JP3736567B2 - Wavelength selective absorption film - Google Patents

Description

  The present invention relates to an optical filter that absorbs near-infrared light and neon light, particularly a wavelength-selective absorption film suitable as a filter for display. Specifically, the transmittance in the visible light region is high, and the change in optical characteristics with time is small. And it is related with the wavelength selective absorption film with a uniform coating-film external appearance.

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

As a filter having near-infrared absorption ability, (1) a filter containing metal ions such as copper and iron on phosphoric acid glass, and (2) a layer having a different refractive index is laminated to interfere with transmitted light. An interference filter that transmits a specific wavelength, (3) an acrylic resin filter containing a copper ion in a copolymer, and (4) a filter in which a layer in which a dye is dispersed or dissolved in a resin are laminated.
Among these, the filter (4) has good workability and productivity, and has a relatively large degree of freedom in optical design, and various methods have been proposed (see Patent Documents 1 to 9).
JP 2002-82219 A JP 2002-138203 A JP 2002-214427 A JP 2002-264278 A JP 2002-303720 A JP 2002-333517 A JP 2003-82302 A Japanese Patent Laid-Open No. 2003-96040 JP 2003-114323 A

  However, some of these methods have the ability to sufficiently block the near infrared rays emitted from the plasma display and do not change with time even when used for a long time. The appearance of the wavelength-selective absorption layer was not fully satisfactory for higher brightness and higher definition and high image quality through high-definition broadcasting.

  The object of the present invention was made to solve the above-mentioned problems of the prior art, and has a large and broad absorption in the near infrared region, and further selectively absorbs neon light. It is a wavelength selective absorption film used for wavelength selective absorption optical filters with high light transmittance in other visible light regions, with little change in optical characteristics over time, and high brightness of displays in recent years and high definition by high vision broadcasting. Another object of the present invention is to provide a wavelength selective absorption film that can cope with high image quality and a coating film appearance of a wavelength selective absorption layer that is highly excellent.

  This invention is made | formed in view of said background art, Comprising: The wavelength selective absorption film which could solve said subject is the following structures. The “film” in the present invention is a concept including a so-called “sheet”. In addition, a front filter for a plasma display using the wavelength selective absorption film of the present invention is also included in the present invention.

The first invention is a composition comprising mainly a near-infrared absorbing dye having a maximum absorption at a wavelength of 800 to 1200 nm, a neon cut dye having a maximum absorption at a wavelength of 550 to 620 nm, and a resin on a transparent substrate film. A wavelength selective absorption film provided with a wavelength selective absorption layer, wherein a surfactant having an HLB of 2 or more and 12 or less is contained in an amount of 0.01% by mass or more and 2.00% by mass or less in the wavelength selective absorption layer. It is a wavelength selective absorption film characterized by this.

A second invention is the wavelength selective absorption film according to the first invention, wherein the near-infrared absorbing dye contains at least a diimmonium salt compound.

A third invention is the wavelength selective absorption film according to the first or second invention, wherein the neon cut dye is a squarylium compound or an azaporphyrin compound.

A fourth invention is the wavelength selective absorption film according to any one of the first to third inventions, wherein the surfactant is a silicone surfactant or a fluorine surfactant.
The fifth invention is any one of the first to third inventions, wherein the amount of change in color tone measured by the following measurement method is less than 2 before and after the aging treatment for 500 hours in an atmosphere of temperature 60 ° C. and humidity 95%. The wavelength selective absorption film described in 1.
Using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., ZE-2000), the wavelength selective absorption layer side is irradiated with light, and the a color value and b value of the Lab color system are used as a D65 light source and 10 degrees as standard light. Measure at viewing angle.
Change amount = √ ((a value before processing−a value after processing) ² + (b value before processing−b value after processing) ² )
6th invention is a wavelength selective absorption filter provided with the wavelength selective absorption film in any one of the said 1st-5th invention.
In a seventh aspect of the invention, a near-infrared absorbing layer is formed by applying and drying a coating solution containing a near-infrared absorbing dye, a neon cut dye, a resin, a surfactant, and an organic solvent on a transparent substrate film. It is a manufacturing method of an absorption film, Comprising: HLB is 2-12, and the said surfactant is 0.01 mass% or more and 2.00 mass% or less with respect to solid content of a coating liquid, It is characterized by the above-mentioned. It is a manufacturing method of the near-infrared absorption film made into.
According to an eighth aspect of the present invention, in the drying of the coating solution, the drying is performed in a two-step drying process using hot air, and the initial drying is performed at 20 ° C. or more and 80 ° C. or less and the air volume is performed at 2 m / second or more and 30 m / second. It is a manufacturing method of the near-infrared absorption film as described in 7th invention characterized by the above-mentioned.
According to a ninth aspect of the invention, in the drying of the coating solution, the latter stage of drying is performed by passing it for 5 seconds or more and 180 seconds or less in a drying zone where the actual temperature of the film is 120 ° C. or more and 180 ° C. or less. It is a manufacturing method of the near-infrared absorption film as described in invention of 8.
A tenth aspect of the invention is a method for producing a near-infrared absorbing film according to any one of the seventh to ninth aspects, wherein a reverse gravure method is used as a method of applying the coating liquid.
An eleventh aspect of the invention is the method for producing a near-infrared absorbing film according to the tenth aspect of the invention, wherein in the reverse gravure method, the gravure diameter is 80 mm or less.

  When the wavelength selective absorption film according to the present invention is installed on the front surface of the plasma display as a wavelength selective absorption filter, it absorbs unnecessary near infrared rays emitted from the display as in the case of the conventional wavelength selective absorption filter, and malfunctions of precision instruments. In addition to preventing unnecessary neon light, the image is sharp and the appearance of the coating film is good. There is an advantage that it can greatly contribute to high image quality.

Hereinafter, the present invention will be described in detail.
(Transparent substrate film)
In the present invention, the transparent substrate film is not particularly limited, but preferably has a total light transmittance of 80% or more and a haze of 5% or less. When the substrate film is inferior in transparency, not only the brightness of the display is lowered but also the sharpness of the image becomes poor.

  Examples of such transparent substrate films include polyester-based, acrylic-based, cellulose-based, polyethylene-based, polypropylene-based, polyolefin-based, polyvinyl chloride-based, polycarbonate, phenol-based, urethane-based plastic films, and the like. The thing which bonded two or more arbitrary types of these is mentioned. A polyester film having a good balance between heat resistance and flexibility is preferable, and a polyethylene terephthalate film is more preferable.

  The polyester film suitable as a transparent substrate film used in the present invention is an aromatic dicarboxylic acid or ester thereof such as terephthalic acid, isophthalic acid or naphthalenedicarboxylic acid as a dicarboxylic acid component, and ethylene glycol or diethylene glycol as a glycol component. Polyester chips obtained by esterification or transesterification of 1,4-butanediol, neopentyl glycol, etc., and then polycondensation are dried, melted with an extruder, and extruded from a T die into a sheet. It is a film manufactured by extending | stretching the unstretched sheet obtained by carrying out at least 1 axial direction, and then performing a heat setting process and a relaxation process.

  The film is particularly preferably a biaxially stretched film from the viewpoint of strength. Examples of the stretching method include a tubular stretching method, a simultaneous biaxial stretching method, a sequential biaxial stretching method, and the like, but a sequential biaxial stretching method is preferable in view of flatness, dimensional stability, thickness unevenness, and the like. The sequential biaxially stretched film is, for example, roll-stretched in the longitudinal direction at a glass transition temperature (Tg) to (Tg + 30 ° C.) of 2.0 to 5.0 times in the longitudinal direction and then preheated with a tenter 120 Stretch in the width direction 1.2 to 5.0 times at ~ 150 ° C. Furthermore, after biaxial stretching, it can be produced by performing heat setting treatment at a temperature of 220 ° C. or higher (melting point−10 ° C.) and then relaxing by 3 to 8% in the width direction. Further, in order to further improve the dimensional stability in the longitudinal direction of the film, a longitudinal relaxation treatment may be used in combination.

  In order to provide the film with handleability (for example, rollability after lamination), it is preferable to incorporate particles and form protrusions on the film surface. As particles to be included in the film, inorganic particles such as silica, kaolinite, talc, calcium carbonate, zeolite, alumina, etc., heat resistant polymer particles such as acrylic, PMMA, nylon, polystyrene, polyester, benzoguanamine / formalin condensate, etc. Is mentioned. From the viewpoint of transparency, the content of particles in the film is preferably small, for example, preferably 1 ppm or more and 1000 ppm or less. Furthermore, it is preferable to select particles having a refractive index close to that of the resin used from the viewpoint of transparency. Moreover, in order to provide various functions as needed, the film may contain a light-resistant agent (ultraviolet ray inhibitor), a pigment, an antistatic agent, and the like.

  The transparent substrate film used in the present invention may be a single layer film or a composite film having two or more layers in which a surface layer and a center layer are laminated. In the case of a composite film, there is an advantage that the functions of the surface layer and the center layer can be designed independently. For example, by containing particles only on the thin surface layer and forming irregularities on the surface, the handling property is maintained, but the thick central layer does not substantially contain particles, so that the composite film as a whole is transparent. Can be further improved. The method for producing the composite film is not particularly limited. However, in consideration of productivity, the raw material for the surface layer and the central layer are extruded from separate extruders, led to one die, and after obtaining an unstretched sheet, at least Lamination by the so-called coextrusion method that is oriented in a uniaxial direction is particularly preferable.

  The thickness of the transparent substrate film varies depending on the material, but when a polyester film is used, the lower limit is preferably 35 μm, more preferably 50 μm. On the other hand, the upper limit of the thickness is preferably 260 μm, more preferably 200 μm. When the thickness is small, not only the handling property becomes poor, but also when heated at the time of drying so as to reduce the residual solvent of the wavelength selective absorption layer, the film tends to be wrinkled and flatness tends to be poor. On the other hand, when the thickness is large, not only is there a problem in terms of cost, but flatness due to curling tends to occur when the material is wound and stored in a roll shape.

(Middle layer)
The wavelength selective absorption film of the present invention has a structure in which a wavelength selective absorption layer is laminated on a transparent base film, but the improvement in the adhesion between the transparent base film and the wavelength selective absorption layer and the transparency of the transparent base film. It is preferable to provide an intermediate layer for the purpose of improving the properties. In addition, when not containing particle | grains in a film, high transparency can be obtained, maintaining handling property by providing the intermediate | middle layer containing particle | grains simultaneously at the time of film manufacture.

  Examples of the resin constituting the intermediate layer include polyester resins, polyurethane resins, polyester urethane resins, acrylic resins, melamine resins, and the like, but resins having good adhesion to the base material and the wavelength selective absorption layer can be used. It is important to select one or more types. Specifically, if the resin constituting the base material and the wavelength selective absorption layer is an ester type, it is possible to select a polyester type or a polyester urethane type having a similar structure. preferable.

  The intermediate layer may contain a crosslinking agent for the purpose of improving adhesion and improving water resistance to form a crosslinked structure. Examples of the crosslinking agent include urea, epoxy, melamine, and isocyanate. In particular, when the resin is whitened under high temperature and high humidity and the strength is lowered, the effect of the crosslinking agent is remarkable. In addition, you may use the graft copolymer resin which has self-crosslinking property as resin, without using a crosslinking agent.

  The intermediate layer may contain various kinds of particles for the purpose of forming irregularities on the surface and improving slipperiness. Examples of the particles to be included in the intermediate layer include inorganic particles such as silica, kaolinite, talc, calcium carbonate, zeolite, and alumina, organic materials such as acrylic, PMMA, nylon, styrene, polyester, and benzoguanamine / formalin condensate. Particles. In addition, it is preferable to select particles having a refractive index close to that of the resin used from the viewpoint of transparency.

  Furthermore, in order to give various functions to the intermediate layer, a surfactant, an antistatic agent, a dye, an ultraviolet absorber, or the like may be contained.

  The intermediate layer may be a single layer if it has the desired function, but may be laminated in two or more layers as necessary.

  The thickness of the intermediate layer is not particularly limited as long as it has a desired function, but is preferably 0.01 μm or more and 5 μm or less. When the thickness is small, the function as an intermediate layer is hardly exhibited. On the contrary, when the thickness is thick, the transparency tends to be poor.

  As a method for providing the intermediate layer, a coating method is preferable. As the coating method, using a known coating method such as gravure coating method, kiss coating method, dip method, spray coating method, curtain coating method, air knife coating method, blade coating method, reverse roll coating method, etc. It can be provided by an in-line coating method in which a coating layer is provided, or an offline coating method in which a coating layer is provided after film production. Of these methods, the in-line coating method is not only excellent in terms of cost, but by adding particles to the coating layer, it is not necessary to include particles in the transparent substrate film, so the transparency is highly improved. Is preferable.

(Wavelength selective absorption layer)
The wavelength selective absorption film of the present invention is provided with a wavelength selective absorption layer comprising a composition mainly containing a near-infrared absorbing dye, a neon cut dye, and a resin directly or via an intermediate layer on a transparent substrate film. Yes. The above-mentioned “mainly containing a near-infrared absorbing dye, a neon-cut dye, and a resin” means that the total content of the near-infrared-absorbing dye, the neon-cut dye, and the resin in the composition is 80% by mass or more. Means that. The total content of the near-infrared absorbing dye, neon cut dye, and resin in the composition is preferably 85% by mass or more, and particularly preferably 90% by mass or more.

  The near-infrared absorbing dye is a dye having a maximum absorption in the near-infrared region with a wavelength of 800 to 1200 nm, and is a diimmonium-based, phthalocyanine-based, dithiol metal complex-based, naphthalocyanine-based, azo-based, polymethine-based, anthraquinone-based , Naphthoquinone, pyrylium, thiopyrylium, squarylium, croconium, tetradehycholine, triphenylmethane, cyanine, azo, and aminium compounds. These compounds are used alone or in admixture of two or more, but they have a large absorption in the near infrared region, a wide absorption region, and a high transmittance in the visible light region. It preferably contains a salt compound.

(In formula, R < ₁ > -R < ₈ > may be same or different, respectively, and represents a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, an aralkyl group, and an alkynyl group. R < ₉ > -R < ₁₂ > may be the same, respectively. Which may be different and represents a hydrogen atom, a halogen atom, an amino group, a cyano group, a nitro group, a carboxyl group, an alkyl group, or an alkoxyl group, and R _{1 to} R ₁₂ can be bonded to a substituent. X ⁻ represents an anion).

When R _{1 to} R _{8 in} the general formula (I) are (a) an alkyl group, (b) an aryl group, (c) an alkenyl group, and (d) an aralkyl group, the following groups can be exemplified.
(A) Alkyl group: methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, t-butyl group, n-amyl group, n-hexyl group, n-octyl Group, 2-hydroxyethyl group, 2-cyanoethyl group, 3-hydroxypropyl group, 3-cyanopropyl group, methoxyethyl group, ethoxyethyl group, butoxyethyl group and the like.
(B) Aryl group: phenyl group, fluorophenyl group, chlorophenyl group, tolyl group, diethylaminophenyl group, naphthyl group and the like.
(C) Alkenyl group: vinyl group, propenyl group, butenyl group, pentenyl group and the like.
(D) Aralkyl group: benzyl group, p-fluorobenzyl group, p-chlorophenyl group, phenylpropyl group, naphthylethyl group and the like.

In addition, examples of the (e) halogen atom, (f) amino group, (g) alkyl group, and (h) alkoxyl group of R _{9 to} R _{12 in} the general formula (I) include the following groups.
(E) Halogen atom: fluorine, chlorine, bromine and the like.
(F) Amino group: diethylamino group, dimethylamino group and the like.
(G) Alkyl group: methyl group, ethyl group, propyl group, trifluoromethyl group and the like.
(H) Alkoxyl group: methoxy group, ethoxy group, propoxy group and the like.

Examples of X ⁻ in the above general formula (I) include fluorine ion, chlorine ion, bromine ion, iodine ion, perchlorate ion, hexafluoroantimonate ion, hexafluorophosphate ion, and tetrafluoroboric acid. Anions such as ions and bis (trifluoromethanesulfonyl) imido ions.

  A commercially available product can be used as the diimmonium salt compound represented by the general formula (I). For example, Kayasorb IRG-022, IRG-023, IRG-024 (manufactured by Nippon Kayaku Co., Ltd.), CIR-1080, CIR-1081, CIR-1083, CIR-1085 (manufactured by Nippon Carlit) are suitable. It is.

  In addition to the diimonium salt compound represented by the general formula (I), the wavelength selective absorption film of the present invention is used in combination with other near-infrared absorbing pigments for the purpose of expanding the absorption range of the near-infrared region and adjusting the color. It is preferable to do.

  Other near-infrared absorbing dyes that can be used in combination with the diimmonium salt compounds include phthalocyanine compounds, dithiol metal complex compounds, cyanine compounds, naphthalocyanine compounds, squarylium salt compounds, pyrylium salt compounds, thioperyllium compounds. Compounds, croconium compounds, indoaniline chelate dyes, indonaphthol chelate dyes, azo dyes, azo chelate dyes, aminium salt dyes, quinone dyes, anthraquinone dyes, polymethine dyes, triphenylmethane dyes, etc. Can be mentioned.

  For example, a commercial item can be used for the phthalocyanine compound. Specifically, Excolor IR-1, IR-2, IR-3, IR-4, IR-10, IR-10A, IR-12, IR-14, TXEX-805K, TXEX-809K, TXEX-810K, Suitable examples include TXEX-811K, TXEX-812K, TXEX-813K, TXEX-814K (manufactured by Nippon Shokubai Co., Ltd.), MIR-369, MIR-389 (manufactured by Mitsui Chemicals, Inc.), and the like.

  Moreover, as said dithiol metal complex type compound, the compound represented by the following general formula (II) is suitable, for example.

(In formula, R < ¹³ > -R < ¹⁶ > may be same or different, respectively, and represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxyl group, an aryl group, an aralkyl group, an amino group. M is nickel, copper, Represents cobalt, palladium, or platinum.)

Specific examples of R ^{13 to} R ^{16 in} the general formula (II) include halogen atoms such as fluorine, chlorine and bromine; methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso -Butyl group, t-butyl group, n-amyl group, n-hexyl group, n-octyl group, 2-hydroxyethyl group, 2-cyanoethyl group, 3-hydroxypropyl group, 3-cyanopropyl group, methoxyethyl group Alkyl groups such as ethoxyethyl group and butoxyethyl group; alkoxyl groups such as methoxy group, ethoxy group, propoxy group and butoxy group; aryl such as phenyl group, fluorophenyl group, chlorophenyl group, tolyl group, diethylaminophenyl and naphthyl group Group: benzyl group, p-fluorobenzyl group, p-chlorophenyl group, phenylpropyl group, naphthylethyl Aralkyl groups such as a group; a dimethylamino group, diethylamino group, dipropylamino group, an amino group, such as a dibutylamino group; and the like. As the dithiol metal complex compound of the above general formula (II), for example, commercially available products such as SIR-128, SIR-130, SIR-132, SIR-159 manufactured by Mitsui Chemicals may be suitably used.

  Examples of cyanine compounds include TZ-103, TZ-104, TZ-105, TZ-109, TZ-111, TZ-114 manufactured by Asahi Denka, CY-9, CY-10, and CY manufactured by Nippon Kayaku. -20, CY-30, IR-301 manufactured by Yamada Chemical, etc. are preferable.

In the present invention, in order to control the target absorption in the near-infrared region and the transmittance in the visible light region, the amount of the near-infrared absorbing dye is 0.01 g / in any surface in the thickness direction of the wavelength selective absorption layer. it is preferable to adjust to exist in m ² or more 1.0 g / m ² or less. When the amount of the near-infrared absorbing dye per unit area is small, the absorbing ability in the near-infrared region tends to be insufficient. On the other hand, when the amount of the near-infrared absorbing dye per unit area is large, there is a problem that the transparency in the visible light region is insufficient and the luminance of the display is lowered.

  In the present invention, the wavelength selective absorption layer needs to contain a neon cut dye. The plasma display has a drawback that it emits so-called neon orange light centering around a wavelength of about 600 nm, and the orange color is mixed with the red color so that a bright red color cannot be obtained. By including a neon cut pigment, the above problem can be solved.

  In the present invention, the neon cut dye is a dye having a maximum absorption in a wavelength range of 550 to 620 nm, and specifically, cyanine-based, squalium-based, azaporphyrin-based, azomethine-based, xanthene-based, oxonol-based, azo-based. Phthalocyanine, quinone, azurenium, pyrylium, croconium, dithiol metal complex, and pyromethene compounds. Among these, squarylium compounds or azaporphyrin compounds are preferable in that they have sharp absorption in the wavelength region of 550 to 620 nm.

The content of the neon cut dye in the wavelength selective absorption layer is preferably adjusted so that the light transmittance at the maximum absorption wavelength at a wavelength of 550 to 620 nm is 30% or less. Specifically, it is preferable to control so that it exists in the range of 0.001 or more and 0.1 g / m ^{2 on} an arbitrary surface in the thickness direction of the wavelength selective absorption layer.

  In the present invention, the near-infrared absorbing dye and the neon cut dye are laminated on the transparent substrate film by a coating method as a composition dispersed or dissolved in the resin. The resin is not particularly limited as long as it can dissolve or disperse the near-infrared absorbing dye uniformly. Polyester, acrylic, polyamide, polyurethane, polyolefin, and polycarbonate resins can be preferably used. Of these, polyester resins are preferred because they are excellent in flexibility and adhesion to the substrate. When the resin is hard, fine cracks may occur 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 of the resin forming the wavelength selective absorption layer is equal to or lower than the device operating temperature, the dyes dispersed in the resin react with each other, or the resin absorbs moisture or the like in the outside air. And the deterioration of the binder resin increases. In the present invention, the glass transition temperature of the resin is not particularly limited as long as it is equal to or higher than the device use temperature, but it is particularly preferably 85 ° C. or higher and 160 ° C. or lower. In addition, the said glass transition temperature is made to heat up at 10 degree-C / min over the temperature range of 25-300 degreeC using a differential scanning calorimeter (the Seiko Instruments Inc. make, DSC6200) based on JIS-K7121. , Means the extrapolated glass transition onset temperature obtained from the DSC curve.

  When the glass transition temperature of the resin is less than 85 ° C., near-infrared absorbing dyes easily move under high temperature and high humidity, so that the dyes or the dyes and the resin easily interact with each other, and the dyes are not modified. It tends to be prominent. For this reason, the spectral characteristics and color tone of the film tend to change.

  On the other hand, when the glass transition temperature of the resin exceeds 160 ° C., when the resin is dissolved in a solvent and applied on a transparent substrate film, the resin must be heated to a sufficient temperature. As a result, the flatness of the base material due to heat wrinkles, and further the deterioration of the pigment occurs. Moreover, when it dries at low temperature, drying time becomes long and productivity worsens, and productivity becomes bad. In addition, there is a possibility that sufficient drying cannot be performed, so that the solvent remains in the coating film, the apparent glass transition temperature of the resin is lowered as described above, and the dye is likely to be modified.

  The near-infrared absorbing pigment content in the wavelength selective absorption layer is preferably 1% by mass or more and 10% by mass or less based on the resin. The upper limit of the content of the near-infrared absorbing dye is more preferably 8% by mass, and particularly preferably 6% by mass with respect to the resin. Further, the lower limit of the content of the near-infrared absorbing dye is more preferably 2% by mass, and particularly preferably 3% by mass with respect to the resin.

  When the amount of the near infrared absorbing dye in the resin is small, it is necessary to increase the coating amount of the wavelength selective absorption layer in order to achieve the target near infrared absorbing ability. In this case, if the coating film is sufficiently dried, it is necessary to increase the temperature and / or the time for a long time, and the deterioration of the pigment and the poor flatness of the base material are likely to occur. In particular, when a diimmonium salt compound is used as a near-infrared absorbing dye, the diimmonium salt compound is easily denatured at high temperatures or high humidity, and absorption in the near-infrared region is reduced or a part of the visible light region is reduced. The transmittance tends to decrease, and the color tone tends to change easily. On the other hand, when the amount of the near-infrared absorbing dye in the resin is large, the distance between the dyes in the resin becomes shorter. For this reason, the interaction between the dyes becomes strong, and even if the residual solvent is reduced, the dyes are likely to be denatured over time.

  In this invention, a wavelength selection absorption layer is formed by apply | coating and drying the coating liquid containing a near-infrared absorption pigment | dye, a neon cut pigment | dye, resin, and an organic solvent on a transparent base film. At this time, it is important to contain a surfactant in the coating solution. By containing the surfactant, the coating appearance of the wavelength selective absorption layer, in particular, dents due to minute bubbles and adhesion of foreign matter, etc., and repelling in the drying process are improved. Furthermore, the surfactant is bleed and localized on the surface of the wavelength selective absorption layer by coating and drying the surfactant under specific conditions. As a result, not only the durability of the surface of the wavelength selective absorption layer is improved, but also the surface of the wavelength selective absorption layer is slippery, and handling is possible without forming surface irregularities on the wavelength selective absorption layer or / and the opposite surface. It becomes easy to wind in a roll shape.

  As the surfactant, known cationic, anionic, and nonionic surfactants can be suitably used. However, in order to suppress the deterioration of the dye due to the interaction with the near infrared absorbing dye or the neon cut dye, the surfactant has a polar group. The nonionic type | system | group which is not carried out is preferable, and also the silicone type or fluorine-type surfactant excellent in surface active ability is preferable.

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

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

  It is important that the content of the surfactant is 0.01% by mass or more and 2.00% by mass or less with respect to the resin constituting the wavelength selective absorption layer. When the surfactant content is low, the effect of improving the appearance of the coating film and imparting slipperiness is insufficient. Conversely, when the surfactant content is high, the wavelength selective absorption layer absorbs moisture. In some cases, the deterioration of the pigment may be promoted.

  In the present invention, it is important that the HLB of the surfactant is 2 or more and 12 or less. The lower limit value of HLB is preferably 3, particularly preferably 4. On the other hand, the upper limit value of HLB is preferably 11, particularly preferably 10. When a surfactant with a low HLB is used, the surface of the wavelength selective absorption layer becomes water-repellent, and even when stored in a high temperature / high humidity environment for a long time, the deterioration of the near infrared absorbing dye can be suppressed. It is possible to easily provide slipperiness. On the other hand, when a surfactant having an HLB that is too low is used, the leveling property is insufficient due to insufficient surface activity. On the other hand, when a surfactant having an excessively high HLB is used, not only the slipping property of the wavelength selective absorption layer is insufficient, but also the wavelength selective absorption layer easily absorbs moisture, and the temporal stability of the dye is poor. It becomes.

  In addition, HLB is a value that WCGriffin of Atlas Powder, Inc. in the United States named Hydorophil Lyophile Balance and indexed the balance between hydrophilic group and lipophilic group contained in the surfactant molecule as a characteristic value. . The lower the HLB, the more lipophilic, and the higher the HLB, the higher the hydrophilicity.

  The localization of the surfactant on the surface of the wavelength selective absorption layer differs depending on the type of resin used and the solvent, but it is most likely that HLB is most likely to occur in the vicinity of 7, and the initial drying is under mild conditions. Easy to convert. The degree of localization of the surfactant on the surface of the wavelength selective absorption layer is, for example, comparing the content of the surfactant in the wavelength selective absorption layer with the amount of the surfactant on the surface of the wavelength selective absorption layer. Can be confirmed. For example, in the case of a silicone-based surfactant, by comparing the amount of Si in the wavelength selective absorption layer quantified by chemical analysis with the amount of Si on the surface of the wavelength selective absorption layer quantified by ESCA analysis, the wavelength selective absorption layer The degree of localization of the surfactant on the surface of the surface can be confirmed.

  In the present invention, the wavelength selective absorption layer is laminated by applying and drying a coating liquid containing a resin, a near infrared absorbing dye, a neon cut dye, a surfactant, and an organic solvent on a transparent substrate film. The coating solution needs to be diluted with an organic solvent from the viewpoint of coating properties.

  Examples of the organic solvent include (1) alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, tridecyl alcohol, cyclohexyl alcohol, 2-methylcyclohexyl alcohol, and (2) ethylene glycol. , Glycols such as diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, glycerin, (3) 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 Glycol ethers such as ether acetate, ethylene glycol monoethyl acetate, ethylene glycol monobutyl acetate, diethylene glycol monomethyl acetate, diethylene glycol monoethyl acetate, diethylene glycol monobutyl acetate, (4) ethyl acetate, isopropylene acetate, n-butyl acetate, etc. Examples include esters, (5) ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, isophorone, diacetone alcohol, etc. These may be used alone or in combination of two or more. Can do.

  Preferably, ketones having excellent dye solubility are contained in an amount of 30% by mass to 80% by mass with respect to the total organic solvent used in the coating solution, and other organic solvents are considered in view of leveling properties and drying properties. It is preferable to select. The boiling point of the organic solvent is preferably 60 ° C. or higher and 180 ° C. or lower. When the boiling point is low, the solid content concentration of the coating solution changes during coating, and the coating thickness is difficult to stabilize. On the other hand, when the boiling point is high, the amount of the organic 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, neon-cut dye, and resin in an organic solvent include stirring, dispersion, or pulverization under heating. By heating, the solubility of the pigment and the resin can be improved, and the deterioration of the coating appearance due to undissolved substances can be suppressed. Moreover, it becomes possible to form a coating layer having excellent transparency by dispersing or pulverizing the resin and the pigment and dispersing them in the coating solution in the form of fine particles having a size of 0.3 μm or less. A well-known thing can be used as a disperser or a grinder. Examples thereof include 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 shaker, a butterfly mixer, a planetary mixer, and a Henschel mixer.

  If there is contamination or undissolved material having a size of 1 μm or more in the coating solution, the appearance after coating becomes poor. Therefore, it is necessary to remove it with a filter or the like before coating. Various filters can be suitably used as the filter, but it is preferable to use a filter having a filtration performance capable of removing 99% or more of foreign matters having a size of 1 μm. When a coating solution containing contaminants and undissolved substances having a size of 1 μm or more is applied and dried, a dent or the like is generated around the coating solution, which may cause a defect of 100 to 1000 μm in size.

  The solid content concentration of the resin and the pigment contained in the coating solution is preferably 10% by mass or more and 30% by weight. When the solid content concentration is low, it takes time to dry after coating, resulting in poor productivity and an increase in the amount of solvent remaining in the coating film, resulting in poor temporal stability. 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 solution 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 with an organic solvent so that it is in this range.

  In the present invention, as a method for applying the wavelength selective absorption layer on the transparent substrate film, gravure coating method, kiss coating method, dip method, spray coating method, curtain coating method, air knife coating method, blade coating method, reverse roll coating Conventionally used methods such as a method, a bar coat method, and a lip coat 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, the frequency of occurrence of ridges in the flow direction increases.

The coating amount of the wavelength selective absorption layer after drying is not particularly limited, but the lower limit is preferably 1 g / m ² , more preferably 3 g / m ² , and the upper limit is preferably 50 g / m ² , more preferably 30 g / m. ² . When the coating amount after drying is small, the near-infrared absorbing power tends to be insufficient. Therefore, when the abundance of the near-infrared absorbing dye or neon cut dye in the resin is increased, the distance between the dyes is shortened, and the interaction between the dyes is strengthened. As a result, the deterioration of the dye is likely to occur, and the temporal stability becomes poor. Conversely, when the coating amount after drying is large, the near-infrared absorbing ability is sufficient, but the transparency in the visible light region is lowered, and the brightness of the display is lowered. Therefore, if the amount of the near-infrared absorbing dye in the resin is reduced, the optical characteristics can be adjusted, but drying tends to be insufficient. As a result, the temporal stability of the dye becomes poor due to the residual solvent in the coating film. On the other hand, when the drying is sufficient, the flatness of the substrate becomes poor.

  As a method of applying the wavelength-selective absorbing layer forming coating solution on the transparent substrate film and drying it, known hot air drying, infrared heaters and the like can be mentioned. Hot air drying with a high drying speed is preferred.

  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. The lower limit of the drying temperature is more preferably 30 ° C. When the initial drying is performed strongly (the hot air temperature is high and the hot air volume is large), the surfactant is less likely to be localized on the surface. As a result, the wavelength selective absorption layer is not only difficult to be improved in durability and imparting slipperiness, but also tends to cause minute defects of the coating film, such as fine coating from foam, fine peeling, and cracks. Conversely, when initial drying is weakened (the hot air temperature is low and the hot air volume is small), the coating appearance is good. However, it takes time to dry and there are problems in terms of productivity (cost) as well as problems such as brushing. When the surfactant is not added to the wavelength selective absorption layer forming coating solution, the above-mentioned minute defects are likely to occur, and the initial drying needs to be considerably weakened.

  In the reduction drying process, it is necessary to increase the temperature higher than the initial drying to reduce the solvent in the coating film, and the preferable temperature is 120 ° C. or higher and 180 ° C. or lower. Particularly preferably, the lower limit is 140 ° C and the upper limit is 170 ° C. When the temperature is low, the solvent in the coating film is difficult to decrease and becomes a residual solvent, resulting in insufficient stability of the dye over time. On the other hand, when the temperature is high, not only the flatness of the base material becomes poor due to heat wrinkles, but also the near-infrared absorbing 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 will increase, resulting in poor stability over time. Conversely, if the time is long, not only will the productivity be poor, but heat wrinkles will occur on the substrate. Therefore, the flatness becomes poor. The upper limit of the passage time is particularly preferably 30 seconds from the viewpoint of productivity and flatness.

  At the end 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 cool the actual temperature of the substrate 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.

(Wavelength selective absorption filter)
In the present invention, the wavelength selective absorption filter has a low light transmittance in the near infrared region having a wavelength of 800 to 1200 nm and a neon light region having a wavelength of 550 to 650 nm, and a visible light region having a wavelength of 400 to 800 nm excluding the neon light region. It means a filter with high light transmittance. The light transmittance in the near infrared region is preferably as low as possible, specifically 40% or less, more preferably 30% or less. When the light transmittance is high, absorption of near infrared rays emitted from the plasma display is insufficient, and malfunction of an electronic device using a near infrared remote controller cannot be prevented.

The wavelength selective absorption filter preferably has sharp absorption in a neon light region with a wavelength of 550 to 620 nm, and further with a wavelength of 570 to 600 nm. The light transmittance at the maximum absorption wavelength in the neon light region is 40% or less, preferably 30% or less. When the light transmittance in this region is high, the neon light emitted from the plasma display is absorbed and the effect of improving the red color is lost. In addition, when the absorption in this region is wide, there is a problem that the luminance of the display is lowered because the entire transmittance of the visible light region is lowered. The higher the transmittance in the visible light region other than 550 to 620 nm, the better, preferably 50% or more, and more preferably 60% or more. When the transmittance is low, the color of the display is hindered and the image has a low luminance.
The adjustment of the transmittance can be controlled by the type of the above-mentioned near infrared absorbing dye or neon cut dye and the abundance of the near infrared absorbing dye or neon cut dye per unit area.

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

  The color tone of the wavelength selective absorption filter is adjusted by mixing the above-mentioned types of near-infrared absorbing dyes and neon-cutting dyes, the abundance of near-infrared-absorbing dyes and neon-cutting dyes per unit area, and other color correction dyes. Can be controlled. In addition, when laminating a colored adhesive layer or other functional layers (antireflection layer, electromagnetic wave absorbing layer, ultraviolet absorbing layer, etc.) on the front or back of the wavelength selective absorption filter described later, the natural color is included. It is preferable to adjust the color tone of the wavelength selective absorption filter.

  The wavelength selective absorption layer of the present invention should have a coating appearance that does not have a defect of a diameter of 300 μm or more, more preferably 100 μm. A defect with a diameter of 300 μm or more is detected as a bright spot when it is installed on the front surface of the plasma display and an image is displayed, and the defect becomes noticeable. A defect having a diameter of 100 μm or more and less than 300 μm may be emphasized by the lens effect by bonding such as adhesive processing, and must be controlled so as not to exist in the wavelength selective absorption layer as much as possible. Also, streaks, unevenness, etc. with a thin coating layer become prominent on the front surface of the display and become a problem.

  It is preferable that the wavelength selective absorption filter does not change the light transmittance and the visible light transmittance in the near infrared region and neon light region even when left for a long time under 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.

  In order to improve the stability over time, the amount of residual solvent in the wavelength selective absorption layer can be controlled by controlling the type of organic solvent used in the coating liquid for forming the wavelength selective absorption layer, the thickness of the coating layer, the drying conditions, etc. Can be reduced. The residual solvent amount in the wavelength selective absorption layer can also be reduced by adjusting the content of the pigment in the resin constituting the wavelength selective absorption layer. The amount of residual solvent in the wavelength selective absorption layer is preferably as small as possible, and is preferably controlled to 3% by mass or less. When the amount of residual solvent in the wavelength selective absorption layer is 3% by mass or less, there is substantially no difference in stability over time. However, in order to further reduce the amount of residual solvent, for example, if drying is performed under severe conditions, problems such as poor planarity of the filter and alteration of the dye may occur. Moreover, productivity is reduced by a method such as drying under reduced pressure.

  In the present invention, for the purpose of blocking harmful electromagnetic waves emitted from the display, a conductive layer may be provided directly or via an adhesive on the same surface as the wavelength selective absorption layer or on the opposite surface. Either a metal mesh or a conductive thin film may be used for the conductive layer. When a metal mesh is used, it is necessary to have a metal mesh conductive layer having an aperture ratio of 50% or more. If the aperture ratio of the metal mesh is low, the electromagnetic shielding property is good, but there is a problem that the light transmittance is lowered. For this reason, an aperture ratio of 50% or more is necessary to obtain a good light transmittance. Become. As the metal mesh used in the present invention, a metal foil having high electrical conductivity is subjected to etching treatment to form a mesh, a woven mesh using metal fibers, or metal on the surface of polymer fibers. You may use the fiber adhered using methods, such as plating. The metal used for the electromagnetic wave absorbing layer is not particularly limited as long as it has high electrical conductivity and good stability, but is not particularly limited, but from the viewpoint of workability, cost, etc., preferably copper, nickel, Tungsten etc. are good.

  When a conductive thin film is used, the transparent conductive layer may be any conductive film, but is preferably a metal oxide. Thereby, a higher visible light transmittance can be obtained. In the present invention, when it is desired to improve the conductivity of the transparent conductive layer, it is preferably a repeating structure of three or more layers of metal oxide / metal / metal oxide. Conductivity can be obtained while maintaining a high visible light transmittance by multilayering the metal. Used in the present invention. The metal oxide may be any metal oxide as long as it has electrical conductivity and visible light transmittance. Examples include tin oxide, indium oxide, indium tin oxide, zinc oxide, titanium oxide, and bismuth oxide. The above is an example and is not particularly limited. The metal layer used in the present invention is preferably gold, silver or a compound containing them from the viewpoint of conductivity.

  Furthermore, when the conductive layer is multi-layered, for example, when the number of repeated layers is 3, the thickness of the silver layer is preferably 50 to 200 mm, more preferably 50 to 100 mm. When the film thickness is thicker than this, the light transmittance decreases, and when it is thin, the resistance value increases. Further, the thickness of the metal oxide layer is preferably 100 to 1000 mm, more preferably 100 to 500 mm. If it is thicker than this, it will be colored to change its color tone, and if it is thin, the resistance value will increase. In addition, when three or more layers are formed, for example, when five layers are formed such as metal oxide / silver / metal oxide / silver / metal oxide, the thickness of the central metal oxide is the other metal. It is preferable that it is thicker than the thickness of the oxide layer. By doing so, the light transmittance of the entire multilayer film is improved.

  In the present invention, an antireflection layer or an anti-flicker layer may be provided directly or via an adhesive on the same surface as the wavelength selective absorption layer of the wavelength selective absorption film or on the opposite surface.

  In the wavelength selective absorption filter, a layer having an ultraviolet absorbing ability may be provided for the purpose of improving light resistance. In order to impart ultraviolet absorbing ability, an ultraviolet absorber may be added to any of the wavelength selective absorption layer, transparent substrate film, pressure-sensitive adhesive, antireflection layer, and glare prevention layer. The wavelength selective absorption filter having this ultraviolet absorption layer is particularly preferably disposed on the front surface of the display so that the ultraviolet absorption layer is on the surface side (the side opposite to the display side) of the wavelength selective absorption layer. As the opposite-side ultraviolet absorber, known ones such as organic ultraviolet inhibitors and inorganic ultraviolet inhibitors can be used.

  Next, examples and comparative examples of the present invention will be shown. The characteristic value measurement method and effect evaluation method used in the present invention are as follows.

<Viscosity of coating solution>
The coating solution was adjusted to 20 ° C. and measured using a B-type viscometer (BL) manufactured by Tokyo Keiki Co., Ltd., at a rotor rotational speed of 60 rpm.

<Total light transmittance, haze>
Using a haze meter (Nippon Denshoku Industries, NDH2000), the total light transmittance and haze were measured.

<Transmissivity>
Using a spectrophotometer (Hitachi U-3500 type), indoor air was measured as a reference for transmittance in the wavelength range of 200 to 1100 nm so that light was irradiated to the wavelength selective absorption layer side. The transmittance in the near-infrared region was determined from the average value of transmittances at wavelengths of 900 to 1100 nm. Moreover, the transmittance | permeability in visible region was calculated | required from the average value of the transmittance | permeability with a wavelength of 450-700 nm.

<Color tone>
Using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., ZE-2000), the wavelength selective absorption layer side is irradiated with light, and the a color value and b value of the Lab color system are used as a D65 light source and 10 degrees as standard light. Measured at viewing angle.

<Stability over time>
After being allowed to stand for 500 hours in an atmosphere at a temperature of 60 ° C. and a humidity of 95%, the above spectral characteristics and color tone were measured.
First, the average values of the transmittance in the near infrared region and the transmittance in the visible light region were obtained before and after the aging treatment, the amount of change was obtained from the following formula (1), and ranking was performed according to the following criteria.
◎: Change in transmittance less than 5% ○: Change in transmittance from 5% to less than 10% △: Change in transmittance from 10% to less than 20% ×: Change in transmittance from 20% or more

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

Next, ranking was performed according to the following criteria based on the amount of change of the following formula (2) before and after the color tone was processed.
◎: Change in color tone is less than 1 ○: Change in color tone is 1 or more and less than 2 Δ: Change in color tone is 2 or more and less than 4 ×: Change in color tone is 4 or more

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

<Appearance of coating film>
(1) Minute defects The wavelength selective absorption film was placed on a white film (Toyobo Co., Ltd., Crisper K1212; 100 μm) and observed under a three-wavelength fluorescent lamp to evaluate the minute defects. In addition, the number of defects having a size of 300 μm or more per 100 m ² was measured as the minute defects, and was ranked according to the following criteria. The number of defects was measured as follows.
First, mark all the defects that are visually observed (if the number of defects is large, stop halfway), then check the size of the defects with an optical microscope, and check for defects with a size of 300 μm or more. Count the number.
◎: Less than 1 micro defect ○: 1 or more and less than 5 △: Micro defect is 5 or more and less than 10 ×: 10 or more micro defects

(2) Poor coating The wavelength selective absorption film was placed on a white film (Toyobo Co., Ltd., Crisper K1212; 100 μm) and observed under a three-wavelength fluorescent lamp, and the appearance of the coating film per 100 m ² (coating unevenness, streak) Etc.), and ranking was performed according to the following criteria.
◎: Even if the wavelength selective absorption film is observed while moving, no poor coating is observed ○: When the wavelength selective absorption film is observed, some poor coating is observed △: Wavelength selection When observing while moving the absorption film, a poorly coated part is observed. ×: A poorly coated part is observed even in a stationary state.

<Winding characteristics>
The film was ranked according to the following criteria based on the amount of roll misalignment at the end face of the roll after winding the film around a 6-inch paper tube in a roll shape at a speed of 20 m / min at a winding tension of 200 N / m.
◎: Winding deviation is less than 1 mm ○: Winding deviation is 1 mm or more and less than 2 mm △: Winding deviation is 2 mm or more and less than 4 mm ×: Winding deviation is 4 mm or more, or winding is impossible

Example 1
(Base material)
A polyethylene terephthalate resin having an intrinsic viscosity of 0.62 dl / g is charged into a twin-screw extruder, melt-extruded from a T-die at 290 ° C., and solidified while being applied with static electricity on a cooled rotating metal roll. A stretched sheet was obtained.
Next, the unstretched sheet was heated to 90 ° C. with a roll stretching machine and longitudinally stretched by 3.5 times, and then the coating amount after drying the following coating liquid A on the longitudinally stretched film was 0.5 g / The intermediate coating layer was formed by coating on both sides so as to be m ^2, and passing it for 20 seconds under a hot air of 120 m at a wind speed of 10 m / sec. Further, the film was heated by a tenter to 140 ° C. and transversely stretched 3.7 times, and then heat treated while being relaxed by 5% in the width (lateral) direction at 235 ° C. to obtain a film. The obtained biaxially stretched polyethylene terephthalate film having an intermediate coating layer had a thickness of 100 μm, a total light transmittance of 90.2%, and a haze of 0.5%.

(Composition of coating liquid A for intermediate coating layer)
・ Ion-exchanged water 50.0% by mass
・ Isopropyl alcohol 28.9% by mass
・ Acrylic-melamine resin 10.0% by mass
(Nippon Carbite, A-08, solid content: 46% by mass)
・ Polyester resin 10.0% by mass
(Toyobo, MD-1250, solid content: 30% by mass)
・ 1.0% by mass of organic particles
(Nippon Shokubai, Eposta MA1001)
・ Surfactant 0.1% by mass
(Dow Corning, Paintad 32)

(Lamination of wavelength selective absorption layer)
The following coating liquid B (solid content concentration: 17% by mass, viscosity: 40 cps) is applied onto the above intermediate coating layer using an oblique gravure with a diameter of 60 mm so that the coating amount after drying is 8.5 g / m ^2. It was coated by reverse method, dried for 20 seconds with hot air of 5 m / second at 40 ° C., 20 seconds with hot air of 20 m / second at 150 ° C., and further for 10 seconds with hot air of 20 m / second at 90 ° C., and dried. A wavelength selective absorption film was prepared.
(Coating liquid B for wavelength selective absorption layer)
Mix at the following mass ratio, dissolve the dye and resin under heating (40 ° C.), and remove the undissolved material using a filter with a nominal filtration accuracy of 1 μm to create a coating solution.
・ Cyclopentanone 41.50% by mass
・ Toluene 41.50% by mass
-Copolyester resin having a fluorene ring 16.15% by mass
(Kanebo, O-PET OPN-IR)
・ Diimonium salt compound 0.5653 mass%
(Nippon Kayaku IRG-022)
・ Nickel metal complex 0.1547% by mass
(MIR101, manufactured by Midori Chemical)
・ Cyanine compound 0.0461% by mass
(Yamada Chemical Industries, IR301)
・ Cyanine-based processed product 0.0939% by mass
(Nippon Kayaku CY-10)
・ Squarylium salt compound 0.0471% by mass
(Kyowa Hakko, SD184)
・ Silicon surfactant 0.0340% by mass
(Dow Corning Paintad 57, HLB = 6.7)

  Table 1 shows the physical properties of the obtained wavelength selective absorption film. A film having strong absorption in the near infrared region and high transmittance in the visible light region was obtained. Moreover, the stability over time and the coating appearance were also good.

Example 2
A wavelength selective absorption film in the same manner as in Example 1 except that the surfactant in the coating solution for the wavelength selective absorption layer is changed to a silicone surfactant having a HLB of 11 (manufactured by Nihon Unicar, FZ-2105). Got. Since it was changed to a highly hydrophilic surfactant, the temporal stability under high temperature and high humidity was slightly inferior. Further, since the effect of imparting slipperiness to the surface due to localization was insufficient, some winding deviation occurred. All were practical levels.

Example 3
Wavelength selective absorption in the same manner as in Example 1 except that the surfactant in the coating solution for the wavelength selective absorption layer was changed to a silicone surfactant having an HLB of 3 (manufactured by Nihon Unicar, FZ-2136). A film was obtained. Since the surfactant was changed to a highly hydrophobic surfactant, the leveling property was slightly inferior and a small amount of minute defects were generated.

Example 4
A wavelength selective absorption film was obtained in the same manner as in Example 1 except that 0.02% by mass of the surfactant was contained in the coating solution for the wavelength selective absorption layer with respect to the resin. Since the content of the surfactant was reduced, the leveling property was slightly inferior and a small amount of micro defects were generated.

Example 5
A wavelength selective absorption film was obtained in the same manner as in Example 1 except that the surfactant was added in an amount of 1.5% by mass based on the resin in the coating liquid for the wavelength selective absorption layer. Since the surfactant content was increased, the stability over time was slightly poor.

Example 6
A wavelength selective absorption film was obtained in the same manner as in Example 1 except that the surfactant in the coating liquid for wavelength selective absorption layer was 2.5 mass% with respect to the solid content. Since the content of the surfactant in the wavelength selective absorption layer was large, the temporal stability was poor.

Comparative Example 1
A wavelength selective absorption film was obtained in the same manner as in Example 1 except that the surfactant in the coating liquid for wavelength selective absorption layer was not used. Since no surfactant was added, many micro defects occurred. In addition, slipping was poor and it was difficult to roll up in a roll.

Comparative Example 2
Wavelength selective absorption film in the same manner as in Example 1 except that the surfactant in the coating liquid for wavelength selective absorption layer was changed to a silicone surfactant having an HLB of 1 (manufactured by Nihon Unicar, FZ-2110). Got. Since surfactants other than the constituent requirements of the present invention were used, leveling properties were insufficient and a lot of minute defects occurred. Further, winding slip occurred because the slipperiness of the surface was too strong.

Comparative Example 3
A wavelength selective absorption film was obtained in the same manner as in Example 1 except that the surfactant in the coating solution for the wavelength selective absorption layer was changed to a silicone surfactant having a HLB of 14 (manufactured by Toshiba Silicone Co., Ltd., TSF4440). It was. Since surfactants other than the constituent requirements of the present invention were used, leveling properties were insufficient and minute defects were generated. Moreover, the slipperiness of the surface was slightly insufficient, and the winding slip occurred.

Example 7
A wavelength selective absorption film was prepared in the same manner as in Example 1 except that the wavelength selective absorption layer was provided by the following method.
(Lamination of wavelength selective absorption layer)
The following coating liquid C (solid content concentration: 21 mass%, viscosity: 30 cps) is applied onto the above intermediate coating layer using an oblique gravure with a diameter of 60 cm so that the coating amount after drying is 9.3 g / m ^2. It was coated by reverse, dried for 20 seconds with hot air of 5m / sec at 40 ° C, 20 seconds with hot air of 20m / sec at 150 ° C, and further for 10 seconds with hot air of 20m / sec at 90 ° C, and dried. A selective absorption film was prepared.
(Coating liquid C for wavelength selective absorption layer)
The mixture was mixed at the following mass ratio, the dye and the resin were dissolved under heating, and the undissolved material was removed using a filter with a nominal filtration accuracy of 1 μm to prepare a coating solution.
・ Methyl ethyl ketone 39.073 mass%
・ Toluene 37.073 mass%
-Acrylic resin 6.23 mass%
(Made by Mitsubishi Rayon, BR-80)
・ Acrylic resin 14.54% by mass
(Made by Mitsubishi Rayon, BR-83)
・ Diimonium salt compound 0.6588% by mass
(Nippon Kayaku IRG-022)
-Phthalocyanine compound 0.3668% by mass
(Nippon Shokubai, IR-10A)
・ Azaporphyrin-based compound 0.1137% by mass
(Yamada Chemical, TAP-2)
・ Silicon surfactant 0.0654% by mass
(Nihon Unicar, FZ-2130; HLB = 7.0)

  The wavelength selective absorption film of the present invention has low transmittance in the near infrared region and neon light region, high transmittance in the visible light region, and good coating film appearance. By installing an optical filter with a wavelength selective absorption film as a component, it is possible to express a good image, and it is possible to prevent malfunction of precision equipment using a near-infrared remote controller. Can contribute.

Claims (11)

A wavelength selective absorption layer comprising a composition mainly containing a near-infrared absorbing dye having a maximum absorption at a wavelength of 800 to 1200 nm, a neon cut dye having a maximum absorption at a wavelength of 550 to 620 nm, and a resin on a transparent substrate film. A wavelength selective absorption film provided, wherein the wavelength selective absorption layer contains a surfactant having an HLB of 2 to 12 in an amount of 0.01% by mass to 2.00% by mass. Selective absorption film. 2. The wavelength selective absorption film according to claim 1, wherein the near-infrared absorbing dye is mainly composed of a diimmonium salt compound. The wavelength selective absorption film according to claim 1 or 2, wherein the neon cut pigment is a squarylium compound or an azaporphyrin compound. Wavelength selective absorption film according to any one of claims 1 to 3, wherein the surfactant is a silicone-based surfactant or a fluorinated surfactant. The wavelength-selective absorption according to any one of claims 1 to 4, wherein the amount of change in color tone measured by the following measurement method is less than 2 before and after aging treatment in an atmosphere of temperature 60 ° C and humidity 95% for 500 hours. the film.
Using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., ZE-2000), the wavelength selective absorption layer side is irradiated with light, and the a color value and b value of the Lab color system are used as standard light, D65 light source, 10 degrees. Measure at viewing angle.
Change amount = √ ((a value before processing−a value after processing)) ² + (B value before processing-b value after processing) ² ) A wavelength selective absorption filter comprising the wavelength selective absorption film according to claim 1. A method for producing a wavelength-selective absorption film in which a coating solution containing a resin, a near-infrared absorbing dye, a neon cut dye, a surfactant, and an organic solvent is applied and dried on a transparent substrate film to form a near-infrared absorbing layer. The surfactant has an HLB of 2 or more and 12 or less, and is contained in an amount of 0.01% by mass or more and 2.00% by mass or less based on the solid content of the coating solution. Manufacturing method. In the drying of the coating solution, the drying is performed in a two-stage drying process using hot air, the initial drying is performed at 20 ° C. or more and 80 ° C. or less, and the air volume is performed at 2 m / sec or more and 30 m / sec. Item 8. A method for producing a wavelength selective absorption film according to Item 7. 8. The wavelength selection according to claim 7, wherein in the drying of the coating solution, the latter stage drying is performed by passing it through a drying zone where the actual temperature of the film is 120 ° C. or more and 180 ° C. or less for 5 seconds or more and 180 seconds or less. Production method of absorbent film. The method for producing the near-infrared absorbing film according to claim 7, wherein a reverse gravure method is used as a method of applying the coating solution. The near-infrared absorbing film according to claim 10, wherein the diameter of the gravure is 80 mm or less in the reverse gravure method.