JP5614270B2 - Heat ray shielding film and manufacturing method thereof - Google Patents

Description

  The present invention relates to a heat ray blocking film excellent in heat ray reflectivity, visible light permeability, scratch resistance and heat cracking prevention property, and a method for producing the same.

  In recent years, due to increasing interest in energy conservation measures, there has been an increasing demand for heat ray blocking films that can be attached to window glass of buildings and vehicles to block the transmission of solar heat rays from the viewpoint of reducing the load on cooling equipment. Yes.

  The light emitted from the sun has a wide spectrum from the ultraviolet region to the infrared light region. Visible light has a wavelength range of 380 to 780 nm ranging from purple to yellow to red light, and occupies about 45% of sunlight. As for infrared light, those close to visible light are called near-infrared rays (wavelength 780 to 2500 nm), and more than that are called mid-infrared rays and occupy about 50% of sunlight. The intensity of light energy in this region is as small as about one-tenth or less compared with ultraviolet light, but the thermal effect is large, and when absorbed by a substance, it is released as heat, resulting in an increase in temperature. For this reason, it is also called a heat ray, and by blocking these rays, the temperature rise in the room can be suppressed. Further, it is possible to suppress the heat of the winter in the cold region from being dissipated outside.

  As a heat ray blocking film, a type that reflects heat rays (for example, see Patent Documents 1 and 2) and a type that absorbs heat rays (for example, see Patent Documents 3 and 4) are known.

  The type that absorbs heat rays is mainly a type in which an infrared absorber such as a metal oxide or pigment is added to the resin for coating. If there is a part that absorbs solar radiation and a part that does not absorb solar radiation, the temperature difference in the glass Therefore, there is a problem that there is a high possibility of inducing thermal cracking of the glass plate.

  On the other hand, the type that reflects heat rays is a method of forming a laminated film having a configuration in which a high refractive index layer and a low refractive index layer are alternately laminated by using a dry film forming method such as a vapor deposition method or a sputtering method. A multilayer film in which resin layers having different refractive indexes are formed in a multilayer structure has been proposed.

  However, although the type that reflects heat rays does not have problems such as thermal cracking, the dry film forming method and the multilayer film forming method have a large vacuum apparatus used for forming a laminated film or a complicated film forming apparatus. The manufacturing cost is high, it is difficult to increase the area, and there is no flexibility.

  Furthermore, in recent years, due to increased interest in energy saving measures, there has been a growing demand for further improvement in heat ray blocking performance, and a type that uses both reflection and absorption of heat rays has also been proposed (for example, Patent Document 5). However, even if a type that uses both reflection and absorption of heat rays is used in combination, thermal cracking, which is the fundamental problem of the heat ray absorption type, has not been solved. A film is desired.

JP 2007-33296 A JP 2000-117871 A JP 2000-927 A Japanese Patent Application Laid-Open No. 08-281860 Special table 2008-528313

  The present invention has been made in view of the above-mentioned problems and situations, and its solution is to achieve both high-efficiency thermal barrier properties and thermal crack prevention properties, and furthermore, the manufacturing cost is low and the area is increased. It is possible to provide a heat ray shielding film that is flexible, has low haze, and high visible light transmittance, and a method for producing the same.

  The above-mentioned problem according to the present invention is solved by the following means.

  1. One surface on the substrate has at least two heat ray reflection units composed of two or more layers having different refractive indexes, and an ultraviolet curable resin is disposed on the opposite surface on the substrate. A heat ray blocking film having a heat ray absorbing layer containing tin-doped indium oxide (ITO) or antimony doped tin oxide (ATO), wherein the heat ray absorbing layer contains a heat conductive filler. .

  2. The surface roughness of the heat ray absorbing layer is such that the arithmetic average surface roughness (Ra) is in the range of 5 to 10 nm and the maximum cross-sectional height (Rt) is in the range of 100 to 500 nm. The heat ray shielding film according to the first item.

  3. The said heat conductive filler contains a silica or an alumina, and an average particle diameter exists in the range of 0.15-1.0 micrometer, The heat ray blocking film of the said 1st term | claim or the 2nd item | term characterized by the above-mentioned .

  4). At least one of the two or more layers having different refractive indexes contains metal oxide particles and a water-soluble polymer, according to any one of items 1 to 3 above, The heat ray shielding film as described.

  5. It is a manufacturing method of the heat ray blocking film which manufactures the heat ray blocking film as described in any one of said 1st term | claim-4th, Comprising: The layer which comprises the said heat ray blocking film is formed using a water-system coating liquid The manufacturing method of the heat ray blocking film characterized by having the process to do.

  By the above means of the present invention, it is possible to achieve both high-efficiency thermal barrier properties and thermal cracking prevention properties, and furthermore, the manufacturing cost is low, the area can be increased, the flexibility is high, and the visible light is low haze. A heat ray shielding film having a high transmittance and a method for producing the same can be provided.

  That is, in the present invention, by having both the heat ray reflective layer and the heat ray absorbing layer and containing a specific heat conductive filler in the heat ray absorbing layer, or by forming an appropriate uneven shape on the film surface, The heat radiation phenomenon of the heat ray absorbing layer can be improved. As a result, it is possible to obtain a heat ray blocking film that suppresses thermal cracking and has high efficiency heat ray blocking properties. Furthermore, in the formation of the constituent layer, by using an aqueous coating solution, a manufacturing cost can be reduced, an area can be increased, a flexible, low haze and high visible light transmittance film can be obtained. You can also.

  The heat ray blocking film of the present invention has at least two heat ray reflecting units composed of two or more layers having different refractive indexes on one surface on the substrate, and is opposite to the substrate. The heat ray blocking film has a heat ray absorbing layer containing an ultraviolet curable resin and tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO) on the surface, and the heat ray absorbing layer contains a heat conductive filler. It is characterized by that. This feature is a technical feature common to the inventions according to claims 1 to 4.

  As an embodiment of the present invention, from the viewpoint of manifestation of the effect of the present invention, the surface roughness of the heat ray absorbing layer is an arithmetic average surface roughness (Ra) within a range of 5 to 10 nm and a maximum cross-sectional height. (Rt) is preferably in the range of 100 to 500 nm. Furthermore, it is preferable that the said heat conductive filler contains a silica or an alumina and has an average particle diameter in the range of 0.15-1.0 micrometer.

  In the present invention, it is preferable that at least one of the two or more layers having different refractive indexes contains metal oxide particles and a water-soluble polymer.

  The method for producing the heat ray shielding film of the present invention is preferably a production method of an embodiment having a step of forming a layer constituting the heat ray shielding film using an aqueous coating solution.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

<Overview of heat ray blocking film>
The heat ray blocking film of the present invention has at least two heat ray reflecting units composed of two or more layers having different refractive indexes on one surface on the substrate, and is opposite to the substrate. It is characterized by being a heat ray blocking film having a heat ray absorbing layer containing an ultraviolet curable resin and tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO) on the surface. Moreover, the said heat ray absorption layer contains a heat conductive filler, It is characterized by the above-mentioned.

  In the present invention, from the viewpoint of manifestation of the effects of the present invention, the surface roughness of the heat-absorbing layer has an arithmetic average surface roughness (Ra) in the range of 5 to 10 nm and a maximum cross-sectional height (Rt). Is preferably in the range of 100 to 500 nm.

  As described above, the heat ray blocking film of the present invention has both a heat ray reflective layer and a heat ray absorbing layer, and contains a specific heat conductive filler in the heat ray absorbing layer, or an uneven shape suitable for the film surface. By forming, the heat radiation phenomenon of the heat ray absorbing layer can be improved, and as a result, heat cracking can be suppressed and a heat ray shielding film having high efficiency heat ray shielding properties can be obtained.

  Moreover, as a method for producing the heat ray shielding film of the present invention, the production cost is low by adopting the production method of an embodiment having a step of forming a layer constituting the heat ray shielding film using an aqueous coating solution. Further, it is possible to produce a heat ray blocking film that can be increased in area, is flexible, has low haze, and high visible light transmittance.

  As a basic optical characteristic of the heat ray blocking film of the present invention, the transmittance in the visible light region shown in JIS R3106-1998 is 50% or more, and the region having a wavelength of 900 to 1400 nm exceeds the reflectance of 50%. And the transmittance in the wavelength region of 900 to 1400 nm is preferably 10% or less.

"Base material"
The substrate (also referred to as “support”) according to the present invention is not particularly limited as long as it is formed of a transparent organic material.

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

  The thickness of the support is preferably about 5 to 200 μm, more preferably 15 to 150 μm.

  Further, the support according to the present invention has a visible light region transmittance of 85% or more, particularly 90% or more, as shown in JIS R3106-1998. When the support is at least the above-mentioned transmittance, it is advantageous in that the transmittance in the visible light region shown in JIS R3106-1998 is 50% or more when it is used as a heat ray shielding film.

  Further, the support using the above resin or the like may be an unstretched film or a stretched film. A stretched film is preferable from the viewpoint of strength improvement and thermal expansion suppression.

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

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

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

<Heat ray absorbing layer>
The heat ray blocking film of the present invention has a heat ray absorbing layer containing an ultraviolet curable resin and tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO) on the surface opposite to the substrate surface having the heat ray reflecting unit. The heat ray absorbing layer contains a heat conductive filler.

  As an embodiment of the present invention, from the viewpoint of manifestation of the effect of the present invention, the surface roughness of the heat-absorbing layer is such that the arithmetic average surface roughness (Ra) is in the range of 5 to 10 nm and the maximum cross-sectional height. (Rt) is preferably in the range of 100 to 500 nm. Furthermore, it is preferable that the said heat conductive filler contains a silica or an alumina and has an average particle diameter in the range of 0.15-1.0 micrometer.

<UV curable resin>
The heat ray absorbing layer according to the present invention contains an ultraviolet curable resin and tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO).

  In the present invention, the ultraviolet curable resin is more advantageous than other resins in terms of hardness, smoothness, and dispersibility of ITO, ATO, and heat conductive metal oxide.

  The ultraviolet curable resin can be used without particular limitation as long as it forms a transparent resin composition by curing, and examples thereof include silicone resins, epoxy resins, vinyl ester resins, acrylic resins, and allyl ester resins. . Particularly preferably, an acrylic resin can be used from the viewpoints of hardness, smoothness, and transparency.

  Examples of the acrylic resin composition include acrylate compounds having a radical reactive unsaturated compound, mercapto compounds having an acrylate compound and a thiol group, epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, polyethylene glycol acrylate, glycerol methacrylate and the like. What dissolved the polyfunctional acrylate monomer etc. are mentioned. Specifically, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) ) Acrylate, polyethylene glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified diphosphate ( (Meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylo Propane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris ( Acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate, etc. Is mentioned. Examples of the cationic polymerizable monomer include alicyclic epoxides such as 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate, glycidyl ethers such as bisphenol A diglycidyl ether, 4-hydroxy Examples include vinyl ethers such as butyl vinyl ether, oxetanes such as 3-ethyl-3-hydroxymethyloxetane, and the like. It is also possible to use any mixture of the above resin compositions, especially if it is a photosensitive resin containing a reactive monomer having one or more photopolymerizable unsaturated bonds in the molecule. There is no limit.

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

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

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

<Heat ray absorbent>
The heat ray absorbing layer according to the present invention is characterized by containing tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO).

  In the present invention, tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO) is used as the inorganic heat ray absorbent from the viewpoints of visible light transmittance, heat ray absorbability, dispersibility in the resin, and the like. Cost.

  As an average particle diameter, 5-100 nm is preferable from a viewpoint of a dispersibility or a heat ray absorptivity, and 10-50 nm is especially preferable.

  The measurement of the average particle diameter in the present invention is obtained by taking an image with a transmission electron microscope, randomly extracting, for example, 50 ITO or ATO particles, measuring the particle diameter, and averaging these. Moreover, when the shape of particle | grains is not spherical, it defines as what was calculated by measuring a major axis.

  The content of the ITO and ATO particles in the heat ray absorbing layer depends on the content of the entire layer, but is preferably in the range of 1 to 80%, particularly 5 to 50% when expressed in terms of content% of the entire layer. If the content is 1% or more, a sufficient heat ray absorption effect appears, and if it is 80% or less, a sufficient amount of visible light can be transmitted.

  In the present invention, other heat ray absorbents such as metal oxides other than ITO and ATO, organic systems, and metal complexes can be used in combination within the range where the effects of the present invention are exhibited. For example, diimonium compounds, aluminum compounds, phthalocyanine compounds, organometallic complexes, cyanine compounds, azo compounds, polymethine compounds, quinone compounds, diphenylmethane compounds, triphenylmethane compounds, and the like can be used in combination.

<Thermal conductive filler>
The heat ray blocking film of the present invention is characterized by containing a heat conductive filler in the heat ray absorbing layer.

  The heat conductive filler that can be used in the present invention is not particularly limited as long as it can efficiently dissipate the heat absorbed by the ITO or ATO particles, and examples thereof include copper, aluminum, silver, and stainless steel. Metal oxide such as metal, iron oxide, aluminum oxide, titanium oxide, silicon oxide, cerium oxide, etc., metal nitride such as boron nitride, aluminum nitride, chromium nitride, silicon nitride, tungsten nitride, magnesium nitride, molybdenum nitride, lithium nitride And fine particles of silicon carbide, zirconium carbide, tantalum carbide, titanium carbide, iron carbide, boron carbide and other metal carbides. In particular, a metal oxide is preferable because it has little influence on the dispersibility of the resin and the visible light transmittance. More preferably, thermal conductivity = high heat dissipation efficiency and no photocatalytic property, and therefore aluminum oxide (alumina) and silicon oxide (silica) are preferable, and aluminum oxide is more preferable.

  Various shapes can be applied as the shape. For example, particles, fine particles, nanoparticles, aggregated particles, tubes, nanotubes, wires, rods, needles, plates, irregular shapes, rugby balls, hexahedrons, large particles and fine particles are combined Various shapes such as a complex particle shape and a liquid can be exemplified. Particles and needles are advantageous from the viewpoint of heat dissipation efficiency.

  The heat conductive filler may be subjected to a surface treatment with various surface treatment agents such as a silane treatment agent in order to enhance the adhesiveness at the interface with the resin or improve the dispersibility.

  As an average particle diameter, 0.01-2.0 micrometers is preferable, 0.05-1.5 micrometers is especially preferable, More preferably, it is 0.15-1.0 micrometer. It is preferable for the average particle size to fall within this range since the heat dissipation efficiency and the visible light transmittance are increased.

  In the present application, a converted value in which the particle diameter of the thermally conductive filler whose shape is not spherical is equivalent to the particle diameter of a sphere having a volume equivalent to the volume of the thermally conductive filler is adopted.

  Although content in the said heat conductive filler is based on the said whole layer content, when expressed with content% of the whole layer, it is preferable that it is the range of 1-50%, especially 5-30%. If the content is 1% or more, a sufficient heat dissipation effect appears, and if it is 50% or less, a sufficient amount of visible light can be transmitted.

  In the present invention, the surface roughness of the heat ray absorbing layer is measured in accordance with JIS B 0601 (2001), the arithmetic average surface roughness (Ra) is in the range of 5 to 10 nm, and the maximum cross-sectional height (Rt ) Is preferably in the range of 100 to 500 nm.

  By making the surface roughness, heat dissipation efficiency from the surface can be increased, and thermal cracking can be suppressed. In particular, the heat conductive filler is arranged on the surface, and by performing the above surface roughness, it is particularly effective because the heat dissipation efficiency and surface area can be increased, and the particle size of the heat conductive filler in that case is 150 to 1000 nm. The range of is preferable. The surface roughness of the heat ray absorbing layer can be measured by the following method.

<Measurement of surface roughness by atomic force microscope>
The surface roughness of the heat ray absorbing layer according to the present invention can be measured based on an image obtained by an atomic force microscope according to the following method and conditions in accordance with JIS B 0601 (2001).

  Cut the measurement sample into 1 cm square size, set it on a horizontal sample stage on the piezo scanner, approach the cantilever to the sample surface, and when the atomic force is reached, scan in the XY direction, At this time, the unevenness of the sample is caught by the displacement of the piezo in the Z direction.

  With respect to the concavo-convex image obtained by the atomic force microscope, two straight lines are arbitrarily drawn in a direction perpendicular to the direction in which the concave portions and / or convex portions are connected, and a contour curve (cross-sectional curve) is drawn on the portion on the straight line. Ask for each.

  Next, the roughness is obtained from the contour curve (cross-sectional curve) on these straight lines. 20 places are measured at different places, and the arithmetic average is Ra. In addition, the sum of the maximum value of the peak height of the contour curve (cross section curve) in the evaluation length and the maximum value of the depth is taken as the maximum cross section height.

The measurement conditions used in the present invention are as follows.
Apparatus: Nanoscope IIIa AFM (manufactured by Digital Instruments)
Cantilever: Silicon single crystal Scanning mode: Tapping mode Scanning speed: 0.5Hz
Measurement field: 125 μm ²
Z range: Ra of 7 to 15 times Ra obtained from the cross section curve Flatten filter mode: Flatten auto order: 3
Spring constant K: 11 N / m
Resonance frequency F: 127 kHz
<Configuration of heat ray reflective layer unit>
The heat ray blocking film of the present invention is characterized by having at least two heat ray reflecting units composed of two or more layers having different refractive indexes on one surface on a substrate.

  In the following, among two or more layers having different refractive indexes, a layer having a relatively high refractive index is referred to as a “high refractive index layer”, and a layer having a relatively low refractive index is referred to as “low refractive index layer”. It will be called a “refractive index layer”.

  In the reflection type of the heat ray blocking film, the larger the difference in the refractive index between the high refractive index layer and the low refractive index layer, the better from the viewpoint of increasing the heat ray (infrared) reflectance with a small number of layers. In the invention, the difference in refractive index between the adjacent high refractive index layer and the low refractive index layer may be 0.1 or more in at least two units composed of the high refractive index layer and the low refractive index layer. preferable. Especially preferably, it is 0.3 or more, More preferably, it is 0.4 or more.

  The number of units depends on the difference in refractive index between the high refractive index layer and the low refractive index layer, but is preferably 40 units or less, more preferably 20 units or less, and even more preferably 10 units or less.

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

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

  The preferable refractive index of the high refractive index layer in the present invention is 1.80 to 2.50, more preferably 1.90 to 2.20. Moreover, as a preferable refractive index of a low-refractive-index layer, it is 1.10-1.60, More preferably, it is 1.30-1.50.

  In the heat ray blocking film of the present invention, a layer structure in which the layer adjacent to the substrate is a low refractive index layer containing silicon oxide and the outermost layer is also a low refractive index layer containing silicon oxide is preferable.

  In a preferred embodiment, the high refractive layer and the low refractive index layer in the present invention each contain metal oxide particles and a water-soluble resin.

[Metal oxide particles]
Examples of the metal oxide particles according to the present invention include titanium dioxide, zirconium oxide, zinc oxide, synthetic amorphous silica, colloidal silica, alumina, colloidal alumina, lead titanate, red lead, yellow lead, zinc yellow, oxidation Examples thereof include chromium, ferric oxide, iron black, copper oxide, magnesium oxide, magnesium hydroxide, strontium titanate, yttrium oxide, niobium oxide, europium oxide, lanthanum oxide, zircon, and tin oxide.

  The content of the metal oxide particles is preferably 50% by mass or more and 95% by mass or less, and more preferably 60% by mass or more and 90% by mass or less. By setting the content of the metal oxide particles to 50% by mass or more, it becomes easy to increase the refractive index difference between the high refractive index layer and the low refractive index layer, and the content of the metal oxide particles is 95% by mass or less. By doing so, the flexibility of the film is obtained, and it becomes easy to form the heat ray blocking film.

  In each refractive index layer, the mass ratio (F / B) between the metal oxide particles (F) and the water-soluble polymer (B) that is a binder constituting each layer is in the range of 0.5 to 20. It is preferable that there is, and more preferably 1.0 to 10.

As the metal oxide particles used in the high refractive index layer according to the present invention, TiO ₂ , ZnO, and ZrO ₂ are preferable. From the viewpoint of stability of the metal oxide particle-containing composition described later for forming the high refractive index layer. Then, TiO ₂ (titanium dioxide sol) is more preferable. Of TiO _2, the rutile type is preferable because the catalyst activity is low and the weather resistance of the high refractive index layer and the adjacent layer is high, and the refractive index is high.

  Examples of the method for preparing the titanium dioxide sol that can be used in the present invention include JP-A 63-17221, JP-A 7-819, JP-A 9-165218, and JP-A 11-43327. Can be a reference.

  As other methods for preparing titanium dioxide sol, refer to, for example, JP-A-63-17221, JP-A-7-819, JP-A-9-165218, JP-A-11-43327, and the like. be able to.

  The preferable primary particle diameter of the titanium dioxide fine particles is 4 to 50 nm, and more preferably 4 to 30 nm.

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

  The silicon dioxide particles according to the present invention preferably have an average particle size of 100 nm or less. The average particle diameter of primary particles of silicon dioxide dispersed in a primary particle state (particle diameter in a dispersion state before coating) is preferably 20 nm or less, more preferably 10 nm or less. Moreover, as an average particle diameter of secondary particle | grains, it is preferable from a viewpoint with few hazes and excellent visible light transmittance | permeability that it is 30 nm or less.

The volume average particle diameter of the titanium oxide particles according to the present invention is a method of observing the particles themselves using a laser diffraction scattering method, a dynamic light scattering method, or an electron microscope, or appears on the cross section or surface of the refractive index layer. the method of observing the particle image with an electron microscope, 1,000 arbitrary particle diameter of the particles (primary particle size) is measured, the particle diameter of _{d 1, d 2 ··· d i} ··· d k respectively In a group of titanium oxide particles in which n ₁ , n ₂ ... N _i ... _K are present, and the volume per particle is v _i , the volume average particle diameter m _v = The average particle size weighted by the volume represented by {Σ (v _i · d _i )} / {Σ (v _i )}.

(Water-soluble polymer)
In the present invention, it is preferable that at least one of two or more layers having different refractive indexes contains metal oxide particles and a water-soluble polymer.

  The water-soluble polymer that can be used in the present invention is preferably at least one selected from polymers having reactive functional groups, inorganic polymers, thickening polysaccharides, and gelatin.

  The “water-soluble” of the “water-soluble polymer” according to the present invention refers to solubility that dissolves 1% by mass or more in an aqueous medium at 25 ° C.

  The concentration of the water-soluble polymer in the coating solution for forming a high refractive layer and the coating solution for forming a low refractive index layer according to the present invention is preferably 0.3 to 3.0% by mass, and 0.35 to 2%. More preferably, it is in the range of 0.0 mass%.

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

(Polymer having reactive functional group)
As one of the water-soluble polymers that can be used in the present invention, a polymer having a reactive functional group is preferably used.

  Examples of the water-soluble polymer applicable to the present invention include polymers having reactive functional groups, such as polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate- Acrylic resins such as acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, or acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene- Styrene acrylic resin such as methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-styrene Sodium sulfonate copolymer, styrene -2-hydroxyethyl acrylate copolymer, styrene-2-hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer Vinyl acetate copolymers such as vinyl naphthalene-maleic acid copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic acid copolymer, and salts thereof Is mentioned. Among these, particularly preferable examples include polyvinyl alcohol, polyvinyl pyrrolidones, and copolymers containing the same.

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

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

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

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

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

  Anion-modified polyvinyl alcohol is described in, for example, polyvinyl alcohol having an anionic group as described in JP-A-1-206088, JP-A-61-237681 and JP-A-63-307979. Examples thereof include a copolymer of vinyl alcohol and a vinyl compound having a water-soluble group, and modified polyvinyl alcohol having a water-soluble group as described in JP-A-7-285265.

  Nonionic modified polyvinyl alcohol includes, for example, a polyvinyl alcohol derivative in which a polyalkylene oxide group as described in JP-A-7-9758 is added to a part of vinyl alcohol, and JP-A-8-25795. The block copolymer of the vinyl compound and vinyl alcohol which have the described hydrophobic group is mentioned. Polyvinyl alcohol can be used in combination of two or more, such as the degree of polymerization and the type of modification.

  In the present invention, a curing agent may be used when a polymer having a reactive functional group is used. When the polymer having a reactive functional group is polyvinyl alcohol, boric acid and a salt thereof described later and an epoxy curing agent are preferable.

(Inorganic polymer)
As one of the water-soluble polymers that can be used in the present invention, an inorganic polymer such as a zirconium atom-containing compound or an aluminum atom-containing compound is preferably used.

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

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

  Structural formulas of typical compounds among the inorganic polymers containing the zirconyl atom are shown below.

  However, s and t represent integers of 1 or more.

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

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

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

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

  The structural formula of Takibine # 1500 is shown below.

  However, s, t, and u represent an integer of 1 or more.

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

(Thickening polysaccharide)
In the present invention, it is preferable to use a thickening polysaccharide as the water-soluble polymer.

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

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

  Examples of the thickening polysaccharide applicable to the present invention include β1-4 glucan (eg, carboxymethylcellulose, carboxyethylcellulose, etc.), galactan (eg, agarose, agaropectin, etc.), galactomannoglycan (eg, locust bean gum). , Guaran, etc.), xyloglucan (eg, tamarind gum, etc.), glucomannoglycan (eg, salmon mannan, wood-derived glucomannan, xanthan gum, etc.), galactoglucomannoglycan (eg, softwood-derived glycan), arabino Galactoglycan (for example, soybean-derived glycan, microorganism-derived glycan, etc.), Glucarnoglycan (for example, gellan gum), glycosaminoglycan (for example, hyaluronic acid, keratan sulfate, etc.), alginic acid and alginate, agar, κ -Natural polymer polysaccharides derived from red algae such as carrageenan, λ-carrageenan, ι-carrageenan, fur celerane and the like, preferably from the viewpoint of not reducing the dispersion stability of the metal oxide fine particles coexisting in the coating solution The structural unit preferably has no carboxylic acid group or sulfonic acid group. Such polysaccharides include, for example, pentoses such as L-arabitose, D-ribose, 2-deoxyribose and D-xylose, and hexoses such as D-glucose, D-fructose, D-mannose and D-galactose only. It is preferable that it is a polysaccharide. Specifically, tamarind seed gum known as xyloglucan whose main chain is glucose and side chain is glucose, guar gum known as galactomannan whose main chain is mannose and side chain is glucose, cationized guar gum, Hydroxypropyl guar gum, locust bean gum, tara gum, and arabinogalactan whose main chain is galactose and whose side chain is arabinose can be preferably used. In the present invention, tamarind, guar gum, cationized guar gum, and hydroxypropyl guar gum are particularly preferable.

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

  As content of thickening polysaccharide, 5 mass% or more and 50 mass% or less are preferable, and 10 mass% or more and 40 mass% or less are more preferable. However, when used in combination with other water-soluble polymers or emulsion resins, it may be contained in an amount of 3% by mass or more. When the content is 50% by mass or less, the relative content of the metal oxide becomes appropriate, and it becomes easy to increase the refractive index difference between the high refractive index layer and the low refractive index layer.

<gelatin>
The two or more layers having different refractive indexes constituting the heat ray reflective unit according to the present invention can contain gelatin.

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

(Curing agent)
In the present invention, it is preferable to use a curing agent in order to cure the water-soluble polymer as a binder.

  The curing agent applicable to the present invention is not particularly limited as long as it causes a curing reaction with a water-soluble polymer. However, when the water-soluble polymer is polyvinyl alcohol, boric acid and its salt are preferable. . In addition, known compounds can be used and are generally compounds having groups capable of reacting with water-soluble polymers or compounds that promote the reaction between different groups of water-soluble polymers. It is appropriately selected depending on the kind of molecule. Specific examples of the curing agent include, for example, epoxy curing agents (diglycidyl ethyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-diglycidyl cyclohexane, N, N-diglycidyl- 4-glycidyloxyaniline, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, etc.), aldehyde-based curing agents (formaldehyde, glioxal, etc.), active halogen-based curing agents (2,4-dichloro-4-hydroxy-1,3,5) -S-triazine, etc.), active vinyl compounds (1,3,5-trisacryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, etc.), aluminum alum and the like.

  Boric acid or a salt thereof refers to an oxygen acid having a boron atom as a central atom and a salt thereof. Specifically, orthoboric acid, diboric acid, metaboric acid, tetraboric acid, pentaboric acid and octaboron Examples include acids and their salts.

  Boric acid having a boron atom and a salt thereof as a curing agent may be used as a single aqueous solution or as a mixture of two or more. Particularly preferred is a mixed aqueous solution of boric acid and borax.

  The aqueous solutions of boric acid and borax can be added only in relatively dilute aqueous solutions, respectively, but by mixing both, a concentrated aqueous solution can be obtained and the coating solution can be concentrated. Further, there is an advantage that the pH of the aqueous solution to be added can be controlled relatively freely.

  The total amount of the curing agent used is preferably 1 to 600 mg per 1 g of the water-soluble polymer.

[Surfactant]
A surfactant may be added to at least one of the two or more layers having different refractive indexes constituting the heat ray reflective unit according to the present invention. As the activator species, any of anionic, cationic and nonionic types can be used. In particular, acetylene glycol-based nonionic surfactants, quaternary ammonium salt-based cationic surfactants and fluorine-based cationic surfactants are preferred.

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

[Other additives]
Subsequently, the other additive applicable to each layer from which the refractive index which comprises the heat ray reflective unit which concerns on this invention differs is demonstrated.

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

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

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

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

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

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

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

(Emulsion resin)
Each layer having different refractive indexes constituting the heat ray reflective unit according to the present invention can contain an emulsion resin.

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

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

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

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

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

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

(Other additives for refractive index layer)
Various additives applicable to each layer having different refractive indexes constituting the heat ray reflective unit according to the present invention are listed below. For example, the ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988 and JP-A-62-261476, JP-A-57-74192, JP-A-57-87989, JP-A-60- No. 72785, 61-146591, JP-A-1-95091, JP-A-3-13376, etc., various surfactants of anion, cation or nonion, JP-A-59 No. 42993, 59-52689, 62-280069, 61-242871, and JP-A 4-219266, etc., whitening agent, sulfuric acid, phosphoric acid, acetic acid , PH adjusters such as citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate, antifoaming agents, lubricants such as diethylene glycol, preservatives, Antistatic agents, can also contain various known additives such as a matting agent.

[Method for producing heat ray blocking film]
Various methods can be adopted as a method for producing the heat ray shielding film of the present invention. In this invention, it is preferable that it is a manufacturing method of the aspect which has the process of forming the layer which comprises the said heat ray blocking film especially using an aqueous coating liquid. That is, the heat ray blocking film of the present invention is composed of a high refractive index layer and a low refractive index layer on a base material and is formed by laminating units. It is preferable to form a laminate by wet coating and drying alternately with the refractive index layer coating solution.

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

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

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

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

  On the other hand, the method for forming the heat ray absorbing layer is not particularly limited, but it is preferably formed by a wet coating method such as a spin coating method, a spray method, a blade coating method, a dip method, or a dry coating method such as a vapor deposition method.

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

  In the formation of the UV-cutting layer, additives such as an antioxidant, a plasticizer, a matting agent, and a thermoplastic resin can be added to the above-described resin as necessary. Moreover, as a solvent used when forming a smooth layer using the coating liquid which melt | dissolved or disperse | distributed resin in the solvent, a well-known thing can be used.

[Application of heat ray blocking film]
The heat ray shielding film of the present invention can be applied to a wide range of fields. For example, pasting to facilities exposed to sunlight for a long time such as outdoor windows of buildings and automobile windows, film for window pasting such as heat ray reflecting film to give heat ray reflecting effect, film for agricultural greenhouse, etc. Used mainly for the purpose of improving weather resistance.

  In particular, it is suitable for a member in which the heat ray shielding film according to the present invention is bonded to glass or a glass substitute resin base material directly or via an adhesive.

  The adhesive is placed so that the heat ray blocking film is on the sunlight (heat ray) incident surface side when bonded to a window glass or the like. Further, when the heat ray blocking film is sandwiched between the window glass and the base material, it can be sealed from ambient gas such as moisture, which is preferable for durability. Even if the heat ray blocking film of the present invention is installed outdoors or on the outside of a vehicle (for external application), it is preferable because of environmental durability.

  As an 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.

  Moreover, you may use the polyvinyl butyral resin used as an intermediate | middle layer of a laminated glass, or ethylene-vinyl acetate copolymer type resin. Specifically, plastic polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., Mitsubishi Monsanto Co., Ltd.), ethylene-vinyl acetate copolymer (manufactured by DuPont, Takeda Pharmaceutical Co., Ltd., duramin), modified ethylene-vinyl acetate copolymer (Mersen G, manufactured by Tosoh Corporation). In addition, you may add and mix | blend an ultraviolet absorber, an antioxidant, an antistatic agent, a heat stabilizer, a lubricant, a filler, coloring, an adhesion adjusting agent etc. suitably in a contact bonding layer.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.
Example 1
<Production of heat ray blocking film>
(Preparation of coating solution 1 for high refractive index layer)
To 10.3 parts of pure water, 1.03% acid-treated gelatin (isoelectric point: 9.5, average molecular weight: 20,000) as a thickening polysaccharide, 140.3 parts, 14.8% picolinic acid 17.3 parts of an aqueous solution and 2.58 parts of a 5.5% aqueous solution of boric acid were added and mixed respectively. Thereafter, 38.2 parts of the following titanium oxide dispersion 1 was added and mixed, and 0.067 parts of Surflon S221 (manufactured by AGC Seimi Chemical Co., Ltd.) was further added as a fluorine-based cationic surfactant. Finally, it was finished to 223 parts with pure water to prepare a coating solution 1 for a high refractive index layer. In addition, content of Surflon S221 which is surfactant in the coating liquid 1 for high refractive index layers is 0.03%.

<Preparation of titanium oxide dispersion 1>
28.9 parts of a 20.0% titanium oxide sol containing rutile-type titanium oxide fine particles having a volume average particle diameter of 35 nm, 5.41 parts of a 14.8% picolinic acid aqueous solution, and 2.1% of lithium hydroxide A titanium oxide dispersion was prepared by mixing and dispersing 3.92 parts of the aqueous solution.

(Preparation of coating solution 1 for low refractive index layer)
9.18 parts of a 23.5% aqueous solution of polyaluminum chloride (manufactured by Taki Chemical Co., Ltd., Takibaine # 1500), 510 parts of a 10% aqueous solution of colloidal silica (Nissan Chemical Co., Snowtex OS), and boric acid 103.4 parts of a 5.5% aqueous solution and 4.75 parts of a 2.1% aqueous solution of lithium hydroxide are mixed and dispersed, and finished to 1000 parts with pure water to prepare silicon oxide dispersion 1. did.

  Next, in 17.6 parts of pure water, 26.2 parts of a 1.0% tamarind seed gum aqueous solution, 3.43 parts of a 5.0% solution of polyvinyl alcohol (PVA217, manufactured by Kuraray Co., Ltd.), 2 0.06 part of a 1% picolinic acid aqueous solution was added and mixed, and then 96.5 parts of the silicon oxide dispersion 1 was added and mixed. Further, 0.045 part of Surflon S221 (manufactured by AGC Seimi Chemical Co., Ltd.) was added as a fluorine-based cationic surfactant. Finally, it was finished to 150 parts with pure water to prepare a coating solution 1 for a low refractive index layer. In addition, content of Surflon S221 which is surfactant in the coating liquid 1 for low refractive index layers is 0.03%.

(Preparation of outermost coating solution)
In the preparation of the coating solution 1 for the low refractive index layer, the addition amount (0.03%) of Olfin E1004 (manufactured by Nissin Chemical Co., Ltd.), which is an acetylene glycol nonionic surfactant, is 0. A coating solution for the outermost layer was prepared in the same manner except that the content was changed to 06%.

(Method for forming heat ray reflective laminate)
Using a slide hopper coating apparatus capable of simultaneous coating of 15 layers, a total of 14 layers of the above-prepared coating solution 1 for the low refractive index layer and coating solution 1 for the high refractive index layer were alternately laminated, On the polyethylene terephthalate film (Toyobo A4300: double-sided easy-adhesion layer) having a thickness of 50 μm heated to 45 ° C. while keeping a total of 15 layers on which the above coating solution for the outermost layer was laminated at 45 ° C. After applying, after setting the film surface by blowing cold air for 1 minute under the condition that the film surface is 15 ° C. or lower, the hot air of 80 ° C. is blown and dried to form the heat ray reflective laminate film 1 consisting of 15 layers. Produced.

(Preparation of coating solution 1 for heat ray absorbing layer)
Add 100 parts of photopolymerization initiator Irgacure 184 (BASF Japan) and 100 parts of ITO powder (super fine particle ITO manufactured by Sumitomo Metal Mining) to 100 parts of UV-7600B (UV curable hard coat material) manufactured by Nippon Synthetic Chemical Co., Ltd. And it diluted with methyl ethyl ketone as a solvent, and produced the heat ray absorption layer coating liquid 1 with a solid content of 30%.

(Method for forming heat ray absorbing layer and heat ray blocking film 1 production)
The heat ray absorbing layer coating solution 1 was applied to the heat ray reflective laminate film 1. After coating with a wire bar on the support so that the (average) film thickness after drying is 4 μm, the curing conditions are set in an air atmosphere using a UV curing device (using a high-pressure mercury lamp) manufactured by Eye Graphics. Curing at 400 mJ / cm ² , followed by drying conditions; drying at 80 ° C. for 3 minutes to produce a heat ray blocking film 1 with a heat ray absorbing layer.

(Preparation of heat ray blocking film 2)
An amount corresponding to 10% of the total solid content of PMMA (1) (MP5500 (particle size 0.4 μm)) was added to the coating solution 1 for heat ray absorbing layer, and the heat ray shielding film 2 was produced in the same manner as the heat ray shielding film 1. .

(Preparation of heat ray blocking film 3)
One layer each of the coating solution 1 for the low refractive index layer and the coating solution 1 for the high refractive index layer, and the above-mentioned coating solution for the outermost layer were laminated on each of the three layers in the same manner as the heat ray reflective laminate film 1, A reflective laminate film 3 was produced. Furthermore, 10% of the total solid content of silica (Hibeshika FQ particle size 0.5 μm made by Ube Nitto Chemical) is added to the coating solution 1 for the heat ray absorbing layer, and the heat ray shielding film 3 is produced in the same manner as the heat ray shielding film 1. did.

(Preparation of heat ray blocking film 4)
10 parts by mass of diimonium dye (CIR-RL, manufactured by Nippon Carrit Co., Ltd.) is added in place of the ITO powder of the coating solution 1 for heat ray absorbing layer, and further silica (Hibeshika FQ particle size 0.5 μm, manufactured by Ube Nitto Chemical) is added to the total solid content. An amount corresponding to 10% of the above was added, and the heat ray shielding film 4 was produced in the same manner as the heat ray shielding film 1.

(Preparation of heat ray blocking film 5)
Cesium-containing tungsten oxide (average particle size 44 nm, Sumitomo Metal Mining YMF-1) is added in place of the ITO powder of the coating solution 1 for heat ray absorbing layer, and further silica (1) (Hi-Plesica FQ made by Ube Nitto Chemical Co., Ltd., particle size 0) 0.5 μm) was added in an amount corresponding to 10% of the total solid content, and the heat ray shielding film 5 was produced in the same manner as the heat ray shielding film 1.

(Preparation of heat ray blocking film 6)
Acrylic resin: LR-360 made by Mitsubishi Rayon is added instead of UV-7600B (UV curable hard coat material) of coating solution 1 for heat ray absorbing layer, and heat ray shielding film is the same as heat ray shielding film 1 except for UV irradiation. 6 was produced.

(Preparation of heat ray blocking film 7)
The heat ray blocking film 7 is produced in the same manner as the heat ray blocking film 1 by adding an amount corresponding to 10% of the total solid content of Ag: silver nanoparticles DOWA electronics (particle size: 0.02 μm) to the coating solution 1 for the heat ray absorbing layer. did.

(Preparation of heat ray blocking film 8)
TiO ₂ : Titanium oxide particles FTR-700 Made by Sakai Chemical (particle size 0.2 μm) in an amount corresponding to 10% of the total solid content is added to the heat ray absorbing layer coating solution 1, and the heat ray shielding is performed in the same manner as the heat ray shielding film 1. Film 8 was produced.

(Preparation of heat ray blocking film 9)
Silica (2) (Hibeshika FQ particle size 2.0 μm, manufactured by Ube Nitto Chemical Co., Ltd.) in an amount corresponding to 10% of the total solid content is added to the coating solution 1 for the heat ray absorbing layer, and the heat ray shielding film 9 is added in the same manner as the heat ray shielding film 1. Was made.

(Preparation of heat ray blocking film 10)
To the heat ray absorbing layer coating solution 1, silica (1) (Hibeshika FQ particle size 0.5 μm, manufactured by Ube Nitto Chemical Co., Ltd.) is added in an amount corresponding to 10% of the total solid content. Was made.

(Preparation of heat ray blocking film 11)
Add the amount corresponding to 10% of the total solid content of alumina (1) (NANOBYK-3600 alumina dispersion particle size 0.04 μm manufactured by Big Chemie) to the coating solution 1 for the heat ray absorbing layer, and cut the heat ray in the same manner as the heat ray shielding film 1 Fill 11 was produced.

(Preparation of heat ray blocking film 12)
An amount corresponding to 10% of the total solid content of alumina (2) (manufactured by Daimei Chemical Co., Ltd. TM-5D particle size 0.2 μm) is added to the coating solution 1 for the heat ray absorbing layer, and the heat ray shielding film 12 is added in the same manner as the heat ray shielding film 1. Was made.

(Preparation of heat ray blocking film 13)
An amount corresponding to 10% of the total solid content of alumina (3) (Amatex AO-802, particle size 0.5 μm) is added to the coating solution 1 for the heat ray absorbing layer, and the heat ray shielding film 13 is added in the same manner as the heat ray shielding film 1. Was made.

(Preparation of heat ray blocking film 14)
The heat ray reflective laminate is formed on a polyethylene terephthalate film (Toyobo A4300: double-sided easy adhesion layer) having a thickness of 50 μm and a ZnO-2.0% Ga ₂ O ₃ layer (dielectric layer: first layer) having a thickness of 10 nm. - silver thin film layer having a thickness of 12nm (metal thin film layer: second _{layer) - ZnO-2.0% Ga 2} O 3 layer having a thickness of 10 nm (dielectric layer: third layer) - silver thin film layer having a thickness of 12nm (Metal thin film layer: 4th layer) was laminated | stacked by the sputtering method under the vacuum of 6.65 * 10 < ^-3 > Pa (5 * 10 < ^-5 > torr), and the heat ray reflective laminated body film 14 was produced. Furthermore, silica (Hibeshika FQ particle size 0.5 μm, manufactured by Ube Nitto Chemical Co., Ltd.) in an amount corresponding to 10% of the total solid content is added to the coating solution 1 for the heat ray absorbing layer, and the heat ray shielding film 14 is produced in the same manner as the heat ray shielding film 1. did.

(Preparation of heat ray blocking film 15)
10 layers each of the coating solution 1 for the low refractive index layer and the coating solution 1 for the high refractive index layer, and a total of 21 layers on which the coating solution for the outermost layer was laminated, were formed in the same manner as the heat ray reflective laminate film 1. A reflective laminate film 15 was produced. Further, 10% of the total solid content of silica (Hi-Plesica FQ particle size 0.5 μm manufactured by Ube Nitto Chemical) is added to the coating solution 1 for the heat ray absorbing layer, and the heat ray shielding film 15 is produced in the same manner as the heat ray shielding film 1. did.

(Preparation of heat ray blocking film 16)
Add ATO powder (Ultra Fine Particles ATO manufactured by Sumitomo Metal Mining) instead of ITO powder of coating solution 1 for heat ray absorbing layer, and further add silica (1) (High pressureica FQ particle size 0.5μm manufactured by Ube Nitto Chemical) An amount corresponding to 10% of the above was added, and the heat ray shielding film 16 was produced in the same manner as the heat ray shielding film 1.

  Table 1 shows the main components of Samples 1 to 16, which are heat ray blocking films produced as described above.

<Evaluation of heat ray blocking film>
About each produced said heat ray blocking film, the following characteristic value measurement and performance evaluation were performed.

(Measurement of heat ray reflectance)
Using the spectrophotometer (using an integrating sphere, manufactured by Hitachi, Ltd., U-4000 type), the reflectance in the 800 to 1400 nm region of each heat ray blocking film was measured, and the average value was obtained. It was.

(Measurement of heat ray transmittance)
Using the spectrophotometer (using an integrating sphere, manufactured by Hitachi, Ltd., U-4000 type), the transmittance of each heat ray blocking film in the region of 800 to 1400 nm was measured, and the average value was obtained. It was.

<Measurement of haze value>
It measured with the haze meter (Nippon Denshoku Kogyo KK make, NDH2000), and it was set as the standard of transparency.

(Evaluation of heat cracking prevention)
The heat ray blocking films obtained in Examples and Comparative Examples were attached to a glass plate having a width of 200 mm, a length of 300 mm, and a thickness of 1.5 mm with an acrylic adhesive to obtain a sample for evaluating thermal cracking prevention properties. And the box (height 150mm, width 240mm, length 340mm) which the upper surface and bottom face which were produced with the 30-mm-thick foamed polystyrene prepared was prepared, and these samples were mounted in the opening part of each box, While measuring the temperature of the internal glass sample surface (film surface side) with a thermocouple, it was exposed to sunlight on a clear day in August. Thereafter, the temperature of the sample surface was observed, and each MAX temperature was measured. Similarly, the surface temperature of the glass plate alone was also measured, and the difference from the surface temperature of the sample was used as a measure of the thermal cracking property. The smaller the temperature difference, the better the thermal cracking prevention. The determination was according to the following criteria. Until △, there is no actual harm and is an acceptable level.

○: ~ 0.5 ° C
Δ: 0.5 to 1.0 ° C.
X: 1.0 degreeC ~
(Scratch resistance test)
The surface of the film was rubbed 10 times under a load of 200 g using steel wool # 0000, and then the level of scratching was confirmed. The determination was in accordance with the following criteria. OK until the level of △.

◯: Not at all △: Slightly scratched 1 to 2 △: Slightly scratched 1-2 △: Scratch 3 or more ×: Scratch 10 or more Seen.

(Surface roughness measurement method; AFM measurement)
Cut the measurement sample into 1 cm square size, set it on a horizontal sample stage on the piezo scanner, approach the cantilever to the sample surface, and when the atomic force is reached, scan in the XY direction, At this time, the unevenness of the sample was captured by the displacement of the piezo in the Z direction.

  With respect to the concavo-convex image obtained by the atomic force microscope, two straight lines are arbitrarily drawn in a direction perpendicular to the direction in which the concave portions and / or convex portions are connected, and a contour curve (cross-sectional curve) is drawn on the portion on the straight line. I asked for each.

  Next, the roughness was obtained from the contour curve (cross-sectional curve) on these straight lines. 20 places were measured at different locations, and the arithmetic average was taken as Ra. Moreover, the sum of the maximum value of the peak height of the contour curve (cross section curve) in the evaluation length and the maximum value of the depth was taken as the maximum cross section height.

The measurement conditions used in the present invention are as follows.
Apparatus: Nanoscope IIIa AFM (manufactured by Digital Instruments)
Cantilever: Silicon single crystal Scanning mode: Tapping mode Scanning speed: 0.5Hz
Measurement field: 125 μm ²
Z range: Ra of 7 to 15 times Ra obtained from the cross section curve Flatten filter mode: Flatten auto order: 3
Spring constant K: 11 N / m
Resonance frequency F: 127 kHz
The above measurement / evaluation results are shown in Table 1.

  As is clear from the results shown in Table 1, it can be seen that the sample according to the heat ray blocking film of the present invention is superior to the comparative sample in the measurement / evaluation performance.

Claims (5)

One surface on the substrate has at least two heat ray reflection units composed of two or more layers having different refractive indexes, and an ultraviolet curable resin is disposed on the opposite surface on the substrate. A heat ray blocking film having a heat ray absorbing layer containing tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO), containing a heat conductive filler in the heat ray absorbing layer ,
As for the surface roughness of the heat ray absorbing layer, the arithmetic average surface roughness (Ra) is in the range of 1.3 to 12.0 nm, and the maximum cross-sectional height (Rt) is in the range of 70 to 680 nm. Heat ray blocking film characterized by   The surface roughness of the heat ray absorbing layer is such that the arithmetic average surface roughness (Ra) is in the range of 5 to 10 nm and the maximum cross-sectional height (Rt) is in the range of 100 to 500 nm. The heat ray shielding film according to claim 1.   The said heat conductive filler contains a silica or an alumina, and an average particle diameter exists in the range of 0.15-1.0 micrometer, The heat ray blocking film of Claim 1 or Claim 2 characterized by the above-mentioned.   4. At least one of two or more layers having different refractive indexes contains metal oxide particles and a water-soluble polymer. Heat ray blocking film.   It is a manufacturing method of the heat ray blocking film which manufactures the heat ray blocking film as described in any one of Claim 1- Claim 4, Comprising: The layer which comprises the said heat ray blocking film is formed using a water-system coating liquid. The manufacturing method of the heat ray blocking film characterized by having a process.