JP2014231199A - Transparent laminate film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent laminate film which is subjected to less microwarp so as to ensure view performance when stuck to a vehicle window glass, and which has excellent heat ray reflection performance.SOLUTION: A transparent laminate film includes a transparent laminate layer part 14 and an adhesive layer 16 disposed sequentially on a surface of a transparent polymer film 12. The transparent laminate part 14 is obtained by alternately laminating a metal oxide thin film and a metal thin film. The transparent laminate film has an image clarity of 80% or more to be measured according to JIS K7374 under conditions that an incidence angle of 80 degrees and an optical comb width of 0.125 mm in a state in which the transparent laminate film is stuck to a glass surface with an adhesive layer 16 interposed therebetween.

Description

  The present invention relates to a transparent laminated film suitably used for a window glass of a vehicle such as an automobile.

  A heat ray reflective film may be applied to a window glass of a building such as a building or a house or a window glass of a vehicle such as an automobile for the purpose of shielding sunlight. Since it is applied to the window, the heat ray reflective film is required to have transparency as well as solar shading. As this type of heat ray reflective film, a film having a multilayer film in which metal oxide layers and metal layers are alternately laminated and an adhesive layer formed on the multilayer film is known (Patent Document 1). ). This type of heat ray reflective film has an excellent heat insulating property that improves the cooling and heating effect in the room due to the multilayer film.

International Publication No. 2010/074050

  A driver of a vehicle such as an automobile checks the outside state through the window glass. For this reason, a driver | operator will always see the heat ray reflective film affixed on the window glass. Then, even a minute distortion that does not matter when attached to the window glass of a building may cause a problem in a vehicle in which safety is important. In particular, the windshield is angled, and the driver tends to move his / her line of sight, so distortion is more noticeable and prone to problems. Therefore, there is a demand for a heat-reflective film that has a small amount of distortion and ensures a good viewability when pasted on a vehicle window glass.

  The problem to be solved by the present invention is to provide a transparent laminated film excellent in heat ray reflectivity, which has a small distortion and has a good viewability when pasted on a window glass of a vehicle.

  In order to solve the above-mentioned problems, a transparent laminated film according to the present invention comprises a transparent laminated portion in which metal oxide thin films and metal thin films are alternately laminated on the surface of a transparent polymer film, and an adhesive layer. In this order, the image sharpness measured in accordance with JIS K7374 is 80% under the conditions of an incident angle of 80 degrees and an optical comb width of 0.125 mm in a state of being attached to a glass surface through an adhesive layer. This is the gist of the above.

  At this time, the pressure-sensitive adhesive layer is preferably in contact with the uppermost layer of the transparent laminated portion. Moreover, it is preferable that the thickness of an adhesive layer exists in the range of 2-30 micrometers.

  According to the transparent laminated film of the present invention, the transparent laminated film in which the metal oxide thin film and the metal thin film are alternately laminated on the surface of the transparent polymer film and the adhesive layer are provided in this order. And image sharpness measured in accordance with JIS K7374 under the condition of an incident angle of 80 degrees and an optical comb width of 0.125 mm in a state of being attached to a glass surface through an adhesive layer is 80% or more. Therefore, it is excellent in heat ray reflectivity, and there is little minute distortion, and the viewability is ensured when pasted on the window glass of a vehicle.

  At this time, if the pressure-sensitive adhesive layer is in contact with the uppermost layer of the transparent laminated portion, it is easy to increase the image definition. And when the thickness of the pressure-sensitive adhesive layer is in the range of 2 to 30 μm, both viewability and adhesiveness can be achieved.

It is sectional drawing of the transparent laminated film which concerns on one Embodiment of this invention. It is sectional drawing which shows the state which constructed the transparent laminated film which concerns on one Embodiment to window glass. It is sectional drawing of the transparent laminated film of another example. It is a schematic diagram explaining the measuring method of image definition.

  The transparent laminated film according to this embodiment will be described in detail.

  FIG. 1 is a cross-sectional view of a transparent laminated film according to an embodiment of the present invention. As shown in FIG. 1, the transparent laminated film 10 includes a transparent polymer film 12, a transparent laminated portion 14, an adhesive layer 16, and a protective layer 18. The transparent laminated portion 14 is provided on the surface of the transparent polymer film 12. The pressure-sensitive adhesive layer 16 is provided in contact with the transparent laminated portion 14. The protective layer 18 is provided on the surface opposite to the surface on which the transparent laminated portion 14 of the transparent polymer film 12 is formed. The protective layer 18 may be provided as necessary. In addition, a separator (release film) 20 may be provided on the surface of the pressure-sensitive adhesive layer 16 before use (before film construction).

  As shown in FIG. 2, the transparent laminated film 10 is attached to a transparent base material 22 such as a window glass via an adhesive layer 16. Then, the protective layer 18 provided on the surface opposite to the surface on which the transparent laminated portion 14 of the transparent polymer film 12 is formed appears on the surface. The transparent laminated film 10 is usually disposed on the indoor side. Since the solar radiation inserted from the outdoors is reflected by the transparent laminated part 14, the transparent laminated film 10 has favorable solar radiation shielding property. Moreover, since the air-conditioning effect in a room improves with the transparent laminated part 14, the transparent laminated film 10 is equipped with the outstanding heat insulation.

  The transparent laminated film according to the present invention has an image clarity measured in accordance with JIS K7374 under the condition of an incident angle of 80 degrees and an optical comb width of 0.125 mm in a state of being attached to a glass surface through an adhesive layer. Is 80% or more. When the image definition at this time is 80% or more, there is little minute distortion, and excellent viewability is ensured when pasted on the window glass of a vehicle.

The optical comb has a plurality of slits (0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, 2.0 mm) having different slit intervals, and the image definition is determined by the direction in which the optical comb is arranged in the slits. Is calculated using the following formula from the maximum light amount at the light transmitting portion and the minimum light amount at the light shielding portion.
C (n) = (M−m) / (M + m) (%)
However,
C (n): Image sharpness (%) when the slit distance of the optical comb is n (mm)
M: Maximum light amount when slit distance n (mm) of optical comb m: Minimum light amount when slit distance n (mm) of optical comb

  As the image definition, a value when the difference in image definition is likely to appear and the slit interval n is small (0.125 mm) is obtained. Further, when the surface of the transparent laminated film is poor, streaks are generated in the feeding direction (MD direction) of the film, and the image definition in the MD direction tends to be particularly bad. It can be said that the smoother the surface is, the closer the image definition in the MD direction and the image definition in the direction orthogonal to the feeding direction (TD direction) are. Therefore, the image definition is an average value of the image definition in the MD direction and the image definition in the TD direction. In addition, the image definition in the MD direction is an image definition calculated when the film feeding direction (MD direction) is aligned with the direction in which the slit of the optical comb extends, and the image definition in the TD direction is This is the image definition calculated when the TD direction is aligned with the direction in which the slit of the optical comb extends.

  When measuring the image definition, a float glass having a thickness of 3 mm is used as the plate glass to which the transparent laminated film is attached. Assuming that the transparent laminated film is affixed to the indoor side, the light from the light source is incident from the glass surface opposite to the surface on which the transparent laminated film is affixed. The angle of incidence of light from the light source is assumed to be 80 degrees, assuming that the mounting angle of the windshield of a vehicle such as an automobile is 10 degrees. In addition, since the observed distortion is more emphasized by setting the angle of incidence of light, it is easier to measure minute distortion.

  The image definition (small distortion) is easily affected by the surface state of the pressure-sensitive adhesive layer that becomes the light incident surface. As shown in FIG. 3, the conventional transparent laminated film 30 has a transparent laminated portion 14, a top coat layer 24 made of a thermoplastic resin, and an adhesive layer 26 in this order on the surface of the transparent polymer film 12. The protective layer 18 is provided on the surface of the transparent polymer film 12 opposite to the surface on which the transparent laminated portion 14 is formed. The top coat layer 24 and the pressure-sensitive adhesive layer 26 are formed by coating, and the pressure-sensitive adhesive layer 26 cannot be formed by coating on the surface of the coated top coat layer 24. For this reason, the adhesive layer 26 is formed on the surface of the separator 20 by coating. Therefore, the conventional transparent laminated film 30 has the transparent laminated film 14 and the topcoat layer 24 formed on the surface of the transparent polymer film 12, and the adhesive layer 26 formed on the surface of the separator 20, Are formed by bonding. Since the separator 20 has large surface unevenness from the viewpoint of releasability, when the adhesive layer 26 is applied and formed on the surface of the separator 20, the unevenness is transferred onto the surface of the adhesive layer 26 after the separator 20 is peeled off. The This transfer surface of the pressure-sensitive adhesive layer 26 becomes a surface to be affixed to the transparent substrate 22 and becomes a light incident surface. For this reason, in the conventional transparent laminated film 30, the surface irregularities formed in the pressure-sensitive adhesive layer 26 are observed as minute distortions, and there is a problem in that the viewability is deteriorated due to a decrease in image definition.

  Therefore, in order to improve the image definition in the present invention, the surface of the pressure-sensitive adhesive layer serving as the light incident surface may be smoothed. For this purpose, 1) an adhesive layer is applied and formed on the transparent polymer film side where a smooth transparent laminated portion is formed instead of a separator, 2) the thickness of the adhesive layer is controlled to be thin, and 3) an adhesive. It is necessary to devise measures such as reducing the ratio of the solid content of the material forming the agent layer to lengthen the time until the coating liquid is dried, and 4) controlling the linear speed during coating small. In addition, when the ratio of the solid content of the material forming the pressure-sensitive adhesive layer is small, it is easy to reduce the thickness of the pressure-sensitive adhesive layer.

  According to the method 1), the surface roughness of the pressure-sensitive adhesive layer is reduced, and the distortion is improved. According to the method 2), dripping of the coating liquid is suppressed, and distortion is improved. According to the method 3), the viscosity of the coating solution is lowered, the leveling property of the coating film during drying is improved, the surface unevenness is reduced, and the distortion is improved. Moreover, since the ratio of the liquid component is large, the time until drying can be lengthened, the leveling property of the coating film during drying is improved, the surface unevenness is reduced, and the distortion is improved. According to the method 4), the leveling property of the coating film during drying is improved, the surface irregularities are reduced, and the distortion is improved. Each of the methods 1) to 4) is an effective method for improving the image sharpness. However, by adopting any one of these methods, the image sharpness can be within the specific range of the present invention. Rather, it is necessary to combine these methods. By combining these methods, the image definition can be adjusted within the specific range of the present invention.

  As a device used for coating, a die coater, a reverse coater or the like can be used.

  If the structure has a smooth layer on the surface of the smooth transparent laminate, the pressure-sensitive adhesive layer does not have to be formed directly on the surface of the smooth transparent laminate, but forms another smooth layer. It is more preferable that the pressure-sensitive adhesive layer is directly formed by coating because it is not necessary to do so. Moreover, in this invention, since the formation of an adhesive layer can be performed following formation of a transparent laminated part, it is not necessary to form the topcoat layer conventionally formed on the surface of the transparent laminated part. From the viewpoint of smoothness, the transparent laminated portion preferably has a surface roughness Ra of 0.14 μm or less. According to the manufacturing method of the transparent laminated part mentioned later, it is easy to set the surface roughness of a transparent laminated part in the said range.

  The thickness of the pressure-sensitive adhesive layer is preferably 30 μm or less from the viewpoint of easy improvement of distortion and easy peeling (excellent reworkability). More preferably, it is 22 μm or less. Moreover, it is preferable that it is 2 micrometers or more from a viewpoint of being excellent in adhesiveness. More preferably, it is 5 μm or more.

  The material for forming the pressure-sensitive adhesive layer preferably contains at least a pressure-sensitive adhesive and a liquid as solids from the viewpoint of coating and forming the pressure-sensitive adhesive layer. Moreover, you may add various additives as needed. Examples of the pressure-sensitive adhesive include acrylic resin-based pressure-sensitive adhesives, silicone resin-based pressure-sensitive adhesives, and urethane-based pressure-sensitive adhesives. Examples of the liquid component include solvents such as ethyl acetate, butyl acetate, and toluene.

  The solid content concentration is preferably 30% by mass or less from the viewpoint of controlling the time until drying of the coating solution to be long although it depends on the type of pressure-sensitive adhesive. More preferably, it is 28 mass% or less. On the other hand, if the solid content concentration is too low, convection is likely to occur during drying, and drying unevenness occurs, so that it becomes easy to form skin-like irregularities on the surface after drying. Therefore, it is preferable that it is 12 mass% or more from a viewpoint of ensuring sufficiently the thickness of an adhesive layer, suppressing the surface unevenness | corrugation of a yuzu skin shape. More preferably, it is 14 mass% or more.

  The viscosity of the coating liquid forming the pressure-sensitive adhesive layer is preferably 2000 Pa · s or less from the viewpoint of excellent leveling properties of the coating film. More preferably, it is 1500 Pa · s or less. On the other hand, it is preferable that it is 0.08 Pa.s or more from the viewpoints of ensuring a sufficient thickness of the pressure-sensitive adhesive layer and suppressing surface irregularities on the skin. More preferably, it is 0.1 Pa · s or more. The viscosity of the coating liquid is the viscosity at the coating temperature (23 ° C.), and is measured using a viscometer (dip cup) based on DIN 53 211. At this time, the orifice diameter No. of model 321 (DIN 53 211). Select any one of 1 to 5, measure the time from the moment the sample flows down to the completion of the flow, and specify the viscosity from the flow-out time / viscosity relationship diagram.

  The linear velocity during coating of the coating solution for forming the pressure-sensitive adhesive layer is preferably 30 m / min or less from the viewpoint of excellent leveling properties of the coating film. More preferably, it is 25 m / min or less. In addition, although it does not specifically limit as a minimum of the linear velocity at the time of coating of a coating liquid, it can be 10 m / min or more.

  A transparent polymer film is a base material used as a base for forming a transparent laminated part. The material of the transparent polymer film is not particularly limited as long as it has transparency in the visible light region and can form a thin film on the surface without hindrance.

  Specific examples of the material for the transparent polymer film include polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polystyrene, polyimide, polyamide, polybutylene terephthalate, polyethylene naphthalate, Examples thereof include polymer materials such as polysulfone, polyethersulfone, polyetheretherketone, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, triacetylcellulose, polyurethane, and cycloolefin polymer. These may be used alone or in combination of two or more. Among these, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, and cycloolefin polymer are more preferable materials from the viewpoint of excellent transparency, durability, and processability.

  The transparent laminated part consists of a multilayer laminated structure in which metal oxide thin films and metal thin films are alternately laminated in the order of metal oxide thin film, metal thin film, metal oxide thin film, ... from the transparent polymer film side. . It is preferable that a metal oxide thin film is disposed on the innermost layer on the transparent polymer film side and the outermost layer on the opposite side of the transparent polymer film. A barrier film may be further formed on one or both surfaces of the metal thin film. The barrier film is a thin film layer attached to the metal thin film, and is counted as one layer together with the metal thin film. The barrier film suppresses diffusion of elements constituting the metal thin film into the metal oxide thin film.

  The metal oxide thin film exhibits functions such as enhancing transparency (excellent transparency in the visible light region) by being laminated together with the metal thin film, and can mainly function as a high refractive index layer. . High refractive index means a case where the refractive index for light of 633 nm is 1.7 or more. The metal thin film can function mainly as a solar radiation shielding layer. By such a transparent laminated part, it has favorable visible light transmittance (transparency), solar shading, and heat insulation.

  In addition, the number of layers of the transparent laminated portion may be appropriately set depending on optical characteristics such as visible light transparency (transparency), solar shading, heat insulation, and electrical characteristics such as surface resistance of the entire film. Good. The number of layers in the transparent laminate is preferably in the range of 2 to 10 layers in consideration of the material, film thickness, manufacturing cost, etc. of each thin film. In consideration of optical characteristics, odd-numbered layers are more preferable, and 3 layers, 5 layers, and 7 layers are particularly preferable.

  The protective layer is used as one that enhances scratch resistance. Examples of the cured resin for the protective layer include acrylic resin, epoxy resin, and urethane resin. Specific examples include acrylic resins, acrylic / urethane resins, silicon acrylic resins, acrylic / melamine resins, and the like.

  The thickness of the protective layer is preferably 2.0 μm or less from the viewpoint of heat insulating properties (suppressing the heat penetration rate is low). More preferably, it is 1.6 μm or less. Moreover, it is preferable that it is 1.0 micrometer or more from a viewpoint of being excellent in abrasion resistance. More preferably, it is 1.3 μm or more.

  Hereinafter, the metal oxide thin film, the metal thin film, and the barrier film in the transparent laminated portion will be described in detail.

  As the metal oxide of the metal oxide thin film of the transparent laminate, titanium oxide, zinc oxide, indium oxide, tin oxide, indium and tin oxide, magnesium oxide, aluminum oxide Examples thereof include oxides, zirconium oxides, niobium oxides, and cerium oxides. These may be contained alone or in combination of two or more. These metal oxides may be composite oxides in which two or more metal oxides are combined. Among these, titanium oxide, indium and tin oxide, zinc oxide, tin oxide, and the like are preferable from the viewpoint of relatively high refractive index with respect to visible light.

  The metal oxide thin film can be formed by either a vapor phase method or a liquid phase method. The liquid phase method does not need to be evacuated or use a large electric power as compared with the gas phase method. Therefore, it is advantageous in terms of cost, and is excellent in productivity. As the liquid phase method, a sol-gel method can be suitably used from the viewpoint of easily leaving an organic component.

  The metal oxide thin film is mainly composed of the metal oxide described above, but may contain an organic component in addition to the metal oxide. It is because the softness | flexibility of a transparent laminated film can be improved more by containing an organic content. Specific examples of this type of organic component include components derived from a material for forming a metal oxide thin film, such as a component derived from a starting material of a sol-gel method.

  More specifically, as the organic component, for example, an organic metal compound (including a decomposition product thereof) such as a metal alkoxide, metal acylate, metal chelate or the like of a metal oxide, or the above organic metal compound Various additives such as an organic compound (described later) that reacts to form an ultraviolet-absorbing chelate can be exemplified. These may be contained alone or in combination of two or more.

  The lower limit of the content of the organic component contained in the metal oxide thin film is preferably 3% by mass or more, more preferably 5% by mass or more, and still more preferably, from the viewpoint of easily imparting flexibility. It is good that it is 7% by mass or more. On the other hand, the upper limit of the content of the organic component contained in the metal oxide thin film is preferably 30% by mass or less, from the viewpoint of easily ensuring a high refractive index and easily ensuring solvent resistance. More preferably, it is 25 mass% or less, More preferably, it is good in it being 20 mass% or less. The organic content can be examined using X-ray photoelectron spectroscopy (XPS) or the like. Moreover, the kind of said organic content can be investigated using infrared spectroscopy (IR) (infrared absorption analysis) etc.

  More specifically, as the sol-gel method, for example, a coating liquid containing a metal organometallic compound that constitutes a metal oxide is coated in a thin film shape, and this is dried as necessary to obtain a metal oxide. Examples include a method of forming a precursor thin film of a thin film and then hydrolyzing and condensing an organometallic compound in the precursor thin film to synthesize an oxide of a metal constituting the organometallic compound. . According to this, a metal oxide thin film containing a metal oxide as a main component and containing an organic component can be formed. Hereinafter, the above method will be described in detail.

  The coating liquid can be prepared by dissolving the organometallic compound in a suitable solvent. In this case, specific examples of the organometallic compound include organic compounds of metals such as titanium, zinc, indium, tin, magnesium, aluminum, zirconium, niobium, cerium, silicon, hafnium, and lead. Can do. These may be contained alone or in combination of two or more.

  Specific examples of the organometallic compound include metal alkoxides, metal acylates, and metal chelates of the above metals. A metal chelate is preferable from the viewpoint of stability in air.

  As the organic metal compound, in particular, a metal organic compound that can be a metal oxide having a high refractive index can be preferably used. Examples of such organometallic compounds include organic titanium compounds.

  Specific examples of the organic titanium compound include M-O-R bonds such as tetra-n-butoxy titanium, tetraethoxy titanium, tetra-i-propoxy titanium, and tetramethoxy titanium (R represents an alkyl group). , M represents a titanium atom) and an acylate of titanium having an M—O—CO—R bond (R represents an alkyl group and M represents a titanium atom) such as isopropoxy titanium stearate. Examples thereof include titanium chelates such as diisopropoxy titanium bisacetylacetonate, dihydroxy bis lactato titanium, diisopropoxy bis triethanolaminato titanium, diisopropoxy bis ethyl acetoacetate titanium, and the like. These may be used alone or in combination. These may be either monomers or multimers.

  The content of the organometallic compound in the coating liquid is preferably from 1 to 20% by mass, more preferably from 3 to 20% from the viewpoint of the film thickness uniformity of the coating film and the film thickness that can be applied at one time. It is good if it exists in the range of 15 mass%, More preferably, 5-10 mass%.

  Specific examples of the solvent for dissolving the organometallic compound include alcohols such as methanol, ethanol, propanol, butanol, heptanol and isopropyl alcohol, organic acid esters such as ethyl acetate, acetonitrile, acetone and methyl ethyl ketone. Examples thereof include ketones such as tetrahydrofuran, cycloethers such as dioxane, acid amides such as formamide and N, N-dimethylformamide, hydrocarbons such as hexane, aromatics such as toluene, and the like. These may be used alone or in combination.

  At this time, the amount of the solvent is preferably 5 to 100 times the amount of the solid content weight of the organometallic compound from the viewpoint of the film thickness uniformity of the coating film and the film thickness that can be applied at one time. More preferably, the amount is 7 to 30 times, and further preferably 10 to 20 times.

  When the amount of the solvent is more than 100 times, the film thickness that can be formed by a single coating becomes thin, and a tendency to require many coatings to obtain a desired film thickness is observed. On the other hand, when the amount is less than 5 times, the film thickness becomes too thick, and there is a tendency that the hydrolysis / condensation reaction of the organometallic compound does not proceed sufficiently. Therefore, the amount of the solvent is preferably selected in consideration of these.

  The coating liquid is prepared, for example, by mixing an organometallic compound weighed so as to have a predetermined ratio, an appropriate amount of solvent, and other components added as necessary, with a stirring means such as a stirrer for a predetermined time. It can be prepared by a method such as stirring and mixing. In this case, the components may be mixed at a time or may be mixed in a plurality of times.

  In addition, as a coating method of the coating liquid, from the viewpoint of easy uniform coating, a micro gravure method, a gravure method, a reverse roll coating method, a die coating method, a knife coating method, a dip coating method, a spin coating method, a bar coating method, and the like. Various wet coating methods such as a coating method can be exemplified as suitable ones. These may be appropriately selected and used, and one or more may be used in combination.

  Further, when the coated coating liquid is dried, it may be dried using a known drying apparatus. In this case, as the drying conditions, specifically, for example, a temperature range of 80 ° C to 120 ° C, Examples of the drying time include 0.5 minutes to 5 minutes.

  Specific examples of the means for hydrolyzing and condensing the organometallic compound in the precursor thin film include various means such as irradiation with light energy such as ultraviolet rays, electron beams, and X-rays, and heating. can do. These may be used alone or in combination of two or more. Among these, preferably, irradiation with light energy, particularly ultraviolet irradiation can be suitably used. Compared with other means, it is possible to produce a metal oxide at a low temperature in a short time, and it is difficult to give heat load such as thermal degradation to the transparent polymer film (especially in the case of ultraviolet irradiation, There is an advantage that simple equipment can be used.) In addition, there is an advantage that an organic metal compound (including a decomposition product thereof) or the like is easily left as an organic component.

  Furthermore, when a sol-gel method using light energy at the time of sol-gel curing is employed, a rough metal oxide thin film can be obtained as compared with a metal oxide thin film formed by sputtering or the like. Therefore, when water is applied to a laminated laminated film on a window glass of a building, even when water remains between the window glass, good water drainage can be obtained and the water application workability can be improved. This is because there are advantages such as being able to.

  In this case, specific examples of the ultraviolet irradiator to be used include a mercury lamp, a xenon lamp, a deuterium lamp, an excimer lamp, a metal halide lamp, and the like. These may be used alone or in combination of two or more.

  Further, the amount of light energy to be irradiated can be variously adjusted in consideration of the type of the organometallic compound mainly forming the precursor thin film, the thickness of the precursor thin film, and the like. However, if the amount of light energy to be irradiated is too small, it is difficult to increase the refractive index of the metal oxide thin film. On the other hand, if the amount of light energy to be irradiated is excessively large, the transparent polymer film may be deformed by heat generated during the light energy irradiation. Therefore, these should be noted.

When the light energy to be irradiated is ultraviolet light, the light amount is preferably 300 to 8000 mJ / cm at a measurement wavelength of 300 to 390 nm from the viewpoint of the refractive index of the metal oxide thin film, damage to the transparent polymer film, and the like. ² , more preferably in the range of 500 to 5000 mJ / cm ² .

  When light energy irradiation is used as a means for hydrolyzing and condensing the organometallic compound in the precursor thin film, it reacts with the organometallic compound in the coating liquid described above to absorb light (for example, absorbs ultraviolet rays). It is preferable to add an additive such as an organic compound that forms a chelate. When the above additives are added to the coating solution as the starting solution, light energy is irradiated where the light-absorbing chelate has been formed in advance, so that the metal oxide thin film is formed at a relatively low temperature. This is because a high refractive index can be easily achieved.

  Specific examples of the additive include additives such as β diketones, alkoxy alcohols, and alkanolamines. More specifically, examples of the β diketones include acetylacetone, benzoylacetone, ethyl acetoacetate, methyl acetoacetate, diethyl malonate, and the like. Examples of the alkoxy alcohols include 2-methoxyethanol, 2-ethoxyethanol, 2-methoxy-2-propanol, and the like. Examples of the alkanolamines include monoethanolamine, diethanolamine, and triethanolamine. These may be used alone or in combination.

  Of these, β diketones are particularly preferred, and acetylacetone can be most preferably used.

  The blending ratio of the additive is preferably 0.1 to 1 mol of the metal atom in the organometallic compound from the viewpoint of easiness in increasing the refractive index and stability in the state of the coating film. It is good that it is in the range of 2 times mole, more preferably 0.5 to 1.5 times mole.

  The film thickness of the metal oxide thin film can be adjusted in consideration of solar shading, visibility, reflection color, and the like. The lower limit value of the thickness of the metal oxide thin film is preferably 10 nm or more, more preferably 15 nm, from the viewpoints of easily suppressing the red and yellow coloring of the reflected color and obtaining high transparency. As described above, more preferably, it is 20 nm or more. On the other hand, the upper limit value of the thickness of the metal oxide thin film is preferably 90 nm or less, more preferably 85 nm, from the viewpoints of easily suppressing the green color of the reflected color and easily obtaining high transparency. Hereinafter, more preferably, it is 80 nm or less.

  Metals of the metal thin film include metals such as silver, gold, platinum, copper, aluminum, chromium, titanium, zinc, tin, nickel, cobalt, niobium, tantalum, tungsten, zirconium, lead, palladium, and indium. An alloy etc. are mentioned. These may be contained alone or in combination of two or more.

  As the metal of the metal thin film, silver or a silver alloy is preferable from the viewpoints of being excellent in visible light transmittance, heat ray reflectivity, conductivity, and the like when laminated. More preferably, from the viewpoint of improving durability against environment such as heat, light, and water vapor, the main component is silver, and at least one metal element such as copper, bismuth, gold, palladium, platinum, and titanium is included. It should be a silver alloy. More preferably, a silver alloy containing copper (Ag—Cu alloy), a silver alloy containing bismuth (Ag—Bi alloy), a silver alloy containing titanium (Ag—Ti alloy), or the like may be used. This is because there are advantages such as a large silver diffusion suppression effect and cost advantage.

  In the case of using a silver alloy containing copper, in addition to silver and copper, for example, other elements and inevitable impurities may be contained as long as they do not adversely affect the aggregation / diffusion suppression effect of silver.

  Specific examples of the other elements include elements that can be dissolved in Ag such as Mg, Pd, Pt, Au, Zn, Al, Ga, In, Sn, Sb, Li, Cd, Hg, and As. ; Be, Ru, Rh, Os, Ir, Bi, Ge, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Co, Ni, Si, Tl, Pb, etc. in Ag-Cu alloys Element which can be precipitated as a single phase in Y; La, Ce, Nd, Sm, Gd, Tb, Dy, Ti, Zr, Hf, Na, Ca, Sr, Ba, Sc, Pr, Eu, Ho, Er, Tm Examples include elements capable of precipitating intermetallic compounds with Ag such as Yb, Lu, S, Se, and Te. These may be contained alone or in combination of two or more.

  When using a silver alloy containing copper, the lower limit of the copper content is preferably 1 atomic% or more, more preferably 2 atomic% or more, and even more preferably 3 atomic% or more, from the viewpoint of obtaining the effect of addition. Good to be. On the other hand, the upper limit of the copper content is preferably 20 atomic% or less, more preferably 10 atomic%, from the viewpoint of manufacturability such as easy to ensure high transparency and easy production of a sputtering target. Hereinafter, it is more preferable that it is 5 atomic% or less.

  Further, when using a silver alloy containing bismuth, in addition to silver and bismuth, for example, other elements and inevitable impurities may be included as long as they do not adversely affect the aggregation / diffusion suppression effect of silver. good.

  Specific examples of the other elements include elements that can be dissolved in Ag such as Mg, Pd, Pt, Au, Zn, Al, Ga, In, Sn, Sb, Li, Cd, Hg, and As. ; Be, Ru, Rh, Os, Ir, Cu, Ge, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Co, Ni, Si, Tl, Pb, etc., in Ag-Bi alloys Element which can be precipitated as a single phase in Y; La, Ce, Nd, Sm, Gd, Tb, Dy, Ti, Zr, Hf, Na, Ca, Sr, Ba, Sc, Pr, Eu, Ho, Er, Tm Examples include elements capable of precipitating intermetallic compounds with Ag such as Yb, Lu, S, Se, and Te. These may be contained alone or in combination of two or more.

  When using a silver alloy containing bismuth, the lower limit of the bismuth content is preferably 0.01 atomic% or more, more preferably 0.05 atomic% or more, and still more preferably, from the viewpoint of obtaining the effect of addition. It may be 0.1 atomic% or more. On the other hand, the upper limit of the bismuth content is preferably 5 atomic% or less, more preferably 2 atomic% or less, and still more preferably 1 atomic% from the viewpoint of manufacturability such as easy production of a sputtering target. It is good to be below.

  In addition, when using a silver alloy containing titanium, other than silver and titanium, for example, other elements and inevitable impurities may be included as long as they do not adversely affect the aggregation / diffusion suppression effect of silver. good.

  Specific examples of the other elements include elements that can be dissolved in Ag such as Mg, Pd, Pt, Au, Zn, Al, Ga, In, Sn, Sb, Li, Cd, Hg, and As. ; Be, Ru, Rh, Os, Ir, Cu, Ge, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Co, Ni, Si, Tl, Pb, Bi, etc., Ag-Ti system Elements that can be precipitated as a single phase in the alloy; Y, La, Ce, Nd, Sm, Gd, Tb, Dy, Zr, Hf, Na, Ca, Sr, Ba, Sc, Pr, Eu, Ho, Er, Tm Examples include elements capable of precipitating intermetallic compounds with Ag such as Yb, Lu, S, Se, and Te. These may be contained alone or in combination of two or more.

  When using a silver alloy containing titanium, the lower limit value of the titanium content is preferably 0.01 atomic% or more, more preferably 0.05 atomic% or more, and still more preferably, from the viewpoint of obtaining an addition effect. It may be 0.1 atomic% or more. On the other hand, the upper limit of the content of titanium is preferably 2 atomic% or less, more preferably 1.75 atomic% or less, and still more preferably, from the viewpoint that a complete solid solution is easily obtained when it is formed into a film. Is preferably 1.5 atomic% or less.

  Note that the proportion of subelements such as copper, bismuth and titanium can be measured using ICP analysis. Further, the metal (including alloy) constituting the metal thin film may be partially oxidized.

  The lower limit of the thickness of the metal thin film is preferably 3 nm or more, more preferably 5 nm or more, and further preferably 7 nm or more from the viewpoints of stability, heat ray reflectivity, and the like. On the other hand, the upper limit value of the thickness of the metal thin film is preferably 30 nm or less, more preferably 20 nm or less, and further preferably 15 nm or less, from the viewpoint of transparency of visible light, economy, and the like.

  Here, as a method of forming the metal thin film, specifically, for example, physical vapor deposition (PVD) such as vacuum deposition, sputtering, ion plating, MBE, laser ablation, thermal CVD, etc. Examples thereof include a vapor phase method such as a chemical vapor deposition method (CVD) such as a plasma CVD method. The metal thin film may be formed using any one of these methods, or may be formed using two or more methods.

  Of these methods, sputtering methods such as a DC magnetron sputtering method and an RF magnetron sputtering method can be preferably used from the viewpoint of obtaining a dense film quality and relatively easy film thickness control.

  In addition, the metal thin film may be oxidized within the range which does not impair the function of a metal thin film by receiving the post-oxidation etc. which are mentioned later.

  The barrier film attached to the metal thin film mainly has a barrier function that suppresses diffusion of elements constituting the metal thin film into the metal oxide thin film. Moreover, by interposing between a metal oxide thin film and a metal thin film, it can also contribute to the improvement of adhesiveness of both. The barrier film may have discontinuous portions such as floating islands as long as the diffusion can be suppressed.

  Specific examples of the metal oxide constituting the barrier film include titanium oxide, zinc oxide, indium oxide, tin oxide, indium and tin oxide, and magnesium oxide. And aluminum oxide, zirconium oxide, niobium oxide, cerium oxide, and the like. These may be contained alone or in combination of two or more. Further, these metal oxides may be double oxides in which two or more metal oxides are combined. Note that the barrier film may contain inevitable impurities in addition to the metal oxide.

  Here, the barrier film is mainly composed of a metal oxide contained in the metal oxide thin film from the viewpoint of excellent diffusion suppression effect of the metal constituting the metal thin film and excellent adhesion. good.

More specifically, for example, when a TiO ₂ layer is selected as the metal oxide thin film, the barrier film is a titanium oxide layer mainly composed of an oxide of Ti that is a metal contained in the TiO ₂ layer. Good to have.

  When the barrier film is a titanium oxide layer, the barrier film may be a thin film layer formed as titanium oxide from the beginning, or a thin film layer formed by post-oxidation of a metal Ti layer, Alternatively, it may be a thin film layer formed by post-oxidizing a partially oxidized titanium oxide layer.

  The barrier film is mainly composed of a metal oxide in the same manner as the metal oxide thin film, but is set to be thinner than the metal oxide thin film. This is because the diffusion of the metal constituting the metal thin film occurs at the atomic level, so that it is not necessary to increase the film thickness to a sufficient level to ensure a sufficient refractive index. Moreover, by forming it thinly, the film-forming cost is reduced correspondingly, and it can contribute to the reduction of the manufacturing cost of the transparent laminated film.

  The lower limit value of the thickness of the barrier film is preferably 1 nm or more, more preferably 1.5 nm or more, and further preferably 2 nm or more, from the viewpoint of easily ensuring barrier properties. On the other hand, the upper limit value of the film thickness of the barrier film is preferably 15 nm or less, more preferably 10 nm or less, and still more preferably 8 nm or less from the viewpoint of economy.

  When the barrier film is mainly composed of titanium oxide, the lower limit value of the atomic molar ratio Ti / O of titanium to oxygen in the titanium oxide is 1.0 / 4.0 or more from the viewpoint of barrier properties and the like. Preferably, 1.0 / 3.8 or higher, more preferably 1.0 / 3.5 or higher, even more preferably 1.0 / 3.0 or higher, most preferably 1.0 / 2.8. It is good to be above.

  When the barrier film is mainly composed of titanium oxide, the upper limit of the atomic molar ratio Ti / O of titanium to oxygen in the titanium oxide is preferably 1.0 / 0.5 or less, more preferably 1.0 / 0.7 or less, more preferably 1.0 / 1.0 or less, even more preferably 1.0 / 1.2 or less, most preferably 1 0.0 / 1.5 or less is preferable.

  The Ti / O ratio can be calculated from the composition of the layer. As a composition analysis method of the layer, energy dispersive X-ray fluorescence analysis (EDX) can be preferably used from the viewpoint of enabling comparatively accurate analysis of the composition of an extremely thin thin film layer.

  A specific composition analysis method will be described. First, using an ultrathin section method (microtome) or the like, a test piece having a thickness of 100 nm or less in the cross-sectional direction of the laminated structure including the layer to be analyzed is prepared. Next, the laminated structure and the position of the layer are confirmed by a transmission electron microscope (TEM) from the cross-sectional direction. Next, an electron beam is emitted from the electron gun of the EDX apparatus and is incident on the vicinity of the center of the film thickness of the layer to be analyzed. Electrons incident from the surface of the test specimen enter to a certain depth and generate various electron beams and X-rays. By detecting and analyzing characteristic X-rays at this time, the constituent elements of the layer can be analyzed.

  As the barrier film, a vapor phase method can be suitably used from the viewpoint that a dense film can be formed, and a thin film layer of about several nm to several tens of nm can be formed with a uniform film thickness.

  Specific examples of the vapor phase method include physical vapor deposition methods (PVD) such as vacuum deposition, sputtering, ion plating, MBE, and laser ablation, thermal CVD, and plasma CVD. Examples thereof include chemical vapor deposition (CVD) and the like. As the vapor phase method, a sputtering method such as a DC magnetron sputtering method or an RF magnetron sputtering method is preferable from the viewpoint of excellent adhesion at the film interface as compared with a vacuum deposition method and the like and easy control of the film thickness. Can be used.

  Each barrier film that can be included in the laminated structure may be formed using any one of these vapor phase methods, or may be formed using two or more methods. May be.

  The barrier film may be formed as a metal oxide thin film from the beginning by using the above-described vapor phase method, or a metal thin film or a partially oxidized metal oxide thin film is once formed. Later, it can be formed by oxidizing it afterwards. The partially oxidized metal oxide thin film refers to a metal oxide thin film that has room for further oxidation.

  When forming a metal oxide thin film from the beginning, specifically, for example, a gas containing oxygen as a reactive gas is mixed with an inert gas such as argon or neon as a sputtering gas, and the metal and oxygen are mixed. A thin film may be formed while reacting (reactive sputtering method). For example, when a titanium oxide layer having the Ti / O ratio is obtained by using the reactive sputtering method, the oxygen concentration in the atmosphere (the volume ratio of the gas containing oxygen to the inert gas) is the film thickness range described above. The optimum ratio may be appropriately selected in consideration of the above.

  On the other hand, when a metal thin film or a partially oxidized metal oxide thin film is formed and then post-oxidized later, specifically, after the above-described laminated structure is formed on the transparent polymer film, The metal thin film in the structure or the partially oxidized metal oxide thin film may be post-oxidized. Note that the sputtering method or the like may be used for forming the metal thin film, and the reactive sputtering method or the like described above may be used for forming the partially oxidized metal oxide thin film.

  Examples of the post-oxidation technique include heat treatment, pressure treatment, chemical treatment, and natural oxidation. Of these post-oxidation techniques, heat treatment is preferable from the viewpoint of enabling post-oxidation relatively easily and reliably. Examples of the heat treatment include a method of causing the transparent polymer film having the above-described laminated structure to exist in a heating atmosphere such as a heating furnace, a method of immersing in warm water, a method of microwave heating, and a metal in the laminated structure. Examples thereof include a method of energizing and heating a thin film, a partially oxidized metal oxide thin film, and the like. These may be performed in combination of one or two or more.

  As heating conditions at the time of the heat treatment, specifically, for example, preferably 30 ° C. to 60 ° C., more preferably 32 ° C. to 57 ° C., more preferably 35 ° C. to 55 ° C., heating When present in the atmosphere, the heating time is preferably selected from 5 days or longer, more preferably 10 days or longer, and even more preferably 15 days or longer. This is because the post-oxidation effect, the thermal deformation / fusion suppression of the transparent polymer film 12 and the like are good within the above heating condition range.

  The heating atmosphere during the heat treatment is preferably an atmosphere containing oxygen or moisture, such as in the air, a high oxygen atmosphere, or a high humidity atmosphere. Particularly preferably, it is in the air from the viewpoint of manufacturability and cost reduction.

  When the post-oxidation thin film described above is included in the laminated structure, the moisture and oxygen contained in the metal oxide thin film are consumed during the post-oxidation. The thin film becomes difficult to chemically react. Specifically, for example, when the metal oxide thin film is formed by a sol-gel method, the water and oxygen contained in the metal oxide thin film are consumed during post-oxidation. The starting material (metal alkoxide, etc.) by the sol-gel method remaining in the thin film and moisture (adsorbed water, etc.), oxygen, etc. are difficult to undergo a sol-gel curing reaction by sunlight. Therefore, it is possible to relieve internal stress caused by volume change such as curing shrinkage, and it is easy to suppress interfacial peeling of the laminated structure, and to improve durability against sunlight.

  Hereinafter, the present invention will be described in detail using Examples and Comparative Examples.

Example 1
<Preparation of transparent laminated film>
As the transparent laminated film according to Example 1, a transparent laminated film having a transparent laminated portion having a roughly seven-layer laminated structure described below and an adhesive layer laminated in contact with the transparent laminated portion was produced.

(Preparation of coating solution)
First, a coating solution used for forming a TiO ₂ thin film by a sol-gel method was prepared. That is, tetra-n-butoxytitanium tetramer (manufactured by Nippon Soda Co., Ltd., “B4”) as titanium alkoxide, and acetylacetone as an additive that forms an ultraviolet-absorbing chelate, n-butanol and isopropyl It mix | blended with the mixed solvent with alcohol, and this was mixed for 10 minutes using the stirrer, and the coating liquid was prepared. At this time, the composition of tetra-n-butoxy titanium tetramer / acetylacetone / n-butanol / isopropyl alcohol was 6.75% by mass / 3.38% by mass / 59.87% by mass / 30.00% by mass, respectively. did.

(Formation of transparent laminate)
As the transparent polymer film, a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., “Cosmo Shine (registered trademark) A4100”) (hereinafter referred to as “PET film”) having an easy-adhesion layer on one side is used. A TiO ₂ thin film was formed as a first layer on the surface (PET surface) side opposite to the easily adhesive layer surface side of this PET film by the following procedure.

That is, the coating liquid was continuously applied to the PET surface side of the PET film with a gravure roll having a predetermined groove volume using a micro gravure coater. Next, the coating film was dried at 100 ° C. for 80 seconds using an in-line drying furnace to form a precursor film of a TiO ₂ thin film. Then, using an in-line ultraviolet irradiator [high pressure mercury lamp (160 W / cm)], the precursor film was continuously irradiated with ultraviolet rays for 1.5 seconds at the same linear velocity as that during the coating. Thereby, a TiO ₂ thin film (first layer) was formed on the PET film by a sol-gel method using ultraviolet energy at the time of sol-gel curing (hereinafter sometimes abbreviated as “(sol gel + UV)”).

  Next, each thin film constituting the second layer was formed on the first layer.

That is, a lower metal Ti thin film was formed by sputtering on the first TiO ₂ thin film using a DC magnetron sputtering apparatus. Next, an Ag—Cu alloy thin film was formed on the lower metal Ti thin film by sputtering. Next, an upper metal Ti thin film was formed on the Ag—Cu alloy thin film by sputtering.

At this time, the film formation conditions of the upper and lower metal Ti thin films were as follows: Ti target (purity 4N), vacuum ultimate pressure: 5 × 10 ⁻⁶ (Torr), inert gas: Ar, gas pressure: 2.5 × 10 ⁻³ (Torr), input power: 1.5 (kW), and film formation time: 1.1 seconds.

The film formation conditions of the Ag—Cu alloy thin film are as follows: Ag—Cu alloy target (Cu content: 4 atom%), vacuum ultimate pressure: 5 × 10 ⁻⁶ (Torr), inert gas: Ar, gas pressure: 2.5 × 10 ⁻³ (Torr), input power: 1.5 (kW), and film formation time: 1.1 seconds.

Next, as the third layer, a TiO ₂ thin film by (sol gel + UV) was formed on the second layer. Here, the film forming procedure according to the first layer is performed twice to obtain a predetermined film thickness.

Next, as the fourth layer, each thin film constituting the fourth layer was formed on the third layer. Here, a film forming procedure according to the second layer was performed. However, when the Ag—Cu alloy thin film was formed, the film formation conditions described above were as follows: Ag—Cu alloy target (Cu content: 4 atomic%), vacuum ultimate pressure: 5 × 10 ⁻⁶ (Torr), inert gas : Ar, gas pressure: 2.5 × 10 ⁻³ (Torr), input power: 1.8 (kW), and film formation time: 1.1 seconds, thereby changing the film thickness.

Next, as the fifth layer, a TiO ₂ layer having the same configuration as the third layer (sol gel + UV) was formed on the fourth layer.

  Next, as the sixth layer, each thin film having the same configuration as the second layer was formed on the fifth layer.

Next, as the seventh layer, a TiO ₂ layer by (sol gel + UV) was formed on the sixth layer. Here, a predetermined film thickness is obtained by performing the film formation procedure according to the first layer once.

  Next, the obtained film with a transparent laminated portion is heat-treated in the heating furnace at 40 ° C. for 300 hours in the atmosphere to thermally oxidize the metal Ti thin film contained in the laminated structure, thereby obtaining a titanium oxide. A thin film was formed.

In addition, the refractive index (measurement wavelength is 633 nm) of the TiO ₂ thin film was measured by FilmTek 3000 (manufactured by Scientific Computing International).

Moreover, content of the organic component contained in the TiO ₂ thin film was measured by X-ray photoelectron spectroscopy (XPS).

  Moreover, the EDX analysis was performed about the titanium oxide thin film formed by thermally oxidizing the metal Ti thin film, and Ti / O ratio was calculated | required as follows.

  That is, a film with a transparent laminated portion is cut out by a microtome (LKB Co., Ltd., “Ultrome V2088”), and the thickness of the laminated structure including the titanium oxide thin film (barrier thin film) to be analyzed is 100 nm or less in thickness. A piece was made. The cross section of the produced test piece was confirmed with a field emission electron microscope (HRTEM) (manufactured by JEOL Ltd., “JEM2001F”). Then, using an EDX apparatus (resolution of 133 eV or less) (“JED-2300T” manufactured by JEOL Ltd.), an electron beam is emitted from the electron gun of this apparatus, and a titanium oxide thin film (barrier thin film) to be analyzed The elemental element of the titanium oxide thin film (barrier thin film) was analyzed by detecting the incident characteristic X-ray and analyzing it.

Further, the content of the subelement (Cu) in the alloy thin film was determined as follows. That is, under each film forming condition, a test piece in which an Ag—Cu alloy thin film was formed on a glass substrate was separately prepared, and this test piece was immersed in a 6% HNO ₃ solution and eluted with ultrasonic waves for 20 minutes. Then, it measured by the concentration method of ICP analysis method using the obtained sample solution.

  Moreover, the film thickness of each thin film was measured from the cross-sectional observation of the test piece by the said field emission electron microscope (HRTEM) (the JEOL Co., Ltd. make, "JEM2001F").

  Table 1 shows the detailed layer structure of the transparent laminated portion.

(Preparation of adhesive layer forming coating solution)
Acrylic resin adhesive (“Main Agent: BPS5260, Curing Agent: BHS8515” manufactured by Toyo Ink Co., Ltd.) and solvent (mass ratio, ethyl acetate: toluene = 1: 1), solid content (adhesive component) concentration 24. What was adjusted to 4 mass% was used. When the viscosity at 23 ° C. was measured for the obtained coating solution using a viscometer (dip cup) (“MODEL 321” manufactured by Eriksen) conforming to the international standard DIN 53 211, it was 0.90 Pa · s. It was.

(Formation of adhesive layer)
A pressure-sensitive adhesive layer was formed by applying a coating liquid for forming a pressure-sensitive adhesive layer directly on the surface of the transparent laminate, followed by drying and curing. Using a lip coater, the clearance between the coater head and the film winding roll was set to 100 μm, and coating was performed under the condition of a line speed of 25 m / min. The drying time was 1.12 minutes, and the thickness of the pressure-sensitive adhesive layer was 18 μm.

(Examples 2 to 4)
The solid content concentration of the coating liquid for forming the pressure-sensitive adhesive layer was set to the concentration shown in Table 1, and each coating condition was the same as that described in Table 1 except that the coating conditions were set to those shown in Table 1.

(Comparative Example 1)
A commercially available heat ray reflective film (“V-KOOOLVK70” manufactured by Southwall Technologies, Inc.) was used. This heat ray reflective film is composed of a PET film as a base film, a heat ray reflective film is formed on the base film, a PET layer is formed on the heat ray reflective film, and an adhesive layer is formed on the PET layer. Has been.

(Comparative Example 2)
Using a 25 μm thick PET film (“Toyobo Ester Film E7302” manufactured by Toyobo Co., Ltd.) having a release silicone layer on one side as a separator, the adhesive layer forming coating solution is applied to the surface of the separator instead of the surface of the transparent laminate. After coating, the pressure-sensitive adhesive layer was formed by drying and curing. Subsequently, the film with a transparent laminated part and the separator with an adhesive layer were bonded together, and the adhesive layer was arrange | positioned on the surface of a transparent laminated part by peeling a separator. Table 1 shows the solid content concentration and coating conditions of the coating solution for forming the pressure-sensitive adhesive layer.

(Comparative Example 3)
The solid content concentration of the coating liquid for forming the pressure-sensitive adhesive layer was set to the concentration shown in Table 1, and each coating condition was the same as that described in Table 1 except that the coating conditions were set to those shown in Table 1.

  The transparent laminated films of Examples and Comparative Examples were attached to one side of a 3 mm thick float glass, and image clarity and optical properties were measured. In addition, the surface state of the pressure-sensitive adhesive layer was evaluated with a single transparent laminated film, and the viewability was evaluated with the transparent laminated film attached to one side of the float glass. The measurement light at the time of optical property evaluation was made incident from the glass surface side. These results are shown in Table 2.

(Image clarity)
As shown in FIG. 4, in a state where the transparent laminated film 1 is attached to the plate glass 2 through the pressure-sensitive adhesive layer, light is incident from the glass surface side at an incident angle of 80 degrees, and the light transmitting portion of the optical comb 3 The maximum light amount and the minimum light amount at the light shielding part were measured by the light receiving part 4. An optical comb 3 having a plurality of slits (0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, 2.0 mm) with different slit intervals is used, and the optical comb 3 is in the direction of the arrow in which the slits are arranged. Moved to. The image definition is a value when the slit interval is 0.125 mm, and is an average value of the image definition in the MD direction and the image definition in the TD direction.

(Visible light transmittance, visible light reflectance)
In accordance with JIS A5759, by using a spectrophotometer (manufactured by Shimadzu Corporation, “UV3100”), a transmission spectrum with a wavelength of 300 to 1000 nm is measured, and a visible light transmittance and a visible light reflectance are calculated. Asked.

(Solar radiation transmittance)
In accordance with JIS A5759, a transmission spectrum with a wavelength of 300 to 2500 nm was measured using a spectrophotometer (manufactured by Shimadzu Corporation, “UV3100”), and the solar transmittance was calculated.

(Surface condition of the adhesive layer)
In a room where a fluorescent lamp (60 W) is installed on the ceiling, the film sample is arranged so that the fluorescent lamp is aligned with the A4 size film sample with the separator peeled off at the end of the line of sight, and the MD in the adhesive layer surface of the film sample The pressure-sensitive adhesive layer surface of the film sample was visually observed so that the angle formed between the direction straight line and the line of sight was 10 °, and it was examined whether streaks or irregularities were observed on the surface. Similar observations were made in the TD direction. At this time, when no streak and unevenness were observed on the surface of the film in both the MD direction and the TD direction, “O” passed, but no streak was observed on the surface of the film in both the MD direction and the TD direction. Is acceptable, but is slightly inferior “Δ”, and a case where streaks and irregularities are observed on the surface of the film in both the MD direction and the TD direction is regarded as “failed”.

(Viewability)
A film sample of A4 size was attached to float glass (thickness 3 mm) and dried to prepare a sample for evaluation of viewability. Next, in the same manner as in the evaluation method “(Surface condition of the pressure-sensitive adhesive layer)”, the sample for evaluating viewability was visually observed from the glass side. The evaluation criteria are the same as the evaluation criteria of “(Surface condition of pressure-sensitive adhesive layer)”.

  In the comparative example, the image definition is less than 80%, the surface state of the pressure-sensitive adhesive layer is poor, and the viewability is poor. On the other hand, in the examples, the image clarity is 80% or more, the surface state of the pressure-sensitive adhesive layer is good, and the viewability is excellent.

  Although the embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the spirit of the present invention. .

DESCRIPTION OF SYMBOLS 10 Transparent laminated film 12 Transparent polymer film 14 Transparent laminated part 16 Adhesive layer 18 Protective layer 20 Separator 22 Transparent base material

Claims (3)

On the surface of the transparent polymer film, it has a transparent laminate portion in which metal oxide thin films and metal thin films are alternately laminated, and an adhesive layer in this order,
The image sharpness measured according to JIS K7374 is 80% or more under the conditions of an incident angle of 80 degrees and an optical comb width of 0.125 mm in a state of being attached to a glass surface through an adhesive layer. A transparent laminated film.   The transparent laminated film according to claim 1, wherein the pressure-sensitive adhesive layer is in contact with the uppermost layer of the transparent laminated portion.   The thickness of an adhesive layer is in the range of 2-30 micrometers, The transparent laminated film of Claim 1 or 2 characterized by the above-mentioned.

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