KR100584195B1 - Optical film manufacture method for lcd - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical film in which micro-patterns of 200 μm or less, such as prisms, spherical or aspherical microlenses, holograms, and channel shapes, are continuously arranged. By combining the advantages, the optical film can be manufactured to improve productivity, and the desired optical performance of the produced film can be obtained.

The manufacturing method of the present invention for realizing this, the film supply step that the optical film fabric is continuously supplied; Resin coating step of applying a UV resin to a predetermined thickness on one surface of the film to be supplied; A drying step of passing a drying furnace for supplying infrared rays or heat so that the resin applied on the film is solidified in a semi-solidified state; Hot embossing step of passing the dried film between the heated embossing roll to form an embossed structure of the resin; And a UV curing step of irradiating UV light to the resin part of the film on which the hot embossing is performed.

LCD, Optical, Film, Prism, Sheet, Display, Manufacturing

Description

Manufacturing method of optical film for liquid crystal display device {OPTICAL FILM MANUFACTURE METHOD FOR LCD}

1 is a schematic diagram of a device configuration for manufacturing a film of the present invention.

<Explanation of symbols for the main parts of the drawings>

1 film feed roll 2 coater

3: support roll 4: drying furnace

5: hot embossing unit 6: UV curing unit

7: film winding roll 8: guide roll

10: film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical film in which micro-patterns of 200 μm or less, such as prisms for liquid crystal displays (LCDs), spherical or aspherical microlenses, holograms, channel shapes, and the like, are continuously arranged. The present invention relates to a film manufacturing method for more easily manufacturing an optical film having a fine pattern used in a backlight unit, which is a component of an apparatus.

Liquid crystal display (Liquid Crystal Display), which has recently been in the spotlight as a general image display means, has a very low power consumption unlike a conventional cathode ray tube, and has a thin and light characteristic because it does not use an electron gun. It is spreading.

Since the LCD does not have the ability to emit light by itself, a method of controlling the amount of light by reflecting or transmitting light is used. A light source device used in a transmissive LCD which is generally used is called a backlight unit. The performance of the LCD is greatly affected by the performance of the backlight unit.

Meanwhile, an optical film having a fine pattern for a display is adopted as the backlight unit. In the related art, such an optical film was manufactured by hot embossing or UV embossing.

Among them, in the case of hot embossing, the manufacturing method is widely known and the method is the most commonly used because of the relatively simple process, but when the optical properties are required, the performance of the product depends on the optical properties of the film, It is difficult to obtain the desired optical properties. In addition, heat shrinkage from heating and cooling is limited by the desired roll or embossing depth, making it difficult to accurately reproduce the shape, and even if the shrinkage is corrected, if the structure is complex, the shape change due to torsion or thickness deviation is corrected. There was a problem that was difficult to do.

In addition, in the case of UV embossing, it is possible to select a product that can have optimal optical properties according to the type of resin used as a method that is rapidly spreading in recent years, so that it is easy to meet the desired physical properties. Since it does not go through the processor has the advantage of minimizing the distortion of the shape.

However, the process of embossing the liquid phase is complicated and difficult, and in the case of UV resins, most of them are anaerobic, so it is necessary to pay special attention to the curing method.

The present invention has been proposed to improve the above-mentioned problems in the prior art, and the desired optical performance of the film can be obtained while making it easy to form the embossing in the manufacturing process of the optical film with the fine pattern. The purpose is to provide a manufacturing method.

The object is, the film supply step that the optical film fabric is continuously supplied; Resin coating step of applying a UV resin to a predetermined thickness on one surface of the film to be supplied; A drying step of passing through a drying furnace using infrared rays or heat so that the resin applied on the film is solidified in a sol-gel state; Hot embossing step of passing the dried film between the heated embossing roll to form an embossed structure of the resin; And it can be achieved through the manufacturing method of the optical film for a liquid crystal display device comprising a UV curing step of irradiating the UV light to the resin portion of the hot embossing film.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the device configuration for manufacturing the optical film is a film supply roll 1 for continuously supplying the film fabric 10 as shown in Figure 1, and the UV resin on the upper surface of the film 10 to be supplied A coater (Coater; 2) which is a device for supplying the coating to a predetermined thickness, a support roll (3) for supporting the film 10 to which the resin is applied from the coater (2), and the applied UV resin A drying furnace 4 for drying the resin at a predetermined temperature, a hot embossing portion 5 in which rollers for forming an embossing structure are mounted in pairs on the resin coating portion of the film 10, and an embossing film. (10) It consists of the UV hardening part 6 which irradiates UV light to an upper surface, and the film winding roll 7 by which the film which passed each process is wound.

Embossing rolls paired in the hot embossing step is preferably used that is heated to a low temperature of 50 ℃ or less.

Moreover, it is preferable that the density | concentration of the volatile solvent of resin apply | coated on the said film shall be less than 50%.

In addition, the film is preferably a polycarbonate, polyester, acrylic, celluloid-based transparent and flexible film having a glass transition temperature of 50 ℃ or more is preferably used.

      As the film base material, a polymer film having a transparent material and a flexible material can be used. The polymer film may be made of one polymer selected from the group consisting of acrylate, polycarbonate, polyester, and polyvinyl chloride as a material, and the polymer film may be formed on a multilayer film or polyester in which acrylate is laminated on polycarbonate. Multilayer films in which acrylates are laminated can be used.

        In addition, the fine pattern formed in the hot embossing step has a width and height of less than 200㎛, the shape is formed of a binary pattern of prism, spherical or aspherical microlenses, holograms, channels.

In addition, the drying method is preferably in the form of applying heat to the opposite side of the surface on which the UV resin is applied.

In the figure, reference numeral 8 denotes a guide roll for guiding the film 10 conveyance along the conveying direction.

Looking at the optical film manufacturing process according to the invention as follows.

That is, while the film 10 wound on the film supply roll 1 is supplied continuously and at a slow speed along the transport path, the UV resin is applied to the upper surface of the film 10 at the installation position of the coater 2. It will be coated in thickness. At this time, the UV resin to be applied is added with a volatile solvent that can be dried after, the coating thickness can be adjusted by adjusting the vertical height of the support roll (3) or the feed rate of the film (10).

On the other hand, the film 10, the coating of the resin is guided by the guide roll 8 passes through the drying furnace 4, in which the drying is made by irradiating with infrared light or hot air in the drying furnace. As a result, the volatile solvent contained in the resin is vaporized. Then, the UV resin on the film 10 subjected to the drying process is hardened in a semi-solidified state. In addition, as the volatile solvent is vaporized, the coating thickness of the UV resin is reduced, and the amount of reduction can be accurately controlled according to the concentration of the volatile solvent in the UV resin. For example, if the concentration of volatile solvent in the UV resin is 20%, the UV resin thickness of 100㎛ decreases to 80㎛ as it passes through the drying furnace, and the amount of thickness deviation in the initial coating is also reduced by 20% to the thickness of the initially applied UV resin. Accuracy is also improved. However, if the volatile solvent exceeds 70%, the bubble when volatilizing becomes huge and may leave traces on the surface. In addition, if the surface of the applied UV resin is dried first, bubbles may stay inside, so heat must be applied to the opposite side of the surface where the UV resin is applied, so that the volatile solvent inside the UV resin is vaporized first. do.

Subsequently, the film 10 proceeds downward again and passes between the pair of heated embossing rolls 5a in the hot embossing part 5 to form an embossed shape of the resin part through the hot embossing process, and continuously UV. As the UV light is irradiated while passing through the embossing portion 6, the sol-gel UV resin is completely cured to complete the final optical film product.

In the present invention, since the film temperature is heated to a glass transition temperature that is easily plastically deformed, as in a general hot embossing process, embossing is not carried out but embossing the UV resin in a semi-solid state like sol-gel, so that low temperature (50 ° C.) molding is possible. will be. In this way, problems such as heat deformation and heat shrinkage caused by high temperature embossing can be eliminated in advance. In addition, the UV curing step is advantageous because there is no release problem between the stamper or mold and liquid UV resin, which is a problem in conventional UV embossing.

In this way, the optical film having the micropattern of the present invention, which is manufactured by sequentially passing each process of hot embossing and UV embossing, is wound on the film winding roll 7 and stored.

Therefore, the difficulty of embossing the liquid UV resin is to be overcome, and the optical performance of the produced film can be maintained.

In addition, although specific embodiments of the present invention have been described and illustrated above, it is obvious that the method for manufacturing a film having a micropattern of the present invention may be variously modified and implemented by those skilled in the art.

However, such modified embodiments are not to be understood individually from the technical spirit or prospect of the present invention, such modified embodiments will belong to the appended claims of the present invention.

The present invention as described above, by combining the advantages of the hot embossing method and the UV embossing method to produce an optical film having a fine pattern, productivity can be improved, and the desired pattern of the film having a fine pattern produced together It can be seen that it is a useful invention to obtain optical performance.

Claims (10)

delete A film supply step in which an optical film fabric is continuously supplied, a resin application step of applying UV resin to a surface of the film to be supplied, and infrared or heat to dry the resin applied on the film. The drying step of passing through the drying furnace using the, the hot embossing step of forming a fine pattern structure of the resin by passing the dried film through the heated embossing roll and irradiated with UV light to the resin portion of the film is hot embossing UV curing step is made, In the drying step, the resin applied on the film is dried in a semi-solid state of sol-gel state, and the embossing rolls paired in the hot embossing step are heated to a low temperature of 50 ° C. or less. The manufacturing method of the optical film for display devices. delete delete delete delete delete delete delete delete

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