KR20140074836A - Surface-treated laminated film and polarising plate using it - Google Patents

Abstract

The present invention relates to a surface-treated laminated film (10), wherein a surface treatment layer (18) is formed on the surface of the acrylic resin layer (12) of a laminated film (16) in which the acrylic resin layer (12) is laminated on a polycarbonate-based resin layer (15), H or pencil hardness harder than the H is provided to the surface treatment layer (18), the laminated film (16) has a total film thickness of 35-100 micrometers and an internal haze of 5% or less, the thickness of the polycarbonate-based resin layer (15) is 2-45% relative to the total film thickness of the laminated film (16), and the thickness of the acrylic resin layer (12) is 30 micrometers or more. When the acrylic resin layer is laminated on both surfaces of the polycarbonate-based resin layer (15), the surface treatment layer (18) is formed on one surface to satisfy the above requirements.

Description

TECHNICAL FIELD [0001] The present invention relates to a surface-treated laminated film and a polarizing plate using the laminated film.

The present invention relates to a surface-treated laminated film in which a multilayer laminated film is subjected to a surface treatment. The present invention also relates to a polarizing plate comprising the surface-treated laminated film as a protective film and laminated on a polarizing film.

Background Art [0002] Recently, a liquid crystal display device which is small in power consumption, operates at a low voltage, and is light in weight and thin is widely used in information display devices such as a cellular phone, a portable information terminal, a monitor for a computer, and a television. Such an information display device is required to have reliability under a severe environment depending on its use. For example, a liquid crystal display device for a car navigation system may have a very high temperature or humidity in the car in which it is placed, and therefore, the temperature and humidity conditions required are more severe than those of ordinary monitors for a television or a personal computer. In a liquid crystal display device requiring such a strict temperature and / or humidity condition, a polarizing plate constituting it is required to have high durability.

The polarizing plate usually has a structure in which a transparent protective film is laminated on both sides or one side of a polarizing film made of a polyvinyl alcohol-based resin in which dichroic dye is adsorbed and oriented. Conventionally, triacetylcellulose has been widely used for this protective film and has been bonded to a polarizing film through an adhesive made of an aqueous solution of a polyvinyl alcohol-based resin. However, the polarizing plate in which the protective film made of triacetylcellulose is laminated has a high moisture permeability of triacetyl cellulose, so that when used for a long time under a high humidity environment, the polarization performance may deteriorate or the protective film and the polarizing film may peel off.

Thus, it has been attempted to use an acrylic resin film having a lower moisture permeability than triacetylcellulose film as a protective film of a polarizing plate. For example, Japanese Patent Application Laid-Open No. 2011-123169 (Patent Document 1) discloses an acrylic resin film having a longitudinal shrinkage of 0.5% or more when heated at 100 占 폚 for 10 minutes to an active energy containing an oxetane compound and a cation polymerization initiator Discloses that a polarizing plate is laminated on a polarizing film made of a polyvinyl alcohol-based resin with the pre-curable resin composition as an adhesive. As described above, it is expected to improve the moisture resistance of the polarizing plate by using an acrylic resin film having a low moisture permeability as a protective film of the polarizing plate.

However, it is known that the acrylic resin film is inferior in toughness and is liable to break. Further, when a polarizing plate having an acrylic resin film as a protective film is produced, if the acrylic resin film is broken, there is a possibility that cracks may contaminate the manufacturing process.

Japanese Patent Application Laid-Open No. 2012-18383 (Patent Document 2) discloses a rubber composition comprising an acrylic resin and rubber elastomer particles incorporated therein, which improves the impact resistance upon film formation and the film formability when formed into a film, It has been proposed to suppress tight winding when the film is rolled up. The acrylic resin film in which the rubber elastomer particles are blended is improved in impact resistance to suppress the breakability as described above. However, when the content of the rubber elastomer particles is large, the elastic modulus of the film is lowered and the heat resistance of the polarizing plate may be lowered .

Although the resin film subjected to the surface treatment may be used as a protective film of a polarizing plate, even an acrylic resin film containing rubber elastomer particles is likely to be very easily broken by surface treatment. For this reason, in the case of the acrylic resin film, prevention of breakage at the time of sticking to a polarizing film becomes a big problem. For example, Japanese Patent Application Laid-Open No. 12121144 (Patent Document 3) discloses an acrylic resin film in which rubber elastic particles are blended and formed by melt extrusion, in which the impact absorption energy by the Charpy impact test in the mechanical extrusion direction (MD) The impact absorption energy of the MD is 5 kJ / m < 2 >, the impact of TD is 187 kJ / m < 2 >, and the same impact absorption energy in the direction And an absorption energy of 8 kJ / m < 2 > is shown. In this document, the Charpy impact test in a state of being bonded by bonding a surface protective film to a base film having an impact absorption energy of less than 50 kJ / m 2 by the Charpy impact test, which is a typical example of the acrylic resin film subjected to such surface treatment, It is difficult to break the film so that the impact absorption energy of the polarizing film becomes 50 kJ / m < 2 > or more, so that the conjugation work for the polarizing film can be performed stably.

As described above, when the surface protective film is laminated, it is difficult to break, but there still remains a problem of rupture of the film in the step of bonding the surface treatment protective film and an increase in cost due to an increase in the number of steps.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laminated film based on an acrylic resin film, which is subjected to surface treatment and is hard to break. Another object of the present invention is to provide a laminated film capable of stably carrying out operations when an acrylic resin film is used as a base and when the film is applied to another film including a polarizing film.

It is still another object of the present invention to provide a polarizing plate in which production stability is ensured by using a surface-treated laminated film which is difficult to break, as a protective film of a polarizing film.

The present inventors have found out that the film is hard to break even after the acrylic resin layer is subjected to the surface treatment by laminating the acrylic resin layer on one side or both sides of the flexible polycarbonate resin layer, And the present inventors have completed the present invention.

That is, according to the present invention, there is provided a surface-treated laminated film having a polycarbonate resin layer, an acrylic resin layer and a surface treatment layer, wherein the acrylic resin layer is laminated on one side or both sides of the polycarbonate resin layer, When the acrylic resin layer is laminated on one surface of the polycarbonate resin layer and on the opposite surface of the acrylic resin layer to the polycarbonate resin layer and when the acrylic resin layer is laminated on both surfaces of the polycarbonate resin layer, A surface treatment layer is formed on the side opposite to the polycarbonate resin layer of the resin layer and the surface treatment layer is provided with a hardness harder than H or hardness and the polycarbonate resin layer and the one side or both sides The total thickness of the acrylic resin layers stacked on the substrate is from 35 mu m to 100 mu m and the internal heights of not more than 5% Wherein the thickness of the polycarbonate resin layer is 2% to 45% of the total thickness of the polycarbonate resin layer and the acrylic resin layer, and the thickness of the acrylic resin layer on which the surface treatment layer is formed is A surface-treated laminated film having a thickness of 30 탆 or more is provided.

In the surface-treated laminated film, it is preferable that the acrylic resin layer is formed of an acrylic resin composition containing rubber elastomer particles having an average particle diameter of 10 nm to 300 nm in an amount of 30 wt% or less based on the total amount . The surface-treated laminated film may have a pressing strength of 20 N or more.

These surface-treated laminated films are suitably used as a protective film of a polarizing film made of a polyvinyl alcohol-based resin in which a dichroism dye is adsorbed and aligned. In this case, it is preferable that the polycarbonate-based resin layer and the acrylic resin layer laminated on one or both surfaces thereof have an in-plane retardation value of 100 nm or less in total.

Further, according to the present invention, a polarizing film made of a polyvinyl alcohol-based resin in which the above-mentioned surface-treated laminated film and a dichroic dye are adsorbed and oriented, and a protective film made of a transparent resin are laminated in this order, And the film is disposed so as to face the surface opposite to the surface treatment layer of the surface treatment laminated film.

In this polarizing plate, the surface-treated laminated film and the protective film may each be attached to the polarizing film through the cured layer of the active energy ray-curable adhesive. In addition, the protective film may have the function of a retardation film.

The single-layer film of the acrylic resin subjected to the surface treatment has a weak resistance to external force and is easily broken, but the surface-treated laminated film of the present invention in which the polycarbonate resin layer is laminated is difficult to break. For this reason, production stability can be improved when it is applied to another layer, for example, a polarizing film, and a functional film, for example, a polarizing plate in which another layer is further laminated can be industrially advantageously produced.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing one preferred form of the surface-treated laminated film according to the present invention. Fig.
2 is a schematic cross-sectional view showing another preferred embodiment of the surface-treated laminated film according to the present invention.
3 is a schematic cross-sectional view showing one preferred form of the polarizing plate to which the surface-treated laminated film according to the present invention is applied.
4 is a schematic cross-sectional view showing another preferred form of the polarizing plate to which the surface-treated laminated film according to the present invention is applied.

Hereinafter, the present invention will be described in detail with reference to the drawings appropriately. As shown in Fig. 1, the surface-treated laminated film 10 of the present invention is obtained by laminating the first acrylic resin layer 12 on one side of the polycarbonate resin layer 15, The first acrylic resin layer 12 and the second acrylic resin layer 13 are laminated on both surfaces of the carbonate resin layer 15 and the surface treatment layer 18 is formed on the surface of the first acrylic resin layer 12 It is.

[Acrylic resin layer]

The acrylic resin used for the first acrylic resin layer 12 and the second acrylic resin layer 13 is typically a methacrylic resin. The methacrylic resin is a polymer mainly composed of methacrylic acid ester, and may be a homopolymer of methacrylic acid ester or a copolymer of 50% by weight or more of methacrylic acid ester and 50% by weight or less of other monomer. As the methacrylic acid ester, an alkyl ester of methacrylic acid is generally used.

The preferable monomer composition of the methacrylic resin is 50% by weight to 100% by weight of alkyl methacrylate, 0% by weight to 50% by weight of alkyl acrylate, 0% by weight to 49% by weight of the other monomers, More preferably 50% by weight to 99.9% by weight of alkyl methacrylate, 0.1% by weight to 50% by weight of alkyl acrylate, and 0% by weight to 49% by weight of the other monomers.

Examples of the alkyl methacrylate include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and the like, and the number of carbon atoms of the alkyl group is usually 1 to 8, 1 to 4. Among them, methyl methacrylate is preferably used.

Examples of the alkyl acrylate include methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. The number of carbon atoms of the alkyl group is usually 1 to 8, preferably 1 to 4.

The monomers other than alkyl methacrylate and alkyl acrylate may be monofunctional monomers having one polymerizable carbon-carbon double bond in the molecule, or even a polyfunctional monomer having at least two polymerizable carbon-carbon double bonds in the molecule However, monofunctional monomers are preferably used. Examples of the monofunctional monomer include styrene-based monomers such as styrene, -methylstyrene and vinyltoluene, cyanide alkenyl such as acrylonitrile and methacrylonitrile, acrylic acid, methacrylic acid, maleic anhydride, N- Substituted maleimide and the like. Examples of the polyfunctional monomer include polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate and trimethylolpropane triacrylate, allyl acrylate, allyl methacrylate, cinnamic acid An alkenyl ester of an unsaturated carboxylic acid such as allyl, a polyalkenyl ester of a polybasic acid such as diallyl phthalate, diallyl maleate, triallyl cyanurate, triallyl isocyanurate, an aromatic polyalkenyl compound such as divinylbenzene .

The alkyl methacrylate, the alkyl acrylate, and the monomers other than the alkyl acrylate, and the monomers other than the alkyl acrylate, and the monomers other than these may be used in combination.

In the present invention, an acrylic resin composition obtained by blending rubber elastic particles with an acrylic resin is preferably used. In the acrylic resin composition, it is preferable that the content of the rubber elastomer particles is small in order to prevent the decrease of the elastic modulus. On the other hand, in order to increase the film formability, it is preferable to blend a large amount of rubber elastomer particles. Thus, it is only necessary to determine the compounding amount of the rubber elastomer particles in consideration of the film formability and the elastic modulus of the film. Therefore, the rubber elastomer particles used are particles containing a layer exhibiting rubber elasticity. The rubber elastomer particles may be particles composed of only the layer exhibiting rubber elasticity, or may be particles of a multi-layer structure having another layer together with the layer exhibiting rubber elasticity. Examples of the rubber elastomer include olefin rubber elastomer, diene rubber elastomer, styrene-diene rubber elastic copolymer, and acrylic rubber elastomer. Among them, an acrylic rubber elastomer is preferably used from the viewpoints of surface hardness, light resistance and transparency of the surface-treated laminated film.

The acrylic rubber elastic polymer can be composed of a polymer mainly composed of an alkyl acrylate. This may be a homopolymer of alkyl acrylate or a copolymer of 50 wt% or more of alkyl acrylate and 50 wt% or less of other monomers. As the alkyl acrylate, generally, the alkyl group having 4 to 8 carbon atoms is used. When a monomer other than alkyl acrylate is copolymerized, examples thereof include alkyl methacrylates such as methyl methacrylate and ethyl methacrylate, styrene monomers such as styrene and alkyl styrene, unsaturated monomers such as acrylonitrile and methacrylonitrile (Meth) acrylate, an alkenyl ester of an unsaturated carboxylic acid such as allyl (meth) acrylate or methallyl (meth) acrylate, a dialkenyl ester of a dibasic acid such as maleic diallyl, an alkylene glycol di And unsaturated carboxylic acid diesters of glycols such as acrylate.

The rubber elastomer particles are preferably particles of a multi-layer structure having a layer of acrylic rubber elastomer. Specifically, it is possible to use a two-layer structure having a hard polymer layer mainly composed of alkyl methacrylate on the outer side of the acrylic rubber elastic polymer, or a two-layer structure having a rigid polymer mainly composed of methacrylic acid alkyl on the inner side of the acrylic rubber elastic polymer Layer structure having a three-layer structure. Examples of the monomer composition in the polymer mainly composed of alkyl methacrylate which constitutes the hard polymer layer formed on the inner side or the outer side of the acrylic rubber elastic polymer include an acrylic resin, The monomer composition of the polymer is the same as that of the monomer composition. In particular, a monomer composition mainly composed of methyl methacrylate is preferably used. The acrylic rubber elastomer particles having such a multi-layer structure can be produced, for example, by the method described in Japanese Patent Publication No. 55-27576.

The average particle diameter of the rubber elastomer particles is preferably in the range of 10 nm to 350 nm. As a result, a slight irregularity is formed on the surface of the film, so that the slidability can be increased. The average particle diameter of the rubber elastomer particles is more preferably 30 nm or more, still more preferably 50 nm or more, still more preferably 300 nm or less, further preferably 280 nm or less.

The average particle diameter of the acrylic rubber elastomer particles of the multi-layer structure is measured as follows. That is, when such rubber elastomer particles are mixed with an acrylic resin to form a film and the cross section thereof is dyed with an aqueous solution of ruthenium oxide, only the rubber elastomer layer is colored and observed in a nearly circular shape, and the acrylic resin in the parent layer is not dyed . Thus, from the cross-section of the thus-dyed film, a thin piece is prepared using a microtome or the like, and this is observed with an electron microscope. Then, 100 dyed rubber elastomer particles are randomly extracted to calculate the respective particle diameters, and the number average value is taken as the average particle diameter. The average particle diameter of the obtained rubber elastomer particles becomes a number average particle diameter because it is measured by such a method.

When an outermost layer is a hard polymer mainly composed of methyl methacrylate and rubber elastomer particles in which an acrylic rubber elastomer is wrapped are used, when the rubber elastomer particles are mixed with the acrylic resin of the matrix, the outermost layer of the rubber elastomer particles And is mixed with the acrylic resin of the matrix. Therefore, when the cross section is dyed with ruthenium oxide and observed with an electron microscope, the rubber elastomer particles are observed as particles except for the outermost layer. Specifically, when the inner layer is an acrylic rubber elastomer and the outer layer is a hard polymer mainly composed of methyl methacrylate, when a rubber elastomer particle having a two-layer structure is used, the acrylic rubber elastomer portion of the inner layer is dyed, Layer structure in which the innermost layer is a hard polymer mainly composed of methyl methacrylate and the intermediate layer is an acrylic rubber elastomer and the outermost layer is a hard polymer mainly composed of methyl methacrylate In the case of using the elastomer particles, the center portion of the innermost layer is not dyed, and only the acrylic rubber elastomer portion of the intermediate layer is observed as a dyed two-layer structure. In the present invention, when acrylic rubber elastomer particles having a multilayer structure are used as the rubber elastomer particles, the average particle diameter of the acrylic rubber elastomer portion is taken as the average particle diameter of the rubber elastomer particles.

Such rubber elastomer particles are preferably blended in a proportion of not more than 30% by weight, more preferably not more than 25% by weight, and still more preferably not more than 20% by weight based on the total amount of the rubber-like elastomer particles and the acrylic resin. If the amount is too large, the surface hardness of the resultant surface-treated laminated film becomes low, which is not preferable. In order to prevent the lowering of the modulus of elasticity of the acrylic resin as described above, it is preferable to reduce the content of the rubber elastomer particles. On the other hand, in order to improve the film formability of the film and the impact resistance of the resultant surface- Rubber elastomer particles are preferably blended in the above-mentioned ratio in order to improve the slidability. The amount of the rubber elastomer particles is preferably not less than 3%, more preferably not less than 5%, based on the total amount of the acrylic elastomer and the acrylic resin. Further, in the present invention, in the case of using multi-layered particles having different layers together with the layer exhibiting rubber elasticity as the rubber elastomer particles, the weight of the portion constituted by the layer exhibiting rubber elasticity and the layer on the inside thereof is regarded as the weight . For example, when the acrylic rubber elastomer particles having the above-described three-layer structure are used, the total weight of the acrylic rubber elastomer portion of the intermediate layer and the hard polymer portion mainly composed of methyl methacrylate of the innermost layer is Weight. When the acrylic rubber elastomer particles of the above-mentioned three-layer structure are dissolved in acetone, the hard polymer portion mainly composed of the acrylic rubber elastomer portion of the intermediate layer and the methyl methacrylate of the innermost layer remains as an insoluble matter, The total weight ratio of the intermediate layer to the innermost layer in the rubber elastomer particles can be easily obtained.

A predetermined amount of rubber elastomer particles may be blended with an acrylic resin and a small amount of a lubricant may further be blended to obtain a raw material for the surface-treated laminated film. When the lubricant is added, the acrylic resin film can be prevented from being tightly wound when rolled in a roll form, thereby improving defects in the wound state. The lubricant may be one having a function of improving the slidability of the surface of the acrylic resin film. Examples of the compound having such a function include a stearic acid compound, an acrylic compound, and an ester compound. Among them, a stearic acid-based compound is preferably used as a lubricant.

Examples of the stearic acid-based compound to be a lubricant include stearic acid itself, stearic acid esters such as methyl stearate, ethyl stearate and stearic acid monoglyceride, stearic acid amide, sodium stearate, calcium stearate, zinc stearate Hydroxystearic acid, sodium 12-hydroxystearate, zinc 12-hydroxystearate, calcium 12-hydroxystearate, 12-hydroxystearic acid, Hydroxystearic acid such as sodium laurylsulfate, lithium laurate and magnesium 12-hydroxystearate, and metal salts thereof. Among them, stearic acid is preferably used.

The blending amount of the lubricant may be 0.15 parts by weight or less, preferably 0.1 parts by weight or less, more preferably 0.07 parts by weight or less, based on 100 parts by weight of the total of the acrylic resin and rubber elastomer particles. If the blending amount of the lubricant is too large, there is a fear that the lubricant may bleed out from the film or lower the transparency of the film.

The rubber-like elastomer particles and, if necessary, the acrylic resin composition in which the lubricant is blended may be finally made into the compositions described so far, and the production method thereof is arbitrary. For example, first, a rubber elastomer particle is prepared, and a monomer as a raw material of the acrylic resin is polymerized in the presence of it to produce an acrylic resin of the matrix, and a composition in which rubber elastic particles are blended with the acrylic resin, A method in which a predetermined amount of the lubricant is added, a method in which the rubber elastomer particles and the acrylic resin are mixed at a predetermined ratio, and, if desired, a predetermined amount of the lubricant is added thereto and mixed by melt kneading or the like.

The acrylic resin may contain various additives such as a fluorescent brightener, a dispersant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent and an antioxidant, if necessary.

The ultraviolet absorber is a compound which absorbs ultraviolet rays having a wavelength of 400 nm or less. When the surface-treated laminated film is used as a protective film of a polyvinyl alcohol-based polarizing film, an effect of improving the durability of the polarizing plate in which the protective film is stuck to the polarizing film can be obtained by blending the ultraviolet absorbing agent. As the ultraviolet absorber, known ones such as benzophenone ultraviolet absorber, benzotriazole ultraviolet absorber, acrylonitrile ultraviolet absorber and the like can be used. Specific examples thereof include 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] Butylphenyl) -5-chlorobenzotriazole, 2,4-di-tert-butyl-6- (5-chlorobenzotriazol- 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, and the like. Among them, 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] is one of preferable ultraviolet absorbers. The blending amount of the ultraviolet absorber can be selected within the range that the transmittance at the wavelength of 370 nm or less of the surface treatment laminated film is preferably 10% or less, more preferably 5% or less, further preferably 2% or less. Examples of the method of containing an ultraviolet absorber include a method of blending an ultraviolet absorber into an acrylic resin in advance and pelletizing it and forming the film into a film by melt extrusion or the like, a method of directly adding an ultraviolet absorber during melt extrusion molding, and the like , Any method can be used.

The infrared absorbing agent is a compound that absorbs infrared rays having a wavelength of 800 nm or more. Examples of the compound include a nitroso compound, a metal complex salt thereof, a cyanine compound, a squalinium compound, a thiol nickel complex salt compound, a phthalocyanine compound, a naphthalocyanine compound, a triarylmethane compound, an iminium compound, , An naphthoquinone compound, an anthraquinone compound, an amino compound, an aminium salt compound, a carbon black, an indium tin oxide, an antimony tin oxide, an oxide, a carbide or a boride of a metal belonging to Group 4A, 5A or 6A of the periodic table And the like. These infrared absorbing agents are preferably selected so as to be able to absorb infrared rays (light having a wavelength in a range of about 800 nm to about 1100 nm), and two or more kinds of infrared absorbing agents may be used in combination. The compounding amount of the infrared absorber can be suitably adjusted, for example, so that the light transmittance at the wavelength of 800 nm or more of the surface-treated laminated film is 10% or less.

2, when the first acrylic resin layer 12 and the second acrylic resin layer 13 are laminated on both sides of the polycarbonate resin layer 15, the rubber elastic particles and each layer of the above- May be different from each other. For example, when the content of the rubber elastic particles of the first acrylic resin layer 12 is reduced, it is advantageous in that the pencil hardness can be increased. On the other hand, if the content of the rubber elastomer particles in the second acrylic resin layer 13 is increased, it is advantageous in terms of improving impact resistance, film formability and adhesion to the polarizing film.

[Polycarbonate-based resin layer]

The polycarbonate resin used for the polycarbonate resin layer 15 can be obtained, for example, by reacting a divalent phenol and a carbonylating agent with an interfacial polycondensation method, a melt ester exchange method or the like. In addition, the carbonate prepolymer can be obtained by a solid- , Those obtained by polymerizing a cyclic carbonate compound by a ring-opening polymerization method, and the like.

Examples of the dihydric phenol include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis { ) Phenyl} methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) (Bisphenol A), 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2- Bis {(3-isopropyl-4-hydroxyphenyl) propane, 2,2-bis {(4-hydroxy-3,5-dibromo) phenyl} propane, Phenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) (4-hydroxyphenyl) -3,3-dimethylbutane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2- Bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, -Isopropylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9- (4-hydroxyphenyl) -o-diisopropylbenzene,?,? '- bis (4-hydroxyphenyl) diisopropylbenzene,?,? '- bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester, and the like, and if necessary, two or more of these may be used.

Among them, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2- Phenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2- Bisphenol selected from bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and?,? '- bis (4-hydroxyphenyl) It is preferable to use bisphenol A alone or in combination with bisphenol A alone or in combination with 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and bisphenol A, 2,2-bis { (4-hydroxy-3-methyl) phenyl} propane and?,? '- bis (4-hydroxyphenyl) -m-diisopropylbenzene.

Examples of the carbonylating agent include a carbonyl halide such as phosgene, a carbonate ester such as diphenyl carbonate, and a haloformate such as a dihaloformate of a dihydric phenol, and if necessary, May be used.

The polycarbonate resin may contain the same additives as those described in the section of the acrylic resin layer.

[Laminated film]

The first acrylic resin layer 12 is formed on one surface of the polycarbonate resin layer 15 made of the polycarbonate resin as described above or the first acrylic resin layer 12 is formed on both surfaces of the polycarbonate resin layer 15 ) And the second acrylic resin layer 13 are formed to obtain the laminated film 16 to be the base material of the surface treated laminated film 10 of the present invention. The method of forming the laminated film 16 is appropriately selected. For example, a co-extrusion molding method in which each resin is melted by an extruder and laminated using a feed block method or a multi-manifold method, or a method in which a polycarbonate- , And a method of coating an acrylic resin on the surface of the film by dissolving it in a solvent as required is advantageously employed. Among them, a co-extrusion molding method is preferably used.

In the coextrusion molding method, the molten resin is brought into close contact with a roll or a belt to form a film. The number, arrangement and material of the rolls or belts are not particularly limited. However, the molten resin may be sandwiched between two metal rolls, or may be brought into contact with and passed through a metal roll and a metal belt, Is preferable for increasing the surface precision of the film surface to improve the surface treatment property. Or a method in which a molten resin is brought into contact with both the metal roll and the metal roll having elasticity so that the molten resin is in contact with both of them in a plane is suitable for obtaining a film in which the distortion during molding is reduced to reduce the anisotropy of strength and heat shrinkability Do. The metallic elastic roll includes, for example, a cylindrical metal thin film which is disposed so as to cover the outer peripheral surface of the axial roll and the molten resin, and is provided between the axial roll and the metal thin film at a temperature A controlled fluid is enclosed, or a metal belt is wound on the surface of a rubber roll, for example.

The laminated film 16 thus obtained has a thickness of 35 mu m to 100 mu m, preferably 40 mu m to 95 mu m, and more preferably 45 mu m to 90 mu m.

The film thickness of the polycarbonate resin layer 15 is 2% to 45% of the total film thickness of the laminated film 16. The ratio of the film thickness of the polycarbonate resin layer 15 to the total film thickness of the laminated film 16 is preferably 5% or more, more preferably 10% or more, and still more preferably 40% or less. If the ratio of the film thickness of the polycarbonate resin layer 15 occupying the total film thickness of the laminated film 16 is too small, the laminated film 16 becomes less resistant to external force and is likely to break. On the other hand, if the ratio of the film thickness of the polycarbonate resin layer 15 to the total film thickness of the laminated film 16 is too large, the surface hardness becomes insufficient.

As shown in Figs. 1 and 2, the surface treatment layer 18 is formed on the surface of the first acrylic resin layer 12. The thickness of the first acrylic resin layer is 30 占 퐉 or more, preferably 35 占 퐉 or more, and more preferably 40 占 퐉 or more. The thicker the first acrylic resin layer, the better the surface hardness of the resultant surface-treated laminated film becomes.

2, when the first acrylic resin layer 12 and the second acrylic resin layer 13 are laminated on both sides of the polycarbonate resin layer 15 to have a three-layer structure, the first acrylic resin layer 12, The film thickness of the first acrylic resin layer 12 and the thickness of the second acrylic resin layer 13 may be the same or different. When these thicknesses are made different, thickening the first acrylic resin layer 12 on which the surface treatment layer 18 is formed is advantageous because the surface hardness is increased. In this case, the film thickness of the second acrylic resin layer 13 is preferably 2 m or more in order to maintain the strength. On the other hand, when the film thicknesses are the same, it is preferable that the thickness of the polycarbonate resin layer 15 occupying the entire film thickness of the laminated film 16 is 35% or less from the viewpoint of maintaining the surface hardness , More preferably not more than 30%.

The laminated film 16 needs to have high transparency and specifically, the internal haze measured according to JIS K7105-1981 " Optical property testing method of plastic " is set to 5% or less. When the internal haze exceeds 5%, it is not preferable since the surface-treated laminated film of the present invention is applied to a polarizing plate and white luminance is lowered when the polarizing plate is attached to an image display device, resulting in darkening of the screen. It is more preferable that the internal haze is 3% or less.

Next, the retardation value of the laminated film 16 will be described. When the refractive index in the in-plane slow axis direction of the film is n _x , the refractive index in the in-plane fast axis direction (direction orthogonal to the slow axis direction) is n _y and the thickness is d, the in-plane retardation value Ro is expressed by the following formula Is defined.

_{Ro = (n x -n y)} × d (I)

When the surface-treated laminated film 10 of the present invention is applied to an optical use, for example, a polarizing plate, the laminated film 16 as a source of the surface-treated laminated film has an in-plane retardation Ro at a wavelength of 590 nm of 100 nm Or less.

[Surface-treated laminated film]

The surface treatment layer 18 is formed on the surface of the first acrylic resin layer 12 of the laminated film 16 to form the surface treated laminated film 10. As an example of the surface treatment, there is a hard coat treatment for the purpose of preventing scratches on the surface in a process of assembling the liquid crystal module. There is also a functional surface treatment such as antistatic treatment. In addition, the antistatic function can be imparted to the other part of the polarizing plate on which the surface-treated laminated film 10 is mounted, in addition to being provided by subjecting the laminated film 16 to surface treatment. As the functional surface treatment for the laminated film 16, there are also other antireflection treatment and antifouling treatment. Further, there is also an antiglare treatment for the purpose of improving the visibility, preventing the external light from being reflected, and reducing the moire caused by the interference of the prism sheet and the color filter. The laminated film 16 in which the first acrylic resin layer 12 is laminated on one side of the polycarbonate resin layer 15 is used as the single layer acrylic resin film, When such a surface treatment is performed on the laminated film 16 in which the first acrylic resin layer 12 and the second acrylic resin layer 13 are laminated on both sides of the polycarbonate resin layer 15, So that it is possible to suppress the breakability.

<Surface Treatment Layer>

The hard coat layer has a function of increasing the surface hardness of the surface treated laminated film 10 and is provided for the purpose of preventing scratches on the surface. The hard coat layer can be measured by a pencil hardness test specified in JIS K 5600-5-4: 1999 "General test methods for paints - Part 5: Mechanical properties of coatings - Section 4: Scratch hardness (pencil method) It is assumed that it represents a hard value. The material forming such a hard coat layer is generally cured by heat or light. Examples thereof include organic hard coat materials such as organic silicon type, melamine type, epoxy type, acrylic type and urethane acrylate type, and inorganic hard coat materials such as silicon dioxide. Of these, urethane acrylate-based and polyfunctional acrylate-based hard coat materials are particularly preferable because of good adhesiveness and excellent productivity.

The hard coat layer may contain various fillers for the purpose of adjusting the refractive index, improving the flexural modulus, stabilizing the volume shrinkage ratio, and further improving the heat resistance, antistatic property, and anti-scattering property. The hard coat layer may contain additives such as an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a leveling agent, and an antifoaming agent.

The antistatic layer is provided for the purpose of imparting conductivity to the surface of the laminated film 16 and suppressing the influence of static electricity. The antistatic layer may be formed, for example, by applying a resin composition containing a conductive material (antistatic agent). Specifically, an antistatic hard coat layer can be formed by allowing an antistatic agent to coexist in the hard coat material used for forming the above-mentioned hard coat layer.

The antireflection layer is a layer for preventing reflection of external light and is provided directly on the surface of the first acrylic resin 12 of the laminated film 16 or through another layer such as a hard coat layer. The surface-treated laminated film 10 provided with the antireflection layer preferably has a reflectance of 2% or less at an incident angle of 5 DEG with respect to light having a wavelength of 430 nm to 700 nm, and more preferably has a reflectance at the same incident angle with respect to light having a wavelength of 550 nm 1% or less.

The thickness of the antireflection layer may be about 0.01 탆 to 1 탆, but it is more preferably 0.02 탆 to 0.5 탆. The antireflection layer is made of a low refractive index layer having a refractive index smaller than that of the layer (laminated film 16, hard coat layer or the like) on which the antireflection layer is provided, specifically, a refractive index of 1.30 to 1.45; a low refractive index layer A plurality of thin film high refractive index layers made of an inorganic compound and a plurality of alternately laminated layers.

The material forming the low refractive index layer is not particularly limited as long as the refractive index is small. For example, a resin material such as an ultraviolet ray-curable acrylic resin, a hybrid material in which inorganic fine particles such as colloidal silica are dispersed in a resin, and a sol-gel material containing an alkoxysilane. Such a low refractive index layer may be formed by applying a polymer after polymerization, or may be formed by applying the monomer in the form of a monomer or oligomer to be a precursor, and then polymerizing and curing it. Further, each of the materials preferably contains a compound having a fluorine atom in the molecule in order to impart antifouling properties.

As the sol-gel material for forming the low refractive index layer, it is very suitably used to have a fluorine atom in the molecule. A typical example of a sol-gel material having fluorine atoms in the molecule is polyfluoroalkylalkoxysilane. The polyfluoroalkylalkoxysilane is, for example, represented by the formula:

CF ₃ (CF ₂ ) _n CH ₂ CH ₂ Si (OR) ₃

, Wherein R represents an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 0 to 12. Among them, a compound in which n is 2 to 6 in the above formula is preferable.

Specific examples of the polyfluoroalkylalkoxysilane include the following compounds.

3,3,3-trifluoropropyltrimethoxysilane,

3,3,3-trifluoropropyltriethoxysilane,

3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyltrimethoxysilane,

3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyltriethoxysilane,

3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl trimethoxysilane,

3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl triethoxysilane and the like.

The low refractive index layer may be composed of a thermosetting fluorine compound or a cured product of an active energy ray-curable fluorine compound. The cured product preferably has a dynamic friction coefficient in the range of 0.03 to 0.15, and preferably has a contact angle to water in the range of 90 to 120 ^° . As the curable fluorine compound, a polyfluoroalkyl group-containing silane compound (for example, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10 , 10-heptadecafluorodecyltriethoxysilane, etc.), and fluorine-containing polymers having a crosslinkable functional group.

The fluorine-containing polymer having a crosslinkable functional group can be prepared by copolymerizing a fluorine-containing monomer with a monomer having a crosslinkable functional group or by copolymerizing a monomer having a fluorine-containing monomer with a functional group, And then adding the compound.

Examples of the fluorine-containing monomer to be used herein include fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, fluorine such as perfluoro-2,2-dimethyl-1,3- Olefins, partially or completely fluorinated alkyl ester derivatives of (meth) acrylic acid, and fully or partially fluorinated vinyl ethers.

Examples of the monomer having a crosslinkable functional group or the compound having a crosslinkable functional group include monomers having a glycidyl group such as glycidyl acrylate and glycidyl methacrylate; monomers having a carboxyl group such as acrylic acid and methacrylic acid; Monomers having a hydroxyl group such as acrylate and hydroxyalkyl methacrylate, monomers having an alkenyl group such as allyl acrylate and allyl methacrylate, monomers having an amino group, and monomers having a sulfonic acid group.

The material for forming the low refractive index layer may be composed of a sol in which inorganic compound fine particles such as silica, alumina, titania, zirconia, magnesium fluoride, etc. are dispersed in an alcohol solvent from the viewpoint of improving scratch resistance. Therefore, the inorganic compound fine particles to be used preferably have a smaller refractive index from the viewpoint of antireflection property. These inorganic compound fine particles may have voids, and hollow fine particles of silica are particularly preferable. The average particle diameter of the hollow fine particles is preferably in the range of 5 nm to 2,000 nm, and more preferably in the range of 20 nm to 100 nm. The average particle diameter referred to herein is the number average particle diameter determined by transmission electron microscope observation.

The antifouling layer is provided for imparting water repellency, oil repellency, cold resistance and antifouling property. A preferred material for forming the antifouling layer is a fluorine-containing organic compound. Examples of the fluorine-containing organic compound include perfluoro fluorine, perfluorosilane, and these high-molecular compounds. The method of forming the antifouling layer may be a physical vapor deposition method, a chemical vapor deposition method, a wet coating method, or the like, which is exemplified by vapor deposition or sputtering depending on the material to be formed. The average thickness of the antifouling layer is usually about 1 nm to 50 nm, preferably 3 nm to 35 nm.

The antiglare layer is a layer having a fine concavo-convex shape on the surface, and is preferably formed of the hard coat material described above.

The antiglare layer having fine irregularities on its surface can be obtained by forming a coating film containing organic fine particles or inorganic fine particles on the surface of the laminated film 16 and providing irregularities based on the fine particles or a method of providing organic fine particles or inorganic fine particles , Or a method of transferring the concave-convex shape by pressing on a roll having a concave-convex shape on its surface (also referred to as an embossing method) after forming a coating film which does not contain a concavo-convex pattern. The formation of such a coating film can be carried out, for example, by applying a coating liquid composed of a composition in which organic or inorganic fine particles are mixed with a curable transparent resin on the surface of the laminated film 16. [

When fine particles are blended to form the antiglare layer, the fine particles preferably have an average particle diameter of 0.5 mu m to 5 mu m and a difference in refractive index from the transparent resin of 0.02 to 0.2. By using fine particles having an average particle diameter and a difference in refractive index from the transparent resin within this range, it is possible to effectively develop haze. The average particle diameter of the fine particles can be obtained by a dynamic light scattering method or the like. In this case, the average particle diameter becomes the weight average particle diameter.

As the inorganic fine particles for forming the antiglare layer, silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate, calcium phosphate and the like can be used. As the organic fine particles, resin particles are generally used. For example, crosslinked polyacrylic acid particles, methyl methacrylate / styrene copolymer resin particles, crosslinked polystyrene particles, crosslinked polymethyl methacrylate particles, silicone resin particles, polyimide Particles and the like.

The transparent resin for dispersing the inorganic fine particles or organic fine particles is preferably selected from a material having a high hardness (hard coat). As such a transparent resin, a photo-curable resin, a thermosetting resin, an electron beam-curable resin or the like can be used, but a photo-curing resin is preferably used from the viewpoints of productivity and hardness of the resulting film. As the photo-curing resin, a polyfunctional acrylate is generally used. Examples thereof include di- or tri-acrylate of trimethylolpropane, tri- or tetra-acrylate of pentaerythritol, polyfunctional urethane acrylate which is the reaction product of an acrylate having at least one hydroxyl group in the molecule with a diisocyanate . These polyfunctional acrylates may be used alone or in combination of two or more thereof as required.

Also, a mixture of a polyfunctional urethane acrylate, a polyol (meth) acrylate, and a (meth) acrylic polymer having an alkyl group containing two or more hydroxyl groups may be used as a photo-curable resin. The polyfunctional urethane acrylate constituting the photo-curing resin is produced, for example, by using (meth) acrylic acid and / or (meth) acrylic acid ester, polyol and diisocyanate. Specifically, a hydroxy (meth) acrylate having at least one hydroxyl group in the molecule is prepared from (meth) acrylic acid and / or a (meth) acrylic acid ester and a polyol and reacted with a diisocyanate to prepare a polyfunctional urethane acrylate can do. The polyfunctional urethane acrylate thus produced may also be a photocurable resin itself which has been previously disclosed. In the preparation, (meth) acrylic acid and / or (meth) acrylic acid ester may be used individually or in combination of two or more kinds. Polyol and diisocyanate may be used either individually or in combination. More than one species may be used in combination.

The (meth) acrylic acid ester which is a raw material of the polyfunctional urethane acrylate may be a straight chain or cyclic alkyl ester of (meth) acrylic acid. Specific examples thereof include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and cyclohexyl (Meth) acrylate such as cyclohexyl (meth) acrylate.

The polyol as another raw material in addition to the polyfunctional urethane acrylate is a compound having at least two hydroxyl groups in the molecule. Examples of the solvent include ethylene glycol, propylene glycol, 1,3-propanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,3-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol esters of hydroxypivalic acid, cyclohexane Dimethylol, 1,4-cyclohexanediol, spiroglycol, tricyclodecane dimethylol, hydrogenated bisphenol A, ethylene oxide added bisphenol A, propylene oxide added bisphenol A, trimethylol ethane, trimethylol propane, glycerin, 1,3,5-triol, pentaerythritol, dipentaerythritol, tripentaerythritol, glucose and the like.

The diisocyanate which is another raw material of the polyfunctional urethane acrylate is a compound having two isocyanate groups (-NCO) in the molecule, and various aromatic, aliphatic or alicyclic diisocyanates can be used. Specific examples include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, Dimethyl-4,4'-diphenyl diisocyanate, xylylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and a nucleophilic addition product of a diisocyanate having an aromatic ring therebetween .

The polyol (meth) acrylate constituting the photocurable resin together with the polyfunctional urethane acrylate is a (meth) acrylate of a compound having at least two hydroxyl groups in the molecule (that is, a polyol). Specific examples thereof include pentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, Diol di (meth) acrylate, and the like. These polyol (meth) acrylates may be used alone or in combination. The polyol (meth) acrylate preferably comprises pentaerythritol triacrylate and / or pentaerythritol tetraacrylate.

The (meth) acrylic polymer having an alkyl group having two or more hydroxyl groups constituting the photo-curable resin together with these polyfunctional urethane acrylate and polyol (meth) acrylate has two or more hydroxyl groups in one structural unit Lt; / RTI &gt; For example, a polymer containing 2,3-dihydroxypropyl (meth) acrylate as a constituent unit or a polymer containing 2,3-dihydroxypropyl (meth) acrylate and 2-hydroxyethyl (meth) And a polymer containing a rate as a constitutional unit.

By using the acrylic photocurable resin as described above, the adhesion with the first acrylic resin layer 12 is improved, and the mechanical strength is improved, whereby the adhesion of the scratched surface can be effectively prevented.

Such a photocurable resin is combined with a photopolymerization initiator to form a photocurable resin composition. Examples of the photopolymerization initiator include acetophenone, benzophenone, benzoin ether, amine, and phosphine oxide. Examples of the compound classified as an acetophenone photopolymerization initiator include 2,2-dimethoxy-2-phenylacetophenone (also, benzyldimethylketal), 2,2-diethoxyacetophenone, 1- (4-methylthiophenyl) propane-1-one, 2-methyl-2-methylphenyl- . Examples of the compound classified as a benzophenone-based photopolymerization initiator include benzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, and the like. Examples of compounds classified as benzoin ether photopolymerization initiators include benzoin methyl ether, benzoin propyl ether, and the like. Examples of the compound classified as an amine-based photopolymerization initiator include N, N, N ', N'-tetramethyl-4,4'-diaminobenzophenone (alias, Michler's ketone). Examples of the phosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like. In addition, a xanthene-based compound or a thioxantone-based compound is also known as a photopolymerization initiator.

These photopolymerization initiators are commercially available. Examples of representative commercial products include "Irgacure 907", "Irgacure 184", and "Lucirin TPO" sold by BASF of Germany.

A solvent is added to the photo-curable resin composition if necessary. In this case, for example, any organic solvent capable of dissolving each component constituting the composition such as ethyl acetate and butyl acetate can be used. Of course, two or more kinds of organic solvents may be mixed and used.

The photo-curing resin composition may contain a leveling agent, for example, a fluorine-based or silicone-based leveling agent. Silicone leveling agents include reactive silicones, polydimethylsiloxanes, polyether-modified polydimethylsiloxanes, and polymethylalkylsiloxanes. Among silicone leveling agents, preferred are leveling agents based on reactive silicones and siloxanes. When a leveling agent made of reactive silicon is used, slipperiness is imparted to the surface of the hard coat layer, and excellent scratch resistance can be maintained for a long period of time. When a siloxane leveling agent is used, film formability can be improved.

When the photo-curable resin is used for forming the antiglare layer, inorganic or organic fine particles are dispersed in each component constituting the photo-curable resin composition described above, and then the resin composition is coated on the laminated film 16 And a hard coat layer (antiglare layer) in which fine particles are dispersed in the transparent resin can be formed by irradiating light.

On the other hand, in the case of forming an antiglare layer having a fine surface irregularity shape by the embossing method, the mold having the fine unevenness formed thereon is used to transfer the shape of the mold to the resin layer formed on the first acrylic resin layer 12 . In the case of forming the fine irregular surface shape by the embossing method, the resin layer to which the irregular shape is transferred may or may not contain inorganic or organic fine particles. An active energy ray curable resin is suitably used for the transfer of the concavo-convex shape according to the emboss method. Particularly preferably, a UV embossing method using an ultraviolet curable resin is employed.

In the UV embossing method, an ultraviolet-curable resin layer is formed on the surface of the first acrylic resin layer 12, and the ultraviolet-curable resin layer is hardened while being pressed against the uneven surface of the metal mold, thereby transferring the uneven surface of the mold to the ultraviolet- do. Specifically, an ultraviolet ray-curable resin is coated on the first acrylic resin layer 12, and ultraviolet rays are irradiated from the side of the laminate film 16 while the coated ultraviolet-ray-curable resin is in close contact with the uneven surface of the mold, Then, the surface-treated laminated film 10 on which the ultraviolet-curable resin layer after curing is formed is peeled off from the mold, thereby transferring the shape of the mold to the ultraviolet-curable resin layer. The kind of the ultraviolet ray hardenable resin is not particularly limited, and various kinds of the above-mentioned ultraviolet ray hardenable resins can be used. Further, a visible light curable resin which can be cured to visible light having a longer wavelength than ultraviolet light may be used by appropriately selecting a photopolymerization initiator instead of the ultraviolet curable resin.

The thickness of the antiglare layer is not particularly limited, but is generally 2 탆 or more and 30 탆 or less, preferably 3 탆 or more, and more preferably 20 탆 or less. If the antiglare layer is too thin, a sufficient hardness can not be obtained and the surface tends to be damaged. On the other hand, if the antiglare layer is too thick, it tends to be easily cracked or the film tends to curl due to curing shrinkage of the antiglare layer, have.

The haze value of the antiglare layer is preferably in the range of 5% to 50%. If the haze value is too small, sufficient antiglare performance can not be obtained, and the non-visible light is liable to appear on the screen. On the other hand, if the haze value is too large, the non-visualization of the external light can be reduced, but the tightness of the black display screen is lowered.

<Pressing strength of surface-treated laminated film>

According to the present invention, the first acrylic resin layer 12 is laminated on one side of the polycarbonate resin layer 15 or the first acrylic resin layer 12 is formed on both sides of the polycarbonate resin layer 15, The surface treated laminated film 10 in which the second acrylic resin layer 13 is formed and the surface treatment layer 18 is further provided on the first acrylic resin layer 12 can have a pressing strength of 20 N or more . If the pressing strength is low, the surface-treated laminated film 10 tends to break due to lack of strength in the step of bonding the surface-treated laminated film 10 to another layer, for example, a polarizing film, . Then, once the film is broken, it is necessary to clean it again and notify (pass) it again, and it takes a long time until the conjugation resumes, so an extra cost is incurred. It is more preferable that the pressing strength is 22 N or more. Here, the pressurized strength means the impact strength of a film specified in JIS K7124-2: 1999 "Plastic Film and Sheet-Impact Test Method According to the Dart Method of Free Fall", Part 2: Instrument Through Method And the stress is measured. This instrument penetration method is a method in which the film is horizontally fixed with a pair of clamps having through-holes and the maximum stress when the striker is vertically penetrated at a constant speed is read using a load cell. The larger the maximum stress at this time, the more difficult the film is to break.

[Polarizer]

The surface-treated laminated film 10 described above with reference to Figs. 1 and 2, as shown in the schematic cross-sectional diagrams in Figs. 3 and 4, shows the side of the polycarbonate resin layer 15 in the case of Fig. 1, 2, the polarizing plate 20 can be formed by attaching the second acrylic resin layer 13 side to the polarizing film 22. [ In this bonding, an adhesive is generally used, and in Fig. 3 and Fig. 4, bonding is performed through the adhesive layer 23. [ An adhesive is applied to either the side of the polycarbonate resin layer 15 of the surface treated laminated film 10 or the side of the second acrylic resin layer 13 and the polarizing film 22, do.

The transparent resin film 26, which is also a protective film, can be applied to the surface of the polarizing film 22 opposite to the surface to which the surface-treated laminated film 10 is bonded. The transparent resin film 26 may be made of the same material as that of the surface-treated laminated film 10, or may be made of a different material. The transparent resin film 26 can also be bonded to the polarizing film 22 using an adhesive. In FIGS. 3 and 4, the transparent resin film 26 is also bonded to the transparent resin film 26 through the adhesive layer 24.

<Polarizing Film>

The polarizing film 22 constituting the polarizing plate 20 may be prepared by a known method such as a step of uniaxially stretching a polyvinyl alcohol based resin film, a step of staining the polyvinyl alcohol based resin film with a dichroic dye, A step of adsorbing a dichroic dye, a step of treating a polyvinyl alcohol-based resin film adsorbed with a dichroic dye with an aqueous solution of boric acid, and a step of washing with water after treatment with an aqueous solution of boric acid. The thus obtained polarizing film has an absorption axis in the uniaxially stretched direction.

As the polyvinyl alcohol-based resin, a saponified polyvinyl acetate-based resin can be used. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamides having an ammonium group, and the like.

The saponification degree of the polyvinyl alcohol-based resin is usually from 85 mol% to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehyde may be used. The polymerization degree of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

Such a polyvinyl alcohol-based resin film is used as the original film of the polarizing film. The method of forming the polyvinyl alcohol-based resin is not particularly limited, and a known method is employed. The film thickness of the polyvinyl alcohol-based original film is not particularly limited, but is, for example, about 10 탆 to 150 탆.

The uniaxial stretching of the polyvinyl alcohol based resin film can be carried out before, simultaneously with, or after dyeing with a dichroic dye. In the case where uniaxial stretching is carried out after dyeing, this uniaxial stretching may be carried out before the boric acid treatment or during the boric acid treatment. It is also possible to perform uniaxial stretching in these plural steps.

The uniaxial stretching may be carried out by passing between the separated rolls having different main speeds, or may be carried out by placing them between the rollers. The uniaxial stretching may be dry stretching in which stretching is performed in the atmosphere, or wet stretching in which a polyvinyl alcohol based resin film is stretched by using a solvent such as water or an organic solvent. The draw ratio is usually about 3 to 8 times.

The dyeing by the dichroic dye of the polyvinyl alcohol-based resin film can be carried out by, for example, a method of immersing the polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic dye. Iodine or a dichroic organic dye is used as the dichroic dye. The polyvinyl alcohol-based resin film is preferably subjected to immersion treatment with water before the dyeing treatment.

When iodine is used as the dichroism dye, a method in which a polyvinyl alcohol resin film is dipped in an aqueous solution containing iodine and potassium iodide is generally used. The content of iodine in the aqueous solution is usually 0.01 to 1 part by weight per 100 parts by weight of water. The content of potassium iodide is usually about 0.5 to 20 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is usually about 20 ° C to 40 ° C. The immersion time (dyeing time) for this aqueous solution is usually about 20 seconds to 1,800 seconds.

On the other hand, when a dichroic organic dye is used as the dichroic dye, a method in which a polyvinyl alcohol-based resin film is dipped in an aqueous solution containing a water-soluble dichroic organic dye is usually employed. Dichroic content of the organic dye in the aqueous solution of water per 100 parts by weight normally 1 × 10 ^- is about ⁴ parts by weight to 10 parts by weight, preferably from 1 × 10 ^- is about ³ parts by weight to 1 part by weight. The aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80 캜. The immersion time (dyeing time) for this aqueous solution is usually about 10 seconds to 1,800 seconds.

The boric acid treatment after dyeing with the dichroic dye can be carried out by dipping the dyed polyvinyl alcohol resin film in an aqueous solution containing boric acid. The amount of boric acid in the aqueous solution containing boric acid is usually about 2 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. When iodine is used as the dichroic dye, it is preferable that the aqueous solution containing boric acid contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight per 100 parts by weight of water. The immersion time for the boric acid-containing aqueous solution is usually about 60 seconds to 1,200 seconds, preferably 150 seconds to 600 seconds, more preferably 200 seconds to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50 ° C or higher, preferably 50 ° C to 85 ° C, and more preferably 60 ° C to 80 ° C.

The polyvinyl alcohol resin film after boric acid treatment is usually subjected to water washing treatment. The water washing treatment is carried out, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The temperature of the water in the water washing treatment is usually about 5 ° C to 40 ° C. The immersion time is usually about 1 second to about 120 seconds.

After washing with water, drying treatment is carried out to obtain a polarizing film. The drying treatment can be carried out using a hot-air dryer or a far-infrared heater. The drying treatment is usually carried out at a temperature of about 30 ° C to 100 ° C, preferably 50 ° C to 80 ° C. The drying treatment time is usually about 60 seconds to 600 seconds, preferably 120 seconds to 600 seconds.

By the drying treatment, the water content of the polarizing film is reduced to a practically acceptable level. The water content thereof is usually 5% by weight to 20% by weight, preferably 8% by weight to 15% by weight. If the moisture content is less than 5% by weight, flexibility of the polarizing film may be lost and the polarizing film may be damaged or broken after drying. On the other hand, when the moisture content exceeds 20% by weight, the thermal stability of the polarizing film tends to be insufficient.

The thickness of the polarizing film on which the dichroic dye thus obtained is adsorbed and oriented can usually be about 5 占 퐉 to 40 占 퐉.

&Lt; Transparent resin film adhered to the other surface of the polarizing film &

As described earlier with reference to Figs. 3 and 4, the transparent resin film 26 can be attached to the opposite side of the surface to which the surface-treated laminated film 10 of the polarizing film 22 is adhered. The transparent resin film 26 is not particularly limited as long as it functions as a protective film or a retardation film of a polarizing plate, and examples thereof include a triacetyl cellulose film, a polycarbonate film, a polyethylene terephthalate film, an acrylic resin film, Based resin film, an olefin-based resin film, or the like. Of these, an olefin-based resin film is preferably used.

The olefinic resin is a resin obtained by polymerizing, for example, a chain olefin monomer such as ethylene or propylene, or a cyclic olefin monomer such as norbornene or other cyclopentadiene derivatives using a polymerization catalyst.

Examples of the olefin-based resin obtained from the chain olefin monomer include a polyethylene-based resin and a polypropylene-based resin. Among them, polypropylene which is a homopolymer of propylene is preferable. Also preferred is a polypropylene-based copolymer resin in which propylene is used as a main component and a comonomer copolymerizable therewith is usually copolymerized in a proportion of 1 wt% to 20 wt%, preferably 3 wt% to 10 wt% .

The comonomer copolymerizable with propylene is preferably ethylene, 1-butene or 1-hexene. Of these, ethylene is preferably used because it is relatively excellent in transparency and drawability, and a polypropylene copolymer resin in which ethylene is copolymerized in a proportion of 1 to 20 wt%, particularly 3 to 10 wt% It is one of them. When the copolymerization ratio of ethylene is 1% by weight or more, transparency and stretchability are improved. On the other hand, if the proportion exceeds 20% by weight, the melting point of the resin may be lowered and the heat resistance required for the protective film or the retardation film may be impaired.

Examples of the polypropylene resin include commercially available products such as "Prime polypropylene" sold by Prime Polymer Co., Ltd. under the trade name of "Novatech" and "Wintech" sold by Japan Polypropylene Co., "" Sumitomonobrene "sold by Sumitomo Chemical Co., Ltd., and" San Aroma "sold by San Aroma Co., Ltd., and the like.

The olefin-based resin obtained by polymerizing the cyclic olefin monomer is generally also referred to as a cyclic olefin-based resin, an alicyclic olefin-based resin, or a norbornene-based resin. Herein, it is referred to as a cyclic olefin resin.

As the cyclic olefin-based resin, ring-opening metathesis polymerization is carried out using, for example, cyclopentadiene and norbornene or a derivative thereof obtained by the Diels-Alder reaction from olefins as a monomer, followed by ring- Resin: ring-opening metathesis polymerization is carried out using dicyclopentadiene and tetracyclododecene or its derivative obtained by the Diels-Alder reaction from olefins or (meth) acrylates as monomers, followed by hydrogenation A resin obtained by conducting ring-opening metathesis copolymerization using two or more kinds of norbornene, tetracyclododecene, these derivatives, or other cyclic olefin monomers, followed by hydrogenation; At least one kind selected from borane, tetracyclododecene and derivatives thereof To the olefin and an aliphatic or aromatic compound having a vinyl group may be added to the resin obtained by copolymerization or the like.

For example, "TOPAS" (Topaz), which is produced by TOPAS ADVANCED POLYMERS GmbH of Germany and sold by Polyplastics Co., Ltd., Japan, and JSR Co., Ltd., which are commercially available from Polyplastics Co., "Arton", which is manufactured and sold, "Zeonoa" and "Zeonex", which are manufactured and sold by Japan Zeon Corporation, and "Apel", which is manufactured and sold by Mitsui Chemicals, Inc.

The transparent olefin resin or the cycloolefin resin may be formed into a film to form a transparent resin film 26 bonded to one side of the polarizing film 22. [ The method of film formation is not particularly limited, but a melt extrusion film forming method is preferably adopted.

The olefin resin film can also be easily obtained as a commercially available product. For example, in case of a polypropylene resin film, "FILMAX CPP film" sold by FILMAX under the trade name, " "TOYOBO", which is sold by Toyo Boseki Co., Ltd., "Toray Pan" sold by Toor Films Processing Co., Ltd., Japan Poly Ace Co., Ltd. &Quot; Nippon Polyes, " which are sold by Nippon Polyurethane Industry Co., Ltd., and "Tyco FC" sold by Futamura Chemical Co., Examples of the cycloolefin resin film include "Zeonoah film" sold under the trade name of Japan Zeon Co., Ltd. and "Aton film" sold by JSR Corporation.

The transparent resin film 26 may be provided with an optical functional film laminated on its surface or coated with an optical functional layer. Examples of such optically functional film and optical functional layer include an easy-to-adhere layer, a conductive layer, and a hard coat layer.

By stretching the above-described olefin-based resin film to impart refractive index anisotropy to the film, the function of the retardation film can be imparted. The stretching method may be appropriately selected according to the refractive index anisotropy required, and is not particularly limited. For example, longitudinal uniaxial stretching, transverse uniaxial stretching, or biaxial stretching in the transverse direction are adopted.

The olefin resin has a positive refractive index anisotropy so that the refractive index becomes the largest in the direction in which the stress is applied, so that the uniaxially stretched film usually gives refractive index anisotropy of n _x > n _y ≒ n _z . Herein, n _x is the refractive index of the film in the in-plane slow axis direction (in the direction in which the refractive index is maximum in the plane, and in the stretching direction in the resin having positive refractive index anisotropy), and n _y is the in- Axis), and n _z is the refractive index in the normal direction of the film. A film obtained by biaxially stretching an olefin resin in order gives a refractive index anisotropy usually n _x > n _y > n _z .

In order to impart a desired refractive index characteristic, the retardation film may be produced by a method in which a thermally shrinkable film is laminated to a target film and is subjected to stretching or shrinking the film together with stretching. This operation is usually carried out in order to obtain a retardation film whose refractive index anisotropy is n _x > n _z > n _y or n _z > n _x ≥n _y .

A retardation film made of an olefin-based resin can also be commercially available. For example, in the case of a phase difference film made of a cyclic olefin based resin, "Zeonoah film" marketed by Japan Zeon Co., Ltd. under the trade name "Aaton film" marketed by JSR Co., Ltd. and marketed by Sekisui Chemical Co., And "Essenia phase difference film ".

[Bonding of polarizing film, surface-treated laminated film and transparent resin film]

The adhesion of the polarizing film 22 to the polycarbonate resin layer 15 or the second acrylic resin layer 13 of the surface treated laminated film 10 and the bonding of the polarizing film 22 and the transparent resin film 26 An adhesive is used as described above. The adhesion surface of the polycarbonate resin layer 15 constituting the surface treated laminated film 10 or the polarizing film 22 of the second acrylic resin layer 13 and the surface of the polarizing film 22 At least one of the concave surfaces for the processing laminated film 12 and at least one of the concave surfaces of the polarizing film 22 to the transparent resin film 26 and the concave surface to the polarizing film 22 of the transparent resin film 26 It is preferable that corona discharge treatment, plasma irradiation treatment, electron beam irradiation treatment and other surface activation treatment are performed on one side.

The adhesives for forming the adhesive layers 23 and 24 shown in Figs. 3 and 4 can be arbitrarily selected from those which exhibit an adhesive force with respect to each member. Typically, an aqueous adhesive, that is, an active energy ray-curable adhesive containing a component dissolving an adhesive component in water or dispersing an adhesive component in water, or a component cured by irradiation with an active energy ray can be given. From the viewpoint of productivity, an active energy ray-curable adhesive is preferably used.

First, the water-based adhesive will be described. For example, a composition using a polyvinyl alcohol-based resin or a urethane resin as a main component may be mentioned as a preferable adhesive.

When a polyvinyl alcohol-based resin is used as the main component of the water-based adhesive, the polyvinyl alcohol-based resin may be a partially saponified polyvinyl alcohol, a fully saponified polyvinyl alcohol, a carboxyl group-modified polyvinyl alcohol, an acetoacetyl group-modified polyvinyl alcohol, Or a modified polyvinyl alcohol-based resin such as polyvinyl alcohol-modified polyvinyl alcohol and amino group-modified polyvinyl alcohol. When a polyvinyl alcohol-based resin is used as an adhesive component, the adhesive is often prepared as an aqueous solution of a polyvinyl alcohol-based resin. The concentration of the polyvinyl alcohol-based resin in the aqueous adhesive solution is usually about 1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of water.

In order to improve the adhesiveness, it is preferable to add a curing component such as glyoxal or a water-soluble epoxy resin or a crosslinking agent to an aqueous adhesive containing a polyvinyl alcohol resin as a main component. Examples of the water-soluble epoxy resin include polyamide polyamines obtained by reacting epichlorohydrin with polyamide polyamines obtained by the reaction of polyalkylene polyamines such as diethylene triamine and triethylene tetramine with dicarboxylic acids such as adipic acid Epoxy resins. Examples of commercially available products of such polyamide polyamine epoxy resins include "Sumirez Resin 650" and "Sumirez Resin 675" sold by Sumika Chemtech Co., Ltd. and "WS-525" sold by PMC Japan Co., And they can be used very well. The amount of the curing component or crosslinking agent to be added is usually 1 to 100 parts by weight, preferably 1 to 50 parts by weight, based on 100 parts by weight of the polyvinyl alcohol-based resin. When the addition amount is small, the adhesiveness improving effect is small. On the other hand, when the addition amount is large, the adhesive layer tends to have low resistance to external force.

When a urethane resin is used as a main component of the water-based adhesive, a mixture of a polyester-based ionomer-type urethane resin and a compound having a glycidyloxy group can be mentioned as an example of a suitable adhesive composition. The polyester-based ionomer-type urethane resin referred to herein is a urethane resin having a polyester skeleton in which a small amount of an ionic component (hydrophilic component) is introduced. The ionomeric urethane resin is very suitable as an aqueous adhesive since it emulsifies in water directly without using an emulsifier and becomes an emulsion. Use of a polyester-based ionomer-type urethane resin for bonding a polarizing film and a protective film is disclosed, for example, in Japanese Patent Application Laid-Open Nos. 2005-70139, 2005-70140, 2005-181817, to be.

On the other hand, when an activating energy ray-curable adhesive is used, a component (hereinafter sometimes simply referred to as "curable component") which is cured by irradiation of an active energy ray constituting the component is an epoxy compound, an octacene compound, have. When a cationic polymerizable compound such as an epoxy compound or an octacene compound is used, a cationic polymerization initiator is incorporated. When a radical polymerizable compound such as an acrylic compound is used, a radical polymerization initiator is added. Among them, an adhesive which makes the epoxy compound one of the curable components is preferable, and an adhesive which makes the alicyclic epoxy compound having an epoxy group directly bonded to the saturated carbon ring as one of the curable components is preferable. It is also effective to use an oxetane compound in combination therewith.

The epoxy compounds are commercially available, for example, from "Epicoat" series sold by Japan Epoxy Resin Co., Ltd. under the trade name "Epiclon" series sold by DIC Co., Ltd., "Adeka Resin" series sold by ADEKA Corporation, "Denakol" series sold by Nagase Chemtex Co., Ltd., "Dow Epoxy" series sold by Dow Chemical Co., And "Tepik" sold by Nissan Chemical Industries,

Alicyclic epoxy compounds to which an epoxy group is bonded directly to a saturated carbon ring can also be easily obtained from commercial products. For example, "Seroxide" series sold by Daicel Chemical Industries, Ltd. and " "Series, and" Saracuia "series sold by Dow Chemical.

Oxetane compounds are also commercially available. Examples thereof include "Aronoxetane" series sold by Donga Synthetic Co., Ltd., and "ETERNACOLL" series sold by Ube Industries, Ltd., etc.

Cationic polymerization initiation system. Commercially available products can be easily obtained. For example, the "Kayarad" series sold by Nippon Yakiniku Co., Ltd., the "Saracuia" series sold by Union Carbide Co., TAS "," BBI "and" DTS "sold by Midori Kagaku Co., Ltd.," Adeka Optoma "series sold by ADEKA Co., Ltd., And the "RHODORSIL" series, which are sold from.

The active energy ray-curable adhesive may contain a photosensitizer as required. By using a photosensitizer, the reactivity is improved and the mechanical strength and adhesive strength of the cured layer can be further improved. Examples of the photosensitizer include carbonyl compounds, organic sulfur compounds, persulfates, redox compounds, azo and diazo compounds, anthracene compounds, halogen compounds, and photoreducation pigments.

In addition, various kinds of additives can be added to the active energy ray-curable adhesive within the range not deteriorating the adhesiveness thereof. Examples of the additives include an ion trap agent, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, a defoaming agent and the like. In addition, a curing component which is cured by a reaction mechanism different from the cationic polymerization may also be added within the range not deteriorating the adhesiveness.

The above-described active energy ray-curable adhesive is applied to the surface of the polycarbonate resin layer 15 of the surface-treated laminated film 10 or the surface of the second acrylic resin layer 13 or the polarizing film 22, And the adhesive layer 23 is cured by irradiating an active energy ray thereon to bond the polarizing film 22 and the polycarbonate resin layer 15 or the second acrylic resin layer 13 to each other. The polarizing film 22 and the transparent resin film 26 are applied to the concave surface of the polarizing film 22 and the transparent resin film 26. The polarizing film 22 and the transparent resin film 26 are bonded to each other. The adhesive for forming the adhesive layer 23 and the adhesive for forming the adhesive layer 24 may have the same composition or different compositions, but it is preferable to conduct the irradiation of the active energy ray for curing the both at the same time.

The active energy rays used for curing the active energy ray curable adhesive include, for example, X-rays having a wavelength of 1 nm to 10 nm, ultraviolet rays having a wavelength of 10 nm to 400 nm, visible rays having a wavelength of 400 nm to 800 nm . Among them, ultraviolet rays are preferably used from the viewpoints of ease of use and ease of preparation of the active energy ray-curable adhesive, stability and curing performance. Examples of the ultraviolet light source include low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, ultra high pressure mercury lamps, chemical lamps, black light lamps, microwave excited mercury lamps, metal halide lamps and the like having luminous distribution with a wavelength of 400 nm or less.

The thickness of the adhesive layer obtained by using the active energy ray-curable adhesive is usually about 1 to 50 mu m, but is preferably in the range of 1 to 10 mu m.

[Use of Polarizer]

The polarizing plate 20 having the configuration shown in Figs. 3 and 4 as a representative example can be a liquid crystal panel used in a liquid crystal display by being attached to the viewer side of the liquid crystal cell. Another polarizing plate is generally bonded to the opposite side of the liquid crystal cell. The pressure-sensitive adhesive layer can be provided on the outer side of the transparent resin film 26, that is, on the side opposite to the coplanar surface with respect to the polarizing film 22. [ The pressure-sensitive adhesive layer is generally formed of an acrylic pressure-sensitive adhesive having acrylic acid ester as a main component and an acrylic resin copolymerized with an acrylic monomer containing a functional group as a pressure-sensitive adhesive component. When the pressure-sensitive adhesive layer is attached to the liquid crystal cell in this way, the surface-treated laminated film 10 becomes a liquid crystal panel arranged on the viewer side. The liquid crystal cell constituting the liquid crystal panel can be various ones used in this field.

Example

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the examples,% and parts representing the content or amount are based on the weight unless otherwise noted.

In the examples and comparative examples, the inner haze and the in-plane retardation value Ro of the laminated film before the formation of the surface treatment layer produced by coextrusion and the pressing strength, the pencil hardness and the total haze of the surface- .

[Measurement of internal haze of laminated film]

The haze was measured in accordance with JIS K7105-1981 &quot; Optical property test method of plastic &quot; in a state in which a sample of the laminated film was immersed in a quartz cell containing dimethyl dimethyl phthalate (surface haze was substantially zero).

[Measurement of in-plane retardation value Ro of the laminated film]

The in-plane retardation value Ro of the laminated film was measured at a wavelength of 590 nm using a phase difference measuring apparatus "KOBRA-WR" manufactured by Prince Measurement Instruments Co.,

[Measurement of pressing strength of surface-treated laminated film]

The pressing strength of the surface-treated laminated film was measured by using the "LF Plus Lloyd Material Testing Machine" obtained from Yasuda Precision Machinery Co., Ltd., JIS K7124-2: 1999 "Impact test method by plastic film and sheet-free fall dart method Part 2: Instrument penetration method &quot;. At this time, the inner diameter of the test piece clamp (the diameter of the circle against which the test piece was impacted) was set to 15 mm, and the striker having a semi-spherical striking surface with a diameter of 10 mm was set at the center. The impact test speed was 0.5 mm / min. The striker-contacted surface was an acrylic resin layer on the side opposite to the surface treatment layer formation side, that is, the polycarbonate resin layer or the surface treatment layer was not formed. The maximum stress due to the impact test was regarded as the pressing strength.

[Measurement of pencil hardness of surface-treated laminated film]

The pencil hardness of the surface treated laminated film can be measured by the method described in JIS K5600-5-4: 1999 "General Test Methods for Paints - Part 5: Mechanical Properties of Coating Films - Section 4: Scratch Hardness (Pencil Method)" According to the pencil hardness test, the surface-treated laminated film on which the hard coat layer was formed was placed on a glass plate so that the surface-treated layer was positioned thereon.

[Measurement of total haze of surface-treated laminated film]

The haze value of the surface-treated laminated film sample was measured in accordance with JIS K7136: 2000 &quot; Method of obtaining haze of plastic-transparent material &quot;.

[ Example  1 to 4]

(A) Production of laminated film

Wherein the innermost layer is made of a hard polymer polymerized by using methyl methacrylate and a small amount of allyl methacrylate, and the intermediate layer is composed of a soft polymer polymer comprising butyl acrylate as a main component and further styrene and a small amount of allyl methacrylate Layer elastic elastomeric particle composed of a rubber elastic body and a rigid polymer polymerized by using an outermost layer of methyl methacrylate and a small amount of ethyl acrylate as the rubber elastic body, . Further, in this rubber elastic body particle, the total weight of the innermost layer and the intermediate layer was 70% of the whole particles. On the other hand, "ALTUGLAS HT121" which is a methyl methacrylate resin made by ARKEMA Co., Ltd. was prepared, and the above rubber elastomer particles were compounded in the ratio described in the column of "high amount" To prepare an acrylic resin composition. In Table 1 to 3, &quot; high solids content &quot; is the ratio of the total weight of the innermost layer and the intermediate layer in the rubber-like elastic particles to the acrylic resin composition.

As the polycarbonate resin, "Caliber 301-10" manufactured by Sumikastar Theory Polycarbonate Co., Ltd. was used.

The pellets of the acrylic resin composition were poured into a single screw extruder of 65 mm diameter into a single screw extruder of 45 mm diameter into a 45 mm diameter screw extruder and melted and integrated by melt lamination in a multi- And extruded through a T-die. The obtained film was sandwiched between a pair of metal rolls whose surfaces were smooth, and a laminated film having a two-layer structure with a thickness of 80 mu m was produced. At this time, by controlling the extrusion amount of the extruder, the ratio of the polycarbonate-based resin layer to the total film thickness of the laminated film was as shown in the column of &quot; PC layer ratio &quot; Table 1 shows the measurement results of the internal haze and the in-plane retardation value Ro of the obtained laminated film.

(B) Preparation of coating liquid for forming a surface treatment layer

(Reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate), and the weight ratio of the former / the latter to the latter is 60/40 , A total concentration of both of them was 60%, and a leveling agent was further compounded. The pentaerythritol triacrylate and the polyfunctional urethane acrylate constituting the photocurable resin composition are collectively referred to as " curable acrylate ". To 100 parts of the curable acrylate of the photo-curing resin composition, 1 part of a photopolymerization initiator "Irgacure 184 &quot; manufactured by BASF was added to prepare a coating liquid for forming a surface treatment layer.

(C) Preparation of surface-treated laminated film

The coating liquid for forming a surface treatment layer prepared in the above (B) was coated on the surface of the acrylic resin layer of the laminated film prepared in the above (A) so that the coating film thickness after drying was 6 탆, And the coating film was dried for a minute. After drying, the coating film was cured by irradiating light from a high-pressure mercury lamp having a strength of 20 mW / cm 2 from the coating film side to 400 mJ / cm 2 in terms of h-line converted light quantity to prepare a surface treatment layer having a surface treatment layer formed on the surface of the acrylic resin layer Thereby producing a laminated film. Table 1 shows the results of the measurement of the pressing strength, the pencil hardness and the total haze of the obtained surface-treated laminated film. In addition, even when the film was bent with the surface treatment layer-formed surface facing outward, the film was not broken, and the film had good bending resistance.

[ Example  5]

(A) Production of laminated film

A laminated film having a thickness of 80 占 퐉 was prepared in accordance with (A) of Examples 1 to 4 except that the three-layer structure of the first acrylic resin layer / the polycarbonate resin layer / the second acrylic resin layer was used. At this time, the ratio of the amount of the rubber elastomer particles in the acrylic resin to the total thickness of the laminated film occupied by the polycarbonate-based resin layer was as shown in the columns of "high rubber amount" and "PC layer ratio" The composition and thickness of the first and second acrylic resin layers were the same. Table 1 shows the measurement results of the internal haze and the in-plane retardation value Ro of the obtained laminated film.

(C) Preparation of surface-treated laminated film

A surface-treated layer was formed on one surface of the acrylic resin layer of the laminated film prepared in the above (A) in the same manner as in (C) of Examples 1 to 4 to prepare a surface-treated laminated film. Table 1 shows the results of the measurement of the pressing strength, the pencil hardness and the total haze of the obtained surface-treated laminated film. Also, the bending resistance was good.

[ Comparative Example  1-3]

(A) Production of laminated film

A single layer film of acrylic resin having a thickness of 80 占 퐉 was produced in accordance with Examples 1 to 4 (A) except that pellets of the same acrylic resin were put into both of a single screw extruder of 65 mmφ and a single screw extruder of 45 mm did. At this time, the compounding amount of the rubber elastomer particles in the acrylic resin was as shown in the column of &quot; high solids content &quot; Table 1 shows the measurement results of the internal haze and the in-plane retardation value Ro of the obtained film.

(C) Production of surface treated film

A surface-treated layer was formed on one surface of the single-layer film prepared in the above (A) in the same manner as in (C) of Examples 1 to 4 to prepare a surface-treated film. Table 1 shows the measurement results of the pressure-sensitive adhesive strength, the pencil hardness and the total haze of the obtained surface-treated film. Since they do not have a polycarbonate-based resin layer, they break when the film is bent with the surface treatment layer-forming side facing outward, and the bending resistance is poor.

[ Comparative Example  4 ~ 6]

The amount of the rubber elastomer particles in the acrylic resin and the ratio of the polycarbonate resin layer to the total film thickness of the laminated film are as shown in the columns of "high rubber amount" and "PC layer ratio", respectively, A laminated film and a surface treated laminated film were produced in accordance with Examples 1 to 4. The results of measurement of the physical properties of each of the obtained films are shown in Table 1. These surface-treated laminated films are good in endurance due to the application of the polycarbonate resin layer, but the film of Comparative Example 4 contains too much rubber elastomer particles in the acrylic resin, and the films of Comparative Examples 5 and 6 are laminated films The ratio of the polycarbonate-based resin layer to the entire film thickness was too large and did not show desired pencil hardness.

[ Comparative Example  7]

The amount of the rubber elastomer particles in the acrylic resin and the ratio of the polycarbonate resin layer to the total film thickness of the laminated film are as shown in the columns of "high rubber amount" and "PC layer ratio", respectively, A laminated film having a three-layer structure and a surface-treated laminated film were produced in accordance with Example 5. The results of measurement of the physical properties of each of the obtained films are shown in Table 1. This surface-treated laminated film had a favorable bendability, but the thickness (25 탆) of the acrylic resin layer on which the surface treatment layer was formed was too thin and did not show the desired pencil hardness.

[ Example  6 ~ 7]

(A) Production of laminated film

The first acrylic resin composition was adjusted in accordance with Examples 1 to 4 (A) except that the amounts of the rubber elastomer particles were changed to the amounts described in the column of &quot; high amount &quot; of the &quot; PMMA- The second acrylic resin composition was adjusted in accordance with (A) of Examples 1 to 4, except that the amount of the particles was changed to the amount described in the column of &quot; high amount of PMMA-2 layer &quot;

The pellets of the first acrylic resin composition were applied to a single screw extruder of 65 mmφ in a single screw extruder of 45 mmφ in the same polycarbonate resin as used in Examples 1 to 4, The pellets were put into a 40 mm diameter uniaxial extruder, melted, melt-laminated and integrated in a multi-manifold manner, and extruded through a T-die at a set temperature of 260 占 폚. The resultant film was sandwiched between a pair of metal rolls having smooth surfaces to produce a laminated film having three layers of a first acrylic resin layer / polycarbonate resin layer / second acrylic resin layer having a thickness of 60 占 퐉 . At this time, by adjusting the extrusion amount of the extruder, the ratio of the polycarbonate-based resin layer to the total film thickness of the laminated film was as shown in the column of &quot; PC layer ratio &quot; Table 2 shows the measurement results of the internal haze and the in-plane retardation value Ro of the obtained laminated film.

(C) Preparation of surface-treated laminated film

A surface-treated layer was formed on the surface of the first acrylic resin layer of the laminated film prepared in the above (A) in the same manner as in (C) of Examples 1 to 4 to prepare a surface-treated laminated film. Table 2 shows the results of the measurement of the pressure strength, pencil hardness and total haze of the obtained surface-treated laminated film. Also, the bending resistance was good.

[ Example  8 ~ 9]

The proportion of the rubber elastomer particles in the acrylic resin and the ratio of the polycarbonate resin layer to the total film thickness of the laminated film were as shown in the columns of "rubber weight" and "PC layer ratio", respectively, And a thickness of 60 mu m, and a laminated film and a surface-treated laminated film were produced according to Examples 1 to 4, respectively. Table 3 shows the results of measurement of physical properties of each of the obtained films.

[ Comparative Example  8]

A single-layer film and a surface-treated film were produced in the same manner as in Comparative Example 1 except that the thickness was changed to 60 탆. Table 3 shows the results of measurement of physical properties of each of the obtained films. Since there was no polycarbonate-based resin layer, the resulting surface-treated film had poor bending resistance.

Industrial availability

The single-layer film of the acrylic resin subjected to the surface treatment has a weak resistance to external force and is easily broken, but the surface-treated laminated film of the present invention in which the polycarbonate resin layer is laminated is difficult to break. For this reason, it is possible to industrially advantageously produce a functional film, for example, a polarizing plate in which the production stability in the case of bonding to another layer, for example, a polarizing film can be enhanced and another layer is further laminated.

10 ... ... Surface treated laminated film,
12 ... ... A first acrylic resin layer,
13 ... ... A second acrylic resin layer,
15 ... ... A polycarbonate-based resin layer,
16 ... ... Laminated film,
18 ... ... Surface treatment layer,
20 ... ... Polarizer,
22 ... ... Polarizing film,
23, 24 ... ... Adhesive layer,
26 ... ... Transparent resin film.

Claims (8)

A surface-treated laminated film having a polycarbonate-based resin layer, an acrylic resin layer and a surface-treated layer,
Wherein the acrylic resin layer is laminated on one side or both sides of the polycarbonate resin layer,
When the acrylic resin layer is laminated on one surface of the polycarbonate resin layer, the acrylic resin layer is formed on the opposite surface of the acrylic resin layer from the polycarbonate resin layer and the acrylic resin layer is formed on both surfaces of the polycarbonate resin layer The surface treatment layer is formed on the side of the one acrylic resin layer opposite to the polycarbonate resin layer,
Wherein the surface treatment layer imparts hardness of H or harder than that,
The polycarbonate-based resin layer and the acrylic resin layer laminated on one or both surfaces thereof have a total thickness of 35 mu m to 100 mu m and an internal haze of 5% or less,
The thickness of the polycarbonate resin layer is 2% to 45% with respect to the total film thickness of the polycarbonate resin layer and the acrylic resin layer laminated on one side or both sides thereof,
Wherein the thickness of the acrylic resin layer on which the surface treatment layer is formed is 30 占 퐉 or more. The method according to claim 1,
Wherein the acrylic resin layer is formed of an acrylic resin composition containing rubber elastomer particles having an average particle size of 10 nm to 350 nm in a proportion of 30 wt% or less based on the total amount. The method according to claim 1 or 2,
A surface treated laminated film having a pressing strength of 20 N or more. The method according to any one of claims 1 to 3,
A surface-treated laminated film used as a protective film of a polarizing film made of a polyvinyl alcohol-based resin in which a dichroic dye is adsorbed and oriented. The method of claim 4,
Wherein the polycarbonate-based resin layer and the acrylic resin layer laminated on one or both sides thereof have an in-plane retardation value of 100 nm or less. The surface treated laminated film according to claim 4 or 5,
A polarizing film made of a polyvinyl alcohol-based resin in which a dichroic dye is adsorbed and oriented,
A protective film made of a transparent resin is stacked in this order,
Wherein the polarizing film is disposed so as to face a surface opposite to the surface treatment layer of the surface-treated laminated film. The method of claim 6,
Wherein the surface-treated laminated film and the protective film are attached to the polarizing film through a cured layer of an active energy ray-curable adhesive, respectively. The method according to claim 6 or 7,
Wherein the protective film has a function of a retardation film.

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