JP2781301B2 - Easy-adhesive polyester film and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an easily adhesive polyester film and a method for producing the same, and more particularly, to a highly processed product of the film, such as a magnetic tape for audio, a magnetic tape for video, a magnetic tape for computer, a floppy disk, X The present invention relates to a polyester film having excellent adhesiveness and blocking resistance, which is useful as a base material for a radiographic film, a telephone card, a membrane, a diazo microfilm, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art It is known that a thermoplastic polyester, for example, polyethylene terephthalate or its copolymer, polyethylene naphthalate or its copolymer, or a blend of these with a small proportion of another resin is melt-extruded to form a film. It is. It is also known that the resulting biaxially stretched and heat-set polyester film is superior in heat resistance, gas barrier properties, electrical properties and chemical resistance to films made of other resins. However, since the surface is highly crystallographically oriented, the surface has high cohesiveness and poor adhesion to, for example, paints, adhesives, and inks.

Therefore, as a method for improving the adhesiveness, physical treatment such as corona treatment, ultraviolet treatment, plasma treatment, EB treatment or flame treatment or chemical treatment such as treatment with chemicals such as alkali, aqueous amine, and trichloroacetate phenols. It has been known. However, these methods have practical disadvantages such as deterioration of the adhesive force with time and contamination of the working environment due to volatilization of the chemical.

As another means, there is known a method in which a primer layer is provided by applying an easily-adhesive coating agent to a film surface by a process other than the ordinary polyester film forming process. However, in this method, an organic solvent is usually used as a solvent for the coating agent, and it is difficult to say that the coating atmosphere is sufficiently clean. There are safety and hygiene problems such as deterioration.

[0005] By the way, if this primer treatment is carried out in a polyester film forming process using an aqueous coating agent, there is no adhesion of dust in a clean environment, and there is no danger of explosion or deterioration of the environment due to the aqueous solvent. This is advantageous in terms of film performance, economy, and safety. Due to such advantages, it has been proposed to use a water-soluble or water-dispersible polyester resin or acrylic resin as a primer (Japanese Patent Application Laid-Open No. 54-43017, Japanese Patent Publication No. 49-10 / 1979).
No. 243, JP-A-52-19786, JP-A-52-1
No. 9787). However, the polyester-based resin has a drawback that blocking tends to occur when the film is wound into a roll, and the acrylic resin has a drawback of poor adhesion to a film, mechanical strength, and adhesion to a magnetic layer. There is. For the purpose of improving these drawbacks, it has been proposed to use a mixture of the above-mentioned polyester resin and the above-mentioned acrylic resin (JP-A-58-12465).
No. 1), however, it is hard to say that improvement of these defects is sufficient.

Japanese Patent Application Laid-Open No. 63-46237 discloses that an acrylic monomer is obtained by radical polymerization of an acrylic monomer in the presence of a water-dispersible sulfonated polyester modified with a specific sulfonic acid metal salt compound. It has been proposed to use modified polymers. However, since the water dispersibility of the sulfonated polyester is insufficient, it is hard to say that the above disadvantage is sufficiently improved.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide various coatings applied to polyester films, such as offset inks, gravure inks, silk screen inks, UV inks, magnetic paints, gelatin compositions, adhesives, Has a thin primer layer with excellent adhesion to electrophotographic toner, chemical matte paint, diazo paint, hard coat paint, UV paint, heat sealability-imparting composition, inorganic film-forming substance, etc. An object of the present invention is to provide an easily adhesive polyester film.

It is another object of the present invention to provide a preferred method for producing such an easily adhesive polyester film.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
According to the present invention: At least one surface of the polyester film has the following formula (I)

[0010]

Embedded image

Wherein A is an aromatic group or an aliphatic group, X ₁
Is an ester-forming functional group, X ₂ is the same or different ester-forming functional group or a hydrogen atom as X ₁ , R ₁ , R ₂ ,
R ₃ and R ₄ are the same or different groups selected from an alkyl group and an aryl group, and m represents a positive integer. A primer mainly comprising a copolymer obtained by subjecting a radical polymerizable monomer mainly composed of an acrylic monomer to aqueous phase radical polymerization in the presence of a modified polyester modified with a quaternary phosphonium salt of sulfonic acid represented by the following formula: 1. An easily-adhesive polyester film provided with a thin layer, and An easily-adhesive polyester film characterized by applying an aqueous primer solution containing the copolymer to at least one surface of the polyester film before the crystal orientation is completed, and then performing drying, stretching and heat treatment to complete the crystal orientation of the film. Is achieved.

In the present invention, the polyester constituting the polyester film is a linear saturated polyester synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Specific examples of such polyester include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylene dimethylene terephthalate), polyethylene-2,6-naphthalenedicarboxylate, and the like. A coalescence or a blend of these with a small proportion of another resin is also included.

The polyester film of the present invention is obtained by subjecting such a linear saturated polyester resin to melt extrusion, forming it into a film by a conventional method, and subjecting it to orientation crystallization and heat treatment crystallization. This polyester film was used as a heat of crystal fusion by a differential scanning calorimeter in a nitrogen stream [10 ° C. /
At a heating rate of 1 min] is usually 4 cal / g
It is preferable that the crystal is oriented so as to exhibit the above.

In the present invention, the polyester film before the completion of the crystal orientation is an unstretched film obtained by melting the polyester to form a film as it is; orienting the unstretched film in either the longitudinal direction or the transverse direction. A uniaxially stretched film; a film stretched and oriented at a low magnification in two directions, that is, a longitudinal direction and a lateral direction (a biaxially stretched film before being finally stretched in a longitudinal direction or a lateral direction to complete oriented crystallization). ) Etc.

In the present invention, the thin primer layer is represented by the following formula (I):

[0016]

Embedded image

Wherein A is an aromatic group or an aliphatic group, and X ₁
Is an ester-forming functional group, X ₂ is the same or different ester-forming functional group or a hydrogen atom as X ₁ , R ₁ , R ₂ ,
R ₃ and R ₄ are the same or different groups selected from an alkyl group and an aryl group, and m represents a positive integer. And a copolymer obtained by subjecting a radical polymerizable monomer having an acrylic monomer as a main component to an aqueous phase radical polymerization in the presence of a modified polyester modified with a quaternary phosphonium salt of sulfonic acid.

The modified polyester is a polybasic acid or an ester-forming derivative thereof, a diol or an ester-forming derivative thereof and a sulfonic acid 4 represented by the above formula (I).
A substantially linear polymer synthesized from a compound of a secondary phosphonium salt. Examples of the polybasic acid component of this polymer include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, and pyromellitic acid. Examples thereof include melitic acid and dimer acid. Two or more of these components can be used. Further, a small proportion of unsaturated polybasic acids such as maleic acid, fumaric acid, itaconic acid, and hydroxycarboxylic acids such as p-hydroxybenzoic acid and p- (β-hydroxyethoxy) benzoic acid may be used together with these components. it can. The proportion of the unsaturated polybasic acid component or hydroxycarboxylic acid component is at most 10 mol%, preferably 5 mol% or less.

The diol component includes ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, dimethylol. Propionic acid, glycerin, trimethylolpropane,
Poly (ethylene oxide) glycol, poly (tetramethylene oxide) glycol, the following formula

[0020]

Embedded image And the like. Two or more of these components can be used.

In the above formula (I) representing a quaternary phosphonium salt of sulfonic acid, A represents an aromatic group or an aliphatic group, and among them, an aromatic group is preferable. X ₁ represents an ester-forming functional group.

[0022]

Embedded image

And the like. X ₂ represents an ester-forming functional group or a hydrogen atom which is the same as or different from X _1, and among them, an ester-forming functional group is preferable. R ₁ , R ₂ , R ₃ and R ₄ are the same or different groups selected from an alkyl group and an aryl group. m is a positive integer.

Such a quaternary phosphonium sulfonic acid salt can be easily synthesized by generally reacting a corresponding sulfonic acid with a phosphine or a corresponding metal salt of a sulfonic acid with a quaternary phosphonium halide.

Preferred examples of the quaternary phosphonium sulfonic acid salt include tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate, ethyltributylphosphonium 3,5-dicarboxybenzenesulfonate, and 3,5-dicarboxybenzenesulfonate. Benzyltributylphosphonium carboxybenzenesulfonate, phenyltributylphosphonium 3,5-dicarboxybenzenesulfonate,
3,5-dicarboxybenzenesulfonic acid tetraphenylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid ethyltriphenylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid butyltriphenylphosphonium salt, 3,5-dicarboxy Benzenesulfonic acid benzyltriphenylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid tetrabutylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid ethyltributylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid benzyl Tributylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid phenyltributylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid tetraphenylphosphonium salt, 3,5-dica Ethyl triphenylphosphonium bomethoxybenzenesulfonate, butyltriphenylphosphonium 3,5-dicarbomethoxybenzenesulfonate, benzyltriphenylphosphonium 3,5-dicarbomethoxybenzenesulfonate, tetracarboxybenzenesulfonate Butylphosphonium salt, 3-carboxybenzenesulfonic acid tetraphenylphosphonium salt, 3-carbomethoxybenzenesulfonic acid tetrabutylphosphonium salt, 3-carbomethoxybenzenesulfonic acid tetraphenylphosphonium salt, 3,5-di (β
-Hydroxyethoxycarbonyl) benzenesulfonic acid tetrabutylphosphonium salt, 3,5-di (β-hydroxyethoxycarbonyl) benzenesulfonic acid tetraphenylphosphonium salt, 3- (β-hydroxyethoxycarbonyl) benzenesulfonic acid tetrabutylphosphonium salt, 3- (β-hydroxyethoxycarbonyl) benzenesulfonic acid tetraphenylphosphonium salt, 4-
Hydroxyethoxybenzenesulfonic acid tetrabutylphosphonium salt, 2,6-dicarboxynaphthalene-4-
Examples thereof include tetrabutylphosphonium sulfonic acid salt and α-tetrabutylphosphonium sulfosuccinic acid. The above quaternary phosphonium salts of sulfonic acid may be used alone or in combination of two or more.

In order to introduce the quaternary phosphonium sulfonic acid salt into the polyester, the quaternary phosphonium sulfonic acid salt may be added to the polyester synthesis reaction system before the completion of the polyester synthesis.

The introduction ratio is preferably 0.5 to 60 mol%, more preferably 1 to 40 mol%, based on the polybasic acid component constituting the polymer. When the introduction ratio of the sulfonic acid quaternary phosphonium salt is less than 0.5 mol%, it is difficult to obtain a good aqueous dispersion. On the other hand, when it exceeds 60 mol%, the resulting polyester is easily water-soluble.
The physical properties of the obtained polyester are undesirably reduced.
In order to easily disperse the polyester in water, it is preferable to copolymerize a small amount of a hydrophilic group such as diethylene glycol, poly (ethylene oxide) glycol, poly (tetramethylene oxide) glycol and the like.

Acrylic monomers polymerized in the presence of the aqueous solution or dispersion of the modified polyester include, for example, alkyl acrylates and alkyl methacrylates (where the alkyl group is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, 2-hydroxyethyl acrylate, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc.);
Hydroxy-containing monomers such as hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate; acrylamide, methacrylamide, N-methylmethacrylamide, N-methylacrylamide, N-methylolacrylamide;
Amide group-containing monomers such as N-methylol methacrylamide, N, N-dimethylolacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-phenylacrylamide; N, N-
Amino group-containing monomers such as diethylaminoethyl acrylate and N, N-diethylaminoethyl methacrylate; epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate; acrylic acid, methacrylic acid and salts thereof (sodium salt, potassium salt, ammonium salt) And other monomers containing a carboxyl group or a salt thereof.

These can be used in combination with other radically polymerizable monomers. Other radically polymerizable monomers include crotonic acid, itaconic acid, fumaric acid, maleic acid and salts thereof (eg, sodium salt, potassium salt, ammonium salt, etc.), vinyl acetate, vinylidene chloride, styrene, α-methylstyrene , Vinyl isocyanate, vinyl methyl ether, vinyl ethyl ether,
Vinyltrisalkoxysilane, alkylmaleic acid monoester, alkylfumaric acid monoester, alkylitaconic acid monoester, vinyl chloride, styrenesulfonic acid, vinylsulfonic acid and salts thereof (eg, sodium salt, potassium salt, ammonium salt, etc.), Examples include ethylene monomers such as maleic anhydride and itaconic anhydride, and epoxy group-containing monomers such as allyl glycidyl ether. These monomers can be copolymerized using one kind or two or more kinds.

The amount of the other radically polymerizable monomer is preferably at most 20 mol%, more preferably at most 10 mol%, per 100 mol of the acrylic monomer.

A method of radically polymerizing a radical polymerizable monomer having an acrylic monomer as a main component in an aqueous phase in the presence of an aqueous solution or a water dispersion of a modified polyester is as follows.
It is generally carried out by dispersing a radical polymerizable monomer in water and introducing a predetermined amount of an aqueous solution or aqueous dispersion of a modified polyester having a quaternary phosphonium group of sulfonic acid together with one or more emulsifiers if necessary. . The modified polyester having a quaternary phosphonium group of sulfonic acid is
Compared to a polyester having a sodium sulfonate group or a polyester having a quaternary ammonium sulfonate group, it can itself act as a very good emulsifier for dispersing a radically polymerizable monomer in water. Other,
Ordinary surfactants such as alkali metal salts of long-chain alcohol sulfates (eg, sodium lauryl sulfate, ethanolamine lauryl sulfate, etc.), alkali metal salts of long-chain sulfonic acids, and polyoxyethylene glycols and derivatives thereof. Even if such a nonionic emulsifier is used, there is no problem.

In the above radical polymerization, peroxide compounds (for example, persulfate, hydrogen peroxide, etc.), organic peroxides (for example, lauroyl peroxide, benzoyl peroxide, t-butyl hydroperoxide, etc.), azo compounds (For example, azodiisobutyronitrile and the like) and a peroxide compound (preferably water-soluble) and a reducing agent (for example, ferrous salt (sulfate) or sulfurous acid or alkali metal bisulfite). Start with a conventional free radical generator such as a combined redox system.

Conventional chain transfer agents such as mercaptans (eg, dodecyl mercaptan, tetradecyl mercapran, etc.) may be added to the reaction mixture to adjust the molecular weight of the final copolymer.

The temperature at which the polymerization is carried out can be varied within wide limits. Generally between 10 and 100 ° C., preferably between 20 and 100 ° C.
Temperatures between 80 ° C. are good.

In the present invention, the polymer forming the thin primer layer is a graft copolymer or a block copolymer obtained by reacting a water-soluble or water-dispersible modified polyester with a radical polymerizable monomer having an acrylic monomer as a main component by the above-mentioned reaction. It seems to have formed.
The ratio between the modified polyester and the radical polymerization type polymer in this copolymer is preferably 5:95 to 95: 5, more preferably 10:90 to 90:10 by weight. The molecular weight of the modified polyester is 5000 to 200,000,
To 100,000 it is preferred, and molecular weight is 500 to 50,000 radical polymerization type polymer, and further 1,000 to 10,000 are preferred. Particularly in the practice of the present invention, the modified polyester which is not chemically bonded to the radical polymer and / or the free radical polymer which is not chemically bonded to the polyester is present in the final primer solution or the thin primer layer. If they do not, it is unnecessary to remove them from the resulting emulsion.

The concentration of the water-soluble or water-dispersible modified polyester and the radical polymerizable monomer mainly composed of an acrylic monomer in the aqueous polymerization phase can be arbitrarily selected. It is preferably at most 60% by weight. The product obtained after the radical polymerization can be used directly in the process according to the invention. Various processes can also be performed.
If the presence of unreacted monomers in the final primer solution hinders the practice of the present invention, the unreacted monomers are removed from the resulting emulsion. If one or more of the reaction components contains a free acid group, the base can be neutralized by adding an inorganic or organic base. For example, neutralization can be performed using an alkali metal base (for example, sodium hydroxide, potassium hydroxide, etc.) or ammonium water.

The aqueous primer solution in the present invention contains the above-mentioned copolymer (modified polyester-radical polymerization type polymer), and the copolymer is dissolved and dispersed in an aqueous medium. In this aqueous primer solution,
It may contain a small amount of organic solvent as long as it does not affect the modified polyester-radical polymerization polymer or other additives. This organic solvent can be present during the reaction between the radical polymerizable monomer and the modified polyester having a quaternary phosphonium group of sulfonic acid. That is, the monomer can be dispersed in a water / organic solvent system, or a modified polyester having a quaternary phosphonium group of sulfonic acid can be dissolved or dispersed in a water / organic solvent system and reacted.

The aqueous primer solution may be used by adding a required amount of a surfactant such as an anionic surfactant, a cationic surfactant, or a nonionic surfactant. As such a surfactant, the surface tension of the aqueous coating solution is 40 dy.
Those which can fall to ne / cm or less and promote wetting to the polyester film are preferable. For example, polyoxyethylene alkylphenyl ether, polyoxyethylene-fatty acid ester, sorbitan fatty acid ester, glycerin fatty acid ester, fatty acid metal soap, alkyl sulfate , Alkyl sulfonates, alkyl sulfosuccinates, quaternary ammonium chloride salts, alkylamine hydrochlorides and the like. Further, within the range not to lose the effect of the present invention, for example, an antistatic agent, an ultraviolet absorber, a pigment,
Other additives such as an organic filler, an inorganic filler, a lubricant, and an antiblocking agent can be mixed.

The application of the aqueous primer solution to the polyester film may be carried out in the usual application step, that is, a step of applying the biaxially stretched heat-fixed polyester film separately from the production step of the film. However, in this step, refuse, dust, and the like are easily entangled, and coating in a clean atmosphere is desirable for advanced products such as magnetic tapes and floppy disks. From such a viewpoint, coating during the polyester film production process is preferable. In particular, it is preferable to apply the aqueous primer solution to one or both surfaces of the polyester film before the crystal orientation is completed in this step. At that time, the solid content concentration of the aqueous primer solution is usually 30
% By weight or less, more preferably 10% by weight or less. Amount of coating film 1m ² per running from 0.5 to 20
g, more preferably 1 to 10 g.

As the coating method, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method, or the like may be applied alone or in combination.

The polyester film to which the aqueous primer solution has been applied and before the completion of the crystal orientation is dried and led to steps such as stretching and heat setting. For example, a vertically uniaxially stretched polyester film to which an aqueous primer solution has been applied is guided to a stenter and is horizontally stretched and thermally fixed. During this time, the coating solution dries and forms a continuous film on the film. Drying may be performed before or during stretching.

The orientation and crystallization conditions of the polyester film,
For example, stretching, heat setting, and the like can be performed under conditions conventionally accumulated in the art.

The thus-obtained polyester film having a thin primer layer is problematic when a conventional aqueous polyester resin and / or acrylic resin is used, and furthermore, a modified polyester or a sulfonic acid having a sodium sulfonate group is used. An object of the present invention is to solve the problem when a reaction product of a modified polyester having a quaternary ammonium group and an acrylic monomer is used, and to provide an ink for cellophane, a magnetic paint, a gelatin composition, a toner composition for electrophotography, and a chemical mat paint. It shows high adhesion to a very wide range of paints such as diazo paints, UV inks and the like, and shows good blocking resistance without tackiness.

[0044]

The present invention will be described in more detail with reference to the following examples. In addition, the part in an Example means a weight part. Each characteristic value was measured by the following method.

1. Adhesiveness (A) Magnetic paint A magnetic paint is applied to a sample polyester film with a Mayer bar so that the thickness after drying becomes about 4 μm.
Dry at 00 ° C. for 3 minutes. Thereafter, aging was performed at 60 ° C. for 24 hours, and then a scotch tape No. 600 (manufactured by 3M) having a width of 12.7 mm and a length of 15 cm was adhered so as to prevent air bubbles from entering, and a manual load described in JIS C2701 (1975) was applied thereon. Roll it in tightly and cut into tape width. The strength when this is peeled off by 180 ° is measured.

From the strength at this time, ○: 30 g / 12.7 mm or more Δ: 20-30 g / 12.7 mm ×: Less than 20 g / 12.7 mm (Evaluation paint) Urethane resin Nipporan 2304 (manufactured by Nippon Polyurethane Co., Ltd.) 20 parts PVC / vinegar resin Esrec A (manufactured by Sekisui Chemical Co., Ltd.) 55 parts Dispersant Ratio P (RIKEN Vitamin Co., Ltd.) 1 part Magnetic agent CTX-860 (manufactured by Toda Chemical Co., Ltd.) 500 parts is dissolved in a mixed solvent of methyl ethyl ketone / toluene / cyclohexanone to make a 40% liquid, and dispersed by a sand grinder for 2 hours. Thereafter, 25 parts (corresponding to solid content) of coronate L as a cross-linking agent are added, and the mixture is stirred well to obtain a magnetic paint.

(B) UV Ink An ultraviolet-curable printing ink (flash dry FD manufactured by Toyo Ink Co., Ltd.) is placed on a sample polyester film.
O-red APN) was printed by an RI tester (manufactured by Akira Seisakusho), and then cured with a medium-pressure mercury lamp (80 W / cm, single-lamp type; manufactured by Nippon Battery Co., Ltd.) UV curing apparatus to obtain a 6.0 μm thick sheet. Form a UV ink layer. A cut is made on the UV ink layer using a cutter knife, a cellophane tape is adhered, and 90 ° peeling is performed. The peeled state is displayed in five stages (good: 5 ← → 1:
evil).

(C) Offset ink An ink HS-OS manufactured by Kuboi Ink Co., Ltd. was applied on a sample polyester film to a thickness of 8 μm (Dry) using a geser, dried at 120 ° C. for 1 minute, and further dried at room temperature for 1 minute. After air-drying, make a cut on the ink with a cutter knife and apply cellophane tape.
90 ° peeling is performed, and the peeled state is displayed in five stages. (Good: 5 ← → 1: Bad).

(D) Screen Ink An ink Sericol EG manufactured by Teikoku Ink was applied to a thickness of 8 μm (Dry) on a sample polyester film using a geser and air-dried at room temperature for one day. A notch cut is made on the ink with a cutter knife, and a cellophane tape is adhered to the ink. Peeling is performed at 90 °, and the peeled state is displayed in five stages. (Good: 5 ← → 1: Bad).

The five-grade evaluation of the above inks follows the criteria in Table 1.

[0051]

[Table 1]

2. Blocking resistance The treated and untreated surfaces of the two films were superimposed, and a pressure of 6 kg / cm ² G was applied to the film under an atmosphere of 60 ° C. × 80% RH for 17 hours. Yes (5
g number per cm width). ：: 4 g / 5 cm or less △: 4 to 10 g / 5 cm ×: 10 g / 5 cm or more

3. Surface Slippery (Film Slippery) A static friction coefficient (μs) is measured using a slippery measuring device manufactured by Toyo Tester Co. according to ASTM D1894-63. However, the thread plate is a glass plate and the load is 1
kg.

The film slippery is determined based on the following criteria. ：: good (less than μs 0.6) △: slightly poor (μs 0.6 to 0.8) ×: bad (μs 0.8 or more)

4. FIG. 1 is a schematic view of an apparatus for evaluating film running property. In FIG. 1, 1 is a payout reel, 2 is a tension controller, 3, 5, 6, 8, 9, and 11 are free rollers, 4 is a tension detector (entrance), 7 is a chrome-plated fixing pin (5 mmφ), and 10 is A tension detector (outlet), 12 is a guide roller, and 13 is a take-up reel.

As shown in FIG. 1, the film was attached to a fixed pin having an outer diameter of 5 mm at an angle θ = (15
(2/180) π radian (152 °), and move and rub at a speed of 3.3 cm per second. The tension controller 2 is adjusted so that the entrance tension (T ₁ ) becomes 30 g, the vehicle is run for 10 m, rewinded, and the running is repeated again. This reciprocation is one time. Then, it is observed whether or not there is a substance deposited on the fixed pin after running 30 times repeatedly, and evaluated at the following level. ：: Almost no sediment is observed Δ: Some trace of adhesion ×: Many.

[0057]

EXAMPLE 1 The acid component was composed of terephthalic acid (53 mol%), isophthalic acid (45 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (2 mol%), and the glycol component was ethylene glycol ( 100 parts of a polyester (90% by mol) and 1,4-butanediol (10% by mol) (intrinsic viscosity: 0.35 measured in o-chlorophenol at 25 ° C.) were heated to 900 parts of tetrahydrofuran at 64 ° C. under normal pressure. While dissolving. Thereafter, a mixture of 900 parts of deionized water and 1 part of a nonionic surfactant (HLB 12.8) was gradually added with high-speed stirring. After the entire amount was added, the mixture was heated again to 80 ° C. to remove the tetrahydrofuran by evaporation to obtain a 10% by weight aqueous dispersion of polyester. This aqueous dispersion was heated to 60 ° C. under normal pressure, and 1 part of ammonium persulfate was added. Thereafter, the mixture was heated to 80 ° C.
, 150 parts of ethyl acrylate, 48 parts of methacrylic acid and 2 parts of t-dodecyl mercaptan were gradually added. Then, 560 parts of deionized water containing 1 part of ammonium persulfate and 2 parts of sodium hydrogen carbonate were gradually added. After the addition was completed, the reaction was further continued for 3 hours, and then cooled to room temperature.

This reaction product has a solid content of 25 wt.
%, A stable aqueous emulsion having a particle size of 60 nm. This latex solid content has a weight composition of polyester 21% methyl methacrylate 38% ethyl acrylate 31% methacrylic acid 10% based on the weight of the solid content.

14.4 parts of this aqueous emulsion and polyoxyethylene nonylphenyl ether (Nippon Oil & Fats Co., Ltd.)
, NS208.5) was added to 85.2 parts of deionized water to obtain an aqueous primer solution.

0.015 parts of calcium carbonate having an average particle size of 0.55 μm and silica 0.20 having an average particle size of 0.01 μm
Of polyethylene terephthalate having an intrinsic viscosity of 0.62 measured in o-chlorophenol at 25 ° C containing 25 parts by weight on a rotating cooling drum maintained at 20 ° C to obtain an unstretched film having a thickness of 190 µm. After stretching 3.5 times in the axial direction, the aqueous primer solution was applied to one surface of a uniaxially stretched film by a roll coating method. The average coating amount at this time was 80 mg / m ² in terms of solid content.
Subsequently, the film was stretched 3.9 times in the transverse direction at 110 ° C.
C. to obtain a biaxially oriented polyester film having a thickness of 14 .mu.m.

Table 2 shows the properties of the surface of this film coated with an aqueous primer.

[0062]

Example 2 In Example 1, the acid components were terephthalic acid (68 mol%), isophthalic acid (20 mol%), trimellitic acid (2 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate. (10 mol%)
One-sided coating in exactly the same manner as in Example 1 except that 100 parts of a polyester comprising 1,4-butanediol as a glycol component (intrinsic viscosity 0.25 measured in o-chlorophenol at 25 ° C.) was used. A polyester film was obtained.

Table 2 shows the properties of the surface of the film coated with the aqueous primer.

[0064]

Example 3 The acid component was composed of terephthalic acid (45 mol%), isophthalic acid (50 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (5 mol%), and the glycol component was ethylene glycol ( 94 mol%) and the following formula

[0065]

Embedded image

100 parts of a polyester (having an intrinsic viscosity of 0.30 measured in o-chlorophenol at 25 ° C.) consisting of glycol (6 mol%) shown in the above is dissolved in 900 parts of tetrahydrofuran while heating at 64 ° C. under normal pressure. Was.
Thereafter, 900 parts of deionized water and a nonionic surfactant (H
LB 12.8) 2 parts of the mixture were added slowly with high speed stirring. After the entire amount was added, the mixture was heated again to 80 ° C. to remove the tetrahydrofuran by evaporation to obtain a 10 wt% aqueous polyester solution. This aqueous solution was heated to 60 ° C. under normal pressure, and 1 part of ammonium persulfate was added. Thereafter, the mixture was heated to 80 ° C., and a mixture of 150 parts of methyl methacrylate, 170 parts of ethyl acrylate, 30 parts of methacrylic acid, 3 parts of crotonic acid, 18 parts of vinyl acetate and 2 parts of t-dodecylmercaptan was gradually added. Then, 980 parts of deionized water containing 1 part of ammonium persulfate and 2 parts of sodium hydrogen carbonate were gradually added. After the addition was completed, the reaction was further continued for 4 hours and then cooled to room temperature.

This reaction product has a solid content of 20 wt.
%, A stable aqueous emulsion having a particle size of 85 nm. This latex solid content has a weight composition of polyester 21.6% methyl methacrylate 32% ethyl acrylate 36% methacrylic acid 6% crotonic acid 0.6% vinyl acetate 3.8% based on the weight of the solid content.

18 parts of this aqueous emulsion and polyoxyethylene nonylphenyl ether (manufactured by NOF Corporation)
NS208.5) 0.4 part was added to 81.6 parts of deionized water to obtain an aqueous primer solution.

Polyethylene terephthalate having an intrinsic viscosity of 0.60 measured in o-chlorophenol at 25 ° C. containing 0.20 part of silica having an average particle size of 0.23 μm was mixed with 2
Melt extruded onto a rotating cooling drum maintained at 0 ° C. to a thickness of 9
2. A 50 μm unstretched film was obtained, and then 3.
After stretching 5 times, the aqueous primer solution was applied to both sides of the uniaxially stretched film by a roll coating method. The average coating amount at this time was 80 mg / m ² in terms of solid content. Subsequently, the film is stretched 3.6 times in the transverse direction at 120 ° C. and further 205 ° C.
To obtain a biaxially oriented polyester film having a thickness of 75 μm.

Table 2 shows the characteristics of this film.

[0071]

Comparative Example 1 In Example 1, the acid components consisted of terephthalic acid (55 mol%) and isophthalic acid (45 mol%), and the glycol components were ethylene glycol (90 mol%) and 1,4-butanediol (10 mol%). %) Was obtained in the same manner as in Example 1 except that 100 parts of a polyester (intrinsic viscosity 0.25 measured in o-chlorophenol at 25 ° C.) was used. This aqueous emulsion had a large particle size, a sediment was generated over time, and was unstable. Using this aqueous emulsion, a biaxially oriented polyester film having an aqueous primer coating on one side was obtained in exactly the same manner as in Example 1.

Table 2 shows the properties of the surface of the film coated with the aqueous primer.

[0073]

Comparative Example 2 In Example 1, tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (2 mol%) was replaced with 5-sodium sulfoisophthalic acid (2 mol%).
Except that the particle size was changed to 300.
nm aqueous emulsion was obtained. Using this aqueous emulsion, a biaxially oriented polyester film having an aqueous primer coating on one side was obtained in exactly the same manner as in Example 1.

Table 2 shows the properties of the aqueous primer-coated surface of this film.

[0075]

Comparative Example 3 The acid component was composed of terephthalic acid (53 mol%), isophthalic acid (45 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (2 mol%), and the glycol component was ethylene glycol ( 100 parts of a polyester (90% by mol) and 1,4-butanediol (10% by mol) (intrinsic viscosity: 0.35 measured in o-chlorophenol at 25 ° C.) were heated to 900 parts of tetrahydrofuran at 64 ° C. under normal pressure. While dissolving. Thereafter, a mixture of 900 parts of deionized water and 1 part of a nonionic surfactant (HLB 12.8) was gradually added with high-speed stirring. After the entire amount was added, the mixture was heated again to 80 ° C. to remove the tetrahydrofuran by evaporation to obtain a 10 wt% aqueous polyester dispersion. On the other hand, 100 parts of methyl methacrylate, 79 parts of ethyl acrylate, 25 parts of methacrylic acid
Parts and 2 parts of t-dodecyl mercaptan in deionized water 47
After adding to 4 parts, the mixture was heated to 80 ° C. While maintaining at 80 ° C., 1 part of ammonium persulfate and 2 parts of sodium hydrogen carbonate were gradually added to complete the reaction, and then cooled to room temperature. The obtained acrylic polymer is a 30 wt% aqueous dispersion. This latex solid has a weight composition of methyl methacrylate 49% ethyl acrylate 39% methacrylic acid 12% based on the weight of the solid.

[0081] 8.1 parts of this aqueous dispersion of the polyester and 9.3 parts of the aqueous dispersion of the acrylic polymer were mixed with polyoxyethylene nonylphenyl ether (Nippon Oil & Fats Co., Ltd .;
S208.5) 0.4 parts of deionized water was added to 82.2 parts of deionized water to obtain an aqueous primer solution. Average particle size 0.55μm
0.015 parts of calcium carbonate and average particle size 0.01 μm
Polyethylene terephthalate having an intrinsic viscosity of 0.62 measured in o-chlorophenol at 25 ° C containing 0.20 parts of silica was melt-extruded onto a rotating cooling drum maintained at 20 ° C to obtain an unstretched film having a thickness of 190 µm. Then, after stretching 3.5 times in the machine axis direction, the aqueous primer solution was applied to one surface of a uniaxially stretched film by a roll coating method. The average coating amount at this time was 80 mg /
m ² . Subsequently, the film was stretched 3.9 times in the horizontal direction at 110 ° C., and further heat-treated at 220 ° C. to obtain a biaxially oriented polyester film having a thickness of 14 μm.

Table 2 shows the properties of the surface of the film coated with the aqueous primer.

[0078]

Example 4 The acid component was composed of terephthalic acid (49 mol%), isophthalic acid (39 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (12 mol%), and the glycol component was ethylene glycol ( 60 mol%) and 1,4-butanediol (40 mol%), both ends of which are carboxyl-containing polyesters (intrinsic viscosity 0.30 measured in o-chlorophenol at 25 ° C) were synthesized. By reacting p-hydroxymethylbenzoyl peroxide, a polyester having a radical reaction initiating group at both terminals was obtained.

100 parts of the obtained polyester was dissolved in 900 parts of tetrahydrofuran while heating at 64 ° C. under normal pressure. Thereafter, a mixture of 900 parts of deionized water and 5 parts of a nonionic surfactant (HLB 12.8) was gradually added with high-speed stirring. After the addition of the entire amount, the mixture was heated again to 80 ° C. to remove tetrahydrofuran by evaporation to obtain a 10 wt% aqueous dispersion of polyester. This aqueous dispersion is treated under normal pressure for 6 hours.
Heat to 0 ° C. and add 1 part ammonium persulfate. Thereafter, the mixture was heated to 80 ° C., and a mixture of 45 parts of methyl methacrylate, 40 parts of ethyl acrylate, 15 parts of methacrylic acid and 2 parts of t-dodecyl mercaptan was gradually added. Then, 230 parts of deionized water containing 1 part of ammonium persulfate and 2 parts of sodium hydrogen carbonate were gradually added. After the addition was completed, the reaction was further continued for 3 hours, and then cooled to room temperature.

This reaction product had a solid content of 15 wt.
%, A stable aqueous emulsion having a particle size of 80 nm. This latex solid content was a polyester-acrylic polymer block polymer having a weight composition of polyester 50% methyl methacrylate 22.5% ethyl acrylate 20% methacrylic acid 7.5% based on the weight of the solid content. .

60 parts of this aqueous emulsion and polyoxyethylene nonylphenyl ether (manufactured by NOF Corporation)
NS208.5) was added to 39.0 parts of deionized water to obtain an aqueous primer solution.

A polyethylene-2,6-naphthalate having an intrinsic viscosity of 0.50 measured in o-chlorophenol at 25 ° C. was melt-extruded on a rotating cooling drum maintained at 20 ° C. to obtain an unstretched film having a thickness of 190 μm. Next, after stretching 4.2 times in the machine axis direction, the aqueous primer solution was applied to one surface of the uniaxially stretched film by a roll coating method.
The average coating amount at this time was 400 mg / m ² in terms of solid content. Subsequently, the film was stretched 4.5 times in the transverse direction at 145 ° C., and further heat-treated at 210 ° C. to obtain a biaxially oriented polyester film having a thickness of 10 μm.

Table 2 shows the properties of the surface of the film coated with the aqueous primer.

[0084]

Comparative Example 4 In Example 4, except that tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (12 mol%) was changed to 5-sodium sulfoisophthalic acid (12 mol%) as an acid component constituting the polyester. In the same manner as in Example 4, a biaxially oriented polyester film was obtained.

Table 2 shows the properties of the surface of the film coated with the aqueous primer.

[0086]

Example 5 The acid component was composed of 2,6-naphthalenedicarboxylic acid (60 mol%), isophthalic acid (35 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (5 mol%). As components, ethylene glycol (60 mol%), 1,4-butanediol (35 mol%) and the following structural formula

[0087]

Embedded image

100 parts of a polyester (intrinsic viscosity 0.35 measured in o-chlorophenol at 25 ° C.) consisting of glycol (5 mol%) shown in the above is dissolved in 900 parts of tetrahydrofuran while heating at 64 ° C. under normal pressure. Was.
Thereafter, 900 parts of deionized water and a nonionic surfactant (H
LB 12.8) 3 parts of the mixture were added slowly with high speed stirring. After the entire amount was added, the mixture was heated again to 80 ° C. to remove the tetrahydrofuran by evaporation to obtain a 10 wt% aqueous polyester dispersion. This aqueous dispersion was heated to 60 ° C. under normal pressure, and 1 part of ammonium persulfate was added. Then 80
C., and a mixture of 20 parts of methyl methacrylate, 10 parts of ethyl acrylate, 5 parts of methacrylic acid, 5 parts of glycidyl methacrylate, 2 parts of crotonic acid and 2 parts of t-dodecyl mercaptan was gradually added. Then, 380 parts of deionized water containing 1 part of ammonium persulfate and 2 parts of sodium hydrogen carbonate were gradually added. After the addition was completed, the reaction was further continued for 3 hours, and then cooled to room temperature.

This reaction product has a solid content of 10 wt.
%, A stable aqueous emulsion having a particle size of 100 nm. This latex solid content has a weight composition of polyester 71% methyl methacrylate 14% ethyl acrylate 7% methacrylic acid 3.5% glycidyl methacrylate 3.5% crotonic acid 1% based on the weight of the solid content.

This aqueous emulsion (45 parts) was mixed with polyoxyethylene nonyl phenyl ether (manufactured by NOF Corporation,
NS208.5) was added to 54.5 parts of deionized water to obtain an aqueous primer solution.

Polyethylene terephthalate having an intrinsic viscosity of 0.62 measured in o-chlorophenol at 25 ° C.
Extrusion on a rotary cooling drum maintained at 0 ° C.
2. A 70 μm unstretched film was obtained, and then 3.
After stretching 5 times, the aqueous primer solution was applied to one surface of a uniaxially stretched film by a roll coating method. The average coating amount at this time was 160 mg / m ² in terms of solid content. Subsequently, stretch 3.9 times in the transverse direction at 110 ° C and further 230 ° C
To obtain a biaxially oriented polyester film having a thickness of 20 μm.

Table 2 shows the properties of the surface of this film coated with the aqueous primer.

[0093]

EXAMPLE 6 The acid component was composed of terephthalic acid (35 mol%), isophthalic acid (45 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (20 mol%), and the glycol component was ethylene glycol ( 70 mol%), 1,4-butanediol (10 mol%) and polyethylene glycol having a molecular weight of 400 (20 mol%).
Mol%) of a polyester (intrinsic viscosity 0.30 measured in o-chlorophenol at 25 ° C) of 100 parts.
1895 parts of deionized water and nonionic surfactant (HLB
12.8) The mixture was added to 5 parts of the mixture, heated to 95 ° C. and dissolved with stirring. After cooling to 80 ° C., 40 parts of methyl methacrylate, 20 parts of ethyl acrylate, 7 parts of glycidyl methacrylate and 2 parts of t-dodecyl mercaptan were gradually added. Then, after slowly adding 1 part of ammonium persulfate and 2 parts of sodium hydrogen carbonate,
The reaction was continued at 80 ° C. for 3 hours. After completion of the reaction, the resultant was cooled to room temperature.

This reaction product had a solid content of 8 wt%,
It was a stable aqueous emulsion having a particle size of 60 nm. This latex solid has a weight composition of 60% polyester, 24% methyl methacrylate, 12% ethyl acrylate, 12% glycidyl methacrylate, 4% based on the weight of the solids.

56.3 parts of this aqueous emulsion and polyoxyethylene nonylphenyl ether (Nippon Oil & Fats Co., Ltd.)
Ltd., NS208.5) to obtain an aqueous primer solution was added to 0.5 parts of deionized water 43.2 parts <br/>.

Polyethylene terephthalate having an intrinsic viscosity of 0.60 measured in o-chlorophenol at 25 ° C. containing 0.20 part of silica having an average particle size of 0.23 μm was added to 20
Melt extrusion on a rotating cooling drum maintained at a temperature of
0 μm unstretched film was obtained, and then 3.5 mm in the machine axis direction.
After double stretching, the aqueous primer solution was applied to both sides of the uniaxially stretched film by a roll coating method. The average coating amount at this time was 80 mg / m ² in terms of solid content. Subsequently, the film is stretched 3.6 times in the transverse direction at 120 ° C., and further 205 ° C.
To obtain a biaxially oriented polyester film having a thickness of 75 μm.

Table 2 shows the characteristics of this film.

[0098]

EXAMPLE 7 The acid component was composed of terephthalic acid (90 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (10 mol%), and the glycol components were diethylene glycol (90 mol%) and cyclohexane-1, 100 parts of a polyester composed of 4-dimethanol (10 mol%) (intrinsic viscosity 0.40 measured in o-chlorophenol at 25 ° C.) was added to tetrahydrofuran 9
The solution was dissolved in 00 parts while heating to 64 ° C. under normal pressure. Then 900 parts of deionized water and nonionic surfactant (HLB)
12.8) One part of the mixture was added slowly with high speed stirring. After the entire amount was added, the mixture was heated again to 80 ° C. to remove the tetrahydrofuran by evaporation to obtain a 10% by weight aqueous dispersion of polyester. This aqueous dispersion was heated to 60 ° C. under normal pressure, and 1 part of ammonium persulfate was added. Then 80 ° C
And a mixture of 190 parts of methyl methacrylate, 150 parts of ethyl acrylate, 48 parts of methacrylic acid and 2 parts of t-dodecyl mercaptan was gradually added. Then, 560 parts of deionized water containing 1 part of ammonium persulfate and 2 parts of sodium hydrogen carbonate were gradually added. After the addition was completed, the reaction was further continued for 3 hours, and then cooled to room temperature.

This reaction product has a solid content of 25 wt.
%, A stable aqueous emulsion having a particle size of 50 nm. The latex solids have a weight composition of 21% polyester, 39% methyl methacrylate, 30% ethyl acrylate, 30% methacrylic acid, 10% based on the weight of the solids.

This aqueous emulsion (14.4 parts) and polyoxyethylene nonylphenyl ether (Nippon Oil & Fats Co., Ltd.)
Ltd., NS208.5) to obtain an aqueous primer solution were added 0.4 parts of deionized water 85.2 parts <br/>.

0.015 parts of calcium carbonate having an average particle size of 0.55 μm and silica 0.20 having an average particle size of 0.01 μm
Parts of polyethylene terephthalate having an intrinsic viscosity of 0.62 measured in o-chlorophenol at 25 ° C.
Melt extruded onto a rotating cooling drum maintained at 0 ° C to a thickness of 1
2. A 90 μm unstretched film was obtained, and then 3.
After stretching 5 times, the aqueous primer solution was applied to one surface of a uniaxially stretched film by a roll coating method. The average coating amount at this time was 80 mg / m ² in terms of solid content.
Subsequently, the film was stretched 3.9 times in the transverse direction at 110 ° C.
C. to obtain a biaxially oriented polyester film having a thickness of 14 .mu.m.

The properties of the surface of the film coated with the aqueous primer are shown in Table 2.

[0103]

Example 8 The acid component was composed of terephthalic acid (90 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (10 mol%), and the glycol components were diethylene glycol (90 mol%) and cyclohexane-1, 100 parts of a polyester composed of 4-dimethanol (10 mol%) (intrinsic viscosity 0.35 measured in o-chlorophenol at 25 ° C.) is mixed with 100 parts of tetrahydrofuran 9
The solution was dissolved in 00 parts while heating to 64 ° C. under normal pressure. Then 900 parts of deionized water and nonionic surfactant (HLB)
12.8) One part of the mixture was added slowly with high speed stirring. After the entire amount was added, the mixture was heated again to 80 ° C. to remove the tetrahydrofuran by evaporation to obtain a 10% by weight aqueous dispersion of polyester. This aqueous dispersion was heated to 60 ° C. under normal pressure, and 1 part of ammonium persulfate was added. Then 80 ° C
Then, a mixture of 40 parts of methyl methacrylate, 20 parts of ethyl acrylate, 7 parts of glycidyl methacrylate and 2 parts of t-dodecyl mercaptan was gradually added. Then, 610 parts of deionized water containing 1 part of ammonium persulfate and 2 parts of sodium hydrogen carbonate were gradually added. After the addition was completed, the reaction was further continued for 3 hours and then cooled to room temperature.

This reaction product has a solid content of 10 wt.
%, A stable aqueous emulsion having a particle size of 50 nm. The latex solids have a weight composition of polyester 60% methyl methacrylate 24% ethyl acrylate 12% glycidyl methacrylate 4% based on the weight of the solids.

18 parts of this aqueous emulsion and polyoxyethylene nonylphenyl ether (manufactured by NOF Corporation,
NS208.5) 0.2 part was added to 81.8 parts of deionized water to obtain an aqueous primer solution.

0.015 part of calcium carbonate having an average particle size of 0.55 μm and silica 0.20 having an average particle size of 0.01 μm
Parts of polyethylene terephthalate having an intrinsic viscosity of 0.62 measured in o-chlorophenol at 25 ° C.
Melt extruded onto a rotating cooling drum maintained at 0 ° C to a thickness of 1
2. A 90 μm unstretched film was obtained, and then 3.
After stretching 5 times, the aqueous primer solution was applied to one surface of a uniaxially stretched film by a roll coating method. The average coating amount at this time was 80 mg / m ² in terms of solid content. Subsequently, the film was stretched 3.9 times in the horizontal direction at 110 ° C., and further heat-treated at 220 ° C. to obtain a biaxially oriented polyester film having a thickness of 14 μm.

Table 2 shows the characteristics of the surface of the film coated with the aqueous primer.

[0108]

EXAMPLE 9 The acid component was composed of terephthalic acid (85 mol%) and tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate (15 mol%), and the glycol components were diethylene glycol (30 mol%) and cyclohexane-1,3. 100 parts of a polyester made of 4-dimethanol (70 mol%) (intrinsic viscosity 0.35 measured in o-chlorophenol at 25 ° C.) is added to 1900 parts of deionized water and dissolved at 80 ° C. with heating and stirring. Was. Then 80
After adding 1 part of ammonium persulfate while maintaining the temperature at ° C, a mixture of 50 parts of methyl methacrylate, 30 parts of ethyl acrylate, 20 parts of glycidyl methacrylate and 2 parts of t-dodecyl mercaptan was gradually added. Next, 1 part of ammonium persulfate and 2 parts of sodium hydrogen carbonate were added, and the mixture was heated to 80 ° C. and reacted for 3 hours. After the reaction was completed, it was cooled to room temperature.

This reaction product had a solid content of 9.5 wt.
%, A stable aqueous emulsion having a particle size of 50 nm. This latex solid has a weight composition of 50% polyester, 25% methyl methacrylate, 15% ethyl acrylate, 15% glycidyl methacrylate, 10% based on the weight of the solids.

This aqueous emulsion (18.9 parts) and polyoxyethylene nonylphenyl ether (Nippon Oil & Fats Co., Ltd.)
Ltd., NS208.5) was added 0.2 parts of deionized water 80.9 parts <br/> obtain an aqueous primer solution.

0.015 parts of calcium carbonate having an average particle size of 0.55 μm and silica 0.20 having an average particle size of 0.01 μm
Parts of polyethylene terephthalate having an intrinsic viscosity of 0.62 measured in o-chlorophenol at 25 ° C.
Melt extruded onto a rotating cooling drum maintained at 0 ° C to a thickness of 1
2. A 90 μm unstretched film was obtained, and then 3.
After stretching 5 times, the aqueous primer solution was applied to one surface of a uniaxially stretched film by a roll coating method. The average coating amount at this time was 80 mg / m ² in terms of solid content. Subsequently, the film was stretched 3.9 times in the horizontal direction at 110 ° C., and further heat-treated at 220 ° C. to obtain a biaxially oriented polyester film having a thickness of 14 μm.

Table 2 shows the properties of the surface of the film coated with the aqueous primer.

[0113]

[Table 2]

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for measuring a coefficient of dynamic friction to evaluate film running property.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Feeding reel 2 Tension controller 3,5,6,8,9,11 Free roller 4 Tension detector (entrance) 7 Fixing pin 10 Tension detector (exit) 12 Guide roller 13 Take-up reel

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FIB29L 7:00 9:00 C08L 67:00 (72) Inventor Satomi Miura 3-37-19 Koyama, Sagamihara City, Kanagawa Prefecture Teijin Shares (72) Inventor Tomoki Nakamura 77 Kitayoshida-cho, Matsuyama-shi, Ehime Teijin Co., Ltd. Matsuyama Office (56) References JP-A-63-46237 (JP, A) JP-A-63-37121 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B32B 27/36 C08J 7/04 B29C 55/00-55/30 B05D 7/00-7/26 C08G 67/00- 69/00 B29K 67:00 B29L 7:00 B29L 9:00

Claims (4)

(57) [Claims] 1. A polyester film having the following formula (I) on at least one surface thereof: Wherein A is an aromatic group or an aliphatic group, X ₁ is an ester-forming functional group, X ₂ is an ester-forming functional group or a hydrogen atom which is the same or different from X ₁ , R ₁ , R ₂ , R ₃ and R ₄
Represents the same or different group selected from an alkyl group and an aryl group, and m represents a positive integer. A sulfonic acid 4
A primer thin layer mainly composed of a copolymer obtained by subjecting a radical polymerizable monomer mainly composed of an acrylic monomer to aqueous phase radical polymerization in the presence of a modified polyester modified with a secondary phosphonium salt. An easily adhesive polyester film characterized by the following. 2. The easily adhesive polyester film according to claim 1, wherein the radical polymerizable monomer used in combination with the acrylic monomer is an ethylene monomer. 3. The polyester film having the following formula (I) on at least one surface of the polyester film before the completion of the crystal orientation. Wherein A is an aromatic group or an aliphatic group, X ₁ is an ester-forming functional group, X ₂ is an ester-forming functional group or a hydrogen atom which is the same or different from X ₁ , R ₁ , R ₂ , R ₃ and R ₄
Represents the same or different group selected from an alkyl group and an aryl group, and m represents a positive integer. A sulfonic acid 4
An aqueous primer solution containing a copolymer obtained by subjecting a radical polymerizable monomer having an acrylic monomer as a main component to aqueous phase radical polymerization in the presence of a modified polyester modified with a quaternary phosphonium salt is applied, and then dried and stretched. And a heat treatment to complete the crystal orientation of the film. 4. The method according to claim 3, wherein the radical polymerizable monomer used in combination with the acrylic monomer is an ethylene monomer.