JPH07276593A - Easy adhesive polyester film - Google Patents

Abstract

PURPOSE:To obtain an easy adhesive polyester film excellent in antistatic properties and blocking resistance by forming a film of a mixture based on water-soluble copolyester containing specific wt.% of a polyoxyalkylene glycol component and acrylic wax on at least the single surface of a polyester base film. CONSTITUTION:An easy adhesive polyester film is obtained by forming a film of a mixture based on water-soluble copolyester containing a polyoxyalkylene glycol in an amt. of 1-below 30wt.% and acrylic wax on at least the single surface of a polyester film. The content of aromatic dicarboxylic acid as an acid component of water-soluble copolyester is set to 60mol% or more, pref., 70mol% or more, more pref., 80mol% or more from an aspect imparting excellent antistatic properties, blocking resistance and solvent resistance. When aromatic dicarboxylic acid is below 60mol%, antistatic properties, blocking resistance and solvent resistance are easy to deteriorate.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an easily adhesive polyester film. Specifically, it has excellent antistatic properties, slipperiness, adhesion, blocking resistance, etc., and is suitable as a base film used for magnetic recording materials, various photographic materials, packaging materials, electrical 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 magnetic recording materials.

[0002]

2. Description of the Related Art Polyesters, particularly polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate or poly-1,4-cyclohexanedimethylene terephthalate and polyesters containing these as main constituents are excellent. It has physical and chemical properties and is widely used as a fiber, film or sheet, and also as a molded product thereof.

In particular, since polyester films have excellent heat resistance, chemical resistance and mechanical properties, they are used in many applications such as magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials and general industrial materials. It is 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.

In particular, films used for magnetic tapes, floppy disks, etc. are required to have flatness and smoothness for high reliability and high density of magnetic recording. There is a strong demand for improvement of the adhesive force with the base film. However, when the film is provided with an adhesive force to the magnetic coating material, conversely, blocking occurs between the films, which deteriorates various workability and deteriorates magnetic recording performance. On the other hand, in the manufacturing process of a base film or a magnetic tape, when passing through a process having many kinds of rolls at a high speed, a charging phenomenon occurs due to friction between the rolls and the film or between the films. As a result, the workability is lowered and the magnetic recording performance is deteriorated. Therefore, in order to impart adhesiveness to the film, it is necessary to simultaneously satisfy the properties of the film such as antistatic property, slipperiness and antiblocking property. At the same time, there is a demand for an easily-adhesive substance which is resistant to various solvents contained in various coatings applied or printed on the film surface.

However, since polyester itself is generally inactive and poor in adhesiveness, various coatings such as magnetic paints, chemical mat paints, diazo photosensitive paints, gelatin compositions, heat seal imparting compositions are formed on the film surface. object,
When applying or printing ink, etc., physical treatment such as corona discharge or plasma or chemical treatment using alkali or amine chemicals is performed on the film surface to improve adhesion with the coating. Various methods are known, including a method of coating an easily adhesive substance and the like. However, the physical or chemical surface treatment method complicates the steps, not only increases the cost, but also fails to obtain sufficient adhesiveness.

On the other hand, the method of coating an easily adhesive substance can be carried out in the production process of the polyester film, is advantageous in terms of cost, and can select an adhesive substance which can be applied to various coatings. It is possible. Further, from the viewpoints of handleability of the polyester film and workability during film production, it has been proposed that various water-dispersed or water-soluble copolyesters and the laminating or coating of the copolyesters on the polyester film. For example, JP-B-47-40873 and JP-A-50-1
No. 21336 and Japanese Patent Laid-Open No. 50-134086, polyesters obtained by copolymerizing an ester-forming metal sulfonate compound and polyethylene glycol and films obtained by laminating these polyesters are disclosed in JP-A-63-63.
No. 66239 discloses a polyester obtained by copolymerizing an ester-forming sulfonic acid metal salt compound and polytetramethylene glycol, JP-A-50-83497, JP-A-55-2536, and JP-A-54-3848. JP-A-59-215318 discloses an ester-forming sulfonic acid metal salt compound and a polyester obtained by copolymerizing an aliphatic dicarboxylic acid component, and further diethylene glycol. For example, there is a film undercoated with a polyester copolymerized with 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 are copolymerized as in JP-B-47-40873, water solubility and adhesiveness are exhibited but blocking resistance is improved. Inferior, antistatic property cannot be obtained. Japanese Patent Laid-Open No. 50-121336,
JP-A-50-134086 and JP-A-63-6
When a large amount of an ester-forming sulfonic acid metal salt compound and a polyalkylene glycol component are copolymerized as in 6239, water solubility, blocking resistance and antistatic property are not preferable. Further, JP-A-50-834
97, JP53-2536, JP54.
As described in JP-A-3848 and JP-A-59-215318, when an ester-forming sulfonic acid metal salt compound, an aliphatic dicarboxylic acid component, and further diethylene glycol are copolymerized, adhesiveness is exhibited, There are drawbacks such as poor blocking resistance and inability to obtain antistatic properties.

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

[0010]

The above-mentioned object of the present invention is to provide a water-soluble copolyester containing a polyoxyalkylene glycol component in an amount of 1% by weight or more and less than 30% by weight on at least one side of a polyester film. The skeleton of the film is an easily-adhesive polyester film formed by forming a coating film of a mixture mainly composed of acrylic wax.

The water-soluble copolyester of the present invention is not particularly limited as long as it is a water-soluble copolyester containing a polyoxyalkylene glycol component in an amount of 1% by weight or more and less than 30% by weight. The aromatic dicarboxylic acid as an acid component is preferably 60 mol% or more, more preferably 70 mol% or more, and particularly 80 mol% or more is excellent in antistatic property, antiblocking property and solvent resistance. It is preferable from the point. If the aromatic dicarboxylic acid content is less than 60 mol%, the antistatic property, antiblocking property and solvent resistance tend to be poor. The aromatic-aromatic dicarboxylic acid is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, diphenyletherdicarboxylic acid, and the like, and among these, preferable aromatic dicarboxylic acids include terephthalic acid and Isophthalic acid and naphthalenedicarboxylic acid. The water-soluble copolyester of the present invention contains an ester-forming alkali metal sulfonate compound in an amount of 5 to 40 mol%, preferably 7 to 30 mol%, and more preferably from the viewpoint of imparting water solubility. 10 to 20 mol%, particularly preferably 11
It is preferable to add -15 mol%. When the amount of the ester-forming alkali metal sulfonate compound is less than 5 mol%, it is difficult to obtain sufficient water solubility and adhesiveness. on the other hand,
If it exceeds 40 mol%, the adhesiveness will reach saturation, and conversely the antistatic property, antiblocking property and solvent resistance will tend to be reduced.
The ester-forming sulfonic acid alkali metal salt compound is not particularly limited, and examples thereof include sulfoterephthalic acid, 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene-
Examples thereof include alkali metal salts such as 2,6-dicarboxylic acid, and among them, lithium, sodium and potassium salts of 5-sulfoisophthalic acid and sulfoterephthalic acid are more preferably used.

The glycol component of the water-soluble copolyester of the present invention is an aliphatic glycol having 2 to 8 carbon atoms and / or an aliphatic cyclic glycol having 6 to 16 carbon atoms 80 to 99.
Mol%, diethylene glycol 1 to 20 mol%, preferably alicyclic glycol 82 to 95 mol%, diethylene glycol 5 to 18 mol%, more preferably alicyclic glycol 84 to 93 mol%. % And 7 to 16 mol% of diethylene glycol. Aliphatic glyco with 2 to 8 carbon atoms
And / or diethylene glycol exceeding 20 mol%, the blocking resistance and solvent resistance tend to be poor. On the other hand, an aliphatic glycol having 2 to 8 carbon atoms and /
Or 99 mol% of an alicyclic glycol having 6 to 16 carbon atoms
Or more than 1 mol% diethylene glycol
If it is less than the above range, the blocking resistance is good, but the water solubility and the adhesiveness tend to be poor.

Examples of the C2-C8 aliphatic glycol and / or C6-C16 alicyclic glycol of the present invention include, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2 -Cyclohexane dimethanol, 1,3
There may be mentioned glycols such as cyclohexane dimethanol and 1,4-cyclohexane dimethanol.
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 and 1 , 4-cyclohexane dimethanol. These glycols may be used alone or in combination of two or more. The diethylene glycol in the present invention is usually ethylene glycol.
It contains diethylene glycol, which is a by-product during the production of polyester as a component.

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

The water-soluble copolyester of the present invention can be produced by any conventionally known method and is not particularly limited. For example, a copolyester consisting of terephthalic acid, 5-sodium sulfoisophthalic acid as an acid component and ethylene glycol or diethylene glycol as a glycol component will be described.
Direct esterification reaction of terephthalic acid, 5-sodium sulfoisophthalic acid and ethylene glycol, diethylene glycol, or alkyl ester of terephthalic acid, alkyl ester of 5-sodium sulfoisophthalic acid and ethylene glycol, diethylene glycol
And the like, and a second step in which the reaction product of the first step is subjected to a polycondensation reaction. At this time, as a reaction catalyst, a conventionally known alkali metal, alkaline earth metal,
Manganese, cobalt, zinc, antimony, germanium, titanium compounds and the like may be brought in, and phosphorus compounds and the like may be used as a coloring preventing agent.

The water-soluble copolyester of the present invention includes
It is necessary that the polyoxyalkylene glycol component is contained in an amount of 1% by weight or more and less than 30% by weight, preferably 4 to 25% by weight, particularly preferably 7 to 20% by weight.
Generally, when the content of polyoxyalkylene glycol in the water-soluble copolyester becomes large, the water solubility decreases. In the water-soluble copolyester of the present invention, the content of diethylene glycol in the water-soluble copolyester is closely related to this solubility, and as the content of diethylene glycol increases, the solubility of the polymer improves. It has been found. That is, the polyoxyalkylene glycol-containing water-soluble copolyester becomes more difficult to be water-solubilized as the content increases due to the crystallinity of polyoxyalkylene glycol, but by increasing the amount of diethylene glycol, It is estimated that the crystallization effect can improve the solubility. When the content of the polyoxyalkylene glycol component is less than 1% by weight, antistatic property,
Poor solvent resistance. On the other hand, polyoxyalkylene glyco-
On the other hand, when the content of the component is 30% by weight or more, the antistatic property, water solubility and blocking resistance are adversely affected. The type of the polyoxyalkylene glycol component is not particularly limited, but the number average molecular weight of the polyoxyalkylene glycol component is 400 to 10,000 from the viewpoint of having excellent water solubility, adhesiveness and antistatic property. The number average molecular weight is preferably 500 to 6000, more preferably the number average molecular weight is 600 to 4000. Examples of such polyoxyalkylene glycol component include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like. Among them, polyethylene glycol is preferable from the viewpoint of water solubility and antistatic property.

The method for incorporating the polyoxyalkylene glycol component of the present invention into the copolyester is not particularly limited. For example, the polyoxyalkylene glycol component may be added at any stage of the process for producing the copolyester. Examples thereof include a method of adding and a method of melt-kneading the copolyester and the polyoxyalkylene glycol component using an extruder or the like. On this occasion,
The polyoxyalkylene glycol component can be added by any method such as powder, melting or solution state.

The intrinsic viscosity of the water-soluble copolyester of the present invention is not particularly limited, but it is preferably 0.3 dl / g or more from the viewpoint of adhesiveness, and further 0.4 d.
It is preferably 1 / g or more.

The water-soluble copolyester may optionally contain a flame retardant, a heat stabilizer, an ultraviolet absorber, a pigment,
Dyes, fatty acid esters, organic lubricants such as waxes or antifoaming agents such as polysiloxy acid may be blended, and clay, mica, titanium oxide, calcium carbonate, kaolin, wet type and wet type for the purpose of imparting lubricity. Inorganic particles such as dry-process silica, colloidal silica, calcium phosphate, barium sulfate, and alumina, as well as organic particles containing acrylic acid, styrene, or the like as a constituent component may be blended.

The water-soluble copolyester 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 rigor in terms of physical and chemical senses, but also includes an aqueous solution that is mostly dissolved in water and partially dispersed.

The acrylic wax in the present invention is
Although not particularly limited, a higher fatty acid ester of acrylic acid is preferable from the viewpoints of antistatic property and slipperiness. The carbon number of the higher fatty acid is preferably in the range of 10-24. When the carbon number of the higher fatty acid is less than 10, the slipperiness tends to be poor, and when it is 25 or more, the compatibility tends to be poor. Examples of the higher fatty acid having 10 to 24 carbon atoms include, but are not limited to, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and behenic acid. However, among them, stearic acid is particularly preferably used in terms of slipperiness.

These higher fatty acid esters of acrylic acid may be used alone or as a mixture of several kinds. In addition, some components such as styrene may be copolymerized. Although the molecular weight of the acrylic wax is not particularly limited, it is 10,000 or more, preferably 100,000 or more in view of its properties such as stability and heat resistance. Also, the form is not particularly limited, but an aqueous dispersion is preferably used in terms of stability, uniformity, handling property, and the like. Further, the viscosity is preferably 300 cps or less due to its handleability, and the ionic property is preferably anion or nonion due to the ease of mixing with other coating agents, and the one having good dilution stability is preferred. Although the particle size of the acrylic wax emulsion is not particularly limited, it is 1 μm or less, preferably 0.5 μm or less from the viewpoint of stability and uniformity. The solid content of the acrylic wax in the water dispersion is usually 70
A weight percentage of less than is preferable because of its stability. Such an aqueous emulsion is not particularly limited by its production method, and for example, when stearyl acrylate is taken as an example, after radical polymerization of acrylic acid and stearyl alcohol as raw materials, hot water containing a surfactant is used. Method of adding and stirring at high speed to finely disperse, a method of adding an organic solvent solution of stearyl acrylate polymer to water containing a surfactant under high speed stirring to add finely, and desolvating if necessary, etc. It is possible to use those manufactured in. Alternatively, methods such as emulsion polymerization and emulsion polymerization can be applied. The solid content concentration in these aqueous liquids depends on the coating method, but is 50
It is preferably not more than wt%, more preferably not more than 30 wt%.

Although the antistatic property and the effect of imparting lubricity of the acrylic wax of the present invention have not been sufficiently clarified, it is presumed that acrylic acid contributes to the antistatic property and higher fatty acids contribute to the lubricity. ing. In running triboelectric charging with a metal roll or a silicone roll in a normal conveying process, a general water-soluble copolyester shows a negative charge, whereas an acrylic wax shows a positive charge. From this charge train, the negative charge of the water-soluble copolyester and the positive charge of the acrylic wax are offset,
As a result, it is considered that the triboelectrification preventing property is imparted. Regarding the effect of adding slipperiness of the acrylic wax,
Since the acrylic wax of the present invention has a larger surface free energy dispersive component than paraffin wax, it is presumed that similar effects are exhibited in a mixed system with a water-soluble copolyester. There is. Various additives may be used in combination in the composition as long as the effects of the present invention are not impaired. Examples thereof include antistatic agents, heat-resistant agents, antioxidants, organic and inorganic particles, pigments and the like.

The coating film (coating) in the present invention is formed mainly of a mixture of the above water-soluble copolyester and the above acrylic wax. The term "mainly composed of water-soluble copolyester and wax" means that the mixture is contained in an amount of 80% by weight or more, preferably 90% by weight or more of the coating film.

In the present invention, 70 to 99.9% by weight of the water-soluble copolyester, preferably 8%, of the coating film is used.
It is preferable that 5 to 99% by weight of wax and 30 to 0.1% by weight of wax are mixed, preferably 15 to 1% by weight. If the amount of the water-soluble copolyester is 70% by weight or less, the adhesiveness tends to be poor. On the contrary, if it is 99.9% by weight or more, it is easy to slip,
Blocking resistance tends to be poor. Within the range of the present invention, it is preferable in terms of compatibility of antistatic property, slipperiness, adhesiveness, and blocking resistance. A known crosslinking agent such as a silane coupling agent may be added to the coating film as another component. The thickness of the coating film is not particularly limited, but 0.001 to 1 μm, particularly 0.01 to 0.2 μm is preferable.

The polyester film substrate in the present invention is a polyester film formed by a known method, that is, a film formed by melting polyester, extruding it into a sheet, and stretching it in at least one direction. The mechanical characteristics of the normal balance type,
It is desirable that the type is uniaxially strengthened or biaxially strengthened. Also, it is desirable that the surface of the polyester film be smooth,
Specifically, the surface roughness of the film has a cutoff value of a stylus type surface roughness meter of 0.08 mm and an Ra value of 0.003 to.
It is desirable to be in the range of 0.030 μm.

The Ra value is a roughness curve obtained by removing undulations from a sectional curve obtained from a stylus type surface roughness meter by using an appropriate cutoff value, and a center line (a portion above the center line and It is the arithmetic mean of the absolute values of the height (lowness) of the roughness curve (according to DIN 4768) from the lower part (obtained so that the areas are equal).

The polyester forming the film base may be any polyester 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
And polyethylene-p-oxybenzoate are typical examples.

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

The method for producing the film of the present invention will be described. However, it is not limited to this. Substantially non-oriented, crystalline polyethylene terephthalate raw material,
Melt at 270 ° C to 300 ° C and extrude into a sheet,
A film is produced by cooling and solidifying with a casting drum at -30 ° C to obtain an unstretched sheet, followed by biaxial stretching and heat treatment. Biaxial stretching may be either longitudinal or transverse sequential stretching or biaxial simultaneous stretching, and the stretching ratio is not particularly limited, but usually 2.0 to 5.0 times both longitudinal and transverse are suitable. Alternatively, it may be re-stretched in either the longitudinal or horizontal direction after the longitudinal or transverse stretching. The thickness of the polyester is not particularly limited, but 2 to 200 μm is preferably used.

The method for laminating the coating film for the easy-adhesion layer of the easily-adhesive polyester film of the present invention is most preferably a method of applying it 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 coated is subjected to corona discharge treatment, and the coating liquid is coated to the treated surface. The applied film is dried while passing through a zone that is heated step by step, and the width of the film is 2.5.
It is stretched by about 5 times. More continuously 150-250
It is obtained by a method of introducing a heating zone at a temperature of ℃ to complete the crystal orientation. The coating liquid used in this case is preferably an aqueous system from the viewpoint of environmental pollution and explosion proof. As the method of coating on the substrate film, a known coating method such as a reverse coat method, a gravure coat method, a rod coat method, a die coat method, and a wire bar method can be used. . In the coating layer (easy-adhesion layer), known additives within a range that does not impair the effects of the present invention, for example, heat stabilizers, oxidation stabilizers, weathering stabilizers, ultraviolet absorbers, organic lubricants, pigments , Dyes, organic or inorganic fine particles, fillers, antistatic agents, nucleating agents and the like may be added. As the coating composition, the water-soluble copolyester preferably contains about 0.5 to 10% by weight of the water-soluble copolyester in water. The water-soluble copolyester paint can be prepared, for example, by adding the water-soluble copolyester to hot water at about 60 to 90 ° C. and stirring. The wax paint preferably contains a wax component in water in an amount of about 1 to 50% by weight.
It is preferable to add, for example, about 1% by weight of a nonionic surfactant, a phosphoric acid ester, ammonium oleate, 2-amino-2-methylpropanol, etc., because the wax can be easily dispersed in water. It is preferable that the water-soluble copolyester paint and the wax paint are 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 method is not limited to this. After PET is dried according to a conventional method, it is melt extruded, and the extruded sheet-like melt is cooled and solidified to prepare an unstretched PET film. This film is 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 side of this film is subjected to corona discharge treatment, and the treated surface is coated with an aqueous coating agent within the scope of the present invention diluted with water to a predetermined concentration. Then, the coated film is stretched 2.5 to 5.0 times in the width direction while being heated to 90 to 140 ° C., and then 160 to 240.
It is introduced into a heat treatment zone at 0 ° C. and heat treatment is performed for 1 to 10 seconds. During this heat treatment, a relaxation treatment of 3 to 12% in the width direction may be performed if necessary.

In the above example, the polyester substrate to which the easy-adhesion layer is applied also contains a polymer in which a compound having a sulfonic acid and / or a salt thereof is copolymerized, polyethylene glycol and an acrylic wax. You can In this case, there are advantages such as improvement in slipperiness, blocking resistance, and adhesion between the coating layer and the base film. When a composition containing a polymer in which a compound having a sulfonic acid and / or a salt thereof is copolymerized, polyethylene glycol and an acrylic wax is contained, the addition amount is 5 ppm or more and less than 20% by weight. Are preferable from the viewpoints of slipperiness, blocking resistance, and improved adhesiveness. Needless to say, it may be a coating composition (including recycled pellets of the easily adhesive polyester film of the present invention) provided on the base film.

The easily-adhesive polyester film thus obtained has good winding properties and slitting properties, and by applying a coating agent according to the application to the coating layer side, various applications such as magnetic recording materials and cellophane are possible. For printing various inks such as inks, offset inks, UV curable inks, for easy adhesion of electrophotographic toners, for easy adhesion of chemical mat paints,
The diazo paint is preferably used as a base film for easy adhesion, for inorganic coating such as vapor deposition, and the like.

[0035]

[Characteristic value measuring method and evaluation method] The characteristic measuring method and the effect evaluating method in the present invention are as follows.

(1) Intrinsic viscosity of copolymerized polyester:
[Η] It was measured at 25 ° C using an o-chlorophenol solvent.

(2) Water-solubility of copolyester 2 g of copolyester was put in 100 g of water to prepare 60
After stirring and dissolving at 2 ° C. for 2 hours and cooling, the mixture is filtered with a 2 μm filter. The water solubility of the copolyester was determined by the dissolved state and the amount of the supernatant.

◯: The aqueous solution was transparent or slightly clouded, but almost no filtered matter was observed.

Δ: The aqueous solution was slightly cloudy, and a filtered substance was observed.

X: It was difficult to dissolve, or the aqueous solution was strongly clouded, and a large amount of filtered substances was observed.

(3) Adhesion An aqueous solution of copolyester and wax is coated on a polyester film substrate to form an easy-adhesion layer, and a magnetic coating (Die Ferracoat CAD-430) is provided on the surface of the easy-adhesion layer.
1: A coating consisting of 100 parts by weight of Dainichiseika Kogyo Co., Ltd. and 1 part by weight of a curing agent, Sumidule N75 (Sumitomo Bayer Co., Ltd.) was coated with a bar coat to a thickness of 5 μm after drying.
Coating, and dried at 100 ° C. for 5 minutes to form a coating layer. Cellophane adhesive tape (Nichiban Co., Ltd.) on the coated surface
Product), and after passing through a nipple roll having a linear pressure of 50 / kg / cm, it is rapidly peeled in the direction of 180 degrees. The area of the coated surface adhering to the cellophane adhesive tape at that time was determined to determine the adhesiveness.

A: The area of the coated surface adhered to the cellophane adhesive tape is less than 5%, and the adhesive property is excellent.

◯: The area of the coated surface attached to the cellophane adhesive tape is 5% to less than 10%, and the adhesiveness is slightly excellent.

Δ: The area of the coated surface adhered to the cellophane adhesive tape is less than 10 to 30%, and the adhesiveness is slightly inferior.

X: The area of the coated surface attached to the cellophane adhesive tape is 30% or more, and the adhesiveness is poor.

(4) Antistatic property A polyester film having no easy-adhesion layer laminated on the surface of a metal drum rotating body, and a load of 255 g on the end of the easy-adhesion layer of the film having the easy-adhesion layer laminated while rotating.
And rub along the metal drum rotating body for 5 seconds. Immediately after that, the electrostatic potential of the film was measured by an electrostatic meter to determine the antistatic property.

◯: Charge amount +3 KV or more to less than +7 KV Δ: Charge amount 0 KV or more to less than +3 KV ×: Charge amount less than 0 KV (minus charge) or +7 KV
Above Static meter: Statidon TH type manufactured by Shishido Electrostatic Co., Ltd. Measuring distance 50 mm from the head opening Rotating metal drum: Dimension 65 mm Width × 150 mm φ Rotation speed 860 rpm Measurement sample: 30 mm Width × 300 mm length (5) Easy solvent resistance Methyl ethyl ketone, toluene, and acetone were each dropped as an organic solvent on the surface of the easily adhesive layer of the film provided with the adhesive layer, and the state of cloudiness of the easily adhesive layer was evaluated.

◯: Almost white turbidity Δ: Slightly turbidity ×: White turbidity (6) Blocking resistance The easily adhesive layer surface of the film provided with the easily adhesive layer and the biaxially oriented PE
Stacked T-films (Stacking area: 3 cm x 4
cm) with a load of 500 g / 12 cm ² at 60 ° C. 8
After leaving it in 0% RH for 72 hours, the shear stress of the overlapped portion was measured with a Tensilon tensile tester at a tensile speed of 20.
It was measured in cm / min and judged according to the following criteria.

[0049] ◎: 0kg / cm ² (not completely ^{blocking) ○: 0.1kg / cm 2 ~1kg} / cm 2 or less ^{△: 1kg / cm 2 ~3kg /} cm 2 or less ×: 3kg / cm ² or more (7) Smoothness (Static friction coefficient μs, Dynamic friction coefficient μd) The friction coefficient between films is ASTM-D-1894-
According to No. 63, static friction coefficient μs and dynamic friction coefficient μd were measured using a surface quality measuring device HEIDON-14DR manufactured by Shinto Kagaku Co., Ltd., sample moving speed 200 mm / min, load 200.
g, contact area 63.5 mm x 63.5 mm, measured under the conditions of: Analyzing recorder-TYPE: HEIDON
It was recorded and evaluated at 3655E-99. Generally 10
When a long film (about 20,000 m) having a thin film of about μm is wound, the required value of slipperiness is preferably 0 in μs.
It was 65 or less, and the slipperiness was judged according to the following criteria.

◯: μs = 0.65 or less Δ: μs = 0.65 or more and less than 0.80 ×: μs = 0.8 or more (8) Thickness of coating layer Hitachi transmission electron microscope HU-12 type Using, the ultrathin film section of the laminated film was observed to determine the thickness.

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

Next, the present invention will be explained based on examples, but the present invention is not necessarily limited to these.

[0053]

【Example】

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, diethylene glycol 4.
0 parts by weight, polyethylene glycol of number average molecular weight 600
13.0 parts by weight and calcium acetate 0.1 parts by weight,
0.3 parts by weight of lithium acetate, 0.03 antimony trioxide
After adding parts by weight and carrying out an ester exchange reaction according to a conventional method, 0.05 parts by weight of trimethyl phosphate was added. Then gradually raise the temperature and reduce the pressure, and finally 280 ° C., 1 mmH
A polycondensation reaction was carried out at g or less to obtain a water-soluble copolyester. The composition of the obtained water-soluble copolyester was measured by NMR ( ¹³ C-NMR spectrum). As a result, the acid component was 88 mol% terephthalic acid, 12 mol% 5-sodium sulfoisophthalic acid, and the glycol component was ethylene glycol. -89 mol%, diethylene glycol 11
%, The polyethylene glycol content was 12% by weight, and the intrinsic viscosity was 0.60 dl / g.

2 g of the obtained water-soluble copolyester was put in 100 g of water, dissolved by stirring at 80 ° C. for 2 hours, cooled, and then filtered with a 2 μm filter to obtain a water-soluble copolyester aqueous solution having a concentration of 2% by weight. Got The aqueous solution of the water-soluble copolyester was almost transparent, and no filter-filtered substance was observed.

On the other hand, as a wax to be mixed with the water-soluble copolyester, a wax having a solid content of 40% by weight and a molecular weight of about 500,000 stearyl acrylate aqueous dispersion was diluted with water to obtain a solid content of 2% by weight. As an aqueous dispersion of stearyl acrylate, 10 parts by weight was added to an aqueous solution of a water-soluble copolyester, and the mixture was thoroughly mixed and stirred to obtain the coating material of the present invention.

[Coating Composition] 1) 90 parts by weight of water-soluble copolyester 2) wax 10 parts by weight of stearyl acrylate On the other hand, intrinsic viscosity of 0.60 containing 0.2% by weight of silicon dioxide having an average particle diameter of 0.2 μm After thoroughly drying the polyethylene terephthalate of No. 1, supplied to an extruder, melted at 280 ° C., filtered through a sintered metal filter of 10 μm cut, 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 period, a wire electrode is arranged on the sheet side to obtain 6,000.
A DC voltage of V was applied. Unstretched PE thus obtained
The T film 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 corona discharge treatment in an air atmosphere, and the treated surface was coated with a coating composition having the above composition by a gravure coat method so that the coating layer thickness after biaxial stretching was 0.04 μm. The coated uniaxially stretched film is introduced into a tenter to dry the water in a preheating step at 110 ° C, and then stretched 3.5 times in the width direction while gripping with a clip while heating at 120 ° C.
Heat treatment is performed at 5 ° C for 5 seconds, the coating layer thickness is 0.04 μm,
An easily-adhesive polyester film having a film thickness of 10 μm was obtained. The characteristics of the obtained film are shown in Table 2. This film was excellent in charging characteristics, slipperiness, magnetic coating adhesion, blocking resistance, solvent resistance, and surface smoothness.

Example 2 As in Example 1, the acid component was terephthalic acid 87.5.
Mol%, 12.5 mol% of 5-sodium sulfoisophthalic acid, 91 mol% of ethylene glycol and 9 mol% of diethylene glycol as the glycol component, and the content of polyethylene glycol is 15% by weight. The intrinsic viscosity was 0.62 dl / g. As in Example 1, 2
An aqueous solution of a water-soluble copolymerized polyester of wt% was prepared.
On the other hand, an easily adhesive polyester film having a coating layer thickness of 0.04 μm and a film thickness of 10 μm was obtained in exactly the same manner as in Example 1 except that the compounding ratio of the added wax was changed as follows.

[Coating composition] 1) Water-soluble copolyester 94 parts by weight 2) Stearyl acrylate 6 parts by weight Table 2 shows the characteristics of the easily adhesive polyester film obtained.

Comparative Example 1 As the water-soluble copolyester, the water-soluble copolyester having the same composition as that used in Example 2 was used to obtain a water-soluble copolyester aqueous solution having a concentration of 2% by weight. The aqueous solution of water-soluble copolyester is almost transparent,
No superficial items were found.

Using this coating agent alone, in the same manner as in Example 1, the coating layer thickness was 0.04 μm, and the film thickness was 10 μm.
To obtain an easily adhesive polyester film. The properties of the obtained easily adhesive polyester film are shown in Table 2, but the slipperiness was poor.

Examples 3 to 5 and Comparative Examples 2 to 4 In the same manner as in Example 1, using a water-soluble copolyester having a composition shown in Table 1 at a concentration of 2% by weight and a wax at a concentration of 2% by weight. Then, 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 have antistatic property, slipperiness, adhesiveness, blocking resistance,
The solvent resistance was good.

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

Example 6 As a base film, instead of the polyethylene terephthalate used in Example 1, a water-soluble copolymerized polyester obtained by copolymerizing 15 wt% of the polyethylene glycol used in Example 2 and acrylic acid were used. An easily-adhesive polyester film having a coating layer thickness of 0.04 μm and a film thickness of 10 μm was obtained in exactly the same manner as in Example 1, except that the stearyl wax was mixed with polyethylene terephthalate.
That is, 88 mol% of terephthalic acid as an acid component, 5-
Water-soluble copolymer consisting of 12% by weight of a polyester comprising 12 mol% of sodium sulfoisophthalic acid, 89 mol% of ethylene glycol as a diol component, and 11 mol% of diethylene glycol and 12% by weight of polyethylene glycol having a molecular weight of 600. 10% by weight of a mixture of 90 parts by weight of polyester and 10 parts by weight of oleyl wax acrylate was mixed with polyethylene terephthalate and used. The properties of the film thus obtained are shown in Table 2 and are as follows:
It can be seen that the base layer having sodium sulfonate, polyethylene glycol and stearyl acrylate has better lubricity, blocking resistance and adhesiveness.

[0065]

[Table 1]

[Table 2]

[0066]

According to the present invention, a coating film of a mixture mainly composed of a water-soluble copolymerized polyester containing a specific amount of a polyoxyalkylene glycol component and an acrylic wax is formed on at least one surface of the polyester. An easily-adhesive polyester film made of, which is excellent in antistatic property, easy smoothness, water solubility, blocking resistance, solvent resistance,
It is preferably used for magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials, general industrial materials and the like.

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Claims (7)

[Claims] 1. A mixture mainly composed of a water-soluble copolymerized polyester containing a polyoxyalkylene glycol component in an amount of 1% by weight or more and less than 30% by weight and an acrylic wax on at least one surface of a polyester film substrate. An easily-adhesive polyester film having a coating film formed thereon. 2. The easily adhesive polyester film according to claim 1, wherein the acrylic wax is a higher fatty acid ester of acrylic acid. 3. The easily adhesive polyester film according to claim 2, wherein the higher fatty acid has a carbon number in the range of 10 to 24. 4. The coating film comprises 70 to 99.9% by weight of the water-soluble copolyester and 30 to 30% of an acrylic wax.
The easily adhesive polyester film according to claim 1, which is formed of a mixture containing 0.1% by weight as a main component. 5. The polyoxyalkylene glycol component is polyethylene glycol, and the number average molecular weight thereof is 400 to 10,000.
4. The easily adhesive polyester film according to 4 above. 6. A polyester film substrate, a polymer in which a compound having a sulfonic acid and / or a salt thereof is copolymerized, and an acrylic wax are added at 5 pp each.
The easily-adhesive polyester film according to any one of claims 1 to 5, wherein the polyester film contains m or more and less than 20% by weight. 7. The easily adhesive polyester film according to claim 6, wherein the polyester film substrate further contains polyoxyalkylene glycol.