JP2006184820A - Near-infrared absorption film and near-infrared absorption filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a near-infrared absorption film and a near-infrared absorption filter excellent in durability while maintaining a near-infrared blocking effect and visible light transmittance in a broad wavelength region. <P>SOLUTION: The near-infrared absorption film is obtained by laminating, on a transparent base film, a near-infrared absorption layer comprising a composition containing a transparent resin and one or more near-infrared absorbing dyes having maximum absorption at a wavelength of 800-1,100 nm, wherein one of the near-infrared absorbing dyes is an aromatic diimmonium compound having bis(trifluoromethanesulfonyl)imidic acid as a counter anion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention particularly relates to a near-infrared absorbing film and a near-infrared absorbing filter suitable for a front panel of a plasma display (PDP) and a near-infrared cut film for automobiles. More specifically, the present invention relates to a near-infrared absorbing film and a near-infrared absorbing filter that are excellent in durability.

  An optical film having near-infrared absorbing ability has a property of blocking near-infrared rays 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. A near-infrared ray is cut on the front side.

  As a film having near infrared absorption ability, (1) a film containing metal ions such as copper and iron on phosphoric acid glass, and (2) a layer having different refractive indexes are laminated to interfere with transmitted light. (3) An acrylic resin film containing a copper ion in a copolymer, and (4) a film in which a layer in which a pigment is dispersed or dissolved is laminated. Among these, the film (4) has good workability and productivity, has a relatively large degree of freedom in optical design, and various methods have been proposed (for example, see Patent Documents 1 to 7).

  Some of these methods have the ability to sufficiently block the near infrared rays emitted from the plasma display. However, when a diimmonium-based compound is used as a dye, deterioration due to heat, oxidation, etc. proceeds, and there is a problem in terms of durability of the filter.

  As a solution to the above problem, a near-infrared absorbing film having a near-infrared absorbing layer containing a diimonium-based compound having an endothermic peak at a temperature of 220 ° C. or higher in differential scanning calorimetry is disclosed (for example, Patent Document 8). reference). However, it did not reach a level that satisfies the market demand.

Moreover, the pigment | dye used for said near-infrared absorption film is not good in weather resistance, For example, when using as an optical filter which interrupts | blocks the near-infrared ray discharge | released from a plasma display, the further improvement was calculated | required strongly. In addition to having the ability to absorb near infrared rays, the optical filter preferably provides other functions such as color tone adjustment for imparting specific absorption to the visible light region, antireflection, and scratch resistance on the surface. . As a measure for solving the above-mentioned problem, for example, a multilayer type near-infrared absorption panel in which functional layers having various functions are multilayered is disclosed (for example, see Patent Document 9).
In Patent Document 9, an electromagnetic wave absorption layer, an antireflection layer, and an ultraviolet absorption layer are disclosed as functional layers having functions other than near infrared absorption ability. However, the ultraviolet absorbing layer is not described in detail in the specification. For the multilayering of the electromagnetic wave absorption layer and the antireflection layer described in detail, a method of bonding a functional film having each function to a near infrared absorption film is used.

  Further, a filter for directly attaching a plasma display panel is disclosed in which a near-infrared cut film that combines an antireflection function including an antistatic layer and an ultraviolet absorbing layer is directly attached to the surface of the plasma display panel (see, for example, Patent Document 10). .

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

  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 (for example, refer patent document 11). Also in this patent document 11, the method of bonding an ultraviolet absorber containing film and a sheet | seat containing a near-infrared absorption pigment | dye is disclosed.

  On the other hand, the structure which multi-functionalized with one base film is disclosed (refer patent document 12). In Patent Document 12, an antireflection function and an ultraviolet absorption function are added as functions other than the near infrared absorption function. However, the structure currently disclosed in patent document 12 is mix | blended with the adhesion layer for fixing the laminated body which a ultraviolet absorber has a near-infrared absorption function to a transparent hard board | substrate. Therefore, when actually used as a filter, the layer having an ultraviolet absorbing function is located on the side opposite to the outside light side of the layer having a near infrared absorbing function, and is caused by the ultraviolet rays in the outside light, which is a problem in actual use. The effect of suppressing the deterioration of the near-infrared absorbing dye is not exhibited. Therefore, it did not satisfy the market demand for improving the weather resistance of near-infrared absorbing dyes by external light.

The laminate having optical characteristics that satisfy the market requirements in the above-described known technology has a configuration in which two or more functional films having respective functions are bonded together. Therefore, not only the deterioration of the optical characteristics due to the increase of the interface due to the bonding cannot be improved, but also the problem that it is economically disadvantageous because a bonding step is required remains. Moreover, since total thickness becomes thick, it has the subject that 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 weather resistance due to external light cannot be expressed.
JP 2002-82219 A JP 2002-214427 A JP 2002-264278 A JP 2002-303720 A JP 2002-333517 A JP 2003-82302 A JP 2003-96040 A JP 2003-114323 A Japanese Patent No. 3308545 JP 2002-189423 A JP 2003-4904 A JP 2002-138203 A

  The object of the present invention is made in the background of the problems of the prior art, and provides a near-infrared absorbing film excellent in durability while maintaining the blocking property of near-infrared rays and the transmittance of visible light in a wide wavelength region. There is. Furthermore, the near infrared ray absorbing film excellent in blocking properties of near infrared rays and its durability and weather resistance, the near infrared ray absorbing film excellent in optical properties such as antireflection, suppression of the generation of iris-like colors (interference fringes), and few appearance defects An object of the present invention is to provide a near-infrared absorbing filter in which the workability of sticking to an adherend is improved by thinning the near-infrared absorbing film.

  The near-infrared absorbing film of the present invention capable of solving the above-mentioned problems is composed of a transparent resin and a composition containing a near-infrared absorbing dye having a maximum absorption at a wavelength of 800 to 1100 nm on a transparent substrate film. 1. A near-infrared absorption film comprising a near-infrared absorption layer, wherein one of the near-infrared absorption dyes is an aromatic diimmonium compound having bis (trifluoromethanesulfonyl) imidic acid as a counter anion. It is a near-infrared absorbing film. Moreover, it is a near-infrared absorption filter characterized by laminating | stacking the adhesion layer which consists of transparent adhesives on the surface of the near-infrared absorption layer of said near-infrared absorption film.

  The near-infrared absorbing film of the present invention is excellent in durability while maintaining the blocking property of near-infrared rays and the transmission of visible light in a wide wavelength region, and therefore requires a function of absorbing near-infrared rays such as a plasma display. It can be suitably used as an optical filter for a display device or the like. In addition, 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, while maintaining near infrared blocking properties and visible light transmission in a wide wavelength region, It is excellent in durability, and furthermore, it can maintain a thin film state with a single base film configuration and can provide various other functions, so the workability of sticking to the adherend is improved and it is economical It can also be suitably used as an optical filter for a display device or the like that is required to have a function of absorbing near infrared rays such as a plasma display.

  Hereinafter, the present invention will be described in detail.

  The material of the base film in the present invention is not limited as long as it is a transparent body. For example, a biaxially oriented polyester film composed of a polyester resin such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene-2,6-naphthalate is preferable from the viewpoint of mechanical properties, optical properties, heat resistance, and economy. The polyester may be a homopolymer or a blend of two or more polyesters. Further, it may be a copolyester. In the case of a copolymerized polyester, two or more components are used as at least one of a dicarboxylic acid component or a glycol component as a copolymerization component. Dicarboxylic acid components include aliphatic dicarboxylic acids such as adipic acid and sebacic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and 2,6-naphthalenedicarboxylic acid; trimellitic acid and pyromellitic acid A polyfunctional carboxylic acid or the like is 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; and alicyclic glycols such as 1,4-cyclohexanedimethanol. A polyethylene glycol having a number 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. A film made of cellulose triacetate (TAC) is also preferable because of excellent optical properties such as transparency.

  In the present invention, it is important that one of the near infrared absorbing dyes is an aromatic diimmonium compound having bis (trifluoromethanesulfonyl) imidic acid as a counter anion. For example, the compound shown by the following general formula (I) can be mentioned.

In the aromatic diimmonium compound represented by the general formula (I), R ^{1 to} R ⁸ represent a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, an aralkyl group, and an alkynyl group, and are the same. Or different. R ^{9 to} R ¹² represent a hydrogen atom, a halogen atom, an amino group, a cyano group, a nitro group, a carboxyl group, an alkyl group, or an alkoxy group, and may be the same or different. What can couple | bond a substituent with R < ¹ > -R < ¹² > may have a substituent. X ⁻ represents an anion, and X is bis (trifluoromethanesulfonyl) imidic acid.

  In the present invention, it is a preferred embodiment that a near-infrared absorbing dye having a structure other than the above-mentioned diimmonium-based compound is used in combination for the purpose of imparting good near-infrared blocking properties in the entire near-infrared region. Near-infrared absorbing dyes other than diimonium compounds include polymethine, metal complex, squarylium, cyanine, phthalocyanine, indoaniline, naphthalocyanine, azo, anthraquinone, naphthoquinone, pyrylium, thiopyrylium , Croconium-based, tetradehydrocholine-based, triphenylmethane-based, aminium-based and the like.

  In the present invention, it is preferable to use one or more of these dyes in combination. The near-infrared absorbing dye that can be used in combination with the specific diimmonium compound is preferably a cyanine compound. Furthermore, it is a more preferable embodiment that the anion of the cyanine compound is a metal complex.

  The cyanine compound is not limited as long as it has a near-infrared absorbing ability. For example, cyanine compounds having cations represented by the following general formulas (II) to (IV) are preferable.

In the above general formulas (II) to (IV), ring A and ring A ′ represent a benzene ring, naphthalene ring or pyridine ring, and R ¹³ and R ¹³ ′ represent a halogen atom, a nitro group, a cyano group, An aryl group having 6 to 30 carbon atoms, an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, wherein R ¹⁴ , R ¹⁵ and R ¹⁶ are a halogen atom and an aryl group having 6 to 30 carbon atoms; Represents an alkyl group having 1 to 8 carbon atoms, and C and C ′ are an oxygen atom, a sulfur atom, a selenium atom, propane-2,2-diyl, butane-2,2-diyl, and a cyclohexane having 3 to 6 carbon atoms. Represents alkane-1,1-diyl, —NH— or —NB ¹ —, B, B ′ and B ¹ represent an organic group having 1 to 30 carbon atoms, and r and r ′ represent an integer of 0 to 2. Show.

In the cyanine compounds represented by the general formulas (II) to (IV), examples of the halogen atom represented by R ¹³ and R ¹³ ′ include fluorine, chlorine, bromine and iodine. Examples of the aryl group having 6 to 30 carbon atoms include phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl, 3-isopropylphenyl, 4-isopropylphenyl, and 4-butyl. Phenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4- (2-ethylhexyl) phenyl, 4-stearylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-ditert-butylphenyl, 2,5-di Tertiary butylphenyl, 2,6-di-tert-butylphenyl, 2,4-ditertiary pentylph Alkenyl, 2,5-di-tert-amyl phenyl, 2,5-di-tert-octylphenyl, 2,4-dicumylphenyl, cyclohexylphenyl, biphenyl, 2,4,5-trimethylphenyl, and the like.

In R ¹³ and R ¹³ ′ of the general formulas (II) to (IV), examples of the alkyl group having 1 to 8 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, secondary butyl, tertiary butyl, isobutyl, Examples include amyl, isoamyl, tertiary amyl, hexyl, cyclohexyl, cyclohexylmethyl, 2-cyclohexylethyl, heptyl, isoheptyl, tertiary heptyl, n-octyl, isooctyl, tertiary octyl, and 2-ethylhexyl. Examples of the alkoxy group having 1 to 8 carbon atoms represented by R ¹³ and R ¹³ ′ include methyloxy, ethyloxy, isopropyloxy, propyloxy, butyloxy, pentyloxy, isopentyloxy, hexyloxy, heptyloxy, octyloxy , 2-ethylhexyloxy. Examples of the halogen atom represented by R ¹⁴ , R ¹⁵ and R ¹⁶ , the aryl group having 6 to 30 carbon atoms, and the alkyl group having 1 to 8 carbon atoms include those exemplified above for R ¹³ .

  Examples of C3-C6 cycloalkane-1,1-diyl in C and C ′ in the general formulas (II) to (IV) include cyclopropane-1,1-diyl, cyclobutane-1,1-diyl, Examples include 2,4-dimethylcyclobutane-1,1-diyl, 3-dimethylcyclobutane-1,1-diyl, cyclopentane-1,1-diyl, cyclohexane-1,1-diyl.

In the cations of the above general formulas (II) to (IV), the organic group having 1 to 30 carbon atoms represented by B, B ′ and B ¹ includes methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, Tributyl, isobutyl, amyl, isoamyl, tertiary amyl, hexyl, cyclohexyl, cyclohexylmethyl, 2-cyclohexylethyl, heptyl, isoheptyl, tertiary heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl, nonyl, isononyl , Decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, peptadecyl, octadecyl and other alkyl groups, vinyl, 1-methylethenyl, 2-methylethenyl, propenyl, butenyl, isobutenyl, pentenyl, hexenyl, heptenyl, octenyl, decenyl, Alkenyl groups such as ntadecenyl, 1-phenylpropen-3-yl, phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl, 3-isopropylphenyl, 4-isopropylphenyl, 4 -Butylphenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4- (2-ethylhexyl) phenyl, 4-stearylphenyl, 2,3-dimethyl Phenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-ditert-butylphenyl, cyclohexylphenyl, etc. Alkylaryl group, benzyl, phenethyl , 2-phenyl-2-yl, diphenylmethyl, triphenylmethyl, styryl, and the like arylalkyl groups cinnamyl and the like.

  These may be interrupted by an ether bond or a thioether bond. For example, 2-methoxyethyl, 3-methoxypropyl, 4-methoxybutyl, 2-butoxyethyl, methoxyethoxyethyl, methoxyethoxyethoxyethyl, 3-methoxybutyl, 2-phenoxyethyl, 3-phenoxypropyl, 2-methylthioethyl , 2-phenylthioethyl. Further, these groups may be substituted with an alkoxy group, an alkenyl group, a nitro group, a cyano group, a halogen atom or the like.

In the above general formulas (II) to (IV), it is preferable that R ¹⁴ is a halogen atom because the near-infrared absorption effect of the optical filter is excellent. Further, when C and C ′ are groups selected from propane-2,2-diyl, butane-2,2-diyl, and cycloalkane-1,1-diyl having 3 to 6 carbon atoms, the photostability is high. Therefore, it is preferable.

  Further, the counter anion of the cyanine compound has a function of de-exciting (quenching) the active molecule in the excited state. As such an anion, a metal complex is preferable. Although the structure is not limited, for example, a benzenedithiol metal complex compound is preferable. Examples of the anion of the benzenedithiol metal complex compound include anions represented by the following general formula (V).

In the anion represented by the general formula (V), M represents a nickel atom or a copper atom, R ¹⁷ and R ¹⁷ ′ represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, or 6 to 6 carbon atoms. 30 represents an aryl group, —SO ₂ —Z group, and Z represents an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 30 carbon atoms which may be substituted with a halogen atom, a dialkylamino group, or a diarylamino group. , Piperidino group and morpholino group, q and q ′ each represent an integer of 1 to 4.

In the anion represented by the general formula (V), the halogen atom represented by R ¹⁷ and R ¹⁷ ′, the alkyl group having 1 to 8 carbon atoms, and the aryl group having 6 to 30 carbon atoms may be the above general formula (II ), and in ~ (IV) those exemplified in R ^13. The same applies to an alkyl group having 1 to 8 carbon atoms represented by Z. Examples of the aryl group having 6 to 30 carbon atoms which may be substituted with the halogen atom include those exemplified as R ¹³ in the general formulas (II) to (IV), or those having 1 to 4 benzene rings. Examples thereof include those substituted with a halogen atom. Furthermore, examples of the alkyl group and aryl group contained in the dialkylamino group or diarylamino group include those exemplified for R ¹³ in the above general formulas (II) to (IV).

  The cyanine compound comprising the above cation and anion according to the present invention is a salt of the above cation and anion, and can be produced according to a conventionally known method. For example, a cation having the above structure and a halogen anion such as chlorine anion, bromine anion, iodine anion, fluorine anion; perchlorate anion, chlorate anion, thiocyanate anion, phosphorus hexafluoride anion, antimony hexafluoride anion, four Inorganic anions such as boron fluoride anion, organic sulfonate anions such as benzenesulfonate anion, toluenesulfonate anion, trifluoromethanesulfonate anion; octyl phosphate anion, dodecyl phosphate anion, octadecyl phosphate anion, phenyl phosphate anion A salt compound with an organic phosphate anion such as nonylphenyl phosphate anion, 2,2′-methylenebis (4,6-ditert-butylphenyl) phosphonate anion, and the anion and tetraethylammonium cation It can be easily obtained by salt compound salt exchange with tetraalkylammonium cations such as tetrabutylammonium cations.

It is important that the near-infrared absorbing dye is provided on the base material so as to achieve the desired near-infrared absorption and transmittance in the visible range, and preferably 0.01 g / m ² or more. A near-infrared absorbing dye is present in the near-infrared absorbing layer so as to be 1.0 g / m ² or less. When the amount of the near-infrared absorbing dye is small, the absorbing ability in the near-infrared region may be insufficient. On the other hand, if it is large, the transparency in the visible light region is insufficient and the brightness of the display tends to decrease.

  A method of laminating the near-infrared absorbing dye on the substrate film in a state of being dispersed or dissolved in the resin is recommended. The resin is not particularly limited as long as it can dissolve or disperse the near-infrared absorbing dye uniformly, but synthetic resins such as polyester, acrylic, polyamide, polyurethane, polyolefin, polycarbonate, and polystyrene compounds. Natural polymers such as gelatin and cellulose derivatives can be preferably used. Furthermore, O-PET (manufactured by Kanebo), ZEONEX (registered trademark; manufactured by Nippon Zeon), ARTON (manufactured by JSR), Optrez (manufactured by Hitachi Chemical), Byron (registered trademark; manufactured by Toyobo), etc. may be used. it can. Of these, polyester resins and acrylic resins that are excellent in flexibility and adhesion to the substrate are preferred. Particularly preferred is a polyester resin 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 equal to or lower than the device operating temperature, the deterioration of the dye and the binder resin increases due to the interaction between the dyes dispersed in the resin and the hydrolysis of the resin by absorbing moisture in the outside air. 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, but is particularly preferably 85 ° C. or higher and 160 ° C. or lower. When the glass transition temperature is less than 85 ° C., the interaction between the dye and the resin, the interaction between the dyes, and the like may occur, and the dye may be modified. If 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 substrate. Poor planarity and further deterioration of the dye are likely to occur. When dried at a low temperature, the drying time is long and the productivity is deteriorated, resulting in poor productivity. 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 it is easy to cause modification of the pigment.

  The amount of the near-infrared absorbing dye in the resin is preferably 1% by mass or more and 10% by mass or less. When the amount of near-infrared absorbing dye in the resin is small, it is necessary to increase the coating amount of the near-infrared absorbing layer in order to achieve the target near-infrared absorbing ability. On the other hand, if sufficient drying is desired, a high temperature and / or a long time are required. Therefore, the problem of deterioration of the pigment and poor flatness of the base material is likely to occur. Conversely, when the amount of 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 is likely to be denatured over time.

  In the present invention, it is a preferred embodiment that a near-infrared absorbing layer contains a surfactant having an HLB of 2 or more and 12 or less. In the present invention, the near-infrared absorbing layer expressing the 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 a substrate and laminated. In a more preferred embodiment, the coating liquid contains a surfactant having an HLB of 2 or more and 12 or less. By adding a surfactant, the dispersibility of the near-infrared absorbing dye in the binder resin is improved, and the coating appearance of the near-infrared absorbing layer, in particular, dents from adhesion of foreign matter, etc. due to minute bubbles, and drying The repellency in the process is improved and the appearance of the near-infrared absorbing layer is improved. Furthermore, when the surface active agent bleeds on the surface of the coating film when the coating liquid is applied and dried, the slipping property is imparted, and the handling property can be achieved without forming surface irregularities on the near-infrared absorbing layer or / and the opposite surface. It becomes good and it becomes easy to wind up in roll shape.

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

  Silicone surfactants include dimethyl silicone, amino silane, acrylic silane, vinyl benzyl silane, vinyl benzyl amino silane, glycid silane, mercapto silane, dimethyl silane, polydimethyl siloxane, polyalkoxy siloxane, hydrodiene modified siloxane, vinyl modified siloxane, hydroxy Examples include 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, and alkylene oxide-modified siloxane.

  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 surfactant is preferably contained in the near-infrared absorbing layer in an amount of 0.01% by mass to 2.00% by mass. 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. HLB is a characteristic value indexed by the balance between the hydrophilic group and the lipophilic group contained in the surfactant molecule. The smaller the value, the higher the lipophilicity, and vice versa. Means.

  In the present invention, the near-infrared absorbing layer is laminated by applying and drying a coating liquid on the base film, and the coating liquid is an organic solvent in consideration of coating properties. It is important to dilute with 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. , Polyethylene glycol, propylene glycol, dipropylene glycol, glycerin and other glycols, 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, Examples thereof include ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, isophorone and diacetone alcohol, and these can be used alone or in combination 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 methods such as stirring, dispersion and pulverization under heating. By heating, the solubility of the pigment and the resin can be improved, and a defect in the coating appearance due to undissolved substances is prevented. Further, if the resin and the pigment are dispersed and pulverized and dispersed in the coating liquid in a fine particle state of 0.3 μm or less, a layer having excellent transparency can be formed. As the disperser and 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 application becomes poor. Therefore, it is important to remove it with a filter or the like before application. Various known filters can be suitably used as the filter, but it is preferable to use a filter capable of removing 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, drying after coating takes time and productivity is inferior, and the amount of 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 amount of solvent and the like so as to be in this range.

  In the present invention, the method for applying the near infrared absorbing layer on the substrate film includes gravure coating method, kiss coating method, dip method, spray coating method, curtain coating method, air knife coating method, blade coating method, reverse roll. Conventionally used methods such as a 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 undulation lines are generated in the flow direction.

Although the adhesion amount of the near-infrared absorbing layer after drying is not particularly limited, the preferable lower limit is 1 g / m ² , and particularly preferably 3 g / m ² . On the other hand, a preferable upper limit is 50 g / m ² , particularly preferably 30 g / m ² or less. When the amount of adhesion after drying is small, there is a problem that the absorption capacity of near infrared rays is insufficient, and even if the absorption capacity of near infrared rays is increased to a desired level by increasing the amount of 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. On the contrary, when the amount of adhesion 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. Optical properties can be adjusted by reducing the amount of near-infrared absorbing pigment present in the resin, but drying tends to be inadequate, and residual solvent in the coating results in poor stability over time, resulting in sufficient drying. In such a case, the flatness of the substrate becomes poor.

  Examples of the method for applying the coating liquid on the substrate film and drying the substrate include known hot air drying and infrared heaters. 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. If the initial drying is carried out too strongly (hot air temperature is high, hot air volume is large), minute defects of the coating such as fine coat removal, fine repellency and cracks are likely to occur. Conversely, if the initial drying is too weak (the hot air temperature is low, the hot air volume is small), the appearance will be good, but it will take time to dry and there will be a problem in terms of cost.

  In the reduction drying process, it is important to set 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. In particular, when the hot air temperature is lower than the glass transition temperature of the resin, it is difficult for the solvent to decrease in the coating film. On the other hand, when the temperature is high, not only does the flatness of the base material become poor due to heat wrinkles, but there is a problem that the near-infrared dye is deteriorated by heat. The passing time is preferably 5 seconds or more and 180 seconds or less. If the time is short, the amount of solvent remaining in the coating film increases and the aging stability becomes poor. Conversely, if the time is long, not only the productivity becomes poor, but heat wrinkles occur on the substrate. As a result, 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.

  It is preferable that the near-infrared absorbing layer does not change the near-infrared transmittance and the visible-light transmittance even when left at high temperature 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. The near-infrared absorbing layer of the present invention has improved stability over time as compared with a conventionally known method. Since it is also influenced by the amount of residual solvent in the infrared absorption layer and the adjustment state of the content of the pigment in the resin, it is also a preferred embodiment to consider these points. 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 it becomes 3 mass% or less, there will be 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, adverse effects such as poor flatness of the film occur.

  As the coating appearance of the above-mentioned near infrared absorbing layer, it is desirable not to have a defect of a diameter of 300 μm or more, more preferably 100 μm. The defect of 300 μm or more becomes 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 the present invention, it is a preferred embodiment to perform color tone correction by containing one kind of dye having absorption in the visible light region. For example, since a plasma display emits so-called neon orange light centered around 600 nm, there is a disadvantage that orange is mixed with red and a vivid red cannot be obtained. The said subject can be solved by mix | blending the color correction pigment | dye which has maximum absorption in the wavelength range of 550-620 nm with said near-infrared absorption layer and / or a base film. This color correction dye preferably has a sharp absorption at 550 to 620 nm, more preferably 570 to 600 nm. The transmittance at the maximum absorption wavelength at a wavelength of 550 to 620 nm is preferably 50% or less, particularly preferably 30% or less. When the transmittance at the maximum absorption wavelength at a wavelength of 550 to 620 nm exceeds 50%, the neon light emitted from the plasma display is not sufficiently absorbed, and the color purity tends to be lowered. In addition, when the absorption in this region is wide, the balance of R, G, and B light is lost, and the contrast tends to decrease.

  Examples of the color correction dye having a maximum absorption at a wavelength of 550 to 620 nm include cyanine-based, squalium-based, azomethine-based, xanthene-based, oxonol-based, azo-based, phthalocyanine-based, quinone-based, azulenium-based, pyrylium-based, and croconium-based. And dyes such as dithiol metal complex, pyromethene, and tetraazaporphyrin compounds. Of these, squarylium compounds are preferred because they have sharp absorption in neon light. Although the layer which mix | blends a color correction pigment | dye is not limited, It is a preferable embodiment to mix | blend with a near-infrared absorption layer with the said near-infrared absorption pigment | dye.

  As the color tone of the near-infrared absorbing film, 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.

  In the near-infrared absorbing film of the present invention, various stabilizers can be used for the purpose of stabilizing against light or heat. Examples of the stabilizer include hydroquinone derivatives, hydroquinone diether derivatives, phenol derivatives, Examples include derivatives of spiroindane or methylenedioxybenzene, derivatives of chromane, spirochroman or coumaran, derivatives of hydroquinone monoether or paraaminophenol, bisphenol derivatives, nitroso compounds), diimmonium compounds, antioxidants, hindered amine light stabilizers, and the like.

  In this invention, it is a preferable embodiment to mix | blend a ultraviolet absorber with a base film. By this embodiment, the weather resistance with respect to the external light of a near-infrared absorption layer is improved. This ultraviolet absorber is not limited as long as it is a compound having ultraviolet absorbing ability and can withstand heat in the production process of the base 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, benzotriazoles, benzophenones, cyclic imino esters, 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.

  As the benzotriazole ultraviolet absorber, 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-benzotriazo 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'-(methacryloyl) Oxyethyl) phenyl] -5-tert-butyl-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-nitro-2H-benzotriazole, and the like.

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

  Examples of the cyclic imino ester ultraviolet absorber include 2,2 ′-(1,4-phenylene) bis (4H-3,1-benzoxazin-4-one), 2-methyl-3,1-benzoxazine-4. -One, 2-butyl-3,1-benzoxazin-4-one, 2-phenyl-3,1-benzoxazin-4-one, 2- (1- or 2-naphthyl) -3,1-benzoxazine -4-one, 2- (4-biphenyl) -3,1-benzoxazin-4-one, 2-p-nitrophenyl-3,1-benzoxazin-4-one, 2-m-nitrophenyl-3 , 1-benzoxazin-4-one, 2-p-benzoylphenyl-3,1-benzoxazin-4-one, 2-p-methoxyphenyl-3,1-benzoxazin-4-one, 2-o- Methoxyphenyl 3,1-benzoxazin-4-one, 2-cyclohexyl-3,1-benzoxazin-4-one, 2-p- (or m-) phthalimidophenyl-3,1-benzoxazin-4-one, 2 , 2 '-(1,4-phenylene) bis (4H-3,1-benzoxazinon-4-one) 2,2'-bis (3,1-benzoxazin-4-one), 2,2' -Ethylenebis (3,1-benzoxazin-4-one), 2,2'-tetramethylenebis (3,1-benzoxazin-4-one), 2,2'-decamethylenebis (3,1- Benzoxazin-4-one), 2,2′-p-phenylenebis (3,1-benzoxazin-4-one), 2,2′-m-phenylenebis (3,1-benzoxazin-4-one) ), 2,2 '-(4,4'-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-benzoxazin-4-one) ), 2,2 '-(2-chloro-p-phenylene) bis (3,1-benzoxazin-4-one), 2,2'-(1,4-cyclohexylene) bis (3,1-benzo Oxazin-4-one), 1,3,5-tri (3,1-benzoxazin-4-one-2-yl) benzene, 1,3,5-tri (3,1-benzoxazin-4-one) -2-yl) naphthalene and 2,4,6-tri (3,1-benzoxazine-4 -On-2-yl) naphthalene, 2,8-dimethyl-4H, 6H-benzo (1,2-d; 5,4-d ') bis- (1,3) -oxazine-4,6-dione, 2,7-dimethyl-4H, 9H-benzo (1,2-d; 5,4-d ′) bis- (1,3) -oxazine-4,9-dione, 2,8-diphenyl-4H, 8H -Benzo (1,2-d; 5,4-d ') bis- (1,3) -oxazine-4,6-dione, 2,7-diphenyl-4H, 9H-benzo (1,2-d; 5,4-d ') bis- (1,3) -oxazine-4,6-dione, 6,6'-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 6, 6'-bis (2-ethyl-4H, 3,1-benzoxazin-4-one), 6,6'-bis (2-phenyl-4H, 3,1-benzoo Sadin-4-one), 6,6′-methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-methylenebis (2-phenyl-4H, 3,1-benzo) Oxazin-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 (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-sulfonylbis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6, 6'-carbonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-carbonylbis (2-phenyl-4H, 3,1-benzoxazin-4-one), 7,7'-methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7'-methylenebis (2-phenyl-4H, 3,1-benzoxazin-4-one), 7,7'-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7'-ethylenebis (2-methyl-4H, 3,1-benzoxazin-4-one) 7,7'-oxybis (2-methyl- 4H, 3,1-benzoxazin-4-one), 7,7′-sulfonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7′-carbonylbis (2- Methyl-4H, 3,1-benzoxazin-4-one), 6,7'-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,7'-bis (2- Phenyl-4H, 3,1-benzoxazin-4-one), 6,7'-methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,7'-methylenebis (2- Phenyl-4H, 3,1-benzoxazin-4-one) 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 above-mentioned ultraviolet absorber is a near-infrared absorbing dye for expressing the near-infrared absorbing ability, which is the main function of the near-infrared absorbing film of the present invention described later, is inferior in weather resistance and is included in external light It is to suppress the phenomenon that the performance of the near-infrared absorbing dye is deteriorated due to ultraviolet rays. 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 above characteristics is preferably from 0.1 to 4% by mass, more preferably from 0.3 to 2% by mass, based on the resin such as 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.

  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 (VI) as a copolymerization component Ultraviolet absorbing compound containing tetracarboxylic acid diimide and naphthalenedicarboxylic acid represented by general formula (VII) (Mitsubishi Chemical, Novapex U-110), acrylic having 2- (2-hydroxylphenyl) benzotriazole skeleton in the side chain The properties such as the UV-cut performance and transparency of the target polymer (made by BASF, UVA-1635) are preferable.

（上記一般式（VI）において、Ｒ¹⁸、Ｒ¹⁹はアルキレン基等、Ｄはヒドロキシ基等を示す。）

(In the general formula (VI), R ¹⁸ and R ¹⁹ are alkylene groups, etc., and D is 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 tends to be lowered.

  The method for blending the ultraviolet absorber is not limited. For example, in the case of a polyester resin, polymerization or melt extrusion is preferred. 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 preferable blending method.

  The case where a base film is a polyester film is demonstrated. First, a polyester resin and an ultraviolet absorber are blended to prepare a master pellet. The said master pellet is a pellet which does not contain the particle | grains aiming at slipperiness | lubricity provision substantially. The raw material pellets obtained by mixing the master pellets and the polyester resin are sufficiently vacuum-dried, then supplied to an extruder, melt-extruded into a sheet, and cooled and solidified on a casting roll to form an unstretched polyester sheet. At this time, the resin temperature up to the melting part, kneading part, melt line, gear pump, and filter of the extruder is 280 to 290 ° C., and the resin temperature up to the subsequent melt line and flat die is 270 to 280 ° C. It is preferable in order to prevent sublimation at the die outlet of the absorbent and contamination of 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 It is 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. By performing high-precision filtration of the molten resin using a filter medium having a filter particle size (initial filtration efficiency of 95%) of 20 μm or less, productivity may be reduced, but a film with few protrusions due to coarse particles is obtained. This is an important process.

  Foreign matter existing in the raw material polymer and UV absorber sublimate and contaminate the roll, and if they are attached to the film, the orientation of the polyester molecules is disturbed around this foreign matter 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 include particles for imparting slipperiness in the base film, or to include only a small amount so as not to impair the transparency, but the particle content is small. 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 was gripped with a clip, led 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.

  In the present invention, as described in claim 5, the base film has a laminated structure of at least three layers, and the ultraviolet absorber is contained in an intermediate layer (a layer other than the surface layer) of the laminated structure of the base film. It is a more preferable embodiment. In other words, both surface layers do not contain an ultraviolet absorber. According to this embodiment, sublimation of the UV absorber in the extrusion process at the time of film formation is suppressed, and this is caused by the contamination of the discharge outlet of the die and the cooling roll that cools the extrusion raw material due to the sublimated product, or the contamination. Generation of defects in the film is suppressed. Moreover, since the bleeding of the ultraviolet absorber from the inside of the film is suppressed, the contamination of the roll and the tenter in the film forming process by the ultraviolet absorber that has been bleed out is reduced, and the occurrence of a film defect due to the contamination is generated. It is suppressed. In addition, occurrence of adhesion inhibition caused by bleeding out of the ultraviolet absorber is suppressed.

  The layer thickness ratio in the case of carrying out by the above method is not limited and is arbitrary, but it is preferable that the thicknesses of both surface layers are 3 to 15% of the total thickness, respectively. 5 to 10% is more preferable. When the ratio of the outermost layer (one side) is lower than 3%, sublimation and bleeding out of the organic ultraviolet absorber contained in the near infrared absorption layer cannot be sufficiently prevented. Moreover, when higher than 15%, the said prevention effect is saturated and the ultraviolet-ray absorption effect of a near-infrared absorption layer may be insufficient, and it is not preferable.

  The polyester resin constituting each layer of the base film (biaxially oriented laminated polyester film) in the present invention may be the same type or different types, but from the viewpoint of ease of production management and recovery of waste resin, etc., the same type, A preferred embodiment is to use polyethylene terephthalate resin for all layers.

  The present inventors have established a method for evaluating the degree of uneven distribution in the thickness direction of the ultraviolet absorbent film expressed as an effect of multilayering of the base film using surface IR analysis. Details of the evaluation method will be described in the evaluation method of the embodiment, but it is preferable to manage the effect of multilayering by the numerical value obtained by this evaluation method. The degree of uneven distribution of the ultraviolet absorber in the thickness direction is greatly affected by the thickness ratio of the surface layer and the intermediate layer of the base film, but even with the same thickness component ratio, for example, the molten resin transfer tube after the film-forming filter or It also changes depending on the resin temperature of the flat die. The degree of uneven distribution of the ultraviolet absorber represented by the above numerical values is preferably 0.20 or less. 0.10 or less is more preferable, and 0.05 or less is particularly preferable.

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 further 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 film from being scratched, (a) the film surface itself or the roll surface, in particular, the roll surface in contact with the film should not cause “defects” that cause scratches, and (b) the contact. It is important that the film does not shift in the machine and transverse directions on the surface of the roll. 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 blower 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.

  Furthermore, in the winding step after stretching, the surface on the end side in the width direction of the film is pressed with a roller with a protrusion to form an uneven portion on the portion, and the film on which the uneven portion is formed The roll is wound by a winding mechanism, and the protrusions on the roller with the protrusions are tapered so that the top of the protrusions are rounded, and the radius of curvature of the top surface is 0. By setting it to 4 mm or less, it is possible to prevent the film and the defect from coming into contact with each other in the film winding apparatus.

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

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

  Further, by setting the relationship between the relative speeds of the plurality of rolls to a speed profile that is closest to the amount of deformation due to the temperature and tension of the film, it is possible to reduce the vertical shift of the film. Furthermore, in the coating step of the coating 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 driving roll, it is preferable to control the rotation spots to 0.01% or less.

  Although the thickness of said base film can be arbitrarily set without limitation, 0.038 to 0.188 mm is a preferable range. If it is less than 0.038 mm, the handleability of the near-infrared absorbing film is deteriorated, which is not preferable. Conversely, if it exceeds 0.188 mm, the handling property of the near-infrared absorbing film and the workability when sticking to an adherend such as a plasma display deteriorate, which is not preferable. In addition, it cannot respond to market demands for thin films.

  In this invention, it is a preferable embodiment to laminate | stack the surface layer which has an antireflection function on the opposite surface of the near-infrared absorption layer of the said base film. The antireflection function refers to a function of preventing surface reflection, increasing light transmittance, and simultaneously preventing “glare”. The method for providing the antireflection function can be arbitrarily selected without limitation. For example, a layer having a different refractive index is laminated on the surface of the base material, and the interference is reduced by using interference of reflected light at the interface of the layer. Is preferred.

  As the method for forming the antireflection film of the above method, there are mainly the following two methods. 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 or inorganic / organic hybrid.

  In the present invention, when forming the above-described antireflection film, hard processing that imparts scratch resistance, antistatic processing that imparts antistatic properties, and adhesion of dirt such as fingerprints, sebum, sweat, and cosmetics are prevented. In addition, it is a preferred embodiment to combine a functional layer that imparts a function suitable as a near-infrared absorbing filter, such as an antifouling process that imparts a function that can be easily wiped off even if attached. In particular, hard processing has a strong market demand, and the pencil hardness of the surface having an antireflection function is preferably 1H or more. Although the method of the hard processing is not limited and is arbitrary, a preferred embodiment is made of a polymer mainly composed of a polyfunctional monomer.

  By forming the surface layer having the above-described antireflection function, reflection of external light is suppressed when the near-infrared absorbing film of the present invention is actually used, and it is used as an optical filter of a display device such as a plasma display panel. If it is, a function of improving the visibility of the surface of the image is given. On the other hand, when the antireflection function is added, the influence of iris-like colors (interference fringes) that are manifested by the interference of light at the interface with the functional layer becomes more prominent, and countermeasures are required. As a method for suppressing the iris-like color, it is known that a method of providing an intermediate layer having an intermediate refractive index between both interfaces is effective in order to reduce the difference in refractive index between the interfaces. In the present invention, as the intermediate layer, at least one of an aqueous polyester resin and a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, or a water-soluble zirconium acylate compound is used. And the main component of the adhesive layer (hereinafter referred to as interference fringe suppressing easy adhesive layer) is laminated to suppress the occurrence of the iris-like color and the adhesion between the antireflection layer and the base film. Is recommended as a preferred embodiment.

  The water-based polyester resin constituting the interference fringe-suppressing easy-adhesion layer is dissolved in water or a water-soluble organic solvent such as an aqueous solution containing less than 50% by mass of an alcohol, alkyl cellosolve, ketone solvent, or ether solvent The polyester resin which shows property or dispersibility is shown. In order to impart water to the polyester resin, it is important to introduce a hydrophilic group such as a hydroxyl group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, and an ether group, but from the viewpoint of coating film properties and adhesion. Introduction of sulfonic acid groups is preferred. In particular, the amount of the sulfonic acid group to be introduced (for example, using a sulfonic acid group-containing polyvalent carboxylic acid such as 5-sulfoisophthalic acid) is 1 to 10 mol% out of 100 mol% of the total acid component of the polyester. Is more preferable. If the amount of sulfonic acid groups is less than 1 mol%, the polyester itself is poor in aqueous expression and the compatibility with water-soluble titanium or zirconium chelate compounds or acylate compounds is also reduced, so that a uniform and transparent coating film can be obtained. It becomes difficult. Moreover, when there are more sulfonic acid groups than 10 mol%, the moisture resistance at the time of adhesion | attachment will fall easily. Furthermore, the glass transition temperature of the aqueous polyester is preferably 40 ° C. or higher.

  For this reason, the dicarboxylic acid component of the aqueous polyester preferably contains an aromatic group such as terephthalic acid, isophthalic acid, or naphthalenedicarboxylic acid as a main component. Moreover, as a glycol component, aromatics, such as glycol with comparatively few carbon numbers, such as ethylene glycol, propane glycol, 1, 4- butanediol, neopentyl glycol, or the ethylene oxide adduct of bisphenol A, are preferable. Further, there is no particular problem even if a rigid component such as biphenyl or a dicarboxylic acid component or diol component having a high refractive index atom such as bromine or sulfur is used as a polyester raw material within a range where the physical properties of the film do not deteriorate. If the glass transition temperature of the polyester is less than 40 ° C., the moisture resistance at the time of adhesion tends to decrease, and the refractive index of the polyester also decreases, so that the refractive index of the coating film also decreases. The suppression of the iris-like color at is likely to decrease.

  The other main component constituting the interference fringe-suppressing adhesive layer is a water-soluble titanium or zirconium chelate compound or acylate compound. The water-soluble in the present invention means solubility in an aqueous solution containing less than 50% by mass of water or a water-soluble organic solvent. Examples of water-soluble titanium chelate compounds include diisopropoxybis (acetylacetonato) titanium, isopropoxy (2-ethyl-1,3-hexanediolato) titanium, diisopropoxybis (triethanolaminato) titanium, di -N-butoxybis (triethanolaminato) titanium, hydroxybis (lactato) titanium, ammonium salt of hydroxybis (lactato) titanium, ammonium beloxocitrate ammonium salt and the like. Examples of the water-soluble titanium acylate compound include oxotitanium bis (monoammonium oxalate), and examples of the water-soluble zirconium compound include zirconium tetraacetylacetonate and zirconium acetate.

  In the present invention, the blending ratio of the two components constituting the interference fringe suppression easy-adhesion layer is such that a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, Alternatively, the mixing ratio (mass ratio) of at least one water-soluble zirconium acylate compound is preferably 90/10 to 5/95. 85/15 to 10/90 is more preferable, and 80/20 to 15/85 is particularly preferable. When the water-based polyester resin is less than 10, the adhesion with the base film is lowered, and the adhesive layer is formed by the so-called in-line coating method, which is performed before stretching or after uniaxial stretching in the film forming process of the base film. In this case, the stretchability as a coating film is lowered, and a uniform film is not formed at the time of stretching, so that the transparency which is important for optical use is lowered. In addition, adhesion with the functional layer is also a problem. On the other hand, when the amount of the water-based polyester resin is more than 95, crosslinking with a water-soluble titanium or zirconium chelate compound or acylate compound becomes poor and the refractive index is lowered. As a result, the moisture resistance of the easy-adhesion layer is lowered, and the effect of suppressing iris colors is likely to be lowered.

  The interference fringe-suppressing adhesive layer of the present invention may be used in combination with vinyl resin such as alkyd resin, polyurethane resin, acrylic resin and polyvinyl alcohol as long as the effect of the aqueous polyester resin is not affected. . Further, the combined use of the crosslinking agent is not particularly limited as long as the above effect is not adversely affected. Examples of crosslinking agents that can be used include adducts of urea, melamine, benzoguanamine, and the like with formaldehyde, amino resins such as alkyl ether compounds composed of these adducts and alcohols having 1 to 6 carbon atoms, polyfunctional epoxy compounds, A polyfunctional isocyanate compound, a block isocyanate compound, a polyfunctional aziridine compound, an oxazoline compound, etc. are mentioned.

  In the present invention, functional layers are laminated on both sides of the base film as described above. Therefore, it is a preferred embodiment that both surfaces of the base film are provided with an easy-adhesion layer (referred to as a general-purpose easy-adhesion layer for distinction from the interference fringe suppressing different adhesive layer). The formation of the interference fringe suppressing easy adhesive layer is one method, but is not limited. Examples of the resin constituting the general-purpose easy-adhesion layer include copolymer polyester resins, polyurethane resins, acrylic resins, styrene-maleic acid graft polyester resins, acrylic graft polyester resins, and the like. It is preferable to do. 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 they have excellent adhesiveness.

  Regarding the adjustment of the coating solution used for forming the general-purpose 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 for the general-purpose easy-adhesion layer of the present invention preferably contains a branched glycol component as a constituent component. Examples of the branched glycol component include 2,2-dimethyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, and 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, Such as 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, which is a constituent component of the copolymerized polyester resin, terephthalic acid and isophthalic acid are most preferable. If the amount is small, other dicarboxylic acid, for example, aromatic dicarboxylic acid such as diphenylcarboxylic acid or 2,6-naltalenedicarboxylic 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-sodium sulfoisophthalic acid, 4- Examples thereof include sulfonaphthalene isophthalic acid-2,7-dicarboxylic acid and 5- (4-sulfophenoxy) isophthalic acid and salts thereof.

  The polyurethane resin used for the general-purpose 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. 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. Since the resin during the preparation of the coating solution is hydrophilic, the water resistance is poor, 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 above carboxylic acid anhydrides, ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 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 important 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. The above composition is prepared to have an appropriate concentration and viscosity when used. Usually, when heated to about 80 to 200 ° C., the bisulfite of the blocking agent is dissociated and the active isocyanate group is regenerated. A polyurethane polymer is produced by a polyaddition reaction that occurs 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 mass%, the applicability | paintability to a base film is unsuitable, and the adhesiveness between a surface layer and the said film will become inadequate. When the content is less than 10% by mass, 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 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 the aqueous coating solution is applied to the surface of the base film, a known anionic surfactant and a nonionic surfactant are added to increase the wettability to the film and to apply the coating solution uniformly. A necessary 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 proportion 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 this invention, it is preferable to set it as the structure made to contain in the general purpose easy-adhesion layer from the transparency point, without making the particle | grains aiming at slipperiness imparting in a base film. 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 preferable 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. In addition, 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 important to dispose the filter medium so that the coating solution is precisely filtered immediately before coating in order to remove coarse aggregates of particles in the coating solution. The filter medium for microfiltration of the coating liquid used in the present invention is preferably a filter medium having a filter particle size of 25 μm or less (initial filtration efficiency 95%). When the particle size is 25 μm or more, it is difficult to sufficiently remove coarse agglomerates. Many coarse agglomerates that could not be removed are coarsely agglomerated particles on the easy-adhesion layer when applied, dried, uniaxially or biaxially stretched. May spread and be recognized as an aggregate of 100 μm or more. Such aggregates in the coating layer cause optical defects. 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 general-purpose easy-adhesion layer can be applied by any known method. For example, 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.

Although the process of apply | coating the said coating liquid may be a normal application process, ie, the process of apply | coating to the base film which carried out biaxial stretching and heat setting, it is preferable to apply during the manufacturing process of the said 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 applied 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 is heated there to form a laminated polyester film in which a stable film is formed by a thermal crosslinking reaction. In order to obtain sufficient adhesion with the near-infrared absorbing layer and the hard coat layer, the final coating amount is 0.01 g / m ² or more per 1 m ^{2 of} film, and heat treatment is performed at 100 ° C. for 1 minute or more. is important. 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, a near-infrared absorption filter is formed by laminating | stacking the adhesion layer which consists of a transparent adhesive on the surface of the near-infrared absorption layer of the said near-infrared absorption film as described in Claim 9. By laminating the pressure-sensitive adhesive layer, the near-infrared absorbing film of the present invention can be fixed to various devices and members, or combined with a functional sheet. For example, the laminate having the above optical characteristics as a near-infrared absorbing filter is fixed by directly attaching it to the surface of the plasma display panel or by attaching it to a translucent sheet having an electromagnetic wave absorbing function. be able to. The transparent adhesive is known without limitation, and examples thereof include acrylic adhesives such as butyl acrylate, rubber adhesives, and TPE adhesives based on thermoplastic elastomer resins such as SEBS and SBS. It is done.

  In the present invention, as described above, it is important to form the adhesive layer on the surface of the near-infrared absorbing layer. Since the ultraviolet absorbing layer can be set on the outside light side with respect to the near infrared absorbing layer when it is attached to, for example, a plasma display or the like through the adhesive layer with the above configuration, the ultraviolet absorbing function disclosed in Patent Document 12 The layer having a near infrared absorption function is located on the side opposite to the outside light side of the layer having a near infrared absorption function, and the problem that the effect of suppressing the deterioration of the near infrared absorption dye due to ultraviolet rays in the outside light, which is a problem during actual use, is not expressed. Satisfying the market demand for improving the weather resistance of near-infrared absorbing dyes by external light.

  In the near-infrared absorption filter of the present invention, the total thickness of the laminate including the adhesive layer is not limited and can be arbitrarily set according to market requirements, 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 other hand, when the thickness exceeds 0.2 mm, the handling property of the laminate and the workability when adhering to a plasma display or the like deteriorate, which is not preferable. In addition, it cannot respond to market demands for thin films. In other words, the near-infrared absorption filter has been requested by the market from the viewpoint of the handleability of the near-infrared absorption filter and the workability when sticking to a plasma display or the like. Since it was manufactured by bonding functional films and sheets, most of the total thickness exceeded 0.2 mm. In the present invention, by adopting the above-described configuration, it is possible to meet the market demand for thinning of the near-infrared absorption filter while maintaining high functionality. Moreover, since the bonding process required in the prior art can be omitted, it is economically advantageous.

  The layering of the layers having each function on the base film in the present invention can be applied in any order except that the adhesion layer is finally laminated. The coating may be performed sequentially for each functional layer or simultaneously using a multilayer coater.

  In the present invention, for example, it is a preferred embodiment that the near-infrared absorption filter having the above-described configuration is directly attached to the plasma display via an adhesive layer. The near-infrared absorption filter thinned with high function by the above method can be attached to the plasma display to exhibit its function.

Moreover, in this invention, it is another 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. According to the above embodiment, the near-infrared absorbing film can be provided with an electromagnetic wave absorbing 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) Conductive mesh made of metal fibers or metal-coated organic fibers (2) Edging processed by edging into a lattice shape or punching metal shape using a technique such as photolithography after laminating a metal film on a transparent film or sheet Conductive mesh composite sheet (3) Conductive printed mesh composite sheet obtained by pattern-printing conductive paint on transparent film or sheet (4) Transparent conductor in which transparent conductive layer such as silver thin film or ITO thin film is laminated on transparent film or sheet

  In this invention, it is also possible to use as a near-infrared absorption film as a structure which laminated | stacked the antireflection layer and the near-infrared absorption layer on each single side | surface, without forming the said adhesion layer. Although there is no limitation in the fixing method of the near-infrared absorption film to to-be-adhered bodies, such as a plasma display panel, when using it by the said method, It is a preferable embodiment to carry out using an adhesive agent or an adhesive. In this case, it is important to fix and use the near infrared absorption layer 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 (manufactured by Hitachi, U-3500 type), the transmittance at a wavelength of 200 to 1100 nm is continuously measured so that light is transmitted from the near infrared absorption layer side. Data was taken every 10 nm. In the measurement of transmittance, the air layer was measured as a standard. The ultraviolet transmittance is the transmittance at 380 nm, the transmittance in the visible light region is the average value of the transmittance at 450 to 700 nm, the transmittance in the neon light region is the average value of the transmittance at 570 to 600 nm, and the near infrared ray As the transmittance of the region, an average value of transmittances of 900 to 1100 nm was obtained.

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

3. Stability over time The film was allowed to stand for 500 hours in an atmosphere of temperature 60 ° C. and humidity 95% RH, and then the spectral characteristics and color tone described above were measured. The amount of change before and after the aging treatment of the transmittance in the near infrared region at wavelengths of 800 to 1100 nm was obtained from the following formula (1) and ranked according to the following criteria.
◎: Change in transmittance is less than 5% ○: Change in transmittance is from 5% to less than 10% △: Change in transmittance is from 10% to less than 20% ×: Change in transmittance is 20% or more Change (% ) = (| Transmittance before processing−transmittance after processing | / transmittance before processing) × 100
... (1)

Moreover, it calculated | required from the variation | change_quantity of following formula (2) before and behind color-tone processing, and performed ranking according to the following judgment criteria.
A: 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 ) ^1/2
... (2)

4). Weather resistance Test samples were evaluated under the following conditions by an accelerated weather resistance test. An irradiation test using a UV auto fade meter (manufactured by Suga Test Instruments Co., Ltd., FAL-AU-H-BR) is conducted at a black panel temperature of 63 ° C. for 192 hours, and the test sample before and after the test is transmitted at the maximum absorption wavelength in the near infrared region. The rate 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). Said evaluation was performed by sticking a sample to a 2 mm-thick SUS plate through an adhesive layer and irradiating ultraviolet rays from the surface layer side.
R (%) = (T / T ₁ ) × 100 (3)

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

6). Surface hardness of antireflection layer The surface of the surface layer having an antireflection function was evaluated by pencil scratch hardness. The samples were evaluated after conditioning for 2 hours under conditions of a temperature of 25 ° C. and a relative humidity of 60% RH. 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, the surface of the base film was measured.

7). Appearance of coating film of near-infrared absorbing layer containing near-infrared absorbing pigment A laminated film on which a near-infrared absorbing layer was laminated was placed on a white film and evaluated by observing it under a three-wavelength fluorescent lamp.

(7-1) 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

(7-2) Coating failure Coating failures such as coating unevenness and streaks were ranked according to the following criteria.
◎: Some appearance defects are not observed when observed while moving near-infrared absorbing film. ○: Some appearance defects are observed when observed while moving near-infrared absorbing film. △: Appearance defects are found when observed while moving near-infrared absorbing film. : Appearance defects can be seen even when stationary

8). Adhesiveness of antireflection layer and near-infrared absorbing layer to substrate film Adhesiveness was determined by a test method according to 8.5.1 of JIS-K5400. That is, 100 grid-like cuts that reach the base film from both surfaces are attached using a cutter guide with a gap interval of 2 mm, and cellophane adhesive tape (Nichiban, No. 405; 24 mm width) is applied to the grid-like cut surface. The film was rubbed with a plastic piece so as not to leave bubbles or poorly adhered parts, and then completely adhered, and then peeled off vertically to determine the adhesiveness from the following formula (4). 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)

9. Interference fringes A near-infrared absorption filter was cut to a size of 10 × 15 cm to obtain a measurement sample. The measurement sample was attached to black glossy paper through an adhesive layer. With the hard near infrared absorption filter surface of this sticking body as the upper surface, the reflected light was visually observed from obliquely above using National Parook Three-Wave Daylight White (FL 15EX-N 15W) as a light source. The results of visual observation are ranked according to the following criteria. In addition, observation is performed by five persons familiar with the above evaluation, and the highest rank is set as the evaluation rank. If two ranks have the same number, the center of the rank divided into three is adopted. For example, ◎ and ○ are 2 people each and △ is 1 person, ○ is ◎, ◎ is 1 person and ○ and △ are 2 people each, ○, ◎ and △ are 2 people each and ○ is 1 In the case of names, ○ is adopted.
◎: Iridescent colors are not observed even when observed from all angles. ○: Some iris colors are observed depending on the angle. △: Slightly iris colors are observed. X: Clear iris colors are observed. Be done

10. Evaluation of surface scratches on substrate film 16 film pieces of 250 mm × 250 mm were evaluated. This evaluation was performed 24 hours after the start of film formation. A fluorescent lamp of 20 W × 2 lamps is arranged as a projector at 400 mm below the XY table, and a test piece to be measured is placed on a mask having a slit width of 10 mm provided on the XY table. When light is incident so that the angle formed between the line connecting the projector and the light receiver and the vertical direction of the surface of the test piece is 12 °, if there is a scratch on the test piece at the incident position, that part shines. The amount of light in that portion is converted into an electrical signal by a CCD image sensor camera placed 500 mm above the XY table, the electrical signal is amplified, differentiated, and compared with a threshold (threshold) level and a comparator, resulting in an optical defect. The detection signal is output.

  In addition, a CCD image sensor camera is used to input an image of a flaw, the video signal of the input image is analyzed according to a predetermined procedure, the size of the optical defect is measured, and the position of the defect of 50 μm or more is displayed. To do. Detection of optical defects by the above method is performed on both sides of the test piece. Defects due to scratches are selected from the optical defect portions detected in the above method. The sample was cut into an appropriate size so that the portion determined to be a scratch by the above method was near the center, and a shape observation test piece was collected. About the said test piece, it observes from the orthogonal | vertical direction with respect to the surface which detected the fault of the test piece using the three-dimensional shape measuring apparatus (the product made from Micromap, TYPE550), and measures the magnitude | size of a damage | wound.

In addition, when observed from the direction perpendicular to the surface of the test piece, that is, the film surface, the concavity and convexity of the flaws close to each other within 50 μm were the same flaws. The length and width of the rectangle having the smallest area covering the outermost part of these scratches is defined as the length and width of the scratch. The depth (length difference between the highest and lowest scratches) and length of these scratches are measured. From this result, the number of scratches (pieces / m ² ) having a depth of 1 μm or more and a length of 3 mm or more was determined and judged according to the following criteria.
◎: 30 pieces / m ² or less ○: 31-50 pieces / m ²
Δ: 51 to 100 / m ²
×: 101 pieces / m ² or more

11. Evaluation of foreign matter on the surface of the base film From the optical defects detected by the method described in the above-mentioned scratch evaluation, defects caused by foreign matters were selected, and the test pieces of the above-mentioned portions were sampled. Al vapor deposition was performed on the surface where the defect of the test piece was detected, and the film was observed from a direction perpendicular to the film surface with a non-contact type three-dimensional roughness meter (manufactured by Micromap, TYPE 550). The number of foreign matters having a maximum diameter of 20 μm or more (pieces / m ² ) was determined and judged according to the following criteria.
◎: 2 pieces / m ² or less ○: 3-5 pieces / m ²
Δ: 6 to 10 pieces / m ²
×: 11 pieces / m ² or more

12 Evaluation of uneven distribution of UV absorber in the thickness direction in the base film Absorbance ratio (X) of the characteristic absorption of the UV absorber to the characteristic absorption of the polyester on the surface layer of the base polyester film (B) by FT-IR and the center of the film The absorbance ratio (Y) determined in the same manner as above was measured by the following method and expressed as X / Y. The smaller the value, the higher the degree of uneven distribution of the ultraviolet absorber.

X: The IR spectrum (I) of the surface layer of the blank sample (polyethylene terephthalate film containing no UV absorber) and the IR spectrum (II) of the surface layer of the sample of the present invention are measured. The difference spectrum between (I) and (II) is taken and the absorbance at 1700-1800 cm ⁻¹ (
X taken ultraviolet absorber characteristic absorption) and the (absorption at 1505cm ^-1, which derived from IR spectra of II) (absorbance ratio of the absorption of polyethylene terephthalate) (1700~1800cm ^-1 / ^{1505cm -1)} Asked.
Y: 50% of the total thickness of the sample of the present invention was shaved off in the thickness direction, and the exposed surface (film center portion) was measured in the same manner as described above to obtain Y.

The IR spectrum was measured by the following method.
FT-IR equipment: Digilab FTS-7000e
Single reflection ATR device: Thunderdome by Thermo Spectra-Tech
IRE: Ge
Incident angle: 45 °
Resolution: 8cm ^-1
Integration count: 128 times

Example 1
1. Manufacture of base film (1) Preparation of UV absorber-containing masterbatch Dried cyclic iminoester UV absorber (Cysarb UV-3638; 2,2 '-(1,4-phenylene) bis, manufactured by Cytec Corporation) (4H-3,1-benzoxazin-4-one)) 10 parts by mass, 90 parts by mass of polyethylene terephthalate (PET) resin (Toyobo Co., Ltd., ME-553) containing no particles are mixed, and a kneading extruder is used. A master batch was prepared. The extrusion temperature at this time was 285 ° C., and the extrusion time was 7 minutes.

(2) Preparation of coating solution for forming general-purpose easy-adhesion layer A coating solution for forming general-purpose easy-adhesion layer was prepared according to the following method. Dimethyl terephthalate (95 parts by mass), dimethyl isophthalate (95 parts by mass), ethylene glycol (35 parts by mass), neopentyl glycol (145 parts by mass), zinc acetate (0.1 parts by mass) and antimony trioxide (0. 1 part by mass) was charged into a reaction vessel, and a transesterification reaction was performed at 180 ° C. over 3 hours. Next, 5-sodium sulfoisophthalic acid (6.0 parts by mass) was added and an esterification reaction was performed at 240 ° C. over 1 hour, followed by a polycondensation reaction to obtain a polyester resin. 6.7 parts by mass of a 30% by mass aqueous dispersion of the obtained polyester resin, 20% by mass aqueous solution of a self-crosslinking polyurethane resin containing an isocyanate group blocked with sodium bisulfite (Elastolone H 3) 40 parts by mass, elastron catalyst (Daiichi Kogyo Seiyaku Co., Ltd., Cat 64) 0.5 parts by mass, water 47.8 parts by mass and isopropyl alcohol 5 parts by mass, respectively, and anionic surface activity 1% by mass of the coating agent with respect to the coating solution and 5% by mass of colloidal silica particles (manufactured by Nissan Chemical Industries, Snowtex OL) with respect to the solid content of the coating solution were used as the coating solution.

(3) Film formation of base film 90 parts by mass of pellets (Toyobo, ME-553) containing no PET resin particles having an intrinsic viscosity of 0.62 dl / g, and 10 parts by weight of the above-mentioned UV absorber-containing masterbatch The parts were dried under reduced pressure at 135 ° C. for 6 hours (133.32 Pa: 1 Torr) and then supplied to the extruder. The resin temperature up to the melting part, kneading part, melt line, gear pump and filter of the extruder was 280 ° C., and the resin temperature was 275 ° C. in the subsequent melt line and die. The filter used was a stainless sintered body (nominal filtration accuracy: 95% of particles having a size of 10 μm or more).

  The resin melt-extruded into a sheet form from the slit part of the die is wound around a casting drum (roll diameter 400φ, Ra 0.1 μm or less) having a surface temperature of 30 ° C. by using an electrostatic application casting method, and then solidified by cooling, and an unstretched film made. 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 uniaxially oriented. A film was obtained. With respect to all the rolls used at the time of film production, the roll surface roughness was controlled so that Ra was 0.1 μm or less, and roll cleaners were installed at the preheating inlet and the cooling roll in the longitudinal stretching step. The roll diameter in the longitudinal stretching step was 150 mm, and the film was brought into close contact with the roll by employing a suction roll, electrostatic close contact, and part nip contact apparatus.

Thereafter, a coating solution for forming a general-purpose 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, applied to both sides by a reverse roll method, and dried. After coating, the end of the film was subsequently held with a clip and guided to a hot air zone heated to 130 ° C. After drying, the film was stretched 4.0 times in the width direction. Furthermore, it heat-processed at 230 degreeC for 5 second, and 3% of relaxation | loosening processes were performed in the width direction in this heat processing process, and the base film was obtained. The thickness of the film was 100 μm, and the coating amount of the general-purpose 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. Moreover, even if it produced for a long time, generation | occurrence | production of surface defects, such as a surface crack and a surface foreign material (evaluation by the method described as an evaluation method) was suppressed, and the high quality laminated | multilayer film was able to be produced stably.

2. Formation of antireflection layer (surface layer) UV curable hard coat paint (manufactured by Dainichi Seika Co., Ltd., Seika Beam EXF-01B) is applied to the substrate film by reverse coating method so that the film thickness after drying is 5 μm. Worked. Next, after drying the solvent, ultraviolet rays were irradiated at 800 mJ / cm ² with a high-pressure mercury lamp to form a hard coat layer. 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 was coated and dried at 140 ° C. for 20 seconds to form a high refractive index layer. Next, 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 were mixed and hydrolyzed. This low refractive index layer was coated so that the film thickness after drying was 0.09 μm, and dried at 140 ° C. for 1 minute to form a low refractive index layer. Further, on the low-refractive index layer, a par _{3 made of} C ₃ F ₇ — (OC ₃ F ₆ ) ₃₄ —O— (CF ₂ ) ₂ —C ₂ H ₄ —O—CH ₂ Si (OCH ₃ ) _{3 is used.} A coating solution in which a fluoropolyether group-containing silane coupling agent was diluted with perfluorohexane to 0.5% by mass was applied. Subsequently, it dried at 120 degreeC for 1 minute, and formed the antifouling layer with a film thickness of 8 nm as an outermost surface layer.

  Table 1 shows the characteristic values of the surface layer of the obtained laminated film. 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 wiping property of an oil-based pen and the wiping property of a fingerprint. The wiping property of the oil-based pen is to draw a line on the surface of the outermost layer with an oil-based pen, and the wiping property of the fingerprint is the cellulose nonwoven fabric (Asahi Kasei, Bencotton). M-3) was wiped off, and the ease of removal was visually determined. Both were completely wiped off.

3. Formation of near-infrared absorption layer Coating after drying on a base film surface of a laminated film obtained by laminating a surface layer on the above base film with a coating liquid having the following composition (solid content concentration: 17% by mass, viscosity: 40 cps) It applied by reverse using the oblique gravure of diameter 60cm so that quantity might be 8.5 g / m < ² >. Next, it was dried by passing it through hot air of 5 m / second at 40 ° C. for 20 seconds, hot air of 20 m / second at 150 ° C. for 20 seconds, and further passing hot air of 20 m / second at 90 ° C. for 10 seconds. Created.

[Coating solution for forming near-infrared absorbing layer]
An organic solvent, a resin, a dye, and a surfactant were mixed at the following mass ratio, the dye and the resin were dissolved under heating, and undissolved substances were removed with a film having a nominal filtration accuracy of 1 μm to prepare a coating solution.
・ Cyclopentanone 41.35% by mass
・ Toluene 41.35% by mass
-Copolyester resin having a fluorene skeleton 16.40% by mass
(Made by Kanebo, polyester resin O-PET)
・ Diimonium salt compound 0.61% by mass
(Nippon Carlit, CIR-1085; anion is bis (trifluoromethanesulfonyl) imido ion type)
・ Cyanine compound 0.05% by mass
(Asahi Denka Kogyo, TZ-114; anion is a metal complex type)
-Phthalocyanine compound 0.16% by mass
(Nippon Shokubai, IR-14)
・ Squarylium salt compound 0.05% by mass
(Kyowa Hakko Kogyo, SD-184)
・ Silicone-based surfactant 0.03% by mass
(Dow Corning, Paintad 57; HLB = 6.7)

  Table 1 shows the physical properties of the obtained near-infrared absorbing 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. In addition, the stability over time and weather resistance were excellent, and the coating appearance was also good.

Comparative Example 1
In Example 1, the near-infrared absorption film of this comparative example 1 was obtained like Example 1 except changing the following (1)-(4). Table 1 shows the properties of the near-infrared absorbing film obtained in Comparative Example 1.
(1) The composition of the near infrared absorbing layer is changed as follows.
・ Cyclopentanone 41.37% by mass
・ Toluene 41.36% by mass
-Copolyester resin having a fluorene skeleton 16.40% by mass
(Kanebo, O-PET)
・ Diimonium salt compound 0.58% by mass
(Nippon Carlit, CIR-1081; anion is hexafluoroantimonate ion type)
・ Cyanine compound 0.05% by mass
(Asahi Denka Kogyo, TZ-114; anion is a metal complex type)
-Phthalocyanine compound 0.16% by mass
(Nippon Shokubai, IR-14)
・ Squarylium salt compound 0.05% by mass
(Kyowa Hakko Kogyo, SD-184)
・ Silicone-based surfactant 0.03% by mass
(Dow Corning, Paintad 57; HLB = 6.7)
(2) Cancel the blending of the UV absorber into the base film.
(3) Stop the lamination of the general-purpose easy-adhesion layer on the base film on both sides.
(4) Cancel the incorporation of the surfactant into the coating solution for forming the near infrared absorbing layer.

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

Example 2
1. Manufacture of base film (1) Preparation of UV absorber-containing masterbatch Dried cyclic iminoester UV absorber (Cysarb UV-3638; 2,2 '-(1,4-phenylene) bis, manufactured by Cytec Corporation) (4H-3,1-benzoxazin-4-one)) 10 parts by mass, 90 parts by mass of polyethylene terephthalate (PET) resin (Toyobo Co., Ltd., ME-553) containing no particles are mixed, and a kneading extruder is used. A master batch was prepared. The extrusion temperature at this time was 285 ° C., and the extrusion time was 7 minutes.

(2) Preparation of coating solution for formation of interference fringe suppression easy adhesion layer Dimethyl terephthalate (95 parts by mass), 95 parts by mass of dimethyl isophthalate, ethylene glycol (97 parts by mass), neopentyl glycol (70 parts by mass), zinc acetate ( 0.1 parts by mass) and antimony trioxide (0.1 parts by mass) were charged into a reaction vessel, and a transesterification reaction was performed at 180 ° C. over 3 hours. Next, 5-sodium sulfoisophthalic acid (12.1 parts by mass) was added, and after performing esterification reaction at 240 ° C. for 1 hour, polycondensation reaction was performed to obtain a polyester resin. 40 parts by mass of the obtained polyester aqueous dispersion (B-1), 18 parts by mass of a 44% by mass solution of hydroxybis (lactato) titanium (manufactured by Matsumoto Pharmaceutical, TC310), 150 parts by mass of water and 100 parts by mass of isopropyl alcohol, respectively Further, 1% by mass of the anionic surfactant with respect to the coating solution, and 2% by mass of colloidal silica fine particles (manufactured by Nippon Shokuhin Kasei Co., Ltd., Cataloid SI80P; average particle size 80 nm) as silica with respect to the resin solid content. The coating liquid was added.

(3) Preparation of coating solution for forming general-purpose easy-adhesion layer A coating solution for forming general-purpose 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, 20% by mass aqueous solution of a self-crosslinking polyurethane resin containing an isocyanate group blocked with sodium bisulfite (Elastolone H 3) 40 parts by mass, elastron catalyst (Cat 64) 0.5 parts by mass, water 47.8 parts by mass and isopropyl alcohol 5 parts by mass, respectively, and further anionic surfactant 1% by mass, Colloidal silica particles (Nissan Chemical Industries, Snowtex OL) were added in an amount of 5% by mass to obtain a coating solution.

(4) Film formation of base film 90 parts by mass of pellets (ME-553, manufactured by Toyobo Co., Ltd.) not containing polyethylene terephthalate resin particles having an intrinsic viscosity of 0.62 dl / g as an intermediate layer raw material, and the master batch 10 The mass part was dried under reduced pressure at 135 ° C. for 6 hours (133.32 Pa: 1 Torr), and then supplied to the extruder 2 (for the intermediate layer B layer). Polyethylene terephthalate pellets (ME-553, manufactured by Toyobo Co., Ltd.) containing no particles are dried under reduced pressure (135.32 Pa: 1 Torr) at 135 ° C. for 6 hours, and then extruded into an extruder 1 (for outer layer A layer and outer layer C layer). The temperature of the resin to the melter, kneading part, melt line, gear pump, and filter is 280 ° C, and the melt line is 275 ° C in the subsequent melt line. And extruded. 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 melt-extruded resin was wound around a casting drum (roll diameter: 400φ, Ra: 0.1 μm or less) having a surface temperature of 30 ° C. by using an electrostatic application casting method, and solidified by cooling 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. Further, the discharge amount of each extruder was adjusted so that the ratio of the thicknesses of both surface layers was 10% with respect to the total thickness. Next, the cast film is heated to 100 ° C. using a heated roll group and an infrared heater, and then stretched 3.5 times in the longitudinal direction (running direction) with a roll group having a difference in peripheral speed, and a uniaxially oriented film Got. With respect to all the rolls used in the film production, the surface roughness of the roll was controlled to 0.1 μm or less by Ra, and roll cleaners were installed at the preheating inlet and the cooling roll in the longitudinal stretching step. The roll diameter in the longitudinal stretching step was 150 mm, and the film was brought into close contact with the roll by employing a suction roll, electrostatic close contact, and part nip contact apparatus.

  Thereafter, the coating liquids for forming the interference fringe-suppressing easy-adhesion layer and the general-purpose easy-adhesion layer described above are each finely filtered with a felt type polypropylene filter medium having a filtration particle size (initial filtration efficiency of 95%) of 25 μm, and each side is applied by the reverse roll method. It was applied and dried one by one. After coating, the end of the film is gripped with a clip, 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. The base film was obtained by 3% relaxation treatment in the width direction.

The thickness of the film was 100 μm, and the coating amount of each 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. In addition, the occurrence of surface defects such as surface scratches and surface foreign matter is suppressed even if produced for a long time, both the surface scratches on the surface of the base film evaluated by the above method and the results of the evaluation of foreign matter on the surface are ◎, High quality laminated film could be produced stably. Moreover, the uneven distribution degree of the ultraviolet absorber of the thickness direction in a base film was 0.

2. Formation of Antireflection Layer (Surface Layer) An antireflection layer was formed in the same manner as in Example 1 on the interference fringe-suppressing adhesive layer of the base film. The same characteristics as in Example 1 could be imparted. Furthermore, since the interference fringe suppression easy adhesion layer was laminated, when the interference fringe was evaluated by the above evaluation method, the result was ◎.

3. Formation of near-infrared absorbing layer A near-infrared absorbing film of Example 2 was obtained in the same manner as in Example 1 except that the binder resin was changed to a polyester resin having a glass transition point of 110 ° C. Table 1 shows the properties of the near-infrared absorbing film obtained in Example 2. The near-infrared absorbing film obtained in Example 2 was high quality like the near-infrared absorbing film obtained in Example 1.

Comparative Example 2
In Example 2, a near-infrared absorbing film of Comparative Example 2 was obtained in the same manner as Example 2 except that the following changes (1) to (4) were made. Table 1 shows the properties of the near-infrared absorbing film obtained in Comparative Example 2.
(1) The composition of the near infrared absorbing layer is changed as follows.
・ Cyclopentanone 41.37% by mass
・ Toluene 41.36% by mass
-Copolyester resin having a fluorene skeleton 16.40% by mass
(Kanebo, O-PET)
・ Diimonium salt compound 0.58% by mass
(Nippon Carlit, CIR-1083; anion is hexafluorophosphate ion type)
・ Cyanine compound 0.05% by mass
(Asahi Denka Kogyo, TZ-114; anion is a metal complex type)
-Phthalocyanine compound 0.16% by mass
(Nippon Shokubai, IR-14)
・ Squarylium salt compound 0.05% by mass
(Kyowa Hakko Kogyo, SD-184)
・ Silicone-based surfactant 0.03% by mass
(Dow Corning, Paintad 57; HLB = 6.7)
(2) Cancel the blending of the UV absorber into the base film.
(3) The lamination of the interference fringe suppressing easy adhesion layer and the general-purpose easy adhesion layer on the base film is canceled on both sides.
(4) Cancel the incorporation of the surfactant into the coating solution for forming the near infrared absorbing layer.

  The near-infrared absorbing film obtained in Comparative Example 2 has poor durability. Moreover, since the ultraviolet ray transmittance is high, the near-infrared absorbing dye is greatly deteriorated by light and the weather resistance is inferior. Moreover, since each easily bonding layer is not formed, the adhesiveness with respect to the base film of an antireflection layer or a near-infrared absorption layer is inferior. Furthermore, since the incorporation of the surfactant into the coating solution for forming the near infrared absorbing layer was canceled, the dispersibility of the near infrared absorbing dye and the color adjusting dye for cutting neon light in the binder resin was poor, and the near infrared absorbing layer The film appearance was inferior. Furthermore, since the interference fringe suppression easy adhesion layer was not laminated | stacked on the interface of an antireflection layer and a base film, the evaluation result of the interference fringe was x.

Examples 3 and 4 and Comparative Examples 3 and 4
The front panel of the plasma display panel (Fujitsu, PDS4211J-H) was removed, and n-butyl acrylate (78.78) was applied to the near-infrared absorbing layer of the near-infrared absorbing films obtained in Examples 1 and 2 and Comparative Examples 1 and 2. 4 mass%), 2-ethylhexyl acrylate (19.6 mass%) and film thickness after drying a transparent adhesive which is an acrylic ester copolymer comprising a composition of acrylic acid (2 mass%) by a comma coater method Then, a separator film made of polyethylene terephthalate having a thickness of 0.038 mm and treated with silicone was laminated on the surface to obtain a composite of a near-infrared absorbing filter and a separator film. The separator film was peeled off from the composite, and it was attached to a plasma display panel via an adhesive layer, and the function was evaluated. The near-infrared absorbing film has a small thickness and a composite adhesive layer. Therefore, if the film 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.

  Since the filters (Examples 3 and 4) using the near-infrared absorbing film obtained in Examples 1 and 2 are provided with a near-infrared absorbing effect, interference with the infrared remote control device installed in the vicinity could be prevented. . In addition, since the weather resistance and stability over time are excellent, the above functions were stable even after long-term use. Furthermore, the following effects were confirmed.

(1) Since the antireflection property is imparted to the surface, 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.

  The filter using the near-infrared absorbing film of Comparative Example 1 (Comparative Example 3) and the filter using the near-infrared absorbing film of Comparative Example 2 (Comparative Example 4) are inferior in stability over time and weather resistance. Increased disturbance to infrared remote control devices. Moreover, since the coating film appearance of the near-infrared absorbing layer was inferior, the image quality was deteriorated due to the above-mentioned defects. Furthermore, since the adhesiveness at the interface of each layer was inferior, partial peeling of the interface occurred due to long-term use, and the image quality was deteriorated.

Example 5
The near-infrared absorption filter produced in Example 3 was plated with nickel and copper by electroless plating on a mesh in which fibers with a wire diameter of 0.03 mm were knitted longitudinally and horizontally at a density of 135 per inch through an adhesive layer. Affixed to the conductive mesh. The front panel of the plasma display panel (manufactured by Fujitsu, PDS4211J-H) was removed, and the composite was attached with an adhesive to evaluate the function. In addition to the effects confirmed in Example 3, an electromagnetic wave shielding effect was exhibited.

Example 6
The near-infrared absorption filter produced in Example 3 was attached to a plasma display panel with an optical adhesive and the near-infrared absorption layer side was attached to the plasma display panel for evaluation, and the same results as in Example 3 were obtained. It was.

The near-infrared absorbing film of the present invention is excellent in durability while maintaining the blocking property of near-infrared rays and the transmittance of visible light in a wide wavelength region, and is required to have a function of absorbing near-infrared rays such as a plasma display. It can be suitably used as an optical film for a display device or the like. In addition, 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, while maintaining near infrared blocking properties and visible light transmission in a wide wavelength region, It is excellent in durability, and furthermore, it can maintain a thin film state with a single base film configuration and can provide various other functions, so the workability of sticking to the adherend is improved and it is economical Remote control that blocks near-infrared intrusion by absorbing near-infrared rays generated from video output devices such as plasma displays or lighting fixtures, and uses light in the near-infrared region for communication / The malfunction of the infrared communication port can be prevented, and thus the malfunction of the devices controlled by these remote control devices can be prevented. In addition, it can be used for a wide range of applications such as forgery prevention of cash card ID cards and the like, and contributes greatly to the industry.

Claims (9)

  A near-infrared absorbing film formed by laminating a transparent resin and a near-infrared absorbing layer comprising a composition containing a transparent resin and a near-infrared absorbing dye having a maximum absorption at a wavelength of 800 to 1100 nm, A near-infrared absorbing film, wherein one of the infrared absorbing dyes is an aromatic diimmonium compound having bis (trifluoromethanesulfonyl) imidic acid as a counter anion.   The near-infrared absorbing film according to claim 1, wherein a cyanine compound is further used as the near-infrared absorbing dye.   The near-infrared absorbing film according to claim 1 or 2, wherein the counter anion of the cyanine compound is a metal complex.   The near-infrared absorbing film according to claim 1, wherein the base film contains an ultraviolet absorber.   The near-infrared absorbing film according to claim 4, wherein the base film has a laminated structure of at least three layers, and the ultraviolet absorber is contained in an intermediate layer of the laminated structure.   The near-infrared absorbing film according to any one of claims 1 to 5, wherein an antireflection layer is laminated on the surface opposite to the near-infrared absorbing layer laminated on the base film.   At least one surface of the base film is mainly composed of an aqueous polyester resin and at least one of a water-soluble titanium chelate compound, a water-soluble titanium acylate compound, a water-soluble zirconium chelate compound, or a water-soluble zirconium acylate compound. The near-infrared absorbing film according to any one of claims 1 to 6, wherein an adhesion modified layer as a constituent component is laminated.   The near-infrared absorbing film according to any one of claims 1 to 7, wherein the near-infrared absorbing layer contains a surfactant having an HLB of 2 or more and 12 or less. A near-infrared absorption filter, comprising an adhesive layer made of a transparent adhesive on the surface of the near-infrared absorption layer of the near-infrared absorption film according to claim 1.