JPS60203434A - Manufacture of transparent conductive film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a transparent conductive film using a polyethersulfone or polysulfone film obtained by a melt extrusion method, and more specifically, on at least one side of the film, A coating solution containing a silane compound having a vinyl group, a polyfunctional vinyl compound photosensitizer, and a solvent as main components is applied, dried, and then reacted and cured by ultraviolet irradiation. After that, a transparent conductive layer is formed on the cured product layer. The present invention relates to a method for manufacturing a transparent conductive film.

In recent years, there has been a remarkable growth in display elements using liquid crystals, and as a result, the number of transparent electrodes is increasing. Conventionally, the electrodes used in liquid crystal display devices are made of Saba glass, which is made by forming a conductive thin film on a thin glass plate, and the electrode circuit is formed by etching the conductive thin film. I came. However, in response to demands for device bookkeeping, weight reduction, and IT mass production, transparent electrodes in which a conductive thin film is formed on a transparent polymer film have become widely studied, and some of them have begun to be put into practical use.

On the other hand, although transparent conductive films using polymeric films are superior from the viewpoints of thinning, weight reduction, mass production, and high strength, they are not as good as glass in the case of fc, in which a conductive layer is formed directly on the film. It is also true that there are problems. That is, (2) the abrasion resistance of the conductive thin film during the double-bottoming process of the electrode teeth for the purpose of aligning the liquid crystal increases, and the surface resistance increases.

@ A transparent conductive film using a uniaxially oriented polyester film is a polymer film that has been put into practical use or is close to being put into practical use, but in addition to having poor heat resistance, the optical axis is the polarizing plate axis because the support has optical anisotropy. It is difficult for non-wealth to match strictly. It is also difficult to obtain a film with uniform axial directions.

θ A so-called cast film can be considered as a non-optically active film, but its productivity is extremely low.

, O has poor closeness with the conductive layer thin film, and has poor moisture and heat resistance reliability.
Disconnection easily occurs during circuit processing.

etc.

In order to eliminate these drawbacks, the inventors of the present invention investigated various polymer films, and developed polyether sulfone, which is a heat-resistant, non-optically active film, and which can be obtained by extrusion and has good transparency. I chose this film because I found it to be excellent. However, when a conductive thin film is simply formed on a polyethersulfone or polysulfone film, the adhesion between the thin film and the film is significantly poor, and the moisture resistance of the conductivity deteriorates significantly, making it unusable and abrasion resistant. There were disadvantages such as poor bendability and easy disconnection during circuit processing and element assembly.

The present inventors attempted vinyl silane and acrylic silane treatment using conventional methods as a method to eliminate these defects caused by adhesion. As a result, it has been found that the adhesion to the conductive film formed by sputtering is significantly improved. However, since these compounds are monofunctional monomers, when attempting to polymerize and fix them through treatments such as heating, only a so-called thermoplastic resin with a linear structure can be obtained, and the treated film must be a film with a low melting point. We have discovered a phenomenon in which fine wrinkles are generated in the conductive film layer due to instability during thermal processes such as sputtering and heat treatment of rubbing agent, resulting in p-deformation and fine wrinkles in the conductive film layer. The inventors of the present application have conducted intensive studies to overcome this phenomenon and its drawbacks, and have arrived at the present invention. That is, a method has been discovered in which the coating film itself is three-dimensionally crosslinked to form a stable coating film that is difficult to deform.

The details of the present invention will be described below.

The film used in the present invention is polyether sulfone (hereinafter referred to as PES film) obtained by melt extrusion method.
Alternatively, it is a polysulfone (hereinafter referred to as PS film) film, which has excellent heat resistance and transparency, and is also an excellent film for transparent electrodes without optical rotation. Next, PES film and it,
Adjust the coating liquid to be applied on the PS film. First, as coupling agents, all so-called vinyl-based 7-ran coupling agents having reactive carbon-carbon double bonds in the molecule, such as vinyl silane and/or acrylic 7-ran, can be used, and solutions of these coupling agents can be used. can also be used as appropriate.

Next, a polyfunctional vinyl compound having two or more reactive 2-east bonds is added to the coupling agent. Examples of these compounds include epoxy diacrylate, urethane diacrylate, polyester diacrylate, trimethylolpropane triacrylate, and polyethylene glycol diacrylate. Polyfunctional acrylates such as acrylate, polyfunctional methacrylates such as butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, hexanediol dimethacrylate, trimethylolpropane triacrylate, diallyl phthalate, triaryl isocyanurate, triaryl trimellitate, etc. Polyfunctional aryl compounds, etc. are used as appropriate.

The ratio of the polyfunctional vinyl compound to the vinyl silane coupling agent is critical, and the latter is blended in an amount of 10 to 100 parts by weight per 100 parts of the vinyl silane coupling agent.

If the amount is less than 10 parts by weight, the coating layer will be thermally weak and the improvement effect will not be achieved, and if it is more than 100 parts by weight, the adhesion to the conductive film will decrease and the effect of the coupling agent will be halved. Next, a photosensitizer is added, and common photosensitizers such as benzophenone, benzoin methyl ether, and benzoin ether ether are used alone or in combination.

The mixture thus obtained is then diluted with a solvent, in which case a solvent that is a good solvent for the formulation, a poor solvent for PES films and pS films, and has an affinity for the mixture should be selected. This is important, and as such solvents, solvents belonging to the Selonerupes and Carbitols are preferably used.

Furthermore, adding a small amount of a good solvent to the PGS film is also an effective means for achieving uniform coating. Further, the dilution rate is appropriately determined from the viewpoints of coating thickness and coating workability. Further, addition of coloring inhibitors, leveling agents, antifoaming agents, bluing agents, wetting improvers, etc. is also an effective means for achieving the present invention.

The coating solution thus obtained is applied to at least one side of the PES film by a dipping method, percoater method, roll coater method,
Apply by a single method such as spray method or spin code method.

The coating thickness is preferably as thin as possible on the premise of uniform coating, but is generally about 1 to 5 μm for this purpose. After drying to remove the solvent and form a coating film, the coating surface is irradiated with ultraviolet rays to form a crosslinked cured coating film. A transparent conductive layer is then formed on the coating of the obtained film.

In this case, oxides such as indium oxide, tin oxide, cadmium oxide, etc. are used alone or in combination and are formed by a sputtering method or an ion bulleting method.

The thus obtained transparent conductive film has a conductive layer firmly integrated with the support layer, so it has excellent wear resistance, circuit processability,
This transparent conductive film has excellent moisture resistance and solvent resistance, and unlike the case where a coupling agent is used alone, a strong three-dimensionally crosslinked coating film is formed, so it has excellent heat resistance and is of great industrial significance. Examples are shown below.

Example r-methacryloxyglobil trimethoxysilane ioo
m Dobe Trimethylolpropane Triacrylate 30
Parts by weight Neopentyl glycol diacrylate 20 parts by weight Benzoin isobutyl ether 5m! Ei part Butyl cellosolve 500 parts by weight The above composition was mixed at room temperature to obtain a homogeneous solution. 10
The above solution was uniformly applied onto one side of a PE8 film with a thickness of 0 μm using a roll coater method, and the solvent was removed by heating at 80°C. Irradiated for seconds. The thickness of the obtained cured coating film was 5 μm. On this coating film, a transparent conductive layer of indium oxide and tin oxide is applied to a thickness of 300 mm by sputtering.
It was formed in Properties of the obtained transparent conductive film are listed in Table 1.

Comparative example 1 r-methacryloxypropyltrimethoxysilane 10
0 parts by weight Penzoin phytyl ether 3 m [1 part] After uniformly mixing the above composition at room temperature,
Roll coater on one side of 00 μm thick PES film
A coating layer with a thickness of 3 μm was provided by uniformly applying the coating layer using a method.

The coating layer was cured by ultraviolet irradiation under the same conditions as in the examples, and a transparent conductive layer was formed on the coating layer by sputtering. Obtained.

Various properties of the 7'C transparent conductive film are listed in Table 1.

Comparative example 2 r-methacryloxypropyltrimethoxysilane 10
Parts by weight Methyl methacrylate) 301i [Oki part 2-Hydroxyethyl methacrylate 20 parts by weight Trimeterolgloban triacrylate 30 parts by weight Neopentyl glycol diacrylate 1.01 m Dobe Benzoin isobutyl ether 3 parts by weight Butylceronelupe 350
The above composition was mixed at room temperature to obtain a homogeneous solution. The composition was uniformly applied onto one side of a 100 .mu.m thick PES film by a roll coater method, and when the solvent was removed by heating at 80.degree. C., a 4 .mu.m thick coating layer was obtained.

The coating layer was cured by ultraviolet irradiation and a transparent conductive layer was formed on the coating layer by sputtering under the same conditions as in the examples. The properties of the obtained transparent conductive film are shown in Table 1.

As described above, although the transparent conductive film obtained in Comparative Example 1 had good adhesion between the coating layer and the conductive layer, it was significantly inferior in heat resistance and solvent resistance.
The fc transparent conductive film obtained in Comparative Example 2 had a heat resistance of 1.
Although the solvent resistance was good, the moisture resistance and abrasion resistance were significantly lowered due to poor adhesion between the coating layer and the conductive layer. On the contrary, the transparent conductive films obtained in the Examples of the present invention had excellent properties that eliminated all of the above-mentioned drawbacks.

Claims (1)

[Claims] On at least one side of a non-optically active polyether sulfone or polysulfone film obtained by melt extrusion,
A silane compound having a reactive divalent bond in the molecule, a polyfunctional vinyl compound having two or more reactive divalent bonds in an amount of 10 to 100 parts by weight per 100 parts by weight of the coupling agent, and a photosensitizer. , and a coating solution whose main components are a solvent that dissolves these is applied, and after drying, a coating film of 10 μm or less is formed, and after drying at a temperature of 100 ° C. or less, it is cured by irradiation with ultraviolet light, and vapor deposited on the coating film. 1. A method for producing a transparent conductive film, which comprises forming a conductive thin film containing indium oxide as a main component by a method or a sputtering method.