KR101501989B1 - Optical film using release film and method of producing the same - Google Patents

Abstract

The present invention relates to a method for manufacturing an optical film. The method includes the steps of: supplying filling resin between a support film and an intaglio pattern film by applying the support film between the intaglio pattern film and a drum roll; and performing primary curing (low pressure) at the intaglio pattern film side and secondary curing (high pressure) at the release film side by irradiating UV rays in curing, thereby filling the intaglio pattern without changing materials or applying complicated processes.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical film using a release film,

The present invention relates to an optical film and a method of manufacturing the same. More particularly, the present invention relates to an optical film and a method of manufacturing the same, The present invention also relates to an optical film to which a release film is applied, wherein the secondary curing (low pressure) is a side of the engraved pattern film, and the secondary curing (high pressure)

An optical sheet is used in the backlight unit of the LCD to promote the refraction and diffusion of light, thereby increasing the uniformity and brightness of the light. The optical sheet includes a diffusion sheet for diffusing light, a prism sheet for collecting light diffused on the upper surface of the diffusion sheet to transmit the diffused light to the liquid crystal display panel, and a protective sheet for protecting the diffusion sheet and the prism sheet .

Many functional optical sheets have been applied to liquid crystal displays, organic light emitting (OLED) and touch screens widely used in displays. Although the conventional optical sheet for a backlight unit for a liquid crystal display, a polarizing sheet, a wide viewing angle sheet, and a transparent electrode film have been continuously improved in performance, there is an increasing demand for more advanced optical functions and slimmer lenses. There are many attempts to maintain thinning even if it improves. In addition, various efforts have been made for high quality and high productivity.

In addition to the inherent properties of such optical sheets, it is common to apply a certain patterning treatment to the surface in order to increase the diffusing ability and brightness of light. In recent years, a large amount of processing is performed by the roll-to-roll method. In the roll-to-roll method, there are a hard mold type using a metal mold in which a pattern is processed and a soft mold type using a film-forming mold.

In the patterning process of the hard mold method or the soft mold method, a pattern of an active area (an area appearing on the display screen) is in contact with a plurality of guide rolls.

The hard mold method is difficult to realize a hemispherical microlens pattern, whereas the soft mold method has a merit that various patterns including a microlens pattern can be realized.

However, if the movement speed of the mold is increased to increase the productivity of the optical sheet, bubbles may be formed in the pattern or the coating liquid may not be injected completely, resulting in non-uniformity of the shape of the optical sheet. Particularly, in the case of a hemispherical microlens pattern, bubbles are more serious. At this time, slight damage to the pattern causes a decrease in optical characteristics or an appearance defect.

In the case of the soft mold method, unevenness in the uncoated region occurs due to the stitch portion, thereby causing a failure in pressing upon winding. When the film is wound and stored, the pressing by the step is transferred to the inner wound product, .

The releasing film is a releasing film formed by applying a silicone composition and an inorganic particle exhibiting antistatic effect to a cross section or both sides of a polyester film (PET) in order to obtain a uniform running property and an excellent adhesiveness, and has a uniform peeling force, It is a functional film which is used as a substrate film for protecting the adhesive layer of electric and electronic parts and display materials or forming ceramics of a multi-layer ceramic capacitor (MLCC).

The release film has good surface roughness and thickness uniformity and has excellent applicability to various applications and process conditions. It is used for temporary support and adhesive layer protection of adhesive parts. It is used for multi-layer ceramic capacitors (MLCC) Varistors and chip inductors, and is used as a substrate film for display materials such as ACF anisotropic conductive films and DAF (Die Attached film).

In the process of the optical film using the conventional release film, resin is injected between the drum roll and the engraved pattern film adjacent to the engraved pattern film after the intaglio patterning, and the resin is supplied onto the engraved pattern film to be filled or run, Filled with a blade or a squeeze. However, when the width of the pattern is minute and the depth is deep, that is, when the fine pattern has a large aspect ratio, there is a limit in improving defects due to the unfilled region and bubble generation. As an alternative to this, there is a case in which the viscosity of the resin is controlled or a multiple filling process in which the resin is filled little by little is used, but in this case, the productivity is lowered.

SUMMARY OF THE INVENTION The present invention has been conceived in order to solve the above-described problems, and it is an object of the present invention to provide a support film between a support film and an engraved pattern film, It is intended to fill the engraved pattern without application.

The purpose of the invention is to minimize deformation of the film by irradiating UV on the side of the engraved pattern film for primary curing (low pressure) at the time of curing and for secondary curing (high pressure) at the side of the release film.

A method of manufacturing an optical film to which a release film of the present invention is applied includes the steps of: laminating a first pressure-sensitive adhesive layer laminated on at least one surface of an optical film; Laminating an engraved pattern film on one surface of the first pressure sensitive adhesive layer; Preparing a release film on the other side of the first pressure-sensitive adhesive layer; A step of running a support film between the engraved pattern film and the drum roll, and a step of supplying a filling resin between the engraved pattern film and the support film.

Further, the primary curing at a low pressure during curing of the engraved pattern film side is characterized by UV irradiation of a secondary curing at a high pressure during curing of the release film.

The optical film to which the release film of the present invention is applied is characterized in that a support film runs between the engraved pattern film and the drum roll, and a filling resin is supplied between the engraved pattern film and the support film.

The optical film to which the release film of the present invention is applied has the effect of improving the productivity by improving the defects due to the non-filling in the conventional patterning process by applying the support film and simplifying the manufacturing process.

In addition, by irradiating UV on the releasing film side, primary curing (low pressure) at the pattern film side and secondary curing (high pressure) at the curing side can minimize the deformation of the film and enable production of high quality products.

Fig. 1 is a configuration diagram of a soft-mold type manufacturing apparatus.
2 is a block diagram of a manufacturing apparatus of a hard mold type.

Best Mode for Carrying Out the Invention The present invention will be described in more detail with reference to the drawings and examples. It is to be understood that the terms used in the embodiments of the present invention and the like are merely illustrative in order to facilitate understanding of the present invention and should not be construed as limiting the scope of the present invention.

A method of manufacturing an optical film to which a release film of the present invention is applied includes the steps of: laminating a first pressure-sensitive adhesive layer laminated on at least one surface of an optical film; Laminating an engraved pattern film on one surface of the first pressure sensitive adhesive layer; Preparing a release film on the other side of the first pressure-sensitive adhesive layer; And running the support film between the engraved pattern film and the drum roll, and supplying the filling resin between the engraved pattern film and the support film.

Further, the primary curing at a low pressure during curing of the engraved pattern film side is characterized by UV irradiation of a secondary curing at a high pressure during curing of the release film.

The optical film includes, but is not limited to, a polarizing film, a viewing angle enlargement film, an anti-reflection (AR) film, an anti-glare (AG) film, a diffusion film (sheet)

As the ultraviolet curable resin, an ultraviolet curable resin conventionally used can be used without limitation, and an ultraviolet curable acrylic resin can be preferably used.

Specifically, for example, the ultraviolet curable resin may include one or more reactive (polymerizable, non-polymerizable) oligomers and / or one or more reactive monomers (monofunctional and polyfunctional). When the reactive oligomer and the reactive monomer are mixed and used, there is no particular limitation. For example, 10 to 90 parts by weight of the total oligomer relative to 100 parts by weight of the ultraviolet curable resin, 100 parts by weight of the ultraviolet curable resin 10 to 90 parts by weight may be used.

The reactive oligomer may have a substitution structure such as an unsaturated group such as an acrylic group, a methacrylic group, an aryl group, and a vinyl group, and an epoxy group as a reactive functional group, and may be a urethane acrylate oligomer, Acrylate oligomer, acrylate oligomer, epoxy acrylate oligomer, polyester acrylate oligomer, polyether acrylate oligomer, silicone acrylate oligomer, melamine acrylate oligomer, acrylic acrylate oligomer and polybutadiene acrylate oligomer. The above-mentioned reactive groups can be substituted. These may be used individually or in combination of two or more.

Examples of the reactive monomer include but are not limited to ethylhexyl (meth) acrylate, oxydecyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- Acrylate, isobornyl (meth) acrylate, tetrahydrofuran (meth) acrylate, cyclohexyl (meth) acrylate, (Meth) acrylate, dicyclopentene (meth) acrylate, dicyclopentenoxymethyl (meth) acrylate, 2-ethoxyethoxyethyl Acrylates such as hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di Acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, (Meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meta) acrylate, diisocyanate di (meth) acrylate, ) Acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylol propane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, Propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol Hexa (meth) acrylate, and the like, or a mixture of two or more thereof.

(Meth) acrylate such as dipentaerythritol hexa (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-hydroxyethyl (meth) acrylate, Acrylate and the like can be mixed and used.

As the ultraviolet curing resin, a mixture of one or more thermoplastic resins may be used. As the thermoplastic resin, for example, urethane, polyester, acrylic, butyral, cellulose, Or a mixture of two or more thereof.

In the method for producing an optical film to which the release film of the present invention is applied, additives such as a photopolymerization initiator, a surfactant, a leveling agent, an anti-settling agent, a photosensitizer, a stabilizer, an ultraviolet absorber, an infrared absorber, Species or two or more species.

As the above additives, it is preferable to use a photopolymerization initiator and / or a photosensitizer, in particular, in order to use an ultraviolet curable resin. Examples of such a photopolymerization initiator include conventional initiators such as benzophenones, acetphenols, N-butylamine, triethylamine, poly-n-butylphosphine, and the like can be used as the photosensitizer. The photoinitiator may be, for example, have. Other additives such as surfactants and leveling agents can also be used without limitation as those commonly used in the art.

The pattern forming method of the present invention may be any one of a soft mold method and a hard mold method, but is not limited thereto.

Hereinafter, the soft mold method will be described in more detail with reference to FIG. 1 as a pattern forming method of the present invention.

A first roll 120 on which a base film 110 is wound and a second roll 150 on which a patterned optical sheet 112 is wound are provided on both sides and an optical sheet on which a base film and a pattern are formed is conveyed Guide rolls 130a to 130e are provided between the first roll 120 and the second roll 150. [ Between the guide roll 130c and the guide roll 130d, a pattern molding part 140 for applying a coating liquid to the base film 110 is disposed close to the base film 110. The pattern molding part serves as a pattern roll.

The pattern molding unit 140 includes a molding mold 142 having a film shape in which a pattern is formed, a master roll 142 for applying a coating liquid onto the base film by patterning the coating liquid according to a pattern embodied in a molding mold, 144 and pattern guide rolls 146a, 146b for feeding the forming mold.

The forming mold 142 is formed as an elongated belt type having a pattern layer on which a pattern is formed on a film-like base layer. The forming mold serves to pattern the coating liquid like the conventional pattern roll. In Fig. 5, only a part of the pattern embodied in the pattern layer of the forming mold is shown. In actual practice, the pattern is implemented over the entire molding mold.

In mounting the molding die 142, the molding die is wrapped on an extension line connecting the master roll 144 and the guide rolls 146a and 146b, and both ends of the molding die are connected.

A coating liquid injecting means 160 for injecting a coating liquid is provided at a point where the base film 110 is drawn into the pattern molding unit 140. The point where the base film and the molding mold 142 are closely contacted with each other is heat or UV And a curing unit 170 for curing the coating liquid.

5, the number and position of the guide rollers 130a to 130e and the pattern guide rollers 146a and 146b may be changed according to the operation state.

Hereinafter, the hard mold method will be described in more detail with reference to FIG. 2 as a pattern forming method of the present invention.

The base film 10 is wound and the second roll 50 on which the first roll 20 and the patterned optical sheet 12 are wound is provided on both sides to support and drive the base film 10, A guide roll 30a to 30d for feeding the base film and a pattern roll 40 for forming a pattern on the base film are provided between the first roll and the second roll. A coating liquid injecting means 60 for supplying a coating liquid 62 for forming a pattern is provided at a point where the base film 10 is drawn into the pattern roll 40. Around the pattern roll, A curing means 70 for curing the coating liquid is provided.

The base film 10 is unwound from the first roll 20 and is conveyed along the guide rolls 30a to 30d to come into contact with the pattern roll 40. [ At this time, the coating liquid 60 is injected from the coating liquid injecting means 60 to the point where the base film is drawn into the pattern roll, and the injected coating liquid is applied to the base film 10 in a pattern shape by the pattern roll 40 And the coating liquid applied to the base film is cured by heat or UV emitted from the curing means 70 provided around the pattern roll. Therefore, the patterned coating liquid is applied to the base film while passing through the pattern roll.

At this time, the guide roll 30b for pulling the base film 10 into the pattern roll 40 serves to adjust the gap of the pattern to be formed on the base film. That is, when the guide roll 30b is brought into close contact with the pattern roll, the base film is brought into close contact with the pattern roll, so that the thickness of the pattern to be formed becomes thin. On the contrary, if the guide roll 30b is spaced apart from the pattern roll, The thickness of the pattern becomes thick because a large amount of coating liquid is introduced.

The base film (optical sheet 12) having the pattern formed by passing through the pattern roll 40 is separated by the guide roll 30c and separated from the pattern roll, and is then wound on the second roll 50. [

110, 10: base film
112, 12: optical sheet
120, 20: first roll
130a, 130b, 130c, 130d, 130e, 30a, 30b, 30c, 30d,
140: Pattern molding part
142, 12: Molding mold
144, 40: master roll
146a, 146b, 46a, 46b: pattern guide rolls
150, 50: second roll
160, 60: coating liquid injection means
170, 70: Curing means

Claims (4)

Stacking a first pressure-sensitive adhesive layer laminated on at least one surface of the optical film;
Laminating an engraved pattern film on one surface of the first pressure sensitive adhesive layer;
Preparing a release film on the other side of the first pressure-sensitive adhesive layer;
Running a support film between the engraved pattern film and the drum roll, and
And supplying a filler resin between the engraved pattern film and the support film. ≪ RTI ID = 0.0 > 11. < / RTI >
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