JP2001105714A - Base polyester film for ink jet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base polyester film for ink jet which can satisfy the adhesion to an ink receiving layer and water resistance in ink jet printing. SOLUTION: This base polyester film for ink jet has a constitution wherein a coat layer prepared by mixing a polyester resin containing a sulfonic acid group and/or a sulfonate group with a polyvinyl alcohol derivative in a solid weight ratio of 50/50-95/5 is formed at least on one surface of a polyester film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate polyester film for ink jet, and more particularly, the present invention relates to a substrate polyester film for ink jet capable of satisfying adhesiveness to an ink receiving layer and water resistance in ink jet printing. It is about.

2. Description of the Related Art Biaxially oriented polyester films have excellent properties such as dimensional stability, mechanical properties, heat resistance, transparency and electrical properties. It is widely used as a base film for many uses such as various photographic materials and graphic arts materials.

[0002] Generally, biaxially oriented polyester films have a highly crystalline orientation on the surface, so that various types of paints and resins,
It has the disadvantage of poor adhesion to ink. For this reason, conventionally, studies have been made to impart adhesiveness to the polyester film surface by various methods.

Conventionally, methods for imparting adhesiveness include, for example, surface activation methods such as corona discharge treatment, ultraviolet irradiation treatment, and plasma treatment of the surface of a polyester film serving as a substrate, and chemicals such as acid, alkali, and amine aqueous solutions. And a method in which various resins such as an acrylic resin, a polyester resin, a urethane resin, and a polyolefin resin are provided as a primer layer on a film surface (JP-A-58-29626, JP-A-Showa 6-29).
0-149442, JP-A-62-152850, JP-A-1-108037, etc.).

[0004]

However, the above-mentioned polyester film has a problem that the adhesion to the ink receiving layer in ink jet printing is insufficient. An object of the present invention is to improve the disadvantages of the prior art and to provide a laminated polyester film capable of satisfying the adhesiveness to an ink receiving layer and the water resistance in ink jet printing.

[0005]

In order to achieve the above object, the ink-jet base polyester film of the present invention comprises:
On at least one surface of the polyester film, a coating layer formed by mixing a polyester resin containing a sulfonic acid group and / or a sulfonic acid group and a polyvinyl alcohol derivative at a solid content weight ratio of 50/50 to 95/5 is formed. In a preferred embodiment, the polyvinyl alcohol derivative is a polyvinyl acetal resin.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the substrate polyester film for ink jet of the present invention, the polyester of the polyester film is a generic name of polymers having an ester bond as a main bonding chain of a main chain. Ethylene terephthalate, ethylene-2,6-
Naphthalate, butylene terephthalate, ethylene-
α, β-bis (2-chlorophenoxy) ethane-4,
At least one selected from 4′-dicarboxylate and the like
Those having the main components as the main components can be used. One of these components may be used alone, or two or more of them may be used in combination. Among them, it is particularly preferable to use a polyester containing ethylene terephthalate as a main component when comprehensively judging quality, economy and the like. When heat acts on the film, polyethylene-2,6-naphthalate, which is excellent in heat resistance and rigidity, is more preferable.

[0007] Further, these polyesters may further contain some other dicarboxylic acid component or diol component, preferably 2 or more.
0 mol% or less may be copolymerized. Further, in the polyester, various additives such as antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents And a nucleating agent may be added to such an extent that its properties are not deteriorated.

The intrinsic viscosity of the above-mentioned polyester (25 ° C.
Measured in o-chlorophenol) is 0.4-1.2.
dl / g is preferable, and more preferably 0.5 to 0.8 d
Polyesters in the 1 / g range are preferred in practicing the present invention.

[0009] The polyester film using the above polyester is preferably biaxially oriented when the coating layer is provided. With a biaxially oriented polyester film, generally, a polyester sheet or film in an unstretched state is stretched about 2.5 to 5 times in each of the longitudinal direction and the width direction, and then subjected to a heat treatment to complete the crystal orientation. And shows a biaxially oriented pattern in wide-angle X-ray diffraction.

[0010] The thickness of the polyester film is not particularly limited and may be appropriately selected, but is usually 1 to 500 µm, preferably 5 to 300 µm from the viewpoint of mechanical strength and handleability. Further, the obtained films can be used by being bonded by various methods.

As the polyester film of the present invention, a white polyester film is preferably used in addition to a transparent polyester film. The white polyester film is not particularly limited as long as it is a polyester film colored white, and preferably has a whiteness of 85 to 150%, more preferably 90 to 1%.
30%, and the optical density is preferably 0.5 to 5, more preferably 1 to 3. For example, when a base film having a small whiteness is used, the pattern or coloring on the opposite surface is transmitted and the appearance of the printed layer on the surface is easily impaired.On the other hand, when the optical density is small, sufficient light reflection is not obtained. However, when viewed with the naked eye, whiteness is reduced and the opposite surface is affected, which is not preferable.

The method for obtaining such optical density and whiteness is not particularly limited, but it can be usually obtained by adding a resin incompatible with inorganic particles or polyester. The amount to be added is not particularly limited, but in the case of inorganic particles, preferably 3 to 35% by weight, more preferably 5 to 2% by weight.
5% by weight. On the other hand, when adding an incompatible resin, it is preferably 3 to 35% by volume, more preferably 5 to 2% by volume.
5% by volume.

The inorganic particles are not particularly limited, but preferably have an average particle size of 0.1 to 4 μm, more preferably 0.3 to 4 μm.
Inorganic particles of up to 1.5 μm can be used as typical examples. Specifically, barium sulfate, calcium carbonate, calcium sulfate, titanium oxide, silica, alumina, talc, clay and the like or a mixture thereof can be used. These inorganic particles can be used as other inorganic compounds such as calcium phosphate, titanium oxide, mica. , Zirconia, tungsten oxide, lithium fluoride, calcium fluoride and the like. Further, among the above-mentioned inorganic particles, those having a Mohs hardness of 5 or less, preferably 4 or less are more preferable because the whiteness is further increased.

The resin incompatible with the above-mentioned polyester is not particularly limited. For example, when mixed with polyethylene terephthalate or polyethylene-2,6-naphthalate, acrylic resin, polyethylene,
Polypropylene, a modified olefin resin, a polybutylene terephthalate resin, a phenoxy resin, polyphenylene oxide, or the like can be used, and may be used in combination with the above-described inorganic particles. For example, in particular, a white polyester film having a specific gravity of 0.5 to 1.5, which has a cavity therein and has a hollow inside, is preferably mixed with a resin incompatible with inorganic particles or polyester and biaxially stretched, since the printing characteristics are improved. .

In the polyester film for ink jet of the present invention, a polyester resin containing a sulfonate group and a polyvinyl alcohol derivative are coated on at least one surface of a polyester film as a base material in a solid content weight ratio of 50/50 to 95/5. A coating layer formed by mixing at a predetermined ratio is formed.

The polyester resin used in the coating layer according to the present invention is not particularly limited as long as it contains a sulfonic acid group and / or a sulfonic acid group and has an ester bond in a main chain or a side chain. It can be obtained by polycondensation from an acid component and a glycol component. Although not particularly limited, the polyester resin is preferably copolymerized with a monomer having a sulfonate group in an amount of 2 to 15 mol%. If the amount of the sulfonic acid salt group is too small, there is a tendency that sufficient adhesiveness and water resistance cannot be obtained.

The acid component constituting the polyester resin includes terephthalic acid, isophthalic acid, phthalic acid, 2,5-
Dimethyl terephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bisphenoxyethane-p, p'-
Dicarboxylic acid, phenylindanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecandioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4
-Such as cyclohexanedicarboxylic acid and ester-forming derivatives thereof, and also as an acid component containing a sulfonic acid group or a sulfonate group, for example, sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfoisophthalic acid, Sulfonaphthalene-2,7-dicarboxylic acid, sulfo-p-xylylene glycol, 2-sulfo-
Alkali metal salts such as 1,4-bis (hydroxyethoxy) benzene, alkaline earth metal salts, ammonium salts and the like, and as an acid component containing a carboxylic acid group and its base, trimellitic acid, trimellitic anhydride, pyromellitic acid Acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, 1,
2,3,4-butanetetracarboxylic acid, 1,2,3,4
-Pentanetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-cyclohexene-
1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid,
1,2,5,6-naphthalenetetracarboxylic acid, ethylene glycol bistrimellitate, 2,2 ', 3,3'
-Diphenyltetracarboxylic acid, thiophene-2,3
Alkali metal salts such as 4,5-tetracarboxylic acid and ethylenetetracarboxylic acid, alkaline earth metal salts, and ammonium salts can be used, but are not limited thereto.

The glycol components constituting the polyester resin include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol,
Polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octane Diol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1,
3-diol, neopentyl glycol, 2-ethyl-
2-butyl-1,3-propanediol, 2-ethyl-
2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexane Dimethanol, 1,4-cyclohexanedimethanol, 2,2
4,4-tetramethyl-1,3-cyclobutanediol, 4,4′-thiodiphenol, bisphenol A,
4,4'-methylenediphenol, 4,4 '-(2-norbornylidene) diphenol, o-, m-, and p
-Dihydroxybenzene, p, p'-isopropylidenediphenol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-
1,4-diol and the like can be used, but the present invention is not limited thereto.

In the present invention, the method for introducing a sulfonic acid group and / or a sulfonic acid group into the polyester resin is not particularly limited, but the component containing a sulfonic acid group or a sulfonic acid group in the acid component as described above. Is preferably used. Also,
Sulfonate groups include alkali metal salts (Li, N
a, K, etc.), alkaline earth metal salts (Mg, Ca, Ba)
And the like, but are not limited thereto.

The polyvinyl alcohol derivative used for the coating layer according to the present invention is not particularly limited as long as it is a resin containing a vinyl alcohol unit, but the polyvinyl alcohol resin itself is not included in the derivative.
Although not particularly limited, a polyvinyl acetal resin can be preferably used as the derivative. Although not particularly limited, the polyvinyl acetal resin preferably contains a vinyl acetal group, a vinyl alcohol group, and a vinyl acetyl group. The aldehyde used to generate the vinyl acetal group of the polyvinyl acetal resin is not particularly limited as long as it can generate a vinyl acetal group, for example, formaldehyde, acetaldehyde, propyl aldehyde, butyl aldehyde, benzaldehyde , O-
Examples thereof include chlorobenzaldehyde, palmitaldehyde, chloroacetaldehyde, crotonaldehyde, glyoxal, and thiodialdehyde.

The polyvinyl alcohol derivative used in the coating layer according to the present invention may be copolymerized with other copolymer components to such an extent that the effects of the present invention are not impaired. Other copolymerization components include alkyl acrylates and alkyl methacrylates (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, Lauryl, stearyl, cyclohexyl, phenyl, benzyl, phenylethyl, etc.), 2-
Hydroxyl group-containing compounds such as hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide, N Amide group-containing compounds such as -methylol methacrylamide, N, N-dimethylolacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-phenylacrylamide, N, N-diethylaminoethyl acrylate, N, N-diethylamino Amino group-containing compounds such as ethyl methacrylate; epoxy group-containing compounds such as glycidyl acrylate and glycidyl methacrylate; Compounds containing a carboxyl group or a salt thereof such as lylic acid, methacrylic acid and salts thereof (alkali metal salt, alkaline earth metal salt, ammonium salt, etc.), epoxy group-containing compounds such as allyl glycidyl ether, vinyl sulfonic acid and Carboxyl groups such as salts thereof (lithium salts, sodium salts, potassium salts, ammonium salts, etc.), crotonic acid, itaconic acid, maleic acid, fumaric acid and salts thereof (lithium salts, sodium salts, potassium salts, ammonium salts, etc.) Or a compound containing a salt thereof, a compound containing an acid anhydride such as maleic anhydride, itaconic anhydride, vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl maleic acid Monoesters, alkyl fumaric acid monoesters, acrylonitrile, methacrylonitrile, alkyl itaconic acid monoesters, vinylidene chloride, vinyl acetate, vinyl chloride, etc., which are copolymerized using one or two or more kinds However, the present invention is not limited to these.

In forming the coating layer according to the present invention, the polyester resin containing a sulfonate group and the polyvinyl alcohol derivative are mixed in a solid content ratio of 50/50 to 50/50.
95/5, said ratio being more preferably between 70/30 and 90/10. When the ratio is out of this range, when the amount of the polyester resin is small, the adhesion and the water resistance to the base polyester film are insufficient, and when the amount of the polyvinyl alcohol derivative is small, the adhesion and the water resistance to the ink receiving layer are insufficient. I do.

In the coating layer according to the present invention, a block resin modified with another resin, for example, a modified polyester copolymer (for example, acryl, urethane, epoxy, etc.) may be used as long as the effects of the present invention are not impaired. Copolymers, graft copolymers, etc.), acrylic resins, urethane resins, epoxy resins, polycarbonate resins, silicone resins, alkyd resins, urea resins and phenolic resins, and water-soluble resins described below as resins contained in the ink receiving layer. And / or a water-dispersible resin. Furthermore, in the coating layer according to the present invention, various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, a lubricant, and a pigment, as long as the effects of the present invention are not impaired. , A dye, organic or inorganic fine particles, a filler, an antistatic agent and a nucleating agent.

It is optional to add particles to the coating layer according to the present invention. However, the addition of these particles is preferable because the lubricity, blocking resistance, and adhesion to the ink receiving layer are improved. . The particles are not particularly limited, but silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate and the like can be used. The average particle size is not particularly limited, but is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, and most preferably 0.08 to 2 μm.
It is. The mixing ratio with respect to the total resin in the coating layer is not particularly limited, but is preferably 0.05 to 8 parts by weight, more preferably 0.1 to 3 parts by weight in terms of solids weight ratio.

The thickness of the coating layer according to the present invention is not particularly limited, but is preferably 0.02 to 5 μm, more preferably 0.03 to 2 μm, and most preferably 0.05 to 0.05 μm.
０．５0.5 μm. If the thickness of the layer is too small, the adhesion to the ink receiving layer may be poor.

The method for forming the above-mentioned coating layer is not particularly limited, but various coating methods such as a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, a die coating method and a spray coating method are used. be able to. Preferably, a method of applying a resin dissolved and dispersed in an organic solvent or water is used in the production process of the polyester film.

The ink-receiving layer formed on the coating layer of the polyester film of the ink-jet base material of the present invention contains a water-soluble resin and / or a water-dispersible resin, and absorbs ink-jet ink. If there is, it is not particularly limited. Examples of the water-soluble resin and / or the water-dispersible resin include, for example, methyl cellulose, hydroxyethyl cellulose, carboxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylethyl cellulose, cellulose sulfate, potato starch, potato starch, oxidized starch, starch phosphate, carboxylation Starch, hydroxyethylated starch, cyanoethylated starch, acrylic acid-grafted starch, dextrin, corn starch, konjac, seaweed, agar, sodium alginate, troloioi, tragacanth gum, gum arabic, locust bean gum, guar gum, pectin, carrageenan, glue, gelatin, Casein, soy protein, albumin, fully or partially saponified polyvinyl alcohol and its aniline Cation modified product, polyvinyl alcohol having a degree of acetalization or butyralization of 30% or less, polyacrylamide and its copolymer, polyvinylpyrrolidone and its copolymer, poly-N-vinylacetamide and its copolymer, polyethylene Oxide, ethylene oxide-propylene oxide copolymer, polybutylene oxide, carboxylated polyethylene oxide, polyacrylic acid and its sodium salt, styrene-
Examples thereof include a maleic anhydride copolymer and an ethylene-maleic anhydride copolymer, but are not particularly limited to these compounds. These water-soluble resins or water-dispersible resins may be used alone or in combination of two or more.

It is optional to add a cationic substance, particles or a cross-linking agent to the ink receiving layer. However, the addition of such a substance improves ink absorbency, adsorptivity, coloring, etc., and is therefore preferable. is there. As the cationic substance,
Although not particularly limited, those having a quaternary ammonium salt in the composition and using chloride, sulfate, nitrate and the like as a counter ion are preferable, and a cationic surfactant and a polymer having a cationic group may be applied. Can be. The particles are not particularly limited, but silica, colloidal silica, alumina, alumina sol, zeolite, titanium oxide, kaolin, kaolinite, talc, mica, calcium carbonate and the like can be used. Examples of the crosslinking agent include, but are not particularly limited to, methylolated or alkylolated urea-based, melamine-based,
Acrylamide-based, polyamide-based resins, epoxy compounds, isocyanate compounds, oxazoline-based compounds, aziridine compounds, various silane coupling agents, various titanate-based coupling agents, and the like can be used. Further, in the ink receiving layer, various additives, for example, antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, lubricants, pigments, dyes, organic or inorganic fine particles, fillers,
An antistatic agent and a nucleating agent may be blended.
Further, the thickness of the ink receiving layer is not particularly limited,
It is 5 to 100 μm, preferably 10 to 50 μm. If the ink receiving layer is too thin, the ink absorbency, image resolution, etc. may be poor. On the other hand, if the ink receiving layer is too thick, the drying rate may be low and the production efficiency may be poor.

The above-mentioned ink-receiving layer is formed by a method of applying the ink-receiving layer forming coating liquid on an inkjet base polyester film by using a coating apparatus and drying. As a coating method, for example, a blade coat method,
Air knife method, roll coat method, brush coat method, gravure coat method, kiss coat method, extrusion method, slide hopper (slide beat)
System, curtain coat system, spray system and the like can be used.

Next, the method for producing a base polyester film for ink jet of the present invention will be described with reference to an example using a polyethylene terephthalate (hereinafter abbreviated as “PET”) film, but the present invention is not limited to this. Not something.

For example, intrinsic viscosity 0.5 to 0.8 dl / g
After vacuum drying PET pellets, it is supplied to an extruder,
Melted at 260 to 300 ° C, extruded into a sheet from a T-shaped die, and applied with a surface temperature of 10 to 10 using an electrostatic application casting method.
The film was wound around a mirror casting drum at 60 ° C. and cooled and solidified to prepare an unstretched PET film. This unstretched film was stretched 2.5 to 5 times in the longitudinal direction (the direction of film movement) between rolls heated to 70 to 120 ° C.
At least one side of this film was subjected to a corona discharge treatment, and the treated surface was coated with the coating liquid for forming a coating layer of the present invention.
The coated film is gripped with a clip and
After being guided to a hot air zone heated to 50 ° C. and dried, the film is stretched 2.5 to 5 times in the width direction, and subsequently 160 to 250 ° C.
, And heat-treated for 1 to 30 seconds to complete the crystal orientation. During this heat treatment step, a 3 to 12% relaxation treatment may be performed in the width direction or the longitudinal direction as necessary. Biaxial stretching may be any of longitudinal, horizontal sequential stretching or simultaneous biaxial stretching, and, after longitudinal and transverse stretching,
The film may be stretched in any of the vertical and horizontal directions. The coating liquid used in this case is preferably water-based in view of environmental pollution and explosion-proof properties.

[Method for Measuring Characteristics and Method for Evaluating Effects] The method for measuring characteristics and the method for evaluating effects in the present invention are as follows.

(1) Adhesiveness On a coating layer of an inkjet base polyester film, an ink receiving layer forming coating liquid, N
S-141LX / Julima SPO manufactured by Nippon Junyaku Co., Ltd.
(75/25 parts by weight) of the aqueous solution was applied by a gravure coater so that the applied thickness after drying was about 11 μm, and dried at 120 ° C. Evaluation film at 23 ° C, 6
After conditioning for 1 day at 5% RH, 1 mm ²
100 cross cuts, a cellophane tape was stuck thereon and pressed with a rubber roller (load 19.6).
(5 reciprocations with N), and peeled in the 90 ° direction. The adhesion was evaluated by the number of remaining ink receiving layers (（: 75 to
100, Δ: 50 to 74, ×: 0 to 49). At this time, "O" was regarded as good adhesiveness.

(2) Water resistance An ink receiving layer is formed in the same manner as in the above method (1).
The film for evaluation was conditioned at 23 ° C. and 65% RH for 1 day, and then printed on the ink receiving layer using an inkjet printer (PM-750C manufactured by Seiko Epson Corporation). Five minutes after printing, the water resistance was evaluated based on the presence or absence of the ink receiving layer falling off when a cut was made in the printed area with a cutter and rubbed with a finger (○: no change in the ink receiving layer,
X: The ink receiving layer dropped off). At this time, “O” was defined as good water resistance.

[0035]

Next, embodiments of the present invention will be described with reference to examples, but the present invention is not necessarily limited thereto.

Example 1 0.015% by weight of colloidal silica having an average particle size of 0.4 μm and an average particle size of 1.5 μm
containing 0.005% by weight of colloidal silica
After T was dried under reduced pressure (3 Torr) at 180 ° C. for 5 hours, it was supplied to an extruder and melted at 280 ° C., and these polymers were filtered with high precision and extruded into a sheet shape from a T-shaped die.

This was wound around a casting drum having a surface temperature of 25 ° C. using an electrostatic application casting method, and cooled and solidified to form an unstretched film. This unstretched film was stretched 3.2 times in the longitudinal direction at 90 ° C.

The film was subjected to a corona discharge treatment in air for 3 seconds, and a coating liquid for forming a resin layer kept at 25 ° C. was applied to the treated surface. The coated uniaxially stretched film is heated to 100 ° C. while being gripped with clips, stretched 3.5 times in the width direction in a state where the water content in the coating liquid on the film is 50% by weight or less, and then at 225 ° C. for 10 seconds. Heat treatment of the base material PET
The thickness of the film is 100 μm and the thickness of the coating layer is 0.15
A μm inkjet base polyester film was obtained.

Table 1 shows the results of the evaluation of the thus-obtained substrate-laminated polyester film for ink jet.

(Examples 2 and 4, Comparative Examples 1, 2, 4 to
7) Except for changing the coating liquid for forming the coating layer in Example 1,
A film was obtained in the same manner as in Example 1.

Example 3, Comparative Example 3 A biaxially stretched polyester film ("Lumirror" E20, manufactured by Toray Industries, Inc., thickness: 50 μm) was subjected to a corona discharge treatment in air, and the coating liquid for forming a coating layer was reversed. Coating was performed using a coater to obtain a film having a coating layer thickness of 0.2 μm.

Comparative Example 8 A film was formed in the same manner as in Example 1 except that the resin layer of Example 1 was not formed.

In each of the above Examples and Comparative Examples,
The resins and the like used for forming the coating layer are as follows.

A1: polyester resin (terephthalic acid (4
0 mol%), 5-sodium sulfoisophthalic acid (10
Mol%), ethylene glycol as the glycol component
(45 mol%), copolymerized polyester containing diethylene glycol (5 mol%) A2: Polyester resin (terephthalic acid (2
5 mol%), isophthalic acid (8 mol%), sebacic acid (5 mol%), trimellitic acid (12 mol%), ethylene glycol (30 mol%) as a glycol component, neopentyl glycol (20 mol%)
A3: acrylic resin (methyl methacrylate (45 mol%), butyl acrylate (30 mol%), acrylic acid (10 mol%),
B1: Polyvinyl acetal resin (acetalization degree: 8 mol%) B2: Polyvinyl butyral resin (butyralization degree: 63)
B3: polyvinyl alcohol resin (degree of saponification: 88 mol%, degree of polymerization: 1800) C1: epoxy-based crosslinking agent

[0045]

[Table 1]

[0046]

According to the present invention, there can be obtained an excellent inkjet base polyester film capable of satisfying the adhesiveness to an ink receiving layer and the water resistance in inkjet printing.

Continued on the front page F term (reference) 2H086 BA15 BA19 BA35 BA37 4F100 AK15 AK16 AK21B AK23B AK41A AK41B AK42A AL05B AL06B BA02 BA10A BA10B CC00B EJ38A GB90 JB07 JL11 YY00B

Claims (2)

[Claims] 1. A polyester film containing a sulfonic acid group and / or a sulfonic acid group and a polyvinyl alcohol derivative are mixed on at least one surface of a polyester film at a solid content weight ratio of 50/50 to 95/5. A substrate polyester film for inkjet, comprising a coating layer formed thereon. 2. The inkjet base polyester film according to claim 1, wherein the polyvinyl alcohol derivative is a polyvinyl acetal resin.