JP3210232B2 - 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.
The present invention relates to an antistatic polyester film having excellent adhesion, antistatic properties at low humidity, and excellent abrasion resistance.

[0002]

2. Description of the Related Art Biaxially stretched polyester films are used in a wide range of applications because of their excellent properties such as transparency, dimensional stability, mechanical properties, electrical properties, and chemical resistance.

However, a general polyester film is
Since it has a high degree of electrical insulation, it is easy to generate and accumulate static electricity, causing various obstacles due to static electricity. Above all, although it has been widely used as an OHP film than before, the conventional OHP polyester film has insufficient antistatic properties, and two or more films overlap due to static electricity charged when used in a copying machine. May cause a trouble that the sheet is transported (hereinafter, referred to as “double feed”).

In addition, when used as a plate making film, static electricity generated interferes with work such as superposition and peeling, and may significantly impair the workability.

Conventionally, as a method for improving the antistatic property, a method of kneading an anionic compound such as an organic sulfonate, a metal powder, a carbon powder or the like into a substrate film, a method of vapor-depositing a metal compound, and the like. Is known,
There have been problems such as reduced transparency and high processing cost.

As a method for improving the antistatic property, a method of forming a film of a synthetic resin (binder) to which an antistatic agent is added in advance on a film surface is known. In this case, an anionic compound or a cationic compound having good coatability is used as an antistatic agent, but it was difficult to satisfy the antistatic property under low humidity.

Incidentally, the phosphoric acid-based antistatic agent has excellent antistatic properties even under low humidity, and is applied to an unstretched or uniaxially stretched polyester film as a coating solution and then stretched and heat-treated. In coating method), excellent electrical conductivity and antistatic property can be exhibited, as disclosed in JP-A-6-255055 and Japanese Patent Publication No. 1-49114.
No. 6,009,036. However, these methods have poor coatability due to poor wettability of the phosphoric acid-based antistatic agent to the polyester film, and a good coated appearance cannot be obtained without pretreatment such as corona discharge treatment. Further, in general, when a phosphoric acid-based antistatic agent is used, there is a disadvantage that a coating film is easily scraped off, so that its use has been limited.

[0008]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies to solve the above-mentioned problems and found that a specific surfactant and a fluorine-based organic fine filler were combined with a phosphate ester-based antistatic agent. By doing so, it is possible to produce a coating solution without a pretreatment such as corona discharge treatment, so that it can be manufactured at a low processing cost, and has an excellent coating appearance,
The present inventors have found that a very useful antistatic polyester film having antistatic properties, adhesive properties and abrasion resistance can be obtained, and have completed the present invention.

[0009]

That is, according to the present invention, (1) 5 to 40% by weight of a phosphate ester type antistatic agent and (2) HLB of at least one side of a polyester film are used.
The following surfactants 1 to 20% by weight, (3) at least one kind of binder component selected from acrylic copolymers and polyester copolymers 40 to 90% by weight, and (4) fluorinated organic fine fillers 0.1 to 4% by weight % Is applied, and then dried and stretched to form a coating, thereby forming an antistatic polyester film.

In the present invention, the polyester constituting the polyester film is a linear saturated polyester synthesized from an aromatic dibasic acid or its ester-forming derivative and a diol or its ester-forming derivative. Specific examples of such polyester include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylene dimethylene terephthalate), and polyethylene-2,6.
-Naphthalenedicarboxylate and the like, and a copolymer of these or a blend thereof with a small proportion of another resin is also included. Among them, polyethylene terephthalate and polyethylene-2,6-naphthalenedicarboxylate are particularly preferred.

These polyesters may be used, if necessary, for example, inorganic lubricants such as silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc, titanium oxide, barium sulfate, etc., cross-linked silicone resins, cross-linked polystyrene resins, Contains organic lubricants such as cross-linked acrylic resin, urea resin, melamine resin, etc., other resins such as polyethylene, polypropylene, ethylene-propylene copolymer, olefinic ionomer, antioxidant, ultraviolet absorber, fluorescent brightener, etc. You can also.

In the present invention, the polyester film is a biaxially stretched film, preferably a transparent biaxially stretched film. Its thickness is 5-500 μm, preferably 20-500 μm,
Particularly preferably, it is 50 to 300 μm. If the thickness is less than 5 μm, the film is unsuitable due to its stiffness depending on the application. On the other hand, if the film is too thick, for example, more than 500 μm, the film-forming properties tend to be poor.

In the present invention, the antistatic coating provided on at least one surface of the polyester film comprises (1) 5 to 40% by weight of a phosphate ester type antistatic agent, and (2) surfactants having an HLB of 12 or less. 20% by weight, (3) 40 to 90% by weight of at least one binder component selected from an acrylic copolymer and a polyester copolymer, and (4) a coating composition containing 0.1 to 4% by weight of a fluorine organic fine filler. It is formed by applying and drying and stretching the agent.

In the present invention, examples of the phosphate-based antistatic agent (1) constituting the coating agent include conventionally known compounds. Among them, phosphate ester-based low molecular weight compounds such as phosphorus Acid alkyl ester sodium salt, phosphoric acid alkyl ester potassium salt, aryl phosphate sodium salt, aryl phosphate potassium salt, dialkyl phosphate sodium salt, dialkyl phosphate potassium salt, diaryl phosphate sodium salt, phosphoric acid Potassium diaryl ester, sodium polyalkylene oxide phosphate,
Preferable examples include potassium polyalkylene oxide salts and substituted phosphoric acid partial ester salts. It is preferable to use one selected from these or a combination of two or more.

In the present invention, the surfactant (2) is HLB
Is a surfactant of 12 or less. Here, HLB is Hy
Drophile-Lipophile Balance is an abbreviation for the balance between a lipophilic portion and a hydrophilic portion in a surfactant molecule, and is proposed by Mr. Griffin of Atlas. Its value can be calculated by the following equation (I).

[0016]

HLB = 20 (1−M _O / M) (I) (where M _O is the molecular weight of the hydrophobic group and M is the molecular weight of the surfactant)

The phosphoric acid ester-based antistatic agent (1) of the present invention has a drawback that coating is easily generated on a polyester film due to its high hydrophilicity. If the agent is used in combination, the hydrophilicity can be reduced or uniform application becomes possible. HLB is 1
If it exceeds 2, hydrophilicity becomes strong, and repelling spots occur.

As the surfactant having an HLB of 12 or less,
For example, polyethylene oxide / polypropylene oxide block copolymer, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxypropylene alkyl ether, polyoxypropylene alkylphenyl ether, poly (oxyethylene / oxypropylene) alkyl ether, poly ( (Oxyethylene / oxypropylene) alkyl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl phenyl ester, polyoxyethylene monoalkylate, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, glycerin fatty acid ester and the like. In some cases, these may be combined with other surfactants having an HLB of more than 12 as long as they do not cause spots.

The components of the acrylic copolymer used as the binder (3) in the present invention include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, sodium acrylate, ammonium acrylate, 2-hydroxy Ethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, sodium methacrylate, ammonium methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide And the like. These monomers can be used in combination with other unsaturated monomers such as styrene, vinyl acetate, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, and divinylbenzene.

The acrylic copolymer (3) is a modified acrylic copolymer, for example, an acrylic copolymer is a polyester,
It can also be used as a block polymer or graft polymer modified with polyurethane, silicone, epoxy, phenolic resin and the like.

In the present invention, the polyester copolymer (3)
Acid components that form
Examples thereof include dimer acid. Two or more of these components can be used. Further, it is also possible to use a small proportion of unsaturated polybasic acids such as maleic acid, fumaric acid, itaconic acid and hydroxycarboxylic acids such as p-hydroxybenzoic acid and p- (β-hydroxyethoxy) benzoic acid together with these components. it can. The proportion of the unsaturated polybasic acid component or hydroxycarboxylic acid component is at most 10 mol%, preferably 5 mol% or less.

The polyol components forming the polyester copolymer include ethylene glycol, 1,4-
Butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, poly (ethylene oxide) glycol, poly (Tetramethylene oxide) glycol, and ethylene oxide adducts and propylene oxide adducts of bisphenol A of the following formula

[0023]

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[0024]

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And the like. Two or more of these can be used.

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

In order to facilitate the aqueous liquefaction of the polyester, it is possible to copolymerize a small amount of a compound having a sulfonic acid group or a compound having a carboxylic acid group, which is more preferable.

Examples of the sulfonic acid group-containing compound include 5-Na sulfoisophthalic acid, 5-ammonium sulfoisophthalic acid, 4-Na sulfoisophthalic acid, 4-methylammonium sulfoisophthalic acid,
Na sulfoisophthalic acid, 5-K sulfoisophthalic acid,
Examples thereof include alkali metal sulfonic acid salt compounds such as 4-K sulfoisophthalic acid, 2-K sulfoisophthalic acid, and Na sulfosuccinic acid, and amine sulfonate compounds.

Examples of the carboxylic acid group-containing compound include trimellitic anhydride, trimellitic acid, pyromellitic anhydride, pyromellitic acid, trimesic acid, cyclobutanetetracarboxylic acid, dimethylolpropionic acid, etc. Metal salts and the like.

The polyester copolymer can also be used as a modified polyester copolymer, for example, a block copolymer or a graft polymer obtained by modifying a polyester copolymer with acryl, polyurethane, silicone, epoxy, phenol resin or the like.

The polyester copolymer or acrylic copolymer of the binder (3) in the present invention also has an easy adhesive property, for example, has an excellent adhesive action to an OHP toner. From the viewpoint of this adhesive action, a polyester copolymer is more preferable.

In the present invention, the fluorine-containing organic fine filler (3) constituting the coating liquid is a synthetic polymer containing a fluorine atom in the molecule, for example, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoro. Polymers or copolymers such as ethylene, vinylidene fluoride and vinyl fluoride are used. These can also be used as a copolymer with a vinyl monomer such as ethylene, propylene, vinylidene chloride, or perfluoroalkyl vinyl ether. Among these, polytetrafluoroethylene, polyhexafluoropropylene, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / ethylene copolymer, polychlorotrifluoroethylene, chlorotrifluoroethylene / ethylene copolymer, Tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, polyvinylidene fluoride and polyvinyl fluoride are preferred, and polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, and tetrafluoroethylene / ethylene copolymer are particularly preferred. .

The average particle size of the fluorinated organic fine filler (4) is 10 to 1000 nm, preferably 20 to 500 nm, particularly preferably 50 to 400 nm. If the average particle size is less than 10 nm, the abrasion resistance may be insufficient, while if it exceeds 1000 nm, the coating material may be unstable.

In the present invention, a phosphate ester-based antistatic agent (1), a surfactant (2) having an HLB of 12 or less, at least one binder selected from an acrylic copolymer and a polyester copolymer ( 3) and the proportion of the phosphate salt-based antistatic agent (1) is 5 to 40% by weight, preferably 10
~ 30% by weight. When the proportion exceeds 40% by weight, the adhesion becomes insufficient, and when the proportion is less than 5% by weight, the antistatic property becomes insufficient, which is not preferable. The ratio of surfactant (2) is 1
-20% by weight, preferably 3-15% by weight. If the proportion exceeds 20% by weight, the blocking property is not sufficient, while if it is less than 1% by weight, the wettability of the coating agent to the polyester film is insufficient, and the appearance of the coating is unfavorably deteriorated. The proportion of the fluorinated organic fine filler (4) is 0.1 to 4% by weight, preferably 0.5 to 3% by weight. If this proportion exceeds 4% by weight, the adhesion decreases, while if it is less than 0.1% by weight, the shaving property deteriorates, which is not preferred.

The antistatic coating in the present invention is preferably an aqueous coating, but a coating using an organic solvent as a solvent (organic coating).
It is also possible to use as. Examples of the solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, methanol, ethanol, n
-Propananol, isopropanol and the like. These can be used alone or in combination of two or more.

[0036] Such coating agents include, for example, ultraviolet absorbers, pigments, defoaming agents, and the like within a range not to impair the object of the present invention.
Adding other additives such as coatability improvers, lubricants, anti-blocking agents, melamine-based, urea-based, guanamine-based, epoxy-based, aziridine-based, blocked isocyanate-based crosslinking agents, coupling agents, etc. Can be.

In the present invention, the solid content of the coating composition is usually
It is at most 30% by weight, more preferably at most 20% by weight. This solid concentration is preferably 0.4% by weight or more.

In the present invention, a coating material containing each of the above-mentioned components is applied to at least one surface of a polyester film. The film is a polyester film before crystal orientation is completed.

As the polyester film before the completion of the crystal orientation, an unstretched film obtained by melt-extruding the polyester into a film as it is, and the unstretched film was stretched and oriented in either the longitudinal direction or the transverse direction. Examples include a uniaxially stretched film, a film stretched and oriented at a low magnification in two directions, that is, a longitudinal direction and a lateral direction (a biaxially stretched film before being finally stretched in a longitudinal direction or a lateral direction to complete orientation crystallization) and the like. can do. Of these,
Films uniaxially stretched in the machine direction are preferred.

As a method of applying the coating agent to the polyester film, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a microgravure coating method, a reverse coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method, or the like may be applied alone or in combination. The water-based coating composition may contain a small amount of an organic solvent for the purpose of assisting the stability of the coating composition or the coating property of the coating composition.

The coating amount is preferably 0.5 to 50 g, more preferably 5 to 30 g, per m ² of the running film. The thickness of the final dried coating film (coating) needs to be 0.01 to 1 μm, and preferably 0.02 to 0.6 μm. The coating thickness is 0.0
If it is less than 1 μm, sufficient antistatic properties cannot be obtained.
On the other hand, if it exceeds 1 μm, the blocking resistance decreases, which is not preferable.

The coating can be performed on only one side or both sides depending on the use of the film. After coating, the coating is dried to form a uniform coating.

In the present invention, after the coating agent is applied to the polyester film, drying and stretching are carried out. Preferably, the drying is carried out at 90 to 130 ° C. for 2 to 20 seconds. This drying can also serve as a pre-heat treatment for the stretching treatment or a heat treatment for the stretching.

The stretching treatment of the polyester film is carried out at a temperature
It is preferred that the film be stretched at 70 to 140 ° C. in the longitudinal direction by 2.5 to 7 times, in the transverse direction by 2.5 to 7 times, in the area magnification of 8 times or more, and more preferably in 9 to 28 times. When re-stretching, it is preferable to stretch at a magnification of 1.05 to 3 times (however, the area magnification is the same as described above). The heat setting after stretching is at a temperature higher than the final stretching temperature and below the melting point.
It is preferable to carry out for 1 to 30 seconds. For example, in the case of a polyethylene terephthalate film, it is preferable to heat set at 170 to 240 ° C. for 2 to 30 seconds.

The antistatic polyester film thus obtained has, for example, a light transmittance of 90% or more and a surface resistivity (temperature of 23 ° C., humidity of 35%) of 1 × 10 ^12.
Ω / □ or less, and further 1 × 10 ¹⁰ to 1 × 10 ¹¹ Ω / □, which are excellent in film appearance, transparency, adhesion, antistatic properties under low humidity, and abrasion resistance. It can be preferably used as a film for magnetic tape, display, OHP, printing, plate making, packaging film, etc., and is particularly useful as an OHP film.

[0046]

EXAMPLES The present invention will be further described below with reference to examples. The characteristics in the examples were obtained by the following method.

1. Appearance of coating film The appearance of coating film is visually determined.も の indicates that the coating surface is uniform and has no defect, and X indicates that the coating surface has spots and repelling defects.

2. Light transmittance (transparency) The light transmittance (transparency) is measured using a HR-100 haze meter manufactured by Murakami Color Research Laboratory in accordance with ASTM D1003.

3. Coefficient of friction (slipperiness) According to ASTM D 1894-63, using a slippery measuring machine manufactured by Toyo Tester Co., Ltd., the surface and the back of the film are combined, and a static friction coefficient (μs) is measured by applying a load of 1 kg.

4. Using a Gakken abrasion tester (manufactured by Tester Sangyo Co., Ltd.) on which dry gauze is set, apply 1 g on the coating surface of the sample film.
Rubbing treatment is performed five times while applying a load of 00 g, and the damage state of the coating film surface is visually determined.も の indicates that the surface hardly changes before and after the treatment, △ indicates that the coating film is slightly damaged, and X indicates that the coating film has clearly fallen off.

5. FUJI XEROX Copier (vivace
Information is printed using a 500-type machine, and the toner adhesion is observed and evaluated.

6. Surface resistivity (antistatic) The surface resistivity of the sample film was measured by Takeda Riken Co., Ltd.
Using a specific resistance measuring instrument, measured temperature 23 ° C, measured humidity 35%
Under the conditions described above, the surface specific resistance (Ω / □) after one minute at an applied voltage of 500 V is measured. 1 × 10 ¹² Ω / □ or less is preferable.

Example 1 A copolymerized polyester (Tg) having an intrinsic viscosity of 0.55 made from terephthalic acid, isophthalic acid, 5-Na sulfoisophthalic acid, ethylene glycol and an ethylene oxide adduct of bisphenol A represented by the following structural formula = 80 ° C) to prepare an aqueous dispersion having a solid content concentration of 5%, which was designated as an aqueous liquid A.

[0054]

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On the other hand, a polyester (intrinsic viscosity 0.66) made from terephthalic acid and ethylene glycol was heated at 20 ° C.
And then stretched 3.6 times in the machine axis direction. Then, 68% by weight of the aqueous liquid A and the sodium salt of dipentyl phosphate phosphate as an antistatic agent were added. Aqueous solution (concentration 5% by weight) 2
An aqueous dispersion (concentration: 5%) of 0% by weight of an aqueous solution (concentration: 5% by weight) of polyoxyethylene nonyl ether (HLB = 11.3) as a surfactant and 10% by weight of polytetrafluoroethylene (average particle size: 210 nm) 2% by weight) and a water-based coating prepared by mixing 2% by weight with a kiss coat method in an amount of 5 g / m ² (wet). Subsequently, the film was stretched 3.9 times in the transverse direction to obtain a coating-coated biaxially stretched polyester film having a thickness of 100 μm.

Table 1 summarizes the coating appearance, light transmittance, friction coefficient, abrasion resistance, toner adhesion, and surface resistivity of the processed surface of the film.

Example 2 An acrylic copolymer (number average molecular weight: 259000) prepared from methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate and N-methylol methacrylamide was used at a solid concentration of 5%.
To prepare an aqueous liquid B.

The aqueous liquid A used in Example 1 was replaced with the aqueous liquid B
A biaxially stretched polyester film coated with a coating film was obtained in exactly the same manner as in Example 1 except that the film was changed to.

Table 1 summarizes the coating appearance, light transmittance, friction coefficient, abrasion resistance, toner adhesion, and surface resistivity of the treated surface of the film.

Example 3 The surfactant used in Example 1 was polyoxyethylene nonyl phenyl ether (HLB).
= 10.7) to obtain a coating-coated biaxially stretched polyester film in exactly the same manner as in Example 1.

Table 1 shows the coating appearance, light transmittance, friction coefficient, abrasion resistance, toner adhesion and surface resistivity of the treated surface of the film.

Example 4 The aqueous coating composition used in Example 1 was prepared by adding 35% by weight of an aqueous liquid A, 30% by weight of an aqueous liquid B, and an aqueous solution of dioctyl phosphate potassium salt as an antistatic agent (concentration: 5% by weight). %) And polyoxyethylene nonylphenyl ether (HLB =
10.8) and 5% by weight of an aqueous dispersion (concentration 5% by weight) of polyhexafluoropropylene (average particle diameter 150 nm) (5% by weight). A coating film-coated biaxially stretched polyester film was obtained in exactly the same manner as in Example 1 except for the change.

Table 1 summarizes the coating appearance, light transmittance, friction coefficient, abrasion resistance, toner adhesion, and surface resistivity of the processed surface of the film.

Comparative Example 1 The coating composition used in Example 1 was composed of 70% by weight of aqueous liquid A, and an aqueous solution of dipentyl phosphate sodium salt as an antistatic agent (concentration: 5% by weight).
The coating was carried out in exactly the same manner as in Example 1 except that the coating composition was changed to 10% by weight of an aqueous solution (concentration: 5% by weight) of polyoxyethylene nonyl ether (HLB = 11.3) as a surfactant. A film-coated biaxially stretched polyester film was obtained.

Table 1 summarizes the coating appearance, light transmittance, friction coefficient, abrasion resistance, toner adhesion, and surface resistivity of the treated surface of the film.

Comparative Example 2 The surfactant used in Example 1 was polyoxyethylene nonyl phenyl ether (HLB).
= 14.2), except that a biaxially stretched polyester film coated with a coating film was obtained in the same manner as in Example 1.

Table 1 summarizes the coating appearance, light transmittance, friction coefficient, abrasion resistance, toner adhesion and surface resistivity of the treated surface of this film.

Comparative Example 3 An aqueous liquid A (60% by weight), an aqueous solution of dipentyl phosphate potassium salt as an antistatic agent (concentration: 5% by weight) was prepared using the coating composition used in Example 1 as an aqueous solution A (60% by weight).
% By weight and an aqueous solution of polyoxyethylene nonylphenyl ether (HLB = 10.7) as a surfactant (concentration: 5%).
% By weight) and 10% by weight of an aqueous liquid (concentration: 5% by weight) of crosslinked acrylic resin particles (average particle diameter: 200 nm) except that the coating composition is changed to a coating composition consisting of 10% by weight. A biaxially stretched polyester film was obtained.

Table 1 summarizes the coating appearance, light transmittance, friction coefficient, abrasion resistance, toner adhesion, and surface resistivity of the treated surface of the film.

Comparative Example 4 The coating composition used in Example 1 was prepared by adding 50% by weight of an aqueous liquid A and an aqueous solution (concentration: 5% by weight) of potassium salt of dipentyl phosphate as an antistatic agent.
% By weight and an aqueous solution of polyoxyethylene nonylphenyl ether (HLB = 10.7) as a surfactant (concentration: 5%).
% By weight) and an aqueous dispersion of polytetrafluoroethylene (average particle size 210 nm) (concentration: 5% by weight) 20
A coating film-coated biaxially stretched polyester film was obtained in exactly the same manner as in Example 1 except that the coating composition was changed to a coating composition consisting of 100% by weight.

Table 1 shows the coating appearance, light transmittance, friction coefficient, abrasion resistance, toner adhesion and surface resistivity of the treated surface of the film.

Comparative Example 5 Example 1 was repeated except that the antistatic agent used in Example 1 was changed to sodium dodecyl sulfonate.
A coated biaxially stretched polyester film was obtained in exactly the same manner as described above.

Table 1 shows the coating appearance, light transmittance, friction coefficient, abrasion resistance, toner adhesion and surface resistivity of the treated surface of the film.

Comparative Example 6 Table 1 shows the light transmittance, friction coefficient, blocking property, abrasion resistance and surface resistivity of the surface of the biaxially stretched polyester film obtained in Example 1 without applying the coating liquid. Are shown together.

[0075]

[Table 1]

[0076]

According to the present invention, an antistatic coating film of a specific composition is provided on at least one side of the polyester film, so that it has excellent coating appearance, antistatic properties under low humidity, and has excellent abrasion resistance. An excellent antistatic polyester film, particularly a film for OHP and a film for plate making, can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 27/00-27/42 C08J 7/04

Claims (9)

(57) [Claims] (1) at least one surface of a polyester film: (1) 5 to 40% by weight of a phosphate ester type antistatic agent,
(2) 1 to 20% by weight of a surfactant having an HLB of 12 or less, (3) 40 to 90% by weight of at least one binder selected from an acrylic copolymer and a polyester copolymer, and (4)
An antistatic polyester film with improved abrasion resistance, characterized in that a coating containing a composition comprising 0.1 to 4% by weight of a fluorine organic fine filler is applied, and then dried and stretched to form a coating. . 2. The amount of the phosphate ester-based antistatic agent is 1
The antistatic polyester film according to claim 1, wherein the amount is 0 to 30% by weight. 3. The amount of a surfactant having an HLB of 12 or less is 3
The antistatic polyester film according to claim 1, wherein the amount is from 15 to 15% by weight. 4. The amount of the fluorinated organic fine filler is from 0.5 to
The antistatic polyester film according to claim 1, which is 3% by weight. 5. The antistatic polyester film according to claim 1, wherein the binder is a polyester copolymer. 6. The antistatic polyester film according to claim 1, wherein the thickness of the coating is 0.01 to 1 μm. 7. The antistatic polyester film according to claim 1, wherein the polyester film is a transparent film. 8. A plate-making film comprising the antistatic polyester film according to claim 7. 9. An OHP film comprising the antistatic polyester film according to claim 7.