JP2006205668A - Antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film excellent in light antireflection properties, suppressing an iris-like hue under a fluorescent lamp, and excellent in the adhesion and moist heat-resistant adhesion with a hard coat layer and economical efficiency. <P>SOLUTION: The antireflection film is constituted by laminating the hard coat layer and an antireflection layer on the surface of the coating layer of a base material film which has the coating layer. The base material film is a biaxially stretched polyester film having the coating layer formed from an aqueous coating solution, which contains an aqueous polyester resin (A) and at least one kind of a compound (B) selected from a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound and a water-soluble zirconium acylate compound as main constituent components and is characterized in that the mixing ratio (mass ratio) of (A)/(B) is 10/90-95/5 and stretched at least in one direction. The reflectivity at a wavelength of 550 nm of the surface of the antireflection layer is 2.0% or below. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a front surface of a display screen of a touch panel, a liquid crystal display (LCD), a cathode ray tube (CRT) of a television or a computer, a plasma display (PDP), a field emission display (FED), a surface electric field display (SED), electronic paper, etc. It is related with the anti-reflective film which can be mounted | worn and can suppress reflection of external light, glare, an iris-like color, etc.

  Display boards, displays, and electronic bulletin boards reflect external light and illumination light on their surfaces, and light sources and bright surroundings are reflected, reducing visibility. Reflections with antireflection layers on their surfaces Prevention films are commonly used. The antireflection film is generally one in which a single layer or a multilayer antireflection layer is formed on one side of a plastic film. When the antireflection layer is a single layer, the antireflective effect can be obtained by forming the low refractive index layer made of a material having a lower refractive index than that of the plastic film so that the thickness is ¼ wavelength or an odd multiple thereof. Is obtained. In addition, when the antireflection layer is a multilayer, it is possible to obtain an antireflection effect by alternately laminating the low refractive index layer and the high refractive index layer to two or more layers and appropriately controlling the thickness of each layer. Is also known. In addition, a hard coat layer is generally formed between the plastic film and the antireflection layer as necessary, and an antifouling layer is also formed on the antireflection layer.

  As a method of forming the antireflection layer, a dry coating method in which an antireflection layer is formed on the surface of the base material by vapor deposition or sputtering, an antireflection coating liquid is applied to the surface of the base material, and the antireflection layer is dried. A wet coating method for forming, or a combined method using both methods.

For example, a dry coating method, a wet coating method, and a combination method thereof are disclosed in Patent Documents 1 to 7, Patent Documents 8 to 15, and Patent Document 16, respectively.
JP-A-11-305006 JP 2000-121804 A JP 2000-141556 A JP 2000-338307 A JP 2002-6107 A JP 2003-149407 A JP 2003-215309 A JP 2001-296403 A JP 2003-131209 A JP 2003-139908 A JP 2003-227901 A Japanese Patent Laid-Open No. 2004-4404 JP 2004-175047 A JP 2004-175076 A JP 2004-212619 A JP 2004-21184 A

  In recent years, in applications such as displays and decorative materials, along with the further increase in screen size (larger area) and higher quality, in addition to the above-mentioned antireflection properties, the suppression of iris-like colors (interference fringes) under fluorescent lights The demand level is getting higher. In addition, fluorescent lamps are mainly in the three-wavelength form for daylight color reproducibility, and interference fringes are more easily observed. However, the film obtained by the above prior art cannot satisfy the market demand for interference fringe reduction.

  In order to prevent the surface from being scratched, the antireflection film is generally provided with a hard coat layer on the surface of the transparent substrate film and an antireflection layer on the surface of the hard coat layer. However, when a hard coat layer is provided on the surface of the transparent substrate film, light interference occurs due to a difference in refractive index between the transparent substrate film and the hard coat layer, and interference fringes are generated. For example, in the case of a hard coat film, the difference between the refractive index of the hard coat layer (for example, 1.49 for acrylic resin) and the refractive index of the polyester film for the base material (for example, 1.62 for PET) is large. Iridescent colors (interference fringes) are generated by the interference between the reflected light at the hard coat layer surface (ie, air / hard coat layer interface) and the reflected light at the hard coat layer / polyester film interface. It is considered to be.

  In order to prevent the occurrence of interference fringes, metal oxide fine particles are contained in the hard coat layer to increase the refractive index of the hard coat layer and reduce the difference in refractive index between the hard coat layer and the polyester film of the substrate. A method is disclosed (see, for example, Patent Document 17). However, by including metal oxide fine particles in the hard coat layer, the original functions of the hard coat layer, such as transparency, chemical resistance, scratch resistance, and antifouling property, are lowered. Further, when an antireflection layer is further provided on the hard coat layer, it is necessary to optimize the antireflection layer in accordance with the change in the refractive index of the hard coat layer.

  In addition, as another method for suppressing interference fringes of the hard coat layer, paying attention to the variation in the local thickness of the film, after producing an easy-adhesive film, the film is subjected to a calendering treatment, A method for reducing the variation in thickness is disclosed (for example, see Patent Document 18). However, the above method evaluates the interference fringes by the film alone, and when the hard coat layer is laminated, no investigation is made on the interference fringes based on the difference in the refractive index of the interface, and the number of steps is further increased. There is a problem in terms of productivity.

  In addition, an invention in which the area ratio of interference fringes is defined by paying attention to the uneven thickness of the layers constituting the hard coat film is disclosed (for example, see Patent Document 19). However, the level of thickness spots and the reduction method are not specifically described in the specification. For example, in order to reduce the thickness unevenness of each layer, it is necessary to strictly control the thickness of each layer, which is problematic in terms of productivity or yield.

  Furthermore, paying attention to the back surface reflectance of the film itself, a method of laminating a hard coat layer having a specific hardness while suppressing the back surface reflectance is also disclosed (for example, see Patent Document 20). However, in the method described in Patent Document 20, a coat layer having a specific refractive index and a specific thickness is provided on the opposite surface of the hard coat layer of the hard coat film, and the back surface reflectance is controlled to be 0.1% or less. Must. Therefore, it is necessary to design the film including the back side. In addition, when the film is manufactured, it is necessary to control the back surface reflectance so that the back surface reflectance is always 0.1% or less, and when the back surface reflectance is out of range, it is necessary to change the conditions. The control of the reflectance is complicated.

JP-A-7-151902 JP 2001-71439 A JP 2002-241527 A JP 2002-210906 A

Further, on the transparent substrate film, a medium refractive index layer having a refractive index of 1.5 to 1.7, a high refractive index layer having a refractive index of 1.6 to 1.8, and a refractive index lower than that of the middle refractive index layer. A film having antireflective properties and suppressing interference fringes is disclosed by laminating a low refractive index layer made of a material having a refractive index in this order from the transparent base film side (see Patent Document 21). . In this method, suppression of interference fringes is expressed by a medium refractive index layer having a refractive index of 1.5 to 1.7, and in order to exhibit the effect, the medium refractive index layer is usually 1 μm or less. Requires a thin film with a thickness of 50 to 500 nm, and if the accuracy of the thickness of the layer is not increased, spots occur in the interference fringe suppression effect. However, this method is produced by a method of applying a medium refractive index layer to a transparent base film and laminating it, that is, the so-called offline coating method, and has a problem that it is difficult to accurately laminate the thickness of the thin film. Moreover, there exists a subject that the drying temperature of an application layer has a limit and adhesive durability with a base film, especially adhesion durability, such as heat-and-moisture resistance, is inferior. It is also disadvantageous in terms of economy.
JP 2003-75603 A

  The object of the present invention was made to solve the above-mentioned problems of the prior art, and is excellent in anti-reflection properties, suppresses iris-like colors under fluorescent lamps, and adheres to the hard coat layer. Another object of the present invention is to provide an antireflection film that is excellent in adhesion (moisture and heat resistance) under high temperature and high humidity, and further excellent in economic efficiency.

  The antireflection film of the present invention capable of solving the above problems is a base film having a coating layer, and a hard coat layer and an antireflection layer are laminated in this order on the surface of the coating layer of the base film. The base film is an aqueous polyester resin (A), a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, or a water-soluble zirconium. After applying and drying an aqueous coating solution having at least one acylate compound (B) as a main component and a mixing ratio (mass ratio) of (A) / (B) of 10/90 to 95/5 A biaxially stretched polyester film having a coating layer stretched in at least one direction, and the reflectance of the antireflection layer surface at a wavelength of 550 nm is 2.0% or less. And characterized in that.

  The base film preferably has a total light transmittance of 85% or more. Moreover, it is preferable that the said water-based polyester resin (A) is a copolymerization polyester resin which contains 1-10 mol% of aromatic dicarboxylic acid components containing a sulfonic-acid metal base with respect to all the dicarboxylic acid components of polyester. Further, the aqueous polyester resin (A) preferably has a glass transition temperature of 40 ° C. or higher.

  The hard coat layer is preferably composed of an electron beam, an ultraviolet curable acrylic resin, or a siloxane thermosetting resin.

  The antireflection film of the present invention has excellent antireflection properties, suppresses iris-like colors under fluorescent lamps, and has excellent adhesion to a hard coat layer and adhesion under high temperature and high humidity (moisture and heat resistance). Furthermore, since it is more economical, it is useful as a member or a decorative material used for optical equipment such as a touch panel, a computer, a television, a display such as a liquid crystal display.

(Base film)
<Biaxially oriented polyester film>
In the present invention, the biaxially stretched polyester film used as a base film is a film composed of a polyester resin, and mainly comprises at least one of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate as a constituent component. To do. Among these polyester resins, polyethylene terephthalate is most preferable from the balance between physical properties and cost. Moreover, a polyester film can improve chemical resistance, heat resistance, mechanical strength, etc. by biaxially stretching.

  In order to improve light resistance, the biaxially stretched polyester film can contain an ultraviolet absorber in the film so that the light transmittance at a wavelength of 380 nm can be 30% or less.

  Examples of the ultraviolet absorber include an organic ultraviolet absorber and an inorganic ultraviolet absorber, and an organic ultraviolet absorber is preferable from the viewpoint of transparency. Any known organic ultraviolet absorbers can be used. Among them, benzotriazole, benzophenone, and cyclic iminoesters are preferred, and cyclic iminoesters are particularly preferred from the viewpoint of heat resistance. Two or more of the above ultraviolet absorbers may be used in combination.

  Examples of the benzotriazole ultraviolet absorber include 2- [2′-hydroxy-5 ′-(methacryloyloxymethyl) phenyl] -2H-benzotriazole and 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl. ] -2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxypropyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyhexyl) phenyl]- 2H-benzotriazole, 2- [2'-hydroxy-3'-tert-butyl-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-tert-butyl -3 '-(methacryloyloxyethyl) phenyl] -2H-ben Triazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-chloro-2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyethyl) phenyl] -5 -Methoxy-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-cyano-2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxy) Ethyl) phenyl] -5-tert-butyl-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-nitro-2H-benzotriazole, and the like.

  Examples of the benzophenone ultraviolet absorber include 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, , 4-dihydroxybenzophenone, 2-hydroxy-4-acetoxyethoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy Examples include benzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-5,5'-disulfobenzophenone, disodium salt, and the like.

  Examples of the cyclic imino ester ultraviolet absorber include 2,2 ′-(1,4-phenylene) bis (4H-3,1-benzoxazin-4-one), 2-methyl-3,1-benzoxazine-4. -One, 2-butyl-3,1-benzoxazin-4-one, 2-phenyl-3,1-benzoxazin-4-one, 2- (1- or 2-naphthyl) -3,1-benzoxazine -4-one, 2- (4-biphenyl) -3,1-benzoxazin-4-one, 2-p-nitrophenyl-3,1-benzoxazin-4-one, 2-m-nitrophenyl-3 , 1-benzoxazin-4-one, 2-p-benzoylphenyl-3,1-benzoxazin-4-one, 2-p-methoxyphenyl-3,1-benzoxazin-4-one, 2-o- Methoxyphenyl 3,1-benzoxazin-4-one, 2-cyclohexyl-3,1-benzoxazin-4-one, 2-p- (or m-) phthalimidophenyl-3,1-benzoxazin-4-one, 2 , 2 '-(1,4-phenylene) bis (4H-3,1-benzoxazinon-4-one) 2,2'-bis (3,1-benzoxazin-4-one), 2,2' -Ethylenebis (3,1-benzoxazin-4-one), 2,2'-tetramethylenebis (3,1-benzoxazin-4-one), 2,2'-decamethylenebis (3,1- Benzoxazin-4-one), 2,2'-p-phenylenebis (3,1-benzoxazin-4-one), 2,2'-m-phenylenebis (3,1-benzoxazin-4-one) ), 2,2 '-(4,4'-Diff Nylene) bis (3,1-benzoxazin-4-one), 2,2 '-(2,6- or 1,5-naphthalene) bis (3,1-benzoxazin-4-one), 2,2 '-(2-Methyl-p-phenylene) bis (3,1-benzoxazin-4-one), 2,2'-(2-nitro-p-phenylene) bis (3,1-benzoxazine-4-one) ON), 2,2 '-(2-chloro-p-phenylene) bis (3,1-benzoxazin-4-one), 2,2'-(1,4-cyclohexylene) bis (3,1- Benzoxazin-4-one), 1,3,5-tri (3,1-benzoxazin-4-one-2-yl) benzene and the like.

  1,3,5-tri (3,1-benzoxazin-4-on-2-yl) naphthalene, and 2,4,6-tri (3,1-benzoxazin-4-on-2-yl) ) Naphthalene, 2,8-dimethyl-4H, 6H-benzo (1,2-d; 5,4-d ') bis- (1,3) -oxazine-4,6-dione, 2,7-dimethyl- 4H, 9H-benzo (1,2-d; 5,4-d ') bis- (1,3) -oxazine-4,9-dione, 2,8-diphenyl-4H, 8H-benzo (1,2 -D; 5,4-d ') bis- (1,3) -oxazine-4,6-dione, 2,7-diphenyl-4H, 9H-benzo (1,2-d; 5,4-d' ) Bis- (1,3) -oxazine-4,6-dione, 6,6'-bis (2-methyl-4H, 3,1-benzoxazine 4-one), 6,6'-bis (2-ethyl-4H, 3,1-benzoxazin-4-one), 6,6'-bis (2-phenyl-4H, 3,1-benzoxazine- 4-one), 6,6'-methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-methylenebis (2-phenyl-4H, 3,1-benzoxazine- 4-one), 6,6′-ethylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-ethylenebis (2-phenyl-4H, 3,1-benzo) Oxazin-4-one), 6,6'-butylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-butylenebis (2-phenyl-4H, 3,1-benzo) Oxazin-4-one), 6,6'-oxybis 2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-oxybis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6,6′-sulfonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-sulfonylbis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6,6'- Carbonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-carbonylbis (2-phenyl-4H, 3,1-benzoxazin-4-one), 7,7 '-Methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7'-methylenebis (2-phenyl-4H, 3,1-benzoxazin-4-one), 7,7 '-Bis (2-methyl-4H, 3 , 1-benzoxazin-4-one), 7,7′-ethylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7′-oxybis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7′-sulfonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7′-carbonylbis (2-methyl-) 4H, 3,1-benzoxazin-4-one), 6,7'-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,7'-bis (2-phenyl- 4H, 3,1-benzoxazin-4-one), 6,7'-methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,7'-methylenebis (2-phenyl- 4H, 3,1-benzoxazin-4-one) It can also be used as a cyclic imino ester based ultraviolet absorber.

  When the ultraviolet absorbent is an ultraviolet absorbent having a thermal decomposition starting temperature of 290 ° C. or more, it is preferable because process contamination during the production of the base film can be reduced. When a polyester containing an ultraviolet absorber having a thermal decomposition start temperature of less than 290 ° C is melted and extruded into a rotating cooling roll in the form of a sheet, the decomposed product of the ultraviolet absorber adheres to the roll and then reattaches to the film. As a result, the film is scratched and easily becomes an optical defect.

  The light resistance of the film can be improved by incorporating a UV absorber in the polyester film. That is, it is possible to suppress deterioration of the film due to ultraviolet rays contained in external light.

  For example, the film having good light resistance preferably has a transmittance of 20% or less at a wavelength of 380 nm, more preferably 10% or less. When the transmittance at a wavelength of 380 nm exceeds 30%, the light resistance of the film deteriorates, which is not preferable.

The content of the low molecular weight type UV absorber satisfying these characteristics is preferably 0.1 to 4% by mass, and preferably 0.3 to 2% by mass with respect to the constituent resin of the UV absorbing layer. More preferred. If the amount of the ultraviolet absorber is too small, the ultraviolet absorbing ability is decreased, and if it is too large, the film may be yellowed or the film-forming property of the film may be deteriorated.

  In addition, it is also recommended to use a polymer type as the ultraviolet absorber in order to avoid problems caused by bleeding on the film surface. Moreover, adhesiveness with the other layer laminated | stacked also increases by reducing the bleed-out to a film. The polymer type ultraviolet absorber means a polymer having a skeleton useful as an ultraviolet absorber in the side chain. In consideration of compatibility with polyester, polyester ultraviolet absorbers and acrylic polymer ultraviolet absorbers are preferred. For example, polyester has terephthalic acid as a dicarboxylic acid component, ethylene glycol and / or 1,4-butanediol as a diol component, and naphthalenetetracarboxylic acid diimide represented by the general formula (I) as a copolymerization component. Polyester ultraviolet absorbers synthesized from naphthalenedicarboxylic acid represented by the general formula (II) (Mitsubishi Chemical, Novapex U-110) and acrylics having a 2- (2-hydroxylphenyl) benzotriazole skeleton in the side chain A polymer (manufactured by BASF, UVA-1635) or the like is preferable because it can maintain characteristics such as transparency in addition to the intended ultraviolet absorption characteristics.

  In the above general formula (I), R represents an organic residue (such as an alkylene group), and X represents a hydroxyl group or the like.

  The content of the polymer type ultraviolet absorber is preferably 0.1 to 20% by mass, more preferably 0.5 to 15% by mass with respect to the constituent resin of the ultraviolet absorbing layer. If the amount of the ultraviolet absorber is too small, the ultraviolet absorbing ability is decreased, and if it is too large, the film may be yellowed or the film-forming property of the film may be deteriorated.

  As for the biaxial used for the base film, the polyester film adopts a laminated structure of at least 3 layers (3 layers, 4 layers, 5 layers, etc.), and both surface layers do not substantially contain an ultraviolet absorber. It is preferable to use an ultraviolet absorbing layer in which an ultraviolet absorber is contained in an intermediate layer (base material intermediate layer).

  When an ultraviolet absorber is contained in a biaxially stretched polyester film having a single layer structure, the ultraviolet absorber is sublimated in the extrusion process at the time of film formation, and the polyester is melt-extruded into a die outlet or a sheet. It may adhere to a cooling roll used for cooling, a tenter used for stretching, and the like, and may adhere to the extruded molten polyester, causing optical defects. However, by adopting the base film having the above-described laminated structure, it is possible to drastically suppress bleeding out of the ultraviolet absorber contained in the intermediate layer on the film surface during film production. Therefore, contamination of the die discharge port, the cooling roll, the tenter, etc. is reduced, and the occurrence of film defects due to the contamination is suppressed. Moreover, the fall of the adhesiveness between each layer by the bleed-out of a ultraviolet absorber is also suppressed.

  When the biaxially stretched polyester film used for the base film has a three-layer structure, only the base intermediate layer contains an ultraviolet absorber. In the case of four or more layers, any one or more layers except both surface layers may contain the ultraviolet absorber, and all the layers except both surface layers may contain. In addition, “substantially” of “substantially not containing an ultraviolet absorber” in both surface layers is unavoidable, for example, when a bleed from a layer containing an ultraviolet absorber diffuses into both surface layers. The purpose is to exclude the case where a UV absorber is mixed. The most preferable laminated structure of the biaxially stretched polyester film used for the base film is a three-layer structure, and the base material intermediate layer is a structure of an ultraviolet absorbing layer.

  When a biaxially stretched laminated polyester film having a three-layer structure is used for the base film, the thickness ratio of each layer is not limited and is arbitrary, but the lower limit of the thickness of both surface layers is preferably 3% of the total thickness. 5% is particularly preferable. On the other hand, the upper limit of the thickness of both surface layers is preferably 15% of the total thickness, particularly preferably 10%. If either one of the two surface layers is too thin, sublimation and bleeding out of the ultraviolet absorber may not be sufficiently prevented. In either case, if the thickness is too large, the effect of preventing the sublimation / bleed out of the ultraviolet absorber is saturated, and depending on the balance with the content of the ultraviolet absorber, The ultraviolet absorber concentration (abundance per unit area) decreases, and the ultraviolet absorption effect may be insufficient, which is not preferable.

  In the biaxially stretched laminated polyester film, each layer is preferably made of polyester. These polyesters may be all the same type, all different types, or only some of the layers may be the same type, but from the viewpoint of ease of production management and recovery of waste resin, etc. It is a preferred embodiment that PET is used for all layers.

  In addition, in the laminated polyester film formed by disposing the polyester resin composition layer containing the ultraviolet absorber in the intermediate layer, the anti-bleeding effect of the ultraviolet absorption inhibitor by the surface layer is determined using the surface IR analysis method. This can be confirmed by evaluating the degree of uneven distribution of the ultraviolet absorber at The degree of uneven distribution of the ultraviolet absorber in the thickness direction of the film is greatly influenced by the thickness ratio of both the surface layer and the intermediate layer of the laminated polyester film. However, even if the thickness ratio is the same, it varies depending on, for example, the melt line after the filter and the resin temperature of the flat die in the melt extrusion process during film production.

  In the present invention, when a laminated polyester film formed by arranging a polyester resin composition layer containing an ultraviolet absorber in an intermediate layer is used as a base film, the degree of uneven distribution of the ultraviolet absorber in the film thickness direction is preferably 0.00. It is controlled to be 20 or less, more preferably 0.10 or less, particularly preferably 0.05 or less.

  Although the blending method of the ultraviolet absorber to the polyester film is not limited, it is preferable to blend at the time of polyester polymerization or melt extrusion. In this case, it is a preferred embodiment that a master batch pellet containing an ultraviolet absorber is prepared in advance and added thereby. For example, the following method is illustrated as a preferred embodiment. First, polyester and a UV absorber are blended to prepare a master batch pellet. This master batch pellet is a pellet that does not substantially contain particles for the purpose of imparting slipperiness. The master batch pellets and raw material pellets mixed with virgin polyester pellets are fully vacuum dried, then supplied to an extruder, melt extruded into a film, cooled and solidified on a casting roll to produce an unstretched polyester film. Film. For the lamination of each layer, a co-extrusion method in which polyester pellets constituting each layer are extruded from separate extruders and led to one die to form an unstretched film having a laminated structure can be preferably employed.

  At the time of the above melt extrusion, the resin temperature to the extruder melting part, kneading part, polymer tube, gear pump and filter is 280 to 290 ° C, and the resin temperature to the subsequent polymer tube and flat die is 270 to 280 ° C. It is preferable in terms of preventing sublimation at the die discharge port of the ultraviolet absorber and contamination of the cooling roll.

  In addition, it is desirable to perform high-precision filtration in order to remove foreign substances contained in the polyester at an arbitrary place where the molten polyester is maintained at about 280 ° C. If such foreign matter remains on the base film, it may cause optical defects and scratches.

  The filter medium used for high-precision filtration of molten polyester is not particularly limited, but if it is a filter medium made of a stainless steel sintered body, aggregates mainly composed of Si, Ti, Sb, Ge, and Cu, and high melting point organic substances It is preferable because of its excellent removal performance. Furthermore, the filter particle size (initial filtration efficiency 95%) of the filter medium is preferably 20 μm or less, and more preferably 15 μm or less. When the filter particle size of the filter medium (initial filtration efficiency 95%) exceeds 20 μm, foreign matters having a size exceeding 20 μm that cause the above-mentioned optical defects and scratches cannot be sufficiently removed. Productivity may decrease by performing high-precision filtration of the molten resin using a filter medium having a filter particle size (initial filtration efficiency of 95%) of 20 μm or less. However, the above-mentioned high-precision filtration is recommended as one of important processes during film production from the viewpoint of reducing protrusions due to coarse particles and suppressing the generation of scratches during film production.

  If the foreign material that remains in the raw material polyester remains, or if UV absorbers that bleed out from the molten polyester during film formation and contaminate the die discharge port adhere to the film, the stretching process during film formation The orientation of the polyester molecules is disturbed around the foreign matter and the ultraviolet absorber (hereinafter collectively referred to as “foreign matter”), and optical distortion occurs. Because of this optical distortion, it is recognized as a defect that is considerably larger than the size of the actual foreign matter, and the quality may be significantly impaired. For example, a foreign matter having a size of 20 μm may be optically recognized as a size of 50 μm or more, and may be recognized as an optical defect having a size of 100 μm or more.

  Further, as the transparency of the film increases, optical defects due to minute foreign matters tend to become clearer. As the film becomes thicker, the content of foreign matters per unit area of the film in a plan view tends to be larger than that of a thin film, and this problem is further increased. Therefore, it is preferable to remove foreign matters in the polyester as much as possible, and it is recommended to employ the various methods described above.

  The obtained unstretched film is stretched 2.5 to 5.0 times in the longitudinal direction (longitudinal direction: traveling direction during production of the laminated film) with a roll heated to 80 to 120 ° C. to obtain a uniaxially oriented film. Subsequently, the end of the film is gripped with a clip and guided to a hot air zone heated to 120 to 150 ° C., stretched 2.5 to 5.0 times in the width direction, and heat treated at 200 to 250 ° C. A biaxially stretched polyester film used for a substrate can be obtained by performing a relaxation treatment to about 3% in the width direction as necessary during the heat treatment step.

The biaxially stretched polyester film obtained by the above method preferably has 100 / m ² or less scratches having a depth of 1 μm or more and a length of 3 mm or more present on the surface. The number of scratches is more preferably 30 pieces / m ² or less, and particularly preferably 10 pieces / m ² or less. If the number of scratches is within such a range, problems due to optical defects do not occur.

  As a technique for preventing the occurrence of scratches on the film, (a) the film surface itself or the roll surface, in particular, the roll surface in contact with the film should not cause “defects” that cause scratches; Examples include preventing the film from shifting in the vertical and horizontal directions on the surface. The above-mentioned “defects” refer to all factors that cause fine scratches on the film by coming into contact with the film, such as scratches, deposits, deposits, and foreign matters formed on the roll surface. Therefore, by eliminating these defects, it is possible to reduce the occurrence of scratches on the film surface. In order to prevent the occurrence of the above defects, for example, the following methods can be employed.

  In order to prevent the surface roughness of the roll used at the time of manufacturing the base film from being 0.1 μm or less in Ra, and to prevent the generation of scratches such as deposits, deposits and foreign matters on the roll surface, the longitudinal stretching step A method of installing a roll cleaner on the roll of the preheating inlet and the cooling roll of the above is mentioned.

  In addition, there is a method in which the cleanness in the base film manufacturing process is set to class 1000 or less (1000 particles or less of 0.5 μm or more in a volume per cubic foot), especially around the roll, class 100 or less, cast It is preferable to use clean air of class 100 or less for the blower cooling device for cooling the anti-roll surface in the process. Furthermore, before the said base film manufacture, the method of cleaning a roll by the operation | work etc. which scrape off the defect on a roll using an abrasives is also mentioned. In addition, in order to prevent the film from adsorbing dust or the like due to the generation of static electricity and causing a defect, there is a method of providing a static eliminator so that the charge amount of the film becomes ± 1500 V or less in all steps. The process from casting the biaxially oriented polyester film to the tenter, which will be described later, is a process in which scratches are likely to occur, and this section is laid out compactly and the passage time is 5 minutes or less also contributes to the suppression of defects. Can do.

  About a roll, it can be made the structure where the fault of a roll surface does not contact a film directly by forming a water film on the roll surface, or using an air floating type roll. Moreover, the adhesion of the defect to a roll surface can be reduced and the defect of a roll surface can be reduced because the oligomer amount which precipitates from a film shall be 1000 ppm or less.

  Furthermore, in the winding process after stretching, the surface on the end side in the width direction of the film is pressed with a roller with a protrusion to form an uneven portion on the portion, and the film on which the uneven portion is formed is wound. The take-up mechanism is configured to be wound in a roll shape, and the protrusion on the roller with the protrusion is formed in a tapered shape, the top of the protrusion is rounded, and the curvature radius of the top surface is 0.4 mm or less. By setting, it is possible to prevent the film and the defect from coming into contact with each other in the film winding device.

  It is also effective as a scratch generation prevention method to prevent the film from shifting on the roll surface. For example, the following methods can be employed. For example, by reducing the diameter of the roll, using a suction roll, electrostatic contact, and using a part nip contact device, etc., it is possible to suppress the occurrence of long scratches by increasing the adhesion of the film to the roll. it can. In particular, reducing the diameter of the roll also subdivides the amount of shift of the film and can contribute to the prevention of long scratches. In addition, many of the scratches increase in length and frequency toward the end in the roll width direction, and it is difficult to obtain a scratch-free portion at the end in the roll width direction. By trimming around the center of the direction, a film with few scratches can be obtained.

  In addition, as a cause of occurrence of longitudinal scratches or lateral scratches, deformations such as expansion and contraction in the longitudinal direction or the lateral direction of the film can be mentioned, respectively. These film deformations are mainly caused by changes in the film temperature. Therefore, for example, by suppressing the temperature change of the film on the roll surface, the amount of film deformation due to such temperature can be reduced, and the occurrence of vertical scratches and horizontal scratches can be prevented. Specifically, the temperature change of the film per roll is 40 ° C. or less, preferably 30 ° C. or less, more preferably 20 ° C. or less, still more preferably 10 ° C. or less, and particularly preferably 5 ° C. or less. Is recommended. Examples of the method for suppressing the temperature change of the film on the roll surface include air cooling between rolls and water cooling through a water tank. Furthermore, the temperature change of the film on the roll surface per roll can be reduced by increasing the number of rolls. Preferably, the number of rolls in the longitudinal stretching step is 10 or more.

  Further, by setting the relationship between the relative speeds of the plurality of rolls to a speed profile that is closest to the amount of deformation due to the temperature and tension of the film, it is possible to reduce the vertical shift of the film. Furthermore, in the coating step of the coating solution for forming an adhesion modified layer, which will be described later, the drying condition is completed at the beginning of the dryer section, and the film is cooled to the outlet so that the film temperature at the dryer outlet is 40 ° C. or lower. Moreover, the shift of the film due to temperature change can be reduced.

  In addition, if the tension during running of the film is too low, the gripping force is lowered and deviation occurs, and if it is too high, the stress deformation becomes large and deviation occurs, so that the optimum tension range is 4.9 to 29.4 MPa. It is preferable to adjust by the driving roll speed and tension adjusting means. Moreover, the shift | offset | difference of the film on a roll surface can be suppressed by making the friction coefficient between the film and roll in the use temperature at the time of manufacture 0.2 or more.

  Furthermore, it is preferable to use a special bearing for the free roll and to set the rotational resistance to 19.6 N or less. For the driving roll, it is preferable to control the rotation spots to 0.01% or less.

  The sequential biaxial stretching method has been described above, but the stretching method may be a simultaneous biaxial stretching method. Further, it may be a multistage stretching method.

  In addition, in order to improve the handling properties such as film slipperiness, rollability and blocking resistance, and wear characteristics such as abrasion resistance and scratch resistance, inert particles are generally added to the polyester film of the base material. It is included. However, when the polyester film is used as a base film for an antireflection film, it is required to have excellent handling properties while maintaining high transparency. From the viewpoint of transparency, the total light transmittance of the easily adhesive polyester film of the substrate is preferably 85% or more, particularly preferably 90% or more. The higher the total light transmittance is, the better the transparency is (100% is ideal), but the handling property is lowered and the production at the industrial level becomes difficult. Therefore, the upper limit of the total light transmittance may be 96% from the viewpoint of maintaining the handling property and practical characteristics for transparency.

  From the viewpoint of transparency, the inert particles in the base film cause light to scatter, so the content of particles is preferably as low as possible. Therefore, it is preferable to adopt a multilayer structure in which particles are contained only in the surface layer of the film, or a laminated structure in which particles are not substantially contained in the film and fine particles are contained only in the coating layer.

  In particular, from the viewpoint of transparency, when inert particles are not substantially contained in the polyester film, inorganic and / or heat-resistant polymer particles are contained in the aqueous coating solution in order to improve the handleability of the film. It is important to form irregularities on the surface of the coating layer. Note that “substantially no inert particles” means, for example, in the case of inorganic particles, a content which is below the detection limit when quantitatively analyzing the elements derived from the particles by fluorescent X-ray analysis. Means. This is because even if particles are not actively included, foreign matter may be mixed in from the outside during raw polymer production or film production, or dirt inside the device may be peeled off and mixed into the film. is there.

<Coating layer>
The antireflection film of the present invention uses a biaxially stretched polyester film having a coating layer as a base film, and a hard coat layer and an antireflection layer are laminated in this order on the surface of the coating layer of the base film. In the present invention, the intermediate layer between the biaxially stretched polyester film and the hard coat layer comprises an aqueous polyester resin (A), a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, Alternatively, an aqueous coating solution having at least one water-soluble zirconium acylate compound (B) as a main constituent and a mixing ratio (mass ratio) of (A) / (B) of 10/90 to 95/5 It is important that the coating layer be stretched in at least one direction after being coated and dried. The composition ratio (A / B; mass ratio) of the constituent components (A) and (B) of the coating layer is more preferably 15/85 to 90/10.

  The coating layer is heated with heat during the stretching process of the polyester film, so that at least one of a titanium chelate compound, a titanium acylate compound, a zirconium chelate compound, or a zirconium acylate compound (B) is in contact with the polyester resin. A uniform film is formed by a crosslinking reaction. That is, since the metal chelate compound or metal acylate compound is decomposed by heat treatment, the compound is not present in the coating layer after the heat treatment in a state added to the coating solution.

Therefore, the content of the metal chelate compound or metal acylate compound in the coating solution is calculated from the content of the metal element (Ti or Zr) in the coating layer after the heat treatment as follows.
(1) First, the type of chelate or acylate contained in the coating solution is identified from the chelate or acylate residue in the coating layer.
(2) Next, the content of the metal chelate compound or metal acylate compound in the coating solution is calculated from the content of the metal element (Ti or Zr) in the coating layer.

  The refractive index of the coating layer is higher than that of the polyester resin (A) alone by increasing the composition ratio of at least one of the titanium chelate compound, the titanium acylate compound, the zirconium chelate compound, or the zirconium acylate compound (B). Can also be high. In order to increase the refractive index of the coating layer, it can also be achieved by including metal fine particles in the coating layer. However, by including metal fine particles, the stretchability of the coating layer and the adhesion between the hard coat layer and the substrate film are lowered.

  In the polyester resin (A) used in the present invention, an active site such as a hydroxyl group or a carboxyl group may be introduced into the molecular chain. A cross-linking reaction takes place in this place, resulting in a dense film.

  Moreover, in order to give the same crosslinkability with an acrylic resin, it is necessary to introduce a crosslinkable functional group. However, since the refractive index of the acrylic resin itself is low, even when a titanium chelate compound, a titanium acylate compound, a zirconium chelate compound, or a zirconium acylate compound is used in combination, the refractive index is controlled to be the same as that of the coating layer of the present invention. It is difficult.

  Furthermore, since the polyester resin (A), which is a constituent component of the coating layer, is involved in adhesion to the polyester film, the composition ratio (A / B) of the aqueous polyester resin (A) and the compound (B) is 10 When the ratio is less than / 90, the adhesion with the base film is lowered, and the stretchability as a coating layer is lowered, and it is not uniform during stretching. Therefore, the transparency required for optical use decreases, and the adhesion with the hard coat layer formed on the coating layer becomes a problem. On the other hand, when the composition ratio (A / B) between the aqueous polyester resin (A) and the compound (B) exceeds 95/5, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, or a water-soluble Crosslinking by the zirconium acylate compound (B) becomes poor, and the refractive index also decreases. For this reason, the adhesion (humidity and heat resistance) under high temperature and high humidity is lowered, and the effect of suppressing iris-like colors under a fluorescent lamp is insufficient.

  The aqueous polyester resin (A) of the present invention is dissolved or dispersed in water or a water-soluble organic solvent (for example, an aqueous solution containing less than 50% by mass of alcohol, alkyl cellosolve, ketone, or ether). Means a polyester resin capable of In order to impart water resistance to the polyester resin, it is important to introduce a hydrophilic group such as a hydroxyl group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, or an ether group into the molecular chain of the polyester resin. Among the hydrophilic groups, sulfonic acid groups are preferable from the viewpoint of coating film properties and adhesion.

  When the sulfonic acid group is introduced into the polyester, the sulfonic acid compound is more preferably 1 to 10 mol% in the total acid component of the polyester. When the amount of the sulfonic acid group is less than 1 mol%, the polyester resin does not exhibit water, and a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, or a water-soluble zirconium acylate compound Since the compatibility with at least one of (B) also decreases, it becomes difficult to obtain a uniform and transparent coating layer. Moreover, when the amount of sulfonic acid group exceeds 10 mol%, it becomes easy to be inferior to the adhesiveness (humidity heat resistance) under high temperature and high humidity.

  Further, the aqueous polyester resin (A) preferably has a glass transition temperature of 40 ° C. or higher. For this reason, the acid component of the polyester resin (A) is preferably composed mainly of an aromatic group such as terephthalic acid, isophthalic acid, or naphthalenedicarboxylic acid. The glycol component is preferably a glycol having a relatively small carbon number such as ethylene glycol, propane glycol, 1,4-butanediol, or neopentyl glycol, or an aromatic system such as an ethylene oxide adduct of bisphenol A. Further, as a raw material of the polyester resin (A), a rigid component such as biphenyl or a dicarboxylic acid component or diol component having a high refractive index atom such as bromine or sulfur may be used within a range in which the physical properties of the film do not deteriorate. Good. When the glass transition temperature of the polyester resin (A) is less than 40 ° C., the adhesiveness (humidity heat resistance) under high temperature and high humidity tends to be insufficient. Furthermore, since the refractive index of the polyester resin (A) also decreases, the refractive index of the coating layer also decreases. As a result, the suppression of iris color under fluorescent lamps tends to be insufficient.

  The other main component of the coating layer is at least one (B) of a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, or a water-soluble zirconium acylate compound. The above water-soluble means to dissolve in water or an aqueous solution containing less than 50% by mass of a water-soluble organic solvent.

  Examples of water-soluble titanium chelate compounds include diisopropoxybis (acetylacetonato) titanium, isopropoxy (2-ethyl-1,3-hexanediolato) titanium, diisopropoxybis (triethanolaminato) titanium, di -N-butoxybis (triethanolaminato) titanium, hydroxybis (lactato) titanium, ammonium salt of hydroxybis (lactato) titanium, ammonium beloxocitrate ammonium salt and the like.

  Examples of the water-soluble titanium acylate compound include oxotitanium bis (monoammonium oxalate), and examples of the water-soluble zirconium compound include zirconium tetraacetylacetonate and zirconium acetate.

  In the coating layer, a resin other than the main component, for example, an acrylic resin, a polyurethane resin, a polyester resin, an alkyd resin, a vinyl resin such as polyvinyl alcohol, etc. is used in a range that does not affect the effect of the present invention. It doesn't matter. Further, the combined use of the crosslinking agent is not particularly limited as long as the effect of the present invention is not affected. Examples of crosslinking agents that can be used include adducts of urea, melamine, benzoguanamine, and the like with formaldehyde, amino resins such as alkyl ether compounds composed of these adducts and alcohols having 1 to 6 carbon atoms, polyfunctional epoxy compounds, A polyfunctional isocyanate compound, a block isocyanate compound, a polyfunctional aziridine compound, an oxazoline compound, etc. are mentioned.

  In the present invention, the coating liquid used for forming the coating layer includes an aqueous polyester resin (A), a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, or a water-soluble It is an aqueous coating liquid mainly composed of at least one zirconium acylate compound (B) and an aqueous solvent. When applying the above aqueous coating solution to the surface of the polyester film, an appropriate amount of a known anionic surfactant or nonionic surfactant is added to improve the wettability to the film and coat the coating solution uniformly. It is preferable to do.

  In addition, in the aqueous coating solution, inorganic and / or heat-resistant polymer particles, antistatic agents, ultraviolet absorbers, etc. in order to impart other functions such as handling properties, antistatic properties and antibacterial properties to the film. Additives such as organic lubricants, antibacterial agents, and photo-oxidation catalysts can be included.

  As the solvent used in the coating solution, alcohols such as ethanol, isopropyl alcohol and benzyl alcohol may be mixed in addition to water in a range of less than 50% by mass with respect to the total coating solution. Furthermore, if it is less than 10 mass%, you may mix in the range which can melt | dissolve organic solvents other than alcohol. However, the total amount of alcohols and other organic solvents in the coating solution is preferably less than 50% by mass.

<Manufacture of base film>
The method for producing an easy-adhesive polyester film that serves as a base material for the antireflection film of the present invention will be described by taking a polyethylene terephthalate (hereinafter abbreviated as PET) film as an example, but is not limited to this.

  After sufficiently drying the PET resin in a vacuum, it is supplied to an extruder, melted and extruded at about 280 ° C. from a T-die into a rotating cooling roll into a sheet, cooled and solidified by an electrostatic application method, and unstretched PET. Get a sheet. The unstretched PET sheet may have a single layer structure or a multilayer structure by a coextrusion method. As described above, the polyester film constituting the base film is a multi-layer structure composed of at least three layers, and only the base intermediate layer contains an ultraviolet absorber, and the ultraviolet absorber in both surface layers is not substantially contained. Is preferred. Moreover, it is preferable not to contain an inert particle substantially in PET resin.

  The obtained unstretched PET sheet is stretched 2.5 to 5.0 times in the longitudinal direction with a roll heated to 80 to 120 ° C. to obtain a uniaxially stretched PET film. Furthermore, the edge part of a film is hold | gripped with a clip, it guide | induces to the hot air zone heated at 70-140 degreeC, and is extended | stretched 2.5 to 5.0 times in the width direction. Then, it guide | induces to the heat processing zone of 160-240 degreeC, and heat-processes for 1 to 60 seconds, and completes crystal orientation.

  In any stage of the film production process, the aqueous coating solution is applied to at least one surface of the PET film. The coating layer may be formed on both sides of the PET film. The solid content concentration of the resin composition in the aqueous coating solution is preferably 2 to 35% by mass, particularly preferably 4 to 15% by mass.

  As a method for applying this aqueous coating solution to a PET film, any known method can be used. For example, reverse roll coating method, gravure coating method, kiss coating method, die coater method, roll brush method, spray coating method, air knife coating method, wire bar coating method, pipe doctor method, impregnation coating method, curtain coating method, etc. These methods are applied alone or in combination.

  In the present invention, it is important that the coating layer is formed by applying the aqueous coating solution to an unstretched or uniaxially stretched PET film, drying it, stretching it at least uniaxially, and then performing a heat treatment. The film coated with the coating solution is guided to a tenter and heated for transverse stretching and heat treatment. At that time, the chelate compound or the acylate compound can form a stable crosslinked coating layer by a thermal crosslinking reaction. On the other hand, in the case of a coating layer obtained by applying and drying the coating solution on a biaxially stretched PET film, the heat amount is suppressed in order to reduce the deterioration of the transparency of the polyester film due to heat treatment and the change in physical properties. I must. Therefore, the amount of heat is insufficient to perform the thermal crosslinking reaction, and a uniform crosslinked coating layer cannot be formed.

In the present invention, the coating amount of the finally obtained coating layer is preferably 0.02 to 0.5 g / m ² . If the coating amount of the coating layer is less than 0.02 g / m ² , not only the effect on adhesiveness is almost lost, but also the effect of suppressing iris-like colors under a fluorescent lamp tends to be insufficient. On the other hand, when the coating amount exceeds 0.5 g / m ² , the effect of suppressing the iris color under a fluorescent lamp tends to be insufficient.

  In the present invention, the coating layer is formed by the so-called in-line coating method in which the coating layer is formed in the production process of the polyester film in order to develop the adhesion layer and the function of suppressing interference fringes in the coating layer. is important. The in-line coating method can be processed at a higher temperature than the off-line coating method, improves durability adhesion with the hard coat layer, and is advantageous in terms of economy. In addition, since it is an in-line coating method, after coating, the coating film is stretched to reduce the thickness of the coating film, so there is an advantage that variation in coating film thickness due to variation in coating amount is suppressed compared to the offline coating method. . In the present invention, the effect of reducing interference fringes greatly varies due to variations in the thickness of the coating film. Therefore, there is an advantage that interference fringes can be stably reduced by suppressing the thickness variation of the coating film by the in-line coating method.

(Hard coat layer)
The antireflection film of the present invention has a laminated structure composed of a biaxially stretched polyester film / intermediate coating layer / hard coat layer / antireflection layer.

  The hard coat layer underlying the antireflection layer is provided to prevent scratches on the surface of the antireflection layer. Therefore, the hard coat layer preferably has a hardness of H or higher in a pencil hardness test based on JIS-K5400, and particularly preferably has a hardness of 2H or higher. Moreover, it is important that the hard coat layer used for the antireflection film is transparent. If these characteristics are satisfied, the composition of the hard coat layer is not limited.

  Generally, the hard coat layer is composed of a thermosetting resin and / or an ionizing radiation type resin. The coating liquid containing uncured thermosetting resin and / or ionizing radiation-type resin is formed on a transparent substrate sheet by coating and curing using a known coating method. The thickness of the hard coat layer is preferably 1 to 15 μm. When the thickness of the hard coat layer is less than 1 μm, the effects on the chemical resistance, scratch resistance, antifouling property and the like as the hard coat layer are almost lost. On the other hand, when the thickness exceeds 15 μm, the flexibility of the hard coat layer is lowered, and the possibility of occurrence of cracks or the like increases. Moreover, the curing time at the time of the formation becomes long, so that the productivity is lowered and the manufacturing cost is increased, which is not preferable.

  In the present invention, for the purpose of imparting anti-glare properties in addition to excellent anti-reflection properties to the obtained anti-reflection film, it is possible to provide fine irregularities on the hard coat layer, the adhesive layer or the primer layer. The hard coat layer (irregular shape thereof) is in direct contact with the antireflection layer, and the refractive index of the hard coat layer is formed to be smaller than the refractive index of the antireflection layer.

  In the present invention, the hard coat layer is formed of a hard coat layer containing the electron beam, the ultraviolet curable acrylic resin, or the siloxane-based thermosetting resin on at least one surface of the easy-adhesive polyester film of the substrate. Apply the coating solution. The coating solution need not be diluted, but may be diluted with an organic solvent according to the viscosity, wettability, coating layer thickness, etc. of the coating solution. After applying the hard coat layer-forming coating solution on the coating layer on at least one side of the easy-adhesive polyester film, the hard coat layer is dried as necessary, and in accordance with the curing conditions of the curable resin, The hard coat layer is formed by curing the coating layer by irradiating with electron beam or ultraviolet light and heating.

  Examples of the thermosetting resin and / or ionizing radiation type resin (these may be collectively referred to as a reaction curable resin in the present invention) include, for example, those having an acrylate functional group, Low molecular weight polyester, polyether, acrylic resin, epoxy resin, polyurethane, alkyd resin, spiroacetal resin, polybutadiene, polythiol polyene resin, polyfunctional compound (meth) acrylate (hereinafter referred to as acrylate and methacrylate) Is described as (meth) acrylate.) Monofunctionals such as oligomers or prepolymers and reactive diluents such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, vinyltoluene, N-vinylpyrrolidone Monomers, as well as polyfunctional monomers, For example, trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) Examples include those containing a relatively large amount of acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate and the like.

  Further, when the ionizing radiation curable resin is used as an ultraviolet curable resin, among them, as a photopolymerization initiator, for example, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, thioxanthone It is preferable to use n-butylamine, triethylamine, tri-n-butylphosphine or the like as a photosensitizer.

The ionizing radiation curable resin includes a reactive organosilicon compound represented by the general formula R _m Si (OR ′) _n (wherein R and R ′ represent an alkyl group having 1 to 10 carbon atoms, m + n = 4, and m and n are each integers). Examples of the silicon compound include tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, and tetra-tert-butoxysilane. , Tetrapentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane , Methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropyl Pokishishiran, dimethyl-butoxy silane, methyl dimethoxy silane, methyl diethoxy silane, hexyl trimethoxy silane, and the like to.

  Moreover, it is one of the preferable embodiments that conductive fine particles are blended in the hard coat layer to impart antistatic properties to the antireflection film.

  As the refractive index of the hard coat layer, a refractive index of around 1.5 which is widely used for an antireflection film can be applied. On the other hand, it is also one preferred embodiment to employ a means for reducing the number of antireflection layers described later by increasing the refractive index of the hard coat layer.

(Antireflection layer)
In the present invention, it is important that an antireflection layer is laminated on the surface of the hard coat layer so that the reflectance at 550 nm of the antireflection layer surface is 2.0% or less. The reflectance is more preferably 1.6% or less, and further preferably 1.2% or less. When the reflectance exceeds 2.0%, the antireflection property deteriorates, which is not preferable. The reflectance is most preferably 0%, but it is technically difficult to make the reflectance less than 0.01%.

  The composition of the antireflection layer and the formation method thereof are not limited as long as the above characteristics are satisfied. For example, the material used for the antireflection layer may be inorganic, organic, or a hybrid compound thereof. In addition, the antireflection film is formed by applying an antireflection coating solution on the surface of the base material and drying it by a dry coating method in which an antireflection film is formed on the surface of the base material by vapor deposition or sputtering. You may implement by any method of the wet coating method to form, or those combined methods.

  The number of layers in the antireflection layer is not limited, and may be a single layer or two or more return layers. Note that at least one layer is preferably provided with a layer having a low refractive index of the hard coat layer.

  In general, the dry coating method has a low film-forming speed and increases productivity, so that it is preferable to carry out the wet coating method or a combination method from the viewpoint of economy. In the case of imparting antifouling properties to the surface of the antireflection layer, it is a preferred embodiment that the uppermost layer of the antireflection layer is a low refractive index layer using a fluorine-based compound.

  EXAMPLES Next, although this invention is demonstrated in detail using an Example and a comparative example, naturally this invention is not limited to a following example. The evaluation method used in the present invention is as follows.

(1) Glass transition temperature Based on JIS K7121, using a differential scanning calorimeter (Seiko Instruments Co., Ltd., DSC6200), the temperature was raised at a rate of 20 ° C / min over a temperature range of 25-300 ° C, and from the DSC curve The obtained extrapolated glass transition start temperature was defined as the glass transition temperature.

(2) Total light transmittance Based on JIS K7105, the total light transmittance of the film was calculated | required using the turbidimeter (Nippon Denshoku Industries Co., Ltd. make, NDH2000).

(3) Light transmittance Using a spectrophotometer (manufactured by Hitachi, U-3500 type), the light transmittance in the wavelength region of 300 to 500 nm was measured using the air layer as a standard, and the light transmittance at a wavelength of 380 nm was determined. .

(4) Evaluation of scratches on film surface 16 film pieces of 250 mm × 250 mm are evaluated. This evaluation is made for 24 hours after the start of film formation. A fluorescent lamp of 20 W × 2 lamps is arranged as a projector at 400 mm below the XY table, and a test piece to be measured is placed on a mask having a slit width of 10 mm provided on the XY table. When light is incident so that the angle formed between the line connecting the projector and the light receiver and the vertical direction of the surface of the test piece is 12 °, if there is a scratch on the test piece at the incident position, that part shines. The amount of light in that portion is converted into an electrical signal by a CCD image sensor camera placed 500 mm above the XY table, the electrical signal is amplified, differentiated, and compared with a threshold (threshold) level and a comparator, resulting in an optical defect. The detection signal is output. Also, using a CCD image sensor camera, a scratch image is input, the video signal of the input image is analyzed by a predetermined procedure, the size of the optical defect is measured, and the position of the defect of 50 μm or more is displayed. To do. Detection of optical defects by this method is performed on both sides of the test piece.

A defect due to scratches is selected from the optical defect portion detected in the above method. A portion determined to be scratched by the above method is cut into an appropriate size, and a shape observation test piece is collected. The test piece is observed from a direction perpendicular to the surface on which the defect of the test piece is detected using a three-dimensional shape measuring apparatus (manufactured by Micromap, TYPE 550), and the size of the scratch is measured. In addition, the unevenness | corrugation of the flaw which adjoins within 50 micrometers is set to the same flaw when observing from a perpendicular direction with respect to the surface of a test piece, ie, a film. The length and width of the rectangle with the smallest area covering the outermost part of these scratches are taken as the length and width of the scratch. Measure the depth (the difference between the highest and lowest heights) and length of these scratches. From this result, the number (number / m ² ) of scratches having a depth of 1 μm or more and a length of 3 mm or more is determined and determined according to the following criteria.
◎: 30 pieces / m ² or less ○: 31-50 pieces / m ²
Δ: 51 to 100 / m ²
×: 100 pieces / m ² or more

(5) Foreign matter evaluation on film surface In the above scratch evaluation, defects caused by foreign matter are selected from the optical defects detected by the described method, and the test piece of the portion is sampled. Al is vapor-deposited on the surface where the defect of the test piece is detected, and observed from a direction perpendicular to the film surface with a non-contact type three-dimensional roughness meter (manufactured by Micromap, TYPE 550). The number of foreign matters having a maximum diameter of 20 μm or more (pieces / m ² ) is obtained and determined according to the following criteria.
◎: 2 pieces / m ² or less ○: 3-5 pieces / m ²
Δ: 6 to 10 pieces / m ²
X: 11 pieces / m ² or more.

(6) Evaluation of uneven distribution of ultraviolet absorber in the thickness direction of the film In the thickness direction of the laminated polyester film (B), the absorption ratio X of the characteristic absorption of the ultraviolet absorber to the characteristic absorption of the polyester in the surface layer of the film by FT-IR. The absorbance ratio Y of the characteristic absorption of the ultraviolet absorber with respect to the characteristic absorption of the polyester at the center of the is measured by the following method and expressed as X / Y. The smaller the value, the higher the degree of uneven distribution of the ultraviolet absorber.

X is obtained by the following method. First, the IR spectrum (I) of the surface layer of a blank sample (polyethylene terephthalate film not containing an ultraviolet absorber) and the IR layer spectrum (II) of the evaluation film are measured. Next, the difference spectrum between (I) and (II) is taken, the absorbance at 1700-1800 cm ^-1 (characteristic absorption of the UV absorber), and the absorption at 1505 cm ^-1 obtained from the IR spectrum of (II) The absorbance ratio (1700 to 1800 cm ⁻¹ / 1505 cm ⁻¹ ) with respect to (absorption of polyethylene terephthalate) is determined and set as X.

  Moreover, about the thickness direction, the film for evaluation is shaved off 50% of the total thickness, and the exposed surface (center portion in the film thickness direction) is subjected to the same measurement as described above to obtain the absorbance ratio, which is Y. .

The IR spectrum is measured under the following conditions using an FT-IR apparatus (manufactured by Digilab, FTS-7000e).
Single reflection ATR device: manufactured by Thermo Spectra-Tech
"Thunderdome"
IRE: Ge
Incident angle: 45 °
Resolution: 8cm ^-1
Integration count: 128 times

(7) Initial adhesion The adhesion between the hard coat layer and the substrate film is determined according to the description in 8.5.1 of JIS-K5400.

Specifically, 100 grid-like cuts that penetrate the hard coat layer and reach the base film are made on the hard coat layer surface using a cutter guide having a gap interval of 2 mm. Next, a cellophane adhesive tape (manufactured by Nichiban Co., Ltd., No. 405; 24 mm width) is attached to the grid-shaped cut surface and rubbed with an eraser to be completely attached. Then, the cellophane adhesive tape is peeled off vertically from the hard coat layer surface of the hard coat film, and the number of squares peeled off from the hard coat layer surface of the hard coat film is visually counted. Seeking adhesion with In addition, what has peeled partially among squares is counted as a square which peeled.
Adhesiveness (%) = (1−number of peeled squares / 100) × 100

(8) Moisture and heat resistance The hard coat film was allowed to stand in an environment of 60 ° C. and 95 RH% for 500 hours in a high-temperature and high-humidity tank.
Thereafter, the adhesion between the hard coat layer and the substrate film was determined in the same manner as in (4) above, and ranked according to the following criteria.
A: 100%
○: 96% or more and less than 100% △: 80% or more and less than 96% ×: less than 80%

(9) Interference fringe improvement (iris color)
The hard coat film was cut into an area of 10 cm (film width direction) × 15 cm (film longitudinal direction) to prepare a sample film. A black glossy tape (manufactured by Nitto Denko Corporation, vinyl tape No. 21; black) was bonded to the surface opposite to the hard coat layer surface of the obtained sample film. With the hard coat surface of the sample film as the top surface, the positional relationship where the reflection is the strongest visually observed from diagonally above using a three-wavelength daylight white color (National Palook, FL 15EX-N 15W) as a light source (distance 40 to distance from the light source) (60 cm, angle of 15 to 45 °).

The results of visual observation are ranked according to the following criteria. The observation is performed by five people who are familiar with the evaluation, and the highest rank is the evaluation rank. If two ranks have the same number, the center of the rank divided into three is adopted. For example, ◎ and ○ are 2 people each and △ is 1 person, ○ is ◎, ◎ is 1 person and ○ and △ are 2 people each, ○, ◎ and △ are 2 people each and ○ is 1 In the case of names, ○ is adopted.
◎: Iridescent colors are not observed even when observed from all angles. ○: Some iris colors are observed depending on the angle. △: Slightly iris colors are observed. X: Clear iris colors are observed. Be done

(10) Reflectance Using a spectrophotometer (manufactured by Shimadzu Corporation, UV-3150), the light reflectance at a wavelength of 550 nm was measured from the surface on the antireflection layer side. The unit of reflectance is%.

(11) Pencil hardness Based on the pencil hardness test method shown by JIS-K5400, the pencil hardness of the surface of the antireflection layer was measured.

(Polyester resin polymerization)
In a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 186 parts by mass of dimethyl terephthalate, 186 parts by mass of dimethyl isophthalate, 23.7 parts of dimethyl 5-sodium sulfoisophthalate, 137 of neopentyl glycol Mass parts, 191 parts by mass of ethylene glycol, and 0.5 parts by mass of tetra-n-butyl titanate were charged, and a transesterification reaction was performed from 160 ° C. to 220 ° C. over 4 hours. Next, the temperature was raised to 255 ° C., and the pressure of the reaction system was gradually reduced, followed by reaction for 1 hour 30 minutes under a reduced pressure of 29 Pa to obtain a copolymerized polyester resin (A-1). The obtained copolyester resin was light yellow and transparent.

  In the same manner, copolymer polyester resins (A-2, A-3, A-4) having other compositions were obtained. Table 1 shows the results of the composition and weight average molecular weight measured by NMR for these copolyester resins.

Example 1
(A) Preparation of polyester aqueous dispersion To a reactor equipped with a stirrer, a thermometer and a reflux device, 20 parts by mass of a polyester resin (A-1) and 15 parts by mass of ethylene glycol monobutyl ether were added, and the mixture was stirred under 100. The resin was dissolved while heating at 0 ° C. After the resin was completely dissolved, 65 parts by mass of water was gradually added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while stirring to prepare a milky white polyester aqueous dispersion (B-1) having a solid content of 20% by mass. Similarly, instead of the polyester resin (A-1), polyester resins (A-2) to (A-4) are used to prepare an aqueous dispersion, and the aqueous dispersions (B-2) to (B) are respectively used. -4).

(B) Preparation of coating liquid 40 parts by mass of the obtained polyester aqueous dispersion (B-1), 44% by mass of hydroxybis (lactato) titanium (manufactured by Matsumoto Pharmaceutical Co., Ltd., TC310) 18 parts by mass, water 150 1 part by mass of spherical anionic surfactant (Neopelex No6F powder; dodecylbenzene sulfonate) manufactured by Kao Corporation and 1 part by mass of the coating liquid, respectively. (Catalyst Kasei Kogyo Co., Ltd., Cataloid SI80P; average particle size 80 nm) An aqueous dispersion was added in an amount of 2% by mass as silica to the resin solids to prepare a coating solution (hereinafter abbreviated as coating solution (C-1)). .

(C) Preparation of UV Absorber-Containing Masterbatch Dried UV absorber (Cytec, CYASORB UV-3638; 2,2 '-(1,4-phenylene) bis (4H-3,1-benzoxazine-4 -On) 90 parts by mass of 10 parts by mass of polyethylene terephthalate resin pellets (ME553 manufactured by Toyobo Co., Ltd.) containing no particles were mixed, and a master batch was prepared using a kneading extruder, at an extrusion temperature of 285 ° C. The extrusion time was 7 minutes.

(D) Production of easy-adhesive polyester film (base film) having a coating layer 90 parts by mass of polyethylene terephthalate resin pellets (ME553, manufactured by Toyobo Co., Ltd.) having an intrinsic viscosity of 0.62 dl / g and substantially free of particles Then, 10 parts by mass of the UV-absorber-containing masterbatch prepared by the above method was dried under reduced pressure (135 Pa) at 135 ° C. for 6 hours, and then supplied to the extruder 2 (for the intermediate B layer). Polyethylene terephthalate resin pellets (ME553, manufactured by Toyobo Co., Ltd.) containing no particles were dried at 135 ° C. under reduced pressure (133 Pa) for 6 hours, and then supplied to the extruder 1 (for outer layer A layer and outer layer C layer). The resin temperature up to the extruder, melting part, kneading part, polymer tube, gear pump, filter is 280 ° C, then the polymer tube is 275 ° C, laminated in a three-layer confluence block, and made into a sheet from the die base And pushed out.

  These polymers were each filtered using a stainless steel filter medium (nominal filtration accuracy: 95% of particles having a size of 10 μm or more). The flat die was controlled so that the resin temperature was 275 ° C. The melt-extruded resin was wound around a casting drum (roll diameter 400φ, Ra 0.1 μm or less) having a surface temperature of 30 ° C. using an electrostatic application casting method, and solidified by cooling to prepare an unstretched sheet. The discharge rate at this time was 48 kg / hr, and the obtained unstretched sheet had a width of 300 mm and a thickness of 1400 μm. Further, the discharge amount of each extruder was adjusted so that the ratio of the thicknesses of both surface layers was 10% with respect to the total thickness.

  Next, the cast film is heated to 100 ° C. using a heated roll group and an infrared heater, and then stretched 3.5 times in the longitudinal direction (running direction) with a roll group having a difference in peripheral speed, and uniaxially oriented. A film was obtained. With respect to all rolls used in the production of the film, the surface roughness of the roll was controlled to be 0.1 μm or less by Ra, and roll cleaners were installed at the preheating inlet and the cooling roll in the longitudinal stretching step. The roll diameter in the longitudinal stretching step was 150 mm, and the film was brought into close contact with the roll by employing a suction roll, electrostatic close contact, and part nip contact apparatus.

Subsequently, the coating liquid (C-1) was microfiltered with a felt type polypropylene filter medium having a filtration particle size (initial filtration efficiency of 95%) of 25 μm, and the coating amount after drying on one side of the PET film by a reverse roll method was 0. After applying to 5 g / m ² , it was dried at 80 ° C. for 20 seconds. After coating, the film edge is subsequently held with a clip and guided to a hot air zone heated to 130 ° C., dried, stretched 4.0 times in the width direction, and heat treated at 230 ° C. for 5 seconds. In the process, 3% relaxation treatment was performed in the width direction to obtain an easily adhesive polyester film having a coating layer. The thickness of the obtained film was 100 μm, and the coating amount of the coating layer was 0.01 g / m ² . Moreover, the obtained easily-adhesive polyester film was high quality with few scratches and foreign matters on the surface.

(E) Manufacture of hard coat film 5 parts by mass of methyl ethyl ketone is added to 5 parts by mass of hard coat agent (manufactured by Dainichi Seika, Seika Beam EXF01 (B); solid content 100% by mass) on the coated surface of the above-mentioned easily adhesive polyester film. The added solution was applied using a # 8 wire bar and dried at 70 ° C. for 1 minute to remove the solvent. Next, the hard coat layer surface was irradiated with ultraviolet rays under the conditions of irradiation energy of 200 mJ / cm ² and irradiation distance of 15 cm using a high pressure mercury lamp while the film coated with the hard coat layer was run at a feeding speed of 5 m / min. A hard coat film having a hard coat layer of 3 μm was obtained.

(F) Production of antireflection film (Preparation of high refractive index coating agent)
80 parts of methyl methacrylate, 20 parts of methacrylic acid, 1 part of azoisobutyronitrile, 200 parts of isopropyl alcohol were charged into a reaction vessel and reacted at 80 ° C. for 7 hours in a nitrogen atmosphere to give a polymer having a weight average molecular weight of 30000. An alcohol solution was obtained. The obtained polymer solution was further diluted with isopropyl alcohol to a solid content of 5% to obtain an acrylic resin solution B. Next, the obtained acrylic resin solution B was mixed as follows to obtain a coating solution for forming a high refractive index layer.

-Acrylic resin solution B 5 parts by mass-Bisphenol A diglycidyl ether 0.25 parts by mass-Titanium oxide particles having an average particle size of 20 nm 0.5 parts by mass-Triphenylphosphine 0.05 parts by mass-Isopropyl alcohol 14.25 parts by mass

(Preparation of low refractive index coating agent)
2,2,2-trifluoroethyl acrylate (45 parts by mass), perfluorooctylethyl acrylate (45 parts by mass), acrylic acid (10 parts by mass), azoisobutyronitrile (1.5 parts by mass), methyl ethyl ketone ( 200 parts by mass) was charged in a reaction vessel and reacted at 80 ° C. for 7 hours under a nitrogen atmosphere to obtain a methyl ethyl ketone solution of a polymer having a weight average molecular weight of 20,000. The obtained polymer solution was diluted with methyl ethyl ketone to a solid content concentration of 5% by mass to obtain a fluoropolymer solution C. The obtained fluoropolymer solution C was mixed as follows to obtain a coating solution for forming a low refractive index layer.

Fluoropolymer solution C 44 parts by mass 1,10-bis (2,3-epoxypropoxy) -1 part by mass 2,2,3,3,4,4,5,5,6,6,7,7
8,8,9,9-hexadecafluorodecane (Kyoeisha Chemical, Fluorite FE-16)
・ Triphenylphosphine 0.1 parts by mass ・ Methyl ethyl ketone 19 parts by mass

(Preparation of antireflection film)
On the hard coat layer, the coating solution for forming a high refractive index layer obtained by the above method was applied and dried at 150 ° C. for 2 minutes to form a high refractive index layer having a thickness of 0.1 μm. On this high refractive index layer, the coating solution for forming a low refractive index layer obtained by the above method was applied and dried at 150 ° C. for 2 minutes to form a low refractive index layer having a thickness of 0.1 μm. Next, the resulting film was irradiated with ultraviolet rays at an output of 1000 mJ / cm ² to completely cure the hard coat layer, thereby obtaining an antireflection film.

Example 2
48 parts by mass of polyester aqueous dispersion (B-2), 44 parts by mass of hydroxybis (lactato) titanium (manufactured by Matsumoto Pharmaceutical Co., Ltd., TC310) 15 parts by mass, 150 parts by mass of water and 100 parts by mass of isopropyl alcohol Furthermore, 1% by mass of an anionic surfactant (Neopelex No6F powder; dodecylbenzenesulfonate; manufactured by Kao Corporation) and spherical colloidal silica fine particles (catalyst chemical industry, Cataloid SI80P; average) (A particle size of 80 nm) An aqueous dispersion was added in an amount of 2% by mass as silica with respect to the resin solid content to prepare a coating solution (hereinafter abbreviated as coating solution (C-2)).
In Example 1, except that only the coating solution was changed to the coating solution (C-2), a biaxially stretched PET film and an antireflection film having a coating layer on one side were obtained in the same manner as in Example 1. .

Example 3
Polyester aqueous dispersion (B-3) 12 parts by mass, diisopropoxybis (triethanolaminato) titanium 80% by mass solution (manufactured by Matsumoto Pharmaceutical Co., Ltd., TC400) 17 parts by mass, water 150 parts by mass and isopropyl alcohol 100 parts by mass of each was mixed, and further anionic surfactant (Neopelex No6F powder; dodecylbenzenesulfonate) manufactured by Kao Corporation, 1% by mass with respect to each coating solution, spherical colloidal silica fine particles (manufactured by Catalyst Kasei Kogyo) Cataloid SI80P; average particle size 80 nm) 2% by mass of an aqueous dispersion as silica was added to the resin solid content to prepare a coating solution (hereinafter abbreviated as coating solution (C-3)).
In Example 1, except that only the coating solution was changed to the coating solution (C-3), a biaxially stretched PET film and an antireflection film having a coating layer on one side were obtained in the same manner as in Example 1. .

Example 4
24 parts by mass of polyester aqueous dispersion (B-4), 11 parts by mass of diisopropoxybis (acetylacetonate) titanium, 150 parts by mass of water and 100 parts by mass of isopropyl alcohol were mixed, respectively, and an anionic surfactant ( 1% by mass of Neoperex No6F powder (dodecylbenzene sulfonate), manufactured by Kao Corporation, and each coating liquid, spherical colloidal silica fine particles (catalyst chemical industry, Cataloid SI80P; average particle size 80 nm), an aqueous dispersion of resin solid 2% by mass as silica was added to the minute to prepare a coating solution (hereinafter abbreviated as coating solution (C-4)).
In Example 1, a biaxially stretched PET film having a coating layer on one side and an antireflection film were obtained in the same manner as in Example 1 except that only the coating solution was changed to the coating solution (C-4). .

Example 5
32 parts by mass of polyester aqueous dispersion (B-4), 10 parts by mass of zirconium acetate, 150 parts by mass of water and 100 parts by mass of isopropyl alcohol were mixed, respectively, and an anionic surfactant (Neopelex No6F powder manufactured by Kao Corporation) 1% by mass of dodecylbenzene sulfonate) with respect to the coating liquid, and 2% by mass of spherical colloidal silica fine particles (catalyst chemical industry, Cataloid SI80P; average particle size of 80 nm) as silica with respect to the resin solid content. Then, a coating solution was prepared (hereinafter abbreviated as coating solution (C-5)).
In Example 1, a biaxially stretched PET film having a coating layer on one side and an antireflection film were obtained in the same manner as in Example 1 except that only the coating solution was changed to the coating solution (C-5). .

Comparative Example 1
80 parts by mass of polyester aqueous dispersion (B-1), 150 parts by mass of water and 100 parts by mass of isopropyl alcohol were mixed, and an anionic surfactant (Neopelex No6F powder manufactured by Kao Corporation; dodecylbenzene sulfonate) ) 1% by mass with respect to the coating solution, and 2% by mass of spherical colloidal silica fine particles (catalyst chemical industry, Cataloid SI80P; average particle size 80 nm) as an aqueous dispersion as silica with respect to the resin solid content to prepare a coating solution (Hereinafter abbreviated as coating solution (C-6)). Using this coating solution, a biaxially stretched PET film and an antireflection film having a coating layer on one side were obtained in the same manner as in Example 1.
In Example 1, except that only the coating solution was changed to the coating solution (C-6), a biaxially stretched PET film and an antireflection film having a coating layer on one side were obtained in the same manner as in Example 1. .

Comparative Example 2
64 parts by mass of an aqueous polyester dispersion (B-1), 10 parts by mass of a self-crosslinking polyurethane resin having a blocked isocyanate group (Daiichi Kogyo Seiyaku Co., Ltd., Elastron H-3), an elastron catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64) ) 1 part by mass, and further 1% by weight of anionic surfactant (Kao Corporation, Neopelex No6F powder; dodecylbenzene sulfonate), respectively, with respect to the coating solution, spherical colloidal silica fine particles (catalyst chemicals, Cataloid SI80P) Average particle size of 80 nm) 2% by mass of an aqueous dispersion as silica with respect to the resin solid content was added to prepare a coating solution (hereinafter abbreviated as coating solution (C-7)).
In Example 1, a biaxially stretched PET film and an antireflection film having a coating layer on one side were obtained in the same manner as in Example 1 except that only the coating solution was changed to the coating solution (C-7). .

Comparative Example 3
A 44% by weight solution of hydroxybis (lactato) titanium (manufactured by Matsumoto Pharmaceutical Co., Ltd., TC310) 40 parts by weight, 150 parts by weight of water and 100 parts by weight of isopropyl alcohol were mixed, respectively, and an anionic surfactant (Kao Corporation). Manufactured by Neoperex No6F powder; dodecylbenzene sulfonate) 1% by weight with respect to the coating solution, spherical colloidal silica fine particles (catalyst chemical industry, Cataloid SI80P; average particle size 80 nm) with respect to the resin solids 2% by mass of silica was added to prepare a coating solution (hereinafter abbreviated as coating solution (C-8)).
In Example 1, except that only the coating solution was changed to the coating solution (C-8), a biaxially stretched PET film and an antireflection film having a coating layer on one side were obtained in the same manner as in Example 1. .

Comparative Example 4
32 parts by mass of a polyester aqueous dispersion (B-2), 5 parts by mass of a self-crosslinking polyurethane resin having a blocked isocyanate group (Daiichi Kogyo Seiyaku Co., Ltd., Elastoron H-3), an elastotron catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64) ) 0.5 part by mass, niobium oxide 10 mass% aqueous solution (manufactured by Taki Chemical Co., Ltd., SAM-0) 64 parts by mass, and anionic surfactant (Naoperex No6F powder manufactured by Kao Corporation; dodecylbenzenesulfone) 1% by mass of each acid salt) with respect to the coating liquid, and 2% by mass of spherical colloidal silica fine particles (catalyst chemical industry, Cataloid SI80P; average particle size 80 nm) as an aqueous dispersion with a resin solid content of 2% by mass. (Hereinafter abbreviated as coating solution (C-9)).
In Example 1, a biaxially stretched PET film having a coating layer on one side and an antireflection film were obtained in the same manner as in Example 1 except that only the coating solution was changed to the coating solution (C-9). .

Comparative Example 5
Acrylic resin emulsion having a solid content of 20% by mass (methyl methacrylate / ethyl acrylate / acrylic acid / N-methylolacrylamide = 60/40/2/4; mass ratio), 80 parts by mass, di-n-butoxybis (triethanolaminato) ) 3.2 parts by weight of titanium, 150 parts by weight of water and 100 parts by weight of isopropyl alcohol were mixed, and an anionic surfactant (Naopelex No6F powder; dodecylbenzenesulfonate) manufactured by Kao Corporation was applied to each coating solution. 1% by mass, 2% by mass of spherical colloidal silica fine particles (catalyst chemical industry, Cataloid SI80P; average particle size 80 nm) aqueous dispersion as silica with respect to the resin solid content was prepared to prepare a coating solution (hereinafter, coating) Liquid (C-10)).
In Example 1, except that only the coating solution was changed to the coating solution (C-10), a biaxially stretched PET film and an antireflection film having a coating layer on one side were obtained in the same manner as in Example 1. .

Comparative Example 6
Acrylic resin emulsion having a solid content of 20% by mass (methyl methacrylate / ethyl acrylate / acrylic acid / N-methylolacrylamide = 25/75/4/2: mass ratio) 48 parts by mass, titanium-modified aqueous resin (Matsumoto Pharmaceutical Co., Ltd.) 6.4 parts by mass, ORGATICS WS680), 150 parts by mass of water and 100 parts by mass of isopropyl alcohol are mixed, and an anionic surfactant (manufactured by Kao Corporation, Neopelex No6F powder; dodecylbenzenesulfonate) 1% by mass of each of the coating liquid and 2% by mass of spherical colloidal silica fine particles (catalyst chemical industry, Catalloy SI80P; average particle size of 80 nm) as an aqueous dispersion was added to the resin solids as 2% by mass. (Hereinafter abbreviated as coating solution (C-11)).
In Example 1, a biaxially stretched PET film and an antireflection film having a coating layer on one side were obtained in the same manner as in Example 1 except that only the coating solution was changed to the coating solution (C-11). .

Comparative Example 7
In Example 1, an uncoated biaxially stretched PET film was obtained in the same manner as in Example 1 except that the coating layer was not provided during the production of the base film. In the same manner as in Example 1, an antireflection film in which a hard coat layer and then an antireflection layer were laminated on one side of this uncoated film was obtained.

Comparative Example 8
In Example 1, an antireflection film was obtained in the same manner as in Example 1 except that the hard coat layer was not formed and the antireflection layer was laminated directly on the coating layer of the base film.

Comparative Example 9
In Example 1, a hard coat film was obtained in the same manner as in Example 1 except that the antireflection layer was not laminated. The evaluation results are shown in Table 2.

Comparative Example 10
In Example 1, except that the extrusion and casting during the production of the polyester film were made into a single layer, only the layer containing the UV absorber was used, the coating layer was stopped, and the antireflection layer was stopped. In the same manner as in Example 1, a hard coat film was obtained.

  Table 2 shows the coating layer configuration of the base film, and Table 3 shows the film characteristics of the base film, hard coat film, and antireflection film.

  The antireflection film of the present invention has excellent antireflection properties, suppresses iris-like colors under fluorescent lamps, particularly under the three-wavelength daylight fluorescent lamps for daylight color reproducibility, and is hardened with a base film and a hard film. Excellent adhesion to the coating layer, adhesion under high temperature and high humidity (moisture and heat resistance), and economic efficiency. Touch panel, liquid crystal display (LCD), television and computer cathode ray tube (CRT), plasma It is useful as a member or decoration material for optical equipment to be mounted on the front of display screens such as displays (PDP), field emission displays (FED), surface electric field displays (SED), and electronic paper, and contributes greatly to the industry. be able to.

Claims (5)

  A base film having a coating layer, and an antireflection film in which a hard coat layer and an antireflection layer are laminated in this order on the surface of the coating layer of the base film, wherein the base film is an aqueous polyester resin (A) and at least one of a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, or a water-soluble zirconium acylate compound (B) as main components, A biaxially stretched polyester film having a coating layer stretched in at least one direction after applying and drying an aqueous coating solution having a mixing ratio (mass ratio) of A) / (B) of 10/90 to 95/5. And an antireflection film having a reflectance of 2.0% or less at a wavelength of 550 nm on the surface of the antireflection layer.   The antireflection film according to claim 1, wherein the base film has a total light transmittance of 85% or more.   The aqueous polyester resin (A) is a copolyester resin containing 1 to 10 mol% of an aromatic dicarboxylic acid component containing a sulfonic acid metal base with respect to the total dicarboxylic acid component of the polyester. Item 3. The antireflection film according to Item 1 or 2.   4. The antireflection film according to claim 1, wherein the aqueous polyester resin (A) has a glass transition temperature of 40 ° C. or higher.   5. The antireflection film according to claim 1, wherein the hard coat layer includes an electron beam, an ultraviolet curable acrylic resin, or a siloxane thermosetting resin as a constituent component.