WO2018124007A1 - Stretched film and retardation film - Google Patents

Abstract

This stretched film comprises a resin composition including a methacrylic resin (A) and a polycarbonate resin (B), wherein the methacrylic resin (A) contains: 10-50 mass% of a structural unit (a1) derived from a methacrylate polycyclic aliphatic hydrocarbon ester; and 50-90 mass% of a structural unit (a2) derived from a (meth)acrylate ester other than methacrylate polycyclic aliphatic hydrocarbon ester. The mass ratio (A)/(B) of the methacrylic resin (A) to the polycarbonate resin (B) is 85/15 to 50/50.

Description

Stretched film and retardation film

The present invention relates to a stretched film and a retardation film. More specifically, the present invention relates to a stretched film and a retardation film having desired retardation, excellent heat resistance, and high tear strength.

The methacrylic resin has characteristics suitable as an optical material such as low water absorption, high transparency, and good UV resistance or scratch resistance. However, methacrylic resins have lower heat resistance and mechanical strength than other optical resins. Various proposals have been made to improve heat resistance or mechanical strength.

For example, Patent Document 1 discloses a structural unit (a1) derived from a methacrylic acid polycyclic aliphatic hydrocarbon ester of 10 to 50% by mass and a structure derived from a methacrylic acid ester other than the methacrylic acid polycyclic aliphatic hydrocarbon ester. A methacrylic resin (A) containing 50 to 90% by mass of the unit (a2) and 0 to 20% by mass of a structural unit (a3) derived from an acrylate ester, and a polycarbonate resin (B) A stretched film comprising a resin composition containing a methacrylic resin (A) to B) in a mass ratio (A) / (B) of 95/5 to 99.9 / 0.1 is disclosed.

Patent Document 2 contains 50 to 90% by mass of a structural unit (a1) derived from methyl methacrylate and 10 to 50% by mass of a structural unit (a2) derived from a polycyclic aliphatic hydrocarbon ester of methacrylic acid and is a weight average. A film comprising 1 to 9% by mass of a methacrylic resin (A) having a molecular weight of 80,000 or more and 1 to 9% by mass of a polycarbonate resin (B), having a film thickness of 1 to 200 μm and stretched in at least one direction. A film is disclosed.

Patent Document 3 includes 50 to 90% by mass of a structural unit (a1) derived from methyl methacrylate and 10 to 50% by mass of a structural unit (a2) derived from a polycyclic aliphatic hydrocarbon ester of methacrylic acid. A methacrylic acid polycyclic aliphatic carbonization containing a methacrylic resin (A) having a molecular weight of 80,000 or more and 80% by mass or more and a polycarbonate resin (B) and / or a phenoxy resin (C) of 1 to 9% by mass. The hydrogen ester content is 3.0% by mass or less, and the total content of the dimer and trimer comprising the polymerizable monomer is 1.0% by mass or less. A stretched film having a loss on heating of 1% or less when held at 280 ° C. for 5 minutes in a nitrogen atmosphere is disclosed.

Patent Document 4 includes 50 to 95% by weight of methyl methacrylate, 5 to 50% by weight of (meth) acrylic acid ester substituted with an alkyl group substituted with a cycloalkyl group, a cycloalkyl group or an alkylcycloalkyl group, A resin having a viscosity average molecular weight of 80,000 to 300,000 comprising a copolymer obtained by polymerizing a monomer component comprising 0.1 to 20% by weight of monomer units other than these, a polycarbonate resin, And a molded product obtained by molding the resin composition.

Patent Document 5 discloses methyl methacrylate 59-90% by weight, an alkyl group substituted with a cycloalkyl group, a cycloalkyl group, a cycloalkyl group substituted with an alkyl group, an alkyl group substituted with a phenyl group, a phenyl group, Alkyl group substituted with a naphthyl group, naphthyl group, dicyclopentanyl group or (meth) acrylic acid ester substituted with dicyclopentenyl group 10 to 40% by weight, and alkyl acrylate 0.4 to 0.8% by weight %, A resin composition containing a resin obtained by polymerizing a monomer component containing 1%, an aromatic polycarbonate resin having a weight average molecular weight of 20000 to 60000, a resin film obtained by molding the resin composition, and the resin film A stretched film formed by stretching is disclosed.

Patent Document 6 includes an alkyl (meth) acrylate monomer, a (meth) acrylate monomer containing an aliphatic ring and / or an aromatic ring, an imide monomer, and a styrene monomer. A resin composition containing an acrylic copolymer containing at least one kind, a resin containing an aromatic ring and / or an aliphatic ring in the main chain, and an optical film containing the same are disclosed.

WO2015 / 186629A JP 2016-48363 A JP 2016-1113579 A JP 2014-31459 A Japanese Patent Laying-Open No. 2015-147858 Special table 2012-518052 gazette WO2014 / 162370A JP 2014-127282 A Japanese Patent Laying-Open No. 2015-057664

The films disclosed in Patent Documents 1 to 3 and the like have a small birefringence developed by stretching, and thus it is not easy to adjust the in-plane direction retardation or the thickness direction retardation to a desired value.

A resin composition containing a copolymer obtained by polymerizing a monomer component containing a (meth) acrylic acid ester substituted with a monocyclic aliphatic hydrocarbon group such as a cyclohexyl group has low heat resistance (patent document) 4).

A copolymer obtained by polymerizing a monomer component containing a (meth) acrylic acid ester substituted with an aromatic hydrocarbon group such as a phenyl group or a naphthyl group, Since the elastic modulus is large, the phase difference changes greatly when external stress applied when bent, or internal stress caused by expansion / contraction due to temperature change, and it is not easy to keep the retardation constant. (Patent Document 5).
The resin composition disclosed in Patent Document 6 uses at least one of an imide monomer and a styrene monomer in order to improve heat resistance.
Since the sign of polystyrene's intrinsic birefringence is opposite to the sign of polycarbonate's intrinsic birefringence, the use of a styrenic monomer reduces the birefringence developed by stretching and adjusts the retardation to the desired value. It is not easy. Further, when a styrene monomer is used, the photoelastic coefficient increases, so that when an external stress or an internal stress is applied, the phase difference changes greatly, and it is not easy to keep the retardation constant.
In addition, when an imide monomer is used, a cyclic structure is introduced into the main chain of the acrylic resin as described in paragraph 0010 of patent document 8, paragraph 0008 of patent document 9, and the like. The film itself is easily broken and has poor mechanical strength.

An object of the present invention is to provide a stretched film and a retardation film having desired retardation, excellent heat resistance, and high tear strength.

As a result of intensive studies to solve the above problems, the present invention including the following aspects has been completed.

That is, the present invention includes the following aspects.
[1] Structural unit derived from methacrylic acid polycyclic aliphatic hydrocarbon ester (a1) 10 to 50% by mass, and structure derived from (meth) acrylic acid ester other than methacrylic acid polycyclic aliphatic hydrocarbon ester A methacrylic resin (A) containing 50 to 90% by mass of the unit (a2);
With polycarbonate resin (B)
A stretched film comprising a resin composition containing a methacrylic resin (A) to a polycarbonate resin (B) in a mass ratio (A) / (B) of 85/15 to 50/50.

（式（1）中、Ｘは炭素数１０以上の多環式脂肪族炭化水素基である。） [2] The stretched film according to [1], wherein the methacrylic acid polycyclic aliphatic hydrocarbon ester is a compound represented by the formula (1).

(In the formula (1), X is a polycyclic aliphatic hydrocarbon group having 10 or more carbon atoms.)

[3] The stretched film according to [2], wherein X is an isobornan-2-yl group or a tricyclo [5.2.1.0 ^2,6 ] decan-8-yl group.
[4] The structural unit (a2) contains 50 to 90% by mass of the structural unit derived from methyl methacrylate with respect to the total structural unit of the methacrylic resin (A), and any one of [1] to [3] The stretched film as described in one.
[5] The structural unit (a2) contains any structural unit derived from an acrylate ester in an amount of 0 to 20% by mass based on the total structural unit of the methacrylic resin (A). The stretched film as described in one.

[6] The stretched film according to any one of [1] to [5], wherein the total amount of the methacrylic resin (A) and the polycarbonate resin (B) is 80 to 100% by mass with respect to the mass of the resin composition. .
[7] The stretched film according to any one of [1] to [6], which has a thickness of 10 to 80 μm.
[8] The stretched film according to any one of [1] to [7], wherein an in-plane retardation with respect to light having a wavelength of 589 nm is 20 to 400 nm.

[9] Structural unit derived from methacrylic acid polycyclic aliphatic hydrocarbon ester (a1) 10 to 50% by mass, and structure derived from (meth) acrylic acid ester other than methacrylic acid polycyclic aliphatic hydrocarbon ester A methacrylic resin (A) containing 50 to 90% by mass of the unit (a2) and a polycarbonate resin (B), the mass ratio of the methacrylic resin (A) to the polycarbonate resin (B) (A) / (B) 85/15 to 50/50, the resin composition contained is molded to obtain a raw film.
Biaxially stretching the raw film,
A method for producing a stretched film.
[10] The production method according to [9], wherein the biaxial stretching is performed at an area ratio of 1.5 to 8 times.

[11] A retardation film comprising the stretched film according to any one of [1] to [8].
[12] A polarizing plate having the retardation film according to [11].

The stretched film of the present invention has a desired in-plane direction retardation or thickness direction retardation, and is excellent in heat resistance and mechanical strength. The retardation film of the present invention can be suitably used for viewing angle compensation in LCD (liquid crystal display), antireflection of light in OLED (organic light emitting diode display) and 3D display.

The stretched film of the present invention comprises a resin composition containing a methacrylic resin (A) and a polycarbonate resin (B).
The mass ratio (A) / (B) of the methacrylic resin (A) to the polycarbonate resin (B) is preferably 85/15 to 50/50, more preferably 83/17 to 55/45, and still more preferably 80/20. -60/40, more preferably 78 / 22-60 / 40. When the mass ratio (A) / (B) of the methacrylic resin (A) to the polycarbonate resin (B) is within this range, the retardation can be adjusted to a desired value by stretching.

The total amount of the methacrylic resin (A) and the polycarbonate resin (B) is preferably 80 to 100% by mass, more preferably 90 to 100% by mass, and most preferably 96 to 100% by mass with respect to the mass of the resin composition. %.

The methacrylic resin (A) contains the structural unit (a1) and the structural unit (a2).

The structural unit (a1) is derived from methacrylic acid polycyclic aliphatic hydrocarbon ester. More specifically, the structural unit (a1) is preferably a unit formed by an addition polymerization reaction with a methacryloyl group in a methacrylic acid polycyclic aliphatic hydrocarbon ester. The resin composition containing the methacrylic resin (A) using the structural unit (a1) derived from the methacrylic acid polycyclic aliphatic hydrocarbon ester has high transparency and is excellent in heat resistance and mechanical strength. In addition, the structural unit (a1) derived from the polycyclic aliphatic hydrocarbon ester of methacrylic acid reduces the photoelastic coefficient of the resin composition, so that the change in phase difference is small even when internal stress or external stress is applied. The retardation can be kept constant.

The methacrylic acid polycyclic aliphatic hydrocarbon ester is preferably a compound represented by the formula (1).

X in the formula (1) is a polycyclic aliphatic hydrocarbon group, preferably a bridged cyclic aliphatic hydrocarbon group having two or more rings. The bridged cyclic aliphatic hydrocarbon is an alicyclic hydrocarbon having a structure in which two non-adjacent carbon atoms constituting a ring are connected by a carbon chain composed of one or more carbon atoms. Such a bridged cyclic aliphatic hydrocarbon may have a condensed ring structure or a spiro ring structure in addition to the structure linked by carbon chains. The number of carbon atoms constituting the polycyclic aliphatic hydrocarbon group is preferably 7 or more, more preferably 10 or more, and further preferably 10 to 20.

The polycyclic aliphatic hydrocarbon group is not particularly limited, and examples thereof include an octahydropentalen-1-yl group, an octahydropentalen-2-yl group, and an octahydro-1-H-inden-4-yl group. , Octahydro-1-1H-inden-5-yl group, hexahydro-1,5-methano-pentalen-3A-yl group, decahydronaphthalen-1-yl group, decahydronaphthalen-2-yl group, octahydrocyclo Penta [c, d] pentalen-2A-2a (2H) -yl group, 3a, 6a-dimethyloctahydropentalen-2-yl group, tetradecahydroanthracen-9-yl group, androstan-4-yl group Condensed polycyclic aliphatic hydrocarbon groups such as cholestan-2-yl group and cholestan-5-yl group; norbornan-2-yl group, 2-methylnor Lunan-2-yl group, 2-ethylnorbornan-2-yl group, 1,3,3-trimethylnorbornan-2-yl group, 1,2,3,3-tetramethylnorbornan-2-yl group, 2- Ethyl-1,3,3-trimethylnorbornan-2-yl group, isobornan-2-yl group, 2-methylisobornan-2-yl group, 2-ethylisobornan-2-yl group, decahydro-2 , 5-methano-7,10-methanonaphthalen-1-yl group, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, 8-methyltricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, 8-ethyltricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, adamantane-1-yl group, adamantane-2-yl group, 2 -Methyladamantan-2-yl group, 2-ethyladamanta N-2-yl group, decahydro-3,6-methano-2,2,7,7-tetramethylnaphthalen-1-yl group and the like; a cyclic cycloaliphatic hydrocarbon group such as spirobicyclopentan-2-yl Group, a spirobicyclopentan-3-yl group, a spirobicyclohexane-2-yl group, a spirobicyclohexane-3-yl group, a polycyclic aliphatic hydrocarbon group having a spiro structure, or a derivative thereof. it can.

Examples of the polycyclic aliphatic hydrocarbon group having 10 or more carbon atoms include octahydrocyclopenta [c, d] pentalen-2A-2a (2H) -yl group, 3a, 6a-dimethyloctahydropentalen-2-yl Group, tetradecahydroanthracen-9-yl group, androstan-4-yl group, cholestan-2-yl group, cholestane-5-yl group, 1,3,3-trimethylnorbornan-2-yl group, 1, 2,3,3-tetramethylnorbornan-2-yl group, 2-ethyl-1,3,3-trimethylnorbornan-2-yl group, isobornan-2-yl group, 2-methylisobornan-2-yl Group, 2-ethylisobornan-2-yl group, decahydro-2,5-methano-7,10-methanonaphthalen-1-yl group, tricyclo [5.2.1.0 ^2,6 ] decane-8 -I Group, 8-methyltricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, 8-ethyltricyclo [5.2.1.0 ^2,6 ] decan-8-yl group Adamantane-1-yl group, adamantane-2-yl group, 2-methyladamantan-2-yl group, 2-ethyladamantan-2-yl group, decahydro-3,6-methano-2,2,7,7 -Tetramethylnaphthalen-1-yl group, spirobicyclohexane-2-yl group, spirobicyclohexane-3-yl group and the like.
Among these, 1,3,3-trimethylnorbornane-2-yl group, 1,2,3,3-tetramethylnorbornane-2-yl group, 2-ethyl-1,3,3-trimethylnorbornane-2-yl group Yl group, isobornan-2-yl group, 2-methylisobornan-2-yl group, 2-ethylisobornan-2-yl group, decahydro-2,5-methano-7,10-methanonaphthalene-1 -Yl group, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, 8-methyltricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, 8- Ethyltricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, adamantane-1-yl group, adamantane-2-yl group, 2-methyladamantan-2-yl group, 2-ethyladamantane -2-yl group is more preferred, Down 2-yl group, tricyclo [5.2.1.0 ^{2, 6]} are more preferred decan-8-yl group, tricyclo [5.2.1.0 ^2,6] decan-8-yl group ( The common name: dicyclopentanyl group) is particularly preferred.

The structural unit (a2) is derived from (meth) acrylic acid ester (hereinafter referred to as (meth) acrylic acid ester (a2)) other than methacrylic acid polycyclic aliphatic hydrocarbon ester.

(Meth) acrylic acid ester (a2) includes methacrylic acid monocyclic aliphatic hydrocarbon esters such as cyclohexyl methacrylate, cyclopentyl methacrylate, cycloheptyl methacrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate , Isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate , Methacrylate acyclic aliphatic hydrocarbon esters such as dodecyl methacrylate: 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, glycidyl methacrylate, alicyclic methacrylate , Benzyl methacrylate, phenoxyethyl methacrylate, phenyl methacrylate; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, s-butyl acrylate, acrylic acid Acrylic acid acyclic aliphatic hydrocarbon ester such as t-butyl, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate; acrylic acid such as phenyl acrylate Aromatic hydrocarbon esters; Acrylic alicyclic hydrocarbon esters such as cyclohexyl acrylate and norbornenyl acrylate; Among these, methacrylic acid acyclic aliphatic hydrocarbon ester and acrylic acid ester are preferable, and methyl methacrylate and acrylic acid acyclic aliphatic hydrocarbon ester are more preferable.

The structural unit (a2) preferably contains a structural unit derived from methyl methacrylate. The content of structural units derived from methyl methacrylate is preferably 50 to 90% by mass, more preferably 60 to 88% by mass, based on all structural units of the methacrylic resin (A).

The structural unit (a2) may contain a structural unit derived from an acrylate ester as necessary. The content of the structural unit derived from the acrylate ester is preferably 0 to 20% by mass, more preferably 0 to 10% by mass, based on all structural units of the methacrylic resin (A). Examples of the acrylate ester preferably used in the present invention include methyl acrylate, ethyl acrylate, and butyl acrylate.

The methacrylic resin (A) used in the present invention may further contain a structural unit (a3). The structural unit (a3) is a monomer having a polymerizable carbon-carbon unsaturated bond (hereinafter referred to as monomer (a3) other than methacrylic acid polycyclic aliphatic hydrocarbon ester and (meth) acrylic acid ester (a2)). It is a structural unit derived from.

As the monomer (a3), for example, vinyl having only one polymerizable carbon-carbon double bond in one molecule such as acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, styrene, acrylic acid, methacrylic acid, etc. Examples thereof include system monomers.

The methacrylic resin (A) used in the present invention preferably has a structural unit (a1) of 10 to 50% by mass and a structural unit (a2) of 50 from the viewpoint of high glass transition temperature and low shrinkage under high temperature and high humidity. And 90 to 20% by mass and structural unit (a3) 0 to 20% by mass, more preferably 12 to 40% by mass, structural unit (a2) 60 to 88% by mass, and structural unit (a3) ) 0-10% by mass, more preferably 15-35% by mass of structural unit (a1), 65-85% by mass of structural unit (a2), and 0-5% by mass of structural unit (a3), Most preferably, it contains only 15 to 35% by mass of the structural unit (a1) and 65 to 85% by mass of the structural unit (a2).

The methacrylic resin (A) used in the present invention has a weight average molecular weight (hereinafter sometimes referred to as “Mw”) of preferably 80,000 or more, more preferably 80000 to 200000, still more preferably 90000 to 16000, Preferably it is 100,000-130,000. A film obtained using a methacrylic resin (A) having an Mw of 80000 or more has high strength, is difficult to break, and is easy to stretch. Therefore, the film can be made thinner. Moreover, since Mw is 200,000 or less, since the methacryl resin (A) has improved moldability, the thickness of the resulting film tends to be uniform and excellent in surface smoothness.

From the viewpoint that the methacrylic resin (A) used in the present invention can increase the moldability of the resin composition regardless of the molecular weight of the polycarbonate resin (B) used in combination with the methacrylic resin (A). Mw is preferably 30,000 to 100,000, more preferably 40,000 to 90,000, still more preferably 45,000 to 85,000. When the Mw of the methacrylic resin (A) is within this range, it is possible to appropriately select the polycarbonate resin (B) having characteristics suitable for the purpose of use of the resin composition, the strength is high, and the retardation is easily adjusted. A stretched film can be obtained.

The methacrylic resin (A) used in the present invention is the ratio of Mw to the number average molecular weight (hereinafter sometimes referred to as “Mn”) (Mw / Mn: hereinafter, this value may be referred to as “molecular weight distribution”). Is preferably 1.2 to 5.0, more preferably 1.3 to 3.5. When the molecular weight distribution is 1.2 or more, the fluidity of the methacrylic resin (A) is improved, and the film tends to be excellent in surface smoothness. When the molecular weight distribution is 5.0 or less, the film tends to be excellent in impact resistance and toughness. Mw and Mn are values obtained by converting a chromatogram measured by gel permeation chromatography (GPC) into a molecular weight of standard polystyrene.

The methacrylic resin (A) used in the present invention has a melt flow rate of preferably 0.1 to 5 g / 10 min, measured at 230 ° C. under a load of 3.8 kg in accordance with JIS K7210. The amount is preferably 0.5 to 4 g / 10 minutes, more preferably 0.8 to 3 g / 10 minutes.

The glass transition temperature of the methacrylic resin (A) used in the present invention is preferably 120 ° C. or higher, more preferably 123 ° C. or higher, still more preferably 124 ° C. or higher, and particularly preferably 125 ° C. or higher. The upper limit of the glass transition temperature of the methacrylic resin (A) is usually 140 ° C. The glass transition temperature can be controlled by adjusting the proportion of structural units derived from methacrylic acid polycyclic aliphatic hydrocarbon ester. When the glass transition temperature is in this range, the heat resistance of the film is improved and deformation such as heat shrinkage hardly occurs. Here, the glass transition temperature is a midpoint glass transition temperature measured according to JIS K 7121 (temperature increase rate 20 ° C./min).

The method for producing the methacrylic resin (A) used in the present invention is not particularly limited. For example, it can be produced by a known polymerization reaction such as radical polymerization or anionic polymerization. The adjustment of the methacrylic resin (A) to the above-mentioned characteristic values is performed by adjusting the polymerization conditions, specifically, the polymerization temperature, the polymerization time, the type and amount of the chain transfer agent, the type and amount of the polymerization initiator, etc. Can be done by adjusting. Adjustment of resin characteristics by adjusting polymerization conditions is a technique well known to those skilled in the art.

When radical polymerization is used in the production of the methacrylic resin (A), it is possible to select a suspension polymerization method, a bulk polymerization method, a solution polymerization method, or an emulsion polymerization method. In such a polymerization method, it is preferable to carry out by a suspension polymerization method or a bulk polymerization method from the viewpoint of productivity and thermal decomposition resistance.
The bulk polymerization method is preferably performed by a continuous flow method.
The polymerization reaction is performed using a polymerization initiator, the above-described monomer, and a chain transfer agent as necessary.

The polymerization initiator used in radical polymerization for producing the methacrylic resin (A) is not particularly limited as long as it generates a reactive radical. The polymerization initiator has a one-hour half-life temperature of preferably 60 to 140 ° C, more preferably 80 to 120 ° C.
Examples of the polymerization initiator include t-hexyl peroxyisopropyl monocarbonate, t-hexyl peroxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, t -Butyl peroxypivalate, t-hexyl peroxypivalate, t-butyl peroxyneodecanoate, t-hexylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxy Neodecanoate, 1,1-bis (t-hexylperoxy) cyclohexane, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, 2,2'-azobis (2-methylpro Pionitrile), 2,2'-azobis (2-methylbutyronitrile), dimethyl 2,2'- And azobis (2-methylpropionate). Of these, t-hexylperoxy 2-ethylhexanoate, 1,1-bis (t-hexylperoxy) cyclohexane, and dimethyl 2,2′-azobis (2-methylpropionate) are preferable.

These polymerization initiators can be used alone or in combination of two or more. The addition amount and addition method of the polymerization initiator are not particularly limited as long as they are appropriately set according to the purpose. For example, the amount of the polymerization initiator used in the suspension polymerization method is preferably 0.0001 to 0.1 parts by mass, more preferably 100 parts by mass of the total amount of monomers to be subjected to radical polymerization. 0.001 to 0.07 parts by mass.

The chain transfer agent used in radical polymerization for the production of the methacrylic resin (A) is not particularly limited. For example, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, 1,4-butanedithiol, 1,6-hexanedithiol, ethylene glycol bisthiopropionate, butanediol bisthioglycolate, butanediol bisthiol Alkyl mercaptans such as propionate, hexanediol bisthioglycolate, hexanediol bisthiopropionate, trimethylolpropane tris- (β-thiopropionate), pentaerythritol tetrakisthiopropionate; α-methylstyrene Dimer; terpinolene and the like can be mentioned. Of these, alkyl mercaptans such as n-octyl mercaptan and pentaerythritol tetrakisthiopropionate are preferred. These chain transfer agents can be used alone or in combination of two or more.

The amount of the chain transfer agent used is preferably 0.1 to 1 part by mass, more preferably 0.15 to 0.8 part by mass with respect to 100 parts by mass of the total amount of monomers subjected to radical polymerization. More preferably, it is 0.2 to 0.6 parts by mass, and most preferably 0.2 to 0.5 parts by mass. The amount of the chain transfer agent used is preferably 2500 to 10,000 parts by mass, more preferably 3000 to 9000 parts by mass, and further preferably 3500 to 6000 parts by mass with respect to 100 parts by mass of the polymerization initiator.

Each monomer, polymerization initiator and chain transfer agent used for the production of the methacrylic resin (A) may be mixed together and supplied to the reaction vessel, or they may be reacted separately. You may supply to a tank. In the present invention, a method of mixing all and supplying the mixture to the reaction vessel is preferable.

When a solvent is used in radical polymerization for the production of methacrylic resin (A), the solvent is not limited as long as it can dissolve the monomer and methacrylic resin (A), but aromatic carbonization such as benzene, toluene, ethylbenzene, etc. Hydrogen is preferred. These solvents can be used alone or in combination of two or more. The usage-amount of a solvent can be suitably set from a viewpoint of the viscosity and productivity of a reaction liquid. The amount of the solvent used is, for example, preferably 100 parts by mass or less, more preferably 90 parts by mass or less, with respect to 100 parts by mass of the total amount of the polymerization reaction raw materials.

In the case of suspension polymerization, the temperature during radical polymerization for producing the methacrylic resin (A) is preferably 50 to 180 ° C, more preferably 60 to 140 ° C.
In the bulk polymerization method, the temperature is preferably 100 to 200 ° C, more preferably 110 to 180 ° C. When the temperature at the time of radical polymerization in the bulk polymerization method is 100 ° C. or higher, the reaction rate is improved, the viscosity of the polymerization solution can be lowered, and the productivity tends to be improved. Moreover, when the temperature at the time of radical polymerization in the bulk polymerization method is 200 ° C. or less, it is easy to control the polymerization rate, further suppress the production of by-products, and tend to suppress the coloring of the methacrylic resin.

Radical polymerization may be performed using a batch type reaction apparatus or a continuous flow type reaction apparatus. In a continuous flow reactor, for example, a polymerization reaction raw material (mixed solution containing a monomer, a polymerization initiator, a chain transfer agent, etc.) is prepared under a nitrogen atmosphere, and the mixture is supplied to a reactor at a constant flow rate. The liquid in the reactor is withdrawn at a flow rate corresponding to the supply amount. As the reactor, a tubular reactor that can be in a state close to plug flow and / or a tank reactor that can be in a state close to complete mixing can be used. In addition, continuous flow polymerization may be performed in one reactor, or continuous flow polymerization may be performed by connecting two or more reactors. In the present invention, it is preferable to employ at least one continuous flow tank reactor. The amount of liquid in the tank reactor at the time of radical polymerization is preferably 1/4 to 3/4, more preferably 1/3 to 2/3, with respect to the volume of the tank reactor. The reactor is usually equipped with a stirring device. Examples of the stirring device include a static stirring device and a dynamic stirring device. Examples of the dynamic agitation device include a Max blend type agitation device, an agitation device having a grid-like blade rotating around a vertical rotation shaft arranged in the center, a propeller type agitation device, and a screw type agitation device. . Among these, a Max blend type stirring apparatus is preferably used from the point of uniform mixing property.

When the methacrylic resin (A) is produced by the suspension polymerization method, a granular polymer can be obtained by washing, dehydrating and drying by a known method after the completion of the polymerization.
When the methacrylic resin (A) used in the present invention is produced by the bulk polymerization method, volatile components such as unreacted monomers are removed as necessary after the completion of the polymerization. The removal method is not particularly limited, but heating devolatilization is preferable. Examples of the devolatilization method include an equilibrium flash method and an adiabatic flash method. The devolatilization temperature by the adiabatic flash method is preferably 200 to 280 ° C, more preferably 220 to 260 ° C. The time for heating the resin by the adiabatic flash method is preferably 0.3 to 5 minutes, more preferably 0.4 to 3 minutes, and further preferably 0.5 to 2 minutes. When devolatilization is performed within such a temperature range and heating time, a methacrylic resin (A) with little coloring is easily obtained. The removed unreacted monomer can be recovered and used again for radical polymerization. The yellow index of the recovered monomer may be high due to heat applied during the recovery operation. The recovered monomer is preferably purified by an appropriate method to reduce the yellow index.

As a method for producing the methacrylic resin (A) by anionic polymerization, for example, an anionic polymerization is carried out in the presence of a mineral salt such as an alkali metal or alkaline earth metal salt using an organic alkali metal compound as a polymerization initiator (special feature). No. 7-25859), a method of anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound (see JP-A-11-335432), an anion using an organic rare earth metal complex as a polymerization initiator Examples thereof include a polymerization method (see JP-A-6-93060).

In the anionic polymerization for producing the methacrylic resin (A), it is preferable to use alkyllithium such as n-butyllithium, sec-butyllithium, isobutyllithium or t-butyllithium as a polymerization initiator. Moreover, it is preferable to make an organoaluminum compound coexist from a viewpoint of productivity. Examples of the organoaluminum compound include compounds represented by AlR ¹ R ² R ³ .
(In the formula, R ¹ , R ² and R ³ each independently have an alkyl group which may have a substituent, an optionally substituted cycloalkyl group or an optionally substituted group. It represents an aryl group, an aralkyl group which may have a substituent, an alkoxyl group which may have a substituent, an aryloxy group which may have a substituent, or an N, N-disubstituted amino group. , R ² and R ³ may be an aryleneoxy group which may have a substituent formed by bonding.

Specific examples of the organoaluminum compound include isobutyl bis (2,6-di-t-butyl-4-methylphenoxy) aluminum, isobutyl bis (2,6-di-t-butylphenoxy) aluminum, isobutyl [2,2 And '-methylenebis (4-methyl-6-t-butylphenoxy)] aluminum.
In anionic polymerization, ether or a nitrogen-containing compound can coexist in order to control the reaction.

The polycarbonate resin (B) used in the present invention is not particularly limited. Examples of the polycarbonate resin (B) include a polymer obtained by a reaction between a polyfunctional hydroxy compound and a carbonate ester-forming compound. In the present invention, an aromatic polycarbonate resin is preferred from the viewpoint of compatibility with the methacrylic resin (A) and good transparency of the resulting film.

The polycarbonate resin (B) used in the present invention has a melt flow at 300 ° C. and a load of 1.2 kg from the viewpoints of compatibility with the methacrylic resin (A), transparency of the resulting film, surface smoothness, toughness and the like. The rate is preferably 1 to 100 g / 10 minutes, more preferably 2 to 60 g / 10 minutes, still more preferably 2 to 40 g / 10 minutes.

The polycarbonate resin (B) used in the present invention was measured by gel permeation chromatography (GPC) from the viewpoints of compatibility with the methacrylic resin (A), transparency of the resulting film, surface smoothness, and the like. The weight average molecular weight calculated by converting the chromatogram into the molecular weight of standard polystyrene is preferably 1300 to 75000, more preferably 4700 to 68000, and still more preferably 27000 to 64000. The melt flow rate or the weight average molecular weight of the polycarbonate resin (B) can be adjusted by adjusting the amount of the terminal stopper or branching agent.

The glass transition temperature of the polycarbonate resin (B) used in the present invention is preferably 120 ° C. or higher, more preferably 130 ° C. or higher, still more preferably 135 ° C. or higher, and still more preferably 140 ° C. or higher. The upper limit of the glass transition temperature of the polycarbonate resin is usually 180 ° C. Here, the glass transition temperature is a midpoint glass transition temperature measured according to JIS K 7121 (temperature increase rate 20 ° C./min).

The method for producing the polycarbonate resin (B) is not particularly limited. Examples thereof include a phosgene method (interfacial polymerization method) and a melt polymerization method (transesterification method). In addition, the aromatic polycarbonate resin preferably used in the present invention may be obtained by subjecting a polycarbonate resin raw material produced by a melt polymerization method to a treatment for adjusting the amount of terminal hydroxy groups.

Examples of the polyfunctional hydroxy compound that is a raw material for producing the polycarbonate resin (B) include 4,4′-dihydroxybiphenyls which may have a substituent; bis (hydroxy) which may have a substituent Phenyl) alkanes; bis (4-hydroxyphenyl) ethers optionally having substituents; bis (4-hydroxyphenyl) sulfides optionally having substituents; Bis (4-hydroxyphenyl) sulfoxides which may be substituted; bis (4-hydroxyphenyl) sulfones which may have a substituent; bis (4-hydroxyphenyl) ketones which may have a substituent; Bis (hydroxyphenyl) fluorenes optionally having substituents; Dihydroxy-p-terphenyls optionally having substituents; Dihydroxy-p-quarterphenyls which may have a group; bis (hydroxyphenyl) pyrazines which may have a substituent; bis (hydroxyphenyl) menthanes which may have a substituent; Bis [2- (4-hydroxyphenyl) -2-propyl] benzenes optionally having substituents; Dihydroxynaphthalenes optionally having substituents; Dihydroxys optionally having substituents Examples thereof include benzenes; optionally substituted polysiloxanes; optionally substituted dihydroperfluoroalkanes.

Among these polyfunctional hydroxy compounds, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) diphenylmethane, 1,1-bis ( 4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3-phenylphenyl) propane, 4,4′- Dihydroxybiphenyl, bis (4-hydroxyphenyl) sulfone, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 3,3-bis (4-hydroxyphenyl) pentane, 9,9-bis ( 4-hydroxy-3-methylphenyl) fluorene, bis (4-hydroxyphenyl) ether, 4, 4′-dihydroxybenzophenone, 2,2-bis (4-hydroxy-3-methoxyphenyl) 1,1,1,3,3,3-hexafluoropropane, α, ω-bis [3- (2-hydroxyphenyl) ) Propyl] polydimethylsiloxane, resorcin, and 2,7-dihydroxynaphthalene are preferred, and 2,2-bis (4-hydroxyphenyl) propane is particularly preferred.

Examples of carbonate ester-forming compounds include various dihalogenated carbonyls such as phosgene, haloformates such as chloroformate, and carbonate ester compounds such as bisaryl carbonate. The amount of the carbonate ester-forming compound may be appropriately adjusted in consideration of the stoichiometric ratio (equivalent) of the reaction.

The reaction for producing the polycarbonate resin (B) is usually performed in a solvent in the presence of an acid binder. Examples of acid binders include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and cesium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, trimethylamine, triethylamine, tributylamine, Tertiary amines such as N, N-dimethylcyclohexylamine, pyridine, dimethylaniline, trimethylbenzylammonium chloride, triethylbenzylammonium chloride, tributylbenzylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide Quaternary ammonium salts, quaternary phosphonium salts such as tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, etc. It can be mentioned. Furthermore, if desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfide may be added to this reaction system. The amount of the acid binder may be appropriately adjusted in consideration of the stoichiometric ratio (equivalent) of the reaction. For example, an acid binder may be used in an amount of 1 equivalent or more, preferably 1 to 5 equivalents, per mole of hydroxyl group of the starting polyfunctional hydroxy compound.

Also, a known end terminator or branching agent can be used in the reaction for producing the polycarbonate resin (B). End terminators include pt-butyl-phenol, p-phenylphenol, p-cumylphenol, p-perfluorononylphenol, p- (perfluorononylphenyl) phenol, p- (perfluorohexylphenyl) Phenol, pt-perfluorobutylphenol, 1- (p-hydroxybenzyl) perfluorodecane, p- [2- (1H, 1H-perfluorotridodecyloxy) -1,1,1,3,3,3 -Hexafluoropropyl] phenol, 3,5-bis (perfluorohexyloxycarbonyl) phenol, perfluorododecyl p-hydroxybenzoate, p- (1H, 1H-perfluorooctyloxy) phenol, 2H, 2H, 9H- Perfluorononanoic acid, 1,1,1,3,3,3-tetraph B-2-propanol, and the like.

Examples of branching agents include phloroglysin, pyrogallol, 4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) -2-heptene, 2,6-dimethyl-2,4,6-tris (4- Hydroxyphenyl) -3-heptene, 2,4-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptane, 1,3,5-tris (2-hydroxyphenyl) benzene, 1,3,5- Tris (4-hydroxyphenyl) benzene, 1,1,1-tris (4-hydroxyphenyl) ethane, tris (4-hydroxyphenyl) phenylmethane, 2,2-bis [4,4-bis (4-hydroxyphenyl) ) Cyclohexyl] propane, 2,4-bis [2-bis (4-hydroxyphenyl) -2-propyl] phenol, 2,6-bis (2-hydroxy) 5-methylbenzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane, tetrakis (4-hydroxyphenyl) methane, tetrakis [4- (4-hydroxyphenyl) Isopropyl) phenoxy] methane, 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric acid, 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole, 3,3 -Bis (4-hydroxyaryl) oxindole, 5-chloroisatin, 5,7-dichloroisatin, 5-bromoisatin and the like.

The polycarbonate resin (B) may contain a unit having a polyester, polyurethane, polyether or polysiloxane structure in addition to the polycarbonate unit.

The resin composition used in the present invention may contain a filler as necessary within a range not impairing the effects of the present invention. Examples of the filler include calcium carbonate, talc, carbon black, titanium oxide, silica, clay, barium sulfate, and magnesium carbonate. The content of the filler is preferably 3% by mass or less, more preferably 1.5% by mass or less, with respect to the mass of the resin composition.

The resin composition used in the present invention may contain other polymers as long as the effects of the present invention are not impaired. Other polymers include polyolefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1 and polynorbornene; ethylene ionomers; polystyrene, styrene-maleic anhydride copolymer, high impact polystyrene, Styrene resins such as AS resin, ABS resin, AES resin, AAS resin, ACS resin, MBS resin; phenoxy resin; methyl methacrylate polymer other than methacrylic resin (A), methyl methacrylate-styrene copolymer; polyethylene terephthalate, Polyester resins such as polybutylene terephthalate; polyamides such as nylon 6, nylon 66, polyamide elastomer; polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol Copolymer, polyacetal, polyvinylidene fluoride, polyurethane, modified polyphenylene ether, polyphenylene sulfide, silicone modified resin; acrylic rubber, acrylic elastomer, silicone rubber; styrene thermoplastic elastomer such as SEPS, SEBS, SIS; IR, EPR, Examples thereof include olefinic rubbers such as EPDM. The content of the other polymer is preferably 10% by mass or less, more preferably 5% by mass or less, and most preferably 0% by mass with respect to the mass of the resin composition.

In the resin composition used in the present invention, an antioxidant, a thermal deterioration inhibitor, an ultraviolet absorber, a light stabilizer, a lubricant, a mold release agent, a polymer processing aid, as long as the effects of the present invention are not impaired. It may contain additives such as an antistatic agent, a flame retardant, a dye / pigment, a light diffusing agent, an organic dye, a matting agent, an impact modifier, and a phosphor.

The antioxidant alone has an effect of preventing oxidative deterioration of the resin in the presence of oxygen. For example, phosphorus antioxidants, hindered phenol antioxidants, thioether antioxidants and the like can be mentioned. Among these, from the viewpoint of preventing the deterioration of optical properties due to coloring, phosphorus-based antioxidants and hindered phenol-based antioxidants are preferable, and the combined use of phosphorus-based antioxidants and hindered phenol-based antioxidants is more preferable. preferable.
When a phosphorus antioxidant and a hindered phenol antioxidant are used in combination, it is preferable to use a phosphorus antioxidant / hindered phenol antioxidant at a mass ratio of 0.2 / 1 to 2/1. It is preferable to use 0.5 / 1 to 1/1.

Examples of phosphorus antioxidants include 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite (manufactured by ADEKA; trade name: ADK STAB HP-10), tris (2,4-di-) t-Butylphenyl) phosphite (manufactured by BASF; trade name: IRUGAFOS168), 3,9-bis (2,6-di-t-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3 , 9-diphosphaspiro [5.5] undecane (manufactured by ADEKA; trade name: ADK STAB PEP-36).

Examples of hindered phenol antioxidants include 3,5-di-tert-butyl-4-hydroxytoluene, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate. ] (Made by BASF; trade name IRGANOX 1010), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (made by BASF; trade name IRGANOX 1076) and the like are preferable.

The thermal degradation inhibitor can prevent thermal degradation of the resin by trapping polymer radicals that are generated when exposed to high heat in a substantially oxygen-free state.
Examples of the thermal degradation inhibitor include 2-t-butyl-6- (3′-t-butyl-5′-methyl-hydroxybenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd .; trade name Sumilizer GM), 2,4-di-t-amyl-6- (3 ′, 5′-di-t-amyl-2′-hydroxy-α-methylbenzyl) phenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd .; trade name Sumilyzer GS) is preferable. .

The ultraviolet absorber is a compound having an ability to absorb ultraviolet rays, and is mainly said to have a function of converting light energy into heat energy.
Examples of the ultraviolet absorber include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, succinic anilides, malonic esters, formamidines, and the like. Among these, benzotriazoles, triazines, or ultraviolet absorbers having a maximum molar extinction coefficient ε _{max at a} wavelength of 380 to 450 nm of 100 dm ³ · mol ⁻¹ cm ⁻¹ or less are preferable.

Benzotriazoles are preferable as ultraviolet absorbers used when the film of the present invention is applied to optical applications because it has a high effect of suppressing deterioration of optical properties such as coloring due to ultraviolet irradiation. Examples of benzotriazoles include 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol (manufactured by BASF; trade name TINUVIN329), 2- (2H- Benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol (manufactured by BASF; trade name TINUVIN234), 2,2′-methylenebis [6- (2H-benzotriazole-2) -Yl) -4-t-octylphenol] (manufactured by ADEKA; LA-31), 2- (5-octylthio-2H-benzotriazol-2-yl) -6-tert-butyl-4-methylphenol and the like are preferable. .

In addition, an ultraviolet absorber having a maximum molar extinction coefficient ε _{max at} wavelengths of 380 to 450 nm of 1200 dm ³ · mol ⁻¹ cm ⁻¹ or less can suppress discoloration of the resulting film. Examples of such an ultraviolet absorber include 2-ethyl-2′-ethoxy-oxalanilide (manufactured by Clariant Japan, trade name: Sundebore VSU).
Of these ultraviolet absorbers, benzotriazoles are preferably used from the viewpoint of suppressing resin degradation due to ultraviolet irradiation.

Further, when it is desired to efficiently absorb a short wavelength of 380 nm or less, a triazine UV absorber is preferably used. Examples of such an ultraviolet absorber include 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine (manufactured by ADEKA; LA-F70), Hydroxyphenyl triazine-based UV absorbers (manufactured by BASF; TINUVIN477 and TINUVIN460), 2,4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine Can be mentioned.

Furthermore, when it is desired to particularly effectively absorb light having a wavelength of 380 nm to 400 nm, WO2011 / 089794A1, WO2012 / 124395A1, JP2012-012476, JP2013-023461, JP2013-112790, UV absorption of metal complexes having a heterocyclic ligand disclosed in JP2013-194037, JP2014-62228, JP2014-88542, JP2014-88543, etc. It is preferable to use as an agent.

Examples of the heterocyclic ring ligand include 2,2′-iminobisbenzothiazole, 2- (2-benzothiazolylamino) benzoxazole, 2- (2-benzothiazolylamino) benzimidazole, (2 -Benzothiazolyl) (2-benzimidazolyl) methane, bis (2-benzoxazolyl) methane, bis (2-benzothiazolyl) methane, bis [2- (N-substituted) benzimidazolyl] methane and the like and their derivatives it can. As the central metal of such a metal complex, copper, nickel, cobalt, and zinc are preferably used. In order to use these metal complexes as ultraviolet absorbers, it is preferable to disperse the metal complexes in a medium such as a low molecular compound or a polymer.
The amount of the metal complex added is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the resin composition. Since the metal complex has a large molar extinction coefficient at a wavelength of 380 nm to 400 nm, the amount to be added is small in order to obtain a sufficient ultraviolet absorption effect. If the amount added is small, deterioration of the resin film appearance due to bleeding out or the like can be suppressed. Moreover, since the metal complex has high heat resistance, there is little deterioration and decomposition during molding. Furthermore, since the metal complex has high light resistance, the ultraviolet absorption performance can be maintained for a long time.

In addition, the maximum value ε _max of the molar extinction coefficient of the ultraviolet absorber is measured as follows. Add 10.00 mg of UV absorber to 1 L of cyclohexane and dissolve it so that there is no undissolved material by visual observation. This solution is poured into a 1 cm × 1 cm × 3 cm quartz glass cell, and the absorbance at a wavelength of 380 to 450 nm and an optical path length of 1 cm is measured using a U-3410 spectrophotometer manufactured by Hitachi, Ltd. The maximum value ε _max of the molar extinction coefficient is calculated from the molecular weight (M _UV ) of the ultraviolet absorber and the maximum value (A _max ) of the measured absorbance according to the following formula.
ε _max = [A _max / (10 × 10 ⁻³ )] × M _UV

The light stabilizer is a compound that is said to have a function of capturing radicals generated mainly by oxidation by light. Suitable light stabilizers include hindered amines such as compounds having a 2,2,6,6-tetraalkylpiperidine skeleton.

Examples of the lubricant include stearic acid, behenic acid, stearamide acid, methylene bisstearamide, hydroxystearic acid triglyceride, paraffin wax, ketone wax, octyl alcohol, and hardened oil.

The mold release agent is a compound having a function of facilitating separation of the molded product from the mold. Examples of the mold release agent include higher alcohols such as cetyl alcohol and stearyl alcohol; glycerin higher fatty acid esters such as stearic acid monoglyceride and stearic acid diglyceride. In the present invention, it is preferable to use a higher alcohol and a glycerin fatty acid monoester in combination as a release agent. When higher alcohols and glycerin fatty acid monoester are used in combination, the mass ratio of higher alcohols / glycerin fatty acid monoester is preferably 2.5 / 1 to 3.5 / 1, and preferably 2.8. More preferably, it is used in the range of / 1 to 3.2 / 1.

As the polymer processing aid, polymer particles having a particle diameter of 0.05 to 0.5 μm, which can be usually produced by an emulsion polymerization method, can be used. The polymer particles may be single layer particles composed of polymers having a single composition ratio and single intrinsic viscosity, or multilayer particles composed of two or more kinds of polymers having different composition ratios or intrinsic viscosities. May be. Among these, particles having a two-layer structure having a polymer layer having a low intrinsic viscosity in the inner layer and a polymer layer having a high intrinsic viscosity of 5 dl / g or more in the outer layer are preferable. The polymer processing aid preferably has an intrinsic viscosity of 3 to 6 dl / g. Specific examples include Metablene-P series manufactured by Mitsubishi Rayon Co., Ltd. and Paraloid series manufactured by Dow Chemical Co., Ltd. The amount of the polymer processing aid blended in the film of the present invention is preferably 0.1 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the methacrylic resin (A). When the amount is 0.1 parts by mass or more, good processing characteristics are obtained, and when the amount is 5 parts by mass or less, the surface smoothness is good.

Examples of the impact resistance modifier include a core-shell type modifier containing acrylic rubber or diene rubber as a core layer component; a modifier containing a plurality of rubber particles.
As the organic dye, a compound having a function of converting ultraviolet rays that are harmful to the resin into visible light is preferably used.
Examples of the light diffusing agent and matting agent include glass fine particles, polysiloxane-based crosslinked fine particles, crosslinked polymer fine particles, talc, calcium carbonate, and barium sulfate.
Examples of the phosphor include a fluorescent pigment, a fluorescent dye, a fluorescent white dye, a fluorescent brightener, and a fluorescent bleach.

These additives may be used alone or in combination of two or more. In addition, these additives may be added to the polymerization reaction liquid when producing the methacrylic resin (A) or the polycarbonate resin (B), or to the produced methacrylic resin (A) or the polycarbonate resin (B). It may be added, or may be added when preparing the resin composition used in the present invention. The total amount of additives contained in the film of the present invention is preferably 7% by mass or less, more preferably 5% by mass or less, more preferably 5% by mass or less, based on the methacrylic resin (A), from the viewpoint of suppressing poor appearance of the film. Preferably it is 4 mass% or less.

The method for preparing the resin composition used in the present invention is not particularly limited. For example, a method of polymerizing a monomer mixture containing methyl methacrylate in the presence of polycarbonate resin (B) to produce methacrylic resin (A), or melt-kneading methacrylic resin (A) and polycarbonate resin (B) Examples thereof include a method, a method in which a methacrylic resin (A) and a polycarbonate resin (B) are dissolved in a solvent and mixed together (solution mixing method). Among these, the melt-kneading method is preferable because the process is simple. When melt-kneading, other polymers and additives may be mixed as necessary, and after mixing methacrylic resin (A) with other polymers and additives, mixed with polycarbonate resin (B). Alternatively, the polycarbonate resin (B) may be mixed with other polymers and additives and then mixed with the methacrylic resin (A), or other methods may be used. The kneading can be performed using, for example, a known mixing apparatus or kneading apparatus such as a kneader ruder, an extruder, a mixing roll, or a Banbury mixer. Of these, a twin screw extruder is preferred. The temperature at the time of mixing and kneading can be appropriately adjusted according to the melting temperature of the methacrylic resin (A) and the polycarbonate resin (B) to be used, but is preferably 110 ° C to 300 ° C.
Examples of the solvent that can be used in the solution mixing method include dichloromethane, tetrahydrofuran, methyl ethyl ketone, and the like.

The glass transition temperature of the resin composition used in the present invention is preferably 120 ° C. or higher, more preferably 123 ° C. or higher, still more preferably 124 ° C. or higher, and particularly preferably 125 ° C. or higher. The upper limit of the glass transition temperature of the resin composition used in the present invention is not particularly limited, but is preferably 130 ° C. Here, the glass transition temperature is a midpoint glass transition temperature measured according to JIS K 7121 (temperature increase rate 20 ° C./min).

In the resin composition used in the present invention, Mw determined by GPC measurement is preferably 30,000 to 200,000, more preferably 72,000 to 180,000, still more preferably 75,000 to 150,000. The resin composition used in the present invention has a molecular weight distribution (Mw / Mn) determined by GPC measurement of preferably 1.2 to 5.0, more preferably 1.5 to 3.5. When the Mw and molecular weight distribution are in this range, the impact resistance and toughness are excellent.

The resin composition used in the present invention has a melt flow rate determined by measurement under conditions of 230 ° C. and a load of 3.8 kg, preferably 0.1 to 30 g / 10 minutes, more preferably 0.5 to 20 g. / 10 minutes, most preferably 1.0 to 10 g / 10 minutes.

The resin composition used in the present invention has a 1.0 mm-thickness haze of preferably 1.0% or less, more preferably 0.7% or less, and even more preferably 0.5% or less.

The resin composition used in the present invention can be formed into a film in any form such as pellets, granules, and powders.

The stretched film of the present invention is not particularly limited by the production method. For example, there may be mentioned a method comprising forming the resin composition to obtain a raw film, and then stretching the raw film in at least one direction. The resin composition can be formed into a raw film using, for example, a solution casting method, a melt casting method, an extrusion molding method, an inflation molding method, or a blow molding method. Of these, the extrusion method is preferred. According to the extrusion method, a stretched film having excellent transparency, improved toughness, excellent handleability, and excellent balance between toughness, surface hardness and rigidity can be obtained. The temperature of the resin composition discharged from the extruder is preferably set to 160 to 270 ° C., more preferably 190 to 240 ° C.

Among the extrusion molding methods, from the viewpoint of obtaining a stretched film having good surface smoothness, good specular gloss, and low haze, the resin composition is extruded from a T-die in a molten state, and then the two or more specular surfaces are extruded. A method including forming by sandwiching with a roll or a mirror belt is preferable. The mirror roll or the mirror belt is preferably made of metal. The linear pressure between the pair of mirror rolls or the mirror belt is preferably 10 N / mm or more, more preferably 30 N / mm or more.

Also, the surface temperature of the mirror roll or the mirror belt is preferably 130 ° C. or less. The pair of mirror rolls or mirror belts preferably have at least one surface temperature of 60 ° C. or higher. When the surface temperature is set to such a value, the resin composition discharged from the extruder can be cooled at a speed faster than natural cooling, and the stretched film of the present invention having excellent surface smoothness and low haze is produced. Easy to do.

The resin composition is preferably melt filtered through a filter before molding. By molding using a melt-filtered resin composition, it is easy to obtain a stretched film with few defects due to foreign matters, gels and the like. The filter used for melt filtration is not particularly limited. The filter is appropriately selected from known ones in terms of operating temperature, viscosity, required filtration accuracy, and the like. Specific examples of the filter include nonwoven fabric made of polypropylene fiber, cotton, polyester fiber, viscose rayon fiber, glass fiber, etc .; phenol resin impregnated cellulose film; metal fiber nonwoven fabric sintered film; metal powder sintered film; wire mesh; Can be mentioned. Among these, from the viewpoint of heat resistance, durability and pressure resistance, it is preferable to use a plurality of laminated metal fiber nonwoven fabric sintered films. Although there is no restriction | limiting in particular in the filtration precision of the said filter, It is preferable that it is 30 micrometers or less, It is more preferable that it is 10 micrometers or less, It is further more preferable that it is 5 micrometers or less.

For the stretching treatment, a known method used in the field of resin films can be employed. The stretching process is usually carried out in this order through heating, stretching, heat setting, and cooling. By this stretching treatment, it is possible to obtain a stretched film that has high mechanical strength and is difficult to crack. Examples of the stretching method include a uniaxial stretching method, a simultaneous biaxial stretching method, a sequential biaxial stretching method, a tuber stretching method, and an oblique stretching method. The temperature during stretching is preferably 100 to 200 ° C., more preferably 120 to 160 ° C., from the viewpoint that uniform stretching can be performed and a stretched film with high strength can be obtained. The stretching speed during stretching is preferably 100 to 5000% / min on the basis of length. The draw ratio in the biaxial stretching is preferably an area ratio of 1.5 to 8 times. After stretching, a stretched film with less heat shrinkage can be obtained by performing heat setting or relaxing the stretched film.

The thickness of the stretched film of the present invention is usually from 1 μm to 200 μm, preferably from 10 μm to 80 μm, more preferably from 15 μm to 60 μm.

The stretched film of the present invention has a haze at a thickness of 50 μm, preferably 0.2% or less, more preferably 0.1% or less. Thereby, it is excellent in surface glossiness and transparency. Further, in optical applications such as a liquid crystal protective film and a light guide film, the use efficiency of the light source is preferably increased. Furthermore, it is preferable because it is excellent in shaping accuracy when performing surface shaping.

The stretched film of the present invention has an in-plane retardation with respect to light having a wavelength of 589 nm, preferably 10 to 500 nm, more preferably 20 to 400 nm, still more preferably 25 to 300 nm, and particularly preferably 30 to 200 nm.
The film of this invention can set the thickness direction retardation with respect to the light of wavelength 589nm according to the intended purpose of a film. The stretched film of the present invention has a thickness direction retardation with respect to light having a wavelength of 589 nm, preferably 10 to 200 nm, more preferably 20 to 170 nm, and particularly preferably 35 to 160 nm.

The resin composition used in the present invention has positive intrinsic birefringence. When the original film made of the resin composition is uniaxially stretched, a stretched film having a refractive index in the stretching direction larger than a refractive index in a direction perpendicular thereto and an Nz coefficient of about 1 can be obtained. Also, when biaxially stretched raw film, the refractive indices n _x and n _y in a plane is greater than the refractive index n _z in the thickness direction, Nz coefficient is greater than 1 or the thickness direction retardation Rth is positive, A stretched film having a value of can be obtained.

The in-plane direction retardation Re is defined by _{Re = (n x -n y)} × d. The thickness direction retardation Rth is defined by Rth = ((n _x + _ny ) / 2−n _z ) × d. The Nz coefficient is defined by Nz = (n _x −n _z ) / (n _x −n _y ).
Here, n _x is a refractive index in a slow axis direction of the film, n _y is a refractive index in a fast axis direction of the film, n _z is a refractive index in the thickness direction of the film, d [nm ] Is the thickness of the film. The slow axis is an axis in the direction in which the refractive index in the film plane becomes maximum. The fast axis is an axis in a direction perpendicular to the slow axis in the plane.

A functional layer may be provided on the surface of the stretched film of the present invention. Examples of the functional layer include a hard coat layer, an antiglare layer, an antireflection layer, an anti-sticking layer, a diffusion layer, an antiglare layer, an antistatic layer, an antifouling layer, and a slippery layer such as fine particles.

The stretched film of the present invention has high transparency, small shrinkage due to heat and water absorption, uniform thickness, and excellent surface smoothness. Moreover, since retardation can be easily adjusted to a desired value and can be thinned, a retardation film, a polarizer protective film, a liquid crystal protective plate, a surface material of a portable information terminal, a display of a portable information terminal It is suitable for window protective films, light guide films, transparent conductive films coated with silver nanowires and carbon nanotubes on the surface, and front plate applications for various displays.

Since the stretched film of the present invention has high transparency and heat resistance, an IR cut film, a crime prevention film, a scattering prevention film, a decorative film, a metal decorative film, a solar cell backsheet, a flexible solar cell front sheet, and a shrink It can be used for films and films for in-mold labels.

The polarizing plate of the present invention has a polarizer and the stretched film of the present invention laminated on the polarizer. The stretched film of the present invention may be laminated on both sides of the polarizer or may be laminated on one side. When the stretched film of the present invention is laminated on one side of the polarizer as a polarizer protective film, an optical film other than the stretched film of the present invention can be laminated on another side. Examples of the optical film include a polarizer protective film, a viewing angle adjusting film, a retardation film, and a brightness enhancement film. Lamination can also be performed via an adhesive layer.

For example, the polarizing plate according to a preferred embodiment of the present invention is formed by laminating the stretched film of the present invention, the easily adhesive layer, the adhesive layer, the polarizer, the adhesive layer, and the stretched film of the present invention in this order. Or the laminated thing of the optical film other than the stretched film of this invention, an easily bonding layer, an adhesive bond layer, a polarizer, an adhesive bond layer, and the stretched film of this invention can be mentioned.

The polarizer is a known optical element. As a polarizer, what consists of polyvinyl alcohol-type resin can be mentioned. The polyvinyl alcohol resin used for the polarizer has a polymerization degree of preferably 100 to 5000, more preferably 1400 to 4000. A polyvinyl alcohol-type resin film can be manufactured by the casting method, the casting method, the extrusion method etc., for example. The thickness of the polyvinyl alcohol-based resin film used for the polarizer can be appropriately set according to the purpose and use of the LCD in which the polarizing plate is used, but is typically 5 to 80 μm.
In addition, polarized light produced by coating, such as a method of transferring the polyvinyl alcohol coated on the base film to the stretched film of the present invention after stretching, and a method of transferring to the stretched film of the present invention via an adhesive layer A child can be used.

The adhesive layer that can be provided on the polarizing plate of the present invention is not particularly limited as long as it is optically transparent. As an adhesive constituting the adhesive layer, for example, a water-based adhesive, a solvent-based adhesive, a hot-melt adhesive, an active energy ray-curable adhesive, or the like can be used. Of these, water-based adhesives and active energy ray-curable adhesives are suitable.

The water-based adhesive is not particularly limited. The aqueous adhesive may be in the form of an aqueous solution or latex. Examples of the water-based adhesive include a vinyl polymer-based adhesive, a gelatin-based adhesive, a polyurethane-based adhesive, an isocyanate-based adhesive, a polyester-based adhesive, and an epoxy-based adhesive. Of these, an adhesive containing a vinyl polymer is preferable. As the vinyl polymer, a polyvinyl alcohol resin is preferable. The adhesive containing a polyvinyl alcohol-based resin can contain a water-soluble crosslinking agent such as boric acid, borax, glutaraldehyde, melamine, or oxalic acid. An adhesive containing a polyvinyl alcohol-based resin is suitable because it has excellent adhesiveness with a polarizer made of a polyvinyl alcohol-based resin film. An adhesive containing a polyvinyl alcohol-based resin having an acetoacetyl group is more preferably used because it improves the durability of the polarizing plate. The solid content contained in the aqueous adhesive is usually 0.5 to 60% by mass. If necessary, the water-based adhesive may contain an additive such as a crosslinking agent, a catalyst such as an acid, and a metal compound filler. With the metal compound filler, the fluidity of the adhesive layer can be controlled, the film thickness can be stabilized, and a polarizing plate having a good appearance, uniform in-plane and no adhesive variation can be obtained.

As the active energy ray-curable adhesive, a compound having a monofunctional or bifunctional (meth) acryloyl group or a compound having a vinyl group is used as a curable component, and an epoxy compound, an oxetane compound, a photoacid generator, It is also possible to use a photocationic curing component mainly composed of
As the active energy ray, an electron beam or an ultraviolet ray can be used.

The method for forming the adhesive layer is not particularly limited. For example, it can be formed by applying the adhesive to an object and then heating or drying. Application | coating of an adhesive agent may be performed with respect to a polarizer protective film, and may be performed with respect to a polarizer. After forming the adhesive layer, both can be laminated by pressing the polarizer protective film and the polarizer together. In the lamination, a roll press machine or a flat plate press machine can be used. The heating and drying temperature and drying time are appropriately determined according to the type of adhesive. The thickness of the adhesive layer is preferably 0.01 to 10 μm, more preferably 0.03 to 5 μm in the dry state.

The easy adhesion layer (adhesiveness enhancement layer) that can be provided on the polarizing plate of the present invention improves the adhesion of the surface where the polarizer protective film and the polarizer are in contact. The easy adhesion layer can be provided by an easy adhesion treatment or the like. Examples of the easy adhesion treatment include surface treatment such as corona treatment, plasma treatment, and low-pressure UV treatment. The easy adhesion layer can be provided by a method of forming an anchor layer or a combination of the surface treatment and the method of forming an anchor layer. Among these, a corona treatment, a method of forming an anchor layer, and a method of using these in combination are preferable.

Examples of the anchor layer include a silicone layer having a reactive functional group. The material of the silicone layer having a reactive functional group is not particularly limited. For example, an isocyanate group-containing alkoxysilanol, an amino group-containing alkoxysilanol, a mercapto group-containing alkoxysilanol, a carboxy-containing alkoxysilanol, an epoxy group-containing Examples include alkoxysilanols, vinyl-type unsaturated group-containing alkoxysilanols, halogen group-containing alkoxysilanols, and isocyanate group-containing alkoxysilanols. Of these, amino silanols are preferred. By adding a titanium-based catalyst or tin-based catalyst for efficiently reacting silanol to the silanol, the adhesive strength can be strengthened. Moreover, you may add another additive to the silicone which has the said reactive functional group. Examples of other additives include tackifiers such as terpene resins, phenol resins, terpene-phenol resins, rosin resins, and xylene resins; stabilizers such as ultraviolet absorbers, antioxidants, and heat stabilizers. . Moreover, the layer which consists of what saponified cellulose acetate butyrate resin as an anchor layer is also mentioned.

The anchor layer is formed by coating and drying by a known technique. The thickness of the anchor layer is preferably 1 to 100 nm, more preferably 10 to 50 nm in a dry state. During coating, the anchor layer forming chemical may be diluted with a solvent. The dilution solvent is not particularly limited, and examples thereof include alcohols. The dilution concentration is not particularly limited, but is preferably 1 to 5% by mass, more preferably 1 to 3% by mass.

The optical film other than the stretched film of the present invention is not particularly limited by the material constituting it. Examples of the material for the optical film include cellulose resin, polycarbonate resin, cyclic polyolefin resin, and methacrylic resin.

Cellulose resin is an ester of cellulose and fatty acid. Specific examples of cellulose ester resins include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Among these, cellulose triacetate is particularly preferable. Many products of cellulose triacetate are commercially available, which is advantageous in terms of availability and cost. Examples of commercially available cellulose triacetate products are trade names “UV-50”, “UV-80”, “SH-80”, “TD-80U”, “TD-TAC”, “UZ-” manufactured by FUJIFILM Corporation. TAC "," KC series "manufactured by Konica Minolta, and the like.

The cyclic polyolefin resin is a general term for resins that are polymerized using a cyclic olefin as a polymerization unit, and is described in, for example, JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, and the like. Can be mentioned. Specific examples include cyclic olefin ring-opening (co) polymers, cyclic olefin addition polymers, copolymers of cyclic olefins and α-olefins such as ethylene and propylene (typically random copolymers), And the graft polymer which modified these by unsaturated carboxylic acid or its derivative (s), those hydrides, etc. can be mentioned. Specific examples of the cyclic olefin include norbornene monomers.

Various products are commercially available as cyclic polyolefin resins. As specific examples, trade names “ZEONEX” and “ZEONOR” manufactured by ZEON Corporation, “ARTON” manufactured by JSR, “TOPAS” manufactured by Polyplastics, and “Product Name” manufactured by Mitsui Chemicals, Inc. APEL ".

As the methacrylic resin used for the optical film other than the stretched film of the present invention, any appropriate methacrylic resin can be adopted as long as the effects of the present invention are not impaired. For example, methacrylic acid ester polymer such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, methyl methacrylate-acrylic acid ester- ( (Meth) acrylic acid copolymer, (meth) methyl acrylate-styrene copolymer (MS resin, etc.), polymer having an alicyclic hydrocarbon group (eg, methyl methacrylate-cyclohexyl methacrylate copolymer, etc.) Can be mentioned. Further, as the methacrylic resin, for example, an acrylic resin obtained by copolymerizing methyl methacrylate and a maleimide monomer described in, for example, Acrypet VH or Acrypet VRL20A manufactured by Mitsubishi Rayon Co., Ltd. or JP2013-033237A or WO2013 / 005634 A. , An acrylic resin having a ring structure in the molecule described in WO2005 / 108438 A, a methacryl resin having a ring structure in the molecule described in JP-A-2009-197151, and obtained by intramolecular crosslinking or intramolecular cyclization reaction. Mention may be made of a high glass transition temperature (Tg) methacrylic resin.

Examples of the methacrylic resin used for the optical film other than the stretched film of the present invention include a methacrylic resin having a lactone ring structure. It is because it has high mechanical strength by high heat resistance, high transparency, and biaxial stretching. Examples of the methacrylic resin having a lactone ring structure include JP 2000-230016, JP 2001-151814, JP 2002-120326, JP 2002-254544, JP 2005-146084, and the like. And a methacrylic resin having a lactone ring structure as described in 1. above.

The stretched film or polarizing plate of the present invention can be used for an image display device. Specific examples of the image display device include a self-luminous display device such as an organic light emitting diode display, a plasma display, and a field emission display (FED), and a liquid crystal display device (LCD). The liquid crystal display device includes a liquid crystal cell and the polarizing plate disposed on at least one side of the liquid crystal cell.

Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited to the following examples. The physical property values and the like were measured by the following method.

(Polymerization conversion)
A column (GLC-G-230 Sciences Inc., INERT CAP 1 (df = 0.4 μm, ID 0.25 mm, length 60 m)) was placed on a gas chromatograph (Shimadzu Corporation, GC-14A). The polymerization conversion was calculated based on the results of analysis under conditions where the injection temperature was 180 ° C., the detector temperature was 180 ° C., and the column temperature was raised from 60 ° C. to 200 ° C. at 10 ° C./min.

<Composition ratio of resin structural units>
Using a nuclear magnetic resonance apparatus (ULTRA SHIELD 400 PLUS manufactured by Bruker), a ¹ H-NMR spectrum was measured under the conditions of 1 mL of deuterated chloroform, room temperature, and 64 integrations with respect to 10 mg of the resin composition. The composition ratio of the structural units in the resin was calculated from the spectrum.

(Weight average molecular weight (Mw), molecular weight distribution (Mw / Mn))
Mw and Mw / Mn were calculated from the values obtained by measuring chromatograms under gel gel permeation chromatography (GPC) under the following conditions and converting them to the molecular weight of standard polystyrene.
GPC device: manufactured by Tosoh Corporation, HLC-8320
Detector: Differential refractive index detector Column: TSKgel SuperMultipore HZM-M manufactured by Tosoh Corporation and Super HZ4000 connected in series were used.
Eluent: Tetrahydrofuran Eluent flow rate: 0.35 ml / min Column temperature: 40 ° C
Calibration curve: Created using 10 standard polystyrene data

(Glass transition temperature Tg)
In accordance with JIS K7121, using a differential scanning calorimeter (DSC-50 (product number) manufactured by Shimadzu Corporation), the temperature was raised once to 230 ° C., then cooled to room temperature, and then from room temperature to 230 ° C. The DSC curve was measured under the condition of increasing the temperature at ° C / min. The midpoint glass transition temperature obtained from this DSC curve was defined as the glass transition temperature in the present invention.

(Melt flow flow rate of polycarbonate resin (MFR _B ))
MFR _B was measured under the conditions of 300 ° C., 1.2 kg load, and 10 minutes in accordance with JIS K7210.

(Methacrylic resin has a melt flow rate (MFR _A))
MFR _A is in compliance with JIS K7210, 230 ° C., was measured at 3.8kg load of 10 minutes condition.

(Total light transmittance (T _t ))
The total light transmittance was measured according to JIS K7210 using a haze meter (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.) for a 0.1 mm thick raw film.

(Haze (H))
In accordance with JIS K7136, haze (H) was measured using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150) for a 0.1 mm thick raw film.

(In-plane direction retardation (Re))
A 40 mm × 40 mm test piece was set in an automatic birefringence meter (KOBRA-HBR manufactured by Oji Scientific Co., Ltd.), and the phase difference at a wavelength of 589 nm and an incident angle of 0 ° was measured.
The thickness d [nm] of the test piece was measured using a digimatic indicator (manufactured by Mitutoyo Corporation). The average refractive index n required for calculating the refractive indices n _x, n _y and n _z were measured by Abbe refractometer (Atago Co., Ltd. DR-M4).
From the measured values of the phase difference and the thickness d, it was converted into in-plane retardation (Re) at a film thickness of 40 μm.

(Thickness direction retardation (Rth))
A test piece of 40 mm × 40 mm is set on an automatic birefringence meter (KOBRA-WR manufactured by Oji Scientific Co., Ltd.), the phase difference at a wavelength of 589 nm and an incident angle of 40 ° is measured, and the refractive index is calculated from the value and the average refractive index n. n _x, calculates the n _y and n _z, further thickness direction retardation _{Rth (= ((n x +} n y) / 2-n z) × d) was calculated. n _x is a plane slow axis direction of the refractive index, n _y is the refractive index of the direction perpendicular in the plane with respect to the slow axis, n _z is a refractive index in the thickness direction.
The thickness d [nm] of the test piece was measured using a digimatic indicator (manufactured by Mitutoyo Corporation). The average refractive index n required for calculating the refractive indices n _x, n _y and n _z were measured by Abbe refractometer (Atago Co., Ltd. DR-M4).
From the measured values of the main refractive indexes _nx , _ny and _nz and the thickness d, it was converted into a thickness direction retardation (Rth) at a film thickness of 40 μm.

(Tear strength)
A film piece having a length of 40 mm and a width of 10 mm was cut out to prepare a test piece having a cut of 20 mm in the length direction. This was set in a small tensile testing machine, and a tear test was performed at a tear speed of 60 mm / min. In the chart of the measured tear load, the average value of the load in the portion where the load was stable was taken as the tear strength.

[Production Example 1]
In an autoclave equipped with a stirrer and a sampling tube, 84 parts by mass of purified methyl methacrylate (MMA), 15 parts by mass of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl (TCDMA) methacrylate, and acrylic A monomer mixture was prepared by adding 1 part by mass of methyl acid (MA). To the monomer mixture, 0.006 parts by mass of 2,2′-azobis (2-methylpropionitrile) (AIBN) and 0.38 parts by mass of n-octyl mercaptan (NOM) are added and dissolved to obtain a raw material liquid. It was. The oxygen gas in the tank reactor and the piping was purged with nitrogen gas.
The raw material liquid was supplied to the tank reactor at a constant flow rate so that the average residence time was 120 minutes, and bulk polymerization was performed at a polymerization conversion rate of 57% by mass.
The liquid discharged from the tank reactor was heated to 250 ° C., supplied to a twin-screw extruder controlled at 260 ° C. at a constant flow rate, and adiabatic flushed at the inlet of the extruder. Volatiles (monomer, dimer, trimer, etc.) removed by the adiabatic flash were discharged from the open vent. Also, volatile components mainly composed of unreacted monomers are discharged from a vent reduced to 6 Torr provided downstream from the twin-screw extruder inlet, and the remaining resin components are extruded into a strand shape with a screw. did. The strand was cut with a pelletizer to obtain a pellet-shaped methacrylic resin <PMMA1>.
The methacrylic resin <PMMA1> was a resin having a weight average molecular weight (Mw) of 67,000 and Mw / Mn of 1.81, containing 85% by mass of MMA structural unit, 14% by mass of TCDMA structural unit, and 1% by mass of MA structural unit.

[Production Example 2]
In an autoclave, 73 parts by mass of MMA, 27 parts by mass of TCDMA, 0.06 parts by mass of AIBN, 0.01 parts by mass of 1,1-bis (t-butylperoxy) cyclohexane, 0.18 parts by mass of NOM, 200 parts by mass of water, Dispersant 2 64 parts by mass and 33 parts by mass of pH adjusting agent were added. While stirring the inside of the autoclave, the liquid temperature was raised from room temperature to 70 ° C. and maintained at 70 ° C. for 180 minutes. Then, it maintained at 120 degreeC for 60 minutes, and was made to superpose | polymerize. The liquid temperature was lowered to room temperature, and the polymerization reaction liquid was extracted from the autoclave. The solid content was removed from the polymerization reaction solution by filtration, and the residue was washed with water and dried in hot air at 80 ° C. for 24 hours to obtain a bead-like methacrylic resin <PMMA2>.
The methacrylic resin <PMMA2> was a resin having a weight average molecular weight (Mw) of 124,000 and Mw / Mn of 2.06, containing 75% by mass of MMA structural units and 25% by mass of TCDMA structural units.

[Production Example 3]
MMA 80 mass parts, TCDMA 20 mass parts, AIBN 1 mass part, and toluene 130 mass parts were put into the flask. After bubbling with nitrogen, the liquid temperature was raised from room temperature to 60 ° C. while stirring the solution, and the polymerization reaction was carried out by maintaining at 60 ° C. for 330 minutes. Thereafter, a solution obtained by dissolving 2 parts by mass of 4-methoxyphenol in 30 parts by mass of toluene was added dropwise thereto. The liquid temperature was lowered to room temperature, and the reaction solution was added dropwise to methanol, which is a poor solvent. The precipitated solid content was taken out by filtration, and the filtrate was washed with methanol and vacuum dried at 60 ° C. for 24 hours to obtain a powdered methacrylic resin <PMMA3>.
The methacrylic resin <PMMA3> was a resin having a weight average molecular weight (Mw) of 129000 and Mw / Mn of 1.97, containing 80% by mass of MMA structural units and 20% by mass of TCDMA structural units.

[Production Example 4]
In an autoclave, 77 parts by mass of MMA, 22 parts by mass of TCDMA, 1 part by mass of MA, 0.06 parts by mass of AIBN, 0.01 parts by mass of 1,1-bis (t-butylperoxy) cyclohexane, 0.35 parts by mass of NOM, 184 parts by mass of water Then, 1.2 parts by mass of a dispersant and 15 parts by mass of a pH adjusting agent were added. While stirring the inside of the autoclave, the liquid temperature was raised from room temperature to 70 ° C. and maintained at 70 ° C. for 180 minutes. Then, it maintained at 120 degreeC for 60 minutes, and was made to superpose | polymerize. The liquid temperature was lowered to room temperature, and the polymerization reaction liquid was extracted from the autoclave. The solid content was removed from the polymerization reaction solution by filtration, and the residue was washed with water and vacuum dried at 80 ° C. for 24 hours to obtain a bead-like methacrylic resin <PMMA4>.
The methacrylic resin <PMMA4> was a resin having a weight average molecular weight (Mw) of 73,000 and Mw / Mn of 2.03, containing 78% by mass of MMA structural units, 21% by mass of TCDMA structural units, and 1% by mass of MA structural units.

[Production Example 5]
A methacrylic resin <PMMA5> was obtained in the same manner as in Production Example 2, except that 27 parts by mass of TCDMA was changed to 27 parts by mass of cyclohexyl methacrylate (CHMA) and the amount of NOM was changed to 0.20 parts by mass.
The methacrylic resin <PMMA5> was a resin having a weight average molecular weight (Mw) of 110000 and Mw / Mn of 2.04, containing 75 mass% of MMA structural units and 25 mass% of CHMA structural units.

[Production Example 6]
<PMMA6> was obtained by the same method as in Production Example 5 except that 27 parts by mass of CHMA was changed to 20 parts by mass of CHMA.
The methacrylic resin <PMMA6> was a resin having a weight average molecular weight (Mw) of 149000 and Mw / Mn of 2.01, containing 80 mass% of MMA structural units and 20 mass of CHMA structural units.

The following commercially available methacrylic resin and polycarbonate resin were prepared.
Methacrylic resin <PMMA7>: Kuraray Parapet HR-S, MMA structural unit 99 mass%, and MA structural unit 1 mass%, MFR _A (230 ° C. 3.8 kg) 2.4 g / 10 min polycarbonate resin <PC1>: Mitsubishi Engineering Plastics Iupilon S1000, MFR _B (300 ° C. 1.2 kg) 7.5 g / 10 min Polycarbonate resin <PC2>: Mitsubishi Engineering Plastics Iupilon S2000, MFR _B (300 ° C. 1.2 kg ) 10 g / 10 min polycarbonate resin <PC3>: Sumika Chemical scan Tyrone polycarbonate manufactured by caliber _{301-40, MFR B (300 ℃ 1.2kg} ) 40g / 10 min polycarbonate resin <PC 4>: Mitsubishi engineering plastics Co. IUPILON _{3000, MFR B (300 ℃ 1.2kg} ) 30g / 10 minutes

[Example 1]
60 parts by mass of methacrylic resin <PMMA2> and 40 parts by mass of polycarbonate resin <PC1> were melt-kneaded at 230 ° C. and 100 rpm with a melt kneader (Labo-Plastomill 4M150 manufactured by Toyo Seiki) to obtain a resin composition. .
The obtained resin composition was subjected to hot press molding at 230 ° C. with a hot press molding machine (compression molding machine AYS.10 manufactured by Shinfuji Metal Industry Co., Ltd.) to obtain a raw film having a thickness of about 0.1 mm. .
The glass transition temperature (Tg), total light transmittance (Tt), and haze (H) of the raw film were measured. The results are shown in Table 1.
The raw film was cut into a length of 50 mm and a width of 30 mm, and uniaxially stretched at a length standard of 1.5 times at 140 ° C. with a tensile tester (5566, manufactured by Instron), and the stretched film was stretched without relaxation. Obtained. Further, the tear strength and retardation Re and Rth of the obtained stretched film were determined. The results are shown in Table 1.

[Example 2]
The raw material was the same as in Example 1 except that 60 parts by weight of methacrylic resin <PMMA2> and 40 parts by weight of polycarbonate resin <PC1> were changed to 70 parts by weight of methacrylic resin <PMMA2> and 30 parts by weight of polycarbonate resin <PC1>. Films and stretched films were obtained and their physical properties were measured. The results are shown in Table 1.

[Example 3]
A raw film and a stretched film were obtained in the same manner as in Example 1 except that 60 parts by weight of the methacrylic resin <PMMA2> was changed to 60 parts by weight of the methacrylic resin <PMMA1> and the stretching temperature was changed to 135 ° C. It was measured. The results are shown in Table 1.

[Example 4]
Example, except that 60 parts by weight of methacrylic resin <PMMA2> and 40 parts by weight of polycarbonate resin <PC2> were changed to 70 parts by weight of methacrylic resin <PMMA3> and 30 parts by weight of polycarbonate resin <PC2>, and the stretching temperature was changed to 145 ° C. The raw film and the stretched film were obtained by the same method as 1, and their physical properties were measured. The results are shown in Table 1.

[Example 5]
Example, except that 60 parts by weight of methacrylic resin <PMMA2> and 40 parts by weight of polycarbonate resin <PC2> were changed to 70 parts by weight of methacrylic resin <PMMA3> and 30 parts by weight of polycarbonate resin <PC4>, and the stretching temperature was changed to 145 ° C. The raw film and the stretched film were obtained by the same method as 1, and their physical properties were measured. The results are shown in Table 1.

[Example 6]
Example, except that 60 parts by mass of methacrylic resin <PMMA2> and 40 parts by mass of polycarbonate resin <PC2> were changed to 70 parts by mass of methacrylic resin <PMMA4> and 30 parts by mass of polycarbonate resin <PC2> and changed to a stretching temperature of 145 ° C. The raw film and the stretched film were obtained by the same method as 1, and their physical properties were measured. The results are shown in Table 1.

[Comparative Example 1]
Example except for changing 60 parts by weight of methacrylic resin <PMMA2> and 40 parts by weight of polycarbonate resin <PC1> to 80 parts by weight of methacrylic resin <PMMA5> and 20 parts by weight of polycarbonate resin <PC3>, and changing the stretching temperature to 135 ° C. The raw film and the stretched film were obtained by the same method as 1, and their physical properties were measured. The results are shown in Table 2.

[Comparative Example 2]
Example of Example except that 60 parts by mass of methacrylic resin <PMMA2> and 40 parts by mass of polycarbonate resin <PC1> were changed to 90 parts by mass of methacrylic resin <PMMA1> and 10 parts by mass of polycarbonate resin <PC1>, and the stretching temperature was changed to 130 ° C. The raw film and the stretched film were obtained by the same method as 1, and their physical properties were measured. The results are shown in Table 2.

[Comparative Example 3]
Example except that 60 parts by weight of methacrylic resin <PMMA2> and 40 parts by weight of polycarbonate resin <PC1> were changed to 90 parts by weight of methacrylic resin <PMMA1> and 10 parts by weight of polycarbonate resin <PC2> and changed to a stretching temperature of 130 ° C. The raw film and the stretched film were obtained by the same method as 1, and their physical properties were measured. The results are shown in Table 2.

[Comparative Example 4]
A raw film and a raw film were prepared in the same manner as in Example 1 except that 60 parts by weight of methacrylic resin <PMMA2> and 40 parts by weight of polycarbonate resin <PC1> were changed to 100 parts by weight of methacrylic resin <PMMA1> and the stretching temperature was changed to 130 ° C. Stretched films were obtained and their physical properties were measured. The results are shown in Table 2.

[Comparative Example 5]
The raw material is the same as in Example 1 except that 60 parts by weight of methacrylic resin <PMMA2> and 40 parts by weight of polycarbonate resin <PC1> are changed to 60 parts by weight of methacrylic resin <PMMA7> and 40 parts by weight of polycarbonate resin <PC2>. Films were obtained and their physical properties were measured. The results are shown in Table 2. The raw film obtained in Comparative Example 5 was not subjected to stretching treatment because the haze was too high.

[Comparative Example 6]
The raw material was the same as in Example 3 except that 60 parts by weight of methacrylic resin <PMMA1> and 40 parts by weight of polycarbonate resin <PC2> were changed to 70 parts by weight of methacrylic resin <PMMA6> and 30 parts by weight of polycarbonate resin <PC4>. Films and stretched films were obtained and their physical properties were measured. The results are shown in Table 2.

In the examples, a stretched film having high retardation and high tear resistance such as tear strength after stretching is obtained even with a small molecular weight. On the other hand, Comparative Example 1 and Comparative Example 6 are inferior in mechanical strength such as low heat resistance and low tear strength even with a large molecular weight. In Comparative Examples 2 to 4, the retardation is small and the tear strength is low.

Claims (12)

Structural unit derived from methacrylic acid polycyclic aliphatic hydrocarbon ester (a1) 10 to 50% by mass and structural unit derived from (meth) acrylic acid ester other than methacrylic acid polycyclic aliphatic hydrocarbon ester (a2 ) A methacrylic resin (A) containing 50 to 90% by mass;
With polycarbonate resin (B)
A stretched film comprising a resin composition containing a methacrylic resin (A) to a polycarbonate resin (B) in a mass ratio (A) / (B) of 85/15 to 50/50. The stretched film of Claim 1 whose methacrylic acid polycyclic aliphatic hydrocarbon ester is a compound represented by Formula (1).

(In the formula (1), X is a polycyclic aliphatic hydrocarbon group having 10 or more carbon atoms.) The stretched film according to claim 2, wherein X is an isobornan-2-yl group or a tricyclo [5.2.1.0 ^2,6 ] decan-8-yl group. The stretching unit according to any one of claims 1 to 3, wherein the structural unit (a2) contains 50 to 90% by mass of a structural unit derived from methyl methacrylate with respect to all structural units of the methacrylic resin (A). the film. The stretching unit according to any one of claims 1 to 4, wherein the structural unit (a2) contains a structural unit derived from an acrylate ester in an amount of 0 to 20% by mass based on all structural units of the methacrylic resin (A). the film. The stretched film according to any one of claims 1 to 5, wherein the total amount of the methacrylic resin (A) and the polycarbonate resin (B) is 80 to 100% by mass relative to the mass of the resin composition. The stretched film according to any one of claims 1 to 6, which has a thickness of 10 to 80 µm. The stretched film according to any one of claims 1 to 7, wherein an in-plane retardation with respect to light having a wavelength of 589 nm is 20 to 400 nm. Structural unit derived from methacrylic acid polycyclic aliphatic hydrocarbon ester (a1) 10 to 50% by mass and structural unit derived from (meth) acrylic acid ester other than methacrylic acid polycyclic aliphatic hydrocarbon ester (a2 ) A methacrylic resin (A) containing 50 to 90% by mass and a polycarbonate resin (B), the mass ratio (A) / (B) of the methacrylic resin (A) to the polycarbonate resin (B) is 85 / The raw resin film is obtained by molding the resin composition contained at 15-50 / 50,
A method for producing a stretched film, comprising biaxially stretching the raw film. The production method according to claim 9, wherein the biaxial stretching is performed at an area ratio of 1.5 to 8 times. A retardation film comprising the stretched film according to any one of claims 1 to 8. A polarizing plate having the retardation film according to claim 11.