JP4765651B2 - Laminated film - Google Patents

Description

  The present invention relates to a laminated film, and more specifically, a polyester film and a hard coat are directly laminated, and a protrusion film is formed at the interface thereof, whereby interference fringes are reduced, and a laminated film having an unevenly distributed structure on the opposite surface is provided. By providing, it reduces the reflection of the surface opposite to the antireflection surface when it is used as the antireflection film, thereby reducing the total reflectance of the antireflection surface.

Laminated films having a hard coat layer on the surface are widely used for antireflection films, touch panel films, nameplate films, and the like.
In particular, in recent years, the market for monitors and large thin televisions using technologies such as liquid crystal, plasma, and rear production has been remarkably expanded, and highly functional films that meet the requirements have been developed for the members applied to these. Among them, the antireflection film that prevents the reflection of the screen surface is provided with a hard coat layer for preventing scratches based on a triacetate film or a polyester film, a high refractive index layer, and a low refractive index layer on it. Most of them provide an antireflection function by canceling interfacial reflection between layers.

  However, when the hard coat layer is provided directly on the polyester film in the sophistication of the required functions, interference fringes due to poor adhesion and refractive index difference between the film and the hard coat layer and thickness unevenness appear and are visually recognized. It will be bad. Further, when a primer layer is provided at the interface in order to improve the adhesiveness, although the adhesiveness improving effect is recognized, the interference fringes cannot be eliminated similarly.

  In order to improve these phenomena, a method of improving the coating film thickness accuracy, increasing the refractive index of the hard coat layer and reducing the difference in refractive index (see Patent Document 1), hot pressing the surface of the base film A method of providing a hard coat layer on the surface (Patent Document 2), applying a hard coat agent using a solvent that dissolves the base film, and dissolving or swelling the base film so that there is no reflective interface For example, a method for reducing interference fringes (Patent Document 3) has been proposed.

  However, there is a limit to the accuracy of the coating thickness, and there is a limit to increasing the refractive index with only the resin component. Further, the method using a hot press has the disadvantage that even if the interference fringes can be reduced, the haze increases and the transparency is poor, and the image looks whitish. Furthermore, in the dissolution and swelling methods, applicable resins are limited, and highly biaxially oriented polyester films are limited to special solvents such as orthochlorophenol, and the working environment is extremely bad.

In order to improve the above-mentioned drawbacks, we proposed a method of directly bonding by applying a hard coat layer in a film forming process without providing a primer layer and curing it in a heat treatment process (Patent Document 4). Furthermore, it has been found that interference fringes can be reduced by forming a fine protrusion structure at the interface between the base film and the hard coat layer (Patent Document 4).

However, in recent years, there has been a demand for further reduction of the reflectance of the antireflection film, and in particular, reduction of the total reflectance by preventing not only the surface reflection but also the reflection of the opposite surface of the base film is desired. .
JP 2002-241527 A JP-A-8-197670 JP 2003-205563 A JP-A-2005-41205

  In order to meet the higher requirements for antireflection films, the present invention has excellent adhesion to a base film, good wear resistance, reduced interference fringes, excellent visibility, and high reflectivity. An object of the present invention is to provide a laminated film effective for reduction.

The present invention provides a laminated film in which a hard coat layer is directly laminated on one side of a polyester film and a laminated film is provided on the other side, a protrusion structure is formed between the polyester film and the hard coat layer, and the laminated film is A laminated film comprising a mixture of polyester and / or polyurethane and an acrylic resin as a main component, and an unevenly distributed structure in which the acrylic resin on the surface side (non-base film side) of the laminated film is distributed at a high concentration It is.

  By applying the laminated film of the present invention to an antireflection film, it is excellent in adhesion between the base film and the hard coat layer, wear resistance, interference fringes are reduced, and further effective in reducing the total reflectance. .

  Examples of the polyester of the base polyester film in the present invention include polyethylene terephthalate, polyethylene naphthalate, polypropylene terephthalate, polybutylene terephthalate, and polypropylene naphthalate, and a mixture of two or more of these may be used. Further, it may be a polyester in which these and other dicarboxylic acid components or diol components are copolymerized. In this case, in the film in which the crystal orientation is completed, the crystallinity is preferably 25% or more, more preferably Is preferably 30% or more, more preferably 35% or more. When the crystallinity is less than 25%, dimensional stability and mechanical strength tend to be insufficient. The crystallinity can be obtained by a density gradient method (JIS-K7112 (1980)) or a Raman spectrum analysis method.

  When the above-described polyester is used, its intrinsic viscosity (measured in o-chlorophenol at 25 ° C. according to JIS K7367) is preferably 0.4 to 1.2 dl / g, more preferably 0.5 to 0.8 dl / g.

  The base film used in the present invention may be a composite film having a laminated structure of two or more layers. As the composite film, for example, a composite film that is substantially free of particles in the inner layer portion and provided with a layer containing particles in the surface layer portion can be exemplified, and the inner layer portion and the surface layer portion are chemically separated. Different polymers or the same kind of polymers may be used. When used for a display which is the intended use of the present invention, it is preferable in terms of optical properties such as transparency that the substrate film does not contain particles.

  The base film in the present invention has sufficient thermal stability of the film, particularly dimensional stability and mechanical strength, and from the viewpoint of improving the flatness, in the state where the hard coat layer is provided, biaxial stretching is performed. A crystal-oriented film is preferred. The crystal orientation by biaxial stretching means that the thermoplastic resin film before the crystal orientation is completed is stretched about 2.5 to 5 times in the longitudinal direction and / or the width direction, and then the crystal orientation is completed by heat treatment. Which shows a biaxially oriented pattern by wide-angle X-ray diffraction.

  The thickness of the base film used in the present invention is appropriately selected according to the use in which the laminated film of the present invention is used, but from the viewpoint of mechanical strength and handling properties, it is preferably 10 to 500 μm, more preferably Is 20 to 300 μm.

  The base film of the present invention may contain various additives, resin compositions, cross-linking agents and the like within a range that does not impair the effects of the present invention. For example, antioxidants, heat stabilizers, ultraviolet absorbers, organic and inorganic particles (for example, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, barium sulfate, carbon black, zeolite, titanium oxide, Metal fine powders), pigments, dyes, antistatic agents, nucleating agents, acrylic resins, polyester resins, urethane resins, polyolefin resins, polycarbonate resins, alkyd resins, epoxy resins, urea resins, phenol resins, silicone resins, rubber resins , Wax composition, melamine crosslinking agent, oxazoline crosslinking agent, methylolated, alkylolized urea crosslinking agent, acrylamide, polyamide, epoxy resin, isocyanate compound, aziridine compound, various silane coupling agents, various titanates And the like can be mentioned system coupling agent.

  In particular, when used for a plasma display, the base film preferably has an ultraviolet cut function, and preferably contains an ultraviolet absorber, in order to use a dye having a color correction or near infrared cut function.

  Preferred examples of the ultraviolet absorber include salicylic acid compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, benzoxazinone compounds, cyclic imino ester compounds, and the like. Of these, benzoxazinone compounds are most preferred from the viewpoints of UV-cutting property and color tone. These compounds may be used alone or in combination of two or more. Moreover, combined use of stabilizers, such as HALS (hindered amine light stabilizer) and antioxidant, is more preferable.

  Examples of benzoxazinone-based compounds that are preferable materials include 2-p-nitrophenyl-3,1-benzoxazin-4-one and 2- (p-bezoylphenyl) -3,1-benzoxazine-4. -One, 2- (2-naphthyl) -3,1-benzoxazin-4-one, 2-2'-p-phenylenebis (3,1-benzoxazin-4-one), 2,2 '-( 2,6-naphthylene) bis (3,1-benzoxazin-4-one) and the like can be exemplified. The amount of these compounds added is preferably 0.5 to 5% by weight, preferably 1 to 5% by weight, in the base film.

  Further, it is preferable to use a cyanoacrylate-based tetramer compound in combination in order to impart further excellent light resistance. The cyanoacrylate tetramer compound is preferably contained in the base film in an amount of 0.05 to 2% by weight. The cyanoacrylate-based tetramer compound is a compound based on a tetramer of cyanoacrylate, such as 1,3-bis (2′cyano-3,3-diphenylacryloyloxy) -2, 2-bis-. (2 'cyano-3,3-diphenylacryloyloxymethylpropane). When using together with this, it is suitable to add 0.3 to 3 weight% of the above-mentioned ultraviolet absorber in a base film.

  The laminated film of the present invention preferably has a transmittance of 5% or less at a wavelength of 380 nm, and can be achieved by the addition of the above-described ultraviolet absorber. Thereby, when especially applying to the member for plasma displays, a base film, a dye pigment | dye, etc. can be protected from an ultraviolet-ray. The transmittance is a transmittance at a wavelength of 380 nm with an integrating sphere 130-063 (manufactured by Hitachi, Ltd.) having a diameter of 60 mm and a 10 degree inclined spacer attached to a spectroscopic hardness meter U-3410 (manufactured by Hitachi, Ltd.). Is what we asked for.

  The laminated film of the present invention has a total light transmittance of 90% or more, preferably 92% or more, more preferably 94% or more. When the total light transmittance is less than 90%, the sharpness of the image is hindered when an antireflection film is used.

  The haze of the laminated film of the present invention is 1.5% or less, preferably 1.0% or less, more preferably 0.8% or less. However, a configuration in which the haze is set to be 3.5% or more and 10% or less can be used particularly for the purpose of preventing reflection. These can be arbitrarily selected according to the application.

  Furthermore, it is preferable that b value of the laminated | multilayer film of this invention is 1.5 or less, More preferably, 1.0 or less is good. If the transmission b value exceeds 1.5, the film itself appears slightly yellowish, which may impair the sharpness of the image. The transmission b value is measured according to JIS-K7105 (1981) using a spectroscopic color difference meter SE-2000 type (manufactured by Nippon Denshoku Industries Co., Ltd.).

  In the laminated film of the present invention, a hard coat layer is directly laminated on at least one surface of the base film. This hard coat layer is mainly composed of a polyfunctional acrylate, and is intended to improve adhesion to the base material. It is preferable to use 1 to 3 functional acrylates for improving the brittleness of the hard coat layer in combination with the system crosslinking agent.

  In the present invention, the polyfunctional acrylate refers to 4 or more, more preferably 5 or more (meth) acryloyloxy groups in one molecule (provided that “... (Meth) acryl ...” in this specification). Is a monomer, oligomer, or prepolymer having "... acrylic ... or ... meta acrylic ...". As monomers, oligomers and prepolymers having 4 or more (meth) acryloyloxy groups in one molecule, there are 4 hydroxyl groups of a polyhydric alcohol having 4 or more alcoholic hydroxyl groups in 1 molecule. The compound etc. which become the esterified substance of the above (meth) acrylic acid can be mentioned.

  Specific examples include pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  The polyfunctional acrylate component in the hard coat layer-forming coating material is 40 to 95% by weight, preferably 50 to 80% by weight. When the use ratio is too small, the hard coat film hardness is low, and when it is too large, cracks are likely to occur.

  In the present invention, it is preferable to use a melamine-based crosslinking agent for the purpose of expressing the adhesiveness between the base film and the hard coat layer. The type of melamine crosslinking agent is not particularly limited, but melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, a compound partially or completely etherified by reacting a methylolated melamine with a lower alcohol, or these A mixture or the like can be used. As the melamine-based crosslinking agent, a monomer, a condensate composed of a multimer of two or more, or a mixture thereof can be used. As the lower alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butanol, isobutanol and the like can be used. The functional group has an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group in one molecule, and an imino group type methylated melamine, a methylol group type melamine, or a methylol group type methylated melamine. And fully alkyl methylated melamine. Among them, methylolated melamine and fully alkylated melamine are preferable in terms of adhesiveness.

  The amount of the melamine-based crosslinking agent is not particularly limited, but it is 2 to 50 parts by weight, preferably 5 to 40 parts by weight, more preferably 100 parts by weight of the polyfunctional acrylate, in solid content in the hard coat layer forming coating material. The amount of 10 to 35 parts by weight is preferable from the viewpoint of the balance between adhesion and hardness. When the addition amount is less than this range, the adhesiveness is lowered, and when it is more, the hardness may be lowered.

  In addition, it is preferable to add an acid catalyst for the purpose of accelerating the curing of the melamine crosslinking agent. Examples of the acid catalyst include p-toluene sulfonic acid, dodecylbenzene sulfonic acid, dimethyl pyrophosphoric acid, styrene sulfonic acid and derivatives thereof. Further, what is blocked with ethanolamine or the like is the stability of the coating. It is suitable.

In the present invention, in addition to the above polyfunctional acrylate and melamine-based crosslinking agent, the following compositions are preferably used in combination for the purpose of improving the brittleness of the hard coat layer and improving the coating property and flatness by lowering the viscosity. . For example, as a low viscosity acrylate having two or more ethylenically unsaturated double bonds in one molecule,
(A) C2-C12 alkylene glycol (meth) acrylic acid diesters: ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl Glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and the like.

  (B) (Meth) acrylate diesters of polyoxyalkylene glycol: diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, Polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, etc.

  (C) Ethylene oxide of bisphenol A or hydride of bisphenol A and (meth) acrylic acid diesters of propylene oxide adducts: 2,2′-bis (4-acryloxyethoxyphenyl) propane, 2,2′-bis ( 4-acryloxypropoxyphenyl) propane and the like.

  (D) Two or more molecules in a molecule obtained by reacting a terminal isocyanate group-containing compound obtained by reacting a diisocyanate compound and two or more alcoholic hydroxyl group-containing compounds in advance with an alcoholic hydroxyl group-containing (meth) acrylate. Urethane (meth) acrylates having a (meth) acryloyloxy group.

  (E) Epoxy (meth) acrylates having two or more (meth) acryloyloxy groups in the molecule obtained by reacting a compound having two or more epoxy groups in the molecule with acrylic acid or methacrylic acid.

  (F) Compounds having one ethylenically unsaturated double bond in the molecule: methyl (meth) acrylate, ethyl (meth) acrylate, n- and i-propyl (meth) acrylate, n-, sec-, and t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, hydroxyethyl (meth) acrylate, polyethylene Glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, N-hydroxyethyl (meth) acrylamide, N-vinylpyrrolidone, N Vinyl-3-methylpyrrolidone, etc. N- vinyl-5-methyl pyrrolidone. These monomers may be used alone or in combination of two or more. The amount of these compounds added may be set as appropriate, but when the main purpose is a hard coat function, it is preferably in the range of 10 to 40 parts by weight with respect to 100 parts by weight of the polyfunctional acrylate.

  In the present invention, a reactive diluent can be used. A reactive diluent is a coating agent component having a group that reacts with a monofunctional or polyfunctional acrylic oligomer as well as serving as a solvent in the coating process as a coating medium. It will be.

  Specific examples of these acrylic oligomers and reactive diluents are as follows: Shinzo Yamashita, Tosuke Kaneko, “Crosslinking Agent Handbook”, Taiseisha 1981, pp. 267-275, 562-593. However, the present invention is not limited to these. The amount of the low-viscosity acrylate is not particularly limited, but is 3 to 50 parts by weight, preferably 8 to 40 parts by weight, more preferably 16 to 25 parts by weight with respect to 100 parts by weight of the polyfunctional acrylate in the solid content of the hard coat layer. It is preferable in terms of the balance between adhesiveness and hardness. The following commercially available products can be applied to the above compounds.

  Mitsubishi Rayon Co., Ltd. (Product name “Diabeam” series, etc.), Nagase Sangyo Co., Ltd. (Product name “Denacol” series, etc.), Shin Nakamura Co., Ltd. (Product name “NK Ester” series, etc.), Dainippon Ink Chemical Industry Co., Ltd. (trade name “UNIDIC” series, etc.), Toa Gosei Chemical Industry Co., Ltd. (trade name “Aronix” series, etc.), Nippon Oil & Fats Co., Ltd. (trade name “Blemmer” series, etc.), Nippon Kayaku Co., Ltd. (trade name “KAYARAD” series, etc.), Kyoeisha Chemical Co., Ltd. (trade names “light ester” series, “light acrylate” series, etc.) can be used. In forming the hard coat layer of the present invention, it is preferable to use a leveling agent to smooth the surface of the hard coat layer. Typical leveling agents include silicone-based, acrylic-based, and fluorine-based agents, but when only smoothness is required, silicone-based is effective with a small amount of addition. As the silicone leveling agent, polydimethylsiloxane as a basic skeleton and a polyoxyalkylene group added (for example, SH190 manufactured by Toray Dow Corning Silicone Co., Ltd.) is preferable.

On the other hand, in the case where a laminated film is further provided on the hard coat layer, it is necessary not to impair the coating property and adhesiveness of the laminated film. As such a leveling agent, “ARUFON-UP1000 series, UH2000 series, UC3000 series (trade name): manufactured by Toagosei Co., Ltd.” or the like is preferably used. The leveling agent is preferably added in an amount of 0.01 to 10 parts by weight in the hard coat layer forming composition. In the present invention, it is applied as a hard coat layer modifier within a range that does not impair the effects of the present invention. Property improvers, antifoaming agents, thickeners, antistatic agents, inorganic particles, organic particles, organic lubricants, organic polymer compounds, UV absorbers, light stabilizers, dyes, pigments, stabilizers, etc. Can be used.

  In the present invention, it is necessary to form a protrusion structure between the hard coat layer and the base polyester film. By forming this projection structure, the interference fringes can be remarkably reduced. The shape of the protrusion is not particularly limited, but is preferably circular or elliptical. The size of the protrusion is 50 to 500 μm, preferably 60 to 300 μm, more preferably 80 to 200 μm, and the average size in the width direction. Is 10 to 100 μm, preferably 15 to 60 μm, more preferably 20 to 50 μm, and the average height of the protrusions is 0.03 to 1.0 μm, preferably 0.05 to 0.5 μm. It is desirable in terms of conversion and transparency.

The size of the protrusion is determined by the following method. 1000 × 1000 (μm ² ) was photographed on the hard coat surface of the laminated film using a differential interference microscope at a total magnification of 200 ×, and the interface of the protrusion was identified by the density of the image, and the length of all protrusions of the image capturing part Measure the size in the axial direction (length direction) and the minor axis direction (width direction). Measure 10 locations at different locations and determine the resulting protrusion size data.

  In order to form the protrusion having the specific size, the following method can be used. That is, the hard coat layer forming composition is applied to at least one side of the polyester film before the crystal orientation is completed, and thereafter, the end portion is held and guided into the tenter, and 1.05 to 1.5 times in the width direction. This is a method in which the crystal orientation is completed while relaxing by 3 to 10% at 180 to 245 ° C. after performing the first stretching and further performing the second stretching by 2.0 to 5.0 times in the width direction. . By applying this method, a projection structure is formed between the polyester film and the hard coat layer which are the object of the present invention, and the size in the length direction and the size in the width direction of the projection can be obtained.

  In order to reduce the total reflectivity, which is the object of the present invention, a main component is a mixture of polyester and / or polyurethane and an acrylic resin on the opposite surface of the base film provided with the hard coat layer of the laminated film. The laminated film needs to have an unevenly distributed structure in which the acrylic resin concentration on the surface side (non-base film side) of the laminated film is distributed at a high concentration. By adopting this structure, a stepwise decrease in refractive index or a gradient structure is formed in the base polyester film and laminated film, so that incident light from the hard coat layer side is less reflected on the opposite surface of the base film. In addition, the total reflectance can be reduced. For this purpose, polyester and / or polyurethane having a structure close to that of the base polyester film and having a refractive index relatively close to each other in the laminated film are coordinated at a high concentration on the substrate side, and the refractive index is relatively on the laminated film surface side. An unevenly distributed structure in which a low acrylic layer is coordinated at a high concentration is preferable. Here, the polyester applied to the laminated film of the present invention has, for example, an ester bond in the main chain or side chain, and is obtained by polycondensation from a dicarboxylic acid and a diol. As the dicarboxylic acid component constituting the polyester resin, aromatic, aliphatic, and alicyclic dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, and the like can be used. Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 1,2-bisphenoxyethane-p, p'-dicarboxylic acid And phenylindanedicarboxylic acid. These dicarboxylic acids and ester-forming derivatives thereof are preferably 30 mol% or more, preferably 40 mol% or more, more preferably 50 mol% or more of the total carboxylic acid. Aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4- Cyclohexanedicarboxylic acid and the like and ester-forming derivatives thereof can be used. Examples of the glycol component constituting the polyester resin include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentane. Diol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1, 3-diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2 2,4-trimethyl-1,6-hexanediol, 1 2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and the like can be used bisphenol A. Polyester resins are those that dissolve or disperse in a solvent or water. In particular, when a laminated film is provided by in-line coating, an aqueous system is preferable. For this purpose, a compound containing a carboxylate group or a compound containing a sulfonate group is copolymerized. It is preferable to do. When the laminated film is required to have heat and moisture resistance, it is preferable to select a compound containing a carboxylate group.

  Examples of the compound containing carboxylic acid and its base include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, 1,2 3,4-butanetetracarboxylic acid, 1,2,3,4-pentanetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) ) -3-Methyl-3-cyclohexene-1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, ethylene Glycol bistrimellitate, 2,2 ′, 3,3′-diphenyltetracarboxylic acid, thiophene-2,3,4,5-teto Carboxylic acid, ethylene tetracarboxylic acid and their alkali metal salts, alkaline earth metal salts, and ammonium salts.

  Examples of the compound containing sulfonic acid and its base include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, sulfo-p-xylylene glycol, 2- Examples include sulfo-1,4-bis (hydroxyethoxy) benzene and alkali metal salts, alkaline earth metal salts, and ammonium salts thereof. In addition, a modified body containing a polyester resin as a main component, for example, a block copolymer, a random copolymer, a graft copolymer or the like modified with acrylic, urethane, epoxy, or the like can also be used. Of these, examples of compounds that constitute particularly preferable polyester resins include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, adipic acid, trimellitic acid, 5-sulfoisophthalic acid, and 4-sulfonaphthalene-2 as dicarboxylic acid components. Examples of the 1,7-dicarboxylic acid and glycol component include ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, and 1,4-hexanediol.

  Polyester resins synthesized from these compounds can be obtained by ordinary transesterification and polycondensation reactions. The glass transition point of the polyester resin produced by the above is 0 to 90 ° C., preferably 5 to 75 ° C. from the viewpoint of adhesion to the base film. As the polyurethane resin, a water-soluble or water-dispersible resin is preferably used, and its main structure is composed of a polyol and an isocyanate.

  In addition, those in which a carboxylate group, a sulfonate group, a sulfuric acid half ester group, or the like is introduced to increase the affinity for water are particularly suitable. Examples of polyol compounds constituting the main skeleton of polyurethane include polyethylene glycol, polypropylene glycol, polyethylene / propylene glycol, polytetramethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, and triethylene glycol. , Polycaprolactone, polyhexamethylene adipate, polytetramethylene adipate, trimethylolpropane, trimethylolethane, glycerin, acrylic polyol, polycarbonate polyol and the like. Examples of the isocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, an adduct of tolylene diisocyanate and trimethylolpropane, an adduct of hexamethylene diisocyanate and trimethylolpropane, and the like. The polyurethane resin may contain a chain extender and a crosslinking agent as necessary. For example, ethylene glycol, propylene glycol, butanediol, diethylene glycol, ethylenediamine, diethylenetriamine and the like can be mentioned. Moreover, in order to provide ionicity, the method of using the compound which has an anionic group other than the said composition, or reacting the compound which has the unreacted isocyanate group of the produced | generated polyurethane resin and an anionic group, etc. can be used. The anionic group can be arbitrarily selected from a sulfonic acid group, a carboxylic group and an ammonium salt, alkali metal salt or alkaline earth metal salt thereof.

Examples of monomer components constituting the acrylic resin include alkyl acrylates and alkyl methacrylates (wherein the alkyl groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups). 2-ethylhexyl group, lauryl group, stearyl group, cyclohexyl group, phenyl group, benzyl group,
Phenylethyl group, etc.), hydroxy group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-methyl acrylamide, N-methyl methacryl Amide group-containing monomers such as amide, N-methylolacrylamide, N-methylolmethacrylamide, N, N-dimethylolacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-phenylacrylamide, N, N-diethylamino Amino group-containing monomers such as ethyl acrylate, N, N-diethylaminoethyl methacrylate, glycidyl acrylate, glycidyl methacrylate Glycidyl group-containing monomers such as acrylic acid, methacrylic acid and their salts (lithium salts, sodium salts, potassium salts, etc.) and the like, and monomers containing such salts can be used. What copolymerized 2 or more types can be used. Further, the following monomers may be used in combination. For example, allyl glycidyl ether, styrene sulfonic acid and its salt, crotonic acid, itaconic acid, maleic acid, fumaric acid and their salts, anhydride, vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxy Silane, alkyl maleic acid monoester, alkyl fumaric acid monoester, acrylonitrile, methacrylonitrile, alkyl itaconic acid monoester, vinyl chloride, vinylidene chloride, vinyl acetate and the like can be used.

  Various acrylates containing fluorine, such as trifluoroethyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, 2, 2, 3, 3-tetrafluoropropyl (meth) acrylate, 2, 2, 3, 4, 4,4-hexafluorobutyl (meth) acrylate and the like. Further, block copolymers of acrylic and polyester, urethane, epoxy resin, etc., graphs and copolymers can be used.

  Among these, preferred acrylic resins include methyl acrylate, ethyl acrylate, N-methylol acrylamide, acrylic acid, and a copolymer of fluorine-containing acrylate and methacrylate. These acrylic resins can be dissolved or dispersed in an organic solvent or water, but it is preferable to use a method of laminating within the base polyester film manufacturing process (in-line coating method), which dissolves and disperses in water. Acrylic resins are preferred.

These acrylic resins may be thermoplastic or self-crosslinking type.
The above-mentioned polyester resin and / or polyurethane resin and acrylic resin are used as a mixed coating liquid, but in addition to this, even in combination with various crosslinking agents for the purpose of improving adhesiveness, heat resistance, and moisture resistance good. As the cross-linking agent, melamine-based, epoxy-based, isocyanate-based, oxazoline-based and the like can be arbitrarily selected. However, melamine-based and oxazoline-based are preferable from the viewpoints of coating stability, adhesion to a substrate, heat and heat resistance, etc. Is preferred. The type of melamine crosslinking agent is not particularly limited, but melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, a compound partially or completely etherified by reacting a methylolated melamine with a lower alcohol, or these A mixture or the like can be used. As the melamine-based crosslinking agent, a monomer, a condensate composed of a multimer of two or more, or a mixture thereof can be used. As the lower alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butanol, isobutanol and the like can be used. The functional group has an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group in one molecule, and an imino group type methylated melamine, a methylol group type melamine, or a methylol group type methylated melamine. And fully alkyl methylated melamine. Among them, methylolated melamine and fully alkylated melamine are preferable in terms of adhesiveness.

  The amount of the melamine-based crosslinking agent is not particularly limited, but it is preferably 2 to 50% by weight, preferably 5 to 40% by weight, more preferably 10 to 35% by weight in solid content in the coating material.

  The combination of the above-described polyester and / or polyurethane and acrylic resin constituting the laminated film of the present invention is not particularly limited, but polyester and acrylic resin, polyurethane and acrylic resin, polyester, polyurethane and acrylic resin, and further these It can be set as the structure which added said crosslinking agent. The mixing ratio of the acrylic resin in the above combination is preferably 10 to 80% by weight in the solid content of the coating material in order to express the adhesiveness to the substrate and the effect of reducing the reflectance. In the case of a three-component system, the mixing ratio of polyester and polyurethane is arbitrary in the range of 1/99 to 99/1. The thickness of the laminated film is not particularly limited, but 0.05 to 1 μm, preferably 0.08 to 0.5 μm is desirable for adhesion and reflectance reduction.

  In addition to the above components, a heat-resistant agent, an ultraviolet absorber, a near infrared absorber, a conductive material, various organic and inorganic particles, a dye, etc. may be added to the laminated film within the range not impairing the effects of the present invention. good.

  In the present invention, it is preferable to use the following production method in order to exhibit the effect. That is, a hard coat layer-forming composition is applied to one side of a longitudinally stretched film stretched 3.0 to 4.0 times at 75 to 90 ° C. in the longitudinal direction, and polyester resin and / or polyurethane resin and acrylic are applied to the opposite side. An aqueous dispersion of a resin (added with a crosslinking agent if necessary) is applied, and then the end is gripped and guided into the tenter, preheated at a temperature of 70 to 80 ° C., and 1.05 to 1.5 in the width direction. Perform 4 times the first stage stretching, and further perform the second stage stretching 2.0 to 5.0 times in the width direction at 85 to 95 ° C, and then relax 3 to 10% at 180 to 245 ° C. In this way, the crystal orientation is completed.

  In the present invention, the base film and the hard coat layer are directly laminated. The presence of the adhesive layer is not preferable because interference fringes are generated due to a difference in refractive index from the base film or the hard coat layer, or the adhesive layer is deteriorated due to ultraviolet rays or inferior in durability at high temperature and high humidity. According to the production method of the present invention, extremely high adhesiveness can be imparted without interposing an adhesive layer at the interface between the base film and the hard coat layer. This is because the protrusion forming portion forms a mixed state of the base polyester composition and the hard coat composition in this production method. That is, according to the opinion of the present inventors, a specific hard coat coating agent is applied to a uniaxially stretched film oriented in the machine direction by longitudinal stretching, and then finely stretched in the width direction under particular conditions, It has been found that fine cracks are generated in the material film, and the hard coat coating material penetrates into the crack portion and further extends in the width direction to form protrusions mixed with the polyester and the hard coat composition.

  Next, an example of the method for producing the laminated film of the present invention will be described by taking polyethylene terephthalate (hereinafter abbreviated as PET) as an example of the base film, but is not limited thereto.

  PET pellets (intrinsic viscosity 0.62 dl / g) containing 0.2% by weight of alumina particles having an average particle diameter of 0.1 μm were vacuum dried at 180 ° C. for about 2 hours to sufficiently remove moisture, and then an extruder. And melt extruded at a temperature of 260 to 300 ° C., and formed into a sheet form from a T-shaped die. The sheet-like material thus obtained is cooled and solidified on a mirror-like cooling drum to obtain an unstretched sheet. At this time, it is preferable to use an electrostatic application method for the purpose of improving the adhesion to the cast drum. Thereafter, the obtained unstretched sheet is stretched 3.0 to 4.0 times in the longitudinal direction with a roll group heated to 75 to 80 ° C. Next, a hard coat layer-forming coating comprising a polyfunctional acrylate, a melamine-based cross-linking agent, a leveling agent, etc. is applied to one side of the uniaxially stretched film in this manner, and a polyester resin and / Or Apply a mixed water dispersion of polyurethane resin and acrylic resin (if necessary, combined with melamine crosslinking agent). Then, the film is guided to the tenter while holding both ends of the film with clips. After preheating to 75 to 85 ° C. in the tenter, fine stretching in the first step width direction is performed 1.05 to 1.5 times in the width direction. After that, second-stage stretching of 2.0 to 5.0 times at 75 to 85 ° C. is continuously performed in the width direction, and further heat fixing is performed while relaxing 3% to 10% at 180 to 245 ° C. To complete the crystal orientation.

  The coating means for forming the hard coat layer forming coating and the laminated film are not particularly limited, and various coating methods such as reverse coating, gravure coating, rod coating, bar coating, die coating or spray coating. The method etc. can be used. The laminated film of the present invention thus obtained can be provided with a hard coat layer and a laminated film all at once in the film forming process, so that the productivity is good, the surface hardness is high, the hard coat layer and the base film The adhesiveness is excellent, there is almost no foreign matter defect, the occurrence of interference fringes is small, the visibility can be improved, and the reflectance when an antireflection film is obtained can be reduced. The laminated film of the present invention is particularly preferably used as an antireflection film substrate for displays, a substrate for touch panels, a substrate for windowing, a substrate for nameplates, and the like.

  Although the thickness of a hard-coat layer should just be determined according to a use, 1 micrometers-20 micrometers are preferable normally, More preferably, they are 2 micrometers-10 micrometers. When the thickness of the hard coat layer is less than 1 μm, even if it is sufficiently cured, the surface hardness is not sufficient because it is too thin, and the surface tends to be scratched. On the other hand, when the thickness exceeds 20 μm, The cured film tends to crack due to curling during bending or stress such as bending.

  Moreover, you may provide printing layers, such as a pattern, in the outermost layer of a hard-coat layer in the range which does not impair the effect of this invention.

  Further, the obtained laminated film can be used by being attached to various functional films by various methods, and an adhesive layer can be laminated on the other surface, or a conductive layer can be provided.

  For example, the laminated film of the present invention is bonded to a counterpart material using various adhesives on the opposite side of the surface provided with the hard coat layer, and the hard coat layer functions such as wear resistance and scratch resistance to the counterpart material Can also be used. The adhesive used at this time is not particularly limited as long as it is an adhesive that adheres two objects by its adhesive action, and an adhesive made of rubber, acrylic, silicone or polyvinyl ether is used. it can. In addition, pasting with a near-infrared reflective layer or an electromagnetic wave shielding film can also be applied as a configuration of the front filter.

  When the laminated film of the present invention is used as an antireflection film for a plasma display or the like, it can be suitably used by providing a high refractive index on the hard coat layer and further providing a low refractive index layer thereon. .

  Although it does not specifically limit as a high refractive index layer, It is a thing with a refractive index of about 1.55-1.70, and it is preferable that a laminated thickness shall be 0.03-0.15 micrometer. Such a high refractive index layer can be obtained by finely dispersing metal compound particles in a binder component. For example, a general-purpose resin such as polyester, acrylic, urethane, or epoxy is used as a binder component, and as a high refractive index metal compound particle dispersed therein, for example, tin-containing antimony oxide particles, zinc-containing antimony oxide particles, tin-containing indium oxide particles, oxidation Zinc / aluminum oxide particles, antimony oxide particles, titanium oxide particles, zirconium oxide particles and the like can be used, but a composition which can simultaneously add an antistatic function is more preferable, and tin-containing indium oxide particles are particularly preferable. The metal compound particles having an average primary particle diameter (sphere equivalent diameter according to the BET method) of 0.5 μm or less, preferably 0.001 to 0.3 μm, are preferable in terms of maintaining transparency. Organic conductive materials such as polypyrrole, polyaniline, and polythiophene can be added to these metal compounds for the purpose of further improving the conductivity.

  The low refractive index layer preferably has a refractive index of about 1.30 to 1.40, and the lamination thickness is about 0.01 to 0.15 μm. As a material for forming the low refractive index layer, a known material can be applied, and a fluorine compound, a compound having a perfluoroalkyl group, and the like are preferable. It can also be achieved by filling hollow fine particles in the binder resin. Such hollow particles are disclosed, for example, in JP-A-2001-233611, J. Pat. AM. Chem. soc. 2003, 125, 316-317 and the like.

[Characteristic measurement method and effect evaluation method]
The characteristic measurement method and effect evaluation method in the present invention are as follows.

(1) Adhesive peel test: Under normal conditions (23 ° C., relative humidity 65%), 100 crosscuts of 1 mm ² were put on the hard coat layer of the laminated film, and cellophane tape (registered trademark) manufactured by Nichiban Co., Ltd. A test method in which the test piece is peeled in a 90-degree direction after being stuck on it, reciprocated three times with a load of 19.6 N using a rubber roller, and pressed. Based on the number of remaining hard coat layers, evaluation is performed according to the following criteria.
◯: 80 or more hard coat layers remain after two peel tests Δ: 80 or more hard coat layers remain after one peel test ×: one peel After the test, less than 80 hard coat layers remain.

(2) SW hardness The load on the surface of the hard coat layer was changed with steel wool # 0000, and rubbed 10 times (speed 10 cm / s) under a constant load at each load, resulting in scratch resistance (no scratches). The maximum load was measured. 2 kg / cm ² was a practically acceptable level and was accepted.

(3) Haze (%)
It measured based on JISK-7105 using fully automatic direct reading haze computer HGM-2DP (made by Suga Test Instruments Co., Ltd.). In the measurement, the laminated film 1m2 was divided into 20 equal parts, and the haze at the center of the divided sample was measured. As the haze value, an average value at 20 locations was obtained.

(4) Projection size (μm)
An area of 1000 μm × 1000 μm was photographed with a differential interference microscope at 200 times on the hard coat surface of the laminated film, and the length and width of all protrusions in the field of view were measured from the image, and the average value was obtained.

(5) Interference fringe level evaluation In order to eliminate the effect of back surface reflection, the A4 size sample sheet colored with black magic ink was prepared after roughening the non-hard coat surface with # 240 sandpaper. In a dark room, the degree of interference fringes was visually observed while changing the viewing angle by placing it directly under 30 cm of a three-wavelength fluorescent lamp (National Parrook, three-wavelength daylight white (F · L 15EX-N 15W), and the following evaluation was performed. Level B or higher was considered good.

No interference fringes: Level A
Although very weak interference fringes are visible, there is no unevenness in the surface: Level B
Very weak interference fringes but uneven in the surface: Level C
Weak interference fringes are visible: Level D
Strong interference fringes: Level E.

(6) Visibility A color photograph was placed under the laminated film with the hard coat surface up, and the clarity and unevenness of the image when viewing the photograph through the laminated film were visually observed. ○ The above was judged good.

The image looks clear: ◎
Slightly blurred image but no unevenness: ○
Some parts of the image are blurred: △
The image is blurred overall: ×.

(7) Total light transmittance (%)
The total light transmittance in the thickness direction of the laminated film was determined using a fully automatic haze computer HGM-2DP (manufactured by Suga Test Instruments Co., Ltd.). 1 m ² was divided into 20 equal parts, and the vicinity of the center was measured to obtain an average value of 20 points.

(8) Phase structure of laminated film An ultra-thin section of the cross-section of the laminated film of the laminated film is cut out, and TEM (transmission electron) is obtained by staining freezing ultra-thin section method by RuO ₄ staining, OsO ₄ staining, or both double staining. A microscope: H7100FA type manufactured by Hitachi, Ltd.) was observed at a magnification of 200,000 to 1,000,000, and a photograph was taken. The phase separation state was visually observed from the cross-sectional photograph. If this method is used, the polyester resin and the polyurethane resin are dark on the image, and the acrylic resin is light, so that the resin layer can be distinguished. The density of the cross section of the laminated film was determined from this cross-sectional photograph. When the density of the image was observed from the surface to the inside and the surface side was light, it was determined that the acrylic resin was unevenly distributed at a high density. In addition, the resin type in the phase separation state is determined by creating the same laminated film for each of the resin types used in the laminated film, observing the degree of dyeing by the same method as above, and determining the phase separation lamination from the concentration difference depending on the resin type. Membrane components can also be identified.

(9) Preparation of antireflection film and measurement of reflectance The following high refractive index layer and low refractive index layer were provided in this order on the hard coat surface of the laminated film to prepare an antireflection film. A black paint was applied to the laminated film surface of the antireflection film and colored so that the transmittance at a wavelength of 550 nm was 3% or less. An absolute reflection spectrum at an incident angle of 5 degrees and a wavelength region of 380 to 800 nm is measured from the low refractive index layer surface using a spectrophotometer (UV-3150) manufactured by Shimadzu Corporation, and an average reflectance at a wavelength of 400 to 700 nm (every 20 nm wavelength). The average reflectance) and the minimum reflectance between the regions were determined.

<Formation of high refractive index layer>
A mixed-dispersed coating material of 6 parts by weight of tin-containing indium oxide particles, 2 parts by weight of urethane acrylate, 18 parts by weight of methanol, 54 parts by weight of polypropylene glycol monoethyl ether, and 20 parts by weight of isopropyl alcohol was prepared. The refractive index of the coating film using this paint was 1.64.

This paint was applied on the hard coat surface of the laminated film, dried at 80 ° C. for 2 minutes, and then cured by irradiating with 1.0 J / cm ² ultraviolet rays. The coating thickness was 0.1 μm.

<Formation of low refractive index layer>
While adjusting 219 parts by weight of methyltrimethoxysilane at 20 ° C. ± 5 ° C., 89 parts by weight of 0.5N formic acid was added with stirring to effect hydrolysis. After 60 minutes, 412 parts by weight of isopropyl alcohol was mixed to prepare a treatment liquid (X1).

  Similarly, 158 parts by weight of 3,3,3-trifluoropropyltrimethoxysilane was hydrolyzed by adding 41 parts by weight of 1N formic acid while stirring at 30 ° C. ± 10 ° C. After 60 minutes, 521 parts by weight of isopropyl alcohol was mixed to prepare a treatment liquid (X2).

  Next, a silica slurry comprising 144 parts by weight of porous silica particles having an outer shell with a primary particle diameter of 50 nm (porosity 40%) and 560 parts by weight of isopropyl alcohol was prepared. 720 parts by weight of treatment liquid (X1), 720 parts by weight of treatment liquid (X2), 704 parts by weight of silica slurry, 356 parts by weight of methanol, 4272 parts by weight of isopropyl alcohol, and 713 parts by weight of polypropylene glycol monoethyl ether A refractive index coating solution was prepared. The refractive index of the coating film using this coating liquid was 1.37. This coating solution was applied on the high refractive index layer, dried at 80 ° C. for 2 minutes, and then heat treated at 130 ° C. for 2 minutes to cure the coating film. The thickness of the coating film was 0.1 μm.

  Next, although this invention is demonstrated based on an Example, this invention is not necessarily limited to these.

Example 1
A polyethylene terephthalate (hereinafter referred to as PET, intrinsic viscosity 0.62 dl / g) chip containing 0.015% by weight of alumina particles having an average particle size of 0.2 μm and 0.005% by weight of colloidal silica having an average particle size of 1.5 μm, After sufficiently drying in vacuum at 180 ° C for 3 hours, feeding to an extruder, melting at 285 ° C, extruding into a sheet from a T-shaped die, and a mirror cast drum having a surface temperature of 20 ° C using an electrostatic application casting method And then cooled and solidified to obtain an unstretched sheet. The unstretched sheet thus obtained was stretched 3.2 times in the longitudinal direction with a group of rolls heated to 80 ° C. to obtain a uniaxially stretched film. The following hard coat forming coating was applied to one side of this uniaxially stretched film to a thickness of 20 μm by the metabar method. Also, the following coating for forming a laminated film is applied to the opposite surface, and both ends of the film coated with the coating are guided to the 78 ° C. preheating zone while holding the clips with the clips, and subsequently in the 80 ° C. heating zone in the width direction. The film was stretched 1.1 times. Furthermore, after continuously stretching 3.3 times in the width direction at 90 ° C, heat treatment for 15 seconds is performed in a heat treatment zone at 220 ° C while relaxing in the width direction of 5%, and the coating film is cured and heat-set. Went. Thus, a laminated film having a total thickness of 125 μm, a hard coat layer thickness of 5 μm, and a laminated film thickness of 0.1 μm was prepared. As shown in Table 1, the characteristics of this laminated film were excellent in transparency, free from interference fringes, excellent in visibility, extremely excellent in adhesion, and excellent in wear resistance (SW hardness). Moreover, it had the structure where the acrylic resin was unevenly distributed in the surface layer part from the cross section of the laminated film. The average reflectance of the antireflection film prepared using this laminated film was 1.05%, and the minimum reflectance was 0.42%.

<Hard coat forming coating formulation>
-Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (KAYARAD-DPHA: manufactured by Nippon Kayaku Co., Ltd.) 100 parts by weight-alkylated melamine (Cymel 350: manufactured by Nippon Cytec Industries Co., Ltd.) 20 parts by weight 15 parts by weight of trimethylolpropane / ethylene oxide modified triacrylate (M-350: manufactured by Toagosei Co., Ltd.) 1 part by weight of sulfonic acid block catalyst (catalyst 602: manufactured by Nihon Cytec Industries, Inc.) ARUFON UP1000 Toagosei Co., Ltd.) 0.2 parts by weight <Laminated film forming coating agent>
・ Polyester resin (terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid / ethylene glycol / 1,4-butanediol (30/15/5/30/20 mol%) 50 parts by weightAcrylic resin (Nicazole A08: Japan) Carbide Industries Co., Ltd.)
50 parts by weight A 3% by weight aqueous dispersion having the above solid content ratio.

(Examples 2-9)
A laminated film was produced in the same manner as in Example 1 except that the composition of the laminated film was changed as shown in Table 1. As a result, as shown in Table 1, a phase separation structure was observed in any of the formulations, and acrylic was unevenly distributed in the surface layer part. The properties of this laminated film and the properties as an antireflection film were good as shown in Table 1.
In addition, the polyurethane resin and melamine crosslinking agent which were used as a component of a laminated film here are shown below.
・ Polyurethane resin (Hydran AP-40: manufactured by Dainippon Ink Co., Ltd.)
Melamine cross-linking agent (Nicalak MW12LF: manufactured by Sanwa Chemical Co., Ltd.)

(Comparative Example 1)
A laminated film was prepared in the same manner except that only the polyester resin was used as the laminated film coating material of Example 1. This film has a high reflectance because the laminated film is made only of a polyester resin.

(Comparative Example 2)
A laminated film was prepared in the same manner except that only the acrylic resin was used as the laminated film coating material of Example 1. Since this film consists only of acrylic resin, the difference in refractive index from the base film was increased, and the reflectance was increased.

(Comparative Examples 3 and 4)
A laminated film was prepared in the same manner except that the laminated film coating composition of Example 1 was changed to the configuration shown in Table 1. Since the laminated film having these structures does not have a phase separation structure, it has a high reflectance.

(Comparative Example 5)
A laminated film was prepared in the same manner except that the laminated film of Example 1 was not provided. Since no laminated film was provided, there was no effect of reducing the reflectance.

  The present invention is a laminated film obtained by laminating a hard coat layer having excellent adhesion, transparency, interference fringes, and visibility with a base film, and a laminated film having a unique structure on the opposite surface. Thus, when it is used as an antireflection film, it has an effect of reducing reflection on the back surface, and can be developed for various uses such as an antireflection film such as a plasma television, a touch panel film, and a nameplate film.

Claims (1)

In the laminated film in which the hard coat layer is directly laminated on one side of the polyester film and the laminated film is provided on the other side, the average size in the length direction is 50 to 500 μm and the width direction between the polyester film and the hard coat layer. A projection structure having an average size of 10 to 100 μm and an average height of 0.03 to 1.0 μm is formed, and the laminate film is mainly composed of a mixture of polyester and / or polyurethane and an acrylic resin, and the laminate film A laminated film having an unevenly distributed structure in which the acrylic resin concentration on the surface side (non-base film side) is distributed at a high concentration.