JPH10157040A - Laminated polyester film for being stuck to automobile window - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain easily a laminated polyester film for being stuck to an automobile window which has an intermediate layer containing a dye having a light shielding property and a most exterior layer of excellent transparency by a method wherein the laminated polyester film is composed of an oriented polyester film equipped with specific characteristics. SOLUTION: A laminated polyester film for being stuck to an automobile window is an oriented polyester film composed of three or more layers, which satisfies simultaneously the formulae: CA/CB<=0.3, 0.02<=DA/DZ<=0.8, 0.005<=Ra<=0.05, H<=5. In the formulae, CA indicates a dye concentration in the most exterior layer (a dye concentration in the most exterior layer wherein the die concentration is higher when the dye concentration in the most exterior layer varies; %), CB indicates a dye concentration in the intermediate layer (an average value of respective layers excepting the most exterior layers on both sides when there are plurality of intermediate layers; %), DA indicates a sum of a most exterior layer thickness (μm), DZ indicates a thickness of total layer (μm), Ra indicates a center line average roughness on a film surface (μm), and H indicates a film haze of the total layers (%).

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 for attaching a vehicle window. More specifically, the present invention relates to a laminated polyester film for attaching to an automobile window having an intermediate layer containing a dye having a light-shielding property and an outermost layer having excellent transparency.

[0002]

[Prior art] Polyester film is excellent in heat resistance, water resistance, chemical resistance, mechanical strength, dimensional stability, etc., and has been used in various industrial applications, and its applications are expanding and diversifying. I have. With such diversification, the required characteristics have become more and more severe, but at present it has not been sufficiently satisfied. For example, in applications containing dyes such as automotive window application films, X-ray bluish films, display applications, mixing of colors,
Even if a good dye such as heat resistance and dispersibility is selected, the inside of the casting roll, longitudinal stretching roll and tenter will be contaminated during film production due to the sublimability of the dye, and other brands cannot be manufactured. turn into. for that reason,
Actually, the above-mentioned colored film cannot be manufactured, or even if manufactured, the cost is extremely high.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide easily a laminated polyester film for affixing an automobile window having an intermediate layer containing a dye having a light-shielding property and an outermost layer having excellent transparency. Things.

[0004]

Means for Solving the Problems As a result of intensive studies in view of the above-mentioned problems, the present inventor has found that even if a film containing a dye which easily sublimates is used, the film manufacturing process can be performed by adopting a specific film structure. It has been found that the dye can be prevented from sublimation and the transparency can be improved, and the present invention has been completed. That is, the gist of the present invention resides in an oriented polyester film comprising three or more layers, which simultaneously satisfies the following formulas (1) to (4).

[0005]

## EQU2 ## CA / CB ≦ 0.3 0.02 ≦ DA / DZ ≦ 0.8 0.005 ≦ Ra ≦ 0.05 H ≦ 5 (in the above formula) , CA is the dye concentration in the outermost layer (if the dye concentration in the outermost layer is different, the dye concentration in the outermost layer having the higher dye concentration;%), and CB is the dye concentration in the intermediate layer (there is a plurality of intermediate layers). In the case, the average value of each layer excluding the outermost layers on both sides;
%), DA is the sum of the outermost layer thicknesses (μm), DZ is the thickness of all layers (μm), and Ra is the center line average roughness of the film surface (μm).
m), H represents the film haze (%) of all layers)

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
As the laminated polyester referred to in the present invention, a polyester obtained by extruding a layer extruded by a co-extrusion method in which all layers are co-melt extruded from a die and then heat-fixing as necessary is preferable.
Hereinafter, a film having a three-layer structure will be described as a laminated polyester film. However, the laminated polyester film in the present invention is not limited to a three-layer polyester film as long as it satisfies the configuration, and is a multilayer of three or more layers. Is also good. In the present invention, the polymer constituting each layer of the multilayer film is exemplified by a polyester obtained by using an aromatic dicarboxylic acid or an ester thereof and a glycol as a main starting material.
The above is ethylene terephthalate unit or ethylene-
Polyesters having 2,6-naphthalate units are preferred. Other third components may be contained within the above range.

As the aromatic dicarboxylic acid component, in addition to terephthalic acid and 2,6-naphthalenedicarboxylic acid,
For example, isophthalic acid, phthalic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, p-oxyethoxybenzoic acid, etc.) can be used. As the glycol component, in addition to ethylene glycol, for example, one or more of diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, and the like can be used. In the film of the present invention, the outermost layer is a layer constituting two exposed surfaces, and the other layers are called intermediate layers. The limiting viscosity (IV) of the polyester composition constituting the outermost layer and the intermediate layer is usually 0.52 to 0.75, preferably 0.55 to 0.70, and more preferably 0.5 to 0.70.
8 to 0.67. If the IV value is less than 0.52, the heat resistance and mechanical strength of the film tend to be poor. On the other hand, when the IV value exceeds 0.75, the negative value becomes too large in the extrusion step during the production of the polyester film, and as a result, the productivity may be reduced.

The dye concentration (CA) of the outermost layer in the present invention.
The ratio (CA / CB) of the dye to the dye concentration (CB) of the intermediate layer is 0.3 or less, preferably 0.1 or less, and more preferably 0.05 or less. When CA / CB exceeds 0.3,
The dye tends to sublimate during the film manufacturing process, which causes contamination of the film forming line, which is not preferable. When the dye concentration in the outermost layer is different, the dye concentration in the outermost layer having the higher dye concentration is CA, and when there are a plurality of intermediate layers, the average value of each layer excluding the outermost layers on both sides is CB. And

In the present invention, the ratio (DA / DZ) between the sum of the outermost layer thicknesses (DA) and the thickness of all layers (DZ) is 0.02.
-0.8, preferably 0.08-0.6, and more preferably 0.15-0.5. If DA / DZ is less than 0.02, it is not preferable because sublimation of the dye in the intermediate layer cannot be sufficiently prevented during the heat-setting treatment during the film forming process. On the other hand, when DA / DZ exceeds 0.8, the intermediate layer becomes thin, and the content of the dye becomes too large to obtain a film having high light-shielding properties. As a result, the intrinsic viscosity of the polyester decreases, It is not preferable because the properties of the film itself are lost, the thickness of the intermediate layer becomes uneven, and color unevenness occurs. In addition, the film thickness of all the layers of the laminated polyester film of the present invention is usually 10 to 50 μm, generally 25 μm.

The Ra (center line average roughness) of the film surface of the present invention is 0.005 to 0.05 μm, preferably 0.1 to 0.05 μm.
01 to 0.04 μm. If the Ra is less than 0.05 μm, the film surface is undesirably flawed or rolled in the film forming step. On the other hand, when Ra exceeds 0.05 μm, the degree of surface roughening of the film becomes too large, and the transparency of the film is impaired. The film haze in the present invention is 5% or less, preferably 4% or less, and more preferably 2% or less.
% Or less. When the film haze exceeds 5%, the opaque feeling becomes strong when used as an automotive window film, which is not preferable.

The dye contained in the intermediate layer of the present invention is preferably considered in consideration of the heat resistance during the production of the polyester and the dispersibility in the polyester. From the viewpoint of the chemical structure, anthraquinone dyes and phthalocyanine dyes are preferred. Dyes and the like are preferred, and disperse dyes and oil-soluble dyes are suitable for dyeing. These dyes are generally used by appropriately selecting and mixing several kinds, and the content in the raw material polyester is preferably in the range of 0.01 to 10% by weight. For the outermost layer of the laminated film of the present invention, to improve workability such as a winding step during film production and a coating during automobile window film production, laminating step, etc. It is preferable to impart a lubricating property, and for that purpose, fine inert particles may be added to the film.

The fine inert particles used in the present invention have an average particle size of 0.5 to 3.0 μm, more preferably 0.8 to 3.0 μm.
It is preferably 2.0 μm. Particles having an average particle size of less than 0.5 μm tend to have poor workability. If the average particle size exceeds 3.0 μm, the planarity of the film surface may be impaired, or the transparency may be impaired. Further, the addition amount of the inert particles is usually 0.005 to 1.0% by weight, preferably 0.01 to 0.7% by weight. If the amount of the inert particles is less than 0.005% by weight, the winding properties of the film tend to be poor. On the other hand, when the amount of the inert particles exceeds 1.0% by weight, the degree of surface roughening of the film becomes too large, and the transparency of the film tends to be impaired.

Examples of the inert particles that can be used in the present invention include silicon oxide, titanium oxide, zeolite, silicon nitride, boron nitride, celite, alumina, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, and barium sulfate. , Calcium phosphate, lithium phosphate, magnesium phosphate, lithium fluoride, aluminum oxide, silicon oxide, titanium oxide, kaolin, talc, carbon black, silicon nitride, boron nitride and those described in JP-B-59-5216. Examples of the crosslinked polymer fine powder include, but are not limited to, these. In the present invention, the inert particles to be blended may be a single component, or two or more components may be used simultaneously. In addition, in the present invention, the method for incorporating the inert particles and the dye into the polyester is not particularly limited, a method of adding to the polymerization step, a method of kneading the particles and the dye using an extruder and a master batch. Etc. are adopted.

In order to use the film of the present invention for application to automobile windows, it is preferable to provide a coating layer having an adhesive property to the hard coat layer. However, also in that case, it is preferable that Ra and H of the film satisfy the above conditions. The coating layer forming agent is not particularly limited, and may be a water-soluble or water-dispersible polyester composition, a polyurethane composition, a polyacryl composition,
Styrene-butadiene copolymer and acrylonitrile-butadiene copolymer are preferred. When a coating layer is provided on the film of the present invention, it is preferable that sticking between the films, that is, so-called blocking is small.
If there is blocking, the film sticks when winding and slitting after film formation, and in extreme cases, the film may be broken.

[0015] The blocking properties and water resistance of the above coating layer,
A crosslinking agent may be contained for improving solvent resistance and mechanical strength. Examples of the crosslinking agent include methylolated or alkylolated urea-based, melamine, guanamine-based, alkylamide-based, polyamide-based compounds, epoxy compounds,
Oxazoline compounds, aziridine compounds, blocked isocyanate compounds, silane coupling agents, dialcohol aluminate coupling agents, zircoaluminate coupling agents, peroxides, heat or photoreactive vinyl compounds and photosensitive resins. No. In the present invention, the coating layer may contain particles for improving the slipperiness of the coating layer. Examples of the particles include inert inorganic particles such as colloidal silica, alumina, calcium carbonate, and titanium dioxide, and fine particles obtained from a polystyrene-based resin, a polyacryl-based resin, and a polyvinyl-based resin, or organic particles represented by cross-linked particles thereof. You. The coating liquid used to obtain the coating layer may be, if necessary, a defoaming agent, a coating improver, a thickener, a low-molecular antistatic agent, an organic lubricant, an antioxidant, an ultraviolet absorber, a foaming agent. Agents, dyes, pigments and the like.

Further, the coating liquid may contain a small amount of an organic solvent for the purpose of improving dispersion in water or improving film forming performance as long as water is used as a main medium. When the organic solvent is used by mixing with water as a main medium, it is preferable to use the organic solvent within a range that dissolves in water. Examples of the organic solvent include aliphatic or alicyclic alcohols such as n-butyl alcohol, n-propyl alcohol, isopropyl alcohol, ethyl alcohol, and methyl alcohol; glycols such as ethylene glycol, propylene glycol, and diethylene glycol; and n-butyl. Cellsolve, Ethylcellsolve, Methylcellsolve,
Glycol derivatives such as propylene glycol monomethyl ether, ethers such as dioxane and tetrahydrofuran, esters such as ethyl acetate and amyl acetate, ketones such as methyl ethyl ketone and acetone, and amides such as N-methylpyrrolidone, and the like. It is not limited. These organic solvents may be used alone or in combination of two or more as necessary.

When a coating layer is provided on the film of the present invention,
The thickness is usually 0.02
It is 0.5 μm, preferably 0.01 to 0.3 μm, more preferably 0.03 to 0.2 μm. When the thickness of the coating layer is more than 0.5 μm, the films are likely to block each other, and particularly when the stretched coated film is redrawn for the purpose of increasing the strength of the film, the film adheres to the roll during the process. May be easier. If the thickness of the coating layer is less than 0.02 μm, the effect of improving the adhesiveness tends to be small.

The film may be subjected to a chemical treatment or a discharge treatment before the application in order to improve the coating property and adhesion of the coating agent to the film. Further, in order to improve the surface characteristics of the coating layer of the biaxially stretched film of the present invention, the surface of the coating layer may be subjected to a discharge treatment after the formation of the coating layer. As a method of forming the coating layer, there are a method of forming the biaxially stretched film at the time of manufacturing the film and a method of forming the film after the biaxial stretching, and the former is more preferable. As a specific example of the former, for example, after a thin film forming liquid is applied to the surface of an unstretched film, the film is stretched by a biaxial method. Alternatively, a method of applying a thin film-forming liquid to the surface of a uniaxially stretched film and then stretching the film in the perpendicular direction may be mentioned, but a method of using these in combination is also suitable.

When the stretching treatment is not performed after the application, the adhesion between the formed coating layer and the base film tends to be weak, and the adhesion suitable for practical use may not be obtained. In order to achieve these industrially advantageously, it is preferable to apply in the manufacturing process of the biaxially stretched film, but it is not limited thereto. As a method of applying the above-mentioned coating liquid to a polyester film, Yuji Harazaki, Maki Shoten,
A reverse roll coater, a gravure coater, a rod coater, an air doctor coater, and the like shown in “Coating System” published in 1979 can be used.
The method for producing a laminated film of the present invention will be specifically described, but is not particularly limited to the following examples as long as the constitutional requirements of the present invention are satisfied.

The polyester containing a predetermined amount of the dye (for the intermediate layer) and the polyester containing the predetermined amount of the inert particles (for the outermost layer) as necessary (for the outermost layer) are supplied to separate melt extrusion devices, and the respective polymer Heat to a temperature above the melting point and melt. Next, the molten polymer was joined and laminated in a laminar flow form in an extrusion die and extruded from a slit-shaped die.
It is quenched and solidified to a temperature equal to or lower than the glass transition temperature on a rotating cooling drum to obtain a substantially amorphous unoriented sheet. In this case, in order to improve the flatness of the sheet, it is preferable to increase the adhesion between the sheet and the rotary cooling drum. In the present invention, the electrostatic application adhesion method and / or the liquid application adhesion method are preferably employed.

In the present invention, the sheet thus obtained is biaxially stretched to form a film. The stretching conditions are specifically described as follows. Preferably, the unstretched sheet is stretched 2 to 6 times at 70 to 145 ° C in the machine direction to form a longitudinally uniaxially stretched film, and then at 90 to 160 ° C in the transverse direction.
It is preferred that the film be stretched up to 6 times and heat-treated at 150 to 250 ° C for 1 to 600 seconds. Further, at this time, in the maximum temperature zone of the heat treatment and / or the cooling zone at the outlet of the heat treatment, 0.1% in the longitudinal direction and / or the transverse direction.
A method of relaxing by about 20% is preferred. Further, re-longitudinal stretching and re-lateral stretching can be added as necessary.

When the laminated film of the present invention is processed into a film to be applied to an automobile window, it is necessary to improve properties required according to the required properties, for example, adhesion, antistatic properties, weather resistance and surface hardness. After completion of the longitudinal stretching, so-called in-line coating may be performed in which the coating is performed before the entrance of the tenter for the transverse stretching and the coating is dried in the tenter. In addition, various coatings may be performed by offline coating after the production of the laminated film. Such a coat may be on one side or both sides. As the material for the coating, any of an aqueous system and / or a solvent system may be used in the case of off-line coating, but an aqueous system or an aqueous dispersion system is preferable in the case of in-line coating.

[0023]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention. The methods for measuring physical properties used in the present invention are shown below. (1) Viscosity (IV) 1 g of polymer was prepared by mixing phenol / tetrachloroethane = 1 /
It was dissolved in 100 ml of a 1 (weight ratio) mixed solvent and measured at 30 ° C. (2) Lamination Thickness of Film A small piece of film was fixed and molded with an epoxy resin, cut with a microtome, and a cross section of the film was observed with a transmission electron microscope photograph. Of the cross sections, two are substantially parallel to the film surface, and the interface is observed by light and dark. The distance between the two interfaces and the film surface was measured from ten photographs, and the average value was defined as the lamination thickness.

(3) Average particle size: Centrifugal sedimentation type particle size distribution analyzer SA- manufactured by Shimadzu Corporation
The particle size was measured using a CP3 type by the sedimentation method based on Stokes' resistance law. The average particle size was determined using a value of 50% of the integrated (volume basis) in the equivalent spherical distribution of the particles obtained by the measurement. (4) Center line average roughness (Ra) According to the method described in Japanese Industrial Standard JIS B0601, a surface roughness measuring instrument (SE-3) manufactured by Kosaka Laboratory Co., Ltd.
Using F), the center line average roughness of the film surface (Ra)
I asked. The tip radius of the stylus is 2 μm and the load is 30
mg and the cutoff value was 0.08 mm.

(5) Film haze According to JIS-K7105, the turbidity of the film was measured with an integrating sphere turbidity meter NDH-300A manufactured by Nippon Denshoku Industries Co., Ltd. (6) Color spot The visible light transmittance in the width direction of the film was measured according to JIS-A5759.
10 points were measured at intervals of 10 cm according to the method described in the above, and color spots were determined according to the following criteria. : Tv (min) / Tv (max) ≦ 2% ×: Tv (min) / Tv (max)> 2% (However, the visible light transmittance was 10c in the width direction of the film.)
When measuring 10 points at m intervals, the minimum value of the visible light transmittance is defined as Tv (min) and the maximum value is defined as Tv (max).)

(7) Adhesion to Hard Coat Layer A hard coat agent having the following composition was applied to the polyester film surface using a # 20 bar, dried at 90 ° C. for 1 minute to remove the solvent, and then subjected to 120 watts with a high pressure mercury lamp. / Cm, an irradiation distance of 15 cm, and a 9 μm hard coat layer were formed under the conditions of 10 m / min. Next, a cross cut was made on the hard coat layer so as to have 100 cross-cuts with a width of 1 inch.
Perform a peel test using the 0 degree pull-out method (pulling speed: 2
Inch / min), and the adhesion was evaluated according to the following criteria. : Cross section peeling ≦ 5 pieces △: 5 <cross section peeling <20 pieces ×: cross section peeling ≦ 20 pieces

[Hard Coating Composition] Seika Beam EXY-26 (S) (manufactured by Dainichi Seika Kogyo Co., Ltd.) 30 parts Methyl ethyl ketone 35 parts Toluene 35 parts

{Production of Polyester-A} Starting with 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol, 0.09 part by weight of magnesium acetate tetrahydrate was placed in a reactor as a catalyst, and the reaction starting temperature was raised to 150 parts.
C., and the reaction temperature was gradually increased with the removal of methanol by distillation. After 4 hours, the transesterification reaction was substantially completed. 0.04 parts of ethyl acid phosphate, 0.04 parts of antimony trioxide, and silica particles having an average particle size of 1.85 μm were added to the reaction mixture.
After adding 05 parts by weight, a polycondensation reaction was carried out for 4 hours. That is, the temperature was gradually raised from 230 ° C. to 280 ° C. On the other hand, the pressure gradually decreases from the normal pressure and finally reaches 0.1.
It was 3 mmHg. After 4 hours from the start of the reaction, the reaction was stopped and the polymer was discharged under nitrogen pressure. The viscosity of the obtained polyester was 0.65.

Polyester-B and polyester-
Production of B1 In the production of Polyester-A, a method similar to that of Polyester-A was used except that 0.05 parts by weight of silica particles having an average particle size of 1.85 μm were not added and the polycondensation reaction was performed for 3 hours and 15 minutes. Polyester-B was obtained. The viscosity of the obtained polyester was 0.53. Polyester-B was subjected to solid-state polymerization at 225 ° C.-0.3 mmHg for 15 hours. The viscosity of the obtained polyester-B1 was 0.78. << Production of Polyester-C >> Polyester-B1 10
After drying 0 parts by weight, 0.4 parts by weight of Diaresin Red HS, 0.8 parts by weight of Blue H3G and 0.3 parts by weight of Yellow F manufactured by Mitsubishi Chemical Corporation are melt-kneaded with a vented twin-screw extruder. Then, polyester-C was obtained. The viscosity of the obtained polyester was 0.61.

{Production of Polyester-D} In the production of Polyester-A, the average particle size was 3.24 μm instead of 0.05 parts by weight of silica particles having an average particle size of 1.85 μm.
Polyester-D was obtained in the same manner as in Polyester-A, except that the silica particles were 0.05 parts by weight. {Production of Polyester-E} In the production of Polyester-A, 0.05% of silica particles having an average particle size of 1.85 μm were used.
Polyester-E was obtained in the same manner as for polyester-A, except that 0.2 parts by weight of silica particles having an average particle size of 1.85 μm was used instead of parts by weight.

Example 1 Polyester-C was dried at 180 ° C. for 4 hours and dried at 285 ° C.
In the main extruder set to
It was fed to a sub-extruder set at 5 ° C. After the polymer of the sub-extruder is branched into the front and back two layers (outermost layer) of the film, it is combined with the polymer from the sub-extruder by a feed block through a gear pump and a filter, and extruded into a sheet. Using a set rotating cooling drum, it is quenched and solidified using the electrostatic application cooling method, and has a thickness of 342 μm.
A substantially amorphous sheet was obtained. The obtained amorphous sheet was stretched 3.6 times at 83 ° C. in the longitudinal direction and 3.8 times at 90 ° C. in the transverse direction, and then subjected to a heat treatment at 225 ° C. for 3 seconds.
3μm / 19μm / 3μm thickness configuration and total thickness 25μ
m was prepared.

Example 2 In Example 1, after stretching 3.6 times in the longitudinal direction at 83 ° C., 65 parts by weight of a polyurethane-based resin (Dai Nippon Ink's [Hydran AP-40]), polyester Resin (Dainippon Ink [Fine-Tex ES
-670]), 20 parts by weight, a melamine-based cross-linking agent (10 parts by weight from Dainippon Ink [Beckamine J-101], colloidal silica (Nissan Chemical Industries [Snowtex YL])) 5
A water-based paint consisting of parts by weight is applied with a coating thickness of 0.1 after drying.
A biaxially stretched film was produced in the same manner as in Example 1 except that the film was applied to a thickness of μm and stretched 3.8 times in the transverse direction at 93 ° C.

Comparative Example 1 The procedure of Example 1 was repeated except that 33 parts by weight of polyester-A and 67 parts by weight of polyester-C were used instead of polyester-A, and the mixture was fed to a sub-extruder set at 285 ° C. A biaxially stretched film was produced in the same manner as in Example 1. Comparative Example 2 A biaxially stretched film was produced in the same manner as in Example 1, except that the thickness composition ratio of the laminated polyester film was changed to 0.1 μm / 24.8 μm / 0.1 μm.

Comparative Example 3 A biaxially stretched film was produced in the same manner as in Example 1, except that the thickness ratio of the laminated polyester film was changed to 11 μm / 3 μm / 11 μm. Comparative Example 4 A biaxially stretched film was produced in the same manner as in Example 1 except that polyester-D was used instead of polyester-A, and was fed into a sub-extruder set at 285 ° C. did.

Comparative Example 5 Biaxial stretching was carried out in the same manner as in Example 1 except that polyester-E was used instead of polyester-A, and was fed into a sub-extruder set at 285 ° C. A film was produced. The properties of the obtained biaxially stretched polyester film are summarized in Table 1 below.

[0036]

[Table 1]

[0037]

According to the present invention, it is possible to easily provide a laminated polyester film for affixing an automobile window having an intermediate layer containing a dye having a light-shielding property and an outermost layer having excellent transparency. The industrial value is high.

Claims (2)

[Claims] An oriented polyester film comprising three or more layers, wherein the laminated polyester film satisfies the following formulas at the same time. ## EQU1 ## CA / CB≤0.3 0.02≤DA / DZ≤0.8 0.005≤Ra≤0.05 H≤5 (in the above formula) , CA is the dye concentration in the outermost layer (if the dye concentration in the outermost layer is different, the dye concentration in the outermost layer having the higher dye concentration;%), and CB is the dye concentration in the intermediate layer (there is a plurality of intermediate layers). In the case, the average value of each layer excluding the outermost layers on both sides;
%), DA is the sum of the outermost layer thicknesses (μm), DZ is the thickness of all layers (μm), and Ra is the center line average roughness of the film surface (μm).
m), H represents the film haze (%) of all layers) 2. The surface of at least one outermost layer of the laminated polyester film for automobile windows according to claim 1,
A laminated polyester film for attaching to an automobile window, comprising a coating layer having easy adhesion to a hard coat layer.