JP5741158B2 - Infrared reflective film and infrared reflector using the same - Google Patents

Description

  The present invention is an infrared reflective film having an infrared reflective layer in which layers having different refractive indexes are alternately laminated on a substrate, and a reducing layer further containing an organic acid as a reducing agent, and the infrared reflective film The present invention relates to an infrared reflector adapted for.

  In recent years, many window films have been used that are bonded to the window glass surface of buildings. One of them is a film that has the function of suppressing the intrusion of infrared rays and preventing the temperature inside the building from rising excessively, reducing the use of cooling and achieving energy saving.

  Layers having different refractive indexes as a film reflecting infrared rays, such as a vapor deposition method, a dry film forming method such as a sputtering method (Patent Document 1), and a coating method (Patent Documents 1 and 2) in which a coating liquid is coated and laminated on a substrate A method of alternately stacking layers is disclosed.

  In order to realize a high refractive index of these infrared reflective layers, a structure containing titanium-based oxide, zinc-based oxide or the like in the high-refractive index layer is an effective means. Patent Document 1 discloses titanium oxide, A technique for forming a high refractive index layer by dispersing zinc oxide fine particles into a dispersion and coating the substrate is described.

  On the other hand, since titanium oxide has a photocatalytic function by UV, there is a concern that the plastic base material is decomposed by being exposed to sunlight for a long time. For this purpose, it is common to contain a UV absorber in any of the layers that are configured to suppress the photocatalytic action.

  However, once the window film is constructed, it is assumed that it will be used for several years. If it is used for a long time, the photocatalytic action of the titanium-based oxide cannot be suppressed due to a decrease in the ability of the UV absorber. For this reason, it is colored by modification of the plastic substrate or the like, or the flexibility is lost and the strength of the film is lost and the film becomes brittle. In addition, the binder of the titanium-based oxide-containing layer is also decomposed and modified, and the interface with the adjacent low-refractive index layer is disturbed, so that the infrared reflectance is lowered and the function of suppressing the room temperature is lowered. was there.

JP-A-8-110401 JP 2007-33296 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an infrared reflective film with little film strength deterioration, reduced infrared reflectance and color tone change even when exposed to sunlight for a long time. It is in.

  The above object of the present invention is achieved by the following configurations.

  1. In an infrared reflective film comprising a low refractive index layer and a high refractive index layer alternately laminated, and an infrared reflective layer having a titanium-based oxide in at least one of the alternate laminated layers is formed on any one surface of the substrate. The infrared reflective film has a reducing layer containing an organic acid as a reducing agent.

  2. 2. The infrared reflective film as described in 1 above, wherein the reducing layer is formed in a direction parallel to the substrate.

  3. 3. The infrared reflective film as described in 1 or 2 above, wherein the reducing layer is formed between the substrate and the alternate lamination.

  4). 4. An infrared reflector, wherein the infrared reflective film according to any one of 1 to 3 is provided on at least one surface of a substrate.

  According to the present invention, it is possible to provide an infrared reflective film with little deterioration in film strength, a decrease in infrared reflectance and a change in color tone even when exposed to sunlight for a long time.

It is a schematic sectional drawing of the layer structure of the infrared reflective film used for the Example.

  It is known that titanium-based oxides make oxygen molecules in the vicinity active oxygen by their catalytic ability, and the active oxygen decomposes surrounding organic compounds. As a result of intensive studies in view of the above problems, the present inventor has a function of trapping oxygen in the vicinity of a titanium-based oxide by having a reduction layer containing the organic acid of the present invention as a reducing agent, and titanium-based oxidation. A film having a reduction layer containing an organic acid as a reducing agent as a layer different from an infrared reflection layer containing a titanium-based oxide, having a function of not making the catalytic activity ability of the product effective. It has been found that the constitution can increase the titanium-based oxide concentration of the high refractive index layer and increase the refractive index of the layer, and the present invention has been achieved.

<Infrared reflective film>
The infrared reflective film of the present invention is formed by alternately laminating a low refractive index layer and a high refractive index layer, and an infrared reflective layer having a titanium-based oxide in at least one of the alternate laminated layers is provided on either side of the substrate. The infrared reflective film has a reducing layer containing an organic acid as a reducing agent.

  As the basic optical characteristics of the infrared reflective film of the present invention, the transmittance in the visible light region shown in JIS R3106-1998 is 50% or more, and the region having a wavelength exceeding 900% to 1400 nm exceeds the reflectance of 50%. And the transmittance in a wavelength region of 900 nm to 1400 nm is 30% or less. The transmittance in the wavelength region of 900 nm to 1400 nm is preferably 10% or less.

"Base material"
As the base material of the present invention, those formed of a transparent organic material are preferable.

  For example, methacrylic acid ester, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate, polystyrene (PS), aromatic polyamide, polyether ether ketone, polysulfone, polyether sulfone, polyimide, poly Examples include resin films such as ether imide, and resin films formed by laminating two or more layers of the above resins. From the viewpoint of cost and availability, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC) and the like are preferably used.

  As for the thickness of a base material, about 5-200 micrometers is preferable, More preferably, it is 15-150 micrometers.

  Further, the substrate according to the present invention has a visible light region transmittance of 85% or more, particularly 90% or more, as shown in JIS R3106-1998. When the base material is at least the above-mentioned transmittance, it is advantageous and preferable for the transmittance in the visible light region shown in JIS R3106-1998 to be 50% or more when an infrared shielding film is used.

  In addition, the base material using the above-described resins or the like may be an unstretched film or a stretched film. A stretched film is preferable from the viewpoint of strength improvement and thermal expansion suppression.

  The base material used in the present invention can be produced by a conventionally known general method. For example, an unstretched substrate that is substantially amorphous and not oriented can be produced by melting a resin as a material with an extruder, extruding it with an annular die or a T-die, and quenching. In addition, the unstretched substrate is uniaxially stretched, tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, tubular-type simultaneous biaxial stretching, and other known methods, such as the substrate flow (vertical axis) direction, or A stretched substrate can be produced by stretching in the direction perpendicular to the flow direction of the substrate (horizontal axis). The draw ratio in this case can be appropriately selected according to the resin as the raw material of the base material, but is preferably 2 to 10 times in each of the vertical axis direction and the horizontal axis direction.

  In addition, the base material used in the present invention may be subjected to relaxation treatment or off-line heat treatment in terms of dimensional stability. It is preferable that the relaxation treatment is performed in a process from the heat setting in the stretching process of the polyester film to the winding in the transversely stretched tenter or after exiting the tenter. The relaxation treatment is preferably performed at a treatment temperature of 80 to 200 ° C, more preferably a treatment temperature of 100 to 180 ° C. Moreover, it is preferable that the relaxation rate is in the range of 0.1 to 10% in both the longitudinal direction and the width direction, and more preferably, the relaxation rate is 2 to 6%. The relaxed base material is subjected to the following off-line heat treatment to improve the heat resistance and further improve the dimensional stability.

In the base material of the present invention, it is preferable to apply the undercoat layer coating solution inline on one side or both sides in the film forming process. In the present invention, undercoating during the film forming process is referred to as in-line undercoating. Examples of resins used in the undercoat layer coating solution useful in the present invention include polyester resins, acrylic-modified polyester resins, polyurethane resins, acrylic resins, vinyl resins, vinylidene chloride resins, polyethyleneimine vinylidene resins, polyethyleneimine resins, and polyvinyl alcohol resins. , Modified polyvinyl alcohol resin, gelatin and the like, and any of them can be preferably used. A conventionally well-known additive can also be added to these undercoat layers. The undercoat layer can be coated by a known method such as roll coating, gravure coating, knife coating, dip coating or spray coating. The coating amount of the undercoat layer is preferably about 0.01 to ² g / m ² (dry state).

<Low refractive index layer and high refractive layer>
In the present invention, the infrared reflective layer is formed by alternately laminating a low refractive index layer and a high refractive index layer, and has a titanium-based oxide in at least one of the alternate laminated layers. The low refractive index layer and the high refractive index layer are a layer having a low refractive index material and a layer having a high refractive index material, respectively.

  As the infrared reflective film, the larger the difference in the refractive index between the high refractive index layer and the low refractive index layer, the better from the viewpoint of increasing the infrared reflectance with a small number of layers. It has at least two or more units composed of a refractive index layer and a low refractive index layer, and the refractive index difference between the adjacent high refractive index layer and low refractive index layer is 0.1 or more. Preferably it is 0.3 or more, More preferably, it is 0.4 or more. The upper limit is about 1.40 due to the availability of materials.

  The number of units in which two layers each of a low refractive layer and a high refractive layer are laminated as one unit depends on the refractive index difference between the high refractive index layer and the low refractive index layer, but is preferably 40 units or less, more preferably Is 20 units or less, more preferably 10 units) or less.

  A layer having an intermediate refractive index can be provided between the low refractive index layer and the high refractive index layer. However, from the viewpoint of ease of difference in refractive index and cost, the infrared reflective layer is higher than the low refractive index layer. A refractive layer is preferably laminated.

  Incidentally, in the present invention, the refractive indexes of the high refractive index layer and the low refractive index layer can be determined according to the following method.

  A sample in which each refractive index layer for measuring a refractive index is coated as a single layer on a substrate is prepared, and the sample is cut into 10 cm × 10 cm, and then the refractive index is obtained according to the following method. Using a U-4000 type (manufactured by Hitachi, Ltd.) as a spectrophotometer, the back side on the measurement side of each sample is roughened, and then light absorption is performed with a black spray to reflect light on the back side. In this case, the reflectance in the visible light region (400 nm to 700 nm) is measured at 25 points under the condition of regular reflection at 5 degrees to obtain an average value, and the average refractive index is obtained from the measurement result.

  The preferable refractive index of the high refractive index layer in the present invention is 1.70 to 2.50, more preferably 1.80 to 2.20. Moreover, as a preferable refractive index of a low-refractive-index layer, it is 1.10-1.60, More preferably, it is 1.30-1.50.

  The high refractive index layer and the low refractive index layer in the present invention are both preferable embodiments containing a water-soluble resin and metal oxide particles as a high refractive index material or a low refractive index material. In the present invention, at least one of the high refractive index layer and the low refractive index layer contains a titanium-based oxide described later as a metal oxide. Preferably, the high refractive index layer contains a titanium-based oxide.

  Examples of metal oxides other than titanium oxide include zirconium oxide, zinc oxide, synthetic amorphous silica, colloidal silica, alumina, colloidal alumina, lead titanate, red lead, yellow lead, zinc yellow, chromium oxide, Examples include ferric oxide, iron black, copper oxide, magnesium oxide, magnesium hydroxide, yttrium oxide, niobium oxide, europium oxide, lanthanum oxide, zircon, and tin oxide. Both low refractive index layer and high refractive index layer Also, these metal oxides may be mixed.

  The content of the metal oxide including titanium oxide, which will be described later, is preferably 20% by mass or more and 95% by mass or less, and preferably 30% by mass or more and 60% by mass or less, based on the total solid content of the layer containing the metal oxide. Is more preferable. By setting the metal oxide content to 20% by mass or more, the high refractive index layer can have a higher refractive index, and the low refractive index layer can have a lower refractive index. By setting it as the mass% or less, the softness | flexibility of a film | membrane is obtained and it becomes easy to form an infrared shielding film.

The metal oxide used in the high refractive index layer according to the present invention is preferably a titanium-based oxide, ZnO, or ZrO ₂ described later, and the stability of the metal oxide particle-containing composition described later for forming the high refractive index layer. From the viewpoint of properties, titanium-based oxides are more preferable.

  In the low refractive index layer according to the present invention, as the metal oxide particles, silicon dioxide particles are preferably used, and acidic colloidal silica sol is particularly preferably used.

  The silicon dioxide particles according to the present invention preferably have an average particle size of 100 nm or less. The average particle diameter of primary particles of silicon dioxide dispersed in a primary particle state (particle diameter in a dispersion state before coating) is preferably 20 nm or less, more preferably 10 nm or less. In addition, the average particle size of the secondary particles is preferably 30 nm or less from the viewpoint of low haze and excellent visible light transmittance.

  In the infrared reflective layer of the present invention, the layer adjacent to the base material is a low refractive index layer containing silica, and the outermost layer opposite to the layer adjacent to the base material is also a low refractive index layer containing silica. A layer structure is preferred.

<Titanium-based oxide>
In the present invention, it is necessary to have a titanium-based oxide in any one of the alternating layers. Titanium-based oxides are excited when irradiated with ultraviolet rays, and have a photocatalytic action such that nearby oxygen molecules are made active oxygen. Specific examples of titanium-based oxides include anatase-type titanium oxide, rutile-type titanium oxide, brookite-type titanium oxide, strontium titanate, and these titanium-based oxides, including tin, barium, vanadium, manganese, cobalt, nickel, gallium, Dissimilar metal atoms such as aluminum, germanium, antimony, indium, palladium, ruthenium, rhodium, niobium, zirconium, magnesium, yttrium, lanthanum, europium, zinc, lead, chromium, iron, copper, silver, gold, platinum, tungsten, cerium The compound which doped was mentioned. The doping amount is preferably 0.001% by mass to 30% by mass.

  A preferable titanium-based oxide as an effect of the present invention is rutile titanium oxide having a high refractive index and a low photocatalytic ability.

  In addition, as a preferred embodiment of the titanium-based oxide in the present invention, a titanium-based oxide sol in which fine-particle titanium-based oxide is dispersed in water or an organic solvent is preferable. The titanium-based oxide sol is preferable from the viewpoint of producing an infrared reflective layer, such as being easy to mix with other resins to make a coating solution.

  Examples of methods for preparing titanium-based oxides that can be used in the present invention include JP-A-63-17221, JP-A-7-819, JP-A-9-165218, and JP-A-11-43327. Reference can be made to a publication.

  As other methods for preparing titanium-based oxides, see, for example, JP-A-63-17221, JP-A-7-819, JP-A-9-165218, JP-A-11-43327, etc. Can be.

  The primary particle diameter preferable as the volume average particle diameter of the titanium-based oxide fine particles is 4 nm to 50 nm, and more preferably 4 nm to 30 nm.

The volume average particle diameter of the titanium-based oxide particles according to the present invention refers to a method of observing the particles themselves using a laser diffraction scattering method, a dynamic light scattering method, or an electron microscope, and a cross section or surface of the refractive index layer. the method of appearing particle image is observed with an electron microscope to measure the particle diameter of 1,000 randomly selected particles, particles each having a particle diameter of _{d 1, d 2 ··· d i} ··· d k N ₁ , n ₂ ..., N _i ..., N _{k in} a group of titanium oxide particles, where the volume per particle is v _i , the volume average particle diameter m _v = It is an average particle size weighted by a volume represented by {Σ (v _i · d _i )} / {Σ (v _i )}.

  In the present invention, the layer containing a titanium-based oxide may be either a low-refractive index layer, a high-refractive index layer, or both, but an embodiment in which a titanium-based oxide is preferably contained on the high-refractive index layer side is preferable. . A titanium-based oxide and the above-described metal oxide may be mixed, or a plurality of types of titanium-based oxides may be mixed. Among the metal oxides contained in any of the layers, the preferable titanium-based oxide content is 30% by mass to 100% by mass, and preferably 70% by mass to 100% by mass. The higher the titanium oxide content, the better from the viewpoint of increasing the refractive index of the layer.

《Water-soluble resin》
The infrared reflective layer constituting the infrared reflective film in the present invention preferably contains a water-soluble resin.

  Examples of these water-soluble resins include gelatin, synthetic resins, inorganic polymers, thickening polysaccharides and the like, and gelatin is particularly preferred in the present invention. One or a mixture of these water-soluble resins may be used.

  The water-soluble resin according to the present invention is a polymer compound that dissolves in an amount of 5% by mass or more in an aqueous medium, and preferably 10% by mass or more.

  The concentration of the water-soluble polymer in the coating liquid for forming a high refractive layer and the coating liquid for forming a low refractive index layer according to the present invention is preferably 0.5 to 60% by mass, and is in the range of 5 to 40% by mass. It is more preferable that

  Hereinafter, the details of each water-soluble resin will be described.

"gelatin"
The water-soluble resin according to the present invention is particularly preferably gelatin.

  Examples of gelatin according to the present invention include acid-treated gelatin and alkali-treated gelatin, as well as enzyme-treated gelatin and gelatin derivatives that undergo enzyme treatment in the gelatin production process, that is, amino groups, imino groups, hydroxyl groups as functional groups in the molecule. It may be modified by treatment with a reagent having a group and a carboxyl group and a group obtained by reacting with it. The general method for producing gelatin is well known and is described, for example, in T.W. H. James: The Theory of Photographic Process 4th. ed. Reference can be made to descriptions such as 1977 (Machillan) 55, Science Photo Handbook (above) 72-75 (Maruzen), Fundamentals of Photographic Engineering-Silver Salt Photographs 119-124 (Corona).

《Synthetic resin》
Examples of water-soluble resins applicable to the present invention include so-called synthetic resins such as polyvinyl alcohols, polyvinyl pyrrolidones, alkylene oxides, polyacrylic acid, acrylic acid-acrylonitrile copolymers, potassium acrylate-acrylonitrile copolymers. Acrylic resin such as polymer, vinyl acetate-acrylic acid ester copolymer, or acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid- Styrene acrylic resin such as acrylic ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, or styrene-α-methylstyrene-acrylic acid-acrylic ester copolymer, styrene-sodium styrenesulfonate Copolymer, styrene 2-hydroxyethyl acrylate copolymer, styrene-2-hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer Vinyl acetate copolymers such as polymers, vinyl naphthalene-maleic acid copolymers, vinyl acetate-maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and the like Salt. Among these, particularly preferable examples include polyvinyl alcohols and copolymers containing the same.

  The weight average molecular weight of the water-soluble polymer is preferably 1,000 or more and 200,000 or less. Furthermore, 3,000 or more and 40,000 or less are more preferable.

  The polyvinyl alcohol preferably used in the present invention includes, in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate, modified polyvinyl alcohol such as polyvinyl alcohol having a cation-modified terminal and anion-modified polyvinyl alcohol having an anionic group. Alcohol is also included.

  The polyvinyl alcohol obtained by hydrolyzing vinyl acetate preferably has an average degree of polymerization of 1,000 or more, and particularly preferably has an average degree of polymerization of 1,500 to 5,000. The degree of saponification is preferably 70 to 100%, particularly preferably 80 to 99.5%.

  Examples of the cation-modified polyvinyl alcohol have primary to tertiary amino groups and quaternary ammonium groups in the main chain or side chain of the polyvinyl alcohol as described in JP-A-61-110483. Polyvinyl alcohol, which is obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.

  Examples of the ethylenically unsaturated monomer having a cationic group include trimethyl- (2-acrylamido-2,2-dimethylethyl) ammonium chloride and trimethyl- (3-acrylamido-3,3-dimethylpropyl) ammonium chloride. N-vinylimidazole, N-vinyl-2-methylimidazole, N- (3-dimethylaminopropyl) methacrylamide, hydroxylethyltrimethylammonium chloride, trimethyl- (2-methacrylamidopropyl) ammonium chloride, N- (1, 1-dimethyl-3-dimethylaminopropyl) acrylamide and the like. The ratio of the cation-modified group-containing monomer of the cation-modified polyvinyl alcohol is 0.1 to 10 mol%, preferably 0.2 to 5 mol%, relative to vinyl acetate.

  Anion-modified polyvinyl alcohol is, for example, polyvinyl alcohol having an anionic group as described in JP-A-1-2060888, as described in JP-A-61-237681 and JP-A-63-330779, Examples thereof include a copolymer of vinyl alcohol and a vinyl compound having a water-soluble group, and modified polyvinyl alcohol having a water-soluble group as described in JP-A-7-285265.

  Nonionic modified polyvinyl alcohol is, for example, a polyvinyl alcohol derivative obtained by adding a polyalkylene oxide group to a part of vinyl alcohol as described in JP-A-7-9758, and described in JP-A-8-25595. And a block copolymer of a vinyl compound having a hydrophobic group and vinyl alcohol. Polyvinyl alcohol can be used in combination of two or more, such as the degree of polymerization and the type of modification.

  In the present invention, when these polymers are used, a curing agent may be used. For example, in the case of polyvinyl alcohol, boric acid and a salt thereof and an epoxy curing agent described later are preferable.

<Inorganic polymer>
As one of the water-soluble polymers according to the present invention, it is preferable to use an inorganic polymer such as a zirconium atom-containing compound or an aluminum atom-containing compound.

  The compound containing a zirconium atom applicable to the present invention excludes zirconium oxide, and specific examples thereof include zirconium difluoride, zirconium trifluoride, zirconium tetrafluoride, hexafluorozirconium salt (for example, Potassium salt), heptafluorozirconate (for example, sodium salt, potassium salt or ammonium salt), octafluorozirconate (for example, lithium salt), fluorinated zirconium oxide, zirconium dichloride, zirconium trichloride, tetrachloride Zirconium, hexachlorozirconium salt (for example, sodium salt and potassium salt), zirconium oxychloride (zirconyl chloride), zirconium dibromide, zirconium tribromide, zirconium tetrabromide, zirconium bromide oxide, zirconium triiodide, four Diiodide Konium, zirconium peroxide, zirconium hydroxide, zirconium sulfide, zirconium sulfate, zirconium p-toluenesulfonate, zirconyl sulfate, sodium zirconyl sulfate, acidic zirconyl sulfate trihydrate, potassium zirconium sulfate, zirconium selenate, zirconium nitrate, nitric acid Zirconyl, zirconium phosphate, zirconyl carbonate, zirconyl ammonium carbonate, zirconium acetate, zirconyl acetate, zirconyl ammonium acetate, zirconyl lactate, zirconyl citrate, zirconyl stearate, zirconyl phosphate, zirconium oxalate, zirconium isopropylate, zirconium butyrate, Zirconium acetylacetonate, acetylacetone zirconium butyrate, zirconium stearate butyrate, Benzalkonium acetate, bis (acetylacetonato) dichloro zirconium and tris (acetylacetonato) chloro zirconium, and the like.

  Among these compounds, zirconyl chloride, zirconyl sulfate, sodium zirconyl sulfate, acidic zirconyl sulfate trihydrate, zirconyl nitrate, zirconyl carbonate, zirconyl ammonium carbonate, zirconyl acetate, zirconyl ammonium acetate, zirconyl stearate are more preferable. Zirconyl carbonate, zirconyl ammonium carbonate, zirconyl acetate, zirconyl nitrate and zirconyl chloride, particularly preferably zirconyl ammonium carbonate, zirconyl chloride and zirconyl acetate. Specific product names of the above compounds include Zircozole ZA-20 (Zirconyl Acetate) manufactured by Daiichi Rare Element Chemical Industry, Zircosol ZC-2 (Zirconyl Chloride) manufactured by Daiichi Rare Element Chemical Industry, First Rare Element Chemical Industry Zircosol ZN (zirconyl nitrate) and the like manufactured by the company are listed.

  The inorganic polymer containing a zirconyl atom may be used alone, or two or more different compounds may be used in combination.

  A compound containing a zirconium atom may be used alone, or two or more different compounds may be used in combination.

  Further, the compound containing an aluminum atom in the molecule that can be used in the present invention does not contain aluminum oxide. Specific examples thereof include aluminum fluoride, hexafluoroaluminic acid (for example, potassium salt), aluminum chloride, Basic aluminum chloride (eg, polyaluminum chloride), tetrachloroaluminate (eg, sodium salt), aluminum bromide, tetrabromoaluminate (eg, potassium salt), aluminum iodide, aluminate (eg, Sodium salt, potassium salt, calcium salt), aluminum chlorate, aluminum perchlorate, aluminum thiocyanate, aluminum sulfate, basic aluminum sulfate, potassium aluminum sulfate (alum), ammonium aluminum sulfate (ammonium alum) Sodium aluminum sulfate, aluminum phosphate, aluminum nitrate, aluminum hydrogen phosphate, aluminum carbonate, polysulfuric acid aluminum silicate, aluminum formate, aluminum acetate, aluminum lactate, aluminum oxalate, aluminum isopropylate, aluminum butyrate, ethyl acetate aluminum diisopropylate, aluminum Examples thereof include tris (acetylacetonate), aluminum tris (ethylacetoacetate), aluminum monoacetylacetonate bis (ethylacetoacetonate), and the like.

  Among these, aluminum chloride, basic aluminum chloride, aluminum sulfate, basic aluminum sulfate, and basic aluminum sulfate silicate are preferable, and basic aluminum chloride and basic aluminum sulfate are most preferable. Specific product names of the above compounds include TAKIBAIN # 1500, which is polyaluminum chloride (PAC) manufactured by Taki Chemical, polyaluminum hydroxide (Paho) manufactured by Asada Chemical Co., and Purachem manufactured by Riken Green Co., Ltd. WT is listed, and various grades are available.

  1-100 mass parts is preferable with respect to 100 mass parts of inorganic oxide particles, and, as for the addition amount of the said inorganic polymer, 2-50 mass parts is still more preferable.

《Thickening polysaccharide》
In the present invention, it is also preferable to use a thickening polysaccharide as the water-soluble resin.

  The thickening polysaccharide that can be used in the present invention is not particularly limited, and examples thereof include generally known natural simple polysaccharides, natural complex polysaccharides, synthetic simple polysaccharides, and synthetic complex polysaccharides. The details of these polysaccharides can be referred to “Biochemical Encyclopedia (2nd edition), Tokyo Chemical Doujinshi”, “Food Industry”, Vol. 31 (1988), p.

  The thickening polysaccharide referred to in the present invention is a saccharide polymer and has a characteristic that promotes a viscosity difference between a low temperature and a high temperature. Furthermore, the viscosity increase is caused by adding the thickening polysaccharide according to the present invention to the coating solution containing the metal oxide fine particles, and the viscosity increase range is such that the viscosity at 15 ° C. is 1.0 mPas. -A polysaccharide that causes an increase of s or more, preferably 5.0 mPa · s or more, more preferably a polysaccharide having a viscosity increasing ability of 10.0 mPa · s or more.

  Examples of the thickening polysaccharide applicable to the present invention include β1-4 glucan (eg, carboxymethylcellulose, carboxyethylcellulose, etc.), galactan (eg, agarose, agaropectin, etc.), galactomannoglycan (eg, locust bean gum). , Guaran, etc.), xyloglucan (eg, tamarind gum, etc.), glucomannoglycan (eg, salmon mannan, wood-derived glucomannan, xanthan gum, etc.), galactoglucomannoglycan (eg, softwood-derived glycan), arabino Galactoglycan (for example, soybean-derived glycan, microorganism-derived glycan, etc.), Glucarnoglycan (for example, gellan gum), glycosaminoglycan (for example, hyaluronic acid, keratan sulfate, etc.), alginic acid and alginate, agar, κ -Natural polymer polysaccharides derived from red algae such as carrageenan, λ-carrageenan, ι-carrageenan, fur celerane and the like, preferably from the viewpoint of not reducing the dispersion stability of the metal oxide fine particles coexisting in the coating solution The structural unit preferably has no carboxylic acid group or sulfonic acid group.

  Such polysaccharides include, for example, pentoses such as L-arabitose, D-ribose, 2-deoxyribose and D-xylose, and hexoses such as D-glucose, D-fructose, D-mannose and D-galactose only. It is preferable that it is a polysaccharide. Specifically, tamarind seed gum known as xyloglucan whose main chain is glucose and side chain is glucose, guar gum known as galactomannan whose main chain is mannose and side chain is glucose, cationized guar gum, Hydroxypropyl guar gum, locust bean gum, tara gum, and arabinogalactan whose main chain is galactose and whose side chain is arabinose can be preferably used.

  In the present invention, tamarind, guar gum, cationized guar gum, and hydroxypropyl guar gum are particularly preferable.

  In the present invention, it is further preferable to use two or more thickening polysaccharides in combination.

  As content of thickening polysaccharide, 5 mass% or more and 50 mass% or less are preferable, and 10 mass% or more and 40 mass% or less are more preferable. However, when used in combination with other water-soluble polymers or emulsion resins, it may be contained in an amount of 3% by mass or more. When there are few thickening polysaccharides, the film surface will be disordered at the time of drying of a coating film, and the tendency for transparency to deteriorate will become large. On the other hand, if the content is 50% by mass or less, the relative content of the metal oxide becomes appropriate, and it becomes easy to increase the difference in refractive index between the high refractive index layer and the low refractive index layer.

<Surfactant>
A surfactant may be added to at least one of the high refractive layer and the low refractive index layer of the present invention. As the activator species, any of anionic, cationic and nonionic types can be used. In particular, acetylene glycol-based nonionic surfactants, quaternary ammonium salt-based cationic surfactants and fluorine-based cationic surfactants are preferred.

  Further, the addition amount of the surfactant according to the present invention is preferably in the range of 0.005 to 0.30% by mass as the solid content when each coating solution is 100% by mass, and more preferably 0.000. It is preferable that it is 01-0.10 mass%.

"Additive"
Next, other additives that can be applied to the infrared reflective layer as a dispersion stabilizer or a crack preventing agent will be described.

"amino acid"
In the present invention, an amino acid can be further added.

  The amino acid referred to in the present invention is a compound having an amino group and a carboxyl group in the same molecule, and may be any type of amino acid such as α-, β-, and γ-, but has an isoelectric point of 6.5 or less. It is preferably an amino acid. Some amino acids have optical isomers, but in the present invention, there is no difference in effect due to optical isomers, and any isomer having an isoelectric point of 6.5 or less is used alone or in racemic form. be able to.

  For a detailed explanation of amino acids applicable to the present invention, reference can be made to the descriptions of pages 268 to 270 of the Chemical Dictionary 1 (reprinted edition, published in 1960).

  In the present invention, preferred amino acids include glycine, alanine, valine, α-aminobutyric acid, γ-aminobutyric acid, β-alanine, serine, ε-amino-n-caproic acid, leucine, norleucine, phenylalanine, threonine, asparagine, asparagine. Acid, histidine, lysine, glutamine, cysteine, methionine, proline, hydroxyproline and the like. For use as an aqueous solution, the solubility at the isoelectric point is preferably 3 g or more with respect to water 100, for example, Glycine, alanine, serine, histidine, lysine, glutamine, cysteine, methionine, proline, hydroxyproline, etc. are preferably used, and from the viewpoint that the metal oxide particles have a gentle hydrogen bond with the binder, serine, hydride having a hydroxyl group. It is more preferable to use a Kishipurorin.

《Lithium compound》
In the present invention, at least one of the high refractive layer and the low refractive index layer can contain a lithium compound together with the metal oxide particles and the water-soluble polymer.

The lithium compound applicable to the present invention is not particularly limited. For example, lithium carbonate, lithium sulfate, lithium nitrate, lithium acetate, lithium orotate, lithium citrate, lithium molybdate, lithium chloride, lithium hydride, water Lithium oxide, lithium bromide, lithium fluoride, lithium iodide, lithium stearate, lithium phosphate, lithium hexafluorophosphate, lithium aluminum hydride, lithium hydride triethylborate, lithium triethoxyaluminum hydride, tantalate Lithium, lithium hypochlorite, lithium oxide, lithium carbide, lithium nitride, lithium niobate, lithium sulfide, lithium borate, LiBF ₄ , LiClO ₄ , LiPF ₄ , LiCF ₃ SO _{3 and the} like are mentioned. Lichiu But from the viewpoint of sufficiently exhibiting the effect of the present invention.

  In the present invention, the addition amount of the lithium compound is preferably in the range of 0.005 to 0.05 g, more preferably 0.01 to 0.03 g, per 1 g of metal oxide particles present in the refractive index layer.

<Emulsion resin>
In the present invention, the high refractive index layer or the low refractive index layer according to the present invention may contain an emulsion resin.

  The emulsion resin referred to in the present invention is resin fine particles obtained by emulsion-polymerizing an oil-soluble monomer in an aqueous solution containing a dispersant and using an initiator.

  In general, as a dispersant used in the polymerization of an emulsion, in addition to a low molecular weight dispersant such as an alkyl sulfonate, an alkyl benzene sulfonate, diethylamine, ethylenediamine, and a quaternary ammonium salt, polyoxyethylene is used. Examples thereof include polymer dispersants such as nonylphenyl ether, polyethylene ethylene laurate ether, hydroxyethyl cellulose, and polyvinylpyrrolidone.

  The emulsion resin according to the present invention is a resin in which fine (average particle size 0.01 to 2 μm) resin particles are dispersed in an aqueous medium in an emulsion state. An oil-soluble monomer is dispersed in a polymer having a hydroxyl group. Obtained by emulsion polymerization using an agent. There is no fundamental difference in the polymer component of the resulting emulsion resin depending on the type of dispersant used, but when emulsion polymerization is performed using a polymer dispersant having a hydroxyl group, the presence of hydroxyl groups is present on at least the surface of fine particles. It is presumed that the chemical and physical properties of the emulsion are different from emulsion resins polymerized using other dispersants.

  The polymer dispersant containing a hydroxyl group is a polymer dispersant having a weight average molecular weight of 10,000 or more, and has a hydroxyl group substituted at the side chain or terminal. For example, an acrylic polymer such as sodium polyacrylate or polyacrylamide is used. Examples of such a polymer include those obtained by copolymerization of 2-ethylhexyl acrylate, polyethers such as polyethylene glycol and polypropylene glycol, and polyvinyl alcohol. Polyvinyl alcohol is particularly preferable.

  Polyvinyl alcohol used as a polymer dispersant is an anion-modified polyvinyl alcohol having an anionic group such as a cation-modified polyvinyl alcohol or a carboxyl group in addition to ordinary polyvinyl alcohol obtained by hydrolysis of polyvinyl acetate. Further, modified polyvinyl alcohol such as silyl-modified polyvinyl alcohol having a silyl group is also included. Polyvinyl alcohol has a higher effect of suppressing the occurrence of cracks when forming the ink absorbing layer when the average degree of polymerization is higher, but when the average degree of polymerization is within 5000, the viscosity of the emulsion resin is not high, and at the time of production Easy to handle. Accordingly, the average degree of polymerization is preferably 300 to 5000, more preferably 1500 to 5000, and particularly preferably 3000 to 4500. The saponification degree of polyvinyl alcohol is preferably 70 to 100 mol%, more preferably 80 to 99.5 mol%.

  Examples of the resin that is emulsion-polymerized with the above polymer dispersant include homopolymers or copolymers of ethylene monomers such as acrylic acid esters, methacrylic acid esters, vinyl compounds, and styrene compounds, and diene compounds such as butadiene and isoprene. Examples of the polymer include acrylic resins, styrene-butadiene resins, and ethylene-vinyl acetate resins.

《Other additives》
Various additives applicable to the high refractive index layer and the low refractive index layer according to the present invention are listed below. For example, ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988 and JP-A-62-261476, JP-A-57-74192, JP-A-57-87989, and JP-A-60-72785. No. 61-146591, JP-A-1-95091 and JP-A-3-13376, etc., and JP-A-59-42993, 59-52689, Fluorescent whitening agents, sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide described in JP-A-62-280069, JP-A-61-228771 and JP-A-4-219266 Contains various known additives such as pH adjusters such as potassium carbonate, antifoaming agents, lubricants such as diethylene glycol, preservatives, antistatic agents, matting agents, etc. It is also possible.

<< Reducing layer containing organic acid as reducing agent >>
The reducing layer containing the organic acid of the present invention as a reducing agent will be described.

  The reducing layer according to the present invention is a layer containing an organic acid as a reducing agent. If this organic acid has a role of reacting with oxygen molecules and consuming oxygen molecules before oxygen molecules react with titanium-based oxides when oxygen molecules are mixed in the reflective layer, there is no particular limitation. No. Specific examples of such organic acids include formic acid, acetic acid, oxalic acid, lactic acid, glucuronic acid, citric acid, phthalic acid, ascorbic acid, erythorbic acid, paratoluenesulfonic acid, α-ketoisocaproic acid, vanillylmandelic acid, and the like. Among them, ascorbic acid and erythorbic acid are preferable in the present invention.

  The content of these reducing agents is preferably 0.1% by mass to 50% by mass of the reducing layer, and more preferably 1% by mass to 30% by mass. If it exceeds 0.1% by mass, the long-term storage stability of the infrared reflective film tends to be improved, and if it is less than 50% by mass, the appearance quality of the coating film is improved.

  The reducing layer preferably has a binder component in addition to the reducing agent. The binder may be a solvent-based binder such as polyvinyl butyral resin, polyacrylate resin, polyurethane resin, polyimide resin, polyamide resin, aramid resin, polyamideimide resin, photocurable acrylic resin, thermosetting acrylic resin, or the like. Any of the above-mentioned aqueous binders may be used, but in the present invention, an aqueous binder is preferable, and polyvinyl alcohol is more preferable.

  In addition, additives similar to the above-described infrared reflection layer, such as a surfactant, can be added as necessary.

<< Configuration of reducing layer containing organic acid as reducing agent >>
In order to obtain the effect of the present invention, the reducing layer only needs to be present in the constituted infrared reflective film, and the same side as the infrared reflective layer on the substrate or the vertical of the edge of the infrared reflective film. It is preferable to be provided on the edge surface. Either a configuration in which a reducing layer is formed in a direction parallel to the substrate and the film surface, a configuration in which a reducing layer is installed on the vertical edge surface of the film end, or a configuration having both, may be used. More preferably, the layer is formed in a direction parallel to the film surface. Usually, since it sticks to glass on a window film, it is preferable that the adhesion layer mentioned later is installed in the outermost surface. The outermost layer on the side opposite to the adhesive layer is provided with a hard coat layer described later for the purpose of protecting the film. As an example of the configuration of the present invention, a base material and an infrared reflection layer are present between the adhesive layer and the hard coat layer, and at the same time, a reduction layer is also present between the adhesive layer and the hard coat layer. In this configuration, a configuration in which a reducing layer is also present on the vertical edge surface of the film end is also a preferable example. The base material, the infrared reflective layer, and the reducing layer may be laminated in any order, and any layer may be present in plural layers. Further, another functional layer can be combined at an arbitrary position between the adhesive layer and the hard coat layer.

  The thickness of the reducing layer is preferably 0.5 to 50 μm, more preferably 1 to 20 μm. When the thickness is more than 0.5 μm, the durability of the infrared reflective film tends to be improved, and when the thickness is less than 20 μm, the transparency of the film tends to be improved.

  Note that the reducing layer may serve as either the hard coat layer or the infrared absorption layer described above, or both.

《Adhesive and adhesive layer》
An adhesive layer can be provided on any outermost surface of the infrared reflective film of the present invention.

  As an adhesive which comprises the adhesive layer of this invention, an acrylic adhesive, a silicone adhesive, a urethane adhesive, a polyvinyl butyral adhesive, an ethylene-vinyl acetate adhesive etc. can be illustrated, for example.

  When the infrared reflective film of the present invention is attached to a window glass, a method of applying water to the window and attaching the adhesive layer of the infrared reflective film to a wet glass surface, the so-called water application method is preferably used. It is done. For this reason, an acrylic pressure-sensitive adhesive that has a weak adhesive force in the presence of water is preferably used.

  The acrylic pressure-sensitive adhesive used in the present invention may be either solvent-based or emulsion-based, but is preferably a solvent-based pressure-sensitive adhesive because it is easy to increase the adhesive strength and the like, and among them, those obtained by solution polymerization are preferable. Examples of raw materials for producing such an acrylic solvent-based pressure-sensitive adhesive by solution polymerization include, for example, acrylic acid esters such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and acryl acrylate, and agglomerates as the main monomer serving as a skeleton. As a comonomer to improve strength, vinyl acetate, acrylonitrile, styrene, methyl methacrylate, etc., to further promote cross-linking, to give stable adhesive force, and to maintain some adhesive force even in the presence of water Examples of the functional group-containing monomer include methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate, glycidyl methacrylate, and the like. Since the adhesive layer of the laminated film requires a particularly high tack as the main polymer, those having a low glass transition temperature (Tg) such as butyl acrylate are particularly useful.

  This adhesive layer contains additives such as stabilizers, surfactants, UV absorbers, flame retardants, antistatic agents, antioxidants, thermal stabilizers, lubricants, fillers, coloring, adhesion modifiers, etc. It can also be made. In particular, when it is used for window sticking as in the present invention, the addition of an ultraviolet absorber is effective in order to suppress the deterioration of the infrared reflective film due to ultraviolet rays.

  The thickness of the adhesive layer is preferably 1 μm to 100 μm, more preferably 3 to 50 μm. When it is thicker than 1 μm, an adhesive force sufficient for improving the adhesiveness can be obtained. On the other hand, when the thickness is less than 100 μm, not only the transparency of the infrared reflective film is improved, but also, when the film is attached to the window glass and then peeled off, no cohesive failure occurs between the adhesive layers, and the glass surface is not damaged. There is a tendency for the adhesive material to remain stiff.

  Note that the adhesive layer may also serve as the above-described reducing layer.

<Infrared absorbing layer>
The infrared reflective film in this invention can have an infrared absorption layer in arbitrary positions.

  An example of the infrared absorption layer is a layer containing an ultraviolet curable resin, a photopolymerization initiator, and an infrared absorber.

  The ultraviolet curable resin is more advantageous than other resins in terms of hardness, smoothness, and dispersibility of ITO, ATO and heat conductive metal oxide. The ultraviolet curable resin can be used without particular limitation as long as it forms a transparent resin composition by curing, and examples thereof include silicone resins, epoxy resins, vinyl ester resins, acrylic resins, and allyl ester resins. . Particularly preferably, an acrylic resin can be used from the viewpoints of hardness, smoothness, and transparency.

  The acrylic resin in the present invention is a reaction in which a photosensitive group having photopolymerization reactivity is introduced on the surface as described in International Publication No. 2008/035669 from the viewpoint of hardness, smoothness, and transparency. It is preferable to contain reactive silica particles (hereinafter also simply referred to as “reactive silica particles”). Here, examples of the photopolymerizable photosensitive group include a polymerizable unsaturated group represented by a (meth) acryloyloxy group. The photosensitive resin contains a photopolymerizable photosensitive group introduced on the surface of the reactive silica particles and a compound capable of photopolymerization, for example, an unsaturated organic compound having a polymerizable unsaturated group. It may be. In addition, a polymerizable unsaturated group-modified hydrolyzable silane reacts with a silica particle that forms a silyloxy group and is chemically bonded to the silica particle by a hydrolysis reaction of the hydrolyzable silyl group. Can be used as conductive silica particles. Here, the average particle diameter of the reactive silica particles is preferably 0.001 to 0.1 μm. By setting the average particle diameter in such a range, transparency, smoothness, and hardness can be satisfied in a well-balanced manner.

  Moreover, a fluorine-containing vinyl monomer can also be used for the acrylic resin of this invention at the point which can adjust a refractive index. Examples of the fluorine-containing vinyl monomer include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, etc.), (meth) acrylic acid moieties or fully fluorinated alkyl ester derivatives (for example, biscoat 6FM (trade name) And R-2020 (trade name, manufactured by Daikin) and the like, and fully or partially fluorinated vinyl ethers.

  Moreover, as a photoinitiator, a well-known thing can be used and it can be used by 1 type, or 2 or more types of combination.

In the present invention, as an inorganic infrared absorber, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), lanthanum hexaboride, etc. from the viewpoint of visible light transmittance, infrared absorptivity, suitability for dispersion in resin, and the like. (LaB ₆ ), tungsten cesium oxide (Cs _0.33 WO ₃ ) and the like are preferable, and these may be used alone or in combination. As an average particle diameter, 5-100 nm is preferable and especially 10-50 nm is preferable. If it is less than 5 nm, dispersibility in the resin and infrared absorptivity deteriorate. On the other hand, if it is larger than 100 nm, the visible light transmittance is undesirably deteriorated. The measurement of the average particle diameter in the present invention is obtained by taking an image with a transmission electron microscope, randomly extracting, for example, 50 particles, measuring the particle diameter, and averaging these. If the particle shape is not spherical, the major axis is measured and calculated.

  The content of the inorganic infrared absorbing material in the infrared absorbing layer depends on the entire layer content, but when expressed in% of the entire layer, it is in the range of 1 to 80%, particularly 5 to 50%. preferable. If the content is 1% or more, a sufficient infrared absorption effect appears, and if it is 80% or less, a sufficient amount of visible light can be transmitted.

  In the present invention, other infrared absorbers such as metal oxides other than those described above, organic compounds, and metal complexes may be used in combination within the range where the effects of the present invention are exhibited. For example, diimonium compounds, aluminum compounds, phthalocyanine compounds, organometallic complexes, cyanine compounds, azo compounds, polymethine compounds, quinone compounds, diphenylmethane compounds, triphenylmethane compounds, and the like can be used in combination.

  The thickness of the infrared absorption layer is preferably 0.1 μm to 50 μm, more preferably 1 to 20 μm. When it becomes thicker than 0.1 μm, the infrared absorption ability tends to be improved. Conversely, when it becomes thinner than 50 μm, the crack resistance of the coating film is improved.

《Hard coat layer》
The infrared reflective film of the present invention is made of a resin that is cured by heat, ultraviolet light, or the like, as a surface protective layer for improving scratch resistance, on the uppermost layer on the opposite side of the adhesive layer through the base material and the infrared reflective layer. It is preferable to laminate a hard coat layer.

  The curable resin used in the hard coat layer is curable with heat or ultraviolet light, and is easy to mold. Therefore, an ultraviolet curable resin, particularly one having a pencil hardness of at least 2H is preferable. The pencil hardness can be measured by the method described in JIS K5600-5-4.

  Examples of such an ultraviolet curable resin are synthesized from a polyfunctional acrylate resin such as acrylic acid or methacrylic acid ester having a polyhydric alcohol, and acrylic acid or methacrylic acid having a diisocyanate and a polyhydric alcohol. Examples of such polyfunctional urethane acrylate resins. Furthermore, polyether resins, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins or polythiol polyene resins having an acrylate-based functional group can also be suitably used.

  Reactive diluents for these resins include 1,6-hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, hexanediol ( Bi- or higher functional monomers and oligomers such as (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (metha) acrylate, dipentaerythritol hexa (meth) acrylate, neopentyl glycol di (meth) acrylate, and the like Acrylates such as N-vinylpyrrolidone, ethyl acrylate, propyl acrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl Methacrylic acid esters such as acrylate, isooctyl methacrylate, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, and nonylphenyl methacrylate, tetrahydrofurfuryl methacrylate, and its derivatives such as caprolactone, styrene, α-methylstyrene, acrylic acid, etc. These are not limited to one type, and two or more types may be used in combination.

  Furthermore, as photosensitizers (radical polymerization initiators) for these resins, benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl methyl ketal; acetophenone, 2, Acetophenones such as 2-dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexyl phenyl ketone; anthraquinones such as methylanthraquinone, 2-ethylanthraquinone and 2-amylanthraquinone; thioxanthone, 2,4-diethylthioxanthone, 2,4- Thioxanthones such as diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone, 4,4-bismethi Benzophenones such as aminobenzophenone and azo compounds, and the like. These can be used alone or as a mixture of two or more thereof, and further, tertiary amines such as triethanolamine and methyldiethanolamine; benzoic acid derivatives such as 2-dimethylaminoethylbenzoic acid and ethyl 4-dimethylaminobenzoate, etc. It can be used in combination with a photoinitiator aid or the like. The amount of these organic peroxides and photopolymerization initiators used is 0.5 to 20 parts by mass, preferably 1 to 15 parts by mass with respect to 100 parts by mass of the polymerizable component of the resin composition.

  In addition, the above-mentioned curable resin may be blended with known general paint additives as necessary. For example, a silicone-based or fluorine-based additive that imparts leveling, surface slip properties, etc. is effective in preventing scratches on the surface of the cured film, and when using ultraviolet rays as active energy rays, the additive air Bleeding to the interface can reduce the inhibition of curing of the resin by oxygen, and an effective degree of curing can be obtained even under low irradiation intensity conditions.

  The hard coat layer preferably contains inorganic fine particles. Preferred inorganic particles include fine particles of an inorganic compound containing titanium, silica, zirconium, aluminum, magnesium, zinc, tin, or the like. The inorganic fine particles preferably have a particle size of at most 1000 nm, particularly in the range of 10 to 500 nm, in order to ensure visible light transmission. In addition, since inorganic fine particles have a higher bond strength with the curable resin forming the hard coat layer, they can be prevented from falling out of the hard coat layer, so that a photosensitive resin having photopolymerization reactivity such as a monofunctional or polyfunctional acrylate. It is preferable that a functional group is introduced on the surface.

  The thickness of the hard coat layer is preferably 0.1 μm to 50 μm, more preferably 1 to 20 μm. When it becomes thicker than 0.1 μm, the hard coat property tends to be improved. Conversely, when it becomes thinner than 50 μm, the transparency of the infrared reflecting film tends to improve.

  Note that the hard coat layer may serve as either the above-described reduction layer or infrared absorption layer, or both.

<< Infrared reflective film manufacturing method >>
The infrared reflective film of the present invention is formed by laminating a unit composed of a high refractive index layer and a low refractive index layer on a substrate to form an infrared reflective layer. Specifically, it is preferable to form a laminate by wet application and drying of an aqueous high refractive index layer coating solution and a low refractive index layer coating solution alternately.

  Examples of the coating method include a roll coating method, a rod bar coating method, an air knife coating method, a spray coating method, a curtain coating method, or US Pat. Nos. 2,761,419 and 2,761,791. A slide bead coating method using an hopper, an extrusion coating method, or the like is preferably used.

  When the slide bead coating method is used, the viscosity of the high refractive index layer coating solution and the low refractive index layer coating solution in simultaneous multilayer coating is preferably in the range of 5 to 100 mPa · s, more preferably 10 to 10 mPa · s. The range is 50 mPa · s. Moreover, when using a curtain application | coating system, the range of 5-1200 mPa * s is preferable, More preferably, it is the range of 25-500 mPa * s.

  Further, the viscosity at 15 ° C. of the coating solution is preferably 100 mPa · s or more, more preferably 100 to 30,000 mPa · s, further preferably 3,000 to 30,000 mPa · s, and most preferably 10 , 30,000 to 30,000 mPa · s.

  As a coating and drying method, the water-based high-refractive index layer coating solution and the low-refractive index layer coating solution are heated to 30 ° C. or more, and after coating, the temperature of the formed coating film is set to 1 to 15 ° C. It is preferably cooled once and dried at 10 ° C. or higher, and more preferably, the drying conditions are a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 10 to 50 ° C. Moreover, as a cooling method immediately after application | coating, it is preferable to carry out by a horizontal set system from a viewpoint of the formed coating-film uniformity.

  As the coating method of the reducing layer according to the present invention, any known method can be used, for example, die coater method, gravure roll coater method, blade coater method, spray coater method, air knife coat method, dip coat method, transfer The method etc. are mentioned preferably and can be applied alone or in combination. A solvent suitable for the binder used in the reduction layer can be used and coating can be performed using a coating solution. If the solvent can dissolve the binder, a known solvent can be used. If the solvent is the same as that of the infrared reflection layer described above, a multilayer coating can be applied simultaneously with the infrared reflection layer.

  In order to install the reducing layer on the vertical edge surface at the end of the film, for example, a dip coating method, a die coater method, a transfer method, and the like are preferably used, and these can be applied alone or in combination.

  As an adhesive coating method, any known method can be used. For example, a die coater method, a gravure roll coater method, a blade coater method, a spray coater method, an air knife coating method, a dip coating method, a transfer method, etc. are preferable. Can be used alone or in combination. These can be appropriately formed into a solution in a solvent capable of dissolving the pressure-sensitive adhesive, or can be applied using a dispersed coating solution, and known solvents can be used.

  The adhesive layer may be formed directly on the infrared reflective film by the previous coating method, or once coated on a release paper and dried, and then a plastic film is bonded to the adhesive. May be transferred. The drying temperature at this time is preferably such that the residual solvent is reduced as much as possible. For this purpose, the drying temperature and time are not specified, but preferably a drying time of 10 seconds to 5 minutes is provided at a temperature of 50 to 150 ° C. Is good. In addition, since the adhesive has fluidity, the reaction is not yet completed immediately after drying by heating, and curing is necessary to complete the reaction and obtain a stable adhesive force. In general, when heated at room temperature for about one week or longer, for example, about 50 ° C. is preferably 3 days or longer. In the case of heating, if the temperature is raised too much, the flatness of the plastic film may be deteriorated.

  The method for forming the infrared absorption layer and the hard coat layer is not particularly limited, but the die coater method, gravure roll coater method, spin coating method, spray method, blade coating method, air knife coating method, dip coating method, transfer method, etc. It is preferably formed by a wet coating method or a dry coating method such as a vapor deposition method.

  As a method of curing by ultraviolet irradiation, ultraviolet rays in a wavelength region of 100 to 400 nm, preferably 200 to 400 nm, emitted from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp, etc. It can be performed by irradiating an electron beam having a wavelength region of 100 nm or less emitted from a curtain type electron beam accelerator.

<Infrared reflector>
The infrared reflector of the present invention represents an embodiment in which the infrared reflective film of the present invention is provided on at least one surface of a substrate.

  As the substrate, a plastic substrate, a metal substrate, a ceramic substrate, a cloth substrate and the like are preferable, and the infrared reflective film of the present invention is applied to a substrate in various forms such as a film shape, a plate shape, a spherical shape, a cubic shape and a rectangular parallelepiped shape. Says the state of installation. Among them, a plate-like ceramic substrate is preferable, and an infrared reflector in which the infrared reflection film of the present invention is provided on a glass plate is preferable. As an example of the glass plate, for example, a float plate glass and a polished plate glass described in JIS R 3202 are preferable, and the glass thickness is preferably 0.01 mm to 20 mm. When it is thicker than 0.01 mm, the effect of long-term durability of the present invention is further obtained, and when it is thinner than 20 mm, the infrared reflectance of the infrared reflective film of the present invention is effectively obtained.

  As a method for providing the infrared reflective film of the present invention on the substrate, a method in which an adhesive layer is applied to the infrared reflective film as described above, and is attached to the substrate via the adhesive layer is preferably used.

  As a pasting method, a dry pasting method in which a film is pasted on a substrate as it is, and a water pasting method as described above can be applied, but in order to prevent air from entering between the base member and the infrared reflection film, From the viewpoint of ease of construction, such as positioning of the infrared reflective film on the substrate, it is more preferable to bond by a water bonding method.

  The infrared reflector of the present invention refers to an embodiment in which the infrared reflective film of the present invention is provided on at least one surface of the substrate. A state in which a plurality of substrates are provided may be used. For example, the aspect which provided the infrared reflective film of this invention on both surfaces of the above-mentioned plate glass, the adhesion layer was coated on both surfaces of the infrared reflective film of this invention, and the above-mentioned plate glass was bonded together on both surfaces of the infrared reflective film A laminated glass-like embodiment may be used.

<Application of infrared reflective film>
The infrared reflective film of the present invention can be applied to a wide range of fields. For example, film for window pasting such as heat ray reflective film, which is attached to window glass exposed to sunlight, such as outdoor windows of buildings and automobile windows, and gives a heat ray reflecting effect to suppress an excessive rise in indoor temperature, vinyl for agriculture As a film for a house, etc., it is mainly used for the purpose of an agricultural film provided with a heat ray reflection effect for suppressing an excessive increase in the temperature inside the house.

  Also, like laminated glass for automobiles, the infrared reflective film of the present invention is sandwiched between glass and glass, and used as a heat ray reflective film for automobiles. In this case, the infrared reflective film can be sealed from outside air gas, It is preferable from the viewpoint of durability.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

(Preparation of coating solution for low refractive index layer)
3 parts by weight of acid-treated gelatin (isoelectric point: 9.5, average molecular weight: 20,000) as a water-soluble resin is added to 187 parts by weight of pure water, and the temperature is raised to 40 ° C. while stirring and mixing to dissolve the gelatin. As a result, an aqueous gelatin solution was obtained.

  Subsequently, 10.0 mass% acidic silica sol (Snowtex OXS: manufactured by Nissan Chemical Industries, Ltd.) containing silica fine particles having an average particle diameter of 5 nm was gradually added to 10 parts by mass with stirring and mixed. Furthermore, 0.02 parts by mass of Surflon S221 (manufactured by AGC Chemical Co.) was added as a fluorine-based cationic activator to prepare a coating solution for a low refractive index layer. As described below, 0.1 g of formalin (manufactured by Kanto Chemical Co., Inc.) was added as a curing agent immediately before application to the substrate.

(Preparation of coating solution for high refractive index layer)
3 parts by mass of acid-treated gelatin (isoelectric point: 9.5, average molecular weight: 20,000) as a water-soluble resin is added to 182 parts by mass of pure water, and the temperature is raised to 40 ° C. while stirring and mixing to dissolve the gelatin. As a result, an aqueous gelatin solution was obtained.

  Subsequently, the gelatin aqueous solution was gradually added and mixed with stirring to 15 parts by mass of a 20.0% by mass titanium oxide sol containing rutile type titanium oxide fine particles having an average particle diameter of 35 nm. Furthermore, 0.07 parts by mass of Surflon S221 (manufactured by AGC Chemical Co., Ltd.) was added as a fluorine-based cationic activator to prepare a coating solution for a high refractive index layer. As described below, 0.1 g of formalin (manufactured by Kanto Chemical Co., Inc.) was added as a curing agent immediately before application to the substrate.

  In addition, when the refractive index of these application layers was measured by the above-mentioned method, the low refractive index layer 1 was 1.43 and the high refractive index layer 1 was 1.98.

(Preparation of coating liquid OR-1 for reducing layer)
By adding 8.1 parts by mass of polyvinyl alcohol resin (PVA224: manufactured by Kuraray Co., Ltd.) as a water-soluble resin to 190 parts by mass of pure water, the temperature is raised to 85 ° C. while stirring and mixing to dissolve the polyvinyl alcohol resin. An alcohol resin aqueous solution was obtained.

  Next, ascorbic acid (manufactured by Kanto Chemical Co., Inc.) as a reducing agent was added in 1.5 parts by mass and dissolved and mixed. Furthermore, as a fluorine-based cation activator, 0.05 part by mass of Surflon S221 (manufactured by AGC Chemical Co., Ltd.) is added, 0.35 part by mass of boric acid is added, and the mixture is stirred and mixed for a reducing layer containing an organic acid as a reducing agent. Coating liquid OR-1 was prepared.

(Preparation of coating liquid OR-2 for reducing layer)
In the preparation of the reducing layer coating liquid OR-1, the reducing layer coating liquid OR-2 containing an organic acid as a reducing agent was prepared in the same manner except that the reducing agent ascorbic acid was changed to erythorbic acid. did.

(Preparation of coating liquid OR-3 for reducing layer)
Polyvinylpyrrolidone resin is obtained by adding 8.95 parts by mass of polyvinylpyrrolidone resin (PVP K-85: manufactured by Nippon Shokubai Co., Ltd.) as a water-soluble resin to 190 parts by mass of pure water and dissolving the polyvinylpyrrolidone resin with stirring and mixing. An aqueous solution was obtained.

  Next, phthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reducing agent was added in 1 part by mass and dissolved and mixed. Further, 0.05 part by mass of Surflon S221 (manufactured by AGC Chemical Co., Ltd.) was added as a fluorine-based cationic activator and mixed by stirring to prepare a reducing layer coating solution OR-3 containing an organic acid as a reducing agent.

(Preparation of coating solution OR-4 for comparative reduction layer: comparison)
In the preparation of the coating liquid OR-1 for the reducing layer, ascorbic acid is not added, but a reducing agent is not contained in the same manner except that polyvinyl alcohol is increased from 8.1 parts by mass to 9.6 parts by mass. A comparative reducing layer coating solution OR-4 was prepared.

(Preparation of coating solution OR-5 for comparative reduction layer: comparison)
In the preparation of the coating liquid OR-1 for the reducing layer, a comparative reduction not containing an organic acid is performed in the same manner except that a compound having a UV absorption function, TINUVIN 1130 (manufactured by BASF Japan) is added instead of ascorbic acid. A layer coating solution OR-5 was obtained.

(Preparation of hard coat layer coating solution)
7.5 parts by mass of UV curable hard coat material (UV-7600B: manufactured by Nippon Synthetic Chemical Co., Ltd.) is added to 90 parts by mass of methyl ethyl ketone solvent, and then photopolymerization initiator (Irgacure 184: manufactured by BASF Japan) 0.5 mass Part was added and mixed with stirring. Subsequently, 2 parts by mass of ITO powder (ultrafine particle ITO: manufactured by Sumitomo Metal Mining Co., Ltd.) was added and stirred at high speed with a homogenizer to prepare a hard coat layer coating solution.

(Creation of adhesive layer coating solution)
60 parts by mass of ethyl acetate and 20 parts by mass of toluene were mixed, and further 20 g of acrylic adhesive (Arontack M-300: manufactured by Toagosei Co., Ltd.) was added and mixed by stirring to prepare an adhesive coating solution.

<Creation of infrared reflective film>
(Preparation of infrared reflection film 1 of the present invention)
Hereinafter, the sample of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of the layer structure of the infrared reflective film used in the examples. The production of the infrared reflective film 1 of the present invention will be described with reference to FIG.

  As a base material 1, a coating liquid OR-1 for reducing layer containing an organic acid as a reducing agent on one side of a polyethylene terephthalate (PET) film (Toyobo A4300: double-sided easy-adhesion layer) having a size of 30 cm × 30 cm and a thickness of 50 μm is wired. The reduction layer 2 was applied by applying with a bar and drying with hot air at 50 ° C. for 5 minutes.

  Next, on the same side as the reducing layer 2, a slide hopper coating apparatus capable of simultaneously coating 21 layers is used, and the above-prepared coating solution for the low refractive index layer and the coating solution for the high refractive index layer are placed on the side close to the reducing layer. 11 layers of low refractive index layers, 10 layers of high refractive index layers, and 21 layers in total were heated alternately at 45 ° C., and simultaneous multilayer coating was performed on the reducing layer. Immediately thereafter, cold air was blown for 1 minute under conditions where the film surface was 15 ° C. or lower, and then dried by blowing hot air of 50 ° C. to form an infrared reflective layer 3 consisting of 21 layers.

Furthermore, the coating liquid for hard-coat layers was apply | coated to the PET film surface on the opposite side to an infrared reflective layer with a wire bar, and it dried with hot air at 70 degreeC for 3 minutes. Thereafter, the hard coat layer 4 was formed by curing under a curing condition of 400 mJ / cm ² with a UV curing apparatus (using a high-pressure mercury lamp) manufactured by Eye Graphics Co., Ltd. in the atmosphere.

  The pressure-sensitive adhesive layer was prepared by applying the pressure-sensitive adhesive layer 6 to the separator film 5 and then bonding it to the above film.

  As the separator film 5, a 25 μm-thick polyester film (therapy: manufactured by Toyo Metallizing Co., Ltd.) was used. On the separator film, an adhesive coating solution was applied with a wire bar, and dried at 50 ° C. for 2 minutes to prepare a film with an adhesive layer.

  The infrared reflective layer side of the obtained infrared reflective film and the adhesive layer side of the film with an adhesive layer were bonded by a bonding machine. At this time, the tension at the time of bonding on the infrared reflective film side was 10 kg / m, and the tension at the time of bonding of the film with the adhesive layer was 30 kg / m.

  Finally, the obtained film was cut into 25 cm × 25 cm to obtain an infrared reflective film 1 having the layer structure of FIG.

  When the cross section of the coating film was observed by SEM, the thickness of the reducing layer was 2 μm, the thickness of the low refractive index layer was 170 nm, and the thickness of the high refractive index layer was 130 nm. The hard coat layer was 3 μm, and the adhesive layer was 15 μm.

(Creation of infrared reflection films 12 and 15 for comparison with infrared reflection films 2 and 3 of the present invention)
In the production of the infrared reflective film 1 having the layer structure of FIG. 1 (A), a reducing layer containing an organic acid as a reducing agent is contained as a reducing agent from the reducing layer coating liquid OR-1. In the same manner, except for changing to the reducing layer coating liquid OR-2, the reducing layer coating liquid OR-3, the comparative reducing layer coating liquid OR-4, and the comparative reducing layer coating liquid OR-5, red External reflection films 2 and 3 and comparative infrared reflection films 12 and 15 were prepared, respectively.

(Preparation of infrared reflective films 4 and 5 of the present invention)
In preparation of the infrared reflective film 1, only the coating order of the reducing layer 2 and the infrared reflective layer 3 was changed, and the infrared reflective film 4 shown by the layer structure of FIG. 1 (B) was obtained. Furthermore, in preparation of the infrared reflective film 4, only the reducing layer was changed from the reducing layer coating liquid OR-1 prepared above to the reducing layer coating liquid OR-3, and the infrared reflective film 5 was similarly prepared. .

(Preparation of infrared reflection films 6 and 7 of the present invention)
In the production of the infrared reflective film 1, the order of application of the reducing layer is changed before the application of the hard coat layer, and the layer shown in FIG. The infrared reflective film 6 shown by the structure was obtained. Further, in the production of the infrared reflective film 6, the infrared reflective film 7 was similarly produced by changing only the reducing layer from the reducing layer coating liquid OR-1 created above to the reducing layer coating liquid OR-3. .

(Preparation of infrared reflection films 8 and 9 of the present invention)
After a comparative infrared reflective film 14 having no reducing layer, which will be described later, was prepared once, the obtained film was cut to 25 cm × 25 cm, and then the cut film cross-section 4 surface was 5 mm in the reducing layer coating liquid OR-1. Soaked for 5 seconds and pulled up. Thereafter, the film was dried with hot air at 50 ° C. for 5 minutes to obtain an infrared reflective film 8 of the present invention in which a reducing layer was coated on the film cross section.

  In the production of the infrared reflection film 8, only the reduction layer was changed from the reduction layer coating liquid OR-1 created above to the reduction layer coating liquid OR-3, and the infrared reflection film 9 was similarly produced.

  The layer structure of the infrared reflective films 8 and 9 is shown in FIG.

(Infrared reflective film 10 of the present invention, creation of comparative infrared reflective film 13)
After the infrared reflective film 1 was cut into 25 cm × 25 cm, the cut film cross-section 4 was dipped in the reducing layer coating solution OR-1 for 5 mm for 5 seconds and pulled up. Thereafter, the film was dried with hot air at 50 ° C. for 5 minutes to obtain an infrared reflective film 10 of the present invention in which a reducing layer containing an organic acid as a reducing agent was coated on the film cross section.

  After the infrared reflective film 12 was cut to 25 cm × 25 cm, the cut four cross sections of the film were immersed in a comparative reducing layer coating solution OR-4 containing no reducing agent for 5 mm for 5 seconds and pulled up. Then, the comparative infrared reflective film 13 was obtained by drying with hot air at 50 ° C. for 5 minutes.

  The layer structure of the infrared reflective films 10 and 13 is shown in FIG.

(Preparation of the infrared reflective film 11 of the present invention)
In preparation of the infrared reflective film 1, the hard coat layer was applied without applying the reducing layer coating solution.

  Subsequently, a reduction layer coating solution OR-1 containing an organic acid as a reducing agent is applied onto the hard coat layer with a wire bar so that the dry film thickness is 2 μm, and dried with hot air at 50 ° C. for 5 minutes. Was applied as a reducing agent.

  After the obtained film was cut into 25 cm × 25 cm, the cut four cross sections of the film were immersed in the reducing layer coating solution 0R-1 for 5 mm for 5 seconds and pulled up. Thereafter, the film was dried with hot air at 50 ° C. for 5 minutes to obtain an infrared reflective film 11 of the present invention in which a reducing layer OR-1 containing an organic acid as a reducing agent was coated on the film cross section.

  The layer structure of the infrared reflective film 11 is shown in FIG.

(Preparation of comparative infrared reflection film 14)
In preparation of the infrared reflective film 1, the comparative infrared reflective film 14 which does not have a reduction layer was created by the same method by not applying the reduction layer coating liquid OR-1.

  The layer structure of the infrared reflective film 14 is shown in FIG.

<< Creation of infrared reflectors 1-15 >>
About each of the obtained infrared reflective films 1-15, after peeling a separator, it is about 300 mm per minute using the press roller prescribed | regulated to JISZ0237 to the float plate glass of thickness 3mm and 300mmx300mm as a base | substrate. Infrared reflectors 1 to 15 were made by reciprocating once and crimping at high speed.

<Evaluation>
(Light-resistant forced deterioration conditions)
For the infrared reflector attached to the glass as described above, use a metal halide lamp type weather resistance tester (manufactured by Daipura Wintes Co., Ltd.), place the sample so that light enters from the glass surface, and the sample surface radiation intensity : 2.16 MJ / m ² or less, a black panel temperature of 63 ° C., a relative humidity of 50%, and a film was forcibly deteriorated under an irradiation time of 500 hours. The initial measured value before forced degradation and the measured value after forced degradation were measured by the following methods. By measuring the infrared reflectance change, the film color tone change, the stress at the time of film extension and the elongation at break, the intensity change, infrared reflectance change and color tone change when exposed to sunlight for a long time were evaluated.

(Evaluation of infrared reflectance)
The reflectance in the 800-1400 nm area | region was measured for the infrared reflector affixed on glass using the spectrophotometer (The integrating sphere use, the Hitachi Ltd. make, U-4000 type | mold). The sample was placed so that light intrusion during the measurement came from the glass surface. The measurement was performed 3 times, the average value was calculated | required, and it was set as the infrared reflectance. Infrared reflective film that can withstand practical use when the difference in infrared reflectivity before and after forced deterioration of light resistance (Δ reflectivity) is smaller is a highly durable infrared reflector, and Δ reflectivity is 20 or less. It is.

(Color change)
The color tone of the infrared reflector affixed to the glass was measured using a color difference meter (Gretag) in accordance with JIS Z 8721. Based on JIS Z 8729, b ^* was recorded as the measured value, and the change in the value was used as an index of color tone change. A smaller b ^* difference (Δb ^* ) before and after forced deterioration of light resistance is a more durable infrared reflector, and an infrared reflector that can withstand practical use with Δb ^* of 5 or less.

(Elongation stress and elongation at break)
The infrared reflective film affixed to the glass was peeled off, and the adhesive layer was peeled off with ethanol. Thereafter, the sample was cut into a strip shape having a length of 180 mm and a width of 10 mm with a single-blade razor. Next, the strip-shaped sample was pulled using a tensile tester (manufactured by Toyo Seiki Co., Ltd.), and the 100% elongation stress (MPa) and elongation at break (%) in each direction were determined from the obtained load-strain curve. .

  The measurement was performed in an atmosphere of 25 ° C. under the conditions of an initial length (distance between marked lines) of 40 mm, a distance between chucks of 100 mm, a crosshead speed of 100 mm / min, a chart speed of the recorder of 200 mm / min, and a load cell 245N. . In addition, this measurement was performed 10 times and the average value was used. The smaller the difference between the stress at elongation and the elongation at break (Δ elongation stress, Δ elongation at break) before and after forced deterioration of light resistance, the more highly durable infrared reflective film, the Δ elongation stress is 40 or less In addition, it is an infrared reflection film having a Δbreak elongation of 55 or less and can withstand practical use.

  Table 1 summarizes the outline of the configuration of the sample and the results obtained by the above evaluation.

  As shown in Table 1, by adopting the configuration of the present invention, even in an environment exposed to high UV illuminance, the film is deteriorated in strength, reduced in infrared reflectance, and has little change in color tone. A reflector can be provided. In particular, when the reducing layer containing an organic acid as a reducing agent is installed between the alternating layers that are the base material and the infrared reflecting layer, the effect of the present invention is particularly prominent.

DESCRIPTION OF SYMBOLS 1 Base material 2 Reducing layer 3 Infrared reflective layer 4 Hard coat layer 5 Separator film 6 Adhesive layer

Claims (5)

In an infrared reflective film comprising a low refractive index layer and a high refractive index layer alternately laminated, and an infrared reflective layer having a titanium-based oxide in at least one of the alternate laminated layers is formed on any one surface of the substrate. , have a reduced layer the infrared reflective film contains an organic acid as a reducing agent,
Infrared-reflective film wherein the reducing layer, characterized that you have been formed between the substrate and alternately stacked.   The infrared reflective film according to claim 1, wherein the reducing layer is formed in a direction parallel to the base material. The infrared reflective film according to claim 1, wherein the reducing layer has a binder component. The infrared reflective film according to any one of claims 1 to 3, wherein the low refractive index layer and the high refractive index layer contain a water-soluble resin and metal oxide particles. An infrared reflector, wherein the infrared reflective film according to any one of claims 1 to 4 is provided on at least one surface of a substrate.

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