JP2013006300A - Antistatic film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antistatic film in which blocking, transfer to a heat sealing layer or the like can hardly occur even when coming in contact with the heat sealing layer.SOLUTION: The antistatic film has an antistatic layer at least on one surface of a polyester film. The antistatic layer includes a polymer (A) having a quaternary ammonium group and a carboxyl group at its side chain, a modified silicone (B) and a crosslinking agent (C) and a mass ratio (A/C) of the polymer (A) to the crosslinking agent (C) is 95/5 to 70/30.

Description

  The present invention relates to an antistatic film.

Polyester film is excellent in mechanical properties, heat resistance, and transparency, and is widely used as a base film and process film for packaging food applications, industrial packaging materials, information storage materials, building materials, electronic materials, printing materials, etc. in use.
However, in general, plastic films and their laminates are prone to static electricity due to contact friction and peeling during processing and product use, and dust and small dust are likely to adhere to them. Therefore, when used as packaging materials for foods and pharmaceuticals, there is a risk of contamination and contamination. In addition, there is a problem that the suitability for paper feeding and paper discharge deteriorates due to double sheet picking and slippage during printing and processing. For this reason, for example, a film in which an antistatic treatment is applied to a base film is used for applications such as a carrier tape cover tape that do not like charging.
For example, Patent Document 1 discloses a film in which an antistatic layer containing a polymer having a quaternary ammonium group and a carboxyl group in the side chain and a crosslinking agent is formed on a base film. Describes that it is excellent in antistatic performance, heat resistance and adhesion. However, in order to use this film as a carrier tape cover tape, etc., when a heat seal layer is formed on the back side of the film, this film has easy adhesion, so it is stored in a roll state under high temperature and high humidity. Then, blocking occurred, and the antistatic layer sometimes moved to the heat seal layer.

JP 2006-160883 A

  An object of the present invention is to provide an antistatic film that is less susceptible to blocking, transition to a heat seal layer, and the like even when in contact with a heat seal layer.

As a result of intensive studies, the present inventors have found that the above problem can be solved by forming an antistatic layer containing a specific polymer, a modified silicone resin, and a crosslinking agent on at least one surface of the polyester film. The invention has been reached.
That is, the gist of the present invention is as follows.
(1) The polyester film has an antistatic layer on at least one side, and the antistatic layer has a polymer (A) having a quaternary ammonium group and a carboxyl group in the side chain, a modified silicone (B), and a crosslinking agent ( An antistatic film comprising C) and having a mass ratio (A / C) of the polymer (A) to the crosslinking agent (C) of 95/5 to 70/30.
(2) The antistatic film according to (1), wherein the modified silicone (B) is an amino-modified silicone, an epoxy-modified silicone, a carboxyl-modified silicone, or an acrylic-modified silicone.
(3) The crosslinking agent (C) is at least one selected from an epoxy compound, a melamine resin, an isocyanate compound, a silane coupling agent, polyvinyl alcohol, and a polyamine compound (1) or (2) The antistatic film as described.
(4) The antistatic film according to any one of (1) to (3), wherein the antistatic layer further contains a surfactant (D).
(5) The content of the modified silicone (B) is 5 to 60 parts by mass with respect to 100 parts by mass in total of the polymer (A) having a quaternary ammonium group and a carboxyl group in the side chain and the crosslinking agent (C). The antistatic film according to any one of (1) to (4), wherein the antistatic film is present.

  Since the antistatic film of the present invention is excellent in coating film uniformity, antistatic performance, heat resistance, slipperiness, and blocking resistance, it is used for packaging materials, information storage materials, building materials, printing materials, electronic materials, etc. be able to. In addition, since the antistatic layer does not block or migrate even when it comes into contact with a layer having slight adhesiveness or heat sealability, the antiadhesive layer or heat sealability is not deteriorated. Therefore, even if a heat seal layer is formed on the antistatic film of the present invention, it can be stored in a roll state under high temperature and high humidity.

The polyester film constituting the antistatic film of the present invention is not particularly limited, but preferably has a melting point of 220 ° C. or higher, more preferably 246 ° C. or higher in order to cope with high temperature and high speed. If the melting point of the polyester film is less than 220 ° C., when heat-sealed like a carrier tape, the film may extend in the length direction or shrink in the width direction when heated. There is a possibility that the width is reduced, and it is impossible to seal with an appropriate width.
Examples of the polyester include polybutylene terephthalate, polyethylene terephthalate, polyethylene 2,6-naphthalate and blends and copolymers thereof, and polyethylene terephthalate is particularly preferable from the viewpoint of balance of cost and mechanical strength.
In addition, in order to prevent the repellency of the polyester film to achieve good coating properties and to improve the adhesion between the coating film and the film, the film surface is treated in-line with corona discharge or ion blow. Or you may go offline.

  The manufacturing method of a polyester film is not specifically limited. An example is given below. First, the dried polyester chip is melt-mixed with an extruder and then extruded with a T-die to produce a rapidly cooled unstretched film. The unstretched film is pre-heated and simultaneously biaxially stretched in the longitudinal and lateral directions, or the unstretched film is preheated and then stretched in the length direction using the roll speed difference, and then gripped with a clip in the width direction. Can be produced by a sequential biaxial stretching method or the like. It is desirable to use the sequential biaxial stretching method from the viewpoint that the stretching ratio and the balance can be easily changed. The draw ratio is not particularly limited, but considering that it does not deform at the time of high temperature sealing, it is preferably 3 times or more in the length direction, 3 times or more in the width direction, and preferably 10 times or more, and more preferably 11 times or more, particularly 12 times or more. Is desirable. It is desirable to perform heat setting and heat relaxation in order to take strain after stretching.

The antistatic layer constituting the antistatic film of the present invention needs to contain a polymer (A) having a quaternary ammonium group and a carboxyl group in the side chain. The polymer (A) may be a polymer having an electrostatic polarization relaxation property (ion conducting polymer), and the quaternary ammonium group in the polymer (A) is promptly formed by electrostatic polarizability and ionic conductivity. It is possible to impart a sufficient electrostatic polarization relaxation property.
The polymer (A) is preferably a polyacrylic copolymer having a quaternary ammonium group in the side chain and also having a carboxyl group in the side chain. Polyacrylic copolymer is effective for polyester film due to its ability to remarkably improve adhesion, durability, heat resistance, etc. due to the crosslinking reaction with crosslinking agent (C), and the electrostatic polarization relaxation performance of the polymer. Antistatic property can be imparted. In addition, in order to apply a polymer (A) to a polyester film, without using an organic solvent, it is preferable that it is water-soluble or water-dispersible.
As a specific example of the monomer constituting the polyacrylic copolymer, the monomer having a quaternary ammonium salt is not particularly limited, but examples thereof include dimethylaminoethyl (meth) acrylate quaternized compounds, (Meth) acrylic acid etc. are mentioned as a monomer which has, Furthermore, (meth) acrylic acid ester, styrene, and other vinyl derivatives are mentioned as another monomer.
Although the composition ratio of these monomers can be varied within a wide range, the monomer having a quaternary ammonium group is preferably 15 to 25 mol% based on the total monomers of the copolymer, It is preferable that the monomer which has a carboxyl group is 5-10 mol%, and it is preferable that another monomer is 65-80 mol%. When the copolymerization amount of the monomer having a quaternary ammonium group or the monomer having a carboxyl group exceeds this range, the coating liquid using the resulting polymer (A) has an increased viscosity, and the film becomes a film. The coatability of the coating may deteriorate.

  In the present invention, the counter ion of the quaternary ammonium group in the side chain is not particularly limited, and examples thereof include halogen ions such as chlorine and bromine, phosphate ions, acetate ions, sulfate ions, etc., and alkyl sulfates from the viewpoint of heat resistance. It is desirable to use ions. Specific examples of the alkyl sulfate ion include methyl sulfate and ethyl sulfate. One or more of these ions are used in the polymer.

  The antistatic layer constituting the antistatic film of the present invention needs to contain a modified silicone (B). Although it does not specifically limit as modified silicone (B), The thing which has an amino group, an epoxy group, a carboxyl group, a thiol group, a silanol group, etc. in the terminal and side chain of organosiloxanes, such as dimethylsiloxane and diphenylsiloxane, in a molecule | numerator Examples thereof include a silicone copolymer using an organosiloxane skeleton and a monomer / oligomer having an unsaturated bond such as acrylic or vinyl ether as constituent molecules, and a silicone-modified epoxy resin having an organosiloxane skeleton. The number of end groups is not limited to one and may be plural. The presence or absence of reactivity of the modified silicone resin (B) used is not limited, but in terms of compatibility and suppression of migration, reactive modified silicone resin, and further, an amino-terminated or epoxy-terminated organosiloxane or silicone copolymer, Silicone-modified epoxy resins are preferred, and silicone copolymers and silicone-modified resins are particularly preferred. Unmodified silicone has low compatibility in the antistatic layer and is likely to segregate on the surface, thus improving the blocking resistance, but it can easily move to the seal layer during roll storage, resulting in unstable seal strength. There is not preferable.

  The content of the modified silicone (B) in the antistatic layer is not particularly limited, but with respect to a total of 100 parts by mass of the polymer (A) having a quaternary ammonium group and a carboxyl group in the side chain and the crosslinking agent (C), 5-60 mass parts is preferable, 10-60 mass parts is more preferable, and 20-60 mass parts is further more preferable. When the content of the modified silicone (B) is less than 5 parts by mass, the anti-blocking property may not be sufficient, and when it exceeds 60 parts by mass, the antistatic performance is deteriorated or the coating film is cohesive. May decrease and adhesion may be insufficient.

The antistatic layer constituting the antistatic film of the present invention needs to contain one or more crosslinking agents (C). Although it does not specifically limit as a crosslinking agent, An epoxy compound, a melamine type resin, an isocyanate compound, a silane coupling agent, a polyamine compound, and polyvinyl alcohol are mentioned. In the present invention, it is desirable to use two or more selected from these in combination.
When no cross-linking agent is included, the cohesiveness of the coating film and the adhesion to the substrate are insufficient, the seal bar may be removed, and the antistatic layer is scraped and deposited due to insufficient scratch resistance. May cause poor appearance and adhesion / short circuit on electronic components. In addition, it is preferable that a crosslinking agent (C) is water-soluble or water-dispersible in order to apply to a polyester film, without using an organic solvent.

  Examples of the epoxy compound include bifunctional derivatives such as diethylene glycol diglycidyl ether, glycerin diglycidyl ether, and bisphenol A diglycidyl ether, and trifunctional derivatives such as trimethylolpropane triglycidyl ether. In addition, since the residual of a chlorine ion is unavoidable from the relationship which uses epichlorohydrin for a raw material, the epoxy compound from which the chlorine ion was removed as much as possible is desirable.

  Although it does not specifically limit as a melamine type resin, A trimethylol melamine, a hexamethylol melamine, a trismethoxymethyl melamine, a hexakis methoxymethyl melamine, etc. are mentioned.

  The isocyanate compound is not particularly limited, and examples thereof include aromatic polyisocyanates such as toluene diisocyanate and diphenylmethane diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, cyclohexane diisocyanate, and butane diisocyanate, and derivatives thereof. A blocked isocyanate compound is preferred in terms of adjusting the reactivity and increasing the stability of the coating solution.

  Examples of the silane coupling agent include epoxy alkyl silanes and aminoalkyl silanes, and γ-glycidoxypropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, and the like are preferable.

Examples of the polyamine compound include highly polar and high density polyamines such as polyethyleneimine and polyamidoamine having a branched structure composed of primary, secondary, and tertiary amines.
In addition, examples of the water-soluble resin include a polyvinyl alcohol resin, and the polyvinyl alcohol resin preferably has a saponification degree of 89% or more and a molecular weight of 100 to 1,000.

  The mass ratio (A / C) of the polymer (A) and the crosslinking agent (C) needs to be 95/5 to 70/30, and preferably 90/10 to 80/20. . If the crosslinking agent (C) is less than 5%, the adhesion may not be good, and if it exceeds 30%, the antistatic performance may be lowered.

  In addition, as a catalyst for the crosslinking agent (C), imidazole derivatives such as 2-methylimidazole and 2-ethyl-4-methylimidazole, epoxy ring-opening reaction catalysts such as polyamine and polyethyleneimine derivatives, and melamine such as valatoluenesulfonic acid Crosslinking catalysts, catalysts for urethane crosslinking such as imidazole and organotin compounds may be used. The amount of these catalysts is not particularly limited, but is preferably 5 to 30% by mass, particularly 5 to 15% by mass, based on the total mass of the polymer (A) and the crosslinking agent (C). When the amount of the catalyst exceeds 30% by mass, the antistatic layer becomes brittle, not only the adhesiveness is lowered, but also stickiness is likely to occur under high humidity.

The antistatic layer constituting the antistatic film of the present invention preferably contains a surfactant (D). Surfactant (D) is added in order to bring out the antistatic performance of polymer (A) having electrostatic polarization relaxation properties to a higher degree, and in particular to stabilize antistatic properties without depending on humidity. Preferably, it is a low molecular ion conduction type surfactant.
Specifically, it can be selected from general anionic surfactants, cationic surfactants, and nonionic surfactants. In particular, a compound having a quaternary ammonium salt and a compound having a sulfonate are preferable from the viewpoint of compatibility with a coating solution, coating suitability, adhesion, and blocking resistance.
The addition amount of the surfactant (D) is preferably 1 to 10 parts by mass and more preferably 1 to 5 parts by mass with respect to 100 parts by mass in total of the polymer (A) and the crosslinking agent (C). preferable. If the addition amount is less than 1 part by mass, the effect of preventing static charge is not sufficient, and if it exceeds 10 parts by mass, the surface opposite to the coated surface of the base film is contaminated, or after the subsequent process such as laminating, May be transferred to the slightly adhered layer or the heat seal layer.

  In the antistatic film of the present invention, the thickness of the antistatic layer is preferably 0.05 to 0.5 μm. When the thickness of the antistatic layer is less than 0.05 μm, the antistatic performance may not be exhibited. When the thickness exceeds 0.5 μm, the antistatic performance is saturated and uneconomical, and the coating concentration and viscosity are reduced. Since coating is performed with a high setting, appearance defects tend to occur.

Since the antistatic layer of the antistatic film of the present invention is formed with the above composition, the surface resistivity can be less than 1 × 10 ¹² Ω / □ at 23 ° C. and 50% RH.

  In the present invention, the antistatic layer of the antistatic film is formed by applying a coating liquid containing the polymer (A), the modified silicone (B), and the crosslinking agent (C). The coating liquid is preferably a water-soluble and / or water-dispersed solution from the viewpoint of safety and hygiene in the production process. Moreover, 5-30 mass% is preferable and the density | concentration of a coating liquid has more preferable 10-20 mass% from coating workability | operativity.

In the present invention, the coating solution preferably contains a dispersion defoamer (E). By adding a dispersion antifoaming agent to the coating solution, a highly polar polymer (A), a modified silicone (B), a crosslinking agent (C), and a surfactant (D) are mixed and dispersed uniformly for coating. It becomes possible to prepare the liquid, and this makes it possible to suppress foaming during coating and to obtain an antistatic polyester film excellent in the uniformity of the coating film.
Examples of the dispersion antifoaming agent (E) include nonionic surfactants, and acetylene glycol compounds and ethylene oxide adducts thereof are preferable. Specifically, 3,6-dimethyl-4-decyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, and ethylene oxide were added thereto. Compounds are also effective.
The amount of the dispersion antifoaming agent (E) added is preferably 0.5 to 3 parts by mass, which is larger than the amount usually used for 100 parts by mass of the coating liquid.

As a method for producing the antistatic film of the present invention, the above coating solution is applied to a stretched film and then dried, or after the coating solution is applied to the film before completion of biaxial orientation crystallization and dried. And a method of heat treatment after stretching in at least one direction.
The method of applying the coating liquid to the film can be a general coating method, such as Mayer bar coat, air knife coat, reverse roll coat, reverse gravure roll coat, gravure roll coat, lip coat, die coat, etc. The method is mentioned.
The coating liquid application amount is preferably 1 to 10 g / m ² . When extending | stretching a film after application | coating and drying, it is preferable that the drying conditions after coating are 50-90 degreeC and 10 to 60 second. Further, the stretching temperature is preferably 110 to 130 ° C., and the stretching ratio is preferably 3 to 4 times. Further, when heat treatment is performed after stretching, the heat treatment temperature is preferably 220 to 240 ° C. and the time is preferably 5 to 15 seconds.
In addition, you may mix | blend additives, such as antioxidant and a lubricant, with the coating liquid and the polyester film of a base material in the range which cannot prevent the effect of this invention.

  The antistatic film obtained by the above production method can be used as it is, but the antistatic surface or the uncoated surface may be subjected to a surface treatment such as corona discharge or ion blow as a surface treatment.

  EXAMPLES The present invention will be specifically described with reference to examples, but the present invention is not limited to only these examples. In addition, the evaluation method used for the Example and the comparative example was shown below.

Antistatic property:
The antistatic property was evaluated by the surface specific resistance value on the surface of the antistatic layer of the antistatic film. The antistatic film was allowed to stand for 3 hours at a temperature of 23 ° C. and a humidity of 50% RH, and then at the same temperature and humidity, a high resistance meter HT-260 measuring instrument manufactured by Dia Instruments Co. was used. The surface resistivity (Ω / □) was measured.

Slipperiness:
According to JIS K 7125, the film was allowed to stand for 3 hours at 23 ° C. × 50% RH, and then the dynamic friction coefficient of the antistatic surface was measured.

Heat-resistant:
According to JIS C2318, the dry heat shrinkage rate in the TD direction at 150 ° C. for 30 minutes was measured, and less than 0.5% was evaluated as ○, and 0.5% or more was evaluated as ×.

Adhesion:
Using a rotary static tester (Kyoto Chemical Research Co., Ltd., manufactured by Koa Shokai), the antistatic surface and 60/40 white cloth (white cloth with dyeing fastness test) were rubbed at 400 rpm for 1 minute at a load of 300 g. The case where it was not seen was evaluated as ◯, and the case where the coating film was taken on a white cloth and the film was whitened was evaluated as ×.

Blocking resistance:
The prepared antistatic film was cut to a width of 10 mm and pasted on a 3-inch paper tube in a state where the heat seal layers of the laminated films 1 to 3 prepared as described below and the antistatic layer of the antistatic film were in contact with each other. After being attached, a PET film ("PET-12" manufactured by Unitika) was wound 2000 m from the top of the laminated film and stored in a hot air dryer at 60 ° C for 3 days. After cooling, the wound PET film was removed, and the anti-blocking property was evaluated by the resistance when the antistatic film was peeled off from the heat seal layer of the laminated film using tweezers.
○: It peels off smoothly.
(Triangle | delta): Although it peels, there exists resistance.
X: Although peeled off, the film extends and curls.
Xx: It does not peel off.

Migration:
Affixed to a 3-inch paper tube with the antistatic surface of the prepared antistatic film in contact with the heat seal surface of the laminated film 1, and then put the PET film ("PET-12" manufactured by Unitika) on the laminated film And then stored in a hot air dryer at 60 ° C. for 3 days. After removing the wound PET film, the antistatic film was peeled off from the heat seal layer of the laminated film using tweezers, and an acrylic antistatic agent (“Bondip” manufactured by Konishi Co., Ltd.) was applied to the exposed heat seal surface of the laminated film 1. PA-100 ") was applied so that the dry film thickness was 0.1 µm, and the appearance when dried at 80 ° C for 60 seconds was evaluated.
○: No coating spots.
X: Repelling occurs.

[Reference: Preparation of laminated film 1]
45 parts by mass of a styrene-butadiene copolymer (“Clurelen” manufactured by Denki Kagaku Kogyo Co., Ltd.) having a styrene content of 30% by mass, 45 parts by mass of a polyolefin resin (“Tafmer” manufactured by Mitsui Chemicals, Inc.), and impact-resistant polyethylene (Toyo Styrene) A resin mixture (for heat seal layer) consisting of 10 parts by mass was manufactured. Moreover, the resin mixture (for support layers) which consists of 60 mass parts of polyolefin resin ("Tuffmer" by Mitsui Chemicals) and 40 mass parts of low density polyethylene ("UBE polyethylene" by Ube Industries) was created.
A two-layer film composed of a heat seal layer / support layer having a heat seal layer of 10 μm, a support layer of 20 μm, and a total thickness of 30 μm was prepared from these resin mixtures by T-die co-extrusion. At that time, the film extruded from the T die is sandwiched between a matte roll made of silicon rubber and a metal cooling roll (heat seal layer side) whose average surface roughness (Ra) is adjusted to 0.8 μm and taken off. It was. The surface roughness (Ra) on the heat seal layer side of the obtained two-layer film was 0.4 μm.
To this bilayer film, an anchor agent EL530 manufactured by Toyo Morton Co., Ltd. was diluted with ethyl acetate on a biaxially stretched polyethylene terephthalate film (Embret S-16 manufactured by Unitika Co., Ltd.) (base layer) having a thickness of 16 μm. After coating and drying so as to be 3 g / m ² , extrusion lamination is performed through melt-extruded low density polyethylene using the surface on the support layer side of the two-layer film as a laminated surface, and heat seal layer / support layer / low A laminated film 1 composed of a density polyethylene layer / base material layer was prepared.

[Reference: Preparation of laminated film 2]
An acrylic antistatic agent (“Bondip PA-100” manufactured by Konishi Co., Ltd.) was applied to the heat seal layer surface of the laminated film 1 so that the dry film thickness was 0.1 μm, and dried at 80 ° C. for 60 seconds. A laminated film 2 was obtained.

[Reference: Preparation of laminated film 3]
As a resin mixture for the heat seal layer, 85 parts by mass of a styrene-butadiene copolymer styrene-butadiene block copolymer resin (“SR Resin” manufactured by JSR Corporation, styrene content 40% by mass, butadiene content 60% by mass), and tackifying A laminated film 3 was obtained in the same manner as the laminated film 1 except that a resin mixture consisting of 15 parts by mass of an aromatic petroleum resin (“YS Resin SX-100” manufactured by Yashara Chemical Co., Ltd.) as a resin was used.

Example 1
As a polymer (A) having a quaternary ammonium group and a carboxyl group in the side chain, polymer (A1) (methyl sulfate / quaternary product of methyl methacrylate / ethyl acrylate / acrylic acid / dimethylaminoethyl methacrylate, 45/5 Copolymerized at a mass ratio of / 5/45, solid content concentration 30% by mass) 30 kg (solid content 9 kg), and polyethyleneimine (Epomin P-1000 manufactured by Nippon Shokubai Co., Ltd.) as the crosslinking agent (C1) After adding 3 kg (solid content: 30% by mass) (solid content: 0.9 kg) and stirring vigorously with a propeller stirrer, Adecamin 4MAC-30 (manufactured by Asahi Denka Kogyo Co., Ltd., solid content concentration: 30 mass) as a surfactant (D) %) 1 kg (solid content 0.3 kg) was added and stirred.
Next, 1 kg of acetylene glycol type surfactant (Orphine E1004 manufactured by Nissin Chemical Industry Co., Ltd., 100% by mass of active ingredient) is added as a dispersion antifoaming agent (E), followed by stirring for 30 minutes and further stirring. As a crosslinking agent (C2), 1 kg of an epoxy compound (manufactured by Nagase Kasei Kogyo Co., Ltd., Denacol EX1610, solid content concentration of 100% by mass) (solid content of 1 kg) was added and stirred for 60 minutes. Subsequently, it diluted with the pure water and adjusted the total solid content density | concentration to 10 mass% (coating liquid A).
Thereafter, FZ-4658 (manufactured by Toray Dow Corning, amino-modified silicone, solid content 21%) was diluted with water as a modified silicone (B1) with respect to 28 parts by mass of the coating liquid A, and adjusted to 10% by mass. 12 parts by mass of the product was added to obtain a coating liquid B. The coating liquid B was prepared at 20 to 25 ° C.
The coating liquid B is applied to the corona surface of a biaxially stretched polyester film (Embret S-25 manufactured by Unitika Ltd., center surface average roughness 0.03 μm) with a Mayer bar so that the dry film thickness is 0.12 μm. And then dried at 180 ° C. for 20 seconds to obtain an antistatic film.

Examples 2-16
An antistatic film was obtained in the same manner as in Example 1 except that the composition of the polyester film and the coating solution was changed as shown in Table 1. In addition, the following were used as a component which comprises a polyester film and a coating liquid.
Polyester film:
PTH-25 (Unitika's biaxially stretched polyester film, center surface average roughness 0.15 μm)
PTHA-25 (Biaxially stretched polyester film manufactured by Unitika Ltd., center surface average roughness 0.25 μm)
Polymer (A2) having quaternary ammonium group and carboxyl group in side chain:
Copolymerized monomers of methyl methacrylate / ethyl acrylate / acrylic acid / dimethylaminoethyl methacrylate quaternary chloride at a mass ratio of 45/5/5/45 (solid content concentration 30%)
Modified silicone (B):
B2: Toray Dow Corning FZ-4602, epoxy-modified silicone, solid content 29%
B3: BY22-840SR manufactured by Toray Dow Corning, carboxyl group-modified silicone, solid content 36%
B4: DY33-440F manufactured by Toray Dow Corning, elastomer powder emulsion, solid content 63%
B5: BY22-856SR manufactured by Toray Dow Corning, amino-modified silicone, solid content 34%
B6: Charine R170EM manufactured by Nissin Chemical Industry Co., Ltd., acrylic silicone emulsion, solid content 45%
B7: Charine FE-230N manufactured by Nissin Chemical Co., acrylic silicone emulsion, solid content 30%
B8: Polon NWS manufactured by Shin-Etsu Chemical Co., Ltd., modified silicone emulsion, solid content 29%
B9: Shin-Etsu Chemical Polon MF-52, amino-modified silicone emulsion, solid content 32%

Example 17
Polyester chips (relative viscosity 1.38 (20 ° C., phenol / tetrachloroethane = 50/50, 0.5 g / dl)) are melt extruded at 280 ° C., and tightly cooled to the casting drum by the T-die method-electrostatic pinning method. Then, an unstretched film having a thickness of 210 μm was formed. Subsequently, this unstretched film was stretched 3.8 times with a longitudinal stretching roll heated to 90 ° C. On one side of the longitudinally stretched film, a reverse clavia coater was used to apply the coating solution B so as to have a coating amount of 5 g / m ² , followed by drying in a 58 ° C. oven, and then 4.8 at 120 ° C. Double-stretched. Next, after heat treatment at 230 ° C. for 10 seconds, the film was cooled and wound up to obtain an antistatic film.

Comparative Examples 1-15
An antistatic film was obtained in the same manner as in Example 1 except that the composition of the polyester film and the coating solution was changed as shown in Table 1. However, the obtained film was inferior to any of blocking resistance, heat resistance and migration. In addition, the following were used as a component which comprises a polyester film and a coating liquid, and the other component was added to the prepared coating liquid A.
Polyester film:
F865 (biaxially stretched film of isophthalic acid copolymer polyethylene terephthalate manufactured by Toray Industries, Inc.)
Other ingredients:
BY22-749SR (manufactured by Toray Dow Corning, silicone emulsion)
KM-740T (Shin-Etsu Chemical Co., Ltd., silicone emulsion)
KM-862T (Shin-Etsu Chemical Co., Ltd., silicone emulsion)
Shilton AMT-08L (Mizusawa Chemical Co., Ltd., spherical sodium silicate)
Aerosil OX50 (Nippon Aerosil, fumed silica)
Resem O-642 (manufactured by Chukyo Yushi Co., Ltd., polyamide release agent)
Arrow Base CD-1200 (manufactured by Unitika Ltd., polyolefin dispersion)
Amide AP-1 SA20 (manufactured by NOF Corporation, aliphatic amide dispersion)
Separ M-835 (manufactured by Chukyo Yushi Co., Ltd., low molecular weight anti-blocking agent)

  Tables 1 and 2 collectively show the structures and characteristics of the antistatic films obtained in Examples and Comparative Examples.

Claims (5)

  The polyester film has an antistatic layer on at least one side, and the antistatic layer comprises a polymer (A) having a quaternary ammonium group and a carboxyl group in the side chain, a modified silicone (B), and a crosslinking agent (C). An antistatic film comprising a polymer (A) and a crosslinking agent (C) having a mass ratio (A / C) of 95/5 to 70/30.   The antistatic film according to claim 1, wherein the modified silicone (B) is amino-modified silicone, epoxy-modified silicone, carboxyl-modified silicone, or acrylic-modified silicone.   The antistatic film according to claim 1 or 2, wherein the crosslinking agent (C) is at least one selected from an epoxy compound, a melamine resin, an isocyanate compound, a silane coupling agent, polyvinyl alcohol, and a polyamine compound. .   The antistatic film according to any one of claims 1 to 3, wherein the antistatic layer further contains a surfactant (D). The content of the modified silicone (B) is 5 to 60 parts by mass with respect to 100 parts by mass in total of the polymer (A) having a quaternary ammonium group and a carboxyl group in the side chain and the crosslinking agent (C). The antistatic film according to claim 1, wherein the antistatic film is a film.