JP3373888B2 - Method for producing transparent conductive laminate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a transparent conductive laminate. More specifically, the present invention provides a transparent conductive laminate having a low resistance, a good light-transmitting property, and an excellent etching property, which can be produced while suppressing the generation of cracks and curls. The present invention relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, a transparent conductive laminate having a transparent conductive layer provided on the surface of a polymer film as a substrate has been widely used for transparent heat ray reflectors, transparent sheet heating elements, transparent electrodes and the like. ing. The transparent conductive layer formed in this transparent conductive laminate is a metal thin film type such as gold (Au), silver (Ag), palladium (Pd), indium oxide (I
n ₂ O ₃ ), tin oxide (SnO ₂ ), a mixture of these, ITO, zinc oxide (ZnO) and other metal oxide thin film types, and further TiO ₂ / Ag / TiO ₂ and other metal / metal oxides. Various types such as the multi-layer thin film type are known. Among these, metal oxide thin films such as ITO have excellent light-transmitting properties and conductivity, and also have excellent etching characteristics, and are characterized by easy patterning of electrodes. It is a thing. Therefore, it is preferably used for a transparent electrode of a display that requires a fine pattern.

Such a metal oxide thin film is formed by various film forming methods such as a vacuum vapor deposition method, a sputtering method, an ion plating method and a CVD method.

[0004]

However, when a metal oxide thin film such as ITO is formed on a transparent polymer film substrate by the above film forming method, the film substrate is more difficult than the glass substrate. Low heat resistance (heat distortion temperature
250 ℃ or less), it is difficult to raise the substrate temperature to 250 ℃ or more to form a film, improve the reactivity with the introduced gas, or increase the film formation rate to several tens of liters / sec or more. There was a problem. Therefore, in the conventional film forming method, the surface resistance is 30 Ω / cm ² or less, and further 10 / Ωcm
^I less than ² and light transmittance of 70% or more (wavelength 550 nm)
It was practically difficult to form a TO film.

In addition, a metal thin film mainly composed of Ag is ITO
For a transparent conductive layer having a multi-layered structure sandwiched between metal oxides such as TiO ₂ and TiO ₂ , it is difficult to control the film thickness in the width direction when a metal thin film mainly composed of Ag is formed over a large area, and sufficient transparency is obtained. There is a problem that the stability of characteristics such as optical property and conductivity cannot be obtained. Moreover, in the case of this multilayer structure, there is a problem that etching is not easy because of the multilayer structure.

Further, in order to obtain sufficient conductive characteristics by the conventional method, the film thickness of the transparent conductive layer must be increased to some extent, which lowers the translucency and causes cracks in the thin film. However, there is a problem that the transparent polymer film substrate curls. This invention has been made in view of the circumstances as described above, eliminates the drawbacks of the conventional method for producing a transparent conductive laminate, has low resistance, has high translucency, and has excellent etching properties. Another object of the present invention is to provide an improved method for producing a transparent conductive laminate, which is capable of producing a transparent conductive laminate without cracks and curling.

[0007]

In order to solve the above problems, the present invention provides a transparent polymer film substrate on which a transparent conductive layer containing indium oxide (In ₂ O ₃ ) as a main component is pressed. In a method of continuously laminating by ion plating by gradient discharge, the temperature of both sides of the film substrate immediately before film formation, and the temperature of the film formation surface and substrate surface immediately after film formation are 80 ° C or less, respectively. To provide a method for producing a transparent conductive laminate, which is characterized by producing a transparent conductive laminate having a low resistance and high translucency.

The polymer film substrate is not particularly limited as long as it is a transparent polymer film having heat resistance, and one having heat resistance even at 100 ° C. or higher is exemplified as a suitable one. Further, the organic polymer is cast or extruded, and if necessary, in the longitudinal direction and / or
Alternatively, it may be stretched in the width direction.
Examples of the material include polyester, polyolefin, polyamide, aromatic polyamide, polyamideimide, polyetherimide, polyethersulfone, polysulfone, polyetheretherketone, polyarylate, polyphenylene sulfide, polyphenylene oxide, and polyparabanic acid. be able to. Further, it may be a copolymer with these copolymers or other organic polymers, or may contain other organic polymers. It is possible to add known additives such as antistatic agents, ultraviolet absorbers, infrared absorbers, plasticizers and lubricants to the organic polymer. These polymer films can be formed by laminating two or more of the same kind or different kinds, and have been subjected to surface treatment such as corona discharge treatment, plasma treatment and surface roughening treatment in advance, or a known anchor coat treatment. It may be. The thickness of the polymer film is also not particularly limited, but it is preferably in the range of 50 to 250 μm from the viewpoint of flexibility and shape retention.

As the transparent conductive layer formed on the transparent polymer film substrate, indium oxide (In
₂ O ₃ ) or tin oxide (SnO ₂ ) 3-1
It is preferable to use a single layer of ITO mixed with 5% by weight. Its thickness is preferably 1000 to 10000Å,
Within this range, the surface resistance can be set to 30 Ω / cm ² , and even 10 Ω / cm ² or less. If it deviates from this range, the light-transmitting property will be lowered and the properties such as conductivity will be insufficient. The transparent conductive layer may be formed once or may be divided into a plurality of layers. It suffices that a predetermined surface resistance be obtained. In addition, the single layer improves the etching property as compared with the multi-layer structure. No delamination occurs.

Ion plating by pressure gradient type discharge is used for forming the transparent conductive layer. This pressure gradient type ion plating is a discharge method in which an intermediate electrode is provided between a cathode and an anode and a pressure gradient is provided between the vacuum degree on the cathode side and the vacuum degree on the anode side. Is applied to. As a result, a film forming speed several tens to several hundreds times that of the conventional vacuum evaporation method or sputtering method can be realized.

Further, in the present invention, in the production of the transparent conductive laminate, the temperature of both surfaces of the transparent polymer film substrate is set immediately before the film formation, and the temperature of the film formation surface and the substrate surface is further formed immediately after the film formation. Are adjusted to 80 ° C. or less, and more preferably to a temperature range of −20 to 60 ° C., for example. By controlling the temperature immediately before and immediately after this film formation, it is possible to prevent heat damage to the transparent polymer film substrate and a sharp temperature gradient in the thickness direction, and there is no crack and good quality transparent conductive material with little curl. It is possible to form a laminated body. The obtained laminate has low resistance and high light transmissivity. For example, the surface resistance is 30 Ω / cm ² , further 10 Ω / cm ² or less, and the light transmittance is 70% (wavelength 550 nm) or more. Before film formation, it is desirable that the transparent polymer film base material is heated in the atmosphere or in a vacuum in a temperature range where the base material is not deformed to degas the water contained in the base material.

FIG. 1 is a sectional view showing an example of a manufacturing apparatus which can be used in the manufacturing method of the present invention. In this example, two temperature adjusting rolls (4) and (5) are provided between the unwinding roll (1) and the winding roll (2) and the can roll (3). The temperature control rolls (4) and (5) can be set to an appropriate temperature, and the transparent height as a base material that is conveyed by being wound on these rolls (1), (2), (3), (4) and (5). Both the front and back surfaces of the molecular film (6) and the film formation surface of the transparent conductive layer can be heated or cooled.

When forming a film, the transparent polymer film (6) is fed from the unwinding roll (1) to the temperature control roll (4).
After being set on the take-up roll (2) via (5), the can roll (3) and the temperature control rolls (4) and (5), the inside of the vacuum tank (7) is depressurized by a vacuum pump or the like.
Next, a pressure gradient type plasma gun (8) discharges toward a hearth (9) filled with a film forming material such as ITO to generate a plasma beam to evaporate the film forming material, and a transparent polymer film ( 6) Form a film on top. At this time, if necessary, a reactive gas such as oxygen gas can be introduced through the reactive gas inlet (10).

[0014]

[Operation] In the method for producing a transparent conductive laminate of the present invention, when the transparent conductive laminate is produced by ion plating by pressure gradient type discharge effective for improving the reaction rate and the film formation rate, In order to adjust the temperature of both sides of the film substrate immediately before film formation and the temperature of the film surface and substrate surface immediately after film formation to a specific range, heat damage to the transparent polymer film substrate and thickness direction It is possible to prevent a sharp temperature gradient in the. It is possible to manufacture a transparent conductive laminate having a low resistance, a high translucency, and an excellent etching property, which is free from cracks and suppresses the occurrence of curling.

[0015]

EXAMPLES Examples will be shown below to describe the method for producing a transparent conductive laminate of the present invention in more detail. Example 1 By ion plating by pressure gradient type discharge, 12
ITO (S
nO ₂ 5% by weight) transparent conductive layer of 150 Å /
A film was formed in sec to obtain a transparent conductive laminate. The film thickness is 7,000Å
Met. In addition, the base film is formed on both sides immediately before film formation as shown in FIG.
The temperature of the can roll is adjusted to 60 ° C. during film formation by the temperature control roll as illustrated in FIG. Cooled.

The pressure gradient discharge was carried out at a vacuum degree of 8 × 10 ^-4 Torr, the discharge current was 200 A, the discharge voltage was 60 V, and oxygen was introduced as a reactive gas at 30 cc / min. The surface resistance of the obtained transparent conductive laminate is 5.5 Ω / cm ² ,
Light transmittance is 75.0% at wavelength 550nm, 7.0% at wavelength 2000nm
Met. There was no crack on the ITO film surface, and the curl height was 1 mm. The etching property was also good. Also, 6
No change in appearance or properties was observed even after standing for 500 hours in an environment of 0 ° C and 95% RH.

Example 2 A film was formed in the same manner as in Example 1 except that the transparent conductive layer was indium oxide (In ₂ O ₃ ). The surface resistance of the obtained transparent conductive laminate was 5.0 Ω / cm ² , and the light transmittance was at the wavelength.
It was 74.0% at 550 nm and 6.0% at a wavelength of 2000 nm. In ₂
There was no crack on the O ₃ film surface and the curl height was 0 mm. The etching property was also good, and no change in appearance or characteristics was observed even after standing for 500 hours in an environment of 60 ° C. and 95% RH.

Comparative Example 1 A film was formed without using the temperature control roll of Example 1.
The surface resistance of the obtained transparent conductive laminate is 6.0 Ω / cm.
² , the light transmittance is 71.0% at the wavelength of 550 nm and at the wavelength of 2000 nm.
It was 8.0%. There was no crack on the ITO film surface and the etching property was relatively good, but the curl height was 6 mm. No change in appearance or characteristics was observed even after being left in an environment of 60 ° C and 95% RH for 500 hours.

Comparative Example 2 ITO was deposited to a film thickness of 250 Å under the same conditions as in Example 1, Ag was similarly deposited thereon to a film thickness of 140 Å, and ITO was further deposited thereon to a film thickness of 250 Å. Laminated. The surface resistance of the obtained transparent conductive laminate having a three-layer structure was 11.0 Ω / cm ² , and the light transmittance was 74.5% at a wavelength of 550 nm and 4.5% at a wavelength of 2000 nm. However, the Ag film was poor in etching property, and immediately after being immersed in a 1N aqueous hydrochloric acid solution, the Ag film was peeled off entirely.
When left in an environment of 60 ° C. and 95% RH for 500 hours, white spots were generated due to deterioration of the Ag film.

In the above examples, the light transmittance, surface resistance, curl and etching property were measured as follows. a. A light transmittance (%) at wavelengths of 550 nm and 2000 nm was measured using a light transmittance spectrophotometer (U-3500 manufactured by Hitachi, Ltd.).

B. Surface resistance The surface resistance (Ω / cm ² ) was measured using a surface resistance meter (Loresta, manufactured by Mitsubishi Petrochemical Co., Ltd.). c. The curl sample was cut into 100 mm square pieces, placed on a flat glass plate, and the curl height (mm) was measured.

D. Etching photosensitive liquid (Tokyo Ohka Kogyo Co., Ltd .: P-R300) with a film thickness of 5
The sample is exposed to light after pattern coating with μ, and a developing solution (P-1S)
To develop. After that, etching was performed with a 1N aqueous hydrochloric acid solution, the photosensitive film was peeled off using a peeling solution (PS), and the breakage of the patterned thin film was observed with an optical microscope.

Of course, the present invention is not limited to the above examples. It goes without saying that various aspects are possible in details such as film forming conditions.

[0024]

As described in detail above, the present invention is suitable for a transparent electrode for a display, a transparent heat ray reflector, a transparent sheet-like heating element, etc., which requires a fine etching pattern, and is free from cracks. Little curl,
It is possible to obtain a transparent conductive laminate having a low resistance, a high light-transmitting property, and an excellent etching property.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a manufacturing apparatus that can be used in the manufacturing method of the present invention.

[Explanation of symbols]

1 Unrolling roll 2 winding roll 3 can roll 4,5 Temperature control roll 6 Transparent polymer film 7 vacuum tank 8 Pressure gradient type plasma gun 9 Hearth 10 Reactive gas inlet

Continuation of the front page (56) Reference JP-A 63-908 (JP, A) JP-A 1-313810 (JP, A) JP-A 2-66158 (JP, A) JP-A 4-230906 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C23C 14/32 C23C 14/08

Claims (6)

(57) [Claims] 1. An ink jet on a transparent polymer film substrate.
Oxide (In₂O ₃) Is the main component of the transparent conductive layer.
Continuous by ion plating with force gradient type discharge
In the method of stacking layers, the film substrate
Surface temperature, and the temperature of the film surface and substrate surface immediately after film formation.
The temperature is adjusted to 80 ° C or less, low resistance and high translucency
To produce a transparent conductive laminate having
Method for producing bright conductive laminate. 2. The production method according to claim 1, wherein the temperature is adjusted within the range of −20 to 60 ° C. 3. The temperature of both sides of the base material and the film-forming surface is controlled by a temperature control roll capable of controlling the temperature.
Manufacturing method. 4. The transparent conductive layer is formed of indium oxide (In ₂
O ₃₎ or its tin oxide (claim 1, 2 or 3 formed from a single layer of a mixture of SnO ₂₎ (ITO)
Either manufacturing method. 5. The manufacturing method according to claim 1.
A transparent polymer film substrate, and an indium oxide (In ₂ O ₃ ) layered on the surface of the transparent polymer film substrate by ion plating by pressure gradient discharge, or a transparent conductive layer containing the same as a main component. A laminated body having a surface resistance of 30 Ω / cm ² or less and a light transmittance of 7
0% (wavelength 550 nm) or more, the transparent conductive laminated body characterized by the above-mentioned. 6. The transparent conductive laminate according to claim 5, which has a surface resistance of 10 Ω / cm ² or less and a light transmittance of 70% or more.