JPH028228A - Polyester film having coating layer - Google Patents

Abstract

PURPOSE:To provide the subject film having a coating layer containing a specific compound and formed by a coating and drawing process and having improved surface properties, especially adhesively. CONSTITUTION:The objective polyester film has a coating layer formed by a coating and drawing process. The coating layer contains a reaction product of (A) a compound having polymerizable unsaturated carbon-carbon bond and (B) a polyester having carboxylic acid component and/or carboxylic acid salt component on the side chain. The amount of the polyester to be reacted with the compound having unsaturated carbon-carbon bond is 5-95wt.%, preferably 10-80wt.%. The thickness of the coating layer is 0.01-5mum and that of the film is 3-500mum.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to surface properties of polyester films.

In particular, it relates to a polyester film with improved adhesion.

[Problems to be solved by conventional technology and invention]

Biaxially oriented polyester film is widely used due to its excellent properties.

Depending on the application, it has drawbacks such as poor adhesion.

Methods for improving the adhesion of biaxially oriented polyester films include forming a copolyester into a film;
There are methods such as blending polymers such as polyether, treating the film with solvents, corona discharge treatment, plasma treatment, etc., but these methods have a limited effect on improving adhesion. An effective method is to laminate polymers with different properties.

As a method for producing a biaxially stretched polyester film having a coating layer, there is a method called a coating/stretching method (in-line coating method) in which a coating solution is applied, and then the film is stretched and heat treated. Compared to the method of applying a coating solution to a biaxially stretched polyester film to form a coating layer, this method can produce a wide product at a relatively low cost because film formation and coating are carried out simultaneously. Not only is the adhesion between the coated layer and the polyester film of the substrate good, the coated layer can be made thinner, but also the surface properties of the coated layer are characteristic.

Coating agents used in the coating and stretching method include polyester, polyurethane, and acrylic resin.

Many proposals have been made, including vinyl resins.

However, although polyester used as a coating agent has good adhesion to the base polyester film, when it is laminated with other materials on top of it, the adhesion is often insufficient. If the copolymerization component or amount of copolymerization is increased, a problem arises in that the adhesion (blocking property) deteriorates.

For this reason, the applicant of the present application has
In qt, si publication, they proposed a polyester film in which a coating liquid containing polyester and acrylic resin was applied to the film and then stretched, and it was confirmed that the film was useful in practice.

However, coating liquids simply containing these resins may have problems such as immersion properties, coating strength, water resistance, solvent resistance, transparency, and adhesion depending on the application.

[Means for Solving the Problems] In view of the above-mentioned problems, the inventors of the present invention conducted extensive studies and found that a polyester film having a specific coating layer has excellent adhesive properties. 1. Completed the present invention. I ended up doing it.

That is, 1. The gist of the present invention is a polyester film having a coating layer obtained by a coating and stretching method, wherein the coating layer contains a compound (5) having a polymerizable carbon-carbon unsaturated bond and a carboxyl group in the side chain. The present invention relates to a polyester film having a coating layer characterized by containing a reaction product with a polyester having an acid component and/or a carboxylate component.

The present invention will be explained in more detail below.

The polyester of the polyester film in the present invention is polyethylene terephthalate whose constituent units are ethylene terephthalate or more, or polyethylene naphthalate whose constituent units are ethylene naphthalate.

The polyester film of the present invention may contain inorganic particles, organic particles, organic lubricants, antistatic agents, stabilizers, dyes, pigments, and organic polymers as a composition, if necessary. In order to impart slipperiness to a polyester film, fine particles are included in the film composition, but the type, size, and composition of the protrusion-forming agent are determined depending on the required properties such as lingering properties and transparency of the product to be used. The amount is selected accordingly.

Examples of compounds having a polymerizable carbon-carbon unsaturated bond (hereinafter abbreviated as compounds) in the present invention include the following.

(1) (meth)acrylate alkyl ester methyl (
meth)acrylate, ethyl(meth)acrylate, n
-propyl (meth)acrylate, i-propyl (meth)acrylate, lauryl (meth)acrylate, diflomprobyl (meth)acrylate, tribromophenyl (meth)acrylate or alkoxyalkyl (meth)acrylate, n-butyl (meth)acrylate,
i-Butyl (meth)acrylate-t-butyl (meth)
Acrylate + 5ec-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, pentyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl ( meth)acrylate (2) Those with a hydroxyl group Co-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, co-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate )
acrylate, dihydroxybutyl(meth)acrylate, 3-chlorocohydroxypropyl(meth)acrylate, gecohydroxyethyl fumarate, monocohydroxyethylmonobutyl fumarate or polyethylene glycol mono(meth)acrylate. Hydroxyalkyl esters of α,β-ethylenically unsaturated carboxylic acids (3) Those having a carboxyl group (meth)acrylic acid-crotonic acid, maleic acid,
Examples include unsaturated mono- or dicarboxylic acids such as fumaric acid, itaconic acid or citraconic acid, as well as monoesters of these dicarboxylic acids and monohydric alcohols.

β-ethylenically unsaturated carboxylic acids, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (
Meta) acrylate.

3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, lI-hydroxybutyl (meth)acrylate, J-chlorocohydroxybrobyl (meth)acrylate, di alpha, beta-unsaturated carboxylic acid hydroxyalkyl esters such as co-hydroxyethyl fumarate, mono-2-hydroxyethyl-motuptylfumarate or polyethylene glycol mono(meth)acrylate and maleic acid, succinic acid, phthalic acid, hexa hydrophthalic acid, tetrahydrophthalic acid,
Benzenetricarboxylic acid.

Adducts of unapolycarboxylic acids with anhydrides such as benzenetetracarboxylic acid, "Himic acid" [Hitachi Chemical product], tetrachlorophthalic acid or dodecynylsuccinic acid (4) Glycidyl (meth)acrylate having an epoxy group , (β-methyl)glycidyl (meth)acrylate.

(meth)allyl glycidyl ether or the above α, β
- Ethylenically unsaturated carboxylic acids or equimolar adducts of hydroxyl group-containing vinyl monomers such as mono(meth)acryloyloxymonoethyl phthalate and the polycarboxylic anhydride;
“Ebikuron 200, 1I00. Dada l.

gso or 1osoJ [epoxy resin manufactured by Dainippon Ink & Chemicals ■], "Epicoat T2g, 100/or ioo da" (epoxy resin manufactured by Shell), "Araldite T, oti or box4!" C Ciba, Switzerland
Geigy epoxy resin), “Chissonox 22/
J [Epoxy compound manufactured by Chisso ■] or [Bunacol-
Products obtained by addition reaction of various polyepoxy compounds having at least moss epoxy groups in 7 molecules in equimolar ratios, such as EX-6//J (epoxy compound manufactured by Nagashio Sangyo ■) (5) Those containing an amide group (meth)acrylamide, dimethyl (meth)acrylamide, N-t-butyl (meth)acrylamide, diacetone acrylamide.

N-methylol (meth)acrylamide, N.

N'-methylenebis(meth)acrylamide.

Reaction product of (meth)acrylamide and glyoxal,
co-acrylamide-co-methylpropane sulfone ff
i, N, N-bis(carboxymethyl)acrylamide, (acryloylaminomethyl)iminodiacetic acid, dimethylaminepropylmethacrylamide and its cationized product, acrylamide-3-methylbutyldimethylamine and its cationized product (6) Halogenated vinyl compound Vinyl chloride, vinylidene chloride, vinyl fluoride or vinylidene fluoride (7) Unsaturated dicarboxylic acid ester dibutyl maleate, dicoethylhexyl maleate,
Dibutyl fumarate, zicoethyl fumarate, dibutyl itaconate, zicoethylhexylitaconate In addition to the above-mentioned compounds, aromatic compounds such as styrene, α-methylstyrene-ptert-phthylstyrene, vinyltoluene, (meth)acrylonitrile, N-vinyl formamide), N-vinylacetamide, N-vinylpyrrolidone.

N-vinylsuccinimide, N-vinyloxazolidone, N-vinylpyridine or vinyl acetate, vinyl esters such as vinyl benzoate, Heopa (vinyl ester manufactured by Shell), Viscoat gF1gFM,
JF or 7FMJ [fluorine-containing acrylic monomer manufactured by Osaka Organic Chemical ■] perfluorocyclohexyl (meth)acrylate, diperfluorocyclohexyl fumarate is N-/-7" propyl perfluorooctane sulfonamide ethyl ( Compounds with perfluoroalkyl groups such as meth)acrylate, silicone monomers such as vinyl ethoxysilane and α-methacryloxypropyltrimethoxysilane, 2-(meth)acryloyloxyethyl acid phosphate, diptyl(-
Phosphorous atom-containing vinyl monomers represented by the general formula (meth)acryloyloxyethyl) phosphate.

Dialkylaminoalkyl (meth)acrylates such as dimethylamine ethyl (meth)acrylate and diethylaminoethyl (meth)acrylate, ethylene sulfonic acid and its alkali metal salts such as sodium and potassium, or vinyl methyl sulfone, vinyl ethyl sulfone,
Vinyl alkyl sulfones such as vinyl ethyl sulfone,
Vinylsulfonamides such as vinylsulfonamide, vinylsulfonanilide, vinylsulfonemethylanilide, styrenesulfonic acid and its alkali metal salts such as sodium and potassium, 2-acryloyloxyethyltrimethylammonium chloride, j-(2-acryloyloxyethyl Cationic compounds such as dimethyldimethylammonio)propionate, Daicel Chemical Industries ■
Plaxel FA and FM (trade names), which are ε-cagzoloctam addition monomers manufactured by Co., Ltd., and styrene-based styrene-acrylonitrile, which is a so-called macromonomer that functions as a polymerizable monomer although it is a polymer.

Methyl metabutyl acrylate, silicone.

Examples include, but are not limited to, those having a reactive group at the terminal group such as fluorine-based polymers, and conjugated diene compounds such as butadiene.

In the present invention, a polyester having a carboxylic acid component and/or a carboxylate component in its side chain (hereinafter referred to as polyester 0
) is obtained by reacting a saturated or unsaturated polyester with a compound having a carboxylic acid group and/or a carboxylic acid group. Here, the saturated polyester includes terephthalic acid, isophthalic acid, 2. Aromatic dicarboxylic acids such as j-naphthalene dicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid, oxycarboxylic acids such as oxybenzoic acid, and their ester-forming derivatives can be used; Ingredients include (c) ethylene glycol, aliphatic glycols such as 4'-7'' tandiol, diethylene glycol, and triethylene glycol; and alicyclic glycols such as F-cyclohexane dimetatool.

Aromatic diols such as p-xylene diol.

polyethylene glycol, polypropylene glycol,
Poly(oxyalkylene) glycols such as polytetramethylene glycol can be used. Although these polyesters are linear, they can also be made into branched polyesters by using trivalent or higher ester forming components.

Examples of unsaturated polyesters include Tokko Shoda S-22o1 and 1I&-20! O1 publication, Dada '113 da publication, published in 1923! g-71233 publication,! ;0-3g
As is known from Publication No. 23, etc., a resin having a copolymerizable unsaturated group in the resin skeleton obtained by reacting it with other raw material components, using a raw material component having a copolymerizable unsaturated group as an essential component, - Or, Special Publication Sho Q9-Riff No. 916,
S: As in Publication No. 0-1,223, a saturated polyester having no copolymerizable unsaturated groups is first obtained, and then reactive with functional groups such as hydroxyl groups or carboxyl groups present in the saturated polyester. For example, those with an epoxy group and a vinyl group such as glycidyl (meth)acrylate, and those with an alkoxysilanol group and a vinyl group such as vinylmethoxysilane and (meth)acryloxyethyltrimethoxysilane. What you have.

Those with an acid anhydride group and a vinyl group such as maleic anhydride and tetrahydrophthalic anhydride, 2-hydroxypropyl (
Examples include, but are not limited to, those obtained by adding a vinyl monomer having an isocyanate group and a vinyl group, such as an equimolar adduct of meth)acrylate-hexamethylene diisocyanate, to a saturated polyester. Further, these saturated or unsaturated polyesters may have a sulfonic acid group.

The method of introducing a carboxylic acid component and/or a carboxylate component into the side chain of this saturated or unsaturated polyester is as follows:
A method of reacting a dioxy compound having a carboxylic acid or a carboxylic acid group with a polyester as disclosed in JP-A-47-221:030;
axssi.

A method of radically grafting an unsaturated carboxylic acid or an unsaturated carboxylic acid salt onto a polyester as shown in Japanese Patent Publication No. 62-223527, and a method of reacting a polyester with a halogenoacetic acid as shown in JP-A-62-223527. A method for introducing a substituent into an aromatic ring by
QJ/1! Examples include, but are not limited to, a method of reacting a polyester with a polycarboxylic anhydride compound as shown in the following publication.

The molecular weight, amount of carboxylic acid groups, and amount of carboxylic acid bases of polyester 0 are appropriately selected depending on the type or amount of the compound having a polymerizable carbon-carbon unsaturated bond to be reacted later.

The molecular weight is preferably 3ooo to 5ooo.

, more preferably from 5ooo to 3ooo.

The amount of carboxylic acid groups and the amount of carboxylic acid bases (converted to the amount of carboxylic acid groups) are 30 to 3o.

A range of K OHmy /y (amount of acid neutralization with potassium hydroxide per 11 polymers) is preferred. Polyester 0
If the molecular weight is less than 3,000, the coatability, adhesion and mechanical properties of the initial reaction product and the product after the reaction may be poor. Handling and coating properties deteriorate, which is undesirable. When the amount of carboxylic acid groups or carboxylic acid bases is less than 7 o K OH1n9/9-, hydrophilicity and affinity with other compounds decrease.

If it exceeds 3ooKOHm9/P, water resistance and mechanical properties may deteriorate, which is not preferable.

In the present invention, the reaction between the first compound and the polyester (B) is performed by mixing the polyester dispersed or dissolved in water or a solvent with a compound having a carbon-carbon unsaturated bond as a reaction catalyst.

Hydrogen peroxide, benzoyl peroxide, tertiary butyl peroxide, di-tertiary butyl peroxide, acetyl peroxide, azobisisobutyronitrile,
Cumene hydroperoxide, ammonium persulfate,
Potassium persulfate, 2,2-azobisamidinomethane, λ
, 2-azobisaminoethane or their hydrochloride.

Polymerization initiators such as sulfate, flF nitrate, diceric ammonium, or 2-hydroxy-cotatyl-l-phenylpropan-l-one, t-(1-47probylphenyl)-2-hydroxy-comethylpropane-l-
It can be carried out by a known method using a photopolymerization initiator such as On, but is not limited thereto. This reaction may be carried out homogeneously or heterogeneously. For example, if this polyester 0 is present in the medium as a dispersion, a shell-core structure will result in one reaction.

The proportion of polyester in the reaction product of compound (5) and polyester in the present invention varies depending on the required properties, but is preferably in the range of 5% by weight to qs% by weight, more preferably 10% by weight. ~gO wt%. If polyester 0 is less than S weight %, the adhesion to the polyester film and coating strength may decrease], and if it exceeds 95 weight %, the useful properties of compound (4) are effective for the reaction product. This is because it may not be introduced in some cases.

The coating solution containing the reaction product of the first compound and polyester (B) in the present invention can be used in a state dissolved in an organic solvent, but in order to be used in the coating and stretching method, it must be water-soluble or a water dispersion. It is preferable that there be. The method of making this reaction product water-soluble or water dispersion is to use the carboxylic acid or carboxylate of the polyester part of this reaction product as a hydrophilic group, or to make a hydrophilic compound as a carbon-carbon unsaturated bond compound. 1 depending on how it is used together etc.
By making the reaction product hydrophilic, this becomes possible using a known method. The medium of the coating liquid in the present invention is preferably water, but in order to improve the agglomeration stability of the coating agent, the applicability to the polyester film of the substrate, the film-forming property of the coating agent, etc., alcohols, cellosolves, N. - An organic solvent such as methylpyrrolidone may be added to the coating solution.

The coating liquid used in the present invention includes methylol- or alkylol-based urea-based, melamine-based, and guanamine-based crosslinking agents to improve the adhesion (blocking property), water resistance, and solvent resistance of the coating layer. , acrylamide-based, polyamide-based compounds, epoxy compounds, aziridine compounds, block polyisocyanates, silane coupling agents, titanium coupling agents.

Zirco-aluminate coupling agent, heat, peroxide,
It may contain a photoreactive vinyl compound, a photosensitive resin, or the like. In addition, silica is used as an inorganic fine particle to improve adhesion and damage.

Silica sol, alumina, alumina sol, zirconium sol, kaolin, talc, calcium carbonate, titanium oxide,
It may contain barium salt, carbon blank, molybdenum sulfide, antimony oxide sol, etc., and further contains antifoaming agents, coating improvers, thickeners, antistatic agents, organic lubricants, organic It may contain polymer particles, antioxidants, ultraviolet absorbers, blowing agents, dyes, pigments, and the like.

Furthermore, the coating solution of the present invention may contain polymers other than the polymers of the present invention in order to improve the properties of the coating solution or coating layer.

As a method for applying the above-mentioned coating liquid to a polyester film, there is a reverse roll coder as shown in "Coating Method" written by Yuji Harasaki, published by Maki Shoten, 1979,
A method in which a coating solution is applied to an unstretched polyester film using a gravure coater, a rod coater, an air doctor coater, or other coating equipment, and then biaxially stretched sequentially or simultaneously. There is a method of stretching in a direction perpendicular to the uniaxial stretching direction, or a method of coating a biaxially stretched polyester film and further stretching in the transverse and/or longitudinal direction.

The above-mentioned stretching step is preferably carried out at 60-/jO<0>C, and the stretching ratio is at least 9 times or more, preferably 6 to 20 times in terms of one area ratio.

The stretched film is heat treated at 750-25[theta]C.

Furthermore, in the maximum temperature zone of the heat treatment and/or the cooling zone of the heat treatment outlet, the temperature is 0.2 to 20 in the longitudinal and transverse directions.
% relaxation is preferred.

In particular, the coating solution is applied to a biaxially stretched polyester film that has been stretched 2 to 6 times by a roll stretching method at 60 to 1JO DEG C., and then suitably dried.

Alternatively, it is preferable to immediately stretch the axially stretched polyester film 2 to 6 times at gO to 130°C in a direction perpendicular to the previous stretching direction without drying, and then heat treat it at 759 to 239°C for 1-boo seconds.

According to this method, it is possible to dry the coating layer at the same time as stretching, and the thickness of the coating layer can be reduced according to the stretching ratio, and a film suitable as a polyester film base material can be produced at a relatively low cost. can.

The coating liquid in the present invention may be applied to only one side of the polyester film, or may be applied to both sides of the polyester film. When the polyester film of the present invention is coated only on one side, a coating layer other than the coating liquid of the present invention may be formed on the opposite side as necessary to impart other properties to the polyester film of the present invention.

In order to improve the applicability and adhesion of the coating agent to the film, the film may be subjected to chemical treatment or discharge treatment before coating. Also, the adhesion of the biaxially stretched polyester film of the present invention to the coating layer.

In order to improve coating properties and the like, the coating layer may be subjected to a discharge treatment after the coating layer is formed.

The polyester film coated with the coating solution of the present invention obtained as described above preferably has a thickness of 3 to 500μ, and the thickness of the coating layer preferably ranges from o, oiμ to Sμ. , more preferably in the range of 0.02μ to 7μ. If the thickness of the coating layer is less than 0.0/μ, it is difficult to obtain a uniform coating layer, so uneven coating tends to occur on the product (if it is thicker than Sμ).

This is undesirable because the slipperiness decreases and the film becomes difficult to handle.

〔Example〕

The present invention will be explained below with reference to Examples.

The present invention is not limited by the following examples unless it goes beyond the gist thereof.

[Production of coating agent <1)] According to the method described in JP-A-42-21103/g, terephthalic acid in the dicarboxylic acid was SO mol, isophthalic acid was Sθ mol, ethylene glycol in the glycol was 73 mol, A polyester containing 27 mol of diethylene glycol and pyromellitic anhydride were reacted in xylene, and after xylene was removed, a polyester having a molecular weight of 11 and a carboxylic acid group weight of 7119 KOH/l was obtained. The carboxylic acid groups of this polyester were neutralized with ammonia to obtain an aqueous dispersion of polyester with a solid content concentration of 2 0 wt%. This aqueous dispersion trooFf and benzoyl peroxide 2 were prepared according to the method described in JP-A-1S2-21S7310.
y-, methyl methacrylate is? , polyoxyethylene alkyl ether phosphate 3. Sf, ion exchange water 311. ! An emulsified dispersion of a polymerization initiator consisting of rf was mixed in a reaction vessel, and after purging with nitrogen, the temperature was raised to 70'C. Next, add methyl methacrylate'12fI- and butyl acrylate 30? to this dispersion while stirring. , glycidyl methacrylate 13? What is the temperature of the dispersion of the acrylic monomer liquid consisting of? The mixture was added dropwise over 2 hours while adjusting the temperature to S - f 0°C, and stirring was continued for 70 hours at Ktro°C, followed by cooling to room temperature.

An aqueous dispersion of a reaction product of an acrylic compound and a polyester having a carboxylic acid group whose pH was adjusted to g with ammonia was obtained.

[Manufacture of coating agent (It)]

Japanese Patent Publication No. 4. ? -1 Carboxylic acid group amount t, s m manufactured by Nippon Gosei Kagaku Kogyo ■ according to the method described in I&Co J7 Publication
Solids concentration of y/K OH/t, 7 o wt%
Polyester W-9!0/ which is a water-dispersed polyester of
(Product name) at 300 fP and deionized water for 1 s.

Vinyl sulfonic acid 00 da? , polyoxyethylene alkyl ether phosphate ester/fP, vinegar 2 vinyl/7
After stirring and mixing Lt, the atmosphere was replaced with nitrogen and the temperature of 1 dispersion was lowered to 60°C.
℃. To this was added 1 ammonium persulfate haf dissolved in 120 fl lc of deionized water with stirring. Furthermore, methyl methacrylate t b o! F; Ethethyl acrylate 120? , methacrylic acid 36? Roton acid, S? .

t-dodecyl mercaptan 7.3? mixed solution for 3 hours 3
It was added continuously for 0 minutes. The temperature inside the reaction vessel at this time was raised from 6 (11℃ to gO℃ in 90 minutes, and then adjusted to tro℃. When it reached go℃, deionized water was added Ot, ifM Ammonium sulfate 3
? , polyoxyethylene alkyl ether phosphate ester 86? .

A mixture of sodium bicarbonate λ, Of was added continuously over t hours, the reaction was continued for an additional 2 hours, and the reaction product of the reactive compound and the polyester having a carboxylic acid group was cooled to room temperature. A water dispersion was obtained.

Example 1 Polyethylene terephthalate having intrinsic viscosities of o, t, and p was melt-extruded at a temperature of 210 to 3θO<0>C.

Cast on a cooling drum using the electrostatic adhesion method,
An amorphous film with a thickness of 1 trsμ was obtained.

This film was stretched 3.5 times in the longitudinal direction using qsc.

An aqueous dispersion consisting of 90 parts (solid weight parts) of coating agent (I) and 10 parts of curkyol melamine was applied to one side of this film, and the film was further stretched 3.5 times in the transverse direction at 119°C. A heat treatment was performed at .degree. C. to obtain a base polyester film having a coating thickness of O and OS.mu..

Polyurethane rO part CI is applied to the coating layer surface of the obtained film.
parts), nitrocellulose 2om.

30 parts of vinyl chloride vinyl acetate resin, 7.5 parts of incyanate compound, carbon black fuco part, lecithinda part, γ-iron oxide q6θ part, and methyl ethyl ketone.

Solvent qo in equal ratio of toluene and methyl isobutyl ketone
Apply dispersed magnetic paint to part o using a ball mill method - go
After heat treatment at .degree. C. for 2 hours, a film having a magnetic layer thickness of S.mu. was obtained. A polyester adhesive tape was attached to the magnetic layer surface of the obtained film, and a T-peel test was performed using a tensile tester, and the peel strength was found to be % inch width/10L? It showed excellent adhesion. On the contrary.

When a magnetic layer was formed in the same manner as before on the side of this film that did not have a coating layer, the peel strength was 3 gf, which was insufficient adhesion for practical use.

That is, the polyester film having the coating layer of the present invention had good adhesion to the magnetic layer and was useful as a base material for magnetic tape.

Example λ Polyethylene terephthalate with intrinsic viscosity o, b s,
An amorphous film with a thickness of 120μ was obtained.

This film was stretched 3.3 times in the machine direction at 95°C.

An aqueous dispersion consisting of 5 parts (by weight) of the above-mentioned coating agent (1), io parts of alkylol melamine, and 5 parts of silica sol was applied to both sides, and the mixture was further heated at 110°C for 3.3 g in the lateral direction.
Stretched twice and heat treated at 210℃ to obtain a coating layer thickness of 0.10.
A biaxially stretched polyester film having a thickness of 75 μm and a base polyester film thickness of 75 μm was obtained.

The magnetic paint of Example 1 was applied to one side of the obtained film to form a magnetic layer in the same manner as in Example. In order to evaluate the adhesion between this magnetic layer and the polyester film of the present invention, a scratch test was conducted on the magnetic layer with the edge of a coin, but cohesive failure occurred in the magnetic layer, and the coating of the magnetic layer and the polyester film of the present invention A magnetic layer remains at the interface with the magnetic layer.

Adhesion was good. On the other hand, stretching was carried out in the same manner as in this example except that no coating layer was provided.

When a magnetic layer was provided on a heat-treated double-stretched polyester film and a coin scratch test was conducted, interfacial peeling easily occurred between the magnetic layer and the base polyester film.

That is, the polyester film of the present invention has good adhesion to the magnetic layer and is useful in magnetic disk applications.

Example 3 A polyester film having the coating layer of Example C was provided with an ultraviolet curable coating layer of (G) and [F] + (Q), and a cellophane tape manufactured by Nichiban Co., Ltd. with a width of igas was placed on the surface to prevent air bubbles. Paste it to a length of 7Cr to prevent it from entering, apply a constant load on it with a manual load roll at 3 o'clock, fix one end of the polyester film, connect one end of cellophane tape to a weight of 5001, Adhesiveness was evaluated by a method in which peeling started in the /100 direction after a weight fell naturally over a distance of 3 cm.

(G) So-called solid printing is carried out on a polyester film using an offset printing tester, RT Tester (product name), using off-cent ink manufactured by Moroboshi Ink ■, and UV-curable PCD white (product name) manufactured by Ushio Ink ■. Curing conditions / 20 using UV irradiation device UvH-2000 type (product name)
UV curing was carried out at w/Crn and film speed of 10 m/min to obtain a film with a printing ink layer thickness of lμ.

0 El, an ultraviolet curing insulating paint manufactured by Acheson Japan
ectrodag lIs o SS (Product name)
is applied to polyester film using screen printing method,
UV curing conditions with the above-mentioned UV irradiation device / A Ovt
/ Crn - UV curing was carried out at a film speed tom of 1 minute to obtain a film with an insulating layer thickness of iooμ (3 coats were applied).

(q FS-7072, an ultraviolet curable surface hardening agent manufactured by Mitsubishi Rayon ■, was diluted with 1 ton of methyl ethyl to a solid concentration of 30% by weight, and applied to a polyester film using a #6 bar coater! After drying for seconds,
Ultraviolet curing conditions with the above-mentioned ultraviolet irradiation device / & Ow
/ CHI.

UV curing was carried out at a film speed of SmZ min.

A film with a surface hardening layer having a thickness of 2 μm was obtained.

In the cellophane tape peel test, there was no peeling between the ultraviolet cured layer of (g)-a, O and the base polyester film, and although the cellophane tape peel test was repeated for the ultraviolet cured layer of No peeling was observed in the second test, and the adhesion was good. On the other hand, a biaxially stretched polyester film was drawn and heat treated in the same manner as in this example except that no coating layer was provided.

In a peel test using cellophane tape, the coating layer was (G).

In the case of (g), peeling occurred at the interface between the ultraviolet-cured layer and the base polyester film in one test.

(In the case of Q, so-called lifting was observed at the interface at the j-th time, and the adhesion was poor.

That is, the polyester film having the coating layer of the present invention has good adhesion to the ultraviolet curable coating layer, and is useful as a base material for labels, wiring boards, surface-cured films, and the like.

The thickness of the coating layer was o and i sμ in the same manner as in Example A except that the coating agent (It) was used instead of the coating agent CI).

A biaxially stretched polyester film having a thickness of 75 μm was obtained as a base polyester film.

One side of the obtained film was coated with the following 0. The coating layers (Ro) and (B) were formed to a thickness of 5 μm using a percoater.

B Eastman fist Cellulose butyrate, manufactured by Kodak ■ Diazotype 5D-10 (trade name), a polyvinyl alcohol-vinyl acetate based emulsilon for screen printing (product name) manufactured by Kurita Chemical Research Institute Manufactured polyvinyl alcohol
These 0.0. In order to evaluate the adhesion of the interface of the film on which the coating layer (Tan) was formed, a peel test using cellophane tape was conducted in the same manner as in Example 3, and there was no peeling, indicating good adhesion. On the other hand, a biaxially stretched polyester film that was stretched and heat-treated in the same manner as in this example except that no coating layer was provided had a 0. In a peel test using cellophane tape of the film on which the coating layer of F5 was formed, peeling occurred at the interface between the coating layer of 0. (transfer) and (b) and the base polyester film in all cases.

In other words, the polyester film having the coating layer of the present invention has good adhesion to a binder used in plate-making applications, and is useful as a base material in plate-making applications.

Example S 2g of polyethylene terephthalate with an intrinsic viscosity of 0.66
It was melt extruded at a temperature of 0 to 300°C and cast onto a cooling drum to obtain an amorphous film with a thickness of 39μ. This film was stretched 3.3 times in the longitudinal direction at 95°C, coating agent (1) was applied to one side of the film, further stretched 3.5 times in the transverse direction at 710°C, and heat treated at 21OC. A biaxially stretched polyester film was obtained, the thickness of the coating layer was o, ot, μ, and the thickness of the base polyester film was da, θμ.

On the coated layer side of this film, a heat-sensitive dye sublimation ink layer is formed using cellulose acetate L-jO (product name) manufactured by Daicel Chemical Industries, Ltd., and on the opposite side, a so-called heat-resistant ink layer is formed using curable silicone. Formed an easily dissipated layer. This film was installed in a thermal transfer printer and printed on a recording material made of synthetic paper with a dyed image-receiving layer.

Only one printed image was clearly sublimated and dyed onto the recording material.

On the other hand, if the heat-sensitive sublimation ink layer of this example is formed directly on a polyester film without a coating layer, the ink layer may peel off during the film slitting process, or the ink layer itself may become attached to the recording material during heat-sensitive transfer. There were cases of transfer.

That is, the polyester film having the coating layer of the present invention has good adhesion to the heat-sensitive sublimation ink layer, and is useful as a base material for a film for heat-sensitive transfer.

〔Effect of the invention〕

The film of the present invention has excellent adhesive properties and is useful as a base material for various uses such as magnetic recording media, labels, wiring boards, plate making, and thermal transfer.

Applicant: Diafoil Co., Ltd.

Claims (1)

[Claims] (1) A polyester film having a coating layer obtained by a coating stretching method, in which a compound (A) having a polymerizable carbon-carbon unsaturated bond and a carboxylic acid component in the side chain and/or A polyester film having a coating layer characterized by containing a reaction product with a polyester (B) having a carboxylate component.