JPH11348215A - Laminated polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve energy saving, the scattering prevention of glass, and the like when being stuck on the window of an automobile or the like by laminating a resin containing metal-added metal oxide particles, or metal oxide particles on one surface of a polyester film colored by a dye or pigment. SOLUTION: In this laminated film, its clearness is ensured at the time when an image is viewed through a film and a heat ray cutting property is excellent, and the film is formed such that a resin-layer containing metal and added metal particles, or metal oxide particles is laminated on one surface of a polyester film colored by a dye or pigment. As metal-added metal oxide particles used herein, there are given tin-added indium oxide particles, or antimony-added tin oxide particles, and as metal oxide particles, there are given indium oxide particles, or tin oxide particles. In addition, a dye and pigment may be used by one kind or two kinds or more combinedly, and a content in a colored polyester film is made to be 0.01-10 wt.% normally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated polyester film, and more particularly, to a laminated polyester film having good heat ray cutting properties in which a colored polyester film is laminated with a metal-added metal oxide particle or a resin layer containing metal oxide particles. .

[0002]

2. Description of the Related Art Conventionally, indium oxide and tin oxide have been formed on a biaxially stretched polyethylene terephthalate film as a film that is transparent to light in the visible region and reflective or absorptive to light in the infrared region. (Japanese Patent Laid-Open No. 57-67441, etc.). On the other hand, JP-A-9-310031 and JP-A-9-316
No. 115, Japanese Patent Application Laid-Open No. 9-316363, etc.
A composition or a coating film in which an organic infrared absorbing agent is added to a metal oxide such as antimony-doped tin oxide, indium-doped tin oxide, and vanadium oxide is described.

However, a selective light transmitting laminate in which a coating of indium oxide and tin oxide is provided on a polyethylene terephthalate film by sputtering,
Since it is necessary to use a device that requires control of a high vacuum and a highly accurate atmosphere, not only the production cost is increased, but also the size of a film that can be formed is limited. On the other hand, a coating film of a composition containing an organic infrared absorber in addition to metal oxides such as antimony-doped tin oxide, indium-doped tin oxide, and vanadium oxide has a low transmittance in the visible light region, and the film is colored. In this case, the original color of the colored film is hard to come out. Further, since the organic infrared absorbing agent absorbs infrared rays, the organic infrared absorbing agent is likely to deteriorate, and it is difficult to maintain a constant infrared absorbing ability for a long time.

[0004] In addition, a film colored by a high-pressure dyeing method or the like absorbs light rays when irradiated with sunlight, and is in a state where the colored film is easily deteriorated. Therefore, there is a limit to the ability of a colored film to maintain its original color for a long period of time and to suppress fading or deterioration of the film due to sunlight.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and the problem to be solved is that transparency is good, and clarity when an image is viewed through a film is secured.
Provide a film that excels in heat ray cutability and is excellent in energy saving and glass shatter prevention when used by being attached to vehicle windows such as automobile windows, train windows, airplane windows, building windows, etc. It is in.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies in view of the above-mentioned circumstances, and as a result, have found that the above problems can be easily solved by adopting a specific structure, thereby completing the present invention. Reached. That is, the gist of the present invention is that a laminated polyester film is characterized in that a resin layer containing metal-added metal oxide particles or metal oxide particles is laminated on one surface of a polyester film colored with a dye or a pigment. Exists.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The polyester film referred to in the present invention is, for example, a polyester film that is extruded by a so-called extrusion method, which is melt-extruded from an extrusion die, and a film that is later oriented in the biaxial direction in the longitudinal direction and the lateral direction. Can be mentioned.

The polyester used in the present invention is obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol. As aromatic dicarboxylic acids, terephthalic acid,
Examples of 2,6-naphthalenedicarboxylic acid include aliphatic glycols such as ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Representative polyesters include polyethylene terephthalate (PET), polyethylene-2,
6-naphthalenedicarboxylate (PEN) and the like are exemplified. Further, the polyester used may be a homopolyester or a copolymerized polyester. In the case of a copolyester, it is preferably a copolymer containing 30 mol% or less of a third component. Examples of the dicarboxylic acid component of the copolymerized polyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acids (for example, P-oxybenzoic acid and the like). One or two or more of them may be mentioned, and the glycol component may be one or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol and the like.

In the present invention, it is necessary that a dye or a pigment is incorporated in the colored polyester. Dyes can be classified into natural dyes and synthetic dyes, and examples of natural dyes include indigo (indigo). As synthetic dyes, azo dyes, anthraquinone dyes, indigoid dyes, sulfur dyes, triphenylmethane dyes, pyrazolone dyes, stilbene dyes, diphenylmethane dyes, xanthene dyes, alizarin dyes, acridine dyes, quinone imine dyes (eg, azine dyes, oxazine dyes) Thiazine dyes), thiazole dyes, methine dyes, nitro dyes, nitroso dyes, cyanine dyes and the like.

The pigments can be classified into organic pigments and inorganic pigments. Examples of the organic pigments include phthalocyanine-based, dioxazine-based, and anthraquinone-based pigments such as quinacridone, watch angred, and the like. And dioxazine violet. Examples of the inorganic pigment include titanium white, zinc white, lead white, carbon black, red iron, red, cadmium red, graphite, ultramarine, cobalt blue, cobalt purple, zinc chromate and the like.

These dyes and pigments may be used alone or in combination.
More than one kind can be used in combination, and the content in the colored polyester film is usually 0.01 to 10% by weight, preferably 0.05 to 7.5% by weight, more preferably 0.1 to 10% by weight. It is in the range of 5% by weight. This content is 0.
If it is less than 01% by weight, the degree of coloring is small, and even if it exceeds 10% by weight, the degree of coloring is already saturated.

In the present invention, the method for producing a colored polyester film by adding a dye or a pigment to polyester is not particularly limited.
Known methods can be employed. That is, a method in which a dye or a pigment and a polyester raw material are dry-blended and extruded using a kneading extruder, or the like, may be used. The polyester film of the present invention may contain additives other than dyes and pigments, for example, particles and the like.
It is preferable to mix in the range of 2 to 1% by weight, particularly 0.03 to 0.5% by weight. If the content of particles is small,
There is a tendency that the film surface is flattened and winding characteristics in the film manufacturing process are inferior. On the other hand, when the content of the particles exceeds 1% by weight, the degree of surface roughening of the film becomes too large, and the film tends to be hazy.

The average particle size of the particles other than the dye and pigment is not particularly limited, but may be 0.02 to 3 μm.
m, more preferably 0.02 to 2.5 μm, especially 0.02 to 2
The range of μm is preferred. When the average particle size is less than 0.02 μm, the film surface tends to be flattened, and the winding characteristics in the film manufacturing process tend to be poor. On the other hand, if the average particle size exceeds 3 μm, the degree of surface roughening of the film becomes too large, and the film tends to be hazy.

Examples of the particles that can be used in the present invention include silicon oxide, alumina, calcium carbonate, kaolin, titanium oxide, and fine particles of a crosslinked polymer as described in JP-B-59-5216. Can be. These particles may be used alone or in combination of two or more components. In the present invention, the method of blending the particles with the polyester is not particularly limited, and a known method can be employed. For example, it can be added at any stage of producing the polyester, but is preferably added as a slurry dispersed in ethylene glycol or the like at the esterification stage or at the stage before the end of the transesterification reaction and before the start of the polycondensation reaction, The polycondensation reaction may proceed. Also, using a kneading extruder with a vent,
It is performed by a method of blending a slurry of particles dispersed in ethylene glycol or water with a polyester raw material, or a method of blending dried particles with a polyester raw material using a kneading extruder.

The laminated film of the present invention may have any thickness as long as it can be formed as a film, and exhibits a particularly excellent effect when formed into a film having a thickness of 3 to 200 μm, more preferably 5 to 100 μm, especially 8 to 50 μm. be able to. Next, the method for producing a polyester film in the present invention will be specifically described, but the film of the present invention is not limited to the following production examples.

That is, a molten sheet is extruded from a die using an extruder using the polyester raw material described above,
A method of obtaining an unstretched sheet by cooling and solidifying with a cooling roll is preferred. In this case, to improve the flatness of the sheet,
It is preferable to improve the adhesion between the sheet and the rotary cooling drum, and the electrostatic application adhesion method and / or the liquid application adhesion method are preferably employed.

Next, the obtained unstretched film is stretched biaxially to be biaxially oriented. That is, first, the unstretched sheet is stretched in one direction by a roll or a tenter-type stretching machine. The stretching temperature is usually 70 to 120
° C, preferably 80 to 110 ° C, and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Next, stretching is performed in a direction orthogonal to the stretching direction of the first stage. The stretching temperature is usually 70 to 120 ° C, preferably 80 to 11 ° C.
The stretching ratio is usually 3.0 to 7 times, and preferably 3.5 to 6 times. And then, 130 ° C ~
Heat treatment is performed at a temperature in the range of 250 ° C. under a relaxation of 30% or less to obtain a biaxially stretched film.

During the stretching step, a so-called in-line coating for treating the film surface can be applied. It is not limited to, for example,
After the first-stage stretching is completed, before the second-stage stretching, an aqueous solution, an aqueous emulsion, an aqueous slurry, or the like is used for the purpose of improving antistatic properties, sliding properties, adhesiveness, and the like, and improving secondary workability. A coating process can be applied.

In the above-mentioned stretching, the stretching in one direction is performed by 2
It is also possible to use a method of performing the above steps. In that case,
It is preferable that the stretching is performed so that the stretching ratio in the two directions finally falls within the above range. It is also possible to simultaneously biaxially stretch the unstretched sheet so that the area magnification becomes 10 to 40 times. Further, if necessary, the film may be stretched in the longitudinal and / or transverse directions again before or after the heat treatment.

In the present invention, the metal-added metal oxide particles and the metal oxide particles contained in the resin layer laminated on at least one side of the colored polyester film include tin-added indium oxide particles (ITO) and tin oxide-added oxide. Indium particles, antimony-added tin oxide particles (AT
O), antimony-added zinc oxide particles (AZO), cadmium-added tin oxide particles (CTO), magnesium-added indium oxide particles (MgIn ₂ O ₄ ), cadmium-added gallium oxide particles (CdGa ₂ O ₄ ), zinc-added gallium oxide particles (ZnGa ₂ O ₄ ), indium-doped tin oxide particles (In ₄ Sn ₃ O ₁₂ ), indium-doped tin oxide,
Examples include gallium-added indium oxide particles (GaInO ₃ ), zinc-added indium oxide particles (ZnIn ₂ O ₄ ), tin oxide, indium oxide, and zinc oxide. Among these, tin-added indium oxide particles (ITO) and antimony-added Tin oxide particles (ATO) and tin oxide particles are preferable, and tin-added indium oxide particles (ITO) are particularly preferable in terms of transparency and heat ray cutting properties. These particles may or may not be fired. In the case of firing, the firing atmosphere may be a non-oxygen state (for example, an oxygen-free state or a reduced state) or an aerobic state. Is preferred.

The shape of these particles may be any shape such as a lump, a sphere, an ellipsoid, and a needle. The metal added to the metal-added metal oxide particles may be an oxide or a plurality of metals. These particles may be contained alone or in combination of two or more. The average particle diameter of the metal-added metal oxide particles used in the present invention is usually 0.2 μm.
m or less, preferably 0.1 μm or less. If the average particle size exceeds 0.2 μm, the transparency to visible light tends to decrease.

In the present invention, the resin used for the metal-added metal oxide particles or the resin layer containing the metal oxide particles laminated on at least one surface of the laminated film is a polyester resin, an acrylic resin, a polyurethane resin, a polycarbonate resin, a silicon resin. , Epoxy resin, polystyrene resin, ABS resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyolefin resin, polyamide resin,
Water-soluble alkyd resin, polyvinyl alcohol resin, polybutyl alcohol resin, polyvinyl butyral resin, polyvinyl acetal resin, vinyl acetate resin, acrylic
One or more resins such as styrene resins can be used in combination.

In the present invention, it is preferable to employ an active energy ray-curable resin layer as the resin layer, and the material constituting the active energy ray-curable resin layer is not particularly limited, and examples thereof include various crosslinkable resins. Can be
Specific examples of the crosslinkable resin include acrylic, polyester, urethane, melamine, epoxy, and organic silicate resins, and copolymer resins of a silicon-containing compound and a fluorine-containing compound. Among these, an active energy ray-curable resin is preferable in terms of productivity and the like.

As the active energy ray-curable resin, a curing component such as an unsaturated polyester resin type, an acrylic type, an addition polymerization type, a thiol / acrylic hybrid type, a cationic polymerization type, or a hybrid type of cationic polymerization and radical polymerization is used. be able to. In these,
Acrylic cured resins are preferred in terms of curability, scratch resistance, surface hardness, flexibility and durability.

The acrylic cured resin contains an acrylic oligomer as an active energy ray polymerization component and a reactive diluent. And, if necessary, a photopolymerization initiator,
Contains a photopolymerization initiation aid, a modifier and the like. A typical example of the acrylic oligomer is an oligomer in which a reactive acryloyl group or methacryloyl group is bonded to an acrylic resin skeleton. Other acrylic oligomers include polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, silicone
(Meth) acrylate, polybutadiene (meth) acrylate, and the like. Further, an oligomer in which an acryloyl group or a methacryloyl group is bonded to a rigid skeleton of melamine, isocyanuric acid, cyclic phosphazene or the like can be used.

The reactive diluent functions as a solvent in the coating step as a medium for the coating agent, and has a group which itself reacts with a polyfunctional or monofunctional acrylic oligomer. It becomes a polymerization component. Specific examples of such a reactive diluent include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta ( (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene glycol (meth) acrylate, propylene glycol di (meth) acrylate, (meth) acryloyloxypropyltriethoxysilane, (meth) Acryloyloxypropyltrimethoxysilane and the like can be mentioned.

As the photopolymerization initiator, for example, 2,2-
Ethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, dibenzoyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, p-chlorobenzophenone, p-methoxybenzophenone, Michler's ketone, acetophenone, 2-chlorothioxanthone, anthraquinone, phenyl disulfide, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone and the like.

Examples of the photopolymerization initiation aid include tertiary amines such as triethylamine, triethanolamine and 2-dimethylaminoethanol, alkylphosphines such as triphenylphosphine, and thioethers such as β-thiodiglycol. Can be Examples of the modifier include a coating improver, an antifoaming agent, a thickener, an inorganic particle, an organic particle, a lubricant, an organic polymer, a dye, a pigment, and a stabilizer. These are used within a range that does not inhibit the reaction by the active energy ray, and can improve the properties of the active energy ray-curable resin layer according to the application. Further, an organic solvent can be blended with the composition of the active energy ray-curable resin layer in order to improve workability at the time of coating and control the coating thickness.

The method of blending the metal-added metal oxide particles and the metal oxide particles in the resin is not particularly limited, but a method of adding and adding the particles at an arbitrary stage of polymerizing the resin, and a method of melting the resin. Examples thereof include a method of directly adding and containing the resin, a method of dry-blending the resin and the particles and extruding and kneading with an extruder, and a method of adding and adding the resin dissolved or dispersed with a solvent or the like.

In the present invention, the method of laminating the metal-added metal oxide particles or the resin layer containing the metal oxide particles on one surface of the laminated film is not particularly limited, but a plurality of extruders may be used. Simultaneously extruding polyester and resin containing metal-added metal oxide particles,
A so-called co-extrusion method, in which a resin containing metal-added metal oxide particles and / or a metal oxide particle is melted by an extruder and directly laminated on a polyester film, so-called extrusion, in which they are merged in a feed block or a die and extruded and laminated. After laminating, casting or uniaxial stretching of a polyester film forming line, a slurry in which metal-added metal oxide particles and / or metal oxide particles are added to a resin dissolved in water and / or an alcohol solvent is applied onto the polyester film. A so-called in-line coating (ILC) method, and a so-called off-line coating (OLC) method of applying a metal-added metal oxide particle and / or a paint obtained by adding a metal oxide particle to a resin dissolved in an organic solvent on a polyester film. .

Next, a method for laminating a resin containing metal-added metal oxide particles on a colored polyester film by an off-line coating method in the present invention will be specifically described. However, the present invention is not limited to this. That is, a paint in which metal-added metal oxide particles are dispersed in a resin dissolved in an organic solvent is prepared, and the paint is applied on a colored polyester film by a usual coating method, and dried and solidified to form a laminated film. Can be obtained. In addition, additives such as a dispersant and a coupling agent may be conventionally added to the paint.

[0032]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In the examples and comparative examples, “parts” means “parts by weight”. The measuring method used in the present invention is as follows.

(1) Average particle diameter (d ₅₀ ) Centrifugal sedimentation type particle size distribution analyzer SA manufactured by Shimadzu Corporation
The size of the particles was measured by a sedimentation method based on Stokes' resistance law using Model CP3. (2) Heat-cutting property 50 mm from sample film (300 mm x 300 mm)
A 100 W incandescent lamp was turned on at a distance, and immediately after lighting and 30 minutes later, the back of the hand was held at a position 50 mm away from the sample film on the side opposite to the incandescent lamp, and the heat ray cut property was evaluated according to the following rank.

[0034]

[Table 1] Rank A: Hardly feels heat rays (no problem in practical use) Rank B: Slightly senses heat rays (no problem in practical use)

(3) Degree of color change Using a long life type light resistance tester (manufactured by Suga Test Instruments Co., Ltd.), the laminated polyester film was measured for 10 minutes from the surface of the resin layer containing metal-added metal oxide particles or metal oxide particles.
Light was irradiated for 00 hours, and the color difference before and after the test was visually measured, and ranked as follows.

[0036]

[Table 2] Rank A: Little difference (level with no practical problem) Rank B: Little difference (level without practical problem) Rank C: Difference (level with practical problem)

(4) Clarity 10 c on the gradation color scale [1] in the laser dot color chart manufactured by GE Planning Center Co., Ltd.
The sample films were placed in parallel at a distance of m, and the sharpness was visually judged from the sample film side and classified into the following ranks.

[0038]

[Table 3] Rank A: Little difference compared to the original image Rank B: It is slightly difficult to see the dot density 5% position. Rank C: It is difficult to see the dot density 10% position. Rank D: It is difficult to see the dot density 20% position. , Ranks A and B are levels at which there is no practical problem.

<Production of Polyester> Production Example 1 (Polyester A) 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol and 0.09 part of magnesium acetate tetrahydrate were placed in a reactor, heated to an elevated temperature, and methanol was distilled off. A transesterification reaction was carried out, and it took 4 hours from the start of the reaction to raise the temperature to 230 ° C., thereby substantially terminating the transesterification reaction. Next, an ethylene glycol slurry containing 0.1 part of silica particles having an average particle diameter (d ₅₀ ) of 1.54 μm was added to the reaction system, and 0.04 part of ethyl acid phosphate and 0.01 part of germanium oxide were further added. After that, in 100 minutes, the temperature was increased to 280 ° C. and the pressure was increased to 15 mmHg.
Hg. After 4 hours, the pressure in the system was returned to normal pressure, and polyester A was obtained. The content of the silica particles of the polyester A was 0.1% by weight.

Production Example 2 (Polyester B) Production Example 1 was the same as Production Example 1, except that an ethylene glycol slurry containing 0.1 part of silica particles having an average particle diameter (d ₅₀ ) of 1.54 μm was not added to the reaction system. In the same manner as in the above, polyester B was obtained. Production Example 3 (Polyester C) In Production Example 2, the produced polyester B was dried,
0.4 parts of Diaresin Yellow F manufactured by Mitsubishi Chemical Corporation and 100 parts of Polyester B,
0.7 parts of S and 0.8 parts of the same Diaresin Blue H3G were mixed and extruded by a twin-screw extruder to obtain a colored polyester C.

Production Example 4 (Polyester D) In Production Example 2, the produced polyester B was dried,
0.8 parts of Diaresin Yellow F manufactured by Mitsubishi Chemical Corporation and 100 parts of Polyester B,
1.4 parts of S and 1.6 parts of Diaresin Blue H3G were mixed and extruded by a twin-screw extruder to obtain a colored polyester D.

Production Example 5 (Production of ITO powder) A surfactant (Twin 20 manufactured by Kishida Chemical Co., Ltd.) was added to a mixed aqueous solution of indium nitrate and tin sulfate (molar ratio = 9: 1) with respect to 1 wt% based on the mixed aqueous solution. After the addition, ammonia was added, and after coprecipitation of indium hydroxide and tin hydroxide,
The coprecipitate is heated at 500 ° C. in an oxidizing atmosphere, and the obtained powder is further subjected to a rotary kiln reactor in a nitrogen gas atmosphere for 2 hours.
Heat treatment at 50 ° C. for 60 minutes, partial deoxygenation treatment,
TO powder was obtained.

Production Example 6 (Coating Solution A) An acrylic resin was added to the ITO powder obtained in Production Example 5.
A solvent (xylene / MEK = 80/20) and a surfactant were prepared and dispersed in a sand mill for 24 hours to obtain an average particle size of 0.0
A coating solution A containing 65% by weight of 5 μm ITO particles was obtained. Production Example 7 (Coating Liquid B) A coating liquid B was obtained in the same manner as in Production Example 6, except that ITO powder was not contained.

Production Example 8 (Coating Liquid C) In Production Example 6, the average particle size was changed to 0.
A coating solution C was obtained in the same manner as in Production Example 6 except that 27 μm of titanium oxide particles were added. Example 1 80 parts of polyester A and 20 parts of polyester C were weighed and dry-blended, dried at 180 ° C. for 4 hours in an inert gas atmosphere, and dried at 290 ° C. by a melt extruder.
Extrusion at 4 ° C. and surface temperature of 4
It was cooled and solidified on a cooling roll set at 0 ° C. to obtain an unstretched sheet. The obtained sheet was stretched 3.2 times in the longitudinal direction at 85 ° C. Next, the film was guided to a tenter and set at 100 ° C.
After stretching 3.2 times in the transverse direction, heat fixation was performed at 230 ° C. to obtain a 25 μm colored polyester film. Subsequently, the coating liquid A was coated on one surface of the film with a Mayer bar so that the film thickness after drying was 1.8 μm, and dried at 100 ° C. to obtain a laminated polyester film.

Example 2 A laminated polyester film was obtained in the same manner as in Example 1, except that the coating solution A was coated so that the film thickness after drying was 0.8 μm. Example 3 A laminated polyester film was obtained in the same manner as in Example 1, except that the coating solution A was coated so that the film thickness after drying was 2.7 μm.

Example 4 A laminated polyester film was obtained in the same manner as in Example 1 except that polyester C was changed to polyester D. Comparative Example 1 A laminated polyester film was obtained in the same manner as in Example 1, except that coating liquid B was used instead of coating liquid A.

Comparative Example 2 A laminated polyester film was obtained in the same manner as in Example 4 except that coating liquid B was used instead of coating liquid A. Comparative Example 3 A laminated polyester film was obtained in the same manner as in Example 1, except that coating liquid C was used instead of coating liquid A. The results obtained above are shown in Table 1 below.

[0048]

[Table 4]

[0049]

The laminated polyester film according to the present invention described above has good transparency, ensures sharpness when an image is viewed through the film, and is excellent in heat ray cutting properties, and is used for automobile windows and train windows. Vehicle windows, such as airplane windows,
It is extremely useful when used by being attached to windows of buildings, etc., since it exhibits excellent effects such as energy saving and glass scattering prevention.

Claims (4)

[Claims] 1. A laminated polyester film comprising a polyester film colored with a dye or a pigment, and a resin layer containing metal-added metal oxide particles or metal oxide particles laminated on one surface of the polyester film. 2. The laminated polyester film according to claim 1, wherein the metal-added metal oxide particles are tin-added indium oxide particles or antimony-added tin oxide particles. 3. The laminated polyester film according to claim 1, wherein the metal oxide particles are indium oxide particles or tin oxide particles. 4. The laminated polyester film according to claim 1, wherein the resin layer is made of an active energy ray-curable resin.