JPH10718A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transparent electrically conductive film having favorable etching properties and satisfying impact resistance, transparency, gas barrier properties and flexibility by a method wherein an organic layer, an inorganic layer having barrier properties, an organic layer, an electrically conductive layer easily meltable in dilute acid and a low specific resistance electrically conductive layer are laminated in the named order. SOLUTION: An organic layer 2, an inorganic layer having barrier properties, an organic layer 4, an electrically conductive layer easily meltable in dilute acid and a low specific resistance electrically conductive layer 6 are laminated in the named order onto at least one side of a polymeric film or sheet so as to obtain a laminated film excellent in impact resistance, flexibility and etching properties. The electrically conductive layer 5 is made of the oxide of In and Zn under the composition of the oxide in atomic ratio of Zn/In+Zn=0.15-0.4 and the thickness of which is within the range of 50-200Å. The electrically conductive layer 6 is made of the oxide of In and Sn under the composition of the oxide in atomic ratio of In/In+Sn=0.85-0.95.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive film used for a film liquid crystal display.

[0002]

2. Description of the Related Art As conductive films for liquid crystal, Japanese Patent Publication Nos. 62-32101, 63-34018 and 1
Indium oxide, tin oxide, or a semiconductor film such as an oxide film of tin or indium alloy, or gold, silver, palladium, or an alloy thereof on a polymer film surface such as polyester, polyether sulfone, or polycarbonate described in -12666. And a film formed by combining a semiconductor film and a metal film.

[0003] However, when the above-mentioned transparent conductive film is formed on plastic, there are drawbacks such as the influence of gas from the substrate and difficulty in etching due to crystallization. However, the technology adopted has not yet been established. As an example, as a transparent conductive film soluble in acid, Japanese Patent Application Laid-Open No. Hei 7-168196 proposes a single conductive layer of an amorphous oxide composed of In and Zn, but it is too soluble. In addition, there has been a serious problem that stability between lots, called over-etching on a pattern processing line, is lacking, and design is difficult. Further, the specific resistance is as high as 3 × 10 ⁻⁴ Ω-cm, and there is a problem as a low-resistance transparent conductive film having a surface resistance of 20 Ω / □ or less required for a high-definition pattern. In other words, in order to lower the resistance, if the film thickness is increased, the resistance certainly decreases, but the specific resistance is 3 × 10
^In order to obtain 20 Ω / □ with a film of ^-4 Ω-cm, the film thickness must be 1
It was 500 ° (specific resistance = film thickness × surface resistance), and there was a defect that a so-called bone-like phenomenon in which a pattern could be seen in a liquid crystal display occurred, resulting in a decrease in display quality. In order to avoid the bone appearance phenomenon, the film thickness must be at least 1000 ° or less.

On the other hand, in the method of providing an inorganic layer as a gas barrier layer, a method other than a liquid crystal application is disclosed in Japanese Patent Publication No. 53-1295.
3. For liquid crystal, see JP-A-50-142194.
SiO2 or the like deposited on at least one surface of a polymer film, or vinylidene chloride-based polymer or vinyl alcohol-based polymer described in Japanese Patent Application No. 59-207168 on a polymer film. Japanese Patent Application Nos. 59-201886 and 59-20
It is known to provide a polymer coating layer having relatively gas barrier properties such as 1887.

However, in order to be used for liquid crystal applications, the film liquid crystal needs to have impact resistance, which is the greatest feature of liquid crystal.
This corresponds to a drop or an external pressure. Generally, a DuPont impact tester (JIS-K-5400.6.13)
In B), drop with a weight load of 100 g and drop distance 3
It is desirable to have an impact resistance of 00 mm or more, but in practice, it was about 50 mm, which is not a level that can be safely used in practice.

[0006] The flexibility of the film liquid crystal is required to be free from cracks even when wound around a roll having a diameter of 35 mm.
When it has an inorganic layer composed of an oxide by hydrolysis described in 563, it is generally as thick as about 1 μm, and it is also found in other production methods. There was a drawback mentioned above, and it was not always the case that an inorganic barrier should be provided.

As described above, the film liquid crystal display device includes:
A laminated film having a combination of gas barrier properties, transparent conductivity, impact resistance, and flexibility is an indispensable element, but in practice, pattern processing is particularly important from the viewpoint of yield. However, by combining the layers having these functions, a transparent conductive film that has good workability, can impart transparent conductivity and gas barrier properties, and has sufficient durability as a liquid crystal display device material is still required. It is not produced industrially.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above situation, and has a transparent conductive property which is soluble in a dilute acid and has excellent gas barrier properties, impact resistance and flexibility. The object of the present invention is to provide a film having:

[0009]

The above-mentioned object is achieved by the present invention described below. As shown in FIG. 1, an organic layer 1, an inorganic layer having barrier properties, an organic layer 2, a conductive layer 1 easily soluble in dilute acid, and a conductive layer having a low resistivity are provided on at least one side of a polymer film or sheet. 2 is a laminated film having excellent impact resistance, flexibility, and etching property, and a more preferable embodiment is the impact resistance, in a drop test with a weight load of 100 g in a DuPont impact tester, It has an impact property of a drop distance of 500 mm or more, has a flexibility that does not cause cracks even when wound around a roll of 35 mmΦ, and the conductive layer 1 is made of an oxide of In and Zn, Oxide composition Zn / In + Zn
Has an atomic ratio of 0.15 to 0.4 and a film thickness of 50 to
The organic layer 1 or 2 is an epoxy acrylate prepolymer having a melting point of 50 ° C. or more or a melting point of 5 ° C.
A UV-cured film of a urethane acrylate prepolymer at 0 ° C. or higher, and a thickness of 0.3 to 1.5 μm;
The inorganic layer has a total light transmittance of 85% or more, a surface resistivity at a driving frequency of 30 Hz of 1 × 10 ¹² Ωm or more, and an oxygen barrier property of ² cc / 24 hr · m ² or less. Is a laminated film comprising an oxide of In and Sn, wherein the composition of the oxide In / In + Sn has an atomic ratio of 0.85 to 0.95.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A polymer film or sheet (hereinafter referred to as a film) in the present invention is a thermosetting resin represented by polyether sulfone, polycarbonate, polyarylate, norbornene, ultraviolet curable resin and epoxy resin. Total light transmittance (JIS-K-
7105.5.5), a film having a transparency of 80% or more and a small optical anisotropy, and desirably having heat resistance as much as possible from the viewpoint of processability. In this sense, 223
Polyethersulfone, an ultraviolet curable resin, and a thermosetting resin having the highest Tg at ℃ are more preferable. In addition, the thickness is 0.05 to 0.5 mm in order to have flexibility, which is light to glass, does not break, and has flexibility. It may have a laminated configuration. The optical anisotropy is desirably 0 as much as possible, but the retardation value is 15n.
m or less, and the angle dependence is preferably 45 degrees or less and twice or less. This is a requirement for preventing color misregistration in terms of color difference of 2 or less and angle dependency.

The organic layer is an ultraviolet-cured film of an epoxy acrylate prepolymer having a melting point of 50 ° C. or higher or a urethane acrylate prepolymer having a melting point of 50 ° C. or higher. A curing type may be used. However, an ultraviolet curable resin excellent in productivity is more preferable. Needless to say, adhesion to the polymer film or the inorganic layer is indispensable, and it is necessary to have excellent flexibility and chemical resistance.
For this purpose, a conventional primer layer may be provided.

What is important here is that it is necessary to limit the thickness of the organic layer in order to maintain impact resistance. Although it is true that there is a place depending on the resin formulation, when a thickness of about 2 to 5 μm, which is usually used as the thickness of the coating resin, is applied, the impact resistance test described in the present invention generally causes a drop. Distance 5
This is because a crack is easily generated at about 0 mm. Therefore, in order to use it in a practically sufficiently stable region for liquid crystal applications, a drop distance of 500 mm or more is desirably desirable, and as a result of intensive studies, it has been found that a thickness of the organic layer in the range of 0.3 to 1.5 μm is satisfactory. Things. This is because ultraviolet curable resin has a potential internal stress because of the curing shrinkage of about 10 to 20% at the time of curing, and when a local external force such as an impact test acts, a crack is formed at a stretch. is there. Here, when the thickness of the organic layer is less than 0.3 μm, coating unevenness is liable to occur, and when it exceeds 1.5 μm, the adhesion is reduced and cracks are liable to occur.

The adhesion to the base film when the organic layer is applied to a thickness of 2.5 μm is 200 g / cm,
In the case of a 0.5 μm product, it can be improved to 5 times, that is, 1000 g / cm. As an advantage of further thinning, it is desirable to have transparency as much as possible in liquid crystal applications, and 0.5% for every 0.5 μm reduction even for the thinnest 2 μm usually applied.
This is an effective means from this point of view.

As the inorganic layer, the total light transmittance is 85% or more,
Surface resistivity (JIS-K-6911) 1 × 10 ¹² Ω (1
0-30 Hz) or more, 2 cc / 2 as an oxygen barrier property
There is no practical problem as long as it has a flexibility of 4 hr · m ² or less and does not crack even when wound around a 35 mmφ roll. As the inorganic layer, for example, SiOx,
SixNy, AlxOy, etc., or a multilayer or composite film of these may be considered. The film is formed by vapor deposition such as evaporation, sputtering, ion plating, or CVD, or coating by hydrolysis using metal alkoxide as a raw material. You.

It is desirable that the total light transmittance is as high as possible. However, considering the transmittance of the polymer film and the conductive layer, the material can be used if it is substantially 85% or more. If the total light transmittance is less than 85%, the transparency is insufficient, and it cannot be used for this application.

The surface resistivity at 30 Hz, which is the driving frequency of the liquid crystal, needs to be 1 × 10 ¹² Ω or more. This is because, since the inorganic layer is in direct contact with the liquid crystal layer, the resistivity of the liquid crystal normally used in the TN and STN modes is about 1 × 10 ¹⁰ Ω, so that it is necessary to provide a difference of 100 times or more. 1
If the resistance is less than × 10 ¹² Ω, the current consumption of the cell increases significantly, which is problematic in terms of the life of the cell. For this purpose, SiO ₂ , Si ₃ N ₄ , A
l ₂ O ₃ is preferred. Further, from the viewpoint of the cell life, it is desirable that the amount of ionic impurities is as small as possible, and it is generally desirable that the ionic impurities be 20 ppm or less. For this purpose, it is important to select materials and control impurities during film formation.

It is important that the oxygen barrier property is ² cc / 24 hr · m ² or less as measured by the Mocon method. The most characteristic feature is that there is no change in temperature and humidity compared to organic barriers represented by vinylidene chloride polymer and vinyl alcohol polymer. When the organic barrier is less than ² cc / 24 hr · m ² at normal temperature and normal humidity. There is no problem in practical use. If necessary, the organic layer between the inorganic layer and the conductive layer 1 may be multi-layered as shown in FIG. 2 as long as the required characteristics described in the present invention are satisfied. In addition, prior to the formation of the inorganic layer, a known anchor coat such as a degassing treatment, a corona discharge treatment, a surface treatment such as a flame treatment, or an acrylic epoxy system may be applied in order to enhance the adhesion to the organic layer. Good.

The conductive layer 1 is composed of In and Zn, and the composition of the oxide is usually Zn / In + Zn in an atomic ratio of 0.15 to 0.4 and a film thickness of 50 to 200 °. It is a controllable pattern workability with an HCl concentration of 15 vol%, and the conductivity is in a good range. That is, when Zn / In + Zn is less than 0.15, the specific resistance is extremely increased, the effect of Zn is lost, and the etching characteristic is recognized as an effect without any difference from the generally used oxides of In ₂ O ₃ and SnO _2. I can't. Also, Zn / In
When + Zn exceeds 0.4, the specific resistance similarly increases, and Zn
It becomes impossible to control the etching property as in the case of O alone. For example, when the atomic ratio becomes 0.08, the specific resistance of 0.25 which is the optimum composition is 3.0 × 10 ⁻⁴ Ω-cm (500 °).
Is 1 × 10 ⁻² Ω-cm, and the specific resistance is 30 times or more. At 0.5, it becomes 5 × 10 ⁻⁴ Ω-cm.
The specific resistance becomes 6 times or more. The thickness of the conductive layer 1 is 5
0 to 200 ° is desirable. When it is 200 ° or more, the specific resistance is 1.5 × 10 ⁻⁴ Ω-cm, which is 1.5 × 10 ⁻⁴ Ω-cm of the composite oxide of In ₂ O ₃ and SnO ₂ (5 wt%) normally used for the conductive layer 2.
This is because the conductivity is disadvantageous because it is more than twice as bad.
On the other hand, if the angle is less than 50 °, the specific resistance is greatly increased because the film is a discontinuous film, and the desired good etching characteristics cannot be obtained.

As the conductive layer 2, In ₂ O ₃ , SnO ₂
And is generally widely used because it has the best specific resistance and transparency. In order to obtain a desired resistance value, the film is formed by appropriately considering manufacturing conditions. This is because the composition of the oxide is 0.85 to 0.95 in terms of the atomic ratio of In / In + Sn, and if it is less than 0.85 or exceeds 0.95, the specific resistance increases. In particular, when it is less than 0.85, the acid resistance increases and the etching property is greatly reduced.

[0020]

【Example】

Example 1 As a polymer film, a polyethersulfone film having a thickness of 200 μm and a retardation of 5 nm produced by a melt extrusion method was used. An epoxy acrylate prepolymer (VR-60, manufactured by Showa Polymer Co., Ltd.) having a molecular weight of 1540 and a melting point of 70 ° C.
0 parts by weight, 400 parts by weight of butyl acetate, 100 parts by weight of cellosolve acetate, and 2 parts by weight of benzoin ethyl ether were stirred and dissolved at 50 ° C. to form a uniform solution, which was applied with a gravure roll coater. The solvent was removed by heating for 15 minutes, and the pressure was reduced with a high pressure mercury lamp of 80 w / cm for 15
Irradiate for 30 seconds at a distance of 0.5 cm to cure the resin, 0.5
An organic layer 1 having a thickness of μm was formed.

Next, an initial vacuum degree of 3 × 10 ^-4 Pa was applied to the film by a DC magnetron method, and a mixed gas of oxygen / argon gas 9% was introduced thereinto to form an inorganic layer under the conditions of 3 × 10 ^-1 Pa. Film formation was performed to obtain 500-mm thick SiO ₂ .
The oxygen barrier property of this inorganic film was 1.0 cc / 24 hr · m ² when measured by the Mocon method, and the surface resistivity (JIS-K-6911) at a frequency of 30 Hz was 8.1 × 10 6 when measured. ¹² Ω. The total light transmittance (JIS-K-71055.5) was 89%. Further, the film was wound around a roll having a diameter of 35 mm and observed with a metallographic microscope at a magnification of 1000 times. Next, the organic layer 1 is placed on the inorganic layer.
In the same manner as in the above, an organic layer 2 having a thickness of 0.5 μm was formed.

[0022] As the conductive layer 1, also drawn to an initial vacuum of 3 × 10 ^-4 Pa by a DC magnetron method, introducing oxygen / argon gas 4% of the mixed gas, formed under the conditions of 1 × 10 ^-1 Pa Then, a conductive layer 1 having an atomic ratio of Zn / In + Zn of 0.25 was obtained. As a result of the measurement, the film thickness was 150 ° and the specific resistance was 4.3 × 10 ⁻⁴ Ω-cm.

Next, as the conductive layer 2, the initial vacuum degree is 3 × 10 ^-4 P by the DC magnetron method as in the case of the conductive layer 1.
a, a mixed gas of oxygen / argon gas 3% is introduced,
A film was formed under the conditions of 1 × 10 ^-1 Pa, and a composite oxide of In ₂ O ₃ (In / In + Sn) having a SnO ₂ content of 5 wt%
(Atomic ratio of 0.95) 800 ° was obtained. Conductive layers 1 and 2
Has a specific resistance of 4.95 × 10 ⁻⁴ Ω-cm and a total light transmittance of 8
3%. A resist was applied to the conductive film obtained under the above conditions, exposed to light, and developed to form a 230 μm pitch circuit at an HCl concentration of 15 vol% and a liquid temperature of 40 ° C. as an etchant. 180/50 as line / space
μm. The etching time was 20 seconds, and a good straight line was obtained without any residual.

An impact resistance test was performed using the film prepared from this pattern. In a Dupont impact tester (JIS-K-5400.6.13B), cracks were finally observed at a falling distance of 900 mm when dropped with a weight load of 100 g, which was very good. In addition, as a flexibility test, it was wound around a roll of 35 mmφ, and 10
Observation with a metallographic microscope (× 00) revealed that no cracks were observed as in the case of the inorganic layer alone, and that the specific resistances of the conductive layers 1 and 2 did not change. Etch all the conductive layers again,
When the oxygen barrier was confirmed, 0.8 cc / 24 hr
· M ² and the change was not observed. The evaluation of each characteristic was performed under the same conditions, and in particular, the inorganic layer and the conductive layers 1 and 2 were continuously formed by the same apparatus.

<< Comparative Example 1 >> The same lot film and the same lot material as in Example 1 were used and formed in the same configuration. However, only the thickness of the organic layer 1 was 3 μm. Next, using a film patterned by the same method as in Example 1, an impact resistance test was performed using a DuPont impact tester. When dropped with a weight load of 100 g, cracks were observed at a falling distance of 40 mm.

Comparative Example 2 Except for the conductive layers 1 and 2, the same lot film and the same lot material as in Example 1 were used and formed in the same configuration. For the conductive layer 1, the composition of the target material as the raw material was changed, and the atomic ratio of Zn / In + Zn was 0.5 and the thickness was 400 °. The composition of the conductive layer 2 was the same as in Example 1, and the thickness was 550 °. Next, a film patterned by the same method as in Example 1 was used for 10
When observed with a metallographic microscope at × 00, there was no pattern residue, and the pattern was good. Was. In addition, there were large variations depending on the location, and control was difficult. The specific resistance of the conductive layers 1 and 2 is 3.2 × 10 ⁻⁴ Ω-c.
m, which was not a satisfactory level for a conductive film.

Comparative Example 3 Except for the conductive layers 1 and 2, the same lot film and the same lot material as in Example 1 were used and formed in the same configuration. For the conductive layer 1, the composition of the target material, which is a raw material, was changed so that the atomic ratio of Zn / In + Zn was 0.08 and the thickness was 30 °. The composition of the conductive layer 2 was the same as in Example 1, and the thickness was 900 °. A film patterned by the same method as in Example 1 was used for 1000
A pattern residual was observed under a metal microscope at × 1 magnification.

Comparative Example 4 Using the same lot film and the same lot material as in Example 1, an organic layer 2 was formed in the same configuration. Only one conductive layer with a thickness of 1000
A conductive layer 1 was formed in the same manner as in Example 1 except that the method was changed to Å. Next, when the film patterned by the same method as in Example 1 was observed with a metallographic microscope at a magnification of 1000 times, the over-etching was significantly deviated from the pattern design value of 180/50 μm of line / space. Depending on the situation, there were some places where disconnection occurred, making control difficult.

[0029]

According to the present invention, it has become possible to provide a transparent conductive film having good etching properties, excellent impact resistance, and satisfying transparency, gas barrier properties, and flexibility.

[Brief description of the drawings]

FIG. 1 shows a partial cross-sectional view of a laminated film according to the present invention.

FIG. 2 is a partial cross-sectional view of a laminated film according to the present invention, showing an example in which an organic layer 2 is divided into two layers.

[Explanation of symbols]

 1: polymer film 2: organic layer 1: inorganic layer 4: organic layer 2: conductive layer 16: conductive layer 41, 42: organic layer 2

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C23C 14/08 C23C 14/08 N G02F 1/1333 500 G02F 1/1333 500 1/1343 1/1343

Claims (7)

[Claims] 1. An organic layer 1, an inorganic layer having barrier properties, an organic layer 2, a conductive layer 1 easily soluble in dilute acid, and a conductive layer 2 with low resistivity on at least one side of a polymer film or sheet. A laminated film which is sequentially laminated and is excellent in impact resistance, flexibility and etching properties. 2. The laminated film according to claim 1, wherein the film has an impact resistance of a drop distance of 500 mm or more in a drop test using a DuPont impact tester with a weight load of 100 g. 3. The laminated film according to claim 1, wherein said flexible film has such a flexibility that no cracks are generated even when wound around a roll having a diameter of 35 mm. 4. The conductive layer 1 is composed of an oxide of In and Zn, and the composition of the oxide is Zn / In + Zn of 0.15 to 0.5.
4. The laminated film according to claim 1, wherein the atomic ratio is 4 and the film thickness is in the range of 50 to 200 [deg.]. 5. The organic layers 1 and 2 are ultraviolet cured films of an epoxy acrylate prepolymer having a melting point of 50 ° C. or higher or a urethane acrylate prepolymer having a melting point of 50 ° C. or higher, and have a thickness of 0.3 to 1.5 μm. The laminated film according to claim 1, 2, 3, or 4, wherein 6. The inorganic layer having a total light transmittance of 85% or more;
The surface resistivity at a driving frequency of 30 Hz is 1 × 10 ¹²
6. The composition according to claim 1, wherein the oxygen barrier property is ² cc / 24 hr.m ² or less.
The laminated film according to the above. 7. The conductive layer 2 is composed of an oxide of In and Sn, and the composition of the oxide is 0.85-0.
95, wherein the atomic ratio is 95.
7. The laminated film according to 3, 4, 5 or 6.