KR20040020085A - Transprant Antistatic Triacetyl Cellulose(TAC) Films for Liquid Crystal Display - Google Patents

Abstract

The present invention relates to a transparent antistatic triacetyl cellulose film, and more particularly, in a triacetyl cellulose film for liquid crystal display (LCD), by coating a coating liquid containing a conductive polymer transparent antistatic for a liquid crystal display coated with a conductive polymer film A triacetyl cellulose film.

It is an object of the present invention to provide a transparent antistatic triacetyl cellulose film coated with a conductive polymer film by coating the conductive polymer on a triacetyl cellulose film for liquid crystal display (LCD) as an antistatic agent.

The present invention is to include an organic silicate, colloidal silica in addition to the conductive polymer, which is an antistatic agent, and to coat it on a triacetyl cellulose film to improve anti-glare performance and triacetyl cellulose for LCD polarizing film having an antistatic performance with excellent transparency. Another object is to provide a film.

Description

Transparent antistatic triacetyl cellulose film for liquid crystal display {Transprant Antistatic Triacetyl Cellulose (TAC) Films for Liquid Crystal Display}

The present invention relates to a transparent antistatic triacetyl cellulose film, and more particularly, in a triacetyl cellulose film for liquid crystal display (LCD), by coating a coating liquid containing a conductive polymer transparent antistatic for a liquid crystal display coated with a conductive polymer film A triacetyl cellulose film.

With the development of the industry, the usage time of mobile phones and computers is gradually used for a long time, and as the demand for high-definition and high-definition for visual screens increases, cathode ray tubes (cathod) used in display methods used in existing electronic components Instead of the ray tube (CRT) method, the flat panel display (PDP) and liquid and solids that realize the screen on the principle that ultraviolet rays emitted from the gas filled in the space between the upper and lower plates collide with the phosphor and emit unique visible light. By applying the electro-optical properties of the liquid crystal having intermediate properties to the display device, the display device is made by using the property that the liquid crystal, which is an organic molecule having fluidity like a liquid, is regularly arranged like a crystal, by the external electric field. The use of liquid crystal displays (LCDs) is rapidly increasing. Among them, interest in LCDs that emits no electromagnetic waves such as CRT or PDP, which is generally used, is increasing. Notebooks and various types of touch panels that we usually deal with are products using this LCD.

LCD works by using the polarization difference of light. Before filling the liquid crystal polymer, the polarizer is placed on both edges and the middle liquid crystal polymer enters, and the color mode is changed according to the twist angle generated by the polarizer or the polarizing film. When the polarizing film enters a polarizing material between the triacetyl cellulose film, which is a supporting film, an adhesive is applied on the back surface of the polarizing film to bond with other structures of the LCD. The triacetyl cellulose film used as the supporting film of the polarizing film has a protective film on one side and an adhesive on the other side before being used for LCD. The film is caused by static electricity generated during processing such as removing or applying the protective film. This may be damaged. In addition, since LCD is laminated with multiple layers, if static electricity is generated in any one of the entire multilayer structures during operation, the whole may be damaged and the dust should not be stuck during processing to prevent the distortion of light during use. . Accordingly, attempts have been made to use antistatic treatment on all possible parts of the internal structure. At this time, it should be noted that the generated light must not be discolored, a material that does not reduce the visible light transmittance should be used, and an antistatic agent that does not generate organic or inorganic particles should be used. Recently, the anti-glare treatment of the polarizing film is performed to prevent the reflection of light, and the treated portion should be subjected to the antistatic treatment as well.

In order to antistatically treat the triacetyl cellulose film used as the support film of the LCD polarizing film, it should have transparency in addition to the antistatic ability, which is most commonly used as an ion conductive material antistatic agent. However, this ion-conducting antistatic agent has a small molecular weight, which can cause particles to creep out during use and contaminate the product.The anti-static performance is significantly reduced in an environment without humidity, and the anti-static performance disappears over time. There is a limit.

In addition, when the antistatic treatment of the support film with a thin thickness, the metal oxide can maintain transparency. Particles such as indium tin oxide, doped tin oxide, and doped titanium oxide may be used to induce scattering or refraction of light. It has the disadvantage that it is in shape and very expensive and that particles can act as impurities.

In the present invention, while researching the transparency and the antistatic material as described above, attention has recently been paid attention to the conductive polymer that has been spotlighted as an antistatic treatment agent in various fields. Conductive polymers have high conductivity and at the same time have transparency, they are easy to control conductivity, that is, they do not change the properties of the underlying material, and in particular, there are no impurities and the change in conductivity does not change permanently after many years. Maintaining is a big advantage.

An object of the present invention is to provide a transparent antistatic triacetyl cellulose film coated with a conductive polymer film by coating a conductive polymer having the above advantages as an antistatic agent on a triacetyl cellulose film for liquid crystal display (LCD).

The present invention is to include an organic silicate, colloidal silica in addition to the conductive polymer, which is an antistatic agent, and to coat it on a triacetyl cellulose film to improve anti-glare performance and triacetyl cellulose for LCD polarizing film having an antistatic performance with excellent transparency. The provision of the film is another object.

The present invention relates to a transparent antistatic triacetyl cellulose film, and more particularly, in a triacetyl cellulose film for liquid crystal display (LCD), the conductive polymer film is coated by coating a coating liquid containing conductive polymer to a thickness of 50 to 300 nm. An antistatic triacetyl cellulose film.

The conductive polymers used in the present invention are polyethylene dioxythiophene, polythiophene, polyaniline or polypyrrole, which are contained in the coating solution based on the final solid content of 20 to 40 parts by weight. There is a problem that is difficult to maintain, there is a problem that the transparency is lowered when used in excess of 40 parts by weight of the conductive polymer in the coating liquid coating on the triacetyl cellulose film for liquid crystal display (LCD) in the present invention based on the final solid content after coating It is preferable to contain 20-40 weight part.

When coating the coating solution containing the conductive polymer on the triacetyl cellulose film, coating the coating solution containing the conductive polymer on the triacetyl cellulose film at less than 50 nm has a problem of lowering the antistatic ability, and exceeds 300 nm the triacetyl cellulose film. Since the transparency decreases when coated on, the coating liquid containing the conductive polymer is preferably coated on the triacetyl cellulose film with a thickness of 50 to 300 nm.

In the present invention, a method of attaching a coating liquid containing a conductive polymer such as polyethylenedioxythiophene, polythiophene, polyaniline, or polypyrrole to a triacetyl cellulose film contains a conductive polymer by mixing a conductive polymer and a binder in a solvent. After preparing a coating solution to be coated on a triacetyl cellulose film to a certain thickness. The binder prevents the conductive polymer film coated on the triacetyl cellulose film from being deformed by solvent or external friction, and has a property of making the conductive polymer adhere well to the film. do. For example, Baytron PH and Bayer produced by Bayer, Germany, are dispersed in an aqueous solution, and thus may be coated by mixing a solvent with a water-soluble binder such as acrylic, amide, and urethane.

Among the conductive polymers used in the present invention, polyethylene dioxythiophene has excellent transparency due to the electron donating effect of oxygen atoms adjacent to the polymer backbone, and when coated with a thin thickness, the transparency of the visible region is increased to make the triacetyl cellulose film more clearly. do. On the other hand, polypyrrole and polyaniline itself is green and brown, respectively, because the transparency is slightly reduced, but even if they are uniformly coated on the triacetyl cellulose film several tens to several nanometers can improve the transparency.

In the present invention, the binder used in the coating liquid containing the conductive polymer may include 20-40 parts by weight based on the final solid content after coating in the coating liquid containing the conductive polymer, and the binder may be used in both an organic binder and an inorganic binder. Do. In particular, by controlling the thickness of the coating on the triacetyl cellulose film and using an inorganic binder having a refractive index there is an advantage that may have a low reflection effect.

The organic binder can be used in both water-soluble and solvent-type, and all kinds of binders including acrylic, ester, urethane, imide, epoxy, amide, carbonate, hydroxyl, carbonyl and carboxyl functional groups can be used. When two or more binders are mixed in a ratio of 95: 5 to 5:95, or a binder containing two or more functional groups is used alone, the physical properties are excellent. In addition, when a curing agent such as melamine that cures acrylic is added in an amount of about 1-5 parts by weight based on the binder content, curing may form a conductive polymer coating film having increased resistance to external friction and solvent.

As the inorganic binder, silicate or titanate may be used. In addition to the substituents which are all removed after curing, functional silicates and functional titanates having substituents showing adhesion and compatibility to organic polymer films may be used. Such silicates and titanates may be substituted with alkoxy groups having 1 to 4 carbon atoms. Water used as a curing agent is added in an amount of 3-8 molar ratio based on the silicate or titanate content of the inorganic binder and 0.01-0.1 parts by weight of a curing accelerator such as dibutyl tin dilaurate (DBTDL) is added to the binder content. Can be used.

The solvent used for ease of operation when the conductive polymer is coated on the triacetyl cellulose film may be used 50-70 parts by weight in the coating liquid containing the conductive polymer. In the case of a water-soluble solvent, about 10-15 parts by weight of water having 4 or less carbon atoms and 50-60 parts by weight of alcohol may be used, and a solvent having a high boiling point such as glycol may be used by mixing 1-5 parts by weight with respect to the total solvent weight. have. In the case of a solvent-type solvent, alcohols having 4 or less carbon atoms, toluene xylene, enmethylpyrrolidinone, ketones having 5 or less carbon atoms, or the like can be used alone or in combination of two or more thereof in a ratio of 95: 5 to 5:95. Can be.

Meanwhile, the present invention can simultaneously perform anti-glare and antistatic treatment on the untreated triacetyl cellulose film, using 5-20 parts by weight of the conductive polymer dispersion and 20-40 parts by weight of the organosilicate as a binder and colloidal based on the total weight 100. 20-30 parts by weight of silica is dissolved in 30-45 parts by weight of the above-mentioned solvent, and a solution containing conductive polymers, organosilicates and colloidal silica is coated on a triacetyl cellulose film and cured to obtain a surface glaze of 90%. By reducing the abnormality can be prepared triacetyl cellulose film treated with anti-glare and anti-static at the same time.

In general, when the organic silicate having four alkyl groups is cured, -SiO- bonds such as glass are formed through intermediates, and thus have the characteristics of inorganic materials. This is called colloidal silica. This compound is not completely crosslinked like glass and the reaction is stopped at moderate to external conditions. When the organic silicate is directly reacted, the reaction time is long and the conditions are difficult to use this colloidal silica. In addition to the above advantages, the compound exists in the form of particles of a certain size, so when used for surface coating, it has a property of preventing light from scattering by scattering light.

The present invention will be described in more detail with reference to the following examples. However, these examples are examples of the present invention and they do not limit the scope of the present invention.

<Example 1>

5 parts by weight of a polyethylenedioxythiophene dispersion (Baytron PH, Bayer), 10 parts by weight of an acrylic binder, and 15 parts by weight of water are mixed with 70 parts by weight of a mixture of ethyl alcohol and isopropyl alcohol in a 2: 3 ratio. It was coated with a triacetyl cellulose film at 200 nanometer (nm) by a known method and dried at 80 ° C. for 2 minutes.

Hanba the dried triacetyl cellulose film, measured surface area, wherein the adhesive force, the visible light transmission rate by ASTM regulations surface resistance of 10 ⁶ ohms / square (Ω / □), adhesion is 5B, the visible light transmittance is measured with a contrast of 99% base film It became.

<Example 2>

5 parts by weight of a polyethylenedioxythiophene dispersion (Baytron PH, Bayer), 10 parts by weight of an acrylic binder, and 15 parts by weight of water are mixed with 70 parts by weight of a mixture of ethyl alcohol and isopropyl alcohol in a 2: 3 ratio. The coating was coated with 200 nm (nm) on an anti-glare triacetyl cellulose film (AG-TAC film, FUJI, Japan) by a known method and dried at 80 ° C. for 2 minutes.

After drying the triacetyl cellulose surface area, wherein the film by the ASTM regulations, adhesion, sheet resistance hanba measuring the visible light transmittance is 10 ⁶ ohms / square, adhesion is 5B, the visible light transmittance was measured to be 99% compared to the base film.

<Example 3>

2 parts by weight of ethylenedioxy thiophene as a monomer and 5 parts by weight of ferrictoluenesulfonate as an oxidizing agent and dopant were mixed in 93 parts by weight of a mixture of normal butanol and ethyl alcohol in a ratio of 1: 4. The coating was coated with a thickness of 200 nanometers on a triacetyl cellulose film coated with a micron thickness in advance, and then cured at 80 ° C. for 5 minutes, washed with ethyl alcohol, and dried at 80 ° C. for 1 minute.

After drying, the triacetyl cellulose film was measured for surface area, adhesion, and visible light transmittance according to ASTM-related regulations. The surface resistance was 10 ⁵ ohms / area, adhesion was 5B, and visible light transmittance was 98% of the base film.

<Example 4>

The anti-glare triacetyl cellulose film was precoated to a thickness of 0.1 micron as a pretreatment.

2 parts by weight of monomer ethylenedioxy thiophene and 5 parts by weight of oxidant and dopant ferrictoluenesulfonate were mixed in 93 parts by weight of a mixed solvent in which normal butanol and ethyl alcohol were mixed at a weight ratio of 1: 4, and the mixed solution was pretreated. The anti-glare triacetyl cellulose film was coated with a thickness of 200 nanometers, cured at 80 ° C. for 5 minutes, washed with ethyl alcohol, and dried at 80 ° C. for 1 minute.

After drying, the triacetyl cellulose film was measured for surface area, adhesion, and visible light transmittance according to ASTM-related regulations. The surface resistance was 10 ⁵ ohms / area, the adhesion force was 5B, and the visible light transmittance was 98% of the base film.

Example 5

5 parts by weight of polyethylenedioxythiophene dispersion, 15 parts by weight of organosilicate, and 10 parts by weight of colloidal silica were mixed and added to 70 parts by weight of a solvent in which ethyl alcohol and isopropyl alcohol were mixed at a ratio of 2: 3, and The acetylcellulose film was coated with a thickness of 350 nanometers, and dried at 80 ° C. for 2 minutes and at 100 ° C. for 5 minutes.

After drying, the triacetyl cellulose film was measured for surface area, adhesion, and visible light transmittance according to ASTM-related regulations.The surface resistance was increased to 10 ^6-7 ohms / area, adhesion was 5B, and anti-glare performance was increased by 90% or more. Confirmed.

According to the present invention, it is possible to obtain a triacetyl cellulose for an LCD polarizing film and an anti-glare triacetyl cellulose film having excellent visible light transmittance and an antistatic performance and having a surface resistance of 10 ⁵ -10 ¹⁰ ohms / area.

Claims (4)

In the triacetyl cellulose film for liquid crystal display (LCD), A transparent antistatic triacetyl cellulose film coated with a conductive polymer film by coating a coating solution containing a conductive polymer to a thickness of 50-300nm The transparent antistatic triacetyl cellulose film of claim 1, wherein the conductive polymer comprises 20-40 parts by weight based on the final solid content in the coating solution. The transparent antistatic triacetyl cellulose film of claim 1, wherein the conductive polymer is polyethylene dioxythiophene, polythiophene, polyaniline or polypyrrole. The transparent antistatic triacetyl cellulose film of claim 1, wherein the coating liquid containing the conductive polymer contains an organosilicate and colloidal silica to improve anti-glare performance.