JP3298252B2 - Easy adhesion polyester film - 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. Specifically, it is excellent in antistatic properties, lubricity, adhesiveness, blocking resistance, etc., and is suitable as a base film used in magnetic recording materials, various photographic materials, packaging materials, electric insulating materials, general industrial materials, etc. It relates to an adhesive polyester film. Particularly, the present invention relates to an easily adhesive polyester film suitable as a base film used for a magnetic recording material.

[0002]

2. Description of the Related Art Polyesters, especially polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate or poly-1,4-cyclohexane dimethylene terephthalate, and polyesters based thereon are excellent. It has physical and chemical properties and is widely used as fibers, films or sheets, and also as molded products thereof.

[0003] In particular, polyester films have excellent heat resistance, chemical resistance, and mechanical properties, so that they are used in many applications such as magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials, and general industrial materials. Used.

In these applications, the polyester film is not used alone, and various coatings such as a magnetic paint, a chemical mat paint, a diazo photosensitive paint, a gelatin composition, and a heat seal are applied to the film surface. It is used by applying or printing a composition, ink, or the like.

[0005] In particular, films used for magnetic tapes and floppy disks are required to have flatness and smoothness for high reliability and high density of magnetic recording. There is a strong demand for an improvement in adhesive strength with a base film. However, when an adhesive force to the magnetic paint is applied to the film, blocking occurs between the films, and various workability is deteriorated and magnetic recording performance is deteriorated. On the other hand, in the manufacturing process of a base film or a magnetic tape, when passing through a process having many rolls at a high speed, a charging phenomenon is generally caused by friction between the rolls and the film or between the films. , The workability is reduced and the magnetic recording performance is deteriorated. For this reason, in order to impart the adhesiveness of the film, it is necessary to simultaneously satisfy the properties of the film, such as antistatic property, lubricity, and anti-blocking property. At the same time, an easily-adhesive substance which is resistant to various solvents contained in various coatings applied or printed on the film surface is desired.

However, since the polyester itself is generally inert and has poor adhesiveness, various coatings such as a magnetic paint, a chemical mat paint, a diazo photosensitive paint, a gelatin composition, and a heat-sealing composition are provided on the film surface. object,
When applying or printing ink, etc., in order to improve the adhesiveness with the coating, the film surface is subjected to physical treatment such as corona discharge or plasma, or chemical treatment using alkali or amine chemicals. There are known methods for performing various treatments, and methods for coating easily adhesive substances. However, the physical or chemical surface treatment method complicates the process, not only increases the cost, but also does not provide sufficient adhesiveness.

On the other hand, a method of coating an easily adhesive substance can be carried out in the process of producing a polyester film, which is advantageous in terms of cost, and it is necessary to select an adhesive substance which can cope with various coatings. It is possible. Further, from the viewpoints of handleability of the polyester film and workability at the time of producing the film, various water-dispersed or water-soluble copolymerized polyesters and lamination or coating of the copolymerized polyester on a polyester film have been proposed. For example, Japanese Patent Publication No. 47-40873 and Japanese Patent Application Laid-Open No. 50-1
JP-A-21336 and JP-A-50-134086 disclose a polyester obtained by copolymerizing an ester-forming metal salt compound of sulfonic acid and polyethylene glycol and a film obtained by laminating those polyesters.
JP-A-66239 discloses a polyester obtained by copolymerizing a metal salt compound of an ester-forming sulfonic acid and polytetramethylene glycol, JP-A-50-83497, JP-A-53-2536, and JP-A-54-3848. JP-A-59-215318 discloses an ester-forming sulfonic acid metal salt compound and an aliphatic dicarboxylic acid component, and a polyester obtained by copolymerizing diethylene glycol. Examples include a film undercoated with a polyester obtained by copolymerizing a dicarboxylic acid component.

[0008]

However, the above-mentioned prior art has the following problems. That is, when a large amount of an ester-forming sulfonic acid metal salt compound and a low-molecular-weight polyethylene glycol is contained as disclosed in JP-B-47-40873, water solubility and adhesion are exhibited but blocking resistance is poor. And antistatic properties cannot be obtained. JP-A-50-121336, JP-A-50-134086 and JP-A-63-66
As disclosed in JP-A-239-239, when an ester-forming sulfonic acid metal salt compound and a polyalkylene glycol component are copolymerized in a large amount, water solubility, anti-blocking property and antistatic property are inferior. Further, Japanese Patent Laid-Open No. 50-83497
JP, JP-A-53-2536, JP-A-54-3
As disclosed in JP-A-848 and JP-A-59-215318, when an ester-forming sulfonic acid metal salt compound and an aliphatic dicarboxylic acid component, and further diethylene glycol are copolymerized, adhesiveness is exhibited, but There are drawbacks such as poor blocking properties and inability to obtain antistatic properties.

The present invention solves these drawbacks and has excellent antistatic properties, lubricity, adhesiveness, water solubility, blocking resistance, etc., and is suitable for easy adhesion as a base film used for magnetic recording materials and the like. A polyester film is provided.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-soluble copolyester having a polyoxyalkylene glycol component in an amount of 1% by weight or more and less than 20% by weight on at least one surface of a polyester film. The main component is an easily adhesive polyester film formed by forming a coating film of a mixture mainly composed of a wax and an oxidized wax and / or a natural wax.

The water-soluble copolyester in the present invention is not particularly limited as long as it is a water-soluble copolyester containing 1% by weight or more and less than 20% by weight of a polyoxyalkylene glycol component. The aromatic dicarboxylic acid as an acid component is preferably at least 60 mol%, more preferably at least 70 mol%, and particularly preferably at least 80 mol%, because it is excellent in antistatic properties, anti-blocking properties and solvent resistance. Preferred from the point. When the amount of the aromatic dicarboxylic acid is less than 60 mol%, the antistatic property, antiblocking property and solvent resistance are poor. The aromatic dicarboxylic acid is not particularly restricted but includes, for example, terephthalic acid, isophthalic acid, diphenyletherdicarboxylic acid and the like. Among these, preferred aromatic dicarboxylic acids are terephthalic acid and isophthalic acid. Acid, naphthalenedicarboxylic acid.

The water-soluble copolyester in the present invention contains 5 to 40 mol%, preferably 7 to 30 mol%, of the ester-forming alkali metal sulfonic acid compound based on the total acid component in view of imparting water solubility. More preferably, 10
To 20 mol%, particularly preferably 11 to 15 mol%. If the amount of the ester-forming sulfonic acid alkali metal salt compound is less than 5 mol%, sufficient water solubility and adhesiveness may not be obtained. On the other hand, 40 mol%
If it exceeds, the adhesiveness reaches saturation, and conversely, the antistatic property, the antiblocking property and the solvent resistance decrease. The ester-forming sulfonic acid alkali metal salt compound is not particularly limited, but may be, for example, sulfoterephthalic acid, 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene-2, Examples thereof include alkali metal salts such as 6-dicarboxylic acid, and among them, lithium, sodium, and potassium salts of 5-sulfoisophthalic acid and sulfoterephthalic acid are more preferably used.

The glycol component (glycol component other than the above polyoxyalkylene glycol) of the water-soluble copolymerized polyester in the present invention preferably has 2 to 2 carbon atoms.
Aliphatic glycol of 8 and / or alicyclic glycol of 6 to 16 carbon atoms in an amount of 80 to 99 mol%, more preferably 82 to 95 mol%, and still more preferably 84 to 93 mol%.
And 1 to 20 mol% of diethylene glycol, more preferably 5 to 18 mol%, and still more preferably 7 to 16 mol%.
It is. When the aliphatic glycol having 2 to 8 carbon atoms and / or the alicyclic glycol having 6 to 16 carbon atoms is less than 80 mol% or the diethylene glycol exceeds 20 mol%, blocking resistance and solvent resistance are obtained. Poor nature. On the other hand, aliphatic glycols having 2 to 8 carbon atoms and / or 6 to 1 carbon atoms
When the alicyclic glycol of No. 6 exceeds 99 mol% or the diethylene glycol is less than 1 mol%, the blocking resistance is good, but the water solubility and adhesion are poor.

The aliphatic glycol having 2 to 8 carbon atoms and / or the alicyclic glycol having 6 to 16 carbon atoms in the present invention.
Examples of ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentaneddiol, 1,6-hexanediol, 1,2-cyclohexanedimethanol,
Glycols such as 1,3-cyclohexane dimethanol and 1,4-cyclohexane dimethanol can be mentioned. Preferred aliphatic glycols having 2 to 8 carbon atoms and / or alicyclic glycols having 6 to 16 carbon atoms include:
Ethylene glycol, neopentyl glycol, 1,4
-Butanediol, 1,4-cyclohexanedimethano-
It is. One of these glycols may be used alone, or two or more thereof may be used in combination. Incidentally, the diethylene glycol in the present invention usually includes diethylene glycol which is by-produced during the production of a polyester containing ethylene glycol as a glycol component.

In addition to the above-mentioned acid component and glycol component, the water-soluble copolyester in the present invention may be an aliphatic dicarboxylic acid, an oxyacid or a monofunctional compound or a trifunctional or higher functional compound within a range not to impair the effects of the present invention. Other components such as a polyfunctional compound may be included. The content of these other components is not particularly limited as long as the effects of the present invention are not impaired, but is usually about 30 mol% or less.

The production of the water-soluble copolymerized polyester in the present invention can be carried out by any conventionally known method, and is not particularly limited. For example, a copolymer polyester comprising terephthalic acid and 5-sodium sulfoisophthalic acid as acid components and ethylene glycol and diethylene glycol as glycol components will be described. Terephthalic acid, 5-sodium sulfoisophthalic acid and ethylene glycol A direct esterification reaction of terephthalic acid, an alkyl ester of 5-sodium sulfoisophthalic acid, and a transesterification reaction with ethylene glycol and diethylene glycol. And a second step in which the reaction product of one step is subjected to a polycondensation reaction. At this time, a conventionally known alkali metal, alkaline earth metal, manganese, cobalt, zinc, antimony, germanium, titanium compound or the like is used as a reaction catalyst, and a phosphorus compound or the like may be used as a coloring inhibitor.

The water-soluble copolymerized polyester of the present invention contains a polyoxyalkylene glycol component in an amount of 1% by weight or more and less than 20% by weight, preferably 4 to 19% by weight.
Particularly preferably, it is necessary to contain 7 to 18% by weight. When the content of the polyoxyalkylene glycol component is 1
When the amount is less than the weight%, the antistatic property and the solvent resistance are inferior. On the other hand, when the content of the polyoxyalkylene glycol component is 2
If it is 0% by weight or more, the antistatic property, water solubility and blocking resistance are inferior. Although the type of the polyoxyalkylene glycol component is not particularly limited, the number average molecular weight of the polyoxyalkylene glycol component is from 400 to 10,000 in view of having excellent water solubility, adhesiveness, and antistatic property.
Is preferable, and the number average molecular weight is preferably 500 to 6000, and particularly preferably the number average molecular weight is 600 to 4000. Examples of such a polyoxyalkylene glycol component include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like. Among them, polyethylene glycol is preferred from the viewpoint of water solubility and antistatic properties.

The method for incorporating the polyoxyalkylene glycol component into the copolymerized polyester in the present invention is not particularly limited. For example, the polyoxyalkylene glycol component may be added to the copolymerized polyester at any stage of the production process of the copolymerized polyester. A method of adding, or a method of melt-kneading a copolymerized polyester and a polyoxyalkylene glycol component using an extruder or the like can be used. At this time, the polyoxyalkylene glycol component can be added by any method such as powder, melting or solution.

The intrinsic viscosity of the water-soluble copolymerized polyester in the present invention is not particularly limited, but is preferably at least 0.3 dl / g, more preferably at least 0.4 dl / g from the viewpoint of adhesiveness. .

If necessary, a flame retardant, a heat stabilizer, a UV absorber, a pigment,
Dyes, fatty acid esters, organic lubricants such as waxes or antifoaming agents such as polysiloxy acid may be added, and for the purpose of imparting lubricity and the like, clay, mica, titanium oxide, calcium carbonate, kaolin, wet and Inorganic particles such as dry-process silica, colloidal silica, calcium phosphate, barium sulfate, and alumina, and organic particles containing acrylic acid, styrene, and the like as constituents may be added.

The water-soluble copolymerized polyester to be laminated on the polyester film of the present invention is dissolved in water and used as an aqueous solution. This aqueous solution does not have strictness in a physical or chemical sense, and includes an aqueous solution which is mostly dissolved in water and partially finely dispersed.

The oxidized wax in the present invention is not particularly limited, but a wax to which a carboxyl group, a hydroxyl group, or the like is added by oxidizing an ethylene chain portion of the wax by air oxidation or the like is preferably used. The molecular weight and melting point are not particularly limited, but those having a molecular weight of 1,000 or more are preferable.

Examples of the natural wax include candelilla wax, carnauba wax, wood wax, olicury wax, sugarcane wax and the like. In the present invention, carnauba wax is particularly preferred.

In the present invention, the oxidized wax and the natural wax may be used alone or in combination with the water-soluble copolymerized polyester. Further, a rosin-modified wax may be further mixed with the oxidized wax and / or the natural wax.
The rosin-modified wax is not particularly limited, but in the present invention, a composition comprising the following compounds is particularly preferable. That is, {rosin or disproportionated rosin, or hydrogenated rosin / α, β-substituted ethylene (α-substituent: carboxyl, β-substituent: hydrogen or methyl or carboxyl) adduct} · alkyl or alkenyl (each having 1 carbon atom)
To 8) It is particularly preferable to use an ester adduct of poly (repeating unit: 1 to 6) alcohol. The mixing ratio of the oxidized wax and / or the natural wax (A) and the rosin-modified wax (B) is not particularly limited,
(A) / (B) is 10/90 to 90/10, preferably 20/80 to 80/20, more preferably 30/70 to
It is preferably 70/30. Mixing ratio (A) /
The reason why (B) is adjusted to 90/10 or less is that when emulsified or suspended in water, uniform dispersibility is good and it is suitable for obtaining a uniform coating film. The reason why the ratio is 10/90 or more is that the lubricity after coating is good.

Although the effect of imparting lubricity and the effect of preventing blocking of the oxidized wax or natural wax of the present invention have not been sufficiently elucidated, the wax used in the present invention has a surface free energy dispersing power component which is lower than that of paraffin wax or the like. It is presumed that the same effect is exhibited even in a mixed system with a water-soluble copolymerized polyester, due to the large size and small polar force component.

Further, an oily substance may be further added to the mixture of the oxidized wax and the natural wax or to each of them alone as long as the effects of the present invention are not impaired. Here, the oily substance is a liquid or paste-like oil at normal temperature, and includes vegetable oil, fat, mineral oil, synthetic lubricating oil and the like. Among them, mineral oil and synthetic lubricating oil are suitable, and synthetic lubricating oil is particularly preferable. Examples of the synthetic lubricating oil include olefin polymerization oil, diester oil, polyalkylene glycol oil, silicone oil and the like.

It is desirable that the oily substance is added in an amount of 50 parts by weight or less, preferably 20 parts by weight or less, based on 100 parts by weight of each of the above waxes alone or as a mixture.

Various additives can be used in the above composition within a range not to impair the effects of the present invention. For example, antistatic agents, heat-resistant agents, antioxidants, organic and inorganic particles, pigments and the like can be mentioned.

The coating film (film) in the present invention is a film formed mainly of the above-mentioned water-soluble copolymerized polyester and the above-mentioned oxidized wax or natural wax alone or a mixture thereof. It is. In addition,
The term "mainly composed of the water-soluble copolymerized polyester and the wax" means that the mixture contains 80% by weight or more, preferably 90% by weight of the coating film.
It is desirable that it be contained by weight% or more.

In the present invention, 70 to 99.9% by weight, more preferably 85 to 99% by weight, and preferably 30 to 0.1% by weight of wax, more preferably 15 to 99% by weight of the water-soluble copolymerized polyester based on the coating film. It is preferable that 1% by weight be mixed. 70% by weight of water-soluble copolymerized polyester
The following is not preferable because the adhesiveness becomes poor. Conversely, if the content is 99.9% by weight or more, slipperiness and blocking resistance become poor, which is not preferable. When it is in the above-mentioned range, it is preferable in terms of compatibility of adhesiveness, slipperiness, and blocking resistance. Incidentally, a crosslinking agent such as a known silane coupling agent may be added to the coating film as another component.

Although the thickness of the coating film is not particularly limited,
It is preferably from 0.001 to 1 μm, particularly preferably from 0.01 to 0.2 μm.

The polyester film in the present invention is a polyester film formed by a known method, that is, a film formed by melting and extruding a polyester into a sheet and stretching it in at least one direction. It is desirable that the mechanical properties be any of a normal balance type, a uniaxially strengthened type, and a biaxially strengthened type. The surface of the polyester film is desirably smooth. Specifically, the surface roughness of the film is a cutoff value of a stylus type surface roughness meter of 0.08 mm, and a Ra value of 0.003 to 0.5 mm.
It is desirable that it is within the range of 030 μm.

The Ra value refers to the center line (the portion above the center line) of the roughness curve obtained by removing the undulation from the cross-sectional curve obtained from the stylus type surface roughness meter using an appropriate cutoff value. Is the arithmetic mean of the absolute values of the heights (low) of the roughness curves (according to DIN 4768).

The polyester forming the film is as follows:
Any material may be used as long as it is mainly composed of linear polyester. For example, polyethylene terephthalate
, Polytetramethylene terephthalate, poly-1,4
-Cyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, polyethylene-p-oxybenzoate and the like are typical examples.

The above polyester may be a homopolyester or a copolyester. In the case of a copolyester, as a component to be copolymerized, for example, diethylene glycol, propylene glycol, neopentyl glycol, polyethylene glycol, p-xylylene glycol, 1,4-cyclohexanedimethanol- Diol components such as toluene, adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid,
Examples thereof include a dicarboxylic acid component such as 5-sodium sulfoisophthalic acid, a polyfunctional carboxylic acid component such as tomellitic acid and pyromellitic acid, and p-oxyethoxybenzoic acid. In the case of copolymerization, the component to be copolymerized is desirably 20 mol% or less.

The method for producing the film of the present invention will be described. However, it is not limited to this. A substantially non-oriented, crystalline polyethylene terephthalate raw material,
It is melted at 270 ° C to 290 ° C and extruded in sheet form.
The film is cooled and solidified by a casting drum at -30 ° C to form an unstretched sheet, and then biaxially stretched and heat-treated to produce a film. The biaxial stretching may be any of longitudinal and transverse sequential stretching or biaxial simultaneous stretching, and the stretching ratio is not particularly limited, but usually 2.0 to 5.0 times each in the longitudinal and transverse directions. Alternatively, after stretching in the vertical and horizontal directions, the film may be stretched again in any of the vertical and horizontal directions. The thickness of the polyester is not particularly limited, but is preferably 2 to 200 μm.

The method of laminating the coating film of the adhesive layer of the polyester film of the present invention is most preferably a method of applying during the production process of the polyester film and stretching it together with the substrate. For example, a melt-extruded polyester film before crystal orientation is stretched about 2.5 to 5 times in the longitudinal direction, a surface to be continuously applied is subjected to a corona discharge treatment, and a coating liquid is applied to the treated surface. The coated film is dried while passing through a zone which is heated stepwise, and has a width of 2.5 to 2.5 mm.
It is stretched about 5 times. 150 to 250 ° C continuously
To complete the crystal orientation by the heating zone. The coating solution used in this case is preferably an aqueous solution in view of environmental pollution and explosion-proof properties. Coating methods on the base film are known coating methods such as a reverse coating method, a gravure coating method, a rod coating method, a die coating method, and a wire coating method.
A bar method or the like can be used. Known additives such as a heat stabilizer, an oxidation stabilizer, a weather stabilizer, and the like in the coating layer (easily adhesive layer) within a range not impairing the effects of the present invention.
An ultraviolet absorber, an organic lubricant, a pigment, a dye, organic or inorganic fine particles, a filler, an antistatic agent, a nucleating agent, and the like may be blended.

As for the coating composition, the water-soluble copolymerized polyester was prepared by adding the water-soluble copolymerized polyester to 0.1% in water.
Those containing about 5 to 10% by weight are preferred. The water-soluble copolymerized polyester coating can be prepared, for example, by adding the water-soluble copolymerized polyester to hot water of about 80 to 90 ° C and stirring. The wax paint preferably contains about 1 to 30% by weight of a wax component in water. It is preferable to add a nonionic surfactant, a phosphoric acid ester, ammonium oleate, 2-amino-2-methylpropanol, or the like, for example, in an amount of about 1% by weight, since the wax can be easily dispersed in water. The water-soluble copolymerized polyester coating and the wax coating are preferably mixed and then applied to a polyester film.

Next, the method for producing the easily adhesive polyester film of the present invention will be described, but the present invention is not limited thereto. After drying the PET according to a conventional method, it is melt-extruded, and the extruded sheet-like melt is cooled and solidified to produce an unstretched PET film. 80-1
It is heated to 20 ° C. and stretched 2.0 to 5.0 times in the longitudinal direction to obtain a uniaxially oriented film. One surface of the film is subjected to a corona discharge treatment, and an aqueous coating material of the present invention diluted to a predetermined concentration with water is applied to the treated surface. Next, the coated film is stretched 2.5 to 5.0 times in the width direction while being heated to 90 to 140 ° C., and subsequently 160 to 240
It is guided into a heat treatment zone at a temperature of 1 ° C. and heat-treated for 1 to 10 seconds. During this heat treatment, a relaxation treatment of 3 to 12% may be performed in the width direction as necessary.

In the present invention, a compound having sulfonic acid and / or a salt thereof, and an oxidized wax and / or a natural wax can be contained in the polyester film base, and further a polyoxyalkylene glycol is further contained. You can also. In these cases, there are advantages such as improved slipperiness, blocking resistance, and adhesion between the coating layer and the base film.

Compounds having a sulfonic acid or a salt thereof to be contained in the polyester film substrate include sulfoterephthalic acid, 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid, and 4-sulfonaphthalene-2,6. -Dicarboxylic acids or alkali metal salts thereof, among which lithium, sodium and potassium salts of 5-sulfoisophthalic acid and sulfoterephthalic acid are preferably used.

As the oxidized wax and / or natural wax and polyoxyalkylene glycol to be contained in the polyester film substrate, the same ones as those used for the coating film can be used (however, it is not necessarily used for the coating film). It need not be the same as the one).

When a compound having a sulfonic acid and / or a salt thereof, an oxidized wax and / or a natural wax and a polyoxyalkylene glycol are contained, the content is preferably 5 ppm or more and less than 20% by weight. This is preferred in terms of improving the properties, blocking resistance, and adhesion. Of course, it goes without saying that a coating composition (including regenerated pellets of the easily adhesive polyester film of the present invention) provided on the base film may be partially contained.

The winding property and slitting property of the thus obtained easily adhesive polyester film are good, and by applying a coating material corresponding to the application on the coating layer side, various applications, for example, for magnetic recording materials, cellophane For printing various inks such as inks, offset inks, and ultraviolet curable inks, for electrophotographic toner, for easy adhesion, for chemical mat paint easy adhesion,
It is suitably used as a base film for diazo paints for easy adhesion, inorganic coating such as vapor deposition, and the like.

Method for measuring and evaluating characteristic values The method for measuring characteristics and the method for evaluating effects in the present invention are as follows.

(1) Intrinsic viscosity of copolymerized polyester: [η] Measured at 25 ° C. using an o-chlorophenol solvent.

(2) Water solubility of the copolymerized polyester 2 g of the copolymerized polyester was placed in 100 g of water.
The mixture was stirred and dissolved for 2 hours, cooled, and filtered with a 2 μm filter. The water solubility of the copolymerized polyester was determined based on the dissolved state and the amount of the filtrate. ：: The aqueous solution was transparent or slightly cloudy, but almost no filtered product was observed. Δ: The aqueous solution was slightly cloudy, and a filtered product was observed. ×: The solution was hardly dissolved or the aqueous solution was strongly clouded, and a large amount of filtered product was observed.

(3) Adhesion An aqueous solution of a copolymerized polyester and wax was applied on a polyester film substrate, and a magnetic paint (Diferacoat CAD-430) was applied to the surface of the easy-adhesion layer provided with the easy-adhesion layer.
1: 100 parts by weight of Dainichi Seika Kogyo Co., Ltd.) and 1 part by weight of Sumidur N75 (manufactured by Sumitomo Bayer Ltd.) as a curing agent.
It was applied on a tar and dried at 100 ° C. for 5 minutes to form a coating layer. A cellophane adhesive tape (Nichiban Co., Ltd.)
And passed through a nipple with a linear pressure of 50 kg / cm, and then rapidly peeled in the direction of 180 degrees. At that time, the area of the coated surface adhered to the cellophane adhesive tape was determined to determine the adhesiveness. ◎: The area of the coated surface adhered to the cellophane adhesive tape is 5
%, Which is excellent in adhesiveness. : The area of the coating surface adhered to the cellophane adhesive tape is 5
% To less than 10%, which is slightly superior in adhesiveness. Δ: The area of the coating surface adhered to the cellophane adhesive tape is 1
It is less than 0 to 30% and the adhesiveness is slightly inferior. ×: The area of the coated surface adhered to the cellophane adhesive tape was 3
0% or more, resulting in poor adhesion.

(4) Antistatic Property A polyester film without an easy-adhesion layer is wound around the surface of a rotating metal drum, and a load of 255 g is applied to the end of the easy-adhesion layer of the film with the easy-adhesion layer laminated while rotating.
And rub it along the metal drum rotating body for 5 seconds. Immediately after, the potential charged on the film was measured by an electrostatic measuring device, and the antistatic property was determined. ：: Charge amount -6 kV or more and +6 kV or less △: Charge amount -7 kV or more and +7 kV or less ×: Charge amount less than -7 kV or more than +7 kV Static electricity measuring device: Statiron TH manufactured by Shisido Electrostatic Co., Ltd.
Mold Measurement distance 50mm from head opening Metal drum rotating body: Dimension 65mm width x 150mmφ
Rotational speed 860rpm Measurement sample: 30mm width x 300mm length

(5) Solvent Resistance Methyl ethyl ketone, toluene and acetone were each dropped as organic solvents on the surface of the film provided with the easy-adhesion layer, and the evaluation was made based on the cloudiness of the easy-adhesion layer. : Almost no cloudiness △: Slightly cloudy ×: Cloudy

(6) Blocking resistance The surface of the film provided with the easy-adhesion layer and the biaxially oriented PE
T-film superimposed (overlap area: 3cm × 4
cm) with a load of 500 g / 12 cm ² at 60 ° C.
After leaving for 72 hours in 0% RH, the shear stress at the overlapped portion was measured using a Tensilon tensile tester at a pulling speed of 20%.
It was measured at cm / min and judged according to the following criteria. ◎: 0 kg / cm ² (no blocking at all) ○: 0 kg / cm ² or more and less than 1 kg / cm ² △: 1 kg / cm ² or more and less than 3 kg / cm ² ×: 3 kg / cm ² or more

(7) Slipperiness (static friction coefficient μs, dynamic friction coefficient μd) The coefficient of friction between films is ASTM-D-1894.
The coefficient of static friction μs and the coefficient of dynamic friction μd were measured using a surface property measuring device HEIDON-14DR manufactured by Shinto Kagaku Co., Ltd., using a sample moving speed of 200 mm / min.
g, measured under the conditions of a contact area of 63.5 mm x 63.5 mm, and Analyzing Recorder TYPE: HEIDON
It was recorded and evaluated with 3655E-99. Generally 10 thickness
When winding a long product (around 20,000 m) of a thin film of about μm, the required value of the slipperiness is preferably 0.1 μs in μs.
It was 65 or less, and the slipperiness was determined based on the following criteria. ○: μs = 0.65 or less △: μs exceeds 0.65 and 0.80 or less ×: μs = 0.80 or more

(8) Thickness of Coating Layer Using a transmission electron microscope model HU-12 manufactured by Hitachi, Ltd., an ultrathin film section of the laminated film was observed to determine the thickness.

(9) Surface Roughness According to JIS-B-0601, a cut-off of 0.0 using a stylus type surface roughness meter BE-3E manufactured by Kosaka Laboratory Co., Ltd.
The average surface roughness Ra was measured at 25 mm and the measurement length was 4 mm.

[0055]

According to the present invention, a mixture comprising a water-soluble copolymerized polyester containing a specific amount of a polyoxyalkylene glycol component on at least one surface of the polyester and an oxidized wax and / or a natural wax is mainly used. Easy-to-adhesive polyester film formed with a coating film, excellent in antistatic properties, easy smoothness, water solubility, blocking resistance, solvent resistance, magnetic recording materials, various photographic materials, packaging materials, electricity It is preferably used for insulating materials, general industrial materials and the like.

[0056]

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

Example 1 71.2 parts by weight of dimethyl terephthalate, 14.8 parts by weight of dimethyl 5-sodium sulfoisophthalate, 50.0 parts by weight of ethylene glycol, and 40.0 parts by weight of diethylene glycol.
0 parts by weight, polyethylene glycol having a number average molecular weight of 600
13.0 parts by weight and 0.1 parts by weight of calcium acetate,
0.3 parts by weight of lithium acetate, 0.03 of antimony trioxide
The mixture was transesterified according to a conventional method, and then 0.05 part by weight of trimethyl phosphate was added. Then, the temperature was gradually raised and the pressure was reduced, and finally 280 ° C., 1 mmH
g or less, a polycondensation reaction was carried out to obtain a water-soluble copolymerized polyester. The composition of the obtained water-soluble copolymerized polyester was measured by NMR ( ¹³ C-NMR spectrum). As a result, the acid component was 88 mol% of terephthalic acid, 12 mol% of 5-sodium sulfoisophthalic acid, and the glycol component was ethylene glycol. -89 mol% of diethylene glycol 11
Mol%, the content of polyethylene glycol was 12% by weight, and the intrinsic viscosity was 0.60 dl / g.

2 g of the obtained water-soluble copolyester was placed in 100 g of water, stirred and dissolved at 80 ° C. for 2 hours, cooled, and filtered with a 2 μm filter, and a 2% by weight aqueous solution of a water-soluble copolyester was obtained. I got The aqueous solution of the water-soluble copolymerized polyester was almost transparent, and no filtered product was observed.

On the other hand, as a wax to be mixed with the water-soluble copolymerized polyester, an oxidized wax having a solid concentration of 2% by weight was added to the aqueous solution of the water-soluble copolymerized polyester in an amount of 10% by weight, and the mixture was mixed well and stirred. Agent. [Coating composition] 1) 90 parts by weight of water-soluble copolymerized polyester 2) 10 parts by weight of wax oxidized wax

In order to make the above-mentioned oxidized wax into an aqueous dispersion, a nonionic surfactant, a phosphoric acid ester, ammonium oleate and 2-amino-2-methylpropanol are added in an amount of 1 part by weight, and the mixture is vigorously stirred in water. Further, an aqueous dispersion having a total solid content ratio of 2% by weight was prepared using an ultrasonic dispersing machine.

On the other hand, after sufficiently drying polyethylene terephthalate having an intrinsic viscosity of 0.60 containing 0.2% by weight of silicon dioxide having an average particle diameter of 0.2 μm, it is supplied to an extruder and melted at 280 ° C. And filtered through a 10 μm cut metal sintered filter, and extruded in a sheet form from a T-shaped die.
This was wound around a cooling drum having a surface temperature of 30 ° C. to be cooled and solidified. In order to improve the adhesion between the sheet and the surface of the cooling drum during this time, a wire electrode was arranged on the sheet side and a DC voltage of 6,000 V was applied. The unstretched PET film thus obtained was heated to 95 ° C. and stretched 3.5 times in the longitudinal direction to obtain a uniaxially stretched film. One surface of this film was subjected to a corona discharge treatment in an air atmosphere, and a coating having the above composition was applied to the treated surface by a gravure coating method so that the coating layer thickness after biaxial stretching was 0.04 μm. Guide the applied uniaxially stretched film into a tenter.
After the moisture was dried in a preheating step at 10 ° C., the film was stretched 3.5 times in the width direction while being held at 120 ° C. while being gripped with a clip, and then subjected to a heat treatment at 225 ° C. for 5 seconds to form a coating layer having a thickness of 0.1 mm. An easily adhesive polyester film having a thickness of 04 μm and a film thickness of 10 μm was obtained. Table 2 shows the properties of the obtained film.
Shown in This film was excellent in charging characteristics, lubricity, magnetic paint adhesion, blocking resistance, solvent resistance, and surface smoothness.

Example 2 As in Example 1, the acid component was terephthalic acid 87.5.
Mol%, 5-sodium sulfoisophthalic acid 12.5 mol%, the glycol component is ethylene glycol 91 mol%, diethylene glycol 9 mol%, and the polyethylene glycol content is 15% by weight. The intrinsic viscosity was 0.61 dl / g. In the same manner as in Example 1, 2
A weight% aqueous solution of a water-soluble copolymerized polyester was prepared.
On the other hand, the coating layer thickness was 0.04 μm in exactly the same manner as in Example 1 except that the type of the added wax and the mixing ratio were changed as follows.
m, an easily adhesive polyester film having a film thickness of 10 μm was obtained. [Coating composition] 1) 94 parts by weight of water-soluble copolymerized polyester 2) Wax (a) 65 parts by weight of oxidized wax (b) 35 parts by weight of rosin-modified wax 6 parts by weight ｛hydrogenated rosin / αβ-substituted ethylene (α-substituent: Carboxyl group, β-substituent: methyl) adduct｝ · alkyl (C6) poly (repeating unit: 5) alcohol ester compound

In order to make the above (a) + (b) into an aqueous dispersion, a nonionic surfactant, a phosphoric acid ester, ammonium oleate, and 2-amino-2-methylpropanol were added in an amount of 1 part by weight, and the resulting mixture was added to water. The mixture was vigorously stirred, and an aqueous dispersion having a total solid content ratio of 2.0% by weight was prepared using an ultrasonic disperser. Table 2 shows the properties of the obtained easily adhesive polyester film.

Comparative Example 1 A water-soluble copolymerized polyester having the same composition as that used in Example 2 was used as a water-soluble copolymerized polyester to obtain a 2% by weight aqueous solution of the water-soluble copolymerized polyester. The aqueous solution of the water-soluble copolymerized polyester is almost transparent,
No filtered material was found.

Using this coating agent alone, a coating layer thickness of 0.04 μm and a film thickness of 10 μm were obtained in the same manner as in Example 1.
Was obtained. The properties of the resulting easily adhesive polyester film are shown in Table 2, but were inferior in lubricity.

Examples 3 to 5 and Comparative Examples 2 to 4 In the same manner as in Example 1, a water-soluble copolyester having a composition as shown in Table 1 having a concentration of 2% by weight and a wax having a concentration of 2% by weight were used. An easily adhesive polyester film having a coating layer thickness of 0.04 μm and a film thickness of 10 μm as shown in Table 2 was obtained.

Examples 3 to 5 are within the scope of the present invention and include antistatic properties, slipperiness, adhesion, blocking resistance,
Both solvent resistance was good.

On the other hand, Comparative Examples 2 to 4 were out of the range of the present invention, and were inferior in some properties such as water solubility, antistatic property, slipperiness, solvent resistance and blocking resistance.

Example 6 The same procedure as in Example 1 was repeated except that a water-soluble copolymerized polyester and an oxidized wax were mixed with polyethylene terephthalate in place of the polyethylene terephthalate used in Example 1 as the base film. Thus, an easily adhesive polyester film having a coating layer thickness of 0.04 μm and a film thickness of 10 μm was obtained. That is, 88 mol% of terephthalic acid, 12 mol% of 5-sodium sulfoisophthalic acid as an acid component, and ethylene glycol 8 as a diol component.
Polyethylene terephthalate is mixed with 10% by weight of a mixture of 90% by weight of a water-soluble copolyester consisting of 88% by weight of a polyester comprising 9% by mole, 11% by weight of diethylene glycol, 12% by weight of polyethylene glycol having a molecular weight of 600 and 10% by weight of oxidized wax. Used.
The properties of the film thus obtained are shown in Table 2, and as described above, the base layer containing sodium sulfonate, polyethylene glycol and oxidized wax is more slippery,
It turns out that it is excellent in blocking resistance and adhesiveness.

Example 7 The procedure of Example 1 was repeated, except that a water-soluble copolymerized polyester and an oxidized wax were mixed with polyethylene terephthalate in place of the polyethylene terephthalate used in Example 1 as the base film. Thus, an easily adhesive polyester film having a coating layer thickness of 0.04 μm and a film thickness of 10 μm was obtained. That is, 88 mol% of terephthalic acid, 12 mol% of 5-sodium sulfoisophthalic acid as an acid component, and ethylene glycol 8 as a diol component.
90 parts by weight of a water-soluble copolymerized polyester comprising 9 mol% and 11 mol% of diethylene glycol, and oxidized wax 10
10 parts by weight of the mixture with 10 parts by weight was mixed with polyethylene terephthalate and used. The properties of the film thus obtained are shown in Table 2, and it can be seen that a film having a sodium sulfonate salt and an oxidized wax in the base layer is more excellent in slipperiness, blocking resistance and adhesion.

[0071]

[Table 1]

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[Table 2]

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor: Takashi Mimura 1-1-1 Sonoyama, Otsu City, Shiga Prefecture Toray Industries, Inc. Shiga Plant (56) References JP-A-6-263902 (JP, A) JP-A-4-277532 (JP, A) JP-A-4-220396 (JP, A) JP-A-59-224344 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 7 / 04-7/06 B32B 27/00-27/42

Claims (6)

(57) [Claims] 1. A water-soluble copolymerized polyester containing a polyoxyalkylene glycol component in an amount of 1% by weight or more and less than 20% by weight on at least one surface of a polyester film substrate, and an oxidized wax and / or a natural wax. An easily adhesive polyester film formed by forming a coating film of a mixture mainly composed of: 2. The easily adhesive polyester film according to claim 1, wherein the coating film further contains a rosin-modified wax. 3. The coating film is formed of a mixture mainly composed of 70 to 99.9% by weight of the water-soluble copolymerized polyester, 30 to 0.1% by weight of an oxidized wax and / or a natural wax. The easily adhesive polyester film according to claim 1, wherein: 4. The polyoxyalkylene glycol component is polyethylene glycol, and has a number average molecular weight of 400 to 10,000.
4. The easily-adhesive polyester film according to any one of items 3 to 3. 5. The polyester film substrate according to claim 1, wherein a compound having a sulfonic acid and / or a salt thereof, and an oxidized wax and / or a natural wax are contained in an amount of 5 ppm or more and less than 20% by weight, respectively. 5. The easily adhesive polyester film according to any one of 1 to 4. 6. The easily adhesive polyester film according to claim 5, wherein the polyester film substrate further contains a polyoxyalkylene glycol.