JP2000336309A - 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 an aqueous binder, a water-soluble polymer, 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) 30-80 wt.% of an aqueous binder such as a polyester copolymer, an acrylic copolymer, etc., (B) 10-40 wt.% of a water-soluble polymer such as a polyvinyl alcohol, etc., (C) 3-25 wt.% of fine particle having 20-80 nm average particle diameter (e.g. calcium carbonate, kaolin, etc.), and (D) 5-20 wt.% of aqueous crosslinking agent of formula I (R is a group of formula II, formula III or formula IV) as main components, having 50-70 dyne/cm surface energy to at least one side of a polyester film preferably having 260 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 a good adhesion to an ink receiving layer, and more particularly to an ink useful for image receiving paper, which has excellent concealing properties and excellent adhesion to aqueous ink receiving layers such as ink jet printers. The present invention relates to an easily-adhesive polyester film for an image 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) 30 to 80% by weight of an aqueous binder, and (B) 10 to 40% by weight of a water-soluble polymer. , (C) having an average particle size of 20 to 80
The main component is a component comprising 3 to 25% by weight of fine particles having a particle size of 3 nm and (D) 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 70 dyne / c.
m, which is attained by a polyester film having an ink image-receiving layer and an easily adhering polyester film.

[0005]

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(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. The white polyester film preferably has a gloss of 60 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 in view of 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 print 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) an aqueous binder, (B) a water-soluble polymer,
A coating film mainly composed of (C) fine particles and (D) a crosslinking agent represented by the following formula (I) is laminated.

[0011]

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The (A) aqueous binder used as a component for forming the coating film includes (A-1) a copolymerized polyester, (A-2) an acrylic copolymer, (A-3) an acrylic-modified polyester, and (A-3) an acrylic-modified polyester. -4) Polyurethane.

(Aqueous binder) (A-1) Terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, hexahydroterephthalic acid, 4,4'-diphenyldicarboxylic acid, Carboxylic acid components such as phenylindanedicarboxylic acid, adipic acid, sebacic acid, 5-sulfoisophthalic acid, trimellitic acid, dimethylolpropionic acid and 5-N
a sulfoisophthalic acid, 5-K sulfoisophthalic acid, 5
And dicarboxylic acids having a sulfonic acid group such as -K sulfoterephthalic acid.

Further, as the glycol component constituting the copolymerized polyester (A-1), ethylene glycol, diethylene glycol, neopentylene glycol, 1,4
-Butanediol, 1,6-hexanediol, 1,4
-Hydroxy compounds such as cyclohexanedimethanol, glycerin, trimethylolpropane, and alkylene oxide adducts of bisphenol-A can be mentioned.

(A-1) The copolyester is a copolyester composed of the above-mentioned acid component and glycol component, and is used as an aqueous solution, aqueous dispersion or emulsion.

In the (A-1) copolymerized polyester, the ratio of the dicarboxylic acid component having a sulfonic acid group is 1 to 16 mol%, particularly 1.5 to 1.5 mol%, based on all carboxylic acid components in the molecule.
It is preferable that the content be 14 mol% because the hydrophilicity becomes excellent. If the amount of the dicarboxylic acid component having a sulfonic acid salt group is less than 1 mol%, the hydrophilicity of the copolyester may be insufficient, while if it exceeds 16 mol%, the moisture resistance of the coating film may be undesirably reduced.

The (A-1) copolymerized polyester preferably has a secondary transition point (Tg) of 20 to 90 ° C., particularly preferably 25 to 80 ° C. Tg is 2
If the temperature is lower than 0 ° C., the film is liable to block, while 9
If the temperature exceeds 0 ° C., the abrasion and the adhesiveness of the film are undesirably reduced.

(A-2) The acrylic copolymer 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-hydroxyethyl methacrylate,
Glycidyl methacrylate, acrylic methacrylate,
It is a copolymer obtained by polymerizing two or more monomers such as sodium vinyl sulfonate, sodium methallyl sulfonate, acrylamide, methacrylamide, N-methylol methacrylamide and the like.

These monomers can be used in combination with other unsaturated monomers such as styrene, vinyl acetate, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride and divinylbenzene.

The acrylic copolymer (A-2) may be used as a modified acrylic copolymer such as a block polymer or a graft polymer modified with, for example, polyester, polyurethane, silicone, epoxy, or phenol resin. it can.

(A-3) The acrylic-modified polyester is
Polyester modified with an acrylic resin component,
It is synthesized by polymerizing a polyester and an acrylic resin dissolved or dispersed in water in water.

(A-3) Examples of the components constituting the acrylic-modified polyester include the following polybasic acids or their ester-forming derivatives and polyols or their ester-forming derivatives. That is, as the polybasic acid component,
Terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid, dimer acid, etc. it can. Examples of the polyol component include ethylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylene glycol, dimethylolpropane, and poly (ethylene oxide) glycol. And poly (tetramethylene oxide) glycol. Two or more of these can be used. Also, a small amount of an unsaturated polybasic acid component such as maleic acid and itaconic acid, and a hydroxycarboxylic acid such as p-hydroxybenzoic acid can be used.

As the acrylic resin component of the acrylic modified polyester (A-3), the following vinyl monomers can be exemplified. That is, alkyl acrylate, alkyl methacrylate (alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc. 2-hydroxyethyl acrylate, 2-
Hydroxy-containing monomers such as hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N, N-dialkylacrylamide, N, N-dialkylmethacrylate (Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, and a cyclohexyl group.), N-alkoxy Acrylamide, N-alkoxymethacrylamide, N, N-dialkoxyacrylamide, N, N-dialkoxymethacrylamide (alkoxy groups include methoxy group, ethoxy group, butoxy group, Amide group-containing monomers such as N-methylolacrylamide, N-methylolmethacrylamide, N-phenylacrylamide and N-phenylmethacrylamide, and epoxy groups such as glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether. Containing monomers, such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrenesulfonic acid and salts thereof (such as sodium salt, potassium salt, ammonium salt, and tertiary amine salt). Monomers containing a galoxy group or a salt thereof, monomers of acid anhydrides such as maleic anhydride and itaconic anhydride, vinyl isocyanate, allyl isocyanate, styrene, α-methylstyrene, vinyl methyl ether, vinyl ethyl ether , Vinyl trialkoxysilane, alkyl maleic acid monoester,
Monomers of alkyl fumaric acid monoester, alkyl itaconic acid monoester, acrylonitrile, methacrylonitrile, vinylidene chloride, ethylene, propylene, vinyl chloride, vinyl acetate, butadiene and the like can be mentioned. These monomers can be copolymerized using one kind or two or more kinds.

The present invention is not limited to these exemplified monomers.

Among these, the polyester modified with the acrylic resin component is a resin composed of methyl methacrylate / isobutyl methacrylate / acrylic acid / methacrylic acid / glycidyl methacrylate as the acrylic resin component, and terephthalic acid / isophthalic acid as the polyester. A resin composed of a polyester copolymer composed of / 5-Na sulfoisophthalic acid / ethylene glycol / neopentyl glycol is preferred.

(A-4) The polyurethane can be selected from those prepared for an aqueous dispersion by an ordinary method. Specifically, the following polyol component, polyisocyanate component, and chain length extending component are used. And a usual polymerization reaction using a crosslinking component or the like as a raw material.

The polyol component can be appropriately selected from polyester diol, polycarbonate diol, polyether diol and the like. Specifically, polyesters such as polyethylene terephthalate, polyethylene isophthalate, polyethylene cyclohexanedicarboxylate, polyethylene adipate, polyhexylene adipate, polycaprolactone,
Examples include polyethers such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxypropylene triol, and polyoxytetramethylene glycol, acrylic polyols, and castor oil.

The polyisocyanate component is, specifically,
Xylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, aliphatic diisocyanates such as isophorone diisocyanate, tolylene diisocyanate, phenylene diisocyanate,
4,4'-diphenylmethane diisocyanate, 1,5
-Aromatic diisocyanates such as naphthalene diisocyanate.

Examples of the chain extender or crosslinking agent include ethylene glycol, propylene glycol, butanediol, hexanediol, diethylene glycol, trimethylolpropane, glycerin, hydrazine, ethylenediamine, diethylenetriamine,
4'-diaminodicyclohexylmethane, water and the like. The water dispersible functional group unit contained in these
The introduction may be carried out in any of the constituent units. For example, a method of using dimethylolpropionic acid or the like as a chain extender, introducing a carboxylic acid and neutralizing to form a salt is used. The polyurethane that can be used in the present invention is preferably a copolymerized polyurethane composed of the constituent units in the range described above.

(Water-soluble polymer) As the (B) water-soluble polymer used as a component for forming the coating film, polyvinyl alcohol, polyvinyl pyrrolidone and the like can be preferably mentioned.

Polyvinyl alcohol has a saponification degree of 75.
It is preferably about 95 mol%. If the saponification degree is less than 75 mol%, the moisture resistance of the coating film may be reduced, while if it exceeds 95 mol%, the adhesion to the ink image receiving layer may be reduced. Further, polyvinyl alcohol is preferably cation-modified because of good adhesion to the ink image receiving layer.

Polyvinylpyrrolidone has a K value of 26-1.
00 is preferred. If the K value is less than 26, the strength of the coating film may be weak. Further, when the K value exceeds 100, the adhesiveness to the ink image receiving layer may decrease. In addition, polyvinyl alcohol and polyvinylpyrrolidone are preferable if the average molecular weight is 40,000 or more because the coating film has excellent abrasion resistance.

(Fine Particles) The fine particles (C) used as a component for forming the coating film are organic or inorganic fine particles having a particle diameter of 20 to 80 nm. Such fine particles include calcium carbonate, calcium oxide, aluminum oxide, kaolin, silicon oxide, zinc oxide, crosslinked acrylic resin particles, crosslinked polystyrene resin particles, melamine resin particles,
Examples include cross-linked silicone resin particles. If the particle size of the fine particles is less than 20 nm, the film is likely to be blocked, while if it exceeds 80 nm, the shaving property is undesirably reduced.

(Cross-Linking Agent) The cross-linking agent (D) used as a component for forming the coating film is a compound represented by the following formula (I). Becomes extremely strong.

[0035]

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(Characteristics of Coating Film) In the present invention, the mixing ratio of (A) an aqueous binder, (B) a water-soluble polymer, (C) fine particles, and (D) a crosslinking agent is as follows:
To 80% by weight, (B) 10 to 40% by weight of a water-soluble polymer,
(C) 3 to 25% by weight of fine particles, and (D) 5 to 20% by weight of a crosslinking agent. If the proportion of the component (A) is less than 30% by weight, the adhesion to the polyester film is insufficient, while if it exceeds 80% by weight, the adhesion to the ink image receiving layer is undesirably reduced. When the proportion of the component (B) is less than 10% by weight, the adhesion to the ink image receiving layer is insufficient, while when it exceeds 40% by weight, the blocking resistance is undesirably reduced. When the proportion of the component (C) is less than 3% by weight, the film has insufficient lubricity (transportability). (D) Component ratio is 5
If the amount is less than 20% by weight, the adhesion to the ink image receiving layer after printing by an ink jet printer is insufficient.

The coating film of the present invention needs to have a surface energy of 50 to 70 dyne / cm, particularly preferably 55 to 65 dyne / cm. If the surface energy is less than 50 dyne / cm, the coating properties and adhesion of the aqueous ink image-receiving layer will be poor, and if it exceeds 70 dyne / cm, the adhesion to the polyester film as the substrate will be insufficient, It is not preferable because moisture resistance may be insufficient.

Surface energy of 50 to 70 dyne / c
The coating film of m is a coating film in which (A) an aqueous binder, (B) a water-soluble polymer, (C) fine particles and (D) a crosslinking agent represented by the formula (I) are within the scope of the present invention. 0.02-1
It can be obtained by laminating with a thickness of 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, other components such as a melamine resin, an antistatic agent, a coloring agent, a surfactant, an ultraviolet absorber and the like can be used in addition to the above components as components for forming a coating film.

(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 process, 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.

[0047]

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. 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.

4. 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

5. Surface energy WA Zisman: “Contact Augle, Wettability and Adhe
sion ", Am. Chem. Soc., (1964), the surface energy was defined as the critical surface tension γc measured. 6. Secondary transition point Thermal Analysis 20 manufactured by Dupont.
It was measured at a heating rate of 20 ° C./min with a 00 type differential calorimeter.

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

8. 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

9. 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 °).

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

11. 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.

12. 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.

[0059]

(Equation 1)

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

13. 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 obtain an unstretched film. After stretching the stretched film 3.6 times in the machine axis direction, as an aqueous binder, the acid components are terephthalic acid [60 mol%], isophthalic acid [36 mol%], and 5-Na sulfoisophthalic acid [4 mol%], A glycol component is composed of ethylene glycol [70 mol%] and neopentyl glycol [30 mol%], 51% by weight of a copolymerized polyester (Tg = 40 ° C, hereinafter simply referred to as [E]), and a saponification degree of 86 to 8
Composition comprising 9 mol% of polyvinyl alcohol 20 wt%, crosslinked acrylic resin particles having an average particle diameter of 40 nm 10 wt%, compound (Y) represented by the following formula (II) 10 wt%, and polyoxyethylene lauryl ether 9 wt%. Aqueous solution having a solid content of 4% by weight was applied by 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 of this film is 0.03 μm, the center line average surface roughness is 15 nm, the surface energy is 61 dyne / cm,
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.

[0063]

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[Comparative Example 1] Except that the aqueous liquid was not applied,
Table 1 shows the properties of the biaxially stretched polyester film obtained in the same manner as in Example 1.

Examples 2 to 12 A biaxially stretched polyester film was 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.

[0066]

[Table 1]

As is evident from the results shown in Table 1, the polyester film having good adhesion to the ink image-receiving layer of the present invention is excellent in adhesiveness.

In Tables 1, 2 and 4, E, F, G and H in (A) Types of aqueous binders (Note 1) indicate the following compounds. E: terephthalic acid [60 mol%] isophthalic acid [36
Mol%]. 5-Na sulfoisophthalic acid [4 mol%] /
Copolymerized polyester of ethylene glycol [70 mol%] / neopentyl glycol [30 mol%] (Tg = 4
0 ° C.) F: Acrylic copolymer made from methyl acrylate [65 mol%], ethyl acrylate [28 mol%], 2-hydroxyethyl methacrylate [2 mol%], N-methylol methacrylamide [5 mol%] (Number average molecular weight: 248000) G: A polyester modified with an acrylic resin has an acrylic resin portion of 40% by weight and methyl methacrylate [6].
0 mol%], isobutyl methacrylate [30 mol%], acrylic acid [5 mol%], methacrylic acid [2 mol%], glycidyl methacrylate [3 mol%], and a polyester portion is 60% by weight and an acid component. Terephthalic acid [60 mol%], isophthalic acid [30 mol%], 5-sodium sulfoisophthalic acid [10 mol%], ethylene glycol [80] as a glycol component
Mol%] and neopentyl glycol [20 mol%] H: Terephthalic acid [40 mol%] · isophthalic acid [60
Mol%] / polyethylene polyol consisting of ethylene glycol [16 mol%] diethylene glycol [64 mol%] neopentyl glycol [12 mol%]
Polyurethane containing propionate dimethanol [8 mol%] as a chain extender and isophorone diisocyanate as an isocyanate

In Tables 1, 2 and 4, (B) P, Q, R, T, U, W and X of the kind of water-soluble polymer (Note 2) are the following compounds. Show. P: polyvinyl alcohol having a saponification degree of 86 to 89 mol% Q: polyvinyl alcohol having a saponification degree of 76 to 82 mol% R: polyvinyl alcohol having a saponification degree of 91 to 94 mol% T: polyvinyl pyrrolidone having a K value of 26 to 23 and an average molecular weight of 40,000 U: polyvinylpyrrolidone having a K value of 90 to 100 and an average molecular weight of 12,000,000 W: cation-modified polyvinyl alcohol having a saponification degree of 74 to 80 mol% X: cation-modified polyvinyl alcohol having a saponification degree of 86 to 91 mol%

In Tables 1, 2 and 4, M and N of (C) the type of fine particles (Note 3) indicate the following compounds. 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, 2, and 4, (D) Type of crosslinking agent (Note 4)
Y and Z in the following are compounds of the following formulas (II) and (III).

[0071]

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[0072]

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[Examples 13 to 16 and Comparative Examples 2 to 5]
A biaxially stretched polyester film was prepared in the same manner as in Example 1 except that the ratio of (A) an aqueous binder, (B) a water-soluble polymer, (C) fine particles and (D) a crosslinking agent was changed as shown in Table 2. Obtained. Table 2 shows the properties of the obtained film.

[0074]

[Table 2]

As is evident from the results shown in Table 2, the polyester film having good adhesion to the ink image-receiving layer of the present invention is excellent in adhesiveness and transportability.

[Examples 17 and 18 and Comparative Examples 6 and 7]
(C) 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 3. Table 3 shows the properties of the obtained film.

[0077]

[Table 3]

As is evident from the results shown in Table 3, the ink-receiving layer easily adhesive polyester film of the present invention has excellent blocking resistance.

[Examples 19 and 20 and Comparative Examples 8 and 9]
A biaxially stretched polyester film was prepared in the same manner as in Example 1 except that the ratio of (A) an aqueous binder, (B) a water-soluble polymer, (C) fine particles and (D) a crosslinking agent was changed as shown in Table 4. Obtained. Table 4 shows the properties of the obtained film.

[0080]

[Table 4]

As is evident from the results shown in Table 4, the polyester film having a good adhesion to the ink image-receiving layer of the present invention is excellent in adhesiveness and transportability.

Example 21 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 rotating cooling drum maintained at 20 ° C. After being melt-extruded into 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 binder. And 5-Na sulfoisophthalic acid [4 mol%], and a glycol component composed of ethylene glycol [70 mol%] and neopentyl glycol [30 mol%] (Tg = 40 ° C., hereinafter simply referred to as [E]) ) 51% by weight, degree of saponification 86-8
It comprises 20% by weight of 9% by weight of polyvinyl alcohol, 10% by weight of crosslinked acrylic resin particles having an average particle diameter of 40 nm, 10% by weight of a crosslinking agent (Y) represented by the following formula (II), and 9% by weight of polyoxyethylene lauryl ether. An aqueous liquid having a solid concentration of 4% by weight of the composition was applied by 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 of this film is 0.03 μm, the center line average surface roughness is 58 nm, the gloss is 67, the light transmittance is 3%, the heat shrinkage is 0.9% in the vertical direction, and 0 in the horizontal direction. .2%, sharpness,
The adhesion was good.

[0083]

Embedded image

[0084]

The polyester film having good adhesion to the ink image-receiving layer of the present invention has excellent concealing properties and excellent adhesion to the aqueous ink-image-receiving layer of an ink jet printer or the like, and is useful for an image receiving paper.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shinji Yano 3-37-19 Koyama, Sagamihara City, Kanagawa Prefecture F-term in Sagamihara Research Center, Teijin Limited (Reference) 2H086 BA19 BA31 BA32 BA35 BA41 4F006 AA35 AB20 AB24 AB35 AB37 AB54 AB56 BA01 CA01 4F100 AK01B AK01C AK02B AK02C AK21B AK21C AK25B AK25C AK25J AK41A AK41B AK41C AK41J AK51B AK51C AL01B AL01C AL06B AL06C AR00B AR00C AR00D AS00B AS00C BA03 BA04 BA06 BA10B BA10C BA10D BA13 DD07A DE01B DE01C EH46B EH46C EJ38A GB90 JA03A JA07B JA07C JA20B JA20C JB05B JB05C JB05D JB09B JB09C JD14 JD14D JK06 JL10A JM02B JM02C JN02 JN08A JN21A YY00A YY00B YY00C 4J002 BC033 BE02X BG003 BG01W BG04W BG05W BG06W BG07W BG13W BJ00X CC183 CD134 CD19W CF03W CF04W CF05W CF08W CF14W CK03W CK04W CK05W CP033 DE086 DE106 DE146 DE236 DJ016 DJ036 FD013 FD016 FD104 GS00 4J038 CE022 CG141 CK 032 DB152 DD001 DG001 KA03 MA08 MA14 PC08

Claims (11)

[Claims] 1. A film having a coating film laminated on at least one surface of a polyester film, wherein the coating film comprises (A) 30 to 80% by weight of an aqueous binder, (B) 10 to 40% by weight of a water-soluble polymer, (C) Average particle size is 20 to 80
The main component is a component comprising 3 to 25% by weight of fine particles having a particle size of 3 nm and (D) 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 70 dyne / c.
m, an easily adherent polyester film for an ink image receiving layer. Embedded image 2. The polyester film according to claim 1, wherein the aqueous binder is at least one selected from the group consisting of a polyester copolymer, an acrylic copolymer, an acrylic-modified polyester, and a polyurethane. . 3. The polyester film according to claim 1, wherein (B) the water-soluble polymer is at least one selected from the group consisting of polyvinyl alcohol and polyvinyl pyrrolidone. 4. The water-soluble polymer (B) has a degree of saponification of 75 to 9
2. The polyester film according to claim 1, which is 5 mol% of polyvinyl alcohol. (B) a water-soluble polymer having a saponification degree of 74 to 9;
2. The polyester film according to claim 1, wherein the polyvinyl alcohol is cationically modified at 1 mol%. 6. The water-soluble polymer (B) having a K value of 26 to 1
2. The polyester film according to claim 1, which is polyvinylpyrrolidone having an average molecular weight of 40,000 or more. 7. The polyester film according to claim 1, wherein the polyester film has a glossiness of 60 or more, a light transmittance of 20% or less and a white color. 8. A polyester film having 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. 9. The center line average roughness Ra of the coating film surface is 10 n.
4. The polyester film as set forth in claim 3, wherein the polyester film has a thickness of from m to 250 nm. 10. The polyester film according to claim 7, wherein the polyester film has a light transmittance of 20% or less, is white, and is further provided with an aqueous ink image-receiving layer on the coating film. 11. The polyester film according to claim 10, which is used for an image receiving paper for an ink jet printer.