JPH10230577A - Oriented laminate polyester film for sticking on automobile window - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oriented laminate polyester film for sticking on an automobile window which has an intermediate layer containing dye, wherein sublimation of the dye in a film manufacturing process is suppressed and, moreover, which is excellent in working properties on the occasion of sticking on curved surface glass of an automobile. SOLUTION: This film is composed of three or more layers and has an intermediate layer containing dye. The ratio of the dye concentration (CA) in the outermost layer to the dye concentration (CB) in the intermediate layer is 0.5 or below and the ratio of the sum (DA) of the thickness of the outermost layer to the thickness (DZ) of the layers as a whole is 0.02-0.8, while a heat shrinkage factor (SMD) of the film in the longitudinal direction and the heat shrinkage factor (STD) thereof in the lateral direction at the time of heat treatment for five minutes at a temperature of 180 deg.C are 1.0-5.0% and 2.0% or below respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oriented laminated polyester film for automobile windows, and more particularly to an oriented laminated polyester film for automobile windows having a dye-containing intermediate layer.

[0002]

2. Description of the Related Art Recently, a laminated polyester film having a dye-containing intermediate layer has attracted attention for use in affixing to an automobile window. In such a laminated film, even if a dye having good heat resistance is selected, there is a problem that a casting roll, a longitudinal stretching roll, and a tenter are contaminated during film production due to the sublimation property of the dye.

[0003] The present inventor has sought to solve the above problem.
An intermediate layer is a layer containing a dye, the outermost layers are layers containing no dye, and both of the following formulas are simultaneously satisfied: A polyester film has been proposed (JP-A-8-230126).

[0004]

## EQU00003 ## 0.02.ltoreq.IB-IA.ltoreq.0.10 0.05.ltoreq.dA / dB.ltoreq.0.45 0.05.ltoreq.TA / TB.ltoreq.0.60 (in the above formula) , IA is the viscosity of the polyester composition constituting the intermediate layer, IB is the viscosity of the polyester composition constituting the outermost layer, dA is the thickness of the intermediate layer (μm), dB is the thickness of the outermost layer (μm), TA Is the visible light transmittance (%) of the intermediate layer, TB
Represents the visible light transmittance (%) of the outermost layer. )

The thickness of the intermediate layer of the above-mentioned laminated film is 10.5 μm / 4 μm / 10.5 μm
In accordance with the above equation, the thickness is reduced as compared with each outermost layer. This is based on the reason that the dye-containing intermediate layer is sandwiched between the relatively thick outermost layers to suppress the sublimation of the dye.

However, in the case of a laminated film based on the above-described concept of reducing the thickness of the intermediate layer, the following problems are involved. That is, in the thin intermediate layer, the concentration of the dye necessary for obtaining a film having a high light-shielding property increases, and as a result, the film haze increases due to the turbidity caused by the precipitation of the undissolved dye.

On the other hand, the method of attaching the above-mentioned laminated film to the curved glass of an automobile is mainly a method of attaching a single sheet which is superior in terms of cost reduction and appearance from the conventional method of attaching several laminated films cut into strips. It is becoming. In this case, it is necessary to prevent the generation of wrinkles during laminating the laminated film to an automobile window. However, the laminated film proposed by the above-mentioned publication discloses an improvement in preventing the generation of wrinkles during the laminating. Absent. And. In addition, such a laminated film is required to be more excellent in transparency.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress the sublimation of a dye in a film manufacturing process and to improve the workability in attaching to a curved glass of an automobile. An object of the present invention is to provide an oriented laminated polyester film for attaching an automobile window, which has excellent performance.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventor has found that a specific layer structure can suppress dye sublimation in a film production process, and that the film can be formed into a film having specific properties to improve workability. Gained the knowledge that it could be improved,
The present invention has been completed.

That is, the gist of the present invention resides in an oriented laminated polyester film for application to an automobile window, comprising at least three layers, having a dye-containing intermediate layer, and simultaneously satisfying the following formulas:

[0011]

CA / CB ≦ 0.5 0.02 ≦ DA / DZ ≦ 0.8 1.0 ≦ SMD ≦ 5.0 STD ≦ 2.0 (above) In the formula, CA is the dye concentration in the outermost layer on both sides (however, when 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. (However, when there are a plurality of intermediate layers, the average value of each layer excluding the outermost layers on both sides;%), DA is the sum of the thickness of each outermost layer (μm), DZ is the thickness of all layers (μm), SMD is 180 ° C
Heat shrinkage (%) in the longitudinal direction of the film during heat treatment for 5 minutes
STD represents the heat shrinkage (%) in the transverse direction of the film during the heat treatment at 180 ° C. for 5 minutes. )

The laminated film according to a preferred embodiment of the present invention further satisfies the following formulas from the viewpoint of improving transparency.

## EQU00005 ## where 0.005.ltoreq.Ra.ltoreq.0.05... H.ltoreq.5 (where Ra is the center line average roughness of the film surface (.mu.
m) and H represent the film haze (%) of all layers. )

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The laminated polyester film in the present invention can be obtained by stretching a sheet obtained by a co-extrusion method and then heat-setting as necessary. Hereinafter, a film having a three-layer structure will be described as an example.

As the polyester, a polyester obtained by using an aromatic dicarboxylic acid or an ester thereof and a glycol as main starting materials is used, and at least 80% of the repeating structural units contain an ethylene terephthalate unit or an ethylene-2,6-naphthalate unit. Is preferred. Such polyesters may contain other third components.

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, other than ethylene glycol, for example, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol,
One or more of neopentyl glycol and the like can be used.

In 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 in each layer is usually 0.52
To 0.75, preferably 0.55 to 0.70, and more preferably 0.58 to 0.67. When the IV value is less than 0.52, it is difficult to obtain a film having excellent heat resistance, mechanical strength, and the like. When the IV value exceeds 0.75, the load becomes too large in the extrusion process during film production. May reduce productivity.

The thickness of all layers of the laminated film of the present invention is usually 10 to 50 μm, preferably about 25 μm.

In the laminated film of the present invention, the ratio (C) between the dye concentration (CA) of the outermost layer and the dye concentration (CB) of the intermediate layer is determined.
(A / CB) is 0.5 or less, preferably 0.3 or less, more preferably 0.1 or less, and particularly preferably 0.05 or less. When CA / CB is more than 0.5, the dye is liable to sublimate in the film manufacturing process, so that the film forming line is contaminated.

In the laminated film of the present invention, the ratio (DA / DZ) of the sum (DA) of the thickness of each outermost layer to the thickness (DZ) of all the layers is preferably 0.02 to 0.8, Is 0.08
-0.6, more preferably 0.15-0.5. D
When A / DZ is less than 0.02, sublimation of the dye in the intermediate layer cannot be sufficiently suppressed during the heat setting treatment during the film forming process.
When DA / DZ exceeds 0.8, the intermediate layer becomes thin, and the content of the dye necessary for obtaining a film having high light-shielding properties becomes too large. As a result, the film haze increases due to the turbidity caused by the precipitation of undissolved dye, the intrinsic viscosity of the polyester decreases, the properties of the polyester itself are lost, and the thickness of the intermediate layer becomes uneven, and the color is reduced. Spots occur.

The dye contained in the intermediate layer is preferably an anthraquinone dye or a phthalocyanine dye in terms of heat resistance and dispersibility in terms of chemical structure, and is preferably a disperse dye or an oil-soluble dye in terms of dyeing. It is. In general, these dyes are appropriately selected and used in a mixture of several kinds, and the content in the polyester is preferably 0.01 to 10% by weight.

The outermost layer of the laminated film of the present invention is made of an inert material in order to improve the workability of a winding process during film production, a coating process such as a hard coat layer described later, and a laminating process to an automobile window. It is preferable that the surface is roughened by adding fine particles to impart an appropriate slip property to the film.

The average particle size of the inert fine particles used is usually 0.5 to 3.0 μm, preferably 0.8 to 2.0 μm. When the average particle size is less than 0.5 μm, the workability tends to be inferior, and when the average particle size exceeds 3.0 μm,
The flatness and transparency of the film surface may be impaired. The addition amount of the inert fine particles is usually 0.005 to 1.0.
% By weight, preferably 0.01 to 0.7% by weight. When the addition amount is less than 0.005% by weight, the winding properties of the film tend to be inferior, and when the addition amount exceeds 1.0% by weight, the degree of surface roughening of the film becomes too large, Transparency tends to be impaired.

Specific examples of the inert fine particles include silicon oxide, titanium oxide, zeolite, silicon nitride, boron nitride, celite, alumina, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, calcium phosphate, and lithium phosphate. , Magnesium phosphate, lithium fluoride, aluminum oxide, silicon oxide, titanium oxide, kaolin, talc, carbon black, silicon nitride, boron nitride and JP-B-59-521
No. 6, a crosslinked polymer fine powder as described in JP-A No. 6-No. The inert fine particles may be used in combination of two or more components.

The method of incorporating the inert particles and the dye into the polyester is not particularly limited, but a method of adding the particles and the dye to a polymerization process and a method of kneading the particles and the dye into a master batch using an extruder are employed. .

The laminated film of the present invention is practically used by providing a hard coat layer on the outermost layer on the front side when laminated to an automobile window. The hard coat layer is used in various fields to improve the scratch resistance and the like, and as a polymer for forming the hard coat layer, various photopolymerizable polymers represented by an acrylic resin and the like are known.

When the hard coat layer as described above is formed directly on the surface of a polyester film, the adhesiveness may be poor. Therefore, in the laminated film of the present invention, it is preferable to provide a coating layer having easy adhesion to the hard coat layer. As the coating layer forming agent, a water-soluble or water-dispersible polyester composition, a polyurethane composition, a polyacrylic composition, a styrene-butadiene copolymer, an acrylonitrile-butadiene copolymer, and the like are preferable.

The above coating layer may contain a cross-linking agent for improving blocking properties, water resistance, solvent resistance and mechanical strength. Crosslinking agents 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 aluminum Examples include a nate-based coupling agent, a zircoaluminate-based coupling agent, a peroxide, a thermally or photoreactive vinyl compound, and a photosensitive resin.

The above-mentioned coating layer may contain fine particles in order to improve the slipperiness. Such fine particles may be either inert inorganic particles or organic particles. Examples of the inert inorganic particles include colloidal silica, alumina, calcium carbonate, titanium dioxide, and the like, and examples of the organic particles include fine particles obtained from a polystyrene resin, a polyacrylic resin, and a polyvinyl resin or crosslinked particles thereof. Can be

The coating solution for obtaining the coating layer may be, if necessary, an antifoaming agent, a coating improver, a thickener, a low-molecular antistatic agent, an organic lubricant, an antioxidant, an ultraviolet absorber. , A foaming agent, a dye, a pigment, and the like. Furthermore, when water is used as the main medium, 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. The organic solvent is preferably used in an amount 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, and glycols such as ethylene glycol, propylene glycol and diethylene glycol. , N-butyl cellosolve, ethyl cellosolve, methyl cellosolve, glycol derivatives such as propylene glycol monomethyl ether, dioxane, ethers such as tetrahydrofuran, ethyl acetate, esters such as amyl acetate, methyl ethyl ketone, ketones such as acetone, Amides such as N-methylpyrrolidone are exemplified.
These organic solvents may be used in combination of two or more as necessary.

The thickness of the coating layer is usually 0.02 to 0.5 μm, preferably 0.01 to 0.3 μm, as a thickness after drying.
μm, and more preferably 0.03 to 0.2 μm. When the thickness of the coating layer is more than 0.5 μm, the films are liable to block each other, and particularly when the coated stretched film is re-stretched for increasing the strength of the film, the film easily sticks to the roll in the process. May be. When 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, 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. Specific examples of the former include, for example, a method in which a thin film forming liquid is applied to the surface of an unstretched film and then stretched in a biaxial method, or a method in which the thin film forming liquid is applied to a surface of a uniaxially stretched film and further stretched in a perpendicular direction. Method. A method of using these together is also suitable. As a coating method, a reverse roll coater, a gravure coater, a rod coater, an air doctor coater, or the like can be used.

The laminated film of the present invention has a heat shrinkage (SMD) of 1.0 to 5.0% in the longitudinal direction of the film and a heat shrinkage in the lateral direction of the film in order to improve the workability when affixed to curved glass of an automobile. The shrinkage (STD) is specified to be 2.0% or less. The preferred SMD is 1.5-4.0%, and the preferred STD is 1.5
% Or less. When SMD is less than 1.5% and 5.0
%, Wrinkles occur when the laminated film is attached to the curved glass of an automobile. When the STD exceeds 2.0%, the dimensional stability is deteriorated, and a gap is generated between the film and the glass when the laminated film is attached to the curved glass of an automobile.

In order to improve transparency, the laminated film of the present invention has Ra (center line average roughness) of the film surface of 0.5.
Preferably, the film haze (H) is 5% or less. Preferred Ra is 0.01 to
0.04 μm, preferably H is 4% or less, more preferably H
Is not more than 2%. When Ra is less than 0.05 μm,
If the film surface is scratched or rolled off during the film forming process, and if Ra exceeds 0.05 μm, the degree of surface roughening of the film surface becomes too large, and the transparency of the film is impaired. When H exceeds 5%, opacity becomes strong.

The laminated film of the present invention can be produced, for example, by the following method. First, a polyester blended with a predetermined amount of dye (for the intermediate layer) and a polyester blended with a predetermined amount of inactive particles as needed (for the outermost layer) are supplied to separate melt extrusion devices, respectively. It is heated and melted to a temperature higher than the melting point of polyester.

Next, the polyester is laminated in a laminar flow in an extrusion die, extruded from a slit-shaped die, quenched on a rotary cooling drum to a temperature below the glass transition temperature, and solidified. An unoriented sheet in an amorphous state is obtained. In this case, in order to improve the flatness of the sheet by increasing the adhesion between the sheet and the rotary cooling drum, the electrostatic application adhesion method and / or the liquid application adhesion method are preferably employed.

Next, the above-mentioned sheet is stretched biaxially to form a film. At this time, the film is stretched 2 to 6 times at 70 to 145 ° C in the longitudinal direction and then at 90 to 160 ° C in the transverse direction.
It is preferable to perform 6-fold stretching and perform heat treatment at 150 to 250 ° C. for 1 to 600 seconds. Furthermore, in the maximum temperature zone of the heat treatment and / or the cooling zone at the outlet of the heat treatment, it is preferable that the resin is relaxed in the longitudinal direction and / or the transverse direction by 0.1 to 20%. Further, if necessary, re-longitudinal stretching and re-horizontal stretching can be added.

[0039]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which can be modified in the technical field of the present invention without departing from the scope of the invention. In addition, the physical property measuring method is shown below.

(1) Viscosity (IV): 100 ml of a mixed solvent of phenol / tetrachloroethane = 1/1 (weight ratio)
Was dissolved in 1 g of the polymer, and measured at 30 ° C.

(2) Thickness of each layer of the film: A small piece of the film was fixed with an epoxy resin, cut with a microtome, and the cross section of the film was observed with a transmission electron microscope photograph. The interface is observed by two light and dark lines almost parallel to the film surface. The distance between the two interfaces and the film surface is 1
The measurement was performed from 0 photographs, and the average value was defined as the lamination thickness.

(3) Average particle size: Using a centrifugal sedimentation type particle size distribution analyzer (“SA-CP3 type” manufactured by Shimadzu Corporation), the particle size is measured by a sedimentation method based on Stokes' resistance law. did. The value of 50% integrated (by volume) in the equivalent spherical distribution of the particles obtained by the measurement was defined as the average particle size.

(4) Thermal shrinkage (SMD, STD): A 25 μm thick non-tension film was heat-treated in a 180 ° C. atmosphere for 5 minutes using a hot air circulating furnace (manufactured by Tabai Seisakusho). The length of the film before and after the heat treatment in the longitudinal direction (SMD) and in the transverse direction (STD) was measured, calculated by the following equation, and represented by the average value of five samples.

## EQU6 ## Heat shrinkage (%) = (l ₀ −l ₁ ) / l ₀ × 100 (where l ₀ is the sample length (mm) before heat treatment,
l ₁ represents the sample length (mm) after the heat treatment. If l ₀ is smaller than l ₁ (in the case of expansion), −
(Minus).

(5) Center line average roughness (Ra): Using a surface roughness measuring device (“SE-3F” manufactured by Kosaka Laboratory Co., Ltd.), the center line average roughness of the film surface is determined according to JIS-B0601. (Ra) was determined. The tip radius of the stylus is 2μ.
m, the load is 30 mg, and the cutoff value is 0.08 mm
And

(6) Film haze: Using an integrating sphere turbidity meter ("NDH-300A" manufactured by Nippon Denshoku Industries Co., Ltd.)
The turbidity of the film was measured according to JIS-K7105.

(7) Color spot: According to JIS-A5759,
The visible light transmittance is 1 at 10 cm intervals in the width direction of the film.
Measurement was performed at 0 points, and color spots were determined according to the following criteria.

○: Tv (min) / Tv (max) ≦ 2% ×: Tv (min) / Tv (max)> 2% (However, the minimum value of the visible light transmittance in the measured values is Tv.
(Min) and the maximum value is defined as Tv (max). )

(8) Workability: The condition of wrinkles and surrounding gaps when the film was attached to the curved glass of an automobile was observed, and workability was evaluated based on the following criteria.

[Table 2] ○: No wrinkles and the surrounding gaps are uniform ×: Wrinkles and the surrounding gaps are uneven

(9) Adhesion to Hard Coat (HC) Layer: First, a hard coat agent having the following composition was applied to the film surface with a # 20 bar and dried at 90 ° C. for 1 minute to remove the solvent. 120 w / cm output by high pressure mercury lamp,
Drying was performed under the conditions of an irradiation distance of 15 cm and a moving speed of 10 m / min to form a 9 μm hard coat layer. Next, a cross cut was made on the hard coat layer so as to have 100 grids of 1 inch width, and a peel test was performed by a 90-degree pull-out method (pulling speed: 2 inches / minute), and the adhesiveness was evaluated based on the following criteria. evaluated.

[Table 3] ：: Peeling of grid pattern ≤ 5 pieces △: 5 <Peeling of grid pattern <20 pieces ×: Peeling of grid pattern ≤ 20 pieces

[0049]

[Table 4] <Composition of hard coat agent>

<Production of Polyester (A)> 100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, and 0.09 parts by weight of magnesium acetate tetrahydrate as a catalyst were placed in a reactor, and the reaction starting temperature was 150 ° C. The reaction temperature was gradually increased with the removal of methanol, and the temperature was raised to 230 ° C. after 3 hours. After 4 hours, the transesterification reaction was substantially completed. 0.04 parts by weight of ethyl acid phosphate, 0.04 parts by weight of antimony trioxide were added to the reaction mixture.
4 parts by weight, silica particles having an average particle size of 1.85 μm 0.05
The polycondensation reaction was performed for 4 hours by adding a weight part. 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 0.3 mmH
g. 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.

<Production of Polyester (B) and Polyester (B1)> In the production of polyester (A),
A polyester having a viscosity of 0.53 was prepared in the same manner as in the case of the polyester (A) except that the polycondensation reaction was changed to 3 hours and 15 minutes without adding 0.05 parts by weight of silica particles having an average particle size of 1.85 μm. B) was obtained. -0.3 mmH at 225 ° C
The solid state polymerization of the polyester (B) was carried out for 15 hours under the conditions of g, to obtain a polyester (B1) having a viscosity of 0.78.

<Production of Polyester (C)> Using a vented twin-screw extruder, 100 parts by weight of dried polyester (B1) was added with 0.4% by weight of a red dye ("Diaresin Red HS" manufactured by Mitsubishi Chemical Corporation). Parts, 0.8 parts by weight of a blue dye ("Blue H3G" manufactured by Mitsubishi Chemical Corporation) and 0.3 parts by weight of a yellow dye ("Yellow F" manufactured by Mitsubishi Chemical Corporation) are melt-kneaded to obtain a polyester (C) having a viscosity of 0.61. ) Got.

<Production of Polyester (D)> In the production of polyester (A), an average particle size of 3.24 μm was used instead of 0.05 parts by weight of silica particles having an average particle size of 1.85 μm.
Of the polyester (D) in the same manner as in the case of the polyester (A) except that 0.05 parts by weight of silica particles of
I got

<Production of Polyester (E)> In the production of polyester (A), an average particle size of 1.85 μm was used instead of 0.05 parts by weight of silica particles having an average particle size of 1.85 μm.
A polyester (E) was obtained in the same manner as in the case of the polyester (A) except that 0.2 parts by weight of the silica particles was used.

Example 1 285 of polyester (C) dried at 180 ° C. for 4 hours
The polyester (A) was fed to a sub vented twin screw extruder set to 285 ° C. Front and back two layers of polyester (C) (outermost layer)
The polyester (A) is distributed and extruded into a sheet shape so as to be located at a position, and is rapidly cooled and solidified on a rotating cooling drum having a surface temperature of 30 ° C. by an electrostatic application cooling method to obtain an amorphous sheet having a thickness of 342 μm. . Next, the above 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, heat-treated at 225 ° C. for 3 seconds, and then 5% at 185 ° C. for 2 seconds. After relaxation treatment, a biaxially oriented film having a thickness of 3 μm / 19 μm / 3 μm and a total thickness of 25 μm was obtained.

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 (“Hydran AP-40” manufactured by Dainippon Ink Inc.) Resin (Finetex ES-6 manufactured by Dainippon Ink and Chemicals, Inc.)
70 "), 20 parts by weight, a melamine crosslinking agent (" Beckamine J-101 "manufactured by Dainippon Ink and Chemicals, Inc.), 10 parts by weight, colloidal silica (" Snowtex YL "manufactured by Nissan Chemical Industries, Ltd.)
5 parts by weight of a water-based paint has a coating thickness of 0.1 after drying.
A biaxially stretched film was obtained on one side 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 In Example 1, a sub-extruder set at 285 ° C. was used in place of the polyester (A), using a mixed polyester of 33 parts by weight of the polyester (A) and 67 parts by weight of the polyester (C). , And a biaxially stretched film was obtained in the same manner as in Example 1.

Comparative Example 2 In Example 1, each layer had a thickness of 0.1 μm / 24.8.
A biaxially stretched film was obtained in the same manner as in Example 1, except that the thickness was changed to μm / 0.1 μm.

Comparative Example 3 In Example 1, the thickness of each layer was changed to 11 μm / 3 μm / 1.
A biaxially stretched film was obtained in the same manner as in Example 1 except that the thickness was changed to 1 μm.

Comparative Example 4 In Example 1, biaxial stretching was performed in the same manner as in Example 1 except that after the transverse stretching, a heat treatment was performed at 240 ° C. for 3 seconds, and a relaxation treatment of 12% was performed at 185 ° C. for 2 seconds. A film was obtained.

Comparative Example 5 In Example 1, biaxial stretching was performed in the same manner as in Example 1 except that after the transverse stretching, a heat treatment was performed at 210 ° C. for 3 seconds, and a relaxation treatment of 12% at 185 ° C. was performed for 2 seconds. A film was obtained.

Comparative Example 6 A biaxially stretched film was obtained in the same manner as in Example 1, except that the heat treatment was performed at 225 ° C. for 3 seconds and then the relaxation treatment was omitted.

Reference Example 1 The procedure of Example 1 was repeated, except that the polyester (D) was used in place of the polyester (A), and the mixture was fed to a sub-extruder set at 285 ° C. An axially stretched film was obtained.

Reference Example 2 The procedure of Example 1 was repeated, except that the polyester (E) was used instead of the polyester (A), and the mixture was fed to a sub-extruder set at 285 ° C. An axially stretched film was obtained.

The properties of the obtained biaxially oriented polyester film are summarized in Table 1 below.

[0066]

[Table 5]

[0067]

According to the present invention, there is provided an oriented laminated polyester film having a dye-containing intermediate layer for application to an automobile window, in which the contamination by the dye during production thereof is suppressed, and the workability when applying the film to a curved glass of an automobile. The above-mentioned laminated film having excellent transparency and excellent transparency is provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 67:00 B29L 9:00

Claims (5)

[Claims] 1. An oriented laminated polyester film for attaching to an automobile window, comprising three or more layers, having an intermediate layer containing a dye, and simultaneously satisfying the following formulas: CA / CB ≦ 0.5 0.02 ≦ DA / DZ ≦ 0.8 1.0 ≦ SMD ≦ 5.0 STD ≦ 2.0 (above) In the formula, CA is the dye concentration in the outermost layer on both sides (however, when 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. (However, when there are a plurality of intermediate layers, the average value of each layer excluding the outermost layers on both sides;%), DA is the sum of the thickness of each outermost layer (μm), DZ is the thickness of all layers (μm), SMD is 180 ° C
Heat shrinkage (%) in the longitudinal direction of the film during heat treatment for 5 minutes
STD represents the heat shrinkage (%) in the transverse direction of the film during the heat treatment at 180 ° C. for 5 minutes. ) 2. The value of DA / DZ in the equation is 0.08-0.
The film according to claim 1, which is 6. 3. The ratio DA / DZ in the formula is 0.15 to 0.5.
The film according to claim 1, which is 5. 4. The film according to claim 1, which further satisfies the following formula: ## EQU2 ## where Ra is the center line average roughness of the film surface (μ
m) and H represent the film haze (%) of all layers. ) 5. The method according to claim 1, wherein a coating layer and a hard coat layer are sequentially provided on the surface of one outermost layer, and the coating layer is a coating layer having easy adhesion to the hard coat layer. The film according to any one of the above.