WO2015102336A1

WO2015102336A1 - Polyester film and method for manufacturing same

Info

Publication number: WO2015102336A1
Application number: PCT/KR2014/012968
Authority: WO
Inventors: 조은혜; 김태현; 백상현
Original assignee: 코오롱인더스트리 주식회사
Priority date: 2013-12-30
Filing date: 2014-12-29
Publication date: 2015-07-09
Also published as: KR20150077745A

Abstract

The present invention relates to an antistatic polyester film and, to a polyester film which has a surface resistance lower than that of conventional polyester films and on which a conductive polymer antistatic agent is coated for packaging, an electronic material treating process and a product protection, and a method for manufacturing the polyester film.

Description

Polyester film and preparation method thereof

The present invention relates to an antistatic polyester film, and has a lower surface resistance than a conventional polyester film, and relates to a polyester film coated with a conductive polymer antistatic agent for packaging, electronic material processing, product protection, and a method of manufacturing the same.

The antistatic polyester film produced by the production method of the present invention is useful as a process film and a protective film because resistance to water or a solvent is improved.

In recent years, due to the rapid development of various electronic, electrical, and information communication fields, many fields, such as industrial products and household products, have applied with static electricity, and antistatic functions in these devices and on-site are becoming essential functions. . Antistatic refers to discharging the electric charge accumulated on the insulator surface by an appropriate method. This antistatic performance is required because static electricity is generated in the film manufacturing process or the film processing process, and dust or foreign matter adheres to the product, or when the organic solvent is used as a discharge phenomenon, a risk of ignition occurs. Therefore, providing antistatic performance has become an essential requirement.

An antistatic layer is formed on the film to impart such antistatic performance. When the binder resin used to form the antistatic layer has a low crosslinking density, the coating film is damaged by a solvent used in a later process, and defects may occur. There is a possibility. Therefore, there has been a study to improve the solvent resistance of the binder resin forming the antistatic layer.

The present invention is to provide a polyester film having an antistatic coating layer having improved surface resistance and excellent resistance to moisture or a solvent, and a method of manufacturing the same. That is, the present invention provides a polyester film having a low swelling ratio and a high gel fraction of an antistatic layer and a method of manufacturing the same.

The present invention for achieving the above object is as follows.

The present invention is a polyester film comprising a base layer made of a polyester resin and an antistatic layer laminated on one side or both sides of the base layer,

The antistatic layer is composed of 10 to 75% by weight of a linear polymer having two terminal groups and 25 to 90% by weight of a branched polymer having three or more terminal groups, or a water-dispersible polyurethane resin consisting of a branched polymer having three or more terminal groups, The present invention relates to a polyester film formed by coating and drying an aqueous coating composition comprising a conductive polymer resin selected from polythiophene or polythiophene derivative and water.

In addition, the present invention

a) melt extruding a polyester resin to prepare a polyester sheet;

b) stretching the polyester sheet in the machine direction;

c) 10 to 75% by weight of the linear polymer having two terminal groups and 25 to 90% by weight of the branched polymer having three or more terminal groups on one or both sides of the polyester film drawn in the machine direction, or three terminal groups. Coating an aqueous coating composition comprising a water-dispersible polyurethane resin, a polythiophene or a polythiophene derivative made of a branched polymer, and a water-based coating composition including water and then stretching in a transverse direction; And

d) heat setting the biaxially stretched polyester film;

It relates to a method for producing a polyester film comprising a.

The polyester film according to the present invention has an antistatic property on the coated surface, and prevents the overlapping due to static electricity between the film during the off-sheet operation, there is an advantage that can prevent the problem by the static electricity in the applied product.

In addition, the antistatic layer has excellent antistatic performance and solvent resistance, and has adhesion to the tape and printability, and one surface of the base layer on which the antistatic layer is not formed has adhesiveness and printability. In particular, the solvent resistance of the solvent such as normal hexane, toluene, ethyl acetate, etc. is very excellent, there is a wide range of solvent selection in the post-process.

One aspect of the present invention is a polyester film comprising a base layer made of a polyester resin and an antistatic layer laminated on one side or both sides of the base layer, wherein the antistatic layer is 10 to 75% by weight of a linear polymer having two terminal groups And a conductive polymer resin selected from water-dispersible polyurethane resins, polythiophenes or polythiophene derivatives consisting of 25 to 90% by weight of branched polymers having 3 or more terminal groups, or branched polymers having 3 or more terminal groups, and It relates to a polyester film formed by coating and drying an aqueous coating composition comprising water.

In one aspect of the invention, the antistatic layer may be that the surface resistance of 10 ⁵ ~ 10 ⁹ Ω / sq.

In one aspect of the present invention, the aqueous coating composition may further include any one or two or more additives selected from wetting agents, alcohol solvents, particles, slip agents, crosslinking agents, curing agents.

In one embodiment of the present invention, the water-based coating composition is a water dispersible polyurethane resin 0.1 to 10% by weight, conductive polymer resin 0.1 to 10% by weight, wetting agent 0.1 to 1% by weight, alcohol solvent 0.1 to 10% by weight, crosslinking agent 0.1 to 10% by weight and the rest may be to include water to satisfy 100% by weight.

In one aspect of the present invention, the terminal group may be an isocyanate group in which part or all of the terminal groups are blocked with an inorganic acid salt group.

In one embodiment of the present invention, the water-dispersible polyurethane resin is prepared by reacting 39 to 45% by weight of polyol, 0.3 to 1.2% by weight of trimethylol propane and 50 to 57% by weight of isocyanate compounds to prepare a prepolymer having an isocyanate as an end group. After that, the inorganic acid may be prepared by reacting 3 to 4% by weight, blocking an ionic group at an isocyanate terminal.

In one aspect of the invention, the water-dispersible polyurethane resin may have a weight average molecular weight of 10,000 ~ 20,000g / mol.

In one aspect of the invention, the antistatic layer may be coated by an inline coating method.

In one aspect of the invention, the antistatic layer may be a dry coating thickness of 10 ~ 500nm.

In one aspect of the invention, the polyester film may be that the total thickness of 12 ~ 250㎛.

In addition, the present invention relates to a method for producing a polyester film, one aspect of the production method

a) melt extruding a polyester resin to prepare a polyester sheet;

b) stretching the polyester sheet in the machine direction;

d) heat setting the biaxially stretched polyester film;

It may be to include.

Hereinafter, one aspect of the present invention will be described in more detail.

The present invention is characterized in that an antistatic layer for imparting antistatic performance to one or both surfaces of a polyester film is formed by an inline coating method.

When the antistatic layer is formed by coating the polyester film off-line, there is a problem in that the cost is increased because the process is further increased, and as the coating thickness becomes thick, the cost is increased compared to the inline coating method. Therefore, the present invention is applied by an in-line coating method, by applying an aqueous coating composition for drying and curing in the stretching process to form an antistatic layer, the coating thickness is thin, not only excellent adhesion to the polyester film, but also moisture And resistance to solvents is excellent.

In the present invention, the base layer may be a film made of a polyester resin, and more specifically, polyethylene terephthalate, polyethylene naphthalate. More preferably, polyethylene terephthalate having an intrinsic viscosity in the range of 0.6 to 0.7 is more excellent in weather resistance and hydrolysis resistance. In addition, it is preferable that the polyester film has a thickness of 12 to 300 μm and is advantageous in that it can implement various laminated structures.

In addition, it is possible to impart printability by performing a corona treatment on the opposite surface on which the antistatic coating layer of the polyester film which is the base layer is formed.

In the present invention, the antistatic layer is composed of 10 to 75% by weight of a linear polymer having two terminal groups and 25 to 90% by weight of a branched polymer having three or more terminal groups, or a water-dispersible poly consisting of a branched polymer having three or more terminal groups. It is formed by coating and drying an aqueous coating composition comprising a conductive polymer resin and water selected from a urethane resin, polythiophene or polythiophene derivative, and is coated by an inline coating method.

In addition, if necessary, the aqueous coating composition may further include any one or two or more additives selected from wetting agents, alcohol solvents, particles, slip agents, crosslinking agents, and curing agents.

In order to enable in-line coating, the water-based composition should be used. However, when the water-based composition is made, the durability of the water or the solvent is weakened in the subsequent process. However, the inventors of the present invention mix specific water-dispersible polyurethane resin and conductive polymer resin. According to the use, while in-line coating is possible, the excellent properties of the antistatic coating layer formed, the water resistance and durability was found to be able to express the physical properties equivalent to or more than the existing offline coating to complete the present invention.

The antistatic layer may have a dry coating thickness of 10 to 500 nm and a surface resistance of 10 ⁵ to 10 ⁹ Ω / sq. If the dry coating thickness is less than 10nm, the surface resistance may be high, and if it exceeds 500nm, the cost may increase, the viscosity may increase and the processability may be reduced. It is preferable to apply to a substrate film such as ITO in the process range the surface resistance of ^{^{10 5 ~ 10 9 Ω / sq}} .

More specifically, the water-based coating composition is 0.1 to 10% by weight of water-dispersible polyurethane resin, 0.1 to 10% by weight of conductive polymer resin, 0.1 to 1% by weight of wetting agent, 0.1 to 10% by weight of alcohol solvent, 0.1 to 10 crosslinking agent The weight percent and the balance may be to include water to satisfy 100 weight percent.

The water-dispersible polyurethane resin is a branched polymer having at least three isocyanate functional groups as terminal groups, part or all of the isocyanate groups are blocked with an inorganic acid salt group, and more specifically, blocked with an inorganic salt such as sulfate, Two isocyanate functional groups are included, in which some or all of the isocyanate groups are blocked with inorganic acid groups, and more particularly include linear polymers blocked with inorganic salts such as sulfate.

The water-dispersible polyurethane resin is composed of 10 to 75% by weight of the linear polymer having two terminal groups and 25 to 90% by weight of the branched polymer having three or more terminal groups, or 100% by weight of the branched polymer having three or more terminal groups. It may be. By using such resin, there exists an effect that a crosslinking density improves and solvent resistance improves.

When the content of the branched polymer is less than 25% by weight, the swelling degree and the gel fraction, which are intended in the present invention, may not be satisfied, and it may be difficult to obtain a coating film having excellent adhesion under high temperature and high humidity. In the present invention, the branched polymer means a resin having 3 or 3 or more isocyanate functional groups.

For example, a method of preparing the water-dispersible polyurethane resin may include preparing a prepolymer having an isocyanate as an end group by reacting 39 to 45 wt% of a polyol, 0.3 to 1.2 wt% of a trimethylol propane, and 50 to 57 wt% of an isocyanate compound. After that, it is preferable to use an inorganic acid salt prepared by blocking 3 to 4% by weight of an ionic group of sulfate at an isocyanate end, and the inorganic acid salt is not limited thereto.

In addition, since the gel is not gelled in the range of 10,000 to 20,000 g / mol in weight average molecular weight, it is preferable to obtain a coating film which is water dispersible and excellent in high temperature and high humidity.

The weight average molecular weight can be measured using a GPC-MALS (Multi Angle Light Scattering) system (Wyatt, Inc.), the configuration of the MALS system is as follows.

MALS system configuration

-GPC: Water 1525 Binary HPLC Pump

RI detector: Optilab rex

MALS: Wyatt Dawn 8+

-Column: PLgel 5㎛ Mixed-C (7.5mmΦ × 300mm) × 2 (Polymer Laboratories)

Mobile phase: DMF (50 mM LiCl)

-Flow rate: 0.5mL / min

Temperature: 50 ℃

Injection volume: 0.5%, 500µl

The polyol may be a polyester-based polyol or a polyether-based polyol, preferably a polyester-based polyol. Polyester-based polyols are polyols prepared from the reaction of carboxylic acids, sebacic acids or acid anhydrides with polyhydric alcohols. The type of the polyol is not limited, and it is preferable to use a polyester polyol having a weight average molecular weight of 600 to 3,000 g / mol. Polyester-based polyols include polyols prepared from the reaction of carboxylic acid, sebacic acid or an acid anhydride with a polyhydric alcohol. The type of the polyol is not limited, and it is preferable to use a polyester polyol having a weight average molecular weight of 600 to 3,000 g / mol. Its content is preferably 39 to 45% by weight. When used at less than 39% by weight, the molecular weight is small, the primer layer is too hard, it is difficult to stretch, the coating appearance is not excellent, and when more than 45% by weight, the ILC layer is too soft (Soft) is poor blocking properties Can be.

The trimethylol propane is used to prepare a prepolymer having a trifunctional group, and it is preferable to use 0.3 to 1.2% by weight. When used in less than 0.3% by weight, the crosslinking density is lowered, and anti-blocking property may be lowered, and when used in excess of 1.2% by weight, the crosslinking density becomes too high, resulting in poor elongation. This is not excellent and the adhesion may be bad.

The isocyanate compound is not limited but preferably hexamethylene diisocyanate is used. The content can be prepared a prepolymer having a trifunctional group in the range using 50 to 57% by weight.

The inorganic acid salt is preferably used sodium hydrogen sulfate (Sodium Hydrogen Sulfate), the content is preferably used 3 to 4% by weight.

The water-dispersible polyurethane resin is preferably used 0.1 to 10% by weight of the total water-based coating composition, when less than 0.1% by weight weakened the adhesion of polythiophene-containing water dispersion or polythiophene derivatives In case of using more than 10% by weight, after stretching, the surface resistance may not come out.

The conductive polymer resin is used to impart antistatic properties, and may include polythiophene or polythiophene derivative. More preferably, an aqueous dispersion of polyanion and polythiophene or an aqueous dispersion of polyanion and polythiophene derivative can be used. The said polyanion is an acidic polymer, and is high molecular carboxylic acid, high molecular sulfonic acid, polyvinyl sulfonic acid, etc. Polymer carboxylic acids include polyacrylic and polymethacrylic acid, and polymer sulphonic acid includes polystyrene sulfonic acid. For the polythiophene or polythiophene derivative, it is preferable that the poly anion is excessively present in the solid weight ratio in terms of conductivity, and the poly anion is more than 1% by weight with respect to 1% by weight of polythiophene or polythiophene derivative, 3 The weight% or less is preferable. The conductive polymer resin is preferably used 0.1 to 10% by weight of the total water-based coating composition, when less than 0.1% by weight may be high surface resistance, when the weight exceeds 10% by weight, the viscosity is increased Since the processability can be reduced to increase the best antistatic layer in the above range can be formed.

In addition, it is most preferable that the mixing ratio of the polythiophene-containing water dispersion or the polythiophene derivative to the polyurethane-based resin is 50 to 150% by weight, and if the mixing ratio is less than 50% by weight, the surface resistance may not come out. If it is more than 150% by weight, the adhesion of the polythiophene-containing water dispersion or polythiophene derivative may be weakened and released.

The wetting agent is used to uniformly apply the emulsion onto the polyester film, and it is preferable to use one selected from polyethylene glycol, polyethylene ester, modified silicone, fluorine mixture, etc., since the coating property is greatly improved, and the content thereof is 0.1. It is preferable to use ˜0.5% by weight because of excellent adhesion.

The alcohol solvent is used to uniformly apply the increased wettability, specifically, for example, isopropyl alcohol, ethyl cellussolve, methyl cellusol portion, butyl cellussolve, and the like, and may be 0.1 to 10% by weight. Using is preferable for reasons of coating property and processability.

The crosslinking agent is used to improve solvent resistance, and specifically, for example, any one or more compounds selected from the group consisting of block isocyanate-based, carbodiimide-based, oxazoline-based, epoxy-based and melamine-based may be used. . The content is preferably 0.1 to 10% by weight, more preferably 0.1 to 0.5% by weight. When using less than 0.1% by weight may be a solvent resistance, when used in excess of 10% by weight may not come out of the surface resistance.

In addition, if necessary, particles may be added to improve the blocking property of the coating layer using the emulsion, and inorganic particles and organic particles may be added. The content is preferably used 0.01 to 10% by weight.

In addition, additives such as UV stabilizers, slip agents, curing agents, and the like, which are commonly used in the art, may be further added as necessary.

In addition, the present invention

a) melt extruding a polyester resin to prepare a polyester sheet;

b) stretching the polyester sheet in the machine direction;

d) heat setting the biaxially stretched polyester film;

It relates to a method for producing a polyester film comprising a.

In addition, if necessary, after the step c), further comprising the step of coating a polyacrylic resin or a polyurethane resin on the opposite surface on which the antistatic layer of the polyester film is formed, or after the step d), the antistatic layer is formed Corona treatment to the surface; may be to include more. When coating a polyacrylic resin or a polyurethane resin as described above, the adhesion and printability can be further improved, it may be formed by an in-line coating method. It is preferable that a coating thickness is 50-150 nm of dry coating thickness.

The corona treatment is to further improve printability, and the corona treatment is not limited as long as it is a conventional method in the art.

Step a) is a process of melting the resin in a cylinder to produce a polyester film into a sheet through a T-die in order to produce a polyester film.

Step b) is a process for producing a polyester film by biaxially stretching the polyester sheet, it is preferable that the stretching in the machine direction using one or more rollers.

Next, in step c), an antistatic layer is formed by the in-line coating method, and it is preferable to use an emulsion that is dispersed to be used for the in-line coating. At this time, the composition of the water-based coating composition for forming the antistatic layer is as described above, it is preferable to apply so that the dry coating thickness after stretching is 10 ~ 500nm. The aqueous coating composition is applied to form an antistatic layer, and then stretched in the transverse direction. At this time, it is preferable to use a tenter for lateral stretch.

Next, to remove the moisture used in the antistatic layer, to cure the antistatic layer, and to prevent the shrinkage of the film is subjected to a drying and heat setting process.

Hereinafter, the present invention will be described by way of example for specific description of the present invention.

Hereinafter, the physical properties of the present invention were measured as follows.

1) Surface Resistance

The surface resistance of the antistatic layer of the present invention was evaluated. The measurement method is Mitsubishi Chemical Corp. Surface resistance was measured using a Hiresta-Up MCP-HP450 instrument at 25 ° C., 50% Rh, 10 V (or 100 V), 10 seconds.

2) solvent resistance

The solvent resistance of the antistatic layer of this invention was evaluated. The measuring method was to measure solvent resistance by placing a metal plate having a width of 25 mm × 25 mm and a weight of 915 g on a microfiber cloth in which isopropyl alcohol, ethyl alcohol, normal hexane, toluene, and ethyl acetate were respectively coated, and rubbed 10 times. The condition of the coating side was evaluated based on the following criteria.

◎: When there is little change of antistatic property and there is no wiping degree on microfiber cloth

(Circle): When there is little change of antistatic property and the wiping degree on microfiber cloth is minute

(Triangle | delta): When the change of antistatic property is 10 ² ohms / sq or less, and the wiping degree on a microfiber cloth is about-medium

X: When antistatic property disappears or when the wiping degree on a microfiber cloth is severe

3) Measurement of the physical properties of the coating film using the coating composition

15 g of conductive polymer binder with water-dispersible polyurethane was put in a round bowl with a diameter of 80 mm and a height of 15 mm and dried at 65 ° C. for 72 hours and 120 ° C. for 3 hours. After dipping 1 g of the dry coating film in 50 g of distilled water, the film was left for 24 hours at 70 ° C., and the swelling ratio was measured. Gel Fraction is measured by drying the coated film for 3 hours at 120 ℃ and recording the weight.

G. Swelling Ratio: After dipping about 1g of dry coating film in 50g of distilled water and leaving it at 70 ℃ for 24 hours, remove the coating film and record the weight.

Swelling Ratio = (Weight after leaving-initial weight) / Initial weight * 100

N. Gel Fraction: After leaving the coating film at 120 ℃ for 3 hours, the weight is recorded.

Gel Fraction = (Weight after Drying / Initial Weight) * 100

[Production Example 1]

Preparation of Water Dispersible Polyurethane Binder (1) and Preparation of Conductive Polymer Mixture

Theoretically, water-dispersed polyurethanes with a linear polymer content of 100% by weight were prepared.

40 wt% of polyethyleneadipate diol and 58 wt% of hexamethylene diisocyanate were reacted to prepare a prepolymer having an isocyanate functional group as a terminal group, and then using an ionic group as sodium hydrogengen sulfate. 2 wt% of the prepolymer was reacted with isocyanate, which is a terminal functional group, to prepare a polyurethane having an ionic group and having a weight average molecular weight of 8,000 g / mol. 20 wt% of the polyurethane thus prepared was dispersed in 80 wt% of water to prepare a water dispersible polyurethane binder (1) having a solid content of 20 wt%. The prepared water-dispersible binder was blended with a conductive polymer resin (SY-CP-E421A, Sooyang Chemtech Co., Ltd.) at a weight ratio of 30:70 to prepare a mixed solution.

[Production Example 2]

40 wt% of polyethyleneadipate diol and 58 wt% of hexamethylene diisocyanate were reacted to prepare a prepolymer having an isocyanate functional group as a terminal group, and then using an ionic group as sodium hydrogengen sulfate. 2 wt% of the prepolymer was reacted with isocyanate, which is a terminal functional group, to prepare a polyurethane having an ionic group and having a weight average molecular weight of 8,000 g / mol. 20 wt% of the polyurethane thus prepared was dispersed in 80 wt% of water to prepare a water dispersible polyurethane binder (1) having a solid content of 20 wt%. The prepared water-dispersible binder was blended with an impurity ion removal reinforced conductive polymer resin (SY-CP-E421M, Suyang Chemtech Co., Ltd.) at a weight ratio of 30:70 to prepare a mixed solution.

[Manufacture example 3]

Preparation of Water Dispersible Polyurethane Binder (2) and Preparation of Conductive Polymer Mixture

In theory, a water-dispersed polyurethane having a linear polymer content of 50% by weight and a branched polymer content of 50% by weight was prepared.

40 wt% of polyethyleneadipate diol, 0.6 wt% of trimethylol propane, and 55.9 wt% of hexamethylene diisocyanate were reacted to prepare a prepolymer having an isocyanate functional group as a prepolymer. 3.5 wt% of sodium hydrogen sulfate was reacted with an isocyanate, which is a terminal functional group of the prepolymer, to prepare a polyurethane having a weight average molecular weight of 14,400 g / mol. 20% by weight of the polyurethane thus prepared was dispersed in 80% by weight of water to prepare a water-dispersible polyurethane (2) having a solid content of 20% by weight. The prepared water-dispersible binder was blended with a conductive polymer resin (SY-CP-E421A, Sooyang Chemtech Co., Ltd.) at a weight ratio of 30:70 to prepare a mixed solution.

[Production Example 4]

40 wt% of polyethyleneadipate diol, 0.6 wt% of trimethylol propane, and 55.9 wt% of hexamethylene diisocyanate were reacted to prepare a prepolymer having an isocyanate functional group as a prepolymer. 3.5 wt% of sodium hydrogen sulfate was reacted with an isocyanate, which is a terminal functional group of the prepolymer, to prepare a polyurethane having a weight average molecular weight of 14,400 g / mol. 20% by weight of the polyurethane thus prepared was dispersed in 80% by weight of water to prepare a water-dispersible polyurethane (2) having a solid content of 20% by weight. The prepared water-dispersible binder was blended with an impurity ion removal reinforced conductive polymer resin (SY-CP-E421M, Suyang Chemtech Co., Ltd.) at a weight ratio of 30:70 to prepare a mixed solution.

Production Example 5

Preparation of Water Dispersible Polyurethane Binder (3) and Preparation of Conductive Polymer Mixture

Theoretically, water-dispersed polyurethanes having a content of 100% by weight of branched polymers were prepared.

40 wt% of polyethyleneadipate diol, 1.2 wt% of trimethylol propane, and 54.8 wt% of hexamethylene diisocyanate were reacted to prepare a prepolymer having an isocyanate functional group as a prepolymer. 4.0 wt% of sodium hydrogen sulfate was reacted with an isocyanate, which is a terminal functional group of the prepolymer, to prepare a polyurethane having a weight average molecular weight of 19,000 g / mol. 20 wt% of the polyurethane thus prepared was dispersed in 80 wt% of water to prepare a water dispersible polyurethane having a solid content of 20 wt%. The prepared water-dispersible binder was blended with a conductive polymer resin (SY-CP-E421A, Sooyang Chemtech Co., Ltd.) at a weight ratio of 30:70 to prepare a mixed solution.

[Manufacture example 6]

40 wt% of polyethyleneadipate diol, 1.2 wt% of trimethylol propane, and 54.8 wt% of hexamethylene diisocyanate were reacted to prepare a prepolymer having an isocyanate functional group as a prepolymer. 4.0 wt% of sodium hydrogen sulfate was reacted with an isocyanate, which is a terminal functional group of the prepolymer, to prepare a polyurethane having a weight average molecular weight of 19,000 g / mol. 20 wt% of the polyurethane thus prepared was dispersed in 80 wt% of water to prepare a water dispersible polyurethane having a solid content of 20 wt%. The prepared water-dispersible binder was blended with an impurity ion removal reinforced conductive polymer resin (SY-CP-E421M, Suyang Chemtech Co., Ltd.) at a weight ratio of 30:70 to prepare a mixed solution.

Example 1

Preparation of Coating Composition (1)

15 wt% of the mixed solution of Preparation Example 3, a wetting agent (0.4 wt% of DuPont's ZonylFSH), 5 wt% of isopropyl alcohol and 0.2 wt% of a crosslinking agent (Taxene BI 7987 of Baxenden), water 79.4 wt% (1) was prepared.

Preparation of Polyester Film for Back Sheet

A polyethylene terephthalate chip having a moisture content of 100 ppm or less was injected into a melt extruder, melted, and then extruded through a T-die, followed by quenching and solidifying with a casting drum having a surface temperature of 20 ° C. to prepare a polyethylene terephthalate sheet having a thickness of 2000 μm. .

The prepared polyethylene terephthalate sheet was stretched 3.5 times in the machine direction (MD) at 110 ° C. and then cooled to room temperature. Thereafter, the coating composition 1 was coated on one surface by a bar coating method, and then stretched 3.5 times in a transverse direction (TD) through preheating and drying at 140 ° C. Thereafter, heat treatment was performed at 235 ° C. in a 5-stage tenter, followed by heat setting at 10 ° C. in the machine direction and the transverse direction at 200 ° C., thereby preparing a biaxially stretched film having a thickness of 100 μm having an antistatic layer formed on one surface thereof. The dry coating thickness after stretching of the antistatic layer was 75 nm.

The physical properties of the thus obtained film are shown in Table 1 below.

Example 2

Preparation of Coating Composition (2)

15 wt% of the mixed solution of Preparation Example 4, 0.4 wt% of a wetting agent (ZonylFSH manufactured by DuPont), 5 wt% of isopropyl alcohol, 0.2 wt% of a crosslinking agent (Taxene BI 7987 of Baxenden), and 79.4 wt% of water. (2) was prepared.

Preparation of Polyester Film for Back Sheet

The prepared polyethylene terephthalate sheet was stretched 3.5 times in the machine direction (MD) at 110 ° C. and then cooled to room temperature. Thereafter, the coating composition 2 was coated on one surface by a bar coating method, and then stretched 3.5 times in a transverse direction (TD) through preheating and drying at 140 ° C. Thereafter, heat treatment was performed at 235 ° C. in a 5-stage tenter, followed by heat setting at 10 ° C. in the machine direction and the transverse direction at 200 ° C., thereby preparing a biaxially stretched film having a thickness of 100 μm having an antistatic layer formed on one surface thereof. The dry coating thickness after stretching of the antistatic layer was 75 nm.

The physical properties of the thus obtained film are shown in Table 1 below.

Example 3

Preparation of Coating Composition (3)

15 wt% of the mixed solution of Preparation Example 5, 0.4 wt% of a wetting agent (ZonylFSH of DuPont), 5 wt% of isopropyl alcohol, 0.2 wt% of a crosslinking agent (Taxene BI 7987 of Baxenden), and 79.4 wt% of water (3) was prepared.

Preparation of Polyester Film for Back Sheet

The prepared polyethylene terephthalate sheet was stretched 3.5 times in the machine direction (MD) at 110 ° C. and then cooled to room temperature. Thereafter, the coating composition 3 was coated on one surface by a bar coating method, and then stretched 3.5 times in a transverse direction (TD) through preheating and drying at 140 ° C. Thereafter, heat treatment was performed at 235 ° C. in a 5-stage tenter, followed by heat setting at 10 ° C. in the machine direction and the transverse direction at 200 ° C., thereby preparing a biaxially stretched film having a thickness of 100 μm having an antistatic layer formed on one surface thereof. The dry coating thickness after stretching of the antistatic layer was 75 nm.

The physical properties of the thus obtained film are shown in Table 1 below.

Example 4

Preparation of Coating Composition (4)

15 wt% of the mixed solution of Preparation Example 6, 0.4 wt% of a wetting agent (ZonylFSH from DuPont), 5 wt% of isopropyl alcohol, 0.2 wt% of a crosslinking agent (Taxene BI 7987 of Baxenden), and 79.4 wt% of water (4) was prepared.

Preparation of Polyester Film for Back Sheet

The prepared polyethylene terephthalate sheet was stretched 3.5 times in the machine direction (MD) at 110 ° C. and then cooled to room temperature. Thereafter, the coating composition 4 was coated on one surface by a bar coating method, and then stretched 3.5 times in a transverse direction (TD) through preheating and drying at 140 ° C. Thereafter, heat treatment was performed at 235 ° C. in a 5-stage tenter, followed by heat setting at 10 ° C. in the machine direction and the transverse direction at 200 ° C., thereby preparing a biaxially stretched film having a thickness of 100 μm having an antistatic layer formed on one surface thereof. The dry coating thickness after stretching of the antistatic layer was 75 nm.

The physical properties of the thus obtained film are shown in Table 1 below.

Comparative Example 1

Preparation of Coating Composition (5)

15 wt% of the mixed solution of Preparation Example 1, 0.4 wt% of a wetting agent (ZonylFSH manufactured by DuPont), 5 wt% of isopropyl alcohol, 0.2 wt% of a crosslinking agent (Taxene BI 7987 of Baxenden), and 79.4 wt% of water. (5) was prepared.

Preparation of Polyester Film for Back Sheet

The prepared polyethylene terephthalate sheet was stretched 3.5 times in the machine direction (MD) at 110 ° C. and then cooled to room temperature. Thereafter, the coating composition 5 was coated on one surface by a bar coating method, and then stretched 3.5 times in a transverse direction (TD) through preheating and drying at 140 ° C. Thereafter, heat treatment was performed at 235 ° C. in a 5-stage tenter, followed by heat setting at 10 ° C. in the machine direction and the transverse direction at 200 ° C., thereby preparing a biaxially stretched film having a thickness of 100 μm having an antistatic layer formed on one surface thereof. The dry coating thickness after stretching of the antistatic layer was 75 nm.

The physical properties of the thus obtained film are shown in Table 1 below.

Comparative Example 2

Preparation of Coating Composition (6)

15 wt% of the mixed solution of Preparation Example 2, 0.4 wt% of a wetting agent (ZonylFSH of DuPont), 5 wt% of isopropyl alcohol, 0.2 wt% of a crosslinking agent (Taxene BI 7987 of Baxenden), and 79.4 wt% of water (6) was prepared.

Preparation of Polyester Film for Back Sheet

The prepared polyethylene terephthalate sheet was stretched 3.5 times in the machine direction (MD) at 110 ° C. and then cooled to room temperature. Thereafter, the coating composition 6 was coated on one surface by a bar coating method, and then stretched 3.5 times in a transverse direction (TD) through preheating and drying at 140 ° C. Thereafter, heat treatment was performed at 235 ° C. in a 5-stage tenter, followed by heat setting at 10 ° C. in the machine direction and the transverse direction at 200 ° C., thereby preparing a biaxially stretched film having a thickness of 100 μm having an antistatic layer formed on one surface thereof. The dry coating thickness after stretching of the antistatic layer was 75 nm.

The physical properties of the thus obtained film are shown in Table 1 below.

Table 1

		Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2
Coating Film Properties of Coating Composition	Swelling ratio (%)	80.4	55.4	72.0	48.6	98.0	65.3
Coating Film Properties of Coating Composition	Gel fraction (%)	60	57	67	64	58	55
Surface resistance (Ω / sq) 10V × 10s		10 ⁵	10 ⁶	10 ⁵	10 ⁶	10 ⁵	10 ⁶
After stretching, coating appearance		○	◎	○	◎	○	○
Solvent resistance	Isopropyl Alcohol	◎	◎	◎	◎	○	○
	Ethyl alcohol	◎	◎	◎	◎	△	○
	Normal hexane	◎	◎	◎	◎	△	△
	toluene	◎	◎	◎	◎	△	△
	Ethyl acetate	◎	◎	◎	◎	△	△

As shown in Table 1, it can be seen that the lower the Swelling ratio of the antistatic agent of the embodiment including an antistatic layer according to the present invention, the higher the gel fraction, the higher the solvent resistance to normal hexane, toluene, and ethyl acetate. In addition, in the case of using the antistatic agent from which the impurity ions were removed, the coating appearance was very good, but the surface resistance was higher than that of the antistatic agent without the impurity ion removal.

On the other hand, as shown in Comparative Examples 1 and 2, when only the linear polyurethane resin was included, it was found that solvent resistance to normal hexane, toluene and ethyl acetate was low.

Claims

A polyester film comprising a base layer made of a polyester resin and an antistatic layer laminated on one or both sides of the base layer,

The antistatic layer is composed of 10 to 75% by weight of a linear polymer having two terminal groups and 25 to 90% by weight of a branched polymer having three or more terminal groups, or a water-dispersible polyurethane resin consisting of a branched polymer having three or more terminal groups, A polyester film formed by coating and drying an aqueous coating composition comprising a conductive polymer resin and water selected from polythiophene or polythiophene derivative.
The method of claim 1,

The antistatic layer is an antistatic polyester film having a surface resistance of 10 5 ~ 10 9 Ω / sq.
The method of claim 1,

The aqueous coating composition further comprises any one or two or more additives selected from wetting agents, alcohol solvents, particles, slip agents, crosslinking agents, curing agents.
The method of claim 3, wherein

The aqueous coating composition is 0.1 to 10% by weight of water-dispersible polyurethane resin, 0.1 to 10% by weight of conductive polymer resin, 0.1 to 1% by weight of wetting agent, 0.1 to 10% by weight of alcohol solvent, 0.1 to 10% by weight of crosslinking agent The polyester film containing water to satisfy 100% by weight.
The method of claim 1,

The said terminal group is a polyester film in which one part or all part is an isocyanate group blocked with the inorganic acid salt group.
The method of claim 1,

The water-dispersible polyurethane resin is prepared by reacting 39 to 45% by weight of polyol, 0.3 to 1.2% by weight of trimethylol propane and 50 to 57% by weight of isocyanate compound to prepare a prepolymer having an isocyanate as a terminal group, and then preparing an inorganic acid salt of 3 to 3%. A polyester film prepared by blocking 4% by weight of ionic groups at an isocyanate end.
The method of claim 6,

The water-dispersible polyurethane resin is a polyester film having a weight average molecular weight of 10,000 ~ 20,000g / mol.
The method of claim 1,

The antistatic layer is a polyester film coated by an inline coating method.
The method of claim 1,

The antistatic layer has a dry coating thickness of 10 ~ 500nm polyester film.
The method of claim 1,

The polyester film is a polyester film having a total thickness of 12 ~ 250㎛.
a) melt extruding a polyester resin to prepare a polyester sheet;

b) stretching the polyester sheet in the machine direction;

c) 10 to 75% by weight of the linear polymer having two terminal groups and 25 to 90% by weight of the branched polymer having three or more terminal groups on one or both sides of the polyester film drawn in the machine direction, or three terminal groups. Coating an aqueous coating composition comprising a water-dispersible polyurethane resin, a polythiophene or a polythiophene derivative made of a branched polymer, and a water-based coating composition including water and then stretching in a transverse direction; And

d) heat setting the biaxially stretched polyester film;

Method for producing a polyester film comprising a.
The method of claim 11,

The aqueous coating composition further comprises any one or two or more additives selected from wetting agents, alcohol solvents, particles, slip agents, crosslinking agents, curing agents.
The method of claim 11,

The aqueous coating composition is 0.1 to 10% by weight of water-dispersible polyurethane resin, 0.1 to 10% by weight of conductive polymer resin, 0.1 to 1% by weight of wetting agent, 0.1 to 10% by weight of alcohol solvent, 0.1 to 10% by weight of crosslinking agent Is a method for producing a polyester film containing water to satisfy 100% by weight.