JPH09309190A - Easy-to-adhere polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easy-to-adhere polyester film excellent in the adhesiveness with a metal such as aluminum, having an easy adhesive coating film having a uniform surface, generating no blocking even under a high humidity condition and excellent in transparency. SOLUTION: At least the single surface of a polyester film is coated with an aq. soln. containing a compsn. containing 40-80wt.% of a polyester polymer (A) wherein a secondary transition point is 40-85 deg.C and a ratio of a dicarboxylic acid component having an SO3 M group is 0-6mol% per the total dicarboxylic acid component, 20-70wt.% of an acrylic polymer (B) with a secondary transition point of 25-70 deg.C, 1-20wt.% of an acrylic polymer (C) with a secondary transition point of below 25 deg.C and 1-20wt.% of a surfactant (D) with HLB of 8-18 as main components and the coated film is dried and stretched to obtain an easy adhesive coating film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an easy-adhesive polyester film, and more specifically, it has an easy-adhesive coating film excellent in adhesion to a metal such as aluminum and is suitable for a base film of a vapor deposition film. -Related polyester film.

[0002]

2. Description of the Related Art Biaxially stretched polyester films are
Since it has excellent transparency, dimensional stability, mechanical properties, electrical properties, chemical resistance, etc., it is used as a base film in many fields. The polyester film is also used as a base film of a vapor deposition film, and in this case, a primer layer is provided on the surface of the polyester film for the purpose of imparting adhesiveness to a metal film such as aluminum to be vapor deposited. The primer layer is required to have good adhesiveness to the metal film (easy adhesiveness) and no unevenness on the surface of the primer layer (surface uniformity).

As a polyester film provided with such a primer layer, a hydrophilic polyester is used as a component constituting the primer layer (JP-A-7-19564).
No. 0) and the like are disclosed. However, in this film, sticking (blocking) between the primer layers occurs due to the hydrophilic polyester that is a component of the primer layer, and the usage method thereof is limited.

[0004]

The object of the present invention is to improve the above-mentioned drawbacks, to provide excellent adhesion to a metal film such as aluminum, and to provide a uniform and uniform adhesive coating that is uniform over the entire surface of the coating film. An object of the present invention is to provide an easily-adhesive polyester film having a film, which is suitable as a base film of a vapor deposition film and does not block even under high humidity.

[0005]

The object of the invention is, according to the invention, to at least one side of a polyester film,
The second-order transition point is 40 to 85 ° C., and the SO ₃ M group (where M is the same amount as SO ₃ of a metal atom, an ammonium group, a fourth group).
A secondary amine or a quaternary phosphonium group is shown. The ratio of the dicarboxylic acid component having
Polyester polymer (A) 40 to 80, which is 6 mol%
% By weight, 20 to 70% by weight of the acrylic polymer (B) having a secondary transition point of 25 ° C. or higher and 70 ° C. or lower, and a secondary transition point of 25 ° C.
Less than 1 to 20% by weight of acrylic polymer (C) and H
Easy contact with an easily-adhesive coating film obtained by applying an aqueous liquid containing a composition containing 1 to 20% by weight of a surfactant (D) having an LB of 8 to 18 as a main component, and drying and stretching. Is achieved with a transparent polyester film.

The present invention will be described in more detail below.

[Polyester] In the present invention, the polyester constituting the polyester film is a linear saturated polyester synthesized from an aromatic dibasic acid or its ester-forming derivative and a diol or its ester-forming derivative.

Specific examples of such polyesters include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly-1,4-cyclohexylene dimethylene terephthalate and polyethylene-2,6-naphthalene dicarboxylate. . These polyesters may be the above-mentioned homopolymers or copolymers thereof. Of these polyesters, polyethylene terephthalate and polyethylene-2,6-naphthalene dicarboxylate homopolymers and copolymers are particularly preferable.

If necessary, the above polyester may be made of, for example, silicon oxide, aluminum oxide, magnesium oxide,
Inorganic lubricants such as calcium carbonate, kaolin, talc, titanium oxide and barium sulfate, crosslinked silicone resins, crosslinked polystyrene resins, crosslinked acrylic resins, urea resins, organic lubricants such as melamine resins, polyethylene, polypropylene, ethylene-propylene copolymers, olefins Other resins such as ionomers, antioxidants, ultraviolet absorbers, optical brighteners and the like may be added.

[Polyester Film] In the present invention, the polyester film is preferably a biaxially stretched film, and particularly preferably a transparent biaxially stretched film. The thickness of the polyester film is 5-500μ
m, preferably 20 to 500 μm, particularly preferably 25
３００300 μm. If the thickness is less than 5 μm, the film has a weak rigidity and is not suitable for practical use depending on the application. On the other hand, if the film is too thick, for example, more than 500 μm, it is not preferable because the film forming property is poor.

[Polyester Polymer (A)] In the present invention, the easily adhesive coating has a secondary transition point of 40 to 85 ° C. on at least one side of the polyester film, and SO ₃
A polyester polymer (A) in which the ratio of the dicarboxylic acid component having an M group is 0 to 6 mol% of all dicarboxylic acid components, an acrylic polymer (B) having a second-order transition point of 25 ° C. or higher and 70 ° C. or lower, Application, drying and stretching of an aqueous liquid containing a composition containing an acrylic polymer (C) having a second-order transition point of less than 25 ° C. and a surfactant (D) having an HLB of 8 to 18 as main components. Is obtained by

The above polyester polymer (A) comprises a dicarboxylic acid component and a polyol component, and has an SO ₃ M group (where M is the same amount of metal atom, ammonium group, quaternary amine or quaternary amine as SO ₃₎ . The proportion of the dicarboxylic acid component having a quaternary phosphonium group is 0 to 6 mol% of the total dicarboxylic acid component, and the secondary transition point (Tg) is 4
It is a polyester polymer having a temperature of 0 to 85 ° C, preferably 45 to 80 ° C.

This polyester polymer (A) (hereinafter,
Sometimes referred to as "polymer (A)". If the second-order transition point of (1) is less than 40 ° C, the resulting laminated film will have poor blocking resistance, while if it exceeds 85 ° C, the transparency of the laminated film will decrease.

The proportion of the dicarboxylic acid component having SO ₃ M groups is 0 to 6 mol% of the total dicarboxylic acid component,
Preferably 0.05 to 6 mol%, more preferably 0.1.
Is about 5.5 mol%. If the proportion of the dicarboxylic acid component having an SO ₃ M group is less than 0.05 mol%, the coating film will have poor adhesion, and if it exceeds 6 mol%, the blocking resistance of the laminated film will be poor. The polymer (A) is preferably a water-soluble or dispersible polyester copolymer.

In the above SO ₃ M group, M is a metal atom, an ammonium group, a quaternary amine or a quaternary phosphonium group in the same amount as SO _3, and an alkaline metal atom such as lithium, sodium or potassium, or magnesium. , An alkaline earth metal atom such as calcium, an ammonium group,
A tetraethylammonium group and a tetrabutylphosphonium group are preferable, and sodium and potassium are particularly preferable.

Specific examples of the dicarboxylic acid component having an SO ₃ M group include compounds represented by the following formulas (I) to (V). These can be used alone or in combination of two or more as a copolymerization component of the polymer (A).

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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Examples of the dicarboxylic acid component forming the polymer (A) include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid and phenyl. Examples thereof include indanedicarboxylic acid and dimer acid. Two or more kinds of these components may be used. Furthermore, maleic acid, fumaric acid,
A small proportion of unsaturated polybasic acids such as itaconic acid and hydroxycarboxylic acids such as p-hydroxybenzoic acid and p- (β-hydroxyethoxy) benzoic acid can be used. The ratio of the unsaturated polybasic acid component and the hydroxycarboxylic acid component is at most 10 mol%, preferably 5 mol% or less.

As the polyol component forming the polymer (A), for example, ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4- Cyclohexanedimethanol, xylylene glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, poly (ethyleneoxy) glycol, poly (tetramethyleneoxy) glycol, and an ethylene oxide adduct of bisphenol A represented by the following formula (VI) Alternatively, a propylene oxide adduct represented by the following formula (VII) can be exemplified. Two or more kinds of these components may be used.

[0024]

[Chemical 6]

In the formula (VI), n + m is a number of 2-10.

[0026]

[Chemical 7]

In the formula (VII), n + m is a number of 2-10.

Among the above polyol components, ethylene glycol, bisphenol A ethylene oxide adduct, propylene oxide adduct and 1,4-butanediol are preferable, and ethylene glycol and bisphenol A ethylene oxide adduct and propylene oxide adduct are more preferable. preferable.

As the polymer (A), a modified polyester copolymer, for example, a block polymer or graft polymer obtained by modifying a polyester polymer with an acrylic resin, a polyurethane resin, a silicone resin, an epoxy resin, a phenol resin or the like is used. You can also

The polymer (A) in the present invention can be produced by a conventionally known or used polyester production technique. For example, terephthalic acid or its ester-forming derivative (especially dimethyl ester), isophthalic acid or its ester-forming derivative (especially dimethyl ester), the above-mentioned dicarboxylic acid having an SO ₃ M group, ethylene glycol and propylene oxide adduct of bisphenol A. To form a monomer or an oligomer, followed by polycondensation reaction under vacuum to give a predetermined intrinsic viscosity (the intrinsic viscosity measured at 35 ° C. using o-chlorophenol is 0.2).
~ 0.8 is preferred. ) Polyester can be produced. In that case, it is preferable to use a catalyst that accelerates the reaction, for example, an esterification or transesterification catalyst, a polycondensation catalyst and the like, and various additives such as a stabilizer can be added.

[Acrylic Polymer (B)] In the present invention, the acrylic polymer (B) has a second-order transition point (Tg) of 2
It is an acrylic polymer having a temperature of 5 ° C or higher and 70 ° C or lower, preferably 40 ° C or higher and 66 ° C or lower. This second transition point is 25 ℃
If it is less than 1, the resulting laminated film is inferior in blocking resistance, and if it exceeds 75 ° C., the transparency of the laminated film is deteriorated. The acrylic polymer (B) (hereinafter sometimes referred to as “polymer (B)”) is preferably a water-soluble or dispersible acrylic copolymer.

The constituent components of the polymer (B) include, for example, acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylamide, dimethacrylate. Acetone acrylamide, glycidyl methacrylate and the like can be mentioned, and these components can be used alone. Further, at least one of these components can be used together with another copolymerization component, and two or more of these components can be used in combination.

As the constituent component of the polymer (B), another component can be used as a copolymerization component in the range where the second-order transition point of the polymer (B) is 25 ° C. or higher and 70 ° C. or lower.
Examples of such copolymerization component include methyl acrylate,
Ethyl acrylate, butyl acrylate, sodium acrylate, ammonium acrylate, 2-hydroxyethyl acrylate, sodium methacrylate, ammonium methacrylate, glycidyl methacrylate, acrylic methacrylate, sodium vinyl sulfonate, sodium methallyl sulfonate, styrene sulfonic acid Examples thereof include sodium, methacrylamide, N-methylol methacrylamide and the like.

Further, other unsaturated monomers such as styrene, vinyl acetate, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, and divinylbenzene may be used in combination with the polymer (B) as a copolymerization component. You can also

As the polymer (B), a modified acrylic copolymer, for example, an acrylic copolymer, is used as a polyester resin, a polyurethane resin, a silicone resin, or an epoxy resin in the range where the second-order transition point is 25 ° C. or higher and 70 ° C. or lower. A block polymer or graft polymer modified with a resin, a phenol resin or the like may be used within a range that does not impair the effect.

[Acrylic Polymer (C)] In the present invention, the acrylic polymer (C) has a second-order transition point (Tg) of 2
It is an acrylic polymer having a temperature of less than 5 ° C. Acrylic polymer (C) (hereinafter sometimes referred to as "polymer (C)")
Is preferably a water-soluble or dispersible acrylic copolymer. When the second-order transition point is 25 ° C. or higher, the laminated film obtained has poor adhesion and transparency.

As the constituent components of the polymer (C), for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-butyl methacrylate, n-hexyl methacrylate, Examples thereof include lauryl methacrylate and 2-hydroxyethyl acrylate, and these components can be used alone. Further, at least one of these components can be used together with another copolymerization component, and two or more of these components can be used in combination.

As the constituent component of the polymer (C), other components can be used as a copolymerization component as long as the second-order transition point of the polymer (C) is less than 25 ° C. Examples of the copolymerization component include acrylic acid, sodium acrylate, ammonium acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, sodium methacrylate, ammonium methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, acrylic methacrylate, vinyl. Examples thereof include sodium sulfonate, sodium methallyl sulfonate, sodium styrene sulfonate, acrylamide, methacrylamide, and N-methylol methacrylamide.

Further, the polymer (C) can be used in combination with other unsaturated monomers such as styrene, vinyl acetate, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride and divinylbenzene.

As the polymer (C), a modified acrylic copolymer, for example, an acrylic copolymer, is modified with polyester, polyurethane, silicone, epoxy, phenol resin or the like within a range where the second-order transition point is less than 25 ° C. The block polymer or graft polymer described above can also be used within a range that does not impair the effect.

[Surfactant (D)] In the present invention, the surfactant (D) is a surfactant having an HLB of 8-18. Here, HLB is Hydrophile-Lip
It is an abbreviation for "ophile-balance", which is a numerical representation of the balance between the lipophilic portion and the hydrophilic portion in the molecule of the surfactant, and was proposed by Griffin of Atlas. This value can be calculated by the following formula (1).

[0042]

## EQU1 ## HLB = 20 (1-MO / M) (1) In Formula (1), MO is the molecular weight of the hydrophobic group, and M is the molecular weight of the surfactant.

When the HLB is less than 8, the wettability of the coating material to the polyester film is insufficient and the coating appearance is deteriorated. Further, when the HLB is 18 or more, the blocking resistance of the obtained laminated film is deteriorated.

As the surfactant having an HLB of 8 to 18,
For example, polyethylene oxide / polypropylene oxide block copolymer, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene monoalkylate, polyoxyethylene fatty acid ester, sorbitan fatty acid ester,
Glycerin fatty acid esters and the like can be mentioned. In some cases, these may be used in combination with a surfactant having an HLB other than 8 to 18 as long as application unevenness is not generated.

[Easy-Adhesive Coating Film] The easily-adhesive coating film of the present invention has a secondary transition point of 40 to 85 ° C. on at least one surface of the polyester film and contains all dicarboxylic acid components having SO ₃ M groups. Polyester polymer (A), which accounts for 0 to 6 mol% of the dicarboxylic acid component, and has a second-order transition point of 25.
Acrylic polymer (B) at ˜70 ° C., second-order transition point is 25
Acrylic polymer (C) and HLB below 8 ° C are 8 to 1
It can be obtained by applying an aqueous liquid containing the composition containing the surfactant (D) of No. 8 as a main component, drying and stretching.

In the above composition, the proportion of the polyester polymer (A) is required to be 40 to 80% by weight, preferably 45 to 70% by weight. If this proportion is less than 40% by weight, the coating film will have poor adhesion, whereas if it exceeds 80% by weight, the transparency of the laminated film will decrease.

In the above composition, the proportion of the acrylic polymer (B) is required to be 20 to 70% by weight, preferably 24 to 40% by weight. This ratio is 7
If it exceeds 0% by weight, the blocking resistance of the laminated film will be insufficient, while if it is less than 20% by weight, the easy adhesion of the coating film will be insufficient.

In the above composition, the proportion of the acrylic polymer (C) needs to be 1 to 20% by weight, preferably 3 to 15% by weight. This ratio is 20
If it exceeds 1% by weight, the blocking resistance of the laminated film is deteriorated, while if it is less than 1% by weight, the adhesion of the coating film is insufficient.

In the above composition, the surfactant (D)
It is necessary that the ratio is 1 to 20% by weight, and preferably 3 to 15% by weight. If this proportion exceeds 20% by weight, the blocking resistance of the laminated film becomes insufficient, while if it is less than 1% by weight, the wettability of the aqueous liquid used as a coating liquid to the polyester film is insufficient, and the coating appearance deteriorates.

In the aqueous liquid, compounding agents such as an ultraviolet absorber, a pigment, an antifoaming agent, a coating property improving agent, a lubricant, an antiblocking agent and the like; a melamine-based agent, within a range not impairing the object of the present invention. Other additives such as urea-based, guanamine-based, epoxy-based, aziridine-based, blocked isocyanate-based cross-linking agents and coupling agents can be added.

The solid content concentration in the aqueous liquid in the present invention is
Usually, it is preferably 30% by weight or less, more preferably 20% by weight or less. The lower limit of the solid content concentration in the aqueous liquid is about 0.4% by weight.

In the present invention, an aqueous liquid containing the above-mentioned components is applied to at least one side of the film, which is a stretchable polyester film before the completion of crystal orientation.

Examples of the stretchable polyester film include an unstretched film obtained by melt-extruding polyester into a film as it is, a uniaxially stretched film in which the unstretched film is stretched and oriented in either the longitudinal direction or the transverse direction, A biaxially stretched film obtained by stretching a stretched film in both the longitudinal and transverse directions at a low ratio (a biaxially stretched film before it is finally re-stretched in the longitudinal or transverse direction to complete oriented crystallization), etc. Can be illustrated. Of these, a uniaxially stretched film stretched in the machine direction is particularly preferable.

As the method of applying the aqueous liquid to the polyester film, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a microgravure coating method, a reverse coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method, or the like may be applied alone or in combination. The aqueous liquid may contain a small amount of an organic solvent for the purpose of assisting the stability of the coating material or the coating property of the coating material.

The coating amount of the aqueous liquid is preferably 0.5 to 50 g, and particularly 5 to 30 g per 1 m ² of the running film.
g is preferred. The thickness of the final dry coating film (easy-adhesive coating film) is preferably 0.01 to 1 μm, and particularly 0.02 to
0.6 μm is preferable. When the thickness of the coating film is less than 0.01 μm, sufficient easy adhesion may not be obtained. On the other hand, when it exceeds 1 μm, the blocking resistance of the laminated film may be deteriorated, which is not preferable.

The aqueous liquid can be applied to only one side or both sides depending on the intended use of the film. After application,
A uniform coating film is obtained by drying and stretching.

In the present invention, the polyester film is coated with the aqueous liquid and then dried and stretched. This drying is preferably carried out at 90 to 130 ° C. for 2 to 20 seconds. This drying can also serve as a preheat treatment for stretching or a heat treatment during stretching.

The stretchable polyester film is stretched at a temperature of 70 to 140 ° C. in the longitudinal direction of 2.5 to 7 times, in the transverse direction of 2.5 to 7 times, and in area magnification of 8 times or more, particularly 9 times or more. Stretching up to 28 times is preferable. In the case of re-stretching, it is preferable to stretch in the machine direction and / or the transverse direction at a draw ratio of 1.05 to 3 times within the above range of area draw ratio. The heat setting treatment after stretching is preferably performed at a temperature higher than the final stretching temperature and lower than the melting point of polyester for 1 to 30 seconds. For example, for polyethylene terephthalate film, 170 to 24
It is preferable to heat-fix at 0 ° C. for 2 to 30 seconds.

[Easy-Adhesive Polyester Film] The easily-adhesive polyester film thus obtained has, for example, a light transmittance of 85% or more, and is excellent in coating film appearance, transparency, and moisture resistance under high humidity. It is also useful as an easily adhesive film, especially as a base film for metal vapor deposition.

[0060]

The present invention will be further described below with reference to examples. The properties in the examples were measured by the following methods.

1. Coating unevenness An aluminum film was vapor-deposited on the coated surface of the primer layer and visually evaluated according to the following criteria. A: No coating spots …… Good coating spots B: Very few coating spots …… Slightly good coating spots C: Good coating spots …… Poor coating spots

[0062] 2. Light transmittance (transparency) It was measured according to ASTM D1003 using a HR-100 type haze meter manufactured by Murakami Color Research Laboratory. still,
When the light transmittance is 85% or more, it is practically good, and when the light transmittance is 87% or more, it is particularly good practically.
If the light transmittance is less than 85%, it is not practically sufficient.

3. Blocking resistance (moisture resistance) The front surface and the back surface of a sample film cut into a width of 50 mm are combined, and under a load of 50 Kg / cm ² , 60 ° C. × 80% R
After treatment with H for 17 hours, the peel strength (g / 50 mm) of the portion where the load was applied was measured by a tensile tester. The peel strength was evaluated according to the following criteria. Peel strength ≦ 10 ...... Good blocking resistance 10 <Peel strength ≦ 30 …… Slightly good blocking resistance 30 <Peel strength …… Poor blocking resistance

4. Easy adhesion After depositing an aluminum film on the coated surface of the primer layer,
A cellophane tape (18 mm width: made by Nichiban) is attached on the aluminum vapor-deposited film to a length of 15 cm, and 2 kg is put on this.
Adhesiveness was evaluated by applying a constant load with the above-mentioned manual load roll to bring them into close contact, fixing the film, and peeling one end of the cellophane tape in the 90 ° direction. The easy adhesion property was evaluated according to the following 5 grades. 5: Vapor-deposited layer does not peel at all ・ ・ ・ Easy adhesion is very good 4: Less than 3% of vapor-deposited layer is peeled ・ ・ ・ Good adhesion is good 3: 3-10% of vapor-deposited layer is peeled ・ ・ ・ Ease of adhesiveness is somewhat Good 2-10 to 30% of vapor-deposited layer peels off ・ ・ ・ Easy adhesion is slightly poor 1: 30% or more of vapor-deposited layer peels off ・ ・ ・ Easy adhesion is poor

Example 1 As a dicarboxylic acid component, a terephthalic acid component (96 mol%), an isophthalic acid component (2 mol%) and a 5-Nasulfoisophthalic acid component (compound of the above formula (I)) (2 mol%) ), An ethylene glycol component (60 mol%) as a polyol component and the above formula (VI
Solid of a copolyester (Tg = 78 ° C.) having an intrinsic viscosity of 0.55 dl / g made from a propylene oxide adduct of bisphenol A (n = 1, m = 1) component (40 mol%) represented by I) An aqueous dispersion having a concentration of 4% was prepared to obtain an aqueous liquid A.

Separately, a methyl methacrylate component (50
Copolymer (Tg = 49) of an ethyl acrylate component (35 mol%), an acrylic acid component (5 mol%), a methacrylamide component (5 mol%) and an N-methylolacrylamide component (5 mol%). C.) aqueous dispersion (solid content concentration 4% by weight) was prepared as aqueous liquid B.

Further, a butyl acrylate component (90 mol%), a styrene component (2 mol%) and a sodium methacryl sulfonate component (8 mol%) copolymer (Tg =-
An aqueous dispersion (solid content concentration: 4% by weight) at 45 ° C. was prepared as an aqueous liquid C.

On the other hand, a polyester made from terephthalic acid and ethylene glycol (intrinsic viscosity 0.65 dl
/ G) was melt-extruded on a rotary cooling drum maintained at 20 ° C. to obtain an unstretched film, which was then stretched 3.6 times in the machine axis direction (longitudinal direction) to obtain a uniaxially stretched film.

On one side of this uniaxially stretched film, 55% by weight of the above-mentioned aqueous liquid A, 25% by weight of aqueous liquid B, 10% by weight of aqueous liquid C and an aqueous liquid of polyoxyethylene alkyl ether (HLB = 10.7) which is a surfactant. D (solid content 4% by weight) 10% by weight of primer coating liquid 4 g /
The amount of m ² (wet) was applied by a roll coating method. Subsequently, the film was stretched 4 times in the transverse direction and heat-set at 220 ° C. to obtain a 25 μm-thick biaxially stretched polyester film coated with a primer layer. The film thickness of the primer layer was 0.05 μm. The characteristics of this film are shown in Table 2.

Comparative Example 1 A biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the primer layer was not provided. The characteristics of this film are shown in Table 2.

[Examples 2 to 7 and Comparative Examples 2 and 3] A primer layer was prepared in the same manner as in Example 1 except that the primer coating solution shown in Table 1 was used and the coating film thickness was as shown in Table 2. A biaxially stretched polyester film coated with was obtained. The characteristics of this film are shown in Table 2.

[0072]

[Table 1]

[0073]

[Table 2]

As is clear from the results shown in Tables 1 and 2, the easily adhesive polyester film of the present invention was excellent in coating unevenness, transparency, easy adhesion and blocking resistance.

In Table 1, E, F and G described in the columns of polyester polymer (A), acrylic polymer (B), acrylic polymer (C) and surfactant (D).
And H indicate the following aqueous liquids.

E: Dicarboxylic acid component is terephthalic acid component (78 mol%), isophthalic acid component (17 mol%) and 5-Na sulfoisophthalic acid (compound of the above formula (I))
Copolymerized polyester (Tg = 45 ° C.) of component (5 mol%), polyol component is ethylene glycol component (80 mol%) and neopentyl glycol component (20 mol%)
Is an aqueous dispersion in which the solid content concentration is adjusted to 4%.

F: Methyl methacrylate component (65 mol%), glycidyl methacrylate component (13 mol%),
Copolymer (Tg = 48 ° C.) of butyl acrylate component (12 mol%), β-hydroxyethyl methacrylate component (7 mol%) and N-methoxymethyl acrylamide component (3 mol%) to a solid content concentration of 4%. Prepared water dispersion.

G: Copolymer of ethyl acrylate component (85 mol%), acrylic acid component (8 mol%), methacrylamide component (5 mol%) and N-methylol methacrylamide component (2 mol%) (Tg = (-15 ° C) is an aqueous dispersion in which the solid content concentration is adjusted to 4%.

H: An aqueous solution of polyoxyethylene nonylphenyl ether (HLB = 17.8) as a surfactant (concentration 4% by weight).

[0080]

EFFECTS OF THE INVENTION According to the present invention, it has an excellent adhesiveness to a metal such as aluminum, has a uniform surface and has an easy-adhesive coating film without spots, and has a transparency that does not block even under high humidity. It is possible to obtain an easily-adhesive polyester film which is excellent as a base film for vapor deposition and which is useful.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08J 7/04 CFD C08J 7/04 CFDF C09D 133/00 PGC C09D 133/00 PGC 167/02 PLL 167 / 02 PLL C09J 167/02 JFU C09J 167/02 JFU // B32B 15/08 104 9633-4F B32B 15/08 104Z B29K 67:00 B29L 7:00 9:00

Claims (8)

[Claims] 1. A polyester film having a second-order transition point of 40 to 85 ° C. on at least one surface thereof and having an SO ₃ M group (where M is the same amount of metal atoms and ammonium groups as SO ₃ ,
A quaternary amine or a quaternary phosphonium group is shown. 40% of the polyester-based polymer (A) in which the ratio of the dicarboxylic acid component having) is 0 to 6 mol% of the total dicarboxylic acid component.
80% by weight, 20 to 70% by weight of the acrylic polymer (B) having a secondary transition point of 25 ° C. or higher and 70 ° C. or lower, and a secondary transition point of 2
1 to 20% by weight of an acrylic polymer (C) below 5 ° C and 1 to 20% by weight of a surfactant (D) having an HLB of 8 to 18
An easily-adhesive polyester film provided with an easily-adhesive coating film obtained by coating an aqueous liquid containing a composition containing as a main component, drying and stretching. 2. The easily adhesive polyester film according to claim 1, wherein the composition contains the polyester polymer (A) in an amount of 45 to 70% by weight. 3. The composition comprises 25 parts of an acrylic polymer (B).
The easily-adhesive polyester film according to claim 1, wherein the easily-adhesive polyester film comprises -60% by weight. 4. The composition comprises 3 to 5 parts of the acrylic polymer (C).
The easily adhesive polyester film according to claim 1, which contains 15% by weight. 5. The easily adhesive polyester film according to claim 1, wherein the composition contains the surfactant (D) in an amount of 3 to 15% by weight. 6. The easily adhesive coating has a thickness of 0.02 to 0.6.
The easily adhesive polyester film according to claim 1, which has a thickness of μm. 7. The easily adhesive polyester film according to claim 1, wherein the polyester film is a transparent polyester film. 8. On at least one surface of the easily adhesive coating,
The easily-adhesive polyester film according to claim 1, which is used for a vapor deposition film in which a metal vapor deposition film is laminated.