KR102190057B1 - Copolymer and resin composition - Google Patents

Abstract

A copolymer having a polymer chain (A) having a unit derived from diene and/or olefin, and a polymer chain (B) having a unit derived from a (meth)acrylic monomer and a unit having a cyclic structure in the main chain, wherein the polymer chain ( In B), the (meth)acrylic acid ester-derived unit content ratio is 45% by mass or more and 98% by mass or less.

Description

Copolymer and resin composition

The present invention is a copolymer having a polymer chain having a unit derived from diene and/or olefin, a unit derived from a (meth)acrylic monomer and a polymer chain having a unit having a cyclic structure in the main chain, a resin composition comprising the copolymer , To an optical film formed therefrom, a polarizing plate, an image display device, and a method of manufacturing the copolymer.

Transparent resins are widely used in optical materials such as optical lenses, prisms, mirrors, optical disks, optical fibers, sheets for liquid crystal displays, films, and light guide plates. Conventionally, (meth)acrylic resins have been widely used as such transparent resins, but (meth)acrylic resins are sometimes difficult to achieve both heat resistance and mechanical strength. For example, (meth)acrylic resins can improve heat resistance while maintaining transparency by introducing a ring structure into the main chain (Patent Document 1, etc.), but by introducing a ring structure into the main chain, the resin itself is hard and It tends to become brittle and fragile, or to lower mechanical strength such as cutting-resistant steel during film processing. So, as a method of increasing the strength with a (meth)acrylic resin, Patent Document 2 discloses a method of imparting strength by biaxial stretching, and Patent Document 3 discloses a method of blending a flexible resin having a low glass transition temperature. It is disclosed. However, when the strength is imparted by biaxial stretching, there is a problem that anisotropy of the strength occurs due to the stretching ratio or the like. Moreover, when blending a flexible resin, compatibility with transparency was difficult, and there was room for improvement. Patent Document 4 discloses a copolymer in which a (meth)acrylic polymer is grafted onto a polyolefin, but since such a graft polymer has a low glass transition temperature and insufficient heat resistance, there is room for improvement. In addition, in the case of applying a transparent resin to an optical material, if the resin contains a gelled product, it is preferable that such a gelled product is not included because it causes foreign matter or poor appearance and leads to a decrease in manufacturing efficiency.

Japanese Patent Application Publication No. 2006-171464 Japanese Unexamined Patent Publication No. 2005-162835 Japanese Unexamined Patent Publication No. 2007-100044 Japanese Laid-Open Patent Publication H05-295183

The present invention has been made in consideration of the above circumstances, and the object thereof is a copolymer having excellent transparency, mechanical strength, and heat resistance, and having a balance of these, and having less gelation, and a resin composition containing the same, and It is to provide a method of manufacturing the coalescence.

The present invention includes the following inventions.

[1] A copolymer having a polymer chain (A) having a unit derived from a diene and/or olefin, and a polymer chain (B) having a unit derived from a (meth)acrylic monomer and a unit having a cyclic structure in the main chain,

The copolymer characterized in that the content ratio of the unit derived from the (meth)acrylic acid ester in the polymer chain (B) is 45% by mass or more and 98% by mass or less.

[2] The copolymer according to [1], wherein the polymer chain (B) is grafted onto the polymer chain (A).

[3] The copolymer according to [1] or [2], wherein the ring structure is a lactone ring structure and/or a maleimide structure.

[4] In any one of the above [1] to [3], in the polymer chain (B), the total content ratio of the unit derived from the (meth)acrylic monomer and the unit having a cyclic structure in the main chain is 90% by mass. Phosphorus copolymer.

[5] A resin composition comprising the copolymer according to any one of [1] to [4] and a (meth)acrylic polymer.

[6] The resin composition according to [5], wherein the (meth)acrylic polymer has a unit derived from the (meth)acrylic monomer.

[7] The resin composition according to [5] or [6], wherein the (meth)acrylic polymer has a unit having a ring structure in the main chain.

[8] The resin composition according to any one of [5] to [7], having a glass transition temperature of 100°C or more and less than 100°C, respectively.

[9] The resin composition according to any one of [5] to [8], wherein the insoluble content in chloroform is 10% by mass or less.

[10] An optical film comprising the copolymer according to any one of [1] to [4] or the resin composition according to any one of [5] to [9].

[11] A polarizing plate comprising the optical film according to [10].

[12] An image display device comprising the optical film according to [10].

[13] A method for producing a copolymer according to any one of [1] to [4],

A copolymer characterized by having a process of polymerizing a monomer component including a (meth)acrylic monomer and a monomer having a polymerizable double bond in the ring structure in the presence of a polymer (P1) having a unit derived from diene and/or olefin Method of manufacturing coalescence.

[14] A method for producing a copolymer according to any one of [1] to [4],

A step of polymerizing a monomer component containing a (meth)acrylic monomer in the presence of a polymer (P1) having a unit derived from diene and/or olefin, and

A method for producing a copolymer, comprising a step of forming a ring structure in a main chain of a polymer chain having units derived from a (meth)acrylic monomer formed in the polymerization step.

[15] The method for producing a copolymer according to [13], further comprising a step of filtering the resin solution obtained by the polymerization step.

[16] The method for producing a copolymer according to [14], further comprising a step of filtering the resin solution obtained by the step of forming a ring structure.

The copolymer of the present invention and the resin composition containing the same are excellent in transparency, mechanical strength, and heat resistance, have these in a balanced manner, and produce less gelatinous products. Further, according to the production method of the present invention, there is little generation of gelatinous products, excellent transparency, mechanical strength, and heat resistance, and a copolymer having these in a balanced manner can be obtained.

1. Copolymer]

The copolymer of the present invention has a diene or olefin polymer chain (A) and a (meth)acrylic polymer chain (B) having a ring structure. The copolymer of the present invention is excellent in transparency, mechanical strength (for example, impact strength, etc.), and heat resistance, and at the same time having these in a balanced manner, there is little generation of gelatinous products during production. Hereinafter, the copolymer of the present invention is referred to as "copolymer (P)".

The copolymer (P) has a structure in which a diene or olefin polymer chain (A) and a (meth)acrylic polymer chain (B) having a ring structure are copolymerized. Although the form of the copolymerization is not limited, it is preferably a graft polymer in which a (meth)acrylic polymer chain (B) having a ring structure is grafted to a diene or olefin polymer chain (A). Hereinafter, when the diene or olefin polymer chain (A) is simply referred to as ``polymer chain (A)'', and the (meth)acrylic polymer chain (B) having a ring structure is simply referred to as ``polymer chain (B)'' There is.

The (meth)acrylic polymer chain (B) having a ring structure usually provides a hard and soft resin, but by copolymerizing this with a diene or olefin-based polymer chain (A), and appropriately controlling the composition of the polymer chain (B), A copolymer (P) having both heat resistance and mechanical strength can be obtained. In addition, during production, it is possible to reduce the occurrence of gelatinous products. Although the copolymer (P) thus obtained has a diene or olefin component, it has high transparency. Further, even if the copolymer (P) is blended with a (meth)acrylic polymer, these properties are not impaired, and since it is excellent in dispersibility, transparency is not impaired.

When forming a film from the copolymer (P), a film having high strength and high heat resistance can be obtained without performing orientation treatment such as stretching treatment. Therefore, a film having desired optical properties can be easily obtained. For example, since it has high strength, high heat resistance, and high transparency, an isotropic film or a low phase difference film can be formed efficiently. On the other hand, since anisotropy can be easily expressed due to the ring structure, a retardation film can also be formed by orientation treatment such as stretching treatment. Moreover, when it is set as an optical film, it can be made into that there are few foreign matters and appearance defects.

The polymer chain (A) contained in the copolymer (P) will be described. The polymer chain (A) has at least a unit derived from diene and/or olefin. The unit derived from diene and/or olefin functions as a soft component in the copolymer (P). By including units derived from diene and/or olefin, while securing the transparency of the copolymer (P), the mechanical strength of the copolymer (for example, impact strength, etc.) is increased, and the hard-brittleness is reduced. I can make it.

As diene, 1,3-butadiene (alias: butadiene), 2-methyl-1,3-butadiene (alias: isoprene), 1,3-pentadiene, 1,4-pentadiene, 1,5-hexadiene, 2 Alkadiene, such as ,5-dimethyl-1,5-hexadiene (alias: diisobutene) is preferably used, and among them, 1,3-butadiene, 2-methyl-1,3-butadiene, and 1,3-penta Conjugated dienes such as dienes are more preferred. As the olefin, monoolefins such as ethylene, propylene, 1-butene, isobutylene, 2-methyl-1-butene, 3-methyl-1-butene, 1-tetradecene, and 1-octadecene are preferably used, and among them More preferred are α-olefins, which are alkenes in which the carbon-carbon double bond is at the α-position. The number of carbon atoms of these dienes and olefins is preferably 2 or more, more preferably 3 or more, more preferably 20 or less, more preferably 10 or less, and still more preferably 6 or less. Units derived from diene and/or olefin are defined as units formed by polymerization of these dienes and/or olefins. The olefin-derived unit is not limited to what is actually formed by (co) polymerization of the olefin, and may be formed by hydrogenation of the diene-derived unit.

The polymer chain (A) is, for example, an olefin (co)polymer such as polyethylene, polypropylene, polybutene-1, ethylene-propylene copolymer, and ethylene-butene copolymer; Diene (co)polymers such as polyisoprene, polybutadiene, and isoprene-butadiene copolymer; A copolymer of olefin and diene, such as an ethylene-propylene-diene copolymer and an isobutylene-isoprene copolymer, is contained in the structure of the main chain. The olefin (co)polymer is preferably an α-olefin (co)polymer, the diene (co)polymer is preferably a conjugated diene (co)polymer, and the olefin-diene copolymer is a copolymer of α-olefin and conjugated diene. desirable. Among these, copolymers of α-olefin and conjugated diene, such as polyisoprene and isobutylene-isoprene copolymer, and polyethylene and polypropylene are more preferable.

The polymer chain (A) may further have units derived from other unsaturated monomers in addition to units derived from diene and/or olefin. The other unsaturated monomer is not particularly limited as long as it is a compound having a polymerizable double bond, and examples thereof include vinyl esters such as vinyl acetate and vinyl propionate; Unsaturated carboxylic acids such as (meth)acrylic acid, maleic anhydride, methyl (meth)acrylate, and ethyl (meth)acrylate, and esters thereof; Aromatic vinyl compounds such as styrene, vinyltoluene, methoxystyrene, α-methylstyrene, and 2-vinylpyridine; And vinyl silanes such as vinyl trimethoxysilane and γ-(meth)acryloyloxypropylmethoxysilane. The polymer chain (A) may be a copolymer of these other unsaturated monomers and diene and/or olefin. The content ratio of units derived from diene and/or olefin in the polymer chain (A) is, for example, preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, and 55% by mass The above is still more preferable, 90 mass% or less is preferable, 86 mass% or less is more preferable, and 83 mass% or less is still more preferable.

When the polymer chain (A) has units derived from other unsaturated monomers, the polymer chain (A) may be a random copolymer of diene and/or olefin with other unsaturated monomers, may be a block copolymer, or may be a graft polymer. May be. Among these, it is preferable that it is a block copolymer from the point that the function as a unit soft component derived from a diene and/or olefin is suitably expressed. In this case, the polymer chain (A) has a polymer block (a1) having units derived from diene and/or olefin and a polymer block (a2) having units derived from other unsaturated monomers.

When the polymer chain (A) has a polymer block (a2) having units derived from other unsaturated monomers, since it is easy to increase transparency while securing the mechanical strength of the copolymer (P), the polymer block (a2) Silver is preferably composed of units derived from aromatic vinyl monomers. In this case, in the polymer chain (A), the polymer block (a1) functions as a soft component, and the polymer block (a2) functions as a hard component.

The aromatic vinyl monomer providing the polymer block (a2) is not particularly limited as long as it is a compound in which a vinyl group is bonded to an aromatic ring, and for example, styrene, vinyltoluene, methoxystyrene, α-methylstyrene, α-hydroxymethylstyrene and styrene-based monomers such as α-hydroxyethyl styrene; Polycyclic aromatic hydrocarbon-cyclic vinyl monomers such as 2-vinylnaphthalene; And aromatic heterocyclic vinyl monomers such as N-vinylcarbazole, 2-vinylpyridine, vinylimidazole, and vinylthiophene. Among these, a styrenic monomer is preferable. The styrene-based monomer includes not only styrene, but also a styrene derivative in which an arbitrary substituent is bonded to a polymerizable double-bonded carbon of styrene or a benzene ring, and examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, a halogen group, an amino group, a nitro group, Sulfo group, etc. are mentioned. The alkyl group and alkoxy group bonded to styrene preferably have 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and the alkyl group and alkoxy group bonded to styrene may be substituted with a hydroxyl group or a halogen group at least a part of the hydrogen atoms.

Examples of the polymer chain (A) having a polymer block (a1) having a unit derived from diene and/or olefin and a polymer block (a2) having a unit derived from an aromatic vinyl monomer include styrene-butadiene block copolymer, styrene -Butadiene-styrene block copolymer, hydrogenated product of styrene-butadiene-styrene block copolymer (e.g., styrene-ethylene/butylene-styrene block copolymer, styrene-butadiene/butylene-styrene block copolymer), styrene -Isoprene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenated products of styrene-isoprene-styrene block copolymer (for example, styrene-ethylene/propylene-styrene block copolymer), and the like.

When the polymer chain (A) has a polymer block (a1) having units derived from diene and/or olefin, and a polymer block (a2) having units derived from an aromatic vinyl monomer, the polymer chain (A) has a polymer block (a1) It is preferable that the polymer block (a2) is bonded to both sides of ). By constituting the polymer chain (A) in this way, the polymer chain (A) functions as an elastomer, and the mechanical strength of the copolymer can be increased. In this case, the polymer chain (A) may be a triblock copolymer, a multiblock copolymer, or a radial block copolymer, but it is easy to control the properties of the polymer chain (A), and the copolymer ( It is preferably a triblock copolymer from the viewpoint of easy introduction of the polymer chain (B) into P).

When the polymer chain (A) has a polymer block (a1) having units derived from diene and/or olefin and a polymer block (a2) having units derived from aromatic vinyl monomers, the polymer block (a1) is diene and/or In addition to the units derived from olefins, you may further have units derived from other unsaturated monomers. Examples of other unsaturated monomers in this case include vinyl esters such as vinyl acetate and vinyl propionate; Unsaturated carboxylic acids such as (meth)acrylic acid, maleic anhydride, methyl (meth)acrylate, and ethyl (meth)acrylate, and esters thereof; Aromatic vinyl compounds such as styrene, vinyltoluene, methoxystyrene, α-methylstyrene, and 2-vinylpyridine; And vinyl silanes such as vinyl trimethoxysilane and γ-(meth)acryloyloxypropylmethoxysilane. The polymer block (a1) may be a copolymer of these other unsaturated monomers and diene and/or olefin. In addition, the polymer block (a1) preferably contains a unit derived from diene and/or olefin as a main component, and the content ratio of the unit derived from diene and/or olefin in 100% by mass of the polymer block (a1) is 50% by mass or more. It is preferable, 60 mass% or more is more preferable, and 70 mass% or more is still more preferable. The polymer block (a1) may consist of substantially only units derived from diene and/or olefin, and for example, units derived from diene and/or olefin may be 99% by mass or more.

When the polymer chain (A) has a polymer block (a1) having units derived from diene and/or olefin and a polymer block (a2) having units derived from an aromatic vinyl monomer, the polymer block (a2) is derived from an aromatic vinyl monomer In addition to the unit of, it may further have a unit derived from another unsaturated monomer. Examples of other unsaturated monomers in this case include vinyl esters such as vinyl acetate and vinyl propionate; Unsaturated carboxylic acids such as (meth)acrylic acid, maleic anhydride, methyl (meth)acrylate, and ethyl (meth)acrylate, and esters thereof; Aromatic vinyl compounds such as styrene, vinyltoluene, methoxystyrene, α-methylstyrene, and 2-vinylpyridine; And vinyl silanes such as vinyl trimethoxysilane and γ-(meth)acryloyloxypropylmethoxysilane. The polymer block (a2) may be a copolymer of these other unsaturated monomers and aromatic vinyl monomers. In addition, it is preferable that the polymer block (a2) contains as a main component a unit derived from an aromatic vinyl monomer, and in 100% by mass of the polymer block (a2), the content ratio of the unit derived from the aromatic vinyl monomer is preferably 70% by mass or more, 80 mass% or more is more preferable, and 90 mass% or more is still more preferable. The polymer block (a2) may consist of substantially only units derived from an aromatic vinyl monomer, and for example, the unit derived from an aromatic vinyl monomer may be 99% by mass or more.

In the polymer chain (A), the content ratio of the polymer block (a2) is preferably 10% by mass or more, more preferably 14% by mass or more, even more preferably 17% by mass or more, and further preferably 55% by mass or less, , 50 mass% or less is more preferable, and 45 mass% or less is still more preferable. Thereby, the polymer chain (A) has a soft component and a hard component in balance, and it becomes easy to improve transparency while securing the mechanical strength of the copolymer (P). From the same viewpoint, in the polymer chain (A), the content ratio of the polymer block (a1) is preferably 45% by mass or more, more preferably 50% by mass or more, further preferably 55% by mass or more, and further 90% by mass The following are preferable, 86 mass% or less are more preferable, and 83 mass% or less are still more preferable.

The weight average molecular weight of the polymer chain (A) is preferably 0.1 million or more, more preferably 0.5 million or more, more preferably 10,000 or more, even more preferably 30,000 or more, and 500,000 or less is preferable, 300,000 or less are more preferable, 200,000 or less are still more preferable, and 100,000 or less are still more preferable. By setting the weight average molecular weight of the polymer chain (A) into such a range, it becomes easy to secure the strength and transparency of the copolymer (P).

The polymer chain (B) contained in the copolymer (P) will be described. The polymer chain (B) has at least a unit derived from a (meth)acrylic monomer and has a ring structure. It is preferable that the polymer chain (B) is grafted onto the polymer chain (A), and therefore, the copolymer (P) is a graft polymer, and it is preferable that the polymer chain (B) has a polymer chain (B) as the graft chain of the graft polymer. The transparency of the copolymer (P) can be improved by the polymer chain (B).

The unit derived from the (meth)acrylic monomer of the polymer chain (B) (hereinafter sometimes referred to as ``(meth)acrylic unit'') can be introduced into the polymer chain (B) by polymerizing the (meth)acrylic monomer. have. The (meth)acrylic monomer includes (meth)acrylic acid and its derivatives, and an alkyl group (preferably, an alkyl group having 1 to 4 carbon atoms) may be bonded to the α-position or the β-position of the (meth)acrylic monomer, At least a part of the hydrogen atom in the alkyl group may be substituted with a hydroxyl group or a halogen group. The form of the carboxylic acid contained in the unit derived from the (meth)acrylic monomer is not particularly limited, and forms such as free acid, ester, salt, and acid amide may be mentioned.

The polymer chain (B) has at least a unit derived from a (meth)acrylic acid ester as a (meth)acrylic unit. Examples of (meth)acrylic acid esters that provide units derived from (meth)acrylic acid esters include (meth)acrylic acid esters in which a linear, branched or cyclic aliphatic hydrocarbon group or aromatic hydrocarbon group is bonded to the ester-linked oxygen atom of (meth)acrylic acid. I can.

Examples of (meth)acrylic acid esters having a linear or branched aliphatic hydrocarbon group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and n-butyl (meth)acrylate. , Isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate , 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, ( Alkyl (meth)acrylates, such as heptadecyl meth)acrylate and octadecyl (meth)acrylate, are mentioned. The alkyl group of the alkyl (meth)acrylate is preferably a C1-18 alkyl group, and more preferably a C1-12 alkyl group. In addition, in this specification, description of "C1-18" and "C1-12" means "carbon number 1 to 18" and "carbon number 1 to 12", respectively.

Examples of the (meth)acrylic acid ester having a cyclic aliphatic hydrocarbon group include (meth)acrylic acid cycloalkyl such as cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, and cyclohexyl (meth)acrylate; Crosslinked cyclic (meth)acrylates, such as isobornyl (meth)acrylate, etc. are mentioned. The cycloalkyl group of cycloalkyl (meth)acrylate is preferably a C3-20 cycloalkyl group, and more preferably a C3-12 cycloalkyl group.

Examples of (meth)acrylic acid esters having an aromatic hydrocarbon group include phenyl (meth)acrylate, tolyl (meth)acrylate, xylyl (meth)acrylate, naphthyl (meth)acrylate, binaphthyl (meth)acrylate, and anthryl (meth)acrylate. Aryl (meth)acrylates such as; Aralkyl (meth)acrylates, such as benzyl (meth)acrylate; Aryloxyalkyl (meth)acrylates, such as phenoxyethyl (meth)acrylate, etc. are mentioned. The aryl group of the aryl (meth)acrylate is preferably a C6-20 aryl group, and more preferably a C6-14 aryl group. The aralkyl group of the aralkyl (meth)acrylate is preferably a C6-10 aryl C1-4 alkyl group. The aryloxy alkyl group of the aryloxyalkyl (meth)acrylate is preferably a C6-10 aryloxy C1-4 alkyl group, and more preferably a phenoxy C1-4 alkyl group.

The (meth)acrylic acid ester may have a substituent such as a hydroxyl group, a halogen group, an alkoxy group, or an epoxy group. Examples of such (meth)acrylic acid esters include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate; Halogenated alkyl (meth)acrylates such as chloromethyl (meth)acrylate and 2-chloroethyl (meth)acrylate; (Meth)acrylate alkoxy alcohols such as 2-methoxyethyl (meth)acrylate; Epoxyalkyl (meth)acrylates, such as glycidyl (meth)acrylate, etc. are mentioned. The alkyl group of hydroxyalkyl (meth)acrylate and epoxyalkyl (meth)acrylate is preferably a C1-12 alkyl group. The alkoxyalkyl group of the (meth)acrylic acid alkoxy alcohol is preferably a C1-12 alkoxy C1-12 alkyl group.

In addition to the (meth)acrylic unit, the polymer chain (B) has a unit having a ring structure in the main chain (hereinafter, sometimes referred to as a "ring structural unit"). When the polymer chain (B) has a ring structure in the main chain, the heat resistance of the copolymer (P) can be improved. In addition, improvement in solvent resistance, surface hardness, adhesiveness, oxygen and water vapor barrier properties, and various optical properties can be expected. Moreover, when the copolymer (P) or the resin composition containing this is used as a film or a sheet, dimensional stability and shape stability under high temperature and high humidity conditions can be improved. By stretching the film thus formed, a large retardation can be expressed derived from the ring structure of the polymer chain (B), and application as a retardation film becomes possible. This feature makes it possible to apply the copolymer (P) or a resin composition containing the same to an optical film such as a retardation film or a polarizer protective film having a function of a retardation film.

The ring structure of the main chain of the polymer chain (B) may contain part or all of the (meth)acrylic monomer in the ring structure, or may be a ring structure introduced separately from the (meth)acrylic monomer. When some or all of the (meth)acrylic monomers are included in the ring structure, for example, two carboxylic acid groups derived from adjacent (meth)acrylic monomers can be connected by acid anhydration, imidation, or the like. In addition, when one of the units derived from the adjacent (meth)acrylic monomer has a protic hydrogen atom-containing group such as a hydroxyl group or an amino group, the unit protonic hydrogen atom-containing group derived from the (meth)acrylic monomer and the other A ring structure can also be formed by condensation of the unit carboxylic acid group derived from the (meth)acrylic monomer. When the ring structure is introduced separately from the unit derived from the (meth)acrylic monomer, for example, a (meth)acrylic monomer and a monomer having a polymerizable double bond in the ring structure can be copolymerized.

The ring structure may be any of a 4-membered ring structure, a 5-membered ring structure, a 6-membered ring structure, a 7-membered ring structure, an 8-membered ring structure, and the like, preferably a 5-membered ring structure or a 6-membered ring structure.

As a ring structure, from the viewpoint of heat resistance of the copolymer (P), a lactone ring structure, a cyclic imide structure (for example, a maleimide structure, a glutalimide structure, etc.), a cyclic anhydride structure (for example, a maleic anhydride structure) , Glutaric anhydride structure, etc.) etc. are mentioned preferably. These ring structures may contain only one type in the main chain of the polymer chain (B), or may contain two or more types. Among these, at least one selected from a lactone ring structure, a maleimide structure, a maleic anhydride structure, a glutalimide structure, and a glutaric anhydride structure is preferable.

When the polymer chain (B) has a lactone ring structure as a ring structure of the main chain, the number of reductions of the lactone ring structure is not particularly limited, and may be, for example, any one of a 4-membered ring to an 8-membered ring. Further, from the viewpoint of excellent stability of the ring structure, the lactone ring structure is preferably a 5-membered ring or a 6-membered ring, and more preferably a 6-membered ring.

Examples of the lactone ring structure include structures disclosed in Japanese Patent Laid-Open No. 2004-168882, for example, but the easy introduction of the lactone ring structure, specifically, the polymerization yield of the precursor (polymer before lactone cyclization) is The structure of the following formula (1) from reasons such as high, the lactone ring content in the cyclization condensation reaction of the precursor, and the fact that a polymer having a unit derived from (meth)acrylate can be used as a precursor. Is preferably presented. In the following formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent.

Examples of the substituents for R ¹ , R ² and R ^{3 in} the formula (1) include organic residues such as hydrocarbon groups, and examples thereof include a C1-20 hydrocarbon group that may contain an oxygen atom. Examples of the hydrocarbon group include saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon groups and aromatic hydrocarbon groups. Examples of the aliphatic hydrocarbon group include C1-20 alkyl groups such as methyl group, ethyl group, n-propyl group and isopropyl group; C2-20 alkenyl groups such as ethenyl group and propenyl group; C3-20 cycloalkyl groups, such as a cyclopentyl group and a cyclohexyl group, etc. are mentioned. Examples of the aromatic hydrocarbon group include C6-20 aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, and biphenyl group; C7-20 aralkyl groups, such as a benzyl group and a phenylethyl group, etc. are mentioned. These hydrocarbon groups may contain oxygen atoms, and specifically, one or more hydrogen atoms of the hydrocarbon group may be substituted by at least one group selected from hydroxyl group, carboxyl group, ether group and ester group. have.

The lactone ring structure cyclizes, for example, a unit ester group derived from an adjacent (meth)acrylic acid ester, and a unit protonic hydrogen atom-containing group derived from a (meth)acrylic monomer having a protic hydrogen atom-containing group such as a hydroxyl group or an amino group. By condensing, it can be introduced into the polymer chain (B).

In the lactone ring structure of formula (1), since it is easy to obtain a copolymer (P) having excellent heat resistance and a small birefringence, R ¹ and R ² are each independently a hydrogen atom or a C 1-20 alkyl group, R ³ is preferably a hydrogen atom or a methyl group, R ¹ and R ² are each independently a hydrogen atom or a methyl group, and R ³ is more preferably a hydrogen atom or a methyl group.

The lactone ring structure is, for example, polymerized (preferably copolymerized) with a (meth)acrylic monomer (A) having a hydroxy group and a (meth)acrylic monomer (B) to form a hydroxyl group, an ester group, or a carboxyl group in the molecular chain. After introduction, it can be formed by causing dealcoholization or dehydration cyclization condensation between these hydroxy groups and ester groups or carboxyl groups. The (meth)acrylic monomer (A) having a hydroxy group as a polymerization component is essential, and the (meth)acrylic monomer (B) contains the above monomer (A). The monomer (B) may or may not coincide with the monomer (A). When the monomer (B) matches the monomer (A), the monomer (A) is homopolymerized.

Examples of the (meth)acrylic monomer (A) having a hydroxyl group include 2-(hydroxymethyl)acrylic acid, 2-(hydroxyethyl)acrylic acid, and 2-(hydroxymethyl)acrylate alkyl (e.g., 2-(hydroxy Methyl) methyl acrylate, 2-(hydroxymethyl) ethyl acrylate, 2-(hydroxymethyl) isopropyl acrylate, 2-(hydroxymethyl) n-butyl acrylate, 2-(hydroxymethyl) t-butyl acrylate) , 2-(hydroxyethyl) alkyl acrylate (e.g., 2-(hydroxyethyl) methyl acrylate, 2-(hydroxyethyl) ethyl acrylate), and the like, preferably, a hydroxy allyl moiety The branching monomers include 2-(hydroxymethyl)acrylic acid and alkyl 2-(hydroxymethyl)acrylate. Particularly preferably, 2-(hydroxymethyl) methyl acrylate and 2-(hydroxymethyl) ethyl acrylate are shown.

As the (meth)acrylic monomer (B), a monomer having a vinyl group, an ester group or a carboxyl group is preferable. For example, (meth)acrylic acid, alkyl (meth)acrylate (e.g., methyl (meth)acrylate, (meth) Ethyl acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, cyclohexyl (meth)acrylate, etc.), aryl (meth)acrylate (e.g., phenyl (meth)acrylate , Benzyl (meth)acrylate), 2-(hydroxyalkyl) alkyl acrylate (eg, 2-(hydroxymethyl) methyl acrylate, 2-(hydroxymethyl) such as ethyl 2-(hydroxymethyl) acrylate ) Alkyl acrylate, 2-(hydroxyethyl) alkyl acrylate, such as 2-(hydroxyethyl) methyl acrylate), etc. are mentioned.

The polymer chain (B) may have only one lactone ring structure of formula (1), or may have two or more.

When the polymer chain (B) has a maleic anhydride structure or a maleimide structure as the ring structure of the main chain, the structure of the following formula (2) is preferably shown as the maleic anhydride structure or maleimide structure. In the following formula (2), R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group, R ⁶ represents a hydrogen atom or a substituent, X ¹ represents an oxygen atom or a nitrogen atom, and X ¹ represents an oxygen atom. When n1 = 0, when X ¹ is a nitrogen atom, n1 = 1.

Examples of the substituent for R ⁶ in formula (2) include a hydrocarbon group and the like, and examples thereof include a C1-20 hydrocarbon group which may have a substituent such as halogen. Examples of the hydrocarbon group include saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon groups and aromatic hydrocarbon groups. Examples of the aliphatic hydrocarbon group include C1-6 alkyl groups such as methyl group, ethyl group, n-propyl group and isopropyl group; C2-6 alkenyl groups such as ethenyl group and propenyl group; C3-20 cycloalkyl groups, such as a cyclopentyl group and a cyclohexyl group, etc. are mentioned. Examples of the aromatic hydrocarbon group include C6-20 aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, and biphenyl group; C7-20 aralkyl groups, such as a benzyl group and a phenyl ethyl group, etc. are mentioned. These hydrocarbon groups may have a substituent such as halogen.

When X ¹ is an oxygen atom, the ring structure of formula (2) becomes a maleic anhydride structure. The maleic anhydride structure can be introduced into the polymer chain (B), for example, by copolymerizing maleic anhydride and a (meth)acrylic monomer (eg, (meth)acrylic acid ester).

When X ¹ is a nitrogen atom, the ring structure of formula (2) becomes a maleimide structure. The maleimide structure can be introduced into the polymer chain (B), for example, by copolymerizing maleimide and a (meth)acrylic monomer (eg, (meth)acrylic acid ester). As the maleimide structure, for example, the N-position is unsubstituted maleimide structure, N-methylmaleimide structure, N-ethylmaleimide structure, N-cyclohexylmaleimide structure, N-phenylmaleimide structure, N-naph A tylmaleimide structure, an N-benzylmaleimide structure, and the like. In addition, as maleimide providing a maleimide structure, the N-position is unsubstituted maleimide, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-naphthylmaleimide. Mid, N-benzyl maleimide, etc. can be used.

When the polymer chain (B) has a maleimide structure in which X ¹ is a nitrogen atom, since it is easy to obtain a copolymer (P) having excellent heat resistance and a small birefringence, R ⁴ and R ⁵ are hydrogen atoms, and R ⁶ Is preferably a C3-20 cycloalkyl group or a C6-20 aromatic group (aryl group, aralkyl group, etc.), R ⁴ and R ⁵ are hydrogen atoms, and R ⁶ is more preferably a cyclohexyl group or a phenyl group.

The polymer chain (B) may have only one ring structure of formula (2), or may have two or more types.

When the polymer chain (B) has a glutalimide structure or a glutaric anhydride structure as the ring structure of the main chain, the structure of the following formula (3) is preferably shown as the glutalimide structure or glutaric anhydride structure. In the following formula (3), R ⁷ and R ⁸ each independently represent a hydrogen atom or an alkyl group, R ⁹ represents a hydrogen atom or a substituent, X ² represents an oxygen atom or a nitrogen atom, and X ² represents an oxygen atom. When n2 = 0, when X ² is a nitrogen atom, n2 = 1.

In formula (3), as the alkyl group of R ⁷ and R ⁸ , a linear or branched alkyl group is preferably exemplified. For example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, C1- such as isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, n-hexyl group, isohexyl group, n-heptyl group, isoheptyl group, n-octyl group, 2-ethylhexyl group, etc. 8 alkyl groups, etc. are mentioned. In addition, since it is excellent in heat resistance and it is easy to obtain a copolymer (P) having a small birefringence, R ⁷ and R ⁸ are each independently preferably a hydrogen atom or a C1-4 alkyl group, more preferably a hydrogen atom or a methyl group. .

Examples of the substituent for R ⁹ in formula (3) include a hydrocarbon group and the like, and examples thereof include a C1-20 hydrocarbon group which may have a substituent such as halogen. Examples of the hydrocarbon group include saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon groups and aromatic hydrocarbon groups. As an aliphatic hydrocarbon group, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, n-hexyl group, iso C1-10 alkyl groups such as hexyl group, n-heptyl group, isoheptyl group, n-octyl group, and 2-ethylhexyl group; C2-10 alkenyl groups such as ethenyl group and propenyl group; C3-12 cycloalkyl groups, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group, etc. are mentioned. Examples of the aromatic hydrocarbon group include C6-20 aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, biphenyl group, binaphthyl group, and anthryl group; C7-20 aralkyl groups, such as a benzyl group and a phenylethyl group, etc. are mentioned. These hydrocarbon groups may have a substituent such as halogen. Among these, R ⁹ is a C1-4 alkyl group, a C3-7 cycloalkyl group, a C6-20 aryl group, or a C7-20 aralkyl group in that it is easy to obtain a copolymer (P) having excellent heat resistance and a small birefringence. It is preferably a methyl group, a cyclohexyl group, a phenyl group, or a tolyl group.

When X ² is an oxygen atom, the ring structure of formula (3) becomes a glutaric anhydride structure. The glutaric anhydride structure can be introduced into the polymer chain (B), for example, by acid anhydrating the carboxylic acid groups of two units derived from adjacent (meth)acrylic monomers.

When X ² is a nitrogen atom, the ring structure of formula (3) becomes a glutalimide structure. The glutalimide structure is, for example, imidized with carboxylic acid groups of two units derived from adjacent (meth)acrylic monomers, or unit amide groups derived from adjacent (meth)acrylic acid amides and unit ester groups derived from (meth)acrylic acid esters. It can be introduced into the polymer chain (B) by cyclization condensation.

In the ring structure of formula (3), since it is easy to obtain a copolymer (P) having excellent heat resistance and a small birefringence, R ⁷ and R ⁸ are each independently a hydrogen atom or a methyl group, and R ⁹ is C1- It is preferably a 10 alkyl group, a C3-12 cycloalkyl group, or a C6-20 aromatic group, R ⁷ and R ⁸ are each independently a hydrogen atom or a methyl group, and R ⁹ is a C1-4 alkyl group, a C3-7 cycloalkyl group, a C6- It is more preferable that it is a 20 aryl group or a C7-20 aralkyl group, R ⁷ and R ⁸ are each independently a hydrogen atom or a methyl group, and R ⁹ is more preferably a methyl group, a cyclohexyl group, a phenyl group, or a tolyl group, It is particularly preferable that R ⁷ and R ⁸ are each independently a hydrogen atom or a methyl group, and R ⁹ is a cyclohexyl group or a phenyl group.

The polymer chain (B) may have only one ring structure of formula (3), or may have two or more types.

Among the cyclic structures described above, when a resin composition containing the copolymer (P) is applied to an optical film, from the viewpoint of imparting good surface hardness, solvent resistance, adhesion, barrier properties, and optical properties, the polymer chain (B It is preferable that the ring structural unit of) contains a lactone ring structure and/or a maleimide structure. When the optical film is a retardation film, a positive retardation can be provided, and from the viewpoint of excellent stability of the retardation characteristic, it is more preferable that the ring structural unit of the polymer chain (B) includes a lactone ring structure.

The polymer chain (B) may further have units derived from other unsaturated monomers. The other unsaturated monomer is not particularly limited as long as it is a compound having a polymerizable double bond, and examples thereof include vinyl esters such as vinyl acetate and vinyl propionate; Aromatic vinyl compounds such as styrene, vinyltoluene, methoxystyrene, α-methylstyrene, and 2-vinylpyridine; And vinyl silanes such as vinyl trimethoxysilane and γ-(meth)acryloyloxypropylmethoxysilane. For example, when the polymer chain (B) has a unit derived from an aromatic vinyl monomer, it becomes easy to adjust the refractive index and retardation characteristics of the copolymer (P). For details of the aromatic vinyl monomer, reference is made to the description of the aromatic vinyl monomer of the polymer block (a2). In addition, when the polymer chain (B) is formed from two or more types of monomer components, it is preferable that the polymer chain (B) is a random copolymer.

The copolymer (P) has a unit content ratio of 45% by mass or more and 98% by mass or less in the polymer chain (B). If the content ratio of the unit derived from the (meth)acrylic acid ester in the polymer chain (B) is 45% by mass or more, the generation of gelatinous products can be suppressed when the polymer chain (B) is polymerized and formed, and the copolymer (P) is optically It becomes easy to use suitably for a purpose. Moreover, the mechanical strength of the copolymer (P) also becomes easy to increase. When the content ratio of the unit derived from the (meth)acrylic acid ester in the polymer chain (B) is 98% by mass or less, the copolymer (P) excellent in heat resistance can be obtained. The content ratio of the unit derived from the (meth)acrylic acid ester in the polymer chain (B) is preferably 50% by mass or more, more preferably 55% by mass or more, further preferably 60% by mass or more, and 97% by mass or less. Do.

The content ratio of the cyclic structural unit in the polymer chain (B) is preferably 2% by mass or more, more preferably 3% by mass or more, more preferably 5% by mass or more, and preferably 50% by mass or less, and 45% by mass % Or less is more preferable, and 40 mass% or less is still more preferable. By adjusting the content ratio of the cyclic structural unit in this way, it becomes easy to balance both the heat resistance and mechanical strength of the copolymer (P). In addition, the content ratio of the cyclic structural unit described herein refers to the content of the unit having a cyclic structure contained in the main chain of the polymer chain (B), for example, the content of the structures of formulas (1) to (3) above. Means the ratio.

As for the polymer chain (B), 90 mass% or more is preferable, 93 mass% or more is more preferable, and 95 mass% or more is still more preferable in the total content ratio of a (meth)acrylic unit and a cyclic structural unit. Thereby, it becomes easy to improve the transparency and heat resistance of the copolymer (P). Further, it is preferable that the total content ratio of the unit derived from the (meth)acrylic acid ester and the cyclic structural unit is in such a range.

It is preferable that the polymer chain (B) is grafted to the polymer chain (A). The polymer chain (B) may be bonded to a unit derived from the diene and/or olefin of the polymer chain (A), or may be bonded to a unit other than the unit derived from the diene and/or olefin of the polymer chain (A). have. In the former case, the polymer chain (B) may be directly bonded to a unit derived from the diene and/or olefin of the polymer chain (A), or may be bonded through a linking group.

When the polymer chain (B) is directly bonded to a unit derived from the diene and/or olefin of the polymer chain (A), the polymer chain (B) is a (meth)acrylic unit or a cyclic structural unit that is a diene of the polymer chain (A) and / Or it is preferable to bond directly to the unit derived from an olefin. The polymer chain (B) may be bonded to a unit main chain carbon atom derived from diene and/or olefin, or may be bonded to a carbon atom of a hydrocarbon group bonded to the main chain as a substituent (side chain). When the polymer chain (B) is bonded to the polymer chain (A) in this way, it becomes easier to obtain a copolymer (P) with little gelatinization.

When the polymer chain (B) is bonded to a unit derived from the diene and/or olefin of the polymer chain (A) through a linking group, the linking group is an ester bond (-CO-O-), a urethane bond (-NH-CO-O It is preferable to have at least one selected from -) and an ether bond (-O-), and the linking group may further have a divalent organic group such as a methylene group or a hydroxymethylene group.

When the polymer chain (B) is bonded to a unit other than a unit derived from the diene and/or olefin of the polymer chain (A), for example, a unit in which the polymer chain (A) has a polymerizable functional group (polymerizable double bond) And, the polymer chain (B) is bonded to the polymerizable functional group of the unit, or the polymer chain (A) is an ester bond (-CO-O-), a urethane bond (-NH) in addition to a unit derived from a diene and/or olefin. The polymer chain (B) may be bonded through a linking group such as -CO-O-) ether bond (-O-). The linking group may further have a divalent organic group such as a methylene group or a hydroxymethylene group.

Each form in which the polymer chain (B) described above is grafted onto the polymer chain (A) will be described in detail in the following description of the method for producing the copolymer (P).

The content ratio of the cyclic structural unit in the copolymer (P) is not particularly limited, but the content ratio of the cyclic structural unit in the copolymer (P) is preferably 1% by mass or more, and 3% by mass or more. More preferably, 5 mass% or more is still more preferable, 60 mass% or less is preferable, 50 mass% or less is more preferable, and 40 mass% or less is still more preferable. By adjusting the content ratio of the cyclic structural unit in the copolymer (P) in this way, it becomes easy to balance the heat resistance, transparency, moldability, mechanical strength, and the like of the copolymer (P).

When the copolymer (P) has a lactone ring structure as the cyclic structural unit of the polymer chain (B), from the viewpoint of enhancing the heat resistance and transparency of the copolymer (P), the content ratio of the lactone ring structure in the copolymer (P) is , For example, 1 mass% or more is preferable, 3 mass% or more is more preferable, 5 mass% or more is more preferable, 60 mass% or less is preferable, 50 mass% or less is more preferable, 40 mass% % Or less is more preferable. From the same point of view, when the copolymer (P) has a maleic anhydride structure and/or a maleimide structure as the cyclic structural unit of the polymer chain (B), the content ratio of these cyclic structures in the copolymer (P) is For example, 1 mass% or more is preferable, 3 mass% or more is more preferable, 5 mass% or more is more preferable, 60 mass% or less is preferable, 50 mass% or less is more preferable, 40 mass% or less Is more preferred. When the copolymer (P) has a glutalimide structure and/or a glutaric anhydride structure as the cyclic structural unit of the polymer chain (B), the content ratio of these cyclic structures in the copolymer (P) is, for example, For example, 1 mass% or more is preferable, 3 mass% or more is more preferable, 5 mass% or more is more preferable, 60 mass% or less is preferable, 50 mass% or less is more preferable, 40 mass% or less is More preferable.

The weight average molecular weight of the copolymer (P) is preferably 0.2 million or more, more preferably 0.5 million or more, more preferably 30,000 or more, even more preferably 50,000 or more, particularly preferably 70,000 or more, Moreover, 1 million or less are preferable, 500,000 or less are more preferable, 300,000 or less are still more preferable, and 200,000 or less are still more preferable. By setting the weight average molecular weight of the copolymer (P) in such a range, the molding processability of the copolymer (P) is improved, and the strength of the obtained molded article is easily increased.

The weight average molecular weight of the copolymer (P) is preferably 1.1 times or more, more preferably 1.2 times or more, more preferably 1.3 times or more, and 20 times or less to the weight average molecular weight of the polymer chain (A). , 12 times or less is more preferable, 10 times or less is still more preferable, 7 times or less is even more preferable, and 5 times or less is particularly preferable. Thereby, it becomes easy to provide the copolymer (P) with each characteristic of transparency, mechanical strength, and heat resistance in a balance.

The refractive index of the copolymer (P) is preferably a value close to the refractive index of the polymer chain (A), whereby it becomes easy to secure the transparency of the copolymer (P). Specifically, the difference between the refractive index of the copolymer (P) and the refractive index of the polymer chain (A) is preferably less than 0.1, more preferably 0.05 or less, and even more preferably 0.02 or less. From the same point of view, the refractive index of the polymer chain (A) and the refractive index of the polymer chain (B) in the copolymer (P) are preferably close to each other, and specifically, the difference between the refractive index of the polymer chain (A) and the polymer chain (B) Is preferably less than 0.1, more preferably 0.05 or less, and even more preferably 0.02 or less.

It is preferable that the copolymer (P) has a glass transition temperature of 100°C or more and less than 100°C, respectively. Further, a glass transition temperature of 100°C or higher is referred to as a "glass transition temperature on the high temperature side", and a glass transition temperature of less than 100°C is referred to as a "glass transition temperature on the low temperature side". The copolymer (P) may have a plurality of glass transition temperatures on the high-temperature side, or may have a plurality of glass transition temperatures on the low-temperature side. Because the copolymer (P) has a glass transition temperature on the high-temperature side, the heat resistance of the copolymer (P) increases, and when the copolymer (P) is formed into a film, it does not soften even under high temperature, and molding processability Can increase. Since the copolymer (P) has a glass transition temperature on the low-temperature side, the impact resistance of the copolymer (P) can be improved. The glass transition temperature on the high temperature side of the copolymer (P) is preferably 113°C or higher, more preferably 116°C or higher, and still more preferably 120°C or higher. The glass transition temperature on the low-temperature side of the copolymer (P) is preferably less than 50°C, more preferably less than 20°C, more preferably less than 0°C, and even more preferably less than -20°C. .

The copolymer (P) can be produced by addition polymerization of a monomer component forming the polymer chain (B) on the polymer chain (A). Therefore, the method of preparing the copolymer (P) is to polymerize a monomer component including a (meth)acrylic monomer in the presence of a polymer having a unit derived from diene and/or olefin (hereinafter referred to as ``raw polymer (P1)''). It is preferable to have a step (polymerization step) to perform, and thereby, a monomer component containing a (meth)acrylic monomer can be subjected to addition polymerization to the raw material polymer (P1). In this case, the monomer component containing the (meth)acrylic monomer is, for example, (1) a method of directly bonding to a unit derived from a diene and/or olefin of the raw material polymer (P1), and (2) the raw material polymer (P1). A method in which a unit derived from diene and/or olefin is bonded to the polymerizable functional group of a linking group on the side chain, or (3) a polymerizable functional group in which a unit other than the unit derived from diene and/or olefin of the raw material polymer (P1) has on the side chain Addition polymerization can be performed on the raw material polymer (P1) by any one of the method of bonding to. In this case, the obtained copolymer becomes a graft polymer. In addition, in this specification, the "material polymer (P1)" may be simply referred to as "polymer (P1)".

The raw material polymer (P1) may have at least a unit derived from a diene and/or an olefin, and may further have a unit derived from another unsaturated monomer. For details on units derived from diene and/or olefin of the raw material polymer (P1) and units derived from other unsaturated monomers, the description of units derived from diene and/or olefin of the polymer chain (A) and units derived from other unsaturated monomers is provided. Is referenced. Units derived from diene and/or olefin may have some hydrogen atoms chlorinated. The raw material polymer (P1) may be a block copolymer having a polymer block (a1) having units derived from diene and/or olefin and a polymer block (a2) having units derived from other unsaturated monomers, or the polymer block (a2) It may be composed of units derived from aromatic vinyl monomers. These details also refer to the description of the polymer chain (A). Further, in the method (2), the raw material polymer (P1) has a linking group having a polymerizable functional group in the unit side chain derived from diene and/or olefin, and in the method (3), other than units derived from diene and/or olefin It has a polymerizable functional group in the side chain of the unit of.

The raw material polymer (P1) preferably has a weight average molecular weight of 0.1 million or more, more preferably 0.5 million or more, more preferably 10,000 or more, even more preferably 30,000 or more, and 500,000 or less is preferable, 300,000 or less are more preferable, 200,000 or less are still more preferable, and 100,000 or less are still more preferable. By setting the weight average molecular weight of the raw material polymer (P1) in such a range, the moldability of the copolymer (P) is improved, and the strength and transparency of the copolymer (P) are easily secured. Further, generation of a crosslinked product or a gelled product can be suppressed during a polymerization reaction with a monomer component containing a (meth)acrylic monomer.

In the polymerization step, the raw material polymer (P1) may be used alone or in combination of two or more. In the latter case, it becomes easy to adjust the average molecular weight or the double bond amount as the resin composition.

As the monomer component used for formation of the polymer chain (B), in addition to the (meth)acrylic monomer, as a monomer providing a cyclic structural unit, a monomer having a polymerizable double bond in the cyclic structure can be used. For example, when forming a polymer chain (B) having a maleimide structure in the main chain, it is preferable to use a monomer having a polymerizable double bond in the ring structure. Alternatively, in the case of performing the ring structure forming step after the polymerization step, a monomer capable of forming a ring structure in the step can be used as a monomer component. Moreover, other unsaturated monomers other than that can also be used. For the details of these monomer components, the description of the (meth)acrylic monomer forming the polymer chain (B), the monomer providing the ring structure of the polymer chain (B), and other unsaturated monomer forming the polymer chain (B) Is referenced.

Hereinafter, the method of the above (1) to (3) will be described in detail with respect to the method of addition polymerization of the monomer component containing the (meth)acrylic monomer to the raw material polymer (P1).

In the method of directly bonding the monomer component containing the (meth)acrylic monomer of (1) to the unit derived from the diene and/or olefin of the raw material polymer (P1), a monomer component containing a (meth)acrylic monomer is used as a raw material polymer. It binds to the unit derived from the diene and/or olefin of (P1). In this case, it is preferable that the unit derived from the diene and/or olefin of the raw material polymer (P1) has a double bond derived from the diene. The monomer component containing a (meth)acrylic monomer may be bonded to a double bond derived from diene of the main chain of the raw material polymer (P1), or bonded to an adjacent carbon atom of the double bond. Alternatively, the polymer chain (B) may be bonded to a diene-derived double bond bonded to the main chain of the raw material polymer (P1) as a substituent (side chain), or bonded to an adjacent carbon atom of the double bond. In either case, the obtained copolymer (P) is one in which the polymer chain (B) is directly bonded to the diene and/or olefin-derived unit of the polymer chain (A). In this method, it is preferable that hydrogen having high activity such as the vinyl position and allyl position of the double bond (olefinic double bond) of the diene and/or olefin-derived unit of the raw material polymer (P1) is eliminated, and thereby The monomer component that generates radicals in the portion and forms the polymer chain (B) can be subjected to addition polymerization.

In the method of bonding the monomer component containing the (meth)acrylic monomer of (2) to the polymerizable functional group of the linking group having the diene and/or olefin-derived unit of the raw material polymer (P1) in the side chain, the linking group is a polymerizable functional group. It has a (polymerizable double bond) and bonds to a unit side chain derived from a diene and/or an olefin. In the obtained copolymer (P), the polymer chain (B) is bonded to a unit derived from the diene and/or olefin of the polymer chain (A) through a linking group.

In addition to the polymerizable functional group (polymerizable double bond), the linking group preferably has at least one selected from ester bonds, urethane bonds, and ether bonds, and also has a divalent organic group such as a methylene group or a hydroxymethylene group. May be. The raw material polymer (P1) having such a linking group has a unit derived from a diene and/or olefin, and a polymer having a functional group providing an ester bond, a urethane bond, or an ether bond (hereinafter referred to as ``raw polymer (P2)''). And a compound having a functional group having reactivity with the functional group and having a polymerizable functional group (hereinafter, referred to as a "radical polymerizable compound") can be obtained by reacting.

The functional group providing an ester bond, a urethane bond, or an ether bond refers to a functional group that forms any one of these bonds by reaction with a radical polymerizable compound, and specifically, a carboxyl group or an anhydride group thereof, an epoxy group, or a hydride A hydroxyl group, an isocyanate group, etc. are mentioned preferably. In order to introduce these functional groups into the raw material polymer (P2), these functional groups are added to the polymer having a unit derived from diene and/or olefin (for example, the raw material polymer (P1) used in the production method of (1)). What is necessary is just to react the unsaturated compound of the branch, and the said reaction is usually performed using a radical initiator.

Unsaturated carboxylic acids such as (meth)acrylic acid, fumaric acid, maleic acid and anhydrides thereof, itaconic acid and anhydrides thereof, crotonic acid and anhydrides thereof, citraconic acid and anhydrides thereof, etc. Can be lifted.

Unsaturated compounds having an epoxy group include glycidyl (meth)acrylate, mono and diglycidyl esters of maleic acid, mono and diglycidyl esters of itaconic acid, mono and diglycidyl esters of allylsuccinic acid, p- Unsaturated carboxylic acid glycidyl ester such as glycidyl ester of styrene carboxylic acid; Glycidyl ethers such as allyl glycidyl ether, 2-methyl allyl glycidyl ether, and styrene-p-glycidyl ether; p-glycidylstyrene; Epoxy olefins such as 3,4-epoxy-1-butene and 3,4-epoxy-3-methyl-1-butene; Vinylcyclohexene monooxide, etc. are mentioned.

Examples of unsaturated compounds having a hydroxyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. ; N-methylol (meth)acrylamide; 2-hydroxyacrylate ethyl-6-hexanolide addition polymerization product; Alkenyl alcohols such as 2-propen-1-ol; Alkynyl alcohols such as 2-propyn-1-ol; Hydroxyvinyl ether, etc. are mentioned.

Examples of the unsaturated compound having an isocyanate group include 2-isocyanate ethyl (meth)acrylate and methacryloyl isocyanate.

The radically polymerizable compound has a polymerizable functional group (polymerizable double bond) and a functional group having reactivity with a carboxyl group or its anhydride group, an epoxy group, a hydroxyl group, or an isocyanate group. As a reactive functional group, a hydroxyl group, an epoxy group, an isocyanate group, and a carboxyl group are mentioned, for example.

Examples of radical polymerizable compounds having a hydroxyl group as a reactive functional group include hydroxyalkyl such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. (Meth)acrylate; N-methylol (meth)acrylamide; 2-hydroxyacrylate ethyl-6-hexanolide addition polymerization product; Alkenyl alcohols such as 2-propen-1-ol; Alkynyl alcohols such as 2-propen-1-ol; Hydroxyvinyl ether, etc. are mentioned.

Radical polymerizable compounds having an epoxy group as a reactive functional group include glycidyl (meth)acrylate, mono and diglycidyl esters of maleic acid, mono and diglycidyl esters of itaconic acid, mono and diglycidyls of allylsuccinic acid. Unsaturated carboxylic acid glycidyl esters such as dylic ester and glycidyl ester of p-styrenecarboxylic acid; Glycidyl ethers such as allyl glycidyl ether, 2-methyl allyl glycidyl ether, and styrene-p-glycidyl ether; p-glycidylstyrene; Epoxy olefins such as 3,4-epoxy-1-butene and 3,4-epoxy-3-methyl-1-butene; Vinylcyclohexene monooxide, etc. are mentioned.

Examples of the radically polymerizable compound having an isocyanate group as a reactive functional group include 2-isocyanate ethyl (meth)acrylate and methacryloyl isocyanate.

Examples of the radical polymerizable compound having a carboxyl group as a reactive functional group include unsaturated acids such as (meth)acrylic acid; And carboxyalkyl vinyl ethers such as carboxyethyl vinyl ether and carboxypropyl vinyl ether.

When the functional group of the raw material polymer (P2) is a carboxyl group or an anhydride thereof, a hydroxyl group, an epoxy group, and an isocyanate group are preferably shown as the reactive functional groups of the radical polymerizable compound. Among these, a radically polymerizable compound having a hydroxyl group is particularly preferred. In this case, the raw material polymer (P1) obtained by reaction between the raw material polymer (P2) and the radically polymerizable compound has a polymerizable functional group and a linking group having an ester bond in the side chain.

When the functional group of the raw material polymer (P2) is an epoxy group, a carboxyl group and a hydroxyl group preferably appear as the reactive functional group of the radical polymerizable compound. Among these, a radically polymerizable compound having a carboxyl group is particularly preferred. In this case, the raw material polymer (P1) obtained by reaction of the raw material polymer (P2) with the radical polymerizable compound is a divalent polymer represented by a polymerizable functional group and an ester bond (in detail, -CH(OH)-CH ₂ -OCO-). Organic group) in the side chain.

When the functional group of the raw material polymer (P2) is a hydroxyl group, an isocyanate group, a carboxyl group, and an epoxy group are preferably shown as reactive functional groups of the radical polymerizable compound. Among these, a radically polymerizable monomer having an isocyanate group is particularly preferred. In this case, the raw material polymer (P1) obtained by reaction between the raw material polymer (P2) and the radically polymerizable compound has a linking group having a polymerizable functional group and a urethane bond in the side chain.

When the functional group of the raw material polymer (P2) is an isocyanate group, a hydroxyl group and a carboxyl group preferably appear as reactive functional groups of the radically polymerizable compound. Among these, a radically polymerizable monomer having a hydroxyl group is particularly preferred. In this case, the raw material polymer (P1) obtained by reaction between the raw material polymer (P2) and the radically polymerizable compound has a linking group having a polymerizable functional group and a urethane bond in the side chain.

As a raw material polymer (P1) usable in the production method of (2), for example, LIRUC-102M or UC-203 (both are KURARAY CO., LTD.), which are polyisoprene having an ester bond with a methacryloyl group in the side chain. ), etc.

A method for producing the copolymer (P) (3) will be described. In the method of bonding the monomer component containing the (meth)acrylic monomer of (3) to a polymerizable functional group having a unit other than the diene and/or olefin-derived unit of the raw material polymer (P1) on the side chain, diene and/ Or an olefin and an unsaturated monomer having a polymerizable functional group (polymerizable double bond), or a diene and/or an olefin and a carboxyl group or an anhydride group thereof, an epoxy group, a hydroxyl group, or an unsaturated monomer having a functional group having an isocyanate group The raw material polymer (P1) can be obtained by copolymerizing and further reacting with the radical polymerizable compound having a reactive functional group described above. Alternatively, a (co)polymer having units derived from diene and/or olefin is polymerized with an unsaturated monomer having a polymerizable functional group (polymerizable double bond), or a (co)polymer having units derived from diene and/or olefin is prepared. , By polymerizing with an unsaturated monomer having a carboxyl group or its anhydride group, an epoxy group, a hydroxyl group, or an isocyanate group, and reacting with a radically polymerizable compound having the reactive functional group described above to obtain a raw material polymer (P1). I can. In the presence of the thus obtained raw material polymer (P1), the copolymer (P) is obtained by polymerizing the monomer component containing the (meth)acrylic monomer. In the obtained copolymer (P), the polymer chain (B) is bonded to a unit other than the unit derived from the diene and/or olefin of the polymer chain (A).

When the (co)polymer having a diene and/or olefin, or a unit derived therefrom is polymerized with an unsaturated monomer having a polymerizable functional group, polyfunctional (meth)acrylate, vinyl ether group as the unsaturated monomer having a polymerizable functional group Polyfunctional (meth)acrylic compounds such as containing (meth)acrylate and allyl group containing (meth)acrylate, polyfunctional vinyl ether, polyfunctional allyl compounds, and polyfunctional aromatic vinyls.

Examples of polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, and bisphenol. A alkylene oxide di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 2,2'-[oxybis(methylene)]bisacrylic acid, dialkyl-2,2'-[oxybis(methylene) ]Bis-2-propenoate, etc. are mentioned.

Examples of the vinyl ether group-containing (meth)acrylate include 2-vinyloxyethyl (meth)acrylate, 4-vinyloxybutyl (meth)acrylate, and 2-(vinyloxyethoxy)ethyl (meth)acrylate. I can.

Examples of the allyl group-containing (meth)acrylate include allyl (meth)acrylate, methyl α-allyloxymethylacrylate, stearyl α-allyloxymethylacrylate, 2-decyltetradecyl α-allyloxymethylacrylate, and the like. I can.

Examples of polyfunctional vinyl ethers include ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, trimethylolpropane trivinyl ether, etc. Can be mentioned.

Examples of polyfunctional allyl compounds include ethylene glycol diallyl ether, diethylene glycol diallyl ether, polyethylene glycol diallyl ether, hexanediol diallyl ether, bisphenol A alkylene oxide diallyl ether, trimethylolpropane triallyl ether. And polyfunctional allyl ethers such as ditrimethylolpropane tetraallyl ether; Polyfunctional allyl group-containing isocyanurate such as triallyl isocyanurate; Polyfunctional allyl esters such as diallyl phthalate and diallyl difenate; Bisallylnadiimide compounds and the like; Bisallylnadiimide compounds, etc. are mentioned.

As polyfunctional aromatic vinyl, divinylbenzene etc. are mentioned, for example.

A polymer obtained by polymerizing a (co)polymer having a diene and/or olefin, or a unit derived therefrom with an unsaturated monomer having a functional group having a carboxyl group or an anhydride group thereof, an epoxy group, a hydroxyl group, or an isocyanate group (Hereinafter referred to as ``raw material polymer (P3)'') has a unit derived from diene and/or olefin, and has units other than units derived from diene and/or olefin, and has a carboxyl group or its A functional group having an anhydride group, an epoxy group, a hydroxyl group, or an isocyanate group is bonded. As the raw material polymer (P3), for example, ethylene-(meth)acrylic acid copolymer, ethylene-2-hydroxyethyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate copolymer, ethylene-polyethylene Glycol mono(meth)acrylate copolymer, ethylene-vinyl acetate-(meth)acrylic acid copolymer, ethylene-ethyl(meth)acrylate-(anhydrous) maleic acid copolymer, ethylene-vinyl acetate-(anhydrous) maleic acid copolymer Copolymer, ethylene-vinyl acetate-2-hydroxyethyl (meth)acrylate copolymer, ethylene-vinyl acetate-glycidyl (meth)acrylate copolymer, ethylene-vinyl acetate-polyethylene glycol mono (meth)acrylate copolymer Coalescence, partial saponification of ethylene-vinyl acetate copolymer, etc. Among these, ethylene-(meth)acrylic acid copolymer, ethylene-ethyl(meth)acrylate-(anhydrous)maleic acid copolymer, ethylene-acetic acid Vinyl-glycidyl (meth)acrylate copolymers are preferred.

The raw material polymer (P1) is obtained by reacting the raw material polymer (P3) with the radically polymerizable compound having the reactive functional group described above. For details of the functional groups possessed by the raw material polymer (P3) and the reactive functional groups of the radically polymerizable compound, the description of these in the method (2) above is referred to.

In the reaction of the raw material polymer (P2) and the radical polymerizable compound in the method (2), or in the reaction of the raw material polymer (P3) and the radical polymerizable compound in the method (3), the raw material polymer (P2) or the raw material It is preferable to mix and react so that 0.1 to 10 equivalents of the reactive functional groups of the radically polymerizable compound per 1 equivalent of the functional groups in the polymer (P3). Thereby, the yield of the copolymer (P) finally obtained can be improved.

The above reaction is preferably carried out in a suitable organic solvent, and examples of the organic solvent include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, cellosolve acetate, and the like. The reaction temperature is usually 20°C to 150°C, preferably 50°C to 120°C.

It is preferable that the reaction of the raw material polymer (P2) or the raw material polymer (P3) with the radical polymerizable compound is carried out in the presence of a catalyst. As a catalyst, an acid or a basic compound such as sulfuric acid, paratoluene sulfonic acid, zinc chloride, pyridine, triethylamine, dimethylbenzylamino, etc. can be used in the esterification reaction, and in the urethanization reaction, for example, dibutyl tin laur Rate, etc. can be used.

During the reaction, in order to prevent the formation of a homopolymer of the vinyl monomer, it is preferable to react in an oxygen or air atmosphere, and to add an appropriate amount of a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, phenothiazine, etc. to the reaction system.

In the above methods (1) to (3), in the presence of the raw material polymer (P1) obtained as described above, a (meth)acrylic monomer is included (if necessary, a monomer having a polymerizable double bond in the ring structure is further The copolymer (P) can be obtained by polymerizing the monomer component to be included). Preferably, a copolymer (P) is obtained by graft polymerization of a monomer component containing a (meth)acrylic monomer onto a raw material polymer (P1). The amount of each monomer component containing the (meth)acrylic monomer is appropriately adjusted so that the content ratio of the unit derived from the (meth)acrylic acid ester in the finally obtained polymer chain (B) falls within a desired range. It is preferable to polymerize a monomer component containing a (meth)acrylic monomer in the presence of a raw material polymer (P1) by the method of (1) from the viewpoint of being easy to suppress the formation of a gelled product in the polymerization step. Do. Further, also in the methods (2) and (3) above, the generation of a gelled product can be suppressed by controlling the polymerization reaction such as shortening the polymerization reaction time.

The polymerization of the monomer component can be carried out using a known polymerization method such as a bulk polymerization method, a solution polymerization method, an emulsion polymerization method, and a suspension polymerization method, but it is preferable to use a solution polymerization method. When the solution polymerization method is used, it is possible to suppress the incorporation of minute foreign matter into the copolymer (P), and it becomes easy to apply the copolymer (P) suitably for optical material applications and the like.

As a polymerization mode, either (both) of a batch polymerization method and a continuous polymerization method can be used, for example. In the case of polymerization, the monomer components can be added in batches or can be added in portions.

The polymerization solvent can be appropriately selected according to the composition of the monomer component, and an organic solvent used in a conventional radical polymerization reaction can be used. Specifically, aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; Ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and anisole; Esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and 3-methoxybutyl acetate; Cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; Alcohols such as methanol, ethanol, isopropanol, and n-butanol; Nitriles such as acetonitrile, propionitrile, butyronitrile and benzonitrile; Chloroform; Dimethyl sulfoxide, etc. are mentioned. These solvents may be used alone or in combination of two or more.

The polymerization reaction between the raw material polymer (P1) and the monomer component is preferably carried out in the presence of a polymerization catalyst (polymerization initiator). As a polymerization catalyst, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane)·dihydrochloride, dimethyl-2,2'-azobis(2- Azo compounds such as methylpropionate) and 4,4'-azobis(4-cyanopentanoic acid); Persulfates such as potassium persulfate; Cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-amylperoxy-2-ethylhexano Organic peroxides, such as 8, t-amyl peroxy octoate, t-amyl peroxy isononanoate, t-amyl peroxy isopropyl carbonate, and t-amyl peroxy 2-ethylhexyl carbonate, can be used. These may use only 1 type, and may use 2 or more types together. In the method of (1), it is preferable to use a polymerization catalyst having a strong hydrogen tensile force, and an organic peroxide is preferably used as such a polymerization catalyst. The amount of the polymerization catalyst to be used is preferably 0.01 to 1 part by mass based on 100 parts by mass of the monomer component.

Regarding the respective usage amounts of the raw material polymer (P1) and the monomer component, the raw material polymer (P1) is preferably 0.5 parts by mass or more, and 1 part by mass or more with respect to 100 parts by mass of the total of the raw material polymer (P1) and the monomer component. It is more preferable, 3 mass parts or more is still more preferable, 50 mass parts or less is preferable, 30 mass parts or less is more preferable, and 20 mass parts or less is still more preferable. The monomer component is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, and 99 parts by mass or less based on 100 parts by mass of the total of the raw material polymer (P1) and the monomer component. Is preferable, 98 parts by mass or less are more preferable, and 97 parts by mass or less are still more preferable.

The concentration of the raw material polymer (P1) in the reaction solution is preferably 1% by mass or more, more preferably 3% by mass or more, more preferably 5% by mass or more, and preferably 50% by mass or less, and 30% by mass or less. Is more preferable, and 20 mass% or less is still more preferable. The concentration of the monomer component in the reaction solution is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 80% by mass or less, and more preferably 70% by mass or less. The solvent concentration in the reaction solution is preferably 10% by mass or more, more preferably 20% by mass or more, and more preferably 97% by mass or less, more preferably 95% by mass or less, even more preferably 90% by mass or less, and , 80% by mass or less is even more preferable. It is also possible to appropriately add a raw material polymer (P1), a monomer component, a polymerization catalyst, a reaction solvent, etc. during the polymerization reaction.

The polymerization reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen gas or an air stream. In order to reduce residual monomers, an azobis-based compound and a peroxide may be used together as a polymerization initiator. The reaction temperature is preferably 50°C to 200°C. The reaction time may be appropriately adjusted while looking at the degree of progress of the copolymerization reaction and the degree of formation of a gelled product, and is preferably carried out for, for example, 1 hour to 20 hours.

By the above polymerization step, a copolymer in which a polymer chain containing a unit derived from a (meth)acrylic monomer is bonded to the polymer chain (A) is obtained. In the polymerization step, when a (meth)acrylic monomer and a monomer having a polymerizable double bond in the ring structure (for example, maleic anhydride or maleimide) are used as the monomer component, the (meth)acrylic unit and the ring structure A copolymer (P) in which a polymer chain (B) having units (maleic anhydride structure, maleimide structure) is bonded to the polymer chain (A) is obtained.

On the other hand, in the case of obtaining a copolymer (P) having a lactone ring structure, a glutaric anhydride structure, or a glutalimide structure as the ring structural unit of the polymer chain (B), a ring structure formation step following the polymerization step It is preferable to carry out. In ring structure formation, a ring structure is formed in the main chain of a polymer chain having (meth)acrylic units formed in the polymerization step. Specifically, a condensation reaction between the substituents of the adjacent (meth)acrylic units of the polymer chain having the (meth)acrylic units formed in the polymerization step is carried out to form a ring structure in the main chain of the polymer chain. Condensation reaction includes esterification reaction, acid anhydride reaction, amidation reaction, imidation reaction, and the like. For example, a glutaric anhydride structure can be formed by acid anhydride of two carboxylic acid groups in an adjacent (meth)acrylic unit, and a glutalimide structure can be formed by imidation. In addition, when one of the adjacent (meth)acrylic units has a protic hydrogen atom-containing group such as a hydroxyl group or an amino group, the protonic hydrogen atom-containing group of the one (meth)acrylic unit and the other (meth)acrylic By condensing the carboxylic acid group of the unit, a lactone ring structure can be formed.

In the ring structure formation step, the condensation reaction of adjacent (meth)acrylic units is preferably carried out in the presence of a catalyst (cyclization catalyst). Acids, bases and salts thereof may be organic or inorganic, and are not particularly limited. Among them, it is preferable to use an organophosphorus compound as a catalyst for the cyclization reaction. By using an organophosphorus compound as a cyclization catalyst, the condensation reaction can be carried out efficiently, and coloration of the obtained copolymer (P) can be reduced.

Examples of organic phosphorus compounds that can be used as cyclization catalysts include alkyl (aryl) aphosphonic acids and monoesters or diesters thereof; Dialkyl(aryl)phosphinic acid and esters thereof; Alkyl (aryl) phosphonic acids and monoesters or diesters thereof; Alkyl(aryl)phosphinic acid and esters thereof; Phosphorous acid monoester, diester or tryster; Methyl phosphate, ethyl phosphate, 2-ethylhexyl phosphate, octyl phosphate, isodecyl phosphate, lauryl phosphate, stearyl phosphate, isostearyl phosphate, phenyl phosphate, dimethyl phosphate, diethyl phosphate, di-2-ethylhexyl phosphate, Diisodecyl phosphate, dilauryl phosphate, distearyl phosphate, diisostearyl phosphate, diphenyl phosphate, trimethyl phosphate, triethyl phosphate, triisodecyl phosphate, trilauryl phosphate, tristearyl phosphate, triisoste phosphate Phosphoric acid monoesters, diesters or triesters such as aryl and tripe phosphate; mono-, di- or tri-alkyl (aryl) phosphine; Alkyl(aryl)halogenphosphine; Oxidized mono-, di- or tri-alkyl (aryl) phosphines; And halogenated tetraalkyl (aryl) phosphonium. These may use only 1 type, and may use 2 or more types together. Among these, phosphoric acid monoester or diester is particularly preferred from the viewpoint of high catalytic activity and low colorability. The amount of the cyclization catalyst used is preferably 0.001 to 1 part by mass based on 100 parts by mass of the copolymer obtained in the polymerization step.

The reaction temperature in the ring structure formation step is preferably 50°C to 300°C. The reaction time may be appropriately adjusted while watching the progress of the condensation reaction, and, for example, it is preferably carried out for 5 minutes to 6 hours.

As described above, by performing the polymerization step or the polymerization step and the ring structure forming step, a resin solution containing the copolymer (P) is obtained. It is preferable to remove foreign matter by filtering the resin solution thus obtained with a filter. Therefore, it is preferable that the method for producing the copolymer (P) further includes a step (filtration step) of filtering the resin solution obtained in the polymerization step or the ring structure forming step. By performing the filtration step, the amount of foreign matter in the copolymer (P) can be reduced. Therefore, when the copolymer (P) is used as a raw material for an optical film, there are few surface irregularities and defects, and it becomes easy to obtain an optical film with high transparency. Further, in the present invention, since the generation amount of the gelled product in the polymerization step of the copolymer (P) can be suppressed low, the load applied to the filter in the filtration step can be suppressed, and continuous filtration for a long time is possible. Therefore, the copolymer (P) with a small amount of foreign matter can be obtained with high productivity. The filtration process can be carried out continuously following the polymerization process or the ring structure formation process.

As a filter used for filtration, a conventionally known filter can be used, and although not particularly limited, for example, a leaf disk filter, a candle filter, a pack disk filter, a cylindrical filter, or the like can be used. Among them, leaf disc filters or candle filters having a large effective filtration area are preferred.

The degree of filtration (pore diameter) of the filter may be, for example, 15 μm or less. Further, when the copolymer (P) is used for an optical material such as an optical film, the degree of filtration is preferably 10 µm or less and more preferably 5 µm or less from the viewpoint of reducing optical defects. The lower limit of the degree of filtration is not particularly limited, and is, for example, 0.2 µm or more.

In the filtration step, the resin solution containing the copolymer (P) obtained in the polymerization step or the ring structure forming step may be filtered in its own form, or may be diluted with a solvent or dispersed in a solvent and filtered. If the copolymer (P) is a solid, it may be melted and filtered with a sintered filter or the like, or dissolved or dispersed in a solvent and filtered. Filtration may be performed by heating, or may be performed under pressure.

When the resin solution is provided for filter filtration, the solution temperature can be appropriately set depending on the boiling point of the polymerization solvent, for example, preferably below the boiling point of the polymerization solvent, and more preferably below the boiling point of the polymerization solvent -10°C. . On the other hand, if the temperature of the resin solution used for filter filtration is too low, the viscosity of the resin solution may increase and the load on devices such as gear pumps may increase, so the temperature of the resin solution used for filter filtration is 50 It is preferably at least 80°C, and more preferably at least 80°C.

The viscosity of the resin solution used for filter filtration is preferably 100 Pa·s or less, and more preferably 80 Pa·s or less at 85°C. If the viscosity of the resin solution used for filter filtration is too high, the pressure loss during filter filtration may increase, the filter unit may be damaged, or the filter filtration treatment capacity may decrease due to an increase in viscosity. The pressure loss in filter filtration is preferably 2.5 MPa or less, more preferably 0.5 MPa to 2.0 MPa, and still more preferably 0.5 MPa to 1.5 MPa.

〔2. Resin composition]

The present invention also provides a resin composition containing a copolymer (P) having a polymer chain (A) and a polymer chain (B) described above. The resin composition of the present invention is excellent in transparency, mechanical strength (for example, impact strength, etc.), and heat resistance, and at the same time as having them in a group form, there is little generation of gelatinous products during manufacture. Hereinafter, the resin composition of this invention is called "resin composition (Q)".

The resin composition (Q) may contain the copolymer (P) as a resin component, or may contain another polymer as a resin component. When the resin composition (Q) contains another polymer, a (meth)acrylic polymer can be preferably used as the other polymer, whereby the homogeneity of the resin composition (Q) increases, and the transparency and heat resistance of the resin composition (Q) It becomes easy to increase.

The (meth)acrylic polymer may have a unit derived from the (meth)acrylic monomer described in the polymer chain (B), and preferably, a unit derived from the (meth)acrylic acid ester described in the polymer chain (B). Has. The (meth)acrylic polymer may have units derived from other unsaturated monomers described in the polymer chain (B). The (meth)acrylic polymer has a unit derived from a (meth)acrylic monomer contained in the polymer chain (B) of the copolymer (P) from the viewpoint of enhancing compatibility with the copolymer (P) in the resin composition (Q). More preferable.

It is preferable that the (meth)acrylic polymer has a ring structure, and it is more preferable that it has a ring structure in the main chain. Since the resin composition (Q) contains a (meth)acrylic polymer having a ring structure in the main chain, the heat resistance of the resin composition (Q) can be improved. The main chain ring structure of the (meth)acrylic polymer is a lactone ring structure, a cyclic imide structure (for example, a maleimide structure, a glutalimide structure, etc.), a cyclic anhydride structure (for example, a maleic anhydride structure, an anhydride glue). Tarric acid structure, etc.) are preferably mentioned, and the description of the ring structure of the polymer chain (B) is referred to for details of these ring structures. Among them, it is preferable that the (meth)acrylic polymer has a ring structure similar to that of the polymer chain (B) of the copolymer (P) in its main chain.

It is preferable that the (meth)acrylic polymer has a (meth)acrylic unit of the polymer chain (B) of the copolymer (P) and a cyclic structural unit of the polymer chain (B). When the resin composition (Q) contains such a (meth)acrylic polymer, the compatibility with the copolymer (P) increases, and it becomes easy to improve the transparency and heat resistance of the resin composition (Q), and the resin composition (Q) It is also easier to prepare.

In 100% by mass of the solid content of the resin composition (Q), the content ratio of the copolymer (P) is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, and 5% by mass The above is even more preferable, and it becomes easy to increase the mechanical strength of the resin composition (Q) by this. The upper limit of the content ratio of the copolymer (P) in the resin composition (Q) is not particularly limited, and the resin composition (Q) may be composed of only the copolymer (P), and in the resin composition (Q), a copolymer The content ratio of (P) may be 90 mass% or less, 70 mass% or less, 50 mass% or less, 40 mass% or less, or 30 mass% or less. The solid amount of the resin composition (Q) means the amount of the resin composition (Q) excluding the solvent when the resin composition (Q) contains a solvent.

In 100% by mass of the solid content of the resin composition (Q), the content ratio of the polymer chain (A) of the copolymer (P) is preferably 0.5% by mass or more, more preferably 1% by mass or more, and further 3% by mass or more. It is preferable, and 50 mass% or less is preferable, 30 mass% or less is more preferable, and 20 mass% or less is still more preferable. When the content ratio of the polymer chain (A) in the resin composition (Q) is 0.5% by mass or more, it becomes easy to increase the mechanical strength of the resin composition (Q). When the content ratio of the polymer chain (A) in the resin composition (Q) is 50% by mass or less, it becomes easy to increase the transparency and heat resistance of the resin composition (Q). The content ratio of the polymer chain (A) can be calculated by, for example, ¹ H-NMR.

When the resin composition (Q) contains a (meth)acrylic polymer, in 100% by mass of the solid content of the resin composition (Q), the content of the (meth)acrylic polymer is preferably 1% by mass or more, and further 20% by mass or more. It is preferable, and 30 mass% or more is more preferable, 99 mass% or less is preferable, 95 mass% or less is more preferable, 90 mass% or less is still more preferable.

In 100% by mass of the solid content of the resin composition (Q), the total content ratio of the copolymer (P) and the (meth)acrylic polymer is preferably 50% by mass or more, more preferably 70% by mass or more, and 80% by mass or more. It is more preferable, and 90 mass% or more is still more preferable. The upper limit of the content ratio of the copolymer (P) and the (meth)acrylic polymer in the resin composition (Q) is not particularly limited, and the resin composition (Q) is substantially composed of only the copolymer (P) and (meth)acrylic polymer. May be, for example, in 100% by mass of the solid content of the resin composition (Q), the total content ratio of the copolymer (P) and the (meth)acrylic polymer may be 99% by mass or more.

The resin composition (Q) may contain a polymer other than the (meth)acrylic polymer, and examples of such polymers include olefins such as polyethylene, polypropylene, ethylene-propylene polymer, and poly(4-methyl-1-pentene). Polymer; Halogen-containing polymers such as vinyl chloride and chlorinated vinyl resin; Styrene polymers such as polystyrene, styrene-methylmethacrylic acid copolymer, styrene-acrylonitrile polymer, and acrylonitrile-butadiene-styrene copolymer; Polyesters such as polymer riethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; Polyamides such as nylon 6, nylon 66, and nylon 610; Polyacetal; Polycarbonate; Polyphenylene oxide; Polyphenylene sulfide; Polyetheretherketone; Polysulfone; Polyethersulfone; Polyoxybenzylene; Polyamide imide; Rubber polymers such as ABS resin and ASA resin in which polybutadiene rubber and (meth)acrylic rubber are blended; And the like.

The resin composition (Q) may contain various additives as long as the effect of the present invention is not impaired. Examples of the additive include antioxidants such as hindered phenol, phosphorus, and sulfur; Stabilizers such as light stabilizers, weather stabilizers, and heat stabilizers; Reinforcing materials such as glass fiber and carbon fiber; Ultraviolet absorbers; Near-infrared absorbers; Flame retardants such as tris(dibromopropyl)phosphate, triallyl phosphate, and antimony oxide; Phase difference adjusters such as a phase difference increasing agent, a phase difference reducing agent, and a phase difference stabilizer; Antistatic agents including anionic, cationic, and nonionic surfactants; Coloring agents such as inorganic pigments, organic pigments, and dyes; Organic or inorganic fillers; Resin modifiers; Organic or inorganic fillers; And the like. The content ratio of each additive in the resin composition (Q) is preferably 0 to 5% by mass, more preferably 0 to 2% by mass.

Examples of the ultraviolet absorber include a benzophenone compound, a salicylate compound, a benzoate compound, a triazole compound, and a triazine compound, and known ultraviolet absorbers can be used. Examples of benzophenone compounds include 2,4-dihydroxybenzophenone, 4-n-octyloxy-2-hydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, and the like. I can. As a salicylate compound, p-t-butylphenyl salicylate, etc. are mentioned. Examples of the benzoate-based compound include 2,4-di-t-butylphenyl-3',5'-di-t-butyl-4'-hydroxybenzoate. As the triazole-based compound, 2,2'-methylenebis [4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(3,5 -Di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2H-benzotriazole-2- Yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-benzotriazol-2-yl-4,6-di-tert-butylphenol, 2-[5-chloro(2H) -Benzotriazol-2-yl]-4-methyl-6-t-butylphenol, 2-(2H-benzotriazol-2-yl)-4, 6-di-t-butylphenol, 2-(2H -Benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, etc. are mentioned. Examples of triazine compounds include 2-mono (hydroxyphenyl)-1,3,5-triazine compounds, 2,4-bis (hydroxyphenyl)-1,3,5-triazine compounds, 2,4,6- And tris(hydroxyphenyl)-1,3,5-triazine compounds. As commercially available ultraviolet absorbers, for example, triazine-based ultraviolet absorbers "TINUVIN (registered trademark) 1577", "TINUVIN (registered trademark) 460", "TINUVIN (registered trademark) 477" (BASF Japan Ltd.), and "ADK" STAB (registered trademark) LA-F70" (ADEKA CORPORATION), a triazole-based ultraviolet absorber "ADK STAB (registered trademark) LA-31" (ADEKA CORPORATION), and the like. Only one type of ultraviolet absorber may be used, and two or more types may be used in combination.

As the antioxidant, a compound having a radical trapping function or a peroxide decomposition function can be used, and a known antioxidant can be used. Examples of antioxidants include hindered phenolic antioxidants, hindered amine antioxidants, phosphorus antioxidants, sulfur antioxidants, benzotriazole antioxidants, benzophenone antioxidants, hydroxylamine antioxidants, salicylic acid. Ester-based antioxidants, and triazine-based antioxidants. Among these antioxidants, preferred examples include hindered phenolic antioxidants, hindered amine antioxidants, phosphorus antioxidants, and sulfur antioxidants. More preferably, a hindered phenol-based antioxidant, a hindered amine-based antioxidant, and a phosphorus antioxidant are used. Antioxidants may be used alone or in combination of two or more.

As hindered phenolic antioxidants, 2,4-bis[(laurylthio)methyl]-o-cresol, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl), 1,3,5-tris(4-t-butyl-3-hydroxy-2, 6-dimethylbenzyl), etc. are mentioned.

As hindered amine antioxidants, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(N-methyl-2,2,6,6-tetramethyl-4-piperi) Diyl) sebacate, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexamethylenediamine, 2-methyl-2-(2,2,6 ,6-tetramethyl-4-piperidyl)amino-N-(2,2,6,6-tetramethyl-4-piperidyl)propionamide, tetrakis(2,2,6,6-tetramethyl -4-piperidyl) (1,2,3,4-butanetetracarboxylate, poly[(6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine -2,4-diyl) ((2,2,6,6-tetramethyl-4-piperidyl)imino)hexamethyl((2,2,6,6-tetramethyl-4-piperidyl) Imino)], etc. can be used.

Phosphorous antioxidants include tris(isodecyl)phosphite, tris(tridecyl)phosphite, phenylisooctylphosphite, phenylisodecylphosphite, phenyldi(tridecyl)phosphite, diphenylisooctylphosphite, diphenyl Isodecyl phosphite, diphenyltridecyl phosphite, triphenyl phosphite, tris(nonylphenyl)phosphite, 4,4' isopropylidenediphenol alkyl phosphite, trisnonylphenylphosphite, trisdinonylphenylphosphite Pite and other oligomeric and polymer-type compounds having a phosphite structure can also be used.

As sulfur-based antioxidants, 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis[(octylthio)methyl] -o-cresol, 2,4-bis[(laurylthio)methyl]-o-cresol, etc. are mentioned. Other oligomeric or polymeric compounds having a thioether structure can also be used.

The weight average molecular weight of the resin composition (Q) is preferably 0.2 million or more, more preferably 0.5 million or more, still more preferably 30,000 or more, even more preferably 50,000 or more, and particularly preferably 70,000 or more, Moreover, 1 million or less are preferable, 500,000 or less are more preferable, 300,000 or less are still more preferable, and 200,000 or less are still more preferable. By setting the weight average molecular weight of the resin composition (Q) in such a range, the molding processability of the resin composition (Q) is improved, and the strength of the obtained molded article is easily increased. The weight average molecular weight of the resin composition (Q) refers to the value of the resin composition (Q) in terms of polystyrene measured by gel permeation chromatography, and the resin composition (Q) contains a copolymer (P) and a (meth)acrylic polymer. In the case of containing, the weight average molecular weight of the resin composition (Q) becomes the total weight average molecular weight of these plural types of polymers.

The weight average molecular weight of the resin composition (Q) is preferably 1.1 times or more, more preferably 1.2 times or more, still more preferably 1.3 times or more, to the weight average molecular weight of the polymer chain (A) of the copolymer (P). It is preferably 20 times or less, more preferably 12 times or less, more preferably 10 times or less, even more preferably 7 times or less, and particularly preferably 5 times or less. Thereby, it becomes easy to give the resin composition (Q) each characteristic of transparency, mechanical strength, and heat resistance in a group form.

The refractive index of the resin composition (Q) is preferably a value close to the refractive index of the polymer chain (A) of the copolymer (P), whereby it becomes easy to secure the transparency of the resin composition (Q). Specifically, the difference between the refractive index of the resin composition (Q) and the refractive index of the polymer chain (A) of the copolymer (P) is preferably less than 0.1, more preferably 0.05 or less, and even more preferably 0.02 or less. From the same point of view, the refractive index of the resin composition (Q) is preferably a value close to the refractive index of the copolymer (P), and specifically, the difference between the refractive index of the resin composition (Q) and the refractive index of the copolymer (P) is less than 0.1 Preferably, 0.05 or less is more preferable, and 0.02 or less is still more preferable.

The resin composition (Q) preferably has a total light transmittance of 70% or more, more preferably 80% or more, and still more preferably 90% or more when used as an unstretched film having a thickness of 160 μm. Moreover, it is preferable that the haze is 5.0% or less, 3.0% or less is more preferable, and 1.0% or less is still more preferable. Regarding the internal haze, the internal haze per 100 µm in thickness when used as an unstretched film is preferably 5.0% or less, more preferably 3.0% or less, further preferably 2.0% or less, and even more preferably 1.0% or less.

When the resin composition (Q) is used as an unstretched film having a thickness of 160 μm, it exhibits a sea-island structure, and the island size in the structure is preferably 500 nm or less, more preferably 400 nm or less, and further preferably 350 nm or less. Thereby, when a film is formed from the resin composition (Q), it becomes easy to obtain a film with high transparency. The lower limit of the sea size of the sea-island structure is not particularly limited, and may be, for example, 10 nm or more, or 50 nm or more. The sea-island structure observation of the unstretched film formed from the resin composition (Q) is performed by a scanning electron microscope (STEM), and the method described in the Examples is referred to for a specific measurement method.

The resin composition (Q) preferably has a glass transition temperature of 100°C or more and less than 100°C, respectively. Further, a glass transition temperature of 100°C or higher is referred to as a "glass transition temperature on the high temperature side", and a glass transition temperature of less than 100°C is referred to as a "glass transition temperature on the low temperature side". The resin composition (Q) may have a plurality of glass transition temperatures on the high temperature side, and may have a plurality of glass transition temperatures on the low temperature side. Because the resin composition (Q) has a glass transition temperature on the high-temperature side, the heat resistance of the resin composition (Q) is increased, and when the resin composition (Q) is molded into a film, it does not soften even under high temperature, and molding processability Can increase. Since the resin composition (Q) has a glass transition temperature on the low-temperature side, the mechanical strength and impact resistance of the resin composition (Q) can be improved. The glass transition temperature on the high-temperature side of the resin composition (Q) is preferably 113° C. or higher, more preferably 116° C. or higher, further preferably 120° C. or higher, and enhancing the processability of the resin composition (Q) Is preferably less than 300°C, more preferably less than 200°C, and still more preferably less than 180°C. The glass transition temperature on the low temperature side of the resin composition (Q) is preferably -100°C or higher, more preferably -90°C or higher, more preferably -80°C or higher, and preferably less than 50°C, and lower than 30°C. Is more preferable, and less than 10 degreeC is more preferable.

The resin composition (Q) preferably has an insoluble content of 10% by mass or less with respect to chloroform, more preferably 8% by mass or less, and even more preferably 5% by mass or less. Since the copolymer (P) contained in the resin composition (Q) substantially does not contain a crosslinked structure or, even if it contains, can be suppressed in a small amount, the ratio of the insoluble matter to chloroform of the resin composition (Q) is reduced. It can be done. Therefore, the resin composition (Q) has a small amount of foreign matter contained. For example, when an optical film is formed from the resin composition (Q), there are few surface irregularities and defects, and a film with high transparency can be easily obtained. have. In addition, when removing foreign matter from the resin composition, the load applied to the filter for removing foreign matter is reduced, and manufacturing efficiency is improved.

In contrast, for example, in the elastic organic fine particles having a core-shell structure disclosed in JP 2008-242421 A, since the organic fine particles are graft polymers having a crosslinked structure, they are insoluble in chloroform. Therefore, if a copolymer having such a crosslinked structure is used as a raw material for an optical film that requires high quality, it may cause foreign matter or defects in the film, or when the film is stretched, the surface becomes uneven, and appearance defects such as haze occur. Because it is not desirable. In addition, when removing foreign matter from the resin composition prior to film molding, the organic fine particles may provide a high load to the filter for removing foreign matter and cause a decrease in productivity.

The insoluble content of the resin composition in chloroform is calculated by the method described in Examples. Specifically, by adding 1 g of the resin composition to 20 g of chloroform, filtering this through a membrane filter made by Teflon (registered trademark) having a pore diameter of 0.5 μm, and measuring the amount of insoluble matter collected in the membrane filter, the resin composition Calculate the ratio of insoluble matter to chloroform.

As for the resin composition (Q), when heated at 290 degreeC for 20 minutes, it is preferable that the foaming quantity which arises is 20 pieces/g or less, 10 pieces/g or less are more preferable, and 5 pieces/g or less are still more preferable. Thereby, the appearance of a molded article (for example, a film, etc.) when the resin composition (Q) is heat-molded is improved. The foaming amount was measured using a Melt Indexer specified in JIS K 7210, and the dried resin composition was filled into a cylinder of a Melt Indexer, held at 290°C for 20 minutes, and then extruded into a strand shape. It is carried out by counting the number of occurrences of bubbles existing between the upper mark and the lower mark, and expressing the number of bubbles per 1 g of the resin composition.

The melting viscosity of the resin composition (Q) at 270°C and 100 (/s) measured according to JIS K 7199 (1999) is preferably 50 Pa·s or more, more preferably 100 Pa·s or more, and 5000 Pa·s. s or less is preferable, and 1000 Pa·s or less is more preferable. If the melting viscosity of the resin composition (Q) is within such a range, the molding processability of the resin composition (Q) is improved, and at the same time, it is difficult to generate fish eyes or die lines in the molded body, and the appearance of the molded body is improved. .

The resin composition (Q) preferably has a breakdown energy of 20 mJ or more, more preferably 24 mJ or more, and even more preferably 28 mJ or more, in the case of a 160 µm-thick unstretched film. Thereby, when a film is formed from the resin composition (Q), it becomes easy to obtain a film with high mechanical strength. Breaking energy is calculated by the method described in the examples.

The resin composition (Q) preferably has a trouser tear strength of 15 mJ or more, more preferably 18 mJ or more, and even more preferably 22 mJ or more, when a stretched film having a thickness of 40 µm is used. Thereby, when a film is formed from the resin composition (Q), it becomes easy to obtain a film with high tear strength. Trouser tear strength is calculated by the method described in the Examples.

Resin composition (Q) is preferably 1000 or more times, more preferably 1200 times or more, more preferably 1350 times or more, according to the MIT cut resistance test when a stretched film having a thickness of 40 μm is used. Do. Thereby, when a film is formed from the resin composition (Q), it becomes easy to obtain a high film which is hard to break. The MIT cut resistance test is carried out by the method described in Examples.

The production method of the resin composition (Q) is not particularly limited, but when polymerizing the copolymer (P), it is easy to polymerize and produce the (meth)acrylic polymer as well. In the method for preparing the copolymer (P) described above, in addition to the copolymer (P), a (meth)acrylic polymer corresponding to the polymer chain (B) of the copolymer (P) is simultaneously produced, but at this time, the copolymer (P ) By not separating the (meth)acrylic polymer, the resin composition (Q) containing the copolymer (P) and the (meth)acrylic polymer can be obtained. In this case, the production method of the resin composition (Q) is the polymerization process described in the production method of the copolymer (P), or by the polymerization process and the ring structure forming process, the copolymer (P) and the ( A meth)acrylic polymer is obtained.

The method for producing the resin composition (Q) is not limited to the above method, and the copolymer (P) can be isolated and mixed with another polymer to obtain a resin composition (Q). In addition, in the above-described method for producing the copolymer (P), after the graft copolymerization reaction to the copolymer (P1) is completed, additional monomers are added to perform polymerization to obtain a resin composition (Q). . Alternatively, with respect to the mixture of the copolymer (P) and the (meth)acrylic polymer obtained by the above-described method for preparing the copolymer (P), a separate polymer (for example, a separate (meth)acrylic polymer) It can also be added and made into resin composition (Q). When other polymers are added and mixed, melt-kneading may be performed, and in this case, for example, a general apparatus such as a kneader or a multi-screw extruder can be used.

In the method for producing the resin composition (Q), the filtration step described above may be performed following the polymerization step or the ring structure forming step. By performing the filtration step, the amount of foreign matter in the resin composition (Q) can be reduced, and the resin composition (Q) can be suitably applied to an optical film or the like that requires high quality. For details of the filtration step, reference is made to the description of the filtration step in the method for producing the copolymer (P).

[3. Molding and processing of copolymer and resin composition]

The copolymer (P) and the resin composition (Q) may be used as a liquid or may be used as a cured product. In the latter case, the copolymer (P) and the resin composition (Q) are heated and melted and formed into an arbitrary shape, whereby a molded body can be obtained. The shape of the molded body can be appropriately set according to the application, and for example, plate shape, sheet shape, granular shape, powder shape, block shape, particle agglomerate shape, spherical shape, elliptical spherical shape, lens shape, regular cube shape, column shape, rod shape, conical shape , A tube shape, a needle shape, a fibrous shape, a hollow fiber shape, a porous shape, etc. are mentioned. Injection molding, extrusion molding, vacuum molding, compression molding, blow molding, etc. can be used for the molded article of the copolymer (P) and the resin composition (Q), and the shape in that case is, for example, having a particle diameter of 1 μm to 1000 μm. It is preferable that it is a powder, a cylindrical or spherical pellet having a long diameter of about 1 mm to 10 mm, or a mixture thereof.

The copolymer (P) and the resin composition (Q) can also be molded into a film. As a method of forming the film, known methods such as a solution casting method (solution casting method), a melt extrusion method, a calender method, and a compression molding method can be used. Among these, a solution casting method and a melt extrusion method are preferable.

Examples of the solvent used in the solution casting method include chlorinated aliphatic hydrocarbons such as chloroform and dichloromethane; Aromatic hydrocarbons such as toluene, xylene, and benzene; Alcohols such as methanol, ethanol, isopropanol, n-butanol, and 2-butanol; Cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; Ethers such as diethyl ether, dioxane, and tetrahydrofuran; Ketones such as acetone and cyclohexanone: esters such as ethyl acetate, propyl acetate, and butyl acetate; Dimethylformamide; Dimethyl sulfoxide, etc. are mentioned. These may be used alone or in combination of two or more.

As an apparatus for carrying out the solution casting method, a drum type casting machine, a band type casting machine, a spin coater, etc. are mentioned, for example.

Examples of the melt extrusion method include a T-die method and an inflation method. The temperature (molding temperature) at the time of melt extrusion molding the film is preferably 150°C or higher, more preferably 200°C or higher, further preferably 350°C or lower, and more preferably 300°C or lower.

In the T-die method, a film rolled on a roll is obtained by winding a film extruded from an extruder equipped with a T-die at the tip portion onto a roll. At this time, by controlling the winding temperature and speed, stretching (uniaxial stretching) can be added to the extrusion direction of the film.

In melt extrusion molding, it is preferable to use an extruder. It is preferable that the extruder has a cylinder, a screw installed in the cylinder, and a heating means. Depending on the number of screws, the extruder has a single-screw extruder, a twin-screw extruder, and a multi-screw extruder, and any extruder can be used. The L/D value of the extruder (L is the length of the cylinder of the extruder, and D is the inner diameter of the cylinder) is preferably 10 or more, more preferably 15 or more, and 20 in order to sufficiently plasticize the resin composition to obtain a good kneading state. More preferably more, 100 or less are more preferable, 80 or less are more preferable, and 60 or less are still more preferable. When the L/D value is less than 10, the resin composition cannot be sufficiently plasticized, and a good kneaded state may not be obtained. When the L/D value exceeds 100, the component contained in the resin composition tends to be thermally decomposed due to excessive increase in shear heat generation with respect to the resin composition.

The cylinder setting temperature (heating temperature) of the extruder is preferably 200°C or higher, more preferably 250°C or higher, further preferably 350°C or lower, and more preferably 320°C or lower. When the set temperature is less than 200°C, the melting viscosity of the resin composition becomes excessively high, and there is a fear that the productivity of the film may decrease. When the set temperature exceeds 350°C, the components contained in the resin composition tend to be thermally decomposed.

It is preferred that the extruder has at least one open vent. By using such an extruder, decomposition gas can be sucked in the open vent portion, and the amount of residual volatile components of the obtained film can be reduced. In order to suck the decomposed gas from the open vent part, for example, the open vent part may be in a reduced pressure state, and the degree of decompression at this time is the pressure (absolute pressure) of the open vent part, preferably 1.3 hPa or more, more preferably Is 13.3 hPa or more, 931 hPa or less is preferable, and 798 hPa or less is more preferable. When the pressure of the open vent portion is higher than 931 hPa, a volatile component or a monomer component generated by decomposition of a polymer contained in the resin composition tends to remain in the obtained film. On the other hand, it is industrially difficult to keep the pressure of the open vent portion lower than 1.3 hPa.

In melt extrusion molding, it is preferable to filter the copolymer (P) or resin composition (Q) in the molten state using a polymer filter, and thereby foreign matter contained in the copolymer (P) or resin composition (Q). Can be removed. Thereby, when forming an optical film from the copolymer (P) or the resin composition (Q), the amount of optical defects and visual defects in the finally obtained optical film can be reduced.

The temperature of the melt extrusion molding is preferably 200°C or higher, more preferably 250°C or higher, and more preferably 350°C or lower, and more preferably 320°C or lower, for example. If the temperature of the melt extrusion molding is 200°C or higher, the viscosity of the copolymer (P) or the resin composition (Q) decreases, and the residence time in the polymer filter can be shortened. If the temperature of the melt extrusion molding is 350°C or less, for example, during continuous molding of the film, it becomes difficult to form perforations, flow patterns, stripes and defects in the film, so that a film having a good appearance becomes easy to be obtained.

The configuration of the polymer filter is not particularly limited. For example, a polymer filter in which a plurality of leaf disk filters are arranged in a housing is suitably used. As the filter medium of the leaf disc filter, any type of filter medium can be used, such as a filter medium obtained by sintering metal fiber nonwoven fabric, a filter medium obtained by sintering metal powder, a filter medium by stacking several layers of wire mesh, and a hybrid type filter medium combining these. Among them, a filter medium obtained by sintering a nonwoven metal fiber fabric is preferably used.

The degree of filtration (pore diameter) of the polymer filter is not particularly limited. The degree of filtration is usually 15 µm or less, preferably 10 µm or less, and more preferably 5 µm or less, in view of the size of the foreign matter to be removed. The lower limit of the degree of filtration is not particularly limited, but due to the longer residence time of the copolymer (P) or the resin composition (Q) in the polymer filter, the copolymer (P) or the resin composition (Q) may be thermally deteriorated. And, considering that the productivity of the film is lowered, 1 μm or more is preferable.

The shape of the polymer filter is not particularly limited. As a type of polymer filter, for example, it has a plurality of resin flow ports, an inner flow type having a resin flow path in a center pole, and a cross section contacts the inner circumferential surface of the leaf disk filter at a plurality of vertices or surfaces, And an external type with a resin flow path on the outer surface thereof. Among them, an external type polymer filter is preferably used in view of the fact that the resin retains little.

The residence time of the copolymer (P) or resin composition (Q) in the polymer filter is preferably 20 minutes or less, more preferably 10 minutes or less, and still more preferably 5 minutes or less. The inlet pressure of the polymer filter in melt filtration and the outlet pressure of the filter are, for example, 3 MPa or more and 15 MPa or less and 0.3 MPa or more and 10 MPa, respectively. The pressure loss in melt filtration (the pressure difference between the inlet pressure and the outlet pressure of the polymer filter) is preferably 1 MPa or more and 15 MPa or less. When the pressure loss is 1 MPa or less, the inclination tends to occur in the flow path through which the copolymer (P) or the resin composition (Q) passes through the polymer filter. The slope of the flow path causes the quality of the obtained film to deteriorate. When the pressure loss exceeds 15 MPa, the polymer filter is liable to be damaged.

When melt filtering the copolymer (P) or the resin composition (Q), it is preferable to stabilize the pressure in the polymer filter by providing a gear pump between the extruder and the polymer filter. Melt filtration with a polymer filter can be performed at any timing other than during melt extrusion molding.

In the case of forming a film by a melt extrusion method, it can be formed into a stretched film by stretching. By stretching, the mechanical strength of the film can be further improved. As a stretching method for obtaining a stretched film, a conventionally known stretching method can be applied. For example, uniaxial stretching such as free width uniaxial stretching and constant width uniaxial stretching; Biaxial stretching such as sequential biaxial stretching and simultaneous biaxial stretching; When the film is stretched, a shrinkable film is adhered to one or both sides thereof to form a laminate, and the laminate is heat-stretched to give the film a shrinking force in a direction orthogonal to the stretching direction. And stretching to obtain a birefringent film in which each oriented molecular group is mixed. Biaxial stretching is preferably used from the viewpoint of improving the mechanical strength such as the cutting resistance of the film. In addition, simultaneous biaxial stretching is preferably used from the viewpoint of improving mechanical strength such as cutting resistance in two directions that are perpendicular to the inside of the film surface. Examples of the two directions in which the inside of the plane is arbitrarily orthogonal include a direction parallel to the slow axis in the film plane and a direction perpendicular to the slow axis in the film plane. In addition, stretching conditions, such as a stretching ratio stretching temperature and a stretching speed, can be appropriately set according to a desired mechanical strength or a retardation value, and are not particularly limited.

Examples of the stretching device include a roll stretching machine, a tenter-type stretching machine, a tensile testing machine as a small experimental stretching device, a uniaxial stretching machine, a sequential biaxial stretching machine, and a simultaneous biaxial stretching machine. You can use your device.

The stretching temperature is preferably carried out near the highest glass transition temperature of the copolymer (P) or resin composition (Q). Specifically, it is preferable to carry out within the range of the highest glass transition temperature -30°C to the highest glass transition temperature +50°C, more preferably the highest glass transition temperature -20°C to the highest glass transition temperature +45 It is in the range of °C, more preferably in the range of the highest glass transition temperature -10 °C to the highest glass transition temperature +40 °C. If it is lower than the highest glass transition temperature -30°C, there are cases where a sufficient draw ratio cannot be obtained. If it is higher than the highest glass transition temperature of +50°C, flow (flow) of the resin occurs, making it difficult to perform stable stretching.

The draw ratio defined by the area ratio is preferably in the range of 1.1 to 30 times, more preferably in the range of 1.2 to 20 times, and still more preferably in the range of 1.3 to 10 times. In the case of stretching in one direction, the stretching ratio in one direction is preferably in the range of 1.05 to 10 times, more preferably in the range of 1.1 to 7 times, and still more preferably in the range of 1.2 to 5 times. By setting the draw ratio within this range, it becomes easy to obtain favorable effects such as improvement in mechanical strength of the film according to stretching.

The stretching speed (one direction) is preferably in the range of 10 to 20, 000%/min, more preferably in the range of 100 to 10,000%/min. If it is slower than 10%/min, it takes time to obtain a sufficient draw ratio, and the manufacturing cost tends to increase. If it is faster than 20, 000%/min, there is a concern that rupture of the stretched film may occur.

When the stretched film is applied to the optical film, it is preferable to perform heat treatment (annealing) as necessary after stretching in order to stabilize the optical and mechanical properties of the optical film.

〔4. Optical film)

Since the film formed from the copolymer (P) or the resin composition (Q) is excellent in transparency, it can be suitably used as an optical film. The optical film thus obtained is excellent in mechanical strength and heat resistance. The optical film may be a stretched film or an unstretched film. As an optical film, for example, a protective film for optics (specifically, a protective film on a substrate of various optical disks (VD, CD, DVD, MD, LD, etc.)), a polarizing plate provided in an image display device such as a liquid crystal display A polarizer protective film to be used, a viewing angle compensation film, a light diffusion film, a reflective film, an antireflection film, an anti-glare film, a luminance improving film, a conductive film for touch panels, a retardation film, and the like are mentioned.

The thickness of the optical film is preferably 5 µm or more, more preferably 15 µm or more, and even more preferably 20 µm or more in terms of increasing the strength of the optical film. On the other hand, from the viewpoint of thinning the optical film, the thickness of the optical film is preferably 350 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less. The thickness of the optical film can be measured using, for example, Mitutyo's Digimatic Micrometer.

It is preferable that the optical film has a high light transmittance, for example, the total light transmittance is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more.

The optical film preferably has a haze of 5.0% or less, more preferably 3.0% or less, and even more preferably 1.0% or less from the viewpoint of enhancing transparency. Further, the internal haze is preferably 5.0% or less, more preferably 3.0% or less, more preferably 2.0% or less, and even more preferably 1.0% or less.

The optical film preferably has an in-plane retardation Re of 0 nm or more and 1000 nm or less with respect to light having a wavelength of 589 nm, and a retardation Rth of -1000 nm or more and 1000 nm or less with respect to the light. More preferably, Re is 0 nm or more and 100 nm or less, Rth is -100 nm or more and 100 nm or less, More preferably Re is 0 nm or more and 50 nm or less, Rth is -30 nm or more and 30 nm or less, Particularly preferably Re is 0 nm or more and 10 nm or less , Rth is -10nm or more and 10nm or less. An optical film that exhibits such an in-plane retardation Re and a retardation Rth in the thickness direction has good viewing angle characteristics and contrast characteristics, and can be suitably applied to image display devices including liquid crystal displays. In addition, the in-plane retardation Re is defined as Re = (nx-ny)×d, the retardation Rth in the thickness direction is defined as Rth = d×{(nx+ny)/2-nz}, and nx is the ground in the film plane Refractive index in the slow axis direction (the direction in which the refractive index is the largest in the film plane), ny is the refractive index in the direction perpendicular to nx, nz is the refractive index in the film thickness direction, d is the thickness of the film (nm) Represents.

The optical film may be composed of only a film formed of a copolymer (P) or a resin composition (Q), or may be composed by laminating other optical materials on the film. By laminating other optical materials, additional optical properties can be imparted to the optical film. As another optical material, a polarizing plate, a polycarbonate stretch oriented film, a cyclic polyolefin stretch oriented film, etc. are mentioned, for example.

Each functional coating layer may be installed on the surface of the optical film as necessary. As a functional coating layer, for example, an antistatic layer, an adhesive/adhesive layer, an adhesive layer, an easily adhesive layer, a non-glare layer, an antifouling layer such as a photocatalyst layer, an antireflection layer, a hard coating layer, an ultraviolet ray shielding layer, a heat ray shielding layer, an electromagnetic wave A shielding layer, a gas barrier layer, etc. are mentioned. In addition, an optical adjustment layer for appropriately adjusting the transmittance or reflectance of light incident on the surface of the optical film may be provided.

The optical film of the present invention can be particularly suitably used for a polarizer protective film. The polarizer protective film is not particularly limited except that the copolymer (P) is included. When the optical film is applied to the polarizer protective film, an optical film (polarizer protective film) may be provided on one or both sides of the polarizer to constitute a polarizing plate. The optical film (polarizer protective film) is preferably fixed with an adhesive or pressure-sensitive adhesive directly to the polarizer or indirectly through another layer.

The kind of polarizer is not particularly limited, and examples thereof include a polarizer dyed and stretched with a polyvinyl alcohol film; Polyene polarizers such as dehydration-treated polyvinyl alcohol or dehydrochloric acid-treated polyvinyl chloride; A reflective polarizer using a multilayered body or a cholesteric liquid crystal; A polarizer made of a thin-film crystal film, etc. are mentioned. An example of the structure of a polarizing plate is a structure in which polyvinyl alcohol is dyed with a dichroic substance such as iodine or a dichroic dye, and then uniaxially stretched to obtain a polarizer, and a polarizer protective film (optical film) is installed on one or both sides of the polarizer. Can be mentioned.

The optical film can also be used as a transparent conductive film by forming a transparent conductive layer on the surface. As the material constituting the transparent conductive layer, any material that has been conventionally used as a conductive material in the art can be used. Specifically, an organic conductive compound; Organic conductive polymer; Metal oxides such as indium oxide, tin oxide, zinc oxide, indium-tin oxide (ITO), antimony-tin oxide (ATO), zinc-aluminum oxide, and indium-zinc oxide (IZO); Metals, such as gold, silver, copper, palladium, and aluminum, are mentioned.

The optical film of the present invention (eg, a polarizer protective film, a transparent conductive film) can be suitably used for an image display device. As an image display device, a liquid crystal display device etc. are mentioned, for example. For example, in the case of a liquid crystal display device, the image display unit can be configured to have the optical film of the present invention together with members such as a liquid crystal cell, a polarizing plate, and a backlight. Examples of image display devices other than liquid crystal display devices include an electroluminescence (EL) display panel, a plasma display panel (PDP), a field emission display (FED), a QLED, a micro LED, and the like.

This application claims the benefit of priority based on Japanese Patent Application No. 2017-004468 filed on January 13, 2017. The entire contents of the specification of Japanese Patent Application No. 2017-004468 filed on January 13, 2017 are incorporated herein by reference.

Example

Hereinafter, the present invention will be described in more detail by showing examples and comparative examples, but the present invention is not limited thereto. In addition, in the following description, "part" represents "mass part" and "%" represents "mass%" unless otherwise noted.

(1) Analysis method

(1-1) Weight average molecular weight (Mw) and number average molecular weight (Mn)

The weight average molecular weight and number average molecular weight were calculated in terms of polystyrene using gel permeation chromatography (GPC). The apparatus and measurement conditions used for the measurement are as follows.

-Measurement system: TOSOH CORPORATION, GPC system HLC-8220

-Measurement column configuration

Guard column: TOSOH CORPORATION, TSKguardcolumn Super HZ-L

Separation column: TOSOH CORPORATION, TSKgel SuperHZM-M 2 serial connection

-Reference side column configuration

Reference column: TOSOH CORPORATION, TSKgel SuperH-RC

-Development solvent: Chloroform (Wako Pure Chemical Industries, Ltd., Limited)

-Solvent flow rate: 0.6mL/min

-Standard sample: TSK standard polystyrene (TOSOH CORPORATION, PS-oligomer kit)

(1-2) Glass transition temperature (Tg)

The glass transition temperature was calculated based on JIS K 7121 (2012). Specifically, DSC obtained by using a differential scanning calorimeter (Rigaku Corporation, Thermo plus EVO DSC-8230) and heating about 10 mg of a sample from room temperature to 300°C (heating rate 20°C/min) under a nitrogen gas atmosphere. From the curve, it evaluated by the viewpoint method. Α-alumina was used as a reference. For the glass transition temperature of less than 40℃, a differential scanning calorimeter (Netch Co., Ltd., DSC-3500) was used, and the sample was heated from -100℃ to 60℃ under a nitrogen gas atmosphere (heating rate 10℃/min). From the thus obtained DSC curve, it was evaluated by the viewpoint method. An empty container was used for the reference.

(1-3) Monomer reaction rate

The monomer reaction rate (conversion rate) was calculated by measuring the amount of residual monomer in the polymerization reaction liquid using gas chromatography (Shimadzu Corporation., GC-2014).

(1-4) Gelation evaluation (filtration test)

The gelation evaluation of the resin composition was performed by the filter filtration test. Using a plastic syringe equipped with a filter (GL Sciences Inc., chromatographic disk 13N, pore diameter 0.45 µm) at the tip of the resin composition, a 0.1% by mass chloroform solution is filtered through the resin composition. If clogged and the solution was not filtered by 2 mL, it was evaluated as x.

(1-5) Chloroform insoluble

1 g of the resin composition was added to 20 g of chloroform, and this was filtered through a membrane filter (ADVANTEC, T050A 047A) having a pore diameter of 0.5 μm, and the filtered membrane filter was dried. From the mass M ₀ (g) of the membrane filter before filtration and the mass M ₁ (g) of the membrane filter after filtration after drying, the chloroform insoluble content of the resin composition was required according to the following equation: Chloroform insoluble content (% by mass) = (M ₁ -M ₀ )/1×100.

(1-6) Breaking energy (falling ball test)

The destruction energy was calculated as follows. First, a film was formed from the resin composition by hot pressing to obtain a 160 µm-thick film (unstretched film). Next, on this film, a test of dropping a sphere having a mass of 0.0054 kg from a constant height was performed 10 times, and the average value of the height (break height) when the film was destroyed was calculated. Specifically, when the height is set in several steps, the height at which the film is broken is calculated when the sphere is dropped from the lower height in order, and this is repeated 10 times to calculate the height at which the film is broken for 10 times, and the average value Was calculated as the breaking height. Whether or not the film was broken was judged by visually checking whether or not the film had any deformation after falling into the film. If deformation was observed, the film had been broken. Breakdown energy (E) was calculated according to the following equation: Breakdown energy E(mJ) = sphere mass (kg) x average break height (mm) x 9.8 (m/s ² ).

(1-7) total light transmittance

The resin composition was heat-pressed to form a film, and a 160 µm-thick film (unstretched film) was obtained, and the total light transmittance was measured using a haze meter (NIPPON DENSHOKU INDSUTRIES CO., LTD., NDH-5000). .

(1-8) internal haze

The resin composition was hot-press molded at 250° C. to prepare a film (unstretched film) having a thickness of about 160 μm. A quartz cell was filled with 1,2,3,4-tetrahydronaphthalin (tetraline), the film produced therein was immersed, and a haze meter (NIPPON DENSHOKU INDSUTRIES CO., LTD., NDH-5000) was used. Thus, the haze was measured, and the internal haze per 100 µm in thickness was calculated according to the following equation: Internal haze per 100 µm in thickness (%) = obtained measured value (%) x (100 µm/thickness of film (µm)). Moreover, the measurement was performed using three films, and the internal haze per 100 micrometers of thickness was computed from the average value.

(1-9) Dispersion state (observation of sea-island structure size by STEM)

A 160 µm-thick film (unstretched film) produced by subjecting the resin composition to heat press molding at 250° C. was subjected to phase separation of the film using a scanning electron microscope (Hitachi High-Technologies Corporation., FE-SEMS-4800). The dispersion state (sea-island structure) was observed. Measurement conditions were carried out with an acceleration voltage of 20 kV, an emission current of 5 µA or 10 µA, and W.D. = 8 mm. The island size measured the maximum length of an island portion of 10 arbitrary points, and calculated as the average value.

(1-10) MIT cut resistance test (cut resistance strength)

The resin composition was hot press molded at 250° C. to obtain an unstretched film having a thickness of 160 μm. The obtained unstretched film was cut out to a size of 96 mm x 96 mm, and a sequential biaxial stretching machine (Toyo Seiki Seisaku-sho, Ltd., X-6S) was used, and the resin composition was 240 mm / at a temperature of Tg + 24 °C. Biaxial stretching was sequentially performed so that the stretching ratio was doubled in the longitudinal direction (MD direction) and the transverse direction (TD direction) at a stretching speed of minutes, and cooling was performed to obtain a stretched film having a thickness of 40 µm. The obtained stretched film was cut into a size of 90 mm×15 mm to form a test piece, and a load of 200 g was applied in an atmosphere having a temperature of 23°C and a relative humidity of 50% using an MIT cut resistance tester (TESTER SANGYO CO., LTD., BE-201). Then, according to JIS P 8115 (2001), the number of MIT cutting resistance tests was measured.

(1-11) Trouser tear strength (tear strength)

According to JIS K 7128-1 (1998), Trouser tear strength was calculated. Specifically, the stretched film obtained according to the above (1-10) was cut into a size of 120 mm x 30 mm, left to stand in an atmosphere of a temperature of 23° C. and a relative humidity of 50% for at least 1 hour, and then used as a test piece. Using a graph (Shimadzu Corporation., AGS-X), the test was conducted at a test speed of 200 mm/min, and the average value of the tearing force of 35 mm excluding 20 mm at the start of tearing and 5 mm before the end of tearing was calculated, and the five samples were The average value was taken as the measurement result.

(1-12) phase difference

The stretched film obtained according to the description in (1-10) above was subjected to in-plane retardation Re and thickness direction for light having a wavelength of 590 nm under the condition of an incident angle of 40° using a fully automatic birefringence meter (Oji Scientific Instruments., KOBRA-WR). The phase difference Rth of was measured. The refractive index in the slow axis direction in the plane of the film is nx, the refractive index in the faxt axis direction in the plane of the film is ny, the refractive index in the thickness direction of the film is nz, and the thickness of the film is d. Then, the in-plane retardation Re and the retardation Rth in the thickness direction were respectively calculated from the following equation.

In-plane retardation Re = (nx-ny)×d

Thickness direction retardation Rth = [(nx+ny)/2-nz]×d

(2) Preparation of resin composition

(2-1) Example 1: Preparation of resin composition (A-1)

In a reactor equipped with a stirring device, a temperature sensor, a cooling tube, and a nitrogen introduction tube, an esterified product of a maleic anhydride adduct of polyisoprene and 2-hydroxyethyl methacrylate (KURARAY CO., LTD., UC-102M). ) 3 parts, 26 parts of methyl methacrylic acid (MMA), 1 part of 2-(hydroxymethyl) methyl acrylate (MHMA), and 50 parts of toluene as a polymerization solvent were added, and the temperature was raised to 105°C while passing nitrogen. . Then, 0.09 parts of t-amyl peroxy isononanoate (ARKEMA Yoshitomi, Ltd., LUPEROX (registered trademark) 570) was added as an initiator, and solution polymerization was performed at 105 to 110°C for 30 minutes. 0.01 part of stearyl phosphate was added here as a cyclization catalyst, and reaction was performed for 10 minutes. Thereby, a resin composition containing a lactone ring-containing (meth)acrylic polymer and a graft polymer in which the polymer chain was grafted onto a polyisoprene chain was obtained. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 16%, and the reaction rate of MHMA was 10%. The composition ratio (by mass) of the (meth)acrylic polymer chain bound to the polyisoprene chain calculated from the reaction rate and the (meth)acrylic polymer is MMA:MHMA = 97.7:2.3, and the unit content ratio derived from (meth)acrylic acid ester Silver was 96.2 mass% and the content ratio of the ring structural unit was 3.5 mass%. When a part of the reaction liquid was taken out and a filtration test was performed, it was possible to perform filtration suitably.

Next, 50 parts of methyl ethyl ketone (MEK) were added to the obtained reaction solution, diluted, filtered through a filter made of PTFE (polytetrafluoroethylene) having a pore diameter of 10 μm, and then slowly stirred in a large amount of methanol. Added. At this time, the precipitated white solid was removed, dried at 2.6 kPa, 80°C for about 1 hour, and the solvent was removed to contain a lactone ring-containing (meth)acrylic polymer and a graft polymer in which the polymer chain was grafted onto a polyisoprene chain. To obtain a resin composition (A-1). The weight average molecular weight of the resin composition (A-1) was 138,000, the number average molecular weight was 38,000, and the chloroform insoluble content was 2%.

(2-2) Example 2: Preparation of resin composition (A-2)

In a reactor equipped with a stirring device, a temperature sensor, a cooling tube, and a nitrogen introduction tube, an esterified product of a maleic anhydride adduct of polyisoprene and 2-hydroxyethyl methacrylate (manufactured by KURARAY CO., LTD., UC- 102M) 3 parts, methyl methacrylic acid (MMA) 23 parts, phenylmaleimide (PMI) 3 parts, and 50 parts of toluene as a polymerization solvent were added, and the temperature was raised to 105°C while passing nitrogen thereto. Then, 0.09 parts of t-amyl peroxy isononanoate (ARKEMA Yoshitomi, Ltd., LUPEROX (registered trademark) 570) was added as an initiator, and solution polymerization was performed at 105 to 110°C for 30 minutes. Thereby, a resin composition containing a maleimide ring-containing (meth)acrylic polymer and a graft polymer in which the polymer chain was grafted onto a polyisoprene chain was obtained. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 14%, and the reaction rate of PMI was 21%. The composition ratio (by mass) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the polyisoprene chain calculated from the reaction rate is MMA:PMI=83.6:16.4, and the unit content ratio derived from (meth)acrylic acid ester Silver was 83.6 mass% and the content ratio of the ring structural unit was 16.4 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably.

Next, 50 parts of methyl ethyl ketone (MEK) were added and diluted to the obtained reaction solution, and this was filtered through a PTFE filter with a pore diameter of 10 µm, and then slowly added while stirring in a large amount of methanol. At that time, the precipitated white solid was removed, dried at 2.6 kPa, 80°C for about 1 hour, and the solvent was removed to remove the maleimide ring-containing (meth)acrylic polymer and the graft polymer in which the polymer chain was grafted onto a polyisoprene chain. A resin composition (A-2) containing was obtained. The weight average molecular weight of the resin composition (A-2) was 11.10,000, the number average molecular weight was 31,000, and the chloroform insoluble content was 3%.

(2-3) Comparative example 1: Preparation of resin composition (A-3)

In a reactor equipped with a stirring device, a temperature sensor, a cooling tube, and a nitrogen introduction tube, an esterified product of a maleic anhydride adduct of polyisoprene and 2-hydroxyethyl methacrylate (KURARAY CO., LTD., UC-102M). ) 3 parts, 27 parts of methyl methacrylic acid (MMA), and 50 parts of toluene as a polymerization solvent were added, and the temperature was raised to 105°C while passing nitrogen. Then, 0.09 parts of t-amyl peroxy isononanoate (ARKEMA Yoshitomi, Ltd., LUPEROX (registered trademark) 570) was added as an initiator, and solution polymerization was performed at 105 to 110°C for 30 minutes. Thereby, a resin composition containing a methyl methacrylic acid polymer (PMMA) and a graft polymer in which the polymer chain was grafted onto a polyisoprene chain was obtained. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 16%.

Next, 50 parts of methyl ethyl ketone (MEK) were added and diluted to the obtained reaction solution, and then slowly added while stirring in a large amount of methanol. At that time, the precipitated white solid was removed, dried at 2.6 kPa, 80°C for about 1 hour, and the solvent was removed to obtain a methylmethacrylic acid polymer (PMMA) and a graft polymer in which the polymer chain was grafted onto a polyisoprene chain. The resin composition (A-3) to contain was obtained. The weight average molecular weight of resin composition (A-3) was 124,000, and the number average molecular weight was 31,000.

(2-4) Comparative example 2: Synthesis of resin composition (B-1)

To a reactor equipped with a stirring device, a temperature sensor, a cooling tube, and a nitrogen introduction tube, 48 parts of methyl methacrylic acid (MMA), 2 parts of 2-(hydroxymethyl) methyl acrylate (MHMA), and 50 parts of toluene as a polymerization solvent are added. And it heated up to 105 degreeC, passing nitrogen through this. Then, 0.2 parts of t-amyl peroxy isononanoate (ARKEMA Yoshitomi, Ltd., LUPEROX (registered trademark) 570) was added as an initiator, and solution polymerization was performed at 105 to 110°C for 180 minutes. 0.01 part of stearyl phosphate was added here as a cyclization catalyst, and after reacting for 1 hour, it heated in an autoclave at 240 degreeC for 1 hour. Thereby, a resin composition containing a lactone ring-containing (meth)acrylic polymer was obtained. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 82%, and the reaction rate of MHMA was 88%. The composition ratio (mass basis) of the lactone ring-containing (meth)acrylic polymer calculated from the reaction rate is MMA:MHMA=95.7:4.3, the unit content ratio derived from (meth)acrylic acid ester is 93.1% by mass, and the content ratio of the ring structural unit is It was 6.4 mass%.

Next, 50 parts of methyl ethyl ketone (MEK) were added and diluted to the obtained reaction solution, and then slowly added while stirring in a large amount of methanol. The white solid precipitated at that time was taken out, dried at 2.6 kPa and 200° C. for about 1 hour, and the solvent was removed to obtain a resin composition (B-1) containing a lactone ring-containing (meth)acrylic polymer. The weight average molecular weight of resin composition (B-1) was 138,000, and the number average molecular weight was 57,000.

(2-5) Comparative example 3: Preparation of resin composition (B-2)

In a reactor equipped with a stirring device, a temperature sensor, a cooling tube, and a nitrogen introduction tube, 47 parts of methyl methacrylic acid (MMA), 3 parts of PMI, and 50 parts of toluene as a polymerization solvent are added, and the temperature is raised to 105°C while passing nitrogen through the reactor. Made it. Then, 0.2 parts of t-amyl peroxy isononanoate (ARKEMA Yoshitomi, Ltd., LUPEROX (registered trademark) 570) was added as an initiator, and solution polymerization was performed at 105 to 110°C for 180 minutes. Thereby, a resin composition containing a maleimide ring-containing (meth)acrylic polymer was obtained. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 85%, and the reaction rate of PMI was 82%. The composition ratio (mass basis) of the maleimide ring-containing (meth)acrylic polymer calculated from the reaction rate is MMA:PMI=94.2:5.8, the unit content ratio derived from (meth)acrylic acid ester is 94.2% by mass, and the content ratio of the cyclic structural unit Was 5.8% by mass.

Next, 50 parts of methyl ethyl ketone (MEK) were added and diluted to the obtained reaction solution, and then slowly added while stirring in a large amount of methanol. The white solid precipitated at that time was taken out, dried at 2.6 kPa and 200° C. for about 1 hour, and the solvent was removed to obtain a resin composition (B-2) containing a maleimide ring-containing (meth)acrylic polymer. The weight average molecular weight of resin composition (B-2) was 12.9 million, and the number average molecular weight was 59,000.

(2-6) Example 3: Preparation of resin composition (C-1)

1 part of the resin composition (A-1) obtained in Example 1 and 9 parts of the resin composition (B-1) obtained in Comparative Example 2 were dissolved and mixed in 40 parts of MEK, followed by drying at 2.6 kPa and 150° C. for about 1 hour. By removing the solvent, a resin composition (C-1) was obtained. The weight average molecular weight of resin composition (C-1) was 131,000, and the number average molecular weight was 59,000.

(2-7) Example 4: Preparation of resin composition (C-2)

1 part of the resin composition (A-2) obtained in Example 2, 9 parts of the resin composition (B-2) obtained in Comparative Example 3, 0.01 part of an ultraviolet absorber (ADEKA CORPORATION, LA-31), and an antioxidant (BASF Inc., Irganox (registered trademark) 1010) 0.001 parts and antioxidant (ADEKA CORPORATION, PEP-36) 0.001 parts, dissolved and mixed in 40 parts of MEK, dried at 2.6 kPa, 150°C for about 1 hour, and the solvent was removed. By doing it, a resin composition (C-2) was obtained. The weight average molecular weight of resin composition (C-2) was 132,000, and the number average molecular weight was 51,000.

(2-8) Comparative example 4: Preparation of resin composition (A-4)

In Example 1, in the same manner as in Example 1, except that 3 parts of an esterified product of maleic anhydride of polyisoprene and 2-hydroxyethyl methacrylate was used, 26.7 parts of MMA, and 0.3 parts of MMA were used. Then, polymerization reaction and cyclization reaction were carried out. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 18%, and the reaction rate of MHMA was 12%. The composition ratio (by mass) of the (meth)acrylic polymer chain bound to the polyisoprene chain and the (meth)acrylic polymer calculated from the reaction rate is MMA:MHMA=99.3:0.7, and the unit content ratio derived from the (meth)acrylic acid ester. Silver was 98.9% by mass and the content ratio of the ring structural unit was 1.0% by mass. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. Subsequently, in the same manner as in Example 1, the obtained reaction solution was filtered, reprecipitated, and dried to contain a lactone ring-containing (meth)acrylic polymer, and a graft polymer in which the polymer chain was grafted onto a polyisoprene chain ( A-4) was obtained. The weight average molecular weight of the resin composition (A-4) was 122,000, the number average molecular weight was 31,000, and the chloroform insoluble content was 2%.

(2-9) Comparative example 5: Preparation of resin composition (B-3)

In Comparative Example 2, a polymerization reaction and a cyclization reaction were carried out in the same manner as in Comparative Example 2, except that 49 parts of MMA and 1 part of MHMA were used. The reaction rate of MMA calculated from the amount of residual monomer in the polymerization reaction solution was 81%, and the reaction rate of MHMA was 89%. The composition ratio (mass basis) of the lactone ring-containing (meth)acrylic polymer calculated from the reaction rate is MMA:MHMA=97.8:2.2, the unit content ratio derived from (meth)acrylic acid ester is 96.5% by mass, and the content ratio of the cyclic structural unit is It was 3.2 mass%. Then, in the same manner as in Comparative Example 2, the obtained reaction solution was filtered, reprecipitated, and dried to obtain a resin composition (B-3) containing a lactone ring-containing (meth)acrylic polymer. The weight average molecular weight of resin composition (B-3) was 145,000, and the number average molecular weight was 630,000.

(2-10) Comparative example 6: Preparation of resin composition (C-3)

1 part of the resin composition (A-4) obtained in Comparative Example 4 and 9 parts of the resin composition (B-3) obtained in Comparative Example 5 were dissolved and mixed in 40 parts of MEK, followed by drying at 2.6 kPa and 150° C. for about 1 hour. By removing the solvent, a resin composition (C-3) was obtained. The weight average molecular weight of resin composition (C-3) was 144,000, and the number average molecular weight was 60,000.

(2-11) Comparative example 7: Preparation of resin composition (A-5)

In Example 1, 3 parts of an esterified product of a maleic anhydride adduct of polyisoprene and 2-hydroxyethyl methacrylate was used, 13 parts of MMA and 13 parts of MHMA were used, and stearyl phosphate was used as a cyclization catalyst. A polymerization reaction and a cyclization reaction were performed in the same manner as in Example 1 except that 0.03 parts were used. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 19%, and the reaction rate of MHMA was 13%. The composition ratio (by mass) of the (meth)acrylic polymer chain bound to the polyisoprene and the (meth)acrylic polymer calculated from the reaction rate is MMA:MHMA=59.4:40.6, and the unit content ratio derived from the (meth)acrylic acid ester is The content ratio of 27.4 mass% and the ring structural unit was 67.1 mass %. When a part of the reaction solution was taken out and a filtration test was performed, an increase in pressure of the filter was considered. Subsequently, in the same manner as in Example 1, the obtained reaction solution was filtered, reprecipitated, and dried to contain a lactone ring-containing (meth)acrylic polymer and a graft polymer in which the polymer chain was grafted to polyisoprene ( A-5) was obtained. The weight average molecular weight of the resin composition (A-5) was 181,000, the number average molecular weight was 320,000, and the chloroform insoluble content was 11%.

(2-12) Comparative example 8: Preparation of resin composition (B-4)

In Comparative Example 2, a polymerization reaction and a cyclization reaction were performed in the same manner as in Comparative Example 2, except that 25 parts of MMA and 25 parts of MHMA were used. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 87%, and the reaction rate of MHMA was 85%. The composition ratio (by mass) of the lactone ring-containing (meth)acrylic polymer calculated from the reaction rate is MMA:MHMA=50.6:49.4, the unit content ratio derived from the (meth)acrylic acid ester is 9.2% by mass, and the content ratio of the cyclic structural unit is It was 83.9% by mass. Next, in the same manner as in Comparative Example 2, the obtained reaction liquid was filtered, reprecipitated, and dried to obtain a resin composition (B-4) containing a lactone ring-containing (meth)acrylic polymer. The weight average molecular weight of resin composition (B-4) was 189,000, and the number average molecular weight was 520,000.

(2-13) Comparative example 9: Preparation of resin composition (C-4)

1 part of the resin composition (A-5) obtained in Comparative Example 7 and 9 parts of the resin composition (B-4) obtained in Comparative Example 8 were dissolved and mixed in 40 parts of MEK, followed by drying at 2.6 kPa and 150° C. for about 1 hour. By removing the solvent, a resin composition (C-4) was obtained. The weight average molecular weight of the resin composition (C-4) was 178,000, and the number average molecular weight was 55,000.

(2-14) Example 5: Preparation of resin composition (D-1)

In a reactor equipped with a stirring device, temperature sensor, cooling tube, and nitrogen inlet tube, SEBS triblock copolymer (Kraton, A1536, olefinic double bond amount 0.10mmol/g, styrene unit content 39% by mass, refractive index 1.519) 5 Parts, methylmethacrylic acid (MMA) 73 parts, phenylmaleimide (PMI) 18 parts, n-dodecylmercaptan (nDM) 0.05 parts, and toluene 100 parts as a polymerization solvent were added, and nitrogen was passed through the mixture at 105°C. Heated to. After that, 0.009 parts of t-butylperoxyisopropyl carbonate (Kayaku Akzo Corporation., Kayakarubon (registered trademark) Bic75) was added as an initiator, and 0.018 parts of t- diluted in 5 parts of styrene (St) and 1 part of toluene. Solution polymerization was performed at 105 to 110°C while dropping butyl peroxyisopropyl carbonate at a constant rate over 3 hours, followed by further aging for 4 hours. Thereby, a resin composition comprising a maleimide ring-containing (meth)acrylic polymer formed by polymerization of MMA, PMI, and St, and a graft polymer in which the polymer chain is bonded to the SEBS triblock polymer chain was obtained. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 95%, the reaction rate of PMI was 98%, and the reaction rate of St was 100%. The composition ratio (by mass) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:PMI:St=75.9:18.9:5.2, and (meth)acrylic acid The ester-derived unit content ratio was 75.9 mass%, and the ring structural unit content ratio was 18.9 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably.

Next, the obtained polymerization reaction solution was placed in a vent type screw twin-screw extruder (pore diameter: 15 mm, L/D: 45) with one rear vent number and two fore vents in terms of resin at 600 g/ Introduced at a processing rate of h, devolatilized in this extruder, and extruded, including a maleimide ring-containing (meth)acrylic polymer and a graft polymer in which the polymer chain is bonded to the SEBS triblock polymer chain. A transparent pellet of the resin composition (D-1) was obtained. Moreover, the operating conditions of the twin-screw extruder were barrel temperature 260 degreeC, rotation speed 300 rpm, and the pressure reduction degree 13.3-400 hPa (10-300 mmHg). The weight average molecular weight of the resin composition (D-1) is 15,000, the number average molecular weight is 60,000, the glass transition temperature on the high temperature side is 138°C, the glass transition temperature on the low temperature side is -68°C, and the chloroform insoluble content is 0.3%. , The refractive index was 1.517. The in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film of the resin composition (D-1) were 0.9 nm and 2.9 nm, respectively.

(2-15) Example 6: Preparation of resin composition (D-2)

In Example 5, the same as in Example 5, except that 10 parts of SEBS triblock copolymer (Kraton, A1536), 69 parts of MMA, and 17 parts of PMI were used as the monomer component initially introduced into the reactor. Then, a polymerization reaction was carried out. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 96%, the reaction rate of PMI was 99%, and the reaction rate of St was 100%. The composition ratio (by mass) of the acrylic polymer chain bound to the SEBS triblock copolymer chain and the (meth)acrylic polymer calculated from the reaction rate was MMA:PMI:St=75.2:19.1:5.7, derived from (meth)acrylic acid ester. The unit content ratio of was 75.2 mass%, and the content ratio of the ring structural unit was 19.1 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was subjected to devolatilization in an extruder in the same manner as in Example 6 to obtain pellets of a transparent resin composition (D-2). The weight average molecular weight of the resin composition (D-2) is 148,000, the number average molecular weight is 59,000, the glass transition temperature on the high temperature side is 138°C, the glass transition temperature on the low temperature side is -68°C, and the chloroform insoluble content is 0.3%. , The refractive index was 1.517. The island size of the sea-island structure of the unstretched film of the resin composition (D-2) was 200 nm, and the in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film were 0.2 nm and 3.5 nm, respectively.

(2-16) Example 7: Preparation of resin composition (D-3)

In Example 5, as the monomer component initially introduced into the reactor, 15 parts of SEBS triblock copolymer (Kraton, A1536), 65 parts of MMA and 16 parts of PMI are used, and a monomer component added by dropping A polymerization reaction was carried out in the same manner as in Example 5 except that 4 parts of St were used as a. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 96%, the reaction rate of PMI was 99%, and the reaction rate of St was 100%. The composition ratio (mass basis) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:PMI:St=75.9:19.3:4.9, and (meth)acrylic acid The ester-derived unit content ratio was 75.9 mass%, and the ring structural unit content ratio was 19.3 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was subjected to devolatilization in an extruder in the same manner as in Example 5 to obtain pellets of a transparent resin composition (D-3). The weight average molecular weight of the resin composition (D-3) is 144,000, the number average molecular weight is 530,000, the glass transition temperature on the high temperature side is 137°C, the glass transition temperature on the low temperature side is -68°C, and the chloroform insoluble content is 0.3%. , The refractive index was 1.517. The island size of the sea-island structure of the unstretched film of the resin composition (D-3) was 200 nm, and the in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film were 0.8 nm and 4.5 nm, respectively.

(2-17) Example 8: Preparation of resin composition (D-4)

In Example 5, as a monomer component initially introduced into the reactor, 20 parts of SEBS triblock copolymer (Kraton, A1536), 61 parts of MMA, 15 parts of PMI are used, and a monomer component added by dropping A polymerization reaction was carried out in the same manner as in Example 5 except that 4 parts of St were used as a. The reaction rate of MMA calculated from the amount of residual monomer in the polymerization reaction solution was 97%, the reaction rate of PMI was 99%, and the reaction rate of St was 100%. The composition ratio (mass basis) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:PMI:St=76.1:18.8:5.1, and (meth)acrylic acid The ester-derived unit content ratio was 76.1 mass%, and the ring structural unit content ratio was 18.8 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was subjected to devolatilization in an extruder in the same manner as in Example 5 to obtain pellets of a transparent resin composition (D-4). The weight average molecular weight of the resin composition (D-4) is 145,000, the number average molecular weight is 60,000, the glass transition temperature on the high temperature side is 136°C, the glass transition temperature on the low temperature side is -68°C, and the chloroform insoluble content is 0.4%. , The refractive index was 1.517. The island size of the sea-island structure of the unstretched film of the resin composition (D-4) was 250 nm, and the in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film were 0.5 nm and 6.2 nm, respectively.

(2-18) Example 9: Preparation of resin composition (D-5)

In Example 5, as a monomer component initially introduced into the reactor, a SEBS triblock copolymer (Aldrich, product number 200557, olefinic double bond amount 0.10 mmol/g, styrene unit content 26 mass%, refractive index 1.513) A polymerization reaction was carried out in the same manner as in Example 5 except that 10 parts, 72 parts of MMA, and 16 parts of PMI were used, and 2 parts of St was used as a monomer component added by dropping. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 96%, the reaction rate of PMI was 99%, and the reaction rate of St was 100%. The composition ratio (mass basis) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:PMI:St=79.4:18.3:2.3, and (meth)acrylic acid The ester-derived unit content ratio was 79.4 mass%, and the ring structural unit content ratio was 18.3 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was subjected to devolatilization in an extruder in the same manner as in Example 5 to obtain pellets of a transparent resin composition (D-5). The weight average molecular weight of the resin composition (D-5) was 172,000, the number average molecular weight was 71,000, the glass transition temperature was 138°C, the chloroform insoluble content was 0.4%, and the refractive index was 1.515. The island size of the sea-island structure of the unstretched film of the resin composition (D-5) was 250 nm, and the in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film were 0.5 nm and 4.9 nm, respectively.

(2-19) Example 10: Preparation of resin composition (D-6)

In Example 5, as a monomer component initially introduced into the reactor, SEBS triblock copolymer (Asahikasei Co., Ltd., TAFTEC (registered trademark) H1041, olefinic double bond amount 0.44 mmol/g, styrene unit content 30 A polymerization reaction was carried out in the same manner as in Example 5, except that 10 parts of mass%, refractive index 1.515), 70 parts of MMA and 16 parts of PMI were used, and 4 parts of St was used as a monomer component added by dropping. . The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 97%, the reaction rate of PMI was 99%, and the reaction rate of St was 100%. The composition ratio (mass basis) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:PMI:St=77.4:18.1:4.6, and (meth)acrylic acid The ester-derived unit content ratio was 77.4 mass%, and the ring structural unit content ratio was 18.1 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was subjected to devolatilization in an extruder in the same manner as in Example 5 to obtain pellets of a transparent resin composition (D-6). The weight average molecular weight of the resin composition (D-6) was 135,000, the number average molecular weight was 56,000, the glass transition temperature was 138°C, the chloroform insoluble content was 0.5%, and the refractive index was 1.516. The island size of the sea-island structure of the unstretched film of the resin composition (D-6) was 300 nm, and the in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film were 0.3 nm and 2.3 nm, respectively.

(2-20) Example 11: Preparation of resin composition (D-7)

In Example 5, as a monomer component initially introduced into the reactor, SEBS triblock copolymer (Asahikasei Co., Ltd., TAFTEC (registered trademark) P1083, olefinic double bond amount 2.40 mmol/g, styrene unit content 20 A polymerization reaction was carried out in the same manner as in Example 5, except that 10 parts of mass%, refractive index 1.500) were used, 83 parts of MMA, and 6 parts of PMI were used, and 1 part of St was used as a monomer component added by dropping. . The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 96%, the reaction rate of PMI was 99%, and the reaction rate of St was 100%. The composition ratio (by mass) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:PMI:St=92.6:6.3:1.1, and (meth)acrylic acid The ester-derived unit content ratio was 92.6 mass%, and the ring structural unit content ratio was 6.3 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was subjected to devolatilization in an extruder in the same manner as in Example 5 to obtain pellets of a transparent resin composition (D-7). The weight average molecular weight of the resin composition (D-7) was 1630,000, the number average molecular weight was 620,000, the glass transition temperature was 123°C, the chloroform insoluble content was 0.9%, and the refractive index was 1.500. The in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film of the resin composition (D-7) were 0.3 nm and 4.5 nm, respectively.

(2-21) Example 12: Preparation of resin composition (D-8)

In Example 5, as a monomer component initially introduced into the reactor, SEBS triblock copolymer (Asahikasei Co., Ltd., TAFTEC (registered trademark) H1517, olefinic double bond amount 0.11 mmol/g, styrene unit content 43 A polymerization reaction was carried out in the same manner as in Example 5, except that 10 parts of mass% and refractive index 1.525) were used, 63 parts of MMA, and 24 parts of PMI were used, and 3 parts of St was used as a monomer component added by dropping. . The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 95%, the reaction rate of PMI was 98%, and the reaction rate of St was 100%. The composition ratio (by mass) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:PMI:St=69.3:27.2:3.5, and (meth)acrylic acid The ester-derived unit content ratio was 69.3 mass%, and the ring structural unit content ratio was 27.2 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was subjected to devolatilization in an extruder in the same manner as in Example 5 to obtain pellets of a transparent resin composition (D-8). The weight average molecular weight of the resin composition (D-8) was 166,000, the number average molecular weight was 630,000, the glass transition temperature was 151°C, the chloroform insoluble content was 0.5%, and the refractive index was 1.525. The in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film of the resin composition (D-8) were 0.5 nm and 5.9 nm, respectively.

(2-22) Comparative example 10: Preparation of resin composition (D-9)

In Example 5, as the monomer component initially introduced into the reactor, SEBS triblock copolymer (JSR, Dynaron (registered trademark) 9901P, olefinic double bond amount 0.06 mmol/g, styrene unit content 50% by mass, refractive index) A polymerization reaction was carried out in the same manner as in Example 5 except that 10 parts of 1.530), 30 parts of MMA, and 55 parts of PMI were used, and 5 parts of St was used as a monomer component added by dropping. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 98%, the reaction rate of PMI was 98%, and the reaction rate of St was 100%. The composition ratio (by mass) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:PMI:St=33.3:61.0:5.7, and (meth)acrylic acid The ester-derived unit content ratio was 33.3 mass%, and the ring structural unit content ratio was 61.0 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was subjected to devolatilization in an extruder in the same manner as in Example 5 to obtain pellets of a transparent resin composition (D-9). The weight average molecular weight of the resin composition (D-9) was 149,000, the number average molecular weight was 59,000, the glass transition temperature was 201°C, the chloroform insoluble content was 2.1%, and the refractive index was 1.560. In addition. Stretching of the unstretched film of the resin composition (D-9) was attempted, but the stretching was not possible due to insufficient strength.

(2-23) Comparative example 11: Preparation of resin composition (D-10)

In Example 5, as the monomer component initially introduced into the reactor, SEBS triblock copolymer (Asahikasei Co., Ltd., H1052, olefinic double bond amount 0.27 mmol/g, styrene unit content 20% by mass, refractive index 1.500 ) A polymerization reaction was carried out in the same manner as in Example 5, except that 10 parts, 88.5 parts of MMA and 1.5 parts of PMI were used, and St was not used as a monomer component added by dropping. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 98%, and the reaction rate of PMI was 98%. The composition ratio (mass basis) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:PMI=98.3:1.7, and the unit derived from the (meth)acrylic acid ester. The content ratio was 98.3% by mass, and the content rate of the ring structural unit was 1.7% by mass. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was subjected to devolatilization in an extruder in the same manner as in Example 5 to obtain pellets of a transparent resin composition (D-10). The weight average molecular weight of the resin composition (D-10) was 145,000, the number average molecular weight was 60,000, the glass transition temperature was 112°C, the chloroform insoluble content was 0.4%, and the refractive index was 1.500.

(2-24) Example 13: Preparation of resin composition (D-11)

In a reactor equipped with a stirring device, a temperature sensor, a cooling tube, and a nitrogen introduction tube, a SEBS triblock copolymer (Asahikasei Co., Ltd., H1052, olefinic double bond amount 0.27 mmol/g, styrene unit content 20% by mass, Refractive index 1.500) 10 parts, methyl methacrylic acid (MMA) 75 parts, 2-(hydroxymethyl) methyl acrylate (MHMA) 13.5 parts, n-dodecyl mercaptan (nDM) 0.05 parts, toluene 100 parts as a polymerization solvent And it heated up to 105 degreeC, passing nitrogen through this. After that, 0.009 parts of t-butylperoxyisopropyl carbonate (manufactured by Kayakuaku Co., Ltd., Bismuth Carbon (registered trademark) Bic75) was added as an initiator, and at the same time, 0.015 parts diluted in 2 parts of styrene (St) and 1 part of toluene. Solution polymerization was performed at 105 to 110°C while t-butylperoxyisopropyl carbonate was added dropwise at a constant rate over 2 hours, followed by further aging for 4 hours. To this, 0.07 parts of stearyl phosphate was added as a cyclization catalyst, and a cyclization reaction was carried out for 2 hours under reflux at 90 to 110°C. Thereby, a resin composition comprising a lactone ring-containing (meth)acrylic polymer formed by polymerization of MMA, MHMA and St, and a graft polymer in which the polymer chain is bonded to the SEBS triblock polymer chain was obtained. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 94%, the reaction rate of MHMA was 94%, and the reaction rate of St was 99%. The composition ratio (by mass) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock copolymer chain calculated from the reaction rate is MMA:MHMA:St=82.6:14.9:2.5, and (meth) The unit content ratio derived from acrylic acid ester was 72.9 mass%, the content ratio of the ring structural unit was 22.8 mass%, and the unit content ratio derived from styrene was 2.4 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably.

Next, the obtained polymerization reaction solution was put in an autoclave and subjected to heat treatment at 240°C for 1 hour, and then a vent-type screw twin-screw extruder (pore diameter) with one rear vent and two fore vents. : 15 mm, L/D: 45) in resin conversion at a processing rate of 600 g/h, devolatilization in this extruder, and extruding, the lactone ring-containing (meth)acrylic polymer and the polymer A transparent pellet of the resin composition (D-11) containing the graft polymer in which the chain was bonded to the SEBS triblock polymer chain was obtained. Moreover, the operating conditions of the twin-screw extruder were barrel temperature 260 degreeC, rotation speed 300rpm, and pressure reduction degree 13.3-400hPa (10-300mmHg). The weight average molecular weight of the resin composition (D-11) is 155,000, the number average molecular weight is 59,000, the glass transition temperature on the high temperature side is 127°C, the glass transition temperature on the low temperature side is -54°C, and the chloroform insoluble content is 0.4%. , The refractive index was 1.500. The island size of the sea-island structure of the unstretched film of the resin composition (D-11) was 250 nm, and the in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film were 0.3 nm and 4.9 nm, respectively.

(2-25) Example 14: Preparation of resin composition (D-12)

In Example 13, as a monomer component initially introduced into the reactor, SEBS triblock copolymer (KURARAY CO., LTD., HYBRA (registered trademark) 7125, olefinic double bond amount 0.44 mmol/g, styrene unit content 20) Mass %) was used in 10 parts, MMA in 75 parts, and MHMA in 13.5 parts in the same manner as in Example 13, and polymerization and cyclization were carried out. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 94%, the reaction rate of MHMA was 94%, and the reaction rate of St was 100%. The composition ratio (mass basis) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:MHMA:St=82.7:14.8:2.5, and (meth)acrylic acid The ester-derived unit content ratio was 73.0 mass%, the cyclic structural unit content ratio was 22.7 mass%, and the styrene-derived unit content ratio was 2.4 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was carried out in the same manner as in Example 13, and after autoclave treatment, devolatilization was performed in an extruder to obtain pellets of a transparent resin composition (D-12). The weight average molecular weight of the resin composition (D-12) was 162,000, the number average molecular weight was 61,000, the glass transition temperature was 127°C, the chloroform insoluble content was 0.4%, and the refractive index was 1.500. The island size of the sea-island structure of the unstretched film of the resin composition (D-12) was 250 nm, and the in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film were 0.2 nm and 4.5 nm, respectively.

(2-26) Example 15: Preparation of resin composition (D-13)

In Example 13, as a monomer component initially introduced into the reactor, SEBS triblock copolymer (Asahikasei Co., Ltd., TAFTEC (registered trademark) P1083, olefinic double bond amount 2.01 mmol/g, styrene unit content 20 Mass%) of 6 parts, SEBS triblock copolymer 2 (Asahikasei Co., Ltd., TAFTEC (registered trademark) H1052, olefinic double bond amount 0.27 mmol/g, styrene unit content 20 mass%, refractive index 1.500) to 4 Polymerization and cyclization were carried out in the same manner as in Example 13, except that 75 parts of MMA and 13.5 parts of MHMA were used, and 4 parts of St was used as the monomer component added by dropping. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 94%, the reaction rate of MHMA was 94%, and the reaction rate of St was 100%. The composition ratio (mass basis) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:MHMA:St=82.6:14.9:2.5, and (meth)acrylic acid The ester-derived unit content rate was 72.6 mass%, the cyclic structural unit content rate was 23.0 mass%, and the styrene-derived unit content rate was 2.4 mass%. When a part of the reaction solution was taken out and subjected to a filtration test, it was possible to perform filtration suitably. The obtained polymerization reaction liquid was carried out in the same manner as in Example 13, and after autoclave treatment, devolatilization was performed in an extruder to obtain pellets of a transparent resin composition (D-13). The weight average molecular weight of the resin composition (D-13) is 151,000, the number average molecular weight is 57,000, the glass transition temperature on the high temperature side is 127°C, the glass transition temperature on the low temperature side is -61°C, and the chloroform insoluble content is 0.4%. , The refractive index was 1.500. The island size of the sea-island structure of the unstretched film of the resin composition (D-13) was 150 nm, and the in-plane retardation Re and the retardation Rth in the thickness direction of the stretched film were 0.3 nm and 3.5 nm, respectively.

(2-27) Comparative example 12: Preparation of resin composition (D-14)

In Example 13, as a monomer component initially introduced into the reactor, SEBS triblock copolymer (Asahikasei Co., Ltd., TAFTEC (registered trademark) H1041, olefinic double bond amount 0.45 mmol/g, styrene unit content 30 A polymerization reaction was carried out in the same manner as in Example 13, except that 10 parts of mass %), 40 parts of MMA, and 45 parts of MHMA were used, and 5 parts of St was used as a monomer component added by dropping. The reaction rate of MMA calculated from the amount of residual monomers in the polymerization reaction solution was 94%, the reaction rate of MHMA was 90%, and the reaction rate of St was 100%. The composition ratio (mass basis) of the (meth)acrylic polymer chain and the (meth)acrylic polymer bound to the SEBS triblock polymer chain calculated from the reaction rate is MMA:MHMA:St=45.2:48.7:6.0, and (meth)acrylic acid The ester-derived unit content ratio was 3.7 mass%, the cyclic structural unit content ratio was 82.6 mass%, and the styrene-derived unit content ratio was 6.9 mass%. When a part of the reaction solution was taken out and a filtration test was carried out, the increase in filter pressure was considered. The glass transition temperature of the obtained resin composition (D-14) was 158°C, and the chloroform insoluble content was 10.4%.

In Tables 1 to 3, the results of each Example and Comparative Example were put together. Resin composition A-3 of Comparative Example 1 in which no ring structure was introduced into the graft chain had a low glass transition temperature and low heat resistance. In addition, even if the ring structure is introduced, the resin composition B-1 of Comparative Example 2, the resin composition B-2 of Comparative Example 3, the resin composition B-3 of Comparative Example 5, and the resin of Comparative Example 8 that do not contain a graft polymer Composition B-4 had low impact strength (breaking energy) and low mechanical strength. Resin composition A-4 of Comparative Example 4, resin composition C-3 of Comparative Example 6, resin composition A-5 of Comparative Example 7, resin composition C-4 of Comparative Example 9, resin composition D-9 of Comparative Example 10, In the resin composition D-10 of Comparative Example 11 and the resin composition D-14 of Comparative Example 12, the graft chain has a cyclic structural unit, but the content ratio of the (meth)acrylic acid ester unit in the graft chain is less than 45% by mass to 98% by mass. Since it was more than %, the glass transition temperature was low, the heat resistance was low, the impact strength (breaking energy) was low, the mechanical strength was low, or a gelled product occurred during manufacture, and a large amount of foreign matter was included. On the other hand, each resin composition of Examples 1 to 15 was excellent in transparency, mechanical strength, and heat resistance, and at the same time as having them in a cluster form, there was little generation of gelatinous products.

(Industrial availability)

According to the present invention, since a copolymer and resin composition excellent in transparency, mechanical strength and heat resistance can be obtained, by applying these to an optical film or the like, an excellent polarizer protective film, a polarizing plate, an image display device, and the like can be manufactured.

Claims (19)

A copolymer having a polymer chain (A) having a unit derived from diene and/or olefin, and a polymer chain (B) having a unit derived from a (meth)acrylic monomer and a unit having a cyclic structure in the main chain,
In the polymer chain (B), the content ratio of the unit derived from the (meth)acrylic acid ester is 45% by mass or more and 98% by mass or less,
Copolymer, characterized in that it has a glass transition temperature above 100 ℃ and less than 100 ℃, respectively. The copolymer according to claim 1, wherein the polymer chain (B) is grafted onto the polymer chain (A). The copolymer according to claim 1, wherein the ring structure is a lactone ring structure and/or a maleimide structure. The copolymer according to claim 1, wherein in the polymer chain (B), a total content ratio of a unit derived from the (meth)acrylic monomer and a unit having a ring structure in the main chain is 90% by mass or more. A resin composition comprising the copolymer according to any one of claims 1 to 4 and a (meth)acrylic polymer. The resin composition according to claim 5, wherein the (meth)acrylic polymer has a unit derived from the (meth)acrylic monomer. The resin composition according to claim 5, wherein the (meth)acrylic polymer has a unit having a ring structure in the main chain. The resin composition according to claim 5, wherein the resin composition has a glass transition temperature of 100°C or more and less than 100°C, respectively. The resin composition according to claim 5, wherein the insoluble content in chloroform is 10% by mass or less. An optical film comprising the copolymer according to any one of claims 1 to 4. An optical film comprising the resin composition according to claim 5. A polarizing plate comprising the optical film according to claim 10. A polarizing plate comprising the optical film according to claim 11. An image display device comprising the optical film according to claim 10. An image display device comprising the optical film according to claim 11. As a method for producing the copolymer according to any one of claims 1 to 4,
A copolymer characterized by having a process of polymerizing a monomer component including a (meth)acrylic monomer and a monomer having a polymerizable double bond in the ring structure in the presence of a polymer (P1) having a unit derived from diene and/or olefin Method of manufacturing coalescence. As a method for producing the copolymer according to any one of claims 1 to 4,
A step of polymerizing a monomer component containing a (meth)acrylic monomer in the presence of a polymer (P1) having a unit derived from diene and/or olefin, and
A method for producing a copolymer, comprising a step of forming a ring structure in a main chain of a polymer chain having units derived from a (meth)acrylic monomer formed in the polymerization step. The method for producing a copolymer according to claim 16, further comprising a step of filtering the resin solution obtained in the polymerization step. The method for producing a copolymer according to claim 17, further comprising a step of filtering the resin solution obtained in the ring structure forming step.