KR20120076254A - Resin composition for optical film, optical film using the same and method for preparing thereof - Google Patents

Abstract

PURPOSE: A resin composition for an optical film is provided to have excellent adhesion with a substrate film after forming a prism thin film, and to have moderate viscosity for process condition for manufacturing an optical film, not to induce yellowing phenomenon, and to have excellent thermal stability. CONSTITUTION: A resin composition for an optical film comprises an UV-curable unsaturated compound, an antistatic agent, a silicon additive, and an initiator. The UV-curable unsaturated compound comprises a novolak acrylate derivative. A manufacturing method of the optical film comprises: a step of forming a coating layer by spreading the resin composition for an optical film on a mold carving roll; a step of contacting transparent substrate film on one side of the coating layer; a step of curing the coating layer by irradiating the transparent substrate film with UV rays; and a step of separating the cured coating layer by being attached to the transparent substrate film from an engraved roll.

Description

RESIN COMPOSITION FOR OPTICAL FILM, OPTICAL FILM USING THE SAME AND METHOD FOR PREPARING THEREOF

The present invention relates to a resin composition for an optical film, an optical film using the same, and a manufacturing method thereof. More specifically, the present invention has excellent adhesion even in the wet state with the base film after forming the prism thin film, has excellent scratch resistance and abrasion resistance to minimize the assembly failure rate during the backlight unit assembly process, viscosity suitable for the sheet manufacturing process conditions The present invention relates to a resin composition for an optical film having excellent processability, an optical film using the same, and a method of manufacturing the same.

As a general image display means, there is a liquid crystal display (LCD) which allows a user to recognize the information processed in the information processing device to which the transparency obtained by precisely controlling the alignment of the liquid crystal using the electro-optical characteristics of the liquid crystal. .

On the other hand, the performance of the image display means using the optical film is greatly affected by the performance of the back-light unit. This is because a method of controlling the amount of light by reflecting or transmitting light through the optical film is the basis, and various optical films having excellent optical performance have been proposed to effectively apply the thin film optical film to the image display means.

In the structure of such an optical film, the prism sheet is a film for improving the brightness of the liquid crystal display (LCD). Liquid crystal displays (LCDs) cannot emit light by themselves, so they obtain light using a light source (CCFL or LED), distribute the light through the light guide plate to the entire area, and use a diffusion sheet to provide more uniform brightness. Transform into a light source. In this process, the efficiency of the light released from the initial light source is gradually reduced. Using the prism sheet, the brightness of the light can be increased by converting the side light into front light and condensing the reflected light.

The prism sheet used as the light collecting sheet is an optical film having a thin film flexibility, and serves to increase luminance by forming a surface structured in a linear array of prism shapes on one surface.

The pattern part of the prism sheet is composed of a peak region, a valley region, and a joint region connecting the peak region and the valley region according to the height of the height, and the peak region and the joint region are formed of curved irregularities. The irregularities are irregularly arranged, which has the advantage of improving the viewing angle and acid strength characteristics. However, the method has a disadvantage in that there is no shape restoring property, so that if the scratchability defects appearing in the assembly process during assembly of the backlight unit appear as white spots and white line defects.

Recently, the most important of the required physical properties of the prism sheet of the optical film has excellent reliability, and requires a prism film that minimizes the failure rate due to wear resistance and foreign matter during assembly of the backlight. However, in order to increase the wear resistance, it is necessary to have ductility, and at the same time, it is required to have technically opposing characteristics to have elasticity, and to lower the defective rate of foreign substances due to static electricity.

An object of the present invention is to provide a resin composition for an optical film having excellent adhesion to the base film after forming the prism thin film.

Another object of the present invention is to provide a resin composition for an optical film having a viscosity characteristic suitable for optical film production process conditions including a prism film and the like.

Still another object of the present invention is to provide a resin composition for an optical film having excellent elasticity, scratch resistance and abrasion resistance.

Still another object of the present invention is to provide a resin composition for an optical film having excellent antistatic properties.

Still another object of the present invention is to provide a resin composition for an optical film that is excellent in releasability with a roll of roll and has excellent adhesion reliability.

Still another object of the present invention is to provide a resin composition for an optical film having excellent thermal stability without yellowing.

Still another object of the present invention is to provide an optical film having excellent reliability by using the resin composition for an optical film and minimizing a defect rate due to wear resistance or foreign matter during assembly of the backlight.

One aspect of the present invention relates to a resin composition for an optical film. The resin composition for an optical film includes an ultraviolet curable unsaturated compound, an antistatic agent, a silicone additive, and an initiator, and the ultraviolet curable unsaturated compound includes a novolac acrylate derivative.

In embodiments, the novolac acrylate derivative may be represented by the following Chemical Formula 1:

[Formula 1]

(In Formula 1, R is H, CH ₃ , C ₆ H ₆ , The R ₁ , R ₂ And R _{3 It} is selected from ethylene oxide, a linear or branched alkylene group having 1 to 20 carbon atoms, n is Integer from 0 to 5).

In embodiments, the novolac acrylate derivative may have a weight average molecular weight of 100 ~ 3000 g / mol.

The ultraviolet curable unsaturated compound may further include at least one of an ethoxylated bisphenyl diacrylate derivative, a monofunctional ultraviolet curable monomer and a polyfunctional ultraviolet curable monomer.

In embodiments, the ethoxylated bisphenyl diacrylate derivative may be represented by the following formula (2):

[Formula 2]

(In Formula 2, X is a linear or branched alkylene group of 1 to 10 carbon atoms, n is an integer of 1-50 independently of each other.)

In a specific embodiment, the monofunctional UV curable monomer or the polyfunctional UV curable monomer may include an aromatic (meth) acrylate, an alicyclic (meth) acrylate, a hydroxy group-containing (meth) acrylate, and a fluorene-based (meth) acrylate. , Di (meth) acrylate, tri (meth) acrylate, tetra (meth) acrylate.

In an embodiment, the resin composition for an optical film may include 70 to 99% by weight of an ultraviolet curable unsaturated compound, 0.01 to 10% by weight of an antistatic agent, 0.01 to 10% by weight of a silicone additive, and 0.1 to 10% by weight of an initiator.

In one embodiment, the resin composition for an optical film has a refractive index of 1.56 or more, has a viscosity of 800 ~ 1200 cp at 25 ℃, the brightness may be 2100 cd / m ^{2 or} more.

Another aspect of the present invention provides an optical film using the resin composition for an optical film.

The optical film is formed by applying the resin composition for an optical film on a mold engraving roll to form a coating layer; Contacting one surface of the transparent base film to the coating layer; Irradiating ultraviolet rays to the transparent base film to cure the coating layer; And it may be prepared including a step of separating the coating layer cured by bonding to the transparent substrate film from the roll.

The thickness of the coating layer is preferably formed to be 10-50㎛.

The present invention has excellent adhesion with the base film after forming the prism thin film, has a viscosity characteristic suitable for the optical film manufacturing process conditions, has excellent elasticity, scratch resistance, abrasion resistance, antistatic properties, and excellent releasability with a roll of roll. In addition, it has excellent adhesion reliability, has no yellowing phenomenon and excellent thermal stability using the resin composition for the optical film and the resin composition for the optical film has excellent reliability, and minimizes the defect rate due to wear resistance or foreign matter when assembling the backlight The invention has the effect of providing an optical film.

The resin composition for an optical film of the present invention may include an ultraviolet curable unsaturated compound, an antistatic agent, a silicone additive, and an initiator.

UV Curable Unsaturated Compound

The resin composition of this invention consists of an ultraviolet curable unsaturated compound containing a novolak acrylate derivative.

In embodiments, the novolac acrylate derivative may be represented by the following Chemical Formula 1:

[Formula 1]

(In Formula 1, R is H, CH ₃ , C ₆ H ₆ , The R ₁ , R ₂ And R _{3 It} is selected from ethylene oxide, a linear or branched alkylene group having 1 to 20 carbon atoms, n is Integer from 0 to 5).

Preferably R is C ₆ H ₆ and R ₁ , R ₂ and R ₃ are-(CH ₂ ) _3- .

In embodiments, the novolac acrylate derivative may have a weight average molecular weight of 100 ~ 3000 g / mol. In the above range, there is an advantage of easy viscosity and productivity.

In the present invention, the novolac acrylate derivative is 5 to 80% by weight, preferably 10 to 30% by weight of the ultraviolet curable unsaturated compound. There is an excellent advantage in scratch resistance and adhesion in the above range. More preferably 15 to 25% by weight.

The ultraviolet curable unsaturated compound may further include at least one of an ethoxylated bisphenyl diacrylate derivative, a monofunctional ultraviolet curable monomer and a polyfunctional ultraviolet curable monomer.

For example, in one embodiment, the ultraviolet curable unsaturated compound may include a novolak acrylate derivative, an ethoxylated bisphenyl diacrylate derivative, and a monofunctional ultraviolet curable monomer.

In another embodiment, the UV curable unsaturated compound may include a novolak acrylate derivative, an ethoxylated bisphenyl diacrylate derivative, and a polyfunctional UV curable monomer.

In another embodiment, the ultraviolet curable unsaturated compound may include a novolak acrylate derivative, an ethoxylated bisphenyl diacrylate derivative, a monofunctional ultraviolet curable monomer, and a polyfunctional ultraviolet curable monomer.

The ethoxylated bisphenyl diacrylate derivative may be represented by the following Chemical Formula 2:

[Formula 2]

(In Formula 2, X is a linear or branched alkylene group of 1 to 10 carbon atoms, n is an integer of 1-50 independently of each other.)

Preferably, X can be -C (CH3) 2- or -CH2- and n can be 1-15.

The ethoxylated bisphenyl diacrylate derivatives have a strong resilience by greatly improving the elastic force of the prism layer after curing, and exhibit excellent scratch resistance, thereby minimizing defect rate during assembly of the backlight unit. Preferably, it may contain 10-50 mol% of ethylene oxide groups.

The ethoxylated bisphenyl diacrylate derivative may be used in 0 to 60% by weight, preferably 5 to 55% by weight of the ultraviolet curable unsaturated compound. There is an advantage in scratch resistance in the above range. More preferably, it is 10-50 weight%, Most preferably, it is 15-45 weight%.

The ultraviolet curable unsaturated compound may include a monofunctional ultraviolet curable monomer or a polyfunctional ultraviolet curable monomer.

The monofunctional or polyfunctional UV curable monomer improves the releasability of the soft mold or the nickel-plated metal mold with the roll of roll during the process of the final UV curable high refractive resin, and with the base film at room temperature or high temperature / high humidity after curing. The adhesive force can be improved and the surface hardness of a prism shape can be improved.

The multifunctional ultraviolet curable monomer may be at least bifunctional, preferably 2-4 functional.

The monofunctional or polyfunctional UV-curable monomer can be used without limitation one or more monomers selected from the group of known (meth) acrylate monomers. Specific examples include aromatic (meth) acrylates, alicyclic (meth) acrylates, hydroxy group-containing (meth) acrylates, fluorene-based (meth) acrylates, di (meth) acrylates, and tri (meth) acrylates. , Tetra (meth) acrylate, etc. may be used, but is not necessarily limited thereto.

For example, 1,6-hexanediol mono (meth) acrylate, 2-hydroxy ethyl (meth) acrylate, 2-hydroxy propyl (meth) acrylate, 2-hydroxy butyl (meth) acrylate, 2-hydroxy-3-phenyl oxypropyl (meth) acrylate, 1,4-butanediol (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxy cyclohexyl (meth) acrylic Latene, neopentylglycol mono (meth) acrylate, trimethylol-epan di (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylic Latex, pentaerythritol hexa (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin di (meth) acrylate, t-hydroperfuryl (meth) acrylate, iso-decyl (meth) acrylate , 2- (2-ethoxyethoxy) ethyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, isobornyl (meth) Acrylate, tridecyl (meth) acrylate, ethoxy addition type nonylphenol (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , t-ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, ethoxy addition type bisphenol- A di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, phenoxy-t-glycol (meth) acrylate, 2-methacryloyloxyethyl phosphate, dimethylol tricyclo decaine di (meth )Ah Relate, trimethylolpropanebenzoate acrylate, fluorene (meth) acrylate, phenoxybenzyl acrylate, bisphenol F acrylate, bisphenol A epoxy acrylate, novolac epoxy acrylate, phenylphenoxy ethyl Acrylate, ethoxylated thiodiphenyl diacrylate, phenylthioethyl acrylate and the like.

Preferably, phenoxybenzyl acrylate, bisphenol F acrylate, novolac epoxy acrylate, phenylphenoxyethyl acrylate, bisphenol A epoxy acrylate, ethoxylated thio diphenyl diacrylate, phenylthio Ethyl acrylate and the like.

The monofunctional or polyfunctional UV curable monomer may be used in an amount of 0 to 30% by weight, preferably 5 to 25% by weight of the UV curable unsaturated compound. The wettability to the base film in the above range is not good, the adhesive strength is not lowered, and the flexibility of the polymer backbone is not lowered, so the cracks are less likely to occur after the prism film is manufactured. More preferably, it is 7-20 weight%, Most preferably, it is 7-15 weight%.

The ultraviolet curable unsaturated compound of the present invention may be included in 80 to 99% by weight based on the solids content of the resin composition for an optical film. In the above range, since the photocurable process can be used without a separate process, there is an advantage in production and processability. Preferably, it may be included in 85 to 98% by weight, more preferably 95-96% by weight.

In one embodiment, the ultraviolet curable unsaturated compound includes 40 to 95% by weight of a novolak acrylate derivative, 5 to 45% by weight of an ethoxylated bisphenyl diacrylate derivative, and 0 to 25% by weight of a monofunctional ultraviolet curable monomer. Can be done.

In another embodiment, the UV curable unsaturated compound includes 40 to 95% by weight of a novolak acrylate derivative, 5 to 45% by weight of an ethoxylated bisphenyl diacrylate derivative, and 0 to 25% by weight of a polyfunctional UV curable monomer. Can be done.

In another embodiment, the UV curable unsaturated compound is 45 to 80% by weight of a novolak acrylate derivative, 5 to 45% by weight of an ethoxylated bisphenyl diacrylate derivative, 0 to 20% by weight of a monofunctional UV curable monomer and a multi-tube It may comprise a 0 to 20% by weight of the functional UV-curable monomer.

Antistatic agent

The antistatic agent may prevent the antistatic property during the manufacture or assembly of the final prism film. By adding the antistatic agent, dust in the air is prevented from adhering to the optical member by static electricity.

The antistatic agent according to the present invention may be used an ionic compound. It is preferable that an ionic compound has compatibility with an ultraviolet curable unsaturated compound, and has compatibility with the organic solvent used at the time of preparation of a composition, and can maintain transparency of a composition.

As an ionic compound suitable for this invention, a nitrogen containing onium salt, a sulfur-containing onium salt, or a phosphorus containing onium salt can be used preferably. As specific examples, 1-butylpyridinium tetrafluoroborate, 1-butylpyridinium hexafluorophosphate, 1-butyl-3-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium trifluoromethate Insulfonate, 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide, 1-butyl-3-methylpyridinium bis (pentafluoroethanesulfonyl) imide, 1-hexylpi Lydinium tetrafluoroborate, 2-methyl-1-pyrroline tetrafluoroborate, 1-ethyl-2-phenylindole tetrafluoroborate, 1,2-dimethylindole tetrafluoroborate, 1-ethylcarbazole Tetrafluoroborate, 1-ethyl-3-methylimidazolium Tetrafluoroborate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium trifluoroacetate, 1-ethyl 3-methylimidazolium heptafluorobutyrate, 1-on 3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium perfluorobutanesulfonate, 1-ethyl-3-methylimidazolium dicyanamid, 1- Ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-3-methylimidazolium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-3-methyldi Midazolium tris (trifluoromethanesulfonyl) imide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate,

1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1- Butyl-3-methylimidazolium perfluorobutanesulfonate, 1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methyl Midazolium trifluoromethanesulfonate, 1-octyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-2,3-dimethyl Imidazolium tetrafluoroborate, 1,2-dimethyl-3-propylimidazolium bis (trifluoromethanesulfo ) Imide, 1-methylpyrazolium tetrafluoroborate, 3-methylpyrazolium tetrafluoroborate, tetrahexylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethylammonium tetrafluoroborate, di Allyldimethylammonium trifluoromethanesulfonate, diallyldimethylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethylammonium bis (pentafluoroethanesulfonyl) imide, N, N- Diethyl-N-methyl-N- (2-methoxyethyl) ammonium tetrafluoroborate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium trifluoromethanesulfonate , N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N- (2- Methoxyethyl) ammonium bis (pentafluoroethanesulfonyl) imide, glycidyltrimethylammo Trifluoromethanesulfonate, glycidyltrimethylammonium bis (trifluoromethanesulfonyl) imide, glycidyltrimethylammonium bis (pentafluoroethanesulfonyl) imide, 1-butylpyridinium ( Trifluoromethanesulfonyl) trifluoroacetamide, 1-butyl-3-methylpyridinium (trifluoromethanesulfonyl) trifluoroacetamide, 1-ethyl-3-methylimidazolium (trifluoro Methanesulfonyl) trifluoroacetamide, diallyldimethylammonium (trifluoromethanesulfonyl) trifluoroacetamide, glycidyltrimethylammonium (trifluoromethanesulfonyl) trifluoroacetamide, N , N-dimethyl-N-ethyl-N-propylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-butylammonium bis (trifluoro Methanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-hexylammonium Bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl- N-nonylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dipropylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N -Propyl-N-butylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N- Dimethyl-N-propyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl-N-hexyl Monium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-pentyl -N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dihexylammonium bis (trifluoromethanesulfonyl) imide, trimethylheptylammonium bis (tri Fluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-propylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-pentyl Ammonium Bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-heptylammonium Bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-propyl -N-pentylammonium bis (trifluoromethanesulfonyl) imide, triethylpropylammonium bis (trifluoromethanesulfonyl) imide, triethylpentylammonium Tris (trifluoromethanesulfonyl) imide, triethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-methyl-N-ethylammonium bis (trifluoromethanesulsul Ponyl) imide, N, N-dipropyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-butyl-N-hexylammonium bis (tri Fluoromethanesulfonyl) imide, N, N-dipropyl-N, N-dihexylammonium bis (trifluoromethanesulfonyl) imide,

N, N-dibutyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-hexylammonium bis (trifluoromethanesulfonyl ) Imide, trioctylmethylammonium bis (trifluoromethanesulfonyl) imide, N-methyl-N-ethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, etc. are mentioned. Can be.

The said antistatic agent may be manufactured by synthesis | combination, or a commercial item may be used. As a commercial item, 1-hexyl-3- methyl imidazolium hexafluorophosphate (made by Tokyo Kasei Co., Ltd.), N-methyl-N-propyl piperidinium bis (trifluoro methanesulfonyl) imide ( Kantokagaku Co., Ltd.), 1-ethylpyridinium bromide (manufactured by Tokyo Kasei Co., Ltd.), 1-butyl-3-methylpyridinium trifluoromethanesulfonate (Tokyo Kasei Co., Ltd.) Products).

The antistatic agent may be included in an amount of 0.01 to 10% by weight based on solids content of the resin composition for an optical film. Within this range, an antistatic effect can be exhibited and the ionic components do not significantly rise to the surface in high temperature / high humidity environments so that the adhesion between the interfaces and the mechanical and optical properties of the prism can not be degraded. Preferably, it may be included in 0.1-5% by weight, more preferably 0.3 to 3% by weight.

Silicone additives

The silicone additive may increase the releasability of the composition and the mold mold in the resin composition for an optical film.

The silicone additive is not particularly limited, but polyether modified acrylic functional polydimethyl siloxane or the like may be used.

The silicone additive may be included in an amount of 0.01-10% by weight based on the solids content of the resin composition for an optical film. Within this range, the releasability with the mold mold can be improved and the adhesion between the interfaces in a high temperature, high humidity environment and the mechanical and optical properties of the prism can not be degraded. Preferably, it may be included in 0.1-2% by weight.

Initiator

The initiator is used for curing by ultraviolet rays in the resin composition for an optical film. As the initiator, a photopolymerization initiator, a radical initiator, or the like can be used. For example, benzene ether type, benzyl ketal type, alpha hydroxy alkyl phenone type, aminoalkyl phenone type, phosphine oxide and the like can be used.

As such photoinitiators, commercially available products may include, for example, CIBA Darocure 1173, Irgacure 184, Irgacure 127, Darocure TPO, and the like.

The initiator may be included in 0.1-10% by weight based on the solids content of the resin composition for an optical film. Within this range, the photoreactivity may be high and the mechanical strength of the prism may not be reduced, and optical properties such as yellowing of the prism layer may not be reduced. Preferably, it may be included in 0.5-6% by weight.

In addition to the resin composition may be added to the additives commonly used in the art, and may include a silicone or fluorine modification additive to impart releasability with the metal and polymer mold. These additives are commercially available products such as BYK Chemi's BYK-323, BYK-331, BYK-333, BYK-337, BYK-373, BYK-375, BYK-377, BYK-378, and Daegu. TEGO Glide 410, TEGO Glide 411, TEGO Glide 415, TEGO Glide 420, TEGO Glide 432, TEGO Glide 435, TEGO Glide 440, TEGO Glide 450, TEGO Glide 455, TEGO Rad 2100, TEGO Rad 2200N, TEGO Rad 2250, TEGO Rad 2300 and TEGO Rad 2500 can be used.

The resin composition for an optical film may have a refractive index of 1.56 or more, a viscosity of 800 to 1200 cp at 25 ° C., and a luminance of 2100 cd / m ^{2 or} more.

The present invention provides a method for producing an optical film using the resin composition for an optical film. The method comprises applying a resin composition for an optical film to a mold engraving roll to form a coating layer; Contacting one surface of the transparent base film to the coating layer; Irradiating ultraviolet rays to the transparent base film to cure the coating layer; And it may be prepared including a step of separating the coating layer cured by bonding to the transparent substrate film from the roll.

The prism layer is engraved on the mold engraving roll. As a method of applying the resin composition for an optical film to a mold engraving roll in which a prism layer is imprinted, a conventional coating method may be used.

The base film is made of a transparent material, as a specific material may be used, such as glass, transparent synthetic resin. Generally, a polyethylene terephthalate material can be used.

The ultraviolet ray is a wavelength of 190 ~ 450nm, preferably 250 ~ 430nm, 400 ~ 1500mJ / ㎠, preferably equipped with a D-type bulb (Type-D bulb) to the electrodeless ultraviolet irradiation device (600W / inch) May be irradiated with an energy of 500 ~ 900mJ / ㎠, but is not necessarily limited thereto.

The height of the prism layer of the resulting optical film may be 10-50 μm.

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

Example

Specific specifications of the components used in the following examples and comparative examples are as follows.

A) UV curable unsaturated compound

a1) novolac diacrylate derivative: OPP novolac epoxy acrylate was used.

a2) ethoxylated bisphenyl diacrylate derivative:

a21) ethoxylated bisphenyl diacrylate was used.

a22) ethoxylated bisphenol A diacrylate was used.

a3) mono- or polyfunctional UV curable monomers:

a31) phenoxy benzyl acrylate was used.

a32) Bisphenol A diacrylate was used.

B) Antistatic agent: ammonium salt system was used.

C) Silicone Additive: BYK-3530 from BYK, a polyether modified acrylic functional polydimethyl siloxane, was used.

D) initiator:

d1) 2,4,6-trimethyl benzoyl phosphine oxide manufactured by CIBA was used.

d2) 1-hydroxy cyclohexylphenyl ketone manufactured by CIBA was used.

Example  1-4 and Comparative example  1: Preparation of Resin Composition for Optical Film

The components shown in Table 1 were mixed in the amounts described to prepare a resin composition for an optical film.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 UV Curable Unsaturated Compound a1 50 45 95 75 - a21 20 25 - 20 50 a22 15 15 - - 15 a31 10 10 - - 10 a32 - - - - 20 Antistatic agent 0.5 0.5 0.5 0.5 0.5 Silicone additives 0.5 0.5 0.5 0.5 0.5 Initiator 4 4 4 4 4

Experimental Example: Evaluation of Physical Properties of Prism Film Made of Resin Composition for Optical Film

The resin composition for optical films prepared in Examples and Comparative Examples was coated on a metal plate on which a prism layer was imprinted, and the surface of the transparent PET substrate film (Kolon H32P 125 μm) was brought into contact with the coated surface coated on the metal stamping plate. UV light was irradiated toward the transparent substrate film at the photocured composition. The cured coating layer was separated from the metal plate to form a three-dimensional prism layer having a thickness of 26 μm on one side of the transparent PET substrate film. Ultraviolet rays were used at a wavelength of 190 to 460 nm, but the ultraviolet light system used for photocuring was irradiated with energy of 300mJ / cm 2 by attaching an electrodeless ultraviolet irradiation device (600W / inch) Type-D bulb of US Fusion.

The physical properties of the prepared prism film were evaluated by the following method, and the results are shown in Table 2 below.

<Property evaluation method>

1) refractive index

In order to measure the refractive index of the resin composition for optical films, the refractive index was measured using the refractometer (model name: 4T, Japan ATAGO ABBE). As a light source for the measurement, a D-beam sodium lamp of 589.3 nm was used.

2) Adhesive force (number of residues / 100)

After cutting only the prism layer into 100 matrix structures within the 1 cm x 1 cm region of the prism layer, the number of prism layer regions remaining when the NITTO tape was adhered and vertically released thereon was indicated.

3) flexibility

After the prism layer was formed on the transparent PET base film, when the half of the prism layer was folded outward, the adhesion state between the base film and the coating was visually determined.

◎: Very good, ○: Good, ×: Poor

4) UV yellowing (△ YI)

After standing at 50 ° C. and 0.34 W / m 2 weather-O-meter for 200 hours, color coordinates were measured in the same manner as in the luminance evaluation method.

5) Luminance (Cd / ㎡)

The prism film produced above was fixed to the backlight unit for 15.4 inch liquid crystal display panels, and the brightness | luminance of 25 points and 13 points was measured using the luminance meter (model name: BM-7, TOPCON Japan), and the average value was calculated | required.

6) Antistatic property (surface resistance) (Ω / c㎡)

The surface resistance was measured by applying a constant voltage using DSM-8103 of Dong-A Battery Industry of Japan.

7) Viscosity (CPS)

The resin viscosity at 25 ° C. was measured using a Brookfield Viscometer (DV-II + Pro).

8) Abrasion Resistance

The prism layer of the prepared prism film and the AG-coated portion of the liquid crystal display panel layer are positioned to be in contact with each other, and then 200g, 100g, and 50g weights are placed at intervals of about 3 cm, and then the prism film is placed 5 cm from the center of the panel. After five repetitions, the degree of wear was visually identified.

◎: Very good, ○: Good, △: Normal, ×: Poor

9) Elasticity: Fischer Micro indentaion WIN-HCU was measured by the recovery rate. Cut the prism film to about 10 * 10cm size and place it on the fischer WIN-HCU microindentation measuring cell, and then press it with a force of 10N / cm2 for 10 seconds with a Vickers-type tip and slowly withdraw the force. Let this come up. The recovery rate was calculated by dividing the depth of the remaining surface by rising again from the initial depth.

Evaluation item Example 1 Example 2 Example 3 Example 4 Comparative Example 2 Refractive index of the composition 1.570 1.565 1.580 1.575 1.550 Adhesion 100 100 100 100 85 flexibility ◎ ◎ ◎ ◎ ○ UV yellowing 5.4 5.8 5.7 5.5 6.2 Luminance 2263 2204 2431 2395 2057 Surface resistance 3.2 × 10 ¹¹ 1.5 × 10 ¹¹ 5.4 × 10 ¹¹ 4.2 × 10 ¹¹ 5.4 × 10 ¹² Viscosity 950 930 1050 890 880 Wear resistance ◎ ◎ ◎ ◎ △ Shout 90% 85% 85% 80% 60%

As shown in Table 2, the prism film made of the resin composition for an optical film of the present invention showed all properties such as refractive index, adhesion, flexibility, UV yellowing, brightness, antistatic property, wear resistance, and evenly, the process It was shown to exhibit viscosity characteristics appropriate to the conditions.

Although the above has been described with reference to one embodiment of the present invention, various changes and modifications can be made at the level of those skilled in the art. Such changes and modifications are intended to fall within the scope of the present invention unless they depart from the scope of the present invention. Therefore, the scope of the present invention should be judged by the claims described below.

Claims (11)

An ultraviolet curable unsaturated compound, an antistatic agent, a silicone additive and an initiator, wherein the ultraviolet curable unsaturated compound resin composition for an optical film comprising a novolak acrylate derivative.

The resin composition of claim 1, wherein the novolac acrylate derivative is represented by the following Chemical Formula 1:
[Formula 1]

(In Formula 1, R is H, CH ₃ , C ₆ H ₆ , The R ₁ , R ₂ And R _{3 It} is selected from ethylene oxide, a linear or branched alkylene group having 1 to 20 carbon atoms, n is Integer from 0 to 5).
The resin composition for an optical film according to claim 1, wherein the novolac acrylate derivative has a weight average molecular weight of 100 to 3000 g / mol.
The optical film resin of claim 1, wherein the ultraviolet curable unsaturated compound further comprises at least one of an ethoxylated bisphenyl diacrylate derivative, a monofunctional ultraviolet curable monomer, and a polyfunctional ultraviolet curable monomer. Composition.
The resin composition of claim 4, wherein the ethoxylated bisphenyl diacrylate derivative is represented by the following Chemical Formula 2:

(2)

(In Formula 2, X is a linear or branched alkylene group of 1 to 10 carbon atoms, n is an integer of 1-50 independently of each other.)
The monofunctional UV-curable monomer or the polyfunctional UV-curable monomer according to claim 4, wherein the monofunctional UV-curable monomer is aromatic (meth) acrylate, alicyclic (meth) acrylate, hydroxy group-containing (meth) acrylate, fluorene-based (meth) A resin composition for an optical film, comprising at least one of acrylate, di (meth) acrylate, tri (meth) acrylate, and tetra (meth) acrylate.
The optical film of claim 1, wherein the resin composition for an optical film comprises 70 to 99 wt% of an ultraviolet curable unsaturated compound, 0.01 to 10 wt% of an antistatic agent, 0.01 to 10 wt% of a silicone additive, and 0.1 to 10 wt% of an initiator. Resin composition.
The resin composition according to claim 1, wherein the resin composition for an optical film has a refractive index of 1.56 or more, a viscosity of 800 to 1200 cp at 25 ° C, and a luminance of 2100 cd / m ² or more.
An optical film made of the composition of any one of claims 1 to 8.
Applying the resin composition for an optical film of claim 1 to a mold engraving roll to form a coating layer;
Contacting one surface of the transparent base film to the coating layer;
Irradiating ultraviolet rays to the transparent base film to cure the coating layer; And
Separating the cured coating layer adhered to the transparent base film from the stamp roll;
Optical film production method characterized in that it comprises a step.
The method of claim 10, wherein the coating layer is formed to have a thickness of 10-50 μm.