TWI726126B - Resin composition and film composed of the resin composition - Google Patents

Abstract

Provided is a resin composition and a film composed of the resin composition, which are difficult to generate birefringence and are excellent in heat resistance, film strength, and thermal stability. According to the present invention, a resin composition is provided, which is composed of 17 to 31% by mass of aromatic vinyl monomer units (A), 38 to 63% by mass of (meth)acrylate monomer units (B), and unsaturated dicarboxylic anhydride The monomer unit (C) is composed of 4 to 14% by mass and the conjugated diene monomer unit (D) is composed of 4 to 25% by mass. The absolute value of the value of the following formula 1 is 0.005 or less, formula 1: -0.10×[A ]-0.004×[B]+0.10×[C]+0.09×[D], [A], [B], [C], [D] in formula 1 represent the aromatic vinyl monomer unit (A ), (meth)acrylate monomer unit (B), unsaturated dicarboxylic anhydride monomer unit (C), conjugated diene monomer unit (D), the mass ratio in the resin composition, [A]+ [B]+[C]+[D]=1.

Description

Resin composition and film composed of the resin composition

The present invention relates to a resin composition that is resistant to birefringence, heat resistance, film strength, and thermal stability, and a film composed of the resin composition.

Transparent resin can be used for various purposes such as parts of home appliances, food containers, and groceries. In recent years, in terms of lightness, productivity, and cost, transparent resins have been mostly used as optical components such as retardation films, polarizer protective films, anti-reflection films, diffusion sheets, and light guide sheets in liquid crystal display devices.

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, etc., with a glass plate, and two polarizing plates arranged on both sides of the liquid crystal cell. On both sides of the polarizing plate, TAC (TAC) is used to protect the surface. A polarizer protective film composed of cellulose triacetate) film.

In order to achieve the uniformity of the wide viewing angle range of the liquid crystal display, it is desirable that the polarizer protective film has no birefringence. However, since the TAC film has a slight birefringence, there is a problem of birefringence of incident light in an oblique direction. In addition, with the increase in the size of the display, there is a problem that the birefringence distribution occurs due to the deviation of the external stress, and the contrast is lowered. Therefore, it is desired that the polarizer protective film does not easily change the birefringence caused by the external stress.

As resins for optical films, a copolymer resin obtained by copolymerizing methyl methacrylate, maleic anhydride, and styrene is known (for example, Patent Document 1). In addition, as resins with small birefringence, glutarimide resins (for example, Patent Document 2), methyl methacrylate and N-phenylmaleimide, and N-cyclohexylmaleimide are known. Copolymer resin obtained by copolymerizing imine (for example, Patent Document 3).

【Advanced Technical Literature】

Patent literature

Patent Document 1: International Patent Application WO2014/021264

Patent Document 2: Japanese Patent Application Publication No. 2006-337493

Patent Document 3: JP 2013-109285 A

Although the resin described in Patent Document 1 is excellent in heat resistance and transparency, it is designed to increase the birefringence after the film is formed, so its use is limited. Although the resins described in Patent Documents 2 and 3 are excellent in optical properties, the strength of the film after molding is not strong enough, and therefore the use is limited.

The object of the present invention is to provide a resin composition that is difficult to generate birefringence, is excellent in heat resistance, film strength, and thermal stability, and a film composed of the resin composition.

The main points of the present invention are as follows.

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

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

(3) The resin composition as described in (2), the copolymer (I) contains: 20 to 80% by mass of aromatic vinyl monomer units (A), and (meth)acrylate monomer units (B) 5 to 70% by mass, and 10 to 25% by mass of unsaturated dicarboxylic anhydride monomer unit (C).

(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) has a total light transmittance of 88% or more with a thickness of 2 mm measured based on ASTM D1003.

(6) A film containing the resin composition described in any one of (1) to (5).

(7) The film described in (6) is used as a polarizer protective film.

According to the present invention, it is possible to provide a resin composition and a film composed of the resin composition that are difficult to generate birefringence and are excellent in heat resistance, film strength, and thermal stability.

<Term Description>

In the specification of this 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) that can be used in the resin composition of the present invention include units derived from the following monomers: styrene, o-methylstyrene, m-methylstyrene, and p-methylstyrene. Various styrenes such as methyl styrene, 2,4-dimethyl styrene, ethyl styrene, p-tert-butyl styrene, α-methyl styrene, α-methyl-p-methyl styrene, etc. monomer. Among them, styrene units are preferred. These aromatic vinyl monomer units (A) may be used singly or in combination of two or more kinds.

Examples of the (meth)acrylate monomer unit (B) that can be used in the resin composition of the present invention include units derived from the following monomers: methyl methacrylate, ethyl methacrylate, methyl Various methacrylate monomers such as n-butyl acrylate, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate, isobornyl methacrylate, etc., as well as methyl acrylate, ethyl acrylate, and acrylate Various acrylate monomers such as butyl ester, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, and decyl acrylate. Among them, methyl methacrylate units are preferred. These (meth)acrylate monomer units (B) may be used singly or in combination of two or more kinds.

Examples of the unsaturated dicarboxylic anhydride monomer unit (C) that 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, maleic anhydride units are 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) that can be used in the resin composition of the present invention includes 1,3-butadiene (butadiene), 2-methyl-1,3-butane Diene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2-methylpentadiene, etc. Units of monomers with conjugated double bonds. Among them, the butadiene unit is preferred. These conjugated diene monomer units (D) may be used singly or in combination of two or more kinds.

The resin composition of the present invention may contain other than the aromatic vinyl monomer unit (A), (meth)acrylate monomer unit (B), and other than the aromatic vinyl monomer unit (A), the (meth)acrylate monomer unit (B), and the resin composition within a range that does not inhibit the effects of the invention The units of other vinyl monomers other than the saturated dicarboxylic anhydride monomer unit (C) and the conjugated diene monomer unit (D) are preferably 5% by mass or less. Examples of units of other vinyl monomers include units derived from the following monomers: cyanide vinyl monomers such as acrylonitrile and methacrylonitrile, and vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid. , N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-cyclohexylmaleimide and other N-alkylmaleimide Amine monomers, N-arylmaleimide monomers such as N-phenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide, etc. Of various monomers. Except for aromatic vinyl monomer units (A), (meth)acrylate monomer units (B), unsaturated dicarboxylic anhydride monomer units (C) and conjugated diene monomer units (D), The units of other vinyl monomers contained in the resin composition may be used in combination of two or more types.

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

If the aromatic vinyl monomer unit (A) used in the resin composition is 17% by mass or more, a resin composition that hardly generates birefringence and has good transparency can be obtained; if it is 18% by mass or more, more can be obtained. A resin composition that is less birefringent and has better transparency is preferable. If the aromatic vinyl monomer unit (A) is 31% by mass or less, a resin composition that is hard to birefringence and has good heat resistance can be obtained; if it is 25% by mass or less, it can be more difficult to birefringence and heat resistance. A resin composition with better properties is therefore preferred.

If the (meth)acrylate monomer unit (B) used in the resin composition is 38% by mass or more, a resin composition that hardly generates birefringence and has good heat resistance can be obtained; if it is 45% by mass or more, it can be It is preferable to obtain a resin composition that is more resistant to birefringence and has better heat resistance. If the (meth)acrylate monomer unit (B) is 63% by mass or less, a resin composition that is hard to birefringence can be obtained; if it is 60% by mass or less, a resin composition that is harder to birefringence can be obtained , So it is preferred.

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

If the conjugated diene monomer unit (D) used in the resin composition is 4% by mass or more, a resin composition that hardly generates birefringence and has good film strength can be obtained; if it is 10% by mass or more, more can be obtained. A resin composition that is less birefringent and has better film strength is preferable. If the conjugated diene unit (D) is 25% by mass or less, a resin composition that is hard to birefringence and has good heat resistance can be obtained; if it is 20% by mass or less, it can be more difficult to birefringence and heat resistance. A resin composition with better properties is therefore preferred.

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

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

The resin composition of the present invention has an aromatic vinyl monomer unit (A), a (meth)acrylate monomer unit (B), an unsaturated dicarboxylic anhydride monomer unit (C) and a conjugated diene monomer The components of the unit (D) cancel the birefringence with each other, and the smaller the absolute value of the value of Formula 1 is, the more difficult it is to produce a resin composition, which is preferable. If the absolute value of the value of formula 1 is 0.003 or less, it is preferable to obtain a resin composition that is more difficult to generate birefringence; if the absolute value of the value of formula 1 is 0.001 or less, it is more difficult to obtain A birefringent resin composition is therefore preferable.

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

If 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. If the copolymer (I) is 80 parts by mass or less, a resin composition with good thermal stability can be obtained, so it is preferable; if the copolymer (I) is less than 40 parts by mass, a resin composition with better thermal stability can be obtained, so Preferred.

If the polymer (II) used in the resin composition is 0 parts by mass or more, a resin composition that is less likely to cause birefringence and has good thermal stability can be obtained; if it is 25 parts by mass or more, it can be more difficult to produce birefringence. , A resin composition with better thermal stability, so it is preferred. If the polymer (II) is 60 parts by mass or less, a resin composition that is less likely to be birefringent can be obtained; if it is 50 parts by mass or less, a resin composition that is more difficult to be birefringent can be obtained, so it is preferable.

If the graft copolymer (III) used in the resin composition is 5 parts by mass or more, a resin composition that is hard to birefringence and has good film strength can be obtained; if it is 10 parts by mass or more, it can be more difficult to birefringence. A resin composition with better refraction and film strength is preferable. If the graft copolymer (III) is 60 parts by mass or less, a resin composition that is hard to birefringence and has good heat resistance and thermal stability can be obtained; if it is 45 parts by mass or less, it can be more difficult to birefringence. , A resin composition with better heat resistance and thermal stability, so it is preferred.

In the resin composition of the present invention, if the refractive index of the copolymer (I), the polymer (II), and the graft copolymer (III) relative to the d-line at 23°C is n1, n2, n3, the copolymer (I) The respective mass ratios of ), polymer (II), and graft copolymer (III) are w1, w2, and w3, and the absolute value of the value of Formula 2 is preferably 0.005 or less.

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

If the absolute value of the value of Formula 2 is 0.005 or less, a resin composition with good transparency can be obtained, so it is preferable, more preferably 0.003 or less, and 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. The refractive index of the product obtained by mixing the compound (II) and the graft copolymer (III) is different to maintain transparency.

The mixing order of the components of the copolymer (I), polymer (II), and graft copolymer (III) is not particularly limited. For example, a method of mixing all the components at the same time, and mixing the two components beforehand can be mentioned. The method of mixing with another ingredient, etc. In addition, 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 single-axis or two-axis melt extruder can be used to add the components of the copolymer (I), the polymer (II), and the graft copolymer (III) and various additives. Melt mixing. As a method of mixing with another component, for example, a uniaxial or biaxial melt extruder can be used to pre-mix the copolymer (I) and the polymer (II), and then a uniaxial or biaxial melt extruder can be used. Melt and mix with graft copolymer (III). At this time, various additives may be added and melt-mixed.

Examples of the aromatic vinyl monomer unit (A) that can be used in the copolymer (I) include units derived from the following monomers: styrene, o-methyl styrene, m-methyl styrene, and p-methyl styrene. Styrene, 2,4-dimethyl styrene, ethyl styrene, p-tert-butyl styrene, α-methyl styrene, α-methyl-p-methyl styrene, etc. body. Among them, styrene units are preferred. These aromatic vinyl monomer units (A) may be used singly or in combination of two or more kinds.

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

Examples of the unsaturated dicarboxylic anhydride monomer unit (C) that 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, maleic anhydride units are preferred. The unsaturated dicarboxylic anhydride monomer unit (C) may be used singly or in combination of two or more.

The copolymer (I) may be a range that does not hinder the effect of the invention in the copolymer, except for the aromatic vinyl monomer unit (A), the (meth)acrylate monomer unit (B) and the unsaturated dicarboxylic acid. The copolymerizable vinyl monomer units other than the acid anhydride monomer unit (C) are preferably 5% by mass or less. Examples of units of other copolymerizable vinyl monomers include units derived from the following monomers: cyanide vinyl monomers such as acrylonitrile and methacrylonitrile, vinyl carboxylates such as acrylic acid and methacrylic acid. Acid monomer, N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-cyclohexylmaleimide, etc. Leximine monomer, N-arylmaleimide such as N-phenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide, etc. Various monomers such as monomers. The units of other copolymerizable vinyl monomers may also be used in combination of two or more types.

The structural units of the copolymer (I) are 20 to 80% by mass of aromatic vinyl monomer units (A), 5 to 70% by mass of (meth)acrylate monomer units (B), and unsaturated dicarboxylic anhydride units. Units (C) 10-25% by mass; more preferably, aromatic vinyl monomer units (A) 45-70% by mass, (meth)acrylate monomer units (B) 7-40% by mass, and no The saturated dicarboxylic anhydride monomer unit (C) is 10 to 23% by mass. In addition, the structural unit of the copolymer is an analysis value measured by a predetermined analysis method. In fact, there is a distribution in the structural unit (hereinafter, this distribution is referred to as a composition distribution), and it represents the average value of the composition distribution.

If the aromatic vinyl monomer unit (A) used in the copolymer (I) is 20% by mass or more, a molded body with increased thermal stability and a good appearance when the resin composition is molded can be obtained; if When the content is 45% by mass or more, it is possible to obtain a molded body with further increased thermal stability and a better appearance when the resin composition is molded and processed, so it is preferable. If the aromatic vinyl monomer unit (A) is 80% by mass or less, the compatibility with the polymer (II) will increase and the transparency of the resin composition will be good; if it is 70% by mass or less, it will be compatible with the polymer (II) The compatibility of) is further increased, and the transparency of the resin composition is good, so it is preferable.

If the (meth)acrylate monomer unit (B) used in the copolymer (I) is 5% by mass or more, the compatibility with the polymer (II) will increase, and the transparency of the resin composition will be good; if it is 7 At least mass %, the compatibility with the polymer (II) is further increased, and the transparency of the resin composition is better, so it is preferable. If the (meth)acrylate monomer unit (B) is 70% by mass or less, a molded body with increased thermal stability and good appearance when the resin composition is molded and processed can be obtained; if it is 40% by mass or less, Since it is possible to obtain a molded body with further increased thermal stability and a better appearance when the resin composition is molded and processed, it is preferable.

If the unsaturated dicarboxylic anhydride monomer unit (C) used in the copolymer (I) is 10% by mass or more, the heat resistance will be good, the compatibility with the polymer (II) will increase, and the transparency of the resin composition will be good. So it is preferred. If the unsaturated dicarboxylic anhydride monomer unit (C) is 25% by mass or less, it is possible to obtain a molded body with increased thermal stability and a good appearance when the resin composition is molded and processed, and, in combination with the polymer (II) The compatibility of the resin composition is increased, and the transparency of the resin composition is good; if it is 23% by mass or less, a molded body with further increased thermal stability and a better appearance when the resin composition is molded can be obtained. The compatibility of the substance (II) is increased, and the transparency of the resin composition is good, so it is preferable.

It is preferable that the haze at an optical path length of 10 mm in a 12% by mass chloroform solution of the copolymer (I) measured based on JIS K-7136 is 2% or less. If the haze is 2% or less, the composition distribution of the copolymer (I) is small, and the composition with many unsaturated dicarboxylic anhydride monomer units (C) that are incompatible with the polymer (II) is extremely small, so it can be maintained with The compatibility of the polymer (II) and the transparency of the resin composition are good, so it is preferable. In addition, the haze is adjusted to a solution of 12% by mass of the copolymer in chloroform, filled into a quartz box for measurement with an optical path length of 10 mm, and a haze meter (Hazeguard II manufactured by Toyo Seiki Co., Ltd.) is used in accordance with JIS K-7136. Measured measured value.

The polymerization method of the copolymer (I) is not particularly limited, and it can be produced by a known method such as solution polymerization and bulk polymerization, and solution polymerization is more preferable. The solvent used in the solution polymerization is preferably a non-polymerizable solvent from the viewpoints that it is less likely to produce by-products and have less adverse effects. The type of solvent is not particularly limited. Examples include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetophenone; ethers such as tetrahydrofuran and 1,4-dioxane. ; Aromatic hydrocarbons such as toluene, ethylbenzene, xylene, chlorobenzene, etc., from the viewpoints of the solubility of monomers and copolymers and the ease of solvent recovery, methyl ethyl ketone and methyl isobutyl ketone are preferred . The amount of the solvent added is preferably 10 to 100 parts by mass, and more preferably 30 to 80 parts by mass relative to 100 parts by mass of the obtained copolymer. If 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 solution, and if it is 100 parts by mass or less, it is in terms of obtaining the desired weight average molecular weight (weight average molecular weight, Mw) suitable.

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

The polymerization method is not particularly limited, but from the viewpoint that it can be produced with good productivity by a simple process, the radical polymerization method is preferred. The polymerization initiator is not particularly limited. For example, dibenzoyl peroxide, tert-butyl peroxybenzoate, 1,1-bis(tert-butylperoxy)-2-methylcyclohexane, and peroxide can be used. Isopropyl tert-butyl monocarbonate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyacetate, dicumyl peroxide, 3,3-bis(tert-butylperoxy)butyric acid Well-known organic peroxides such as ethyl ester, and well-known azo compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile, and azobismethylbutyronitrile. These polymerization initiators may be used in combination of two or more kinds. Among them, it is preferable to use an organic peroxide having a 10-hour half-life temperature of 70 to 110°C.

In order to obtain a copolymer (I) with good transparency, it is necessary to perform polymerization while controlling the composition distribution to decrease. In particular, it is required to use unsaturated dicarboxylic anhydride monomer units (C) that are not compatible with the polymer (II). ) The products of more composition can be polymerized in a very few way. Since aromatic vinyl monomers and unsaturated dicarboxylic anhydride monomers have strong cross-copolymerization, they are continuously batched in a manner corresponding to the polymerization speed of aromatic vinyl monomers and (meth)acrylate monomers. A method of adding an unsaturated dicarboxylic anhydride monomer and/or an aromatic vinyl monomer, and also appropriately adjusting the batch addition flow rate according to the polymerization rate is suitable. If the polymerization temperature, the polymerization time, and the addition amount of the polymerization initiator are appropriately adjusted while controlling the polymerization rate, the composition distribution of the copolymer can be reduced more accurately, which is suitable.

Moreover, the method of adjusting the molecular weight can be achieved by adjusting the addition amount of the solvent and the chain transfer agent in addition to the adjustment of the polymerization temperature, the polymerization time, and the addition amount of the polymerization initiator. The chain transfer agent is not particularly limited. For example, well-known chain transfer agents such as n-dodecyl mercaptan, t-dodecyl mercaptan, 2,4-diphenyl-4-methyl-1-pentene, etc. can be used. Agent.

After the polymerization, you can add hindered phenol compounds, lactone compounds, phosphorus compounds, sulfur compounds and other heat stabilizers, hindered amine compounds, benzotriazole compounds and other light stabilizers to the polymerization solution as needed. , Lubricants, plasticizers, colorants, antistatic agents, mineral oil and other additives. The addition amount is preferably less than 0.2 parts by mass relative to 100 parts by mass of all monomer units. These additives may be used alone or in combination of two or more.

The method of recovering the copolymer (I) from the polymerization solution is not particularly limited, and a known devolatilization technique can be used. For example, a method in which the polymerization liquid is continuously supplied to a biaxial devolatilization extruder with a gear pump, and the polymerization solvent, unreacted monomers, etc. are subjected to devolatilization treatment. In addition, the devolatilized components including the polymerization solvent, unreacted monomers, etc. are condensed by a condenser or the like and recovered, and the condensate is purified by a distillation column, whereby the polymerization solvent can be reused.

Examples of the (meth)acrylate monomer unit (B) that can be used in the polymer (II) include units derived from the following monomers: methyl methacrylate, ethyl methacrylate, and methacrylic acid Various methacrylate monomers such as n-butyl ester, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate, isobornyl methacrylate, etc., as well as methyl acrylate, ethyl acrylate, and n-butyl acrylate , 2-methylhexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate and other acrylate monomers. Among them, methyl methacrylate units are preferred. These (meth)acrylate monomer units (B) may be used singly or in combination of two or more.

The copolymer (II) may contain other copolymerizable vinyl monomer units other than the (meth)acrylate monomer unit (B) in a range that does not hinder the effect of the invention, and it is preferably 5 mass% or less. Examples of units of other copolymerizable vinyl monomers include units derived from the following monomers: aromatic vinyl monomers such as styrene, and cyanide vinyl monomers such as acrylonitrile and methacrylonitrile. , Vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid, N-methyl maleimide, N-ethyl maleimide, N-butyl maleimide, N-cyclohexyl horse N-alkyl maleimide monomers such as leximide, N-phenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide Various monomers such as N-aryl maleimide monomers. The units of the other copolymerizable vinyl monomers can also be used in combination of two or more kinds.

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

When continuous polymerization is adopted as the polymerization method of the copolymer (II), the structure of the reactor is preferably a structure in which a complete mixing reactor (CSTR) and a plug flow reactor (PFR) are sequentially connected in series. In addition, one or more CSTRs and PFRs may be connected according to different purposes, but the number of CSTRs is preferably 1 to 2, and especially one is more preferable. The number of PFR is preferably 1 to 3, and especially one is more preferable.

When using solution polymerization as the polymerization method of the polymer (II), there are no particular restrictions on the solvent used. From the viewpoints of availability and solubility, for example, acetone, methyl ethyl ketone, methyl isopropyl 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 Among the solvents such as formamide, dimethyl sulfide, and N-methyl-2-pyrrolidone, toluene and ethylbenzene are preferred from the viewpoint of solubility in the solvent of the polymer (II). The amount of these solvents added is not particularly limited. It is preferably in the range of 1 to 30 parts by mass, and more preferably in the range of 5 to 25 parts by mass relative to 100 parts by mass of the total monomer compound. .

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

The radical polymerization initiator used in the polymerization of the polymer (II) is not particularly limited. For example, known peroxides such as azo compounds, organic peroxides, inorganic peroxides, and hydrogen peroxide can be used. Among them, from the standpoint of easy reaction control and availability, it is preferable to use well-known couplings such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile, and azobismethylbutyronitrile. Nitrogen compounds; dibenzyl peroxide, tert-butyl peroxybenzoate, 1,1-bis(tert-butylperoxy)-2-methylcyclohexane, isopropylperoxy tert-butyl monocarbonate, Well-known organic peroxides such as tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyacetate, dicumyl peroxide, ethyl 3,3-bis(tert-butylperoxy)butyrate, etc. Things.

In the polymerization of the polymer (II), the radical polymerization initiator may be used alone or in combination of two or more kinds. From the viewpoint of polymerization reaction speed and polymerization rate control, a radical polymerization initiator commonly used in the production of existing styrene resins is preferred. Specifically, a 10-hour half-life temperature of 70 to 120°C is used. Azo compounds and organic peroxides are preferred.

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

If the amount of the radical polymerization initiator used is 0.001 parts by mass or more than 0.002 parts by mass relative to 100 parts by mass of the total amount of monomer compounds, a sufficient polymerization rate can be obtained, and therefore, good productivity can be maintained. If the amount of the radical polymerization initiator used is 0.1 parts by mass or less than 0.03 parts by mass relative to 100 parts by mass of the total amount of monomer compounds, the polymerization rate can be suppressed and the reaction control can be facilitated. Therefore, the polymer ( II) The molecular weight control becomes easy.

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

The amount of the chain transfer agent used is not particularly limited as long as it is within the range of the target molecular weight for obtaining the polymer (II), but it is preferable to use 0.05 to 2.0 parts by mass relative to 100 parts by mass of the total monomer compound. In particular, it is more preferable to use 0.2 to 0.8 parts by mass relative to 100 parts by mass of the total amount of monomer compounds. If the use amount of the chain transfer agent is 0.05 parts by mass or more and 2.0 parts by mass or less, the target molecular weight of the (meth)acrylate copolymer (B) can be easily obtained.

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

The method for removing volatile components such as solvents and unreacted monomers used in the polymerization of the polymer (II) is not particularly limited, and known methods can be used, but among them, a method using a devolatilization tank is preferred. When a 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. If the resin temperature is suppressed to 260°C or 240°C or lower, depolymerization due to thermal degradation of the polymer (II) can be suppressed, and a polymer (II) having an excellent hue can be obtained. In addition, the method of adjusting the resin temperature can be performed by adjusting the temperature of the devolatilization tank.

In order to prevent thermal degradation during processing of the polymer (II) and maintain a good hue, any radical scavenger can be used. The radical scavenger is not particularly limited, and examples thereof include antioxidants such as phenol-based compounds, organic phosphorus-based compounds, organic sulfur-based compounds, and amine-based compounds. These radical scavengers may be used alone or in combination of two or more kinds. These radical scavengers undergo a significant thermal history in the process of devolatilizing the volatile components in the styrene-maleimide copolymer in a vented screw extruder, so they are in order to maintain their freedom. The function of the base scavenger, a compound having heat resistance and thermal stability is particularly preferred. For example, a radical scavenger whose 1% heating loss temperature exceeds 300°C is more preferable. It is preferable to add a radical scavenger to the polymerization product after polymerization. If it is added before or during polymerization, the polymerization rate may be low.

The conjugated diene monomer unit (D) that can be used in the resin composition of the present invention includes 1,3-butadiene (butadiene), 2-methyl-1,3-butane Diene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2-methylpentadiene, etc. Units of monomers with conjugated double bonds. Among them, the butadiene unit is preferred. These conjugated diene monomer units (D) may be used singly or in combination of two or more kinds.

Examples of the aromatic vinyl monomer unit (A) that can be used in the graft copolymer (III) include units derived from the following monomers: styrene, o-methylstyrene, m-methylstyrene, Various styrenes such as p-methyl styrene, 2,4-dimethyl styrene, ethyl styrene, p-tert-butyl styrene, α-methyl styrene, α-methyl-p-methyl styrene, etc. Class monomer. Among them, styrene units are preferred. These aromatic vinyl monomer units (A) may be used singly or in combination of two or more kinds.

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

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

The graft copolymer (III) is a copolymer composed of aromatic vinyl monomer units (A), (meth)acrylate monomer units (B) and conjugated diene monomer units (D) A copolymer containing a dendritic structure formed by the combination of diene rubber-like polymers. In addition, the graft copolymer (III) contains the aromatic vinyl monomer units (A) and (former) that are produced as by-products during graft polymerization and are not grafted with the diene rubber-like polymer. A copolymer composed of acrylate monomer units (B). In the presence of a diene rubber-like polymer, the aromatic vinyl monomer unit (A) and the (meth)acrylate monomer unit (B) are polymerized by a known method to obtain a graft copolymer (III) ).

Diene rubber-like polymers that can be used in the graft copolymer (III) include polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, and polyisoprene , Conjugated diene rubbers such as styrene-isoprene copolymers and their hydrogen additives can be used alone 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 known methods such as bulk polymerization, solution polymerization, suspension polymerization, bulk-suspension polymerization, emulsion polymerization, etc. can be used, but the emulsion polymerization method is preferred.

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

For the free radical initiator used in the graft copolymer (III), azo compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, etc. can be used; dibenzyl peroxide, tertiary benzoic acid Organic peroxides such as butyl ester, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyacetate, dicumyl peroxide, 3,3-bis(tert-butylperoxy) ethyl butyrate, etc. Oxides; or inorganic peroxides such as hydrogen peroxide, potassium persulfate, ammonium persulfate, etc., but the use of inorganic peroxides and organic peroxides is preferred, and inorganic peroxides and organic peroxides are used together A redox initiator combined with a reducing agent such as ferrous sulfate is more preferable. In addition, in the polymerization of the graft copolymer (III), the radical polymerization initiator may be used alone or in combination of two or more kinds.

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

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

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

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

In the resin composition, stabilizers, plasticizers, lubricants, antioxidants, ultraviolet absorbers, light stabilizers, colorants, etc. may be blended in the resin composition within a range that does not inhibit the effects of the present invention.

The resin composition of the present invention has a total light transmittance of 2 mm thickness measured based on ASTM D1003 of 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 has excellent transparency even after molding. In addition, the total light transmittance is based on ASTM D1003, using a haze meter (Model NDH-1001DP manufactured by Nippon Denshoku Kogyo Co., Ltd.), and using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.) at a barrel temperature of 230 A mirror sheet with a length of 90 mm, a width of 55 mm, and a thickness of 2 mm formed under molding conditions of 40° C. and a mold temperature of 40° C. is measured.

When the resin composition of the present invention is used as a polarizer protective film, the in-plane retardation (Re) calculated by Formula 3 is calculated as 100 μm, and is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less; Formula 4 The calculated thickness retardation (Rth) is calculated as 100 μm, and is preferably 20 nm or less, more preferably 10 nm or less, and even more preferably 5 nm or less. If the in-plane retardation (Re) is 30nm or less and the thickness retardation (Rth) is 20nm or less, when the film is used in the polarizing plate of the liquid crystal display device, the problem of low contrast of the liquid crystal display device will not occur, so Is appropriate.

(Equation 3) Re=(nx-ny)×d

(Equation 4) Rth=((nx+ny)÷2-nz)×d

In addition, in the above formula, nx, ny, and nz are the respective axis directions 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 film thickness direction is the Z axis. Refractive index, d is the film thickness.

The method for producing the film is not particularly limited, and a known molding processing method such as a melt extrusion film molding method and a solution casting method can be used. As an example of obtaining a film with a small birefringence, a method of using an elastically deformable flexible roller can be cited. In addition, although an unstretched film can be used, in order to increase the strength of the film, a stretched film that has been stretched may be used. The stretching method of the film is not particularly limited. As the uniaxial stretching, a stretched film can be obtained by, for example, a roll stretching method, a tenter stretching method, or a free-web uniaxial stretching method; as a biaxial stretching, a stretched film can be obtained, for example, A stretched film is obtained by a sequential biaxial stretching method combining roll stretching and tenter stretching, 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, and still more preferably 1.0×10 ^-12 Pa ^-1 . If the photoelasticity coefficient is sufficiently small, the change in birefringence caused by external force is reduced, and the birefringence caused by residual stress during molding is not prone to occur. Therefore, the distribution of birefringence in the molded body is reduced. In this case, birefringent fringes will not occur, the contrast at the periphery of the display screen will not decrease, and light leakage will not occur, so it is preferable.

The photoelastic coefficient can be obtained by measuring the in-plane retardation (Re) of the film using a retardation measuring device in a state where a tensile stress is applied to the film. If the in-plane phase difference (Re) under the load f is Re(f) and the width of the test piece is w, the photoelastic coefficient C is C=d Re(f)/df×w, so by calculating the surface The slope of the value of the internal phase difference (Re) with respect to the load applied to the test piece can be calculated. In addition, in the present invention, the phase difference measuring device uses KOBRA-WR manufactured by Oji Measurement Co., Ltd., and a digital force gauge Z2S-DPU-50N manufactured by Yi Motor Co., Ltd. is used to apply stress.

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. Due to the different types of monomers, some have a positive contribution to the photoelastic coefficient of the resin composition, and some Negative contribution, so by appropriately adjusting these compositions, the photoelastic coefficient can be offset and its absolute value can be reduced. For example, the use of styrene and butadiene, which have a positive contribution to the photoelastic coefficient, and methyl methacrylate and maleic anhydride, which have a negative contribution, can offset the photoelastic coefficient and reduce its absolute value.

(Example)

(1) Manufacturing of copolymer (I)

<I-1 Manufacturing Example>

A 20% maleic anhydride solution obtained by dissolving maleic anhydride in methyl isobutyl ketone with a concentration of 25% by mass and tert-butylperoxy-2-ethylhexanoate was prepared in advance. The 2% tert-butylperoxy-2-ethylhexanoate solution obtained by diluting in methyl isobutyl ketone in% method is used for polymerization.

Put into a 50-liter autoclave with a stirrer 25% maleic anhydride solution 1.76 kg, styrene 11.8 kg, methyl methacrylate 3.8 kg, and tert-dodecyl mercaptan 16 g, after replacing the gas phase with nitrogen , While stirring, it took 40 minutes to heat up to 90 ℃. After the temperature was raised, while maintaining 90° C., the 25% maleic anhydride solution and the 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches, respectively. 25% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 1.98kg/hour, from the 4th hour to the 7th hour, 1.58kg/hour, from the 7th hour to the 10th hour It was 0.79 kg/hour until the hour, 0.26 kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 15.81 kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, at a batch rate of 0.12kg/hour from the beginning of the batch addition to the 7th hour, and 0.19kg from the 7th hour to the 13th hour /Hour, change the batch adding speed in stages, adding a total of 1.98kg. The polymerization temperature was maintained at 90°C from the start of the batch addition to the 7th hour, then the temperature was increased to 114°C over 6 hours at a temperature increase rate of 4°C/hour, and the temperature was maintained at 114°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-1). The composition of the obtained copolymer (I-1) was analyzed by the C-13NMR method. Using SYSTEM-21 Shodex (manufactured by Showa Denko Corporation), using a column formed by connecting three PLgelMIXED-Bs in series, a differential refractive index detector, using tetrahydrofuran as a solvent, and using standard polystyrene (PS) (manufactured by PL) A calibration 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, which was filled to a quartz square box for measurement with an optical path length of 10 mm, based on JIS K-7136, using a haze meter (manufactured by Toyo Seiki Co., Ltd.) HAZEGUARD II) measured the haze with 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 with a length of 90 mm, a width of 55 mm, and a thickness of 2 mm was injected under the molding conditions of a barrel temperature of 230°C and a mold temperature of 40°C. Based on ASTM D1003, using fog A meter (Model NDH-1001DP manufactured by Nippon Denshoku Kogyo Co., Ltd.) was used to measure the total light transmittance at a thickness of 2 mm. A molded body with 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 Corporation. Table 1 shows the composition analysis results, molecular weight measurement results, total light transmittance measurement results and refractive index measurement results of the 2 mm-thick mirror sheet of the copolymer (I-1).

<I-2 Manufacturing Example>

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

Put 1.76 kg of 25% maleic anhydride solution, 14 kg of styrene, 1.6 kg of methyl methacrylate, and 16 g of tert-dodecyl mercaptan into a 50-liter autoclave with a stirrer. After replacing the gas phase with nitrogen, The temperature was raised to 96°C over 40 minutes while stirring. After the temperature was raised, while maintaining 96° C., the 25% maleic anhydride solution and the 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches, respectively. 25% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 1.98kg/hour, from the 4th hour to the 7th hour, 1.58kg/hour, from the 7th hour to the 10th hour It was 0.79 kg/hour until the hour, 0.26 kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 15.81 kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, at a batch rate of 0.18kg/hour from the start of the batch addition to the 7th hour, and 0.29kg from the 7th hour to the 13th hour The speed of adding in batches was changed in stages, and 3.0kg was added in total. The polymerization temperature was maintained at 96°C from the start of the batch addition to the 7th hour, then the temperature was increased to 120°C at a temperature increase rate of 4°C/hour for 6 hours, and the temperature was maintained at 120°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-2). The obtained copolymer (I-2) was analyzed in the same way as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance and the refractive index of the 2mm thick mirror sheet were measured. . The measurement results are shown in Table 1.

<Manufacturing Example of I-3>

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

Put 2.4 kg of 10% maleic anhydride solution, 9.6 kg of styrene, 8.0 kg of methyl methacrylate, and 16 g of t-dodecyl mercaptan into a 50-liter autoclave with a stirrer, and replace the gas phase with nitrogen. , While stirring, the temperature was raised to 88°C over 40 minutes. After the temperature was raised, while maintaining 88°C, the 10% maleic anhydride solution and the 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches, respectively. 10% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 2.43kg/hour, from the 4th hour to the 7th hour, 2.31kg/hour, from the 7th hour to the 10th hour It was 1.3 kg/hour until the hour, 0.36 kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 21.63 kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, with batch addition speed from the start of batch addition to the 7th hour at 0.09kg/hour, and from the 7th hour to the 13th hour at 0.15kg /Hour, change the batch adding speed in stages, adding a total of 1.53kg. The polymerization temperature was maintained at 88°C from the start of the batch addition to the 7th hour, then the temperature was increased to 118°C for 6 hours at a temperature increase rate of 5°C/hour, and the polymerization temperature was maintained at 118°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-3). The obtained copolymer (I-3) was analyzed in the same way as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance and the refractive index of the 2mm thick mirror sheet were measured. . The measurement results are shown in Table 1.

<Manufacturing Example of I-4>

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

Put into a 50-liter autoclave with a stirrer 25% maleic anhydride solution 1.92 kg, styrene 2.0 kg, methyl methacrylate 8.2 kg, and tert-dodecyl mercaptan 16 g, after replacing the gas phase with nitrogen , While stirring, the temperature was raised to 88°C over 40 minutes. After the temperature was raised, while maintaining 88° C., styrene, 25% maleic anhydride solution, and 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches, respectively. Styrene was added in batches at a rate of 0.45 kg/hour from the start of the batch addition to the 11th hour, and a total of 4.95 kg was added. 25% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 2.59kg/hour, from the 4th hour to the 7th hour, 1.73kg/hour, from the 7th hour to the 10th hour It was 0.4 kg/hour until the hour, 0.17 kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 17.26 kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, with batch addition speed from the start of batch addition to the 7th hour at 0.06kg/hour, and from the 7th hour to the 13th hour at 0.1kg /Hour, change the batch adding speed in stages, adding 1.02kg in total. The polymerization temperature was maintained at 88°C from the start of the batch addition to the 7th hour, then the temperature was increased to 118°C for 6 hours at a temperature increase rate of 5°C/hour, and the polymerization temperature was maintained at 118°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-4). The obtained copolymer (I-4) was analyzed in the same way as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance and the refractive index of the 2mm thick mirror sheet were measured. . The measurement results are shown in Table 1.

<Manufacturing Example of I-5>

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

Put 1.7 kg of 20% maleic anhydride solution, 15.6 kg of styrene, 1.0 kg of methyl methacrylate, and 16 g of tert-dodecyl mercaptan into a 50-liter autoclave with a stirrer, and replace the gas phase with nitrogen. , While stirring, it took 40 minutes to heat up to 96 ℃. After the temperature was raised, while maintaining 96°C, the 20% maleic anhydride solution and the 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches, respectively. 20% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 1.91kg/hour, from the 4th hour to the 7th hour, 1.53kg/hour, from the 7th hour to the 10th hour It was 0.77kg/hour until the hour, 0.26kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 15.32kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, at a batch rate of 0.18kg/hour from the start of the batch addition to the 7th hour, and 0.29kg from the 7th hour to the 13th hour The speed of adding in batches was changed in stages, and 3.0kg was added in total. The polymerization temperature was maintained at 96°C from the start of the batch addition to the 7th hour, then the temperature was increased to 120°C at a temperature increase rate of 4°C/hour for 6 hours, and the temperature was maintained at 120°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-5). The obtained copolymer (I-5) was analyzed in the same way as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance and the refractive index of the 2mm thick mirror sheet were measured. . The measurement results are shown in Table 1.

<Manufacturing 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 peroxide-2-ethylhexanoate solution was prepared in the same manner as in the production example of (I-1).于聚。 At polymerization.

Put 2.0 kg of 10% maleic anhydride solution, 1.2 kg of styrene, 13.8 kg of methyl methacrylate, and 16 g of tert-dodecyl mercaptan into a 50-liter autoclave with a stirrer, and replace the gas phase with nitrogen. , While stirring, the temperature was raised to 88°C over 40 minutes. After the temperature was raised, while maintaining 88° C., styrene, 10% maleic anhydride solution, and 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches, respectively. Styrene was added in batches at a rate of 0.27 kg/hour from the start of the batch addition to the 11th hour, and a total of 2.97 kg was added. 10% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 2.7kg/hour, from the 4th hour to the 7th hour, 1.8kg/hour, from the 7th hour to the 10th hour It was 0.42 kg/hour until the hour, and 0.18 kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 18.0 kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, with batch addition speed from the start of batch addition to the 7th hour at 0.06kg/hour, and from the 7th hour to the 13th hour at 0.1kg /Hour, change the batch adding speed in stages, adding 1.02kg in total. The polymerization temperature was maintained at 88°C from the start of the batch addition to the 7th hour, then the temperature was increased to 118°C for 6 hours at a temperature increase rate of 5°C/hour, and the polymerization temperature was maintained at 118°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-6). The obtained copolymer (I-6) was analyzed in the same way as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance and the refractive index of the 2mm thick mirror sheet were measured. . The measurement results are shown in Table 1.

<Manufacturing Example of I-7>

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

Put 1.92 kg of 25% maleic anhydride solution, 14.0 kg of styrene, 1.2 kg of methyl methacrylate, and 16 g of tert-dodecyl mercaptan into a 50-liter autoclave with a stirrer, and replace the gas phase with nitrogen. , While stirring, it took 40 minutes to heat up to 96 ℃. After the temperature was raised, while maintaining 96° C., the 25% maleic anhydride solution and the 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches, respectively. 25% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 2.16kg/hour, from the 4th hour to the 7th hour, 1.73kg/hour, from the 7th hour to the 10th hour It was 0.86 kg/hour until the hour, 0.29 kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 17.28 kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, with batch addition speed from the start of batch addition to the 7th hour at 0.21kg/hour, from the 7th hour to the 13th hour, 0.34kg /Hour, change the batch adding speed in stages, adding a total of 3.51kg. The polymerization temperature was maintained at 96°C from the start of the batch addition to the 7th hour, then the temperature was increased to 120°C at a temperature increase rate of 4°C/hour for 6 hours, and the temperature was maintained at 120°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-7). The obtained copolymer (I-7) was analyzed in the same way as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance and the refractive index of the 2mm thick mirror sheet were measured. . The measurement results are shown in Table 1.

<Manufacturing Example of I-8>

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

Put into a 50-liter autoclave with a stirrer 25% maleic anhydride solution 2.24 kg, styrene 13.4 kg, methyl methacrylate 10.0 kg, and tert-dodecyl mercaptan 16 g, after replacing the gas phase with nitrogen , While stirring, the temperature was raised to 94°C in 40 minutes. After the temperature was raised, while maintaining 94° C., the 25% maleic anhydride solution and the 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches. 25% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 2.52kg/hour, from the 4th hour to the 7th hour, 2.02kg/hour, from the 7th hour to the 10th hour It was 1.01 kg/hour until the hour, and 0.34 kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 20.19 kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, at a batch rate of 0.18kg/hour from the start of the batch addition to the 7th hour, and 0.29kg from the 7th hour to the 13th hour The speed of adding in batches was changed in stages, and 3.0kg was added in total. The polymerization temperature was maintained at 94°C from the start of the batch addition to the 7th hour, then the temperature was increased to 118°C over 6 hours at a temperature increase rate of 4°C/hour, and the polymerization temperature was maintained at 118°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-8). The obtained copolymer (I-8) was analyzed in the same way as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance and the refractive index of the 2mm thick mirror sheet were measured. . The measurement results are shown in Table 1.

<1-9 manufacturing example>

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

Put 1.6 kg of 10% maleic anhydride solution, 18.4 kg of styrene, and 16 g of tert-dodecyl mercaptan into a 50-liter autoclave with a stirrer. After replacing the gas phase with nitrogen, the temperature is raised for 40 minutes while stirring. To 96°C. After the temperature was raised, while maintaining 96°C, the 10% maleic anhydride solution and the 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches, respectively. 10% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 1.62kg/hour, from the 4th hour to the 7th hour, 1.2kg/hour, from the 7th hour to the 10th hour It was 0.96 kg/hour until the hour and 0.48 kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 14.4 kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, 0.3kg/hour from the beginning of the batch addition to the 7th hour, 0.48kg from the 7th hour to the 13th hour at the batch addition rate /Hour, change the batch adding speed in stages, adding a total of 4.98kg. The polymerization temperature was maintained at 96°C from the start of the batch addition to the 7th hour, then the temperature was increased to 120°C at a temperature increase rate of 4°C/hour for 6 hours, and the temperature was maintained at 120°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-9). The obtained copolymer (I-9) was analyzed in the same manner as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance and the refractive index of the 2mm thick mirror sheet were measured. . The measurement results are shown in Table 1.

<Manufacturing 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 peroxide-2-ethylhexanoate solution was prepared in the same manner as in the production example of (I-1).于聚。 At polymerization.

Put 1.6 kg of 10% maleic anhydride solution, 1.8 kg of styrene, 14.6 kg of methyl methacrylate, and 16 g of tert-dodecyl mercaptan into a 120-liter autoclave with a stirrer, and replace the gas phase with nitrogen. , While stirring, the temperature was raised to 88°C over 40 minutes. After the temperature was raised, while maintaining 88° C., styrene, 10% maleic anhydride solution, and 2% tert-butylperoxy-2-ethylhexanoate solution were continuously added in batches, respectively. Styrene was added in batches at a rate of 0.18 kg/hour from the start of the batch addition to the 11th hour, and a total of 1.98 kg was added. 10% maleic anhydride solution, with batch addition speed from the start of batch addition to the 4th hour at 2.16kg/hour, from the 4th hour to the 7th hour at 1.44kg/hour, from the 7th hour to the 10th hour It was 0.34 kg/hour until the hour, and 0.14 kg/hour from the 10th hour to the 13th hour, and the batch addition rate was changed step by step, and a total of 14.4 kg was added. 2% tert-butylperoxy-2-ethylhexanoate solution, with batch addition speed from the start of batch addition to the 7th hour at 0.06kg/hour, and from the 7th hour to the 13th hour at 0.1kg /Hour, change the batch adding speed in stages, adding 1.02kg in total. The polymerization temperature was maintained at 88°C from the start of the batch addition to the 7th hour, then the temperature was increased to 118°C for 6 hours at a temperature increase rate of 5°C/hour, and the polymerization temperature was maintained at 118°C for 1 hour to complete the polymerization.

The polymerization liquid is continuously fed to the biaxial devolatilization extruder using a gear pump, and the methyl isobutyl ketone and a trace amount of unreacted monomer are devolatilized, extruded in a linear shape, and cut to obtain Copolymer in pellet shape (I-10). The obtained copolymer (I-10) was analyzed in the same way as (I-1), and the molecular weight, the haze in a 12% by mass chloroform solution, the total light transmittance and the refractive index of the 2mm thick mirror sheet were measured. . The measurement results are shown in Table 1.

(2) Manufacturing of polymer (II)

<Manufacturing Example of II-1>

A complete mixing reactor with a volume of 20 liters with a stirrer, a plug flow reactor with a volume of 40 liters, and a devolatilizer with a preheater are connected in series. 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, 1,1-bis(tert-butylperoxy)cyclohexane (manufactured by NOF Corporation) was further mixed 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) propionic acid n-octadecyl 0.1 parts by mass of alkanol ester (IRGANOX 1076 manufactured by Ciba Specialty Chemicals) was used as a raw material solution. The raw material solution was introduced into a complete mixing type reactor controlled at a temperature of 120°C at a rate of 6 kg per hour. In addition, the complete mixing type reactor was stirred at a stirring speed of 200 rpm. Then, the reaction solution was continuously taken out from the complete mixing type reactor, and introduced into a tower plug flow type reactor adjusted to have a temperature gradient of 130°C to 150°C in the flow direction. While heating the reaction liquid with 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 with a gear pump, extruded in a linear shape, and cut to obtain (II-1) in the shape of pellets. The resulting polymer (II-1) was thermally decomposed at a furnace temperature of 450°C, and the decomposed gas was quantified by gas chromatography, and the composition was analyzed. Using SYSTEM-21 Shodex (manufactured by Showa Denko Corporation), using a column formed by connecting three PLgelMIXED-Bs in series, a differential refractive index detector, using tetrahydrofuran as a solvent, and using standard polystyrene (PS) (manufactured by PL) A calibration 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 with a length of 90 mm, a width of 55 mm, and a thickness of 2 mm was injected under the molding conditions of a barrel temperature of 230°C and a mold temperature of 40°C. Based on ASTM D1003, using fog A meter (Model NDH-1001DP manufactured by Nippon Denshoku Kogyo Co., Ltd.) was used to measure the total light transmittance at a thickness of 2 mm. A molded body with a thickness of 2 mm was produced by press molding, and the refractive index was measured using an Abbe refractometer (DR-M2) manufactured by Eron Corporation. Table 2 shows the composition analysis results, molecular weight measurement results, total light transmittance measurement results and refractive index measurement results of the 2 mm-thick mirror sheet of the polymer (II-1).

【Table 2】

(3) Manufacturing of graft copolymer (III)

<III-1 Manufacturing Example>

To an autoclave with a volume of 200 liters, 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 tert-dodecyl mercaptan, and 160 g of divinylbenzene were added, and polymerized at 60°C for 20 hours while stirring. The temperature was further raised to 70°C and left for 10 hours. The polymerization was completed and polybutadiene was obtained. Olefin rubber latex.

The obtained polybutadiene rubber latex was weighed 36 kg (calculated as solid content), put into an autoclave with a volume of 200 liters, 80 kg of pure water was added, and the temperature was raised to 50° C. under a nitrogen stream while stirring. Here, an aqueous solution obtained by dissolving 1.5 g of ferrous sulfate, 3 g of sodium ethylenediamine tetraacetate, and 100 g of white lump in 2 kg of pure water was added, and 5.7 kg of styrene and methyl methacrylate were added continuously for 5 hours. A mixture of 18.3 kg of ester, 54 g of t-dodecyl mercaptan, and a solution obtained by dispersing 108 g of dicumyl hydrogen peroxide in 8 kg of 5% potassium oleate aqueous solution. After the addition, the temperature was raised to 70°C, and 27 g of dicumyl hydrogen peroxide was added, and then it was left for 2 hours. After the polymerization was completed, the graft copolymer latex was obtained.

Add an antioxidant to the obtained graft copolymer latex, dilute it with pure water to a solid content of 15% by mass, and then raise the temperature to 60°C. While vigorously stirring, add dilute sulfuric acid for precipitation. After it becomes a slurry state, the temperature continues to rise. It was coagulated, dehydrated, washed with water, and dried at 90°C to obtain a powdery graft copolymer (III-1). The obtained (III-1) was dissolved in chloroform, iodine chloride was added, and the double bond in the polybutadiene was reacted, potassium iodide was added to make the remaining iodine chloride into iodine, and the reaction was carried out with sodium thiosulfate. By titration, the amount of polybutadiene in D-1 was determined. Furthermore, the obtained polymer was thermally decomposed at a furnace temperature of 450°C, the decomposition gas was quantified by gas chromatography, and the structure ratio of methyl methacrylate/styrene was measured. From the amount of polybutadiene and methyl methacrylate The structure ratio of ester/styrene calculates the composition of (III-1). Furthermore, a molded body with 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 Corporation. Table 3 shows the results of composition analysis and refractive index measurement of (III-1).

<III-2 Manufacturing Example>

To an autoclave with a volume of 200 liters, 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 tert-dodecyl mercaptan, and 300 g of divinylbenzene were added, and polymerized at 60°C for 20 hours while stirring, and then heated to a temperature of 70°C. After standing for 10 hours, the polymerization was completed. Made of polybutadiene rubber latex.

The obtained polybutadiene rubber latex was weighed 36 kg (calculated as solid content), put into an autoclave with a volume of 200 liters, 80 kg of pure water was added, and the temperature was raised to 50° C. under a nitrogen stream while stirring. Here, an aqueous solution obtained by dissolving 1.5 g of ferrous sulfate, 3 g of sodium ethylenediamine tetraacetate, and 100 g of Rongalite in 2 kg of pure water was added, and each of them was continuously added for 5 hours containing 7.7 kg of styrene and methyl. A mixture of 16.3 kg of methyl acrylate, 54 g of t-dodecyl mercaptan, and a solution obtained by dispersing 108 g of dicumyl hydrogen peroxide in 8 kg of a 5% potassium oleate aqueous solution. After the addition, the temperature was raised to 70°C, and 27 g of dicumyl hydrogen peroxide was added, and then it was left for 2 hours. After the polymerization was completed, the graft copolymer latex was obtained.

Add an antioxidant to the obtained graft copolymer latex, dilute with pure water to a solid content of 15% by mass, and then raise the temperature to 60°C. While vigorously stirring, dilute sulfuric acid is added for precipitation. After it becomes a slurry state, the temperature continues to rise. It was coagulated, dehydrated, washed with water, and dried at 90°C to obtain a powdery graft copolymer (III-2). The obtained (III-2) was dissolved in chloroform, iodine chloride was added, and the double bond in the polybutadiene was reacted, potassium iodide was added to make the remaining iodine chloride into iodine, and the reaction was carried out with sodium thiosulfate. By titration, the amount of polybutadiene in D-1 was determined. Furthermore, the obtained polymer was thermally decomposed at a furnace temperature of 450°C, the decomposition gas was quantified by gas chromatography, and the structure ratio of methyl methacrylate/styrene was measured. From the amount of polybutadiene and methyl methacrylate The structure ratio of ester/styrene calculates the composition of (III-2). Furthermore, a molded body with a thickness of 2 mm was produced by press molding, and the refractive index was measured using an Abbe refractometer (DR-M2) manufactured by Eron Corporation. Table 3 shows the composition analysis results and refractive index measurement results of (III-2).

<III-3 Manufacturing Example>

To an autoclave with a volume of 200 liters, 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 tert-dodecyl mercaptan, and 400 g of divinylbenzene were added, and polymerized at 60°C for 20 hours while stirring. The temperature was further raised to 70°C and left for 10 hours. The polymerization was completed. Made of polybutadiene rubber latex.

The obtained polybutadiene rubber latex was weighed 36 kg (calculated as solid content), put into an autoclave with a volume of 200 liters, 80 kg of pure water was added, and the temperature was raised to 50°C under a nitrogen stream while stirring. Here, an aqueous solution obtained by dissolving 1.5 g of ferrous sulfate, 3 g of sodium ethylenediamine tetraacetate, and 100 g of white lump in 2 kg of pure water was added, and the mixture containing 10.1 kg of styrene and methyl methacrylate was added continuously for 5 hours. A mixture of 13.9 g of ester, 54 g of t-dodecyl mercaptan, and a solution obtained by dispersing 108 g of dicumyl hydrogen peroxide in 8 kg of 5% potassium oleate aqueous solution. After the addition, the temperature was raised to 70°C, and 27 g of dicumyl hydrogen peroxide was added, and then it was left for 2 hours. After the polymerization was completed, the graft copolymer latex was obtained.

Add an antioxidant to the obtained graft copolymer latex, dilute with pure water to a solid content of 15% by mass, and then raise the temperature to 60°C. While vigorously stirring, dilute sulfuric acid is added for precipitation. After it becomes a slurry state, the temperature continues to rise. It was coagulated, dehydrated, washed with water, and dried at 90°C to obtain a powdery graft copolymer (III-3). The obtained (III-3) was dissolved in chloroform, iodine chloride was added, and the double bond in the polybutadiene was reacted, potassium iodide was added to make the remaining iodine chloride into iodine, and the reaction was carried out with sodium thiosulfate. By titration, the amount of polybutadiene in D-1 was determined. Furthermore, the obtained polymer was thermally decomposed at a furnace temperature of 450°C, the decomposition gas was quantified by gas chromatography, and the structure ratio of methyl methacrylate/styrene was measured. From the amount of polybutadiene and methyl methacrylate The structure ratio of ester/styrene calculates the composition of (III-3). Furthermore, a molded body with 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 Corporation. Table 3 shows the composition analysis results and refractive index measurement results of (III-3).

【table 3】

<Example. Comparative Example>

The copolymer (I)(I-1)~(I-10) and polymer (II)(II-1) and graft copolymer (III)(III-1)~(III) described in the above production example -3) After mixing in the proportions (mass%) shown in Table 4 to Table 5, melt and knead with a twin-screw extruder (TEM-35B manufactured by Toshiba Machine Co., Ltd.) at a barrel temperature of 240°C to form The pellets were used to obtain a resin composition.

The composition of the resin composition was calculated from the composition and blending ratio of each component of the copolymer (I), the polymer (II), and the graft copolymer (III). The following evaluations were performed on this resin composition. The evaluation results are shown in Table 4 to Table 5.

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

(In-plane retardation (Re), thickness retardation (Rth))

The unstretched film was cut to a length of 100 mm and a width of 20 mm, and subjected to free end uniaxial stretching using a uniaxial stretching device under the following conditions.

Distance between card heads: 50mm

Stretching temperature: Vicat softening temperature +10℃

Residual heat time: 5 minutes

Stretching speed: 12.5mm/min

Stretching distance: 12.5mm

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

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

Measurement wavelength: 590nm

(Photoelasticity coefficient)

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

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

Measurement wavelength: 590nm

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

(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 was formed using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.) under molding conditions of a cylinder temperature of 230°C and a mold temperature of 40°C. Based on ASTM D1003, the total light transmittance and haze of the test piece were measured using a haze meter (Model NDH-1001DP manufactured by Nippon Denshoku Kogyo Co., Ltd.).

(Vicat softening temperature)

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

(Folding strength)

Regarding the flexural strength of the film, an unstretched film was used to measure the flexural strength under the following conditions. A flexural strength of 100 times or more is qualified.

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

Load (tension): 500g weight

Bending speed: 175 times/min

Bending angle: 45 degrees left and right

Tip radius of bending device: 0.38mm

Test piece width: 15mm

(Thermal stability)

Using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.), under the molding conditions of a cylinder temperature of 250°C and a mold temperature of 60°C, 50 samples of cylindrical molded products with a diameter of 30 mm and a height of 50 mm were produced and visually observed. The number of samples with poor appearance due to thermal decomposition of silver ash, burning pollution, coloring, bubbles, etc. was checked, 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 to 4

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

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

【table 5】

(I-1)~(I-8) of the copolymer (I) of the present invention, (II-1) of the polymer (II) and (III-1)~(III- of the graft copolymer (III) 3) The resin composition obtained by compounding is hardly birefringent, and is excellent in heat resistance, film strength, and thermal stability.

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

(Industrial availability)

According to the present invention, it is possible to provide a resin composition that is difficult to generate birefringence, is excellent in heat resistance, film strength, and thermal stability, and a film composed of the resin composition.

Claims (6)

A resin composition comprising: 17~31% by mass of aromatic vinyl monomer units (A), 38~63% by mass of (meth)acrylate monomer units (B), and unsaturated dicarboxylic anhydride monomer units (C) 4 to 14% by mass, and conjugated diene monomer unit (D) 4 to 25% by mass, the absolute value of the value of the following formula 1 is 0.005 or less, formula 1: -0.10×[A]-0.004 ×[B]+0.10×[C]+0.09×[D], [A], [B], [C], [D] in Formula 1 in turn 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, wherein the resin composition contains: 20~80 parts by mass of copolymer (I), and the copolymer (I) is composed of Composition of aromatic vinyl monomer unit (A), the (meth)acrylate monomer unit (B), and the unsaturated dicarboxylic anhydride monomer unit (C); polymer (II) 0-60 mass Parts, the polymer (II) is composed of the (meth)acrylate monomer unit (B); and 5-60 parts by mass of the graft copolymer (III), the graft copolymer (III) passes The copolymer composed of the aromatic vinyl monomer unit (A) and the (meth)acrylate monomer unit (B) is grafted onto the copolymer composed of the conjugated diene monomer unit (D) Of polymers. The resin composition according to claim 1, wherein the copolymer (I) comprises: 20 to 80% by mass of the aromatic vinyl monomer unit (A), and the (meth)acrylate monomer Unit (B) 5~70% by mass, and The unsaturated dicarboxylic anhydride monomer unit (C) is a copolymer of 10-25% by mass. The resin composition according to claim 1 or 2, wherein the copolymer (I) has an optical path length of 10 mm and a haze of 2% or less in a 12% by mass chloroform solution. The resin composition according to claim 1 or 2, wherein the total light transmittance of a thickness of 2 mm measured based on ASTM D1003 is 88% or more. A film containing the resin composition according to any one of claims 1 to 4. The film according to claim 5, wherein the film is used as a polarizer protective film.