JPH09141808A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film with superior adhesive properties shown to ink or paint, high resistance against a solvent, smooth coat surface and excellent antiblocking characteristic. SOLUTION: A water coating liquid containing polyester resin with at least, 7mol% and 18mol% or less of a component having a sulfonate group, at least, 20mol% and 93mol% or less of a naphthalenedicarboxylic acid component, and a secondary transition point of at least, 60 deg.C and 110 deg.C or less, polyester resin having not more than 7mol% of a component containing a sulfonate group and a secondary transition point of at least, 50 deg.C and 100 deg.C or less, and/or acrylic resin, is applied to at least, one of the faces of a polyester film. After this application, the film is dried and stretched to obtain a laminated film with an easily adhesive coat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film, and more particularly to a laminated film which is excellent in adhesiveness to ultraviolet curable ink and solvent resistance and is useful for graphic materials, membrane films, magnetic cards, printing films and the like. Regarding

[0002]

2. Description of the Related Art Polyester films, especially those made of polyethylene terephthalate or polyethylene naphthalate, are widely used for magnetic recording materials such as magnetic tapes and general industrial materials such as packaging materials, photographic materials and graphic materials. ing.

Since such polyester film has poor adhesion to inks and paints, a method is usually adopted in which an easily adhesive coating film is laminated on the surface and inks and paints are adhered onto this coating film. ing. However, conventional easily-adhesive coating films have poor solvent resistance, and therefore have the drawbacks that the coating films are dissolved or swelled by the solvent used in the ink or paint. Many coatings have been proposed in order to improve such drawbacks. For example, an easily-adhesive coating film applied by using a coating liquid containing a crosslinking agent such as a melamine compound or a methylol compound is known. However, since a coating liquid containing such a cross-linking agent is difficult to use as an aqueous coating liquid, there are problems in disaster prevention and environmental protection, and the quality of the coating liquid deteriorates in a short time during storage as a coating liquid. There is a problem such as. In addition, the film laminated with the conventional easily adhesive coating is
For example, at a temperature of 40 to 70 ° C., the coating film tends to be blocked, so that it is difficult to wind the film into a roll.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned drawbacks and to provide a laminate having excellent adhesion to inks and paints, excellent solvent resistance, and uniform coating film surface and excellent blocking resistance. To provide a film.

[0005]

The object of the present invention is, according to the invention, to at least one side of a polyester film,
7 mol% or more and 18 mol% of components having a sulfonate group
Below, the naphthalene dicarboxylic acid component is 20 mol% or more 9
Polyester resin (A) having 3 mol% or less, secondary transition point of 60 ° C. or more and 110 ° C. or less, component having sulfonate group less than 7 mol%, second transition point of 50 ° C. or more and 100 ° C.
This is achieved by a laminated film provided with an easily adhesive coating film prepared by applying an aqueous coating solution containing the following polyester resin (B) and / or acrylic resin (C), drying and stretching. Hereinafter, the present invention will be described in detail.

[Base Film] In the present invention, a polyester film is used as the base film, and the polyester constituting the base film is a linear polyester composed of a dicarboxylic acid component and a glycol component.

Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid and 4,4'-
Diphenyldicarboxylic acid, phenylindanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,
4′-diphenylmethanedicarboxylic acid, 4,4′-diphenylpropanedicarboxylic acid, hexahydroterephthalic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid and the like can be mentioned. Among these, it is preferable to use, for example, 80 mol% or more of an aromatic dicarboxylic acid, and it is particularly preferable to use terephthalic acid or 2,6-naphthalenedicarboxylic acid.

As the glycol component, for example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, polyethylene glycol. And the like, and ethylene glycol is particularly preferable.

Among such polyesters, a homopolymer of polyethylene terephthalate or polyethylene-2,6-naphthalate has excellent mechanical properties such as a high Young's modulus, and thermal properties such as good heat resistance and dimensional stability. It is preferable because an excellent film can be obtained.

The above-mentioned polyester may be a polyester obtained by copolymerizing the above-mentioned dicarboxylic acid component or glycol component in order to improve the adhesion between the polyester film and the easily adhesive coating. Further, a polyester obtained by copolymerizing a trifunctional or higher polyvalent compound in a small amount within a range in which the polyester is substantially linear (for example, 5 mol% or less) may be used. Further, the above-mentioned polyester can be produced by a conventional method, and it is preferable that the intrinsic viscosity is 0.5 or more because the mechanical properties such as the rigidity of the film are good, and the like.

The above polyester has a mean particle size of 0.1 as a lubricant in order to improve the slipperiness of the film.
It is preferable to add organic or inorganic fine particles of about 01 to 20 μm at a blending ratio of, for example, 0.005 to 20% by weight. Specific examples of such fine particles include silica, alumina, kaolin, calcium carbonate, titanium oxide, barium sulfate, carbon black, crosslinked acrylic resin particles, crosslinked polystyrene resin particles, melamine resin particles, and crosslinked silicone resin particles. .

In addition to the fine particles, a colorant, an antistatic agent,
Antioxidants, organic lubricants (slipping agents), optical brighteners, cross-linking agents, ultraviolet absorbers and the like can be added as necessary.

In the present invention, the film to which the aqueous coating solution is applied is a film which can be stretched after applying the aqueous coating solution. As such a film, an unstretched film, a uniaxially stretched film or a stretchable biaxially stretched film is used. Can be used. Such a film can be obtained by a conventionally known method. For example, an unstretched film can be obtained by melting the polyester in an extruder and extruding it into a film, and cooling it with a rotary cooling drum. By stretching the unstretched film uniaxially in the machine direction or the transverse direction, A uniaxially stretched film can be obtained. Further, the stretchable biaxially stretched film is a method of sequentially biaxially stretching a uniaxially stretched film in the longitudinal direction or the transverse direction in the transverse direction or the longitudinal direction, or simultaneously biaxially stretching an unstretched film in the longitudinal direction and the transverse direction. Can be obtained by the method.

It is preferable that the stretching temperature is not less than the second-order transition point (Tg) of polyester. Further, the stretching ratio is 2 to 8 times in the uniaxial direction in the case of a uniaxially stretched film, and 1.1 to in each direction in the case of a stretchable biaxially stretched film.
It is preferably 8 times, especially 2 to 6 times.

The film provided with the easily adhesive coating can be re-stretched in the machine direction or the transverse direction if necessary, or can be heat-treated at 120 to 270 ° C. The thickness of the polyester film after application of the easily adhesive coating is preferably, for example, 2 to 300 μm, and particularly 3 to 260.
μm is preferred.

[Polyester Resin (A)] In the present invention, the component having a sulfonate group is 7 mol% or more and 18 mol% or less and the naphthalene dicarboxylic acid component is 20 mol% or more 93 on at least one side of the polyester film.
Polyester resin (A) having a secondary transition point of 60 ° C. or more and 110 ° C. or less (hereinafter abbreviated as “polyester resin (A)”), a component having a sulfonate group is less than 7 mol%, a secondary A polyester resin (B) having a transition point of 50 ° C. or higher and 100 ° C. or lower (hereinafter abbreviated as “polyester resin (B)”) and / or an aqueous coating liquid containing an acrylic resin (C) is applied, dried, and stretched. Provide an easily-adhesive coating film made from

This polyester resin (A) is composed of a polyvalent carboxylic acid component and a polyvalent hydroxy compound component, and contains 7 mol% to 18 mol% of a component having a sulfonate group and 20 mol% of a naphthalene dicarboxylic acid component. The polyester is 93 mol% or more and the second transition point is 60 ° C. or more and 110 ° C. or less.

The above-mentioned component having a sulfonate group is
Isophthalic acid or terephthalic acid containing a sulfonate group, such as 5-Na sulfoisophthalic acid, 5-Na
Sulfoterephthalic acid, 5-K Sulfoisophthalic acid, 5-
Examples thereof include ammonium sulfoisophthalic acid and 5-tetrabutylphosphonium sulfoisophthalic acid. The above naphthalenedicarboxylic acid component is, for example, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, or the like.

Other components of the polyester resin (A) other than the above are terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, phenylindanedicarboxylic acid and 4,4'-diphenylsulfonedicarboxylic acid as polyvalent carboxylic acid components. Acid, 4,4'-diphenylmethanedicarboxylic acid, adipic acid, sebacic acid, hexahydroterephthalic acid, dodecanedicarboxylic acid and the like can be mentioned.

As the polyhydric hydroxy compound component, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, Examples include bisphenol A / alkylene oxide adducts, dimethylolpropionic acid, and dimethylolpropionate.

In the polyester resin (A), the component having a sulfonate group is 7 mol% or more with respect to the acid component 18
Mol% or less. If this component is less than 7 mol%, the solvent resistance of the coating film will be insufficient, and if it exceeds 18 mol%, the adhesive property of the coating film will be insufficient.

In the polyester resin (A),
The naphthalene dicarboxylic acid component is 20 mol% or more and 93 mol% or less. If this component is less than 20 mol%, and if it exceeds 93 mol%, the solvent resistance of the coating film becomes insufficient.

Further, the polyester resin (A) has a second-order transition point of 60 ° C. or higher and 110 ° C. or lower. If the second-order transition point is less than 60 ° C, the blocking resistance of the laminated film will be insufficient, and if it exceeds 110 ° C, the coating film will be easily scraped.

The average molecular weight of the polyester resin (A) is preferably 3,000 to 50,000.

[Polyester Resin (B)] The polyester resin (B) in the present invention contains a component having a sulfonate group of less than 7 mol%, which is formed from a polyvalent carboxylic acid component and a polyvalent hydroxy compound component, and has a secondary transition. The point is polyester of 50 ° C. or higher and 100 ° C. or lower.

The above-mentioned component having a sulfonate group is
Isophthalic acid or terephthalic acid containing a sulfonate group, such as 5-Na sulfoisophthalic acid, 5-Na
Sulfoterephthalic acid, 5-K Sulfoisophthalic acid, 5-
Examples thereof include ammonium sulfoisophthalic acid and 5-tetrabutylphosphonium sulfoisophthalic acid.

As components other than the above components of the polyester resin (B), polyvalent carboxylic acid components such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5
-Naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, phenylindanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, adipic acid, sebacine Acid, hexahydroterephthalic acid, dodecanedicarboxylic acid and the like can be mentioned.

As the polyhydric hydroxy compound component, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, Examples include bisphenol A / alkylene oxide adducts, dimethylolpropionic acid, and dimethylolpropionate.

In the polyester resin (B), the component having a sulfonate group is less than 7 mol% based on the acid component. If this component exceeds 7 mol%, the adhesiveness of the coating film will be insufficient.

The polyester resin (B) has a second-order transition point of 50 ° C. or higher and 100 ° C. or lower. If the second-order transition point is less than 50 ° C, the blocking resistance of the laminated film will be insufficient, and if it exceeds 100 ° C, the adhesiveness of the coating film will be insufficient.

The average molecular weight of the polyester resin (B) is preferably 3,000 to 50,000.

[Acrylic Resin (C)] The acrylic resin (C) in the present invention is a copolymer of an unsaturated monomer containing an acrylic acid ester monomer as a main component. Examples of the acrylate-based monomer used as the main component include methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, ethyl crotonic acid, glycidyl methacrylate, and 2-hydroxy acrylate. Examples thereof include ethyl, 2-ethylhexyl acrylate, acrylamide, methacrylamide, acrylic acid, methacrylic acid, sodium acrylate, potassium methacrylate, ammonium acrylate, N-methylol acrylamide, and N-methoxymethyl acrylamide.

As the unsaturated monomer used as the copolymerization component, for example, vinyl chloride, vinyl acetate, styrene, vinyl ether, butadiene, isoprene, sodium vinyl sulfonate and the like can be mentioned for the copolymerization.

The acrylic resin (C) is an acrylic acid salt for improving solubility and dispersibility in an aqueous coating solution.
It is preferable to contain a hydrophilic monomer such as methacrylate, acrylic acid, acrylamide, 2-hydroxyethyl acrylate, N-methylol acrylamide as a copolymerization component. The secondary transition point of acrylic resin (C) is 20
It is preferably in the range of 120 to 120 ° C., and the average molecular weight is preferably 6,000 to 500,000.

[Aqueous coating liquid] In the present invention, in order to apply an easily adhesive coating film to a polyester film, it contains the above polyester resin (A), polyester resin (B) and / or acrylic resin (C). An aqueous coating solution (for example, aqueous solution, emulsion, dispersion) is used. The amount ratio of the polyester resin (A) to the polyester resin (B) and / or the acrylic resin (C) in the aqueous coating liquid is 20 to 90% by weight of the solid content of the polyester resin (A) and the polyester resin (B) 0 to The proportion is preferably 80% by weight and / or 0 to 80% by weight of the acrylic resin (C).

When the amount ratio of the polyester resin (A) to the polyester resin (B) and / or the acrylic resin (C) is in the above range, the adhesion of the coating film to the ink or the paint is good and the solvent resistance is high. It has good properties.

In addition to the above components, a binder resin may be added to the aqueous coating liquid in order to adjust the adhesiveness between the polyester film and the easily adhesive coating film. Examples of the binder resin include acrylic modified polyester resin, silicone resin, polyurethane resin, epoxy resin, vinyl resin, polyether resin, and water-soluble resin.

Further, a surfactant may be added to the aqueous coating liquid in order to improve the wettability of the coating liquid on the polyester film. Examples of the surfactant include polyalkylene oxide polymers, alkylene oxide copolymers, aliphatic alcohol alkylene oxide adducts, long chain aliphatic substituted phenol / alkylene oxide addition polymers, polyhydric alcohol fatty acid esters, long chain fats. Group amide alcohols, quaternary ammonium salts, alkylpyridinium salts, sulfonates and the like can be mentioned.

The aqueous coating liquid further includes a lubricant (inorganic or organic fine particles), an antioxidant, an antistatic agent, a colorant, a pigment, an optical brightener, a plasticizer, a cross-linking agent, a lubricant (lubricant), and an ultraviolet ray. An absorber or the like can be added. As the above-mentioned lubricant, for example, silica, alumina, titanium oxide, inorganic fine particles such as carbon, crosslinked polystyrene resin, crosslinked acrylic resin, melamine resin, crosslinked silicone resin, fluorine resin, urea resin, benzoguanamine resin, polyamide resin, polyester resin, etc. The resin fine particles can be mentioned. Of these lubricants, colloidal silica is particularly preferable.

The total solid content concentration in the aqueous coating solution is preferably 1 to 30% by weight, particularly preferably 2 to 20% by weight. The aqueous liquid may contain a small amount of organic solvent.

[Application of Easy-Adhesive Coating Film] In the present invention, the easy-adhesive coating film is applied by coating the above-mentioned aqueous coating solution on at least one side of the polyester film, followed by heating and drying and stretching. As the coating method of the aqueous coating liquid, any known coating method can be applied, for example, a gravure coating method, a reverse roll coating method, a die coating method, a kiss coating method, a reverse kiss coating method, an offset gravure coating method, a Meyer bar coating method. The roll brush method, spray coating method, air knife coating method, impregnation method, curtain coating method and the like can be applied alone or in combination. The WET coating amount of the aqueous liquid is preferably 1 to 40 g, particularly ^{2 to} 25 g per 1 m ² of the running film.
When the coating amount is within this range, drying is easy and coating spots are less likely to occur, which is preferable.

In the present invention, the unstretched film, the uniaxially stretched film or the stretchable biaxially stretched film may be used as the polyester film to which the aqueous coating liquid is applied. It is preferable to use a uniaxially stretched film having a unidirectional orientation because the easily adhesive coating film has good abrasion resistance and the laminated film can be efficiently produced. For example, polyester is heat-melted by an extruder, extruded into a sheet and cooled to obtain an unstretched film, and the unstretched film is stretched 2 to 8 times in the machine direction to form a uniaxially stretched film. Coating, heat-drying, then stretching in the transverse direction by 2 to 9 times, and if necessary, re-stretching in the longitudinal direction or the transverse direction and / or heat treatment to obtain a laminated film having an easily-adhesive coating film with good abrasion resistance. Can be created.

The thickness of the easily-adhesive coating film applied is from 0.01 to
1 μm, particularly 0.02 to 0.8 μm is preferable. If the thickness of the coating film is less than 0.01 μm, the adhesiveness of the coating film may be insufficient. If it exceeds 1 μm, the surface of the coating film becomes rough and uneven, or the abrasion resistance of the coating film is poor. May be insufficient, which is not preferable.

[Drying and Stretching Temperature] After applying the aqueous coating liquid in the present invention, the drying temperature is preferably 70 to 120 ° C. because the coating liquid can be dried quickly. The heating for this drying can also serve as the heating during the process of stretching the polyester film. Further, the stretching temperature of the polyester film can be 80 to 170 ° C, and the heat treatment temperature can be 120 to 260 ° C.

[0045]

EXAMPLES The present invention will be described in more detail with reference to examples. Each characteristic value was measured by the following method. The average molecular weight is the number average molecular weight.

1. Adhesiveness (Ink Adhesiveness) On the coated surface of the film, an ink containing a terminal bisacrylic polyurethane oligomer, a photopolymerization initiator, a photosensitizer, and a red colorant is applied in an amount of 5 μm and irradiated with ultraviolet rays. And cured to form an ink film. Next, cellophane tape was attached to the coated surface and then peeled off, and the adhesiveness was evaluated from the peeled state as follows. A: Peeling occurred between the cellophane tape and the ink film. (Good adhesion) B: The ink film was peeled off in a state of partial cohesive failure. (Slightly good adhesiveness) C: Peeled between the film and the ink film. (Poor adhesion)

2. Solvent resistance The coated surface of the film was rubbed 5 times with a cloth moistened with methyl ethyl ketone and dried, and then a photomicrograph of the rubbed surface was taken. From the results, the solvent resistance was evaluated as follows. A: No damage is observed on the surface of the coating film. (Good solvent resistance) B: Slight damage is observed on the coating film surface. (Slightly good solvent resistance) C: Significant damage is observed on the coating film surface. (Poor solvent resistance)

[Example 1] Polyethylene terephthalate having an intrinsic viscosity of 0.64 was melted by an extruder, and a film-like molten polymer was extruded from a die onto a rotating cooling drum and rapidly cooled to obtain an unstretched film. The stretched film was stretched 3.6 times in the machine direction to obtain a uniaxially stretched film.
On one side of this uniaxially stretched film, polyvalent carboxylic acid components are 2,6-naphthalenedicarboxylic acid (75 mol%), terephthalic acid (8 mol%) and isophthalic acid (5 mol%).
%), Adipic acid (1 mol%) and 5-Nasulfoisophthalic acid (11 mol%), polyhydric hydroxy component is ethylene glycol (90 mol%), bisphenol A.4 mol ethylene oxide adduct (9 mol%) and 1,4-butane. Copolymerized polyester of diol (1 mol%) (A-1, average molecular weight 15,000, second-order transition point 88 ° C.) 44 parts by weight, polyvalent carboxylic acid component 2,6
-Naphthalenedicarboxylic acid (55 mol%), terephthalic acid (8 mol%), isophthalic acid (33 mol%),
Adipic acid (1 mol%) and 5-Na sulfoisophthalic acid (3 mol%), polyhydric hydroxy component is ethylene glycol (62 mol%), bisphenol A 4 m
41 parts by weight of a copolymerized polyester of ethylene oxide adduct (37 mol%) and 1,4-butanediol (1 mol%) (B-1, average molecular weight 12,000, second-order transition point 70 ° C.), methyl methacrylate component ( 30m
ol%), ethyl methacrylate component (42 mol%),
Methyl acrylate component (3 mol%), ethyl acrylate component (11 mol%), acrylic acid component (1 mol
%), A glycidyl methacrylate component (5 mol%), a 2-hydroxyethyl acrylate component (3 mol%), an acrylamide component (2 mol%) and an N-methoxymethylacrylamide component (3 mol%) (C).
-1, average molecular weight: 95,500) and 6 parts by weight of polyoxyethylene nonylphenyl ether and 9 parts by weight of a 4% by weight aqueous coating solution were applied by a gravure coater. After drying, the film was stretched in the transverse direction by 3.9 times and heat-treated at 223 ° C. to prepare a laminated film having a total thickness of 76 μm and a coating film thickness of 0.06 μm. Table 1 shows the evaluation results of the characteristics of the obtained laminated film.

Comparative Example 1 A polyester film was obtained in the same manner as in Example 1 except that no coating film was applied. Table 1 shows the evaluation results of the characteristics of the obtained film.

[Examples 2 to 8 and Comparative Example 2] Laminated films were prepared in the same manner as in Example 1 except that the components of the aqueous coating liquid and the coating film thickness were changed as shown in Table 1. Table 1 shows the evaluation results of the characteristics of the obtained laminated film.

[0051]

[Table 1]

As is clear from the results shown in Table 1, the laminated film of the present invention was excellent in the ink adhesion component and solvent resistance.

In the coating liquid composition of Table 1, [A-2],
[B-2] and [B-3] are the following polymers.

[A-2]: The polycarboxylic acid component is 2,6
-Naphthalenedicarboxylic acid (76 mol%), terephthalic acid (8 mol%), isophthalic acid (5 mol%) and 5-Na sulfoisophthalic acid (11 mol%), polyvalent hydroxy component is ethylene glycol (96 mol%).
%), Bisphenol A.4 mol ethylene oxide adduct (3 mol%) and 1,4-butanediol (1
mol%) of copolyester (average molecular weight 13,0)
00, secondary transition point 94 ° C)

[B-2]: Polycarboxylic acid component is 2,6
-Naphthalenedicarboxylic acid (46 mol%), terephthalic acid (8 mol%), isophthalic acid (43 mol%),
Adipic acid (1 mol%) and 5-Na sulfoisophthalic acid (2 mol%), polyhydric hydroxy component is ethylene glycol (62 mol%), bisphenol A 4 m
Copolymerized polyester of ol ethylene oxide adduct (37 mol%) and 1,4-butanediol (1 mol%) (average molecular weight 11,000, secondary transition point 64 ° C.)

[B-3]: The polycarboxylic acid component is 2,6
-Naphthalenedicarboxylic acid (41 mol%), terephthalic acid (8 mol%), isophthalic acid (47 mol%),
Adipic acid (1 mol%) and 5-Na sulfoisophthalic acid (3 mol%), polyhydric hydroxy component is ethylene glycol (62 mol%), bisphenol A 4 m
Copolymerized polyester of ol ethylene oxide adduct (37 mol%) and 1,4-butanediol (1 mol%) (average molecular weight 11,000, secondary transition point 61 ° C.)

[0057]

The easily-adhesive coating film of the present invention is applied by using an aqueous coating liquid containing a specific polyester resin and / or a specific acrylic resin. It has excellent adhesion to cured ink and solvent resistance.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C08J 7/04 CFD C08J 7/04 CFDF C09D 167/02 PKX C09D 167/02 PKX // B29K 33:00 67: 00 B29L 9:00 C08L 67:03

Claims (2)

[Claims] 1. A polyester film having a sulfonate group-containing component of 7 mol% or more and 18 mol% or less, a naphthalenedicarboxylic acid component of 20 mol% or more and 93 mol% or less, and a second-order transition point of 60 ° C. or more on at least one surface of the polyester film. Polyester resin (A) having a temperature of 110 ° C or lower, a component having a sulfonate group of less than 7 mol%, and a second-order transition point of 50 ° C or higher and 10
A laminated film provided with an easily-adhesive coating film formed by applying an aqueous coating solution containing a polyester resin (B) and / or an acrylic resin (C) at 0 ° C. or lower, followed by drying and stretching. 2. The aqueous coating liquid comprises 20 to 90% by weight of polyester resin (A), 0 to 80% by weight of polyester resin (B) and / or acrylic resin (C) as solid content.
The laminated film according to claim 1, which comprises 0 to 80% by weight.