JPH08157627A - Antistatic film - Google Patents

Abstract

PURPOSE: To prepare a film useful as a magnetic card, an electronic material, etc., having excellent antistatic properties (stability with time) and antistatic properties at low humidity, by providing a polyester film with an antistatic coating film prepared by coating the surface of the polyester film with an aqueous coating solution containing a specific antistatic agent, drying and drawing. CONSTITUTION: The surface of a polyester film such as a white or transparent polyester film is coated with an aqueous coating solution of an antistatic agent (A) containing a monomer (e.g. a compound of the formula) containing a cationic nitrogen in the molecule or a polymer containing a cationic nitrogen at the side chain and tin oxide. The film is dried and drawn to give the objective film provided with an antistatic coating film. The aqueous coating solution is a composition comprising 5-10wt.% of the component A and 0-95wt.% of an (acrylic modified) polyester resin or an acrylic resin as a binder resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an antistatic film,
More specifically, magnetic cards having excellent antistatic properties (eg telephone cards, prepaid cards), electronic materials, graphic materials, plate making films, OHP films, magnetic tapes (eg audio tapes, video tapes) and magnetic disks (eg floppy disks). The present invention relates to an antistatic film useful for magnetic recording materials such as

[0002]

Films made of polyester such as polyethylene terephthalate and polyethylene naphthalate are widely used for magnetic cards, general industrial materials such as packaging materials, photographic materials and graphic materials, and magnetic recording materials such as magnetic tapes. Has been done. However, such a polyester film has a drawback that it has a large surface resistivity and is easily charged by friction or the like. When the film is charged, dust or dirt is attached to the surface of the film, which causes troubles. In addition, electric discharge occurs in the processing step, and there is a risk of ignition if an organic solvent is used.

As one of the methods for preventing such troubles due to charging, various methods for forming an antistatic coating film on the film surface 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 are 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, a long-chain alkyl compound having a sulfonate group (Japanese Patent Laid-Open No. 4-
No. 28728) and the like, and surfactant type anionic antistatic agents are 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. 3-301). 255139, JP-A-4-28812.
No. 7, JP-A-6-172562), polystyrene sulfonate (JP-A-5-320390) and the like are known.

However, in an antistatic coating film using such a low molecular type antistatic agent, the antistatic agent moves in the coating film, accumulates at the interface, and migrates to the opposite surface of the film (hereinafter There is a problem of "back surface transferability") and a problem of deterioration of antistatic property (hereinafter sometimes referred to as "antistatic property") over time. On the other hand, in the case of antistatic coatings that use high-molecular type antistatic agents, in order to improve antistatic properties, a large amount of antistatic agents must be blended and thick antistatic coatings should be used. Since it is necessary to form it, it is not economical, and there is a problem that the antistatic property deteriorates under low humidity conditions.

[0006]

The object of the present invention is to solve the problems of the prior art and to exhibit a low surface resistivity even if the thickness of the antistatic coating film is thin. To provide.

[0007]

In order to achieve such an object, the present invention has the following constitution. On at least one side of the polyester film, a monomer (A-1) having a cationic nitrogen atom in the molecule and / or a polymer (A-2) having a cationic nitrogen atom in the side chain of the molecule and tin oxide (A-1). An antistatic film provided with an antistatic coating film prepared by applying an aqueous coating solution containing the antistatic agent (A) consisting of (3), drying and stretching.

The present invention will be described in detail below.

[Base Film] In the present invention, the base film is a polyester film, and the polyester constituting the film is a linear polyester composed of a dicarboxylic acid component and a glycol component.

Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, 4,4'-diphenyldicarboxylic acid, adipic acid, sebacic acid and dodecanedicarboxylic acid. Among them, terephthalic acid and 2,6-naphthalenedicarboxylic acid are particularly preferable because they have excellent mechanical properties and thermal properties of the polyester film.

Examples of the glycol component include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol. , Cyclohexanedimethanol, polyethylene glycol, polytetramethylene glycol and the like can be mentioned, and ethylene glycol is particularly preferable since the polyester film is excellent in mechanical properties and thermal properties.

As the polyester, polyethylene terephthalate or polyethylene-2,6-naphthalate can be preferably exemplified. The polyethylene terephthalate or polyethylene-2,6-naphthalate may be a polyester obtained by copolymerizing the above-mentioned dicarboxylic acid component or glycol component, and the polyester may be a polyfunctional carboxylic acid component having a functionality of 3 or more or a polyol component. It may be a polyester copolymerized in a small amount in a linear range (for example, 5 mol% or less). Such a polyester can be produced by a conventional method, and it is preferable that the average molecular weight is 10,000 or more because the mechanical properties of the film will be good.

The above polyester may contain organic or inorganic fine particles as a lubricant, for example, in an amount of 0.001 to 5% by weight in order to improve the slipperiness of the film. Specific examples of such fine particles include calcium carbonate, calcium oxide, amylnium oxide, titanium oxide, graphite, kaolin, silica, alumina,
Silicon oxide, zinc oxide, carbon black, silicon carbide, tin oxide, acrylic resin particles, crosslinked polystyrene resin particles,
Preferable examples are melamine resin particles and silicone resin particles.

In addition to the above-mentioned fine particles, a colorant, a known antistatic agent, antioxidant, organic lubricant, catalyst, fluorescent whitening agent, plasticizer, cross-linking agent, slip agent, ultraviolet absorber, other resin, etc. are required. Can be added according to

As the base film in the present invention, a transparent polyester film or a white polyester film can be used depending on the use of the antistatic film. This transparent polyester film has a light transmittance of 60% or more after stretching, and particularly preferably 80% or more. The white polyester film is a polyester blended with, for example, titanium oxide, barium sulfate, or silicon oxide in an amount of 5 to 30% by weight, and has a light transmittance after stretching of less than 60%, particularly 30% or less. Those are preferable. A white antistatic film using a white polyester film as a base film is particularly preferably used for a magnetic card.

The polyester film of the present invention is
It can be manufactured by a conventionally known method. For example, it can be produced by melting the polyester and casting it on a cooling drum to obtain an unstretched film, and then stretching the unstretched film in the machine direction and then in the transverse direction. Further, it can be stretched again in the machine direction and / or the transverse direction. The stretching treatment is performed by the second-order transition point (T
g) It is preferable to carry out stretching at a temperature higher than 2) in each direction by a factor of 2 or more, more preferably 3 or more. At that time, the area stretching ratio is preferably 8 times or more, and more preferably 9 times or more. The upper limit of the area draw ratio depends on the use of the film, but is preferably 35 times, further preferably 30 times. The oriented crystallization can be completed by heat treatment after stretching.

[Antistatic Agent (A)] In the present invention, the antistatic coating film comprises a monomer (A-) having a cationic nitrogen atom in its molecule on at least one surface of the polyester film.
1) and / or an aqueous coating liquid containing a polymer (A-2) having a cationic nitrogen atom in the side chain of the molecule and an antistatic agent (A) consisting of tin oxide (A-3) is applied, and dried, It is made by stretching.

[Monomer having a cationic nitrogen atom in the molecule (A-1)] A monomer (A-1) having a cationic nitrogen atom in the molecule (hereinafter referred to as "monomer (A-2 ) ”) Is a compound represented by the following (formula I).

[0019]

Embedded image

In formula (I), R ¹ , R ² , R ³ and R ⁴ are hydrogen elements, an alkyl group having 1 to 40 carbon atoms, an aryl group, an alkenyl group, a hydroxyalkyl group represented by HOR ^5- , or R A group represented by ¹ COOR ⁵ — (R ⁵ is an alkylene group having 1 to 10 carbon atoms or a divalent polyoxyalkylene group (preferred repeating units 2 to 50));
X is an ion having a sulfonate group (R ⁶ SO ₃ ^-),
Ion having a sulfate group (R ⁶ OSO ₃ ⁻ ), ion having a carboxylate group (R ⁶ COO ⁻ ), nitrate ion (NO ₃ ⁻ ), halogen ion (Cl
^{-, Br -, I -)} (R 6 represents an alkyl group having 1 to 30 carbon atoms, an aryl group, an aralkyl group). Examples of such compounds are shown below.

[0021]

Embedded image

[Polymer having cationic nitrogen atom in side chain (A-2)] Polymer (A-2) having cationic nitrogen atom in side chain of molecule (hereinafter referred to as "polymer (A-2)" )
Is a polymer represented by the following general formula (formula II).
Such a polymer can be obtained, for example, by polymerizing a compound represented by the following formula (III) having an unsaturated double bond and a cationic nitrogen atom in the molecule.

[0023]

Embedded image

R in the formulas (II) and (III)⁷Is -R
^Five-,-OR^Five-, -C (= O) R^Five-Or-COO
R^Five-(R^FiveIs an alkylene group having 1 to 10 carbon atoms or
Divalent polyoxyalkylene group); R⁸, R⁹And R
^TenIs a hydrogen element, an alkyl group having 1 to 40 carbon atoms, and aryl
Group, alkenyl group, HOR^FiveHydroxy represented by
Alkyl group or R¹COOR^FiveA group represented by-; X is
Ions having a sulfonate group (R⁶SO₃ ^-),monkey
Ions having a phosphate group (R⁶OSO₃ ^-), Carbo
Ions having a xylate group (R⁶COO^-), Night
Rate ion (NO ₃ ^-), Halogen ions (Cl^-,
Br^-, I^-) Etc .; Y and Z are -H, -R ¹¹H, -R
¹¹X, -R¹¹OH, -OH, -X, -COOH, -R¹¹
COOH (R ¹¹Is an alkylene group having 1 to 6 carbon atoms)
It is a group shown. In addition, n is an integer of 2 to 300
It Examples of such compounds include the following compounds.
Can be

[0025]

[Chemical 4]

In the polymer (A-2), a compound having an unsaturated double bond in the molecule and having no cationic nitrogen atom (hereinafter referred to as "other component") has a copolymerization ratio of 0 to 8.
It can be used as a copolymerization component in the range of 0 mol%. Other components include, for example, ethyl acrylate,
Methyl acrylate, acrylic acid, butyl acrylate, sodium acrylate, ammonium acrylate, ethyl methacrylate, methyl methacrylate, methacrylic acid, butyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, acrylamide, methacrylamide, N -Methoxymethylacrylamide, N-methylolacrylamide, styrene, α-methylstyrene,
Examples thereof include vinyl chloride, vinylidene chloride, vinyl acetate, vinyl ether, sodium methacrylic acid and the like.

The average molecular weight of the polymer (A-2) is arbitrary, but it is preferably 1,000 to 500,000. If the average molecular weight is less than 1,000, the back surface transferability of the polymer (A-2) becomes poor, which is not preferable. On the other hand, if the average molecular weight exceeds 500,000, the viscosity of the aqueous coating solution becomes so high that it becomes difficult to uniformly coat the film, which is not preferable.

[Tin oxide (A-3)] This tin oxide (A-
3) may be tin oxide alone, but other oxides (for example, antimony oxide, titanium oxide, yttrium oxide,
It may be a mixture with cerium oxide or the like). Particularly, those doped with antimony metal, antimony oxide or the like are preferable because they have excellent antistatic property. Such tin oxide (A
-3) has an average particle size of 1 to 300 nm, particularly 1 to 30 nm
Is preferable because the antistatic property improving effect is excellent.

In the present invention, tin oxide (A-) accounts for the total weight of the monomer (A-1) and / or polymer (A-2) and tin oxide (A-3) in the antistatic coating. The proportion of 3) is preferably 5 to 95% by weight, particularly preferably 20 to 80% by weight. If this ratio is less than 5% by weight, the antistatic property at low humidity is insufficient, which is not preferable. On the other hand, if the proportion is 95% by weight or more, the surface specific resistance of the antistatic film becomes insufficient, and the antistatic coating becomes too hard and the coating becomes liable to crack, which is not preferable.

[Binder Resin] The antistatic coating film of the present invention comprises an antistatic agent (A) and a binder resin (B) in order to strengthen the adhesion between the coating film and the base film. It is preferred that a composition be included. As the binder resin, polyester resin (B-
1), acrylic resin (B-2), and acrylic modified polyester resin (B-3) can be exemplified, and it is preferable to use one or more resins selected from these resins. In particular, 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 base film is improved, and the polyester resin (B-1) and the acrylic resin are used. It is preferable to use (B-2) because the adhesiveness is good and coloring of the regenerated film can be suppressed when the antistatic film is collected and reused.
The polyester resin (B-1) ratio at this time is preferably higher than the acrylic resin (B-2) ratio.

[Polyester Resin (B-1)] 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, naphthalenedicarboxylic acid, 4,4 '
-Diphenyldicarboxylic acid, adipic acid, sebacic acid,
Preferable examples include dodecanedicarboxylic acid and hexahydroterephthalic acid.

As the glycol component, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, diglycol Preferable examples include propylene glycol, triethylene glycol, bisphenol A-alkylene oxide adduct, hydrogenated bisphenol A-alkylene oxide adduct, 1,4-cyclohexanedimethanol, polyethylene glycol, and polytetramethylene glycol.

The polyester resin (B-1) is preferably copolymerized with a component having a sulfonate group in order to impart hydrophilicity. It is preferable to impart hydrophilicity to the polyester resin (B-1) because the dispersibility in the aqueous coating liquid becomes good. Examples of such components include 5-Na
Examples thereof include sulfoisophthalic acid and 5-K sulfoisophthalic acid.

The polyester resin (B-1) is a small amount (for example, 5 mol% or less) of the trifunctional or higher polyvalent carboxylic acid component and the polyol component as long as it becomes a substantially linear polymer.
It may be a copolymer. Such trifunctional or higher polycarboxylic acid, as the polyol, trimellitic acid,
Pyromellitic acid, dimethylolpropionic acid, glycerin, trimethylolpropane and the like can be exemplified.

[Acrylic Resin (B-2)] The acrylic resin (B-2) is, for example, ethyl acrylate, methyl acrylate, acrylic acid, butyl acrylate, sodium acrylate, ammonium acrylate, ethyl methacrylate, methacryl. Methyl acid, methacrylic acid, butyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, acrylamide, methacrylamide, N-
It is a polymer or copolymer mainly composed of an acrylic monomer such as methoxymethylacrylamide, N-methylolacrylamide, etc., and is styrene, α-methylstyrene, sodium styrenesulfonate, vinyl chloride, vinylidene chloride, acetic acid. It may be a copolymer containing vinyl, vinyl ether, sodium vinyl sulfonate, sodium methacrylic acid, etc. as a copolymerization component.

[Acrylic modified polyester resin (B-
3)] The acrylic modified polyester resin (B-3) is ethyl acrylate, methyl acrylate, acrylic acid, butyl acrylate, sodium acrylate, ammonium acrylate, ethyl methacrylate, methacrylic acid in the presence of the polyester resin. Made by polymerizing acrylic monomers such as methyl, methacrylic acid, butyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, acrylamide, methacrylamide, N-methoxymethyl acrylamide, and N-methylol acrylamide. Copolymer, styrene, α-methylstyrene, sodium styrene sulfonate, vinyl chloride,
It may contain a monomer such as vinylidene chloride, vinyl acetate, vinyl ether, sodium vinyl sulfonate, sodium methallylate as a copolymerization component.

[Other Binder Resins] The antistatic coating film may contain a binder resin other than the above in order to adjust the adhesion between the coating film and the base film. Examples of such resins include polyurethane resins and epoxy resins. Examples thereof include resins, vinyl resins, polyether resins, water-soluble resins and the like.

[Antistatic Coating] The antistatic coating in the present invention is a coating containing the above-mentioned antistatic agent (A), but a coating comprising a composition further containing a binder resin (B). Is preferred. The proportion of the antistatic agent (A) contained in the antistatic coating film is preferably 5% by weight or more, and more preferably 10% by weight or more in order to improve the antistatic property. The proportion of antistatic agent (A) is 5% by weight
If it is less than this, the antistatic property is insufficient.

[Aqueous Coating Liquid] In the present invention, an antistatic coating film is applied using an aqueous coating liquid containing the antistatic agent (A). A lubricant may be added in order to improve the surface slipperiness and the blocking resistance of the film. Examples of such lubricants include polystyrene resin, acrylic resin, melamine resin, silicone resin, fluororesin, urea resin,
Examples thereof include fine particles of benzoguanamine 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 antistatic coating in the form of fine particles.

In the aqueous coating liquid, as other components, a surfactant, an antioxidant, an antistatic agent other than the antistatic agent (A), a colorant, a pigment, an optical brightening agent, a plasticizer, a cross-linking agent, A slip agent (a slipperiness-imparting agent such as wax) and an ultraviolet absorber can be added.

The solid content concentration of the aqueous coating solution is 1 to 30% by weight.
Is preferable, and 2 to 20% by weight is particularly preferable. When the solid content concentration is within this range, the viscosity of the aqueous coating liquid becomes suitable for coating. The aqueous coating solution used in the present invention can be used in any form such as an aqueous solution, an aqueous dispersion, and an emulsion. Also,
The aqueous coating liquid may contain a small amount of solvent.

[Coating of antistatic coating film] In the present invention,
At least one surface of the polyester film is coated with the water-based coating solution, dried by heating, and stretched to apply an antistatic coating film.As a method for applying the water-based coating solution, any known coating method is applied. For example, gravure coating method, reverse roll coating method, die coating method, kiss coating method, reverse kiss coating method, offset gravure coating method, Meyer bar coating method, roll brush method, spray coating method, air knife coating method, impregnation method, curtain The coating method and the like can be applied alone or in combination. WET coating amount of the aqueous coating liquid is the running film 1
1 to ²⁰ g, particularly ^{2 to} 12 g per m ² is preferable. When the coating amount is in this range, drying is easy and coating spots are less likely to occur, which is preferable.

The polyester film to which the aqueous coating solution is applied in the present invention is a stretchable polyester film, for example, an unstretched film obtained by heat-melting polyester to form a film as it is; the unstretched film in the longitudinal direction (longitudinal direction). ) Or a uniaxially-stretched film stretched in either the transverse direction (width direction); a biaxially-stretched film obtained by sequentially stretching a uniaxially stretched film in the machine direction or in the transverse direction or in the transverse direction (further stretchable). Or a biaxially stretched film obtained by simultaneously stretching the unstretched film in the machine direction and the transverse direction (further stretchable); heat fixing and / or heat relaxation of the biaxially stretched film (further stretchable) A biaxially stretched heat-treated film may be mentioned. The thickness of the polyester film after the stretching is 1
˜300 μm is preferred.

When the aqueous coating solution is applied to a uniaxially stretched film of the above-mentioned stretchable polyester film, particularly a uniaxially stretched film in the longitudinal direction, the adhesion of the antistatic coating becomes strong and the coating efficiency is high. This is preferable because an antistatic film can be produced. For example, polyester is heat-melted, extruded into a sheet and cooled to obtain an unstretched film, and the unstretched film is stretched in the machine direction to form a uniaxially stretched film, and then an aqueous coating solution is applied and dried to obtain a transverse direction. The film is stretched, and if necessary, re-stretched in the longitudinal and transverse directions and then heat-treated to prepare an antistatic film coated with an antistatic coating.

In the present invention, it is preferable that the temperature for drying after applying the aqueous coating liquid is 80 to 160 ° C. because the coating liquid can be dried quickly. The heating for this drying can also serve as the heating during the process of stretching the polyester film. The temperature for heat-treating the polyester film may be 180 to 250 ° C.

The thickness of the applied antistatic coating film is 0.005 to 0.005.
3 μm, particularly 0.015 to 1 μm is preferable. If the thickness of the coating film is less than 0.005 μm, the antistatic property may be insufficient, and if it exceeds 1 μm, the coating film may be easily scraped, which is not preferable.

[Antistatic Film] The surface resistivity of the antistatic film of the present invention is preferably 1 × 10 ⁸ to 1 × 10 ¹³ Ω, and particularly 1 × 10 ⁹ to 1 × 10 ¹² Ω. Preferably there is.

The antistatic film of the present invention is
A transparent antistatic film with a light transmittance of about 60% or more,
It may be a white antistatic film having a light transmittance of less than about 60%. A polyester film having a light transmittance after stretching of 60% or more is used for the base film of the transparent antistatic film, and a light transmittance after stretching is less than 60% for the base film of the white antistatic film. It is preferable to use 30% or less of white polyester film. The light transmittance of the antistatic film coated with the antistatic coating is 0.005 to 3 μm for the thickness of the antistatic coating, and the antistatic coating contains a coloring agent or a pigment. The light transmittance of the base film is almost the same as that of the base film when it is not blended at a concentration.

A white antistatic film using a white polyester film as a base film is particularly preferably used for a magnetic card. The magnetic card here is
For example, it is a card in which a magnetic recording layer is provided on one surface of an antistatic film and a pattern layer or the like is printed on the other surface by UV ink or the like, and the thickness of the film is, for example, 100 to 30.
Those having a thickness of 0 μm, particularly 150 to 250 μm are preferably used.

A transparent antistatic film using a transparent polyester film as a base film is preferably used for magnetic recording materials such as magnetic tapes and magnetic disks and electronic materials, graphic films, plate-making films and OHP films. Although the thickness varies depending on the application, for example, a thickness of 15 to 160 μm, particularly 25 to 100 μm is preferably used.

[0052]

EXAMPLES The present invention will be described in more detail with reference to examples. Each characteristic value was measured by the following method. The average molecular weight in the examples means the number average molecular weight.

1. Surface resistivity After leaving the sample film at 21 ° C. × 52% RH for 19 hours, the surface resistivity of the film coated surface was measured using a vibration capacitance type potentiometer TR-84M type (manufactured by Takeda Riken). The applied voltage was 100 Volt.

Separately, a sample film is separately prepared at 24 ° C. × 2.
After standing at 8% RH for 6 hours, the surface resistivity was measured by the same method.

[Example 1] Polyethylene terephthalate having an intrinsic viscosity of 0.62 was melted, cast on a cooling drum, and then stretched 3.4 times in the machine direction at 89 ° C to obtain a uniaxially stretched film. On one side of this uniaxially stretched film,
[CH ₂ = CHCOO (CH ₂ ) ₃ N ⁺ (CH ₃ ) ₃ ]
^{_{[CH 3 NO 3 -] (}} 32 mol%), methyl methacrylate (32 mole%) and butyl acrylate (36 mole%)
A copolymer (a-1: average molecular weight:
9,600) 23% by weight, antimony-doped tin oxide (a
-2) 42% by weight, dicarboxylic acid component terephthalic acid (36 mol%) and isophthalic acid (64 mol%), glycol component ethylene glycol (69 mol%), diethylene glycol (13 mol%) and polyethylene glycol ( 20% by weight of a polyester resin (b-1) which is a copolymer (average molecular weight: 18,600) of an average molecular weight: 3,400 (18 mol%) and polyoxyethylene nonylphenyl ether (c-1: Average molecular weight: 85
0) A 4% by weight aqueous solution of a composition consisting of 15% by weight was applied with a gravure coater. Next, apply the coating film at 98 ° C.
And then stretched 3.8 times in the transverse direction at 109 ° C to give 215
A film having a thickness of 74 μm coated with an antistatic coating was prepared by heat treatment at ℃. The thickness of the antistatic coating film is 0.
The light transmittance was 18 μm and the light transmittance was 85%. The characteristics of this film are shown in Table 1.

[Comparative Example 1] Table 1 shows the characteristics of the film obtained in the same manner as in Example 1 except that the aqueous liquid was not applied.

[Examples 2 to 7 and Comparative Examples 2 and 3] The characteristics of the film obtained in the same manner as in Example 1 are shown, except that the composition and coating thickness of the coating liquid are changed as shown in Table 1. Shown in 1.

Example 8 Polyethylene terephthalate containing 13% by weight of titanium oxide and having an intrinsic viscosity of 0.63 was used as a base film, and the composition of the coating liquid and the coating thickness were changed as shown in Table 1. Table 1 shows the characteristics of the film having a light transmittance of 2% obtained in the same manner as in Example 1 except for the above.

[0059]

[Table 1]

In the antistatic coating composition of Table 1, antistatic agents [a-1], [a-2], [a-3], binder resins [b-1], [a-2], [a]. -3] and the other component [c-1] are the following copolymers, compounds or mixtures, respectively.

[0061]

Embedded image [a-1]: [CH 2 = CHCOO (CH 2)
^{_{3 N + (CH 3) 3}} ] [CH 3 NO 3 -] (32 mol%), methyl methacrylate (32 mole%) and the copolymer obtained by polymerizing butyl acrylate (36 mole%) ( a-1: average molecular weight: 9,600) [a-2] : antimony-doped tin oxide [a-3]: [C 18 H 37 -N + (CH 3) 3] [CH 3
OSO ₃ ^-]

[0062]

Embedded image [b-1]: terephthalic acid (36 mol%) and isophthalic acid (64 mol%) as dicarboxylic acid component, ethylene glycol (69 mol%), diethylene glycol (13 mol%) and polyethylene glycol as glycol component (Average molecular weight: 3,400) (18 mol%) copolymer (average molecular weight: 18,600) [b-2]: [b-1] polyester resin (55% by weight) and ethyl acrylate (14 Mol%), sodium acrylate (2 mol%), ethyl methacrylate (60 mol%), glycidyl acrylate (8 mol%), 2-hydroxyethyl acrylate (14 mol%) and N-methoxymethyl acrylamide (2 mol%). %) Of the copolymer (average molecular weight: 56,000) (45% by weight) obtained by polymerizing [b-3]: [b-1] Riesuteru resin (51 wt%) with respect to methyl acrylate (6 mol%), ammonium acrylate (2 mole%), ethyl methacrylate (7
2 mol%), glycidyl methacrylate (11 mol%) and 2-hydroxyethyl methacrylate (9 mol%)
A copolymer obtained by graft polymerization of (49% by weight).
(Average molecular weight: 39,000) [c-1]: Polyoxyethylene nonylphenyl ether (average molecular weight: 850)

[0063]

Since the antistatic film of the present invention uses an antistatic agent having a specific structure, a high antistatic property can be obtained even with a relatively thin antistatic coating film, and magnetic cards, packaging materials and photographic materials can be obtained. It is useful for graphic materials, plate-making films, OHP films, magnetic recording media and the like.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical indication location B05D 7/24 303 C 7415-4F E 7415-4F B32B 27/18 D 9349-4F 27/36 9349-4F G11B 5/704

Claims (4)

[Claims] 1. A monomer (A-) having a cationic nitrogen atom in its molecule on at least one surface of a polyester film.
1) and / or an aqueous coating liquid containing a polymer (A-2) having a cationic nitrogen atom in the side chain of the molecule and an antistatic agent (A) consisting of tin oxide (A-3) is applied, and dried, An antistatic film provided with an antistatic coating film formed by stretching. 2. An antistatic agent (A) 5-10 is used as the aqueous coating liquid.
0% by weight of polyester resin (B-1), acrylic resin (B-2) and acrylic modified polyester resin (B
The antistatic film according to claim 1, which is an aqueous coating solution containing a composition comprising 0 to 95% by weight of at least one binder resin (B) selected from the group consisting of (3). 3. The antistatic film according to claim 1, wherein the polyester film is a white polyester film and is used for a magnetic card. 4. The antistatic film according to claim 1, wherein the polyester film is a transparent polyester film.