WO2015190536A1

WO2015190536A1 - Optical reflection film, and optical reflection body

Info

Publication number: WO2015190536A1
Application number: PCT/JP2015/066788
Authority: WO
Inventors: 斉藤　洋一
Original assignee: コニカミノルタ株式会社
Priority date: 2014-06-12
Filing date: 2015-06-10
Publication date: 2015-12-17
Also published as: JPWO2015190536A1

Abstract

　The present invention provides an optical reflection body and an optical reflection film that can inhibit and prevent thermal cracking. The optical reflection film according to the present invention comprises a substrate, an optical reflection layer, an infrared-absorbing nanoparticle layer, and a heat dissipation promoting layer, and is characterised in that: the heat dissipation promoting layer is disposed on the outermost layer on the light-incident side; the ratio (d1/d2) of the film thickness (d1) of the infrared-absorbing nanoparticle layer relative to the film thickness (d2) of the heat dissipation promoting layer is 1-100; and the film thickness of the heat dissipation promoting layer is at least 0.1μm but less than 1μm.

Description

Optical reflective film and optical reflector

The present invention relates to an optical reflection film and an optical reflector.

In recent years, as part of energy conservation measures, from the viewpoint of reducing the load on cooling equipment, there is a need for optical reflection films such as infrared shielding films that are attached to window glass of buildings and vehicles and shield the transmission of sunlight heat rays. Is growing.

As a method for forming an optical reflective film, a laminate (reflective layer) having a structure in which a high refractive index layer and a low refractive index layer are alternately laminated is formed by using a dry film forming method such as a vapor deposition method or a sputtering method. A method of forming has been proposed. In recent years, a method for forming a reflective layer of an optical reflective film using a wet coating method instead of a dry film forming method has been actively studied.

For example, Patent Document 1 discloses an infrared light absorption including an infrared light reflective multilayer film having alternating layers of a first polymer species and a second polymer species, and tin oxide or doped tin oxide as metal oxide nanoparticles. A multilayer film product comprising a nanoparticle layer is disclosed. It is described that the solar control multilayer film has a high visible light transmittance and a low infrared transmittance by adopting such a configuration.

JP 2008-528313 A (corresponding to International Publication No. 2006/074168)

However, in the solar control multilayer film described in Patent Document 1, heat cracks may occur in the glass on which the film is attached due to heat generated by infrared light absorption of the metal oxide nanoparticles. Moreover, the solar control multilayer film of the said patent document 1 is inferior to scratch resistance.

Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to provide an optical reflection film and an optical reflector that can suppress and prevent thermal cracking.

Another object of the present invention is to provide an optical reflective film and an optical reflector having improved scratch resistance.

As a result of intensive studies to solve the above problems, the present inventor has found that the above problem can be solved by providing a heat dissipation promoting layer having a specific film thickness, and has completed the present invention.

That is, the above object is an optical reflection film having a base material, an optical reflection layer, an infrared absorption nanoparticle layer, and a heat dissipation acceleration layer, wherein the heat dissipation acceleration layer is disposed on the outermost layer on the light incident side, and the heat dissipation acceleration is achieved. The ratio (d1 / d2) of the film thickness (d1) of the infrared absorbing nanoparticle layer to the film thickness (d2) of the layer is 1 to 100, and the film thickness of the heat dissipation promoting layer is 0.1 μm or more and less than 1 μm It can be achieved by an optical reflection film characterized by being.

The optical reflective film of the present invention is an optical reflective film having a base material, an optical reflective layer, an infrared absorption nanoparticle layer, and a heat radiation promoting layer, wherein the heat radiation promoting layer is disposed on the outermost layer on the light incident side, The ratio (d1 / d2) of the film thickness (d1) of the infrared absorbing nanoparticle layer to the film thickness (d2) of the heat dissipation promoting layer is 1 to 100, and the film thickness of the heat dissipation promoting layer is 0.1 μm or more and 1 μm. It is characterized by being less than. By setting it as the said structure, even if the optical reflection film of this invention has an infrared absorption nanoparticle layer, the heat dissipation promotion layer can thermally radiate | emit the said heat | fever efficiently. For this reason, the optical reflective film of this invention can suppress and prevent the problem of the thermal crack by the infrared-light absorption of a metal oxide nanoparticle.

The infrared light reflective multilayer film of Patent Document 1 has an infrared light absorbing nanoparticle layer containing specific metal oxide particles. However, it has been found that the infrared light reflective multilayer film of Patent Document 1 may cause a phenomenon (heat cracking) that the glass on which the film is stuck is broken during use. The inventor of the present application diligently studied the above phenomenon, and as a result, the metal oxide nanoparticles in the infrared light absorbing nanoparticle layer absorb infrared light to generate heat, and the infrared light absorbing nanoparticle layer is released. It was thought that a phenomenon (thermal cracking) that caused a temperature difference in the glass due to the heat generated was broken. Specifically, the glass temperature also rises due to the heat radiation of the infrared light absorbing nanoparticle layer, and there is a temperature difference between the part that is exposed to sunlight and the part that does not hit the film, and the part where the film is applied and the part that is not applied. It was thought that this caused the glass to break. In addition, this phenomenon is likely to occur when a film is pasted on glass, in particular, multi-layer glass or netted glass. Patent Document 1 describes that a silica-based hard coat layer having a thickness of 1 to 20 μm is provided on the infrared light absorbing nanoparticle layer (paragraph “0041”). However, the hard coat layer cannot sufficiently release the heat of the layer, and as a result, a phenomenon (thermal cracking) that the glass on which the film is stuck is broken by the heat released from the infrared light absorbing nanoparticle layer still occurs. It has been found. Moreover, the hard coat layer having the above thickness is also inferior in scratch resistance.

On the other hand, the heat dissipation promoting layer according to the present invention is characterized by being thin at a specific ratio as compared with the film thickness of the infrared absorbing nanoparticle layer. By setting it as such thickness, the heat | fever which an infrared absorption nanoparticle layer emits is efficiently discharge | released out of an optical reflection film. For this reason, in the optical reflective film of the present invention, even when exposed to sunlight for a long time, thermal cracking hardly occurs or does not occur at all. Moreover, since the heat radiation acceleration | stimulation layer based on this invention functions also as a protective layer, it is excellent also in scratch resistance. For this reason, for example, it is possible to effectively suppress / prevent the generation of scratches caused by a squeegee when water is applied. The above effect can be achieved particularly remarkably when the heat dissipation promoting layer includes a material having a metalloxane skeleton (particularly a material having a polysilazane-derived metalloxane skeleton).

Note that the above is a guess, and the present invention is not limited to the above.

Hereinafter, constituent elements of the optical reflection film according to the present invention, and modes for carrying out the present invention will be described in detail. In the present specification, the “optical reflection film” is a film that can block all or a part of light having a desired wavelength by reflecting light having a desired wavelength (for example, near infrared rays). is there. In this specification, “X to Y” indicating a range means “X or more and Y or less”. Unless otherwise specified, measurement of operation and physical properties is performed under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%.

≪Optical reflection film≫
The optical reflection film according to the present invention includes a base material, an optical reflection layer, an infrared absorption nanoparticle layer, and a heat dissipation promotion layer.

(Base material)
The substrate is not particularly limited, but is preferably a resin substrate from the viewpoint of flexibility, and may be transparent or opaque. For applications that are required to be transparent with visible light from the viewpoint of design, such as automotive applications, it is preferably transparent in the visible light region.

As the resin substrate, for example, polyolefin film (polyethylene, polypropylene, etc.), polyester film (polyethylene terephthalate (PET), polyethylene naphthalate, etc.), polyvinyl chloride, cellulose acetate, etc. can be used, preferably polyester film. It is. Although it does not specifically limit as a polyester film (henceforth polyester), It is preferable that it is polyester which has the film formation property which has a dicarboxylic acid component and a diol component as main structural components. Among polyesters, terephthalic acid, 2,6-naphthalenedicarboxylic acid, and diol component, ethylene glycol and 1,4-cyclohexanedimethanol, are mainly used from the viewpoints of transparency, mechanical strength and dimensional stability. Polyester as a constituent component is preferable. Among these, polyesters mainly composed of polyethylene terephthalate and polyethylene naphthalate, copolymerized polyesters composed of terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol, and mixtures of two or more of these polyesters are mainly used. Polyester as a constituent component is preferable.

The thickness of the substrate is preferably 10 to 300 μm, more preferably 20 to 150 μm. Moreover, the base material may be a laminate of two or more, and in this case, the type may be the same or different.

The resin base material can be manufactured by a conventionally known general method. The resin substrate may be an unstretched film, a stretched film stretched on one side, or a biaxially stretched film. A stretched film is preferable from the viewpoint of strength improvement and thermal expansion suppression.

(Optical reflection layer)
The optical reflective film of the present invention has an optical reflective layer in addition to the substrate. Here, the optical reflection layer is usually formed on the substrate, but the arrangement of the optical reflection layer and the substrate is not limited to the form in which the optical reflection layer is directly provided on the substrate, An intermediate layer is provided, and an optical reflective layer is provided on the intermediate layer, or another intermediate layer (for example, an adhesive layer) is provided on the opposite surface of the substrate to the optical reflective layer. A form including an intermediate layer is also included. Further, the optical reflection layer may be a single layer or a plurality of layers. When there are a plurality of optical reflection layers, the optical reflection layers are not only stacked adjacent to each other. , They may exist at physically separated positions.

The optical reflection layer is a laminate of layers having different refractive indexes, but is preferably a laminate in which high refractive index layers and low refractive index layers are alternately laminated. Here, the terms “high refractive index layer” and “low refractive index layer” mean that the refractive index layer with the higher refractive index is the high refractive index layer when comparing the refractive index difference between two adjacent layers. It means that the lower refractive index layer is a low refractive index layer. Therefore, the terms “high refractive index layer” and “low refractive index layer” mean that each refractive index layer has the same refractive index when attention is paid to two adjacent refractive index layers. All forms other than the forms having the above are included.

Since reflection at the interface between adjacent layers depends on the refractive index ratio between layers, the larger this refractive index ratio, the higher the reflectance. In addition, when the optical path difference between the reflected light on the surface of the layer and the reflected light on the bottom of the layer is a relationship expressed by n · d = wavelength / 4 when viewed as a single layer film, the reflected light is controlled to be strengthened by the phase difference. And reflectivity can be increased. Here, n is the refractive index, d is the physical film thickness of the layer, and n · d is the optical film thickness. By using this optical path difference, reflection can be controlled. Using this relationship, the refractive index and film thickness of each layer are controlled to control the reflection of visible light and near infrared light. That is, the reflectance in a specific wavelength region can be increased by the refractive index of each layer, the film thickness of each layer, and the way of stacking each layer.

The thickness of the optical reflection layer is not particularly limited, and can be appropriately designed so that a desired function is exhibited. The thickness of the optical reflection layer is usually about 1 to 100 μm.

Conventionally known materials can be used as the material for forming the optical reflection layer, and examples thereof include metal oxide materials, polymers, other additives, and combinations thereof.

Examples of the metal oxide material include TiO ₂ , ZrO ₂ , Ta ₂ O _{5 and the} like as high refractive index materials, SiO ₂ and MgF ₂ as low refractive index materials, and Al ₂ as medium refractive index material. O ₃ etc. are mentioned. These metal oxide materials can be formed by a dry film forming method such as vapor deposition or sputtering.

As described above, the optical reflection layer may be in any form, but the high refractive index layer including the first water-soluble polymer and the first metal oxide particles, and the second water-soluble polymer. And low refractive index layers containing second metal oxide particles are alternately stacked (first form) or a third polymer layer containing a third polymer, and a fourth polymer containing a fourth polymer. It is preferable that the four polymer layers are alternately laminated (second form).

Hereinafter, although the above-described embodiment will be described in detail, the present invention is not limited to the following embodiment.

As the first form, for example, the same materials as described in International Publication No. 2013/054912 (US 2014/0233092 A1), JP2013-148849A, JP2013-142089A, and the like are used. The

Specifically, in the first embodiment, the first water-soluble polymer and the second water-soluble polymer can be applied in an aqueous system without using an organic solvent, so that there is little environmental load and flexibility. Since it is high, the durability of the film during bending is improved, which is preferable. Examples of the water-soluble polymer include polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic ester copolymer, Or acrylic resin such as acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene -Styrene acrylic resin such as acrylic acid copolymer or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrenesulfonate copolymer, styrene-2-hydroxyethyl acrylate copolymer Coalescence, styrene-2 -Hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl acetate -Synthetic water-soluble polymers such as maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate copolymers such as vinyl acetate-acrylic acid copolymers and their salts; gelatin, thickened And natural water-soluble polymers such as saccharides. Among these, particularly preferred examples include polyvinyl alcohol, polyvinylpyrrolidones and copolymers containing them, gelatin, thickening polysaccharides (particularly celluloses) from the viewpoint of handling during production and film flexibility. Is mentioned. These water-soluble polymers may be used alone or in combination of two or more.

Polyvinyl alcohol includes modified polyvinyl alcohol in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate. Examples of the modified polyvinyl alcohol include cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, nonion-modified polyvinyl alcohol, and vinyl alcohol polymers.

Specific examples of polyvinyl alcohol include those described in [0075] to [0079] of International Publication No. 2013-054912.

Further, a curing agent for curing polyvinyl alcohol may be used. As an applicable curing agent, for example, boric acid and its salt are preferable. Specific examples of the other curing agent include those described in [0091] to [0096] of International Publication No. 2013-054912.

As the gelatin, in addition to lime-processed gelatin, acid-processed gelatin may be used, and gelatin hydrolyzate and gelatin enzyme-decomposed product can also be used. Further, the hardeners described in [0081] to [0082] of International Publication No. 2013-054912 may be used.

Examples of thickening polysaccharides include natural simple polysaccharides, natural complex polysaccharides, synthetic simple polysaccharides and synthetic complex polysaccharides that are generally known. Reference can be made to the encyclopedia (2nd edition), Tokyo Kagaku Doujin Publishing, “Food Industry”, Vol. 31 (1988), p. 21.

In this embodiment, both the high refractive index layer and the low refractive index layer constituting the optical reflection layer contain metal oxide particles. That is, the high refractive index layer includes first metal oxide particles in addition to the first water-soluble polymer, and the low refractive index layer includes the second metal in addition to the second water-soluble polymer. Contains oxide particles. Here, the first and second metal oxide particles may be the same or different.

As the metal oxide particles, the metal constituting the metal oxide is Li, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Nb, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi and a rare earth metal One or more metal oxides can be used.

The metal oxide particles preferably have an average particle size of 100 nm or less, 1 to 50 nm, or 4 to 40 nm in order of preference. Here, the average particle diameter refers to the primary average particle diameter. When the metal oxide particles are coated (for example, silica-attached titanium oxide), the average particle diameter of the metal oxide particles is the matrix (in the case of silica-attached titanium oxide). , Titanium oxide before treatment).

The content of the metal oxide particles in each refractive index layer is preferably 20 to 90% by mass, and more preferably 40 to 80% by mass with respect to the total mass of the refractive index layer.

In the low refractive index layer, it is preferable to use silicon dioxide (silica) as the metal oxide particles, and it is particularly preferable to use acidic colloidal silica sol.

As the metal oxide contained in the high refractive index layer, high refractive index metal oxide fine particles such as titanium and zirconia, that is, titanium oxide fine particles, Zirconium oxide fine particles are preferred, and rutile (tetragonal) titanium oxide fine particles are more preferred.

Further, as the titanium oxide particles, those obtained by modifying the surface of the aqueous titanium oxide sol to stabilize the dispersion state may be used.

As the titanium oxide sol, a titanium oxide sol particle described in JP-A-2008-266043 is used as a core, and a plurality of coating layers made of hydrated oxides of silicon, tin, and antimony are provided around the titanium oxide sol. A transparent titanium oxide sol in which the sum oxide is the outermost coating layer may be used. In addition, as the titanium oxide sol, acidic oxidation in which the particle surface is coated with colloidal particles of an oxide oxide using a titanium oxide-tin oxide-zirconium oxide-tungsten oxide composite colloidal particle as a core described in International Publication No. 2009/044879. It is also possible to use a product-coated titanium oxide-tin oxide-zirconium oxide-tungsten oxide composite colloidal particle and a sol in which these composite colloidal particles are dispersed.

In addition, as the metal oxide particles contained in the high refractive index layer, core-shell particles produced by a known method can be used. As the method for preparing the aqueous titanium oxide sol, any conventionally known method can be used. For example, JP-A-63-17221, JP-A-7-819, JP-A-9-165218, Reference can be made to the matters described in Japanese Laid-Open Patent Publication No. 11-43327.

Further, the titanium oxide particles may be coated with a silicon-containing hydrated oxide. Here, the “coating” means a state in which a silicon-containing hydrated oxide is attached to at least a part of the surface of the titanium oxide particles. That is, the surface of the titanium oxide particles used as the metal oxide particles may be completely covered with a silicon-containing hydrated oxide, and a part of the surface of the titanium oxide particles is a silicon-containing hydrated oxide. It may be coated. From the viewpoint that the refractive index of the coated titanium oxide particles is controlled by the coating amount of the silicon-containing hydrated oxide, it is preferable that a part of the surface of the titanium oxide particles is coated with the silicon-containing hydrated oxide. . The “silicon-containing hydrated oxide” in the present specification may be any of a hydrate of an inorganic silicon compound, a hydrolyzate and / or a condensate of an organosilicon compound, and preferably has a silanol group. In particular, as the silicon-containing hydrated oxide, silica hydrate is preferable. Titanium oxide coated with silica hydrate is hereinafter also referred to as silica-coated titanium oxide or silica-modified titanium oxide, referred to as silica-attached titanium oxide. ).

The titanium oxide of the titanium oxide particles coated with the silicon-containing hydrated oxide may be a rutile type or an anatase type. The titanium oxide particles coated with a silicon-containing hydrated oxide are more preferably rutile-type titanium oxide particles coated with a silicon-containing hydrated oxide. This is because the rutile type titanium oxide particles have lower photocatalytic activity than the anatase type titanium oxide particles, and therefore the weather resistance of the high refractive index layer and the adjacent low refractive index layer is increased, and the refractive index is further increased. Because.

The coating amount of the silicon-containing hydrated oxide is 2 to 30% by mass, preferably 3 to 10% by mass, more preferably 4 to 8% by mass. This is because when the coating amount is 30% by mass or less, a desired refractive index of the high refractive index layer can be obtained, and when the coating amount is 2% by mass or more, particles can be stably formed.

As a method of coating titanium oxide particles with a silicon-containing hydrated oxide, it can be produced by a conventionally known method. For example, JP-A-10-158015 (Si / Al hydration to rutile titanium oxide) Oxide treatment; a method of producing a titanium oxide sol in which a hydrous oxide of silicon and / or aluminum is deposited on the surface of titanium oxide after peptization in the alkali region of the titanate cake), JP 2000-204301 A (A sol in which a rutile-type titanium oxide is coated with a complex oxide of Si and Zr and / or Al. Hydrothermal treatment), JP 2007-246351 (Oxidation obtained by peptizing hydrous titanium oxide) titanium to hydrosol, wherein ^R ₁ _{n SiX 4-n} (wherein ^{R 1} as stabilizer _C 1 -C ₈ alkyl group, glycidyloxy substituted _C 1 -C Alkyl or C ₂ -C ₈ alkenyl group, X is an alkoxy group, n is 1 or 2. Sodium silicate added in the alkaline range the compound having a complexing effect on organoalkoxysilanes or titanium oxide) Alternatively, it is possible to refer to matters described in, for example, a method for producing a titanium oxide hydrosol coated with a hydrous oxide of silicon by adding, adjusting pH, and aging a silica sol solution.

In addition, the high refractive index layer and / or the low refractive index layer may further include an ultraviolet absorber described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476, Various surfactants such as anionic surfactant, cationic surfactant, nonionic surfactant, amphoteric surfactant, sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate, etc. PH adjusters, antifoaming agents, lubricants such as diethylene glycol, preservatives, antifungal agents, antistatic agents, matting agents, antioxidants, flame retardants, infrared absorbers, dyes, pigments, and various other known additives Etc. may be included.

When the optical reflective layer contains a water-soluble polymer, aqueous coating is possible. As a method for forming the optical reflection layer, in addition to the above-described melt extrusion and stretching methods, a sequential multilayer coating method using a water-soluble polymer and an aqueous solvent; International Publication No. 2013-054912 [0144] to [0156] Examples thereof include the simultaneous multilayer coating method described above.

In the first embodiment, from the viewpoint of productivity, the total number of layers of the high refractive index layer and the low refractive index layer is 100 layers or less, 12 layers or more, more preferably 45 layers or less, 15 layers or more, and further preferably 45 layers. Below are 21 layers or more. The preferred range of the total number of high refractive index layers and low refractive index layers is applicable even when laminated on only one side of the substrate, and when laminated simultaneously on both sides of the substrate. Is also applicable. When laminated on both surfaces of the substrate, the total number of high refractive index layers and low refractive index layers on one surface of the substrate and the other surface may be the same or different. In the near-infrared shielding film of the present invention, the lowermost layer (the layer that contacts the substrate) and the outermost layer may be either a high refractive index layer or a low refractive index layer. However, by adopting a layer structure in which the low refractive index layer is located in the lowermost layer and the outermost layer (uppermost layer), adhesion to the base material of the lowermost layer, blowing resistance of the outermost layer, and hard to the outermost layer Excellent coating properties such as coat layer and adhesion. For this reason, as an optical reflection film (near infrared shielding film) of this invention, the layer structure whose lowermost layer and outermost layer are low refractive index layers is preferable.

In the second embodiment, the third polymer and the fourth polymer are used to adjust the refractive index difference of each layer to obtain an optical reflection layer. For example, one of the alternating third polymer layer and fourth polymer layer is birefringent and oriented, and the other is isotropic. Here, the polymer (third polymer and fourth polymer) contained in the optical reflection layer is not particularly limited, and is not particularly limited as long as the polymer can form the optical reflection layer. For example, as the polymer, resins described in JP-T-2002-509279 and JP-T-2008-528313 can be used. Specifically, polyethylene naphthalate (PEN) and its isomers (for example, 2,6-, 1,4-, 1,5-, 2,7-, and 2,3-PEN), polyalkylene terephthalate ( For example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and poly-1,4-cyclohexanedimethylene terephthalate), polyimide (eg, polyacrylimide), polyetherimide, atactic polystyrene, polycarbonate, polymethacrylate (eg, Polyisobutyl methacrylate, polypropyl methacrylate, polyethyl methacrylate, and polymethyl methacrylate), poly (meth) acrylates (eg, polybutyl acrylate and polymethyl acrylate), Loose derivatives (eg, ethyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate, and cellulose nitrate), polyalkylene polymers (eg, polyethylene, polypropylene, polybutylene, polyisobutylene, and poly (4-methyl) pentene), fluorine Polymer (eg, perfluoroalkoxy resin, polytetrafluoroethylene, fluorinated ethylene-propylene copolymer, polyvinylidene fluoride, and polychlorotrifluoroethylene), chlorinated polymer (eg, polyvinylidene chloride and polyvinyl chloride), polysulfone , Polyethersulfone, polyacrylonitrile, polyamide, silicone resin, epoxy resin, polyvinyl acetate, polyetheramide, ionomer resin, Elastomer (such as polybutadiene, polyisoprene, and neoprene), and polyurethanes. A copolymer, for example a copolymer of PEN (for example 2,6-, 1,4-, 1,5-, 2,7- and / or 2,3-naphthalenedicarboxylic acid or an ester thereof; Acid or ester thereof, (b) isophthalic acid or ester thereof, (c) phthalic acid or ester thereof, (d) alkylene glycol (eg, ethylene glycol, propylene glycol), (e) cycloalkylene glycol (eg, cyclohexanedimethanol) Diol), (f) alkanedicarboxylic acid, and / or (g) a copolymer with cycloalkanedicarboxylic acid (eg, 1,4-, 1,2-cyclohexanedicarboxylic acid), a copolymer of polyalkylene terephthalate (eg, terephthalate) Acid or its ester (B) isophthalic acid or ester thereof, (c) phthalic acid or ester thereof, (d) alkylene glycol (for example, ethylene glycol, propylene glycol), (e) cycloalkane glycol (Eg, cyclohexanedimethanol), (f) alkanedicarboxylic acid, and / or (g) copolymer with cycloalkanedicarboxylic acid (eg, cyclohexanedicarboxylic acid)), styrene copolymer (eg, styrene-butadiene copolymer and styrene-acrylonitrile). Copolymers), and copolymers of 4,4'-dibenzoic acid and ethylene glycol. Further, each individual layer may include a blend of two or more of the above polymers or copolymers (eg, a blend of a copolymer of polyalkylene terephthalate and a copolymer of PEN). Further, as the polymer, a polymer described in JP 2010-184493 may be used. Specifically, a polyester (hereinafter referred to as polyester A) and a polyester (hereinafter referred to as polyester B) containing residues derived from at least three diols of ethylene glycol, spiroglycol and butylene glycol, Can be used. Polyester A is not particularly limited as long as it has a structure obtained by polycondensation of a dicarboxylic acid component and a diol component. The polyester B contains residues derived from at least three kinds of diols, ethylene glycol, spiroglycol and butylene glycol.

Among the above, the optical reflection layer is composed of a third polymer layer containing polyethylene terephthalate (PET) or a copolymer of polyethylene terephthalate (coPET), and poly (methyl methacrylate) (PMMA) or poly (methyl methacrylate). Formed of alternating layers with a fourth polymer layer comprising a copolymer of (coPMMA); a third polymer layer comprising polyethylene terephthalate and a copolymer comprising poly (methyl methacrylate and ethyl acrylate). A third polymer layer comprising cyclohexanedimethanol (PETG) or a copolymer of cyclohexanedimethanol (coPETG) and polyethylene naphthalate (PEN) or polyethylene naphthalate. Copolymer (coPEN) Formed of alternating layers with a fourth polymer layer comprising; or a third polymer layer comprising polyethylene naphthalate or a copolymer of polyethylene naphthalate and poly (methyl methacrylate) or poly (methyl methacrylate) It is preferably formed from alternating layers with a fourth polymer layer comprising a copolymer. In addition, as a useful combination of the alternating third and fourth polymer layers, the combination described in US Pat. No. 6,352,761 is also preferable.

The optical reflection layer can also be formed from the above polymer by melt extrusion and stretching of the polymer as described in US Pat. No. 6,049,419.

In one embodiment, each refractive index layer material is melted at 100 to 400 ° C. so as to have an appropriate viscosity for extrusion, and various additives are added as necessary, so that both polymers are alternately formed into two layers. Can be extruded by an extruder. Next, the extruded laminated film is cooled and solidified by a cooling drum to obtain a laminated body. Thereafter, the laminate is heated and then stretched in two directions to obtain an optical reflection layer.

When stretching in the film transport direction or the direction perpendicular to the film transport direction, the film is preferably stretched at a magnification of 1.5 to 5.0 times, more preferably in the range of 2.0 to 4.0 times.

Also, heat processing can be performed subsequent to stretching. The thermal processing means is not particularly limited and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but is preferably performed with hot air in terms of simplicity. The heat-processed film is usually cooled to Tg or less, and clip holding portions at both ends of the film are cut and wound. The means for cooling is not particularly limited, and can be performed by a conventionally known means. In particular, it is preferable to perform these treatments while sequentially cooling in a plurality of temperature ranges in terms of improving the dimensional stability of the film.

In this embodiment, from the viewpoint of productivity, the range of the total number of high refractive index layers and low refractive index layers is preferably 10 to 5000 layers, more preferably 20 to 2000 layers.

After forming a laminate of a high refractive index layer and a low refractive index layer by simultaneous extrusion of the resin, the laminate is stretched to form a film, and then an optical reflective layer is bonded by thermocompression bonding or adhesion using an adhesive. It can be formed on a substrate.

(Infrared absorbing nanoparticle layer)
The optical reflective film of the present invention has an infrared absorbing nanoparticle layer in addition to the substrate and the optical reflective layer. Here, the infrared absorption nanoparticle layer is usually formed on the optical reflection layer, but not only the form in which the infrared absorption nanoparticle layer is directly provided on the optical reflection layer, but also the optical reflection layer and the infrared absorption nanoparticle layer. Another intermediate layer may be provided between the particle layer. In addition, the infrared absorption nanoparticle layer may be a single layer or a plurality of layers, and when there are a plurality of infrared absorption nanoparticle layers, the infrared absorption nanoparticle layers are adjacent to each other. It may exist not only in a stacked form but also in physically separated positions. Here, the intermediate layer is not particularly limited and is appropriately selected depending on a desired function. Specifically, the intermediate layer includes an adhesive layer, a conductive layer, an antistatic layer, a gas barrier layer, an easy adhesion layer (adhesion layer), an antifouling layer, a deodorant layer, a droplet layer, an easy slip layer, Examples include an abrasion layer, an antireflection layer, an electromagnetic wave shielding layer, a printing layer, a fluorescent light emitting layer, a hologram layer, a release layer, and a colored layer.

The thickness of the infrared absorption nanoparticle layer can be appropriately designed so that a desired function (infrared absorption ability) is exhibited. The thickness of the infrared absorption nanoparticle layer is usually 1 to 20 μm, preferably 1 to 15 μm, more preferably 3 to 10 μm, and particularly preferably about 5 to 10 μm.

The configuration of the infrared absorption nanoparticle layer is not particularly limited, and may be the same as that of the infrared absorption nanoparticle layer applied to a known optical reflection film. Usually, the infrared absorbing nanoparticle layer includes metal oxide nanoparticles and a resin.

Here, since the metal oxide nanoparticles are nanoparticles, transparency of visible light is ensured. The material constituting the metal oxide nanoparticles is not particularly limited as long as it can absorb infrared light. For example, tin, antimony, indium, titanium, silicon, aluminum, zirconium, boron, cerium, tungsten , Nickel, vanadium and zinc oxides and doped oxides, and mixtures thereof. More specifically, tin oxide, antimony oxide, indium oxide, indium doped tin oxide, indium doped zinc oxide (indium zinc composite oxide: IZO), antimony doped indium tin oxide, antimony tin oxide, antimony doped tin oxide (ATO) Antimony doped zinc oxide (antimony zinc composite oxide: AZO), gallium doped zinc oxide (gallium zinc composite oxide: GZO), titanium oxide, zinc oxide, silicon oxide, alumina, zirconia, lanthanum boride, cerium oxide, oxidation Examples include vanadium, nickel oxide, tungsten oxide, cesium tungsten oxide, or a mixture thereof. In addition, oxide nanoparticles containing Cd / Se, GaN, Y ₂ O ₃ , Au, Ag, and Cu can also be used. Among these, in consideration of infrared absorption, antimony-doped zinc oxide, antimony tin oxide, antimony-doped tin oxide, and indium-doped tin oxide are preferable. The metal oxide nanoparticles may be used alone or in the form of a mixture of two or more. In addition, in this specification, the compound doped with another metal means both a state where another metal is mixed in the compound or a state where the compound and another metal (oxide) are bonded. Point to.

The content of the metal oxide nanoparticles in the infrared absorption nanoparticle layer is not particularly limited, but is 30 to 80% by mass with respect to the total amount of the components of the infrared absorption nanoparticle layer (in terms of solid content). It is preferably 45 to 70% by mass. When the content of the metal oxide nanoparticles is in such a range, the infrared absorption nanoparticle layer can exhibit sufficient infrared light absorption (infrared light shielding).

The infrared absorption nanoparticle layer essentially contains metal oxide nanoparticles, but from the viewpoint of weather resistance and absorption spectrum, other infrared absorbers other than the metal oxide nanoparticles are used as long as the effects of the present invention are not impaired. You may mix. The infrared absorber is not particularly limited, and a known infrared absorber can be used, and examples thereof include lanthanum boride, nickel complex compounds, imonium compounds, phthalocyanine compounds, and aminium compounds. The amount of the other infrared absorber in the infrared absorbing nanoparticle layer when the infrared absorbing nanoparticle layer contains another infrared absorber is not particularly limited as long as the effect of the present invention is not impaired, but preferably 0 mass. % And 5% by mass or less, more preferably 0% by mass and 3% by mass or less.

The “nanoparticle” in the metal oxide nanoparticle refers to a particle having an average (secondary) particle size of 1000 nm or less. The size of the metal oxide nanoparticles is not particularly limited, but in view of visible light transmittance, the average particle size is more preferably in the range of 1 to 500 nm, and more preferably in the range of 1 to 200 nm. Those in the range of 5 to 100 nm are particularly preferred. The particle diameter means the maximum distance among the distances between any two points on the outline of the particle (observation surface) observed using an observation means such as a transmission electron microscope. As the value of the average particle size, a value calculated as the number average value of the particle sizes of particles observed in several to several tens of fields using an observation means such as a transmission electron microscope is used.

The resin constituting the infrared absorbing nanoparticle layer is not particularly limited, and examples thereof include a thermosetting resin and an active energy ray curable resin. Of these, active energy ray-curable resins are preferred because they are easy to mold. Such curable resins can be used singly or in combination of two or more. As the curable resin, a commercially available product may be used, or a synthetic product may be used. Here, the active energy ray resin refers to a resin that is cured through a crosslinking reaction or the like by irradiation with active energy rays such as ultraviolet rays or electron beams. As the active energy ray curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the active energy ray curable resin layer is cured by irradiation with an active energy ray such as an ultraviolet ray or an electron beam. Is formed. Typical examples of the active energy ray curable resin include an ultraviolet curable resin, an electron beam curable resin, and the like, and an ultraviolet curable resin that is cured by ultraviolet irradiation is preferable. That is, the infrared absorption nanoparticle layer preferably contains an ultraviolet curable resin and at least one selected from the group consisting of aluminum-doped zinc oxide, antimony tin oxide, antimony-doped tin oxide, and indium-doped tin oxide.

Examples of the ultraviolet curable resin include an ultraviolet curable acrylate resin such as an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, and an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy. Resins and the like are preferably used. Among these, UV curable acrylate resins, particularly UV curable urethane acrylate resins and UV curable polyol acrylate resins are preferred.

The UV curable urethane acrylate resin is generally a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer and further adding 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter, acrylate includes methacrylate). Can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate. For example, a mixture of 100 parts Unidic 17-806 (manufactured by Dainippon Ink Co., Ltd.) and 1 part of Coronate L (manufactured by Nippon Polyurethane Co., Ltd.) described in JP-A-59-151110 is preferably used. It is done. Commercially available products may be used as the ultraviolet curable urethane acrylate resin, and examples of commercially available products include Beamset (registered trademark) 575 and 577 (manufactured by Arakawa Chemical Industry Co., Ltd.), and Murasaki (registered trademark) UV series. be able to.

Examples of the UV curable polyester acrylate resin include those generally formed by reacting polyester polyol with 2-hydroxyethyl acrylate and 2-hydroxy acrylate monomers, and disclosed in JP-A-59-151112. Those described can be used.

As the ultraviolet curable epoxy acrylate resin, an epoxy acrylate is used as an oligomer, and a reactive diluent and a photopolymerization initiator are added to the oligomer and reacted, and JP-A-1-1057738 discloses. Those described can be used.

Examples of the UV curable polyol acrylate resin include ethylene glycol (meth) acrylate, polyethylene glycol di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol. Examples include pentaacrylate, dipentaerythritol hexaacrylate, and alkyl-modified dipentaerythritol pentaacrylate. Commercially available products may be used as the ultraviolet curable polyol acrylate resin, and examples of commercially available products include Sartomer SR295, SR399 (manufactured by Sartomer).

Also, a polymerizable silicone compound may be used in combination (or alone) with an ultraviolet curable resin. The polymerizable silicone compound is preferably used in combination with the ultraviolet curable resin.

The polymerizable silicone compound is a compound having a main skeleton (silicone skeleton) with a siloxane bond and a polymerizable group in the molecule.

The polymerizable group is a group polymerizable with the ultraviolet curable resin, and examples thereof include a group having a polymerizable double bond such as a (meth) acryloyl group and a (meth) acryloyloxy group. A (meth) acryloyl group is preferred. Therefore, it is preferable that a preferable polymerizable silicone compound is silicone (meth) acrylate or silicone (meth) acrylate oligomer (hereinafter collectively referred to as silicone (meth) acrylate).

In addition, the polymerizable silicone compound is an organically modified polymerizable silicone compound containing a site that improves the compatibility with the ultraviolet curable resin in the molecule from the viewpoint of improving the compatibility with the ultraviolet curable resin described above. Preferably there is. Examples of such organically modified polymerizable silicone compounds include urethane modification, amino modification, alkyl modification, epoxy modification, carboxyl modification, alcohol modification, fluorine modification, alkylaralkyl polyether modification, epoxy / polyether modification or polyether modification. And polymerizable silicone compounds.

For example, when the ultraviolet curable resin contains an ultraviolet curable urethane acrylate resin, the polymerizable silicone compound is preferably urethane-modified silicone (meth) acrylate. The urethane-modified silicone (meth) acrylate is obtained by, for example, reacting a polyisocyanate with a silicone compound in which both ends are OH to obtain a terminal isocyanate silicone compound, and the terminal isocyanate silicone compound and the hydroxyl group-containing (meth) acrylate It is obtained by reacting.

Note that the polymerizable silicone compound also forms a polymer, and thus becomes a polymerizable component of the resin.

The resin may be obtained by synthesis or a commercially available product. Examples of commercially available products include EBECRYL1360, EBECRYL350, KRM8495 (manufactured by Daicel Ornex), CN9800, CN990 (manufactured by Arkema), and the like.

It is preferable to use a photopolymerization initiator (radical polymerization initiator) for the ultraviolet curable resin. Photopolymerization initiators include benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzylmethyl ketal; acetophenone, 2,2-dimethoxy Acetophenones such as -2-phenylacetophenone and 1-hydroxycyclohexyl phenyl ketone; anthraquinones such as methylanthraquinone, 2-ethylanthraquinone and 2-amylanthraquinone; thioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, etc. Thioxanthones; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone and 4,4-bismethylaminobenzozonone And azo compounds can be used. These may be used alone or in combination of two or more. In addition, tertiary amines such as triethanolamine and methyldiethanolamine; photoinitiators such as 2-dimethylaminoethylbenzoic acid and benzoic acid derivatives such as ethyl 4-dimethylaminobenzoate can be used in combination. it can. Commercially available photopolymerization initiators may be used. For example, Irgacure (registered trademark) -184, 819, 907, 651, 1700, 1800, 819, 369, 261, DAROCUR-TPO (manufactured by BASF Japan Ltd.), Darocur (Registered trademark) -1173 (manufactured by Merck), Ezacure-KIP150, TZT (manufactured by DKSH Japan), Kayacure (registered trademark) BMS, DMBI (manufactured by Nippon Kayaku Co., Ltd.) and the like. The amount of the photopolymerization initiator used is preferably 0.5 to 30 parts by mass, more preferably 1 to 25 parts by mass with respect to 100 parts by mass of the polymerizable component of the resin.

The blending amount of the resin in the infrared absorbing nanoparticle layer is not particularly limited as long as the effects of the present invention are not impaired, and can be suitably set depending on the purpose. For example, the blending amount of the resin in the infrared absorbing nanoparticle layer is preferably 20 to 70% by mass, preferably 30 to 70% by mass with respect to the total amount (in terms of solid content) of the constituent components of the infrared absorbing nanoparticle layer. More preferably, it is 55 mass%.

Further, the infrared absorbing nanoparticle layer may contain a surfactant as necessary. Thereby, leveling property, water repellency, slipperiness, etc. can be provided. The type of the surfactant is not particularly limited, and an acrylic surfactant, a silicone surfactant, a fluorine surfactant, or the like can be used. In particular, a fluorosurfactant is preferably used from the viewpoint of leveling properties, water repellency, and slipperiness. Examples of the fluorosurfactant include, for example, Megafac (registered trademark) F series (F-430, F-477, F-552 to F-559, F-561, F-562, etc., manufactured by DIC Corporation. ), Megafuck (registered trademark) RS series (RS-76-E, etc.) manufactured by DIC Corporation, Surflon (registered trademark) series manufactured by AGC Seimi Chemical Co., Ltd., POLYFOX series manufactured by OMNOVA SOLUTIONS Corporation, T & K TOKA Corporation Commercially available products such as ZX series, Optool series manufactured by Daikin Industries, Ltd., and Footent (registered trademark) series (602A, 650A, etc.) manufactured by Neos Co., Ltd. can be used. The content of the surfactant in the infrared absorption nanoparticle layer is preferably 0.001 to 0.5% by mass with respect to the total amount of the constituent components of the infrared absorption nanoparticle layer (in terms of solid content). .

The method for forming the infrared absorbing nanoparticle layer is not particularly limited, and a known method can be applied in the same manner or appropriately modified. For example, the method of apply | coating the coating liquid for infrared absorption nanoparticle layer formation on an optical reflection layer can be used.

In the above method, the solvent used for forming the coating solution for forming the infrared absorbing nanoparticle layer is not particularly limited. For example, hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol) , Cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, etc. These solvents may be used alone or You may use it with the form of a 2 or more types of mixture. The amount of the solvent is not particularly limited, and is appropriately set in an amount capable of dissolving and dispersing the cured resin. For example, the concentration (total solid content) of the metal oxide nanoparticles and the resin in the coating solution for forming the infrared absorbing nanoparticle layer is preferably 10 to 60% by mass, and 20 to 50% by mass. Is more preferable.

In the above method, the coating method of the coating solution for forming the infrared absorbing nanoparticle layer is not particularly limited, and examples thereof include conventionally known coating methods such as a bar coating method, a gravure coating method, a reverse coating method, and a die coating method. Can do. After the coating, the coating film is dried and then cured by heating or irradiation with active energy rays. Here, the drying conditions are appropriately set at a temperature at which the solvent used can be removed, but is usually 40 to 120 ° C. In addition, when the curing treatment is performed by heating, the heating condition is not limited as long as the sufficient curing treatment can be performed, but the heat treatment may be performed for 30 minutes to several days within a temperature range of 50 to 150 ° C. preferable. Moreover, the active energy ray irradiation conditions in the case of performing the said hardening process by active energy ray irradiation are not restrict | limited in particular. Since the reactivity varies depending on the irradiation wavelength, illuminance, and light amount of the active energy ray, it is necessary to select an optimum condition depending on the resin to be used. For example, when using an ultraviolet lamp as an active energy ray, the illuminance is preferably 50 ~ 1500mW / cm ^2. The amount of irradiation energy is preferably 50 to 1500 mJ / cm ² .

(Heat dissipation promotion layer)
The optical reflective film of the present invention has a heat dissipation promoting layer in addition to the substrate, the optical reflective layer, and the infrared absorbing nanoparticle layer.

Here, the heat radiation promoting layer is disposed on the outermost layer on the light incident side. The structure of the optical reflection film is not limited as long as it is installed so that sunlight is incident from the heat radiation promoting layer side of the optical reflection film. Preferably, the heat radiation promoting layer is disposed on the outermost layer, and the adhesive layer is disposed on the other outermost layer. In such a form, for example, when the optical reflection film is bonded to the window glass surface on the outdoor (outdoor) side via the adhesive layer, the heat radiation promoting layer is arranged on the sunlight incident side. In the case of the said form, since the heat radiation acceleration | stimulation layer is arrange | positioned in the outermost layer on the side into which sunlight injects, the heat | fever which an infrared absorption nanoparticle layer emits is efficiently discharge | released out of a film.

In addition, the heat dissipation promotion layer is usually formed on the infrared absorption nanoparticle layer, but not only in the form of providing the heat dissipation promotion layer directly on the infrared absorption nanoparticle layer, but also the infrared absorption nanoparticle layer and the heat dissipation promotion Another intermediate layer may be provided between the layers. Preferably, the heat dissipation promoting layer is formed on the infrared absorbing nanoparticle layer, that is, the infrared absorbing nanoparticle layer and the heat dissipation promoting layer are disposed adjacent to each other. By taking the said structure, the metal oxide nanoparticle in an infrared light absorption nanoparticle layer can discharge | release the heat | fever emitted by infrared light absorption more efficiently. For this reason, the thermal crack phenomenon by an optical reflection film can be suppressed and prevented more effectively. Further, the heat dissipation promotion layer may be a single layer or a plurality of layers, and when there are a plurality of heat dissipation promotion layers, not only the form in which each heat dissipation promotion layer is laminated adjacently. , They may exist at physically separated positions. Here, the intermediate layer is not particularly limited and is appropriately selected depending on a desired function. Specifically, examples of the intermediate layer include the same layers as those described in the infrared absorption nanoparticle layer.

In the present invention, the ratio (d1 / d2) of the film thickness (d1) of the infrared absorption nanoparticle layer to the film thickness (d2) of the heat dissipation promoting layer is 1 to 100. That is, the film thickness of the heat dissipation promoting layer is equal to or less than the film thickness of the infrared absorption nanoparticle layer. Thereby, the heat radiation promotion layer can efficiently release the heat generated by the metal oxide nanoparticles by absorption of infrared light to the outside. Here, when the ratio (d1 / d2) is less than 1 (that is, the heat dissipation promoting layer is thicker), the heat dissipation promoting layer is too thick and the heat generated by the infrared absorption nanoparticle layer is sufficiently dissipated outside the film. This is not preferable because heat cracking occurs. Further, when the ratio (d1 / d2) exceeds 100 (that is, the heat dissipation promoting layer is too thin), the heat dissipation promoting layer is too thin and directly receives the heat generated by the infrared absorption nanoparticle layer, and is also an optical reflective film. The heat cracking phenomenon cannot be prevented. From the viewpoint of the effect of improving heat dissipation characteristics and scratch resistance, the ratio (d1 / d2) of the film thickness (d1) of the infrared absorption nanoparticle layer to the film thickness (d2) of the heat dissipation promoting layer is preferably 3-50. Preferably it is 5-20.

In the present invention, the film thickness (dry film thickness) of the heat dissipation promoting layer is 0.1 μm or more and less than 1 μm. Here, if the film thickness (dry film thickness) of the heat radiation promoting layer is less than 0.1 μm, the heat radiation promoting layer is too thin and directly receives the heat generated by the infrared absorption nanoparticle layer, causing thermal cracks in the optical reflective film. The phenomenon cannot be prevented. Further, in this case, the heat dissipation promoting layer cannot exhibit sufficient film protection characteristics and cannot exhibit sufficient scratch resistance. Moreover, since the heat_generation | fever of an infrared absorption nanoparticle layer cannot fully radiate heat outside a film in the film thickness (dry film thickness) of a heat dissipation acceleration | stimulation layer being 1 micrometer or more, it will produce a thermal crack. In particular, when the heat radiation promoting layer is formed using a material having a metalloxane skeleton derived from polysilazane described later, it is not preferable because cracking occurs during coating and drying. Moreover, since the film thickness of the whole film will be restrained if it is the film thickness of the above heat dissipation promotion layer, the film can exhibit the outstanding softness | flexibility (flexibility). Since it is inferior in scratch resistance, it is not preferable again. From the viewpoint of improving the heat dissipation characteristics and scratch resistance, the film thickness (dry film thickness) of the heat dissipation promoting layer is preferably more than 0.1 μm and not more than 0.9 μm, more preferably 0.2 to 0.8 μm. .

The material for forming the heat dissipation promoting layer is not particularly limited as long as it can exhibit heat dissipation, but is preferably a material that can exhibit transparency, scratch resistance, weather resistance, hardness, mechanical strength, and the like.

Generally, an inorganic filler is added to a resin as a heat conductive composition for heat dissipation of electronic parts and the like. As the resin, an acrylic resin, a urethane resin, a melamine resin, an epoxy resin, an organic silicate compound, a silicone resin, or the like can be used. In particular, silicone resins and acrylic resins are preferable in terms of hardness and durability. Further, in terms of curability, flexibility, and productivity, those made of an active energy ray-curable acrylic resin or a thermosetting acrylic resin are preferable. Examples of the inorganic filler include alumina, aluminum nitride, boron nitride, silicon carbide, silicon nitride, magnesium oxide, and zinc oxide. Here, when the content of these inorganic fillers is increased, the thermal conductivity increases, but the flatness and transparency of the coating film surface are deteriorated, and cracks, cracks, voids, etc. are likely to occur on the surface. Sometimes dropped out easily. On the other hand, in the present invention, a material having a metalloxane skeleton (an organic silicate compound or a silicone resin) is particularly preferably used from the viewpoint of heat dissipation and scratch resistance. That is, it is preferable that the heat dissipation promoting layer includes a material having a metalloxane skeleton.

A partially hydrolyzed oligomer of an alkoxysilane compound synthesized by a known method can be used for the thermosetting silicone-based heat dissipation promoting layer. An example of the synthesis method is as follows. First, tetramethoxysilane or tetraethoxysilane is used as an alkoxysilane compound, and a predetermined amount of water is added to the alkoxysilane compound in the presence of an acid catalyst such as hydrochloric acid or nitric acid to remove by-produced alcohol from room temperature to 80 ° C. React with. By this reaction, the alkoxysilane is hydrolyzed, and further, a partially hydrolyzed oligomer of the alkoxysilane compound having an average polymerization degree of 4 to 8 having two or more silanol groups or alkoxy groups in one molecule is obtained by the condensation reaction. Next, a curing catalyst such as acetic acid or maleic acid is added to this and dissolved in an alcohol or glycol ether organic solvent to obtain a thermosetting silicone hard coat liquid. And this is apply | coated to an infrared absorption nanoparticle layer by the coating method in a normal coating material, and a transparent heat dissipation acceleration | stimulation layer is formed by heat-curing at the temperature of 80-140 degreeC. In addition, by using di (alkyl or aryl) dialkoxysilane and / or mono (alkyl or aryl) trialkoxysilane instead of tetraalkoxysilane, a polysiloxane-based transparent heat radiation promoting layer is produced in the same manner. Is possible.

When the heat dissipation promoting layer is made of an inorganic material, it can be formed by depositing, for example, silicon oxide, aluminum oxide, silicon nitride, aluminum nitride, lanthanum oxide, lanthanum nitride, or the like by a vacuum film forming method. Examples of the vacuum film forming method include a resistance heating vacuum deposition method, an electron beam heating vacuum deposition method, an ion plating method, an ion beam assisted vacuum deposition method, and a sputtering method.

In addition, when the heat dissipation promoting layer includes a material having a metalloxane skeleton, it is more preferable to form a film obtained by coating polysilazane and heat-curing it. That is, the material having a metalloxane skeleton is more preferably a material having a polysilazane-derived metalloxane skeleton. By using the material, it is possible to form a heat radiation promoting layer having high thermal conductivity while maintaining flexibility (flexibility). Moreover, since the heat dissipation acceleration | stimulation layer formed using the said material shows a glass-like characteristic, it is excellent also in scratch resistance.

The method for producing such a heat dissipation promoting layer is not particularly limited. For example, a glass-like solution can be obtained by applying and drying a solution to which a catalyst is added in an organic solvent containing polysilazane represented by the following general formula (1), if necessary, and then heating (removing the solvent by evaporation). A transparent heat dissipation promoting layer can be formed.

In the general formula (1), R ₁ , R ₂ and R ₃ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, aryl group, vinyl group or (trialkoxysilyl) alkyl group. . At this time, R ₁ , R ₂ and R ₃ may be the same or different. Here, examples of the alkyl group include linear, branched or cyclic alkyl groups having 1 to 8 carbon atoms. More specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n -Hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like. Examples of the aryl group include aryl groups having 6 to 30 carbon atoms. More specifically, non-condensed hydrocarbon groups such as phenyl group, biphenyl group, terphenyl group; pentarenyl group, indenyl group, naphthyl group, azulenyl group, heptaenyl group, biphenylenyl group, fluorenyl group, acenaphthylenyl group, preadenenyl group , Condensed polycyclic hydrocarbon groups such as acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceantrirenyl group, triphenylenyl group, pyrenyl group, chrysenyl group, naphthacenyl group, etc. Can be mentioned. The (trialkoxysilyl) alkyl group includes an alkyl group having 1 to 8 carbon atoms having a silyl group substituted with an alkoxy group having 1 to 8 carbon atoms. More specific examples include 3- (triethoxysilyl) propyl group and 3- (trimethoxysilyl) propyl group. The substituent optionally present in R ₁ to R ₃ is not particularly limited, and examples thereof include an alkyl group, a halogen atom, a hydroxyl group (—OH), a mercapto group (—SH), a cyano group (—CN), There are a sulfo group (—SO ₃ H), a carboxyl group (—COOH), a nitro group (—NO ₂ ) and the like. Note that the optionally present substituent is not the same as R ₁ to R ₃ to be substituted. For example, when R ₁ to R ₃ are alkyl groups, they are not further substituted with an alkyl group. Of these, R ₁ , R ₂ and R ₃ are preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a phenyl group, a vinyl group, 3 -(Triethoxysilyl) propyl group or 3- (trimethoxysilylpropyl) group.

In the general formula (1), n is an integer, and the polysilazane having the structure represented by the general formula (1) may be determined to have a number average molecular weight of 150 to 150,000 g / mol. preferable. Of these, perhydropolysilazane in which all of R ₁ , R ₂ and R ₃ are hydrogen atoms is preferred.

In another preferred embodiment, the heat dissipation promoting layer contains at least one polysilazane represented by the following general formula (2).

In the general formula (2), R _{1 ′} , R _{2 ′} , R _{3 ′} , R _{4 ′} , R _{5 ′} and R _{6 ′} are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, An aryl group, a vinyl group or a (trialkoxysilyl) alkyl group. In this case, R _{1 ′} , R _{2 ′} , R _{3 ′} , R _{4 ′} , R _{5 ′} and R _{6 ′} may be the same or different. The substituted or unsubstituted alkyl group, aryl group, vinyl group or (trialkoxysilyl) alkyl group in the above is the same as the definition in the general formula (1), and thus the description thereof is omitted.

In the general formula (2), n ′ and p ′ are integers so that the polysilazane having the structure represented by the general formula (2) has a number average molecular weight of 150 to 150,000 g / mol. Preferably, it is defined. Note that n ′ and p ′ may be the same or different.

Of the polysilazanes of the above general formula (2), R _{1 ′} , R _{3 ′} and R _{6 ′} each represent a hydrogen atom, and R _{2 ′} , R _{4 ′} and R _{5 ′} each represent a methyl group; R _{1 '} , R _3' and R _{6 '} each represents a hydrogen atom, R _2' , R _{4 '} each represents a methyl group, and R _5' represents a vinyl group; R _{1 '} , R _3' , R ₄ A compound in which _' and R _6' each represent a hydrogen atom and R _{2 '} and R _5' each represents a methyl group is preferred.

Furthermore, in another preferred embodiment, the heat dissipation promoting layer contains at least one polysilazane represented by the following general formula (3).

In the general formula (3), R _{1 ″} , R _{2 ″} , R _{3 ″} , R _{4 ″} , R _{5 ″} , R _{6 ″} , R _{7 ″} , R _{8 ″} and R _{9 ″} are each independently A hydrogen atom, a substituted or unsubstituted alkyl group, aryl group, vinyl group or (trialkoxysilyl) alkyl group, wherein R _{1 ″} , R _{2 ″} , R _{3 ″} , R _{4 ″} , R _{5 ″} , R _{6 ″} , R _{7 ″} , R _{8 ″} and R _{9 ″} may be the same or different. The substituted or unsubstituted alkyl group, aryl group, vinyl group or (trialkoxysilyl) alkyl group in the above is the same as the definition in the general formula (1), and thus the description thereof is omitted.

In the general formula (3), n ″, p ″ and q ″ are integers, and the polysilazane having the structure represented by the general formula (3) has a number average molecular weight of 150 to 150,000 g / mol. Preferably, n ″, p ″ and q ″ may be the same or different.

Of the polysilazanes of the general formula (3), R _{1 ″} , R _{3 ″} and R _{6 ″} each represent a hydrogen atom, and R _{2 ″} , R _{4 ″} , R _{5 ″} and R _{8 ″} each represent a methyl group. , R _{9 ″} represents a (triethoxysilyl) propyl group, and R _{7 ″} represents an alkyl group or a hydrogen atom.

On the other hand, the organopolysilazane in which a part of the hydrogen atom portion bonded to Si is substituted with an alkyl group or the like has improved adhesion to the base material as a base by having an alkyl group such as a methyl group and is hard. The ceramic film made of brittle polysilazane can be toughened, and there is an advantage that the occurrence of cracks can be suppressed even when the (average) film thickness is increased. For this reason, perhydropolysilazane and organopolysilazane may be selected as appropriate according to the application, and may be used in combination.

Perhydropolysilazane is presumed to have a linear structure and a ring structure centered on 6- and 8-membered rings. The number average molecular weight (Mn) is about 600 to 2000 (polystyrene conversion), and there are liquid or solid substances, and the state varies depending on the molecular weight.

Polysilazane is commercially available in a solution state dissolved in an organic solvent, and the commercially available product can be used as it is as the first barrier layer forming coating solution. Commercially available polysilazane solutions include NN120-10, NN120-20, NAX120-20, NN110, NN310, NN320, NL110A, NL120, NL120A, NL120-20, NL150A, NP110, NP140, manufactured by AZ Electronic Materials Co., Ltd. SP140 etc. are mentioned.

In the case where the heat dissipation promotion layer is formed of a material having a metalloxane skeleton (preferably a metalloxane skeleton derived from polysilazane), the method of forming the heat dissipation promotion layer is not particularly limited, but a coating solution for forming a heat dissipation promotion layer containing polysilazane is applied, A method of curing the coating film by heating is preferred. Here, the coating method is not particularly limited, and examples thereof include conventionally known coating methods such as a bar coating method, a gravure coating method, a reverse coating method, and a die coating method.

The ratio of polysilazane in the solvent is generally 1 to 80% by mass of polysilazane. As the solvent, water and a reactive group (for example, a hydroxy group or an amine group) are not included, and an organic system that is inert to polysilazane and preferably an aprotic solvent is preferable. This includes, for example, aliphatic or aromatic hydrocarbons, halogen hydrocarbons, esters such as ethyl acetate or butyl acetate, ketones such as acetone or methyl ethyl ketone, ethers such as tetrahydrofuran or dibutyl ether, and mono- and polyalkylene glycol dialkyl ethers (Diglymes) or a mixture of these solvents.

As an additional component of this polysilazane solution, further binders such as those conventionally used in the production of paints can be used. For example, cellulose ethers and cellulose esters such as ethyl cellulose, nitrocellulose, cellulose acetate or cellulose acetobutyrate, natural resins such as rubber or rosin resins, or synthetic resins such as polymerized resins or condensed resins such as aminoplasts, in particular Urea resins and melamine formaldehyde resins, alkyd resins, acrylic resins, polyesters or modified polyesters, epoxides, polyisocyanates or blocked polyisocyanates, or polysiloxanes.

After the coating, the coating film is dried and then cured by heating. Here, the drying conditions are not particularly limited as long as a sufficient amount of solvent can be evaporated from the coating film (a coating film can be formed). Specifically, the drying temperature is preferably 10 to 90 ° C, more preferably 20 to 50 ° C. The drying time is preferably 0.5 to 10 minutes, more preferably 1 to 5 minutes. The curing conditions may be any conditions that allow a sufficient curing process (a heat dissipation promoting layer can be formed), but it is preferable to perform a heat treatment for 10 minutes to 5 hours within a temperature range of 50 to 150 ° C.

The optical reflective film of the present invention can suppress and prevent thermal cracking due to infrared light absorption of metal oxide nanoparticles. Moreover, the optical reflective film of this invention is excellent in scratch resistance. Furthermore, the optical reflective film of the present invention satisfies at least one of high visible light transmittance, excellent infrared shielding properties, high flexibility, and peeling inhibition properties. Specifically, the optical reflective film of the present invention has a visible light transmittance (T _vis ) of usually 50% or more, preferably 70% or more (upper limit: 100%) in the region of 400 nm to 780 nm. In the present specification, “visible light transmittance (T _vis )” means a value measured by the method described in the Examples below.

[Application of optical reflective film: Optical reflector]
The optical reflective film of the present invention can be applied to a wide range of fields. In other words, a preferred embodiment of the present invention is an optical reflector formed by providing the optical reflective film on at least one surface of a substrate. For example, film for window pasting such as heat ray reflecting film that gives heat ray reflection effect, film for agricultural greenhouses, etc. Etc., mainly for the purpose of improving the weather resistance. In particular, it is suitable for a member in which the optical reflection film according to the present invention is bonded to glass or a glass substitute resin base material directly or via an adhesive.

Specific examples of the substrate include, for example, glass, polycarbonate resin, polysulfone resin, acrylic resin, polyolefin resin, polyether resin, polyester resin, polyamide resin, polysulfide resin, unsaturated polyester resin, epoxy resin, melamine resin, and phenol. Examples thereof include resins, diallyl phthalate resins, polyimide resins, urethane resins, polyvinyl acetate resins, polyvinyl alcohol resins, styrene resins, vinyl chloride resins, metal plates, and ceramics. The type of resin may be any of a thermoplastic resin, a thermosetting resin, and an ionizing radiation curable resin, and two or more of these may be used in combination. The substrate can be produced by a known method such as extrusion molding, calendar molding, injection molding, hollow molding, compression molding or the like. The thickness of the substrate is not particularly limited, but is usually 0.1 mm to 5 cm.

It is preferable that the adhesive layer or the adhesive layer that bonds the optical reflecting film and the substrate is disposed on the sunlight (heat ray) incident surface side. Further, it is preferable to sandwich the optical reflection film between the window glass and the substrate because it can be sealed from surrounding gas such as moisture and has excellent durability. Even if the optical reflective film according to the present invention is installed outdoors or outside a car (for external application), it is preferable because of environmental durability. Here, the adhesive layer (adhesive layer) preferably has an immediate adhesive force of 2 to 8 N / 25 mm at the time of application to the substrate (eg, glass), and the immediate adhesive force is 4 to 8 N / 25 mm. Immediate adhesive strength refers to the adhesive strength of the adhesive layer measured 24 hours after the optical reflective film was attached to glass. The adhesive strength of the adhesive layer can be adjusted by appropriately selecting the material constituting the adhesive layer.

Further, the adhesive strength between the adhesive layer and the glass at the time of application is 4 to 8 N / 25 mm, and the adhesive layer and the glass at the time of being left for 1 week at 30 ° C. and 60% humidity in the applied state. An adhesive strength with time is preferably 7 to 15 N / 25 mm from the viewpoint of curved surface adhesion. Further, the adhesive strength with time is preferably 10 to 15 N / 25 mm from the viewpoint of improving durability and reducing adhesive residue. The adhesive strength with time refers to the adhesive strength of the adhesive layer measured after a certain period of time when the optical reflective film is attached to glass.

When the optical reflective film of the present invention is bonded to a window glass, water is sprayed on the window, and a method for bonding the adhesive layer of the optical control film to the wet glass surface, the so-called water bonding method is re-stretched, repositioned, etc. From the viewpoint of, it is preferably used. For this reason, a pressure-sensitive adhesive having a low adhesive strength in the presence of water is preferable.

As the pressure-sensitive adhesive (adhesive) applicable to the present invention, an adhesive mainly composed of a photocurable or thermosetting resin can be used.

The adhesive preferably has durability against ultraviolet rays, and is preferably an acrylic adhesive or a silicone adhesive. Furthermore, an acrylic adhesive is preferable from the viewpoint of adhesive properties and cost. In particular, since the peel strength can be easily controlled, a solvent system is preferable among the solvent system and the emulsion system in the acrylic adhesive. When a solution polymerization polymer is used as the acrylic solvent-based pressure-sensitive adhesive, known monomers can be used as the monomer.

Further, a polyvinyl butyral resin or an ethylene-vinyl acetate copolymer resin used as an intermediate layer of laminated glass may be used. Specifically, plastic polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., Mitsubishi Monsanto Co., Ltd.), ethylene-vinyl acetate copolymer (manufactured by DuPont, Takeda Pharmaceutical Company Limited, duramin), modified ethylene-vinyl acetate copolymer (Mersen G, manufactured by Tosoh Corporation). In addition, an ultraviolet absorber, an antioxidant, an antistatic agent, a heat stabilizer, a lubricant, a filler, a colorant, an adhesion adjusting agent, and the like can be appropriately added to the adhesive layer. Among these, it is preferable that an adhesion layer contains a ultraviolet absorber. By providing an adhesive layer containing an ultraviolet absorber, the amount of sunlight (particularly infrared light) (the amount of sunlight absorbed by the heat ray absorbing layer) is further reduced. Moreover, when using the optical control film of this invention for window sticking, degradation of the light reflection film by an ultraviolet-ray can be suppressed.

Here, the ultraviolet absorber is not particularly limited, and a known ultraviolet absorber can be used. For example, benzophenone ultraviolet absorbers such as 2,4-dihydroxy-benzophenone and 2-hydroxy-4-methoxy-benzophenone; 2- (2′-hydroxy-5-methylphenyl) benzotriazole, 2- (2′-hydroxy Benzotriazole UV absorbers such as -3 ', 5'-di-t-butylphenyl) benzotriazole; phenyl salicylate, 2-4-di-t-butylphenyl-3,5-di-t-butyl Phenyl salicylate UV absorbers such as -4-hydroxybenzoate; hindered amine UV absorbers such as bis (2,2,6,6-tetramethylpiperidin-4-yl) sebacate; 2,4-diphenyl-6- ( 2-hydroxy-4-methoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2 Triazine-based UV absorbers such as hydroxy-4-ethoxyphenyl) -1,3,5-triazine; and the like.

In addition to the above, the ultraviolet absorber includes a compound having a function of converting the energy held by ultraviolet rays into vibrational energy in the molecule and releasing the vibrational energy as thermal energy.

In addition, you may use an ultraviolet absorber individually or in mixture of 2 or more types. Moreover, as the ultraviolet absorber, a synthetic product or a commercially available product may be used. Examples of commercially available products include, for example, Tinuvin (registered trademark) 320, Tinuvin (registered trademark) 328, Tinuvin (registered trademark) 234, Tinuvin (registered trademark) 477, Tinuvin (registered trademark) 1577, and Tinuvin (registered trademark) 622. (Above, manufactured by BASF Japan Ltd.), ADK STAB (registered trademark) LA-31 (above, manufactured by ADEKA CORPORATION), SEESORB (registered trademark) 102, SESORB (registered trademark) 103, SEESORB (registered trademark) 501 (or more, Cipro Kasei Co., Ltd.).

The addition amount of the ultraviolet absorber (in terms of solid content) is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass with respect to the pressure-sensitive adhesive. If it is such a range, the sunlight absorption amount of a heat ray absorption layer can be reduced more effectively.

The thickness of the pressure-sensitive adhesive layer (adhesive layer) is preferably 1 to 100 μm, and more preferably 3 to 50 μm. If it is 1 micrometer or more, there exists a tendency for adhesiveness to improve and sufficient adhesive force is acquired. On the contrary, if the thickness is 100 μm or less, not only the transparency of the optical control film is improved, but also when the optical control film is attached to the window glass and then peeled off, no cohesive failure occurs between the adhesive layers, and adhesion to the glass surface There is a tendency that there is no remaining agent.

The method for forming the adhesive layer on the substrate is not particularly limited, but after the adhesive layer coating liquid is applied on the substrate or separator and dried to form the adhesive layer, the adhesive layer and the reflective layer are bonded together. The method is preferred. Examples of the separator used at this time include a silicone-coated release PET film and a silicone-coated PE film. The method of applying the coating solution for the adhesive layer on the separator is not particularly limited, and examples thereof include a method of applying the coating solution by wire bar coating, spin coating, dip coating, etc., and forming a film. It is possible to apply and form a film using a continuous coating apparatus such as a coater or a comma coater.

In the present specification, the “adhesive strength” is obtained by measuring according to JIS A 5759: 2008 6.8 adhesive strength test, and more specifically, measured according to the method described in the following examples. Is done.

The effect of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In the following examples, the operation was performed at room temperature (25 ° C.) unless otherwise specified. Unless otherwise specified, “%” and “part” mean “% by mass” and “part by mass”, respectively.

Example 1 Production of Optical Reflective Film 1 Ethylene glycol and cyclohexanedimethanol (mass ratio 7: 3) as glycol components and terephthalic acid (dicarboxylic acid component: glycol component = 1: 1 (molar ratio)) as the dicarboxylic acid component. The polyalkylene terephthalate used, 2,6-naphthalenedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid (mass ratio 7: 3) as the dicarboxylic acid component, and ethylene glycol as the glycol component (dicarboxylic acid component: glycol component = 1: 1 (molar ratio)) is melted at 320 ° C., and a layer formed from polyalkylene terephthalate is formed from 200 layers of multi-layer extrusion dies so that one side is 1640 nm and the other side is 2460 nm. Tilt and extrude The layer formed from the copolymer of PEN is inclined so that the other side is 1230 nm and the other side is 1840 nm, and the extruded film is alternately extruded, and the extruded film is stretched about 3.3 times in length and about 3.3 times in width. Then, heat setting and cooling were performed to produce an optical reflection layer (thickness: 72 μm) having a reflection wavelength center at a wavelength of 1000 nm.

The optically reflective layer obtained above is a polyethylene terephthalate film (A4300, double-sided easy-adhesive layer, thickness: 50 μm, length 200 m × width 210 mm, manufactured by Toyobo Co., Ltd., hereinafter abbreviated as PET film). The optical reflective layer was formed on the substrate. The thermocompression bonding temperature was 130 ° C., the crimping force was 500 N / cm ² , and the crimping speed was 5 m / min.

An AZO dispersion (product name: Celnax CX-Z610M-F2, average particle size 15 nm, manufactured by Nissan Chemical Industries, Ltd.) is diluted with methanol to an AZO concentration of 40% by mass, and an ultraviolet curable hard coat agent. KRM8495 (manufactured by Daicel Ornex Co., Ltd., a mixture of an acrylate-based cured resin and a polymerization initiator) is added, the total solid content is 30% by mass, the AZO concentration is 50% by mass, and the cured resin is 50% by mass. % (Including polymerization initiator) to prepare a coating liquid 1 for forming an infrared absorbing nanoparticle layer. Using a gravure coater, the infrared absorbing nanoparticle layer forming coating solution 1 is applied on the optical reflective layer so that the dry film thickness becomes 1 μm, and the constant rate drying zone temperature is 50 ° C. and the decreasing rate drying zone temperature is 90 °. After drying at 0 ° C., using an ultraviolet lamp, the irradiance of the irradiated part is 100 mW / cm ² , the irradiation amount is 0.2 J / cm ² , the coating layer is cured, and an infrared absorbing nanoparticle layer having a dry film thickness of 1 μm is formed. It formed on the optical reflection layer.

The above infrared absorbing nanoparticle layer is bar-coated using a 3% by weight perhydropolysilazane liquid (NL120 manufactured by AZ Electronic Materials) in dibutyl ether so that the film thickness after drying is 800 nm. After natural drying for 3 minutes, the film was heat-cured (annealed) in an oven at 90 ° C. for 30 minutes to form a heat dissipation promoting layer having a dry film thickness of 800 nm on the infrared absorption nanoparticle layer.

100 parts by mass of an acrylic resin having a hydroxy group, 50 parts by mass of MKC methyl silicate MS-56 (Mitsubishi Chemical's tetramethyl silicate partial hydrolyzate condensate, n average value = 10), 1 part by mass of dibutyltin laurate, xylene 700 parts by mass and 150 parts by mass of isopropyl alcohol were mixed and stirred to prepare a resin mixture having a solid content of 10% by mass.

The obtained resin mixture was mixed with 2.0 parts by mass of Tinuvin 477 (UV absorber manufactured by BASF Japan Ltd.) to prepare a coating solution 1 for forming an adhesive layer.

Using the pressure-sensitive adhesive layer-forming coating solution 1 prepared above, a wire bar was applied to the opposite side of the heat dissipation promoting layer (the substrate surface on the side where the heat dissipation promoting layer was not formed) and dried. The film thickness of the adhesive layer after drying was 8 μm. A 25 μm thick polyester film (Therapel, manufactured by Toyo Metallizing Co., Ltd.) was bonded as a separator film to the surface of the pressure-sensitive adhesive layer of the film with the pressure-sensitive adhesive layer to produce an optical reflective film 1.

Examples 2 to 13: Production of optical reflection films 2 to 13 In Example 1, except that the thicknesses of the infrared absorption nanoparticle layer and the heat dissipation promoting layer were changed to the thicknesses shown in Table 1 below, respectively. In the same manner as in Example 1, optical reflection films 2 to 13 were produced.

Comparative Examples 1 to 5: Production of optical reflection films 14 to 18 In Example 1, except that the thicknesses of the infrared absorption nanoparticle layer and the heat dissipation promoting layer were changed to the thicknesses shown in Table 1 below, respectively. In the same manner as in Example 1, optical reflection films 14 to 18 were produced.

[Performance evaluation of optical reflective film]
The optical reflective films 1 to 18 obtained in the above examples and comparative examples were evaluated for thermal cracking, flexibility, visible light transmittance and scratch resistance according to the following methods. The results are shown in Table 1.

(Evaluation of thermal cracking)
The optical reflection films 1 to 18 produced above were cut to a width of 15 cm and a length of 30 cm, respectively, and then the adhesive layer side was pasted on a commercially available laminated glass plate having a thickness of 3 mm (dry intermediate layer 6 mm) by a water pasting method. Combined. Next, the laminated glass plate on which the optical reflective film was bonded was used on a roll having a diameter of 15.2 cm (6 inches) and a width of 25 cm, and a steel roller covered with rubber having a thickness of 6 mm. An evaluation sample was prepared by pressure bonding the film and glass with a roller so that only its own weight was applied to the window pasting film surface.

Each sample for evaluation was clamped and fixed to a stand, and a commercially available 40 W halogen lamp was placed 30 cm away from the glass side (the one without the optical reflection film), and 50 cm away from the opposite side. While rotating the fan at a distance and air-cooling, the halogen lamp was irradiated, the time until the glass surface started to crack (crack) was measured, and the time was classified as follows.

(Measurement of flexibility)
Using a 1506 mandrel bendability tester (manufactured by Elcometer) based on JIS K5600-5: 1-1: 1999, the heat radiation promoting layer coating surface is placed outside to cause peeling or to peel off from the transparent support. The starting minimum diameter (mm) was measured.

(Measurement of visible light transmittance (T _vis ))
The average visible light transmittance (T _vis ) in the region of 400 nm to 780 nm of each optical reflection film sample was measured using a spectrophotometer (using an integrating sphere, manufactured by Hitachi, Ltd., U-4100 type).

(Scratch resistance evaluation)
The surface after reciprocating 100 mm of # 0000 steel wool at a stroke of 100 mm and a speed of 30 mm / sec under a load condition of 500 g / cm ² was visually observed, and the results were classified as follows.

As shown in Table 1 above, it can be seen that the optical reflective film of the present invention can effectively suppress and prevent thermal cracking. It is considered that this is because the heat dissipation promoting layer sufficiently releases the heat generated by the infrared absorption nanoparticle layer. Therefore, by using the optical reflective film of the present invention, it is expected that the film is less likely to be cracked even when pasted on laminated glass. In addition, since the heat dissipation promotion layer of the film 17 was too thick, minute cracks occurred in the heat dissipation promotion layer itself during coating and drying.

Example 14: Production of optical reflection film 19 A PET film (A4300, double-sided easy-adhesion layer, thickness: 50 μm, length 200 m × width 210 mm, manufactured by Toyobo Co., Ltd.) was prepared as a transparent resin film.

(Preparation of coating solution 1 for low refractive index layer)
The following constituent materials were added and mixed in this order at 45 ° C., and then finished with 1000 parts of pure water to prepare a coating solution 1 for a low refractive index layer.

(Preparation of coating solution 1 for high refractive index layer)
A coating solution 1 for a high refractive index layer was prepared according to the following procedure.

<Preparation of dispersion of silica-coated titanium oxide particles>
First, a dispersion of silica-coated titanium oxide particles was prepared according to the following method, and a solvent or the like was added thereto.

A dispersion of silica-coated titanium oxide particles was prepared as follows.

The titanium sulfate aqueous solution was thermally hydrolyzed by a known method to obtain titanium oxide hydrate. The obtained titanium oxide hydrate was suspended in water to obtain 10 L of an aqueous suspension of titanium oxide hydrate (TiO ₂ concentration: 100 g / L). To this, 30 L of an aqueous sodium hydroxide solution (concentration 10 mol / L) was added with stirring, the temperature was raised to 90 ° C., and the mixture was aged for 5 hours. The obtained solution was neutralized with hydrochloric acid, filtered and washed with water to obtain a base-treated titanium compound.

Next, the base-treated titanium compound was suspended in pure water and stirred so that the TiO ₂ concentration was 20 g / L. Under stirring, it was added citric acid in an amount of 0.4 mol% with respect to TiO ₂ weight. The temperature was raised to 95 ° C., concentrated hydrochloric acid was added so that the hydrochloric acid concentration was 30 g / L, and the solution temperature was maintained, followed by stirring for 3 hours. Here, when the pH and zeta potential of the obtained mixed liquid were measured, the pH at 25 ° C. was 1.4, and the zeta potential was +40 mV. Further, when the particle size was measured by Zetasizer Nano (manufactured by Malvern), the volume average particle size was 35 nm and the monodispersity was 16%.

1 kg of pure water was added to 1 kg of a 20.0 mass% titanium oxide sol aqueous dispersion containing rutile-type titanium oxide particles to prepare a 10.0 mass% titanium oxide sol aqueous dispersion.

2 kg of pure water was added to 0.5 kg of the 10.0 mass% titanium oxide sol aqueous dispersion, followed by heating to 90 ° C. Thereafter, 0.5 kg of an aqueous silicic acid solution having a SiO ₂ concentration of 0.5% by mass was gradually added. Autoclave The resulting dispersion subjected to 18 hours of heat treatment at 175 ° C., further by concentrating, titanium oxide having a rutile structure coated with SiO _2: containing (coating amount 4 wt%), 20 A dispersion (mass sol dispersion) of silica-coated titanium oxide particles by mass was obtained.

<Preparation of coating solution>
The following constituent materials were sequentially added at 45 ° C. to the sol dispersion of silica-coated titanium oxide particles prepared above, and finally finished with 1000 parts of pure water to prepare a coating solution 1 for a high refractive index layer.

Using a slide hopper type wet coating apparatus capable of 15-layer coating, the above-prepared coating solution 1 for the low refractive index layer and coating solution 1 for the high refractive index layer are kept on the transparent resin film while keeping the temperature at 40 ° C. Fifteen layers were applied. Immediately after coating each refractive index layer coating solution, cold air of 5 ° C. was blown and set. At this time, even if the surface was touched with a finger, the time until the finger was lost (set time) was 5 minutes. After completion of the setting, warm air of 80 ° C. was blown and dried to form an optical reflection layer having a dry film thickness of 2.09 μm on the transparent resin film.

At this time, in the 15-layer optical reflection layer, the lowermost layer and the uppermost layer were low refractive index layers. At this time, the low refractive index layer and the high refractive index layer were alternately laminated.

The coating amount was adjusted so that the layer thickness during drying was 150 nm for each low refractive index layer and 130 nm for each high refractive index layer. The thickness of each layer was confirmed by cutting the produced optical reflection film and observing the cut surface with an electron microscope. At this time, when the interface between the two layers could not be clearly observed, the interface was determined by the XPS depth profile in the thickness direction of TiO ₂ contained in the layer obtained by the XPS surface analyzer.

In the same manner as in Example 1, a coating liquid 1 for forming an infrared absorbing nanoparticle layer was prepared. The infrared absorbing nanoparticle layer-forming coating solution 1 thus prepared was applied onto the optical reflective layer in the same manner as in Example 1 to form an infrared absorbing nanoparticle layer having a dry film thickness of 1 μm. It formed on the optical reflection layer.

The above infrared absorbing nanoparticle layer is bar-coated using a 3% by weight perhydropolysilazane liquid (NL120, manufactured by AZ Electronic Materials) in dibutyl ether so that the thickness of the dried film becomes 800 nm. After natural drying for 3 minutes, the film was heat-cured (annealed) in an oven at 90 ° C. for 30 minutes to form a heat dissipation promoting layer having a dry film thickness of 800 nm on the infrared absorption nanoparticle layer.

In the same manner as in Example 1, a coating solution 1 for forming an adhesive layer was prepared.

Using the prepared coating liquid 1 for forming an adhesive layer, a wire bar was applied to the side opposite to the heat dissipation promoting layer (the substrate surface on the side where the heat dissipation promoting layer was not formed) and dried. The film thickness of the adhesive layer after drying was 8 μm. A 25 μm-thick polyester film (Therapel, manufactured by Toyo Metallizing Co., Ltd.) was bonded as a separator film to the surface of the pressure-sensitive adhesive layer of the film with the pressure-sensitive adhesive layer to prepare an optical reflective film 19.

Examples 15 to 26: Production of optical reflection films 20 to 31 In Example 14, except that the thicknesses of the infrared absorption nanoparticle layer and the heat dissipation promoting layer were changed to the thicknesses shown in Table 2 below, respectively. In the same manner as in Example 14, optical reflective films 20 to 31 were produced.

Comparative Examples 6 to 10: Production of optical reflection films 32 to 36 In Example 14, except that the thicknesses of the infrared absorption nanoparticle layer and the heat dissipation promotion layer were changed to the thicknesses shown in Table 2 below, respectively. In the same manner as in Example 14, optical reflection films 32 to 36 were produced.

[Performance evaluation of optical reflective film]
The optical reflective films 19 to 36 obtained in the above examples and comparative examples were evaluated for thermal cracking, film peeling and scratch resistance. The thermal cracking and film peeling were evaluated according to the following methods. The scratch resistance was evaluated in the same manner as described above. The results are shown in Table 2.

(Evaluation of thermal cracking and film peeling)
The optical reflection films 19 to 36 produced above were cut to a width of 15 cm and a length of 30 cm, and then the adhesive layer side was bonded to a commercially available laminated glass plate having a thickness of 3 mm (dry intermediate layer 6 mm) by a water bonding method. Next, the laminated glass plate on which the optical reflecting film is bonded is used on a roll having a diameter of 15.2 cm (6 inches) and a width of 25 cm, and a steel roller coated with rubber having a thickness of 6 mm. An evaluation sample was prepared by pressure-bonding the film and glass with a roller so that only the optical reflective film surface was applied.

The sample for evaluation thus produced was clamped and fixed to the stand, and a commercially available 40 W halogen lamp was placed 30 cm away from the glass side (the one where the film of the present invention was not applied) and irradiated at 40 W. However, pure water was sprayed on the opposite side for 1 minute, and naturally dried for 29 minutes intermittently for 24 hours. At this time, the time until cracking (cracking) started to occur on the glass surface was measured, and the time was classified as follows. Further, the state of film peeling after 24 hours was visually observed, and the results were classified as follows. These results are shown in Table 2.

As shown in Table 2 above, it can be seen that the optical reflective film of the present invention can effectively suppress and prevent thermal cracking. It is considered that this is because the heat dissipation promoting layer sufficiently releases the heat generated by the infrared absorption nanoparticle layer. Therefore, by using the optical reflective film of the present invention, it is expected that the film is less likely to be cracked even when pasted on laminated glass.

In addition, Table 2 also shows that the optical reflective film of the present invention can more effectively suppress film peeling. This is presumed to be due to the improved water resistance since the wettability of the film surface was improved and the water did not collect easily by providing the heat dissipation diffusion layer. In addition, since the heat dissipation promoting layer was too thick in the film 35, minute cracks occurred in the heat dissipation promoting layer itself during coating and drying.

Furthermore, this application is based on Japanese Patent Application No. 2014-121787 filed on June 12, 2014, the disclosure of which is referenced and incorporated as a whole.

Claims

An optical reflection film having a base material, an optical reflection layer, an infrared absorption nanoparticle layer, and a heat dissipation promoting layer, wherein the heat dissipation promoting layer is disposed on the outermost layer on the light incident side, and the film thickness (d2 The ratio (d1 / d2) of the film thickness (d1) of the infrared absorption nanoparticle layer to 1) is 1 to 100, and the film thickness of the heat dissipation promoting layer is 0.1 μm or more and less than 1 μm. Optical reflective film.
The optical reflection film according to claim 1, wherein the heat dissipation promoting layer includes a material having a metalloxane skeleton.
The optical reflective film according to claim 2, wherein the material having a metalloxane skeleton is a material having a polysilazane-derived metalloxane skeleton.
The optical reflection film according to any one of claims 1 to 3, wherein the infrared absorption nanoparticle layer and the heat dissipation promoting layer are disposed adjacent to each other.
The optical reflection layer includes a high refractive index layer including a first water-soluble polymer and first metal oxide particles, and a low refractive index layer including a second water-soluble polymer and second metal oxide particles. The optical reflective film according to any one of Claims 1 to 4, wherein are laminated alternately.
5. The optical reflection layer according to claim 1, wherein a third polymer layer containing a third polymer and a fourth polymer layer containing a fourth polymer are alternately laminated. The optical reflection film according to item 1.
The infrared absorbing nanoparticle layer includes an ultraviolet curable resin and at least one selected from the group consisting of antimony-doped zinc oxide, antimony tin oxide, antimony-doped tin oxide, and indium-doped tin oxide. The optical reflection film according to any one of 6.
An optical reflector comprising the optical reflecting film according to any one of claims 1 to 7 provided on at least one surface of a substrate.