JP2000108285A - Laminated polyester film for transparent vapor deposition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated polyester film for transparent vapor deposition which is excellent in a gas barrier property. SOLUTION: In a film wherein a coated layer and a vapor deposition layer by a metal or a metallic oxide are successively laminated on a one surface of a biaxially oriented laminated polyester film, the biaxially oriented laminated polyester film is a film wherein a polyester layer A of under 50 mg/m2 of low molecular weight extractability by chloroform solvent, is laminated on at least one side of a polyester layer B. The coated layer is a transparent laminated polyester film for vapor deposition provided on a surface of the polyester layer A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent laminated polyester film formed by forming a metal or metal oxide. More specifically, the present invention relates to a laminated polyester film for transparent vapor deposition having excellent gas barrier properties.

[0002]

2. Description of the Related Art A film for transparent vapor deposition is selected from metals and / or metal oxides to be vapor-deposited to provide gas barrier properties, water impermeability, visible / ultraviolet light blocking properties, heat ray reflectivity, conductivity, and the like. Since various properties such as transparent conductivity and magnetic recording properties can be changed, they are used for various applications. For example, packaging materials, decorative materials, window glass shielding materials,
It is used for gold / silver thread materials, capacitor materials, display materials, wiring board materials, magnetic recording materials, and the like. In particular, in recent years, it has been used in a new application such as a liquid crystal display element, a solar cell, an electromagnetic wave shield, a touch panel, a substrate for an EL, and a part of a transparent conductive sheet used for a color filter, and has been attracting attention. Incidentally, in recent years, the film for transparent vapor deposition has been increasingly required to have improved gas barrier properties.

[0003]

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 provide a laminated polyester film for vapor deposition having excellent gas barrier properties.

[0004]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventor has found that a gas barrier is obtained by laminating a polyester film and reducing low molecular weight substances (oligomers and the like) generated from the surface of the film to be deposited. It was found that the properties were further improved, and the present invention was completed.

That is, the gist of the present invention is to provide a biaxially oriented laminated polyester film in which a coating layer and a deposited layer of metal or metal oxide are sequentially laminated on one side of the biaxially oriented laminated polyester film. Is a film obtained by laminating a polyester layer A having an extraction amount of a low-molecular-weight substance with a chloroform solvent of less than 50 mg / m ^{2 on} at least one surface of the polyester layer B, and the coating layer is provided on the surface of the polyester layer A. Characterized in that the laminated polyester film for transparent vapor deposition is characterized in that:

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
Examples of the laminated film in the present invention include a film obtained by stretching and heat-treating an unstretched film extruded by a so-called co-extrusion method in which all layers are co-melt extruded from a die of an extruder. Hereinafter, a co-extruded three-layer film will be described as a laminated film, but the present invention is not limited to a co-extruded three-layer film unless it exceeds the gist of the present invention. There may be. A two-layer three-layer film of A / B / A having the same front and back layers is also preferable. Among these, both surfaces are different 3
Seed three-layer films are particularly preferred.

The polyester constituting each layer of the laminated film of the present invention is a polyester obtained by using an aromatic dicarboxylic acid or its ester and glycol as main starting materials, and 80% or more of the repeating structural units are ethylene terephthalate units or Refers to a polyester having ethylene-2,6-naphthalate units. Further, 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,
4,4'-diphenyldicarboxylic acid and oxycarboxylic acid (for example, p-oxyethoxybenzoic acid and the like) can be used. On the other hand, as the glycol component, in addition to the ethylene glycol component, for example, diethylene glycol,
One or more of triethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, and the like can be used.

In the laminated film of the present invention, the layers forming both surface layers preferably contain particles. In the present invention, it is preferable that the transparency of the film is satisfied to a high degree, and that the film is provided with slipperiness. It is preferable that both the surface layers after lamination contain particles. Naturally, a film of three types and three layers (A / B / C) having different surface layers is suitably selected.
Only the structure of the seed two layers and the thickness of both surface layers were changed (A / B
/ A ') is also recommended.

The thickness of the surface layer of the film of the present invention is usually from 0.005 to 5 μm, preferably from 0.1 to 3 μm, particularly preferably from 1.0 to 3 μm. The thickness of the surface layer is 5 μm
If the thickness exceeds 0.005, it may be difficult to satisfy the transparency of the film to a high degree.
If it is less than μm, the existing particles may fall off, for example, and lower the final physical properties such as gas barrier properties after vapor deposition.

Examples of the particles used in the present invention include inorganic particles such as calcium carbonate, calcium phosphate, silica, kaolin, talc, titanium dioxide, alumina, barium sulfate, calcium fluoride, zeolite, and molybdenum sulfide.
Examples include crosslinked polymer particles, organic particles such as calcium oxalate, and precipitated particles formed during polyester polymerization.

Among the above particles, crosslinked polymer particles or silica particles are preferably used in order to obtain particularly high transparency and slipperiness. Particularly, among the silica particles, non-monodisperse spherical silica particles such as thyricia, thyroid, and silo block (all of which are trade names) are recommended. This is because it has favorable properties in terms of affinity with the polyester and refractive index, so that the haze value of the film is not increased and the slip property is improved, and the particles are less likely to fall off.

The particles contained in the surface layer may be of one type, or two or more types may be simultaneously mixed. When simultaneously containing crosslinked polymer particles or silica particles and other particles, the total content of the crosslinked polymer particles and silica particles is preferably larger than the content of the other particles. The average particle size of the particles in the surface layer is 0.01 to 3.
0 μm, more preferably 0.1 to 3.0 μm, and its content is 0.01 to 3.0% by weight, more preferably 0.03 to 3.0% by weight.
The preferred range is from .about.0.25% by weight. Average particle size 0.0
If the particle size is less than 1 μm, the ability to form protrusions may be insufficient, and may not contribute to the slipperiness of the film in spite of increasing the haze. On the other hand, when the average particle size exceeds 3.0 μm, unnecessarily large projections are formed on the film. For example, the projections may cause cracks due to deposition after vapor deposition, thereby impairing gas barrier properties. If the particle amount is less than 0.01% by weight, the number of protrusions formed on the surface layer tends to be insufficient, and the film may be insufficiently slid or may be damaged during film production and film processing to deteriorate transparency. Or the gas barrier property may be reduced. On the other hand, when the amount of particles exceeds 3.0% by weight, dropout of particles may increase or haze may become too high.

The content of the particles in the layers other than the surface layer is as follows:
The content is preferably not more than the content of the surface layer. Further, the content of the particles with respect to the polyester of the whole film is 0.1.
It is preferably at most 25% by weight, more preferably at most 0.15% by weight. If the content of the particles with respect to the polyester of the whole film exceeds 0.25% by weight, the transparency of the film may be impaired.

[0014] The use of self-recycled materials and / or other recycled materials especially for layers other than the surface layer is a preferred method without departing from the scope of the present invention. In the laminated polyester film constituting the film of the present invention, as additives other than the above, if necessary, an antistatic agent, a stabilizer, a lubricant, a crosslinking agent, an antiblocking agent, an antioxidant, a coloring agent, a light ray You may mix a blocking agent, an ultraviolet absorber, etc.

The layer (polyester layer A) forming at least one surface of the laminated polyester film constituting the film of the present invention has an extraction amount of a low molecular weight substance by a chloroform solvent of less than 50 mg / m ² in a method defined later. There must be. This extraction amount is 50 mg / m ²
The above does not contribute to the improvement of gas barrier properties, which is the object of the present invention. The amount of extraction is preferably less than 40 mg / m ² , more preferably less than 30 mg / m ² . When performing vapor deposition on the film of the present invention, the vapor deposition is usually performed on the surface constituted by the polyester layer A.

The amount of extraction of the surface composed of the polyester layer A is at least the same as the amount of extraction from the layer constituting the other surface and the amount of extraction from the layer forming the intermediate layer. Or less is preferred. In the measurement of the amount of extraction in the present invention, in the case of a laminated film having the same front and back sides such as A / B / A, the value measured as the laminated film may be used ignoring the amount of extraction from the side. However, as the extraction amount of the intermediate layer and the extraction amount of the A-side and C-side when the front and back are different like A / B / C, values measured as a film of each layer alone are used.

The low molecular weight compound includes a cyclic oligomer mainly composed of a cyclic trimer, a linear oligomer mainly composed of a linear dimer and a linear trimer, terephthalic acid, terephthalic acid monoglycol ester and the like. I do. As a method of forming such a polyester film layer with a low extraction amount of low molecular weight substances, JP-A-48-101462 and JP-A-
As disclosed in JP-A-9-32973 and the like, low molecular weight substances such as oligomers are reduced in the state of chips by further polymerizing the chips once polymerized in a solid phase, and a film is formed using these raw materials. A method of forming a film by removing low molecular weight substances such as oligomers in a chip using a solvent, and a method of extracting and removing low molecular weight substances such as oligomers from a biaxially stretched heat-fixed film using a solvent. Is preferred.

In the former method, in which the solid-state polymerization operation is added, if the temperature and the time in the extrusion step to a film are high and the time is long, the low molecular weight substances such as oligomers having a reduced angle increase due to thermal equilibrium. Therefore, it is preferable to extrude at a temperature as low as possible and in a short time. on the other hand,
It was also found that the amount of low-molecular-weight substances extracted from the biaxially stretched heat-set film depends on the degree of plane orientation of the film.
Therefore, the degree of surface orientation of the surface layer constituting the surface to be deposited is 0.1.
Preferably, it exceeds 160. More preferably 0.1
More than 62 and less than 0.169, particularly preferably 0.
It is more than 162 and less than 0.166.

Further, since the film of the present invention is used for vapor deposition, the film preferably has a low shrinkage. for that reason,
The average refractive index of the polyester film constituting the film of the present invention preferably exceeds 1.6045,
More preferably, it exceeds 1.6050. Further, the shrinkage in the longitudinal direction of the film is preferably low, and the Δn of the polyester film constituting the film of the present invention is preferably minus, that is, the refractive index in the transverse direction is larger than the refractive index in the longitudinal direction.

In the present invention, it is indispensable that the laminated polyester film is coated with the anchor coat agent on the surface of the polyester A layer, which is the surface on which the amount of low molecular weight extracted is small. On the other hand, providing a coating layer on the other surface does not prevent implementation as needed. In addition, this anchor coating treatment is not limited to the secondary processing of the laminated polyester film, and can be performed in the middle of the film manufacturing process. Stretching, heat treatment,
A so-called in-line coating method is preferably applied. In particular, in the biaxially stretched film as in the present invention, it is cost-effective to apply the coating solution to the uniaxially stretched film after the longitudinal stretching, stretch in the dry or undried state in the horizontal direction, and then perform heat treatment or the like. It is also preferable because it is inexpensive.

The anchor coating agent used in the present invention preferably contains at least one of polyester resins, polyurethane resins, and acrylic resins. However, in order to impart flexibility to the coating layer, the amount of the acrylic resin used is preferably minimized as much as possible. These may be used alone, but it is preferable to use two or more kinds in combination. In addition to these, oxazoline group-containing resin, ethylene vinyl alcohol resin, vinyl-modified resin, epoxy resin, modified styrene resin, modified silicon resin, alkyl titanate resin, etc., unless used within the scope of the present invention, are used together. be able to. The polyester resin and the polyurethane resin are preferably water-soluble or water-dispersible resins when performing the in-line coating method.

The above-mentioned polyester resin is preferably a water-soluble or water-dispersible resin not containing a low-molecular hydrophilic dispersant or the like. Such polyester-based resin,
In order to increase the affinity with an aqueous medium, those containing a carboxyl group or a salt thereof (hereinafter, simply referred to as a carboxyl group) are preferable. The polyurethane resin is preferably a water-soluble or water-dispersible resin produced by reacting a polyhydroxy compound and a polyisocyanate compound according to a conventional method, and preferably contains a carboxyl group.

The acrylic resin is a resin containing alkyl acrylate and / or alkyl methacrylate as a main component. Specifically, the content of the alkyl acrylate and / or alkyl methacrylate component is usually 40 to 95 mol%. A non-emulsifier type water-soluble or water-dispersible resin having a copolymerizable and functional group-containing vinyl monomer component content of usually 5 to 60 mol% is desirable. Examples of the functional group in the vinyl monomer include a carboxyl group, an acid anhydride group, a sulfonic acid group or a salt thereof, an amide group or an alkylolated amide group, and an amino group (including a substituted amino group). ,
Examples include an alkylolated amino group or a salt thereof, a hydroxyl group, an epoxy group, and the like, and particularly preferably a carboxyl group, an acid anhydride group, and an epoxy group.

When an oxazoline group-containing resin is used, the addition-polymerizable oxazoline described in JP-B-6-39548 and, if necessary, a water-soluble polymer obtained by polymerizing at least one other monomer. Alternatively, a water-dispersible polymer is preferred. Examples of the addition polymerizable oxazoline include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, and 2-vinyl-5
Methyl 2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-2-oxazoline,
2-isopropenyl-4-methyl-2-oxazoline,
2-isopropenyl-5-ethyl-2-oxazoline and the like, and two or more of these may be used in combination. There is no limitation as long as it is a monomer copolymerizable with addition-polymerizable oxazoline, and examples thereof include methacrylates such as methyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate, methacrylic acid, itaconic acid, and maleic acid. Unsaturated carboxylic acids such as acids, unsaturated nitriles such as methacrylonitrile, methacrylamide, unsaturated nitriles such as N-methylolated methacrylamide, vinyl acetate, vinyl esters such as vinyl propionate,
Vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; and halogen-containing α and β-unsaturated aromatic monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride. More than one species may be used in combination.

Further, when the above resin compound is used, when an epoxy compound such as glycidyl acrylate or glycidyl methacrylate is used in combination, it is cross-linked to a side chain such as a carboxyl group in the resin compound to improve the adhesiveness to a deposited film. Can be. The above-mentioned anchor coating agent is usually diluted with water or an organic solvent and applied as a solution or dispersion to the surface of the polyester film. In the coating solution at this time, a conventionally known crosslinking agent such as a silane coupling agent, an inorganic fine particle, an antifoaming agent, a foaming agent, a coating improver,
Thickeners, antistatic agents, lubricants, polymer particles, antioxidants, ultraviolet absorbers, dyes, pigments and the like can also be added.

As a specific method of applying the anchor coating agent, a known method using an air doctor coater, a rod coater, a reverse roll coater, a gravure coater, a kiss coater or the like is employed. According to the anchor coating treatment, the thin film and the film can be generally brought into close contact with each other, but as a result, good gas barrier properties, adhesion, solvent resistance, and hot water resistance are easily developed.

The thickness of the anchor coat layer (coating layer) is generally 0.005 to 2 μm, preferably 0.01 to 0.8 μm, in accordance with the surface irregularities of the polyester film to be used.
Is selected from the range. When the thickness of the anchor coat layer is 0.
When the thickness is less than 005 μm, coating unevenness tends to occur. On the other hand, when the thickness of the coating layer exceeds 2 μm, the film may be sticky and poor in workability.

The haze of the entire biaxially oriented film constituting the film of the present invention is preferably more than 0.5% and less than 4.0%. If it is 0.5% or less, the workability of the film may be poor, and if it is 4.0% or more, the transparency of the film tends to be poor. The film haze is more preferably 1.
It is in the range of 2 to 2.5%. Further, the center line average roughness of the surface of the biaxially oriented laminated film constituting the film of the present invention on the side not subjected to vapor deposition is preferably more than 0.015 μm and less than 0.035 μm. When the center line average roughness is 0.015 μm or less, the film may become sticky when subjected to vapor deposition, or the workability during processing may be poor. On the other hand, when the center line average roughness is 0.035 μm or more, the transparency of the film tends to be poor.

On the other hand, among the surface layers of the biaxially oriented film, the center line average roughness of the surface provided with the anchor coat layer and subjected to vapor deposition is preferably more than 0.007 μm and 0.030 μm or less. If the center line average roughness is 0.007 μm or less, workability may be poor, and if it exceeds 0.030 μm, gas barrier properties may be poor. Next, the method for producing a laminated polyester film of the present invention will be specifically described.

As a method for obtaining the laminated film of the present invention, a coextrusion method is preferably employed. Hereinafter, an example of lamination by the co-extrusion method will be described. First, a polyester raw material constituting each layer is supplied to an extruder for coextrusion lamination. At this time, a necessary amount of a raw material in which low molecular weight substances such as oligomers are reduced by solid phase polymerization is supplied to at least the surface layer constituting the deposition surface. Thus, lamination is performed using two or three or more multi-manifolds or feed blocks, and extruded as a molten sheet of two or more layers from a slit die. At this time, the thickness of each layer can be set by adjusting the flow rate of the polymer by a fixed-quantity feeder such as a gear pump installed on the melt line. Next, the molten sheet extruded from the die is quenched and solidified at a temperature equal to or lower than the glass transition temperature on a rotary cooling drum to obtain a substantially amorphous unoriented sheet. At this time, in order to improve the flatness and uneven thickness 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 preferable. Used.

In the present invention, it is essential that the sheet thus obtained is stretched biaxially to form a film. As specific stretching conditions, the aforementioned unstretched sheet is usually 70 to 150 ° C., preferably 75 to 130 ° C.
Within the temperature range of ° C., first, usually 3.0 to 7.0 times, preferably 3.2 to 6.0 in one direction, preferably in the roll stretching direction.
Stretch twice. Next, in the direction perpendicular to the first stage, preferably in the direction of the tenter, usually 75 to 150 ° C., preferably 8 ° C.
In a temperature range of 0 to 140 ° C, the film is stretched usually 3.2 to 7.0 times, preferably 3.5 to 6.0 times, to obtain a biaxially oriented film. In addition, it is a preferable method to perform unidirectional stretching in two or more stages in a multi-stage manner. However, in this case, it is naturally preferable that the final stretching ratio is within the above range. Also,
It is also possible to simultaneously biaxially stretch the unstretched sheet so that the area magnification becomes 10 to 40 times. The biaxially oriented film thus obtained is usually obtained at 150 to 250 ° C. for 3 hours.
Elongation, limited shrinkage within 0%, 1 second to 5 under constant length
Heat treated for a minute. Before the heat treatment after the biaxial stretching, it is also possible to perform re-stretching at a temperature of 110 to 180 ° C. in the longitudinal and / or transverse direction by 1.05 to 2.5 times.

In the present invention, it is also possible to apply a coating solution of an aqueous system, ie, an aqueous solution or an aqueous dispersion, and provide a coating layer on the film surface in the above-mentioned film forming step. Examples of the method of providing the coating layer include a method of applying and drying a coating liquid on the surface of an unstretched sheet, and a method of applying and drying a coating liquid on the surface of a uniaxially stretched film. Recommended. Further, if necessary, a combination of the above-mentioned coating methods can be employed. That is, the first layer is applied to an unstretched sheet, dried, stretched uniaxially, and then the second layer is further applied and dried by heat fixing.

When the thus obtained film is used as a vapor-deposited film, the metal and metal oxide to be vapor-deposited are, for example, aluminum, silicon, magnesium,
Metals such as palladium, zinc, tin, nickel, silver, copper, gold, indium, stainless steel, chromium, titanium, aluminum oxide, zinc oxide, antimony oxide, indium oxide, calcium oxide, cadmium oxide, silver oxide, gold oxide, Chromium oxide, silicon oxide, nickel oxide, platinum oxide, palladium oxide, bismuth oxide, magnesium oxide, manganese oxide, molybdenum oxide, vanadium oxide,
A metal oxide such as barium oxide may be mentioned, and as the transparent vapor deposition, alumina oxide and silicon oxide are preferable. In particular, in the present invention, deposition of silicon oxide is particularly preferable because it combines high oxygen gas barrier properties, water vapor barrier properties and transparency, and is industrially inexpensive. Such deposition of silicon oxide may be used alone or as a mixture.

The metal or metal oxide is generally deposited by vacuum deposition, but may be deposited by ion plating, sputtering, CVD or the like.
The deposited film is formed on the surface of the coating layer, and the thickness of the deposited film is appropriately selected depending on the final use of the deposited film.
It is also preferable to provide a resin protective layer on the surface to be vapor-deposited in order to impart adhesiveness, particularly water-resistant adhesiveness and scratch resistance, after vapor deposition.

In the present invention, the thickness of the film is selected from the range of usually 6 to 35 μm, preferably 9 to 25 μm.

[0036]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. The measuring methods and definitions of various physical properties and characteristics in the examples are as follows. “Parts” in Examples and Comparative Examples means “parts by weight”.

(1) Center line average roughness (Ra) The center line average roughness was determined as follows using a surface measuring device (SE-3F) manufactured by Kosaka Laboratory Co., Ltd. That is, a portion having a reference length L (2.5 mm) is extracted from the film cross-sectional curve in the direction of the center line, and the center line of the extracted portion is the x-axis, and the direction of the vertical magnification is the y-axis. When represented by (x), the value given by the following equation was represented by [μm]. The center line average roughness was obtained by obtaining ten cross-sectional curves from the surface of the sample film and expressing the average value of the center line average roughness of the sampled portion obtained from these cross-sectional curves. The tip radius of the stylus is 5
μm, load is 30mg, cut-off is 0.08m
m.

[0038]

[Number 1] ^{_{Ra = 1 / L∫ 0 l f}} | (x) | dx

(2) Haze value (%) of film According to JIS-K-7105-1981, the turbidity of the film was measured with an integrating sphere turbidity meter NDH-300A manufactured by Nippon Denshoku Industries Co., Ltd. (3) Hot water resistance test of vapor-deposited film On the coated surface of the base film, a roll-up type vacuum vapor-deposition device was used to deposit SiO (Sumitomo Sitix Co., Ltd.)
Is evaporated by a high frequency heating method, and the pressure is 8 × 10 ⁻⁵ To.
Under a condition of rr, a silicon oxide vapor-deposited film having a thickness of 25 nm was formed to obtain a vapor-deposited film on which a silicon oxide thin film was formed. This vapor-deposited film is boiled at 90 ° C. for 30 minutes, lightly wiped with water, and heated at 23 ° C. and 50% relative humidity.
After 1 day at 1%, the oxygen transmission rate was measured as follows. That is, in accordance with ASTM D-3985, an oxygen permeability measuring device (OX-TR manufactured by Modern Control Co., Ltd.)
Using AN100), the measurement was carried out under the conditions of 25 ° C. and 95% relative humidity, and judged according to the following criteria. Less than 0.8: 、, 0.8 or more and less than 1.0: （(good),
1.0 or more and less than 2.0: Δ (somewhat poor), 2.0 or more:
X (bad)

(4) Stickiness of the deposited film The deposited film is actually laminated and printed, and in all the steps of vapor deposition, lamination and printing, those that do not cause wrinkles are generated in all the steps. X, and Δ generated in any of the steps. (5) Low-Molecular-Weight Extraction Method A piece of film having a length of 40 mm and a width of 40 mm was immersed in a 20-ml chloroform solution set at 30 ° C. for 60 minutes to extract a low-molecular-weight substance. The measurement was performed using a visible ultraviolet spectrophotometer manufactured by JASCO Corporation.
The amount of low molecular weight extraction was determined from the absorbance of the peak indicated by the wavelength of 246 nm. The same sample was measured at three points, and the average was obtained.

(6) Degree of plane orientation (ΔP), average refractive index (n), and birefringence (Δn) Using an Abbe refractometer manufactured by Atago Optical Co., Ltd., the maximum value nγ of the in-plane refractive index, and The refractive index nβ in the direction at right angles,
The refractive index nα in the thickness direction of the film, the refractive index n (vertical) in the longitudinal direction of the film, and the refractive index n (horizontal) in the lateral direction of the film were measured, and the degree of plane orientation was calculated by the following equation. The refractive index was measured at 23 ° C. using a sodium D line.

[0042]

ΔP = (nγ + nβ) / 2−nα n = (nα + nβ + nγ) / 3 Δn = n (vertical) −n (horizontal)

Example 1 (Production of polyester film) Average particle size 1.45 μm
m, a chip having an intrinsic viscosity of 0.65 containing 0.6 part of amorphous silicon dioxide particles having an oil-absorbing property of 310 ml / 100 g was defined as polyethylene terephthalate (I), and an intrinsic viscosity substantially free of particles obtained by a conventional method. A chip of 0.60 was used as a polyester raw material (II), and this polyester raw material was used in a rotary vacuum polymerization apparatus at a degree of vacuum of 1 Torr and 230 ° C.
For 4 hours to reduce the content of low molecular weight substances by 0.5%
The polyester having a limiting viscosity of 0.75 was used as polyester raw material (III). As a surface layer, polyester (I)
A mixture of 0 part and 70 parts of polyester (III) (polyester A) was used, while polyester (II) was used alone (polyester B) in the intermediate layer.

These were separated from each other in a thickness direction by A /
The mixture was extruded from a die at a temperature of 280 to 300 ° C. so as to be laminated in the order of B / A, and rapidly cooled and cast on a cooling drum while using an electrostatic adhesion method to obtain an unstretched film. At this time, the surface layer was extruded using a biaxial stretching machine. Next, the obtained sheet was stretched 3.9 times in the longitudinal direction at 85 ° C., and an aqueous dispersion coating solution containing 20, 70, and 10 parts by weight of the following coating agents a, b, and c was applied to one surface of the film. It is applied and further stretched 4.6 times in the horizontal direction at 110 ° C., and then heat-treated at 235 ° C., and the thickness of the base polyester film is 12 μm.
Was obtained. At that time, the thickness of the film was 1.35 μm / 9.3 μm / 1.35 μm A /
It was a two-layer three-layer film of B / A.

<Coating Agent> Resin a: water-dispersible polyurethane having a carboxyl group Hydran AP-4 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.)
0-Resin b: Water-dispersed polyester having a carboxyl group, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name Polyester-WR-96
1. Compound c: triethylene glycol glycidyl ether The haze of the obtained film was 1.8% and Ra was 0.02.
9 μm, ΔP is 0.163, n is 1.6051, Δn
Is -0.020, the extracted amount of the low molecular weight of the A layer (surface layer) was 32 mg / m ^2. On the other hand, the extraction amount of the layer B (intermediate layer) was 52 mg / m ² . On one side of the obtained film, vapor deposition was performed by the method described above, and lamination, printing was performed to obtain a product.The gas barrier property was stably ◎, and the stickiness was ○ without any problem in workability. Was very good.

Example 2 Example 1 was repeated in exactly the same manner as in Example 1 except that the longitudinal stretching ratio was 3.2 times and the transverse stretching ratio was 3.5 times.
A 2 μm film was formed. The haze of the obtained film is 1.9%, Ra is 0.033 μm, and ΔP is 0.15.
9, n was 1.6052 and Δn was -0.003.
The extraction amount of the surface layer was 42 mg / m ² , and that of the middle layer was 56 mg / m ² .
mg / m ² , and the gas barrier property after vapor deposition on the film was ○.

Example 3 As polyester A, 20 parts of polyester (I)
Polyester (III) is mixed with 80 parts, polyester (II) is used alone as polyester B, and polyester (I) is used as polyester C in 4 parts.
A sample was prepared in the same manner as in Example 1 except that a mixture of 0 parts and 60 parts of polyester (II) was used to form a three-layer film of A / B / C and applied to the A layer side. Created. The haze of the obtained film was 2.1%.
The Ra of the layer A is 0.020 μm, and the Ra of the layer C is 0.2 μm.
030 μm. ΔP, n, and Δn were the same as in Example 1. The extraction amount of the layer A was 28 mg / m ² , and the extraction amount of the layer C was 56 mg / m ² . The deposition was performed on the surface of the coating layer. The result was ◎ as in Example 1, but the value was more stable, the stickiness was ○, and the workability was better.

Comparative Example 1 A film was prepared in the same manner as in Example 1 except that 30 parts of the polyester (I) and 70 parts of the polyester (II) were mixed to obtain polyester A. The extraction amount of the low molecular weight substance of the film was 52 mg / m
^{Was 2} . When its performance was evaluated, the gas barrier property was Δ.

Comparative Example 2 A film was prepared and vapor-deposited in the same manner as in Comparative Example 1 except that the composition of the coating composition was changed from a, b, and c to d, e, and f shown below. . Although the gas barrier property was ○, it showed a bad value depending on the place and was unstable.

<Coating Agent> Resin d: aqueous acrylic resin 40 parts by weight of ethyl acrylate, methyl methacrylate 30
Parts by weight, a mixture of 20 parts by weight of methacrylic acid and 10 parts by weight of glycidyl methacrylate was subjected to solution polymerization in ethyl alcohol, and after the polymerization, the mixture was heated while adding water to remove the ethyl alcohol, and then adjusted to pH 7.5 with aqueous ammonia. Adjusted coating solution of water-based acrylic resin (non-emulsifier type) ・ Resin e: water-based polyurethane resin water-based paint First, 664 parts by weight of terephthalic acid, 631 of isophthalic acid
Parts by weight, 472 parts by weight of 1,4-butanediol and 447 parts by weight of neopentyl glycol were obtained, and 321 parts by weight of adipic acid and 26 parts of dimethylolpropionic acid were added to the obtained polyester polyol.
8 parts by weight were added to obtain a pendant carboxyl group-containing polyester polyol A, and an aqueous polyurethane-based resin aqueous coating obtained by adding 160 parts by weight of hexamethylene diisocyanate to 1880 parts by weight of the above-mentioned polyester polyol A. Compound f: epoxy compound tri Ethylene glycol diglycidyl ether

[0051]

The film of the present invention has excellent gas barrier properties, and the industrial value of the present invention is high.

Claims (1)

[Claims] 1. A film in which a coating layer and a vapor-deposited layer made of metal or metal oxide are sequentially laminated on one surface of a biaxially oriented laminated polyester film, wherein the biaxially oriented laminated polyester film is a polyester layer B On at least one side, the extraction amount of the low-molecular-weight substance with the chloroform solvent is 5
A laminated polyester film for transparent vapor deposition, wherein the polyester layer A is less than 0 mg / m ² and the coating layer is provided on the surface of the polyester layer A.