KR102027426B1 - Polyester film - Google Patents

Abstract

The present invention relates to a polyester film blocking the oligomer through a primer layer, to block the migration of the oligomer during heating, and to an oligomer-blocking polyester film that can be used for optical purposes with a low haze change rate after heating. will be.

Description

Polyester film {POLYESTER FILM}

The present invention relates to a polyester film blocking the oligomer through a primer layer, to block the migration of the oligomer during heating, and to an oligomer-blocking polyester film that can be used for optical purposes with a low haze change rate after heating. will be.

An optical film is a film used as an optical member for display, and is used as an optical material for LCD BLU, or as an optical member for surface protection of various displays such as LCD, PDP, and touch panel.

Such optical films require excellent transparency and visibility, and use biaxially stretched polyester films having excellent mechanical and electrical properties as base films.

Quality problems and physical property degradation due to oligomers are occurring in the polyester film for display, and the quality problems include polyester as the high temperature is applied in the curing process after prism coating, diffusion coating, or hard coating in the post-processing process of the polyester film. The oligomer is migrated from the inside of the film to generate a whitening phenomenon on the opposite surface of the prism coating, diffusion coating, or hard coating, as shown in FIG. 1. In addition, a diamond mark phenomenon in which a diamond pattern is formed as shown in FIG. 2 occurs due to the pressure of the diamond pattern roll used in the slitting process after the polyester film is manufactured.

When such whitening and diamond mark phenomena occur, the film roll is contaminated in the process and the optical properties of the final product are degraded.

In order to prevent the migration of the oligomer of such a polyester film has been attempted to lower the oligomer content during the polymerization of the polyester film, it was not enough to block the oligomer completely.

In addition, Japanese Patent Application Laid-Open No. 2007-253511 (2007.10.04) discloses a polyester film having a laminated film on at least one side thereof. with a mean size of oligomers precipitated on the particles is a laminated film in terms of area 10㎛ ² or less, the number of the base material is not more than 100 × 100㎛ 100㎛ within the field of view when the laminated polyester film was heated for 60 minutes. This invention seeks to control the outflow of oligomers but does not completely block them.

Japanese Laid-Open Patent No. 2007-253511 (2007.10.04)

It is an object of the present invention to provide a polyester film in which the outflow of the oligomer is completely blocked.

Moreover, an object of this invention is to suppress the rise of haze by the outflow of the surface of an oligomer at the time of heat processing, and to provide the polyester film whose haze change rate is 0.1% or less.

As a result of the present inventors' research to achieve the above object, by using a specific water-dispersible resin composition having oligomer blocking properties as a composition for forming a primer layer, it is possible to block the outflow of the oligomer, and thus the rate of haze change after heating The present invention has been completed by the discovery that a much lower polyester film is produced than this prior art.

In addition, by using a cross-linking agent of a specific structure in the water-dispersible resin composition, it is possible to further improve the oligomer barrier properties and to increase the coating film strength to improve scratch resistance and solvent resistance, thereby reducing appearance defects that may occur during post-processing. At the same time, by using a crosslinking agent having a specific structure, the reaction rate is further increased, thereby increasing the low conversion rate of the crosslinking agent that may occur due to the characteristics of the film forming process and deteriorating the properties of the primer layer caused by the unreacted crosslinking agent in the primer layer and the primer layer. The increase in haze of was improved, and the present invention was found to be able to provide a polyester film having improved oligomer barrier properties by increasing the degree of crosslinking.

The present invention comprises a polyester base film and a primer layer formed by applying a water-dispersible resin composition having oligomer blocking properties on one or both sides thereof, and maintained at 150 ° C. for 60 minutes, followed by a haze change rate according to Equation 1 below. It relates to an oligomer blocking polyester film having a (ΔH) of 0.1% or less.

[Equation 1]

ΔH (%) = (haze of film after holding at 150 ° C. for 60 minutes—haze of film before heating)

In the present invention, the water dispersible resin composition may include an acrylic resin copolymerized with a glycidyl group-containing radical polymerizable unsaturated monomer and a water dispersible polyester resin.

In the present invention, the water-dispersible resin composition has a solid content weight ratio of the acrylic resin (A) copolymerized with the glycidyl group-containing radically polymerizable unsaturated monomer and the water-dispersible polyester resin (B) (A) / (B) = 20 to It can be 80 / 80-20.

In the present invention, the water-dispersible polyester-based resin may be a copolymer of a dicarboxylic acid component containing a sulfonic acid alkali metal salt compound and a glycol component containing diethylene glycol.

In the present invention, the water-dispersible polyester-based resin may contain 20 to 80 mol% of diethylene glycol in the total glycol component.

In the present invention, the water-dispersible polyester-based resin may be a sulfonic acid alkali metal salt compound containing 6 to 20 mol% of the total acid component.

In the present invention, the acrylic resin may be one containing 20 to 80 mol% of the glycidyl group-containing radically polymerizable unsaturated monomer as a copolymerization monomer.

In the present invention, the water-dispersible resin composition may further include any one or more compounds selected from Chemical Formula 1 as a crosslinking agent.

[Formula 1]

Wherein A ₁ to A ₃ are each independently a chemical bond or are selected from (C1-C10) alkylene, and R ₁ to R ₃ are each independently selected from hydrogen and (C1-C10) alkyl. )

In the present invention, the crosslinking agent may be a compound of Formula 2 below.

[Formula 2]

In the present invention, the polyester base film may be a polyethylene terephthalate film.

In the present invention, the polyester base film may be a thickness of 25 ~ 250㎛.

In the present invention, the primer layer may be a dry coating thickness of 20 ~ 200nm.

In the present invention, the water-dispersible resin composition may be applied by an in-line coating method of the polyester film manufacturing process.

The oligomer blocking polyester film of the present invention can be used as a film for display.

The polyester film according to the present invention has optical properties suitable for use as an optical film, it is possible to block the outflow of the oligomer at high temperature conditions, and to prevent haze rise.

1 is a photograph showing the whitening phenomenon of the polyester film leaked oligomer.
Figure 2 is a photograph showing the diamond mark phenomenon of the polyester film spilled oligomer.
3 shows a cross section of a polyester film according to a first aspect of the invention.
4 shows a cross section of a polyester film according to a second aspect of the invention.

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

As shown in FIG. 3, the first aspect of the present invention includes a polyester base film 10 and a primer layer 20 on one surface thereof, and is maintained at 150 ° C. for 60 minutes, followed by haze according to Equation 1 below. It is related with the polyester film which has oligomer blocking property whose change rate ((DELTA) H) is 0.1% or less.

[Equation 1]

ΔH (%) = (haze of film after holding at 150 ° C. for 60 minutes—haze of film before heating)

As shown in FIG. 4, the second embodiment of the present invention includes a polyester base film 10 and a first primer layer 20 and a second primer layer 30 on both surfaces thereof, and at 150 ° C. for 60 minutes. After hold | maintaining, it is related with the polyester film which has the oligomer blocking property whose haze change rate ((DELTA) H) which concerns on following formula 1 is 0.1% or less.

[Equation 1]

ΔH (%) = (haze of film after holding at 150 ° C. for 60 minutes—haze of film before heating)

In the polyester film of the present invention, the primer layer is formed by applying a water-dispersible resin composition having oligomer barrier properties. The present invention is a water-dispersible resin composition having the oligomer barrier properties, by using a specific resin is very improved the barrier properties of the oligomer, and thus the change rate of haze even after heating to 0.1% or less, more specifically 0 to 0.1% The present invention has been found to be very improved. In addition, if the water-dispersible resin composition further comprises a compound according to the formula (1) of the present invention was found that the change rate of haze is more than 0.05%, more specifically 0 to 0.05% to further improve the effect of the present invention It was.

The water-dispersible resin composition includes an acrylic resin copolymerized with a glycidyl group-containing radical polymerizable unsaturated monomer and a water-dispersible polyester resin.

In one embodiment of the present invention, the water-dispersible resin composition has a solid content weight ratio of acrylic resin (A) copolymerized with a glycidyl group-containing radically polymerizable unsaturated monomer and a water-dispersible polyester resin (B) (A) / (B) = 20 to 80/80 to 20. More preferably, it may be used in a weight ratio of 40 to 60/60 to 40. If the solids content of the water-dispersible polyester resin (B) is less than 20% by weight and the solids content of the acrylic resin (A) copolymerized with the glycidyl group-containing radically polymerizable unsaturated monomer is greater than 80% by weight, As particle size increases, staining occurs during inline coating, adhesion and transparency with polyester base film decreases, and the solid content of water-dispersible polyester resin (B) is over 80% by weight, and glycy When the solid content of the acrylic resin (A) copolymerized with a dill-containing radically polymerizable unsaturated monomer is less than 20% by weight, sufficient oligomer blocking effect cannot be expressed.

The water dispersible resin composition of the present invention can be prepared by mixing an aqueous dispersion of the water dispersible polyester resin (B) with an emulsion of an acrylic resin (A) copolymerized with a glycidyl group-containing radical polymerizable unsaturated monomer, It is also possible to superpose | polymerize and produce the glycidyl-group containing radically polymerizable unsaturated monomer or the radically polymerizable unsaturated monomer copolymerizable with a glycidyl group containing radically polymerizable unsaturated monomer in the aqueous dispersion of polyester-type resin (B). At this time, surfactant and a polymerization initiator can be used. The surfactant and the polymerization initiator may be used without limitation as long as it is conventionally used in emulsion polymerization. Specifically, for example, as the surfactant, anionic surfactants, nonionic surfactants or non-reactive surfactants can be used, and these can also be used in combination. The polymerization initiator is a radically polymerizable initiator, and nitrogen compounds such as a peroxide initiator or azobis isobutyronitrile can be used.

The water dispersion composition of the present invention may further include an antifoaming agent, a wetting agent, a surfactant, a thickener, a plasticizer, an antioxidant, a UV absorber, a preservative, and the like, as necessary.

More preferably, by including a compound of Formula 1 as a crosslinking agent, the reaction rate is faster and the primer layer can be formed at a low temperature, thereby completely blocking the oligomer which may be partially leaked by heating after the primer layer is formed. .

[Formula 1]

Wherein A ₁ to A ₃ are each independently a chemical bond or are selected from (C1-C10) alkylene, and R ₁ to R ₃ are each independently selected from hydrogen and (C1-C10) alkyl. )

As a more specific example of Formula 1, a compound of Formula 2 may be used.

[Formula 2]

The compound of Formula 2, while the reaction rate is fast, the reaction temperature is 120 ~ 140 ℃, more specifically 130 ℃ in the preheating zone (Preheating Zone) during the film forming process of the polyester film, accordingly glycidyl group It is possible to react with the glycidyl group of the acrylic resin (A) in which the containing radically polymerizable unsaturated monomer is copolymerized, thereby forming a primer coating film having a more dense structure.

Therefore, in the case of using the compound of Formula 2, it is possible to apply in the in-line coating process during the film forming process of the polyester film, and thus, the process is simplified since the process of applying the primer layer separately after film production is not necessary. Since it is stretched after application by the coating process to form a uniform coating film thickness, it is possible to produce a polyester film having excellent optical properties.

The crosslinking agent is 1 to 40 parts by weight based on 100 parts by weight of the total solid content of the acrylic resin (A) in which the aqueous dispersion of the water-dispersible polyester resin (B) and the glycidyl group-containing radically polymerizable unsaturated monomer in the water dispersion composition are copolymerized. It is preferable to use a weight part, More preferably, it is 5-20 weight part. If it is less than 1 part by weight, its use effect is insignificant, and when it is used in excess of 40 parts by weight, the properties of the main binder may be lowered, thereby lowering the adhesive strength.

In the case where the crosslinking agent is further included, the haze change rate (ΔH) according to the following Equation 1 is 0.05% or less, more specifically 0 to 0.05%, after being maintained at 150 ° C. for 60 minutes, and the scratch resistance and the solvent resistance are further increased. An improved polyester film can be provided.

In the water dispersion composition of the present invention, the water-dispersible polyester-based resin (B) may be a copolymer of a dicarboxylic acid component containing a sulfonic acid alkali metal salt compound and a glycol component containing diethylene glycol.

More specifically, as the dicarboxylic acid component, an aromatic dicarboxylic acid and a sulfonic acid alkali metal salt compound may be used, and the sulfonic acid alkali metal salt compound may contain 6 to 20 mol% of the total acid component.

The dicarboxylic acid component is an aromatic dicarboxylic acid such as phthalic acid, terephthalic acid, dimethyl terephthalate, isophthalic acid, dimethyl isophthalic acid, 2,5-dimethyl terephthalic acid, 2,6-naphthalene dicarboxylic acid, biphenyldicarboxylic acid and the like. Aliphatic dicarboxylic acids, such as an acid, adipic acid, a sebacic acid, alicyclic dicarboxylic acids, such as cyclohexane dicarboxylic acid, etc. can be used.

Specific examples of the sulfonic acid alkali metal salt compound include alkali metal salts such as sulfoterephthalic acid, 5-sulfo isophthalic acid, 4-sulfo isophthalic acid, 4-sulfo naphthalic acid-2,7-dicarboxylic acid, and the like. It is preferable to use 6-20 mol%. When using less than 6 mol%, the dispersion time of resin to water becomes long, dispersibility is low, and when it uses more than 20 mol%, water resistance may fall.

As the glycol component, diethylene glycol and aliphatic glycols having 2 to 8 carbon atoms or alicyclic glycols having 6 to 12 carbon atoms may be used. Specifically, for example, ethylene glycol, 1,3-propanediol, 1,2-propylene glycol, neopentyl glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol , 1,2-cyclohexanedimethanol, 1,6-hexanediol, P-xylene glycol, triethylene glycol and the like can be used. At this time, it is preferable to contain 20-80 mol% of diethylene glycol among all the glycol components.

It is preferable that the number average molecular weights of the said water-dispersible polyester resin (B) are 1000-50000, More preferably, the number average molecular weights are 2000-30000. When the number average molecular weight is less than 1000, the oligomer blocking effect is insignificant, and when the number average molecular weight is more than 50000, water dispersibility may be difficult.

The water-dispersible polyester-based resin (B) is used by uniformly dispersing by heating and stirring the water or water containing an aqueous solvent at 50 ~ 90 ℃. The aqueous dispersion thus prepared has a solid content of 30 wt% or less, more preferably 10 to 30 wt%, for uniform dispersion. The aqueous solvent may be alcohols such as methanol, ethanol, propanol, polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, and the like.

Next, the acrylic resin (A) to which the glycidyl group containing radically polymerizable unsaturated monomer was copolymerized is demonstrated.

Acrylic resin (A) copolymerized with a glycidyl group-containing radically polymerizable unsaturated monomer is a homopolymer of a glycidyl group-containing radically polymerizable unsaturated monomer or another radically polymerizable unsaturated monomer copolymerizable with a glycidyl group-containing radically polymerizable unsaturated monomer. It is resin copolymerized.

 The acrylic resin may be a copolymer monomer containing 20 to 80 mol% of the glycidyl group-containing radical polymerizable unsaturated monomer in all monomer components. Since the glycidyl group-containing radically polymerizable unsaturated monomer improves the strength of the coating film of the primer layer by the crosslinking reaction and increases the crosslinking density, it is possible to block the outflow of the oligomer. Specifically, for example, glycidyl ethers such as glycidyl acrylate, glycidyl methacrylate, and arylglycidyl ether can be used.

Radical polymerizable unsaturated monomers copolymerizable with glycidyl group-containing radical polymerizable unsaturated monomers include vinyl esters, unsaturated carboxylic acid esters, unsaturated carboxylic acid amides, unsaturated nitriles, unsaturated carboxylic acids, allyl compounds, nitrogen-containing vinyl monomers and hydrocarbon vinyl monomers. Or a vinyl silane compound. Vinyl propionate, vinyl stearate, vinyl chloride, etc. can be used as vinyl ester. Unsaturated carboxylic acid esters include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate, butyl methacrylate, butyl maleate, octyl maleate, butyl fumarate, octyl fumarate, hydroxyethyl methacrylate, Hydroxyethyl acrylate, methacrylate hydroxypropyl, hydroxypropyl acrylate and the like can be used. As the unsaturated carboxylic acid amide, acrylamide, methacrylamide, metyrolacrylamide, butoxy methirol acrylamide, and the like can be used. Acrylonitrile etc. can be used as unsaturated nitrile. As the unsaturated carboxylic acid, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic acid acid ester, fumaric acid acid ester, itaconic acid acid ester and the like can be used. As the allyl compound, allyl acetate, allyl methacrylate, allyl acrylate, allyl itaconic acid, diallyl itaconic acid and the like can be used. Vinylpyridine, vinyl imidazole, etc. can be used as a nitrogen-containing vinyl monomer. As the hydrocarbon vinyl monomer, ethylene, propylene, hexene, octene, styrene, vinyltoluene, butadiene and the like can be used. As a vinyl silane compound, dimethyl vinyl methoxy silane, dimethyl vinyl ethoxy silane, methyl vinyl dimethoxy silane, methyl vinyl diethoxy silane, gamma-methacryloxy propyl trimethoxy silane, gamma-methacryloxy propyl dimethoxy silane, etc. Can be used.

The water-dispersible resin composition of the present invention has a solid content of 0.5 to 10% by weight of the acrylic resin copolymerized with the glycidyl group-containing radically polymerizable unsaturated monomer and the water-dispersible polyester resin, 0.1 to 0.5% by weight of the wetting agent, and an average particle diameter. It is preferably a water dispersible or water-soluble composition having a total solid content of 0.5 to 10% by weight, including 0.1 to 1.0% by weight of silica having 100 to 200 nm. It is preferable to adjust the coating thickness in the range of 0.5 to 10 weight% of solid content.

The wetting agent is used to improve the coating property. Specifically, for example, a modified silicone wetting agent such as Dow Corning's Q2-5212, ENBODIC's TEGO WET 250, BYK CHEMIE's BYK 348, etc. may be used. It doesn't happen. Wetting agent is preferably used in 0.1 to 0.5% by weight, it is possible to achieve the desired coating properties in the above range.

Silica having an average particle diameter of 50 nm to 1000 nm is used to improve film winding property, and may be used by Ace Hitech Inc. ACESOL Series, Nano Technology Inc. NYACOL Series, Catalytic Spherical slurry series, and the like. The content is preferably used 0.1 to 1.0% by weight.

In one embodiment of the present invention, the polyester base film may be a polyethylene terephthalate film. The polyester base film may be a thickness of 25 ~ 250㎛.

In the present invention, the primer layer may be a dry coating thickness of 20 ~ 200nm. When the dry coating thickness is less than 20 nm, the oligomer blocking property may not be sufficiently exhibited. When the dry coating thickness is greater than 200 nm, a coating stain may appear, and a blocking phenomenon in which the primer layers stick to each other after winding the film may increase.

In the present invention, the water-dispersible resin composition may be applied by an in-line coating method of the polyester film manufacturing process. That is, after the polyester base film is prepared by the in-line coating method before stretching or before the second stretching after the primary stretching, and may be prepared by stretching, water is evaporated by heating in the stretching and heat setting process primer layer This can be formed. The coating method is not limited as long as it is a known coating method.

Hard coating layer, pressure-sensitive adhesive layer, light diffusing layer, ITO layer, etc. may be formed on top of the polyester film of the present invention, and even after heating the functional coating layer, the outflow of the oligomer may be blocked to maintain optical properties. The polyester film of the present invention is suitable for use as an optical film.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the following Examples.

The physical properties were measured by the following measurement method.

1) Dry coating thickness of primer layer

The cross-section of the film was measured by SEM (Hitachi S-4300) by designating 5 points at 1m intervals in the vertical direction (TD) of the machine direction to which the coating composition was coated. The average value was calculated after 30 point measurement.

2) Haze change rate (△ H)

After forming the primer layer,

When forming double-sided primer layer

After the haze of the film before heating and held at 150 ° C. for 60 minutes, the haze of the film was measured, and the amount of change was calculated according to the following formula (1).

-When forming cross section primer layer

Corona treatment on the opposite side of the primer layer formation, and a hard coating solution (AIKA, Z-711) was applied to Mayer Bar # 4, dried at 80 ° C. for 2 min, and then irradiated with UV (200mj / ㎠ ) Hard coat layer is formed on the surface.

After the haze of the film before heating and held at 150 ° C. for 60 minutes, the haze of the film was measured, and the amount of change was calculated according to the following formula (1).

[Equation 1]

ΔH (%) = (haze of film after holding at 150 ° C. for 60 minutes—haze of film before heating)

3) Average area of oligomer particles after heating

After cutting the polyester film into 100mm × 100mm size, Aging was done for 60 minutes in the oven set at 150 ℃, and then 27000㎛ ² could be observed at 500 times magnification using the reflection mode of microscope (Leica, DM 2500M). The surface area was observed 10 times, and the shortest and longest lengths of the oligomer particles observed 10 times were recorded, and the average area of the oligomer migrated to an area of 1000 μm ² was calculated.

Area per oligomer = (shortest length of oligomer particles × shortest length of oligomer particles)

Oligomer area per unit area (10000 μm ² ) = sum of the area of migrated oligomers / 2.7

Average value of oligomer area observed 10 times

4) Number of oligomer particles after heating

After cutting the polyester film into 100mm × 100mm size, Aging was performed for 60 minutes in the oven set at 150 ℃, and then 27000㎛ ² can be observed at 500 times magnification using the reflection mode of microscope (Leica, DM 2500M). The surface area was observed 10 times and the number of oligomer particles observed 10 times was averaged.

Number of oligomers per unit area (10000㎛ ² ) = (number of oligomers at one time observation / 2.7)

Average value of oligomers observed 10 times

The binder resins used in the following Examples and Comparative Examples are as follows.

1) KLX-007 Binder

The solid content weight ratio of the acrylic resin (A) copolymerized with the glycidyl group-containing radically polymerizable unsaturated monomer and the water-dispersible polyester resin (B) is (A) / (B) = 50/50,

The acrylic resin contains 50 mol% of the glycidyl group-containing radical polymerizable unsaturated monomer as a copolymerization monomer in all monomer components,

The water-dispersible polyester resin contains 50 mol% of diethylene glycol in the total glycol component and 10 mol% of the sulfonic acid alkali metal salt compound in the total acid component.

2) KLX-008 Binder

The solid content weight ratio of the acrylic resin (A) copolymerized with the glycidyl group-containing radically polymerizable unsaturated monomer and the water-dispersible polyester resin (B) is (A) / (B) = 50/50,

The acrylic resin contains 40 mol% of the glycidyl group-containing radical polymerizable unsaturated monomer as a copolymerization monomer in all monomer components,

The water-dispersible polyester-based resin contains 50 mol% of diethylene glycol in the total glycol component and 10 mol% of the sulfonic acid alkali metal salt compound in the total acid component.

3) KLX-030 Binder

The solid content weight ratio of the acrylic resin (A) copolymerized with the glycidyl group-containing radically polymerizable unsaturated monomer and the water-dispersible polyester resin (B) is (A) / (B) = 50/50,

The acrylic resin contains 50 mol% of the glycidyl group-containing radical polymerizable unsaturated monomer as a copolymerization monomer in all monomer components,

The water-dispersible polyester resin contains 40 mol% of diethylene glycol in the total glycol component and 15 mol% of the sulfonic acid alkali metal salt compound in the total acid component.

4) P3208 Binder

Rohm & Haas Co., Ltd., a binder containing 40% by weight of methyl methacrylate, 40% by weight of ethyl acrylate and 20% by weight of melamine.

5) H-3 binder

Made by DAICHI KOGYO SEIYAKU, 9% by weight of polyester polyol (polyethylene adipate diol having a weight average molecular weight of 1000), 10% by weight of hexamethylene diisocyanate, reactive emulsifier with ionic group (Asahi Denka, polyoxyethylene allyl Aqueous polyurethane binder having a solid content of 20% by weight of 1% by weight of adecaria shop SETM), a sulfonic acid ester of glycidyl nonyl phenylether, and 80% by weight of water.

6) Z-561 Binder

Made by Goo Chemical, 40 mol (26 mol%) of 2,6-Naphtalene dicarboxly acid, sodium 2,5-dicarboxylbenzene sulfonate 5 mol (3.3 mol%), 5 mol (3.3 mol%) of dimethyl terephthalic acid and ethylene glycol and 1,4 butylene glycol mixed by 1: 1 to 100 mol (66.66 mol%) prepared by polycondensation reaction 25 % By weight aqueous polyester binder.

Example 1

Preparation of Water Dispersible Resin Composition (1)

0.3 wt% of a silicone wetting agent (Dow Corning, polyester siloxane copolymer-Q2-5212) and 16 wt% of KLX-007 binder (solid content 25% water dispersion composition) and 0.3 wt% of colloidal silica particles having an average particle diameter of 140 nm It was added to water and stirred for 2 hours to prepare a water dispersible resin composition (1) having a total solid content of 4.6% by weight.

Preparation of Oligomeric Blocking Polyester Films

The polyethylene terephthalate chip from which moisture was removed was placed in an extruder, melt-extruded, and then quenched and solidified in 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 80 ° C. and then cooled to room temperature. Thereafter, the prepared water-dispersible resin composition (1) was coated on both sides by a bar coating method, and then heated to 1 ° C. per second to 110 to 150 ° C., preheated and dried, and then 3.5 times in the transverse direction (TD). Stretched. Thereafter, heat treatment was performed at 235 ° C. in a 5-stage tenter, followed by heat setting by relaxing 10% in the longitudinal and transverse directions at 200 ° C. to prepare a biaxially oriented film of 188 μm coated on both sides.

The dry coating thickness of the primer coating layer of the composition was 80 nm. The physical properties of the polyester film thus obtained are shown in Table 1 below.

Example 2

Preparation of Water Dispersible Resin Composition (2)

16 wt% of KLX-007 binder (solid content 25% water dispersion composition), 0.4 wt% of compound of the following [Formula 2] (10 parts by weight based on binder solids), silicone-based wetting agent (Dow Corning, polyester siloxane copolymer- Q2-5212) 0.3 wt% and 0.3 wt% of colloidal silica particles having an average particle diameter of 140 nm were added to water, followed by stirring for 2 hours to prepare a water dispersible resin composition (2) having a total solid content of 4.6 wt%.

[Formula 2]

Preparation of Oligomeric Blocking Polyester Films

The polyethylene terephthalate chip from which moisture was removed was placed in an extruder, melt-extruded, and then quenched and solidified in 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 80 ° C. and then cooled to room temperature. Thereafter, the prepared water-dispersible resin composition (2) was coated on both sides by a bar coating method, and then heated to 1 ° C. per second to 110 to 150 ° C., preheated and dried, and then 3.5 times in the transverse direction (TD). Stretched. Thereafter, heat treatment was performed at 235 ° C. in a 5-stage tenter, followed by heat setting by relaxing 10% in the longitudinal and transverse directions at 200 ° C. to prepare a biaxially oriented film of 188 μm coated on both sides.

The dry coating thickness of the primer coating layer of the composition was 86 nm. The physical properties of the polyester film thus obtained are shown in Table 1 below.

[Examples 3 to 6]

As shown in Table 1, the film was prepared in the same manner as in Example 1 except for changing the type and content of the binder resin and the content of the crosslinking agent.

Comparative Example 1

P-3208 Binder 9.1 wt% (44% solids dispersion composition), 0.3 wt% silicone wetting agent (Dow Corning, polyester siloxane copolymer-Q2-5212), 0.3 wt% water with an average particle diameter of 140 nm It was added for 2 hours and stirred to prepare a water dispersible resin composition having a total solid content of 4.6 wt%.

Comparative Example 2

20 wt% H-3 Binder (solid 20% water dispersion composition), silicone wetting agent (Dow Corning, polyester siloxane copolymer-Q2-5212) 0.3 wt%, colloidal silica particles with an average particle diameter of 140nm 0.3 wt% water It was added for 2 hours and stirred to prepare a water dispersible resin composition having a total solid content of 4.6 wt%.

Comparative Example 3

Z-561 Binder 16% by weight (solid content 25% water dispersion composition), 0.4% by weight of the compound of the formula [2] (10 parts by weight relative to the binder solids), silicon-based wetting agent (Dow Corning, polyester siloxane copolymer- Q2-5212) 0.3 wt%, 0.3 wt% of colloidal silica particles having an average particle diameter of 140 nm was added to water and stirred for 2 hours to prepare a water dispersible resin composition having a total solid content of 4.6 wt%.

TABLE 1

As shown in the table, Examples 1 to 6 of the present invention was found that the haze change rate is very low, 0.1% or less, it was confirmed that the haze change rate is further lowered by using a crosslinking agent, the area and number of oligomers It was confirmed that is significantly lower.

10: polyester base film
20: first primer layer
30: second primer layer

Claims (14)

It includes a polyester base film and a primer layer formed by coating a water-dispersible resin composition having an oligomer barrier property on one or both sides thereof,
The water-dispersible resin composition includes an acrylic resin copolymerized with a glycidyl group-containing radically polymerizable unsaturated monomer, a water-dispersible polyester resin, and a crosslinking agent of the following Chemical Formula 1,
The water-dispersible polyester-based resin is a copolymer of a dicarboxylic acid component containing a sulfonic acid alkali metal salt compound and a glycol component containing diethylene glycol,
The water-dispersible polyester-based resin contains 20 to 80 mol% of diethylene glycol in the total glycol component
The oligomer blocking polyester film whose haze change rate ((DELTA) H) according to following Formula 1 is 0.05% or less after hold | maintaining at 150 degreeC for 60 minutes:
[Equation 1]
ΔH (%) = (haze of film after holding at 150 ° C. for 60 minutes—haze of film before heating)
[Formula 1]

Wherein A ₁ to A ₃ are each independently a chemical bond, or are selected from (C1-C10) alkylene, and R ₁ to R ₃ are each independently selected from hydrogen, (C1-C10) alkyl.
delete The method of claim 1,
The water-dispersible resin composition has a solid content weight ratio of acrylic resin (A) copolymerized with a glycidyl group-containing radically polymerizable unsaturated monomer and water-dispersible polyester resin (B) (A) / (B) = 20 to 80/80 Oligomeric blocking polyester film of ˜20. delete delete The method of claim 1,
The water-dispersible polyester-based resin is an oligomeric blocking polyester film containing 6 to 20 mol% of the sulfonic acid alkali metal salt compound in the total acid component. The method of claim 1,
The acrylic resin is an oligomer-blocking polyester film containing 20 to 80 mol% of the glycidyl group-containing radical polymerizable unsaturated monomer as the copolymer monomer. delete The method of claim 1,
The crosslinking agent is an oligomer blocking polyester film of the compound of formula (2).
[Formula 2]

The method of claim 1,
The polyester base film is an oligomeric blocking polyester film is a polyethylene terephthalate film. The method of claim 1,
The polyester base film is an oligomeric blocking polyester film having a thickness of 25 ~ 250㎛. The method of claim 1,
The primer layer has a dry coating thickness of 20 ~ 200nm oligomer blocking polyester film. The method of claim 1,
The water-dispersible resin composition is an oligomeric barrier polyester film that is applied by an in-line coating method of the polyester film manufacturing process. The oligomer blocking polyester film of claim 1, wherein the oligomer blocking polyester film is a film for display.

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