JP2016133520A - Thermal barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal barrier film that is more durable than a conventional product.SOLUTION: A thermal barrier film 10 is provided for suppressing transmission of light with which the film 10 is irradiated, and includes; a hard coat layer 2 containing an ultraviolet-cured resin obtained by curing a composition containing polyfunctional (meth)acrylate, an infrared-absorbing pigment containing a tungsten oxide, and at least one of a carbon black and a black iron oxide; and a reflection part 1 formed by alternately laminating a low-refractive index layer 1a having a first refractive index and a high-refractive index layer 1b having a refractive index greater than the first refractive index. The reflection part 1 is located upstream on a light incident side and the hard coat layer 2 is located downstream on the light incident side. When irradiated with light of a wavelength in the range of 800-1300 nm, the thermal barrier film exhibits a reflectance equal to or more than 40% for the light.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermal barrier film.

  A solar control multilayer film that performs heat shielding by providing near infrared absorption and reflection functions is known (Patent Document 1). This solar control multilayer film is provided with a hard coat layer to which doped tin oxide such as ATO is added as an infrared absorbing portion.

  Moreover, the heat ray shielding glass which can maintain the outstanding heat ray absorptivity over a long period of time is known (patent document 2). This heat ray shielding glass includes a heat ray absorbing layer containing tungsten oxide and / or composite tungsten oxide, and a heat ray reflective layer containing metal oxide other than tungsten oxide and composite tungsten oxide. .

US Pat. No. 7,632,568 JP 2006-10759 A

  The solar control multilayer film described in Patent Document 1 has excellent heat shielding properties due to infrared absorption, but it has been found that cracking and peeling of the infrared absorption layer may easily occur in a high-temperature and high-humidity environment. . In addition, Patent Document 2 discloses that composite tungsten oxide (CWO) is used to shield infrared rays. However, with the configuration of the infrared absorption unit alone, sufficient heat shielding characteristics are not obtained.

  The inventors of the present invention have examined the cracking and peeling in the near infrared absorption part, and in the film having the reflection part and the near infrared absorption part by the multilayer film, for example, the addition of the composite tungsten oxide to the near infrared absorption part Considered to do. As a result, the film having the composite tungsten oxide in the reflective part and the near-infrared absorbing part by the multilayer film showed very good heat shielding properties, but partially shielded in a long-term high-temperature and high-quality environment. It was found that the thermal performance may vary.

  The present invention has been made in view of these problems, and the problem to be solved by the present invention is to provide a heat-shielding film that exhibits better and more reliable heat-shielding performance than before. In particular, to provide a heat-shielding film with little fluctuation in heat-shielding performance even in an environment exposed to high temperature and high humidity for a long period of time, and with little local deterioration in the film. is there.

  The present inventor has intensively studied to solve the above problems. As a result, the following findings were found. That is, the present inventor, when the heat shielding film is kept under high temperature and high humidity for a long time for heat insulation from sunlight, the organic components constituting the reflective part and the resin base material are decomposed or changed, thereby radicals. Etc. were considered to generate. Then, it was thought that the generated radicals acted on the tungsten oxide, and as a result, a variation in heat shielding properties occurred in a part of the film surface. Therefore, as a result of various studies to prevent the influence on tungsten oxide, carbon is used as a material for suppressing the influence on the tungsten oxide due to the radicals and the like while suppressing the influence of cracking and peeling of the tungsten oxide-containing layer. We have determined that black and black iron oxide are good. Based on this point, the gist of the present invention is as follows.

1. A thermal barrier film that suppresses transmission of irradiated light,
A hard coat layer containing an ultraviolet curable resin obtained by curing a composition containing a polyfunctional (meth) acrylate, an infrared absorbing pigment containing tungsten oxide, and at least one of carbon black and black iron oxide When,
A reflective portion in which a first refractive index layer having a first refractive index and a second refractive index layer having a refractive index larger than the first refractive index are alternately stacked;
The reflection portion is disposed on the upstream side of the light incident side, and the hard coat layer is disposed on the downstream side of the light incident side,
A heat-shielding film having a reflectance of 40% or more when irradiated with light having a wavelength of 800 nm to 1300 nm.

2. The tungsten oxide has the following formula (1)
M ¹ _x WO _y (1)
(Where x is a number satisfying 0 <x ≦ 1, y is a number satisfying 2 ≦ y ≦ 3, and M ¹ is selected from the group consisting of Cs, Rb, K, Ba, Sr and Ca. One or more metal elements)
2. The thermal barrier film according to 1 above, which comprises a compound represented by:

3. 3. The heat shielding film as described in 1 or 2 above, which contains at least carbon black.

  ADVANTAGE OF THE INVENTION According to this invention, the thermal insulation film which has a favorable and reliable thermal insulation performance than before can be provided.

It is sectional drawing of the heat insulation film of this invention. It is a figure which shows the mode of the infrared rays when sunlight (infrared rays) is irradiated to the thermal insulation film of this invention.

Hereinafter, modes for carrying out the present invention will be described. However, the following content is an example of the present invention, and the present invention is not limited to the following content.
In the following description, the expression “to” may be used as a description indicating a numerical range. In the numerical range using this expression, values described on both sides of “˜” are included in the numerical range. For example, the description “6 to 2000” represents “6 or more and 2000 or less”, and this numerical range includes “6” and “2000” at both ends thereof.

  FIG. 1 is a cross-sectional view of the thermal barrier film 10 of the present invention. The thermal insulation film 10 suppresses (shields) the transmission of infrared rays when irradiated with infrared rays. In FIG. 1, for convenience of explanation, the thermal barrier film 10 is shown bonded to a glass 20 that is an adherend by an adhesive layer 21. In addition, the heat shielding film 10 shown in FIG. 1 is a suitable example of the heat shielding film of this invention, and the structure of layers, such as the kind of layer, the order of arrangement | positioning, the number of layers, does not change the summary of this invention. As long as it is arbitrarily changed, it can be implemented.

  As shown in FIG. 1, the heat shielding film 10 is formed by laminating the reflecting portion 1, the base material layer 3, and the hard coat layer 2 in this order from the surface side irradiated with infrared rays (for example, included in sunlight). Become. That is, the reflective portion 1 is disposed on the upstream side of the incident side of light incident on the heat shield film 10, and the hard coat layer 2 is disposed on the downstream side of the incident side of light incident on the heat shield film 10. Among these, the reflective portion 1 includes a low refractive index layer 1a (first refractive index layer having a first refractive index) and a high refractive index layer 1b (second refractive index having a refractive index larger than the first refractive index). Refractive index layers) are alternately laminated. However, the outermost layer of the reflecting portion 1 is a low refractive index layer 1a. That is, both the base material layer 3 and the adhesive layer 21 are in contact with the low refractive index layer 1a.

  The reflection part 1 reflects the infrared rays transmitted through the glass 20 in the reflection part 1 and suppresses the transmission of the infrared rays in the heat shield film 10. The reflection unit 1 may be any type as long as it has such a function. However, in the heat shielding film 10, the low refractive index layer 1a having a small refractive index and the refractive index of the low refractive index layer 1a are used. High refractive index layers 1b having a higher refractive index are alternately stacked.

  The reflection unit 1 has a configuration in which at least one laminate (unit) including alternately a low refractive index layer 1a and a high refractive index layer 1b including a polymer is provided on the base material layer 3. Preferably there is. The number of layers (the total number of refractive index layers) of the low refractive index layer 1a and the high refractive index layer 1b constituting the reflecting portion 1 is not particularly limited, but is preferably 6 to 2000 (that is, 3 to 1000 units). More preferably, it is 10-1500 (namely, 5-750 units), More preferably, it is 10-1000 (namely, 5-500 units). When the number of layers is 6 to 2000, generation of haze can be sufficiently suppressed, and a desired reflectance can be achieved more reliably.

  The magnitude of the refractive index of each of the low refractive index layer 1a and the high refractive index layer 1b is specifically limited if the refractive index of the low refractive index layer 1a is smaller than the refractive index of the high refractive index layer 1b. Not. That is, the refractive index of the high refractive index layer 1b is not particularly limited as long as the refractive index of the high refractive index layer 1b is larger than the refractive index of the low refractive index layer 1a. However, the low refractive index layer 1a preferably has a lower refractive index, but the refractive index is preferably 1.10 to 1.60, more preferably 1.30 to 1.55, and still more preferably 1. .30 to 1.50. The high refractive index layer 1b preferably has a higher refractive index, but the refractive index is preferably 1.70 to 2.50, more preferably 1.80 to 2.20, and even more preferably 1.90. ~ 2.20.

  The reflectance in a specific wavelength region (for example, 800 nm to 1300 nm) is determined by the refractive index difference between two adjacent layers (low refractive index layer 1a and high refractive index layer 1b) and the number of stacked layers, and the larger these refractive index differences are. The same reflectance can be obtained with a small number of layers. The refractive index difference and the number of layers suitable for obtaining a desired reflectance can be calculated using commercially available optical design software. For example, in order to obtain an infrared reflectance (infrared shielding rate) of 90% or more, the number of stacked layers may exceed 100 layers when the refractive index difference is smaller than 0.1. In such a case, not only productivity is lowered, but scattering at the laminated interface is increased, and transparency may be lowered. Therefore, it is preferable that the refractive index difference is large. On the other hand, from the viewpoint of improving the reflectance and reducing the number of layers, there is no upper limit to the difference in refractive index, but it is substantially about 1.4, for example.

  The refractive index difference can be calculated by calculating the difference between the refractive indexes of the low refractive index layer 1a and the high refractive index layer 1b according to the following method. That is, each refractive index layer (low refractive index layer 1a and high refractive index layer 1b) is produced as a single layer using the base material layer 3 as necessary. And after cutting these samples into 10 cm x 10 cm, a refractive index is calculated | required according to the following method.

  First, the surface (back surface) opposite to the measurement surface of each sample is roughened, and then light absorption processing is performed with a black spray so that reflection of light on the back surface is prevented. Next, 25 points of reflectance in the visible light region (400 nm to 700 nm) are measured under the condition of regular reflection at 5 degrees to obtain an average value, and the average refractive index is obtained from the measurement result. For the measurement of the refractive index, for example, a U-4000 type (manufactured by Hitachi, Ltd.) can be used as a spectrophotometer.

  Since reflection at the interface between adjacent layers depends on the refractive index ratio between the layers, the larger the refractive index ratio, the higher the reflectance. When the relationship between the reflected light on the surface of the layer and the optical path difference of the reflected light on the bottom of the layer is expressed as “n · d = wavelength / 4”, the reflected light is strengthened by the phase difference. It can be controlled to meet. Here, n is the refractive index, d is the physical film thickness of the layer, and n · d is the optical film thickness. The reflectance can be increased by controlling the reflected light to be intensified. And reflection can be controlled by utilizing this optical path difference. By using this relationship to control the refractive index and film thickness (layer thickness) of each layer, the reflection of visible light and near-infrared light can be controlled. That is, the reflectance in a specific wavelength region can be improved by the refractive index of each layer, the film thickness of each layer, and the way of stacking each layer.

  The reflection part 1 can be made into a visible light reflection film or a near-infrared reflection film by changing the specific wavelength region that improves the reflectance. That is, the reflection part 1 can use a visible light reflection film if the specific wavelength region for improving the reflectance is set to the visible light region, and can use a near infrared reflection film if it is set to the near infrared region. . Further, if the specific wavelength region for improving the reflectance is set in the ultraviolet light region, an ultraviolet reflecting film can be used.

  When such a film is used in the heat shield film 10 of the present invention, the reflection portion 1 may be a (near) infrared reflection (shield) film. When using an infrared reflective film, the transmittance of light having a wavelength of 550 nm in the visible light region indicated by JIS R3106: 1998 in the infrared reflective film is preferably 50% or more, and preferably 70% or more. More preferably, it is more preferably 75% or more. Moreover, in the said infrared reflective film, it is preferable that the transmittance | permeability of the light of the wavelength of 1200 nm measured by the same method is 35% or less, It is more preferable that it is 25% or less, It is 20% or less Is more preferable. It is preferable to design the optical film thickness and unit so as to be in such a suitable range.

  The material constituting the low refractive index layer 1a and the high refractive index layer 1b is not particularly limited, but the low refractive index layer 1a and the high refractive index layer 1b preferably include a polymer material. If the refractive index layer is formed of a polymer material, a film forming method such as coating, spin coating, or spreading can be selected. Since these methods are simple and do not ask the heat resistance of a base material, there are many choices, and it can be said that it is an effective film forming method particularly for a resin base material. For example, a mass production method such as a roll-to-roll method can be adopted for the coating type, which is advantageous in terms of cost and process time. Moreover, since the film | membrane containing a polymer material has high flexibility, even if it winds up at the time of production or conveyance, these defects do not generate easily and there exists an advantage that it is excellent in handleability.

  The polymer contained in the low refractive index layer 1a and the high refractive index layer 1b is not particularly limited, and specific examples include polyethylene terephthalate, polyethylene terephthalate copolymer, poly (methyl methacrylate), poly (methyl methacrylate). Acrylate) copolymer, cyclohexanedimethanol, cyclohexanedimethanol copolymer, polyethylene naphthalate, polyethylene naphthalate copolymer, poly (methyl methacrylate), poly (methyl methacrylate) copolymer, and the like. In the low refractive index layer 1a and the high refractive index layer 1b, one kind of these polymers can be used alone or a combination of two or more kinds can be used. The polymer may be a synthetic product or a commercially available product. Furthermore, examples of suitable polymer combinations include those described in US Pat. No. 6,352,761. Moreover, it is also possible to form the reflection part 1 by the continuous flat film manufacturing line by the co-extrusion method or the co-casting method etc. using the said polymer.

  The polymer contained in the low refractive index layer 1a and the high refractive index layer 1b is preferably a water-soluble polymer that functions as a binder. Since the low refractive index layer 1a and the high refractive index layer 1b contain a water-soluble polymer, the amount of the organic solvent used can be reduced, so that the burden on the environment can be reduced. Moreover, the softness | flexibility of a coating film can also be achieved. In addition, although the polymer contained in the low refractive index layer 1a and the high refractive index layer 1b may be the same structural component and may be a different structural component, it is preferable that these are different.

  Examples of the water-soluble polymer include gelatin, thickening polysaccharides, polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate- Acrylic resin such as acrylic acid ester copolymer or acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer Styrene-acrylate resins such as styrene-α-methylstyrene-acrylic acid copolymer or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrenesulfonate copolymer, styrene- 2-hydroxyethyl acrylate copolymer Styrene-2-hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer Examples thereof include vinyl acetate-based copolymers such as polymers, vinyl acetate-maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and the like.

  Among these, from the viewpoint of improving effects such as coating unevenness and film thickness uniformity (haze), the low refractive index layer 1a and the high refractive index layer 1b include polyvinyl alcohol, which is polyvinyl alcohol, or a derivative thereof. Is preferred.

  Polyvinyl alcohols that can be used are not particularly limited, and may be used for the low refractive index layer 1a and the high refractive index layer 1b such as International Publication No. 2012/128109, JP2013-121567A, JP2013-148849A, and the like. Known polyvinyl alcohols used can be used in the same manner. Specifically, the polyvinyl alcohol-based resin includes various modified polyvinyl alcohols in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate.

  Polyvinyl alcohol preferably has an average degree of polymerization of 1000 or more, and particularly preferably an average degree of polymerization of 1500 to 5000. The saponification degree is preferably 70 mol% to 100 mol%, particularly preferably 80 mol% to 99.9 mol%.

  Examples of the modified polyvinyl alcohol include cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, nonion-modified polyvinyl alcohol, ethylene-modified polyvinyl alcohol, and vinyl alcohol polymers. Further, as the polyvinyl alcohol-based resin, vinyl acetate-based resin (for example, “Exeval” manufactured by Kuraray Co., Ltd.), polyvinyl acetal resin obtained by reacting polyvinyl alcohol with aldehyde (for example, “S-LEC” manufactured by Sekisui Chemical Co., Ltd.), Silanol-modified polyvinyl alcohol having a silanol group (for example, “R-1130” manufactured by Kuraray Co., Ltd.), modified polyvinyl alcohol-based resin having an acetoacetyl group in the molecule (for example, “Gosefimer (registered trademark)” manufactured by Nippon Synthetic Chemical Industry Co., Ltd. ) Z / WR series ") and the like.

  In addition, the said polyvinyl alcohol may be used independently or may be used in combination of 2 or more type. In addition, as the polyvinyl alcohol, a synthetic product or a commercially available product may be used.

  Further, when the low refractive index layer 1a or the high refractive index layer 1b contains a water-soluble polymer (for example, polyvinyl alcohol), a curing agent can be used to cure the water-soluble polymer. Curing agents include boric acid and its salts, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-diglycidylcyclohexane, N, N-diglycidyl-4-glycidyloxyaniline, sorbitol polyglycidyl Ether, glycerol polyglycidyl ether, etc.), aldehyde-based curing agents (formaldehyde, glyoxal, etc.), active halogen-based curing agents (2,4-dichloro-4-hydroxy-1,3,5, -s-triazine, etc.), active Examples thereof include vinyl compounds (1,3,5-trisacryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, etc.), aluminum alum, borax and the like. The content of the curing agent in the contained low refractive index layer 1a or high refractive index layer 1b is preferably 1% by mass to 10% by mass with respect to the solid content of the contained refractive index layer.

  Furthermore, it is preferable that at least one of the low refractive index layer 1a and the high refractive index layer 1b contains a metal oxide (particle). By containing metal oxide particles, the refractive index difference between the refractive index layers can be increased, and the reflection characteristics are improved. Especially, both the low refractive index layer 1a and the high refractive index layer 1b can contain a metal oxide particle, and can make a refractive index difference larger. By including metal oxide particles, the number of stacked layers can be reduced and a thin film can be obtained. Furthermore, by reducing the number of layers, productivity can be improved and a decrease in transparency due to scattering at the lamination interface can be suppressed.

  As the metal oxide particles, for example, 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 And those that are one or more metals.

Examples of the metal oxide particles that can be suitably used in the high refractive index layer 1a include titanium dioxide, zirconium oxide, cerium oxide, titanium oxide, zinc oxide, alumina, colloidal alumina, lead titanate, red lead, yellow lead, Zinc yellow, chromium oxide, ferric oxide, iron black, copper oxide, magnesium oxide, magnesium hydroxide, strontium titanate, yttrium oxide, hafnium oxide, niobium oxide, tantalum oxide, barium oxide, indium oxide, europium oxide, oxidation Examples include lanthanum, zircon, tin oxide, lead oxide, and double oxides such as lithium niobate, potassium niobate, lithium tantalate, and aluminum / magnesium oxide (MgAl ₂ O ₄ ). .

  Among these, metal oxide particles having a refractive index of 1.90 or more are preferable, and specific examples include zirconium oxide, cerium oxide, titanium oxide, and zinc oxide. Among them, titanium oxide is preferable because it is possible to form a transparent and higher refractive index layer having a higher refractive index, and it is particularly preferable to use rutile (tetragonal) titanium oxide particles. The metal oxide particles used for the high refractive index layer may be used alone or in combination of two or more. In addition, the metal oxide particles preferably have a number average particle size of 100 nm or less, and more preferably 4 nm to 50 nm.

  As the content of the metal oxide particles in the high refractive index layer 1a, color unevenness in the case of applying a film to a glass having a curved shape and a viewpoint of infrared shielding with respect to the solid content of 100% by mass of the high refractive index layer 1a. From the viewpoint of reduction, it is preferably 20% by mass to 80% by mass, more preferably 30% by mass to 75% by mass, and further preferably 40% by mass to 70% by mass.

  Moreover, as a metal oxide particle which can be used suitably in the low refractive index layer 1b, silicon dioxide is preferable and colloidal silica is especially preferable. Such metal oxide particles preferably have an average particle size of 3 nm to 100 nm. The content of the metal oxide particles in the low refractive index layer 1b is preferably 5% by mass to 80% by mass with respect to the solid content of the low refractive index layer 1b from the viewpoint of refractive index. It is further more preferable that it is mass%-75 mass%.

  In addition to the above components, the low refractive index layer 1a and the high refractive index layer 1b are each independently, for example, JP-A-57-74193, JP-A-57-87988, and JP-A-62-2. 261476, JP-A-57-74192, JP-A-57-87989, JP-A-60-72785, JP-A-61-146591, JP-A-1- Japanese Patent Laid-Open No. 95091 and Japanese Patent Laid-Open No. 3-13376, etc., Japanese Patent Application Laid-Open No. 59-42893, Japanese Patent Application Laid-Open No. 59-52689, Japanese Patent Application Laid-Open No. 62-280069, Japanese Patent Application Laid-Open No. Fluorescent brighteners, sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate, etc. described in JP-A-61-228771 and JP-A-4-219266 pH adjusting agents, antifoaming agents, lubricants such as diethylene glycol, preservatives, antistatic agents, may contain various known additives such as a matting agent. It is preferable that content of these additives is 0.1 mass%-10 mass% with respect to solid content of the low refractive index layer 1a or the high refractive index layer 1b to contain.

  Moreover, the low refractive index layer 1a and the high refractive index layer 1b may contain a surfactant for adjusting the surface tension at the time of application. Here, examples of the surfactant include an anionic surfactant, a nonionic surfactant, an amphoteric surfactant, and the like. Among these, an anionic surfactant is preferable. Preferred compounds include those containing a hydrophobic group having 8 to 30 carbon atoms and a sulfonic acid group or a salt thereof in one molecule. The content of the surfactant in each refractive index layer is preferably 0.01% by mass to 5% by mass with respect to the solid content of the low refractive index layer 1a or high refractive index layer 1b.

  Although the manufacturing method of the reflection part 1 is not specifically limited, For example, the method of forming by apply | coating and drying the coating liquid for low refractive index layers and the coating liquid for high refractive index layers is mentioned. The low refractive index layer 1a is formed by drying the coating liquid for low refractive index layer, and the high refractive index layer 1b is formed by drying the coating liquid for high refractive index layer. The coating method is not particularly limited and may be either a sequential coating method or simultaneous multilayer coating, but simultaneous multilayer coating is preferable from the viewpoint of productivity and the like. As a coating method using these, for example, a curtain coating method, a slide bead coating method using a hopper described in US Pat. No. 2,761,419, US Pat. No. 2,761791, an extrusion coating method and the like are preferably used. It is done.

  When the slide bead coating method is used, the temperature of the coating solution for the low refractive index layer and the coating solution for the high refractive index layer when performing simultaneous multilayer coating is preferably a temperature range of 25 ° C to 60 ° C, and 30 ° C to 45 ° C. A temperature range of ° C is more preferred. Moreover, when using a curtain application | coating system, the temperature range of 25 to 60 degreeC is preferable, and the temperature range of 30 to 45 degreeC is more preferable.

  The viscosity of the coating solution for the low refractive index layer and the coating solution for the high refractive index layer at the time of simultaneous multilayer coating is not particularly limited. However, when the slide bead coating method is used, it is preferably in the range of 5 mPa · s to 100 mPa · s, preferably in the range of 10 mPa · s to 50 mPa · s, in the preferable temperature range of the coating liquid. Is more preferable. In the case of using the curtain coating method, the preferable temperature range of the coating solution is preferably in the range of 5 mPa · s to 1200 mPa · s, and more preferably in the range of 25 mPa · s to 500 mPa · s. More preferred. If it is the range of such a viscosity, simultaneous multilayer coating can be performed efficiently.

  Further, the viscosity at 15 ° C. of the coating solution is preferably 100 mPa · s or more, more preferably 100 mPa · s to 30000 mPa · s, further preferably 3000 mPa · s to 30000 mPa · s, and particularly preferably 10000 mPa · s to 30000 mPa · s.

  The thicknesses of the low refractive index layer 1a and the high refractive index layer 1b can be determined according to the refractive indexes of the low refractive index layer 1a and the high refractive index layer 1b, for example. That is, although details will be described later, in the thermal barrier film 10 of the present invention, the reflectance of the light when irradiated with light having a wavelength of 800 nm to 1300 nm is 40% or more. Therefore, the thicknesses of the low refractive index layer 1a and the high refractive index layer 1b may be set so that a value obtained by multiplying the product of the thickness (d) and the refractive index (n) by 4 is within the wavelength. . That is, n and d may be determined so that the above formula of “n · d = wavelength / 4” is satisfied.

  The hard coat layer 2 prevents damage and the like from adhering to the heat shield film 10 and / or absorbs infrared rays that cannot be shielded by the reflecting portion 1. The hard coat layer 2 referred to in the present invention is a layer having a pencil hardness according to JIS K 5600-5-4 of H or higher, preferably 2H or higher. The thickness of the hard coat layer 2 is, for example, 0.1 μm to 20 μm, preferably 0.1 μm to 10 μm, and more preferably 1 μm to 5 μm.

  The hard coat layer 2 can be formed by applying and curing a hard coat layer coating solution. The coating liquid for hard coat layer is preferably one that is cured by ultraviolet rays in consideration of damage to the base film (base layer 3) and productivity. Materials that are cured by ultraviolet rays are easy to procure because they are highly versatile. In addition, ultraviolet curing is efficient because the reaction proceeds quickly in a short time compared to thermal curing. Further, by curing with ultraviolet rays, it is not necessary to perform the treatment at a high temperature, and the influence of heat on the resin component constituting the film is small. Therefore, a PET film or the like that is easily deformed by heat can be used for the base material layer 3, and the characteristics of the PET film that are inexpensive and excellent in handling can be utilized. Moreover, since the thermal effect on the base material layer 3 such as a PET film is small, even when a PET film or the like is used as the base material layer 3, good optical properties are achieved.

  Therefore, in the thermal barrier film 10 of the present invention, the hard coat layer 2 contains an ultraviolet curable resin obtained by curing a composition containing polyfunctional (meth) acrylate. Further, the hard coat layer 2 will be described in more detail later, but it has an infrared absorption pigment containing tungsten oxide having an infrared absorption capability, and at least of carbon black and black iron oxide (for example, triiron tetroxide). One black pigment is included.

  The type of the polyfunctional (meth) acrylate is not particularly limited, and examples thereof include bifunctional (meth) acrylate, trifunctional (meth) acrylate, tetrafunctional (meth) acrylate, pentafunctional (meth) acrylate and the like. . Here, “(meth) acrylate” in the present specification is a general term for acrylate and methacrylate.

  Examples of the bifunctional (meth) acrylate include ethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol di (Meth) acrylate, 1,10-decanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, Tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, neopentyl glycol Adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, Examples thereof include ethylene oxide-modified phosphoric acid di (meth) acrylate, isocyanurate di (meth) acrylate, and allylated cyclohexyl di (meth) acrylate.

Examples of the trifunctional (meth) acrylate include pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, and trimethylolpropane tri (meth) acrylate. , Propylene oxide-modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, and the like.
Furthermore, examples of the tetrafunctional (meth) acrylate include, but are not limited to, pentaerythritol tetraacrylate and ditrimethylolpropane tetraacrylate.

Examples of pentafunctional or higher (meth) acrylates include dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, caprolactone-modified dipentaerythritol hexaacrylate, and propionic acid modification. Examples include dipentaerythritol pentamethacrylate, propionic acid-modified dipentaerythritol pentaacrylate, and caprolactone-modified dipentaerythritol hexamethacrylate. Of these, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate are preferred.
These polyfunctional (meth) acrylates may be used individually by 1 type, and may be used in combination of 2 or more type.

  In addition to the polyfunctional (meth) acrylate, polyfunctional urethane (meth) acrylate, polyfunctional epoxy (meth) acrylate, polyfunctional polyol (meth) acrylate, polyfunctional ester ( Also included are (meth) acrylates and polyfunctional silicon (meth) acrylates. Among these, from the viewpoint of sufficiently suppressing the appearance failure caused by curling of the heat-shielding film 10 and peeling and breaking of the hard coat layer 2, a polyfunctional urethane (meth) acrylate, a polyfunctional epoxy (meth) acrylate, a polyfunctional polyol ( It is preferably at least one of a (meth) acrylate, a polyfunctional ester (meth) acrylate, and a polyfunctional silicon (meth) acrylate. By using these, an appropriate distance can be given between the polymerization functional groups, and the hard coat layer 2 can have sufficient flexibility. That is, flexibility can be imparted while maintaining a certain degree of hardness. Thereby, even if swelling and shrinkage are repeated due to heat, the swelling and shrinkage can be absorbed, so that the heat resistance of the thermal barrier film 10 can be sufficiently enhanced.

  In addition, as polyfunctional (meth) acrylate, polyfunctional urethane (meth) acrylate, polyfunctional epoxy (meth) acrylate, polyfunctional polyol (meth) acrylate, polyfunctional ester (meth) acrylate and polyfunctional silicon (meth) acrylate When at least one of them is used, these may be used alone or in combination with other polyfunctional (meth) acrylates.

  A photopolymerization initiator is usually added to the hard coat layer coating solution. The photopolymerization initiator can be appropriately selected from conventionally known photopolymerization initiators. Examples of such a photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenyl. Acetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl) Propionyl) benzyl] phenyl] -2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hi Loxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4′-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, 2,4,6-trimethylbenzoyl Diphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis (2,6-dimethoxybenzoyl) -2, , It may be mentioned 4-trimethyl pentyl phosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and the like.

  In the present invention, from the viewpoint of photocurability, one or more of these photopolymerization initiators are appropriately selected from those having an excitation wavelength shifted from the ultraviolet absorption wavelength of the inorganic infrared absorber to be used. And preferably used. In addition, a photoinitiator may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

Further, the hard coat layer 2 contains an infrared absorbing pigment containing tungsten oxide as described above. The tungsten oxide in the infrared absorbing pigment is preferably tungsten oxide fine particles represented by the following formula (1).
M ¹ _x WO _y (1)
(Where x is a number satisfying 0 <x ≦ 1, y is a number satisfying 2 ≦ y ≦ 3, and M ¹ is selected from the group consisting of Cs, Rb, K, Ba, Sr and Ca. One or more metal elements)

In the above formula (1), when M ¹ = is cesium, the infrared absorbing pigment is cesium-containing tungsten oxide (CWO). Since the cesium-containing tungsten oxide has a very high infrared shielding ability and only needs to be added in a small amount, the use of the cesium-containing tungsten oxide can further enhance the durability of the thermal barrier film 10.

  The content of the infrared absorbing pigment in the hard coat layer 2 is not particularly limited. However, the content of the infrared absorbing pigment can be, for example, 0.1 g to 5 g, preferably 2 g to 5 g per 10 g of the hard coat layer 2. By setting the content within this range, the rigidity of the hard coat layer 2 and the heat shielding film 10 can be sufficiently increased.

  The hard coat layer 2 includes an infrared absorbing pigment containing tungsten oxide as described above, but may include other infrared absorbing pigments having infrared absorbing ability. For example, as other infrared absorbing pigments having infrared absorbing ability, although not particularly limited, antimony-containing doped tin oxide, indium doped tin oxide, aluminum zinc composite oxide (AZO), gallium doped zinc oxide (GZO), Indium zinc complex oxide (IZO), zinc antimonate, lanthanum hexaboride and the like can be mentioned. By including an infrared absorbing pigment having other infrared absorbing ability such as these, the hard coat layer 2 can be arbitrarily colored according to market preference.

  Further, the hard coat layer 2 includes a black pigment containing at least one of carbon black and black iron oxide. By including such a black pigment, there are obtained advantages of improving the peeling and cracking of the hard coat layer and improving the variation in partial heat shielding properties. Of these, carbon black is preferably used as the black pigment.

  The content of the black pigment in the hard coat layer 2 is not particularly limited. However, the content of the black pigment can be, for example, 0.01 g to 0.5 g per 10 g of the hard coat layer 2. The total amount of the infrared absorbing pigment and the black pigment is not particularly limited, but may be, for example, 0.1 g to 5 g per 10 g of the hard coat layer 2.

  The base material layer 3 supports the reflecting portion 1 and the hard coat layer 2. Examples of the base material layer 3 include a PET film and a melted mixture film of polyethylene naphthalate (PEN) and polymethyl methacrylate (PMMA). The thickness of the base material layer 3 is, for example, 20 μm to 200 μm, preferably 30 μm to 200 μm.

  In addition, the thermal insulation film 10 can be manufactured by arbitrary methods. Specifically, for example, the thermal barrier film 10 can be produced by the method described in the examples described later.

  Moreover, regarding the physical properties of the heat shield film 10, the heat shield film 10 has a reflectance of 40% or more when irradiated with light (infrared rays) having a wavelength of 800 nm to 1300 nm. That is, the reflectance of light having a wavelength in the near infrared region is 40% or more. When the reflectance of light having this wavelength is 40% or more, a heat shield film that exhibits better and more reliable heat shield performance than conventional ones can be obtained. A reflectance can be calculated | required by measuring the range of 800 nm-1300 nm using a near-infrared spectrophotometer V-670 (made by JASCO Corporation).

  This reflectance is preferably achieved by providing the reflecting portion 1 as described with reference to FIG. A state in which light is reflected when the reflection portion 1 is provided to improve the reflectance will be described with reference to FIG.

  FIG. 2 is a view showing the state of infrared rays when sunlight (infrared rays) is irradiated on the heat shield film 10 of the present invention. As shown in FIG. 2, the infrared light incident from the glass 20 side passes through the glass 20 and the adhesive layer 21 and reaches the reflecting portion 1. As described above, in the reflective portion 1, the low refractive index layer 1a is disposed as the outermost layer, and the low refractive index layer 1a and the high refractive index layer 1b are alternately disposed in the inside (see FIG. In Fig. 2, for simplicity of illustration, only one layer is provided between the uppermost layer and the lowermost layer). Therefore, the infrared rays that have passed through the adhesive layer 21 and have entered the low refractive index layer 1a of the reflecting portion 1 cannot enter the high refractive index layer 1b having a high refractive index. The light is reflected at the interface with the high refractive index layer 1b.

  However, depending on the incident angle of infrared rays, some infrared rays enter the high refractive index layer 1b, and the infrared rays pass through the lower refractive index layer 1b and the base material layer 3 to reach the hard coat layer 2. There is also. Therefore, in order to cope with the infrared rays that reach the hard coat layer 2, the hard coat layer 2 contains an infrared absorbing pigment having infrared absorbing ability and a predetermined black pigment as described above. Although these all absorb infrared rays, in FIG. 2, for simplification of illustration, these are not distinguished and are simply indicated by black circles (infrared absorbing material 30).

  That is, the infrared rays incident on the hard coat layer 2 are absorbed by the infrared absorbing material 30 to prevent further passage of infrared rays. That is, the hard coat layer 2 suppresses infrared transmission. Thereby, it can suppress that the infrared rays from the glass 20 side permeate | transmit the thermal insulation film 10, As a result, the temperature rise by the transmitted infrared rays can be suppressed (thermal insulation effect). Therefore, when it is difficult to transmit infrared rays and it is desired to enhance the heat shielding effect, for example, the difference between the refractive index of the low refractive index layer 1a and the refractive index of the high refractive index layer 1b is increased to facilitate reflection. be able to.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Each operation was performed at room temperature (20 ° C. to 25 ° C.) unless otherwise specified.

1. Preparation of raw material solution (1) Preparation of coating solution for high refractive index layer 15.0 mass% titanium oxide sol (SRD-W, volume average particle size: 5 nm, rutile titanium dioxide particles, manufactured by Sakai Chemical Co., Ltd.) 0.5 mass After adding 2 parts by mass of pure water to the part, it was heated to 90 ° C. Next, 0.5 part by mass of an aqueous silicic acid solution (sodium silicate 4 (manufactured by Nippon Kagaku Kogyo Co., Ltd.) diluted with pure water so that the SiO ₂ concentration is 0.5% by mass) was gradually added, Then, heat treatment was performed at 175 ° C. for 18 hours in an autoclave. Cooled after the heat treatment, by concentration using an ultrafiltration membrane, solid concentration, titanium dioxide sol was deposited in 6 wt% SiO ₂ on the surface (hereinafter, referred to as "silica deposited titanium dioxide sol") (volume average Particle size: 9 nm).

  48 parts by mass of an aqueous citric acid solution (1.92% by mass) is added to 140 parts by mass of the silica-attached titanium dioxide sol (20% by mass) thus obtained, and ethylene modified polyvinyl alcohol (Exeval RS manufactured by Kuraray Co., Ltd.) is added. -2117, saponification degree 98 mol%) (8 mass%) 113 mass parts was added and it fully stirred. And the coating liquid for high refractive index layers was prepared by adding 0.4 mass part of 5 mass% aqueous solution (Softazoline LSB-R, Kawaken fine chemical company make) of surfactant.

(2) Preparation of coating solution for low refractive index layer 31 mass parts of acidic colloidal silica 10 mass% aqueous solution (Snowtex OXS, primary particle size: 5.4 nm, manufactured by Nissan Chemical Industries, Ltd.) is heated to 40 ° C. 3 parts by mass of a 3% by mass aqueous solution of boric acid was added. Next, 39 parts by mass of a water-soluble polymer, polyvinyl alcohol (JP-45, manufactured by Nippon Vinegar Poval, polymerization degree 4500, saponification degree 88 mol%) (6% by mass) and 1 part by mass of a surfactant A low-refractive-index layer coating solution was prepared by adding a 5 mass% aqueous solution (SOFTAZOLINE LSB-R, manufactured by Kawaken Fine Chemical Co., Ltd.) in this order at 40 ° C.

(3) Preparation of hard coat layer coating solution Seven types of hard coat layer coating solutions (1) to (7) were prepared according to the following procedure.

(3-1) Preparation of Hard Coat Layer Coating Liquid (1) As a polyfunctional (meth) acrylate monomer, 95 parts by weight of beam set 577 (manufactured by Arakawa Chemical Industries, Ltd., polyfunctional urethane acrylate) and Aronix M305 (Toagosei) 5 parts by mass of Polyfunctional Acrylate, manufactured by the company, and 5 parts by mass of Aronix M402 (manufactured by Toagosei Co., Ltd., polyfunctional acrylate) Then, 195 parts by mass of a cesium-containing tungsten oxide dispersion (YMF-02A, manufactured by Sumitomo Metal Mining) and 5 parts by mass of a carbon black dispersion (KCF-22, manufactured by Sumitomo Metal Mining) as a black pigment are added to this mixture. It was.

  Finally, 367 parts by mass of methyl ethyl ketone as a solvent, 3 parts by mass of Irgacure 184 (manufactured by BASF Japan) as a polymerization initiator, and a fluorosurfactant (Fujigent 650A, Neos Inc.) 0 .05 parts by mass was added to prepare a hard coat layer coating solution (1).

(3-2) Preparation of Hard Coat Layer Coating Liquid (2) Carbon black used in the above-mentioned “Preparation of Hard Coat Layer Coating Liquid (1)” was converted to triiron tetroxide (made by Toda Kogyo Co., Ltd., black iron oxide) The coating liquid for hard coat layer (2) was prepared in the same manner as the above-mentioned “Preparation of coating liquid for hard coat layer (1)” except that the above was changed.

(3-3) Preparation of Hard Coat Layer Coating Liquid (3) Beam Set 577 used in the above-mentioned “Preparation of Hard Coat Layer Coating Liquid (1)” was replaced with Aronix M8060 (manufactured by Toagosei Co., Ltd., polyfunctional ester acrylate) The coating liquid for hard coat layer (3) was prepared in the same manner as in the above-mentioned “Preparation of coating liquid for hard coat layer (1)” except that the above was changed.

(3-4) Preparation of Hard Coat Layer Coating Liquid (4) Beamset 577 used in the above-mentioned “Preparation of Hard Coat Layer Coating Liquid (1)” was used with Eveacryl 3703 (manufactured by Daicel Ornex Co., Ltd., polyfunctional epoxy). A hard coat layer coating solution (4) was prepared in the same manner as in the above-mentioned "Preparation of hard coat layer coating solution (1)" except that the acrylate was changed to acrylate.

(3-5) Preparation of Hard Coat Layer Coating Liquid (5) The above "Hard" except that the cesium-containing tungsten oxide dispersion used in "Preparation of Hard Coat Layer Coating Liquid (1)" is not used. In the same manner as in “Preparation of coating layer coating solution (1)”, a hard coating layer coating solution (5) was prepared.

(3-6) Preparation of Hard Coat Layer Coating Liquid (6) The above “Hard Coat Layer” except that the carbon black dispersion used in “Preparation of Hard Coating Layer Coating Liquid (1)” is not used. In the same manner as in “Preparation of coating liquid for coating (1)”, a coating liquid for hard coat layer (6) was prepared.

(3-7) Preparation of Hard Coat Layer Coating Liquid (7) Beam Set 577, Aronix M305 and Aronix M402 used in “Preparation of Hard Coat Layer Coating Liquid (1)” were mixed with isobornyl acrylate (Daicel). A hard coat layer coating solution (7) was prepared in the same manner as in the above-mentioned "Preparation of hard coat layer coating solution (1)" except that the product was changed to Ornex's monofunctional acrylate.

(3-8) Composition of Hard Coat Layer Coating Liquids (1) to (7) The following Table 1 summarizes the compositions of the hard coat layer coating liquids (1) to (7). As shown in Table 1, the hard coat layer coating liquids (1) to (4) are polyfunctional acrylates (which become ultraviolet curable resins by polymerization), infrared absorbing pigments having infrared absorbing ability, And one or more black pigments selected from the group consisting of carbon black and black iron oxide (corresponding to Examples). The hard coat layer coating solutions (5) to (7) do not contain at least one of a polyfunctional acrylate, an infrared absorbing pigment, and a black pigment (corresponding to a comparative example).

2. Formation of thermal barrier film Thermal barrier films (1) to (9) having a hard coat layer were produced by the following method (Examples 1 to 5 and Comparative Examples 1 to 4).

2-1. Example 1
Each of the prepared coating solution for the high refractive index layer and the prepared coating solution for the low refractive index layer was heated to 40 ° C. Then, simultaneously on a polyethylene terephthalate film (160 mm wide and 50 μm thick substrate, Cosmo Shine A4300 manufactured by Toyobo Co., Ltd .: double-sided easy adhesion layer) heated to 40 ° C. using a slide hopper coating apparatus capable of coating 11 layers. Multi-layer coating was applied. At this time, on the base material, the low refractive index layer was disposed as the lowermost layer and the uppermost layer, and in other cases, these were alternately disposed. In addition, a total of nine layers (excluding the lowermost layer and the uppermost layer) were applied so that the low refractive index layer was 150 nm for each layer and the high refractive index layer was 130 nm for each layer. Immediately after the application, the temperature was increased by blowing cold air of 10 ° C. After the completion of thickening, 60 ° C. warm air was blown and dried to form a reflective part consisting of a total of 11 layers.

Next, the hard coat layer coating liquid (1) prepared on the surface of the base material opposite to the surface on which the reflective portion is formed is dried using a gravure coater with a dry layer thickness (layer thickness after UV curing) of 5 μm. The coating was performed under the following conditions. Then, after drying at 90 ° C. for 1 minute, using an ultraviolet lamp, the coating layer is cured with an illuminance of 100 mW / cm ² and an irradiation amount of 0.5 J / cm ² to form a hard coat layer. 1) was produced (Example 1).

2-2. Example 2
A thermal barrier film (2) was produced in the same manner as in Example 1 except that the hard coat layer coating solution (2) was used instead of the hard coat layer coating solution (1) (Example 2).

2-3. Example 3
A thermal barrier film (3) was produced in the same manner as in Example 1 except that the hard coat layer coating solution (3) was used instead of the hard coat layer coating solution (1) (Example 3).

2-4. Example 4
A heat shield film (4) was produced in the same manner as in Example 1 except that the hard coat layer coating solution (4) was used instead of the hard coat layer coating solution (1) (Example 4).

2-5. Example 5
According to the melt extrusion method described in US Pat. No. 6,049,419, polyethylene naphthalate (PEN) TN8065S (manufactured by Teijin Chemicals Co., Ltd.) and polymethyl methacrylate (PMMA) resin acrypet VH (manufactured by Mitsubishi Rayon Co., Ltd.) And laminated by extrusion. And after extending | stretching this about 3 times in length and width so that it may become (PMMA (152nm) / PEN (137nm)) 64 / (PMMA (164nm) / PEN (148nm)) 64, heat setting and cooling are performed. Thus, a laminate (base material) in which a total of 128 layers were alternately laminated was obtained.

  Here, in the laminate, “(PMMA (152 nm) / PEN (137 nm)) 64” means that 64 units in which PMMA having a thickness of 152 nm and PEN having a thickness of 137 nm are stacked in this order are stacked. It is. The lowermost layer and the uppermost layer were formed by extruding PET (10 μm) and sandwiching the laminate.

  And the heat shielding film (5) was produced like Example 1 except having used this laminated body (base material) (Example 5).

2-6. Comparative Example 1
A heat shield film (6) was produced in the same manner as in Example 1 except that the hard coat layer coating solution (5) was used instead of the hard coat layer coating solution (1) (Comparative Example 1).

2-7. Comparative Example 2
A heat shield film (7) was produced in the same manner as in Example 1 except that the hard coat layer coating solution (6) was used instead of the hard coat layer coating solution (1) (Comparative Example 2).

2-8. Comparative Example 3
A thermal barrier film (8) was produced in the same manner as in Example 1 except that the hard coat layer coating solution (7) was used instead of the hard coat layer coating solution (1) (Comparative Example 3).

2-9. Comparative Example 4
A thermal barrier film (9) was produced in the same manner as in Comparative Example 3 except that the reflecting portion was not provided (that is, only the base material was used) (Comparative Example 4).

3. Evaluation method 3-1. Evaluation of reflectance The reflectance was measured for each of the produced heat-shielding films (1) to (9). The reflectance was measured using a near-infrared spectrophotometer V-670 (manufactured by JASCO Corporation) in the general range of 800 nm to 1300 nm.

3-2. Weather resistance acceleration test A weather resistance acceleration test was performed on each of the produced heat shield films (1) to (9), and the solar heat acquisition rate before and after the test was calculated and evaluated. Moreover, the crack and adhesiveness after a weather-resistance accelerated test were evaluated.

(1) Method of weathering acceleration test The weathering acceleration test was performed as follows. Each of the heat shielding films (1) to (9) was attached to blue glass having a thickness of 3 mm through an adhesive layer. This sample was subjected to a water jet of 18 minutes to xenon light having an intensity of 180 W / m ² using a xenon weather meter (produced by Suga Test Instruments Co., Ltd .; emitting light very similar to sunlight) at 80 ° C. and 50% RH. Repeated drying for 22 minutes and exposed for 500 hours.

(2) Calculation of solar heat acquisition rate change and solar heat acquisition rate distribution As solar heat acquisition rate, about 25 points with the intersection of 1 cm wide grids on each surface of the thermal barrier films (1) to (9) as measurement points , Transmittance and reflectance every 5 nm in the region range of 300 nm to 2500 nm were measured. These measurements were performed using a near-red spectrophotometer V-670.

  Next, using the method described in JIS R3106 (1998), the measurement value and the solar reflection weight coefficient were processed to obtain the solar heat gain rate. The ratio of the arithmetic average value after the test to the arithmetic average value before the test was determined, and the change in the solar heat acquisition rate was evaluated. Further, the variation (distribution) was evaluated with the standard deviation of the solar heat gain rate at 25 points. The rate of change and standard deviation were evaluated according to the following evaluation criteria.

-Ratio of arithmetic average value after test to arithmetic average value before test (change in solar heat gain rate)
5: 1 or more and less than 1.01 4: 1.01 or more and less than 1.02 3: 1.02 or more and less than 1.05 2: 1.05 or more and less than 1.1 1: 1.1 or more Standard deviation of acquisition rate value (distribution of solar heat acquisition rate)
5: 0 or more and less than 0.5 4: 0.5 or more and less than 1.0 3: 1.0 or more and less than 1.5 2: 1.5 or more and less than 2.0 1: 2.0 or more

  The larger the evaluation value of the solar heat gain rate change, the less the variation in the infrared shielding performance, and the better the thermal insulation performance. In addition, regarding the solar heat acquisition rate distribution, the larger the evaluation numerical value, the less the variation in the infrared shielding performance, and the better the heat shielding performance.

(3) Evaluation of cracks The cracks after the weathering acceleration test were evaluated as follows. That is, whether or not cracking occurred in the heat-shielding films (1) to (9) after the weather resistance acceleration test was confirmed visually and with a microscope, and evaluated according to the following evaluation criteria.
5: There are no cracks on the surface, and no streaks are visible even with an optical microscope.
4: There is no crack on the surface, and streaks can be seen with an optical microscope.
3: The crack which can be recognized slightly visually is visible on the surface.
2: The crack which can be understood enough visually is generated.
1: The crack is apparently generated on the entire film.
In this example, 4 or more evaluations were good and 5 was particularly good. That is, it was evaluated that the larger the numerical value, the less deterioration (excellent durability).

(4) Evaluation of adhesion The adhesion after the weathering acceleration test was evaluated as follows.
That is, with respect to the heat shielding films (1) to (9) after the weather resistance acceleration test, 11 cuts reaching the base material such as polyethylene terephthalate film at intervals of 1 mm were made using a cutter knife, and 100 grids were formed. Formed. Then, cello tape (registered trademark) is strongly pressure-bonded to the grid area with the belly of the finger, the end of the tape is peeled off at an angle of 60 °, and the number of remaining grids is counted, thereby reducing the adhesion as follows. Evaluation was made according to criteria.
5: 100-98 pieces remain.
4: 97-81 pieces remain.
3: 80-71 remains.
2: 70-60 pieces remain.
1:59 or less remains.
In this example, 4 or more evaluations were good and 5 was particularly good. That is, it was evaluated that the larger the numerical value, the less deterioration (excellent durability).

4). Evaluation results Table 2 shows the results of the above evaluations.

  As described above, the coating liquids (1) to (4) for the hard coat layer contain polyfunctional (meth) acrylates, infrared absorbing pigments, and black pigments. And in Examples 1-5 which formed the hard-coat layer using these coating liquid (1)-(4) for hard-coat layers, as a comprehensive evaluation, all have the favorable result of (double-circle) or (double-circle). It was.

In particular, polyfunctional (meth) acrylate, CWO (cesium-containing tungsten oxide),
When the coating liquids (1), (3) and (4) for hard coat containing carbon black were used, the best evaluation (evaluation was 5) was obtained for both cracking and adhesion (Example 1 and 3-5).

  From these results, if polyfunctional acrylate is used as a monomer, sufficiently good results are obtained as compared with Comparative Examples 3 and 4 (hard coat layer coating solution (7)) that do not contain polyfunctional acrylate. (Examples 1 to 5). That is, for example, Example 1 and Example 2 are resins obtained using a polyfunctional acrylate, although the structural formulas of the resins constituting the hard coat layer are different. Therefore, it was found that if a polyfunctional acrylate was used, good results could be obtained regardless of the type of polyfunctional acrylate.

  Moreover, if CWO was contained as an infrared absorbing pigment, sufficiently good results were obtained as compared with Comparative Example 1 not containing (Examples 1 to 5). Furthermore, as long as carbon black or black iron oxide was included as a black pigment, sufficiently good results were obtained as compared with Comparative Example 2 in which neither was included (Examples 1 to 5). However, better results were obtained when carbon black was included (Examples 1 and 3 to 5).

  Moreover, in Examples 1-5 which provided the reflection part, compared with the comparative example 4 which does not provide a reflection part, comprehensive evaluation was especially favorable. That is, in Examples 1 to 5 in which the reflective portion was provided, the overall evaluation was “◎” and “◎”, but in Comparative Example 4 in which the reflective portion was not provided, “XX”. Thus, it turned out that a favorable result is obtained by providing a reflection part.

DESCRIPTION OF SYMBOLS 1 Reflection part 1a Low refractive index layer 1b High refractive index layer 2 Hard-coat layer 3 Base material layer 10 Thermal barrier film 21 Adhesive layer

Claims (3)

A thermal barrier film that suppresses transmission of irradiated light,
A hard coat layer containing an ultraviolet curable resin obtained by curing a composition containing a polyfunctional (meth) acrylate, an infrared absorbing pigment containing tungsten oxide, and at least one of carbon black and black iron oxide When,
A reflective portion in which a first refractive index layer having a first refractive index and a second refractive index layer having a refractive index larger than the first refractive index are alternately stacked;
The reflection portion is disposed on the upstream side of the light incident side, and the hard coat layer is disposed on the downstream side of the light incident side,
A heat-shielding film having a reflectance of 40% or more when irradiated with light having a wavelength of 800 nm to 1300 nm. The tungsten oxide has the following formula (1)
M ¹ _x WO _y (1)
(Where x is a number satisfying 0 <x ≦ 1, y is a number satisfying 2 ≦ y ≦ 3, and M ¹ is selected from the group consisting of Cs, Rb, K, Ba, Sr and Ca. One or more metal elements)
The heat insulating film according to claim 1, comprising a compound represented by:   The thermal barrier film according to claim 1, wherein the thermal barrier film contains at least carbon black.