claims 1 to 8 and a (meth)acrylic polymer (Z).

10. A copolymer comprising a structural unit derived from a macromonomer (A) represented by the following formula (1) and a structural unit derived from a comonomer (B) copolymerizable with the macromonomer (A), and a (meth)acrylic polymer (Z), The copolymer has a mass average molecular weight (Mw) of 200,000 or more, The resin composition, wherein the comonomer (B) comprises an aromatic acrylate (B1). 【Transformation 3】 wherein R and R 1 to R n each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group; X 1 to X n each independently represent a hydrogen atom or a methyl group; n represents a natural number from 2 to 10,000; and Z represents a terminal group.

11. the (meth)acrylic polymer (Z) contains a structural unit derived from methyl methacrylate, The resin composition according to claim 9 or 10, wherein the proportion of the structural units derived from methyl methacrylate relative to the total mass of the (meth)acrylic polymer (Z) is 80 mass% or more.

12. A resin molded product obtained by molding the resin composition according to any one of claims 9 to 11.

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