JP3068421B2 - Antistatic 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 film,
More specifically, a magnetic card (for example, a telephone card, a prepaid card), a magnetic tape (for example, an audio tape or a video tape), a magnetic disk (for example, a floppy disk), etc., having excellent antistatic properties and improved back transferability of the antistatic agent. And antistatic films useful for magnetic recording materials, electronic materials, graphic materials, plate making films, OHP films and the like.

[0002]

2. Description of the Related Art Polyester films such as polyethylene terephthalate and polyethylene naphthalate are widely used for magnetic recording materials such as magnetic cards and magnetic tapes and for general industrial materials such as packaging materials, photographic materials and graphic materials. ing. However, such polyester films have the drawback that they have high surface resistivity and are easily charged by friction or the like. When the film is charged, dirt and dust adhere to the film surface, causing troubles. Further, electric discharge occurs in the processing step, and there is a danger of ignition when 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 a 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 type are known, but each has a short and a long. Therefore, antistatic agents are used for different purposes according to the application.

For example, as a low molecular weight antistatic agent, a long chain alkyl compound having a sulfonate group (Japanese Unexamined Patent Publication No.
Surfactant type anionic antistatic agents such as No. 28728) are known, and as a high molecular type antistatic agent, a polymer having an ionized nitrogen element in the main chain (Japanese Patent Laid-Open Publication No. 255139, JP-A-4-28812
No. 7, JP-A-6-172562) and polystyrene sulfonate (JP-A-5-320390) are known.

However, in such an antistatic coating film using a low molecular weight antistatic agent, the antistatic agent moves in the coating film, accumulates at the interface, and migrates to the opposite surface of the film (hereinafter referred to as the film). There is a problem that "backside transferability" may occur) and that the antistatic property (hereinafter sometimes referred to as "antistatic property") deteriorates with time. On the other hand, in the case of an antistatic coating using a polymer type antistatic agent, a large amount of an antistatic agent may be added to improve antistatic properties, or a thick antistatic coating may be used. There is a problem that it is not economical because it needs to be formed, and the antistatic property is reduced under low humidity conditions.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an antistatic film having improved antistatic properties and backside transfer properties.

[0007]

The present invention has the following structure to achieve the above object. An aqueous coating solution containing an antistatic agent (A) composed of a polymer having a phosphate ester group and a sulfonate group in the molecule is applied to at least one surface of the polyester film, and dried and stretched. Antistatic film provided with a coating film.

Hereinafter, the present invention will be described in detail.

[Base Film] In the present invention, the base film is a polyester film, and the polyester constituting the film is a linear polyester comprising 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 of 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, and 1,6-hexanediol. , Cyclohexane dimethanol, polyethylene glycol, polytetramethylene glycol, etc., and ethylene glycol is particularly preferred because the polyester film has excellent mechanical properties and thermal properties.

Preferred examples of the polyester include polyethylene terephthalate and polyethylene-2,6-naphthalate. The polyethylene terephthalate or polyethylene-2,6-naphthalate may be a polyester obtained by copolymerizing the above dicarboxylic acid component or glycol component, and the polyester substantially comprises a trifunctional or higher polyvalent carboxylic acid component or a polyol component. A polyester copolymerized in a small amount within a linear range (for example, 5 mol% or less) may be used. 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 become good.

The above-mentioned polyester may contain, for example, 0.001 to 5% by weight of organic or inorganic fine particles as a lubricant 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, cross-linked polystyrene resin particles,
Melamine resin particles, silicone resin particles and the like can be preferably mentioned.

In addition to the fine particles, a coloring agent, a known antistatic agent, an antioxidant, an organic lubricant, a catalyst, a fluorescent brightener, a plasticizer, a crosslinking agent, a slipping agent, an ultraviolet absorber, and other resins are required. It can be added according to.

The thickness of the polyester film is preferably 1 to 300 μm after stretching. Depending on the use of the antistatic film, a transparent polyester film or a white polyester film can be used as the base film. When a transparent polyester film is used, a light transmittance of 60% or more is preferable, and a white polyester film is used. In this case, for example, a material having a light transmittance of less than 60% containing 5 to 30% by weight of titanium oxide, barium sulfate or silicon oxide is 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 used in the present invention comprises:
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 form 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 at the secondary transition point (T
g) Preferably, the stretching is performed at a higher temperature by stretching at least twice, and more preferably at least three times in each direction. At this time, the area stretching ratio is preferably 8 times or more, more preferably 9 times or more. The upper limit of the area stretching ratio depends on the use of the film, but is preferably 35 times, and more preferably 30 times. After the stretching, heat treatment may be performed to complete the oriented crystallization.

[Antistatic Agent] In the present invention, the antistatic coating film comprises, on at least one surface of the polyester film, an antistatic agent (A) comprising a polymer having a phosphate ester group and a sulfonate group in the molecule. Hereinafter, it may be referred to as “antistatic agent (A)”), and then dried and stretched. This antistatic agent (A)
Is obtained, for example, using a compound having an unsaturated double bond and a phosphate ester group in a molecule of 2 mol% or more and a compound having an unsaturated double bond and a sulfonate group in a molecule of 2 mol% or more. It is a copolymer. Incidentally, the antistatic agent (A) may be a copolymer obtained by using a compound having an unsaturated double bond, a phosphate ester group and a sulfonate group in a molecule of 4 mol% or more.

Examples of the compound having an unsaturated double bond and a phosphate base in the molecule include the following compounds.

[0019]

CH ₂ 2CHCOOROP (＝ O) (OM) ₂ CH ₂ ＣＨCH (CH ₃ ) OROP (＝ O) (OM) ₂ [where R is a divalent organic group and M is a monovalent metal Element, ammonium group, primary to quaternary ammonium group]

The compound having an unsaturated double bond and a sulfonate group in the molecule includes, for example, the following compounds.

[0021]

Embedded image CH ₂ ＣＨCHSO ₃ M CH ₂ ＣC (CH ₃ ) SO ₃ M CH ₂ ＣＨCHC ₆ H ₄ SO ₃ M CH ₂ ＣC (CH ₃ ) C ₆ H ₄ SO ₃ M CH ₂ ＣＨCHCOO (CH ₂ CH ₂ O) ₁₀ RSO ₃ M [where R represents a divalent organic group, M represents a monovalent metal element, an ammonium group, and a primary to quaternary ammonium group]

The above-mentioned divalent organic group includes, for example, -CH
_{2 CH 2 -, - CH 2} CH 2 CH 2 -, - C 6 H 4 -
(O-phenylene group, m-phenylene group, p-phenylene group) and the like. Examples of the monovalent metal element include Na, K and Li. Also,
NH ₄ and an ammonium group, and primary to quaternary ammonium group ^{_{NH 3 R 2 1, NH 2}} R 2 2, NH 1 R 2 3,
NR ² ₄ (R ² is an alkyl group having 1 to 4 carbon atoms: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s- butyl, t- butyl group) is that of.

The antistatic agent (A) is copolymerized with a compound other than the above compound having a phosphate ester group and / or a sulfonate group in the molecule (hereinafter sometimes referred to as “other components”). When the proportion is in the range of 0 to 80 mol%, it can be used as a copolymer component. 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, -Hydroxyethyl acrylate, acrylamide, methacrylamide, N-methoxymethylacrylamide, N-methylolacrylamide, styrene, α-methylstyrene, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl ether, sodium methacrylate and the like.

The average molecular weight of the antistatic agent (A) is optional, but is preferably from 1,000 to 500,000. If the average molecular weight is less than 1,000, the back transferability of the antistatic agent (A) 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 too high, which makes it difficult to apply the solution uniformly to the polyester film.

[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. Preferably, a composition is included. As the binder resin, a polyester resin (B-
1), an acrylic resin (B-2), and an acrylic-modified polyester resin (B-3). One or more, more preferably two or more resins selected from these resins are preferably used. It is preferable to use a polyester resin (B-1) and an acrylic resin (B-2).

[Polyester Resin (B-1)] The polyester resin (B-1) is a linear polyester having a dicarboxylic acid component and a glycol component as constituents.

The dicarboxylic acid component includes terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4 '
-Diphenyldicarboxylic acid, adipic acid, sebacic acid,
Preferred examples include dodecanedicarboxylic acid and hexahydroterephthalic acid.

The glycol components include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, Preferred examples include propylene glycol, triethylene glycol, bisphenol A-alkylene oxide adduct, hydrogenated bisphenol A-alkylene oxide adduct, 1,4-cyclohexanedimethanol, polyethylene glycol, polytetramethylene glycol and the like.

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. Such components include, for example, 5-Na
Sulfoisophthalic acid, 5-K sulfoisophthalic acid and the like can be mentioned.

The polyester resin (B-1) contains a tri- or higher functional polycarboxylic acid component and a polyol component in a small amount (for example, 5 mol% or less) as long as the polymer becomes a substantially linear polymer.
It may be copolymerized. Such trifunctional or more polyvalent carboxylic acid, as a polyol, trimellitic acid,
Examples thereof include pyromellitic acid, dimethylolpropionic acid, glycerin, and trimethylolpropane.

[Acrylic resin (B-2)] Examples of the acrylic resin (B-2) include ethyl acrylate, methyl acrylate, acrylic acid, butyl acrylate, sodium acrylate, ammonium acrylate, ethyl methacrylate, and methacryl. Methyl methacrylate, methacrylic acid, butyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, acrylamide, methacrylamide, N-
It is a polymer or copolymer mainly composed of an acrylic monomer represented by methoxymethyl acrylamide, N-methylol acrylamide, etc., styrene, α-methylstyrene, sodium styrene sulfonate, vinyl chloride, vinylidene chloride, acetic acid It may be a copolymer containing vinyl, vinyl ether, sodium vinyl sulfonate, sodium methacrylate or the like as a copolymer component.

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

[Other Binder Resins] Examples of other binder resins include polyurethane resins, epoxy resins, vinyl resins, polyether resins, and water-soluble resins.

[Antistatic coating film] The antistatic coating film of the present invention is a coating film containing the above-mentioned antistatic agent (A), but further comprising a composition containing a binder resin (B). It is preferred that The ratio 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. 5% by weight of antistatic agent (A)
If it is less than this, the antistatic property is insufficient.

[Aqueous Coating Solution] In the present invention, an antistatic coating is applied using an aqueous coating solution containing the antistatic agent (A). A lubricant can be added to improve the surface slipperiness and improve the blocking resistance of the film. As such a lubricant, for example, polystyrene resin, acrylic resin, melamine resin, silicone resin, fluororesin, urea resin,
Examples include fine particles of a benzoguanamine resin, a polyamide resin, a 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 film in the form of fine particles.

The aqueous coating liquid further contains, as other components, a surfactant, an antioxidant, an antistatic agent other than the antistatic agent (A), a coloring agent, a pigment, a fluorescent brightener, a plasticizer, a crosslinking agent, A slipping agent (slipperiness imparting agent such as wax), an ultraviolet absorber and the like can be blended.

The solid content concentration of the aqueous coating solution is 1 to 30% by weight.
, And particularly preferably 2 to 20% by weight. When the solid content concentration is within this range, the viscosity of the aqueous coating liquid becomes suitable for coating. The aqueous coating liquid 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 a solvent.

[Coating of antistatic coating film] In the present invention,
On at least one side of the polyester film, the aqueous coating liquid is applied, and the antistatic coating is applied by heating, drying, and stretching.As a method of applying the aqueous coating liquid, any known coating method can be used. 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 brushing method, spray coating method, air knife coating method, impregnation method, curtain The coating method or the like can be applied alone or in combination. The amount of WET of the aqueous coating liquid is the running film 1.
The amount is preferably 1 to 20 g, particularly preferably ^{2 to} 12 g per m ² . It is preferable that the coating amount is in this range because drying becomes easy and coating unevenness hardly occurs.

The polyester film to which the aqueous coating liquid is applied in the present invention is a stretchable polyester film, for example, an unstretched film obtained by melting a polyester by hot melting and forming the film as it is; ) Or a uniaxially stretched film stretched in either the transverse direction (width direction); a biaxially stretched film in which a longitudinally or transversely uniaxially stretched film is sequentially stretched in the transverse or longitudinal direction (more stretchable). Or a biaxially stretched film in which an unstretched film is simultaneously stretched in two directions (longitudinal and transverse) (further stretchable); a biaxially stretched film is heat-set and / or thermally relaxed (further stretchable) A biaxially stretched heat treatment film can be used.

The thickness of the polyester film is preferably 10 to 1000 μm for an unstretched film, 2 to 500 μm for a uniaxially stretched film, and 1 to 300 μm for a biaxially stretched film and a biaxially stretched heat-treated film.

When the aqueous coating solution is applied to a uniaxially stretched film, particularly a longitudinally uniaxially stretched film, of the polyester film, the adhesion of the antistatic film becomes strong, and the antistatic film is efficiently formed. This is preferable because a film can be manufactured. For example, the polyester is hot-melted, extruded into a sheet and cooled to form an unstretched film, and the unstretched film is stretched in the longitudinal direction to form a uniaxially stretched film. Then, if necessary, the film is further stretched in the vertical and horizontal directions and then heat-treated to produce an antistatic film coated with an antistatic coating.

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

[Drying and Stretching Conditions] After the aqueous coating solution is applied in the present invention, the drying temperature is preferably from 80 to 150 ° C., since the coating solution can be dried quickly. The heating for drying can also serve as the heating in the process of stretching the polyester film. The heat treatment temperature of the polyester film can be set to 180 to 250 ° C.

[Antistatic Film] The antistatic film of the present invention may be a transparent antistatic film having a light transmittance of 60% or more or a white antistatic film having a light transmittance of less than 60% depending on the use. It can be. A polyester film having a light transmittance of 60% or more is used for a transparent antistatic film base film, and a white polyester having a light transmittance of less than 60%, particularly 30% or less for a white antistatic film base film. It is preferable to use a film.

A white antistatic film using a white polyester film as a base film is particularly preferably used for a magnetic card. In addition, the magnetic card mentioned here is
For example, a card in which a magnetic recording layer is provided on one side of an antistatic film and a picture layer or the like is printed on the other side with 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 180 to 250 μm are preferably used.

[0046]

The present invention will be described in more detail with reference to the following examples. Each characteristic value was measured by the following method.

1. Surface resistivity After the sample film was left at 23 ° C. × 50% RH for 24 hours, the surface resistivity of the film-applied surface was measured using a vibration capacitance type potentiometer TR-84M (manufactured by Takeda Riken Co., Ltd.). The applied voltage was 100 Volt.

2. Back transferability The aqueous liquid application surface and the non-application surface of the sample film were overlapped, a load of 6 kg / cm ² was applied, and the sample film was allowed to stand at 50 ° C. × 70% RH for 8 hours. θ: substitute property of backside transferability) was measured and evaluated according to the following criteria. A: θ ≧ 55 °: good backside transferability B: 55 °> θ ≧ 48 °: slightly good backside transferability C: 48 °> θ: poor backside transferability

The water contact angle was set one minute after the sample film was set on a contact angle measuring device (manufactured by Elma) with the non-aqueous liquid-coated side facing up and a water droplet was dropped at a temperature of 23 ° C. Was measured by reading the contact angle. The water contact angle of the film having no backside transfer is 60 to 75 °, the water contact angle of the film having good backside transferability is 55 ° or more, and the water contact angle of the film having a significant backside transfer (poor backside transferability). The contact angle is less than 48 °.

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.66 was melted and cast on a cooling drum, and then stretched 3.5 times in the machine direction at 92 ° C. to obtain a uniaxially stretched film. On one surface of the uniaxially stretched film, sodium methallylsulfonate (16 mol%), CH ₂ ＣＨCH
COOCH ₂ CH ₂ OP (= O) (OC ₁₀ H ₂₁ ) (ON
a) (72 mol%) and CH ₂ ＣＨCHCOOCH ₂ CH
80% by weight of an antistatic agent (a-1) which is a copolymer (average molecular weight: 9,700) obtained by polymerizing ₂ CH ₂ OP (（O) (ONa) ₂ (12 mol%); The dicarboxylic acid component is terephthalic acid (54 mol%), isophthalic acid (4
0 mol%) and a copolymer of 5-K sulfoisophthalic acid (6 mol%), a glycol component of ethylene glycol (68 mol%), diethylene glycol (12 mol%) and neopentyl glycol (20 mol%) (average molecular weight) : 19,500) polyester resin (b-1)
A 4% by weight aqueous liquid of a composition consisting of 8% by weight and 12% by weight of polyoxyethylene nonylphenyl ether was coated with a gravure coater. Next, the applied film is heated to 95 ° C.
And stretched 3.9 times in the transverse direction at 109 ° C.
A film having a thickness of 70 μm, on which an antistatic coating was applied, was produced by heat treatment at ℃. The thickness of the antistatic coating film is 0.
The light transmittance was 21 μm and the light transmittance was 87%. Table 1 shows the characteristics of this film.

Comparative Example 1 The characteristics of a film obtained in the same manner as in Example 1 except that the aqueous liquid was not applied are shown in Table 1.

[Examples 2 to 8 and Comparative Examples 2 to 4] The characteristics of the films obtained in the same manner as in Example 1 except that the composition and the coating thickness of the coating liquid were changed as shown in Table 1 were shown. It is shown in FIG.

Example 9 Polyethylene terephthalate containing 12% by weight of titanium oxide and having an intrinsic viscosity of 0.62 was used for a base film, and the film thickness was set to 150 μm.
A film having a light transmittance of 2% was obtained in the same manner as in Example 1 except that the composition of the coating solution and the coating thickness were changed as shown in Table 1. Table 1 shows the characteristics of this film.

[0054]

[Table 1]

In the antistatic coating composition shown in Table 1, antistatic agents [a-1], [a-2] and [a-3] and binder resins [b-1], [b-2] and [b] were used. -3] are the following copolymers or mixtures, respectively.

[0056]

Embedded image [a-1]: Sodium methallylsulfonate (16
Mol%), CH ₂ ＣＨCHCOOCH ₂ CH ₂ OP (=
_{O) (OC 10 H 21)} (ONa) (72 mol%), CH ₂ =
CHCOOCH ₂ CH ₂ CH ₂ OP (= O) (ONa)
Copolymer obtained by polymerizing ₂ (12 mol%) (average molecular weight: 9,700) [a-2]: Ethyl acrylate (40 mol%), soda vinyl sulfonic acid (10 mol%) , Methyl acrylate (40 mol%), ammonium acrylate (5 mol%), 2-hydroxyethyl acrylate (5 mol%)
Copolymer (average molecular weight: 92,600). [A-3]: Ethyl acrylate (4 mol%), methyl acrylate (2 mol%), sodium styrene sulfonate (8
3 mol%), methyl methacrylate (9 mol%), 2-hydroxyethyl acrylate (2 mol%) copolymer (average molecular weight: 86,000). [A-4]: C ₁₃ H ₂₇ SO ₃ K (82% by weight) and C ₁₀ H
₂₁ A mixture of OP (= O) (ONa) ₂ (18% by weight).

[0057]

Embedded image [b-1]: Terephthalic acid (54 mol%), isophthalic acid (40 mol%), 5-K sulfoisophthalic acid (6 mol%), ethylene glycol (68 mol%), diethylene glycol (12 mol%) %) And a copolymer of neopentyl glycol (20 mol%) (average molecular weight: 19,
500). [B-2]: Polyester resin (53% by weight) of [b-1], ethyl acrylate (56 mol%), sodium acrylate (7 mol%), ethyl methacrylate (22 mol%), methacrylic acid A mixture of glycidyl (5 mol%), 2-hydroxyethyl acrylate (5 mol%), and N-methoxymethylacrylamide (5 mol%) copolymer (average molecular weight: 76,500) (47% by weight). [B-3]: Ethyl acrylate (30 mol%), ammonium acrylate (5 mol%), methyl methacrylate (45 mol%) with respect to 51 wt% of polyester resin (A-1).
Mol%), glycidyl methacrylate (10 mol%), 2
-A copolymer having a molecular weight of 59,200 grafted with 49% by weight of a copolymer component of hydroxyethyl acrylate (10 mol%).

[0058]

According to the antistatic film of the present invention, an antistatic agent having a small molecule mobility in the antistatic film and an excellent effect of entanglement of molecules is used. Excellent, useful for magnetic recording media such as magnetic cards, packaging materials, photographic materials, graphic materials, plate making films, OHP films, etc.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI B32B 27/18 B32B 27/18 D 27/36 27/36 G11B 5/78 G11B 5/78 // B29K 67:00 B29L 9: 00 (58) Field surveyed (Int.Cl. ⁷ , DB name) C08J ^7/ 00-7/18 B32B 27/00-27/42 C08L 1/00-101/16

Claims (4)

(57) [Claims] 1. An aqueous coating solution containing an antistatic agent (A) comprising a polymer having a phosphate ester group and a sulfonate group in a molecule is applied to at least one surface of a polyester film, and dried and stretched. An antistatic film provided with a provided antistatic coating. 2. An aqueous coating liquid comprising 5 to 100% by weight of an antistatic agent (A) comprising a polymer having a phosphate ester group and a sulfonate group in a molecule, and a polyester resin (B-
1) an aqueous coating liquid containing a composition comprising 0 to 95% by weight of at least one binder resin (B) selected from the group consisting of an acrylic resin (B-2) and an acrylic-modified polyester resin (B-3) The antistatic film according to claim 1, wherein 3. A polyester film having a light transmittance of 6
The antistatic film according to claim 1, which is a white polyester film of less than 0% and is used for a magnetic card. 4. A polyester film having a light transmittance of 6
The antistatic film according to claim 1, which is a transparent polyester film of 0% or more.