JP3455652B2 - Antistatic 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 antistatic polyester film, and more particularly to a magnetic card (for example, a telephone card, a prepaid card) having excellent antistatic properties, back transfer properties, abrasion resistance, blocking resistance, and recovery properties. Cards), electronic materials, graphic materials, plate-making films,
The present invention relates to an antistatic polyester film useful for OHP films, magnetic recording materials (for example, magnetic tapes such as audio tapes and video tapes, magnetic disks such as floppy disks), and particularly useful for magnetic cards.

[0002]

Polyester films are used for magnetic cards, packaging materials, photographic materials, magnetic recording media,
It is widely used as a base film for printing materials, but it is a problem common to plastic films that static electricity is easily generated and various troubles are likely to occur during the film forming process, processing process, and when using the product. There is.

A thick white polyester film is used for magnetic cards such as telephone cards and prepaid cards. However, there are drawbacks in the manufacturing process, processing process, and antistatic property of the final product, and the film surface has a problem. Various methods for forming an antistatic coating film have been proposed and put into practical use. As the antistatic agent to be contained in the antistatic coating film, a low molecular weight type and a high molecular weight type have been conventionally known, but each has its own advantages and disadvantages. Therefore, the antistatic agent is used properly according to its characteristics.

For example, as a low molecular type antistatic agent,
Long-chain alkyl compound having sulfonate group (Patent Document 4)
No. 28728), a surfactant type anionic antistatic agent is known, and as a polymer type antistatic agent, a polymer having an ionized nitrogen element in its main chain (Japanese Patent Application Laid-Open No. Hei 10 (1999) -242242) JP-A-3-255139, JP-A-4-
(JP-A-6-172562).
Or sulfonate-modified polystyrene (JP-A-5-320)
No. 390) and the like are known.

However, in an antistatic coating film using a low-molecular type antistatic agent, a part of the antistatic agent migrates in the coating film and accumulates at the interface to migrate to the opposite surface of the film. There is a problem that the antistatic property deteriorates with time. On the other hand, in the case of antistatic coating film using polymer type antistatic agent, it is necessary to add a large amount of antistatic agent in order to exhibit good antistatic property, or antistatic property with thick film thickness. It is not economical because it is necessary to form a coating film. In addition, when a waste film that does not become a product (for example, the film edge cut and removed from the product) is collected and used as a recycled material for film manufacturing, the coating film components contained in the recycled material during the melt film formation will not be heated. There is a problem that the film is deteriorated and the obtained film is markedly colored and is not practical (recovery is poor). Furthermore, there is a defect that the films are difficult to peel off (blocking), a defect that the coating film is easily peeled off, and the solution thereof is desired.

[0006]

The object of the present invention is to solve the problems of the prior art and to provide an antistatic polyester excellent in antistatic property, back surface transfer property, recoverability, abrasion resistance and blocking resistance. To provide a film.

[0007]

According to the present invention, an antistatic agent (A) containing 4 to 99% by weight of an antistatic agent (A) having a repeating unit represented by the following formula (1) as a main component is provided on at least one side of an aromatic polyester film. And polyester resin (B-
1), at least one binder resin (B) selected from the group consisting of acrylic resin (B-2) and acrylic modified polyester resin (B-3), represented by the following formula (2): An antistatic coating film prepared by applying a coating solution containing a solid content composition of 1 to 15% by weight of a cross-linking agent (C) containing a repeating unit having a repeating structure as described above, drying and stretching is provided. It is an antistatic polyester film characterized in that

[0008]

[Chemical 3]

[In the formula (1), R ¹ and R ² are each H or CH ₃ , R ³ and R ⁶ are alkylene groups each having 2 to 10 carbon atoms, and R ⁴ and R ⁵ are each 1 carbon atoms. To 5 saturated hydrocarbon groups, n and m are each a number from 1 to 40, Y ⁻ is a halogen ion, a mono- or poly-halogenated alkyl ion, a nitrate ion, a sulfate ion, an alkyl sulfate ion, a sulfonate ion or an alkyl sulfonate ion. Indicates. ]

[0010]

[Chemical 4]

[In the formula (2), R ⁷ and R ⁸ each represent H or CH ₃ . ]

In the present invention, the polyester constituting the polyester film is a linear polyester composed of a dicarboxylic acid component and a glycol component. As the dicarboxylic acid component, terephthalic acid, isophthalic acid, 2,6
-Naphthalenedicarboxylic acid, hexahydroterephthalic acid, 4,4'-diphenyldicarboxylic acid, adipic acid,
Examples thereof include sebacic acid and dodecanedicarboxylic acid. Especially from the viewpoint of mechanical properties of film, terephthalic acid, 2,6
-Naphthalenedicarboxylic acid is preferred.

As the glycol component, ethylene glycol, diethylene glycol, propylene glycol,
1,3-propanediol, 1,4-butanediol,
Neopentyl glycol, 1,6-hexanediol,
Examples thereof include cyclohexanedimethanol and polyethylene glycol. In particular, ethylene glycol is preferable from the viewpoint of film rigidity.

The above-mentioned polyester may be a copolyester obtained by copolymerizing the above-mentioned dicarboxylic acid component or glycol component as the third component, and the polyester obtained is essentially a trifunctional or higher polyvalent carboxylic acid component or polyol component. It may be a polyester copolymerized in a small amount in a linearly linear range (for example, 5 mol% or less).

Such a polyester can be produced by a conventional method, and if the intrinsic viscosity of the polyester (in orthochlorophenol, 35 ° C.) is 0.45 or more, the mechanical properties such as high rigidity of the film are improved. preferable. The polyester may contain a white pigment such as titanium oxide and / or barium sulfate. In addition to these, inorganic fillers such as silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc, etc., and heat resistant polymers such as crosslinked silicone resin, crosslinked polystyrene resin, crosslinked acrylic resin, urea resin, melamine resin, etc. Other organic fillers such as polyethylene, polypropylene, ethylene, propylene copolymers, olefinic ionomers, stabilizers, antioxidants, ultraviolet absorbers, optical brighteners and the like can be added as required.

The white polyester film in the present invention contains 5 to 20% by weight of a white pigment such as titanium oxide and barium sulfate, and its surface glossiness can be arbitrarily selected as desired.

In the present invention, the polyester film is preferably a biaxially stretched film and has a thickness of 20.
It is not less than μm, preferably 50 to 500 μm, and particularly preferably 75 to 300 μm. If this thickness is less than 20 μm, the stiffness of the film becomes weak. On the other hand, if the film is too thick, for example, exceeding 500 μm, the film-forming property tends to be poor.

In the present invention, the antistatic coating film provided on at least one surface of the polyester film is formed by applying a coating solution containing the antistatic agent (A), drying and stretching.

The antistatic agent (A) in the present invention is a compound whose main component is a repeating unit having a structure represented by the following formula (1).

[0020]

[Chemical 5]

[In the formula (1), R ¹ and R ² are each H or CH ₃ , R ³ and R ⁶ are alkylene groups each having 2 to 10 carbon atoms, and R ⁴ and R ⁵ are each 1 carbon atoms. To 5 saturated hydrocarbon groups, n and m are each a number from 1 to 40, Y ⁻ is a halogen ion, a mono- or poly-halogenated alkyl ion, a nitrate ion, a sulfate ion, an alkyl sulfate ion, a sulfonate ion or an alkyl sulfonate ion. Indicates. ]

In the antistatic agent (A), Y ⁻ in the formula (1) is an alkyl sulfonate ion represented by R ⁹ SO ₃ ^— (wherein R ⁹ is a saturated hydrocarbon group having 1 to 5 carbon atoms). , R ³ is an ethylene group, and n is 1 to 4
The number is 0, R ⁶ is an ethylene group, and m is 1 to 40.
Is preferable because the adhesiveness between the coating film and the polyester film and the heat resistance of the coating film are good, and especially the antistatic property is excellent.

Further, Y ⁻ in the formula (1) is CH ₃ SO ₃ ⁻ ,
C ₂ H ₅ SO ₃ ⁻ or C ₃ H ₇ SO ₃ ⁻ , R ³ is an ethylene group and n is a number of 2 to 10, R ⁶ is an ethylene group and m is a number of 2 to 10 Some are particularly preferred.

The average molecular weight (number average molecular weight) of the compound having a repeating unit of the structure represented by the formula (1) is arbitrary, but it is 3,000 to 300,000, more preferably 5,000 to 1,000.
It is preferably 00. This average molecular weight is 3000
If the amount is less than the range, the backside transferability of the antistatic agent (A) tends to be deteriorated, and if the average molecular weight exceeds 300,000, the viscosity of the aqueous coating solution tends to be too high, and it tends to be difficult to uniformly coat the film.

The coating liquid for forming the antistatic coating film in the present invention preferably contains a binder resin (B) in order to make the adhesion between the coating film and the polyester film stronger. .

Examples of the binder resin include polyester resin (B-1), acrylic resin (B-2), acrylic modified polyester resin (B-3) and the like, and one or more selected from these resins. It is preferable to use the above resin. Particularly, it is preferable to use the polyester resin (B-1) or the acrylic resin (B-2) because the adhesion between the antistatic coating film and the polyester film becomes good, and the polyester resin (B-1) and the acrylic resin ( It is more preferable to use B-2) together, because the adhesiveness is good and coloring of the recycled film can be suppressed when the antistatic film is collected and reused. When the polyester resin (B-1) and the acrylic resin (B-2) are used in combination, the polyester resin (B-1) is replaced with the acrylic resin (B-
It is preferable to use a larger amount than 2).

The polyester resin (B-1) is a linear polyester having a dicarboxylic acid component and a glycol component as constituent components. As the dicarboxylic acid component, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4-diphenyldicarboxylic acid,
Examples thereof include 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, phenylindanedicarboxylic acid and dimer acid. Two or more kinds of these components can be used. Further, in combination with these components, unsaturated polybasic acids such as maleic acid, fumaric acid and itaconic acid, and hydroxycarboxylic acids such as p-hydroxybenzoic acid and p- (β-hydroxyethoxy) benzoic acid are used in small proportions. You can The ratio of the unsaturated polybasic acid component and the hydroxycarboxylic acid component is at most 10 mol%, preferably 5
It is not more than mol%.

As the glycol component, ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, dimethylol. Propionic acid, glycerin, trimethylolpropane,
Examples thereof include poly (ethyleneoxy) glycol, poly (tetramethyleneoxy) glycol, bisphenol A alkylene oxide adducts, hydrogenated bisphenol A alkylene oxide adducts, and the like. These can use 2 or more types.

Among such polyol components, ethylene glycol, an ethylene oxide adduct of bisphenol A and a propylene oxide adduct, and 1,4-butanediol are preferable, and ethylene glycol and an ethylene oxide adduct of bisphenol A and a propylene oxide adduct are more preferable. preferable.

The polyester resin (B-1) may be copolymerized with a small amount of a compound having a sulfonate group or a compound having a carboxylate group in order to facilitate liquefaction in water. , That is preferable.

Examples of the compound having a sulfonate group include 5-Nasulfoisophthalic acid, 5-ammoniumsulfoisophthalic acid, 4-Nasulfoisophthalic acid, 4-methylammoniumsulfoisophthalic acid, 2-
Na sulfoisophthalic acid, 5-K sulfoisophthalic acid,
Preferable examples include sulfonic acid alkali metal salt-based compounds such as 4-K sulfoisophthalic acid, 2-K sulfoisophthalic acid and Na sulfosuccinic acid, or sulfonic acid amine salt-based compounds.

Examples of the compound having a carboxylic acid group include trimellitic anhydride, trimellitic acid, pyromellitic dianhydride, pyromellitic acid, trimesic acid, cyclobutanetetracarboxylic acid, dimethylolpropionic acid, and the like, or monos thereof. Examples thereof include alkali metal salts. After the copolymerization, the free carboxyl group is reacted with an alkali metal compound or an amine compound to form a carboxylate group.

The acrylic resin (B-2) includes acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, sodium acrylate, ammonium acrylate,
2-hydroxyethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, sodium methacrylate, ammonium methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, acrylonitrile, acrylamide,
Examples thereof include methacrylamide, N-methylol methacrylamide and the like. These monomers may be used in combination with other unsaturated monomers such as styrene, vinyl acetate, vinyl chloride, vinylidene chloride, divinylbenzene, sodium styrenesulfonate, sodium vinylsulfonate and sodium methallylsulfonate. it can.

The acrylic modified polyester resin (B-
3) is acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, sodium acrylate, ammonium acrylate, 2-hydroxyethyl acrylate, methacrylic acid, methacrylic acid in the presence of the polyester resin (B-1). Acrylic monomers exemplified by methyl, ethyl methacrylate, butyl methacrylate, sodium methacrylate, ammonium methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, acrylonitrile, acrylamide, methacrylamide, N-methylol methacrylamide, etc. It is a graft copolymer made by polymerizing styrene, vinyl acetate,
Other unsaturated monomers such as vinyl chloride, vinylidene chloride, divinylbenzene sodium styrene sulfonate, sodium vinyl sulfonate and sodium methallyl sulfonate may be contained as a copolymerization component.

The coating liquid for forming the antistatic coating film of the present invention may contain a binder resin other than the above in order to adjust the adhesion between the coating film and the polyester film. Examples of such resin include polyurethane resin,
Epoxy resin, vinyl resin, polyether resin, water-soluble resin and the like can be mentioned.

The coating liquid for forming the antistatic coating film of the present invention contains a crosslinking agent (C) comprising an oxazoline compound in order to improve the solvent resistance of the coating film or the blocking resistance of the film. Preferably.
Examples of the oxazoline compound include compounds having a repeating unit having a structure represented by the following formula (2) as a main component.

[0037]

[Chemical 6]

[In the formula (2), R ⁷ and R ⁸ each represent H or CH ₃ . ]

The molecular weight of the compound whose main component is a repeating unit having a structure represented by the following formula (2) is 500 to 50.
It is preferably in the range of 00. If the molecular weight is less than 500, the solvent resistance of the antistatic coating film and the blocking resistance of the film may decrease, while if it exceeds 5,000, the stability of the coating liquid decreases and a uniform coating film can be obtained. Sometimes there is not. In such compounds, R ⁷ in the formula (2) is H,
It is particularly preferred that R ⁸ is CH ₃ and the molecular weight is 2000.

In the coating liquid for forming the antistatic coating film of the present invention, the stability of the coating liquid, especially the aqueous coating liquid is improved,
In order to improve the wettability when the coating liquid is applied to the polyester film, a surfactant (D) can be added. Examples of the surfactant (D) include alkylene oxide homopolymers, alkylene oxide copolymers, aliphatic alcohol / alkylene oxide adducts,
Long chain aliphatic substituted phenol / alkylene oxide adducts, polyhydric alcohol fatty acid esters, long chain aliphatic amide alcohols and other nonionic surfactants, compounds having quaternary ammonium salts, compounds having alkylpyridinium salts, sulfonates Examples thereof include a cationic or anionic surfactant such as a compound having a nonionic surfactant, and in particular, a nonionic surfactant has an excellent effect on the adhesion between the coating film and the base film and the blocking resistance of the antistatic film. Therefore, it is preferable.

The antistatic coating film in the present invention is formed by applying a coating liquid containing the above-mentioned antistatic agent (A) and cross-linking agent (C), and further binder resin (B).
And / or a coating liquid containing a surfactant (D) is preferable. The proportion of the antistatic agent (A) contained in the coating liquid is
In order to improve the antistatic property, it is necessary to be 4 to 99% by weight, preferably 10 to 99% by weight. If the proportion of the antistatic agent (A) is less than 4% by weight, the antistatic property will be insufficient. Also, a cross-linking agent (C)
It is necessary that the ratio is 1 to 15% by weight. When the proportion of the cross-linking agent (C) is less than 1% by weight, the solvent resistance of the antistatic coating film is lowered, which is not preferable, while when it exceeds 15% by weight, the stability of the coating liquid is lowered, which is not preferable.

The following examples can be given as particularly preferable embodiments of the antistatic coating film in the present invention. That is, as a particularly preferable solid content composition of the coating liquid for forming the antistatic coating film, the antistatic agent (A) is 10 to 80% by weight, the binder resin (B) is 19 to 80% by weight, and the crosslinking agent (C) is 1. 10 wt% and 0 to 25 wt% of the surfactant (D), the antistatic agent (A) is a repeating unit of the structure represented by the above formula (1) (provided that in the formula (1), R
¹ and R ² are H or CH ₃ , R ³ and R ⁶ are ethylene groups, R ⁴ and R ⁵ are saturated hydrocarbon groups each having 1 to 5 carbon atoms, and n and m are each 1 to 40. , Y ^- is R ⁹ S
The alkyl sulfonate ion represented by O ₃ ^— , R ⁹ represents a saturated hydrocarbon group having 1 to 5 carbon atoms. ) Is the main component, and the binder resin (B) has a second-order transition point 2
It is an acrylic resin (B-2) having a temperature of 0 to 100 ° C., and the surface energy of the antistatic coating film is 37 to 73 dyne /
cm and the contact angle with water is 40 to 110 degrees.

When the antistatic agent (A) is in the range of 10 to 80% by weight, the adhesion between the coating film and the polyester film and the antistatic property are good, and the binder resin (B) is 1
When it is in the range of 9 to 80% by weight, the antistatic property and the adhesion between the coating film and the polyester film are good, and when the content of the crosslinking agent (C) is in the range of 1 to 10% by weight, the solvent resistance of the coating film is high. And the anti-static film have good blocking resistance, and when the surfactant (D) is in the range of 0 to 25% by weight, the adhesiveness between the coating film and the polyester film and the anti-static film blocking resistance are improved. It will be good.

When an antistatic film provided with a coating film formed from the coating liquid of the above embodiment and having the characteristics of the coating film satisfying the above characteristics is used, for example, in a magnetic card, the coating film and the base film are A coating film in the present invention that can obtain particularly excellent adhesiveness and antistatic film blocking resistance, heat resistance, and antistatic property at low humidity is formed by applying an aqueous coating liquid (water as a medium). However, it is also possible to form by applying an organic solvent as a solvent. As this organic solvent, methyl ethyl ketone,
Acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, methanol, ethanol, n-propanol, isopropanol and the like can be exemplified. These may be used alone or in combination of two or more.

In addition, a lubricant is added to the coating liquid of the present invention in order to improve the slipperiness of the coating film surface and the blocking resistance of the film, so long as the properties such as adhesiveness are not impaired. can do. Examples of the lubricant include fine particles of polystyrene resin, acrylic resin, melamine resin, silicone resin, fluororesin, urea resin, benzognamine resin, polyamide resin, polyester resin and the like. The fine particles of these resins may be thermoplastic or thermosetting as long as they are contained in the laminate coating film as fine particles.

Further, within a range not impairing the object of the present invention, other surfactants, ultraviolet absorbers, pigments, lubricants,
Additives such as antiblocking agents, other crosslinking agents such as melamine, epoxy, aziridine, and other antistatic agents can be added to the coating liquid.

The solid concentration of the coating liquid in the present invention is 0.
It is preferably 5 to 30% by weight. When the solid content concentration is less than 0.5% by weight, the wettability to the polyester film is insufficient, and when it exceeds 30% by weight, the coating appearance tends to be deteriorated.

In the present invention, the coating liquid containing the above-mentioned components is applied to at least one side of the polyester film, and the polyester film is preferably a polyester film before crystal orientation is completed. As the polyester film before the oriented crystals are completed, an unstretched film which is a film as it is by heat-melting polyester, a uniaxially stretched film in which the unstretched film is oriented in either the longitudinal direction or the transverse direction, An example is one that has been stretched and oriented in a low-magnification direction in both the machine direction and the transverse direction (a biaxially stretched film before being finally re-stretched in the machine direction and the transverse direction to complete the oriented crystallization). .

As a method of applying the coating liquid to the polyester film, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a micro gravure coating method, a reverse coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method and a curtain coating method may be applied alone or in combination. When an aqueous coating material is used, a small amount of an organic solvent may be included in order to help the stability of the coating material.

The coating amount is preferably 0.5 to 50 g, more preferably 5 to 30 g per 1 m ² of the running film. The thickness of the final dry coating film is preferably 0.02 to 1 μm, more preferably 0.05 to 0.8 μm. The thickness of the coating film is 0.
If it is less than 02 μm, the antistatic property becomes insufficient, while if it exceeds 1 μm, the blocking resistance tends to decrease. The coating can be carried out on only one side or on both sides depending on the intended use of the film. After coating, it is dried to form a uniform coating film.

In the present invention, it is preferable that the polyester film is coated with the coating liquid and then dried, preferably stretched, but the drying is preferably performed at 90 to 130 ° C. for 2 to 20 seconds. The drying can also be a preheat treatment for the stretching treatment or a heat treatment during the stretching. The polyester film is stretched at a temperature of 70 to 140 ° C. in the longitudinal direction of 2.5 to 7 times, in the transverse direction of 2.5 to 7 times, and in area magnification of 8 times or more, and further 9 to 28 times. preferable. In the case of re-stretching, it is preferable to stretch at a draw ratio of 1.05 to 3 times (however, the area magnification is the same as above). The heat setting treatment after the stretching is 1 to above the final stretching temperature and below the melting point.
It is preferably carried out for 30 seconds. For example, for a polyethylene terephthalate film, it is preferable to heat-fix at 170 to 240 ° C for 2 to 30 seconds.

The antistatic polyester film thus obtained has a surface energy of, for example, 37 to 73 dyn.
e / cm, the contact angle with water is 40 to 110 degrees, and the surface resistivity (temperature 23 ° C., humidity 60%) is 3 × 10 ^12.
[Ω / □] or less, particularly 2 × 10 ¹⁰ to 2 × 10 ¹¹ [Ω /
□], adhesiveness, antistatic property, blocking resistance,
It has excellent backside transferability, abrasion resistance, and recoverability, and is extremely useful as a film for magnetic cards.

[0053]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples. The evaluation in the present invention was performed by the following method.

1. Surface resistivity (antistatic property) The surface resistivity of the sample film is measured by Takeda Riken.
Using a specific resistance measuring instrument, measuring temperature 23 ℃, measuring humidity 6
Under the condition of 0%, the surface specific resistance value (Ω / □) after 1 minute at an applied voltage of 500 V is measured. The surface resistivity is 3 x
It is preferably 10 ¹² [Ω / □] or less, more preferably 3 × 10 ¹¹ or less.

2. Blocking resistance: A coating film-coated surface and a non-coated surface of a sample film cut into a width of 50 mm are overlapped with each other, and under a load of 50 kg / cm ² ,
After treating at 60 ° C. × 80% RH for 17 hours, the peeling force between the coated surface and the non-coated surface was measured, and the blocking resistance was evaluated according to the following criteria. Rank A: Peeling force ≦ 10 g (good blocking resistance) Rank B: 10 g <Peeling force ≦ 30 g (slightly poor blocking resistance) Rank C: 30 g <Peeling force (poor blocking resistance)

3. Contact angle to water The sample film was fixed to a contact angle measuring device (manufactured by Elma) with the coated surface facing upward, and the contact angle after 1 minute from dropping a water drop at a temperature of 23 ° C was measured. It was measured by reading.

4. Overlay the coated surface and the non-coated surface of the backside transferable sample film, and
After applying a load of kg / cm ² for 17 hours at 50 ° C. × 70% RH, measure the contact angle of water on the non-coated surface (θ: substitute property of backside transferability) and evaluated. Rank A: θ ≧ 55 ° (rear transfer property is good) Rank B: 55 °> θ ≧ 48 ° (rear transfer property is slightly good) Rank C: 48 °> θ (rear transfer property is poor) The water contact angle of the film without film is 60
The water contact angle of the film having a good back surface transfer property is 55 ° or more, and the water contact angle of the film having a remarkable back surface transfer property (poor back surface transfer property) is less than 48 °.

5. Using a film sample cut to a width of 20 mm in abrasion resistance, apply the coating surface of the film to a cylindrical stainless steel fixed bar with a diameter of 10 mm, run for 80 m under a load of 200 g, and then adhere to the bar. The white powder of the coated film was observed and the abrasion resistance was evaluated according to the following criteria. Rank A: No white powder adhered to the bar (good abrasion resistance) Rank B: Some white powder adhered to the bar (some abrasion resistance was poor) Rank C: Large amount of white powder adhered to the bar (poor abrasion resistance)

6. Coloring degree (recoverability) of recycled film A film without a coating film is crushed and then crushed with an extruder to about 300
Melted at ℃ and made into chips. Next, the obtained chip was melt-cast to form a blank film. The coloring degree of this film was used as a blank. On the other hand, the sample film provided with the coating film was crushed and melted at about 300 ° C. by an extruder to be made into chips. Then, the obtained chips were melt-cast to form a recycled film. The coloring degree of this film was evaluated according to the following criteria. Rank A: The degree of coloring is similar to that of a blank film. Rank B: The film is slightly colored. Rank C: The degree of coloring of the film is large and it is not practical.

7. A 250 μm-thick polyester film was attached to the non-coated surface of the UV ink adhesive sample with an adhesive. Next, an ultraviolet-curable printing ink (Flash Dry FDO Red APN made by Toyo Ink) was printed on the coated surface of the coating film by an RI tester (manufactured by Akira Seisakusho), and then a medium pressure mercury lamp (80 W / cm, single-light type;
Curing was performed with a UV curing device (manufactured by Nippon Battery) to form a UV ink layer having a thickness of 3.0 μm. 1 piece of cellophane tape (18mm width; made by Nichiban) on this UV ink layer
The tape was attached to a length of 5 cm, and a constant load was applied on this by a 2 Kg manual load roll, the film was fixed, and one end of the cellophane tape was peeled in the 90 ° direction to measure the peel adhesive strength. The adhesiveness was evaluated according to the following criteria. Rank A: The ink layer is not peeled at all (good ink adhesion) Rank B: The coating film and the ink layer are partially peeled off in a cohesive failure state (slightly good ink adhesion) Rank C: The coating film and the ink layer are layered Peels off (poor ink adhesion)

[Example 1] Polyethylene terephthalate (containing 10% by weight of titanium oxide) having an intrinsic viscosity of 0.65 (in orthochlorophenol, 35 ° C) was melted and cast on a cooling drum, and then 3. It was stretched 6 times. A 10% by weight aqueous coating solution having the following solid content composition was applied to one surface of this film by a microgravure coating method at 4 g / m ² (we
The amount of t) was applied. After drying the coating film, it was stretched in the transverse direction by 3.6 times and heat-treated at 230 ° C. to obtain a biaxially stretched polyester film having a thickness of 100 μm. The characteristics of this film are shown in Table 1.

<Solid Content Composition of Aqueous Coating Liquid> (I) Polymer Antistatic Agent (A) 20% by Weight: Compound (II) Binder Resin (B) Having Repeating Unit of Structure Shown by Formula (3) 70% by weight: terephthalic acid (22 mol%), isophthalic acid (1 mol%),
2,6-naphthalenedicarboxylic acid (65 mol%),
4,4'-diphenyldicarboxylic acid (12 mol%),
Ethylene glycol (75 mol%), 1,4-cyclohexanedimethanol (10 mol%) and propylene oxide adduct of bisphenol A (15 mol%)
Copolymerized polyester (B-1, Tg: 80)
(° C, average molecular weight: 21,500) (III) Crosslinking agent (C) 5% by weight: Crosslinking agent represented by the following formula (4) (average molecular weight: 2000) (IV) Surfactant (D) 5% by weight: Polyoxyethylene nonyl phenyl ether

[0063]

[Chemical 7]

[0064]

[Chemical 8]

Example 2 Copolyester (B-
1), methyl methacrylate (30 mol%), ethyl acrylate (55 mol%), acrylonitrile (10
mol%) and N-methylol methacrylamide (5 m
ol%) to obtain an acrylic copolymer (B-
2. A biaxially stretched polyester film was obtained in exactly the same manner as in Example 1 except that the number average molecular weight was changed to 258,000. The characteristics of this film are shown in Table 1.

[Example 3] The solid content composition of the coating liquid was 30% by weight of the polymer antistatic agent (A) used in Example 1 and 30% by weight of the copolyester (B-1) used in Example 1. %,
From 30% by weight of the acrylic copolymer (B-2) used in Example 2, 5% by weight of the crosslinking agent (C) used in Example 1 and 5% by weight of the surfactant (D) used in Example 1 A biaxially stretched polyester film was obtained in exactly the same manner as in Example 1 except that the composition was changed. The characteristics of this film are shown in Table 1.

Example 4 Except that the polymer antistatic agent (A) used in Example 3 was changed from [CH ₃ SO ₃ ⁻ ] to [C ₂ H ₅ SO ₃ ⁻ ]. A biaxially stretched polyester film was obtained in the same manner. The characteristics of this film are shown in Table 1.

[Example 5] The solid content composition of the coating liquid was 7% by weight of the polymer antistatic agent (A) used in Example 1,
42% by weight of the copolymerized polyester (B-1) used in Example 4, 41% by weight of the acrylic copolymer (B-2) used in Example 2, 5% by weight of the crosslinking agent (C) used in Example 1 and A biaxially stretched polyester film was obtained in exactly the same manner as in Example 1 except that the composition used in Example 1 was changed to 5% by weight of the surfactant (D). The characteristics of this film are shown in Table 1.

[Example 6] The solid content composition of the coating liquid was 48% by weight of the polymer antistatic agent (A) used in Example 1 and 21% by weight of the copolyester (B-1) used in Example 1. %,
From 21% by weight of the acrylic copolymer (B-2) used in Example 2, 5% by weight of the crosslinking agent (C) used in Example 1, and 5% by weight of the surfactant (D) used in Example 1. A biaxially stretched polyester film was obtained in exactly the same manner as in Example 1 except that the composition was changed. The characteristics of this film are shown in Table 1.

Example 7 A biaxially stretched polyester film was obtained in the same manner as in Example 3 except that the polyethylene terephthalate film as the base film was changed to a polyethylene naphthalate film. The characteristics of this film are shown in Table 1.
Shown in.

[Example 8] The solid content composition of the coating liquid was 20% by weight of the polymer antistatic agent (A) used in Example 1 and 65% by weight of the copolyester (B-1) used in Example 1. %,
10% by weight of the cross-linking agent (C) used in Example 1 and Example 1
A biaxially stretched polyester film was obtained in exactly the same manner as in Example 1 except that the composition of the surfactant (D) used in 5 was changed to 5% by weight. The characteristics of this film are shown in Table 1.

[Comparative Example 1] The solid content composition of the coating liquid was 3% by weight of the polymer antistatic agent (A) used in Example 1, and the composition of Example 1 was used.
The composition was changed to 87% by weight of the copolyester (B-1) used in Example 1, 5% by weight of the crosslinking agent (C) used in Example 1 and 5% by weight of the surfactant (D) used in Example 1. A biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the above steps were performed. The characteristics of this film are shown in Table 1.

[Comparative Example 2] The solid content composition of the coating liquid was 25% by weight of sodium polystyrene sulfonate (antistatic agent (A)).
% By weight, the copolyester used in Example 1 (B-
1) Exactly the same as in Example 1 except that the composition was changed to 65% by weight, 5% by weight of the crosslinking agent (C) used in Example 1 and 5% by weight of the surfactant (D) used in Example 1 To obtain a biaxially stretched polyester film. The characteristics of this film are shown in Table 1.

[Comparative Example 3] The solid content composition of the coating liquid was changed to sodium dodecylbenzenesulfonate (antistatic agent (A)).
25% by weight of the copolymerized polyester (B
-1) Completely the same as Example 1 except that the composition was changed to 65% by weight, 5% by weight of the crosslinking agent (C) used in Example 1 and 5% by weight of the surfactant (D) used in Example 1 A biaxially stretched polyester film was obtained in the same manner. The characteristics of this film are shown in Table 1.

[Comparative Example 4] Table 1 shows the characteristics of the biaxially stretched polyester film obtained in Example 1 without coating the composition.

[Comparative Example 5] The solid content composition of the coating solution was 20% by weight of the polymer antistatic agent (A) used in Example 1 and 75% by weight of the copolyester (B-1) used in Example 1. % And the surfactant (D) used in Example 1 was changed to 5% by weight to obtain a biaxially stretched polyester film in exactly the same manner as in Example 1. The characteristics of this film are shown in Table 1.

[Comparative Example 6] The solid content composition of the coating liquid was 20% by weight of the polymer antistatic agent (A) used in Example 1 and 55% by weight of the copolyester (B-1) used in Example 1. %,
20% by weight of the crosslinking agent (C) used in Example 1 and Example 1
A biaxially stretched polyester film was obtained in exactly the same manner as in Example 1 except that the composition of the surfactant (D) used in 5 was changed to 5% by weight. The characteristics of this film are shown in Table 1.

[0078]

[Table 1]

[0079]

EFFECT OF THE INVENTION The polyester film for antistatic easy adhesion according to the present invention is superior in antistatic property under low humidity as compared with the conventional ones, and further has adhesiveness, blocking resistance, back surface transferability, and abrasion resistance. Thus, it is possible to provide a polyester film which is useful as a magnetic card film having excellent recoverability.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08J 7/04 C08L 1/00-101/16

Claims (8)

(57) [Claims] 1. An antistatic agent (A) containing 4 to 99% by weight of a repeating unit having a structure represented by the following formula (1) as a main component and a polyester resin (B-1) on at least one surface of an aromatic polyester film. ), An acrylic resin (B-2) and an acrylic modified polyester resin (B-3) at least one binder resin (B) 0 selected from the group consisting of
˜95% by weight, and a cross-linking agent (C) having a repeating unit of the structure represented by the following formula (2) as a main component, and a coating liquid containing a solid content composition of 1 to 15% by weight is applied, dried, and stretched. An antistatic polyester film, which is provided with an antistatic coating film prepared by [Chemical 1] [In the formula (1), R ¹ and R ² are each H or CH ₃ , R ³ ,
R ⁶ is an alkylene group having 2 to 10 carbon atoms, R ⁴ ,
R ⁵ is a saturated hydrocarbon group having 1 to 5 carbon atoms, n,
m is a number of 1 to 40, and Y ⁻ is a halogen ion, a mono- or poly-halogenated alkyl ion, a nitrate ion, a sulfate ion, an alkyl sulfate ion, a sulfonate ion or an alkyl sulfonate ion. ] [Chemical 2] [In the formula (2), R ⁷ and R ⁸ each represent H or CH ₃ . ] 2. The formula (1), wherein Y ⁻ is an alkyl sulfonate ion represented by R ⁹ SO ₃ ^— (wherein R ⁹ represents a saturated hydrocarbon group having 1 to 5 carbon atoms). 1. The antistatic polyester film as described in 1. 3. The antistatic polyester film according to claim 1, wherein R ³ in the formula (1) is an ethylene group. 4. The antistatic polyester film according to claim 1, wherein R ⁶ in the formula (1) is an ethylene group. 5. An antistatic agent (A) is a repeating unit having a structure represented by formula (1) (wherein R ¹ and R ² are H or CH ₃ , R ³ and R ⁶ are, respectively) Each is an ethylene group, R ⁴ and R ⁵ are each a saturated hydrocarbon group having 1 to 5 carbon atoms, n and m are each a number from 1 to 40, Y ⁻ is an alkyl sulfonate ion represented by R ⁹ SO ₃ ^— , R ⁹ represents a saturated hydrocarbon group having 1 to 5 carbon atoms) as a main component, and the binder resin (B) has a secondary transition point of 20 to 1
An acrylic resin of 00 ° C., the antistatic coating film is 10 to 80% by weight of the antistatic agent (A), the binder resin (B)
A solid content composition comprising 19 to 80% by weight, 1 to 10% by weight of a crosslinking agent (C) containing a repeating unit having a structure represented by the formula (2) as a main component, and 0 to 25% of a surfactant (D) is used. The surface energy of the antistatic coating film, which is provided by applying an aqueous coating solution containing the same, drying and stretching, has a surface energy of 37 to 73 dyne / c.
The antistatic polyester film according to claim 1, which is used for a magnetic card having m and a contact angle with water of 40 to 110 degrees. 6. The antistatic polyester film according to claim 1, wherein the polyester film is a white polyester film. 7. The antistatic polyester film according to claim 1, wherein the polyester film is a transparent polyester film. 8. A magnetic layer is laminated on the antistatic coating film,
The antistatic polyester film according to claim 6, wherein an ultraviolet curable ink layer is provided on the surface opposite to the magnetic layer.