JP2005062430A - Near infrared-ray absorbing filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a near infrared-ray absorbing filter that has reflection preventiveness, ultraviolet-ray absorptivity, and near infrared-ray absorptivity with one multi-layered film without sticking with an adhesive, has superior optical characteristics, and can suppress deterioration of durability, specially, near infrared-ray absorbing coloring matter due to ultraviolet rays included in external light. <P>SOLUTION: Disclosed is the near infrared-ray absorbing filter constituted by laminating a surface layer (A) having an antireflective function on one surface of a base material film (B) containing an ultraviolet-ray absorbing agent and a near infrared-ray absorbing layer (C) containing coloring matter having maximum absorption in a near infrared-ray absorption area of 800 to 1,000 nm in wavelength on the opposite surface of the base material film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an integrally molded near-infrared absorbing filter having a near-infrared absorptivity, an ultraviolet absorptivity, and an antireflection property with a single film without being bonded with an adhesive. More specifically, the present invention relates to a near-infrared absorption filter that has excellent optical characteristics and durability despite its simplified structure.

An optical filter having near-infrared absorption ability has a property of blocking near-infrared light and allowing visible light to pass therethrough, and is used in various applications.
In recent years, plasma displays have attracted attention as thin large-screen displays. However, there is a problem that electronic devices using near-infrared remote controls malfunction due to near-infrared rays emitted from plasma displays. It is provided on the front.

As a filter having near-infrared absorption ability, (1) a filter containing metal ions such as copper and iron on phosphate glass, and (2) a layer having a different refractive index is laminated to interfere with transmitted light. And (3) an acrylic resin filter containing a copper ion in a copolymer, and (4) a filter in which a layer in which a pigment is dispersed or dissolved is laminated. ing.
Among these, the filter (4) has good workability and productivity, has a relatively large degree of freedom in optical design, and various methods have been proposed (see Patent Documents 1 to 8).
JP 2002-82219 A JP 2002-214427 A JP 2002-264278 A JP 2002-303720 A JP 2002-333517 A JP 2003-82302 A Japanese Patent Laid-Open No. 2003-96040 JP 2003-114323 A

  Some of these methods have the ability to sufficiently block near-infrared rays emitted from plasma displays and do not change over time even when used for a long time. However, I was not satisfied with the improvement in image quality due to refinement.

In particular, the filter of the above (4) has poor weather resistance of the dye used, and its improvement has been strongly demanded. In addition to having the ability to absorb near infrared rays, the filter needs to have other functions such as color tone adjustment for imparting specific absorption in the visible light region, antireflection properties, and scratch resistance on the surface. As a measure for solving the problem, for example, a multilayer type near-infrared absorbing film in which functional layers having various functions are multilayered is disclosed (see Patent Document 9).
WO97 / 38855

  In Patent Document 9, an electromagnetic wave absorbing layer, an antireflection layer, and an ultraviolet absorbing layer are disclosed as layers having functions other than near-infrared absorbing ability. The electromagnetic wave absorbing layer is described in detail. And the antireflection layer, and the ultraviolet absorbing layer is not mentioned at all in the detailed description and examples of the invention. Regarding the multilayering of the electromagnetic wave absorbing layer and the antireflection layer described in detail, a function body having each function is bonded to a near-infrared absorbing film.

In addition, a plasma display panel direct attachment filter is disclosed in which a near-infrared cut film in which an antireflection function including an antistatic layer and an ultraviolet absorption layer are combined is directly attached to the surface of the plasma display panel (see Patent Document 10).
JP 2002-189423 A

  In Patent Document 10, a film having an antireflection function including an antistatic layer and a near-infrared cut film are bonded together by a transparent adhesive (adhesive) agent layer containing an ultraviolet absorber, and further a near-infrared cut film A structure in which a transparent pressure-sensitive adhesive (adhesive) agent layer is combined on the surface is disclosed.

Moreover, although the near-infrared absorber is limited to the nickel complex compound, the composite by ultraviolet absorption and multilayering of a hard-coat layer is disclosed (refer patent document 11).
JP 2003-4904 A

  Also in this patent document 11, it implements by the method of bonding an ultraviolet absorber containing film and a sheet | seat containing a near-infrared absorption pigment | dye.

On the other hand, the structure which multi-functionalized with the base material film of 1 sheet is disclosed (refer patent document 12).
JP 2002-138203 A

  In Patent Document 12, antireflection and ultraviolet absorption functions are added as functions other than the near infrared absorption function. However, in the configuration disclosed in Patent Document 12, an ultraviolet absorber is blended in an adhesive layer for fixing a laminate having a near infrared absorption function to a transparent hard substrate. When actually used, The layer with UV absorbing function is located on the side opposite to the outside light side of the layer with NIR absorbing function, and the effect of suppressing the deterioration of near infrared absorbing dye due to UV rays in outside light, which is a problem during actual use, is manifested. Therefore, it does not satisfy the market demand for improving the weather resistance of near-infrared absorbing dyes by external light.

  The above-mentioned known technology has a structure in which a laminate having optical characteristics satisfying market requirements is formed by bonding two or more functional films having respective functions, and due to an increase in the interface due to bonding. There is still a problem that the optical characteristics have not been improved in terms of deterioration, and a bonding process is required, which is economically disadvantageous. Moreover, it has the subject that the total thickness is thick and the workability | operativity of the sticking to a to-be-adhered body is inferior. On the other hand, a laminate composed of a single base film having a thin total thickness and improved workability for sticking to the adherend is required during actual use, although it has an ultraviolet absorbing function. The effect of improving the weather resistance by external light is not exhibited.

  The object of the present invention is based on the background of the problems of the prior art, and is a single multilayer film that is not bonded with an adhesive, and has antireflection properties, ultraviolet absorption properties, and near infrared absorption properties, and optical characteristics. An object of the present invention is to provide a near-infrared absorbing filter that is excellent in durability and that can suppress deterioration of a near-infrared absorbing dye due to ultraviolet rays contained in outside light, in particular, a near-infrared absorbing filter. Furthermore, it is providing the near-infrared absorption filter by which the workability | operativity of the sticking with respect to a to-be-adhered body was improved by thin film formation.

  As a result of intensive studies to solve the above problems, the present inventors have finally completed the present invention. That is, this invention is a near-infrared absorption filter, Comprising: The surface layer (A) which has an antireflection function on the single side | surface of the base film (B) containing a ultraviolet absorber, and the wavelength 800-1000 nm on the opposite side A near-infrared absorption filter comprising a near-infrared absorption layer (C) containing a dye having maximum absorption in an infrared absorption region.

  The near-infrared absorption filter of the present invention is a multilayer film composed of a single base film without being bonded with an adhesive, has antireflection properties, ultraviolet absorption properties, and near-infrared absorption properties, has excellent optical properties, and Durability, in particular, deterioration of the near-infrared absorbing dye due to ultraviolet rays contained in external light can be suppressed. Furthermore, since it is thinned, the workability of sticking to the adherend is improved, and it is also excellent in economic efficiency, such as an optical display device such as a plasma display that requires a function of absorbing near infrared rays. It can be suitably used as a filter for use.

Hereinafter, the present invention will be described in detail.
The near-infrared absorption filter of the present invention has a maximum absorption in the near-infrared region having a wavelength of 800 to 1000 nm on the surface layer (A) having an antireflection function on one side of the base film (B) containing an ultraviolet absorber and the opposite side. It is important to laminate a near-infrared absorbing layer (C) containing a pigment having In particular, the near-infrared ray of the present invention has been provided with various functions necessary for a near-infrared absorbing filter with a simplified structure in which only the base film (B) containing an ultraviolet absorber is used as a base material and the bonding structure is omitted. This is one of the biggest features of the absorption filter. Moreover, an ultraviolet absorbing layer is constructed at a position where the problem of near-infrared absorbing dye deterioration due to ultraviolet rays contained in the above-mentioned external light can be improved. Have.

  The material of the base film (B) in the present invention is not limited as long as it is a transparent body, but a polyester-based biaxially oriented film such as polyethylene terephthalate, polybutylene terephthalate or polyethylene-2,6-naphthalate has mechanical properties, It is preferable from the viewpoint of optical properties, heat resistance and economy. The polyester biaxially oriented film may be a copolyester. As the copolymer component in the case of the copolymer, the dicarboxylic acid component includes aliphatic dicarboxylic acids such as adipic acid and sebacic acid; terephthalic acid, isophthalic acid, phthalic acid, and 2,6-naphthalenedicarboxylic acid. Aromatic dicarboxylic acids; polyfunctional carboxylic acids such as trimellitic acid and pyromellitic acid are used. Examples of the glycol component include fatty acid glycols such as diethylene glycol, 1,4-butanediol, propylene glycol, and neopentyl glycol; aromatic glycols such as p-xylene glycol; alicyclic glycols such as 1,4-cyclohexanedimethanol; Polyethylene glycol having an average molecular weight of 150 to 20,000 is used. The mass ratio of the copolymerization component is less than 20% by mass. If it is 20% by mass or more, the film strength, transparency, and heat resistance tend to be inferior.

The said base film (B) needs to contain a ultraviolet absorber. The ultraviolet absorbent is not limited as long as it is a compound having ultraviolet absorbing ability and can withstand heat in the production process of the polyester film. Examples of the ultraviolet absorber to be added include an organic ultraviolet absorber and an inorganic ultraviolet absorber, and an organic ultraviolet absorber is preferable from the viewpoint of transparency.
Examples of organic ultraviolet absorbers include, but are not limited to, benzotoazoles, benzophenones, cyclic iminoesters, and combinations thereof. However, from the viewpoint of durability, benzotoazole and cyclic imino ester are particularly preferable. When two or more kinds of ultraviolet absorbers are used in combination, ultraviolet rays having different wavelengths can be absorbed simultaneously, so that the ultraviolet absorption effect can be further improved.

  Examples of the benzotriazole ultraviolet absorber include 2- [2′-hydroxy-5 ′-(methacryloyloxymethyl) phenyl] -2H-benzotriazole, 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-benzo Riazole, 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. It is not limited to these.

  Examples of the cyclic imino ester ultraviolet absorber include 2,2 ′-(1,4-phenylene) bis (4H-3,1-benzoxazinon-4-one), 2-methyl-3,1-benzo. Oxazin-4-one, 2-butyl-3,1-benzoxazin-4-one, 2-phenyl-3,1-benzoxazin-4-one, 2- (1- or 2-naphthyl) -3,1 -Benzoxazin-4-one, 2- (4-biphenyl) -3,1-benzoxazin-4-one, 2-p-nitrophenyl-3,1-benzoxazin-4-one, 2-m-nitro Phenyl-3,1-benzoxazin-4-one, 2-p-benzoylphenyl-3,1-benzoxazin-4-one, 2-p-methoxyphenyl-3,1-benzoxazin-4-one, 2 -O-metoki Phenyl-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-benzoxazine-4) -On), 2,2 '-(4 4'-diphenylene) 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), 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, 1,3,5-tri (3,1-benzoxazine) -4-On-2-yl) naphthalene and 2,4,6-tri (3,1 Benzoxazin-4-one-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-benzoxazin-4-one), 6,6′-bis (2-ethyl- 4H, 3,1-benzoxazin-4-one), 6,6′-bis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6, '-Methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-methylenebis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6,6 '-Ethylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-ethylenebis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6 , 6′-Butylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-butylenebis (2-phenyl-4H, 3,1-benzoxazin-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 ( -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), and 6,7′-methylenebis (2-phenyl-4H, 3 , 1-benzoxazin-4-one) and the like.

  In particular, it is preferable to use an ultraviolet absorber having a decomposition start temperature of 290 ° C. or higher in order to reduce process contamination during film formation.

  The purpose of blending the ultraviolet absorber is to absorb in the near-infrared region contained in the near-infrared absorbing layer (C) that develops the near-infrared absorbing ability that is the main function of the near-infrared absorbing filter of the present invention described later. It is to suppress the phenomenon that the dye is inferior in weather resistance and the performance of the near-infrared absorbing dye is deteriorated due to ultraviolet rays contained in external light. Therefore, it is a preferred embodiment that the transmittance at a wavelength of 380 nm or less is 10% or less. The transmittance at a wavelength of 390 nm or less is more preferably 10% or less, and the transmittance at a wavelength of 400 nm or less is particularly preferably 10% or less. The addition amount of the ultraviolet absorber satisfying the characteristics is preferably from 0.1 to 4% by mass, more preferably from 0.3 to 2% by mass, based on the polyester. If this amount is less than 0.1% by mass, the ultraviolet absorption effect is small, and if it exceeds 4% by mass, the film is yellowed or the film forming property of the polyester film is deteriorated.

（上記一般式（Ｉ）において、Ｒはアルキレン基等、Ｘはヒドロキシ基等を示す）

In the present invention, it is also recommended as a preferred embodiment to add a polymer type ultraviolet absorber that does not cause a problem of bleeding on the surface layer. The polymer type ultraviolet absorber is a polymer having a skeleton useful as an ultraviolet absorber in the side chain. From the viewpoint of compatibility with the polyester resin, polyester-based and acrylic polymer UV absorbers are mainly preferred. For example, the polyester resin is a polyester mainly composed of terephthalic acid as a dicarboxylic acid component, ethylene glycol and / or 1,4-butanediol as a diol component, and naphthalene represented by the general formula (I) as a copolymerization component Ultraviolet absorbing compound containing tetracarboxylic acid diimide and naphthalene dicarboxylic acid represented by general formula (II) (Mitsubishi Chemical Corporation, Novapex U-110), 2- (2-hydroxylphenyl) benzotriazole skeleton as side chain The acrylic polymer (BASF, UVA-1635) and the like having excellent properties such as UV cut performance and transparency are preferable.

(In the above general formula (I), R represents an alkylene group, X represents a hydroxy group, etc.)

  The addition amount 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 polyester. If this amount is less than 0.1% by mass, the effect of preventing UV deterioration is small, and if it exceeds 20% by mass, the film is yellowed or the film-forming property of the polyester film is lowered, which is not preferable.

  The method of blending the polyester film of the UV absorber is not limited, but is preferably during polymerization of the polyester resin or during melt extrusion. In that case, it is a preferred embodiment that the ultraviolet absorber is added as a master pellet. For example, the following method is illustrated as a preferred embodiment.

  First, a polyester resin and an ultraviolet absorber are blended to prepare a master pellet. The master pellet is a pellet that does not substantially contain particles for the purpose of imparting slipperiness. The raw material pellets obtained by mixing the master pellets and the polyester resin are sufficiently vacuum-dried, then supplied to an extruder, melted and extruded into a sheet, and cooled and solidified on a casting roll to form an unstretched polyester sheet. At this time, it is ultraviolet absorption that 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 order to prevent sublimation at the die outlet of the agent and contamination on the take-up roll.

  In addition, high-precision filtration is performed at any place where the molten resin is maintained at about 280 ° C. in order to remove foreign substances contained in the resin. The filter medium used for high-precision filtration of the molten resin is not particularly limited, but in the case of a stainless steel sintered filter medium, the removal performance of aggregates and high melting point organic substances mainly composed of Si, Ti, Sb, Ge, Cu Excellent and suitable. Further, the filter particle size (initial filtration efficiency 95%) of the filter medium is preferably 20 μm or less, particularly 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 of 20 μm or more cannot be sufficiently removed. Productivity may be reduced by performing high-precision filtration of molten resin using a filter medium having a filter particle size (initial filtration efficiency of 95%) of 20 μm or less. However, a film with few coarse protrusions due to coarse particles may be used. It is an important process in obtaining.

  When foreign materials existing in the raw material polymer and UV absorbers sublimate and contaminate the rolls, and there are those attached to the film, the orientation of the polyester molecules is disturbed around these foreign materials in the stretching process during film formation, and optical Distortion occurs. Because of this optical distortion, it is recognized as a defect that is considerably larger than the actual size of the foreign material, so that the quality is significantly impaired. For example, a foreign substance 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. In order to obtain a highly transparent film, it is desirable not to contain particles for imparting slipperiness in the base film, or to contain only a small amount so as not to inhibit transparency, but the particle content is low. As the transparency of the film increases, optical defects due to minute foreign substances tend to become clearer. Further, as the film becomes thicker, the content of foreign matters per unit area of the film tends to be larger than that of a thin film, and this problem is further increased.

  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. In the heat treatment step, a relaxation treatment of 3% in the width direction is performed as necessary to obtain a biaxially oriented polyester film.

The biaxially oriented 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.

  In order to prevent the occurrence of scratches on the film, (a) the film surface itself or roll surface, in particular, the roll surface in contact with the film should not cause “defects” that cause scratches, and (b) the roll in contact. It is important to ensure that the film does not shift longitudinally and laterally 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.

  Preheating of the longitudinal stretching process in order to prevent the surface roughness of the roll used at the time of film production from 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. One method is to install roll cleaners at the inlet and cooling roll.

  In addition, there is a method in which the degree of cleanliness in the film production process is set to class 1000 or less (1000 particles or less of 0.5 μm or more in a volume per cubic foot). It is preferable to use clean air of class 100 or less for the air cooling device for cooling the anti-roll surface.

  Furthermore, there is a method of cleaning the roll by an operation of scraping off defects on the roll using an abrasive before the film production. 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 the casting of the base film to the tenter described later is a process in which scratches are mainly likely to occur, and laying out this section in a compact manner and reducing the passage time to 5 minutes or less can also contribute to the suppression of the occurrence of defects. .

  About a roll, it can be set as 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 setting it as 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.

  Further, 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 that 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 method for preventing scratches to prevent the film from shifting on the roll surface. For example, the following methods can be employed. For example, by reducing the roll diameter, 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 temperature changes in the film. 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 liquid for forming the adhesive property-modified resin layer, which will be described later, the drying condition is completed at the beginning of the dryer section and is cooled to the outlet, whereby the film temperature at the outlet of the dryer is 40 ° C. In the following, film shift 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 drive roll, it is preferable to control the rotation spots to 0.01% or less.

  Although the thickness of said base film (B) can be arbitrarily set without limitation, 0.038-0.188 mm is a preferable range. If it is less than 0.038 mm, the handleability of the near-infrared absorbing filter deteriorates, which is not preferable. On the other hand, when it exceeds 0.188 mm, the handling property of the near-infrared absorption filter and the workability when adhering to an adherend such as a plasma display deteriorate, such being undesirable. In addition, it cannot meet the market demand for thin film.

  In this invention, the layer which has functionality is laminated | stacked on both surfaces of the base film (B) obtained by the said method. Therefore, it is a preferred embodiment that both surfaces of the base film (B) are provided with an easy adhesion layer. Examples of the resin constituting the easy-adhesion layer include copolymer polyester resins, polyurethane resins, acrylic resins, styrene-maleic acid graft polyester resins, acrylic graft polyester resins, and the like, and at least one is used. It is preferable. Among these, a resin composed of a copolyester resin and a polyurethane resin, and a styrene-maleic acid graft polyester resin are particularly preferable because of excellent adhesiveness.

  Regarding the adjustment of the coating solution used for forming the easy-adhesion layer, an example of a coating solution composed of a copolyester resin and a polyurethane resin will be described below. The copolymerized polyester resin used in the easy-adhesion layer of the present invention has a branched glycol component as a constituent component. The branched glycol component referred to here is, for example, 2,2-dimethyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2-methyl-2-butyl-1,3- Propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-2-isopropyl-1,3-propanediol, 2-methyl-2-n-hexyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n-butyl-1,3-propanediol, 2-ethyl-2-n-hexyl-1,3-propanediol, 2,2 -Di-n-butyl-1,3-propanediol, 2-n-butyl-2-propyl-1,3-propanediol, and 2,2-di-n-hexyl-1,3-propanediol And the like. The branched glycol component is contained in the total glycol component in a proportion of preferably 10 mol% or more, more preferably 20 mol% or more. As the glycol component other than the above compounds, ethylene glycol is most preferable. If it is a small amount, diethylene glycol, propylene glycol, butanediol, hexanediol, 1,4 cyclohexanedimethanol or the like may be used.

  As the dicarboxylic acid component contained as a constituent in the copolymerized polyester resin, terephthalic acid and isophthalic acid are most preferable. If the amount is small, other dicarboxylic acids; diphenylcarboxylic acid and 2,6-naltalenedicarboxylic acid aromatic dicarboxylic acid may be added and copolymerized. In addition to the dicarboxylic acid component, 5-sulfoisophthalic acid is preferably used in the range of 1 to 10 mol% in order to impart water dispersibility. For example, sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfo Mention may be made of naphthaleneisophthalic acid-2,7-dicarboxylic acid and 5- (4-sulfophenoxy) isophthalic acid and salts thereof.

  The polyurethane resin used for the easy-adhesion layer is, for example, a resin containing a block-type isocyanate group, in which a terminal isocyanate group is blocked with a hydrophilic group (hereinafter referred to as a block), a heat-reactive water-soluble urethane, etc. Is mentioned. Examples of the isocyanate group blocking agent include bisulfites and sulfonic acid group-containing phenols, alcohols, lactam oximes and active methylene compounds. The blocked isocyanate group makes the urethane prepolymer hydrophilic or water-soluble. When heat energy is applied to the resin during drying or heat setting during film production, the blocking agent is released from the isocyanate group, so the resin fixes a water-dispersible copolyester resin mixed in a self-crosslinked stitch. And reacts with the terminal groups of the resin. The resin under preparation of the coating solution is hydrophilic and has poor water resistance, but when the thermal reaction is completed by coating, drying and heat setting, the hydrophilic group of the urethane resin, that is, the blocking agent is released, so the water resistance is good. A coating film is obtained. Among the above blocking agents, bisulfites are most preferred as those that are suitable for heat treatment and heat treatment and are widely used industrially.

  The chemical composition of the urethane prepolymer used in the above resin is (1) an organic polyisocyanate having two or more active hydrogen atoms in the molecule, or both having two active hydrogen atoms in the molecule. Reaction of a compound having a molecular weight of 200 to 20,000, (2) an organic polyisocyanate having two or more isocyanate groups in the molecule, or (3) a chain extender having at least two active hydrogen atoms in the molecule It is a compound having a terminal isocyanate group, which is obtained by pre-loading.

  The compound (1) generally known is a compound containing two or more hydroxyl groups, carboxyl groups, amino groups or mercapto groups in the terminal or molecule, and particularly preferred compounds include polyether polyols. And polyether ester polyols. Examples of polyether polyols are compounds obtained by polymerizing alkylene oxides such as ethylene oxide and propylene oxide, styrene oxide and epichlorohydrin, or the like, or random polymerization, block polymerization, or addition polymerization to a polyhydric alcohol. There are compounds.

  Examples of the polyester polyol and the polyether ester polyol mainly include linear or branched compounds. Polyvalent saturated or unsaturated carboxylic acids such as succinic acid, adipic acid, phthalic acid and maleic anhydride, or the carboxylic acid anhydride, ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1 Condensation with polyvalent saturated and unsaturated alcohols such as 1,6-hexanediol and trimethylolpropane, polyalkylene ether glycols such as relatively low molecular weight polyethylene glycols and polypropylene glycols, or mixtures of these alcohols Can be obtained. Further, polyesters obtained from lactones and hydroxy acids can be used as the polyester polyol, and polyether esters obtained by adding ethylene oxide or propylene oxide to a pre-manufactured polyester can also be used.

  Examples of the organic polyisocyanate (2) include isomers of toluylene diisocyanate, aromatic diisocyanates such as 4,4-diphenylmethane diisocyanate, aromatic aliphatic diisocyanates such as xylylene diisocyanate, isophorone diisocyanate and 4,4. -Alicyclic diisocyanates such as dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and aliphatic diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate, or a single or a plurality of these compounds with trimethylolpropane and the like in advance. Examples include added polyisocyanates.

  Examples of the chain extender having at least two active hydrogens in (3) above include glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol, glycerin, trimethylolpropane, and Examples include polyhydric alcohols such as pentaerythritol, diamines such as ethylenediamine, hexamethylenediamine, and piperazine, amino alcohols such as monoethanolamine and diethanolamine, thiodiglycols such as thiodiethylene glycol, and water.

  In order to synthesize the urethane polymer of the above (3), it is usually 5 minutes to several times at a temperature of 150 ° C. or less, preferably 70 to 120 ° C., by a single-stage or multi-stage isocyanate polyaddition method using the chain extender. Let react for hours. The ratio of isocyanate groups to active hydrogen atoms can be freely selected as long as it is 1 or more, but it is necessary that free isocyanate groups remain in the obtained urethane prepolymer. Furthermore, the content of free isocyanate groups may be 10% by mass or less, but considering the stability of the urethane polymer aqueous solution after being blocked, it is preferably 7% by mass or less.

  The urethane prepolymer obtained is preferably blocked using bisulfite. Mix with aqueous bisulfite solution and allow reaction to proceed with good agitation for about 5 minutes to 1 hour. The reaction temperature is preferably 60 ° C. or lower. Thereafter, it is diluted with water to an appropriate concentration to obtain a heat-reactive water-soluble urethane composition. When the composition is used, it is prepared to have an appropriate concentration and viscosity. However, when heated to about 80 to 200 ° C., the bisulfite of the blocking agent is dissociated and the active isocyanate group is regenerated, so that the prepolymer A polyurethane polymer is produced by a polyaddition reaction that takes place within or between the molecules of the polymer, or has the property of causing addition to other functional groups.

  As an example of the resin (B) containing the above-mentioned block type isocyanate group, trade name Elastron manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. is typically exemplified. Elastolone is a compound in which an isocyanate group is blocked with sodium bisulfite, and is water-soluble due to the presence of a carbamoylsulfonate group having strong hydrophilicity at the molecular end.

When preparing a coating liquid by mixing the copolymerized polyester resin (A) containing the branched glycol component and the resin (B) containing the block-type isocyanate group used in the present invention, the resin ( The mass ratio of A) to the resin (B) is preferably (A) :( B) = 90: 10 to 10:90, more preferably (A) :( B) = 80: 20 to 20:80. is there. If the ratio of the said resin (A) with respect to solid content mass is less than 10%, the applicability | paintability to a base film will be unsuitable, and the adhesiveness between a surface layer and this film will become inadequate. When it is less than 10%, practical adhesiveness cannot be obtained in a UV curing type hard coat.
In order to promote the thermal crosslinking reaction, a catalyst may be added to the aqueous coating solution used in the present invention, such as various inorganic substances, salts, organic substances, alkaline substances, acidic substances and metal-containing organic compounds. These chemicals are used. Moreover, in order to adjust pH of aqueous solution, you may add an alkaline substance or an acidic substance.

  When applying the aqueous coating solution to the surface of the base film, a known anionic surfactant and nonionic surfactant are required to increase the wettability of the film and coat the coating solution uniformly. An amount can be added and used. As the solvent used in the coating solution, alcohols such as ethanol, isopropyl alcohol and benzyl alcohol may be mixed in addition to water until the ratio of the total coating solution is less than 50% by mass. 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 of alcohols and other organic solvents in the coating solution is less than 50% by mass. If the addition amount of the organic solvent is less than 50% by mass, the drying property is improved at the time of coating and drying, and the appearance of the coating film is improved as compared with the case of using only water. If it exceeds 50% by mass, the evaporation rate of the solvent is high, the coating solution concentration changes during coating, the viscosity rises and the coating property is lowered, and there is a risk of causing poor appearance of the coating film, Furthermore, there is a risk of fire. The solution viscosity of the coating solution is preferably 1.0 PaS (Pascal Sec) or less. When the pressure is 1.0 PaS (Pascal Sec) or higher, streaky coating thickness spots are likely to occur.

  In the present invention, from the viewpoint of transparency, it is preferable that the particles for the purpose of imparting slipperiness are not contained in the base film but are contained in the easy adhesion layer. That is, it is preferable to add particles to the aqueous coating solution to form appropriate protrusions on the film surface. Examples of such particles include calcium carbonate, calcium phosphate, silica, kaolin, talc, titanium dioxide, alumina, barium sulfate, calcium fluoride, lithium fluoride, zeolite, molybdenum sulfide and other inorganic particles, crosslinked polymer particles, oxalic acid There may be mentioned organic particles such as calcium. Among these particles, silica particles are most suitable because they have a relatively close refractive index to that of the polyester resin and can easily obtain high transparency.

  The average particle diameter of the particles added to the aqueous coating solution is usually 0.01 to 1.0 μm, preferably 0.01 to 0.5 μm or less, and more preferably 0.01 to 0.1 μm or less. When the average particle diameter exceeds 1.0 μm, the film surface becomes rough and the transparency of the film tends to be lowered. The particle content contained in the coating solution is usually such that the particle content of the coating film after application and drying is 60% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less. Added. If the particle content of the coating film exceeds 60% by mass, the easy adhesion of the film may be impaired.

  Two or more kinds of the above particles may be blended in the film, or the same kind of particles having different particle diameters may be blended. In any case, it is preferable that the average particle diameter of the whole particle and the total content satisfy the above range. When applying the coating solution, it is necessary to dispose a filter medium so that the coating solution is precisely filtered just before coating in order to remove coarse aggregates of particles in the coating solution. The filter medium for microfiltration of the coating solution used in the present invention needs to have a filtration particle size of 25 μm or less (initial filtration efficiency 95%). When the particle size is 25 μm or more, the coarse agglomerates cannot be sufficiently removed, and many coarse agglomerates that cannot be removed are 100 μm because the coarse agglomerates of particles spread in the easy-adhesion layer when uniaxially or biaxially stretched after coating and drying. These are recognized as aggregates, and as a result, many optical defects occur. The type of filter medium for microfiltration of the coating solution is not particularly limited as long as it has the above performance, and examples thereof include a filament type, a felt type, and a mesh type. The material of the filter medium for finely filtering the coating solution has the above-mentioned performance and is not particularly limited as long as it does not adversely affect the coating solution. Examples thereof include stainless steel, polyethylene, polypropylene, and nylon.

  Various additives such as an antistatic agent, a pigment, an organic filler, and a lubricant may be mixed in the composition of the aqueous coating solution as long as the effect is not lost. Furthermore, since the coating solution is aqueous, other water-soluble resins, water-dispersible resins, emulsions, and the like may be added to the coating solution in order to improve performance as long as the contribution effect is not lost.

  The easy-adhesion layer can be applied by any known method. Examples include reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method, air knife coating method, wire barber coating method, pipe doctor method, impregnation / coating method and curtain coating method. These methods can be performed alone or in combination.

The step of applying the coating solution may be a normal coating step, that is, a step of applying to a base film that has been biaxially stretched and heat-fixed, but is preferably applied during the manufacturing process of the film. More preferably, it is applied to the base film before crystal orientation is completed. The solid content concentration in the aqueous solution is usually 30% by mass or less, preferably 10% by mass or less. The aqueous coating solution is applied so that 0.01 to 5 g, preferably 0.2 to 4 g is adhered per 1 m ² of the running film. The film coated with the aqueous coating solution is guided to a tenter for stretching and heat setting, and heated there to form a stable film by a thermal crosslinking reaction, and becomes a polyester-based film. In order to obtain sufficient adhesion to the infrared absorption layer or hard coat layer, the coating amount at this time is 0.01 g / m ² or more per 1 m ^{2 of} film, and heat treatment at 100 ° C. for 1 minute or more is required. It is. The degree of cleanness when applying the coating solution is preferably a class of 1000 or less from the viewpoint of reducing the adhesion of dust.

  In this invention, it is important to laminate | stack the surface layer (A) which has an antireflection function on the single side | surface of said base film (B). The antireflection function refers to a function of preventing surface reflection, increasing light transmittance, and simultaneously preventing “glare”. The method of imparting the antireflection function can be arbitrarily selected without limitation. For example, a method of laminating layers having different refractive indexes on the surface of a base material and reducing the interference by using interference of reflected light at the interface of the layers Is preferred. As a method for forming the antireflection film of this method, the following two methods can be broadly mentioned. One method is to form an antireflection film on the surface of the substrate by vapor deposition or sputtering, and the other method is to apply an antireflection coating solution to the surface of the substrate and dry it. This is a method for forming an antireflection film. As a general theory, it is said that the former is superior in terms of antireflection characteristics and the latter is superior in terms of economy, but either method may be used in the present invention. The material of the antireflection film is not limited, and may be any of inorganic, organic, and inorganic / organic hybrids.

  In the present invention, when the antireflection film is formed, the hard processing for imparting scratch resistance, the antistatic processing for imparting antistatic properties, and dirt such as fingerprints, sebum, sweat, cosmetics, etc. It is a preferred embodiment to simultaneously perform a process that imparts a function that it is better to have as a near-infrared absorbing filter, such as an antifouling process that imparts a function of preventing and adhering easily even if attached. In particular, hard processing has a strong market demand, and the pencil hardness of the surface having the antireflection function is preferably 1H or more. Although the method of the hard processing is not limited and is arbitrary, it is a preferred embodiment that it is made of a polymer mainly composed of a polyfunctional monomer.

  In the present invention, the near-infrared ray containing a pigment having a maximum absorption in the near-infrared region having a wavelength of 800 to 1000 nm on the opposite surface to the surface layer (A) having the antireflection function of the base film (B) is laminated. It is important to laminate the absorption layer (C). When the near-infrared absorbing layer (C) is laminated, for example, when used as an optical filter for a plasma display, near-infrared light generated by plasma emission can be blocked, so that malfunction of a remote control using near-infrared light can be suppressed. The effect can be expressed. The dye is a diimmonium, phthalocyanine, dithiol metal complex, naphthalocyanine, azo, polymethine, anthraquinone, naphthoquinone, pyrylium, thiopyrylium, squarylium, croconium, tetradehycholine, Examples thereof include compounds such as triphenylmethane, cyanine, azo, and aminium. These are used singly or in combination of two or more, and contain a diimonium salt compound represented by the following formula (III), which has a large absorption in the near infrared region, a wide absorption region, and a high transmittance in the visible region. Is preferred.

  Specific examples of R1 to R8 in the formula (III) include, as the alkyl group, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, and ter-butyl. Group, n-amyl group, n-hexyl group, n-octyl group, 2-hydroxyethyl group, 2-cyanoethyl group, 3-hydroxypropyl group, 3-cyanopropyl group, methoxyethyl group, ethoxyethyl group, butoxyethyl Groups such as phenyl, fluorophenyl, chlorophenyl, tolyl, diethylaminophenyl, naphthyl and the like as aryl groups, and vinyl, propenyl, butenyl, pentenyl and the like as alkenyl groups as aralkyl groups As benzyl, p-fluorobenzyl, p-chlorophenyl, phenylpropyl , And the like naphthylethyl group. R9-12 may be hydrogen, fluorine, chlorine, bromine, diethylamino group, dimethylamino group, cyano group, nitro group, methyl group, ethyl group, propyl group, trifluoromethyl group, methoxy group, ethoxy group, propoxy Groups and the like. X- is fluorine ion, chlorine ion, bromine ion, iodine ion, perchlorate ion, hexafluoroantimonate ion, hexafluorophosphate ion, tetrafluoroborate ion, bis (trifluoromethanesulfonyl) imido ion Etc. However, the present invention is not limited to those mentioned above. Some of these are available as commercial products. For example, Kayasorb IRG-022, IRG-023, IRG-024, Nippon Carlit Co., Ltd. CIR-1080, CIR-1081, CIR-1083, CIR- 1085 etc. can be used suitably.

  The near-infrared absorbing filter of the present invention adds other near-infrared absorbing dyes for the purpose of expanding the near-infrared absorption range and adjusting the color in addition to the diimonium salt compound represented by the above formula (III). You can also

In the present invention, the near-infrared absorbing dye needs to be provided on the substrate so as to achieve the desired near-infrared absorption and transmittance in the visible region, and preferably 0.01 g / m ^2. It is preferably present at 1.0 g / m ² or less. When the amount of near-infrared absorbing dye is small, the absorption ability in the near-infrared region is insufficient, and conversely, when it is large, the transparency in the visible light region is insufficient and the display brightness is lowered. .

  A method of laminating the near infrared absorbing dye on the base film (B) in a state of being dispersed or dissolved in the resin is recommended. The resin is not particularly limited as long as it can uniformly dissolve or disperse the near-infrared absorbing dye, but polyester-based, acrylic-based, polyamide-based, polyurethane-based, polyolefin-based, and polycarbonate-based resins are preferably used. Can be used. Preferably, there is a polyester type excellent in flexibility and adhesion to the substrate. When the resin is hard, there is a problem that minute cracks are generated in the coating film in the post-processing step. Furthermore, the glass transition temperature of the resin is preferably equal to or higher than the guaranteed use temperature of the equipment to be used.

  When the glass transition temperature is lower than the device operating temperature, the dyes dispersed in the resin react with each other, or the resin absorbs moisture in the outside air and the deterioration of the dye and the binder resin increases. In the present invention, the glass transition temperature of the resin is not particularly limited as long as it is equal to or higher than the device use temperature, and particularly preferably 85 ° C. or higher and 160 ° C. or lower. When the glass transition temperature is 85 ° C. or lower, the interaction between the dye and the resin, the interaction between the dyes, and the like occur, and the dye is denatured. In addition, when the glass transition temperature exceeds 160 ° C., the resin must be dissolved in a solvent and heated to a sufficient temperature when applied on a transparent base material. Inferior flatness and further deterioration of the pigment occur. Moreover, when it dries at low temperature, drying time becomes long and productivity worsens, and productivity becomes bad. In addition, there is a possibility that sufficient drying cannot be performed, so that the solvent remains in the coating film, the apparent glass transition temperature of the resin is lowered as described above, and the dye is also modified.

  The amount of the near-infrared absorbing dye in the resin is preferably 1% by mass or more and 10% by mass or less. If the amount of the near-infrared absorbing dye in the resin is small, it is necessary to increase the coating amount of the near-infrared absorbing layer to achieve the target near-infrared absorbing ability. And / or it is necessary to make it long, and the problem of deterioration of a pigment | dye and the flatness of a base material generate | occur | produces. On the contrary, when the amount of the near-infrared absorbing dye in the resin is large, the interaction between the dyes becomes strong, and even if the residual solvent is reduced, the dye tends to be denatured over time.

  In the present invention, the near-infrared absorbing layer (C) that exhibits near-infrared absorbing ability is preferably a method in which a coating liquid mainly containing a resin and a near-infrared absorbing dye is applied and dried on the substrate (B) and laminated. However, in a more preferred embodiment, the coating liquid contains a surfactant having an HLB of 2 or more and 12 or less. By adding the surfactant, dispersibility of the near-infrared absorbing dye in the binder resin is improved, and the coating appearance of the near-infrared absorbing layer (C) containing the near-infrared absorbing dye, particularly due to minute bubbles It is recessed from the adhesion of spills and foreign matters, and repelling in the drying process is improved. Furthermore, the surface active agent bleeds on the surface by coating and drying, so that slipperiness is imparted, and handling properties are improved without forming surface irregularities on the near-infrared absorbing layer or / and the opposite surface, and the surface is wound in a roll shape. Easy to take.

  As the surfactant, known cationic, anionic, and nonionic surfactants can be suitably used. However, nonionic surfactants that do not have a polar group are preferred because of problems such as deterioration of near-infrared absorbing dyes. A silicon-based or fluorine-based surfactant having excellent surface activity is preferable.

  Silicone surfactants include dimethyl silicon, amino silane, acrylic silane, vinyl benzyl silane, vinyl benzyl silyl amino silane, glycid silane, mercapto silane, dimethyl silane, polydimethyl siloxane, polyalkoxy siloxane, hydrodiene modified siloxane, vinyl modified siloxane, Vitroxy modified siloxane, amino modified siloxane, carboxyl modified siloxane, halogenated modified siloxane, epoxy modified siloxane, methacryloxy modified siloxane, mercapto modified siloxane, fluorine modified siloxane, alkyl group modified siloxane, phenyl modified siloxane, alkylene oxide modified siloxane, etc. .

  Fluorosurfactants include ethylene tetrafluoride, perfluoroalkyl ammonium salt, perfluoroalkyl sulfonic acid amide, sodium perfluoroalkyl sulfonate, perfluoroalkyl potassium salt, perfluoroalkyl carboxylate, perfluoroalkyl sulfone. Acid salts, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl trimethyl ammonium salts, perfluoroalkyl amino sulfonates, perfluoroalkyl phosphate esters, perfluoroalkyl alkyl compounds, perfluoroalkyl alkyl betaines, perfluoroalkyl halides, etc. Is mentioned.

  The content of the surfactant is preferably 0.01% by mass or more and 2.00% by mass or less in the near-infrared absorbing layer (C). When the content of the surfactant is small, the coating appearance and slipperiness may be insufficient. On the other hand, when the content of the surfactant is large, the near-infrared absorbing layer easily adsorbs moisture, and the deterioration of the pigment is promoted.

  In the present invention, the HLB of the surfactant is preferably 2 or more and 12 or less. When the HLB is low, the leveling property is insufficient due to insufficient surface activity. On the other hand, when the HLB is high, not only the slipping property is insufficient, but also the near-infrared absorbing layer tends to adsorb moisture, resulting in poor temporal stability. The HLB is a W.A. of Atlas Powder, Inc. of the United States. C. Griffin named Hydrophile Lyophile Balance and indexed the balance of hydrophilic groups and lipophilic groups contained in the surfactant molecules as characteristic values. The lower the value, the more hydrophilic the higher the hydrophilicity. Means high.

  In the present invention, the near-infrared absorbing layer (C) containing a near-infrared-absorbing dye is laminated by applying and drying the coating liquid on the base film (B). It is necessary to dilute with an organic solvent. Examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, tridecyl alcohol, cyclohexyl alcohol, and 2-methylcyclohexyl alcohol, ethylene glycol, diethylene glycol, and triethylene glycol. , Glycols such as polyethylene glycol, propylene glycol, dipropylene glycol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethylene ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol butyl ether, ethylene glycol monomethyl ether acetate Glycol ethers such as ethylene glycol monoethyl acetate, ethylene glycol monobutyl acetate, diethylene glycol monomethyl acetate, diethylene glycol monoethyl acetate, diethylene glycol monobutyl acetate, esters such as ethyl acetate, isopropylene acetate, n-butyl acetate, acetone, methyl ethyl ketone And ketones such as methyl isobutyl ketone, cyclohexanone, cyclopentanone, isophorone and diacetone alcohol can be used, and these can be used alone or in admixture of two or more. Preferably, a ketone system excellent in dissolution of the pigment is contained in the solvent in the coating solution in an amount of 30% by mass to 80% by mass, and other than that, it is preferable to select in consideration of leveling property and drying property. The boiling point of the solvent is preferably 60 ° C. or higher and 180 ° C. or lower. When the boiling point is low, there is a problem that the solid content concentration of the coating liquid changes during coating and the coating thickness is difficult to stabilize. On the other hand, when the boiling point is high, the amount of solvent remaining in the coating film increases and the temporal stability becomes poor.

  Examples of the method for dissolving or dispersing the near-infrared absorbing dye and the resin in a solvent include stirring, dispersion and pulverization methods under heating. By heating, the solubility of the pigment and the resin can be improved, and the poor appearance of the coating due to undissolved substances is prevented. Moreover, it becomes possible to form a layer having excellent transparency by dispersing and pulverizing the resin and the pigment in the coating liquid in a fine particle state of 0.3 μm or less. As the disperser and the pulverizer, known ones can be used. Specifically, a ball mill, a sand mill, an attritor, a roll mill, an agitator, a colloid mill, an ultrasonic homogenizer, a homomixer, a pearl mill, a wet jet mill, a paint Examples include a shaker, a butterfly mixer, a planetary mixer, a Henschel mixer, and the like.

  If contamination or undissolved material of 1 μm or more is present in the coating liquid, the appearance after coating becomes poor. Therefore, it is necessary to remove it with a filter or the like before coating. Various filters can be suitably used as the filter, but it is preferable to use a filter that removes 99% or more of a 1 μm size filter. When a coating liquid containing 1 μm or more of contamination or undissolved material is applied and dried, a dent or the like is generated around the coating liquid, which may be a defect of a size of 100 to 1000 μm.

  The solid content concentration of the resin and pigment contained in the coating liquid is preferably 10% by mass or more and 30% by mass. When the solid content concentration is low, not only the drying after coating takes time and the productivity is inferior, but also the amount of the solvent remaining in the coating film increases, resulting in poor stability over time. On the other hand, when the solid content concentration is high, the viscosity of the coating solution becomes high and the leveling property is insufficient, resulting in a poor coating appearance. The viscosity of the coating liquid is preferably 10 cps or more and 300 cps or less from the viewpoint of coating appearance, and it is preferable to adjust the solid content concentration, the solvent, etc. so as to be in this range.

  In the present invention, as a method for applying the near-infrared absorbing layer C) containing a near-infrared absorber on the base film (B), a gravure coating method, a kiss coating method, a dip method, a spray coating method, a curtain coating method, an air knife Commonly used methods such as a coating method, a blade coating method, a reverse roll coating method, a bar coating method, and a lip coating method can be applied. Among these, a gravure coating method that can be applied uniformly, particularly a reverse gravure method is preferable. The diameter of the gravure is preferably 80 mm or less. When the diameter is large, there is a problem that waviness is generated in the flow direction.

The coating amount after drying is not particularly limited, but the preferred lower limit is 1 g / m ² or more, more preferably 3 g / m ² or more, and the preferred upper limit is 50 g / m ² , more preferably 30 g / m ² or less. When the coating amount after drying is small, there is a problem that the absorption capacity of the near infrared ray is insufficient, and even if the absorption capacity of the near infrared ray is increased by increasing the amount of the near infrared absorption pigment in the resin, The interaction between the dyes becomes strong, the dyes are likely to deteriorate, and the stability over time becomes poor. Conversely, when the coating amount after drying is large, the near-infrared absorbing ability is sufficient, but the transparency in the visible light region is lowered, and the brightness of the display is lowered. By reducing the amount of near infrared absorbing dye in the resin, the optical properties can be adjusted to the intended purpose, but drying tends to be inadequate, and the residual solvent in the coating film causes poor stability over time, so that drying is sufficient. In such a case, the flatness of the substrate becomes poor.

  As a method of applying the coating liquid on the base film (B) and drying, known hot air drying, an infrared heater and the like can be mentioned. Hot air drying with a high drying speed is preferable. In the initial constant rate drying stage after coating, drying is preferably performed at 20 ° C. or more and 80 ° C. or less using hot air of 2 m / sec or more and 30 m / sec. When the initial drying is performed strongly (the hot air temperature is high and the hot air volume is large), minute defects of the coating such as fine coating removal from foam, fine repellency, and cracks tend to occur. Conversely, when initial drying is weak (hot air temperature is low, hot air volume is small), the appearance is good, but drying time is required and there is a problem in terms of cost.

  In the reduction drying process, it is necessary to increase the temperature higher than the initial drying to reduce the solvent in the coating film, and the preferable temperature is 120 ° C. or higher and 180 ° C. or lower. When the temperature is low, there is a problem that the solvent in the coating film is difficult to decrease. On the other hand, when the temperature is high, there is a problem that not only the flatness of the base material becomes poor due to heat wrinkles, but also the near-infrared dye is deteriorated by heat. The passing time is preferably 5 seconds or more and 180 seconds or less. When the time is short, the amount of solvent remaining in the coating film increases, resulting in poor stability over time. Conversely, when the time is long, not only productivity is deteriorated, but heat wrinkles are generated on the substrate. Therefore, the flatness becomes poor.

  In the final stage of drying, it is preferable to set the hot air temperature to be equal to or lower than the glass transition temperature of the resin and to set the actual temperature of the base film to be equal to or lower than the glass transition temperature of the resin in a flat state. When leaving the drying furnace at a high temperature, when the coated surface comes into contact with the roll surface, slippage is poor, and not only scratches but also curls may occur.

  The near-infrared absorbing layer (C) containing the above-mentioned near-infrared-absorbing dye preferably has no change in near-infrared transmittance and visible light transmittance even when left at high temperatures and high humidity. When the temporal stability under high temperature and high humidity is poor, not only the color tone of the image on the display changes, but also the effect of the present invention for preventing malfunction of the electronic device using the near infrared remote controller may be lost. In order to improve the stability over time, it is achieved by reducing the residual solvent in the near-infrared absorbing layer and adjusting the pigment content in the resin, depending on the type of solvent in the coating solution, coating film thickness, drying conditions, etc. can do. The amount of residual solvent in the near-infrared absorbing layer is preferably as small as possible, but is preferably 3% by mass or less. If the amount is 3% by mass or less, there is substantially no difference in stability over time. However, if the drying is performed under severe conditions in order to further reduce the amount of residual solvent, problems such as poor flatness of the filter occur.

  The coating appearance of the near-infrared absorbing layer (C) containing the above-mentioned near-infrared-absorbing dye should be such that there is no defect with a diameter of 300 μm or more, more preferably 100 μm. The defect of 300 μm or more becomes like a bright spot when installed on the front surface of the plasma display, and the defect becomes noticeable. Also, streaks, unevenness, etc. with a thin coating layer become prominent on the front surface of the display and become a problem. The coating appearance can be achieved by satisfying the above requirements.

  In this invention, it is important to laminate | stack the adhesion layer (D) which consists of a transparent adhesive on the surface of the near-infrared absorption layer (C) containing the pigment | dye which has a maximum absorption wavelength in said near infrared region. By laminating the adhesive layer (D), the surface layer (A) having the antireflection function, the base film (B) containing an ultraviolet absorber, and the near infrared absorption containing a pigment having near infrared absorption. The laminate having the optical characteristics as the near-infrared absorbing filter composed of the layer (C) can be adhered and fixed to the surface of the plasma display panel or a translucent sheet having an electromagnetic wave absorbing function. The transparent pressure-sensitive adhesive is not particularly limited, and examples thereof include acrylic pressure-sensitive adhesives such as butyl acrylate, rubber pressure-sensitive adhesives, and TPE pressure-sensitive adhesives based on thermoplastic elastomer resins such as SEBS and SBS. .

  In the present invention, it is a preferred embodiment to perform color tone correction by including any one of the above-mentioned layers (A) to (D) with one kind of dye having absorption in the visible light region. For example, a plasma display emits so-called neon orange light centering around 600 nm, and has a drawback that a bright red color cannot be obtained by mixing orange with red. The problem can be solved by blending a dye having a maximum absorption in the wavelength range of 550 to 620 nm into any of the layers (A) to (D). That is, the dye preferably has a sharp absorption at 550 nm to 620 nm, more preferably 570 to 600 nm. The transmittance at the maximum absorption wavelength is preferably 40% or less, more preferably 30% or less. When the transmittance in this region is high, the neon light emitted from the plasma display is absorbed and the effect of improving the red color is lost. In addition, when the absorption in this region is wide, there is a problem that the luminance of the display is lowered because the entire transmittance of the visible light region is lowered. The higher the transmittance in the visible light region other than 550 to 620 nm, the better, preferably 50% or more, and more preferably 60% or more. When the transmittance is low, the color of the display is hindered and the image has a low luminance. Specifically, dyes such as cyanine, squalium, azomethine, xanthene, oxonol, azo, phthalocyanine, quinone, azulenium, pyrylium, croconium, dithiol metal complex, pyromethene compound, etc. Can be mentioned. Of these, squarylium compounds are preferred because they have sharp absorption in neon light. Although the layer which mix | blends the pigment | dye for such color tone correction | amendment as mentioned above is not limited, It is a preferable embodiment to mix | blend with a near-infrared absorption layer (C) with the said near-infrared absorption pigment | dye.

  As the color tone of the near-infrared absorption filter, when expressed in the Lab color system, the a value is preferably -10.0 to +10.0, and the b value is preferably -10.0 to +10.0. If it is this range, even if it installs in the front surface of a plasma display, it becomes a natural color and is preferable.

  The total thickness of the laminate composed of the above (A) to (D) of the present invention is not limited and can be arbitrarily set according to the market demand, but 0.05 to 0.2 mm is a preferable range. If it is less than 0.05 mm, the handleability of the near-infrared absorbing filter deteriorates, which is not preferable. On the contrary, when it exceeds 0.2 mm, the handleability of the near-infrared absorption filter and the workability when sticking to a plasma display or the like deteriorate, which is not preferable. In addition, it cannot meet the market demand for thin film.

  Although the near-infrared absorption filter is easy to handle and workability when sticking to a plasma display, etc., the near-infrared absorption filter is required to be thinned by the market, but the conventional technology has two or more functional films and sheets. The total thickness was over 0.2 mm. According to the present invention in which the base film is integrated, the market demand for thinning the near infrared absorption filter can be achieved for the first time while maintaining high functionality.

  The order of application of the layers having the respective functions to the base film (B) in the present invention is not limited except that the adhesion layer (D) is finally laminated. The coating may be performed sequentially for each functional layer, or may be performed simultaneously using a multilayer coater.

  In the present invention, it is a preferred embodiment that the near-infrared absorption filter having the above configuration is directly attached to the plasma display via the adhesive layer (D). The function can be exhibited by sticking a near-infrared absorption filter thinned with high function by this method to a plasma display.

Moreover, in this invention, it is a preferable embodiment to laminate | stack the near-infrared absorption filter of the said structure on the translucent sheet | seat which has an electromagnetic wave absorption function through the adhesion layer (D). According to this embodiment, the near-infrared absorption filter can be provided with an electromagnetic wave absorption function, and can be incorporated into, for example, a plasma display. Although the translucent sheet | seat with the electromagnetic wave absorption function in this invention will not be limited if it has both translucency and an electromagnetic wave absorption function, The following are mentioned.
(1) A conductive mesh made of metal fibers or metal-coated organic fibers.
(2) An edging method conductive mesh composite sheet obtained by laminating a metal film on a transparent film or sheet and then edging it into a lattice shape or a punching metal shape by a technique such as photolithography.
(3) A conductive printed mesh composite sheet obtained by pattern-printing a conductive paint on a transparent film or sheet.
(4) A transparent conductor in which a transparent conductive layer such as a silver thin film or an ITO thin film is laminated on a transparent film or sheet.

  In this invention, without forming the said adhesion layer (D), as a near-infrared absorption filter as a structure which laminated | stacked the surface layer (A) and the near-infrared absorption layer (C) on each one side of the base film (B), Can be used. Although there is no limitation on the method for fixing the near-infrared absorbing filter to an adherend such as a plasma display panel when used in this method, it is preferable to use an optical adhesive or pressure-sensitive adhesive. . In this case, it is necessary to fix and use the near-infrared absorbing layer (C) as the adherend side. The function of each functional layer can be expressed by the fixing method.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples. In addition, the evaluation method of the physical property in the following examples is as follows.

1. Light transmittance Using a spectrophotometer (Hitachi U-3500 type), with a wavelength of 200 to 1100 nm, light is transmitted from the near infrared absorbing layer (C) side containing the near infrared absorbing dye, and the air layer is used as a standard. It was measured. The ultraviolet transmittance is a transmittance of 380 nm, the transmittance of the visible light region is an average value of the transmittance of 450 to 700 nm, the transmittance of the neon light region is an average value of the transmittance of 570 to 600 nm,
For the transmittance in the near infrared region, an average value of transmittances of 900 to 1100 nm was determined.

2. Color tone Using a color difference meter (Nippon Denshoku Industries Co., Ltd. ZE-2000), the near infrared absorption layer side is irradiated with light, and the Lab color system a value and b value are D65 light source, 10 degrees as standard light. Measured at viewing angle.

3. Stability over time After being left for 500 hours in an atmosphere at a temperature of 60 ° C. and a humidity of 95%, the spectral characteristics and color tone described above were measured.
The amount of change before and after the temporal treatment of the average value of the transmittance in the near-infrared region and the transmittance in the visible light region was determined from the following formula 1, and ranked according to the following criteria.
◎: Change in transmittance less than 5% ○: Change in transmittance from 5% to less than 10% △: Change in transmittance from 10% to less than 20% ×: Change in transmittance from 20% or more

Change amount (%) = (| transmittance before processing−transmittance after processing | / transmittance before processing) × 100
... (1)

Moreover, it calculated | required from the variation | change_quantity of the following formula 2 before and behind color-aging processing, and ranked by the following judgment criteria.
◎: Change in transmittance is less than 1 ○: Change in transmittance is 1 or more and less than 2 Δ: Change in transmittance is 2 or more and less than 4 ×: Change in transmittance is 4 or more

Change amount = √ ((a value before processing−a value after processing) ² + (b value before processing−b value after processing) ² ) (2)

4). Weather resistance Test samples were evaluated under the following conditions by an accelerated weather resistance test. Irradiation test using an ultraviolet auto fade meter (trade name “FAL-AU-H-BR” manufactured by Suga Test Instruments Co., Ltd.) is performed at a black panel temperature of 63 ° C. for 192 hours, and the maximum in the near infrared region of the test sample before and after the test The transmittance at the absorption wavelength was measured. The transmittance before the test the transmittance after the test and T was T _1. From the measured value, the near infrared absorptive residual rate R (%) was determined by the following formula 3. The evaluation was carried out by a method in which the sample was attached to a SUS plate having a thickness of 2 mm via an adhesive layer (D) and irradiated with ultraviolet rays from the surface layer (A) side.

R (%) = (T / T ₁ ) × 100 (3)

5). Reflectance of surface layer (A) Using a spectrophotometer (Hitachi U-3500 type), according to JIS-R-3106, 5 ° specular reflection on the surface layer (A) side was measured, and the wavelength was 380 to 700 nm. The minimum reflectance of was determined. About the sample of the comparative example which does not laminate | stack a surface layer (A), the surface of the base film (B) was measured.

6). Surface hardness The surface of the surface layer (A) having an antireflection function was evaluated by pencil scratch hardness. The sample was evaluated after conditioning for 2 hours under conditions of a temperature of 25 ° C. and a relative humidity of 60%. The pencil scratch hardness was measured according to JIS-K-5400 using a test pencil specified by JIS-S-6006. The pencil hardness of the evaluation result is that of a pencil in which no scratch is observed at a load of 9.8 N. About the sample of the comparative example which does not laminate | stack a surface layer (A), the surface of the base film (B) was measured.

7). Appearance of near-infrared absorbing layer (C) containing near-infrared absorbing pigment Appearance is evaluated by placing a laminated film on which a near-infrared absorbing layer (C) is laminated on a white film and observing it under a three-wavelength fluorescent lamp. It was.

(1) Minute defects The number of defects having a size of 300 μm or more per 100 m ² was measured and ranked according to the following criteria.
◎: Less than 1 micro defect ○: 1 or more and less than 5 △: Micro defect is 5 or more and less than 10 ×: 10 or more micro defects

(2) Coating failure Coating failures such as coating unevenness and streaks were ranked according to the following criteria.
◎: Appearance is not slightly observed when moving near infrared absorption filter ○: Appearance is slightly observed when moving near infrared absorption filter △: Appearance is defective when observed while moving near infrared absorption filter × : Appearance defects can be seen even when stationary

8). Adhesiveness of Surface Layer (A) and Near Infrared Absorbing Layer (C) to Base Film (B) Adhesiveness was determined by a test method according to JIS-K5400 8.5.1. That is, 100 grid-like cuts that reach the base film from both surfaces are attached using a cutter guide having a gap interval of 2 mm, and cellophane adhesive tape (Nichiban 405 No. 24 mm width) is applied to the grid-like cut surface. After sticking and rubbing with a plastic piece so as not to leave bubbles or poorly adhered parts, they were completely attached, then peeled off vertically, and the adhesiveness was determined from the following formula 4 by visual observation. In addition, what peeled off partially by one square was made into the peeled square.

  Adhesiveness (%) = (1−number of cells peeled / number of cells evaluated) × 100 (4)

Example 1
1. Production of Base Film (B) (1) Preparation of UV Absorber-Containing Masterbatch Dried UV Absorber CYASORB UV-3638 Siatec Co., Ltd. (2,2 ′-(1,4-phenylene) bis (4H-3 , 1-benzoxazinon-4-one)) 10 parts by weight, 90 parts by weight of polyethylene terephthalate (PET) resin (Toyobo Co., Ltd., ME-553) containing no particles are mixed, and a master batch is used using a kneading extruder. Was made. The extrusion temperature at this time was 285 ° C., and the extrusion time was 7 minutes.

(2) Preparation of coating solution for forming an easy-adhesion layer A coating solution for forming an easy-adhesion layer was prepared according to the following method. A reaction vessel was charged with 95 parts by weight of dimethyl terephthalate, 95 parts by weight of dimethyl isophthalate, 35 parts by weight of ethylene glycol, 145 parts by weight of neopentyl glycol, 0.1 part by weight of zinc acetate and 0.1 part by weight of antimony trioxide. The transesterification was carried out over 3 hours. Next, 6.0 parts by mass of 5-sodium sulfoisophthalic acid was added, esterification reaction was performed at 240 ° C. over 1 hour, and then polycondensation reaction was performed to obtain a polyester resin. 6.7 parts by mass of a 30% by mass aqueous dispersion of the obtained polyester resin and a 20% aqueous solution of a self-crosslinking polyurethane resin containing an isocyanate group blocked with sodium bisulfite (Elastotron H-3, manufactured by Daiichi Kogyo Seiyaku) ), 40 parts by mass of elastron catalyst (Cat 64), 0.5 part by mass of water, 47.8 parts by mass of water and 5 parts by mass of isopropyl alcohol. 5% by mass of colloidal silica particles (manufactured by Nissan Chemical Industries, Snowtex OL) was added to the solid content of the coating solution to prepare a coating solution.

(3) Film formation of substrate film (B) 90 parts by mass of pellets (ME-553, manufactured by Toyobo Co., Ltd.) not containing PET resin particles having an intrinsic viscosity of 0.62 dl / g and the above-mentioned UV absorber-containing master 10 parts by mass of the batch was dried under reduced pressure (1 Torr) at 135 ° C. for 6 hours and then fed to the extruder. The resin temperature up to the extruder melt section, kneading section, polymer tube, gear pump, and filter was 280 ° C., and the polymer tube thereafter was 275 ° C., and the sheet was extruded from the die in the form of a sheet. Each of these polymers was filtered using a stainless steel sintered filter medium (nominal filtration accuracy: 10 μm particles, 95% cut). Further, the resin temperature of the flat die was set to 275 ° C. The 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 cooled and solidified to produce an unstretched film. 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. 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 a uniaxially oriented film Got. 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 using a suction roll, electrostatic contact, and part nip contact apparatus. Thereafter, the coating solution for forming an easy-adhesion layer was microfiltered with a felt type polypropylene filter medium having a filtration particle size (initial filtration efficiency of 95%) of 25 μm, and applied to both sides by a reverse roll method and dried. 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 a base film (B). The film thickness was 100 μm, and the coating amount of the easy adhesion layer at this time was 0.01 g / m ² . The transmittance of the obtained film at a wavelength of 380 nm is shown in Table 1. The obtained base film had excellent ultraviolet absorptivity.

2. Formation of surface layer (A) UV-curable hard coat paint (Seika Beam EXF-01B manufactured by Dainichi Seika Co., Ltd.) is applied to the base film (B) by a reverse coating method so as to have a film thickness of 5 μm. Then, after drying the solvent, a hard coat layer was formed by irradiating ultraviolet rays with a high pressure mercury lamp at 800 mJ / cm ² . Next, after drying a coating solution comprising 5 parts by mass of a partially hydrolyzed condensate of γ-aminopropyltrimethoxysilane, 30 parts by mass of methanol, 30 parts by mass of ethanol, and 35 parts by mass of isopropanol, the film thickness is 0.02 μm after drying. It is coated and dried at 140 ° C. for 20 seconds to form a high refractive index coating film layer. Then, 24 parts by mass of tetraethoxysilane, 50 parts by mass of ethanol, 20 parts by mass of water, and 4 parts by mass of hydrochloric acid are dispersed to hydrolyze. A coating material was prepared, and this coating material was coated to a thickness of 0.09 μm after drying, and dried at 140 ° C. for 1 minute to form a low refractive index coating film layer. Further, the low refractive index coating film C ₃ on the layer _{F 7 - (OC 3 F 6} ) 34 -O- (
CF ₂ ) ₂ —C ₂ H ₄ —O—CH ₂ Si (OCH ₃ ) ₃ containing a perfluoropolyether group-containing silane coupling agent diluted to 0.5% by mass with perfluorohexane. Then, an antifouling layer having a thickness of 8 nm was formed and dried at 120 ° C. for 1 minute to form a surface layer (A).

  The characteristic values of the surface layer (A) of the obtained laminated film are shown in Table 1. The laminated film obtained in this example had low surface reflectance and good surface hardness. Also, the antifouling property was excellent. In addition, the said antifouling property was evaluated by the wipeability of an oil-based pen and the wipeability of a fingerprint. The wiping property of the oil-based pen is to draw a line on the surface layer (A) surface with an oil-based pen, and the wiping property of the fingerprint is to apply the fingerprint adhered to the surface layer (A) surface to a nonwoven fabric made of cellulose (BEN Cotton M-3: manufactured by Asahi Kasei Co., Ltd.) and the ease of removal was visually determined. Both were completely wiped off.

3. Formation of near-infrared absorbing layer (C) A base film of a laminated film obtained by laminating a surface layer (A) on the above base film (B) with a coating liquid (solid content concentration: 17%, viscosity: 40 cps) having the following composition: The surface was coated on the surface with a reverse gravure gravure having a diameter of 60 cm so that the coating amount after drying was 8.5 g / m ² , and heated at 40 ° C. with hot air of 5 m / second for 20 seconds and at 150 ° C. with 20 m / second. A near-infrared absorption filter was prepared by passing the sample for 20 seconds with hot air of seconds and further passing it with hot air of 20 m / second at 90 ° C. for 10 seconds and drying.

[Coating solution for forming near-infrared absorbing layer (C)]
The mixture was mixed at the following mass ratio, the dye and the resin were dissolved under heating, and the undissolved material was removed with a filter having a nominal filtration accuracy of 1 μm to prepare a coating solution.
・ Cyclopentanone 41.50% by mass
・ Toluene 41.50% by mass
・ Ester resin 16.15% by mass
(Kanebo O-PET)
・ Diimonium salt compound 0.5653 mass%
(Nippon Kayaku IRG-022)
・ Nickel metal complex 0.1547% by mass
(SIR-128 manufactured by Mitsui Chemicals)
・ Cyanine compound 0.0461% by mass
(IR301 manufactured by Yamada Chemical Industries)
・ Cyanine compound 0.00939 mass%
(Nippon Kayaku CY-10)
・ Squarylium salt compound 0.0471% by mass
(SD184 manufactured by Kyowa Hakko Kogyo)
・ Silicon surfactant 0.0340% by mass
(Dow Corning Paintad 57, HLB = 6.7)

  Table 1 shows the physical properties of the obtained laminated film. A film having strong absorption in the near infrared region and neon light region and high transmittance in the visible light region was obtained. Further, the stability over time and weather resistance were excellent, and the coating appearance was also good.

4). Formation of adhesive layer (D) n on the surface of the near-infrared absorbing layer (C) of the laminated film consisting of the surface layer (A), substrate film (B) and near-infrared absorbing layer (C) obtained by the above method -A transparent pressure-sensitive adhesive comprising an acrylic ester copolymer consisting of butyl acrylate (78.4% by mass), 2-ethylhexyl acrylate (19.6% by mass), and acrylic acid (2% by mass) by a comma coater method. Laminated to a thickness of 0.025 mm after drying, and further laminated with a silicone-treated separator film of 0.038 mm thick polyethylene terephthalate on the surface, surface layer (A), substrate film (B) The composite of the near-infrared absorption filter which consists of a near-infrared absorption layer (C) and the adhesion layer (D), and a separator film was obtained.

  The near-infrared absorption filter obtained in this example has a total thickness of as thin as 0.14 mm and possesses the excellent characteristics as described above. Utilizing the adhesiveness of the layer (D), for example, it can be easily attached to an adherend such as a plasma display. As described above, the near-infrared absorbing filter has a thinner thickness than a conventionally known filter, and thus has excellent workability for sticking.

Comparative Example 1
In Example 1, a near-infrared absorption filter of Comparative Example 1 was obtained in the same manner as Example 1 except that the following changes (1) to (3) were made. Table 1 shows the characteristics of the near-infrared absorbing filter obtained in Comparative Example 1.
(1) Cancel the blending of the ultraviolet absorber into the base film (B).
(2) Cancel the lamination of the easy adhesion layer to the base film (B) on both sides.
(3) Cancel the incorporation of the surfactant into the coating solution for forming the near infrared absorbing layer (C).

  Since the near-infrared absorbing filter obtained in Comparative Example 1 has high ultraviolet transmittance, the near-infrared absorbing dye is greatly deteriorated by light and has poor weather resistance. Moreover, since an easily bonding layer is not formed, the adhesiveness with respect to the base film (B) of a surface layer (A) or a near-infrared absorption layer (C) is inferior. Furthermore, since the incorporation of the surfactant into the coating solution for forming the near infrared absorbing layer (C) was canceled, the dispersibility of the near infrared absorbing pigment and the color tone adjusting pigment for cutting neon light in the binder resin is inferior. The coating film appearance of the near-infrared absorbing layer (C) was inferior.

Comparative Example 2
In the method of Example 1, a near-infrared absorption filter of Comparative Example 2 was obtained in the same manner as Example 1 except that the following changes (4) to (6) were made.
(4) Stop the lamination of the surface layer (A) to the base film (B).
(5) Stop the lamination of the easy adhesion layer to the base film (B) on both sides.
(6) Cancel the compounding of the surfactant into the coating solution for forming the near infrared absorbing layer (C).
Table 1 shows the characteristics of the near-infrared absorbing filter obtained in Comparative Example 2. In addition, since the near-infrared absorption filter obtained by this comparative example 2 is not compounded with the surface layer (A), the surface reflectance and surface hardness evaluated the surface characteristic of the base film (B).

  The near-infrared absorption filter obtained in Comparative Example 2 is inferior in surface reflectance and surface hardness because the surface layer (A) is not combined. Moreover, the antifouling property of the surface was inferior, and the lines and fingerprints drawn with the oil-based pen in the above evaluation remained after wiping. Moreover, since an easily bonding layer is not formed, the adhesiveness with respect to the base film (B) of a near-infrared absorption layer (C) is inferior. Furthermore, since the incorporation of the surfactant into the coating solution for forming the near infrared absorbing layer (C) was canceled, the dispersibility of the near infrared absorbing pigment and the color tone adjusting pigment for cutting neon light in the binder resin is inferior. The coating film appearance of the near-infrared absorbing layer (C) was inferior.

Comparative Example 3
In the method of Example 1, a near-infrared absorption filter of Comparative Example 3 was obtained in the same manner as in Example 1 except that the lamination of the near-infrared absorption layer (C) was canceled. In addition, in this comparative example 3, since lamination | stacking of the near-infrared absorption layer (C) was canceled, the adhesion layer (D) was performed on the base film (B) surface. Table 1 shows the characteristics of the near-infrared absorbing filter obtained in Comparative Example 3. The near-infrared absorption filter obtained in this Comparative Example 3 does not have a basic function as a near-infrared absorption filter because the near-infrared absorption layer (C) is not laminated and has a high transmittance in the near-infrared region. Further, the color tone correction function is not provided.

Comparative Example 4
A near-infrared absorption filter of this comparative example was obtained in the same manner as in Example 1 except that the method in Example 1 was changed as in the following (7) to (10).
(7) Cancel the blending of the ultraviolet absorber into the base film (B).
(8) Stop the lamination of the easy adhesion layer to the base film (B) on both sides.
(9) Cancel the incorporation of the surfactant into the coating solution for forming the near infrared absorbing layer (C).
(10) TINUVIN 386 (3% by mass) manufactured by Ciba Specialty Chemicals as an ultraviolet absorber and IRUGANOX-1010 (1% by mass) manufactured by the same as an antioxidant are blended in the adhesive layer (D).

  Table 1 shows the characteristics of the near-infrared absorbing filter obtained in Comparative Example 4. The near-infrared absorbing filter of Comparative Example 4 is composed of a near-infrared absorbing layer (C) in which a near-infrared absorbing dye is mixed in the near-infrared absorbing layer, so that the effect of improving weather resistance is not exhibited. Is a level. Moreover, since an easily bonding layer is not formed, the adhesiveness with respect to the base film (B) of a near-infrared absorption layer (C) is inferior. Furthermore, since the incorporation of the surfactant into the coating solution for forming the near infrared absorbing layer (C) was canceled, the dispersibility of the near infrared absorbing pigment and the color tone adjusting pigment for cutting neon light in the binder resin is inferior. The coating film appearance of the near-infrared absorbing layer (C) was inferior.

Example 2
In the method of Example 1, except that the ultraviolet absorber is a polymer ultraviolet absorber (manufactured by Mitsubishi Chemical Corporation, Novapex U-110), and the blending amount is changed to 20 parts by mass, Example 1 The near-infrared absorption filter of Example 2 was obtained by the same method as described above. Table 1 shows the characteristics of the near-infrared absorption filter obtained in Example 2. The near-infrared absorption filter obtained in Example 2 was of high quality like the near-infrared absorption filter obtained in Example 1.

Example 3 and Comparative Example 5
Remove the front panel of the plasma display panel (manufactured by Fujitsu, PDS4211J-H), and stick the near-infrared absorption filters obtained in Examples 1 and 2 and Comparative Examples 1 to 4 through the adhesive layer (D). Functional evaluation was performed. The near infrared absorption filters obtained in Examples 1 and 2 were able to confirm the following effects.
(1) Since the antireflection property of the surface is given, the reflection of external light is suppressed, and the reflection of the fluorescent lamp used for indoor lighting is reduced.
(2) Since the surface hardness is high, it is difficult to be damaged.
(3) Since antifouling property is given, even if it touches with a hand and a fingerprint is attached, it can be easily erased by wiping.
(4) Since the tone of neon cut has been improved, color reproducibility has been improved. Specifically, red with orange color becomes pure red, blue with greenish color becomes vivid blue, and white that looks yellowish becomes pure white.
(5) Since a near-infrared absorbing effect is given, interference with an infrared remote control device installed in the vicinity can be prevented.
(6) Since the weather resistance and stability over time are excellent, the function of (5) was stable even after long-term use.

  Since the near-infrared absorption filter of Comparative Example 1 had a poor coating appearance of the near-infrared absorption layer (C), the image quality was deteriorated due to the defects. In addition, since the weather resistance is inferior, the long-term use increases interference with the infrared remote control device installed in the vicinity.

  Since the near-infrared absorption filter of Comparative Example 2 had high surface reflectance, the reflection of external fluorescent light was high and there was a reflection of a fluorescent lamp used for indoor lighting, and the visibility of the screen was low. Moreover, since the surface hardness was low and antifouling property was not given, it was easy to be damaged and the wiping property of the fingerprint adhered when touched by hand was inferior. Furthermore, since the coating film appearance of the near-infrared absorbing layer (C) was inferior, the image quality was deteriorated due to the defects.

  Since the near-infrared absorbing filter of Comparative Example 3 does not have near-infrared absorbing ability, interference with an infrared remote control device installed in the vicinity occurred. Further, since the neon cut property was not imparted, the color reproducibility of the image was inferior.

  The near-infrared absorption filter of Comparative Example 4 has an effect of improving weather resistance against external light because the ultraviolet absorber is combined on the plasma display panel side from the near-infrared absorption layer (C) containing the near-infrared absorbing dye. Therefore, interference with the infrared remote control device installed in the vicinity increased due to long-term use like the near infrared absorption filter of Comparative Example 1. Moreover, since the coating film appearance of the near-infrared absorbing layer (C) was inferior, the image quality was deteriorated due to the defects.

  In addition, the near infrared absorption filters of Comparative Examples 1, 2, and 4 are inferior in adhesiveness at the interface between the base film (C) and the functional expression layer. Decreased.

  In addition, since the near-infrared absorption filter of the present invention is thin and has an adhesive layer combined, if the filter is attached with the surface of the plasma display panel moistened with isopropyl alcohol, air bubbles are mixed in. I was able to stick it cleanly.

Example 4
The near-infrared absorption filters obtained in Examples 1 and 2 and Comparative Examples 1 to 4 were knitted vertically and horizontally at a density of 135 fibers per inch through a pressure-sensitive adhesive layer (D) with a wire diameter of 0.03 mm. The mesh was attached to a conductive mesh plated with nickel and copper by an electroless plating method. The front panel of the plasma display panel (PDS4211J-H, manufactured by Fujitsu Ltd.) was removed, and the composite was attached with an adhesive, and the function was evaluated. In addition to the effects confirmed in Example 3, an electromagnetic wave shielding effect was exhibited.

Example 5
In Example 1 and 2, before laminating the adhesion layer (D), a near-infrared absorption filter comprising a laminate composed of a surface layer (A) / base film (B) / near-infrared absorption layer (C), Evaluation was carried out by attaching an optical adhesive to the plasma display panel with the near infrared absorption layer (C) side as the plasma display panel side, and the same results as in Example 3 were obtained.

  The near-infrared absorption filter of the present invention is excellent in optical characteristics, despite its simplified configuration, and suppresses the deterioration of the near-infrared absorption pigment due to its durability, particularly ultraviolet rays contained in outside light. In addition, the workability of sticking to the adherend has been improved by thinning the film, and by absorbing near infrared rays generated from video output devices such as plasma displays or lighting fixtures, etc. Blocking near-infrared intrusion, preventing malfunction of remote control / infrared communication port that uses light in the near-infrared region for communication, and thus preventing malfunction of devices controlled by these remote control devices, and caching It can be used for a wide range of application fields such as forgery prevention of card ID cards and the like, and contributes greatly to the industry.

Claims (12)

  It is a near infrared absorption filter, and has a maximum absorption in a near infrared absorption region having a wavelength of 800 to 1000 nm on the surface layer (A) having an antireflection function on one side of a base film (B) containing an ultraviolet absorber and on the opposite side. A near-infrared absorption filter, comprising: a near-infrared absorption layer (C) containing a pigment having a colorant.   The near-infrared absorbing filter according to claim 1, wherein an adhesive layer (D) made of a transparent adhesive is laminated on the surface of the near-infrared absorbing layer (C).   The near-infrared absorption filter according to claim 2, wherein the total thickness of the laminate composed of the above (A) to (D) is 0.05 to 0.2 mm.   The near-infrared absorption filter according to any one of claims 1 to 3, wherein the surface layer (A) having the antireflection function has a pencil hardness of 1H or more.   5. The color tone correction according to any one of claims 2 to 4, wherein any one of the layers (A) to (D) contains at least one dye having absorption in the visible light region to correct the color tone. Near infrared absorption filter.   The near-infrared absorption filter according to any one of claims 1 to 5, wherein an easy-adhesion layer is laminated on both surfaces of the base film (B).   The near-infrared absorption filter according to claim 1, wherein the near-infrared absorption layer (C) contains a surfactant having an HLB of 2 or more and 12 or less.   The near-infrared absorbing layer (C) is formed by a coating method using a solution containing a dye having an absorption in the near-infrared region of at least a wavelength of 800 to 1000 nm, a transparent resin, and a surfactant having an HLB of 2 to 12. The near-infrared absorption filter according to claim 1, wherein   The laminate comprising the above (A) to (C) is used with the near-infrared absorbing layer (C) fixed to the plasma display panel with the plasma display panel side being used. Near infrared absorption filter.   A laminate comprising the above (A) to (C) is laminated with a translucent sheet having an electromagnetic wave absorbing function on the near infrared absorbing layer (C) as the translucent sheet side having an electromagnetic wave absorbing function. The near-infrared absorption filter according to any one of claims 1 to 8.   The near-infrared absorption filter according to any one of claims 1 to 8, wherein the laminate comprising (A) to (C) is attached to the surface of the plasma display panel via the adhesive layer (D).   The laminate comprising the above (A) to (C) is laminated on a translucent sheet having an electromagnetic wave absorbing function via an adhesive layer (D). Near infrared absorption filter.