KR100248318B1 - Laminated film - Google Patents

Abstract

(A) an aromatic polyester film; And (B) present on at least one side of the aromatic polyester film (A), wherein (a) the dicarboxylic acid component having a sulfonate group is 1 to 16 mol% based on the total amount of the dicarboxylic acid component, 50 to 80% by weight copolyester having a temperature of 20 to 90 ° C, (b) 10 to 30% by weight of poly (alkylene oxide) having a number average molecular weight of 600 to 2000 and (c) an average particle diameter of 20 to 80 nm A laminated film containing a hydrophilic coating layer containing 3 to 25% by weight of the fine particles (wherein the weight% is based on the sum of the components (a), (b) and (c)) and having a surface energy of 54 dyne / cm or more. . The laminated film provides transparency for overhead projectors and is useful as recording paper for ink jet printers.

Description

Laminated film

The present invention relates to a laminated film. More specifically, in a laminated film having a high surface energy hydrophilic coating layer, for example, by providing an aqueous ink receiving layer thereon to provide excellent transparency for an overhead projector. It is about.

Polyester films represented by polyethylene terephthalate films have been widely used in the past as films for overhead projectors (hereinafter abbreviated as OHP). In this case, in addition to the adhesion to toner, the polyester film also requires transparency and a traveling property. However, the polyester film itself has no adhesiveness to toner and is therefore used after a surface treatment imparting this property.

In recent years, with the spread of color OHP, new OHP film production technologies such as ink jet printing have been developed. In such an OHP film for ink jet printing, formation of an ink receiving layer on the film is required. A porous and good absorbency of the ink is used for the ink receiving layer, but the adhesion to the polyester base film is poor.

In Japanese Patent Laid-Open No. 63-115747

(A) a water-insoluble copolyester comprising a mixed dicarboxylic acid component and a glycol component containing 0.5 to 15 mol% of sulfonic acid metal base-containing dicarboxylic acid with respect to the total amount of the dicarboxylic acid component; and

(B) the following formula

(In formula, n and m are integers of 6-1200, R <_1> , R <_2> is a C1-C4 alkylene group or arylene group, R <_1> R <_2> , and either of R <_1> and R <_2> is A thermoplastic resin film laminate is disclosed in which a layer containing a mixture of a co-condensate represented by an alkylene group or an arylene group having 3 or more carbon atoms is laminated on at least one side thereof.

This film laminate exhibits antistatic properties. In this publication, no laminated film having a coating film containing fine particles is disclosed, and the surface energy of the coating film is not considered at all. Therefore, the publication provides an ink aqueous layer on a coating film, which is advantageously used as transparency for OHP, and no laminated film having a relatively high surface energy having excellent adhesion with the ink aqueous layer has been presented.

An object of the present invention is to provide a novel laminated film.

Another object of the present invention is to provide a laminated film having a high hydrophilic coating layer having high surface energy and excellent conveyability.

Still another object of the present invention is to provide a laminated film having transparency for OHP, which has high transparency and excellent adhesion to an aqueous ink aqueous layer.

It is still another object of the present invention to provide a laminated film for recording paper having high concealability and excellent adhesion to an aqueous ink aqueous layer.

Another object of the present invention is to provide a transparency for OHP having the transparent laminated film as described above of the present invention.

It is still another object of the present invention to provide a recording sheet having a high concealability laminated film as described above.

Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above object and advantages of the present invention are first,

(A) an aromatic polyester film,

(B) present on at least one side of the aromatic polyester film (A), the following composition:

(a) 50 to 80% by weight of a copolyester having a dicarboxylic acid component having a sulfonate group in an amount of 1 to 16 mol% based on the total amount of the dicarboxylic acid component and a secondary transition point temperature of 20 to 90 ° C,

(b) 10 to 30% by weight of polyalkylene oxides having a number average molecular weight of 600 to 2000 and

(c) 3 to 25% by weight of fine particles having an average particle diameter of 20 to 80 nm (wherein the weight% is based on the sum of the components (a), (b) and (c)), and the surface energy of 54 dyne / cm or more It can achieve by the laminated | multilayer film containing the hydrophilic film layer which has.

The laminated | multilayer film of this invention contains an aromatic polyester film (A) and a hydrophilic film layer (B) as mentioned above.

The aromatic polyester of an aromatic polyester film (A) is polyester which uses aromatic dicarboxylic acid as a dicarboxylic acid component, and aliphatic diol as a diol component.

As aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, 2, 6- naphthalene dicarboxylic acid, 4, 4'- diphenyl dicarboxylic acid, etc. are mentioned as a preferable thing, for example.

Moreover, as aliphatic diol, ethylene glycol, 1, 4- butane diol, 1, 4- cyclohexane dimethanol, 1, 6- hexane diol etc. are mentioned as a preferable thing, for example.

Each of these aromatic dicarboxylic acids and aliphatic diols can be used alone or in combination of two or more.

As an aromatic polyester, polyester whose at least 95 mol% of a dicarboxylic acid component is terephthalic acid or 2,6-naphthalene dicarboxylic acid, and at least 95 mol% of an aliphatic diol is ethylene glycol is preferable, and especially polyethylene tere Preference is given to polyesters comprising phthalates and polyethylene-2,6-naphthalene dicarboxylates.

In order to improve the winding property at the time of manufacturing a film, the conveyance property of the film at the time of using as an OHP film, a recording paper, etc., such an aromatic polyester is preferable to contain organic or inorganic fine particles as a lubricant as needed. Examples of such fine particles include inorganic fine particles such as calcium carbonate, calcium oxide, aluminum oxide, kaolin, silicon oxide and zinc oxide; And organic fine particles such as crosslinked acrylic resin particles, crosslinked polystyrene resin particles, melamine resin particles, and crosslinked silicone resin particles. In addition to the fine particles, colorants such as titanium oxide and barium sulfate, antistatic agents, antioxidants, lubricants, catalysts, and other resins may be optionally contained as necessary.

The hydrophilic coating layer (B) contains the copolyester (a), the poly (alkylene oxide) (b), and the fine particles (c) as described above.

The copolyester (a) is 1-16 mol% with respect to the dicarboxylic acid component total amount of the dicarboxylic acid component which has a sulfonate group, and has a secondary transition temperature of 20-90 degreeC.

The dicarboxylic acid component constituting the copolyester (a) is, for example, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, hexahydro terephthalic acid, 4,4 'in addition to the dicarboxylic acid component having a sulfonate group. -Diphenyl dicarboxylic acid, phenylindan dicarboxylic acid, adipic acid, sebacic acid, 5-sulfoisophthalic acid, trimellitic acid, dimethylol propionic acid and the like.

Examples of the dicarboxylic acid component having a sulfonate group include alkali metal salts of 5-sulfoisophthalic acid and alkali metal salts of 5-sulfoterephthalic acid. Of these, alkali metal salts of 5-sulfoisophthalic acid are preferred. As an alkali metal salt, Na salt, Li salt, and K salt are mentioned, for example.

The dicarboxylic acid component having a sulfonate group needs to occupy 1 to 16% by weight relative to the total amount of the dicarboxylic acid component, and preferably 1.5 to 14% by weight.

As the diol constituting the copolyester (a), for example, ethylene glycol, diethylene glycol, neopentylene glycol, 1,4-butane diol, 1,6-hexane diol, 1,6-cyclohexane dimethanol, Glycerin, trimethylol propane, and alkylene oxide adducts of bisphenol-A.

Each of the dicarboxylic acid and diol constituting the copolyester (a) can be used alone or in combination of two or more.

If the dicarboxylic acid component having a sulfonate group in the copolyester (a) is less than 1 mol%, the hydrophilicity of the copolyester is insufficient, whereas if it exceeds 16 mol%, the moisture resistance of the coating film is lowered, which is not preferable.

Moreover, the secondary transition point (Tg) of copolyester (a) needs to be 20-90 degreeC. When Tg is less than 20 degreeC, a film roll is easy to block, and when it exceeds 90 degreeC, since adhesiveness of a film falls, it is unpreferable.

The secondary transition point is preferably 30 to 80 ° C.

As poly (alkylene oxide) (b), the polymer or copolymer of a C2-C4 alkylene oxide is preferable. Examples thereof include poly (ethylene oxide), poly (propylene oxide), poly (ethylene oxide / propylene oxide) copolymers, and the like. Of these, poly (ethylene oxide) and poly (ethylene oxide / propylene oxide) copolymers are particularly preferred.

Poly (alkylene oxide) has a number average molecular weight in the range of 600-2000.

When this molecular weight is less than 600, the blocking property of a film and the moisture resistance of a coating film fall, and when it exceeds 2000, since the adhesiveness of the poly (alkylene oxide) with respect to an ink aqueous layer falls, it is unpreferable.

Preferred number average molecular weight is in the range of 1000 to 1500.

Moreover, as microparticles | fine-particles (c), you may use microparticles | fine-particles of any of organic and inorganic. Examples of such fine particles include inorganic fine particles such as calcium carbonate, calcium oxide, aluminum oxide, kaolin, silicon oxide, and zinc oxide; And organic fine particles such as crosslinked acrylic resin particles, crosslinked polystyrene resin particles, melamine resin particles, and crosslinked silicone resin particles. Among these, organic fine particles are preferable.

The microparticles | fine-particles (c) are the range whose average particle diameter is 20-80 nm.

If the average particle diameter is less than 20 nm, the film roll is easy to block, while if it exceeds 80 nm, the wear resistance of the film is lowered, which is not preferable.

In the present invention, the hydrophilic coating layer (B) is based on the total weight of the components (a), (b) and (c), and 50 to 80% by weight of the component (a) and 10 to 30% by weight of the component (b). And (c) 3 to 25 wt% of the component, preferably 60 to 80 wt% of the component (a), 10 to 20 wt% of the component (b) and 5 to 15 wt% of the component (c).

If the proportion of the component (a) is less than 50% by weight, the adhesion of the coating layer (B) with the polyester film is insufficient, while if the proportion of the component (a) is more than 80% by weight, the adhesion with the ink aqueous layer is unfavorable. . If the proportion of the component (b) is less than 10% by weight, the adhesiveness with the ink aqueous layer is insufficient, whereas if the proportion of the component (b) is more than 30% by weight, blocking resistance is lowered, which is not preferable. Moreover, when the ratio of (c) component is less than 3 weight%, the slipperiness | lubricacy (transport property) of a film runs short, and when it exceeds 25 weight%, since abrasion resistance falls, it is not preferable.

In addition, this hydrophilic coating layer (B) has surface energy of 54 dyne / cm or more.

When surface energy is less than 54 dyne / cm, sufficient adhesiveness cannot be acquired between the ink receiving layer formed on this film layer. The surface energy is preferably at least 60 dyne / cm.

The laminated | multilayer film of this invention has two forms as a base material with a high transparency of an aromatic polyester film (A), and a thing with little transparency.

When the transparency of the base material (A) is high, the light transmittance of the base material (A) is preferably 85% or more, and the haze value is 10% or less.

In this case, it is preferable that the centerline average roughness R _a of the substrate surface is in the range of 5 to 15 nm.

According to the present invention, by using the laminated film of the present invention having this kind of substrate, the light transmittance of the aromatic polyester film (A), which is suitable as the transparency for the overhead projecter, is 85% or more, and the haze value is 10%. Below, the laminated | multilayer film which has an aqueous ink aqueous layer further on the said hydrophilic film layer is provided similarly.

Moreover, when the transparency of a base material is low, the light transmittance of the base material (A) becomes like this. Preferably it is 20% or less and is white.

In this case, Ra on the surface of the substrate is in the range of 100 to 250 nm.

By using the laminated | multilayer film of this invention which has this kind of base material, according to this invention, the aromatic polyester film (A) suitable as a recording paper for inkjet printers has a light transmittance of 20% or less, and is white, and said hydrophilicity The laminated film which has an aqueous ink aqueous layer further on a coating layer is similarly provided.

The ink-aqueous layer is a layer obtained by containing spherical silica such as fine particles having an average particle diameter of 10 to 30 µm and polyvinyl alcohol as a hydrophilic polymer, and a layer obtained from the aqueous slurry illustrated in Japanese Patent Laid-Open No. 1-95091. .

The laminated film of this invention which consists of an aromatic polyester film (A) and a hydrophilic film layer (B) prepares the aqueous liquid containing the said (a), (b) and (c) component which comprises a hydrophilic film layer, for example, It can apply | coat and dry on a stretchable aromatic polyester film, and it can extend | stretch as needed and can manufacture. Application | coating of aqueous solution is preferable application | coating in a clean atmosphere, ie, application | coating in a film manufacturing process. And according to such application | coating, the adhesiveness to the polyester film of a hydrophilic film layer further improves.

When the application of the aqueous liquid to the polyester film is performed in a normal coating step, that is, biaxially stretched and heat-set a polyester film in a step separate from the manufacturing step of the film, dust, garbage, etc. are liable to be rolled up and are not preferable. .

Moreover, a stretchable polyester film is an unstretched polyester film, a uniaxial stretched polyester film, or a biaxially stretched polyester film. Among these, the longitudinally stretched polyester film uniaxially stretched in the extrusion direction (vertical direction) of the film is preferable.

As the hydrophilic coating layer coating method, a known coating method is applied. For example, a roll coating method, a gravure coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method and a curtain coating method can be applied alone or in combination.

The coating amount is 0.5 to 20 g, more preferably 1 to 10 g per 1 m 2 of running film. It is preferable to use an aqueous dispersion or emulsion as an aqueous liquid.

As the component for forming the coating film, other resins such as melamine resin, antistatic agent, colorant, surfactant, ultraviolet absorber and the like can be used for the aqueous solution, in addition to the above components (a), (b) and (c).

Solid content concentration of an aqueous liquid is 2-30 weight% normally, and 2-10 weight% is more preferable.

The stretchable polyester film coated with the aqueous liquid is also introduced into a drying, stretching process. Such a process can be performed on the conditions accumulated conventionally in the art. As preferable conditions, dry conditions are 90-130 degreeCx2 to 10 second, for example, extending | stretching temperature is 90-130 degreeC, the draw ratio is 3 to 5 times in the longitudinal direction, 3 to 5 times in the horizontal direction, and if necessary, again in the vertical direction 1 To 3 times, and the case of heat setting is 180 to 240 ° C x 2 to 20 seconds.

In the laminated | multilayer film of this invention after such a process, it is preferable that the thickness of a polyester film (A) is 50-150 micrometers, and the thickness of a hydrophilic film layer (B) is 0.02-1 micrometer.

The present invention will be described in more detail with reference to the following examples.

In addition, each characteristic value was measured with the following method.

1.adhesive

70 weight% of spherical silica (average particle diameter: 18 micrometers, average pore diameter: 200 cc, average pore volume: 1.5 cc / g) and 30 weight% of polyvinyl alcohol (Kurarese, PVA 117) are contained in the coating film surface of a polyester film. Aqueous slurry (solid content concentration 45% by weight) was applied by drying to a thickness of 20 占 퐉 so as to prevent bubbles from entering a 12.7 mm wide and 150 mm long Scotch tape (NO. 600, manufactured by 3M) on the ink aqueous layer obtained. After sticking and sticking evenly with a manual load roll based on JIS C2701 (1975), it cuts out to tape width. Thus, the peeling state from the polyester film of the ink receiving layer at the time of peeling a scotch tape from the produced sample was observed and adhesiveness was evaluated as follows.

A: Peeling was not observed at all and adhesiveness was favorable.

B: Slight peeling is observed in the foreign material part.

C: Peeling is remarkably observed.

2. Friction Coefficient

According to ASTMD1894-63, using the sleep tester by Toyo Tester Co., the surface and back surface of the film were matched, the load 1kg was applied, and the static friction coefficient was measured. If the coefficient of friction exceeds 0.6, it will interfere with the conveyability of the film.

3. Blocking property

Two sheets of film cut to a width of 50 mm were stacked and treated at 40 ° C. × 50% RH × 17 hours under a load of 50 kg / cm 2, and then the peel strength (g / 50 mm) at the place where the load was applied by a tensile tester was measured. It evaluated as follows by the value of peeling strength.

Good blocking property: Peel strength ≤ 10g / 50mm

Slightly good blocking property: 10g / 50mm <Peel strength ≤ 30g / 50mm

Poor blocking property: 30g / 50mm <Peel strength

4. Surface energy

WA Zisman. "Contact Angle, Wettability and Adhesion", Am. Chem. Soc., (1964)], the measured critical surface tension ( c) was taken as surface energy.

5. Secondary transition point (Tg)

It was measured at the temperature increase rate of 20 degree-C / min by the DuPont Thermal Analyst 2000 type differential calorimeter.

6. Intrinsic Viscosity

The viscosity of the solution by orthochlorophenol solvent was measured and measured at 35 degreeC.

7. Water dispersibility

The coating agent was diluted with water to form an aqueous dispersion of 0.2% by weight, and the light transmittance was measured using a quartz cell with a double beam spectrophotometer (228 A type machine). It evaluated as follows by the measurement result.

Good water dispersibility: light transmittance ≥ 50%

Water Dispersibility Slightly Good: 50%> Light Transmittance ≥ 30%

Poor water dispersibility: 30% ＞ Light transmittance

8. Moisture resistance

In evaluation of the said blocking property, peeling strength (g / 50mm) was measured by the same method except the process conditions being 60 degreeC x 70% RH * 17 hours. It evaluated as follows by the measurement result.

Good moisture resistance: peel strength ≤ 10g / 50mm

Moisture resistance slightly good: 10g / 50mm <Peel strength ≤ 30g / 50mm

Poor moisture resistance: 30g / 50mm ≤ peel strength

9.light transmittance and haze

It measured with the HR-100 type haze meter by Murakami Shikizu Jutsugen Co., Ltd. in accordance with ASTMD1003.

10. Heat Shrinkage

The shrinkage rate after heat treatment of the polyester film at 150 ° C. for 30 minutes was measured at a distance of 30 cm between the shop marks.

11.Centerline mean roughness (Ra) of the surface

In accordance with JIS BO601, using a high precision surface roughness meter SE-3FAT manufactured by Koshikagen Co., Ltd., the chart is drawn under the conditions of a needle radius of 2 μm, load of 30 mg, magnification of 50,000 times, and cut-off of 0.08 mm From the curve, the part of measurement length (L) is pulled out in the direction of its center line, and this part shows the center line as the X axis and the direction of the vertical magnification as the Y axis, and when the illuminance curve is expressed as Y = f (x), The given value is defined as the center line average roughness (Ra: nm) of the surface.

In this measurement, four measurements were made with a reference length of 1.25 mm, and the average was shown.

Example 1

This unstretched sheet from polyethylene terephthalate having an intrinsic viscosity of 0.64 was stretched 3.5 times in the longitudinal direction. On this monoaxially oriented film, 60 mol% of terephthalic acid, 37 mol% of isophthalic acid, and 3 mol% of 5-Na sulfoisophthalic acid, 40 mol% of ethylene glycol, 40 mol% of neopentylene glycol, and bisphenol-A 65% by weight of copolyester (hereinafter referred to as E) (Tg = 30 ° C) consisting of 20 mol% of ethylene oxide adducts, (ii) 16% by weight of polyethylene oxide (hereinafter referred to as P) of number average molecular weight 1000, ( V) A composition consisting of 10% by weight of crosslinked acrylic resin particles having an average particle diameter of 40 nm and 9% by weight of polyoxyethylene nonylphenyl ether, and an aqueous liquid having a solid content concentration of 4% by weight was applied with a roll coater. Subsequently, the longitudinal uniaxial stretched film to which the aqueous liquid was applied was stretched four times in the transverse direction while drying, heat-fixed again at 230 ° C. to obtain a biaxially stretched film having a thickness of 100 μm. The coating film thickness in this film was 0.03 micrometer. The properties of this film are shown in Table 1.

Comparative Example 1

Table 1 shows the properties of the biaxially stretched polyester film obtained in the same manner as in Example 1 except that the aqueous solution was not applied.

EXAMPLES 2-7

A biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the type and ratio of the coating agent was changed as shown in Table 1. The properties of this film are shown in Table 1.

TABLE 1

(Note 1) The numerical value in a kind () of copolyester shows mol%.

F: 2,6-naphthalene dicarboxylic acid (20) and isophthalic acid (76)

5-K sulfoterephthalic acid (4) / ethylene glycol (50)

Neopentylene glycol (50) copolymer (Tg = 42 ° C.)

(2) Types of polyalkylene oxides

Q: polypropylene oxide with a number average molecular weight of 1200

As is apparent from Table 1, the film of the present invention is excellent in adhesiveness and transportability.

[Examples 8 to 11 and Comparative Examples 2 and 3]

(A) The kind of copolyester was changed as shown in Table 2, and the biaxially stretched polyester film was obtained like Example 1 except having used another copolyester of Tg. The characteristic of the obtained film is shown in Table 2. As is apparent from Table 2, the film of the present invention is excellent in blocking, transparency and adhesion.

[Table 2]

(Note 3) Copolymer composition of (A) (Value shows mol%)

[Examples 12 to 16 and Comparative Examples 4 and 5]

A biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the ratio of the dicarboxylic acid component containing the sulfonate group of the copolyester (A) was changed as shown in Table 3. The characteristic of the obtained film is shown in Table 3. As apparent from Table 3, the coating agent used in the present invention is excellent in water dispersibility, and the film of the present invention is excellent in moisture resistance.

TABLE 3

[Examples 17-19 and Comparative Examples 6, 7]

A biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the ratios of copolyester (A), polyalkylene oxide (B), and fine particles (C) were changed as shown in Table 4. The properties of the obtained film are shown in Table 4. As apparent from Table 4, the film of the present invention is excellent in adhesiveness and transportability.

TABLE 4

[Examples 20 and 21 and Comparative Examples 8 and 9]

A biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the ratios of copolyester (A), polyalkylene oxide (B), and fine particles (C) were changed as shown in Table 5. The properties of the obtained film are shown in Table 5. As apparent from Table 5, the film of the present invention is excellent in adhesiveness and transportability.

TABLE 5

[Examples 22 and 23 and Comparative Examples 10 and 11]

A biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the particle diameters of the fine particles (C) were changed as shown in Table 6. The properties of the obtained film are shown in Table 6. As is apparent from Table 6, the film of the present invention is excellent in blocking property and transparency.

TABLE 6

Examples 24 and 25 and Comparative Examples 12 and 13

A biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the ratios of copolyester (A), polyalkylene oxide (B), and fine particles (C) were changed as shown in Table 7. The properties of the obtained film are shown in Table 7. As is apparent from Table 7, the film of the present invention is excellent in transparency and transportability.

TABLE 7

The polyester film of the said Example of this invention is excellent in the adhesiveness between an ink receiving layer and a base film, the transparency of a film and conveyance property are favorable, and are useful as a film for OHP.

Example 26

According to Example 1, a composition consisting of 90% by weight of polyester (covalent viscosity 0.62) consisting of terephthalic acid component and ethylene glycol component and 10% by weight of titanium oxide instead of a uniaxially oriented film made of polyethylene terephthalate having an intrinsic viscosity of 0.64 was prepared. Melt extrusion was carried out on a rotary cooling drum kept at 20 ° C. to form an unstretched film, and then the same procedure as in Example 1 was used except that a uniaxially stretched film was stretched 3.6 times in the longitudinal direction. It was. The properties of the obtained biaxially stretched laminated film are shown in Table 8. Ra of the coating film was 120 nm, and surface energy was 60 dyne / cm. The light transmittance of the polyester base film was 3%. Moreover, the thermal contraction rate of the obtained biaxially stretched laminated film was 0.9% in the longitudinal direction of the film, and 0.2% in the horizontal direction.

Comparative Example 14

Except that the aqueous solution was not applied, the properties of the biaxially stretched polyester film obtained in the same manner as in Example 26 are shown in Table 8.

[Examples 27-33]

Except having changed the kind and ratio of the coating agent as shown in Table 8, it carried out similarly to Example 26, and obtained the biaxially stretched polyester film. The properties of this film are shown in Table 8.

TABLE 8

(Note 1) and (Note 2) The meanings of the symbols are the same as the notes in Table 1.

Examples 33 to 36 and Comparative Examples 15 and 16

The kind of copolyester (A) was changed as shown in Table 9, and the biaxially stretched polyester film was obtained like Example 26 except Tg using the other copolyester. The properties of the obtained film are shown in Table 9. As is apparent from Table 9, the film of the present invention is excellent in blocking property and tack.

TABLE 9

(Note 3) The meanings of the symbols are the same as in Table 2.

[Examples 37 to 41 and Comparative Examples 17 and 18]

A biaxially stretched polyester film was obtained in the same manner as in Example 26 except that the ratio of the dicarboxylic acid component containing the sulfonate group of the copolyester (A) was changed as shown in Table 10. The properties of the obtained film are shown in Table 10. As is apparent from Table 10, the coating agent in the present invention is excellent in water dispersibility, and the film of the present invention is excellent in moisture resistance.

TABLE 10

[Examples 42 to 44 and Comparative Examples 19 and 20]

A biaxially stretched polyester film was obtained in the same manner as in Example 26 except that the ratios of copolyester (A), polyalkylene oxide (B), and fine particles (C) were changed as shown in Table 11. The properties of the obtained film are shown in Table 11. As is apparent from Table 11, the film of the present invention is excellent in adhesiveness and transportability.

TABLE 11

Examples 45 and 46 and Comparative Examples 21 and 22

A biaxially stretched polyester film was obtained in the same manner as in Example 26 except that the ratios of copolyester (A), polyalkylene oxide (B), and fine particles (C) were changed as shown in Table 12. The properties of the obtained film are shown in Table 12. As is apparent from Table 12, the film of the present invention is excellent in adhesiveness and transportability.

TABLE 12

[Examples 47, 48 and Comparative Examples 23, 24]

A biaxially stretched polyester film was obtained in the same manner as in Example 26 except that the particle diameters of the fine particles (C) were changed as shown in Table 13. The properties of the obtained film are shown in Table 13. As is apparent from Table 13, the film of the present invention is excellent in blocking property.

TABLE 13

[Examples 49 and 50 and Comparative Examples 25 and 26]

A biaxially stretched polyester film was obtained in the same manner as in Example 26 except that the ratios of the copolyester (A), the polyalkylene oxide (B), and the fine particles (C) were changed as shown in Table 14. The properties of the obtained film are shown in Table 14. As is apparent from Table 14, the film of the present invention is excellent in adhesiveness and transportability.

TABLE 14

Claims (17)

(A) an aromatic polyester film, and (B) a hydrophilic coating layer present on at least one side of the aromatic polyester film (A), wherein the hydrophilic coating layer has a surface energy of 54 dyne / cm or more and has a composition of the following (a) to (c) Characterized laminated film: (a) 60 to 80% by weight of a copolyester having a dicarboxylic acid component having a sulfonate group in an amount of 1 to 16 mol% of the total dicarboxylic acid components and having a secondary transition point of 20 to 90 ° C. , (b) 10 to 20% by weight of poly (alkylene oxide) having a number average molecular weight of 600 to 2,000, and (c) 5 to 15% by weight of fine particles having an average particle diameter of 20 to 80 nm (wherein the weight% of the components (a), (b) and (c) is the components (a), (b) and (c) Is based on the sum of 2. The laminated film according to claim 1, wherein the dicarboxylic acid component having a sulfonate group contained in the copolyester (a) in the hydrophilic coating layer is an alkali metal salt of 5-sulfoisophthalic acid. The laminated film according to claim 2, wherein the alkali metal salt of 5-sulfoisophthalic acid is a lithium salt, sodium salt or potassium salt. The ratio of the dicarboxylic acid component which has a sulfonate group is 1.5-14 mol% with respect to the total amount of a dicarboxylic acid component, The laminated | multilayer film of Claim 1 characterized by the above-mentioned. The laminated film according to claim 1, wherein the poly (alkylene oxide) (b) in the hydrophilic coating layer is a poly (ethylene oxide) or a poly (ethylene oxide / propylene oxide) copolymer. The laminated film according to claim 1, wherein the fine particles (c) in the hydrophilic coating layer are crosslinked organic polymer fine particles. The laminated film according to claim 1, wherein the hydrophilic coating layer has a surface energy of 60 dyne / cm or more. The laminated film according to claim 1, wherein the aromatic polyester film (A) is a biaxially stretched film having a heat shrinkage of 1% or less upon heating at 150 ° C. for 30 minutes. The laminated film according to claim 8, wherein the aromatic polyester film (A) is a polyethylene terephthalate or polyethylene-2,6-naphthalene dicarboxylate film. The laminated film of Claim 1 whose light transmittance of an aromatic polyester film (A) is 85% or more, and haze value is 10% or less. The centerline average roughness Ra of the surface of an aromatic polyester film (A) exists in the range of 5-15 nm, The laminated | multilayer film of Claim 10 characterized by the above-mentioned. The light transmittance of the aromatic polyester film (A) is 85% or more, and the haze value is 10% or less, and further has an aqueous ink receiving layer on the hydrophilic coating layer. Laminated film. 13. The laminated film of claim 12 having transparency for an overhead projector. The light transmittance of an aromatic polyester film (A) is 20% or less, and is white, The laminated | multilayer film of Claim 1 characterized by the above-mentioned. The centerline average roughness Ra of the surface of an aromatic polyester film (A) exists in the range of 100-250 nm, The laminated | multilayer film of Claim 14 characterized by the above-mentioned. The laminated film according to claim 1, wherein the aromatic polyester film (A) has a light transmittance of 20% or less and is white, and further has an aqueous ink aqueous layer on the hydrophilic coating layer. The laminated film according to claim 16, which is a recording paper for an ink jet printer.