KR20180097286A - Polyester film - Google Patents

Abstract

According to an embodiment of the present invention, a polyester film includes a base material layer containing polyester and a primer layer located on at least one surface of the base material layer. The primer layer includes a binder resin which has a terminal group containing at least one of a thiol group and an epoxy group, and a curing agent. The binder resin includes at least one of a polyester resin, a polyurethane resin, and a polyacrylic resin. An objective of the present invention is to provide a polyester film which has improved attaching and detaching force with a post-processing layer.

Description

Polyester film {POLYESTER FILM}

TECHNICAL FIELD The present invention relates to a polyester film, and more particularly to a polyester film having improved adhesiveness to a post-processing layer.

The polyester film is excellent in dimensional stability, thickness uniformity and transparency, and is widely used as an industrial material for display devices and the like.

The polyester film is an optical base film in particular, and is coated with various resins through post-processing to be used for various purposes. In the post-processing, a UV curable resin is generally used. Therefore, a method of coating a primer layer on the surface of a polyester film for the uniform adhesion between the UV curable resin coating layer and the polyester film applied through post-processing is the most widely used.

As a primer layer, a copolymer polyester resin having excellent adhesiveness to a polyester film is often used. This is because the heat resistance, moisture resistance, and adhesion are inferior, and the prism processing layer, the lens processing layer, the antireflection layer, There is a problem that the adhesiveness is insufficient at the same post-processing.

In recent years, development of a technique for improving the heat resistance, moisture resistance and the like through a method of adding an acrylic or polyurethane binder to the primer layer and improving the reactor structure of the binder and improving the adhesion with the post- .

However, this also causes the primer layer to fall off from the polyester film due to the lack of adhesion, so that there is a growing need to develop a technique for maintaining the uniform adhesion of the polyester film with the post-processing layer.

It is an object of the present invention to provide a polyester film having a high light transmittance and a low haze, while improving adhesion to a post-processing layer.

According to an embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: providing a base layer comprising a polyester; and a primer layer disposed on at least one side of the base layer, wherein the primer layer is formed of at least one of a thiol group and an epoxy group And a curing agent, wherein the binder resin comprises a polyester film comprising at least one of a polyester resin, a polyurethane resin, and a polyacrylic resin.

The curing agent may include at least one of oxazoline, carbodiimide, epoxy, aziridine, and melamine compounds.

The binder resin may include 30 to 70% by weight based on the total weight of the primer layer.

The terminal group may contain 0.01 to 20% by weight based on the total weight of the primer layer.

The curing agent may include 1 to 35% by weight based on the total weight of the primer layer.

The primer layer may further include at least one ion group selected from the group consisting of a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, and a quaternary ammonium salt group.

The polyester film may have an adhesive strength of 95% or more after the moisture resistance test for 360 hours at a temperature of 65 ° C and a humidity of 95%.

As described above, according to the polyester film according to one embodiment of the present invention, the adhesive force to the post-processing layer is improved, and high light transmittance and low haze can be obtained.

1 is a cross-sectional view of a polyester film according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thicknesses are enlarged to clearly indicate layers and regions. Like parts are designated with like reference numerals throughout the specification. It will be understood that when an element such as a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the element directly over another element, Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. Also, although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

Hereinafter, a polyester film according to an embodiment of the present invention will be described in detail with reference to FIG.

1 is a cross-sectional view of a polyester film according to an embodiment of the present invention.

Referring to FIG. 1, a polyester film according to an embodiment of the present invention includes a base layer 20 and a primer layer 10 located on at least one side of the base layer 20.

In other words, the primer layer 10 may be located only on one side of the base layer 20, or on both sides of the base layer 20.

The base layer 20 may be a biaxially stretched polyester film formed of a transparent material so as to sufficiently transmit visible light and containing polyester.

The polyester contained in the base layer 20 may be formed by polymerizing a dicarboxylic acid and a glycol.

Examples of the dicarboxylic acid include dicarboxylic acids such as terephthalic acid, naphthalene dicarboxylic acid, isophthalic acid, diphenylcarboxylic acid, diphenylsulfone dicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodium sulfone dicarboxylic acid, Alicyclic dicarboxylic acids such as aromatic dicarboxylic acids and aliphatic dicarboxylic acids such as hydroxyanic acid, succinic acid, adipic acid, sebacic acid, dimasic acid, maleic acid and fumaric acid and cyclohexanedicarboxylic acid, Oxycarboxylic acid, and the like.

Examples of the glycol include aliphatic glycols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol and neopentin glycol, polyoxyalkylene glycols such as diethylene glycol, polyethylene glycol and polypropylene glycol, cyclohexanedimethanol and the like Alicyclic glycols, aromatic glycols such as bisphenol A and bisphenol S, and the like.

The substrate layer 20 may include, but is not limited to, polyester formed by polymerizing ethylene glycol as a glycol, using terephthalic acid or naphthalene dicarboxylic acid as the dicarboxylic acid, May include polyesters.

In addition, the base layer 20 may further include inorganic particles for improving the properties of the polyester film.

The primer layer 10 may be located on at least one side of the substrate layer 20.

The primer layer 10 according to an embodiment of the present invention may include a binder resin having a terminal group containing at least one of a thiol group and an epoxy group and a curing agent.

The binder resin includes at least one of a polyester resin, a polyurethane resin, and a polyacrylic resin.

In this case, the polyester-based binder resin may include a dicarboxylic acid component and a glycol component, and the polyurethane-based binder resin may include a polyurethane having a molecular weight of 5,000 to 50,000. Examples of the polyacrylic binder resin include methyltetraacryl Methacrylate, butyl acrylate, acrylic acid, and the like.

The binder resin may include 30 to 70% by weight based on the total weight of the primer layer (10).

The polymer terminal of the binder resin may have a terminal group containing at least one of a thiol group and an epoxy group.

The terminal groups may contain 0.01 to 20% by weight, preferably 0.5 to 5% by weight, based on the total weight of the primer layer (10).

If it is contained in an amount of less than 0.01% by weight, it may be difficult to improve the adhesion with the post-treatment layer. If the amount of the additive is more than 20% by weight, stabilization for pass the time It can be degraded.

Next, the curing agent may include at least one compound selected from an oxazoline-based, carbodiimide-based, epoxy-based, aziridine-based and melamine-based compound.

The curing agent may contain 1 to 35% by weight based on the total weight of the primer layer (10), and the glass transition temperature (Tg) is preferably 20 to 100 ° C.

Examples of the oxazoline-based curing agent include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate and the like Acrylic acid ester; Unsaturated carboxylic acids such as methacrylic acid ester, acrylic acid, methacrylic acid, itaconic acid and maleic acid; Unsaturated nitriles such as acrylonitrile and methacrylonitrile; Unsaturated amides such as acrylamide methacrylamide, N-methylol acrylamide and N-methylol methacrylamide; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; Olefins such as ethylene and propylene; Unsaturated monomers such as chloroethylene, vinylidene chloride and vinyl fluoride; And unsaturated aromatic monomers such as styrene, a-methylstyrene, and the like.

Examples of the carbodiimide curing agent include hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, xylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 1,12-diisocyanate dodecane, norbornane Diisocyanate and 2,4-bis- (8-isocyanate octyl) -1,3-dioctylcyclobutane, 4,4'-dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate, etc. . ≪ / RTI >

Examples of the epoxy curing agent include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, dislycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate , Polyepoxy compounds such as glycerol polyglycidyl ether and trimethylolpropane polyglycidyl ether; Neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcinediglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether Diepoxy compounds such as diester ether, polypropylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether; Ethylhexyl glycidyl ether, phenyl glycidyl ether, and glycidyl amine compounds include N, N, N ', N'-tetraglycidyl-m-xylylenediamine, 1 , 3-bis (N, N-diglycidylamino) cyclohexane, and the like.

The primer layer 10 may further contain an ionic group such as a carboxyl group, a sulfonic acid, a phosphoric acid, a phosphonic acid or a quaternary ammonium salt to disperse the water of the binder resin.

The primer layer 10 may have a thickness of 0.02 to 0.3 탆.

The primer layer (10) according to the present invention comprises a binder resin having a terminal group containing at least one of a thiol group and an epoxy group followed by a UV curable resin which is processed on a polyester film Adhesion can be improved by participating in the UV curing reaction.

The polyester film comprising the primer layer 10 according to the present invention may have an adhesion of 95% or more after a moisture resistance test for 360 hours at a temperature of 65 ° C and a humidity of 95%.

Further, the polyester film comprising the primer layer 10 according to the present invention may have a light transmittance of 80% or more and a haze value of 0.4 to 2.4%.

Hereinafter, the structure and effect of the present invention will be described in more detail with reference to examples and comparative examples. However, this embodiment is intended to explain the present invention more specifically, and the scope of the present invention is not limited to these embodiments.

Manufacturing example

(1) Production of base film

The polyethylene terephthalate resin pellets were dried at 135 DEG C for 6 hours under reduced pressure (1.3 hPa), fed to an extruder, melt extruded at 280 DEG C in a sheet form and rapidly quenched and solidified on a metal roll maintained at a surface temperature of 20 DEG C To obtain a casting film.

Next, the casting film was heated to 100 ° C in a heated roll group and an infrared heater, and stretched at a 3.2-fold stretching ratio in the longitudinal direction by a roll group having a peripheral speed difference to produce a uniaxially oriented polyester film.

The uniaxially oriented polyester film was gripped at the ends with clips, introduced into the hot air region and dried. Thereafter, the film was stretched at a stretching ratio of 3.2 times in the transverse direction at 130 캜, heat set at 240 캜 and then transversely relaxed at 200 캜 at 3% to obtain a biaxially oriented polyester film having a thickness of 100 탆 as a base film.

(2) Preparation of Primer Layer Coating Liquid

The binder resin comprising any one of polyurethane, polyacryl, and polyester is in the form of an aqueous dispersion containing 70% by weight of water and 30% by weight of solids, and comprises 80% by weight of the total weight of the coating liquid.

In this case, the polyurethane-based binder resin was prepared by dissolving tolylene diisocyanate, ethylene glycol, and ethylenediamine in a molar ratio of 20: 17: 14, and the polyester-based binder resin was obtained by mixing dimethyl terephthalate, ethylene glycol, 0.1, and the polyacrylic binder resin was prepared in a molar ratio of acetylene, hydrogen cyanide, and neodene catalysts of 80: 70: 0.5, respectively.

0.1 to 5% by weight of a thiol group or an end group of an epoxy group based on the total weight of the coating liquid is polymerized in the binder resin, and 20% by weight of a curing agent containing any one of oxazoline, carbodiimide and epoxy is mixed .

At this time, in order to introduce a carboxyl group as an ionic group, dimethylol propionic acid is copolymerized with a binder resin. In order to polymerize a thiol group as a terminal group, mercaptpropanediol is copolymerized with a binder resin. To polymerize an epoxy group, bisphenol A And epichlorohydrin were copolymerized.

As the curing agent, an acrylic polymer having an oxazoline group and a polyalkylene oxide chain as an oxazoline curing agent, a polymer prepared by using hexamethylene diisocyanate as a carbodiimide curing agent, and an epoxy curing agent Polyhydroxyalkane-polyglyceryl ether was used.

In addition, 0.1% by weight of the fluorine surfactant aqueous dispersion was mixed with the coating liquid in the total weight of the coating liquid, and 0.05% by weight of the silica particle aqueous dispersion of 300 nm in size was mixed to prepare a coating liquid.

(3) Preparation of a polyester film coated with a primer layer

The prepared coating liquid was coated on one side of the polyester base film so that the solid weight was 0.08 g / m ² to form a primer layer having a thickness of 0.02 탆.

Examples 1 to 36

The binder resin, the curing agent and the terminal groups contained in the primer layer were formed as shown in Table 1, and polyester films coated with the primer layers according to Examples 1 to 36 were respectively prepared.

division Binder resin Hardener Horse short Kinds Weight ratio (%) Example 1 Polyurethane Oxazoline system Thiol group 1.0 Example 2 Polyurethane Oxazoline system Thiol group 5.0 Example 3 Polyurethane Carbodiimide system Thiol group 1.0 Example 4 Polyurethane Carbodiimide system Thiol group 5.0 Example 5 Polyurethane Epoxy system Thiol group 1.0 Example 6 Polyurethane Epoxy system Thiol group 5.0 Example 7 Polyurethane Oxazoline system Epoxy group 1.0 Example 8 Polyurethane Oxazoline system Epoxy group 5.0 Example 9 Polyurethane Carbodiimide system Epoxy group 1.0 Example 10 Polyurethane Carbodiimide system Epoxy group 5.0 Example 11 Polyurethane Epoxy system Epoxy group 1.0 Example 12 Polyurethane Epoxy system Epoxy group 5.0 Example 13 Polyacrylic Oxazoline system Thiol group 1.0 Example 14 Polyacrylic Oxazoline system Thiol group 5.0 Example 15 Polyacrylic Carbodiimide system Thiol group 1.0 Example 16 Polyacrylic Carbodiimide system Thiol group 5.0 Example 17 Polyacrylic Epoxy system Thiol group 1.0 Example 18 Polyacrylic Epoxy system Thiol group 5.0 Example 19 Polyacrylic Oxazoline system Epoxy group 1.0 Example 20 Polyacrylic Oxazoline system Epoxy group 5.0 Example 21 Polyacrylic Carbodiimide system Epoxy group 1.0 Example 22 Polyacrylic Carbodiimide system Epoxy group 5.0 Example 23 Polyacrylic Epoxy system Epoxy group 1.0 Example 24 Polyacrylic Epoxy system Epoxy group 5.0 Example 25 Polyester Oxazoline system Thiol group 1.0 Example 26 Polyester Oxazoline system Thiol group 5.0 Example 27 Polyester Carbodiimide system Thiol group 1.0 Example 28 Polyester Carbodiimide system Thiol group 5.0 Example 29 Polyester Epoxy system Thiol group 1.0 Example 30 Polyester Epoxy system Thiol group 5.0 Example 31 Polyester Oxazoline system Epoxy group 1.0 Example 32 Polyester Oxazoline system Epoxy group 5.0 Example 33 Polyester Carbodiimide system Epoxy group 1.0 Example 34 Polyester Carbodiimide system Epoxy group 5.0 Example 35 Polyester Epoxy system Epoxy group 1.0 Example 36 Polyester Epoxy system Epoxy group 5.0

Comparative Examples 1 to 10

A binder resin and a curing agent contained in the primer layer were formed as shown in Table 2 below and a polyester film coated with the primer layer according to Comparative Examples 1 to 10 was prepared using a coating solution containing no terminal groups .

division Binder resin Hardener Horse short Kinds Weight ratio (%) Comparative Example 1 - - - 0 Comparative Example 2 Polyurethane Oxazoline system - 0 Comparative Example 3 Polyurethane Carbodiimide system - 0 Comparative Example 4 Polyurethane Epoxy system - 0 Comparative Example 5 Polyacrylic Oxazoline system - 0 Comparative Example 6 Polyacrylic Carbodiimide system - 0 Comparative Example 7 Polyacrylic Epoxy system - 0 Comparative Example 8 Polyester Oxazoline system - 0 Comparative Example 9 Polyester Carbodiimide system - 0 Comparative Example 10 Polyester Epoxy system - 0

Experimental Example

(1) Haze and transmittance measurement

The haze and the transmittance of the polyester film according to Examples 1 to 36 and Comparative Examples 1 to 10 were measured using a haze meter (NIPPON DENSHOKU).

(2) Measurement of thickness of primer layer

The thickness of the primer layer of the polyester film according to Examples 1 to 36 and Comparative Examples 1 to 10 was measured using a pressure-sensitive meter (ID-Ff125, Mitsutoya) using a micrometer. The thickness was subtracted from the mean value of the remaining values.

(3) Adhesive strength measurement

The adhesive strength between the base film and the primer layer of the polyester film prepared in Examples 1 to 36 and Comparative Examples 1 to 10 was measured at normal temperature and humidity. A coating layer was formed by applying an acrylic UV curable resin to the surface to which the primer layer was adhered using a # 20 wire bar, and a cut line was formed on the film coated with the primer layer by a cutter. The squares were placed. A cellophane tape (No. 405, NICHIBAN Co., Ltd., width: 24 mm) was attached to the film having the cut line and the tape was peeled vertically to visually observe the area of the primer layer remaining on the coating layer. Respectively.

[Equation 1]

The adhesion test for evaluating the moisture resistance after 360 hours at a temperature condition of 65 占 폚 and a humidity of 95% was also carried out in the same manner as described above.

(4) Check coating property

In order to confirm the coating properties between the primer layer and the base film in the polyester films of Examples 1 to 36 and Comparative Examples 1 to 10, a primer layer was applied to the base film using # 0 to # 6 wire bars to prepare a front surface Was coated with a primer layer. It was evaluated that coatings were excellent when there were not more than 2 parts in 100 small square reference (square: 1mmX 1mm) with no naked coating liquid like naked eyes.

The experimental results are shown in Table 3 below.

division Optical property Adhesion Coating property Transmittance (%) Haze (%) Room temperature (%) High temperature intrusion
(%) Coating property Primer layer
Thickness (㎛) Example 1 93.2 0.97 90 60 △ 0.2 Example 2 92.8 0.94 80 60 △ 0.2 Example 3 92.9 1.02 95 90 △ 0.2 Example 4 91.9 1.10 100 100 △ 0.2 Example 5 92.4 1.08 70 80 ○ 0.2 Example 6 92.2 0.99 80 80 △ 0.2 Example 7 92.4 0.94 90 80 △ 0.2 Example 8 93.0 0.94 100 100 △ 0.2 Example 9 93.1 0.94 80 70 ○ 0.2 Example 10 92.9 0.95 90 80 ○ 0.2 Example 11 92.6 0.99 95 85 △ 0.2 Example 12 92.5 0.97 95 80 ○ 0.2 Example 13 92.4 0.94 90 90 ○ 0.2 Example 14 93.0 0.94 90 90 ○ 0.2 Example 15 92.4 0.94 80 75 ○ 0.2 Example 16 91.1 1.10 80 75 ○ 0.2 Example 17 92.2 1.08 90 60 ○ 0.2 Example 18 92.7 0.99 80 50 ○ 0.2 Example 19 92.4 0.94 90 80 ○ 0.2 Example 20 92.9 0.95 70 70 ○ 0.2 Example 21 92.6 0.99 90 90 ○ 0.2 Example 22 92.5 0.97 90 90 ○ 0.2 Example 23 92.9 0.95 80 80 ○ 0.2 Example 24 93.1 0.94 85 85 ○ 0.2 Example 25 92.9 0.95 95 80 ○ 0.2 Example 26 92.5 0.97 90 80 ○ 0.2 Example 27 92.4 0.94 95 80 ○ 0.2 Example 28 88.4 1.72 90 70 X 0.2 Example 29 91.9 0.99 80 80 X 0.2 Example 30 92.2 0.97 70 70 △ 0.2 Example 31 92.4 0.94 80 70 ○ 0.2 Example 32 92.8 0.94 70 70 △ 0.2 Example 33 93.0 0.95 60 50 ○ 0.2 Example 34 93.0 1.00 75 65 ○ 0.2 Example 35 92.2 0.97 85 85 △ 0.2 Example 36 92.4 0.94 90 90 ○ 0.2 Comparative Example 1 93.0 0.95 0 0 ○ 0.2 Comparative Example 2 93.0 1.00 60 40 ○ 0.2 Comparative Example 3 92.2 0.97 50 40 △ 0.2 Comparative Example 4 92.4 0.94 30 25 △ 0.2 Comparative Example 5 92.8 0.94 40 25 △ 0.2 Comparative Example 6 93.0 0.95 50 50 △ 0.2 Comparative Example 7 93.0 1.00 60 45 ○ 0.2 Comparative Example 8 92.2 0.97 20 15 △ 0.2 Comparative Example 9 92.4 0.94 20 10 △ 0.2 Comparative Example 10 93.0 0.95 20 10 △ 0.2

As shown in Table 3, the polyester film according to the Example in which the binder resin having a thiol group or an epoxy group as a terminal group was applied exhibited an adhesive force at a room temperature and a high temperature and humidity condition in comparison with the polyester film according to Comparative Examples 1 to 10 And coating properties were poor.

As described above, according to the polyester film according to the embodiment of the present invention, the adhesion to the post-processing layer can be improved, and high light transmittance and low haze can be obtained.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

10: Primer layer 20: substrate layer

Claims (7)

A base layer comprising polyester, and
And a primer layer disposed on at least one side of the substrate layer,
Wherein the primer layer comprises a binder resin having a terminal group containing at least one of a thiol group and an epoxy group and a curing agent,
Wherein the binder resin comprises at least one of a polyester resin, a polyurethane resin, and a polyacrylic resin. The method of claim 1,
Wherein the curing agent comprises at least one compound selected from the group consisting of oxazoline series, carbodiimide series, epoxy series, aziridine series and melamine series. 3. The method of claim 2,
Wherein the binder resin comprises 30 to 70% by weight based on the total weight of the primer layer. 4. The method of claim 3,
Wherein the terminal group comprises 0.01 to 20% by weight based on the total weight of the primer layer. 3. The method of claim 2,
Wherein the curing agent comprises 1 to 35% by weight based on the total weight of the primer layer. 3. The method of claim 2,
Wherein the primer layer further comprises an ionic group of at least one of a carboxyl group, a sulfonic acid, a phosphoric acid, a phosphonic acid, and a quaternary ammonium salt. The method of claim 1,
Wherein the polyester film has an adhesive strength of 95% or more after a moisture resistance test for 360 hours under a temperature condition of 65 캜 and a humidity of 95%.

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