TW201829602A - Resin composition and film formed of said resin composition - Google Patents

Abstract

Provided are: a resin composition which is not susceptible to the occurrence of birefringence, while having excellent heat resistance, film strength and thermal stability; and a film which is formed of this resin composition. The present invention provides a resin composition which is composed of 17-31% by mass of an aromatic vinyl monomer unit (A), 38-63% by mass of a (meth)acrylic acid ester monomer unit (B), 4-14% by mass of an unsaturated dicarboxylic acid anhydride monomer unit (C) and 4-25% by mass of a conjugated diene monomer unit (D), and wherein the absolute value of formula 1 is 0.005 or less. In formula 1, [A], [B], [C] and [D] respectively represent the mass ratios of the aromatic vinyl monomer unit (A), the (meth)acrylic acid ester monomer unit (B), the unsaturated dicarboxylic acid anhydride monomer unit (C) and the conjugated diene monomer unit (D) in the resin composition; and [A] + [B] + [C] + [D] = 1. Formula 1 -0.10 * [A] - 0.004 * [B] + 0.10 * [C] + 0.09 * [D].

Description

 a resin composition and a film composed of the resin composition  

The present invention relates to a resin composition which is less likely to cause birefringence, heat resistance, film strength, and thermal stability, and a film composed of the resin composition.

The transparent resin can be used for various purposes such as parts of household electrical appliances, food containers, and miscellaneous goods. In recent years, transparent resins have been widely used as optical members such as a retardation film, a polarizer protective film, an antireflection film, a diffusion sheet, and a light guide sheet in a liquid crystal display device in terms of light weight, productivity, and cost.

The liquid crystal display device is composed of a liquid crystal cell formed by sandwiching a transparent electrode, a liquid crystal layer, a color filter or the like with a glass piece, and two polarizing plates disposed on both sides thereof, and TAC (for use on the both sides of the polarizing plate for protecting the surface is used) A polarizer protective film composed of a cellulose triacetate film.

In order to achieve uniformity of a wide viewing angle range of the liquid crystal display, it is desirable that the polarizer protective film has no birefringence, but since the TAC film has a slight birefringence, there is a problem that birefringence occurs in incident light in an oblique direction. Further, as the size of the display increases, there is a problem that the birefringence distribution occurs due to variations in external stress, and the contrast is lowered. Therefore, it is desirable that the birefringence change due to external stress is less likely to occur in the polarizer protective film.

A copolymer resin obtained by copolymerizing methyl methacrylate, maleic anhydride, and styrene is known as a resin for an optical film (for example, Patent Document 1). Further, as a resin having a small birefringence, a glutarylene imine resin (for example, Patent Document 2) or methyl methacrylate, N-phenyl maleimide, and N-cyclohexylmalanium are known. A copolymer resin obtained by copolymerization of an imine (for example, Patent Document 3).

 [First technical literature]  

Patent literature

Patent Document 1: International Patent Application WO2014/021264

Patent Document 2: Japanese Laid-Open Patent Publication No. 2006-337493

Patent Document 3: Japanese Laid-Open Patent Publication No. 2013-109285

The resin described in Patent Document 1 is excellent in heat resistance and transparency, but has a resin design for increasing birefringence after film formation, and thus its use is limited. The resins described in Patent Documents 2 and 3 are excellent in optical properties, but the film strength after molding is not sufficiently large, and thus the use is limited.

An object of the present invention is to provide a resin composition which is less likely to cause birefringence, heat resistance, film strength, and thermal stability, and a film composed of the resin composition.

The gist of the present invention is as follows.

(1) A resin composition comprising: an aromatic vinyl monomer unit (A) 17 to 31% by mass, a (meth) acrylate monomer unit (B) 38 to 63% by mass, an unsaturated dicarboxylic anhydride 4 to 14% by mass of the monomer unit (C) and 4 to 25% by mass of the conjugated diene monomer unit (D), and the absolute value of the value of the following formula 1 is 0.005 or less, and the formula 1:-0.10 × [A] -0.004 × [B] + 0.10 × [C] + 0.09 × [D], wherein [A], [B], [C], and [D] in Formula 1 sequentially represent an aromatic vinyl monomer unit ( A), mass ratio of (meth) acrylate monomer unit (B), unsaturated dicarboxylic anhydride monomer unit (C), conjugated diene monomer unit (D) in resin composition, [A] +[B]+[C]+[D]=1.

(2) The resin composition according to (1), comprising: an aromatic vinyl monomer unit (A), a (meth) acrylate monomer unit (B), and an unsaturated dicarboxylic anhydride monomer unit (C) 20 to 80 parts by mass of the copolymer (I); 0 to 60 parts by mass of the polymer (II) composed of the (meth) acrylate monomer unit (B); and an aromatic vinyl monomer A graft copolymer (III) obtained by grafting a copolymer of unit (A) and (meth) acrylate monomer unit (B) to a polymer composed of conjugated diene monomer unit (D) 5~ 60 parts by mass.

(3) The resin composition according to (2), wherein the copolymer (I) comprises: an aromatic vinyl monomer unit (A) of 20 to 80% by mass, and a (meth) acrylate monomer unit (B) 5 to 70% by mass of the unsaturated dicarboxylic anhydride monomer unit (C) 10 to 25% by mass.

(4) The resin composition according to (2) or (3), wherein the haze of the optical path length of 10 mm in the 12% by mass chloroform solution of the copolymer (I) is 2% or less.

(5) The resin composition according to any one of (1) to (4), wherein the total light transmittance of the thickness of 2 mm measured based on ASTM D1003 is 88% or more.

(6) A film comprising the resin composition according to any one of (1) to (5).

(7) The film according to (6), which is used as a polarizer protective film.

According to the present invention, it is possible to provide a resin composition which is less likely to cause birefringence, is excellent in heat resistance, film strength, and thermal stability, and a film composed of the resin composition.

<phrase description>

In the specification of the present application, the symbol "~" means "above" and "below". For example, the description of "A~B" means A or more and B or less.

Hereinafter, embodiments of the present invention will be described in detail.

Examples of the aromatic vinyl monomer unit (A) which can be used in the resin composition of the present invention include units derived from the following monomers: styrene, o-methyl styrene, m-methyl styrene, and the like. Various styrenes such as methyl styrene, 2,4-dimethyl styrene, ethyl styrene, p-tert-butyl styrene, α-methyl styrene, α-methyl-p-methyl styrene monomer. Among them, a styrene unit is preferred. These aromatic vinyl monomer units (A) may be used singly or in combination of two or more.

The (meth) acrylate monomer unit (B) which can be used in the resin composition of the present invention includes units derived from the following monomers: methyl methacrylate, ethyl methacrylate, methyl group. Various methacrylate monomers such as n-butyl acrylate, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate, isobornyl methacrylate, and methyl acrylate, ethyl acrylate, and acrylic acid Various acrylate monomers such as butyl ester, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, and decyl acrylate. Among them, a methyl methacrylate unit is preferred. These (meth) acrylate monomer units (B) may be used singly or in combination of two or more.

Examples of the unsaturated dicarboxylic anhydride monomer unit (C) which can be used in the resin composition of the present invention include units derived from various acid anhydride monomers such as maleic anhydride, itaconic anhydride, citraconic anhydride, and aconitic anhydride. . Among them, a maleic anhydride unit is preferred. The unsaturated dicarboxylic anhydride monomer unit (C) may be used singly or in combination of two or more.

The conjugated diene monomer unit (D) which can be used in the resin composition of the present invention is exemplified by 1,3-butadiene (butadiene) and 2-methyl-1,3-butylene. Diene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2-methylpentadiene, etc. A unit of a monomer having a conjugated double bond. Among them, a butadiene unit is preferred. These conjugated diene monomer units (D) may be used singly or in combination of two or more.

The resin composition of the present invention may contain, in addition to the aromatic vinyl monomer unit (A), the (meth) acrylate monomer unit (B), or not, in the resin composition in a range that does not inhibit the effects of the invention. The unit of the vinyl monomer other than the saturated dicarboxylic anhydride monomer unit (C) and the conjugated diene monomer unit (D) is preferably 5% by mass or less. Examples of the unit of the other vinyl monomer include a unit derived from a monomer such as a vinyl cyanide monomer such as acrylonitrile or methacrylonitrile, or a vinyl carboxylate monomer such as acrylic acid or methacrylic acid. , N-alkyl maleate, N-methyl maleimide, N-ethyl maleimide, N-butyl maleimide, N-cyclohexyl maleimide, etc. N-aryl maleimide monomer such as amine monomer, N-phenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide, etc. Various monomers. In addition to the aromatic vinyl monomer unit (A), the (meth) acrylate monomer unit (B), the unsaturated dicarboxylic anhydride monomer unit (C), and the conjugated diene monomer unit (D), The unit of the other vinyl monomer contained in the resin composition may be used in combination of two or more.

The structural unit of the resin composition of the present invention is preferably an aromatic vinyl monomer unit (A) of 17 to 31% by mass, a (meth) acrylate monomer unit (B) of 38 to 63% by mass, and an unsaturated dicarboxylic acid. The anhydride monomer unit (C) is 4 to 14% by mass, the conjugated diene monomer unit (D) is 4 to 25% by mass, and more preferably, the aromatic vinyl monomer unit (A) is 18 to 25% by mass, ( The methyl acrylate monomer unit (B) is 45 to 60% by mass, the unsaturated dicarboxylic anhydride monomer unit (C) is 4 to 12% by mass, and the conjugated diene monomer unit (D) is 10 to 20% by mass.

When the aromatic vinyl monomer unit (A) used in the resin composition is 17% by mass or more, a resin composition which is less likely to cause birefringence and has good transparency can be obtained, and if it is 18% by mass or more, more can be obtained. It is preferable that a resin composition having birefringence and transparency is hard to occur. When the amount of the aromatic vinyl monomer unit (A) is 31% by mass or less, a resin composition which is less likely to cause birefringence and has good heat resistance can be obtained, and if it is 25% by mass or less, birefringence and heat resistance can be more difficult to occur. A resin composition which is more excellent is preferable.

When the (meth) acrylate monomer unit (B) used in the resin composition is 38% by mass or more, a resin composition which is less likely to cause birefringence and has good heat resistance can be obtained; if it is 45 mass% or more, it can be used. It is preferable to obtain a resin composition which is more difficult to produce birefringence and has better heat resistance. When the (meth) acrylate monomer unit (B) is 63% by mass or less, a resin composition in which birefringence is hard to occur can be obtained, and if it is 60% by mass or less, a resin composition which is less likely to cause birefringence can be obtained. Therefore, it is preferred.

When the unsaturated dicarboxylic anhydride monomer unit (C) used in the resin composition is 4% by mass or more, a resin composition having good heat resistance can be obtained, which is preferable. When the unsaturated dicarboxylic anhydride monomer unit (C) is 14% by mass or less, a resin composition which is less likely to cause birefringence and has good thermal stability can be obtained, and if it is 12% by mass or less, birefringence can be more difficult to occur. A resin composition having a better thermal stability is preferred.

When the conjugated diene monomer unit (D) used in the resin composition is 4% by mass or more, a resin composition which is less likely to cause birefringence and has a good film strength can be obtained, and if it is 10% by mass or more, more can be obtained. A resin composition having a birefringence and a film strength is less likely to occur, which is preferable. When the conjugated diene unit cell (D) is 25% by mass or less, a resin composition which is less likely to cause birefringence and has good heat resistance can be obtained. When it is 20% by mass or less, birefringence and heat resistance are more difficult to occur. A resin composition which is more excellent is preferable.

In the resin composition of the present invention, the absolute value of the value of Formula 1 is preferably 0.005 or less. Wherein [A], [B], [C], and [D] in Formula 1 sequentially represent an aromatic vinyl monomer unit (A), a (meth) acrylate monomer unit (B), and an unsaturated second. The mass ratio of the carboxylic anhydride monomer unit (C) and the conjugated diene monomer unit (D) in the resin composition, [A] + [B] + [C] + [D] = 1.

(Formula 1) -0.10 × [A] - 0.004 × [B] + 0.10 × [C] + 0.09 × [D]

The resin composition of the present invention is composed of an aromatic vinyl monomer unit (A), a (meth) acrylate monomer unit (B), an unsaturated dicarboxylic anhydride monomer unit (C), and a conjugated diene monomer. It is preferable that the respective components of the unit (D) cancel each other to birefringence, and it is possible to obtain a resin composition in which the birefringence is less likely to occur as the absolute value of the value of the formula 1 is smaller. If the absolute value of the value of Formula 1 is 0.003 or less, a resin composition which is less likely to cause birefringence can be obtained, which is preferable. If the absolute value of the value of Formula 1 is 0.001 or less, it can be more difficult to occur. A birefringent resin composition is preferred.

The resin composition of the present invention preferably comprises the following components: consisting of an aromatic vinyl monomer unit (A), a (meth) acrylate monomer unit (B), and an unsaturated dicarboxylic anhydride monomer unit (C). The copolymer (I) is 20 to 80 parts by mass, and the polymer (II) composed of the (meth) acrylate monomer unit (B) is 0 to 60 parts by mass, and the aromatic vinyl monomer unit ( A) The graft copolymer (III) formed by grafting a copolymer composed of the (meth) acrylate monomer unit (B) to a polymer composed of the conjugated diene monomer unit (D) is 5~ 60 parts by mass, more preferably, the copolymer (I) is 20 to 40 parts by mass, the polymer (II) is 25 to 50 parts by mass, and the graft copolymer (III) is 10 to 45 parts by mass.

When the copolymer (I) used in the resin composition is 20 parts by mass or more, a resin composition having good heat resistance can be obtained, which is preferable. When the copolymer (I) is 80 parts by mass or less, a resin composition having good thermal stability can be obtained, which is preferable, and if it is 40 parts by mass or less, a resin composition having better thermal stability can be obtained, so Preferred.

When the amount of the polymer (II) to be used in the resin composition is 0 parts by mass or more, a resin composition which is less likely to cause birefringence and has good thermal stability can be obtained. If it is 25 parts by mass or more, birefringence which is more difficult to occur can be obtained. A resin composition having better thermal stability is preferred. When the amount of the polymer (II) is 60 parts by mass or less, a resin composition in which birefringence is hard to occur can be obtained, and if it is 50 parts by mass or less, a resin composition which is less likely to cause birefringence can be obtained, which is preferable.

When the amount of the graft copolymer (III) used in the resin composition is 5 parts by mass or more, a resin composition which is less likely to cause birefringence and has a good film strength can be obtained. If it is 10 parts by mass or more, it is more difficult to occur. A resin composition having a higher refractive index and a higher film strength is preferable. When the amount of the graft copolymer (III) is 60 parts by mass or less, a resin composition which is less likely to cause birefringence, heat resistance and thermal stability can be obtained, and if it is 45 parts by mass or less, birefringence which is more difficult to occur can be obtained. A resin composition having better heat resistance and thermal stability is preferred.

The resin composition of the present invention, if the copolymer (I), the polymer (II), and the graft copolymer (III) each have a refractive index of n1, n2, and n3 at 23 ° C with respect to the d line, the copolymer (I) The mass ratio of each of the polymer (II) and the graft copolymer (III) is w1, w2, and w3, and the absolute value of the value of the formula 2 is preferably 0.005 or less.

(Formula 2) n1 × w1/(w1 + w2) + n2 × w2 / (w1 + w2) - n3

When the absolute value of the value of Formula 2 is 0.005 or less, a resin composition having good transparency can be obtained, which is preferable, and is more preferably 0.003 or less, still more preferably 0.001 or less. Since the copolymer (I) and the polymer (II) are compatible, the product obtained by mixing the copolymer (I) and the polymer (II) is transparent, and the copolymer (I) and the polymerization can be reduced by The product obtained by mixing the substance (II) has a difference in refractive index from the graft copolymer (III) to maintain transparency.

The order of mixing the respective components of the copolymer (I), the polymer (II), and the graft copolymer (III) is not particularly limited, and for example, a method of mixing all the components at the same time, and mixing the two components in advance may be mentioned. A method of mixing with another ingredient, and the like. Further, such mixing can be carried out by a conventionally known method.

As a method of mixing all the components at the same time, for example, a uniaxial or biaxial melt extruder can be used, and each component of the copolymer (I), the polymer (II), the graft copolymer (III), and various additives can be added. Melt mixing. As a method of mixing with another component, for example, a copolymer of (I) and polymer (II) may be preliminarily mixed using a uniaxial or biaxial melt extruder, and then a uniaxial or biaxial melt extruder may be used. It is melt-mixed with the graft copolymer (III). At this time, various additives may be added for melt mixing.

Examples of the aromatic vinyl monomer unit (A) which can be used in the copolymer (I) include units derived from the following monomers: styrene, o-methyl styrene, m-methyl styrene, and para Various styrenes such as styrene, 2,4-dimethylstyrene, ethylstyrene, p-tert-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene body. Among them, a styrene unit is preferred. These aromatic vinyl monomer units (A) may be used singly or in combination of two or more.

As the (meth) acrylate monomer unit (B) which can be used in the copolymer (I), a unit derived from the following monomers: methyl methacrylate, ethyl methacrylate, methacrylic acid is exemplified. Various methacrylate monomers such as n-butyl ester, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate, isobornyl methacrylate, and methyl acrylate, ethyl acrylate, and butyl acrylate Various acrylate monomers such as ester, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, and the like. Among them, a methyl methacrylate unit is preferred. These (meth) acrylate monomer units (B) may be used singly or in combination of two or more.

Examples of the unsaturated dicarboxylic anhydride monomer unit (C) which can be used in the copolymer (I) include units derived from various acid anhydride monomers such as maleic anhydride, itaconic anhydride, citraconic anhydride, and aconitic anhydride. Among them, a maleic anhydride unit is preferred. The unsaturated dicarboxylic anhydride monomer unit (C) may be used singly or in combination of two or more.

The copolymer (I) may also contain, in addition to the aromatic vinyl monomer unit (A), the (meth) acrylate monomer unit (B), and the unsaturated dicarboxylic acid, in the range of the copolymer which does not inhibit the effects of the invention. The unit of the copolymerizable vinyl monomer other than the acid anhydride monomer unit (C) is preferably 5% by mass or less. Examples of the other monomer capable of copolymerizing a vinyl monomer include a unit derived from a monomer such as a vinyl cyanide monomer such as acrylonitrile or methacrylonitrile, or a vinyl carboxyl group such as acrylic acid or methacrylic acid. N-alkyl horses such as acid monomer, N-methyl maleimide, N-ethyl maleimide, N-butyl maleimide, N-cyclohexylmaleimide, etc. N-aryl maleimide, such as N-phenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide, etc. Various monomers such as monomers. Other units of the vinyl monomer copolymerizable may be used in combination of two or more.

The structural unit of the copolymer (I) is an aromatic vinyl monomer unit (A) of 20 to 80% by mass, a (meth) acrylate monomer unit (B) of 5 to 70% by mass, and an unsaturated dicarboxylic anhydride single. The unit cell (C) is 10 to 25% by mass; more preferably, the aromatic vinyl monomer unit (A) is 45 to 70% by mass, and the (meth) acrylate monomer unit (B) is 7 to 40% by mass. The saturated dicarboxylic anhydride monomer unit (C) is 10 to 23% by mass. Further, the structural unit of the copolymer is an analytical value measured by a predetermined analysis method, and actually, a distribution exists in the structural unit (hereinafter, the distribution is referred to as a composition distribution), and the average value of the composition distribution is shown.

When the aromatic vinyl monomer unit (A) used in the copolymer (I) is 20% by mass or more, a molded article having an improved thermal stability and a good appearance when the resin composition is subjected to a molding process can be obtained; When the amount is 45% by mass or more, a molded article having a further improved thermal stability and a better appearance when the resin composition is subjected to a forming process can be obtained, which is preferable. When the aromatic vinyl monomer unit (A) is 80% by mass or less, the compatibility with the polymer (II) increases, and the transparency of the resin composition is good. When the content is 70% by mass or less, the polymer (II) The compatibility of the resin composition is further increased, and the transparency of the resin composition is good, which is preferable.

When the (meth) acrylate monomer unit (B) used in the copolymer (I) is 5% by mass or more, the compatibility with the polymer (II) increases, and the transparency of the resin composition is good; When the mass is at least the above, the compatibility with the polymer (II) is further increased, and the transparency of the resin composition is further improved, which is preferable. When the (meth) acrylate monomer unit (B) is 70% by mass or less, a molded article having an improved thermal stability and having a good appearance when the resin composition is subjected to a molding process can be obtained, and if it is 40% by mass or less, Further, it is preferable to obtain a molded body having further improved thermal stability and a better appearance when the resin composition is formed.

When the unsaturated dicarboxylic anhydride monomer unit (C) used in the copolymer (I) is 10% by mass or more, the heat resistance is good, the compatibility with the polymer (II) is increased, and the transparency of the resin composition is good. Therefore it is preferred. When the amount of the unsaturated dicarboxylic anhydride monomer unit (C) is 25% by mass or less, a molded article having an improved thermal stability and a good appearance when the resin composition is subjected to a molding process can be obtained, and the polymer (II) When the compatibility is increased, the transparency of the resin composition is good, and when it is 23% by mass or less, a molded article having further improved thermal stability and having a better appearance when the resin composition is subjected to molding processing can be obtained, and polymerization is carried out. The compatibility of the substance (II) is increased, and the transparency of the resin composition is good, which is preferable.

The haze at a light path length of 10 mm in a 12% by mass chloroform solution of the copolymer (I) measured based on JIS K-7136 is preferably 2% or less. When the haze is 2% or less, since the composition distribution of the copolymer (I) is small, the composition of the unsaturated dicarboxylic anhydride monomer unit (C) which is incompatible with the polymer (II) is extremely small, so that it can be kept The compatibility of the polymer (II) and the transparency of the resin composition are good, which is preferable. In addition, the haze is filled with a solution adjusted to a copolymer of 12% by mass in chloroform to a quartz square box having an optical path length of 10 mm and a haze meter (HAZEGUARD II manufactured by Toyo Seiki Co., Ltd.) in accordance with JIS K-7136. Measured value measured.

The polymerization method of the copolymer (I) is not particularly limited, and it can be produced by a known method such as solution polymerization or bulk polymerization, and more preferably solution polymerization. The solvent used for the solution polymerization is preferably a non-polymerizable solvent from the viewpoint that the by-product is not easily generated and the adverse effect is small. The type of the solvent is not particularly limited, and examples thereof include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetophenone; and ethers such as tetrahydrofuran and 1,4-dioxane. An aromatic hydrocarbon such as toluene, ethylbenzene, xylene or chlorobenzene is preferably methyl ethyl ketone or methyl isobutyl ketone from the viewpoints of solubility of a monomer or a copolymer and ease of solvent recovery. . The amount of the solvent added is preferably from 10 to 100 parts by mass, more preferably from 30 to 80 parts by mass, per 100 parts by mass of the copolymer obtained. When it is 10 parts by mass or more, it is suitable from the viewpoint of controlling the reaction rate and the viscosity of the polymerization liquid, and when it is 100 parts by mass or less, the desired weight average molecular weight (weight average molecular weight, Mw) is obtained. suitable.

The polymerization process may be any one of a batch polymerization method, a semi-batch polymerization method, and a continuous polymerization method, and a batch polymerization method is preferred from the viewpoint of obtaining a desired molecular weight range and transparency.

The polymerization method is not particularly limited, and is preferably a radical polymerization method from the viewpoint of being able to be produced with good productivity by a simple process. The polymerization initiator is not particularly limited, and for example, benzamidine peroxide, t-butyl peroxybenzoate, 1,1-bis(tert-butylperoxy)-2-methylcyclohexane, peroxidation can be used. Tert-butyl monocarbonate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyacetate, dicumyl peroxide, 3,3-di(tert-butylperoxy)butyric acid A well-known organic peroxide such as ethyl ester, or a known azo compound such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile or azobismethylbutyronitrile. These polymerization initiators may be used in combination of two or more. Among them, an organic peroxide having a 10-hour half-life temperature of 70 to 110 ° C is preferably used.

In order to obtain the copolymer (I) having good transparency, it is necessary to carry out polymerization while controlling the composition distribution, and in particular, it is required to use an unsaturated dicarboxylic anhydride monomer unit which is incompatible with the polymer (II). The product of many constituents is polymerized in a very small amount. Since the aromatic vinyl monomer has strong cross-copolymerization with the unsaturated dicarboxylic anhydride monomer, it is continuously batched in a manner corresponding to the polymerization rate of the aromatic vinyl monomer and the (meth) acrylate monomer. A method of adding an unsaturated dicarboxylic anhydride monomer and/or an aromatic vinyl monomer, and adjusting the flow rate of the batch addition according to the polymerization rate is suitable. If the polymerization rate is controlled while appropriately adjusting the polymerization temperature, the polymerization time, and the polymerization initiator addition amount, the composition distribution of the copolymer can be more precisely reduced, which is suitable.

Further, the method for adjusting the molecular weight can be achieved by adjusting the polymerization temperature, the polymerization time, and the amount of the polymerization initiator added, by adjusting the amount of the solvent added and the amount of the chain transfer agent. The chain transfer agent is not particularly limited, and for example, a known chain transfer such as n-dodecyl mercaptan, t-dodecyl mercaptan or 2,4-diphenyl-4-methyl-1-pentene can be used. Agent.

After the completion of the polymerization, a light-resistant stabilizer such as a heat-resistant stabilizer such as a hindered phenol compound, a lactone compound, a phosphorus compound or a sulfur compound, a hindered amine compound or a benzotriazole compound may be added to the polymerization liquid as needed. Additives such as lubricants, plasticizers, colorants, antistatic agents, mineral oils, etc. The amount of addition is preferably less than 0.2 parts by mass based on 100 parts by mass of all the monomer units. These additives may be used singly or in combination of two or more.

The method for recovering the copolymer (I) from the polymerization liquid is not particularly limited, and a known devolatilization technique can be used. For example, a method in which a polymerization liquid is continuously supplied to a biaxial devolatilizing extruder by a gear pump, and a polymerization solvent, an unreacted monomer, and the like are subjected to a devolatilization treatment. In addition, the devolatilization component containing a polymerization solvent, an unreacted monomer, and the like is condensed and recovered by a condenser or the like, and the condensate is purified by a distillation column, whereby the polymerization solvent can be reused.

As the (meth) acrylate monomer unit (B) which can be used in the polymer (II), a unit derived from the following monomers: methyl methacrylate, ethyl methacrylate, methacrylic acid is exemplified. Various methacrylate monomers such as n-butyl ester, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate, isobornyl methacrylate, and methyl acrylate, ethyl acrylate, n-butyl acrylate Various acrylate monomers such as 2-methylhexyl acrylate, 2-ethylhexyl acrylate, and decyl acrylate. Among them, a methyl methacrylate unit is preferred. These (meth) acrylate monomer units (B) may be used alone or in combination of two or more.

The copolymer (II) may be a unit containing a copolymerizable vinyl monomer other than the (meth) acrylate monomer unit (B) in a range that does not inhibit the effects of the invention in the copolymer, and is preferably 5 mass% or less. Examples of the other monomer capable of copolymerizing a vinyl monomer include a unit derived from a monomer such as an aromatic vinyl monomer such as styrene or a vinyl cyanide monomer such as acrylonitrile or methacrylonitrile. , vinyl carboxylic acid monomer such as acrylic acid, methacrylic acid, etc., N-methyl maleimide, N-ethyl maleimide, N-butyl maleimide, N-cyclohexyl horse An N-alkyl maleimide monomer such as N-phenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide Various monomers such as N-arylmaleimide monomers. The unit of the other copolymerizable vinyl monomer may be used in combination of two or more.

The polymerization method of the copolymer (II) is not particularly limited, and it can be produced by a known method such as bulk polymerization, solution polymerization, suspension polymerization, bulk-suspension polymerization or emulsion polymerization, but in order to obtain a polymer having less impurities and good hue. (II), bulk polymerization or solution polymerization is preferred. Further, the polymerization process of the polymer (II) may be any one of batch polymerization, semi-batch polymerization, and continuous polymerization, but from the viewpoint of productivity, continuous polymerization is preferred.

When continuous polymerization is employed as the polymerization mode of the copolymer (II), the structure of the reactor is preferably a structure in which a fully mixed reactor (CSTR) and a plug flow reactor (PFR) are sequentially connected in series. Further, one or a plurality of CSTRs and PFRs may be connected depending on the purpose, but the number of CSTRs is preferably from 1 to 2, and particularly one is more preferable. The number of PFRs is preferably from 1 to 3, and especially one is more preferred.

When the solution polymerization is used as the polymerization method of the polymer (II), the solvent to be used is not particularly limited, and from the viewpoints of availability, solubility, and the like, for example, acetone, methyl ethyl ketone, and methyl group are used. Ketones such as butyl ketone and acetophenone; ethers such as tetrahydrofuran and 1,4-dioxane; aromatic hydrocarbons such as toluene, ethylbenzene, xylene and chlorobenzene; N,N-dimethyl A solvent such as carbamide, dimethyl hydrazine or N-methyl-2-pyrrolidone is preferably toluene or ethylbenzene from the viewpoint of solubility in a solvent of the polymer (II). The amount of the solvent to be added is not particularly limited, and is preferably from 1 to 30 parts by mass, more preferably from 5 to 25 parts by mass, per 100 parts by mass of the total amount of the monomer compound. .

The polymerization method of the polymer (II) is not particularly limited, and from the viewpoint of being able to be produced by a simple process productivity, radical polymerization is preferred, and any radical polymerization initiator can be used.

The radical polymerization initiator to be used in the polymerization of the polymer (II) is not particularly limited, and for example, a known peroxide such as an azo compound, an organic peroxide, an inorganic peroxide or hydrogen peroxide can be used. Among them, from the viewpoint of easy reaction control and easy availability, it is preferable to use a known couple such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile or azobismethylbutyronitrile. Nitrogen compound; benzoic acid peroxide, tert-butyl peroxybenzoate, 1,1-bis(tert-butylperoxy)-2-methylcyclohexane, tert-butyl isopropyl monocarbonate, Known organic peroxidation of tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyacetate, dicumyl peroxide, ethyl 3,3-di(tert-butylperoxy)butyrate, etc. Things.

In the polymerization of the polymer (II), the radical polymerization initiator may be used singly or in combination of two or more. From the viewpoint of the reaction rate of polymerization and the control of the polymerization rate, a radical polymerization initiator which is commonly used in the production of a conventional styrene resin is preferable, and specifically, a 10-hour half-life temperature of 70 to 120 ° C is used. An azo compound or an organic peroxide is preferred.

The amount of use of the radical polymerization initiator is not particularly limited, and is preferably 0.001 to 0.1 part by mass, more preferably 0.002 to 0.03 part by mass, per 100 parts by mass of the total amount of the monomer compound.

When the amount of the radical polymerization initiator used is 0.001 part by mass or more and 0.002 part by mass or more based on 100 parts by mass of the total amount of the monomer compound, a sufficient polymerization rate can be obtained, so that good productivity can be maintained. When the amount of the radical polymerization initiator used is 0.1 part by mass or less and 100 parts by mass or less based on 100 parts by mass of the total amount of the monomer compound, the polymerization rate can be suppressed and the reaction control can be facilitated, so that the polymer can be made ( The molecular weight control of II) becomes easy.

Any chain transfer agent can be used in the polymerization of the polymer (II). The chain transfer agent to be used is not particularly limited, but from the viewpoints of easy availability, easy molecular weight control, and the like, specifically, n-dodecyl mercaptan, t-dodecyl mercaptan, and 2,4-diphenyl can be used. A chain transfer agent such as benzyl-4-methyl-1-pentene. Further, the chain transfer agent may be used singly or in combination of two or more.

The amount of the chain transfer agent to be used is not particularly limited as long as it is within the range of the target molecular weight of the polymer (II), but it is preferably used in an amount of 0.05 to 2.0 parts by mass based on 100 parts by mass of the total amount of the monomer compound. In particular, it is more preferably used in an amount of 0.2 to 0.8 parts by mass based on 100 parts by mass of the total amount of the monomer compound. When the amount of the chain transfer agent used is 0.05 parts by mass or more and 2.0 parts by mass or less, the target molecular weight of the (meth) acrylate type copolymer (B) can be easily obtained.

The polymerization temperature of the polymer (II) is not particularly limited, and in the case of continuous polymerization, the reaction temperature in the CSTR is preferably from 110 ° C to 160 ° C, and particularly preferably in the range of from 120 ° C to 140 ° C. Further, the reaction temperature in the PFR is preferably from 120 ° C to 170 ° C, and particularly preferably in the range of from 130 ° C to 150 ° C. If so, the reaction is easily controlled, and a polymer (II) having a uniform composition can be obtained.

The method of removing the volatile component such as the solvent used in the polymerization of the polymer (II), the unreacted monomer, or the like is not particularly limited, and a known method can be used. However, a method in which a devolatilization tank is used is preferable. When the devolatilization tank is used, it is preferable to keep the temperature of the molten resin at 260 ° C or lower, and it is more preferable to keep it at 240 ° C or lower. When the resin temperature is suppressed to 260 ° C or lower, the depolymerization due to thermal deterioration of the polymer (II) can be suppressed, and the polymer (II) excellent in hue can be obtained. Further, the method of adjusting the resin temperature can be carried out by adjusting the temperature of the devolatilization tank.

In order to prevent thermal deterioration during processing of the polymer (II) and to maintain a good hue, any radical scavenger can be used. The radical scavenger is not particularly limited, and examples thereof include antioxidants such as a phenol compound, an organophosphorus compound, an organic sulfur compound, and an amine compound. These radical scavengers may be used singly or in combination of two or more. These radical scavengers are subjected to a remarkable thermal history in the process of devolatilizing volatile components in the styrene-maleimide copolymer in a vented screw extruder, so in order to maintain freedom The function of the radical scavenger, a compound having heat resistance and thermal stability, is particularly preferred. For example, a radical scavenger having a 1% heat reduction temperature exceeding 300 ° C is more preferable. It is preferred to add a radical scavenger to the polymerization product after polymerization. If it is added before or during the polymerization, the polymerization rate may be low.

The conjugated diene monomer unit (D) which can be used in the resin composition of the present invention is exemplified by 1,3-butadiene (butadiene) and 2-methyl-1,3-butylene. Diene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2-methylpentadiene, etc. A unit of a monomer having a conjugated double bond. Among them, a butadiene unit is preferred. These conjugated diene monomer units (D) may be used singly or in combination of two or more.

Examples of the aromatic vinyl monomer unit (A) which can be used in the graft copolymer (III) include units derived from styrene, o-methyl styrene, m-methyl styrene, and the like. Various styrenes such as p-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, p-tert-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, etc. Monomer. Among them, a styrene unit is preferred. These aromatic vinyl monomer units (A) may be used singly or in combination of two or more.

As the (meth) acrylate monomer unit (B) which can be used in the graft copolymer (III), a unit derived from the following monomers: methyl methacrylate, ethyl methacrylate, and A Various methacrylate monomers such as n-butyl acrylate, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate, isobornyl methacrylate, and methyl acrylate, ethyl acrylate, acrylic acid Various acrylate monomers such as n-butyl ester, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, and decyl acrylate. Among them, a methyl methacrylate unit is preferred. These (meth) acrylate monomer units (B) may be used singly or in combination of two or more.

The graft copolymer (III) may contain, in addition to the conjugated diene monomer unit (D), the aromatic vinyl monomer unit (A), or (meth)acrylic acid, within a range not inhibiting the effects of the invention. The unit of the copolymerizable vinyl monomer other than the ester monomer unit (B) is preferably 5% by mass or less. Examples of the other monomer capable of copolymerizing a vinyl monomer include a vinyl cyanide monomer derived from acrylonitrile or methacrylonitrile, a vinyl carboxylic acid monomer such as acrylic acid or methacrylic acid, and N- N-alkyl maleimide monomer such as methyl maleimide, N-ethyl maleimide, N-butyl maleimide, N-cyclohexyl maleimide , various monomers such as N-phenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide, etc. Unit. The unit of the other copolymerizable vinyl monomer may be used in combination of two or more.

The graft copolymer (III) is a copolymer composed of an aromatic vinyl monomer unit (A) and a (meth) acrylate monomer unit (B) and a conjugated diene monomer unit (D). A copolymer comprising a dendritic structure in which a diene rubbery polymer is combined. Further, the graft copolymer (III) contains aromatic vinyl monomer units (A) and (A) which are formed as by-products during graft polymerization and which are not grafted with the diene rubber-like polymer. a copolymer composed of an acrylate monomer unit (B). In the case where a diene rubbery polymer is present, a graft copolymer (III) is obtained by polymerizing an aromatic vinyl monomer unit (A) and a (meth) acrylate monomer unit (B) by a known method. ).

The diene rubbery polymer which can be used in the graft copolymer (III) may, for example, be a polybutadiene, a butadiene-styrene copolymer, a butadiene-acrylonitrile copolymer or a polyisoprene. A conjugated diene rubber such as a styrene-isoprene copolymer or a hydrogen additive thereof may be used singly or in combination of two or more. Among them, polybutadiene is preferred.

The polymerization method of the graft copolymer (III) is not particularly limited, and a known method such as bulk polymerization, solution polymerization, suspension polymerization, bulk-suspension polymerization, emulsion polymerization, or the like can be employed, but an emulsion polymerization method is preferred.

The polymerization method of the graft copolymer (III) is not particularly limited, but from the viewpoint of being easily produced by a simple process productivity, radical polymerization is preferred, and any radical polymerization initiator can be used.

As the radical initiator used in the graft copolymer (III), an azo compound such as azobisisobutyronitrile or azobiscyclohexanecarbonitrile; benzoic acid peroxide or benzoic acid benzoate may be used. Organic butyl ester, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyacetate, dicumyl peroxide, 3,3-di(tert-butylperoxy) butyrate An oxide; or an inorganic peroxide such as hydrogen peroxide, potassium persulfate or ammonium persulfate, but an inorganic peroxide or an organic peroxide is preferably used, and an inorganic peroxide and an organic peroxide are used together. A redox initiator which is a combination of a reducing agent such as ferrous sulfate is more preferable. Further, in the polymerization of the graft copolymer (III), the radical polymerization initiator may be used singly or in combination of two or more.

The amount of use of the radical polymerization initiator is not particularly limited, and it is preferably 0.1 to 0.5 parts by mass, more preferably 0.5 to 3.5 parts by mass, per 100 parts by mass of the total amount of the monomer compound.

If the amount of the radical polymerization initiator used is relative to a monomer compound composed of a diene rubber-like polymer, an aromatic vinyl monomer unit (A), and a (meth) acrylate monomer unit (B) When the total amount is 100 parts by mass and the amount is 0.1 part by mass or more, a sufficient polymerization rate can be obtained, so that good productivity can be maintained. When the amount of the radical polymerization initiator used is 3.5 parts by mass or less based on 100 parts by mass of the total amount of the monomer compound, the polymerization rate can be suppressed, and the reaction control can be easily performed.

Any chain transfer agent can be used in the polymerization of the graft copolymer (III). The chain transfer agent to be used is not particularly limited, but from the viewpoints of easy availability, easy molecular weight control, and the like, specifically, n-dodecyl mercaptan, t-dodecyl mercaptan, and 2,4-diphenyl can be used. A chain transfer agent such as benzyl-4-methyl-1-pentene. The chain transfer agent may be used singly or in combination of two or more.

The polymerization temperature of the graft copolymer (III) is not particularly limited, and the reaction temperature in the emulsion polymerization is preferably 50° C. or higher and 55° C. or higher from the viewpoint of increasing the polymerization rate and maintaining good productivity. . In addition, from the viewpoint of reducing the amount of coagulum or deposit in the polymerization container and maintaining good productivity, 98 ° C or less is preferable, and 90 ° C or less is particularly preferable.

In the resin composition, a stabilizer, a plasticizer, a lubricant, an antioxidant, an ultraviolet absorber, a light stabilizer, a colorant, or the like may be blended in a range that does not inhibit the effects of the present invention.

The total light transmittance of the resin composition of the present invention measured by ASTM D1003 of 2 mm thickness is 88% or more, preferably 89% or more, and more preferably 90% or more. If the total light transmittance of the thickness of 2 mm is 88% or more, it also has excellent transparency after molding. In addition, the total light transmittance is based on ASTM D1003, using a haze meter (NDH-1001DP type manufactured by Nippon Denshoku Industries Co., Ltd.), and using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.) at a barrel temperature of 230 A value obtained by measuring a mirror sheet having a length of 90 mm, a width of 55 mm, and a thickness of 2 mm formed under molding conditions of a mold temperature of 40 ° C.

When the resin composition of the present invention is used as a polarizer protective film, the in-plane retardation (Re) calculated by the formula 3 is preferably 30 nm or less, more preferably 20 nm or less, still more preferably 10 nm or less, in terms of 100 μm; The calculated thickness phase difference (Rth) is preferably 20 nm or less, more preferably 10 nm or less, and still more preferably 5 nm or less in terms of 100 μm. When the in-plane retardation (Re) is 30 nm or less and the thickness retardation (Rth) is 20 nm or less, when the film is used in a polarizing plate of a liquid crystal display device, the problem of low contrast of the liquid crystal display device does not occur, It is suitable.

(Formula 3) Re=(nx-ny)×d

(Formula 4) Rth={(nx+ny)÷2-nz}×d

Further, in the above formula, nx, ny, and nz are each in the axial direction when the direction in which the in-plane refractive index is the largest is the X-axis, the direction perpendicular to the X-axis is the Y-axis, and the thickness direction of the film is the Z-axis. The refractive index, d is the film thickness.

The method for producing the film is not particularly limited, and a known forming method such as a melt extrusion film forming method or a solution casting method can be used. As an example of obtaining a film having a small birefringence, a method of using an elastically deformable flexible roll can be mentioned. Further, although an unstretched film can be used, a stretched film obtained by stretching a film can also be used in order to increase the film strength. The stretching method of the film is not particularly limited, and as the uniaxial stretching, a stretched film can be obtained by, for example, a roll stretching method, a tenter stretching method, or a free-width uniaxial stretching method; as the biaxial stretching, for example, A stretched film was obtained by a sequential biaxial stretching method in which roll stretching and tenter stretching were combined, and a biaxial stretching method using tubular stretching.

The absolute value of the photoelastic coefficient of the resin composition of the present invention is preferably 5.0 × 10 ^-12 Pa ^-1 or less, more preferably 3.0 × 10 ^-12 Pa ^-1 or less, still more preferably 1.0 × 10 ^-12 Pa ^-1 . If the photoelastic coefficient is sufficiently small, the birefringence change caused by the external force is reduced, and the birefringence due to the residual stress at the time of forming is not easily generated, the birefringence distribution in the molded body is reduced, and thus the polarizing plate used for the liquid crystal display device is used. In this case, birefringent stripes are not generated, and the contrast of the peripheral portion of the display screen is not lowered, and light leakage does not occur, which is preferable.

The photoelastic coefficient can be determined by measuring the in-plane retardation (Re) of the film using a phase difference measuring device while applying tensile stress to the film. When the in-plane phase difference (Re) in the state where the load f is applied is Re (f) and the test piece width is w, the photoelastic coefficient C is C = d Re (f) / df × w, so the surface is obtained by The value of the internal phase difference (Re) can be calculated from the slope of the load applied to the test piece. Further, in the present invention, the phase difference measuring device uses KOBRA-WR manufactured by Oji Scientific Co., Ltd., and applies stress using a digital dynamometer Z2S-DPU-50N manufactured by Essence Motor Co., Ltd.

The method for adjusting the photoelastic coefficient of the resin composition of the present invention is not particularly limited, and the composition ratio can be adjusted, and depending on the type of the monomer, some have a positive contribution to the photoelastic coefficient of the resin composition, and some have a positive effect. Negative contribution, so by properly adjusting these components, the photoelastic coefficient can be offset and its absolute value reduced. For example, styrene, butadiene, and a negative contribution of methyl methacrylate or maleic anhydride, which have a positive contribution to the photoelastic coefficient, can be used to offset the photoelastic coefficient and reduce its absolute value.

(Example)

(1) Manufacture of copolymer (I)

<Production Example of I-1>

A 20% maleic anhydride solution obtained by dissolving maleic anhydride in a concentration of 25% by mass in methyl isobutyl ketone and a mass of 2% by weight of t-butyl peroxy-2-ethylhexanoate were prepared in advance. A 2% solution of 2% t-butylperoxy-2-ethylhexanoate obtained by diluting in methyl isobutyl ketone for polymerization.

In a 50-liter autoclave with a stirrer, 1.76 kg of a 25% maleic anhydride solution, 11.8 kg of styrene, 3.8 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen. The temperature was raised to 90 ° C for 40 minutes while stirring. After raising the temperature, the solution was continuously added in portions of 25% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution while maintaining the temperature at 90 °C. The 25% maleic anhydride solution was 1.98 kg/hr from the start of batch addition to the fourth hour at the batch addition rate, 1.58 kg/hour from the fourth hour to the seventh hour, and from the 7th hour to the 10th. The batch addition rate was changed in stages, and the total addition rate was 15.81 kg, which was 0.79 kg/hr in the hour and 0.26 kg/hour from the 10th hour to the 13th hour. A 2% t-butylperoxy-2-ethylhexanoate solution was added at a batch addition rate of 0.12 kg/hr from the start of batch addition to the seventh hour, and 0.19 kg from the seventh hour to the 13th hour. In the hour/hour mode, the batch addition speed was changed in stages, and a total of 1.98 kg was added. The polymerization temperature was maintained at 90 ° C from the start of the batch addition until the 7th hour, and then the temperature was raised to 114 ° C for 6 hours at a temperature elevation rate of 4 ° C / hour, and held at 114 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-1). The obtained copolymer (I-1) was subjected to composition analysis by a C-13 NMR method. Using a SYSTEM-Shodex (manufactured by Showa Denko), a column in which three PLgelMIXED-Bs are connected in series, a detector with a refractive index, and tetrahydrofuran as a solvent are used, and standard polystyrene (PS) (manufactured by PL) is used. A standard curve was prepared, and the weight average molecular weight (Mw) was measured under the conditions of a temperature of 40 ° C and a concentration of 2% by mass. The obtained copolymer (I-1) was dissolved in chloroform to prepare a 12% by mass chloroform solution, and filled into a quartz square box for measurement with an optical path length of 10 mm, and a haze meter (manufactured by Toyo Seiki Co., Ltd.) was used based on JIS K-7136. HAZEGUARD II) measured the haze of an optical path length of 10 mm in a 12% by mass chloroform solution. Using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.), a mirror sheet having a molding length of 90 mm, a width of 55 mm, and a thickness of 2 mm was formed under the molding conditions of a cylinder temperature of 230 ° C and a mold temperature of 40 ° C, and fog was used based on ASTM D1003. The total light transmittance of 2 mm thickness was measured by a meter (NDH-1001DP type manufactured by Nippon Denshoku Industries Co., Ltd.). A molded body having a thickness of 2 mm was produced by press molding, and the refractive index was measured using an Abbe refractometer (DR-M2) manufactured by ATAGO. The composition analysis result of the copolymer (I-1), the molecular weight measurement result, the total light transmittance measurement result of the 2 mm-thickness mirror sheet, and the refractive index measurement result are shown in Table 1.

<Production Example of I-2>

A 25% maleic anhydride solution and a 2% t-butyl peroxy-2-ethylhexanoate solution were prepared in the same manner as in the production example of (I-1) for polymerization.

In a 50-liter autoclave equipped with a stirrer, 1.76 kg of a 25% maleic anhydride solution, 14 kg of styrene, 1.6 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen. The temperature was raised to 96 ° C for 40 minutes while stirring. After raising the temperature, the solution was continuously added in portions of 25% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution while maintaining 96 °C. The 25% maleic anhydride solution was 1.98 kg/hr from the start of batch addition to the fourth hour at the batch addition rate, 1.58 kg/hour from the fourth hour to the seventh hour, and from the 7th hour to the 10th. The batch addition rate was changed in stages, and the total addition rate was 15.81 kg, which was 0.79 kg/hr in the hour and 0.26 kg/hour from the 10th hour to the 13th hour. A 2% t-butylperoxy-2-ethylhexanoate solution was added at a batch addition rate of 0.18 kg/hr from the start of the batch addition to the 7th hour, and 0.29 kg from the 7th hour to the 13th hour. In the hour/hour mode, the batch addition speed was changed in stages, and a total of 3.0 kg was added. The polymerization temperature was maintained at 96 ° C from the start of the batch addition to the 7th hour, and then the temperature was raised to 120 ° C for 6 hours at a temperature elevation rate of 4 ° C / hour, and maintained at 120 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-2). The obtained copolymer (I-2) was subjected to composition analysis in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance of the mirror sheet of 2 mm thickness, and the refractive index were measured. . The measurement results are shown in Table 1.

<Production Example of I-3>

A 10% maleic anhydride solution obtained by dissolving maleic anhydride in a concentration of 10% by mass in methyl isobutyl ketone was prepared in advance for polymerization. A 2% tert-butyl peroxy-2-ethylhexanoate solution was prepared in the same manner as in the production example of (I-1) for polymerization.

In a 50-liter autoclave with a stirrer, 2.4 kg of a 10% maleic anhydride solution, 9.6 kg of styrene, 8.0 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen. The temperature was raised to 88 ° C over 40 minutes while stirring. After heating, the solution was continuously added in portions of 10% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution while maintaining the temperature at 88 °C. The 10% maleic anhydride solution was 2.43 kg/hr from the start of batch addition to the fourth hour at the batch addition rate, 2.31 kg/hour from the fourth hour to the seventh hour, and from the 7th hour to the 10th. The amount of the batch addition was changed in stages from 1.3 hours per hour to 0.36 kg/hour from the 10th hour to the 13th hour, and a total of 21.63 kg was added. 2% t-butylperoxy-2-ethylhexanoate solution, 0.09 kg/hr from the start of batch addition to the 7th hour, and 0.15 kg from the 7th hour to the 13th hour at the batch addition rate In the hour/hour mode, the batch addition speed was changed in stages, and a total of 1.53 kg was added. The polymerization temperature was maintained at 88 ° C from the start of the batch addition to the 7th hour, and then the temperature was raised to 118 ° C for 6 hours at a temperature elevation rate of 5 ° C / hour, and maintained at 118 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-3). The obtained copolymer (I-3) was subjected to composition analysis in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance of the mirror sheet of 2 mm thickness, and the refractive index were measured. . The measurement results are shown in Table 1.

<Production Example of I-4>

A 25% maleic anhydride solution and a 2% t-butyl peroxy-2-ethylhexanoate solution were prepared in the same manner as in the production example of (I-1) for polymerization.

In a 50-liter autoclave with a stirrer, 1.92 kg of a 25% maleic anhydride solution, 2.0 kg of styrene, 8.2 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen. The temperature was raised to 88 ° C over 40 minutes while stirring. After the temperature was raised, the solution of styrene, 25% maleic anhydride solution, and 2% t-butylperoxy-2-ethylhexanoate was continuously added in batches while maintaining the temperature at 88 °C. Styrene was added in batches at a batch addition rate of 0.45 kg/hr from the start of batch addition to the 11th hour, and a total of 4.95 kg was added. The 25% maleic anhydride solution was 2.59 kg/hr from the start of batch addition to the fourth hour at the batch addition rate, 1.73 kg/hour from the fourth hour to the seventh hour, and from the seventh hour to the tenth The batch addition rate was changed in stages, and the total addition rate was 17.26 kg in a manner of 0.4 kg/hour from the 10th hour to the first 13 hours from the 10th hour to the 13th hour. 2% t-butylperoxy-2-ethylhexanoate solution, 0.06 kg / hour from the start of batch addition to the 7th hour, and 0.1 kg from the 7th hour to the 13th hour at the batch addition rate In the hour/hour mode, the batch addition speed was changed in stages, and a total of 1.02 kg was added. The polymerization temperature was maintained at 88 ° C from the start of the batch addition to the 7th hour, and then the temperature was raised to 118 ° C for 6 hours at a temperature elevation rate of 5 ° C / hour, and maintained at 118 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-4). The obtained copolymer (I-4) was subjected to composition analysis in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance of the mirror sheet of 2 mm thickness, and the refractive index were measured. . The measurement results are shown in Table 1.

<Production Example of I-5>

A 20% maleic anhydride solution obtained by dissolving maleic anhydride in a concentration of 20% by mass in methyl isobutyl ketone was prepared in advance for polymerization. A 2% tert-butyl peroxy-2-ethylhexanoate solution was prepared in the same manner as in the production example of (I-1) for polymerization.

In a 50-liter autoclave with a stirrer, 1.7 kg of a 20% maleic anhydride solution, 15.6 kg of styrene, 1.0 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen. The temperature was raised to 96 ° C for 40 minutes while stirring. After raising the temperature, the solution was continuously added in portions of 20% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution while maintaining the temperature at 96 °C. The 20% maleic anhydride solution was 1.91 kg/hr from the start of batch addition to the fourth hour at the batch addition rate, 1.53 kg/hour from the fourth hour to the seventh hour, and from the 7th hour to the 10th. The method was changed to 0.76 kg/hour from the 10th hour to the 13th hour, and the batch addition speed was changed in stages, and a total of 15.32 kg was added. A 2% t-butylperoxy-2-ethylhexanoate solution was added at a batch addition rate of 0.18 kg/hr from the start of the batch addition to the 7th hour, and 0.29 kg from the 7th hour to the 13th hour. In the hour/hour mode, the batch addition speed was changed in stages, and a total of 3.0 kg was added. The polymerization temperature was maintained at 96 ° C from the start of the batch addition to the 7th hour, and then the temperature was raised to 120 ° C for 6 hours at a temperature elevation rate of 4 ° C / hour, and maintained at 120 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-5). The obtained copolymer (I-5) was subjected to composition analysis in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance of the mirror sheet of 2 mm thickness, and the refractive index were measured. . The measurement results are shown in Table 1.

<Production Example of I-6>

A 10% maleic anhydride solution was prepared in the same manner as in the production example of (I-3), and a 2% tert-butyl peroxy-2-ethylhexanoate solution was prepared in the same manner as in the production example (I-1). For polymerization.

In a 50-liter autoclave with a stirrer, 2.0 kg of a 10% maleic anhydride solution, 1.2 kg of styrene, 13.8 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen. The temperature was raised to 88 ° C over 40 minutes while stirring. After the temperature was raised, a solution of styrene, a 10% maleic anhydride solution, and a 2% t-butylperoxy-2-ethylhexanoate solution were continuously added in portions while maintaining the temperature at 88 °C. Styrene was added in portions at a batch addition rate of 0.27 kg/hr from the start of batch addition to the 11th hour, and a total of 2.97 kg was added. The 10% maleic anhydride solution was 2.7 kg/hour from the start of batch addition to the fourth hour at the batch addition rate, 1.8 kg/hour from the fourth hour to the seventh hour, and from the seventh hour to the tenth The batch addition rate was changed in stages, and the total addition rate was 18.0 kg, which was 0.42 kg/hr in the hour and 0.18 kg/hour from the 10th hour to the 13th hour. 2% t-butylperoxy-2-ethylhexanoate solution, 0.06 kg / hour from the start of batch addition to the 7th hour, and 0.1 kg from the 7th hour to the 13th hour at the batch addition rate In the hour/hour mode, the batch addition speed was changed in stages, and a total of 1.02 kg was added. The polymerization temperature was maintained at 88 ° C from the start of the batch addition to the 7th hour, and then the temperature was raised to 118 ° C for 6 hours at a temperature elevation rate of 5 ° C / hour, and maintained at 118 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-6). The obtained copolymer (I-6) was subjected to composition analysis in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance of the mirror sheet of 2 mm thickness, and the refractive index were measured. . The measurement results are shown in Table 1.

<Production Example of I-7>

A 25% maleic anhydride solution and a 2% t-butyl peroxy-2-ethylhexanoate solution were prepared in the same manner as in the production example of (I-1) for polymerization.

In a 50-liter autoclave with a stirrer, 1.92 kg of a 25% maleic anhydride solution, 14.0 kg of styrene, 1.2 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen. The temperature was raised to 96 ° C for 40 minutes while stirring. After raising the temperature, the solution was continuously added in portions of 25% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution while maintaining 96 °C. The 25% maleic anhydride solution was 2.16 kg/hr from the start of batch addition to the fourth hour at the batch addition rate, 1.73 kg/hour from the fourth hour to the seventh hour, and from the seventh hour to the tenth The method was changed to 0.86 kg/hour from the 10th hour to the 13th hour, and the batch addition speed was changed in stages, and a total of 17.28 kg was added. A 2% t-butylperoxy-2-ethylhexanoate solution was added at a batch addition rate of 0.21 kg/hr from the start of batch addition to the seventh hour, and 0.34 kg from the seventh hour to the 13th hour. In the hour/hour mode, the batch addition speed was changed in stages, and a total of 3.51 kg was added. The polymerization temperature was maintained at 96 ° C from the start of the batch addition to the 7th hour, and then the temperature was raised to 120 ° C for 6 hours at a temperature elevation rate of 4 ° C / hour, and maintained at 120 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-7). The obtained copolymer (I-7) was subjected to composition analysis in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance of the mirror sheet of 2 mm thickness, and the refractive index were measured. . The measurement results are shown in Table 1.

<Production Example of I-8>

A 25% maleic anhydride solution and a 2% t-butyl peroxy-2-ethylhexanoate solution were prepared in the same manner as in the production example of (I-1) for polymerization.

In a 50-liter autoclave with a stirrer, 2.24 kg of a 25% maleic anhydride solution, 13.4 kg of styrene, 10.0 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen. The temperature was raised to 94 ° C for 40 minutes while stirring. After raising the temperature, the solution was continuously added in portions of 25% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution while maintaining 94 °C. The 25% maleic anhydride solution was added at a batch addition rate of 2.52 kg/hr from the start of batch addition to the fourth hour, 2.02 kg/hour from the fourth hour to the seventh hour, and from the seventh hour to the tenth The batch addition rate was changed in stages, and the total addition rate was 20.19 kg, which was 1.01 kg/hr in the hour and 0.34 kg/hour from the 10th hour to the 13th hour. A 2% t-butylperoxy-2-ethylhexanoate solution was added at a batch addition rate of 0.18 kg/hr from the start of the batch addition to the 7th hour, and 0.29 kg from the 7th hour to the 13th hour. In the hour/hour mode, the batch addition speed was changed in stages, and a total of 3.0 kg was added. The polymerization temperature was maintained at 94 ° C from the start of the batch addition until the 7th hour, and then the temperature was raised to 118 ° C for 6 hours at a temperature elevation rate of 4 ° C / hour, and maintained at 118 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-8). The obtained copolymer (I-8) was subjected to composition analysis in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance of the mirror sheet of 2 mm thickness, and the refractive index were measured. . The measurement results are shown in Table 1.

<Manufacturing example of 1-9>

A 10% maleic anhydride solution was prepared in the same manner as in the production example of (I-3), and a 2% tert-butyl peroxy-2-ethylhexanoate solution was prepared in the same manner as in the production example (I-1). For polymerization.

In a 50-liter autoclave equipped with a stirrer, 1.6 kg of a 10% maleic anhydride solution, 18.4 kg of styrene, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen, and then heated for 40 minutes while stirring. To 96 ° C. After the temperature was raised, a 10% maleic anhydride solution and a 2% t-butylperoxy-2-ethylhexanoate solution were successively added in portions while maintaining the temperature at 96 °C. The 10% maleic anhydride solution was 1.62 kg/hr from the start of batch addition to the fourth hour at the batch addition rate, 1.2 kg/hour from the fourth hour to the seventh hour, and from the 7th hour to the 10th. The method was changed to 0.98 kg/hour from the 10th hour to the 13th hour, and the batch addition speed was changed in stages, and a total of 14.4 kg was added. A 2% t-butylperoxy-2-ethylhexanoate solution was added at a batch addition rate of 0.3 kg/hr from the start of batch addition to the seventh hour, and 0.48 kg from the seventh hour to the 13th hour. In the hour/hour mode, the batch addition speed was changed in stages, and a total of 4.98 kg was added. The polymerization temperature was maintained at 96 ° C from the start of the batch addition to the 7th hour, and then the temperature was raised to 120 ° C for 6 hours at a temperature elevation rate of 4 ° C / hour, and maintained at 120 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-9). The obtained copolymer (I-9) was subjected to composition analysis in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance of the mirror sheet of 2 mm thickness, and the refractive index were measured. . The measurement results are shown in Table 1.

<Production Example of I-10>

A 10% maleic anhydride solution was prepared in the same manner as in the production example of (I-3), and a 2% tert-butyl peroxy-2-ethylhexanoate solution was prepared in the same manner as in the production example (I-1). For polymerization.

In a 120-liter autoclave with a stirrer, 1.6 kg of a 10% maleic anhydride solution, 1.8 kg of styrene, 14.6 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan were charged, and the gas phase portion was replaced with nitrogen. The temperature was raised to 88 ° C over 40 minutes while stirring. After the temperature was raised, a solution of styrene, a 10% maleic anhydride solution, and a 2% t-butylperoxy-2-ethylhexanoate solution were continuously added in portions while maintaining the temperature at 88 °C. Styrene was added in portions at a batch addition rate of 0.18 kg/hr from the start of batch addition to the 11th hour, and a total of 1.98 kg was added. The 10% maleic anhydride solution was 2.16 kg/hr from the start of batch addition to the fourth hour at the batch addition rate, 1.44 kg/hour from the fourth hour to the seventh hour, and from the seventh hour to the tenth The batch addition rate was changed in stages, and the total addition rate was 14.4 kg, which was 0.34 kg/hr in the hour and 0.14 kg/hour from the 10th hour to the 13th hour. 2% t-butylperoxy-2-ethylhexanoate solution, 0.06 kg / hour from the start of batch addition to the 7th hour, and 0.1 kg from the 7th hour to the 13th hour at the batch addition rate In the hour/hour mode, the batch addition speed was changed in stages, and a total of 1.02 kg was added. The polymerization temperature was maintained at 88 ° C from the start of the batch addition to the 7th hour, and then the temperature was raised to 118 ° C for 6 hours at a temperature elevation rate of 5 ° C / hour, and maintained at 118 ° C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to a biaxial devolatilizing extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomers are subjected to devolatilization treatment, and are extruded in a line shape and cut off. Pellet-shaped copolymer (I-10). The obtained copolymer (I-10) was subjected to composition analysis in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance of the mirror sheet of 2 mm thickness, and the refractive index were measured. . The measurement results are shown in Table 1.

(2) Manufacture of polymer (II)

<Production Example of II-1>

A 20-liter full-mix reactor with a stirrer, a 40-liter column-type plug flow reactor, and a devolatilizer with a preheater were connected in series. Further, 1,1-di(tert-butylperoxy)cyclohexane (manufactured by Nippon Oil Co., Ltd.) was further mixed in a mixed solution containing 98 parts by mass of methyl methacrylate, 2 parts by mass of ethyl acrylate, and 18 parts by mass of ethylbenzene. PERHEXA C) 0.02 parts by mass, n-dodecyl mercaptan (THIOKALCOL 20 manufactured by Kao Corporation) 0.3 parts by mass, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid 0.1 parts by mass of an alkanol ester (IRGANOX 1076 manufactured by Ciba Specialty Chemicals Co., Ltd.) was used to prepare a raw material solution. This raw material solution was introduced at 6 kg per hour into a fully mixed reactor controlled at a temperature of 120 °C. Further, the fully mixed reactor was stirred at a stirring speed of 200 rpm. Then, the reaction liquid was continuously taken out from the completely mixed type reactor, and a column plug flow type reactor adjusted to have a temperature gradient of 130 ° C to 150 ° C toward the flow direction was introduced. While the reaction liquid was heated by a preheater, it was introduced into a devolatilization tank controlled to a temperature of 240 ° C and a pressure of 1.0 kPa to remove volatile components such as unreacted monomers. The resin liquid was taken out by a gear pump, extruded in a line shape, and cut to obtain a pellet shape (II-1). The obtained polymer (II-1) was thermally decomposed at a furnace temperature of 450 ° C, and the decomposition gas was quantified by gas chromatography to carry out composition analysis. Using a SYSTEM-Shodex (manufactured by Showa Denko), a column in which three PLgelMIXED-Bs are connected in series, a detector with a refractive index, and tetrahydrofuran as a solvent are used, and standard polystyrene (PS) (manufactured by PL) is used. A standard curve was prepared, and the weight average molecular weight (Mw) was measured under the conditions of a temperature of 40 ° C and a concentration of 2% by mass. Using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.), a mirror sheet having a molding length of 90 mm, a width of 55 mm, and a thickness of 2 mm was formed under the molding conditions of a cylinder temperature of 230 ° C and a mold temperature of 40 ° C, and fog was used based on ASTM D1003. The total light transmittance of 2 mm thickness was measured by a meter (NDH-1001DP type manufactured by Nippon Denshoku Industries Co., Ltd.). A molded body having a thickness of 2 mm was produced by press molding, and the refractive index was measured using an Abbe refractometer (DR-M2) manufactured by Ai Rong Co., Ltd. The composition analysis results of the polymer (II-1), the molecular weight measurement results, the total light transmittance measurement results of the 2 mm-thick mirror sheet, and the refractive index measurement results are shown in Table 2.

【Table 2】

(III) Manufacture of graft copolymer (III)

<Production Example of III-1>

Into a 200 liter autoclave, 64 kg of pure water, 1680 g of potassium oleate, 160 g of potassium rosinate, 1.2 kg of sodium carbonate, and 400 g of potassium persulfate were added, and uniformly dissolved under stirring. Then, 80 kg of butadiene, 320 g of t-dodecyl mercaptan, and 160 g of divinylbenzene were added, and polymerization was carried out at 60 ° C for 20 hours while stirring, and the temperature was further raised to 70 ° C for 10 hours, and the polymerization was completed to obtain polybutane. Ethylene rubber latex.

The obtained polybutadiene rubber latex was weighed to 36 kg (calculated as solid content), and placed in an autoclave having a volume of 200 liters, and 80 kg of pure water was added thereto, and the mixture was heated to a temperature of 50 ° C under a nitrogen gas stream while stirring. Here, an aqueous solution obtained by dissolving 1.5 g of ferrous sulfate, 3 g of sodium edetate, and 100 g of a white block in 2 kg of pure water was added, and 5.7 kg of styrene and methacrylic acid were continuously added over 5 hours, respectively. A mixture of 18.3 kg of ester, 54 g of t-dodecyl mercaptan, and a solution obtained by dispersing 108 g of diisopropylbenzene hydrogen peroxide in 8 kg of a 5% aqueous potassium oleate solution. After the end of the addition, the temperature was raised to 70 ° C, and then 27 g of dicumyl hydrogen peroxide was added, followed by standing for 2 hours, and the polymerization was completed to obtain a graft copolymer latex.

An antioxidant is added to the obtained graft copolymer latex, and after dilution with pure water to form a solid content of 15% by mass, the temperature is raised to a temperature of 60 ° C, and while vigorously stirring, dilute sulfuric acid is added to precipitate, and after the slurry state, the temperature continues to rise. The mixture was solidified, dehydrated, washed with water and dried at 90 ° C to obtain a powdery graft copolymer (III-1). The obtained (III-1) is dissolved in chloroform, iodine chloride is added, and after the double bond in the polybutadiene is reacted, potassium iodide is added to make the residual iodine chloride into iodine, which is reversed by using sodium thiosulfate. The amount of polybutadiene in D-1 was determined by titration. Further, the obtained polymer was thermally decomposed at a furnace temperature of 450 ° C, and the decomposition gas was quantified by gas chromatography to determine the structural ratio of methyl methacrylate / styrene, from the amount of polybutadiene and methacrylic acid. The composition ratio of the ester/styrene was calculated as the composition of (III-1). Further, a molded body having a thickness of 2 mm was produced by press molding, and the refractive index was measured using an Abbe type refractometer (DR-M2) manufactured by Aiko Co., Ltd. The composition analysis results and the refractive index measurement results of (III-1) are shown in Table 3.

<Production Example of III-2>

Into a 200 liter autoclave, 64 kg of pure water, 1680 g of potassium oleate, 160 g of potassium rosinate, 1.2 kg of sodium carbonate, and 400 g of potassium persulfate were added, and uniformly dissolved under stirring. Then, 72 kg of butadiene, 8 kg of styrene, 320 g of t-dodecyl mercaptan, and 300 g of divinylbenzene were added, and polymerization was carried out at 60 ° C for 20 hours while stirring, and the temperature was further raised to 70 ° C for 10 hours, and the polymerization was completed. A polybutadiene rubber latex.

The obtained polybutadiene rubber latex was weighed to 36 kg (calculated as solid content), and placed in an autoclave having a volume of 200 liters, and 80 kg of pure water was added thereto, and the mixture was heated to a temperature of 50 ° C under a nitrogen gas stream while stirring. Here, an aqueous solution obtained by dissolving 1.5 g of ferrous sulfate, 3 g of sodium ethylenediaminetetraacetate, and 100 g of Rongalite in 2 kg of pure water was added, and 7.7 kg of styrene and methyl group were continuously added over 5 hours, respectively. A mixture of 16.3 kg of methyl acrylate, 54 g of t-dodecyl mercaptan, and a solution obtained by dispersing 108 g of diisopropylbenzene hydrogen peroxide in 8 kg of a 5% aqueous potassium oleate solution. After the end of the addition, the temperature was raised to 70 ° C, and then 27 g of dicumyl hydrogen peroxide was added, followed by standing for 2 hours, and the polymerization was completed to obtain a graft copolymer latex.

An antioxidant is added to the obtained graft copolymer latex, and after dilution with pure water to form a solid content of 15% by mass, the temperature is raised to a temperature of 60 ° C, and while vigorously stirring, dilute sulfuric acid is added to precipitate, and after the slurry state, the temperature continues to rise. The mixture was solidified, dehydrated, washed with water and dried at 90 ° C to obtain a powdery graft copolymer (III-2). The obtained (III-2) is dissolved in chloroform, iodine chloride is added, and after the double bond in the polybutadiene is reacted, potassium iodide is added to make the residual iodine chloride into iodine, which is reversed by using sodium thiosulfate. The amount of polybutadiene in D-1 was determined by titration. Further, the obtained polymer was thermally decomposed at a furnace temperature of 450 ° C, and the decomposition gas was quantified by gas chromatography to determine the structural ratio of methyl methacrylate / styrene, from the amount of polybutadiene and methacrylic acid. The composition ratio of (III-2) was calculated from the structural ratio of ester/styrene. Further, a molded body having a thickness of 2 mm was produced by press molding, and the refractive index was measured using an Abbe refractometer (DR-M2) manufactured by Ai Rong Co., Ltd. The composition analysis results and the refractive index measurement results of (III-2) are shown in Table 3.

<Production Example of III-3>

Into a 200 liter autoclave, 64 kg of pure water, 1680 g of potassium oleate, 160 g of potassium rosinate, 1.2 kg of sodium carbonate, and 400 g of potassium persulfate were added, and uniformly dissolved under stirring. Then, 60 kg of butadiene, 20 kg of styrene, 320 g of t-dodecyl mercaptan, and 400 g of divinylbenzene were added, and polymerization was carried out at 60 ° C for 20 hours while stirring, and the temperature was further raised to 70 ° C for 10 hours, and the polymerization was completed. A polybutadiene rubber latex.

The obtained polybutadiene rubber latex was weighed to 36 kg (calculated as solid content), and placed in an autoclave having a volume of 200 liters, and 80 kg of pure water was added thereto, and the mixture was heated to a temperature of 50 ° C under a nitrogen gas stream while stirring. Here, an aqueous solution obtained by dissolving 1.5 g of ferrous sulfate, 3 g of sodium edetate, and 100 g of a white block in 2 kg of pure water was added, and 10.1 kg of styrene and methacrylic acid were continuously added over 5 hours, respectively. A mixture of 13.9 g of an ester and 54 g of t-dodecyl mercaptan and a solution obtained by dispersing 108 g of diisopropylbenzene hydrogen peroxide in 8 kg of a 5% aqueous potassium oleate solution. After the end of the addition, the temperature was raised to 70 ° C, and then 27 g of dicumyl hydrogen peroxide was added, followed by standing for 2 hours, and the polymerization was completed to obtain a graft copolymer latex.

An antioxidant is added to the obtained graft copolymer latex, and after dilution with pure water to form a solid content of 15% by mass, the temperature is raised to a temperature of 60 ° C, and while vigorously stirring, dilute sulfuric acid is added to precipitate, and after the slurry state, the temperature continues to rise. The mixture was solidified, dehydrated, washed with water and dried at 90 ° C to obtain a powdery graft copolymer (III-3). The obtained (III-3) is dissolved in chloroform, iodine chloride is added, and after the double bond in the polybutadiene is reacted, potassium iodide is added to make the residual iodine chloride into iodine, which is reversed by using sodium thiosulfate. The amount of polybutadiene in D-1 was determined by titration. Further, the obtained polymer was thermally decomposed at a furnace temperature of 450 ° C, and the decomposition gas was quantified by gas chromatography to determine the structural ratio of methyl methacrylate / styrene, from the amount of polybutadiene and methacrylic acid. The composition ratio of the ester/styrene was calculated as the composition of (III-3). Further, a molded body having a thickness of 2 mm was produced by press molding, and the refractive index was measured using an Abbe type refractometer (DR-M2) manufactured by Aiko Co., Ltd. The composition analysis results and the refractive index measurement results of (III-3) are shown in Table 3.

【table 3】

<Examples. Comparative Examples>

The copolymers (I) (I-1) to (I-10) and the polymer (II) (II-1) and the graft copolymer (III) (III-1) to (III) described in the above Production Examples. -3) After mixing in the ratio (% by mass) shown in Tables 4 to 5, the mixture was melt-kneaded at a cylinder temperature of 240 ° C using a twin-screw extruder (TEM-35B manufactured by Toshiba Machine Co., Ltd.). For the pellets, a resin composition was obtained.

The composition of the resin composition was calculated from the composition and the compounding ratio of each component of the copolymer (I), the polymer (II), and the graft copolymer (III). The resin composition was evaluated as follows. The evaluation results are shown in Tables 4 to 5.

After the pellets were dried at 70 ° C for 4 hours, the sheet-like molten resin obtained by extruding at 260 ° C using a 40 mm Φ single-axis extruder and a T-die of 300 mm width was crimped with a flexible roll, and then a cooling roll was used. After cooling, an unstretched film having a width of 250 mm and a thickness of 100 ± 5 μm was obtained.

(In-plane phase difference (Re), thickness phase difference (Rth))

The unstretched film was cut into a length of 100 mm and a width of 20 mm, and a free end uniaxial stretching was carried out under the following conditions using a uniaxial stretching apparatus.

Distance between chucks: 50mm

Stretching temperature: Vicat softening temperature +10 ° C

Afterheat time: 5 minutes

Stretching speed: 12.5mm/min

Stretching distance: 12.5mm

Regarding the in-plane retardation (Re) and the thickness phase difference (Rth) of the stretched film, the birefringence of the film was measured by the following apparatus.

Phase difference measurement: KOBRA-WR manufactured by Oji Scientific Co., Ltd.

Measurement wavelength: 590 nm

(photoelastic coefficient)

When the unstretched film is used, the in-plane retardation (Re) in the state where the load f is applied is Re (f), and the test piece width is w, the photoelastic coefficient is d Re (f) / df × w, so The photoelastic coefficient was calculated by calculating the slope of the in-plane phase difference (Re) with respect to the slope of the load applied to the test piece.

Phase difference measurement: KOBRA-WR manufactured by Oji Scientific Co., Ltd.

Measurement wavelength: 590 nm

Stress measurement: Digital dynamometer Z2S-DPU-50N manufactured by EMD

(total light transmittance and haze)

A test piece having a length of 90 mm, a width of 55 mm, and a thickness of 2 mm formed by using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.) under a molding condition of a cylinder temperature of 230 ° C and a mold temperature of 40 ° C was obtained. The total light transmittance and haze were measured for this test piece using a haze meter (NDH-1001DP type manufactured by Nippon Denshoku Industries Co., Ltd.) based on ASTM D1003.

(Vicat softening temperature)

The Vicat softening temperature was measured using a test piece of 10 mm × 10 mm and a thickness of 4 mm by a 50 method (load 50 N, temperature increase rate 50 ° C / hour) based on JIS K7206. In addition, the measuring machine used the HDT & VSPT test apparatus manufactured by Toyo Seiki Seisakusho Co., Ltd. The Vicat softening temperature above 110 ° C is acceptable.

(breaking strength)

Regarding the folding strength of the film, the folding strength was measured using the unstretched film under the following conditions. The folding strength is 100 or more.

Device name: MIT-DFOLDING ENDURANCE TESTER (manufactured by Toyo Seiki Co., Ltd.)

Load (tension): 500g weight

Bending speed: 175 times / minute

Bending angle: 45 degrees left and right

Bending device tip radius: 0.38mm

Test piece width: 15mm

(thermal stability)

Using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.), 50 samples of cylindrical molded articles having a diameter of 30 mm and a height of 50 mm were produced under the molding conditions of a cylinder temperature of 250 ° C and a mold temperature of 60 ° C, and visual observation was carried out. The number of samples having poor appearance due to thermal decomposition of silver ash, combustion pollution, coloring, bubbles, and the like was generated, and the thermal stability of the resin composition was evaluated. The evaluation criteria are as follows.

◎: The number of samples with poor appearance is 0

○: The number of samples with poor appearance is 1~4

△: The number of samples with poor appearance is 5~9

×: The number of samples with poor appearance is 10 or more

【table 5】

(I-1) to (I-8) of the copolymer (I) of the present invention and (II-1) of the polymer (II) and (III-1) to (III- of the graft copolymer (III) 3) The resin composition obtained by the mixing is hard to cause birefringence, and is excellent in heat resistance, film strength, and thermal stability.

In Comparative Example 1 to Comparative Example 2 in which Formula 1 does not satisfy the scope of the present invention, the birefringence is large. In Comparative Example 3 in which the formula 1 and the conjugated diene monomer unit did not satisfy the range of the present invention, the birefringence was large and the film strength was poor. Comparative Example 4 using (I-9) in which the unsaturated carboxylic anhydride monomer unit did not satisfy the range of the present invention was inferior in heat resistance. Comparative Example 5 using (I-10) in which the aromatic vinyl monomer unit did not satisfy the range of the present invention was inferior in transparency and thermal stability.

(industrial availability)

According to the present invention, it is possible to provide a resin composition which is less likely to cause birefringence, heat resistance, film strength, and thermal stability, and a film composed of the resin composition.

Claims (7)

 A resin composition comprising: an aromatic vinyl monomer unit (A) of 17 to 31% by mass, a (meth) acrylate monomer unit (B) of 38 to 63% by mass, and an unsaturated dicarboxylic anhydride monomer unit; (C) 4 to 14% by mass and conjugated diene monomer unit (D) 4 to 25% by mass, and the absolute value of the value of the following formula 1 is 0.005 or less, and Formula 1: -0.10 × [A] - 0.004 ×[B]+0.10×[C]+0.09×[D], [A], [B], [C], and [D] in Formula 1 sequentially represent the aromatic vinyl monomer unit (A) The mass ratio of the (meth) acrylate monomer unit (B), the unsaturated dicarboxylic anhydride monomer unit (C), and the conjugated diene monomer unit (D) in the resin composition , [A]+[B]+[C]+[D]=1.    The resin composition according to claim 1, further comprising: 20 to 80 parts by mass of the copolymer (I), the copolymer (I) comprising the aromatic vinyl monomer unit (A), the (A) The acrylate monomer unit (B), the unsaturated dicarboxylic anhydride monomer unit (C); the polymer (II) 0 to 60 parts by mass, the polymer (II) from the (methyl) The acrylate monomer unit (B) is composed; and the graft copolymer (III) is 5 to 60 parts by mass, and the graft copolymer (III) is passed through the aromatic vinyl monomer unit (A) and The copolymer composed of the (meth) acrylate monomer unit (B) is grafted to a polymer composed of the conjugated diene monomer unit (D).    The resin composition according to claim 2, wherein the copolymer (I) comprises: 20 to 80% by mass of the aromatic vinyl monomer unit (A), and the (meth) acrylate monomer The unit (B) is a copolymer of 5 to 70% by mass and 10 to 25% by mass of the unsaturated dicarboxylic anhydride monomer unit (C).    The resin composition according to claim 2 or 3, wherein the copolymer (I) has a haze length of 10 mm or less in a 12% by mass chloroform solution of 2% or less.    The resin composition according to claim 1 or 2, wherein the total light transmittance of the thickness of 2 mm measured based on ASTM D1003 is 88% or more.    A film comprising the resin composition according to claim 1 or 2.    The film according to claim 6, wherein the film is used as a polarizer protective film.