JP2000336308A - Polyester film readily adherent to ink image receiving layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject film having excellent adhesiveness to an ink image receiving layer and opacifying properties, useful as image receiving paper for an ink-jet printer, etc., by laminating a coating film composed of a specific aqueous polyester, an acrylic copolymer, a specified crosslinking agent, etc., having a prescribed surface energy to at least one side of a polyester film. SOLUTION: This film is obtained by laminating a coating film comprising components composed of (A) 15-40 wt.% of an aqueous polyester having 20-90 deg.C glass transition point, (B) 15-40 wt.% of an acrylic copolymer, (C) 15-45 wt.% of a polyvinyl alcohol having 80-99 mol% saponification degree, (D) 3-25 wt.% of fine particles having 20-80 nm average particle diameter and (E) 5-20 wt.% of a crosslinking agent of formula I (R is a group of formula II, formula II or formula III) as main components, having 50-65 dyne/cm surface energy to at least one side of a polyester film preferably having >=60 glossiness, <=20% light transmittance and whiteness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester film having an ink-receiving layer, which is easy to adhere to, and more particularly, to an image-receiving paper excellent in concealing property and excellent in adhesion to water-based ink-receiving layers such as ink jet printers, and water resistance. The present invention relates to an ink-receiving layer easy-adhesion polyester film useful for an ink-receiving layer.

[0002]

2. Description of the Related Art A polyester film represented by a polyethylene terephthalate film has been widely used as a base film of a film for an image receiving paper.
In recent years, with the demand for color printers, new printing methods such as an ink jet method have been developed. An image receiving paper film for such a printing method is disclosed in JP-A-64-364.
No. 79 and Japanese Patent Application Laid-Open No. 1-95091, it is necessary to form an ink image receiving layer on a film. As the ink image receiving layer, a porous material having good ink absorbability is used, but the ink image receiving layer has poor adhesion to a polyester film used as a base film.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink-receiving layer having excellent adhesiveness and concealing properties.
An object of the present invention is to provide an ink-receiving layer easy-adhesion polyester film useful for an image-receiving paper for an ink-jet printer.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
According to the present invention, there is provided a film obtained by laminating a coating film on at least one surface of a polyester film, wherein the coating film comprises: (A) 15 to 40% by weight of an aqueous polyester having a secondary transition point of 20 to 90 ° C; B) Acrylic copolymer 15-4
0% by weight, (C) 15 to 45% by weight of polyvinyl alcohol having a saponification degree of 80 to 90 mol%, and (D) an average particle size of 2
The main component is a component consisting of 3 to 25% by weight of fine particles of 0 to 80 nm and (E) 5 to 20% by weight of a crosslinking agent represented by the following formula (I), and the surface energy of the coating film is 50 to 65 dy.
and ne / cm.

[0005]

Embedded image

(Polyester Film) The polyester constituting the polyester film of the present invention includes, for example, an aromatic dicarboxylic acid component such as terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 4,4'-diphenyl dicarboxylic acid. For example, a polyester composed of a glycol component such as ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and 1,6-hexanediol is preferable,
Especially polyethylene terephthalate, polyethylene-2
6-Naphthalene dicarboxylate is preferred. Also,
Copolymerized polyester such as the above components may be used.

[0007] Organic or inorganic fine particles as a lubricant may be added to the polyester, if necessary, in order to improve the winding property in the production of the film and the transportability of the film in coating the ink image receiving layer. It is preferable to include them. Examples of such fine particles include calcium carbonate, calcium oxide, aluminum oxide, kaolin, silicon oxide, zinc oxide, crosslinked acrylic resin particles, crosslinked polystyrene resin particles, urea resin particles, melamine resin particles, crosslinked silicone resin particles, and the like. Also, besides fine particles, colorants, antistatic agents, antioxidants, lubricants, catalysts, polyethylene, polypropylene, ethylene-propylene-polymer, other resins such as olefinic ionomers, etc., as long as the transparency is not impaired. It can be arbitrarily contained.

It is preferable to use a polyester film (white polyester film) having a gloss of 60 ° or more, a light transmittance of 20% or less and a white color as the polyester film in the present invention. This white polyester film is obtained by adding a white pigment such as titanium oxide and / or barium sulfate to polyester, for example, for 5 to 5 hours.
It can be obtained by containing 20% by weight. Further, the white polyester film preferably has a glossiness of 50 or more from the sharpness of the printed matter when used as an image receiving paper, and preferably has a light transmittance of 20% or less from the design of the printed matter.

The polyester film of the present invention comprises:
A biaxially stretched film having a heat shrinkage of 1% or less when held at 150 ° C. for 30 minutes has good dimensional stability when a polyester film is used as an image receiving paper, and suppresses printing misalignment and the like. It is preferable because it is possible. A biaxially stretched film having such a heat shrinkage is obtained by, for example, setting the film density to 1.390 g / cm ³ or more by heat setting or heat treatment at a temperature of Tg or more of polyester after biaxial stretching. be able to.

(Coating film) In the present invention, (A) aqueous polyester, (B) acrylic copolymer, (C) polyvinyl alcohol, (D) fine particles, and (E) the following formula (I) are used for the polyester film. A coating film containing a crosslinking agent as a main component is laminated.

[0011]

Embedded image

The (A) aqueous polyester used as a component for forming the coating film is a water-soluble or dispersible polyester. Such aqueous polyesters include terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, hexahydroterephthalic acid, 4,4'-
Carboxylic acid components such as diphenyldicarboxylic acid, phenylindanedicarboxylic acid, adipic acid, sebacic acid, 5-sulfoisophthalic acid, trimellitic acid, dimethylolpropionic acid, and 5-Na sulfoisophthalic acid, 5-K
A dicarboxylic acid component having a sulfonate group such as sulfoisophthalic acid or 5-K sulfoterephthalic acid; ethylene glycol, diethylene glycol, neopentylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4- Examples of the polyester include a hydroxy compound component such as cyclohexanedimethanol, glycerin, trimethylolpropane, and an alkylene oxide adduct of bisphenol-A.

(A) When it is necessary to further impart hydrophilicity to the aqueous polyester, a sulfonic acid group or a carboxylic acid group may be introduced into the polyester, or a polyether component may be introduced into the polyester. it can. As a component imparting hydrophilicity, with respect to all carboxylic acid components in the molecule,
It is preferably from 1 to 16 mol%, particularly from 1.5 to 1 mol%.
It is preferably 4 mol%. If the dicarboxylic acid component having a sulfonic acid salt group is less than 1 mol%, the hydrophilicity of the aqueous polyester may be insufficient, while if it exceeds 16 mol%, the moisture resistance of the coating film may be reduced.

The (A) aqueous polyester must have a secondary transition point (Tg) of 20 to 90 ° C.
It is preferable that it is -80 degreeC. If the Tg is less than 20 ° C., the film is likely to be blocked, while if it exceeds 90 ° C., the film has poor abrasion and adhesion, which is not preferable.

The acrylic copolymer (B) used as a component for forming the above-mentioned coating film includes acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, sodium acrylate, ammonium acrylate, 2-hydroxyethyl acrylate, Methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, sodium methacrylate, ammonium methacrylate, 2-
It is a copolymer obtained by polymerizing two or more monomers such as hydroxyethyl methacrylate, glycidyl methacrylate, acrylic methacrylate, sodium vinyl sulfonate, sodium methallyl sulfonate, acrylamide, methacrylamide, and N-methylol methacrylamide. These monomers can be used in combination with other unsaturated monomers such as styrene, vinyl acetate, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, and divinylbenzene. Further, the acrylic copolymer (B) can also be used as a modified acrylic copolymer, for example, a block copolymer modified with polyester, polyurethane, silicone, epoxy, phenol resin, or the like, or a graft copolymer.

The polyvinyl alcohol (C) used as a component for forming the coating film has a saponification degree of 80 to 90.
mol%. This saponification degree is 80mol
%, The moisture resistance of the coating film is reduced, while if it exceeds 90 mol%, the adhesion to the ink image-receiving layer is undesirably reduced.

The fine particles (D) used as the component for forming the coating film are organic or inorganic fine particles having a particle size of 2%.
It is of 0 to 80 nm. Such fine particles include calcium carbonate, calcium oxide, aluminum oxide, kaolin, silicon oxide, zinc oxide, crosslinked acrylic resin particles,
Examples include crosslinked polystyrene resin particles, melamine resin particles, crosslinked silicone resin particles, and the like. When the particle size of the fine particles is 2
If the thickness is less than 0 nm, the film is likely to be blocked, while if it exceeds 80 nm, the shaving property is undesirably reduced.

Further, the crosslinking agent (E) used as a component for forming the coating film is a compound represented by the following formula (I). By using this compound, the adhesiveness between the coating film and the ink image receiving layer is improved. It will be extremely strong.

[0019]

Embedded image

In the present invention, the proportions of (A) the aqueous polyester, (B) the acrylic copolymer, (C) the polyvinyl alcohol, (D) the fine particles and (E) the crosslinking agent are as follows:
(A) 15 to 40% by weight of an aqueous polyester, (B) 15 to 40% by weight of an acrylic copolymer, (C) 15 to 45% by weight of polyvinyl alcohol, (D) 3 to 25% by weight of fine particles,
(E) 5 to 20% by weight of a crosslinking agent. If the proportion of the component (A) is less than 15% by weight, the adhesion to the polyester film is insufficient, while if it exceeds 40% by weight, the adhesion to the ink image receiving layer is undesirably reduced. If the proportion of the component (B) is less than 15% by weight, the water-resistant adhesiveness to the ink image-receiving layer is insufficient, while if it exceeds 40% by weight, the adhesiveness to the polyester film is undesirably reduced. If the proportion of the component (C) is less than 15% by weight, the adhesion to the ink image-receiving layer will be insufficient, while if it exceeds 45% by weight, the blocking resistance will be undesirably reduced. When the ratio of the component (D) is 3
If the amount is less than 25% by weight, the lubricity (transportability) of the film is insufficient. When the proportion of the component (E) is less than 5% by weight, the adhesion to the ink receiving layer after printing with an ink jet printer is insufficient, while when it exceeds 20% by weight, the blocking resistance is reduced and the adhesion to the polyester film is poor. It is not preferable because it decreases.

The coating film of the present invention needs to have a surface energy of 50 to 65 dyne / cm, particularly preferably 52 to 60 dyne / cm. When the surface energy is less than 50 dyne / cm, the coating properties and adhesiveness of the aqueous ink image-receiving layer become poor. When the surface energy exceeds 65 dyne / cm, the adhesion to the polyester film as a substrate becomes insufficient, It is not preferable because moisture resistance may be insufficient.

Surface energy of 50 to 65 dyne / c
m is a coating film in which (A) the aqueous polyester, (B) the acrylic copolymer, (C) the polyvinyl alcohol, (D) the fine particles and (E) the crosslinking agent are within the scope of the present invention. It can be obtained by laminating with a thickness of 02 to 1 μm.

In the polyester film of the present invention, the center line average roughness (Ra) of the coating film surface is preferably in the range of 10 nm to 250 nm. It is preferable because the adhesion between the coating film and the ink image receiving layer, the abrasion resistance of the coating film, and the blocking resistance and transportability of the laminated film are improved. Such R
The coating film having a can be obtained, for example, by using the fine particles in the above-mentioned ratio as a coating film component.

In the present invention, in addition to the above components, other resins such as oxazoline resin, epoxy resin and melamine resin, antistatic agent, colorant,
Surfactants, ultraviolet absorbers and the like can be used.

(Lamination of Coating Film) In the present invention, a coating film composed of the above components is laminated on at least one surface of the polyester film. For example, an aqueous liquid containing a component for forming a coating film is applied to a stretchable polyester film. After that, drying, stretching and, if necessary, heat treatment can be performed to laminate. The solid concentration of this aqueous liquid is usually 30
% By weight or less, more preferably 10% by weight or less.

The stretchable polyester film is an undrawn polyester film, a uniaxially stretched polyester film or a biaxially stretched polyester film.
Among them, a vertically stretched polyester film uniaxially stretched in a film extrusion direction (longitudinal direction) is particularly preferable.

When the aqueous liquid is applied to the polyester film, if it is carried out in a normal application step, that is, in a step separated from the production step of the film in the biaxially stretched and heat-set polyester film, trash, dust and the like are easily entrained. Not preferred. From such a viewpoint, application in a clean atmosphere, that is, application in a film manufacturing process is preferable. According to this coating, the adhesion of the coating film to the polyester film is further improved.

As a coating method, any known coating method can be 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, a curtain coating method and the like can be used alone or in combination. The coating amount is 0.5 to ²⁰ g per 1 m ² of the running film, and 1 to ²
10 g is preferred. The aqueous liquid is preferably used as an aqueous dispersion or an emulsion.

The stretchable polyester film coated with the aqueous liquid is guided to a drying and stretching step, which can be performed under conditions conventionally accumulated in the art. As preferable conditions, for example, the drying condition is 90.
130 ° C. × 2 to 10 seconds, and the stretching temperature is 90 to 13
0 ° C., the stretching ratio is 3 to 5 times in the machine direction, 3 to 5 times in the transverse direction, and 1 to 3 times in the machine direction if necessary.
80 to 240 ° C. × 2 to 20 seconds.

The thickness of the polyester film after such treatment is preferably 50 to 150 μm, and the thickness of the coating film is preferably 0.02 to 1 μm.

[0031]

The present invention will be further described with reference to the following examples.
In addition, each characteristic value was measured by the following method.

1. Adhesiveness before printing 70% by weight of spherical silica (average particle diameter 18μ, average pore diameter 200 angstrom, average pore volume 1.5cc / g) 70% by weight, polyvinyl alcohol (Kuraray PVA117) 30% by weight on the coating surface of the polyester film Is applied in a dry thickness of 20 μm, and a width 1
A 2.7 mm, 150 mm long scotch tape (No. 600, manufactured by 3M Co.) was adhered to prevent air bubbles from entering, and the top was adhered with a manual load roll described in JIS C2701 (1975). Then cut out to tape width. When the scotch tape was peeled from the sample thus prepared, the state of peeling of the ink image receiving layer from the polyester film was observed, and the adhesion was evaluated as follows. A: No peeling was observed at all and good adhesion B: Slight peeling was observed at the foreign matter portion C: Peeling was noticeably observed

2. Adhesion after printing 70% by weight of spherical silica (average particle diameter 18μ, average pore diameter 200 angstrom, average pore volume 1.5cc / g) 70% by weight, polyvinyl alcohol (Kuraray PVA117) 30% by weight on the coating surface of the polyester film Is applied in a dry thickness of 20 μm, and an ink jet printer (PM-750 manufactured by EPSON) is applied thereon.
The image taken by a digital camera or the like in step C) is taken into a personal computer and printed, and the printed image is 12.7 mm wide and 15 cm long.
0mm scotch tape (No. 60 manufactured by 3M)
0) is adhered so that air bubbles do not enter.
2701 (1975), after being leveled and adhered by a manual load roll, cut out to a tape width. When peeling scotch tape from the sample created in this way,
The peeling state of the ink image receiving layer from the polyester film was observed, and the adhesion was evaluated as follows. A: No peeling was observed at all and good adhesion B: Slight peeling was observed at the foreign matter portion C: Peeling was noticeably observed

3. Water-Resistant Adhesion The grease was impregnated with water from above the ink image-receiving layer, rubbed, and the number of rubbings before the ink-image-receiving layer was dropped was evaluated as described below. A: 50 times or more: extremely good water-resistant adhesiveness B: 30 to 50 times: good water-resistant adhesiveness C: less than 30 times: poor water-resistant adhesiveness

4. Coefficient of friction According to ASTM D 1894-63, a static friction coefficient was measured by applying a load of 1 kg with the front and back surfaces of the film together using a slipper measuring device manufactured by Toyo Tester Co., Ltd. If the coefficient of friction exceeds 0.6, film transportability will be impaired.

5. Blocking property Two films cut to a width of 50 mm are stacked, and 50 kg /
After treatment at 40 ° C. × 50% RH × 17 hours under a load of cm ² , the peel strength (g
/ 50 mm). Evaluation was made as follows by the value of the peel strength. Peel strength ≦ 10 g / 50 mm: good blocking property 10 g / 50 mm <peel strength ≦ 30 g / 50 mm—somewhat good blocking property 30 g / 50 mm <peel strength: poor blocking property

6. Surface energy WA Zisman: “Contact Augle, Wettability and Adhe
sion ", Am. Chem. Soc., (1964), the measured critical surface tension γc was used as the surface energy.

7. Secondary transition point Measured at a heating rate of 20 ° C./min using a Thermal Analyst 2000 differential calorimeter manufactured by DuPont.

8. Intrinsic viscosity The viscosity of the solution with orthochlorophenol solvent is 35 ℃
Was measured and determined.

9. Moisture resistance In the evaluation of the blocking property, the treatment condition was 60 ° C.
Peeling strength (g / 50 mm) was measured in the same manner except that x70% RH x 17 hours. Evaluation was made as follows from the measurement results. Peel strength ≦ 10 g / 50 mm: good moisture resistance 10 g / 50 mm <peel strength ≦ 30 g / 50 mm—somewhat good moisture resistance 30 g / 50 mm ≦ peel strength: poor moisture resistance

10. Gloss Gs (60 °) Gloss is measured according to JIS Z 8741-1962 using a gloss meter GM-3D manufactured by Murakami Color Research Laboratory. The measurement angle is 60 °, the number of measurements is n = 5, and the average value is the value of the gloss Gs (60 °).

11. Light transmittance The light transmittance was measured using a HR-100 haze meter manufactured by Murakami Color Research Laboratory in accordance with ASTM D1003.

12. Heat Shrinkage The shrinkage after heat treatment of the polyester film at 150 ° C. for 30 minutes was measured at a distance between the gauge points of 30 cm.

13. Center line average roughness (Ra) According to JIS B0601, using a high-precision surface roughness meter SE-3FAT manufactured by Kosaka Laboratory Co., Ltd., the radius of the needle is 2 μm, the load is 30 mg, and the magnification is 50,000 times. Under the condition of a cutoff of 0.08 mm, a chart is drawn, and a portion of the measured length L is extracted from the surface roughness curve in the direction of the center line thereof,
When the center line of the extracted portion is the X axis and the direction of the vertical magnification is the Y axis, the roughness curve is represented by Y = f (x), and the value given by the following equation is represented in nm.

[0045]

(Equation 1)

In this measurement, the reference length is 1.25 mm, and
Four samples were measured and represented by an average value.

14. Sharpness The polyester film coated with the ink image-receiving layer was printed on an inkjet printer (PM-
The image photographed by a digital camera or the like at 750C) was taken into a personal computer, printed, and the sharpness of the printed matter was visually observed and evaluated as follows. A: Printing is very clear and good ..... Very good clarity. B: Printing is very good and clarity ..... Clarity is very good. C: Printing is unclear and clarity is poor.・ Poor image quality

Example 1 A polyester (intrinsic viscosity: 0.62) comprising a terephthalic acid component and an ethylene glycol component was melt-extruded onto a rotating cooling drum maintained at 20 ° C. to form an unstretched film. After stretching the stretched film 3.6 times in the machine axis direction, as an aqueous polyester, the acid components are terephthalic acid [60 mol%], isophthalic acid [36 mol%] and 5-Na sulfoisophthalic acid [4 mol%], The glycol component is ethylene glycol [60 mol%] and neopentyl glycol [40
Mol%] (Tg = 30 ° C.,
(Hereinafter simply referred to as [F]) 26% by weight, and as an acrylic copolymer, methyl acrylate [65 mol%], ethyl acrylate [28 mol%], 2-hydroxyethyl methacrylate [2 mol%], N-methylol methacrylamide Acrylic copolymer (number average molecular weight: 248000; hereinafter, simply referred to as [T]) prepared from [5 mol%], 25 wt%, polyvinyl alcohol having a saponification degree of 86 to 89 mol%, 20 wt%, average particle size Aqueous solution having a solid content of 4% by weight, comprising 10% by weight of crosslinked acrylic resin particles of 40 nm, 10% by weight of a compound (Y) represented by the following formula (II) as a crosslinking agent and 9% by weight of polyoxyethylene lauryl ether. The liquid was applied with a roll coater.
Next, the vertically stretched film coated with the aqueous liquid is stretched 4 times in the transverse direction while drying, and further heat-set at 230 ° C. to a thickness of 1 mm.
A biaxially stretched film of 00 μm was obtained. The film thickness of this film is 0.04 μm and the center line average surface roughness is 16n
m, the surface energy was 60 dyne / cm, and the heat shrinkage was 0.9% in the vertical direction and 0.2% in the horizontal direction. Table 1 shows the characteristics of this film.

[0049]

Embedded image

Comparative Example 1 Except that no aqueous liquid was applied,
Table 1 shows the properties of the biaxially stretched polyester film obtained in the same manner as in Example 1.

Examples 2 to 9 Biaxially stretched polyester films were obtained in the same manner as in Example 1 except that the types and ratios of the coating agents were changed as shown in Table 1. Table 1 shows the characteristics of this film.

[0052]

[Table 1]

As is apparent from the results shown in Table 1, the ink-receiving layer easily adhesive polyester film of the present invention is excellent in adhesiveness.

In Tables 1, 2, 3 and 5, F, G, H, (A) of the type of aqueous polyester (Note 1)
I, J, K and L indicate the following compounds. F: Terephthalic acid [60 mol%] / isophthalic acid [36
Mol%]. 5-Na sulfoisophthalic acid [4 mol%] /
Copolymerized polyester of ethylene glycol [60 mol%] / neopentyl glycol [40 mol%] (Tg = 3
0 ° C) G: 2,6-naphthalene dicarboxylic acid [20 mol%]
Isophthalic acid [76 mol%] 5-K sulfoterephthalic acid [4 mol%] / ethylene glycol [50 mol%]
Neopentyl glycol [50 mol%] copolymerized polyester (Tg = 42 ° C.) H: terephthalic acid [90 mol%] isophthalic acid [6 mol%] 5-Na sulfoisophthalic acid [4 mol%] / ethylene glycol [ 95 mol%] / copolymerized polyester of neopentyl glycol [5 mol%] (Tg = 68
C) I: terephthalic acid [60 mol%]-isophthalic acid [36
Mol%]. 5-Na sulfoisophthalic acid [4 mol%] /
Ethylene glycol [20 mol%], 1,4-butanediol [70 mol%], neopentyl glycol [10
Mol%] (Tg = 25 ° C.) J: terephthalic acid [85.9 mol%] isophthalic acid [11 mol%] 5-Na sulfoisophthalic acid [4 mol%] / ethylene glycol [57 mol] %] • 1,4-butanediol [40 mol%] • diethylene glycol [2 mol%] and polyethylene glycol (molecular weight 6
00) [0.1 mol%] copolymerized polyester (Tg =
K: terephthalic acid [16 mol%] isophthalic acid [80
Mol%]. 5-Na sulfoisophthalic acid [4 mol%] /
Diethylene glycol [5 mol%], 1,4-butanediol [60 mol%], neopentyl glycol [35
Mol%] (Tg = 17 ° C.) L: 2,6-naphthalenedicarboxylic acid [77 mol%]
Terephthalic acid [19 mol%] 5-Na sulfoisophthalic acid [4 mol%] / ethylene glycol [90 mol%]
-Copolymerized polyester of neopentyl glycol [10 mol%] (Tg = 98 ° C)

In Tables 1, 3 and 5, T and U of (B) the type of acrylic copolymer (Note 2) indicate the following compounds. T: acrylic copolymer (number average) prepared from methyl acrylate [65 mol%], ethyl acrylate [28 mol%], 2-hydroxyethyl methacrylate [2 mol%], N-methylol methacrylamide [5 mol%] U: methyl acrylate [62 mol%], ethyl acrylate [22 mol%], acrylic acid [1 mol%], 2-
Hydroxyethyl methacrylate [10 mol%], N-
Acrylic copolymer made from methylol methacrylamide [5 mol%] (number average molecular weight: 230,000)

In Tables 1, 3 and 5, P, Q and R of (C) the type of polyvinyl alcohol (Note 3) indicate the following compounds. P: polyvinyl alcohol having a saponification degree of 86 to 89 mol% Q: polyvinyl alcohol having a saponification degree of 74 to 78 mol% R: polyvinyl alcohol having a saponification degree of 92 to 95 mol%

In Tables 1, 3, and 5, (D) M and N of the type of fine particles (Note 4) indicate the following fine particles.

M: Crosslinked acrylic particles having an average particle size of 40 nm N: Colloidal silica particles having an average particle size of 80 nm In Tables 1, 3 and 5, (E) the type of crosslinking agent (Note 5)
Y and Z in the following are compounds of the following formulas (II) and (III).

[0059]

Embedded image

[0060]

Embedded image

Examples 10 to 12 and Comparative Examples 2 and 3
(A) A biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the type of the aqueous polyester was changed as shown in Table 2 and copolymerized polyesters having different Tg were used. Table 2 shows the properties of the obtained film.

[0062]

[Table 2]

As is evident from the results shown in Table 2, the ink-receiving layer easily adhesive polyester film of the present invention has excellent blocking resistance and adhesiveness.

Examples 13 to 19 and Comparative Examples 4 to 13
(A) an aqueous polyester, (B) an acrylic copolymer,
A biaxially stretched polyester film was obtained in the same manner as in Example 1, except that the ratio of (C) polyvinyl alcohol, (D) fine particles and (E) the crosslinking agent was changed as shown in Table 3. Table 3 shows the properties of the obtained film.

[0065]

[Table 3]

As is evident from the results shown in Table 3, the polyester film easily adhered to the ink image-receiving layer of the present invention is excellent in adhesiveness and transportability.

[Examples 20 and 21 and Comparative Examples 14 and 1
5] (D) A biaxially stretched polyester film was obtained in the same manner as in Example 1, except that the particle size of the fine particles was changed as shown in Table 4. Table 4 shows the properties of the obtained film.

[0068]

[Table 4]

As is evident from the results shown in Table 4, the ink-receiving layer easily adhesive polyester film of the present invention has excellent blocking resistance.

[Examples 22 and 23 and Comparative Examples 16 and 1
7] Same as Example 1 except that the ratio of (A) aqueous polyester, (B) acrylic copolymer, (C) polyvinyl alcohol, (D) fine particles and (E) cross-linking agent was changed as shown in Table 5. To obtain a biaxially stretched polyester film. Table 5 shows the properties of the obtained film.

[0071]

[Table 5]

As is evident from the results shown in Table 5, the polyester film having good adhesion to the ink image-receiving layer of the present invention is excellent in adhesiveness and transportability.

Example 22 A composition comprising 90% by weight of a polyester (intrinsic viscosity: 0.62) comprising a terephthalic acid component and an ethylene glycol component and 10% by weight of titanium oxide was placed on a rotary cooling drum maintained at 20 ° C. After being melt-extruded to form an unstretched film, and then stretched 3.6 times in the machine axis direction, the acid components are terephthalic acid [60 mol%] and isophthalic acid [36 mol%] as an aqueous polyester. And a copolymerized polyester (Tg = 30 ° C., hereinafter simply referred to as [F]) comprising 5-Na sulfoisophthalic acid [4 mol%] and a glycol component comprising ethylene glycol [60 mol%] and neopentyl glycol [40 mol%] ) 26% by weight, as an acrylic copolymer, methyl acrylate [65 mol%], ethyl acrylate [28 %], 2-hydroxyethyl methacrylate [2 mol%], N-methylol methacrylamide [5 mol%] acrylic copolymer made from (number average molecular weight: 248,000, hereinafter simply [T] as)
25% by weight, 20% by weight of polyvinyl alcohol having a saponification degree of 86 to 89% by mole, 10% by weight of crosslinked acrylic resin particles having an average particle diameter of 40 nm, Compound 1 represented by the following formula (II)
0% by weight and polyoxyethylene lauryl ether 9
An aqueous liquid having a solids concentration of 4% by weight and having a composition of% by weight was applied using a roll coater. Next, the longitudinally stretched film coated with the aqueous liquid was stretched 4 times in the transverse direction while drying, and further heat-set at 230 ° C. to obtain a biaxially stretched film having a thickness of 100 μm. The film thickness on this film is 0.04μ
m, center line average surface roughness is 60 nm, gloss is 62, light transmittance is 3%, heat shrinkage is 0.9% in the vertical direction, 0.2% in the horizontal direction, sharpness and adhesion are It was good.

[0074]

Embedded image

Comparative Example 18 A biaxially oriented polyester film was obtained in the same manner as in Example 20, except that the copolymerized polyester in Example 26 was changed to L. The coating thickness of this film was 0.03 μm, and the center line average surface roughness was 125
nm, the gloss is 39, the light transmittance is 3%, the heat shrinkage is 0.9% in the vertical direction, 0.2% in the horizontal direction, and the sharpness is insufficient.
Adhesion was also insufficient.

[0076]

The polyester film having good adhesion to the ink image-receiving layer according to the present invention has excellent concealing properties and excellent adhesion to water-based ink-receiving layers of ink jet printers and the like, particularly excellent water-resistant adhesiveness, and is suitable for use as an image receiving paper. Useful.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinji Yano 3-37-19 Koyama, Sagamihara-shi, Kanagawa F-term in Sagamihara Research Center, Teijin Limited (Reference) 2H086 BA19 BA31 BA32 BA34 BA41 BA45 4F006 AA35 AB20 AB24 AB34 AB35 AB56 AB74 BA01 CA01 DA04 4F100 AK21B AK25B AK25J AK41A AK41B AL05B BA02 BA10A BA10B CA02B DE01B DE01H EJ38A GB90 HB00 JA03A JA05B JB05B JD14 JK11 JK15 JL10 JN01 JN21 YY00 YY00A YY00B 4J002 BC035 BE02Y BG01X BG025 BG04X BG05X BG06X BG07X BG13X BQ00X CC185 CD134 CD19X CF14W CF27W CP035 DE086 DE106 DE146 DE236 DJ016 DJ036 FA005 FD144 GF00 4J038 CE022 CG142 DB152 DD001 KA03 MA08 MA13 MA14 PC08

Claims (6)

[Claims] 1. A film in which a coating film is laminated on at least one surface of a polyester film, wherein the coating film comprises: (A) 15 to 40% by weight of an aqueous polyester having a secondary transition point of 20 to 90 ° C .; ) Acrylic copolymer 15-4
0% by weight, (C) 15 to 45% by weight of polyvinyl alcohol having a saponification degree of 80 to 90 mol%, and (D) an average particle size of 2
The main component is a component consisting of 3 to 25% by weight of fine particles of 0 to 80 nm and (E) 5 to 20% by weight of a crosslinking agent represented by the following formula (I), and the surface energy of the coating film is 50 to 65 dy.
Ne / cm. An easily adhesive polyester film for an ink image receiving layer. Embedded image 2. The polyester film according to claim 1, wherein the polyester film has a glossiness of 50 or more, a light transmittance of 20% or less, and is white. 3. The polyester film has a viscosity of 3 ° C. at 150 ° C.
2. The polyester film according to claim 1, which is a biaxially stretched film having a heat shrinkage of 1% or less when held for 0 minutes. 4. A coating film having a center line average roughness Ra of 10
3. The polyester film according to claim 2, wherein the thickness of the polyester film is in the range of nm to 250 nm. 5. The polyester film having a light transmittance of 2
3. The polyester film according to claim 2, which is 0% or less and white, and is further provided with an aqueous ink image receiving layer on the coating film. 6. The polyester film according to claim 5, which is used for an image receiving paper for an ink jet printer.