JP2023144752A - Copolymer, resin composition and resin molding - Google Patents

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

The present invention relates to a copolymer, a resin composition, and a resin molded article.

(Meth)acrylic polymers have excellent transparency, weather resistance, high elastic modulus, and surface hardness, so they can be used for front panels of displays such as liquid crystals and organic EL, signage supplies, lighting supplies, home appliances, vehicle interiors and exteriors. It is widely used in materials, industrial materials, construction materials, optical films used in displays such as liquid crystals and organic EL, lenses, light guide plates, light condensing members, etc.
However, (meth)acrylic polymers are brittle materials that are susceptible to impact, and depending on the application, it is required to improve impact resistance while maintaining high elastic modulus and excellent transparency.

Techniques for improving the impact resistance of (meth)acrylic polymers include, for example, block copolymers or graft copolymers (hereinafter also referred to as "block/graft copolymers") having poly(meth)acrylate chains. ) is blended with a (meth)acrylic polymer. In block/graft copolymers, two or more polymer segments are connected to each other by chemical bonds, and when block/graft copolymers are blended with (meth)acrylic polymers, a nanostructure called a "microphase-separated structure" is created. Forms a meter-sized phase-separated structure. Therefore, this resin composition and a resin molded article formed by molding this resin composition can exhibit both the characteristics that a (meth)acrylic polymer and a block/graft copolymer have.

Patent Document 1 describes that a macromonomer, which is a (meth)acrylic polymer having a polymerizable functional group in its molecular structure, is copolymerized with other acrylate monomers and an aromatic vinyl monomer using a suspension polymerization method. A technique has been disclosed in which a block/graft copolymer is produced by a method of manufacturing a block/graft copolymer, and the obtained block/graft copolymer is added to a (meth)acrylic polymer to improve impact resistance.

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 the obtained block/graft copolymer ( It is disclosed that a resin composition added to a meth)acrylic polymer exhibits excellent heat decomposition resistance and transparency.

International Publication No. 2021/193613 Japanese Patent Application Publication No. 2018-159010

However, in the method described in Patent Document 1, since an aromatic vinyl monomer such as styrene is used as a comonomer to be copolymerized with a macromonomer, the Tg of the entire polymer segment consisting of comonomer units becomes high, and Since the mobility of the polymer segment deteriorates, the resulting resin composition and the resin molded article formed from the resin composition had insufficient impact resistance.

In the resin composition described in Patent Document 2, since the mass average molecular weight of the block/graft copolymer is low, the function of the block/graft copolymer is not fully exhibited. The impact resistance of the molded resin product was insufficient.

The object of the present invention is to provide a copolymer which, when blended with a (meth)acrylic polymer, yields a resin composition having a high modulus of elasticity and excellent transparency and impact resistance. An object of the present invention is to provide a resin composition and a resin molded article having excellent impact resistance.

ただし、Ｒ及びＲ^１～Ｒ^ｎは、それぞれ独立に水素原子、アルキル基、シクロアルキル基、アリール基又は複素環基を示し、Ｘ^１～Ｘ^ｎは、それぞれ独立に水素原子又はメチル基を示し、ｎは、２～１０，０００の自然数を示し、Ｚは、末端基を示す。
［２］前記共重合体の総質量に対する前記マクロモノマー（Ａ）に由来する構造単位の割合が、４５質量％以上９９質量％以下である、［１］に記載の共重合体。
［３］前記コモノマー（Ｂ）に由来する構造単位のみからなる重合体のガラス転移温度が、－３５℃以下である、［１］又は［２］に記載の共重合体。
［４］非金属連鎖移動剤に由来する基を含み、
前記共重合体の総質量に対する前記非金属連鎖移動剤に由来する基の割合が、０．０１～０．５質量％である、［１］～［３］のいずれかに記載の共重合体。
［５］前記マクロモノマー（Ａ）が、メチルメタクリレートに由来する構造単位を有し、
前記マクロモノマー（Ａ）の総質量に対する前記メチルメタクリレートに由来する構造単位の割合が、９０質量％以上である、［１］～［４］のいずれかに記載の共重合体。
［６］前記芳香族アクリレート（Ｂ１）が、ベンジルアクリレート、フェノキシエチルアクリレート及びフェニルアクリレートからなる群より選択される少なくとも１種である、［１］～［５］のいずれかに記載の共重合体。
［７］前記コモノマー（Ｂ）が、アルキルアクリレート（Ｂ２）を含む、［１］～［６］のいずれかに記載の共重合体。
［８］前記アルキルアクリレート（Ｂ２）が、メチルアクリレート、エチルアクリレート、ｎ－プロピルアクリレート、ｉ－プロピルアクリレート、ｎ－ブチルアクリレート、ｉ－ブチルアクリレート、ｔ－ブチルアクリレート、２－エチルヘキシルアクリレート、ラウリルアクリレート、トリデシルアクリレート及びｉ－ステアリルアクリレートからなる群より選択される少なくとも１種である、［７］に記載の共重合体。
［９］［１］～［８］のいずれかに記載の共重合体と、（メタ）アクリル系重合体（Ｚ）とを含む、樹脂組成物。
［１０］前記（メタ）アクリル系重合体（Ｚ）が、メチルメタクリレートに由来する構造単位を含み、
前記（メタ）アクリル系重合体（Ｚ）の総質量に対する前記メチルメタクリレートに由来する構造単位の割合が、８０質量％以上である、［９］に記載の樹脂組成物。
［１１］［９］又は［１０］に記載の樹脂組成物を成形してなる、樹脂成形体。 The present invention has the following aspects.
[1] A copolymer containing 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,
The copolymer has a mass average molecular weight (Mw) of 200,000 or more,
A copolymer in which the comonomer (B) contains an aromatic acrylate (B1).

However, 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, and 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.
[2] The copolymer according to [1], wherein the proportion of the structural unit derived from the macromonomer (A) 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] Contains a group derived from a nonmetallic chain transfer agent,
The copolymer according to any one of [1] to [3], wherein the proportion of the group derived from the nonmetallic chain transfer agent 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 unit derived from methyl methacrylate to the total mass of the macromonomer (A) is 90% by 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) contains an alkyl acrylate (B2).
[8] The alkyl acrylate (B2) is methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, The copolymer according to [7], which is at least one selected from the group consisting of 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 ratio of the structural unit derived from the methyl methacrylate to the total mass of the (meth)acrylic polymer (Z) is 80% by mass or more.
[11] A resin molded article formed by molding the resin composition according to [9] or [10].

According to the present invention, there is provided a copolymer which, when blended with a (meth)acrylic polymer, yields a resin composition having a high modulus of elasticity and excellent transparency and impact resistance; A resin composition and a resin molded article having excellent impact resistance can be provided.

Hereinafter, 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 implemented with various modifications within the scope of the gist.
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 the monomer formed by polymerization of the monomer. The "structural unit" may be a unit directly formed by a polymerization reaction, or a part of the unit may be converted into another structure by processing the polymer.
In the present invention, "mass %" indicates the content of a specific component contained in 100 mass % of the total amount.
In the present invention, unless otherwise specified, a numerical range expressed using "~" in this specification means a range that includes the numerical values written before and after "~" as lower and upper limits. For example, "A to B" means greater than or equal to A and less than or equal to B.

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

ただし、Ｒ及びＲ^１～Ｒ^ｎは、それぞれ独立に水素原子、アルキル基、シクロアルキル基、アリール基又は複素環基を示し、Ｘ^１～Ｘ^ｎは、それぞれ独立に水素原子又はメチル基を示し、ｎは、２～１０，０００の自然数を示し、Ｚは、末端基を示す。

However, 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, and 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.

Since the present copolymer contains the macromonomer (A) unit, the resin composition containing the present copolymer and the (meth)acrylic polymer (Z) and the resin molded article formed from the same have a high elastic modulus. , it can be made to have excellent transparency and impact resistance. Moreover, since the present copolymer contains the comonomer (B) unit, the impact resistance of the resin composition and the resin molded article can be further improved.
Details of each of the macromonomer (A) and comonomer (B) will be described later.

The content ratio of the macromonomer (A) units contained in the present copolymer is preferably 45% by mass or more based on the total mass of the present copolymer, since the handleability of the present copolymer is improved. The content is more preferably 47% by mass or more, and even more preferably 50% by mass or more. On the other hand, the content ratio of macromonomer (A) units is 99% by mass based on the total mass of the present copolymer, since the amount of this copolymer used can be suppressed and a modifying effect can be obtained with a small amount added. % or less, more preferably 75% by mass or less, even more preferably 70% by mass or less.
The above upper and lower limits can be arbitrarily combined. The content ratio of macromonomer (A) units to the total mass of the present copolymer is, 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, further still 50% by mass or more and 70% by mass or less. It can be done.

The content ratio of the comonomer (B) units contained in this copolymer is 1% by mass based on the total mass of this copolymer, since it is easier to obtain the effect of improving impact resistance by this copolymer. The content is preferably at least 25% by mass, more preferably at least 30% by mass. On the other hand, the content ratio of comonomer (B) units is preferably 55% by mass or less, more preferably 53% by mass or less, and 50% by mass or less, since transparency is improved when this copolymer is blended into a resin composition. It is more preferably less than % by mass.
The above upper and lower limits can be arbitrarily combined. The content ratio of the comonomer (B) unit to the total mass of the present copolymer is, for example, 1% by mass or more and 55% by mass or less, further 25% by mass or more and 53% by mass or less, further still 30% by mass or more and 50% by mass or less. can do.

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

This copolymer can be obtained by polymerizing a polymerizable composition (X) containing a macromonomer (A) and a comonomer (B). Details of the method for producing the polymerizable composition (X) and this copolymer will be described later.
This copolymer includes all those obtained by subjecting the polymerizable composition (X) to a polymerization reaction. This copolymer may contain a polymer consisting of unreacted macromonomer (A) and comonomer (B) units.

The mass average molecular weight (Mw) of the present copolymer is 200,000 or more, preferably 300,000 or more, and 400,000 or more, from the viewpoint of improving the impact resistance of the resulting resin composition and resin molded article. The above is more preferable. If Mw is 200,000 or more, it can be sufficiently miscible with the (meth)acrylic polymer (Z), resulting in good 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 handling properties of the resin composition, it is preferably 3,500,000 or less, and more preferably 3,000,000 or less. It is preferably 2,000,000 or less, and more preferably 2,000,000 or less.
The above upper and lower limits can be arbitrarily combined. The Mw of the present copolymer can be, for example, 200,000 or more and 3,500,000 or less, further 300,000 or more and 3,000,000 or less, and even 400,000 or more and 2,000,000.
The method for controlling the Mw of the present copolymer to 200,000 or more is not particularly limited. For example, Mw can be controlled by adjusting the polymerization method, the type and amount of polymerization initiator added, the amount of chain transfer agent added, polymerization temperature, etc. according to well-known techniques.

[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) can contain a nonmetallic chain transfer agent, if necessary.
The details of each of the polymerization initiator and nonmetallic chain transfer agent will be described later.

The content ratio of the macromonomer (A) contained in the polymerizable composition (X) is 45% by mass based on the total mass of the polymerizable composition (X), since this copolymer has good handling properties. % or more, more preferably 47% by mass or more, even more preferably 50% by mass or more. On the other hand, the content ratio of the macromonomer (A) is determined based on the total mass of the polymerizable composition (X), since the amount of the present copolymer used can be suppressed and a modifying effect can be obtained with a small amount added. It is preferably 99% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less.
The above upper and lower limits can be arbitrarily combined. The content ratio of the macromonomer (A) to the total mass of the polymerizable composition (X) is, 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, furthermore 50% by mass or more and 70% by mass. % or less.

The content ratio of the comonomer (B) contained in the polymerizable composition (X) is determined based on the total mass of the polymerizable composition (X), since it becomes easier to obtain the impact resistance improvement effect of this copolymer. The content is preferably 1% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more. On the other hand, the content ratio of the comonomer (B) is preferably 55% by mass or less, more preferably 53% by mass or less, and 50% by mass or less, since transparency is improved when this copolymer is blended into a resin composition. % or less is more preferable.
The above upper and lower limits can be arbitrarily combined. The content ratio of the comonomer (B) with respect to the total mass of the polymerizable composition (X) is, for example, 1% by mass or more and 55% by mass or less, further 25% by mass or more and 53% by mass or less, furthermore 30% by mass or more and 50% by mass. It can be as follows.

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

The content ratio of the radical polymerization initiator contained in the polymerizable composition (X) can be appropriately selected by those skilled in the art according to well-known techniques. The content of the radical polymerization initiator is, for example, 0.0001 to 10% by mass based on the total mass of the polymerizable composition (X).

The content ratio of the nonmetallic chain transfer agent contained in the polymerizable composition (X) is preferably 0.01 to 0.5% by mass, and 0.01 to 0.5% by mass, based on the total mass of the polymerizable composition (X). 0.25% by mass is more preferred, and 0.04 to 0.25% by mass is particularly preferred. When the content of the nonmetallic chain transfer agent is 0.01% by mass or more, crosslinking of the resulting copolymer can be sufficiently prevented. If the amount of the nonmetallic chain transfer agent is 0.5% by mass or less, it is possible to prevent the composition distribution of the obtained copolymer from widening, thereby improving the impact resistance of the obtained resin molded article. .

When the polymerizable composition (X) contains a nonmetallic chain transfer agent, the resulting copolymer contains groups derived from the nonmetallic chain transfer agent.
From the viewpoint of keeping the content of the nonmetallic chain transfer agent in the polymerizable composition (X) within the above-mentioned preferable range, the proportion of the groups derived from the nonmetallic chain transfer agent to the total mass of the present copolymer is set to 0. The amount is preferably from 0.01 to 0.5% by weight, more preferably from 0.01 to 0.25% by weight, and particularly preferably from 0.04 to 0.25% by weight.

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

ただし、Ｒ及びＲ^１～Ｒ^ｎは、それぞれ独立に水素原子、アルキル基、シクロアルキル基、アリール基又は複素環基を示し、Ｘ^１～Ｘ^ｎは、それぞれ独立に水素原子又はメチル基を示し、ｎは、２～１０，０００の自然数を示し、Ｚは、末端基を示す。

However, 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, and 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.

Since the present copolymer contains the macromonomer (A) unit, the compatibility between the present copolymer and the (meth)acrylic polymer (Z) described later is improved when producing the resin composition of the present invention. Becomes good. As a result, the resulting resin composition and resin molding have excellent impact resistance and transparency, and a high modulus of elasticity. This copolymer and ( Compatibility with the meth)acrylic polymer (Z) can be improved.

In the formula (1), the alkyl group, cycloalkyl group, aryl group, or heterocyclic group of R and R ¹ to R ⁿ may have a substituent.

Examples of the alkyl groups for R and R ¹ to R ⁿ include branched or straight-chain alkyl groups having 1 to 20 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group. , decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group and the like. Among these, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, and octyl group are Preferably, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, and t-butyl group are more preferable, and methyl group is particularly preferable.

Examples of the cycloalkyl group for R and R ¹ to R ⁿ include cycloalkyl groups having 3 to 20 carbon atoms. Specific examples include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, t-butylcyclohexyl group, isobornyl group, adamantyl group, and the like. From the viewpoint of availability, cyclopropyl group, cyclobutyl group, and adamantyl group are preferred.

Examples of the aryl group for R and R ¹ to R ⁿ include aryl groups having 6 to 18 carbon atoms. Specific examples include phenyl group, benzyl group, naphthyl group, and the like.

Examples of the heterocyclic group for R and R ¹ to R ⁿ include a heterocyclic group having 5 to 18 carbon atoms. Specific examples include γ-lactone group, ε-caprolactone group, and morpholine group. Examples of the heteroatom contained in the heterocycle include an oxygen atom, a nitrogen atom, a sulfur atom, and the like.

Substituents for R or R ¹ to R ⁿ each independently include an alkyl group, an aryl group, a carboxy group, an alkoxycarbonyl group (-COOR'), a carbamoyl group (-CONR'R''), a cyano group, Selected from the group consisting of 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. A group or an atom can be mentioned. Examples of R' or R'' include, independently, the same groups as R (excluding heterocyclic groups).

Examples of the alkoxycarbonyl group as a substituent for R or R ¹ to R ⁿ include a methoxycarbonyl group.
Examples of the carbamoyl group as a substituent for R or R ¹ to R ⁿ include an N-methylcarbamoyl group and an N,N-dimethylcarbamoyl group.
Examples of the amide group as a substituent for R or R ¹ to R ⁿ include a dimethylamide group.
Examples of the halogen atom as a substituent for R or R ¹ to R ⁿ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkoxy group as a substituent for R or R ¹ to R ⁿ include alkoxy groups having 1 to 12 carbon atoms. A specific example is a methoxy group.
Examples of hydrophilic or ionic groups as substituents for R or R ¹ to R ⁿ include alkali salts of carboxyl groups or alkali salts of sulfoxyl groups, poly(alkylene oxides) such as polyethylene oxide groups and polypropylene oxide groups. and cationic substituents such as quaternary ammonium bases.

R and R ¹ to R ⁿ are preferably at least one selected from an alkyl group and a cycloalkyl group, and more preferably an alkyl group.
The alkyl group is preferably a methyl group, ethyl group, n-propyl group or i-propyl group, and from the viewpoint of easy availability, a methyl group is more preferable.

In the above formula (1), from the viewpoint of ease of synthesizing the macromonomer (A), 80 mol% or more of X ¹ to X ⁿ is a methyl group based on 100 mol% of the total number of moles of X ¹ to X ⁿ . It is preferable that there be.

It is preferable that n takes 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.

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 the terminal group of a polymer obtained by known radical polymerization.

The macromonomer (A) preferably contains a structural unit derived from methyl methacrylate (hereinafter also referred to as "MMA unit").
The content ratio of MMA units contained in the 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 the macromonomer (A). If the content of MMA units is 80% by mass or more, the impact resistance and transparency of the resin composition and resin molded article will be better, and the elastic modulus will be higher. On the other hand, the upper limit of the content ratio of MMA units is not particularly limited, and may be 100% by mass, or less than 100% by mass, for example, 99% by mass or less, based on the total mass of the macromonomer (A). You can also do it.
The above upper and lower limits can be arbitrarily combined.

When the macromonomer (A) contains an MMA unit, the macromonomer (A) contains 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 referred to as a "methacrylate unit"). It may further contain at least one member selected from the group consisting of (also referred to as "acrylate unit").
The content ratio of acrylate units contained in the macromonomer (A) is preferably 0.5% by mass or more based on the total mass of the macromonomer (A), since this copolymer has good heat decomposition resistance. , more preferably 2% by mass or more, and even more preferably 4% by mass or more. On the other hand, the content ratio of acrylate units is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total mass of the macromonomer (A), since it can maintain good heat decomposition resistance of the resin composition. More preferably, it is 5% by mass or less.
The above upper and lower limits can be arbitrarily combined.

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. The same monomers as mentioned in "Comonomer forming the comonomer unit of Z)" can be used. These monomers can be used alone or in combination of two or more.
Among the above, monomers constituting the methacrylate unit include n-butyl methacrylate, lauryl methacrylate, dodecyl methacrylate, stearyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, 2-hydroxy Ethyl methacrylate and 4-hydroxybutyl methacrylate are preferred, and n-butyl methacrylate and 2-ethylhexyl methacrylate are more preferred. The monomers constituting the acrylate unit include methyl acrylate, n-butyl acrylate, lauryl acrylate, dodecyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, and 2-hydroxyethyl acrylate. , and 4-hydroxybutyl acrylate are preferred, and methyl acrylate, ethyl acrylate, and n-butyl acrylate are more preferred.

By adjusting the molecular weight of the polymer chain consisting of macromonomer (A) units in the present copolymer, the present copolymer and the (meth)acrylic polymer (Z) can be mixed to form the resin composition of the present invention. When producing this copolymer and the (meth)acrylic polymer (Z), moderate entanglement occurs, so the matrix phase formed by the copolymer and the (meth)acrylic polymer (Z) The interfacial strength between the two is improved, and the impact resistance and elastic modulus of the resulting resin composition and resin molded article are improved.

Here, it is known that the interentanglement molecular weight Me of polymethyl methacrylate is approximately 9,200 g/mol (Report by Wu et al.: POLYMER ENGINEERING AND SCIENCE, JUNE 1992, Vol. 32, No. 12 p823).
Therefore, the mass average molecular weight (Mw) of the macromonomer (A) is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, and particularly preferably 24,000 or more. If the Mw of the macromonomer (A) is 10,000 or more, the polymer chain consisting of macromonomer (A) units and the (meth)acrylic polymer (Z) will become entangled, and the copolymer and (meth) ) The interfacial strength between the acrylic polymer (Z) and the matrix phase formed is improved, and the impact resistance of the resin composition and resin molded article can be improved.
On the other hand, the Mw of the macromonomer (A) is 1. 000,000 or less, more preferably 80,000 or less, even more preferably 60,000 or less, particularly preferably 50,000 or less.
The above upper and lower limits can be arbitrarily combined. The Mw of the macromonomer (A) is, 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, and even 24,000 or more and 50, 000 or less.
In the present invention, Mw of the macromonomer (A) means a mass average molecular weight which is a relative molecular weight determined in terms of polymethyl methacrylate (PMMA) using gel permeation chromatography (GPC).

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 Mws are used together, the macromonomer (A) with a lower Mw plays a role in reducing syrup viscosity and preventing crosslinking of the copolymer, and the macromonomer with a higher Mw plays a role in preventing crosslinking of the copolymer. It is thought that (A) plays a role in ensuring compatibility with the matrix resin when used as an additive.

The raw material monomer constituting the poly(meth)acrylate segment of the macromonomer (A) consists of one or more types of (meth)acrylate. The raw material monomer preferably contains methyl methacrylate, and may further contain a (meth)acrylate other than methyl methacrylate.
(Meth)acrylates other than methyl methacrylate are not particularly limited as long as they are monomers that can be copolymerized with methyl methacrylate. The same monomers as those mentioned in "Comonomer for forming a comonomer" can be used. These monomers can be used alone or in combination of two or more.
Among the above, 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.

The raw material monomer is such that 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 are heat decomposable. From the viewpoint of superiority, it is preferable to include acrylate in part.
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.

[Method for producing macromonomer (A)]
Macromonomer (A) can be produced by a known method. Examples of methods for producing the macromonomer (A) include polymerizing raw material monomers using a cobalt chain transfer agent (US Pat. No. 4,680,352), and chain-transferring an α-substituted unsaturated compound such as α-bromomethylstyrene. A method of polymerizing a raw material monomer as an agent (WO 88/04304), a method of chemically bonding a polymerizable group to one end of a poly(meth)acrylate segment (JP-A-60-133007, US Pat. No. 5,147,952) (Specification of No. 1), and a method using thermal decomposition (Japanese Unexamined Patent Publication No. 11-240854). Among these, the method of polymerizing raw material monomers using a cobalt chain transfer agent is preferred because it requires fewer manufacturing steps and uses a catalyst with a high chain transfer constant.

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, from the viewpoint of simplifying the recovery process of the macromonomer (A), the aqueous dispersion polymerization method is preferred, and the suspension polymerization method is particularly preferred. Further, after the polymerization, the comonomer (B) and the radical polymerization initiator can be added as they are without recovering the macromonomer (A), and the present copolymer can be obtained by a copolymerization reaction.

As the cobalt chain transfer agent, a cobalt chain transfer agent represented by the following formula (2) can be used, and examples thereof include Japanese Patent No. 3587530, Japanese Patent Application Publication No. 6-23209, Japanese Patent Application Publication No. 7-35411, and U.S. Pat. Specification No. 45269945, Specification No. 4694054, Specification No. 4834326, Specification No. 4886861, Specification No. 5324879, International Publication No. 95/17435, Special Publication No. 9-510499, etc. You can use the ones listed in .

ただし、Ｒ_１～Ｒ_４は、それぞれ独立して、アルキル基、シクロアルキル基又はアリール基を示し、Ｘは、それぞれ独立して、Ｆ原子、Ｃｌ原子、Ｂｒ原子、ＯＨ基、アルコキシ基、アリールオキシ基、アルキル基又はアリール基を示す。

However, R ₁ to R ₄ each independently represent an alkyl group, cycloalkyl group, or aryl group, and X each independently represents an F atom, a Cl atom, a Br atom, an OH group, an alkoxy group, an aryl group, and Indicates an oxy group, an alkyl group, or an aryl group.

[Comonomer (B)]
The comonomer (B) is a monomer that copolymerizes with the macromonomer (A).
The presence of the comonomer (B) unit in the present copolymer improves the impact resistance of the resin composition and resin molded article.

Comonomer (B) contains aromatic acrylate (B1).
It is preferable that the comonomer (B) further contains an alkyl acrylate (B2).
The comonomer (B) may contain other monomers (B3) as necessary.

[Aromatic acrylate (B1)]
The refractive index of a polymer consisting of aromatic acrylate (B1) units is higher than the refractive index of a polymer consisting of alkyl acrylate (B2) units. The refractive index of the polymer chain containing the comonomer (B) unit can be adjusted to match the refractive index of the (meth)acrylic copolymer (Z) to be blended with the present copolymer.

Examples of the aromatic acrylate (B1) include benzyl acrylate, phenyl acrylate, phenoxyethyl acrylate, phenoxypolyethylene glycol acrylate, biphenylacrylate, nonyl phenyl acrylate, nonyl phenoxy ethyl acrylate, nonyl phenoxy polyethylene glycol acrylate, cumyl phenol acrylate, Examples thereof include cumylphenoxyethyl acrylate, cumylphenoxylypolyethylene 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.

[Alkyl acrylate (B2)]
When the comonomer (B) contains the acrylate (B2), the obtained resin composition and resin molded article have good transparency and impact resistance, and have a high elastic modulus.
Alkyl acrylate (B2) refers to acrylates in which the ester group is an alkyl group.
Examples of the alkyl group include a straight chain alkyl group, a branched alkyl group, and a cyclic alkyl group. Among these, straight-chain alkyl groups and branched alkyl groups are preferable in that the polymer segment composed of comonomer (B) units has excellent flexibility. The number of carbon atoms in the alkyl group is, for example, 1 to 20. 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.

Since alkyl acrylate (B2) can improve the impact resistance of the resulting resin composition and resin molded article, the glass transition temperature (Tg) of a polymer consisting only of alkyl acrylate (B2) units is 0°C. It is preferable that it is less than

Examples of the alkyl acrylate (B2) include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, Unsubstituted alkyl acrylates such as decyl 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; 2-hydroxyethyl Acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, hydroxyl group-containing acrylate such as glycerol acrylate; 2-acryloyloxyethylhexahydrophthalic acid, 2-acryloyloxypropylhexahydrophthalic acid, 2-acryloyloxyethyl phthalic acid, Carboxy group-containing acrylates such as 2-acryloyloxypropylphthalic acid, 2-acryloyloxyethylmaleic acid, 2-acryloyloxypropylmaleic acid, 2-acryloyloxyethylsuccinic acid, 2-acryloyloxypropylsuccinic acid; Glydicyl Epoxy group-containing acrylates such as acrylate, glycicyl α-ethyl acrylate, and 3,4-epoxybutyl acrylate; Amino group-containing acrylates such as dimethylaminoethyl acrylate and diethylaminoethyl acrylate; 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, N,N'-methylenebisacrylamide, etc. acrylate, etc. These can be used alone or in combination of two or more.

Among the above monomers, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl At least one selected from the group consisting of acrylate, lauryl acrylate, tridecyl acrylate, and i-stearyl acrylate is preferred.
Alternatively, since the Tg of the polymer consisting only of alkyl acrylate (B2) units is less than 0°C, 2-ethylhexyl acrylate, 4-hydroxybutyl acrylate, n-butyl acrylate, n-propyl acrylate, ethyl acrylate and -Hydroxyethyl acrylate is preferred.
Alternatively, methyl At least one selected from the group consisting of acrylate, ethyl acrylate and n-butyl acrylate is preferred.

[Other monomers (B3)]
Other monomers (B3) may be used as long as they are copolymerizable with macromonomer (A) and aromatic acrylate (B1), such as 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, isobornyl methacrylate, 2-methoxyethyl methacrylate, 2 - Methacrylates such as ethoxyethyl methacrylate and phenoxyethyl methacrylate; Hydroxyl group-containing methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, and glycerol methacrylate; 2-methacryloyloxyethylhexahydrophthalic acid, 2- Methacryloyloxypropylhexahydrophthalic acid, 2-methacryloyloxyethyl phthalic acid, 2-methacryloyloxypropylphthalic acid, 2-methacryloyloxyethylmaleic acid, 2-methacryloyloxypropylmaleic acid, 2-methacryloyloxyethylsuccinic acid, 2- Carboxy group-containing methacrylates such as methacryloyloxypropylsuccinic acid; epoxy group-containing methacrylates such as glycidyl methacrylate and 3,4-epoxybutyl methacrylate; amino group-containing methacrylates such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; methacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate, etc. Functional methacrylates; styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene and pt-butylstyrene, vinylethylbenzene, vinyltoluene, vinylxylene, vinylnaphthalene, diphenyl Aromatic vinyls such as ethylene and divinylbenzene; Carboxy group-containing vinyl monomers such as (meth)acrylic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, and monomethyl itaconate; maleic anhydride; Acid anhydride group-containing vinyl monomers such as itaconic anhydride; (meth)acrylamide, N-t-butyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N- Vinyl monomers containing amide groups such as butoxymethyl (meth)acrylamide, diacetone acrylamide, maleic acid amide, maleimide; vinyl monomers such as (meth)acrylonitrile, vinyl chloride, vinyl acetate, vinyl propionate, etc. ; etc. One or more of these can be appropriately selected and used.

The content ratio of aromatic acrylate (B1) contained in the comonomer (B) is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, based on the total mass of the comonomer (B). preferable. When the content of the aromatic acrylate (B1) is 5% by mass or more, the refractive index of the polymer chain containing the comonomer (B) unit can be easily adjusted to 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, even more preferably 35% by mass or less, based on the total mass of the comonomer (B).

The content ratio of alkyl acrylate (B2) contained 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 alkyl acrylate (B2) is 50% by mass or more, the resulting resin composition and resin molded article can have good impact resistance. On the other hand, the content of 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).

The content of the other monomer (B3) is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and 0% by mass or less based on the total mass of the comonomer (B). You can.

The refractive index of the polymer composed of the comonomer (B) units in the present copolymer is not particularly limited, but for example, the refractive index at a wavelength of 589 nm is preferably 1.44 to 1.54, and preferably 1.47 to 1. 51 is more preferred. In particular, from the viewpoint of transparency of the resin composition, it is preferable that the absolute value of the difference in refractive index between the above-mentioned macromonomer (A) and the below-mentioned (meth)acrylic polymer (Z) is 0.05 or less, It is more preferably 0.03 or less, and even more preferably 0.01 or less.
The refractive index of the polymer consisting of comonomer (B) units in this copolymer is the same as the refractive index of a polymer obtained by polymerizing only comonomer (B) under the same conditions as when producing this copolymer. It can be considered.

The copolymerization reaction mechanism of the macromonomer (A) and the comonomer (B) is described in detail in a paper by Yamada et al. (Prog. Polym. Sci. 31 (2006) p835-877). As the comonomer (B), monomers having a double bond and having radical polymerizability can be used alone or in combination of two or more.

The glass transition temperature (Tg) of the polymer consisting of comonomer (B) units in this copolymer is -35°C or lower, since it can improve the impact resistance of the resulting resin composition and resin molded product. The temperature is preferably -37°C or lower, more preferably -40°C or lower. In order to improve the impact resistance, the polymer chain containing the comonomer (B) unit needs to have sufficient mobility in the temperature range above Tg. It is known that the lower the Tg, the better the mobility of polymer chains under the same temperature environment. If the Tg of the polymer composed of comonomer (B) units is −35° C. or lower, the polymer chain containing comonomer (B) units has sufficient mobility, resulting in good impact resistance.
In the present invention, the Tg of the polymer consisting of comonomer (B) units is calculated by adopting the values described in known literature such as Polymer Handbook (POLYMER HANDBOOK FOURTH EDITION 2003) and using the Fox formula. can. Alternatively, the dynamic viscoelasticity measurement of the obtained resin molded article can be carried out, and the value of tan δ can be adopted as Tg.

[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. As the radical polymerization initiator, known organic peroxides such as 2,4-dichlorobenzoyl peroxide and t-butylperoxypivalate, 2,2'-azobisisobutyronitrile, 2,2'- Known azo compounds such as azobis(2,4-dimethylvaleronitrile) can be used.

[Nonmetal chain transfer agent]
By performing the polymerization reaction of the polymerizable composition (X) in the presence of a nonmetallic chain transfer agent, crosslinking of the resulting copolymer can be prevented. Conventionally, it was necessary to prevent crosslinking of the copolymer by the chain transfer effect of the macromonomer (A), and it was necessary to use a low molecular weight macromonomer (A) to increase the mol% of the macromonomer (A) used. there were. Therefore, it has been found that by adding a nonmetallic chain transfer agent, it becomes possible to use a macromonomer (A) with a higher molecular weight, and the impact resistance is further improved.
Examples of nonmetallic chain transfer agents include sulfur-containing chain transfer agents such as t-dodecylmercaptan and n-octylmercaptan, α-methylstyrene dimer, carbon tetrachloride, and terpenoids. Among these, sulfur-containing chain transfer agents are preferred from the viewpoint of easy availability and high chain transfer ability. One or more of these can be appropriately selected and used.

[Method for producing copolymer]
This copolymer can be produced, for example, by a production method including a step of subjecting a polymerizable composition (X) containing a macromonomer (A) and a comonomer (B) to a polymerization reaction.

The polymerization reaction is preferably carried out using a radical polymerization method. Examples of the radical polymerization method include bulk polymerization methods such as bulk polymerization and cast polymerization, 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 preferable because they can simplify the recovery process of the produced copolymer, and suspension polymerization is preferred because the resulting copolymer particles can be easily handled. Legal is preferred.
In the suspension polymerization method, the present copolymer is obtained as spherical particles with an average particle diameter of about 5 μm to 1 mm. The obtained spherical particles are easy to handle, and when used in processing operations such as extrusion and molding, there is little concern about dust scattering, and they are suitably used in resin compositions.
Furthermore, the suspension polymerization method is preferable also because the moldability of the obtained resin composition becomes good. The reason for this is not clear, but it is speculated that trace amounts of abnormal polymers and residual emulsifiers generated during emulsion polymerization cause foreign matter and thickening, and as a result, suspension polymerization is superior to emulsion polymerization. be done.
In the method for producing this copolymer, the case where the polymerization reaction is carried out using a suspension polymerization method will be described in detail below.

[Production of copolymer by suspension polymerization]
In the method for producing the present copolymer, when the present copolymer is produced using the suspension polymerization method, the following steps i) to v) are included: production of the macromonomer (A) and production of the present copolymer. The production of the macromonomer (A) and the present copolymer, including the following steps I) to II) in place of the following i) to ii) among the steps i) to v) below. An example of this is a method of continuously manufacturing.

i) Syrup Preparation Step 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 below 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 polymerizable composition (X) is mixed with the syrup to obtain the polymerizable composition (X). can be heated.
When using a nonmetallic chain transfer agent, it is preferably added during syrup adjustment.

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 polymerization initiator is added after the syrup is once cooled to room temperature or below. , dissolve uniformly. The temperature of the syrup when adding the polymerization initiator is preferably a temperature equal to or lower than the 10-hour half-life temperature of the polymerization initiator minus 15°C.

iii) Preparation step of aqueous solution The polymerizable composition (X) and the aqueous solution are mixed and then stirred to form a suspension in which droplets of the polymerizable composition (X) are dispersed in the aqueous solution. Prepare.
The aqueous solution is an aqueous solution for dispersing the polymerizable composition (X), and can contain a dispersant, an electrolyte, and other auxiliary agents. By appropriately selecting a combination of a dispersant and an electrolyte, when the polymerizable composition (X) is dispersed in the aqueous solution, droplets of the polymerizable composition (X) are formed in the aqueous solution. It is possible to control the dispersibility of
As for the water used in the aqueous solution, deionized water is preferably used since the dispersibility of the droplets of the polymerizable composition (X) is improved.
Examples of dispersants include alkali metal salts of poly(meth)acrylic acid, copolymers of alkali metal salts of (meth)acrylic acid and (meth)acrylic esters, and alkali metal salts of sulfoalkyl (meth)acrylates. and (meth)acrylic ester, an alkali metal salt of polystyrene sulfonic acid, a copolymer of an alkali metal styrene sulfonic acid and (meth)acrylic ester, or a copolymer of a combination of these monomers. Coalescence: Examples include polyvinyl alcohol, methyl cellulose, starch, and hydroxyapatite with a degree of saponification of 70 to 100%. These can be used alone or in combination of two or more. Among these, copolymers of alkali metal salts of sulfoalkyl (meth)acrylates and (meth)acrylic acid esters and copolymers of alkali metal salts of (meth)acrylates and (meth)acrylates have good dispersion stability during suspension polymerization. ) Copolymers of acrylic esters are preferred. The dispersant is used, for example, in an amount of 0.0005 to 0.5 parts by mass based on 100 parts by mass of the polymerizable composition (X).
Examples of the electrolyte include sodium carbonate, sodium sulfate, manganese sulfate, and the like. The electrolyte is used, for example, in an amount of 0.01 to 1.0 parts by weight based on 100 parts by weight of the polymerizable composition (X).

I) Syrup Preparation Step The bead-shaped macromonomer (A) produced by suspension polymerization is dispersed in an aqueous solution, and a solution containing the comonomer (B) is added to prepare the syrup. 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 more preferably in the range of 50°C to 80°C. is even more preferable. When using a nonmetallic chain transfer agent, it is preferably added during syrup adjustment.

II) Polymerization initiator dissolution step When the polymerization initiator reacts at the temperature at which the syrup obtained in step I) is prepared, the syrup is once cooled to room temperature or below, and then the polymerization initiator is added and dissolved uniformly. to obtain a polymerizable composition (X). The temperature of the syrup when adding the polymerization initiator is preferably a temperature equal to or lower than the 10-hour half-life temperature of the polymerization initiator minus 15°C.

iv) Polymerization reaction step Next, the temperature of the obtained suspension is raised while stirring to start the polymerization reaction. It is preferable to remove dissolved oxygen by subjecting the polymerizable mixture and the aqueous solution to vacuum deaeration or nitrogen substitution before the temperature is raised. The polymerization temperature when performing 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, even more preferably 60°C to 80°C. If the polymerization temperature is too low, there is a concern that the reaction will proceed slowly and the polymerization time will become longer. On the other hand, if the polymerization temperature is too high, the cleavage of the adduct radical, which is a reaction intermediate, tends to take priority and the yield of the present copolymer (block/graft polymer) tends to decrease.
In the latter stage of the polymerization reaction, the temperature of the suspension can be raised in order to increase the reaction rate of the polymerizable composition (X) and to eliminate unreacted radical polymerization initiators. The temperature at which the suspension is raised is preferably 80°C or higher, more preferably 85°C or higher. The temperature raising time may be determined by calculating the time until the radical polymerization initiator disappears, and is, for example, about 30 minutes to 2 hours.

v) Recovery Step After the above step, the suspension is cooled to room temperature or below, and then the generated bead-like copolymer is recovered using a known method such as filtration.
If necessary, a cleaning process for removing impurities such as a dispersant and an electrolyte, a process for removing beads containing air bubbles, a drying process, etc. can be performed. The finally obtained bead-like copolymer (block/graft copolymer) is referred to as the present copolymer.

Alternatively, the polymerization reaction may be performed using a bulk polymerization method such as a bulk polymerization method or a cast polymerization method, and may include a step of heating and polymerizing the polymerizable mixture.

[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), if necessary, within a range that does not impair the effects of the present invention.

The content ratio of the (meth)acrylic polymer (Z) contained in the resin composition of the present invention is preferably 10 to 99% by mass, more preferably 20 to 98% by mass, based on the total mass of the resin composition. , more preferably 30 to 90% by weight, particularly preferably 30 to 65% by weight. If the content ratio of the (meth)acrylic polymer (Z) is 10% by mass or more, the resin composition and the resin molded product formed by molding the resin composition will have excellent properties (transparency) that acrylic resin inherently has. , weather resistance, high elastic modulus, surface hardness, etc.). If the content of the (meth)acrylic polymer (Z) is 99% by mass or less, the resin composition and the resin molded product will have good properties such as impact resistance.

The content of the present copolymer in the resin composition of the present invention is preferably 1 to 90% by mass, more preferably 2 to 80% by mass, and 10 to 70% by mass based on the total mass of the resin composition. is more preferred, and 35 to 70% by mass is particularly preferred. If the content of the present copolymer is 1% by mass or more, the resin composition and the resin molded article will have good properties such as impact resistance. If the content of this copolymer is 90% by mass or less, the resin composition and resin molding will have good properties that are inherent to acrylic resin (transparency, weather resistance, high elastic modulus, surface hardness, etc.) can be maintained.
The content ratio of the present copolymer can be appropriately optimized depending on the elastic modulus and impact resistance required for the resin molded article.

The content of the other component (Q) is not particularly limited as long as it does not impair the effects of the present invention. Usually, it is preferably 0 to 20% by weight, more preferably 0.1 to 5% by weight, based on the total weight of the resin composition.

The resin composition of the present invention is suitable as a molding material for use in known melt molding such as injection molding, extrusion molding, compression molding, and blow molding. In particular, the resin composition of the present invention is suitable as a molding material used in injection molding or extrusion molding.

[(meth)acrylic polymer (Z)]
The (meth)acrylic polymer (Z) preferably contains MMA units from the viewpoints of heat resistance, hardness, scratch resistance, weather resistance, transparency, and processability.
The content ratio of MMA units contained 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). preferable. 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 favorably. On the other hand, the upper limit of the content ratio of MMA units is not particularly limited, and the content ratio of MMA units may be 100% by mass, that is, a polymer consisting only of MMA units.

In addition to the MMA unit, the (meth)acrylic polymer (Z) may contain structural units derived from other comonomers (hereinafter referred to as "comonomer units") that can be copolymerized with MMA for various purposes. I can do it.
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. Therefore, the heat decomposition resistance can be improved.
In addition, by adjusting the type and content ratio of comonomer units, the glass transition temperature (Tg), processability, heat resistance, refractive index, weather resistance, mold releasability, and Heat decomposition resistance, etc. can be controlled.

The content ratio of comonomer units in the (meth)acrylic polymer (Z) is determined to improve the properties of the (meth)acrylic polymer, such as heat resistance, hardness, scratch resistance, weather resistance, transparency, and processability. Since it can be maintained, it is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total mass of the (meth)acrylic polymer (Z). On the other hand, the lower limit of the content of comonomer units is not particularly limited, and the polymer may not contain comonomer units, that is, it may be a polymer consisting only of MMA units.

Examples of the comonomer forming the comonomer unit of the (meth)acrylic polymer (Z) include the following a) to i).
a) 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 - (Meth)acrylate monomers other than methyl methacrylate, such as 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) (meth)acrylic acid, 2-(meth)acryloyloxyethylhexahydrophthalic acid, 2-(meth)acryloyloxypropylhexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth) Acryloyloxypropylphthalic acid, 2-(meth)acryloyloxyethylmaleic acid, 2-(meth)acryloyloxypropylmaleic acid, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxypropylsuccinic acid, Carboxyl group-containing vinyl monomers such as crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, and monomethyl itaconate.
d) Vinyl monomers containing acid anhydride groups such as maleic anhydride and itaconic anhydride.
e) Epoxy group-containing vinyl monomers such as glycicyl (meth)acrylate, glycicyl 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) (meth)acrylamide, N-t-butyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, diacetone acrylamide, maleic acid amide , a vinyl monomer containing an amide group such as maleimide.
h) Vinyl monomers such as styrene, α-methylstyrene, vinyltoluene, (meth)acrylonitrile, vinyl chloride, vinyl acetate, and vinyl propionate.
i) 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 Polyfunctional vinyl monomers such as (meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, allyl(meth)acrylate, N,N'-methylenebis(meth)acrylamide, etc. .

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, and methyl acrylate is more preferred, in terms of ease of availability.

The mass average molecular weight (Mw) of the (meth)acrylic polymer (Z) is not particularly limited, and is preferably 30,000 or more and 1,000,000 or less, more preferably 50,000 or more and 500,000 or less. It is preferably 80,000 or more and 200,000 or less. If the Mw of the (meth)acrylic polymer (Z) is 30,000 or more, the properties of the (meth)acrylic polymer such as heat resistance, hardness, scratch resistance, weather resistance, and transparency will not be exhibited. It becomes easier. On the other hand, if the Mw of the (meth)acrylic polymer (Z) is 1,000,000 or less, the melt viscosity will be within an appropriate range and the melt-kneadability and processability will be good.

[Other ingredients (Q)]
Other components (Q) are added to the resin composition as necessary. Other components (Q) include, for example, a mold release agent, an antioxidant, a heat stabilizer, an impact modifier, a softener, a weatherability modifier, a coloring agent, an inorganic pigment, an organic pigment, and carbon black. , ferrite, conductivity imparting agent, ultraviolet absorber, infrared absorber, lubricant, inorganic filler, reinforcing agent, plasticizer, reverse plasticizer, neutralizer, crosslinking agent, flame retardant, preservative, insect repellent, fragrance , radical scavenger, sound absorbing material, core shell rubber, etc.

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

[Resin molded body]
The resin molded article of the present invention is formed 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 article 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 a curved surface.

The resin molded article of the present invention has excellent impact resistance and transparency, and has a high elastic modulus, so it can be used for display front panels such as liquid crystals and organic EL, signage supplies, lighting supplies, home appliances, vehicle interior and exterior materials, industrial It can be suitably used for materials, construction materials, lenses, light guide plates, light condensing members, optical films used in displays such as liquid crystals and organic EL, and the like.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples. "Part" means "part by mass."

[raw materials]
The abbreviations of compounds used in Examples and Comparative Examples are as follows.
MMA: Methyl methacrylate (manufactured by Mitsubishi Chemical Corporation, product name: Acryester (registered trademark) M)
MA: Methyl acrylate (manufactured by Mitsubishi Chemical Corporation)
BA: n-butyl acrylate (manufactured by Mitsubishi Chemical Corporation)
St: Styrene (manufactured by Fujifilm Wako Pure Chemical Industries)
BzA: Benzyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name: Viscoat #160)
Chain transfer agent (2): n-octyl mercaptan (manufactured by 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., product 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, product name: Acrypet (registered trademark) VH001

[Evaluation methods〕
Evaluations in Examples and Comparative Examples were conducted by the following method.

<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 using gel permeation chromatography (GPC).
A solution in which 10 mg of macromonomer (A) was dissolved in 10 mL of tetrahydrofuran and filtered through a 0.45 μm filter was used as a sample for GPC measurement.
A GPC measurement device (manufactured by Tosoh Corporation, model name: HLC-8320), 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, trade name: TSK-GEL SUPER HM-H) were used by connecting them in series.
A differential refractometer (RI) was used as a detector. The measurement was performed under the following conditions: separation column temperature: 40° C., mobile phase: tetrahydrofuran, mobile phase flow rate: 0.6 mL/min, and sample injection amount: 10 μL. A calibration curve was created using several types of polymethyl methacrylate with known molecular weights (manufactured by Polymer Laboratories, peak molecular weight (Mp) 1,560 to 19,500,000) as standard polymers, and Mw and Mn in terms of polymethyl methacrylate were determined.

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

<Glass transition temperature of polymer consisting of comonomer units of copolymer>
The glass transition temperature (Tg) of a polymer made of comonomer units of the copolymer was calculated from the Tg of a polymer made only of each comonomer unit using the Fox equation. For the Tg value of the polymer consisting only of each comonomer unit, the literature value described in Polymer Handbook (POLYMER HANDBOOK FOURTH EDITION 2003) was adopted.

<Charpy impact test>
As an index of the impact resistance of the resin molded article, Charpy impact strength (unit: kJ/m ² ) was measured. The Charpy impact strength was measured using a Charpy impact tester (manufactured by Toyo Seiki Co., Ltd., product name: DG-CP) using a rod-shaped resin molded specimen (without a notch) in accordance with JIS K 7111. It was measured. Five pieces were tested using a 15J hammer, and the average value was determined.
A three-level evaluation was performed according to the following criteria.
AA: Charpy impact strength is 35 kJ/ ^m2 or more A: Charpy impact strength is 25 kJ/m2 or ^more and less than 35 kJ/ ^m2 B: Charpy impact strength is less than 25 kJ/ ^m2

<Bending elasticity test>
Using a rod-shaped resin molded body as a test piece, the bending elastic modulus (unit: MPa) was calculated. The flexural modulus was determined from the stress-strain curve obtained at a room temperature of 23° C. and a test speed of 2 mm/min.
A three-level evaluation was performed according to the following criteria.
AA: Flexural modulus is 2.0 GPa or more A: Flexural modulus is 1.5 GPa or more and less than 2.0 GPa B: Flexural modulus is less than 1.5 GPa

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

[Synthesis of dispersant (1)]
61.6 parts of a 17% by mass aqueous potassium hydroxide solution, 19.1 parts of MMA, and 19.3 parts of deionized water were charged into a reaction apparatus equipped with a stirrer, a cooling tube, and a thermometer. Next, the liquid in the reaction apparatus was stirred at room temperature, and after confirming an exothermic peak, the mixture was stirred for 4 hours. Thereafter, the reaction solution in the reactor was cooled to room temperature to obtain an aqueous potassium methacrylate solution.
Next, in a polymerization apparatus equipped with a stirrer, a cooling tube, and a thermometer, 900 parts of deionized water and a 42% by mass aqueous solution of 2-sulfoethyl sodium methacrylate (manufactured by Mitsubishi Chemical Corporation, trade name: Acryester SEM-Na) were added. 70 parts of the above potassium methacrylate aqueous solution and 7 parts of MMA were added and stirred, and the temperature of the liquid in the polymerization apparatus was raised to 50° C. while purging the inside of the polymerization apparatus with nitrogen. Into the polymerization apparatus, 0.053 part 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 polymerization was started. The temperature of the liquid in the apparatus was raised to 60°C. After adding the polymerization initiator, 1.4 parts of MMA was added in divided portions five times in total (total amount of MMA: 7 parts) every 15 minutes. Thereafter, the liquid in the polymerization apparatus was maintained at 60° C. for 6 hours while stirring, and then cooled to room temperature to obtain a dispersant (1) having a solid content of 8% by mass as a transparent aqueous solution.

[Synthesis of chain transfer agent (1)]
In a synthesis apparatus equipped with a stirring device, under a nitrogen atmosphere, 2.00 g (8.03 mmol) of cobalt (II) acetate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Wako Special Grade) and diphenylglyoxime (Tokyo) were added. 3.86 g (16.1 mmol) of EP grade (manufactured by Kasei Co., Ltd.) and 100 mL of diethyl ether which had been previously deoxidized by nitrogen bubbling were added, and the mixture was stirred at room temperature for 2 hours. Next, 20 mL of boron trifluoride diethyl ether complex (manufactured by Tokyo Kasei Co., Ltd., EP grade) was added, and the mixture was further stirred for 6 hours. The obtained product was filtered, the solid was washed with diethyl ether, and dried at 20° C. for 12 hours under 100 MPa to obtain 5.02 g (7.93 mmol, yield 99% by mass) of chain transfer agent (1) as a brown solid. ) was obtained.

[Production Example 1: Synthesis of macromonomer (A-1)]
In a polymerization apparatus equipped with a stirrer, a cooling tube and a thermometer, 145 parts of deionized water, 0.1 part of sodium sulfate (Na ₂ SO ₄ ) and 0.26 parts of dispersant (1) (solid content 8% by mass) were added. of the mixture and stirred to obtain a homogeneous 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 form an aqueous dispersion. Next, the interior of the polymerization apparatus was sufficiently purged with nitrogen, and the temperature of the aqueous dispersion was raised to 80°C, held for 3 hours, and then raised to 90°C and held for 2 hours. Thereafter, the reaction solution was cooled to 40° C. to obtain an aqueous suspension of 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 weights (Mn, Mn) of the obtained macromonomers are shown in Table 1.

[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 macromonomers are shown in Table 1.

[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 macromonomers are shown in Table 1.

[Production Example 4: Synthesis of copolymer (1)]
In a polymerization apparatus equipped with a stirrer, a cooling tube, and a thermometer, 50 parts of the macromonomer (A-1) obtained in Production Example 1, 145 parts of deionized water, 0.26 parts of the dispersant (1), and sodium sulfate were added. 0.3 part was added and stirred to obtain an aqueous suspension. Next, the temperature inside the polymerization apparatus was raised to 70° C., and then 38.5 parts of BA, 11.5 parts of BzA, and 0.07 parts of chain transfer agent (2) were slowly added. Thereafter, the temperature was maintained at 70° C. for 1 hour while stirring to dissolve the macromonomer (A-1) in BA and BzA to obtain a dispersion. Next, after cooling the inside of the polymerization apparatus to 40° C., 0.3 parts of polymerization initiator (2) was added and stirred for 30 minutes to dissolve. Next, the interior of the polymerization apparatus was sufficiently purged with nitrogen, and the temperature of the aqueous dispersion was raised to 72°C, held for 5 hours, and then raised to 90°C and held for 1 hour. After cooling to 40° C. or below, it was filtered with a filter cloth, and the filtrate was washed with deionized water. Thereafter, the filtrate was dried at 40° C. for 12 hours in a hot air circulation dryer to obtain bead-shaped copolymer (1). Table 2 shows the charging 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 the polymer consisting of comonomer (B) units of copolymer (1) was -42.8°C when calculated using the Fox formula.

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

[Production Example 8: Synthesis of copolymer (5)]
In a polymerization apparatus equipped with a stirrer, a cooling tube, and a thermometer, 60 parts of the macromonomer (A-1) obtained in Production Example 1, 150 parts of deionized water, 0.26 parts of the dispersant (1), and sodium sulfate were added. 0.3 part was added and stirred to obtain an aqueous suspension. Next, the temperature inside the polymerization apparatus was raised to 70°C, and then 33.2 parts of BA and 6.8 parts of St were slowly added. Thereafter, the temperature was maintained at 70° C. for 1 hour while stirring to dissolve the macromonomer (A-1) in BA and St to obtain a dispersion. Next, after cooling the inside of the polymerization apparatus to 40° C., 0.5 part of polymerization initiator (2) was added and stirred for 30 minutes to dissolve. Next, the interior of the polymerization apparatus was sufficiently purged with nitrogen, and the temperature of the aqueous dispersion was raised to 82°C, held for 4 hours, and then raised to 90°C and held for 1 hour. After cooling to 40° C. or below, it was filtered with a filter cloth, and the filtrate was washed with deionized water. Thereafter, the filtrate was dried at 40° C. for 12 hours in a hot air circulation dryer to obtain a bead-shaped copolymer (5). Table 2 shows the charging composition, the Mw of the obtained bead-like copolymer, and the Tg of the polymer composed of comonomer (B) units.

[Production Example 9: Synthesis of copolymer (6)]
In this example, copolymer (6) was produced by a solution polymerization method.
100 parts of toluene and 50 parts of the macromonomer (A-2) obtained in Production Example 2 were placed in a separable flask equipped with a stirrer, a cooling tube, and a thermometer, and stirred at 50°C for 1 hour to form a homogeneous solution. did. Once cooled 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. Thereafter, nitrogen bubbling was performed for 30 minutes while stirring to replace the atmosphere in the separable flask with nitrogen. Next, the temperature was raised to 69° C. to initiate polymerization, and the temperature was maintained for 5 hours, followed by cooling to room temperature to obtain a polymer solution containing copolymer (6). Next, the copolymer (6) obtained by solution polymerization was reprecipitated. First, 200 parts of toluene was added to 100 parts of the polymerization reaction solution to obtain 300 parts of a diluted solution. Next, the diluted solution was poured into 3000 parts of methanol to form a precipitate, and the precipitate was filtered to obtain a recovered solid. This recovered material was dried under reduced pressure to obtain a copolymer (6). Table 2 shows the charging composition, the Mw of the obtained bead-like copolymer, and the Tg of the polymer composed of comonomer (B) units.

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

[Examples 2-5, Comparative Examples 1-2]
A plate-shaped resin was prepared in the same manner as in Example 1, except that the types of copolymers to be blended with the (meth)acrylic polymer (Z-1) and their blending ratios were changed as shown in Table 3. A molded body and a rod-shaped resin molded body were obtained. Table 3 shows the evaluation results of the obtained resin moldings.

[Reference example 1]
A plate-shaped resin molded body and a rod-shaped resin molded body were obtained in the same manner as in Example 1 except that the copolymer was not blended and only the (meth)acrylic polymer (Z-1) was used. . Table 3 shows the evaluation results of the obtained resin moldings.

The resin molded bodies obtained in Examples 1 to 5 had good transparency, 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 copolymer had a mass average molecular weight of less than 200,000.
The resin molded article obtained in Reference Example 1 did not contain a copolymer and therefore had insufficient impact resistance compared to Examples 1 to 6.

As shown in Examples 1 to 5, the resin composition of the present invention has a total light transmittance of 90% or more, a Charpy impact test (no notch) of 35 kJ/m ² or more, and a bending elasticity of 2000 MPa or more. The resin molded body can be made into a resin molded body having a certain ratio. Generally, the impact resistance of a resin molded article tends to decrease as the elastic modulus improves, and there is a so-called trade-off relationship. That is, the resin molded article of the present invention is a resin molded article that has the remarkable property of achieving both contradictory properties, impact resistance and elastic modulus.

Claims (11)

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 in which the comonomer (B) contains an aromatic acrylate (B1).

However, 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, and 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. The copolymer according to claim 1, wherein the proportion of structural units derived from the macromonomer (A) to the total mass of the copolymer is 45% by mass or more and 99% by mass or less. The copolymer according to claim 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. containing groups derived from non-metallic chain transfer agents;
The copolymer according to any one of claims 1 to 3, wherein the proportion of the group derived from the nonmetallic chain transfer agent to the total mass of the copolymer is 0.01 to 0.5% by mass. . The macromonomer (A) has a structural unit derived from methyl methacrylate,
The copolymer according to any one of claims 1 to 4, wherein the proportion of the structural unit derived from methyl methacrylate to the total mass of the macromonomer (A) is 90% by mass or more. 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. The copolymer according to any one of claims 1 to 6, wherein the comonomer (B) comprises an alkyl acrylate (B2). The alkyl acrylate (B2) is 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. A resin composition comprising the copolymer according to any one of claims 1 to 8 and a (meth)acrylic polymer (Z). The (meth)acrylic polymer (Z) contains a structural unit derived from methyl methacrylate,
The resin composition according to claim 9, wherein the ratio of the structural unit derived from the methyl methacrylate to the total mass of the (meth)acrylic polymer (Z) is 80% by mass or more. A resin molded article formed by molding the resin composition according to claim 9 or 10.