JP6559656B2 - Methacrylic resin composition and method for producing the same, molded product, film, and polarizing plate - Google Patents

Description

  The present invention relates to a methacrylic resin composition comprising a methacrylic resin and a polycarbonate resin. Moreover, it is related with the polarizing plate which comprises the film which consists of the said methacrylic resin composition, a molded object, and the said film.

  Various resin films are used for liquid crystal display devices. Of these, triacetyl cellulose is mainly used for the polarizer protective film. Since a film made of triacetyl cellulose has high moisture permeability, the quality of the polarizer tends to be lowered as the film becomes thinner. Improvement of the polarizer protective film is a problem in reducing the thickness of the liquid crystal display device.

  Therefore, a methacrylic resin has been studied as a material for a new polarizer protective film. It is known that toughness increases when a film made of methacrylic resin is stretched (see Patent Document 1). However, when a normal methacrylic resin film is stretched, the phase difference increases, and for example, in the IPS liquid crystal system, the quality of the screen is lowered.

  It is known that a film having a small retardation can be easily obtained by adding a resin such as a polycarbonate resin to a methacrylic resin (Patent Documents 2 to 5). However, these methacrylic resin compositions were not sufficiently stretchable because a polycarbonate resin having a low molecular weight was added to ensure transparency. Specifically, when it was stretched to a thinner film, it was prone to breakage, and when it was stretched at a lower temperature in order to increase the strength of the stretched film, it had a problem of being easily broken. . In addition, in order to increase the heat resistance of the methacrylic resin composition, methacrylic resins with high syndiotacticity (rr) in triplet display generally have a narrow molecular weight distribution, and methacrylic resin compositions using ordinary methacrylic resins. The stretchability was not sufficient.

Japanese Patent Publication No.57-32942 JP-A-5-32846 JP 2012-514759 A JP2013-148655A JP 2014-51649 A

  The present invention has been made in view of the above background, and its object is to provide a methacrylic resin composition that has high transparency, a small retardation in the thickness direction, and is easy to stretch. . Another object of the present invention is to provide a film made of a methacrylic resin composition having a uniform thickness, excellent surface smoothness, high productivity and high strength.

  As a result of repeated studies to achieve the above object, the present inventors have completed the present invention including the following aspects.

[1]: A methacrylic resin composition containing a methacrylic resin, a polycarbonate resin, and a polymer processing aid,
The methacrylic resin has a content of structural units derived from methyl methacrylate of 80% by mass or more and a weight average molecular weight of 200000 or less,
The polycarbonate resin has a viscosity average molecular weight of 1000 or more and 32000 or less, and the content of the polycarbonate resin with respect to 100 parts by mass of the methacrylic resin is 1 part by mass or more and 4 parts by mass or less.
The polymer processing aid has an average degree of polymerization of 3,000 or more and 40,000 or less, and the content of the polymer processing aid with respect to 100 parts by mass of the methacrylic resin is 0.3 parts by mass or more. 6 parts by mass or less,
The methacrylic resin composition whose total amount of the said methacrylic resin and said polycarbonate resin contained in a methacrylic resin composition is 80 mass% or more.

[2]: The content of structural units derived from methyl methacrylate, wherein the methacrylic resin has a triadic syndiotacticity (rr) of 50% or more, a weight average molecular weight of 80,000 to 200,000. The methacrylic resin composition according to [1], wherein is 92 mass% or more and 100 mass% or less.
[3]: The methacrylic resin composition according to [1] or [2], wherein the syndiotacticity (rr) of the methacrylic resin is 58% or more and 85% or less.
[4] The methacrylic resin composition according to any one of [1] to [3], wherein the content of structural units derived from methyl methacrylate in the methacrylic resin is 99% by mass or more.
[5]: The methacrylic resin composition according to any one of [1] to [4], wherein the polycarbonate resin has a viscosity average molecular weight of 5000 or more and 18000 or less.
[6] The methacrylic resin composition according to any one of [1] to [5], wherein the methacrylic resin composition has a weight average molecular weight of 70,000 to 200,000.
[7]: The methacrylic resin composition according to any one of [1] to [6], wherein the molecular weight distribution of the methacrylic resin composition is 1.2 to 2.5.

[8]: A molded article comprising the methacrylic resin composition according to any one of [1] to [7].
[9]: A film comprising the methacrylic resin composition according to any one of [1] to [7].
[10] The film according to [9], having a thickness of 10 to 50 μm.
[11]: The film according to [9] or [10], which is biaxially stretched 1.5 to 8 times in area ratio.
[12]: The film according to any one of [9] to [11], which is used as a polarizer protective film.
[13]: A polarizing plate in which at least one film according to [12] is laminated.
[14]: Polycarbonate having a content of structural units derived from methyl methacrylate of 80% by mass or more and having a weight average molecular weight of 200,000 or less and a viscosity average molecular weight of 1000 or more and 32,000 or less. At least three components of 1 part by mass or more and 4 parts by mass or less of a resin and 0.3 part by mass or more and 6 parts by mass or less of a polymer processing aid having an average degree of polymerization of 3,000 or more and 40,000 or less A method for producing a methacrylic resin composition obtained by mixing.

  According to the present invention, it is possible to provide a methacrylic resin composition that is highly transparent, has a small retardation in the thickness direction, and is easy to stretch. In addition, there is an excellent effect that a film made of a methacrylic resin composition having a uniform thickness and excellent surface smoothness, high productivity and high strength can be provided.

It is sectional drawing which shows an example of the polarizing plate which concerns on embodiment of this invention.

  The methacrylic resin composition of the present invention contains a methacrylic resin, a polycarbonate resin and a polymer processing aid. Moreover, the film of this invention is a film which consists of the said methacryl resin composition.

  In the methacrylic resin used in the present invention, the content of the structural unit derived from methyl methacrylate is 80% by mass or more based on the mass of the methacrylic resin, preferably 92, from the viewpoint of heat resistance of the resulting film. More preferably, it is 95 mass% or more, More preferably, it is 97 mass% or more, Especially preferably, it is 99 mass% or more, Most preferably, it is 100 mass%.

The methacrylic resin used in the present invention may contain a structural unit other than the structural unit derived from methyl methacrylate, for example, ethyl methacrylate, cyclohexyl methacrylate, t-butyl methacrylate, 2-isobornyl methacrylate, Methacrylic acid alkyl esters other than methyl methacrylate such as 8-tricyclo [5.2.1.0 ^2,6 ] decanyl methacrylate and 4-t-butylcyclohexyl methacrylate; methyl acrylate, ethyl acrylate, propyl acrylate Alkyl acrylates such as butyl acrylate and 2-ethylhexyl acrylate; aryl acrylates such as phenyl acrylate; cycloalkyl acrylates such as cyclohexyl acrylate and norbornenyl acrylate; acrylamide It includes structural units derived from a vinyl monomer having only one carbon-carbon double bond - polymerizable carbon in one molecule such as; methacrylamide; acrylonitrile; methacrylonitrile. The structural unit other than the structural unit derived from methyl methacrylate is preferably 8% by mass or less, more preferably 5% by mass or less, further preferably 3% by mass or less, particularly preferably 1% by mass or less, and most preferably 0% by mass. %.

  In the methacrylic resin used in the present invention, the lower limit of the triplet-represented syndiotacticity (rr) is preferably 50%, more preferably 55%, still more preferably 58%, even more preferably from the viewpoint of heat resistance. Preferably it is 59%, most preferably 60%. In the methacrylic resin, from the viewpoint of film forming property, the upper limit of the triplet display syndiotacticity (rr) is preferably 99%, more preferably 85%, still more preferably 77%, and still more preferably 70. %, More preferably 65%, and most preferably 64%. Since the methacrylic resin having such syndiotacticity is not sufficiently stretchable due to the narrow molecular weight distribution, the addition of a polymer processing aid is more effective.

A triplet display syndiotacticity (rr) (hereinafter sometimes simply referred to as “syndiotacticity (rr)”) is a chain of three consecutive structural units (triplet, triad). The two chains (doublet, dad) that are included are the ratio of racemo (denoted as rr). In the chain of molecular units (doublet, diad) in the polymer molecule, those having the same configuration are referred to as “meso”, and those opposite to each other are referred to as “racemo”, which are expressed as m and r, respectively.
The syndiotacticity (rr) (%) of the methacrylic resin is 0.6 to 0 when a ¹ H-NMR spectrum is measured at 30 ° C. in deuterated chloroform and TMS is set to 0 ppm from the spectrum. The area (X) of the .95 ppm region and the area (Y) of the 0.6 to 1.35 ppm region can be measured and calculated by the formula: (X / Y) × 100.

  The methacrylic resin used in the present invention has a weight average molecular weight (hereinafter sometimes referred to as “Mw”) of 200000 or less, preferably 80000-200000, more preferably 85000-160000, and still more preferably 90000-. 120,000. When the Mw is 80000 or more and the syndiotacticity (rr) is 50% or more, the resulting film has high strength, is difficult to break, and is easy to stretch. Therefore, the film can be made thinner. Moreover, since Mw is 200000 or less, since the moldability of a methacrylic resin increases, the thickness of the obtained film tends to be uniform and excellent in surface smoothness.

  The methacrylic resin used in the present invention is a ratio of Mw to number average molecular weight (hereinafter sometimes referred to as “Mn”) (Mw / Mn: hereinafter, this value may be referred to as “molecular weight distribution”). However, it is preferably 1.2 to 2.0, more preferably 1.3 to 1.7. When the molecular weight distribution is 1.2 or more, the fluidity of the methacrylic resin is improved, and the resulting film tends to be excellent in surface smoothness. A film obtained by having a molecular weight distribution of 2.0 or less 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 used in the present invention has a melt flow rate of preferably 0.1 to 5 g / 10 minutes, more preferably 0, as measured under conditions of 230 ° C. and 3.8 kg load in accordance with JIS K7210. 0.5-4 g / 10 min, most preferably 1.0-3 g / 10 min.

  The glass transition temperature of the methacrylic resin used in the present invention is preferably 110 ° C. or higher, more preferably 118 ° C. or higher, still more preferably 120 ° C. or higher, still more preferably 123 ° C. or higher, and most preferably 124 ° C. or higher. The upper limit of the glass transition temperature of the methacrylic resin is usually 140 ° C, preferably 130 ° C. The glass transition temperature can be controlled by adjusting the molecular weight and syndiotacticity (rr). When the glass transition temperature is in this range, deformation such as heat shrinkage of the obtained film is difficult to occur. In addition, a glass transition temperature is the midpoint glass transition temperature measured by the method as described in an Example.

  The method for producing the methacrylic resin is not particularly limited. For example, in known polymerization methods such as radical polymerization method and anionic polymerization method, Mw, syndiotacticity can be adjusted by adjusting polymerization temperature, polymerization time, type and amount of chain transfer agent, type and amount of polymerization initiator, etc. A methacrylic resin having properties such as city (rr) satisfying a desired range can be produced.

  For example, in the case of radical polymerization, the polymerization temperature is preferably 80 ° C. or lower, more preferably 70 ° C. or lower, and further preferably 60 ° C. or lower. By adjusting the temperature in this way, it is easy to increase the syndiotacticity (rr).

In the case of the anionic polymerization method, it is preferable to use alkyllithium such as n-butyllithium, sec-butyllithium, isobutyllithium, or tert-butyllithium as the polymerization initiator. Moreover, it is preferable to make an organoaluminum compound coexist from a viewpoint of productivity. As organoaluminum, the following formula:
AlR ¹ R ² R ³
Wherein R ¹ , R ² and R ³ are each independently an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or an aryl which may have a substituent. R ² represents a 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. And R ³ may be an aryleneoxy group optionally having a substituent formed by bonding each other.
The compound shown by these is mentioned. Specifically, isobutylbis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, isobutylbis (2,6-di-tert-butylphenoxy) aluminum, isobutyl [2,2′-methylenebis ( 4-methyl-6-tert-butylphenoxy)] aluminum and the like.
In the anionic polymerization method, an ether or a nitrogen-containing compound can coexist in order to control the polymerization reaction.

  In the case of producing a methacrylic resin by an anionic polymerization method, an amount smaller than the amount of the polymerization initiator in the course of the polymerization reaction, specifically, preferably 1 mol% to 50 mol with respect to the amount of the polymerization initiator. %, More preferably 2 mol% to 20 mol%, more preferably 5 mol% to 10 mol% of a polymerization terminator, or relative to the amount of the polymerization initiator initially added during the polymerization reaction The weight average molecular weight is adjusted by adding an additional polymerization initiator, preferably 1 mol% to 50 mol%, more preferably 2 mol% to 20 mol%, and even more preferably 5 mol% to 10 mol%. it can.

  As a second method for obtaining a methacrylic resin having desired characteristics such as weight average molecular weight and syndiotacticity (rr), a methacrylic resin that does not satisfy the desired characteristics is mixed in part or does not satisfy the desired characteristics. The method of obtaining the methacryl resin which has desired characteristics (characteristics, such as a weight average molecular weight, a syndiotacticity (rr)), by mixing methacrylic resin suitably is mentioned. Such a method is easy to manage the process. The mixing of a plurality of types of methacrylic resins can be carried out using a known method, for example, a melt kneading apparatus such as a kneader ruder, an extruder, a mixing roll, or a Banbury mixer. The temperature at the time of kneading | mixing can be suitably adjusted according to the melting temperature of the methacryl resin to be used, and is normally 150-300 degreeC.

  As a third production method for obtaining a methacrylic resin having desired characteristics, a monomer is polymerized in the presence of a methacrylic resin that is out of the desired characteristic range to obtain a desired weight average molecular weight, syndiotacticity (rr). There is a method for producing a methacrylic resin having characteristics such as) satisfying a desired range. Such polymerization can be performed in the same manner as the radical polymerization method and the anion polymerization method described above. According to the third manufacturing method, since the thermal history applied to the methacrylic resin is shortened as compared with the second manufacturing method, thermal decomposition of the methacrylic resin is suppressed, and a film with less coloring and foreign matter is easily obtained.

  Among the above methacrylic resin production methods, from the viewpoint that a highly transparent methacrylic resin can be easily produced, a method for producing a methacrylic resin whose characteristics satisfy a desired range by an anionic polymerization method; produced by an anionic polymerization method A method for producing a methacrylic resin whose characteristics satisfy a specified range by mixing a methacrylic resin produced by radical polymerization and a methacrylic resin produced by an anionic polymerization method and another anionic polymerization method A method of producing a methacrylic resin whose characteristics satisfy a desired range by mixing the produced methacrylic resin is preferable, and a methacrylic resin produced by anionic polymerization and a methacrylic resin produced by radical polymerization are mixed. Produces methacrylic resin whose characteristics meet the desired range That method is more preferable.

  The polycarbonate resin used in the present invention is a polymer obtained by a reaction between a polyfunctional hydroxy compound and a carbonate ester-forming compound. The polycarbonate resin is preferably an aromatic polycarbonate resin from the viewpoint of compatibility with a methacrylic resin and good transparency of the resulting film.

  The polycarbonate resin used in the present invention has a viscosity average molecular weight (hereinafter sometimes referred to as “Mv”) of 1000 or more, preferably 3000 from the viewpoint that the polycarbonate hardly bleeds out from the obtained methacrylic resin composition. As mentioned above, More preferably, it is 5000 or more, More preferably, it is 10,000 or more. Moreover, from a compatible viewpoint with a methacryl resin, a viscosity average molecular weight is 32000 or less, Preferably it is 22000 or less, More preferably, it is 18000 or less, More preferably, it is 17000 or less. The higher the syndiotacticity (rr) of the methacrylic resin used, the higher the compatibility with the polycarbonate resin, and the higher the viscosity average molecular weight polycarbonate resin can be used. When such a polycarbonate having a relatively low viscosity average molecular weight is added, the stretchability is lowered, so the addition of a polymer processing aid is more effective.

The viscosity average molecular weight (Mv) of the polycarbonate resin was determined by measuring the specific viscosity η _sp of a solution obtained by dissolving 0.5 g of the polycarbonate resin in 100 mL of methylene chloride at 20 ° C. using a Canon-Fenske viscometer or an Ubbelohde viscometer. The value satisfying the Schnell equation can be calculated from the intrinsic viscosity [η] of a 20 ° C. methylene chloride solution.
η _sp /c=[η]+0.45×[η] ² c
([Η] is intrinsic viscosity, c = 0.5 under the above conditions)
^{[Η] = 1.23 × 10 -} . 4 Mv 0 8 3

Also, 300 ° C. of polycarbonate resin used in the present invention, MVR (melt volume flow rate) value of at 1.2kg, from the viewpoint of the compatibility with the methacrylic resin is preferably 1.0 cm ^3/10 minutes or more, 10 cm ^3/10 minutes or more, more preferably, 25 cm ^3/10 minutes or more is more preferable, 33cm ^3/10 minutes or more is particularly preferable. From the viewpoint of hard polycarbonate methacrylic resin composition obtained may bleed out, preferably 2 × 10 ⁷ cm ^3/10 minutes or less, more preferably 1 × 10 ⁵ cm ^3/10 minutes or less, 10000 cm ^3/10 min more preferably less, and particularly preferably 390cm ^3/10 min.

The polycarbonate resin used in the present invention has a weight average molecular weight (Mw) obtained by converting a chromatogram measured by gel permeation chromatography (GPC) into a molecular weight of standard polystyrene. From the viewpoint of difficulty, Mw is preferably 1300 g / mole or more, more preferably 4700 g / mole or more, further preferably 8500 g / mole or more, and particularly preferably 19,200 g / mole or more. Moreover, from a compatible viewpoint with a methacryl resin, 75000 g / mol or less is preferable, 48300 g / mol or less is more preferable, 38200 g / mol or less is further more preferable, and 35700 g / mol or less is especially preferable.
The viscosity average molecular weight, MVR value, and weight average molecular weight of the polycarbonate resin can be adjusted by adjusting the amount of the terminal terminator or branching agent.

  The glass transition temperature of the polycarbonate resin used in the present invention is preferably 110 ° C. or higher, more preferably 125 ° C. or higher, and further preferably 140 ° C. or higher. The upper limit of the glass transition temperature of the polycarbonate resin is usually 180 ° C.

  The method for producing the polycarbonate resin 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 a polycarbonate resin include 4,4′-dihydroxybiphenyls optionally having substituents; bis (hydroxyphenyl) alkanes optionally having substituents Bis (4-hydroxyphenyl) ethers optionally having substituents; bis (4-hydroxyphenyl) sulfides optionally having substituents; bis optionally having substituents (4-hydroxyphenyl) sulfoxides; bis (4-hydroxyphenyl) sulfones optionally having substituents; bis (4-hydroxyphenyl) ketones optionally having substituents; Bis (hydroxyphenyl) fluorenes that may have; dihydroxy-p-terphenyls that may have a substituent; Dihydroxy-p-quarterphenyls which may be substituted; bis (hydroxyphenyl) pyrazines which may have substituents; bis (hydroxyphenyl) menthanes which may have substituents; Optionally substituted bis [2- (4-hydroxyphenyl) -2-propyl] benzenes; dihydroxynaphthalenes optionally having substituents; dihydroxybenzenes optionally having substituents; Examples thereof include polysiloxanes optionally having a group; dihydroperfluoroalkanes optionally having a substituent.

  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 preferable, and 2,2-bis (4-hydroxyphenyl) propane is particularly preferable.

  Examples of the carbonate ester-forming compound 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 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. And the like. 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. Specifically, 1 equivalent or an excess amount, preferably 1 to 5 equivalents of acid binder may be used per 1 mol of hydroxyl group of the starting polyfunctional hydroxy compound.

  Moreover, a well-known terminal stopper and a branching agent can be used for reaction. As the terminator, p-tert-butyl-phenol, p-phenylphenol, p-cumylphenol, p-perfluorononylphenol, p- (perfluorononylphenyl) phenol, p- (perfluorohexylphenyl) phenol , P-tert-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-par Fluorononanoic acid, 1,1,1,3,3 - such Tetorafuroro-2-propanol.

  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-) -Methylbenzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane, tetrakis (4-hydroxyphenyl) methane, tetrakis [4- (4-hydroxyphenylisopropyl) ) 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 can be mentioned.

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

  The polymer processing aid is a substance containing a large amount of high molecular weight components. It is said that entanglement (network) between polymers occurs between the polymer processing aid and the resin material, and the entanglement point acts as a pseudo-crosslinking point. Therefore, when a polymer processing aid is added, the resin composition can be uniformly stretched in the same manner as when the rubber is deformed. In the case of a resin material to which no polymer processing aid is added, since this pseudo-crosslinking point does not exist, for example, if a thin part exists in the film before stretching, stress is concentrated on that part and the film is stretched locally. In some cases, such as breaking.

  The polymer processing aid used in the present invention is a polymer compound having an average degree of polymerization of 3,000 to 40,000, preferably 60% by mass or more of methyl methacrylate unit and a vinyl monomer copolymerizable therewith. It consists of 40 mass% or less of body units. The average degree of polymerization is preferably 6,000 to 30,000, more preferably 10,000 to 25,000. Examples of vinyl monomers copolymerizable with methyl methacrylate include: methacrylates such as ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, ethyl acrylate, methyl acrylate, butyl acrylate, cyclohexyl acrylate Acrylic acid esters such as styrene, aromatic vinyl compounds such as styrene, p-methylstyrene, o-methylstyrene, maleimide compounds such as N-propylmaleimide, N-cyclohexylmaleimide, N-o-chlorophenylmaleimide, ethylene glycol dimethacrylate , Propylene glycol dimethacrylate, triethylene glycol dimethacrylate, hexanediol dimethacrylate, ethylene glycol diacrylate, propylene glycol diacrylate, triethylene Recall diacrylate, allyl methacrylate, can be mentioned polyfunctional monomers such as triallyl isocyanurate. Examples of such a polymer processing aid include a metablene series manufactured by Mitsubishi Rayon, a paraloid series manufactured by Dow or Kureha. The average degree of polymerization of the polymer processing aid can be determined as a PMMA equivalent degree of polymerization by measuring at 20 ° C. using chloroform as a solvent using an automatic dilution capillary viscometer (Ubbelohde type).

  There is no particular limitation on the polymerization method for producing the polymer processing aid, but it is preferable to use emulsion polymerization. Examples of the emulsifier that can be used in the emulsion polymerization include dialkyl sulfosuccinates such as sodium dioctyl sulfosuccinate and sodium dilauryl sulfosuccinate which are anionic emulsifiers, alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, and sodium dodecyl sulfate. Polyoxyethylene nonyl phenyl ether sulfate such as polyoxyethylene alkyl ether, polyoxyethylene nonyl phenyl ether as nonionic emulsifier, polyoxyethylene nonyl phenyl ether sodium sulfate as nonionic anionic emulsifier, etc. , Polyoxyethylene alkyl ether sulfate such as sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene tridecyl ether acetate It may be used alkyl ether carboxylate such as um like.

  When the pH of the polymerization system is alkaline depending on the type of emulsifier used, an appropriate pH adjuster can be used to prevent hydrolysis of the methacrylic acid alkyl ester and acrylic acid alkyl ester. Examples of pH regulators used include boric acid-potassium chloride-potassium hydroxide, potassium dihydrogen phosphate-disodium hydrogen phosphate, boric acid-potassium chloride-potassium carbonate, citric acid-potassium hydrogen citrate, diphosphate Potassium hydrogen-boric acid, disodium hydrogen phosphate-citric acid and the like can be used.

  The polymerization initiator may be a water-soluble initiator or an oil-soluble initiator alone, or a redox-type initiator. Examples of water-soluble initiators include ordinary inorganic initiators such as persulfate alone. It can also be used as a redox initiator in combination with sulfites, bisulfites, thiosulfates and the like.

  Examples of oil-soluble initiators include organic peroxides such as tert-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, lauroyl peroxide, azo compounds, or sodium formaldehyde sulfoxylate. Although it can also be used as a redox-type initiator in combination with, etc., it is not limited only to this specific example.

  The average degree of polymerization of the polymer processing aid can be arbitrarily adjusted by a chain transfer agent such as n-octyl mercaptan or tert-dodecyl mercaptan, polymerization conditions, or the like.

  The average degree of polymerization of the polymer processing aid of the present invention is in the range of 3,000 to 40,000. If the average degree of polymerization of the polymer processing aid is less than 3,000, the film-forming property may not be improved when the methacrylic resin composition of the present invention is made into a film, or the stretchability is sufficiently improved when stretched. Improvement effect may not be observed. On the other hand, if the average degree of polymerization of the polymer processing aid exceeds 40,000, the transparency may decrease, or the melt tension may become too high and the melt curtain may be easily broken at both ends. . The compounding quantity of a polymer processing aid is 0.3-6 mass parts with respect to 100 mass parts of methacrylic resins, Preferably it is 0.5-3 mass parts. When the blending amount of the polymer processing aid is less than 0.3 parts by mass, the film forming property and stretchability of the methacrylic resin composition are not sufficiently improved. On the other hand, when the blending amount of the polymer processing aid exceeds 6 parts by mass, the glass transition temperature of the methacrylic resin composition is lowered, the transparency is lowered, and further, the melt tension is too high. When the film is formed, both ends of the melt curtain may be easily broken.

  The content of the polycarbonate resin contained in the methacrylic resin composition of the present invention is 1 part by mass or more and 4 parts by mass or less, more preferably 2 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the methacrylic resin. is there.

  The total amount of the methacrylic resin and the polycarbonate resin contained in the methacrylic resin composition of the present invention is 80% by mass or more, preferably 90% by mass or more, more preferably 94% by mass or more, and further preferably 96% by mass or more. is there. The upper limit of the amount is not particularly limited as long as the polymer processing aid can be contained in the methacrylic resin composition of the present invention as long as the effects of the present invention can be obtained.

  The methacrylic resin composition of 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 amount of filler that can be contained in the methacrylic resin composition of the present invention is preferably 3% by mass or less, more preferably 1.5% by mass or less.

  The methacrylic resin composition of 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, Styrenic resins such as AS resin, ABS resin, AES resin, AAS resin, ACS resin, MBS resin; methyl methacrylate-styrene copolymer; polyester resin such as polyethylene terephthalate and polybutylene terephthalate; nylon 6, nylon 66, polyamide elastomer Polyamide such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacetal, polyvinylidene fluoride, polyurethane, modified poly Enylene ether, polyphenylene sulfide, phenoxy resin, silicone modified resin; acrylic rubber, acrylic thermoplastic elastomer, silicone rubber; styrene thermoplastic elastomer such as SEPS, SEBS, SIS; olefin rubber such as IR, EPR, EPDM, etc. Is mentioned. The amount of the other polymer that can be contained in the methacrylic resin composition used in the present invention is preferably 10% by mass or less, more preferably 5% by mass or less, and most preferably 0% by mass.

  In the methacrylic resin composition of the present invention, an antioxidant, a thermal degradation inhibitor, an ultraviolet absorber, a light stabilizer, a lubricant, a mold release agent, an antistatic agent, a flame retardant, and the like within a range not impairing the effects of the present invention. It may contain additives such as dyes and pigments, light diffusing agents, organic dyes, matting agents, impact resistance modifiers, and phosphors.

The antioxidant alone has an effect of preventing oxidative deterioration of the resin in the presence of oxygen. Examples thereof include phosphorus antioxidants, hindered phenol antioxidants, and thioether antioxidants. 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-tert-butylphenyl) octyl phosphite (manufactured by ADEKA; trade name: ADK STAB HP-10), tris (2,4-di-). tert-Butylphenyl) phosphite (manufactured by BASF; trade name: IRGAFOS168), 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa- 3,9-diphosphaspiro [5.5] undecane (manufactured by ADEKA; trade name: ADK STAB PEP-36) is preferred.

  As the hindered phenol-based antioxidant, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (manufactured by BASF; trade name IRGANOX 1010), octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufactured by BASF; trade name IRGANOX1076) is preferred.

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.
As the thermal degradation inhibitor, 2-tert-butyl-6- (3′-tert-butyl-5′-methyl-hydroxybenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd .; trade name Sumilyzer GM), 2,4-ditert-amyl-6- (3 ′, 5′-di-tert-amyl-2′-hydroxy-α-methylbenzyl) phenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd .; trade name Sumitizer 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 in 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-tert-octylphenol] (manufactured by ADEKA; LA-31), 2- (5-octylthio-2H-benzotriazol-2-yl) -6-tert-butyl-4-methylphenol and the like are preferable. .

The maximum value epsilon _max UV absorber or less 1200dm ³ · mol ^-1 cm ^-1 in molar extinction coefficient at a wavelength of 380~450nm can suppress discoloration of the resulting films. 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 wavelength around 380 nm, a triazine ultraviolet absorber is preferably used. As such an ultraviolet absorber, 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine (made by ADEKA; LA-F70), Hydroxyphenyltriazine-based ultraviolet absorbers (manufactured by BASF; TINUVIN477 and TINUVIN460), 2,4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine Is mentioned.

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 Hitachi U-3410 spectrophotometer. 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, stearamic acid, methylene bisstearamide, hydroxystearic acid triglyceride, paraffin wax, ketone wax, octyl alcohol, and hardened oil.

  As a mold release agent, it is a compound which has a function which makes easy mold release from the metal mold | die. Examples of the 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. It is more preferable to use within the range of / 1 to 3.2 / 1.

Examples of the impact 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, and the like.
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. Moreover, these additives may be added to the polymerization reaction liquid when producing a methacrylic resin or a polycarbonate resin, or may be added to the produced methacrylic resin or the polycarbonate resin, or a methacrylic resin composition may be added. It may be added during preparation. The total amount of additives contained in the methacrylic resin composition used in the present invention is preferably 7% by mass or less, more preferably 5% by mass or less, based on the methacrylic resin, from the viewpoint of suppressing poor appearance of the film. More preferably, it is 4 mass% or less.

  The method for preparing the methacrylic resin composition is not particularly limited. Examples thereof include a method of polymerizing a monomer mixture containing methyl methacrylate in the presence of a polycarbonate resin to produce a methacrylic resin, a method of melt-kneading a methacrylic resin and a polycarbonate resin, and the like. 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, methacrylic resin may be mixed with other polymers and additives, and then mixed with polycarbonate resin. The resin may be mixed with methacrylic resin after being mixed with other polymers and additives. 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. Although the temperature at the time of mixing and kneading can be suitably adjusted according to the melting temperature of the methacrylic resin and polycarbonate resin to be used, it is preferably 110 to 300 ° C. The methacrylic resin composition prepared by the above method can be formed into a film in any form such as pellets, granules, and powders.

  The glass transition temperature of the methacrylic resin composition of the present invention is preferably 120 ° C. or higher, more preferably 123 ° C. or higher, and still more preferably 124 ° C. or higher. The upper limit of the glass transition temperature of the methacrylic resin composition is not particularly limited, but is preferably 140 ° C, more preferably 130 ° C.

  Mw determined by measuring the methacrylic resin composition of the present invention by GPC is preferably 70,000 to 200,000, more preferably 72,000 to 16,000, and even more preferably 75,000 to 120,000. The molecular weight distribution determined by measuring the methacrylic resin composition used in the present invention by GPC is preferably 1.2 to 2.5, more preferably 1.3 to 2.0. When the Mw and molecular weight distribution are in this range, the moldability of the methacrylic resin composition becomes good, and it becomes easy to obtain a molded article excellent in impact resistance and toughness.

  The melt flow rate determined by measuring the methacrylic resin composition of the present invention under the conditions of 230 ° C. and 3.8 kg load is preferably 0.1 to 6 g / 10 minutes, more preferably 0.5 to 5 g / 10. Min, most preferably 1.0 to 3 g / 10 min.

  In the methacrylic resin composition of the present invention, the 1.0 mm thickness haze is preferably 1.0% or less, more preferably 0.7% or less, and further preferably 0.5% or less.

  The film of this invention is not specifically limited by the manufacturing method. The film of the present invention can be obtained, for example, by forming the methacrylic resin composition by a known method such as a solution casting method, a melt casting method, an extrusion molding method, an inflation molding method, or a blow molding method. it can. Of these, the extrusion method is preferred. According to the extrusion method, a film having excellent transparency, improved toughness, excellent handleability, and excellent balance between toughness, surface hardness, and rigidity can be obtained. The temperature of the methacrylic resin composition discharged from the extruder is preferably set to 160 to 270 ° C, more preferably 220 to 260 ° C.

  Among the extrusion molding methods, from the viewpoint of obtaining a film having good surface smoothness, good specular gloss, and low haze, the methacrylic resin composition is extruded from a T-die in a molten state, and then it is applied to two or more specular surfaces. 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.

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

  The film of the present invention may be subjected to a stretching treatment. By the stretching treatment, a film that has high mechanical strength and is difficult to crack can be obtained. The stretching method is not particularly limited, and examples thereof include uniaxial stretching, simultaneous biaxial stretching, sequential biaxial stretching, and tuber stretching. The temperature at the time of stretching is preferably from 100 to 200 ° C, more preferably from 120 to 160 ° C, from the viewpoint that the film can be stretched uniformly and a high-strength film can be obtained. In particular, when it is desired to increase the strength, a lower temperature is preferable, for example, 110 to 150 ° C is preferable, and 125 to 140 ° C is more preferable. It is preferable to stretch at or above the glass transition temperature of the methacrylic resin composition. Stretching is usually performed at 100 to 5000% / min on a length basis. After stretching, a film with less heat shrinkage can be obtained by heat-setting or relaxing the film. Although there is no restriction | limiting in a draw ratio, Usually, it shall be about 1.5 to 8 times by area ratio.

In the film of the present invention, the amount of methacrylic resin contained therein is preferably 78 to 98.7% by mass, more preferably 85 to 97% by mass, from the viewpoint that transparency and retardation in the thickness direction are small. It is.
The film of the present invention is preferably 1 to 3.8% by mass, more preferably 2 to 2.9% by mass from the viewpoint that the amount of the polycarbonate resin contained therein is small in retardation in the thickness direction. %.
In the film of the present invention, the amount of the polymer processing aid contained therein is preferably 0.3 to 5.6% by mass, more preferably 0.5 to 2.9 from the viewpoint of stretchability. % By mass.

  The thickness of the film of the present invention is not particularly limited, but when used as an optical film, the thickness is preferably 1 to 300 μm, more preferably 10 to 50 μm, and still more preferably 15 to 40 μm.

  The 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.

When the film of the present invention has an in-plane retardation Re for light having a wavelength of 590 nm and a film thickness of 40 μm, it is preferably 5 nm or less, more preferably 4 nm or less, still more preferably 3 nm or less, particularly preferably 2 nm or less, Most preferably, it is 1 nm or less.
The film of the present invention preferably has a thickness direction retardation Rth for light having a wavelength of 590 nm of −10 nm or more and 10 nm or less, more preferably −5 nm or more and 5 nm or less, even more preferably when the film thickness is 40 μm. Is from −4 nm to 4 nm, even more preferably from −3 nm to 3 nm, particularly preferably from −2 nm to 2 nm, and most preferably from −1 nm to 1 nm.
If the in-plane direction phase difference and the thickness direction phase difference are within such ranges, the influence on the display characteristics of the image display apparatus due to the phase difference can be significantly suppressed. More specifically, interference unevenness and 3D image distortion when used in a liquid crystal display device for 3D display can be significantly suppressed.
The in-plane direction phase difference Re and the thickness direction phase difference Rth are values defined by the following equations, respectively.
Re = (nx−ny) × d
Rth = ((nx + ny) / 2−nz) × d
Here, nx is the refractive index in the slow axis direction of the film, ny is the refractive index in the fast axis direction of the film, nz is the refractive index in the thickness direction of the film, and d (nm) is the film. Is the thickness. The slow axis refers to the direction in which the in-plane refractive index is maximized, and the fast axis refers to the direction perpendicular to the slow axis in the plane.

  Since the film of the present invention has high transparency, high heat resistance, small retardation, and thinness, it is suitable for a polarizer protective film, various films described later, and the like.

  The polarizing plate of the present invention is obtained by laminating at least one polarizer protective film comprising the film of the present invention. Preferably, a polarizer formed from a polyvinyl alcohol-based resin and the polarizer protective film of the present invention are laminated via an adhesive layer.

  As shown in FIG. 1, the polarizing plate according to a preferred embodiment of the present invention includes an adhesive layer 12, an easy-adhesion layer 13, and the polarizer protective film 14 of the present invention on one surface of a polarizer 11. The adhesive layer 15 and the optical film 16 are laminated in this order on the other surface of the polarizer 11.

  The polarizer formed from the polyvinyl alcohol-based resin can be obtained, for example, by dyeing a polyvinyl alcohol-based resin film with a dichroic substance (typically iodine or a dichroic dye) and uniaxially stretching. The polyvinyl alcohol-based resin film is formed by any suitable method (for example, casting method, casting method, extrusion method for casting a solution obtained by dissolving a resin in water or an organic solvent). Can be obtained. The degree of polymerization of the polyvinyl alcohol-based resin is preferably 100 to 5000, and more preferably 1400 to 4000. 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.

  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 aqueous adhesive may be in the form of an aqueous solution or latex. Although it does not specifically limit as an aqueous adhesive, For example, a vinyl polymer type | system | group, a gelatin type, a vinyl type latex type, a polyurethane type, an isocyanate type, a polyester type, an epoxy type etc. can be illustrated. In such an aqueous adhesive, a catalyst such as a crosslinking agent, other additives, and an acid can be blended as necessary. As the water-based adhesive, an adhesive containing a vinyl polymer is preferably used, and the vinyl polymer is preferably a polyvinyl alcohol resin. The polyvinyl alcohol-based resin can contain a water-soluble crosslinking agent such as boric acid, borax, glutaraldehyde, melamine, or oxalic acid. In particular, when a polyvinyl alcohol polymer film is used as the polarizer, it is preferable from the viewpoint of adhesiveness to use an adhesive containing a polyvinyl alcohol resin. Furthermore, an adhesive containing a polyvinyl alcohol-based resin having an acetoacetyl group is more preferable from the viewpoint of improving durability. The water-based adhesive is usually used as an adhesive made of an aqueous solution, and usually contains 0.5 to 60% by mass of a solid content.

  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 adhesive may contain 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.

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 the polarizer protective film or optical film of this invention, and may be performed with respect to a polarizer. After forming the adhesive layer, the polarizer protective film or the optical film and the polarizer can be pressed together to laminate them. 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 which can be provided in the polarizing plate of this invention improves the adhesiveness of the surface where a polarizer protective film and a polarizer contact | connect. 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 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 16 may be the polarizer protective film of the present invention, or any other appropriate optical film. The optical film used is not particularly limited, and examples thereof include films made of cellulose resin, polycarbonate resin, cyclic polyolefin resin, methacrylic resin, and the like.

  Cellulose resin is an ester of cellulose and fatty acid. Specific examples of the cellulose ester resin 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 include trade names “UV-50”, “UV-80”, “SH-80”, “TD-80U”, “TD-TAC”, and “UZ-” manufactured by Fujifilm Corporation. TAC ”,“ KC series ”manufactured by Konica Minolta, and the like.

  Cyclic polyolefin resin is a general term for resins that are polymerized using 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. Resins that are included. Specific examples include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, cyclic olefins and α-olefins such as ethylene and propylene (typically random copolymers), And graft polymers obtained by modifying them with an unsaturated carboxylic acid or a derivative thereof, and hydrides thereof. Specific examples of the cyclic olefin include norbornene monomers.

  Various products are commercially available as the cyclic polyolefin resin. 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 ".

  Any appropriate methacrylic resin may be employed as the methacrylic resin used for the optical film such as the optical film 16 as long as the effects of the present invention are not impaired. For example, polymethacrylate 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) acrylic acid methyl-styrene copolymer (MS resin, etc.), polymer having alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate) -(Meth) acrylic acid norbornyl copolymer).

  Specific examples of the methacrylic resin used in the optical film such as the optical film 16 include, for example, Acrypet VH and Acrypet VRL20A manufactured by Mitsubishi Rayon Co., Ltd. and methyl methacrylate described in JP2013-033237A and WO2013 / 005634. An acrylic resin copolymerized with a maleimide monomer, an acrylic resin having a ring structure in the molecule described in WO 2005/108438, a methacryl resin having a ring structure in the molecule described in JP-A-2009-197151, Examples thereof include a high glass transition temperature (Tg) methacrylic resin obtained by intramolecular crosslinking or intramolecular cyclization reaction.

  As the methacrylic resin, a methacrylic resin having a lactone ring structure can also be used. It is because it has high mechanical strength by high heat resistance, high transparency, and biaxial stretching.

  Examples of the methacrylic resin having the lactone ring structure include JP 2000-230016, JP 2001-151814, JP 2002-120326, JP 2002-254544, and JP 2005-146084. And a methacrylic resin having a lactone ring structure.

  The 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 electroluminescence (EL) display, a plasma display (PD), and a field emission display (FED), and a liquid crystal display device. 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.

  The methacrylic resin composition of the present invention is highly transparent because the methacrylic resin and the polycarbonate resin are compatible with each other, and the retardation in the thickness direction is small even when stretched. Moreover, the film obtained has a high stretchability. Therefore, according to the methacrylic resin composition of the present invention, a thin film having excellent in-plane uniformity and high surface smoothness can be obtained. In addition, the film can be stretched at a low temperature, and a film having high strength can be obtained. Furthermore, by setting the syndiotacticity (rr) of the methacrylic resin to a specific value, it is possible to provide a film having high heat resistance and a small heat shrinkage rate.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to the following Example. The physical property values and the like were measured by the following method. Moreover, Examples 1-5 shall be read as Reference Examples 1-5.

(Polymerization conversion)
The gas chromatograph GC-14A manufactured by Shimadzu Corporation was used as a column for GL Sciences Inc. Inert CAP 1 (df = 0.4 μm, 0.25 mm ID × 60 m) manufactured by the company is connected, the injection temperature is 180 ° C., the detector temperature is 180 ° C., and the column temperature is 60 ° C. (held for 5 minutes). The temperature was increased to 200 ° C. at a rate of temperature increase of 10 ° C./min, the conditions were set to hold for 10 minutes, the measurement was performed, and the polymerization conversion rate was calculated based on this result.

(Weight average molecular weight (Mw), molecular weight distribution (Mw / Mn))
Mw and molecular weight distribution of the methacrylic resins and methacrylic resin compositions obtained in each of the production examples, examples and comparative examples were measured by gel permeation chromatography (GPC) under the following conditions, and the standard polystyrene. The value converted into molecular weight was calculated. The baseline is that the slope of the peak on the high molecular weight side of the GPC chart changes from zero to positive when viewed from the earlier retention time, and the slope of the peak on the low molecular weight side is from negative to zero when viewed from the earlier retention time. A line connecting the points that change to.
GPC device: manufactured by Tosoh Corporation, HLC-8320
Detector: Differential refractive index detector Column: TSKgel SuperMultipore HZM-M manufactured by Tosoh Corporation and Superhz4000 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

(Viscosity average molecular weight (Mv))
The viscosity average molecular weight of the polycarbonate resin was determined by measuring the specific viscosity η _sp of a solution obtained by dissolving 0.5 g of the polycarbonate resin in 100 mL of methylene chloride at 20 ° C. using an Ubbelohde viscometer, and satisfying the following Schnell equation: It was calculated from the intrinsic viscosity [η] of a 20 ° C. methylene chloride solution.
η _sp /c=[η]+0.45×[η] ² c
([Η] is intrinsic viscosity, c = 0.5 under the above conditions)
^{[Η] = 1.23 × 10 -} . 4 Mv 0 8 3

(Syndiotacticity (rr) in triplet display)
The ¹ H-NMR spectrum of the methacrylic resin was measured using a nuclear magnetic resonance apparatus (ULTRA SHIELD 400 PLUS manufactured by Bruker) using deuterated chloroform as a solvent at room temperature at a total number of 64 times. From the spectrum, the area (X) of the region of 0.6 to 0.95 ppm when TMS was set to 0 ppm and the area (Y) of the region of 0.6 to 1.35 ppm were measured. The displayed syndiotacticity (rr) was calculated by the formula: (X / Y) × 100.

(Glass transition temperature Tg)
The methacrylic resin, polycarbonate resin and methacrylic resin composition were heated once to 230 ° C. using a differential scanning calorimeter (DSC-50 (product number)) manufactured in accordance with JIS K7121, and then at room temperature. Then, the DSC curve was measured under the condition that the temperature was raised from room temperature to 230 ° C. at a rate of 10 ° C./min. The midpoint glass transition temperature obtained from the DSC curve measured at the second temperature rise was defined as the glass transition temperature in the present invention.

(Melt Mass Flow Rate (MFR))
The methacrylic resin, which is the raw material of the methacrylic resin composition used in the production of the film in each Example and Comparative Example, was measured under conditions of 230 ° C., 3.8 kg load, and 10 minutes in accordance with JIS K7210.
(Melt volume flow rate (MVR))
The polycarbonate resin, which is the raw material of the methacrylic resin composition used in the production of the film in each Example and Comparative Example, was measured under the conditions of 300 ° C., 1.2 kg load, and 10 minutes in accordance with JIS K7210.

(Surface smoothness)
The surface of the biaxially stretched film obtained in each Example and Comparative Example was visually observed, and the surface smoothness was evaluated according to the following criteria.
A: The surface is smooth.
B: There are irregularities on the surface.

(Average polymerization degree of polymer processing aid)
Using an automatic dilution type capillary viscometer (Ubbelohde type, capillary inner diameter = 0.5 mm), chloroform was used as a solvent at 20 ° C., and the degree of polymerization was calculated as PMMA.

(Heat shrinkage)
A test piece of 100 mm × 30 mm was cut out from the biaxially stretched film obtained in each example and comparative example, a straight line having a length of 70 mm was written on the surface, and a forced hot air circulation system maintained at a temperature of 110 ° C. After heating in a thermostatic oven for 30 minutes, the length of the entered straight line (L (mm)) was read on a scale, and the heat shrinkage rate was determined by the following formula.
Heat shrinkage rate (%) = (70−L) / 70 × 100

(Total light transmittance)
A test piece of 50 mm × 50 mm was cut out from the biaxially stretched film obtained in each Example and Comparative Example, and its total light was measured using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150) according to JIS K7361-1. The transmittance was measured. The methacrylic resin composition was evaluated by molding a 1.0 mm-thick molded body with a hot press and measuring the total light transmittance.

(Haze)
A test piece of 50 mm × 50 mm was cut out from the biaxially stretched film obtained in each Example and Comparative Example, and the haze was measured using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150) according to JIS K7136. did. The methacrylic resin composition was evaluated by molding a 1.0 mm-thick molded body with a hot press and measuring haze.

(Thickness direction retardation Rth and in-plane direction retardation Re)
A test piece of 40 mm × 40 mm was cut out from the biaxially stretched film obtained in each example and comparative example. This test piece was subjected to three-dimensional refraction using an automatic birefringence meter (KOBRA-WR manufactured by Oji Scientific Co., Ltd.) at a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5% from a phase difference value in a 590 nm wavelength and 40 ° tilt direction. The rates nx, ny, and nz were obtained, and the thickness direction phase difference Rth and the in-plane direction phase difference Re were calculated from the above-described equations. The thickness d (nm) of the test piece was measured using a digimatic indicator (manufactured by Mitutoyo Corporation), and the refractive index n was measured by a digital precision refractometer (KPR-20 manufactured by Kalnew Optical Industry Co., Ltd.).

(Extensible)
When the unstretched films obtained in the examples and comparative examples were biaxially stretched, the stretchability was evaluated according to the following criteria. Stretching is performed by cutting an unstretched film into 100 mm × 100 mm, and using a pantograph type biaxial stretching tester (manufactured by Toyo Seiki Co., Ltd.), a glass transition temperature + 10 ° C. stretching temperature, a unidirectional stretching rate of 120% / min, After sequentially biaxially stretching at a stretch ratio of 2 times (4 times in area ratio), it was held for 10 seconds and then cooled.
A: 5 or more samples could be obtained out of 10 samples without cracks or cracks.
B: The film which was able to acquire only 4 samples or less out of 10 samples without a crack and a crack.

<Production Example 1> The inside of a 5 L glass reaction vessel equipped with a stirring blade and a three-way cock was replaced with nitrogen. To this, at room temperature, 1600 g of toluene, 2.49 g (10.8 mmol) of 1,1,4,7,10,10-hexamethyltriethylenetetramine, isobutylbis (2,6-dioxy) having a concentration of 0.45M. -T-Butyl-4-methylphenoxy) 53.5 g (30.9 mmol) of a toluene solution of aluminum and a solution of sec-butyllithium having a concentration of 1.3 M (solvent: cyclohexane 95 mass%, n-hexane 5 mass%) 6.17 g (10.3 mmol) was charged. While stirring, 550 g of distilled and purified methyl methacrylate was added dropwise at −20 ° C. over 30 minutes. After completion of dropping, the mixture was stirred at −20 ° C. for 180 minutes. The color of the solution changed from yellow to colorless. At this time, the polymerization conversion rate of methyl methacrylate was 100%.
The obtained solution was diluted by adding 1500 g of toluene. Next, the diluted solution was poured into 100 kg of methanol to obtain a precipitate. The obtained precipitate was dried at 80 ° C. and 140 Pa for 24 hours. The Mw was 96100, the molecular weight distribution was 1.07, the syndiotacticity (rr) was 83%, and the glass transition temperature was 133 ° C. And the ratio of the structural unit derived from methyl methacrylate was 100 mass%, and the methacryl resin [PMMA1] was obtained.

<Production Example 2> The inside of a 5 L glass reaction vessel equipped with a stirring blade and a three-way cock was replaced with nitrogen. To this, at room temperature, 1600 g of toluene, 2.49 g (10.8 mmol) of 1,1,4,7,10,10-hexamethyltriethylenetetramine, isobutylbis (2,6-dioxy) having a concentration of 0.45M. 5. 53.5 g (30.9 mmol) of a toluene solution of -t-butyl-4-methylphenoxy) aluminum and a solution of sec-butyllithium having a concentration of 1.3 M (solvent: cyclohexane 95%, n-hexane 5%) 17 g (10.3 mmol) was charged. While stirring, 550 g of distilled and purified methyl methacrylate was added dropwise at 20 ° C. over 30 minutes. After completion of dropping, the mixture was stirred at 20 ° C. for 90 minutes. The color of the solution changed from yellow to colorless. At this time, the polymerization conversion rate of methyl methacrylate was 100%.
The obtained solution was diluted by adding 1500 g of toluene. Next, the diluted solution was poured into 100 kg of methanol to obtain a precipitate. The obtained precipitate was dried at 80 ° C. and 140 Pa for 24 hours. The Mw was 81400, the molecular weight distribution was 1.08, the syndiotacticity (rr) was 73%, and the glass transition temperature was 131 ° C. A methacrylic resin [PMMA2] having a content of structural units derived from methyl methacrylate of 100% by mass was obtained.

<Production Example 3> The inside of the autoclave to which the stirrer and the sampling tube were attached was replaced with nitrogen. To this, 100 parts by mass of purified methyl methacrylate, 0.002 parts by mass of 2,2′-azobis (2-methylpropionitrile) (hydrogen abstraction ability: 1%, 1 hour half-life temperature: 83 ° C.), Then, 0.28 parts by mass of n-octyl mercaptan was added and stirred to obtain a raw material liquid. Nitrogen was fed into the raw material liquid to remove dissolved oxygen in the raw material liquid.
The raw material liquid was put to 2/3 of the capacity in a tank reactor connected to the autoclave by piping. First, the polymerization reaction was started in a batch mode while maintaining the temperature at 140 ° C. When the polymerization conversion rate reaches 55% by mass, the raw material liquid is supplied from the autoclave to the tank reactor at a flow rate of an average residence time of 150 minutes, and the reaction liquid is supplied at a flow rate corresponding to the supply flow rate of the raw material liquid. It was extracted from the tank reactor, maintained at a temperature of 140 ° C., and switched to a continuous flow polymerization reaction. After switching, the polymerization conversion in the steady state was 55% by mass.

  The reaction liquid withdrawn from the tank reactor in a steady state was heated by supplying it to a multi-tubular heat exchanger having an internal temperature of 230 ° C. at a flow rate with an average residence time of 2 minutes. Next, the heated reaction liquid was introduced into a flash evaporator, and volatile components mainly composed of unreacted monomers were removed to obtain a molten resin. The molten resin from which volatile components have been removed is supplied to a twin-screw extruder having an internal temperature of 260 ° C., discharged into a strand shape, cut with a pelletizer, pellet-shaped, Mw is 82,000, and the molecular weight distribution is 1.85. A methacrylic resin [PMMA3] having a syndiotacticity (rr) of 52%, a glass transition temperature of 120 ° C. and a content of structural units derived from methyl methacrylate of 100% by mass was obtained.

<Production Example 4> The same operation as in Production Example 3 was performed except that the amount of n-octyl mercaptan was changed to 0.225 parts by mass, Mw was 103600, molecular weight distribution was 1.81, and syndiotacticity ( A methacrylic resin [PMMA4] having an rr) of 52%, a glass transition temperature of 120 ° C. and a proportion of structural units derived from methyl methacrylate of 100% by mass was obtained.

<Production Example 5> The same operation as in Production Example 3 was performed except that the amount of n-octyl mercaptan was changed to 0.30 parts by mass, Mw was 76400, molecular weight distribution was 1.81, and syndiotacticity ( A methacrylic resin [PMMA5] having an rr) of 53%, a glass transition temperature of 119 ° C., and a content of structural units derived from methyl methacrylate of 100% by mass was obtained.

<Production Example 6> 57 parts by mass of methacrylic resin [PMMA2] and 43 parts by mass of methacrylic resin [PMMA4] are mixed and heated to 250 ° C. with a twin screw extruder (trade name: KZW20TW-45MG-NH-600). The methacrylic resin [PMMA6] was manufactured by kneading and extrusion.

  Sumipex MHF (manufactured by Sumitomo Chemical Co., Ltd.) was used as the methacrylic resin [PMMA7].

  Table 1 shows the physical properties of [PMMA1] to [PMMA7].

The polycarbonate resins used in the examples are described below, and the physical properties are shown in Table 2.
PC1: Idemitsu Kosan Co., Toughlon LC1700 (Part); MVR (300 ℃, 1.2Kg ) = 40cm 3/10 minutes, Mv = 16200
PC2: Mitsubishi Engineering Plastics Co., IUPILON HL-4000 (product number); MVR (300 ℃, 1.2Kg ) = 60cm 3/10 minutes, Mv = 15100
PC3: Sumika Stylon Polycarbonate, SD POLYCA SD-2201
W (Part); MVR (300 ℃, 1.2Kg ) = 115cm 3/10 min, Mv = 13000
PC4: Sumika Stylon Polycarbonate Company, SD POLYCA TR-2001
(Part); MVR (300 ℃, 1.2Kg ) = 200cm 3/10 min, Mv = 11400
PC 5: Mitsubishi Engineering Plastics Co., Ltd., AL071; MVR (300 ℃, 1.2Kg) = 1000cm 3/10 minutes or more (it was difficult to have high accurate measurement fluidity)
Mv = 5500
PC 6: 50 parts by weight of PC4 as a mixture of 50 parts by weight of PC5; MVR (300 ℃, 1.2kg ) = 1000cm 3/10 minutes or more (it was difficult to have high accurate measurement fluidity), Mv = 8500

The polymer processing aids used in the examples are described below. Here, MMA means a structural unit derived from methyl methacrylate, and BA means a structural unit derived from butyl acrylate.
B1: Metablene P570A manufactured by Mitsubishi Rayon Co., Ltd. (average polymerization degree: 2384, MMA 53 mass% / BA 47 mass%)
B2: Metablene P550A manufactured by Mitsubishi Rayon Co., Ltd. (average polymerization degree: 7734, MMA 88 mass% / BA 12 mass%)
B3: Paraloid K125P manufactured by Kureha Co., Ltd. (average polymerization degree: 19874, MMA 79% by mass / BA 21% by mass)
B4: Metablene P530A manufactured by Mitsubishi Rayon Co., Ltd. (average polymerization degree: 24455, MMA 80 mass% / BA 20 mass%)
B5: Metablene P531A manufactured by Mitsubishi Rayon Co., Ltd. (average polymerization degree: 37162, MMA 80 mass% / BA 20 mass%)

  2,4,6-Tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine (manufactured by ADEKA; LA-F70) was used as an ultraviolet absorber.

<Example 1>
100 parts by weight of methacrylic resin [PMMA1], 2.5 parts by weight of polycarbonate resin [PC1] and 2 parts by weight of processing aid [B2] are mixed together and a twin-screw extruder (manufactured by Technobel, trade name: KZW20TW-45MG-NH). -600) and kneaded and extruded at 250 ° C. to produce a methacrylic resin composition [1]. The obtained methacrylic resin composition [1] was subjected to hot press molding to form a plate-like molded body of 50 mm × 50 mm × 1.0 mm, and the total light transmittance, haze and glass transition temperature were measured. Table 3 shows the physical properties of the methacrylic resin composition [1].

  The methacrylic resin composition [1] was dried at 80 ° C. for 12 hours. Using a 20 mmφ single-screw extruder (OCS), the methacrylic resin composition [1] is extruded from a 150 mm wide T-die at a resin temperature of 260 ° C., and is taken up by a roll having a surface temperature of 85 ° C. An unstretched film having a thickness of 110 mm and a thickness of 160 μm was obtained.

  The unstretched film obtained by the above-described method is cut into 100 mm × 100 mm, and stretched at a glass transition temperature + 10 ° C., 500% / min in one direction by a pantograph type biaxial stretching tester (manufactured by Toyo Seiki Co., Ltd.). The film was sequentially biaxially stretched at a stretching speed and a stretching ratio of 2 times in one direction (4 times in area ratio), cooled to 100 ° C. or lower over 2 minutes, and a biaxially stretched film having a thickness of 40 μm was obtained. About the obtained biaxially stretched film, surface smoothness, heat shrinkage rate, total light transmittance, haze, in-plane direction retardation Re, thickness direction retardation Rth, and stretching when producing a stretched film from an unstretched film Table 3 shows the measurement results.

<Examples 2 to 11 and Comparative Examples 1 to 7>
Methacrylic resin compositions [2] to [18] were produced in the same manner as in Example 1 except that the formulations shown in Tables 3 and 4 were used. The obtained methacrylic resin compositions [2] to [18] were hot press molded to form a plate-like molded body of 50 mm × 50 mm × 1.0 mm, and the total light transmittance, haze, and glass transition temperature were measured. Tables 3 and 4 show the physical properties of the methacrylic resin compositions [2] to [18].

  A biaxially stretched film was obtained in the same manner as in Example 1 except that the methacrylic resin compositions [2] to [18] were used instead of the methacrylic resin composition [1]. The evaluation results are shown in Table 3 and Table 4.

(Polarizer)
A polyvinyl alcohol film having an average polymerization degree of 2400, a saponification degree of 99.9 mol%, and a thickness of 75 μm was immersed in warm water at 30 ° C. for 60 seconds to swell. Next, the film was stretched to 3.5 times while being dyed in an iodine solution of 0.3% by mass (weight ratio: iodine / potassium iodide = 0.5 / 8) at 30 ° C. for 1 minute. Thereafter, the film was stretched so that the total stretching ratio was 6 times while being immersed in a 4% by mass boric acid aqueous solution at 65 ° C. for 0.5 minutes. After stretching, the film was dried in an oven at 70 ° C. for 3 minutes to obtain a polarizer having a thickness of 22 μm.

<Preparation of polarizing plate X>
The biaxially stretched film of Example 8 was used as the polarizer protective film A. Polyester urethane (Daiichi Kogyo Seiyaku Co., Ltd., trade name: Superflex 210, solid content: 33%) 16.8 g, cross-linking agent (oxazoline-containing polymer, product of Nippon Shokubai Co., Ltd., trade name: Epocross WS-700, solid content: 25%) 4.2 g, 1% by mass of ammonia water 2.0 g, colloidal silica (manufactured by Fuso Chemical Industries, Quartron PL-3, solid content: 20% by mass) 0.42 g and 76.6 g of pure water were mixed. An easy-adhesive composition was obtained.
The resulting easy-adhesive composition was applied to the corona discharge treated surface of the biaxially stretched film of Example 8 subjected to corona discharge treatment with a bar coater so that the thickness after drying was 100 nm. Thereafter, the film was put into a hot air dryer (110 ° C.), and the easy-adhesive composition was dried for about 5 minutes to form an easy-adhesion layer on the biaxially stretched film of Example 8.

  Next, 38.3 parts by mass of N-hydroxyethylacrylamide (manufactured by Kojin Co., Ltd.), 19.1 parts by mass of tripropylene glycol diacrylate (trade name: Aronix M-220, manufactured by Toagosei Co., Ltd.), acryloylmorpholine ( 38.3 parts of Kojin Co., Ltd.) and 1.4 parts by mass of a photopolymerization initiator (trade name: KAYACURE DETX-S, diethylthioxanthone, Nippon Kayaku Co., Ltd.) are mixed and stirred at 50 ° C. for 1 hour. Thus, an active energy ray-curable adhesive was obtained.

The active energy ray-curable adhesive was applied to the easy-adhesion layer side of the polarizer protective film A so that the thickness after drying was 500 nm. Thereafter, one polarizer protective film A was laminated on each side of the above polarizer using a small laminator via an active energy ray curable adhesive. From both sides of the bonded polarizer protective film A, heat to 50 ° C. using an IR heater and irradiate both sides with ultraviolet rays with an integrated irradiation amount of 1000 mJ / cm ² to cure the active energy ray-curable adhesive. A polarizing plate X having a transparent polarizer protective film A on both sides of the polarizer was obtained. When the produced polarizing plate X was put into a constant temperature and humidity machine at 80 ° C. and 90% RH and the degree of deterioration of the polarizer after 100 hours was visually observed, no deterioration was observed.

<Preparation of polarizing plate Y>
A 40 μm thick triacetylcellulose film was immersed in a 10% aqueous sodium hydroxide solution (60 ° C.) for 30 seconds to saponify, and then washed with water for 60 seconds to obtain a polarizer protective film B.

  An acetoacetyl group-containing polyvinyl alcohol resin (average polymerization degree: 1200, saponification degree: 98.5 mol%, acetoacetyl group modification degree: 5 mol%) is 100 parts by mass, and 20 parts by mass of methylolmelamine is 30 ° C. It was dissolved in pure water under temperature conditions to obtain an aqueous solution with a solid content concentration of 0.5%. The obtained aqueous solution was used as an adhesive composition under a temperature condition of 30 ° C.

  The adhesive composition 30 minutes after the preparation was applied to the polarizer protective film B so that the thickness after drying was 50 nm. Thereafter, a polarizer protective film B is laminated on each side of the polarizer described above via an adhesive composition using a small laminator, put into a hot air dryer (70 ° C.), dried for 5 minutes, and polarized. Plate Y was obtained. When the produced polarizing plate Y was put into a constant temperature and humidity chamber of 80 ° C. and 90% RH and the degree of deterioration of the polarizer after 100 hours was visually observed, deterioration was recognized on the entire surface.

  This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2014-88810 for which it applied on April 23, 2014, and takes in those the indications of all here.

The methacrylic resin composition of the present invention has high transparency, small retardation in the thickness direction, high heat resistance, and can be stretched thinly. Therefore, a polarizer protective film, a retardation film, a liquid crystal protective plate, and portable information It is suitable for a surface material of a terminal, a display window protective film for a portable information terminal, a light guide film, a transparent conductive film coated with silver nanowires or carbon nanotubes on the surface, and a front plate for various displays. In particular, since the film of the present invention has a small retardation, it is suitable for a polarizer protective film.
Since the film of the present invention has high transparency and heat resistance, IR cut film, crime prevention film, anti-scattering film, decorative film, metal decorative film, solar cell back sheet, flexible solar, etc. can be used for applications other than optical applications. It can be used for a battery front sheet, a shrink film, and an in-mold label film.

DESCRIPTION OF SYMBOLS 11 Polarizer 12 Adhesive layer 13 Easy-adhesion layer 14 Polarizer protective film 15 Adhesive layer 16 Optical film

Claims (12)

A methacrylic resin composition comprising a methacrylic resin, a polycarbonate resin and a polymer processing aid,
In the methacrylic resin, the content of the structural unit derived from methyl methacrylate is 99% by mass or more, the weight average molecular weight is 200,000 or less, and the triplet syndiotacticity (rr) is 50% or more. der Ru, Ri Do mixtures methacrylic resin produced in a methacrylic resin and a radical polymerization prepared by anionic polymerization,
The polycarbonate resin has a viscosity average molecular weight of 1000 or more and 32000 or less, and the content of the polycarbonate resin with respect to 100 parts by mass of the methacrylic resin is 1 part by mass or more and 4 parts by mass or less.
The polymer processing aid has an average degree of polymerization of 3,000 or more and 40,000 or less,
The content of the polymer processing aid with respect to 100 parts by mass of the methacrylic resin is 0.3 parts by mass or more and 6 parts by mass or less.
The methacrylic resin composition whose total amount of the said methacrylic resin and said polycarbonate resin contained in a methacrylic resin composition is 80 mass% or more.   The methacrylic resin composition according to claim 1, wherein the methacrylic resin has a syndiotacticity (rr) of 58% or more and 85% or less.   The methacrylic resin composition according to claim 1 or 2, wherein the polycarbonate resin has a viscosity average molecular weight of 5,000 or more and 18,000 or less.   The methacrylic resin composition according to any one of claims 1 to 3, wherein the methacrylic resin composition has a weight average molecular weight of 70,000 to 200,000.   The methacrylic resin composition according to any one of claims 1 to 4, wherein the molecular weight distribution of the methacrylic resin composition is 1.2 to 2.5.   The molded object which consists of a methacryl resin composition as described in any one of Claims 1-5.   The film which consists of a methacryl resin composition as described in any one of Claims 1-5.   The film of Claim 7 whose thickness is 10-50 micrometers.   The film of Claim 7 or 8 biaxially stretched 1.5 to 8 times by area ratio.   The film as described in any one of Claims 7-9 used as a polarizer protective film.   A polarizing plate in which at least one film according to claim 10 is laminated. Anionic polymerization in which the content of the structural unit derived from methyl methacrylate is 99% by mass or more, the weight average molecular weight is 200,000 or less, and the syndiotacticity (rr) in triplet display is 50% or more. 100 parts by mass of a methacrylic resin obtained by mixing the methacrylic resin obtained by the above and a methacrylic resin obtained by radical polymerization ,
1000 parts by weight or more and 32000 parts by weight or less of a polycarbonate resin having a viscosity average molecular weight of 1 part by weight to 4 parts by weight;
Polymer processing aid having an average degree of polymerization of 3,000 or more and 40,000 or less 0.3 part by mass or more and 6 parts by mass or less,
A method for producing a methacrylic resin composition obtained by mixing at least three components.

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