KR20190032447A - Resin composition and film made of the resin composition - Google Patents

Abstract

[assignment]
A resin composition which is resistant to birefringence and is excellent in heat resistance, film strength and thermal stability, and a film made of the resin composition.
[Solution]
According to the present invention, there is provided a composition comprising (A) 17 to 31 mass% of an aromatic vinyl monomer unit, (B) 38 to 63 mass% of a (meth) acrylic acid ester monomer unit, 4 to 14 mass% of an unsaturated dicarboxylic acid anhydride monomer unit And 4 to 25 mass% of the conjugated diene monomer unit (D), and the absolute value of the value of (Formula 1) is 0.005 or less. In the formula (1), [A], [B], [C] and [D] are, in order, an aromatic vinyl monomer unit (A), a (meth) acrylic acid ester monomer unit (B), an unsaturated dicarboxylic acid anhydride monomer Represents the mass ratio of the resin composition of the unit (C) and the conjugated diene monomer unit (D), and [A + B + C + D] = 1.
(A) -0.004X [B] + 0.10 占 [C] + 0.09 占 [D]

Description

Resin composition and film made of the resin composition

The present invention relates to a resin composition which is resistant to birefringence and is excellent in heat resistance, film strength and thermal stability, and a film made of the resin composition.

BACKGROUND ART Recently, optical components such as a retardation film, a polarizing plate protective film, an antireflection film, a diffusing plate, and a light guide plate have been widely used in liquid crystal displays, Productivity, and cost.

The liquid crystal display comprises a liquid crystal cell in which a transparent electrode, a liquid crystal layer, a color filter, etc. are sandwiched by a glass plate, and two polarizing plates provided on both sides of the liquid crystal cell. On both sides of the polarizing plate, a triacetylcellulose (TAC) Polarizer protective film is used.

The polarizer protective film is required to have no birefringence in order to achieve uniformity over a wide viewing angle range of the liquid crystal display. However, since the TAC film barely has birefringence, there is a problem that birefringence occurs in incident light in oblique directions. In addition, since there is a problem that the birefringence distribution is caused by the deflection of the external stress due to the enlargement of the display and the contrast is lowered, the polarizer protective film is required to be difficult to change birefringence due to external stress.

As a resin for an optical film, there is known a copolymer resin obtained by copolymerizing methyl methacrylate and maleic anhydride with styrene (for example, Patent Document 1). A copolymer resin obtained by copolymerizing N-phenylmaleimide and N-cyclohexylmaleimide with a resin having a small birefringence (see, for example, Patent Document 2) and methyl methacrylate are known For example, Patent Document 3).

Patent Document 1: WO2014 / 021264 Patent Document 2: JP-A-2006-337493 Patent Document 3: JP-A-2013-109285

The resin described in Patent Document 1 is excellent in heat resistance and transparency, but has a resin design for increasing the birefringence after film forming, and therefore has a limited use. The resins described in Patent Documents 2 and 3 have excellent optical properties but have insufficient film strength after molding, and therefore their use has been limited.

An object of the present invention is to provide a resin composition which is hardly birefringent and has good heat resistance, film strength and thermal stability, and a film made of the resin composition.

The present invention is based on the following points.

(A) 17 to 31 mass% of an aromatic vinyl monomer unit, 38 to 63 mass% of a (meth) acrylic acid ester monomer unit (B), 4 to 14 mass% of an unsaturated dicarboxylic acid anhydride monomer unit (C) And 4 to 25 mass% of a diene monomer unit (D), and the absolute value of the value of (Formula 1) is 0.005 or less. In the formula (1), [A], [B], [C] and [D] are, in order, an aromatic vinyl monomer unit (A), a (meth) acrylic acid ester monomer unit (B), an unsaturated dicarboxylic acid anhydride monomer Represents the mass ratio of the resin composition of the unit (C) and the conjugated diene monomer unit (D), and [A + B + C + D] = 1.

(A) -0.004X [B] + 0.10 占 [C] + 0.09 占 [D]

(Meth) acrylic acid ester monomer unit (B) and the unsaturated dicarboxylic acid anhydride monomer unit (C), (2) 20 to 80 parts by mass of a copolymer (I) comprising an aromatic vinyl monomer unit (A) (A) and a (meth) acrylic ester monomer unit (B) in a polymer comprising 0 to 60 parts by mass of a copolymer (II) composed of an ester monomer unit (B) and a conjugated diene monomer unit And 5 to 60 parts by mass of a graft copolymer (III) in which a copolymer is grafted.

(C) 10 to 70% by mass of an unsaturated dicarboxylic acid anhydride monomer unit (B); and (3) an unsaturated dicarboxylic acid anhydride monomer unit (C), wherein the copolymer (I) comprises 20 to 80% by mass of an aromatic vinyl monomer unit By mass to 25% by mass of the resin (A).

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

(5) The resin composition according to any one of (1) to (4), which has a total light transmittance of 88% or more and a thickness of 2 mm measured according to ASTM D1003.

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

(7) The polarizer protective film according to (6).

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

<Term Explanation>

In the present specification, the symbol " ~ " means " above " and " below ", for example, the description of "A to 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) usable in the resin composition of the present invention include aromatic vinyl monomer units such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, Styrene,? -Methylstyrene,? -Methyl-p-methylstyrene, and other styrene-based monomers. Of these, styrene units are preferred. These aromatic vinyl monomer units (A) may be used alone or in combination of two or more.

As the (meth) acrylic acid ester monomer unit (B) usable in the resin composition of the present invention, there may be mentioned methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, dicyclopentanyl methacrylate Methacrylic acid ester monomers such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate and the like And units derived from each of the acrylic acid ester monomers. Of these, methyl methacrylate units are preferred. These (meth) acrylic acid ester monomer units (B) may be used alone or in combination of two or more.

Examples of the unsaturated dicarboxylic acid anhydride monomer unit (C) that can be used in the resin composition of the present invention include units derived from respective anhydride monomers such as maleic anhydride, itaconic anhydride, citraconic anhydride, and aconitic anhydride. have. Of these, maleic anhydride units are preferred. The unsaturated dicarboxylic acid anhydride monomer unit (C) may be used singly or in combination of two or more.

Examples of the conjugated diene monomer unit (D) usable in the resin composition of the present invention include 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3- , 1,3-pentadiene, 1,3-hexadiene, 2-methylpentadiene, and other monomers. Of these, butadiene units are preferred. These conjugated diene monomer units (D) may be used singly or in combination of two or more.

The resin composition of the present invention contains a vinyl monomer unit other than the aromatic vinyl monomer unit (A), (meth) acrylic acid ester monomer unit (B) unsaturated dicarboxylic acid anhydride monomer unit (C) and conjugated diene monomer unit May be contained in the resin composition within the range not to impair the effects of the invention, and preferably 5% by mass or less. Examples of other vinyl monomer units include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, vinylcarboxylic acid monomers such as acrylic acid and methacrylic acid, N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, , N-alkylmaleimide monomers such as N-cyclohexylmaleimide, and N-arylmaleimide monomers such as N-phenylmaleimide, N-phenylmaleimide and N-chlorophenylmaleimide . Other vinyl monomer units contained in the resin composition other than the aromatic vinyl monomer unit (A), the (meth) acrylic ester monomer unit (B), the unsaturated dicarboxylic acid anhydride monomer unit (C) and the conjugated diene monomer unit (D) Two or more of them may be used in combination.

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

When the aromatic vinyl monomer unit (A) used in the resin composition is 17 mass% or more, a resin composition having little birefringence and having good transparency can be obtained. When the amount is 18 mass% or more, a resin composition having more excellent birefringence and good transparency can be obtained desirable. When the amount of the aromatic vinyl monomer unit (A) is less than 31 mass%, a resin composition having little birefringence and having good heat resistance is obtained. When the amount of the aromatic vinyl monomer unit (A) is less than 25 mass%, birefringence is less likely to occur and a resin composition having excellent heat resistance can be obtained.

When the amount of the (meth) acrylic acid ester monomer unit (B) used in the resin composition is more than 38% by mass, a resin composition having little birefringence and having good heat resistance is obtained. When the amount is more than 45% by mass, a resin composition having more excellent birefringence Which is preferable. When the content of the (meth) acrylic acid ester monomer unit (B) is 63 mass% or less, a resin composition hardly causing birefringence is obtained. When the amount is 60 mass% or less, a resin composition more difficult to cause birefringence can be obtained.

When the amount of the unsaturated dicarboxylic acid anhydride monomer unit (C) used in the resin composition is 4% by mass or more, a resin composition having a good heat resistance can be obtained. If the content of the unsaturated dicarboxylic acid anhydride monomer unit (C) is 14 mass% or less, a resin composition having little birefringence and having good thermal stability is obtained. When the amount of the unsaturated dicarboxylic acid anhydride monomer unit (C) is 12 mass% or less, a resin composition having more excellent birefringence So it is preferable

When the amount of the conjugated diene monomer unit (D) used in the resin composition is 4% by mass or more, a birefringence hardly occurs and a resin composition having good film strength is obtained. When the amount is 10% by mass or more, birefringence is more difficult to occur, Which is preferable. When the amount of the conjugated diene monomer unit (D) is 25% by mass or less, a resin composition having little birefringence and having good heat resistance is obtained. When the amount is 20% by mass or less, a resin composition having more excellent birefringence and heat resistance is obtained.

The resin composition of the present invention preferably has an absolute value of (Formula 1) of 0.005 or less. In the formula (1), [A], [B], [C] and [D] are, in order, an aromatic vinyl monomer unit (A), a (meth) acrylic acid ester monomer unit (B), an unsaturated dicarboxylic acid anhydride monomer Represents the mass ratio of the unit (C) and the conjugated diene monomer unit (D) in the resin composition, and [A + B + C + D] = 1.

(A) -0.004X [B] + 0.10 占 [C] + 0.09 占 [D]

The resin composition of the present invention is characterized in that birefringence is imparted to each component of an aromatic vinyl monomer unit (A), a (meth) acrylic acid ester monomer unit (B), an unsaturated dicarboxylic acid anhydride monomer unit (C) and a conjugated diene monomer unit It is preferable to obtain a resin composition which is less likely to cause birefringence as the absolute value of the value of (Formula 1) becomes smaller. When the absolute value of the value of (Formula 1) is 0.003 or less, a resin composition which is more difficult to obtain than birefringence is obtained. When the absolute value of the value of (Formula 1) is 0.001 or less, a resin composition more difficult to cause birefringence can be obtained Do.

The resin composition of the present invention comprises 20 to 80 parts by mass of a copolymer (I) comprising an aromatic vinyl monomer unit (A), a (meth) acrylic acid ester monomer unit (B) and an unsaturated dicarboxylic acid anhydride monomer unit (C) (A) and a (meth) acrylic acid ester monomer unit (B) are added to a polymer composed of a conjugated diene monomer unit (D) and 0 to 60 parts by mass of a copolymer (II) More preferably 20 to 40 parts by mass of the copolymer (I), and 25 to 25 parts by mass of the polymer (II), wherein the graft copolymer (III) To 50 parts by mass, and the graft copolymer (III) is 10 to 45 parts by mass.

When the amount of the copolymer (I) used in the resin composition is 20 parts by mass or more, a resin composition having a good heat resistance can be obtained. When the amount of the copolymer (I) is 80 parts by mass or less, a resin composition having a good thermal stability can be obtained. When the amount is 40 parts by mass or less, a resin composition having better thermal stability can be obtained.

When the amount of the polymer (II) used in the resin composition is 0 parts by mass or more, a resin composition having little birefringence and having good thermal stability can be obtained. When the amount is more than 25 parts by mass, a resin composition having more excellent birefringence Do. When the amount of the polymer (II) is 60 parts by mass or less, a resin composition that is less likely to cause birefringence is obtained. When the amount is 50 parts by mass or less, a resin composition more difficult to cause birefringence can be obtained.

When the amount of the graft copolymer (III) used in the resin composition is 5 parts by mass or more, a resin composition having little birefringence and having good film strength can be obtained. When the amount is 10 parts by mass or more, a resin composition having more excellent birefringence Therefore, it is preferable. When the amount of the graft copolymer (III) is 60 parts by mass or less, a resin composition having little birefringence and having good heat resistance and thermal stability is obtained. When the amount is 45 parts by mass or less, a resin composition having more excellent heat resistance and thermal stability desirable.

The resin composition of the present invention is characterized in that the copolymer (I), the polymer (II) and the graft copolymer (III) have refractive indices n1, n2 and n3 at 23 deg. W2, and w3, respectively, of the graft copolymer (II) and the graft copolymer (III), the absolute value of the value of (Formula 2) is preferably 0.005 or less.

(W1 + w2) + n2 占 Х 2 / (w1 + w2) -n3

Is preferably 0.005 or less, more preferably 0.001 or less, because the resin composition having excellent transparency can be obtained when the absolute value of the value of (Formula 2) is 0.005 or less. Since the copolymer (I) and the copolymer (II) are compatible systems, the mixture of the copolymer (I) and the copolymer (II) becomes transparent and the copolymer (I) and the copolymer Transparency can be maintained by reducing the refractive index difference of the graft copolymer (III).

There is no particular limitation on the mixing order of the respective components of the copolymer (I), the polymer (II) and the graft copolymer (III). For example, a method of simultaneously mixing all the components, And a method of mixing with another component. Such mixing can be carried out by a conventionally known method.

Examples of the method of simultaneously mixing all the components include a method of adding the respective components of the copolymer (I), the polymer (II) and the graft copolymer (III) and various additives by using a single screw or a twin-screw melt extruder, Can be mixed. Examples of the method of mixing with other components include a method in which the copolymer (I) and the copolymer (II) are preliminarily mixed by using a uniaxial or biaxial melt extruder, The copolymer (III) can be melt-mixed. Also in this case, various additives can be added and melt-mixed.

Examples of the aromatic vinyl monomer unit (A) usable in the copolymer (I) include aromatic vinyl monomer units such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, Styrene,? -Methylstyrene,? -Methyl-p-methylstyrene, and other styrene-based monomers. Of these, styrene units are preferred. These aromatic vinyl monomer units (A) may be used alone or in combination of two or more.

As the (meth) acrylic acid ester monomer unit (B) usable in the copolymer (I), methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate Methacrylic acid ester monomers such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate and the like And units derived from each of the acrylic acid ester monomers. Of these, methyl methacrylate units are preferred. These (meth) acrylic acid ester monomer units (B) may be used alone or in combination of two or more.

Examples of the unsaturated dicarboxylic acid anhydride monomer unit (C) usable in the copolymer (I) include units derived from respective anhydride monomers such as maleic anhydride, itaconic anhydride, citraconic anhydride and aconitic anhydride. have. Of these, maleic anhydride units are preferred. The unsaturated dicarboxylic acid anhydride monomer unit (C) may be used singly or in combination of two or more.

The copolymer (I) is obtained by copolymerizing a copolymerizable vinyl monomer unit other than the aromatic vinyl monomer unit (A), the (meth) acrylic acid ester monomer unit (B) and the unsaturated dicarboxylic acid anhydride monomer unit (C) The content may be included within the range not to impair the effect, and is preferably 5% by mass or less. Examples of other copolymerizable vinyl monomer units include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, vinyl carboxylate monomers such as acrylic acid and methacrylic acid, N-methylmaleimide, N-ethylmaleimide, N-butyl N-alkylmaleimide monomers such as maleimide and N-cyclohexylmaleimide, N-arylmaleimide monomers such as N-phenylmaleimide, N-phenylmaleimide and N-chlorophenylmaleimide . Other copolymerizable vinyl monomer units may be used in combination of two or more.

The constituent unit of the copolymer (I) is 20 to 80% by mass of the aromatic vinyl monomer unit (A), 5 to 70% by mass of the (meth) acrylic acid ester monomer unit (B), the unsaturated dicarboxylic acid anhydride monomer unit (A) 45 to 70 mass%, (meth) acrylic acid ester monomer unit (B) 7 to 40 mass%, unsaturated dicarboxylic acid anhydride monomer unit (C) 10 to 25 mass%, preferably aromatic vinyl monomer unit 23 mass%. The constitutional unit of the copolymer is an analytical value measured by a predetermined analytical method. Actually, the constitutional unit has a distribution (hereinafter, this distribution is referred to as a compositional distribution), and the average value of the compositional distribution is shown.

When the aromatic vinyl monomer unit (A) used in the copolymer (I) is 20 mass% or more, the thermostability is improved and a molded article having a good appearance at the time of molding the resin composition can be obtained. Is further improved and a molded article having a better appearance is obtained when the resin composition is molded. When the amount of the aromatic vinyl monomer unit (A) is 80 mass% or less, compatibility with the polymer (II) improves and transparency of the resin composition becomes good. When the amount is 70 mass% or less, compatibility with the polymer (II) It is preferable since the transparency of the composition is good.

When the amount of the (meth) acrylic acid ester monomer unit (B) used in the copolymer (I) is 5% by mass or more, compatibility with the polymer (II) is improved and transparency of the resin composition is good, ) Is further improved and the transparency of the resin composition is better. When the amount of the (meth) acrylic acid ester monomer unit (B) is 70 mass% or less, the thermal stability is improved and a molded article having a good appearance at the time of molding the resin composition can be obtained. , So that a molded article having a better appearance when molding and processing the resin composition can be obtained, which is preferable.

When the amount of the unsaturated dicarboxylic acid anhydride monomer unit (C) used in the copolymer (I) is 10% by mass or more, it is preferable since the heat resistance is good and the compatibility with the polymer (II) is improved and the transparency of the resin composition is good. When the amount of the unsaturated dicarboxylic acid anhydride monomer unit (C) is 25% by mass or less, the molded article having improved appearance and improved appearance is obtained while improving the thermal stability and improving the compatibility with the polymer (II) The resin composition has good transparency. When the content is 23 mass% or less, the thermostability is further improved. When the resin composition is molded, a molded article having a good appearance can be obtained. Further, compatibility with the polymer (II) Is preferable.

It is preferable that the turbidity of the optical path length 10 mm in the 12 mass% chloroform solution of the copolymer (I) measured according to JIS K-7136 is 2% or less. If the haze is 2% or less, the composition distribution of the copolymer (I) becomes small and the polymer (II) and the unsaturated dicarboxylic acid anhydride monomer unit (C) And good transparency of the resin composition is preferable. The turbidity was measured by charging a solution prepared by adjusting the copolymer to 12% by mass in chloroform into each quartz cell for measurement of an optical path length of 10 mm, and using a haze meter (haze-gardII manufactured by Oriental Chemical Industries, Ltd.) according to JIS K-7136 This is the measured value.

The polymerization mode of the copolymer (I) is not particularly limited, and it can be produced by a known method such as solution polymerization and bulk polymerization, but solution polymerization is more preferable. The solvent used in the solution polymerization is preferably a non-condensed polymer from the viewpoint of less generation of by-products and less adverse effects. Examples of the solvent include, but are not limited to, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and acetophenone, ethers such as tetrahydrofuran and 1,4-dioxane, ethers such as toluene, ethyl And aromatic hydrocarbons such as benzene, xylene and chlorobenzene. Methyl ethyl ketone and methyl isobutyl ketone are preferable from the viewpoints of solubility of monomers and copolymers and ease of solvent recovery. The amount of the solvent to be added is preferably from 10 to 100 parts by mass, more preferably from 30 to 80 parts by mass, based on 100 parts by mass of the copolymer to be obtained. When the amount is 10 parts by mass or more, the reaction rate and the viscosity of the polymerization solution are controlled. When the amount is 100 parts by mass or less, a desired weight average molecular weight (Mw) is obtained.

The polymerization process may be any of a batch polymerization method, a semi-batch polymerization method and a continuous polymerization method, but a batch polymerization method is favorable in order to obtain a desired molecular weight range and transparency.

The polymerization method is not particularly limited, but is preferably a radical polymerization method from the viewpoint that production can be made satisfactorily through a simple process. The polymerization initiator is not particularly limited and examples thereof include dibenzoyl peroxide, t-butyl peroxybenzoate, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, Butylperoxyacetate, dicumylperoxide, ethyl-3,3-di- (t-butylperoxy) butyrate, etc., such as isopropyl monocarbonate, t-butylperoxy-2-ethylhexanoate, Organic peroxides, and known azo compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile, and azobismethylbutyronitrile can be used. These polymerization initiators may be used in combination of two or more. 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 the copolymer (I) having good transparency, it is necessary to carry out polymerization while controlling the composition distribution to be small. Particularly, in the polymer (II), the amount of the unsaturated dicarboxylic acid anhydride monomer unit . Since the aromatic vinyl monomer and the unsaturated dicarboxylic acid anhydride monomer have strong alternating copolymerization, the unsaturated dicarboxylic acid anhydride monomer and / or the aromatic vinyl monomer are continuously added to correspond to the polymerization rate of the aromatic vinyl monomer and the (meth) acrylic acid ester monomer , And the flow rate of the hydrogenated product is appropriately adjusted in accordance with the polymerization rate. Controlling the polymerization rate while appropriately adjusting the polymerization temperature, the polymerization time and the amount of the polymerization initiator added is preferable because the composition distribution of the copolymer can be reduced more precisely.

The method for controlling the molecular weight can be adjusted not only by adjusting the polymerization temperature, the polymerization time, and the amount of the polymerization initiator added, but also by the amount of the solvent added and the amount of the chain transfer agent added. The chain transfer agent is not particularly limited. For example, known chain transfer agents such as n-dodecyl mercaptan, t-dodecyl mercaptan and 2,4-diphenyl-4-methyl-1- .

After completion of the polymerization, the polymerization liquid may contain heat stabilizers such as hindered phenol compounds, lactone compounds, phosphorus compounds and sulfur compounds, light stabilizers such as hindered amine compounds and benzotriazole compounds, lubricants and plasticizers, Additives such as colorants, antistatic agents, and mineral oil may be added. And the amount thereof added is preferably less than 0.2 part by mass based on 100 parts by mass of the whole monomer unit. These additives may be used alone or in combination of two or more.

The method for recovering the copolymer (I) from the polymerization solution is not particularly limited, and a known de-foaming technique can be used. For example, a method of continuously supplying a polymerization liquid to a biaxial demagnetization extruder using a gear pump and subjecting the polymerization solvent or unreacted monomer to a devolatilization treatment may be mentioned. In addition, the devolatilization components including the polymerization solvent and unreacted monomer are condensed and recovered by using a condenser or the like, and the condensate is purified in the distillation column, whereby the polymerization solvent can be reused.

Examples of the (meth) acrylic acid ester monomer unit (B) usable in the polymer (II) include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate , Isobornyl methacrylate and the like, and an acrylic acid ester monomer such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate and decyl acrylate Acrylic acid ester monomer. Of these, methyl methacrylate units are preferred. These (meth) acrylic acid ester monomer units (B) may be used alone or in combination of two or more.

The polymer (II) may contain other copolymerizable vinyl monomer units other than the (meth) acrylic acid ester monomer unit (B) within the range of not hindering the effect of the invention in the copolymer, and preferably 5 mass% or less. Examples of other copolymerizable vinyl monomer units include aromatic vinyl monomers such as styrene, vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, vinylcarboxylic acid monomers such as acrylic acid and methacrylic acid, N-methylmaleimide, N- Alkyl maleimide monomers such as ethyl maleimide, N-butyl maleimide and N-cyclohexyl maleimide, N-alkyl maleimide such as N-phenyl maleimide, N-methyl maleimide and N- Monomers, and the like. Other copolymerizable vinyl monomer units may be used in combination of two or more.

The polymerization mode of the polymer (II) is not particularly limited and can be produced by known methods such as bulk polymerization, solution polymerization, suspension polymerization, bulk-suspension polymerization, emulsion polymerization, etc., Since good polymer (II) can be obtained, bulk polymerization or solution polymerization is preferred. The polymerization process of the polymer (II) may be any of batch polymerization, semi-batch polymerization and continuous polymerization, but continuous polymerization is preferable from the viewpoint of productivity.

When continuous polymerization is employed as the polymerization mode of the polymer (II), the constitution of the reactor is preferably such that a complete mixing reactor (CSTR) and a plug flow reactor (PFR) are connected in series in this order. In addition, CSTR and PFR may be connected to one or more of them, respectively, depending on the purpose, but the number of CSTRs is preferably 1 to 2, more preferably 1. The number of PFR is preferably 1 to 3, more preferably 1.

When the solution polymerization is employed as the polymerization mode of the polymer (II), there is no particular limitation on the solvent to be used, but from the viewpoint of availability and solubility, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene and chlorobenzene, N, N-dimethylformamide, dimethylsulfoxide, N-methyl Pyrrolidone, etc. Among them, toluene and ethylbenzene are preferable from the viewpoint of the solubility of the polymer (II) in a solvent. The amount of such a solvent to be added is not particularly limited, but is preferably in the range of 1 to 30 parts by mass, more preferably 5 to 25 parts by mass, based on 100 parts by mass of the total amount of the monomer compound.

The polymerization method of the polymer (II) is not particularly limited, but radical polymerization is preferred, and any radical polymerization initiator can be used from the viewpoint that production can be made satisfactorily through a simple process.

The radical polymerization initiator used in the polymerization of the polymer (II) is not particularly limited, and for example, known peroxides such as azo compounds, organic peroxides, inorganic peroxides, hydrogen peroxide and the like can be employed. Among them, azo compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile and azobismethylbutyronitrile, benzoyl peroxide, t-butoxycarbonylmethane, and the like are preferable from the viewpoints of ease of reaction control and availability. Butyl peroxybenzoate, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxyisopropyl monocarbonate, t- butylperoxy-2-ethylhexano It is preferable to use an organic peroxide such as diethyl ether, di-t-butyl peroxide, dicumyl peroxide or ethyl-3,3-di- (t-butylperoxy) butylate.

In the polymerization of the polymer (II), the radical polymerization initiator may be used singly or in combination of two or more kinds. From the viewpoint of the polymerization reaction rate and the control of the polymerization rate, it is preferably used in the production of conventional styrenic resins. Specifically, azo compounds and organic peroxides having a 10-hour half-life temperature of 70 to 120 DEG C are preferably used.

The amount of the radical polymerization initiator to be used is not particularly limited, but is preferably 0.001 to 0.1 part by mass, more preferably 0.002 to 0.03 part by mass, based on 100 parts by mass of the total amount of the monomer compound.

When the amount of the radical polymerization initiator to be used is 0.001 parts by mass or 0.002 parts by mass or more based on 100 parts by mass of the total amount of the monomer compound, a sufficient polymerization rate can be obtained and good productivity can be maintained. When the amount of the radical polymerization initiator to be used is 0.1 part by mass or 0.03 part by mass or less based on 100 parts by mass of the total amount of the monomer compound, the polymerization rate can be suppressed and the reaction control becomes easy, so that the molecular weight of the polymer (II) .

Any chain transfer agent may be used for polymerizing the polymer (II). There is no particular limitation on the chain transfer agent to be used, but from the viewpoints of availability and ease of molecular weight control, n-dodecyl mercaptan, t-dodecyl mercaptan and 2,4-diphenyl- A chain transfer agent such as pentene may be used. The chain transfer agent may be used alone, or two or more kinds may be used in combination.

The amount of the chain transfer agent to be used is not particularly limited as long as the target molecular weight of the polymer (II) can be obtained, but it is preferably 0.05 to 2.0 parts by mass based on 100 parts by mass of the total amount of the monomer compounds. More preferably 0.2 to 0.8 parts by mass based on 100 parts by mass of the resin. If the 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) acrylic acid ester-based copolymer (B) can be easily obtained.

The polymerization temperature of the polymer (II) is not particularly limited, but when continuous polymerization is employed, the reaction temperature in the CSTR is preferably 110 ° C to 160 ° C, more preferably 120 ° C to 140 ° C . Further, the reaction temperature in PFR is preferably 120 ° C to 170 ° C, more preferably 130 ° C to 150 ° C. This makes it possible to obtain a polymer (II) which is easy to control the reaction and has a uniform composition.

A method for removing volatile components such as a solvent and an unreacted monomer used for polymerizing the polymer (II) is not particularly limited, and a known method can be used. Of these, a method using a defoaming is preferable. In the case of using the defoaming, the temperature of the molten resin is preferably kept at 260 캜 or lower, more preferably 240 캜 or lower. When the resin temperature is controlled to 260 占 폚 or 240 占 폚 or less, depolymerization due to thermal degradation of the polymer (II) can be suppressed, and a polymer (II) excellent in color can be obtained. The resin temperature can be adjusted by adjusting the temperature of the devolatilization bath.

Any radical scavenger may be used for the purpose of preventing deterioration during processing of the polymer (II) and maintaining a good color. Examples of the radical scavenger include, but are not limited to, antioxidants such as phenol compounds, organic phosphorus compounds, organic sulfur compounds, and amine compounds. These radical scavengers may be used alone or in combination of two or more. In order to maintain the function as a radical scavenger, such a radical scavenger is subjected to a considerable thermal history in the course of stripping volatile components in the styrene-maleimide copolymer in a vent screw extruder, so that a compound having heat resistance and thermal stability Particularly preferred. For example, even more preferred is a radical scavenger with a 1% heat loss temperature above 300 &lt; 0 &gt; C. The radical scavenger is preferably added to the polymerization product after polymerization. The polymerization rate may be lowered before or during the polymerization.

Examples of the conjugated diene monomer unit (D) usable in the resin composition of the present invention include 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3- , 1,3-pentadiene, 1,3-hexadiene, 2-methylpentadiene, and other monomers. Of these, butadiene units are preferred. These conjugated diene monomer units (D) may be used singly or in combination of two or more.

Examples of the aromatic vinyl monomer unit (A) usable in the graft copolymer (III) include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, p- Styrene,? -Methylstyrene,? -Methyl-p-methylstyrene, and other styrene-based monomers. Of these, styrene units are preferred. These aromatic vinyl monomer units (A) may be used alone or in combination of two or more.

Examples of the (meth) acrylic acid ester monomer unit (B) usable in the graft copolymer (III) include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, dicyclopentyl methacrylate Methacrylic acid ester monomers such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate and the like And units derived from each of the acrylic acid ester monomers. Of these, methyl methacrylate units are preferred. These (meth) acrylic acid ester monomer units (B) may be used alone or in combination of two or more.

The graft copolymer (III) is obtained by copolymerizing a copolymerizable vinyl monomer unit other than the conjugated diene monomer unit (D), the aromatic vinyl monomer unit (A) and the (meth) acrylic acid ester monomer unit (B) , Preferably not more than 5% by mass. Examples of other copolymerizable vinyl monomer units include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, vinyl carboxylate monomers such as acrylic acid and methacrylic acid, N-methylmaleimide, N-ethylmaleimide, N-butyl N-alkylmaleimide monomers such as maleimide and N-cyclohexylmaleimide, N-arylmaleimide monomers such as N-phenylmaleimide, N-methylphenylmaleimide and N-chlorophenylmaleimide . Other copolymerizable vinyl monomer units may be used in combination of two or more.

The graft copolymer (III) includes a branch structure in which a copolymer of a aromatic vinyl monomer unit (A) and a (meth) acrylic acid ester monomer unit (B) is bonded to a diene rubber polymer comprising a conjugated diene monomer unit (D) Lt; / RTI &gt; The graft copolymer (III) includes a copolymer composed of an aromatic vinyl monomer unit (A) and a (meth) acrylic acid ester monomer unit (B) which are not grafted to a diene rubber polymer produced as a by- do. The graft copolymer (III) is obtained by polymerizing an aromatic vinyl monomer unit (A) and a (meth) acrylic acid ester monomer unit (B) in a known manner in the presence of a polymer in the form of a diene rubber.

The diene-based rubber-like polymer that can be used in the graft copolymer (III) includes conjugated diene-based rubber such as polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, polyisoprene, styrene-isoprene copolymer, , And they may be used alone or in combination of two or more. Of these, polybutadiene is preferable.

The polymerization mode of the graft copolymer (III) is not particularly limited, but known methods such as bulk polymerization, solution polymerization, suspension polymerization, bulk-suspension polymerization and emulsion polymerization can be employed. Among them, .

The polymerization method of the graft copolymer (III) is not particularly limited, but from the viewpoint that productivity can be improved through a simple process, radical polymerization is preferable, and any radical polymerization initiator can be used.

Examples of the radical initiator used in the graft copolymer (III) include azo compounds such as azobisisobutyronitrile and azobiscyclohexanecarbonitrile, and azo compounds such as benzoyl peroxide, t-butyl peroxybenzoate, t-butyl peroxy- Organic peroxides such as ethylhexanoate, di-t-butyl peroxide, dicumyl peroxide and ethyl-3,3-di- (t-butylperoxy) butylate or organic peroxides such as hydrogen peroxide, potassium sulfate, ammonium persulfate Among them, it is preferable to use an inorganic peroxide and an organic peroxide. It is more preferable to use a Redox initiator in which an inorganic peroxide and an organic peroxide are combined with a reducing agent such as ferrous sulfate. In the polymerization of graft copolymer (III), the radical polymerization initiator may be used singly or in combination of two or more kinds.

The amount of the radical polymerization initiator to be used is not particularly limited, but it is preferably 0.1 to 0.5 parts by mass, more preferably 0.5 to 3 parts by mass based on 100 parts by mass of the total amount of the monomer compound. More preferably 5 parts by mass.

When the amount of the radical polymerization initiator used is 0.1 part by mass or more based on 100 parts by mass of the total amount of the monomer mixture of the diene rubber-like polymer and the aromatic vinyl monomer unit (A) and the (meth) acrylic acid ester monomer unit (B) Good productivity can be maintained because the speed can be achieved. When the amount of the radical polymerization initiator used is 3.5 parts by mass or less based on 100 parts by mass of the total amount of the monomer compound, the polymerization rate can be suppressed and the reaction control becomes easy.

Any chain transfer agent may be used for the polymerization of the graft copolymer (III). There is no particular limitation on the chain transfer agent to be used, but from the viewpoints of availability and ease of molecular weight control, n-dodecyl mercaptan, t-dodecyl mercaptan and 2,4-diphenyl- A chain transfer agent such as pentene may be used. The chain transfer agent may be used alone, or two or more kinds may be used in combination.

The polymerization temperature of the graft copolymer (III) is not particularly limited, but the reaction temperature in the case of employing emulsion polymerization is preferably 50 ° C or more from the viewpoint of increasing the polymerization reaction rate and maintaining good productivity, desirable. From the viewpoint of decreasing the amount of coagulation or adhered matter generated in the polymerization vessel and maintaining good productivity, it is preferably 98 占 폚 or lower, and particularly preferably 90 占 폚 or lower.

The resin composition may be blended with a stabilizer, a plasticizer, a lubricant, an antioxidant, an ultraviolet absorber, a light stabilizer, a colorant, and the like within a range not hindering the effect of the present invention.

The resin composition of the present invention has a total light transmittance of 88% or more, preferably 89% or more, more preferably 90% or more, in a thickness of 2 mm measured according to ASTM D1003. When the total light transmittance of 2 mm in thickness is 88% or more, excellent transparency is obtained even after molding. The total light transmittance was measured in accordance with ASTM D1003 by using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.) and having a length of 90 mm, a width of 55 mm, and a thickness of 2 mm, which was molded under molding conditions of a cylinder temperature of 230 캜 and a mold temperature of 40 캜 , And a haze meter (NDH-1001DP type, manufactured by Nippon Shokuhin Kogyo Co., Ltd.).

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 preferably 30 nm or less, more preferably 20 nm or less, more preferably 10 nm or less , And the thickness retardation (Rth) calculated by (Formula 4) is preferably 20 nm or less, more preferably 10 nm or less, further preferably 5 nm or less in terms of 100 mu m. When the film has an in-plane retardation (Re) of 30 nm or less and a thickness retardation (Rth) of 20 nm or less, when the film is used in a polarizing plate of a liquid crystal display device, problems such as lowered contrast of the liquid crystal display do not occur.

(Expression 3) Re = (nx-ny) Хd

(4) Rth = {(nx + ny) / 2-nz}

In the above formula, nx, ny and nz are refractive indices in the respective axial directions when the direction in which the in-plane refractive index becomes maximum is the X axis, the direction perpendicular to the X axis is the Y axis and the thickness direction of the film is the Z axis And d is the film thickness.

The production method of the film is not particularly limited, and a known molding process such as a melt extrusion film molding method and a solution casting molding method can be used. An example of obtaining a birefringent small film is a method using a flexible roll capable of elastic deformation. An unstretched film may be used, but a stretched film obtained by stretching the film may be used in order to increase the film strength. There are no particular restrictions on the stretching method of the film. Examples of the uniaxial stretching method include a roll stretching method, a tenter stretching method, a free width uniaxial stretching method and a biaxial stretching method, for example, by a combination of roll stretching and tenter stretching A stretched film can be obtained by sequential biaxial stretching or biaxial stretching by tubular stretching.

The absolute value of photoelastic coefficient of the resin composition of the present invention is ^-12 Pa ^-1 or less 5.0Х10 is preferred, and more preferably 3.0Х10 ^-12 Pa ^-1 or less, more preferably 1.0Х10 ^-12 Pa ^-1. Since the photoelastic coefficient is sufficiently small and the birefringence change due to external force is small and the birefringence due to the residual stress at the time of molding is hardly generated, the birefringence distribution in the molded product becomes small. Therefore, when used in a polarizing plate of a liquid crystal display, It is preferable that no unevenness occurs or there is no case where the contrast of the periphery of the display screen is lowered or light leakage occurs.

The photoelastic coefficient can be obtained by measuring the in-plane retardation (Re) of the film using a phase difference measuring apparatus while applying a tensile stress to the film. When the in-plane retardation (Re) in the state where the load f is applied is Re (f) and the width of the test piece is w, the photoelastic coefficient C

C = dRe (f) / df 占 w

, It can be calculated by obtaining the slope of the value of the in-plane retardation (Re) with respect to the load applied to the test piece. In the present invention, the phase difference measuring apparatus was a KOBRA-WR made by Prince Measurement Co., Ltd., and the stress was applied to Digital Force Gage Z2S-DPU-50N of Imadasa Corporation.

The method for controlling the photoelastic coefficient of the resin composition of the present invention is not particularly limited, but it can be controlled according to the composition ratio. Depending on the type of the monomer, the photoelastic coefficient of the resin composition contributes positively and makes a negative contribution. The photoelastic coefficient can be canceled and its absolute value can be made small. For example, styrene, butadiene, which makes a positive contribution to the photoelastic coefficient, and methyl methacrylate and maleic anhydride, which make a negative contribution, can be used to offset the photoelastic coefficient and reduce its absolute value.

[Example]

(A) Preparation of Copolymer (I)

<Production example of I-1>

A 20% maleic anhydride solution dissolved in methyl isobutyl ketone and a 2% maleic anhydride solution diluted with methyl isobutyl ketone to make 2% by mass of t-butyl peroxy-2-ethylhexanoate so that the maleic anhydride concentration is 25% % t-butylperoxy-2-ethylhexanoate solution was previously prepared and used for polymerization.

1.76 kg of a 25% maleic anhydride solution, 11.8 kg of styrene, 3.8 kg of methyl methacrylate and 16 g of t-dodecyl mercaptan were placed in a 50-liter autoclave equipped with a stirrer, and the gas phase portion was replaced with nitrogen gas, The temperature was raised to 90 DEG C for 40 minutes. After warming up, the 25% maleic anhydride solution and the 2% t-butyl peroxy-2-ethylhexanoate solution were continuously added to each while maintaining the temperature at 90 ° C. The 25% maleic anhydride solution contained 1.98 kg / hour from the beginning of the fractionation to 1.58 kg / hour from the 4th hour to the 7th hour, 0.79 kg / hour from the 7th hour to the 10th hour, To 13 hours was changed to a fractionation rate of 0.26 kg / hour in steps so that a total of 15.81 kg was added. In the 2% t-butyl peroxy-2-ethylhexanoate solution, 0.12 kg / hour was applied from the beginning of the fractionation to the 7th hour and 0.19 kg / hour from the 7th hour to 13 hours. And the total amount of 1.98 kg was added. The polymerization temperature was maintained at 90 ° C from the beginning of the fractionation to 7 hours, then the temperature was elevated to 114 ° C at a heating rate of 4 ° C / hour for 6 hours, and further maintained at 114 ° C for 1 hour to terminate the polymerization.

The polymerization liquid was continuously fed to a biaxial demagnetization extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomers were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pellet-like copolymer (I-1) . Composition (I-1) The composition was analyzed by the fmf C-13 NMR method. Three columns of PL gel MIXED-B were arrayed with a SYSTEM-21 Shodex (manufactured by Showa Denko Co., Ltd.) and a differential refractive index detector was used to measure the calibration curve with standard polystyrene (PS) (manufactured by PL) using tetrahydrofuran as a solvent And the weight average molecular weight (Mw) was measured under the conditions of a temperature of 40 캜 and a concentration of 2% by mass. The obtained copolymer (I-1) was dissolved in chloroform to prepare a 12 mass% chloroform solution. The solution was filled in each quartz cell for measurement of the optical path length of 10 mm. The solution was charged in a haze meter (Haze Guard II ) Was used to measure the turbidity of an optical path length of 10 mm in a 12 mass% chloroform solution. Using a injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.), a specular surface plate having a length of 90 mm, a width of 55 mm and a thickness of 2 mm was injection molded under molding conditions of a cylinder temperature of 230 캜 and a mold temperature of 40 캜, And a total light transmittance of 2 mm in thickness was measured using a NDH-1001DP model manufactured by Tokushu Kogyo Co., Ltd.). A molded product having a thickness of 2 mm was produced by press molding, and the refractive index was measured using Abbe's refractometer (DR-M2) manufactured by Atago. As a result of the compositional analysis of the copolymer (I-1), the results of measurement of the total light transmittance transmittance and the refractive index of a 2 mm thick mirror plate as a result of molecular weight measurement are shown in Table 1.

<Production example of I-2>

A 25% maleic anhydride solution and a 2% t-butylperoxy-2-ethylhexanoate solution were used for polymerization in the same manner as in Preparation Example of (I-1).

1.76 kg of a 25% maleic anhydride solution, 14 kg of styrene, 1.6 kg of methyl methacrylate and 16 g of t-dodecyl mercaptan were placed in a 50-liter autoclave equipped with a stirrer, and the gas phase portion was replaced with nitrogen gas. Min to 96 &lt; 0 &gt; C. After warming up, the 25% maleic anhydride solution and the 2% t-butyl peroxy-2-ethylhexanoate solution were continuously added to each while maintaining the temperature at 96 ° C. From the 4th hour to the 7th hour, 1.58kg / hour, from the 7th hour to the 10th hour, 0.79kg / hour, from the 10th hour to the 25th percentile maleic anhydride solution, The rate of addition was varied stepwise until the 13th hour was 0.26 kg / hour of the rate of addition, and a total of 15.81 kg was added. In the 2% t-butyl peroxy-2-ethylhexanoate solution, 0.18 kg / hour was applied from the beginning of the fractionation to the 7th hour, and the fractionation rate was 0.27 kg / And a total of 3.0 kg was added. The polymerization temperature was maintained at 96 deg. C from the beginning of the fractionation to the 7th hour, then the temperature was elevated to 120 deg. C at a heating rate of 4 deg. C / hour for 6 hours, and further maintained at 120 deg.

The polymerization solution was continuously fed to a biaxial extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomer were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pellet-shaped copolymer (I-2) . As a result of compositional analysis, molecular weight and turbidity measurement of a 12 mass% chloroform solution, the results of measurement of the total light transmittance and the refractive index of a 2 mm thick mirror-polished plate were measured for the obtained copolymer (I-2) similarly to (I-1). The measurement results are shown in Table 1.

<Production example of I-3>

A 10% maleic anhydride solution dissolved in methyl isobutyl ketone was prepared in advance so that the concentration of maleic anhydride was 10 mass%, and used for polymerization. The 2% t-butylperoxy-2-ethylhexanoate solution was used for polymerization in the same manner as in Preparation Example of (I-1).

2.4 kg of 10% maleic anhydride solution, 9.6 kg of styrene, 8.0 kg of methyl methacrylate and 16 g of t-dodecylmercaptan were placed in a 50-liter autoclave equipped with a stirrer, and the gaseous portion was replaced with nitrogen gas. Gt; 88 C &lt; / RTI &gt; After the temperature rise, the solution of 10% maleic anhydride and 2% t-butyl peroxy-2-ethylhexanoate was continuously added while maintaining the temperature at 88 ° C. The 10% maleic anhydride solution was 2.43 kg / hour from the 4th hour to the 7th hour, 2.31 kg / hour from the 4th hour to the 10 hour from the 7th hour, The rate of the fractionation was changed stepwise until the time until the fractionation rate of 0.36 kg / hour was reached, and a total of 21.63 kg was added. In the 2% t-butyl peroxy-2-ethylhexanoate solution, the fractionation rate was set to 0.09 kg / hour from the start of the fractionation to the 7th hour and from 0.15 kg / hour until 7 hours to 13 hours And a total of 1.53 kg was added. The polymerization temperature was maintained at 88 占 폚 for 7 hours from the start of the addition, and then the temperature was elevated to 118 占 폚 at a heating rate of 5 占 폚 / hour for 6 hours and further maintained at 118 占 폚 for 1 hour to terminate the polymerization.

The polymerization liquid was continuously fed to a biaxial demagnetization extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomer were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pellet-shaped copolymer (I-3) &Lt; / RTI &gt; Composition analysis and turbidity measurement of a chloroform solution having a molecular weight of 12 mass% were conducted on the obtained copolymer (I-3) in the same manner as in (I-1), and the results of measurement of total light transmittance and refractive index of a 2 mm thick mirror- The measurement results are shown in Table 1.

<Production example of I-4>

A 25% maleic anhydride solution and a 2% t-butylperoxy-2-ethylhexanoate solution were used for polymerization in the same manner as in Preparation Example of (I-1).

1.92 kg of 25% maleic anhydride solution, 2.0 kg of styrene, 8.2 kg of methyl methacrylate and 16 g of t-dodecylmercaptan were placed in a 50-liter autoclave equipped with a stirrer, and the gas phase portion was replaced with nitrogen gas. Gt; 88 C &lt; / RTI &gt; After warming, the styrene, 25% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution were continuously added to each other while maintaining the temperature at 88 占 폚. Styrene was added at a rate of 0.45 kg / hr at the rate of 11 hours from the start of the addition to 4.95 kg in total. The 25% maleic anhydride solution had a rate of 2.59 kg / hour from the beginning of the fractionation to 4 hours, 1.73 kg / hour from 4 hours to 7 hours, 0.4 kg / hour from 7 hours to 10 hours, To the 13th hour was changed in a stepwise manner so that the rate of addition was 0.17 kg / hour, and a total of 17.26 kg was added. In the 2% t-butyl peroxy-2-ethylhexanoate solution, the fractionation rate was set to 0.06 kg / hour from the start of the fractionation to 0.07 kg / hour from the beginning of the fractionation to 0.1 hour / And a total amount of 1.02 kg was added. The polymerization temperature was maintained at 88 占 폚 for 7 hours from the start of the addition, and then the temperature was elevated to 118 占 폚 at a heating rate of 5 占 폚 / hour for 6 hours and further maintained at 118 占 폚 for 1 hour to terminate the polymerization.

The polymerization liquid was continuously fed to a biaxial demagnetization extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomer were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pellet-shaped copolymer (I-4) . As a result of the composition analysis, the molecular weight and the degree of turbidity of the chloroform solution of 12 mass% as a result of the measurement of the total light transmittance and the refractive index of the 2 mm thick mirror-polished plate, the obtained copolymer (I-4) was measured. The measurement results are shown in Table 1.

&Lt; Production example of I-5 >

A 20% maleic anhydride solution dissolved in methyl isobutyl ketone was prepared in advance so that the concentration of maleic anhydride was 20 mass%, and used for polymerization. The 2% t-butylperoxy-2-ethylhexanoate solution was used for polymerization in the same manner as in Preparation Example of (I-1).

1.7 kg of 20% maleic anhydride solution, 15.6 kg of styrene, 1.0 kg of methyl methacrylate and 16 g of t-dodecylmercaptan were placed in a 50-liter autoclave equipped with a stirrer, and the gaseous phase was replaced with nitrogen gas. Min to 96 &lt; 0 &gt; C. After warming, each of the 20% maleic anhydride solution and the 2% t-butyl peroxy-2-ethylhexanoate solution was continuously added while keeping the temperature at 96 ° C. The 20% maleic anhydride solution was fed at a rate of 1.91 kg / hour from the beginning of the fractionation to the 4th hour, 1.53 kg / hour from the 4th hour to the 7th hour, 0.77 kg / hour from the 7th hour to the 10th hour, To the 13th hour was changed in a stepwise manner so that the addition rate was 0.26 kg / hour, and a total of 15.32 kg was added. In the 2% t-butyl peroxy-2-ethylhexanoate solution, 0.18 kg / hour was applied from the beginning of the fractionation to the 7th hour, and the fractionation rate was 0.27 kg / And a total of 3.0 kg was added. The polymerization temperature was maintained at 96 ° C from the beginning of the fractionation to the 7th hour, then the temperature was raised to 120 ° C at a heating rate of 4 ° C / hour for 6 hours, and further maintained at 120 ° C for 1 hour to terminate the polymerization.

The polymerization solution was continuously fed to a biaxial demagnetization extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomer were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pellet-shaped copolymer (I-5) . As to the obtained copolymer (I-5), the results of measurement of the total light transmittance and the refractive index of the 2 mm-thick mirror-polished plate were measured as a result of composition analysis, molecular weight and turbidity measurement of a 12 mass% chloroform solution as in (I-1). The measurement results are shown in Table 1.

&Lt; Production example of I-6 >

The 10% maleic anhydride solution was adjusted in the same manner as in the preparation example of (I-3), and the 2% t-butylperoxy-2-ethylhexanoate solution was used for polymerization in the same manner as in the preparation example of (I- did.

2.0 kg of a 10% maleic anhydride solution, 1.2 kg of styrene, 13.8 kg of methyl methacrylate and 16 g of t-dodecylmercaptan were placed in a 50-liter autoclave equipped with a stirrer, and the gas phase portion was replaced with nitrogen gas. Gt; 88 C &lt; / RTI &gt; After warming, styrene, 10% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution were continuously added to each other while maintaining the temperature at 88 ° C. Styrene was added at a fractionation rate of 0.27 kg / hr from the start of the addition to the 11th hour to add 2.97 kg in total. The 10% maleic anhydride solution was fed at a rate of 2.7 kg / hour from the beginning of the fractionation to the 4th hour, 1.8 kg / hour from the 4th hour to the 7th hour, 0.42 kg / hour from the 7th hour to 10 hours, The rate of the fractionation was changed stepwise until the time until the fractionation rate of 0.18 kg / hour, and a total of 18.0 kg was added. In the 2% t-butyl peroxy-2-ethylhexanoate solution, the fractionation rate was set to 0.06 kg / hour from the start of the fractionation to 0.07 kg / hour from the beginning of the fractionation to 0.1 hour / And a total of 1.02 kg was added. The polymerization temperature was maintained at 88 占 폚 for 7 hours from the start of the addition, and then the temperature was elevated to 118 占 폚 at a heating rate of 5 占 폚 / hour for 6 hours and further maintained at 118 占 폚 for 1 hour to terminate the polymerization.

The polymerization liquid was continuously fed to a biaxial demagnetization extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomer were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pelletized copolymer (I-6) . The obtained copolymer (I-6) was subjected to composition analysis and turbidity measurement of a chloroform solution having a molecular weight of 12 mass% as a result of measurement of the total light transmittance and refractive index of a 2 mm thick mirror plate. The measurement results are shown in Table 1.

&Lt; Production example of I-7 >

Was used for polymerization in the same manner as in Preparation Example of 25% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution (I-1).

1.92 kg of 25% maleic anhydride solution, 14.0 kg of styrene, 1.2 kg of methyl methacrylate and 16 g of t-dodecylmercaptan were placed in a 50-liter autoclave equipped with a stirrer, and the gas phase portion was replaced with nitrogen gas. Min to 96 &lt; 0 &gt; C. After warming up, the 25% maleic anhydride solution and the 2% t-butyl peroxy-2-ethylhexanoate solution were continuously added to each while maintaining the temperature at 96 ° C. In the 25% maleic anhydride solution, 2.16 kg / hour was observed from the beginning of the fractionation to 4 hours, 1.73 kg / hour from 4 hours to 7 hours, 0.86 kg / hour from 7 hours to 10 hours, To the 13th hour was changed in a stepwise manner such that the rate of addition was 0.29 kg / hour, and a total of 17.28 kg was added. The 2% t-butyl peroxy-2-ethylhexanoate solution was added at a rate of 0.21 kg / hour from the beginning of the fractionation to the 7th hour and at a rate of 0.34 kg / hour from 7 hours to 13 hours, And 3.51 kg total was added. The polymerization temperature was maintained at 96 ° C from the beginning of the fractionation to the 7th hour, then the temperature was raised to 120 ° C at a heating rate of 4 ° C / hour for 6 hours, and further maintained at 120 ° C for 1 hour to terminate the polymerization.

The polymerization liquid was continuously fed to a biaxial demagnetization extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomer were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pellet-shaped copolymer (I-7) . As a result of the composition analysis, the molecular weight and the degree of turbidity of the chloroform solution of 12 mass% as a result of the measurement of the total light transmittance and the refractive index of the 2 mm-thick mirror-polished plate, the obtained copolymer (I-7) was measured. The measurement results are shown in Table 1.

<Production example of I-8>

A 25% maleic anhydride solution and a 2% t-butylperoxy-2-ethylhexanoate solution were used for polymerization in the same manner as in Preparation Example of (I-1).

To a 50-liter autoclave equipped with a stirrer was added 2.24 kg of a 25% maleic anhydride solution, 13.4 kg of styrene, 10.0 kg of methyl methacrylate and 16 g of t-dodecylmercaptan, replacing the gaseous portion with nitrogen gas, Lt; RTI ID = 0.0 &gt; 94 C. &lt; / RTI & After the temperature was elevated, the 25% maleic anhydride solution and the 2% t-butyl peroxy-2-ethylhexanoate solution were continuously added to each other while maintaining 94 ° C. The 25% maleic anhydride solution was fed at a rate of 2.52 kg / hour from the beginning of the fractionation to the 4th hour, 2.02 kg / hour from the 4th hour to the 7th hour, 1.01 kg / hour from the 7th hour to the 10th hour, To the 13th hour was changed in a stepwise manner so that the rate of addition was 0.34 kg / hour, and a total of 20.19 kg was added. In the 2% t-butyl peroxy-2-ethylhexanoate solution, 0.18 kg / hour was applied from the beginning of the fractionation to the 7th hour, and the fractionation rate was 0.27 kg / And a total of 3.0 kg was added. The polymerization temperature was maintained at 94 ° C from the beginning of the fractionation to the 7th hour, then elevated to 118 ° C at a heating rate of 4 ° C / hour for 6 hours, and further maintained at 118 ° C for 1 hour to terminate the polymerization.

The polymerization liquid was continuously fed to a biaxial demagnetization extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomers were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pellet type copolymer (I-8) . As to the obtained copolymer (I-8), the results of measurement of the total light transmittance and the refractive index of the 2 mm-thick mirror-polished plate were measured as a result of composition analysis, molecular weight and turbidity measurement of a 12 mass% chloroform solution. The measurement results are shown in Table 1.

&Lt; Production example of I-9 >

The 10% maleic anhydride solution was adjusted in the same manner as in the preparation example of (I-3), and the 2% t-butylperoxy-2-ethylhexanoate solution was used for polymerization in the same manner as in the preparation example of (I- did.

1.6 kg of 10% maleic anhydride solution, 18.4 kg of styrene and 16 g of t-dodecylmercaptan were placed in a 50-liter autoclave equipped with a stirrer, and the gas phase portion was replaced with nitrogen gas. did. After the temperature was elevated, the 10% maleic anhydride solution and the 2% t-butyl peroxy-2-ethylhexanoate solution were continuously added to each while maintaining the temperature at 96 ° C. From the 4th hour to the 7th hour, 1.2kg / hour, from the 7th hour to the 10th hour, 0.96kg / hour from the 10th hour to the 13th hour from the 10th hour, And the rate of addition was changed step by step so that the rate of addition of 0.48 kg / hour until time till 14.4 kg was added. The 2% t-butyl peroxy-2-ethylhexanoate solution was added at a rate of 0.3 kg / hour from the start of the fractionation to the 7th hour and at a rate of 0.48 kg / hour from the 7th hour to the 13 hour- Was changed to add 4.98 kg in total. The polymerization temperature was maintained at 96 ° C from the beginning of the fractionation to the 7th hour, then the temperature was raised to 120 ° C at a heating rate of 4 ° C / hour for 6 hours, and further maintained at 120 ° C for 1 hour to terminate the polymerization.

The polymerization solution was continuously fed to a biaxial demagnetization extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomer were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pelletized copolymer (I-9) . As a result of the composition analysis, the molecular weight and the degree of turbidity of the chloroform solution of 12 mass% as a result of the measurement of the total light transmittance and the refractive index of the 2 mm-thick mirror-polished plate, the obtained copolymer (I-9) was measured. The measurement results are shown in Table 1.

<Production example of I-10>

The 10% maleic anhydride solution was adjusted in the same manner as in the preparation example of (I-3), and the 2% t-butylperoxy-2-ethylhexanoate solution was used for polymerization in the same manner as in the preparation example of (I- did.

1.6 kg of 10% maleic anhydride solution, 1.8 kg of styrene, 14.6 kg of methyl methacrylate and 16 g of t-dodecyl mercaptan were placed in a 120-liter autoclave equipped with a stirrer, and the gas phase portion was replaced with nitrogen gas, The temperature was raised to 88 占 폚 for 40 minutes. After warming, styrene, 10% maleic anhydride solution and 2% t-butylperoxy-2-ethylhexanoate solution were continuously added to each other while maintaining the temperature at 88 ° C. Styrene was added at a fractionation rate of 0.18 kg / hr until the 11th hour from the start of the addition to give a total of 1.98 kg. The concentration of the 10% maleic anhydride solution was 2.14 kg / hour from the beginning of the fractionation to the 4th hour, 1.44 kg / hour from the 4th hour to the 7th hour, 0.34 kg / hour from the 7th hour to the 10th hour, To the 13th hour was varied in the stepwise manner so that the rate of the addition was 0.14 kg / hour, and a total of 14.4 kg was added. In the 2% t-butyl peroxy-2-ethylhexanoate solution, the fractionation rate was set to 0.06 kg / hour from the start of the fractionation to 0.07 kg / hour from the beginning of the fractionation to 0.1 hour / And a total of 1.02 kg was added. The polymerization temperature was maintained at 88 占 폚 for 7 hours from the start of the addition, and then the temperature was elevated to 118 占 폚 at a heating rate of 5 占 폚 / hour for 6 hours and further maintained at 118 占 폚 for 1 hour to terminate the polymerization.

The polymerization solution was continuously fed to a biaxial demagnetization extruder using a gear pump, and methyl isobutyl ketone and a small amount of unreacted monomer were subjected to a devolatilization treatment and extruded into a strand shape and cut to obtain a pellet-like copolymer (I-10) . With respect to the obtained copolymer (I-10), the results of measurement of the total light transmittance and the refractive index of the 2 mm-thick mirror-polished plate were measured as a result of composition analysis, molecular weight and turbidity measurement of a 12 mass% chloroform solution as in (I-1). The measurement results are shown in Table 1.

(B) Production of polymer (II)

<Production example of II-1>

The stirrer was constituted by connecting a complete 20-liter mixing reactor, a 40-liter tower-type plug flow reactor, and a preheater, in series. 0.02 part by mass of 1,1-bis (t-butylperoxy) -cyclohexane (PERHEXA C manufactured by Nippon Oil and Fats Co., Ltd.) was added to a mixed solution consisting of 98 parts by mass of methyl methacrylate, 2 parts by mass of ethyl acrylate and 18 parts by mass of ethylbenzene, 0.3 part by weight of n-dodecyl mercaptan (THIOKALCHOL 20 manufactured by Kao Corp.), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate Ltd.) was mixed to prepare a raw material solution. This raw material solution was controlled at a temperature of 120 캜 at a rate of 6 kg per hour and introduced into a complete mixing reactor. The stirring of the complete mixing reactor was carried out at 200 rpm. Subsequently, the reaction solution was continuously extracted in a complete mixing reactor and introduced into a tower-type plug flow reactor adjusted to have a single layer at 130 ° C and 150 ° C in the direction of flow. This reaction liquid was introduced into a devolatilizer controlled at a temperature of 240 DEG C at a pressure of 1.0 kPa while being heated by a preheater to remove volatile components such as unreacted monomers. This resin liquid was taken out from the gear pump, extruded into strands, and cut to obtain pellet-shaped (II-1). The obtained polymer (II-1) was pyrolyzed at a furnace temperature of 450 ° C to decompose the decomposed gas by a gas chromatography (gas chromatograph) method to analyze the composition. Three columns of PL gel MIXED-B in a SYSTEM-21 Shodex (manufactured by Showa Denko Co., Ltd.) and a differential refractive index detector were used to make a calibration curve using standard polystyrene (PS) (manufactured by PL) using tetrahydrofuran as a solvent , And the weight average molecular weight (Mw) was measured under the conditions of a temperature of 40 占 폚 and a concentration of 2 mass%. Using a injection molding machine (IS-50EPN, manufactured by Toshiba Machine Co., Ltd.), a specular surface plate having a length of 90 mm, a width of 55 mm and a thickness of 2 mm was injection-molded under molding conditions of a cylinder temperature of 230 캜 and a mold temperature of 40 캜, The total light transmittance of 2 mm in thickness was measured using a NDH-1001DP model manufactured by Tokushu Kogyo Co., Ltd.). A molded product having a thickness of 2 mm was prepared by press molding, and the refractive index was measured using Abbe's refractometer (DR-M2) manufactured by Atago. As a result of the compositional analysis of the polymer (II-1), the results of measurement of the total light transmittance transmittance and the measurement results of the refractive index of the 2 mm thick mirror-polished plate are shown in Table 2.

(C) Production of graft copolymer (III)

<Production example of III-1>

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 peroxodisulfate were added to an autoclave having a capacity of 200 liters and dissolved homogeneously under stirring. Subsequently, 80 kg of butadiene, 320 g of t-dodecyl mercaptan and 160 g of divinylbenzene were added and polymerization was carried out at 60 DEG C for 20 hours while stirring. The temperature was raised to 70 DEG C and the mixture was allowed to stand for 10 hours to obtain a polybutadiene rubber latex.

The obtained polybutadiene rubber latex was weighed in an amount of 36 kg in terms of solid content, placed in an autoclave having a capacity of 200 liters, and 80 kg of pure water was added and the temperature was raised to 50 캜 under a nitrogen stream while stirring. An aqueous solution prepared by dissolving 1.5 g of ferrous sulfate, 3 g of sodium ethylenediaminetetraacetate, and 100 g of Longgarit in pure water was placed, and a mixture of 5.7 kg of styrene, 18.3 kg of methyl methacrylate and 54 g of t-dodecyl mercaptan, A solution of 108 g of propylbenzene hydroperoxide in 8 kg of a 5% aqueous solution of potassium oleate was continuously added over 5 hours each. After completion of the addition, the temperature was raised to 70 캜, and 27 g of diisopropylbenzene hydroperoxide was added. The mixture was allowed to stand for 2 hours to complete the polymerization to obtain a graft copolymer latex.

An antioxidant was added to the obtained graft copolymer latex, and the solid content was diluted to 15 mass% with purified water. The temperature was raised to 60 占 폚 and diluted sulfuric acid was added while stirring vigorously to form a slurry state. , Followed by dehydration, washing with water and drying to obtain a powdery graft copolymer (III-1). The obtained compound (III-1) was dissolved in chloroform, and mono-chloride monohydrate was added thereto to react the double bond in the polybutadiene. Potassium iodide was then added to the solution to convert the residual monochloride iodine to iodine, and then reversed with sodium thiosulfate To measure the amount of polybutadiene in D-1. The decomposition gas of the polymer was pyrolyzed at a boiler temperature of 450 ° C, and the decomposition gas was quantified by gas chromatography to determine the composition ratio of methyl methacrylate / styrene. From the amount of polybutadiene and the composition ratio of methyl methacrylate / III-1) was calculated. Further, a molded product having a thickness of 2 mm was prepared by press molding, and the refractive index was measured using Abbe's refractometer (DR-M2) manufactured by Atago. (III-1) and the measurement results of the refractive index are shown in Table 3. &lt; tb &gt; &lt; TABLE &gt;

<Production example of III-2>

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 peroxodisulfate were added to an autoclave having a capacity of 200 liters and dissolved homogeneously under stirring. Subsequently, 72 kg of butadiene, 8 kg of styrene, 320 g of t-dodecylmercaptan and 300 g of divinylbenzene were added and polymerization was carried out at 60 ° C for 20 hours while stirring. The temperature was raised to 70 ° C and the mixture was allowed to stand for 10 hours to complete the polymerization and then polybutadiene rubber latex .

The obtained polybutadiene rubber latex was weighed in an amount of 36 kg in terms of solid content, placed in an autoclave having a capacity of 200 liters, and 80 kg of pure water was added and the temperature was raised to 50 캜 under a nitrogen stream while stirring. An aqueous solution prepared by dissolving 1.5 g of ferrous sulfate, 3 g of sodium ethylenediaminetetraacetate, and 100 g of longalts in 2 kg of pure water was placed, and a mixture composed of 7.7 kg of styrene, 16.3 kg of methyl methacrylate and 54 g of t-dodecyl mercaptan, A solution of 108 g of propylbenzene hydroperoxide in 8 kg of a 5% aqueous solution of potassium oleate was continuously added over 5 hours each. After completion of the addition, the temperature was raised to 70 캜, and 27 g of diisopropylbenzene hydroperoxide was added. The mixture was allowed to stand for 2 hours to complete the polymerization to obtain a graft copolymer latex.

An antioxidant was added to the obtained graft copolymer latex, and the solid content was diluted to 15 mass% with purified water. The temperature was raised to 60 占 폚 and diluted sulfuric acid was added while stirring vigorously to form a slurry state. , Followed by dehydration, washing with water and drying to obtain a powdery graft copolymer (III-2). The obtained compound (III-2) was dissolved in chloroform, and mono-chloride monohydrate was added thereto to react the double bond in the polybutadiene. Potassium iodide was added to the solution to convert the residual monochloride iodine to iodine, and then reversed with sodium thiosulfate To measure the amount of polybutadiene in D-1. The decomposition gas of the polymer was pyrolyzed at a boiler temperature of 450 ° C, and the decomposition gas was quantified by gas chromatography to determine the composition ratio of methyl methacrylate / styrene. From the amount of polybutadiene and the composition ratio of methyl methacrylate / III-2) was calculated. Further, a molded product having a thickness of 2 mm was prepared by press molding, and the refractive index was measured using Abbe's refractometer (DR-M2) manufactured by Atago. (III-2) and the measurement results of the refractive index are shown in Table 3. &lt; tb &gt; &lt; TABLE &gt;

&Lt; Production example of III-3 &

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 peroxodisulfate were added to an autoclave having a capacity of 200 liters and dissolved homogeneously under stirring. Subsequently, 60 kg of butadiene, 20 kg of styrene, 320 g of t-dodecyl mercaptan and 400 g of divinylbenzene were charged, and polymerization was carried out at 60 ° C for 20 hours while stirring. The temperature was raised to 70 ° C and the mixture was allowed to stand for 10 hours to complete polymerization. .

The obtained polybutadiene rubber latex was weighed in an amount of 36 kg in terms of solid content, placed in an autoclave having a capacity of 200 liters, and 80 kg of pure water was added and the temperature was raised to 50 캜 under a nitrogen stream while stirring. An aqueous solution prepared by dissolving 1.5 g of ferrous sulfate, 3 g of sodium ethylenediaminetetraacetate and 100 g of Longgarit in pure water was added to a mixture of 10.1 kg of styrene, 13.9 kg of methyl methacrylate and 54 g of t-dodecylmercaptan, A solution of 108 g of propylbenzene hydroperoxide in 8 kg of a 5% aqueous solution of potassium oleate was continuously added over 5 hours each. After completion of the addition, the temperature was raised to 70 캜, and 27 g of diisopropylbenzene hydroperoxide was added. The mixture was allowed to stand for 2 hours to complete the polymerization to obtain a graft copolymer latex.

An antioxidant was added to the obtained graft copolymer latex, and the solid content was diluted to 15 mass% with purified water. The temperature was raised to 60 占 폚 and diluted sulfuric acid was added while stirring vigorously to form a slurry state. , Followed by dehydration, washing with water and drying to obtain a powdery graft copolymer (III-3). The obtained compound (III-3) was dissolved in chloroform, iodine monochloride was added to react the double bond in the polybutadiene, potassium iodide was added thereto, and the remaining monochloride iodine was changed to iodine, and then reversed with sodium thiosulfate To measure the amount of polybutadiene in D-1. The decomposition gas of the polymer was pyrolyzed at a boiler temperature of 450 ° C. to measure the decomposition gas by gas chromatography to determine the composition ratio of methyl methacrylate / styrene. From the amount of polybutadiene and the composition ratio of methyl methacrylate / -3) was calculated. Further, a molded product having a thickness of 2 mm was prepared by press molding, and the refractive index was measured using Abbe's refractometer (DR-M2) manufactured by Atago. (III-3) and the measurement results of the refractive index are shown in Table 3. &lt; tb &gt; &lt; TABLE &gt;

<Examples and Comparative Examples>

The copolymers (I) (I-1) to (I-10) and the polymers (II) (II-1) and the graft copolymers (III) (Mass%) shown in Tables 4 to 5, and then melt-kneaded at a cylinder temperature of 240 占 폚 with a twin-screw extruder (TEM-35B, manufactured by Toshiba Machine Co., Ltd.) to obtain a resin composition.

The composition of the resin composition was calculated from the composition and mixing ratio of each component of the copolymer (I), polymer (II) and graft copolymer (III). The resin composition was subjected to the following evaluations. The evaluation results are shown in Tables 4 to 5.

The pellets were dried at 70 DEG C for 4 hours and then extruded at 260 DEG C using a 40 mm diameter single-screw extruder and a 300 mm wide T-die. The sheet-like molten resin was pressed on a flexible roll and cooled with a cooling roll to obtain a sheet having a width of 250 mm And an unoriented film of 100 ± 5 μm was obtained.

(In-plane retardation Re, thickness retardation Rth)

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

Distance between chucks: 50 mm

Stretching temperature: Vicat softening point + 10 DEG C

Warm-up time: 5 minutes

Drawing speed: 12.5 mm / min

Drawing distance: 12.5mm

The in-plane retardation (Re) and the thickness retardation (Rth) of the stretched film were measured for birefringence of the film using the following apparatus.

Phase difference measurement: KOBRA-WR

Measured wavelength: 590 nm

(Photoelastic coefficient)

When the in-plane retardation (Re) and the specimen width (w) of the unfragmented film are denoted by Re (f) and w (d), the photoelastic coefficient is dRe (f) / dfХw. (Re) was calculated to calculate the photoelastic coefficient.

Phase difference measurement: KOBRA-WR

Measured wavelength: 590 nm

Stress Measurement: Digital Force Gage Z2S-DPU-50N manufactured by Imada Co.

(Total light transmittance and haze (turbidity))

Test specimens having a length of 90 mm, a width of 55 mm and a thickness of 2 mm were molded under the molding conditions of a cylinder temperature of 230 캜 and a mold temperature of 40 캜 using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.). The haze meter (NDH-1001DP type, manufactured by Nippon Shokuhin Kogyo Co., Ltd.) was measured using a total light transmittance and haze according to ASTM D1003.

(Vicat softening point)

The Vicat softening point was measured according to JIS K7206 using the method 50 (load: 50N, temperature rising rate: 50 ° C / hour) and the test piece having a thickness of 10 mm × 10 mm and a thickness of 4 mm. In addition, the measuring instrument was a HDT & VSPT test device manufactured by Dongyang Kogyo KK. And that the Vicat softening point is 110 ° C or higher.

(Strength of bending strength)

The bending strength of the film was measured using an unstretched film under the following conditions. The bending strength was 100 times or more.

Device name: MIT-D FOLDING ENDURANCE TESTER

Load (tension): 500g Weight

Bending speed: 175 times / minute

Bending angle: 45 degrees left and right angle

Bending device tip radius: 0.38mm

Specimen Width: 15mm

(Thermal stability)

Fifty samples of cylindrically shaped products having a diameter of 30 mm and a height of 50 mm were manufactured under the molding conditions of a cylinder temperature of 250 캜 and a mold temperature of 60 캜 using an injection molding machine (IS-50EPN manufactured by Toshiba Machine Co., Ltd.) The number of samples in which appearance defects resulting from thermal decomposition such as coloration and bubbles occurred was calculated to evaluate the thermal stability of the resin composition. The evaluation criteria are as follows.

&Amp; cir &amp;: The number of samples of appearance defects is 0

A: The number of samples of poor appearance was 1 to 4

DELTA: The number of sample defects was 5 to 9

&Lt; EMI ID = 1.0 &gt; &lt; EMI ID =

(III-1) to (III-3) of the copolymer (I) of the present invention (I-1) to (I- ), The birefringence hardly occurs, and the heat resistance, the film strength, and the thermal stability are excellent.

Comparative Example 1 to Comparative Example 2, in which the formula (1) was below the range of the present invention, exhibited a large birefringence. (Formula 1) and Comparative Example 3 in which the conjugated diene monomer unit was below the range of the present invention had a large birefringence and a poor film strength. Comparative Example 4 using (I-9) in which the unsaturated carboxylic acid anhydride monomer unit was in the range of the present invention was poor in heat resistance. Comparative Example 5 using (I-10) in which the aromatic vinyl monomer unit was in the range of the present invention was poor in transparency and thermal stability.

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

Claims (7)

(B), 38 to 63 mass% of an unsaturated dicarboxylic acid anhydride monomer unit (C), 4 to 14 mass% of an aromatic vinyl monomer unit (A), a conjugated diene monomer A], [B], [C], and [D] in the formula (1) are each in the range of 4 to 25% by mass and the absolute value of the value of the formula (A + B +) represents the mass ratio of the aromatic vinyl monomer unit (A), the (meth) acrylic acid ester monomer unit (B), the unsaturated dicarboxylic acid anhydride monomer unit (C) and the conjugated diene monomer unit C + D] = 1).
(A) -0.004X [B] + 0.10 占 [C] + 0.09 占 [D] The method according to claim 1,
20 to 80 parts by mass of a copolymer (I) comprising an aromatic vinyl monomer unit (A), a (meth) acrylic acid ester monomer unit (B) and an unsaturated dicarboxylic acid anhydride monomer unit (C) (A) and a (meth) acrylic acid ester monomer unit (B) in a polymer comprising a conjugated diene monomer unit (D) and 0 to 60 parts by mass of a copolymer (II) And 5 to 60 parts by mass of a graft copolymer (III) obtained by graft polymerization. 3. The method of claim 2,
Wherein the copolymer (I) comprises 20 to 80 mass% of the aromatic vinyl monomer unit (A), 5 to 70 mass% of the (meth) acrylic acid ester monomer unit (B), 10 to 25 mass of the unsaturated dicarboxylic acid anhydride monomer unit % Of the total weight of the resin composition. The method according to claim 2 or 3,
Wherein the turbidity of the copolymer (I) having an optical path length of 10 mm in a 12 mass% chloroform solution is 2% or less. 5. The method according to any one of claims 1 to 4,
A resin composition having a total light transmittance of 88% or more and a thickness of 2 mm measured according to ASTM D1003. A film comprising the resin composition according to any one of claims 1 to 5. The method according to claim 6,
Polarizer protective film Yongin film.