JP3341512B2 - Laminated polyester film and laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated polyester film.
The present invention relates to a laminated polyester film having excellent antistatic properties.

[0002]

2. Description of the Related Art Biaxially stretched polyester films have excellent properties such as mechanical properties, electrical properties, and dimensional stability.
It is used as a base film in many fields such as photosensitive materials, drafting materials, and photographic materials. However, since the surface is highly crystallographically oriented, it has disadvantages such as poor adhesion to various paints, adhesives, inks, and the like. In particular, for label applications and magnetic recording card applications, the use and storage conditions of the final product differ greatly from individual to individual.For example, labels and magnetic recording cards may temporarily but bend during storage. Conceivable. At this time, if the adhesiveness between the base film and the coating material (decorative layer, magnetic recording layer, etc.) is poor, it peels off at the interface, impairing the product appearance or losing the function as a magnetic recording card. Therefore, studies have been made on imparting easy adhesion to the polyester film surface by various methods.

[0003] As a method of easy adhesion, a surface activation method by corona discharge treatment, ultraviolet irradiation treatment, plasma treatment or the like on the surface of the base polyester film, a surface etching method by chemicals such as acid, alkali, amine aqueous solution, etc .; A method in which various resins such as an acrylic resin, a polyester resin, and a urethane resin are provided as a primer layer
No. 15825, JP-A-58-78761, JP-A-678 / 76
No. 0-248232) is already known. In particular, as a method of providing the primer layer by application and imparting easy adhesion, a coating containing the resin component is applied to a polyester film before completion of crystal orientation, dried, stretched, and subjected to heat treatment to crystallize. A method of completing the alignment (in-line coating method) has been actively performed.

[0004]

In order to impart adhesiveness, an acrylic resin-based water-based coating agent applied on a polyester film has been used. However, these resins have excellent adhesiveness to coatings such as printing inks, but have a disadvantage that they are inferior in adhesiveness to a base polyester film.

On the other hand, there are many proposals for coating an aqueous coating of a polyester resin on a polyester film, such as Japanese Patent Application Laid-Open Nos. 50-39375 and 60-11358. However, although the primer layer formed from the conventional polyester resin aqueous coating has excellent adhesiveness with the base polyester film, it has an excellent adhesiveness with coatings such as printing inks, and further with an adhesiveness when folded. There was the disadvantage of being scarce.

[0006] Further, both the base polyester film and the film provided with a primer layer for improving the adhesiveness are liable to be charged, which has a drawback that not only troubles in the film forming process but also electrostatic damage in the working process are easily caused. Was.

[0007] In this regard, low molecular weight compounds such as alkylbenzene sulfonate groups and alkyl phosphate groups are kneaded into a base film or blended into a coating material and applied. However, the above low molecular weight compounds are inferior in antistatic properties when the added amount is small, and when the added amount is increased to obtain good antistatic properties, conversely, the low molecular weight compounds bleed out to the surface or interface. And the phenomenon that the adhesive property is deteriorated easily occurs.

The present invention solves these problems and provides a laminated polyester film having excellent adhesiveness and antistatic properties and useful for industrial materials such as printing materials such as labels, prepaid cards and graphic materials. Aim.

[0009]

According to the present invention, there is provided a composition comprising, on at least one side of a polyester film, an acrylic resin (A), a polyester resin (B), and a polymer compound (C) having a phosphate group as a main component. provided it becomes more layers, or
First, the polymer compound having a phosphate group (C) is
The Rukoto contain in the molecule is to its gist the alkylene oxide.

The polyester in the present invention is a general term for polymers having an ester bond as a main chain, and preferred polyesters include ethylene terephthalate, ethylene-2,6-naphthalate and ethylene-
α, β-bis (2-chlorophenoxy) ethane-4,
Examples include those having at least one structural unit selected from 4′-dicarboxylate and ethylene-α, β-bis (phenoxy) ethane-4,4′-dicarboxylate as a main component.

Further, as long as the present invention is not impaired, preferably within 20 mol%, other components other than the above may be copolymerized.

The polyester film of the present invention comprises:
Although the above composition is the main component, other types of polymers may be blended as long as the object of the present invention is not impaired, or an antioxidant, a heat stabilizer, a lubricant, an ultraviolet absorber, a nucleating agent And the like may be added to the extent that inorganic or organic additives such as are normally added.

For use in magnetic recording cards and the like, a white polyester film is preferably used as the base film. This white polyester film is not particularly limited as long as it is a whitened polyester film, but preferably has a whiteness of 85 to 150, more preferably 90 to 130, and an optical density of 0.5 to 150.
5.0, preferably 1.2 to 3.0 is suitable.
For example, when a base material having a small whiteness is used in a magnetic recording card, the coloring of the magnetic recording layer or the like is transmitted and the appearance of the printed layer on the surface is easily impaired, while when the optical density is small, sufficient light reflection is not obtained. It is not obtained, and the whiteness decreases when viewed with the naked eye, the effect of the opposite surface appears, or a problem may occur depending on the measurement method at the time of reading magnetic recording.

A method for obtaining such optical density and whiteness is as follows.
Although not particularly limited, it can be usually obtained by adding a resin incompatible with inorganic particles or polyester. The amount to be added is not particularly limited.
It is 5% by weight, preferably 8 to 25% by weight. On the other hand, when an incompatible resin is added, the content is 5 to 35% by volume, preferably 8 to 25% by volume.

The inorganic particles used are not particularly limited.
Average particle size 0.1-4.0 μm, preferably 0.3-1.
5 μm inorganic particles can be mentioned as a representative example. Specifically, barium sulfate, calcium carbonate, calcium sulfate, titanium oxide, silica, alumina, talc,
Clay or the like or a mixture thereof, and these inorganic particles may be used in combination with 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 polyester is not particularly limited. For example, in the case of mixing with polyethylene terephthalate or polyethylene-2,6-naphthalate, acrylic resin, polyethylene, polypropylene, modified olefin resin, polybutylene Examples include terephthalate-based resins, phenoxy resins, polyphenylene oxides, and the like, and of course, may be used in combination with the above-mentioned inorganic particles. In particular, a white polyester film having a specific gravity of 0.5 to 1.3 g / cm ³ , which has a cavity therein and has a specific gravity of 0.5 to 1.3 g / cm ³ , has good printability when a resin incompatible with inorganic particles or polyester is mixed and biaxially stretched. It is preferred.

The polyester film using the above polyester is preferably biaxially oriented in a state where a laminated film is provided.

The thickness of the polyester film is not particularly limited, and is appropriately selected depending on the use.

The acrylic resin (A) which is a composition constituting the laminated film of the present invention is a conventionally known one and is not particularly limited. As the monomer component constituting the acrylic resin, a known component can be used. For example, alkyl acrylate, alkyl methacrylate (the alkyl group is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group,
An ethylhexyl group, a lauryl group, a stearyl group, a cyclohexyl group, a phenyl group, a benzyl group, a phenylethyl group and the like are used as a basic skeleton.

Further, the following monomers may be copolymerized for the purpose of providing a crosslinkable functional group. As the crosslinkable functional group, carboxyl group, hydroxyl group, methylol group, sulfonic acid group,
Examples include an amide group or a methylolated amide group, an amino group (including a substituted amino group), or an alkylolated amino group, a hydroxyl group, an epoxy group, an acid anhydride, and the like.

Examples of the above-mentioned monomer having a crosslinkable functional group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,
-Hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, vinyl sulfonic acid, styrene sulfonic acid, acrylamide, methacrylamide, N-methyl methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, dimethylaminoethyl methacrylate, and the above amino group Can be methylol, glycidyl acrylate, glycidyl methacrylate, and the like, but are not necessarily limited thereto.

The copolymerization ratio of the monomer having a crosslinkable functional group is not particularly limited, but is preferably 1 to 30% by weight.
More preferably, the content is 3 to 20% by weight from the viewpoint of easy adhesion.

Further, in addition to the above, the following compounds such as acrylonitrile, methacrylonitrile, styrenes, mono- or dialkyl esters of maleic acid and itaconic acid, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl pyridine, vinyl pyrrolidone, Alkoxysilane having a vinyl group may be partially used as a copolymer component.

The acrylic resin of the present invention includes a modified polyester copolymer such as acryl, urethane,
It is also possible to use a block copolymer, a graft copolymer, or the like modified with an epoxy or the like.

The molecular weight of the acrylic resin of the present invention is preferably 100,000 or more, more preferably 300,000 or more, from the viewpoint of easy adhesion. In addition, the acrylic resin can be obtained by a known acrylic resin polymerization method, but when applied to the in-line coating method, since it is preferably dissolved or dispersed in water, it is prepared by a method such as emulsion polymerization or suspension polymerization. Acrylic resin aqueous dispersion is desirable.

Preferred acrylic resins include methyl methacrylate, ethyl methacrylate, and butyl methacrylate as main monomers, and monomers having a crosslinkable functional group such as acrylic acid, 2-hydroxyacrylate, acrylic acid, and N-methylol acrylic acid. And the like.

The polyester resin (B) which is a composition constituting the laminated film of the present invention is conventionally known and is not particularly limited. As the dicarboxylic acid component of the polyester resin, terephthalic acid, isophthalic acid, phthalic acid, 2,5-
Dimethyl terephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bis (phenoxy) ethane-p,
p'-dicarboxylic acid, adipic acid, sebacic acid, dodecanedioic acid and the like and ester-forming derivatives thereof.

As the glycol component of the polyester resin, ethylene glycol, 1,3-propanediol,
Examples thereof include 1,4-butanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, and trimethylolpropane.

In order to facilitate the water solubility of the polyester resin, it is preferable to copolymerize a compound containing a carboxylic acid group or a compound containing a sulfonic acid group.

Examples of the compound containing a carboxylate group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid,
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, ethylenetetracarboxylic acid and the like, or alkali metal salts, alkaline earth metal salts and ammonium salts thereof, but are not limited thereto.

Examples of the compound containing a sulfonate group include sulfoterephthalic acid, 5-sulfoisophthalic acid,
-Sulfoisophthalic acid, 4-sulfonaphthalene-2,7
-Dicarboxylic acid, sulfo-p-xylylene glycol,
Examples thereof include, but are not limited to, 2-sulfo-1,4-bis (hydroxyethoxy) benzene and the like, and alkali metal salts, alkaline earth metal salts, and ammonium salts thereof.

As the polyester resin, a modified polyester copolymer, for example, a block copolymer or a graft copolymer modified with acryl, urethane, epoxy or the like can be used.

Preferred polyester resins include terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid as acid components, and ethylene glycol, 1,4-butanediol, neopentyl glycol and diethylene glycol as glycol components. Further, a compound containing a compound containing a carboxylic acid group such as trimellitic acid or pyromellitic acid as a component thereof may be used.

The polyester resin to be laminated on the polyester film of the present invention can be produced by a conventionally known production technique. For example, when a polyester resin comprising terephthalic acid, isophthalic acid, trimellitic acid as an acid component and ethylene glycol and neopentyl glycol as a glycol component is described, terephthalic acid, isophthalic acid, trimellitic acid and ethylene glycol, neopentyl glycol are used. A first step of directly transesterifying or transesterifying terephthalic acid, isophthalic acid, trimellitic acid and ethylene glycol or neopentyl glycol, and a second step of polycondensing the reaction product of the first step And the like.

At this time, conventionally known alkali metals, alkaline earth metals, manganese, cobalt, zinc, antimony, germanium, titanium compounds and the like are used as the reaction catalyst.

The intrinsic viscosity of the polyester resin to be laminated on the polyester film of the present invention is not particularly limited, but is not less than 0.3 dl / g, preferably 0.1 dl / g, from the viewpoint of adhesiveness.
35 dl / g or more, more preferably 0.4 dl / g or more is desirable.

As the polymer compound (C) having a phosphate group of the present invention, a phosphate-based low molecular compound represented by a conventionally known alkyl phosphate ester salt or alkyl ether phosphate ester salt can be used. A phosphate polymer compound copolymerized as a monomer is preferable, and an acrylic resin having a phosphate group is particularly preferable.

As the acrylic resin having a phosphate group, an acrylic resin having an alkylene oxide and a phosphate group is preferable.
It means an acrylic resin composed of a monomer having a phosphate group and other monomers described below. Above all, it is preferable that the alkylene oxide and the phosphate group are present in one monomer, and it is more preferable that the phosphate group is present with the alkylene oxide interposed in the side chain of the acrylic resin.

Here, the alkylene oxide is a repeating unit in the molecule represented by the following formula, and preferable examples include ethylene oxide, propylene oxide, and those containing both ethylene oxide and propylene oxide.

-(RO) _n- (R: alkyl group and its derivative, n: an integer selected from 1 to 9) Further, the phosphate group may be any one formed by addition of a cation. Although it is arbitrarily selected, monovalent cations such as lithium salt, sodium salt, potassium salt, rubidium salt and ammonium salt are preferable, and potassium salt and rubidium salt are particularly preferable in view of antistatic property.

The phosphate group can be prepared by adding a cation to a free phosphate group after copolymerization, or by copolymerizing a monomer having a phosphate group by pre-neutralization and phosphatization as one component of the monomer. And can be obtained by any method.

Examples of such a monomer having a phosphate group via an alkylene oxide include acid phosphooxyethyl acrylate, acid phosphooxyethyl methacrylate, acid phosphooxypropyl acrylate, acid phosphooxypropyl methacrylate, and acid phosphooxypropyl methacrylate. Oxy (polyoxyethylene glycol) monoacrylate, acid phosphooxy (polyoxyethylene glycol) monomethacrylate, acid phosphooxy (polyoxypropylene glycol) monoacrylate, acid phosphooxy (polyoxypropylene glycol) monomethacrylate, 3-
Chloro-2-acid phosphooxypropyl acrylate, 3-chloro-2-acid phosphooxypropyl methacrylate and the like can be mentioned as typical examples.

As other monomer components constituting the acrylic resin having a phosphate group, the above-mentioned known components can be used. For example, alkyl acrylate, alkyl methacrylate (the alkyl group is 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, a lauryl group, a stearyl group, A cyclohexyl group, a phenyl group, a benzyl group, a phenylethyl group, etc.) are used as the basic skeleton.

The above-mentioned monomer having an alkylene oxide and a phosphate group and another monomer can be copolymerized in an arbitrary ratio, but preferably the monomer is at least 20% by weight, more preferably at least 30% by weight, further preferably at least 30% by weight. An amount of 40% by weight or more is desirable from the viewpoint of antistatic properties. In the present invention, the antistatic property means that the surface resistivity is normal (23 ° C., 65% R
H) 5 × 10 ¹¹ Ω / □ or less, preferably 1 × 1
Refers to those of 0 ¹¹ Ω / □ or less.

Further, the following monomers may be copolymerized for the purpose of providing a crosslinkable functional group. As the crosslinkable functional group, carboxyl group, hydroxyl group, methylol group, sulfonic acid group,
Examples include an amide group or a methylolated amide group, an amino group (including a substituted amino group), or an alkylolated amino group, a hydroxyl group, an epoxy group, an acid anhydride, and the like.

Examples of the above-mentioned monomer having a crosslinkable functional group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,
-Hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, vinyl sulfonic acid, styrene sulfonic acid, acrylamide, methacrylamide, N-methyl methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, dimethylaminoethyl methacrylate, and the above amino group Can be methylol, glycidyl acrylate, glycidyl methacrylate, and the like, but are not necessarily limited thereto.

The copolymerization ratio of the above-mentioned monomer having a crosslinkable functional group is not particularly limited, but is preferably 1 to 30% by weight.
More preferably, the content is 3 to 20% by weight from the viewpoint of easy adhesion.

Further, in addition to the above, the following compounds such as acrylonitrile, methacrylonitrile, styrenes, mono- or dialkyl esters of maleic acid and itaconic acid, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl pyridine, vinyl pyrrolidone, Alkoxysilane having a vinyl group may be partially used as a copolymer component.

The acrylic resin of the present invention has a molecular weight of 1
It is preferably at least 100,000, more preferably at least 300,000 from the viewpoint of easy adhesion.

In the present invention, the antistatic property can be further improved by using the organometallic compound (D).

The organometallic compound (D) referred to in the present invention is a compound having titanium, zirconium, aluminum, silicon, tin or the like as a central metal, among which titanium, zirconium, alkoxide, chelate, and acylate are formed. Aluminum is preferred, and alkoxides and chelate compounds of titanium organic compounds are particularly preferred.

As the titanium organic compound, tetraisopropyl titanate formed with alkoxide, tetra (2
-Ethylhexyl) titanate, and the like, and titanium lactate and titanium lactate ammonium salt which form a chelate. Among these, a titanium chelate compound is preferable.

Titanium chelate compounds include O-coordinated titanium chelates such as glycol, β-diketone, hydroxycarboxylic acid, ketoester and ketoalcohol as ligands, and aminoalcohols, oxyquinoline and Schiff bases as ligands. N-coordinated titanium chelates and the like can be mentioned.

In consideration of application to the in-line coating method, a water-soluble titanium chelate compound is preferred in terms of explosion-proof properties, environmental pollution, and the like. Representative water-soluble titanium chelate compounds among the above-mentioned titanium chelate compounds include triethanolamine titanium chelate, diisopropoxy titanium bis (acetyl acetate), titanium lactate, and ammonium titanium lactate. Among them, stability in water is preferable. Particularly preferred are titanium lactate, ammonium titanium lactate, and the like.

The mixing ratio of the acrylic resin (A), polyester resin (B) and polymer compound (C) having a phosphate group of the present invention is not particularly limited, but preferably (A) / (B) = 5. / 95 to 95/5 (weight ratio), particularly preferably 10/90 to 90/10 (weight ratio). (C) is preferably 20 to 500 parts by weight, and more preferably 30 to 3 parts by weight, based on 100 parts by weight of these (A) and (B).
00 parts by weight is desirable. If the proportion of (C) is too small, the antistatic property tends to decrease, and if it is too large, the easy adhesion tends to decrease. Further, with respect to the organometallic compound (D), (D) is preferably 1 to 100 parts by weight, more preferably 2 to 50 parts by weight, based on 100 parts by weight of (A) and (B).

In the present invention, various types of crosslinking agents can be used to further improve the adhesiveness. As the crosslinking agent, melamine, epoxy, isocyanate,
Examples thereof include amine-based, amide-based, and aziridine-based ones, and among them, it is particularly preferable to use a melamine-based crosslinking agent.

Examples of the melamine-based cross-linking agent include those having an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group as a functional group in one molecule. Examples include a methylol-based melamine resin, a methylol-based methylated melamine resin, a completely alkyl-type methylated melamine resin, and the like. Among them, a methylolated melamine resin is most preferable. Further, it is preferable to use an acidic catalyst such as p-toluenesulfonic acid in order to promote the thermal curing of the melamine resin.

The type and amount of the crosslinking agent depend on the mixing ratio of the acrylic resin (A), the polyester resin (B), and the polymer compound (C) having a phosphate group, and the types and contents of the functional groups. It may be appropriately determined depending on the case. For example, when a melamine-based cross-linking agent is used, the resin component 10 is usually used.
2 to 30 parts by weight with respect to 0 parts by weight is suitable.

According to the present invention, the gist of the present invention is to provide a coating film composed mainly of the above-mentioned compositions (A), (B) and (C) on a polyester film having at least one surface thereof. Other resins, for example, an acrylic resin different from the above (A), a polyester resin different from the above (B), as long as the effects of the present invention are not impaired,
A urethane resin, an epoxy resin or the like may be used in combination.

The thickness of the coating layer is not particularly limited, but in the present invention, the dry coating thickness after biaxial stretching is 0.01 to 2.0.
0 μm is preferable, and more preferably 0.02 to 1.0 μm
m, more preferably 0.06 to 0.5 μm.

The laminated film is usually made of a composition mainly composed of an acrylic resin (A), a polyester resin (B) and a polymer compound having a phosphate group (C) as an aqueous coating agent, and this is used as a polyester film. It is formed by coating on the surface. The application means is roughly classified into an in-line coating method and an off-line coating method. Among them, the coating is performed before the crystal orientation of the base polyester film is completed, and then the film is stretched in at least one direction. The in-line coating method is a preferable method because the effect of the present invention can be more remarkably exhibited. That is, one side or both sides of the unstretched or longitudinally stretched base polyester film is subjected to corona discharge treatment, and the treated surface is coated with the acrylic resin (A), polyester resin (B), and phosphate base of the present invention. A water-based coating agent comprising the high molecular compound (C) is applied. Then, while holding the clip continuously, about 80
After guiding to a hot air zone of ~ 130 ° C to remove water, the film is continuously stretched 2.5 to 5.0 times in the width direction. afterwards,
Continuously led to a heat treatment zone of 160-250 ° C,
This is a method of performing a heat treatment for 30 seconds to complete the crystal orientation. Further, even after the stretching in the width direction, at a stage before the heat treatment, the film may be further stretched 1.1 to 1.8 times in the longitudinal direction.

The coating method is a known coating method, for example, a reverse coating method, a gravure coating method, a rod coating method,
Any method such as a die coating method and a spray coating method can be used.

In the coating composition of the present invention, known additives such as antioxidants, as long as the effects of the present invention are not impaired,
Heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic particles, antistatic agents,
A nucleating agent may be added.

In particular, those obtained by adding and blending inorganic particles into the coating composition of the present invention and then biaxially stretching the coating composition are more preferable because they can improve the lubricity.

Typical examples of the inorganic particles to be added include silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate and the like. The average particle diameter of the inorganic particles is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, and still more preferably 0.08 to 2 μm. The mixing ratio with respect to the solid content in the coating material is not particularly limited, 0.05 to 8 by weight ratio
Parts are preferred, and more preferably 0.1 to 3 parts.

Next, the method for producing the laminated polyester film of the present invention will be described by taking polyethylene terephthalate (hereinafter abbreviated as PET) as an example, but is not limited thereto.

After thoroughly drying the PET pellets under vacuum,
It is supplied to an extruder, melt-extruded into a sheet at about 280 ° C., and solidified by cooling to produce an unstretched PET sheet. This sheet is stretched 2.5 to 5.0 times in the longitudinal direction by a roll heated to 80 to 120 ° C. to obtain a uniaxially oriented PET film. Both surfaces of the film are subjected to a corona discharge treatment, and the treated surface is coated with a predetermined concentration of the aqueous coating composition of the present invention. After coating, hold the film end with a clip and
It is led to a hot air zone heated to ~ 130 ° C and stretched 2.5 to 5.0 times in the width direction. Continue 160-240
The heat treatment is conducted to a heat treatment zone of 1 ° C., and heat treatment is performed 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.

Further, a magnetic recording layer or various printing ink layers may be provided on a predetermined surface of the obtained laminated polyester film.

The printing ink in the present invention is not particularly limited, and examples thereof include ultraviolet curable ink, oxidative polymerization ink, and general dry ink. For example, as for the ultraviolet curable ink, as a resin component, an unsaturated polyester as a crosslinking component, an unsaturated acrylic resin such as pentaerythritol tetraacrylate as a crosslinking component, and carbon black as a pigment component, aluminum hydroxide or aluminum powder as main components, Examples thereof include those in which a polymerization initiator such as diethylaminobensophenone is added. The method for providing these printing layers is not particularly limited, and it can be performed by a method such as letterpress, planographic printing, letterpress printing, screen, flat base, rotary printing, transfer, and the like.

The magnetic recording layer in the present invention is not particularly limited, but typical examples include the following. That is, as the magnetic powder, γ-Fe ₂
O ₃ , CrO ₂ , Co-γ-Fe ₂ O ₃ , metal powder
As the binder, vinyl acetate, vinyl resin such as PVC, rubber resin such as acrylonitrile / butadiene copolymer, cellulose such as acetylcellulose and nitrocellulose, epoxy resin, phenolic resin, monomeric isocyanate, Modified isocyanate urethane prepolymer, polyurethane resin used in the form of blocked isocyanate and the like, and a dispersant, a lubricant, an antistatic agent such as carbon, a stabilizer, and a plasticizer, which are optionally added, may be prepared. it can. The method for providing these magnetic recording layers is not particularly limited, and a known method can be used.

[0071]

[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) Thickness of Coating Layer Using a transmission electron microscope model HU-12 manufactured by Hitachi, Ltd., the thickness was determined from a photograph obtained by observing a cross section of the biaxially oriented polyester film provided with the coating layer. Thickness is 30 within the field of view
The average value was used.

(2) Antistatic Property After the sample was allowed to stand in a normal state (23 ° C., relative humidity 65%) for one day or more, the digital ultra-high resistance
The measurement was performed at an applied voltage of 100 V using a microammeter R8340A (manufactured by Advantest Corporation). The antistatic property of 5 × 10 ¹¹ Ω / □ or less was regarded as good.

(3) Adhesion-1 (adhesion of magnetic paint) Diferacoat CAD4301 (Dainichi Seika Kogyo Co., Ltd.)
1 part by weight of Sumidur N-75 (manufactured by Sumitomo Bayer Co., Ltd.) to 100 parts by weight to prepare a paint having a solid content concentration of 20% by weight, apply using a bar coater, and dry at 100 ° C. for 5 minutes. Then, a thickness of about 10 μm was formed on the laminated film.

A 1 mm ² cross cut was applied to the dry paint film.
After inserting "Polyester Adhesive Tape" manufactured by Nitto Denko Corporation and pressing firmly with a finger,
The film was rapidly peeled in the degree direction and was evaluated on a four-point scale according to the number of remaining pieces (A: 100, B: 80 to 99, Δ: 50 to 79, X:
0-49). (A) and (B) were evaluated as having good adhesiveness. (4) Adhesion-2 (UV curable ink adhesion) "FLASH DRY" FD as UV curable ink
-OL black (manufactured by Toyo Ink Mfg. Co., Ltd.) was applied on the laminated film to a thickness of about 2.0 μm by a roll coating method. Thereafter, ultraviolet rays having an irradiation intensity of 80 W / cm were irradiated at an irradiation distance of 9 cm for 8 seconds to be cured.

A 1 mm ² cross cut was applied to the paint dry film.
After putting "00", "Cellophane tape" manufactured by Nichiban Co., Ltd. was adhered thereon, strongly pressed with a finger, then rapidly peeled in the direction of 90 degrees, and evaluated according to four levels based on the remaining number. The evaluation criteria conformed to Adhesion-1. (5) Adhesion-3 (ultraviolet curable ink adhesion) An ultraviolet curable ink layer was provided in the same manner as in (4) above.

After applying "Polyester Adhesive Tape" manufactured by Nitto Denko Corporation to the dried paint film and pressing strongly with a finger, the tape is turned 180 degrees with the tape side inside and the fold is strongly pressed with the finger. After returning to the state, the film was rapidly peeled in the direction of 90 °, and evaluated according to the state of the peeling on a 4-point scale (な い: unremovable, ○: slightly removable, Δ: fairly removable, ×: completely removable). (A) and (B) were evaluated as having good adhesiveness.

(6) Flatness With respect to the ultraviolet-curable ink laminate applied and cured in the above (4), the flatness of the laminate was placed on a glass plate with the ink side up, and the degree of curl was visually observed. It was measured and determined according to the following criteria.

◎: No curl at all, extremely good flatness ：: Slightly curled at the end but good △: Curled up to near the center ×: Significant curl (7) Optical density Macbeth It measured using the transmission densitometer TD-504 manufactured by Corporation.

(8) Whiteness Measured according to JIS-L1015.

[0081]

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

Example 1 PET containing substantially no particles (intrinsic viscosity 0.65 dl)
/ G) After sufficiently vacuum-drying the pellets, the pellets were supplied to a heated extruder at 280 ° C. and extruded in a sheet shape from a T-shaped die. This sheet was wound around a mirror surface drum having a surface temperature of 50 ° C. and cooled and solidified to prepare an unstretched PET film. This PET film was stretched 3.5 times in the longitudinal direction while passing through a group of heating rolls at 95 ° C. to obtain a uniaxially oriented film. Both surfaces of this film were subjected to a corona discharge treatment, and the treated surface was coated with an aqueous coating agent shown below. After coating, the end is guided to a heating zone of 110 ° C while being continuously gripped with clips, stretched 4.0 times in the width direction through preheating and drying, and further heat-treated while relaxing 5% in a heating zone of 210 ° C. And the thickness of the base PET film is 1
A laminated PET film having a thickness of 90 μm and a coating thickness of 0.1 μm was obtained. Table 1 shows the results.

"Water-based coating agent": (A) / (B) / (C) =
3.5% by weight mixed at 40/20/40 (weight ratio)
liquid. However, as the acrylic resin (A), methyl methacrylate / butyl acrylate / acrylic acid is 60/35.
3.5% by weight of an aqueous dispersion of an acrylic resin having a molecular weight of about 300,000 and emulsion-polymerized at a ratio of / 5 (weight ratio). As the polyester resin (B), isophthalic acid / trimellitic acid /
45% neopentyl glycol / diethylene glycol
3.5% by weight of a copolyester resin obtained by condensation polymerization at / 5/25/25 (molar ratio). As the polymer compound (C) having a phosphate group, a molecular weight obtained by emulsion polymerization of acid phosphooxyethyl methacrylate / butyl acrylate / acrylic acid previously neutralized with potassium hydroxide at a ratio of 70/25/5 (weight ratio). A 3.5% by weight solution of about 150,000 phosphate group-containing acrylic resin was prepared.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the acrylic resin was not added to the aqueous coating composition of Example 1 but (B) / (C) = 60/40 (weight ratio). In the same manner as in Example 1, a laminated PET film was obtained. Table 1 shows the results.

Comparative Example 2 Example 1 was repeated except that the polyester resin (B) was not added to the aqueous coating composition of Example 1 and (A) / (C) = 60/40 (weight ratio) was used as the aqueous coating composition. A laminated PET film was obtained in the same manner as described above. Table 1 shows the results.

Comparative Example 3 In the aqueous coating composition of Example 1, the polymer compound (C) having a phosphate group was not added, and (A) / (B) = 7
A laminated PET was prepared in the same manner as in Example 1 except that 0/30 was used.
A film was obtained. Table 1 shows the results.

Comparative Example 4 A laminated PET film was prepared in the same manner as in Example 1 except that sodium dodecylbenzenesulfonate was used in place of the polymer compound (C) having a phosphate group in the aqueous coating composition of Example 1. Obtained. Table 1 shows the results.

Comparative Example 5 A laminated PET film was obtained in the same manner as in Example 1, except that sodium dodecyl phosphate was used in place of the polymer compound (C) having a phosphate group in the aqueous coating composition of Example 1. . Table 1 shows the results.

Comparative Example 6 The same water-based coating agent as in Comparative Example 5 was used except that (A) / (B) / (C)
= 60/30/10 (weight ratio) to obtain a laminated PET film in the same manner. Table 1 shows the results.

Example 2 Methyl methacrylate / butyl acrylate / acrylonitrile / acrylic acid was used as a water-based coating agent of Example 1.
Example 1 except that an aqueous dispersion of an acrylic resin (molecular weight: about 300,000) having a ratio of 5/35/5/5 (weight ratio) was used.
A laminated PET film was obtained in the same manner as described above. Table 1 shows the results.

Example 3 As an aqueous coating composition of Example 1, terephthalic acid / isophthalic acid / trimellitic acid / ethylene glycol / neopentyl glycol / 1,4-butanediol was 3010/1.
A laminated PET film was obtained in the same manner as in Example 1 except that a copolymerized polyester resin subjected to condensation polymerization at 0/20/20/10 (molar ratio) was used. Table 1 shows the results.

Example 4 As an aqueous coating composition of Example 1, acid phosphooxy (polyethylene glycol) previously neutralized with potassium hydroxide was used.
Monomethacrylate (the number of repeating units of oxyethylene glycol n = 5) / butyl acrylate / acrylic acid / N-methylolacrylamide was 70/20/5/5
A laminated PET film was obtained in the same manner as in Example 1, except that an acrylic resin containing a phosphate group having a molecular weight of about 150,000 and emulsion-polymerized at a ratio of (weight ratio) was used. Table 1 shows the results.

Comparative Example 7 A PET film was obtained in the same manner as in Example 1 except that the aqueous coating composition was not applied. Table 1 shows the results.

Example 5 A laminated PET film was obtained in the same manner as in Example 4 except that 10 parts by weight of titanium lactate was further added as an organometallic compound to the water-based coating composition of Example 4. Table 1 shows the results.

Example 6 A laminated PEN film was obtained in the same manner as in Example 4, except that the polyester film was changed from a polyethylene terephthalate film to a polyethylene-2,6-naphthalate (hereinafter abbreviated as PEN) film. . Table 1 shows the results.

Example 7 A laminated PET film was obtained in the same manner as in Example 5, except that 10 parts by weight of a hexamethylolated melamine resin was added as a melamine-based crosslinking agent to the aqueous coating composition of Example 5. Table 1 shows the results.

Example 8 PET (intrinsic viscosity: 0.62 dl / g) pellets in which titanium oxide was finely dispersed by 16% by weight were sufficiently dried under vacuum,
It was fed to a heated extruder at 280 ° C. and extruded from a T-shaped die into a sheet. This sheet is heated to a surface temperature of 50
An unstretched PET film was formed by winding around a mirror-surfaced drum at a temperature of ℃ and solidifying by cooling. 90 times this PET film
3.5 mm in the longitudinal direction while passing through a group of heating rolls at
The film was stretched twice to obtain a uniaxially oriented film. Both surfaces of this film were subjected to a corona discharge treatment, and the treated surface was coated with the aqueous coating agent used in Example 1. After the application, the end is continuously led to a heating zone of 100 ° C. while being gripped by clips, preheated, dried, and stretched 3.5 times in the width direction.
Heat treatment while relaxing 5% in the heating zone of
ET film thickness 190μm, coating thickness 0.1μ
m, an optical density of 1.5 and a whiteness of 85% were obtained as a laminated white PET film. Table 1 shows the results.

Example 9 A laminated white PET film was obtained in the same manner as in Example 8, except that the water-based coating used in Example 5 was used as the water-based coating. Table 1 shows the results.

Example 10 A laminated white PEN film was obtained in the same manner as in Example 8, except that the polyester film was changed from a PET film to a PEN film. Table 1 shows the results.

Example 11 A laminated white PET film was obtained in the same manner as in Example 8, except that the water-based coating used in Example 7 was used as the water-based coating. Table 1 shows the results.

[0101]

[Table 1]

[0102]

The laminated polyester film obtained according to the present invention has improved adhesion and antistatic properties by laminating a composition mainly composed of an acrylic resin, a polyester resin and a compound having a specific antistatic property. It exhibits excellent effects.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI B29C 55/06 B29C 55/06 B32B 27/18 B32B 27/18 D 27/36 27/36 C08L 67/02 C08L 67/02 G11B 5/73 G11B 5/73 // B29K 67:00 B29K 67:00 B29L 7:00 B29L 7:00 9:00 9:00

Claims (9)

(57) [Claims] 1. A laminated film comprising a composition mainly composed of an acrylic resin (A), a polyester resin (B), and a polymer compound having a phosphate group (C) is provided on at least one surface of a polyester film ; Having the phosphate group
Polymer compound (C) reacts with an alkylene oxide
A laminated polyester film characterized by being contained in the molecule . 2. A laminated polyester film according to claim 1 Symbol mounting, characterized in that a polyester resin polyester resin (B) does not contain sulfonate. 3. A laminated polyester film according to claim 1 or 2, wherein the containing organometallic compound (D) in the laminated film. 4. The laminated polyester film according to claim 3, wherein the organometallic compound (D) is at least one selected from a titanium organic compound, a zirconium organic compound, and an aluminum organic compound. 5. A laminated polyester film according to any one of claims 1 to 4, characterized in that it contains melamine crosslinking agent in the laminated film. Claim 6. A polyester film characterized in that it is a polyethylene terephthalate film or polyethylene-2,6-naphthalate film 1-5
The laminated polyester film according to any one of the above. 7. polyester film characterized in that it is a white polyester film according to claim 1-6 noise
A laminated polyester film according to any of the above items 8. A laminate, further comprising a printing ink layer provided on at least one surface of the surface of the laminated polyester film according to any one of claims 1 to 7 . 9. A laminate, further comprising a magnetic recording layer provided on at least one surface of the surface of the laminated polyester film according to any one of claims 1 to 8 .