JPS5947666B2 - Conductive plastic sheet with abrasion resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface conductive plastic sheet having a surface protective layer.

More specifically, a conductive layer is provided on the roughened surface of a plastic film such as a so-called sand mat film or a chemical mat film, which has a roughened surface on one or both sides, and a high-temperature film is further applied thereon to protect the conductive layer. The present invention relates to a surface conductive plastic sheet provided with a molecular protective layer. Recently, there has been a growing demand for glasses with transparent conductive coatings, such as conductive glasses such as ``Nesa Glass'' and ``EL Glass,'' and as the fields of their use have expanded,
Conductive films are being developed to improve the drawbacks of glass (for example, Japanese Patent Laid-Open No. 49-5904).
(See Publication No. 6).

They have the advantage of being lighter, more flexible, and easier to process than glass, but the eye friction of the conductive layer coating has been problematic. However, in some applications of these transparent and conductive plastic sheets, good transparency is not necessarily required, and there are cases where it is sufficient to have a scattering light transmittance like that of frosted glass. In such cases, it has been found that providing a light-transmitting conductive coating on the roughened film provides better durability against abrasion and scratches. However, with the conductive coating directly exposed on the surface, the durability against continuous long-term friction is still not satisfactory. The inventors of the present invention have conducted extensive research in order to improve these defects and obtain a surface conductive plastic sheet with excellent surface strength such as friction resistance and abrasion resistance. The film, in which a polymer protective layer is provided on top of the conductive layer so that the negative part of the conductive layer on the rough surface is exposed, has good friction resistance even though the polymer used is an electrical insulator. The inventors discovered the surprising fact that not only the properties are improved, but also that the surface conductivity is not impaired in any way, leading to the development of the present invention. That is, the present invention provides a conductive layer on the roughened surface of a plastic sheet having at least one surface roughened, and further provides a conductive layer such that a portion of the conductive layer on the convex portion of the roughened surface is exposed. It is a surface conductive plastic sheet on which a polymer protective layer is provided to protect the conductive layer. The structure of the surface conductive plastic sheet of the present invention will be explained with reference to the drawings.

1 to 3 are side sectional views of various embodiments of the present invention, in which 1 is a plastic sheet with a roughened surface, 2 is a conductive layer, and 3 is a polymeric protective layer.

As is clear from the diagram, in the present invention, it is important to provide the polymer protective layer 3 so that the conductive layer 2 on the convex portions of the rough surface is exposed to the surface, thereby maintaining the surface conductivity.

Examples of the roughened plastic sheet used in the present invention include, for example, a so-called sand mat film, which is roughened by blowing sand onto the surface during film molding, and a film surface in which fine inorganic powder is mixed with a binder resin component. There are so-called chemical matte films that are roughened by coating on the surface.

The plastic material may be any material having good dimensional stability and mechanical properties, such as polyester polycarbonate, triacetate resin, polypropylene, and is not particularly limited, but polyester, particularly polyethylene terephthalate, is preferred. The degree of roughening of the roughened surface of the roughened plastic sheet used in the present invention is such that the amplitude of the unevenness and the distribution of the unevenness are not necessarily constant, but the amplitude of the unevenness is 0.1μ to 15μ. , the period of swing width is 50 to 1
000μ is good, preferably the amplitude of the unevenness is 0.5 to 7.
A period of 10 to 500 μ is preferable for 0 μ.

If the amplitude of the unevenness is less than 0.1 μ, the amplitude is too small regardless of the period of the unevenness, so the polymer protection, which is an electrical insulator, is placed on the conductive layer provided on the rough surface. It is difficult to set the coating amount of the protective layer so that the surface conductivity is maintained even if the layer is applied, and it is also difficult to apply the protective layer.
Furthermore, even if coating is possible, the amount of coating is too small and the desired effect of the present invention is small.

If the amplitude of the unevenness exceeds 15μ, and the period is small, the rough surface is too rough, and even if a protective layer is provided, many parts of the conductive layer are exposed at the protrusions, and the rough surface is too rough. Because the surface is rough, the coefficient of friction is large and the durability against continuous friction is low.

Moreover, if the period of the amplitude is large, the surface becomes too smooth and the durability against scratches and the like decreases. The translucency of the roughened plastic sheet used in the present invention is not particularly limited, as the need for translucency may be irrelevant depending on the field of use.

For example, if a plastic sheet is roughened on both sides and an opaque conductive layer is provided on both sides, or if a plastic sheet is roughened on one side and an opaque conductive layer is provided on the roughened surface, then When laminating or overlapping another opaque support, it does not matter whether the roughened plastic sheet has translucency or not, for example, the surface conductivity according to the present invention When the conductive layer of a plastic sheet is made of a transparent conductive insulating coating, if the roughened plastic sheet has light-transmitting properties, the transparent conductive layer provided on the roughened surface can be used. By providing a transparent polymer protective layer on the film, the degree of roughness on the surface is considerably reduced and light transmission is improved. When combined by laminating or overlapping, the colors on the surface of the support, the drawn patterns, characters, etc. can be seen through with the same clarity as ordinary transparent films. Preferably, the roughened plastic sheet used in the present invention has translucency because of the advantages that it can provide. ζThe translucency mentioned here does not mean that the opposite side can be clearly seen through, as with transparent glass, but rather that it can be seen through an air layer, such as with frosted glass or tracing paper, by superimposing it on the original image. This refers to scattering and translucency that makes it impossible to read the original drawings, but allows them to be clearly read when placed in close contact with the original drawings. The conductive layer of the surface conductive sheet of the present invention is, for example, an oxide film containing indium oxide as a main component, aluminum, nickel, chromium, copper gold, silver, indium, manganese, molybdenum, silicon, tin, tungsten,
A thin film of metal such as titanium, zinc, platinum, palladium, tantalum, rhodium, etc., formed on a roughened surface of a plastic sheet by vacuum evaporation, reactive vacuum evaporation power sorting sputtering, plasma spraying, etc. It is a transparent, semi-transparent or opaque conductive coating.

The surface resistance of the conductive layer varies depending on the application, and is preferably 10 3 Ω/square or less if the layer is used for electrostatic purposes, and 10 4 Ω/square or less if the conductive layer is used to directly flow current through the conductive layer. The polymeric substance of the protective coating in the present invention may be any material that can be applied to the surface of the conductive layer provided on the rough surface of the roughened plastic sheet and form a coating, and is not particularly limited. However, for example, polymers that can be used as solvents include polyvinylidene chloride, polyvinylidene chloride-acrylonitrile copolymer, polyvinyl anucol, polyesterne, polycarbonate, polyurethane, polystyrene, polyamide, polyacrylonitrile, or acrylonitrile-butadiene. Examples include styrene copolymers.

Especially polyvinylidene chloride-acrylonitrile copolymer,
Polyvinyl alcohol is preferred as the protective film in terms of performance and ease of film formation. In addition, thermosetting polymers include epoxy, triazine resin, diallyl ester, silicone, phenol, unsaturated polyester, melamine,
Alternatively, urea resin can be mentioned. Among these, epoxy and triazine resins are preferred in terms of the abrasion resistance and organic solvent resistance of the protective film. The thickness of the protective film is not constant because the support is roughened, but the average coating amount (in terms of resin solid content) on the conductive layer is 0.2 to 59/M2.
In particular, it is preferable to provide a polymer layer of 0.6 to 39/M2. 0.2f! If the coating amount is less than /M2, the desired effect of the present invention will be reduced, and if the polymer layer is made thicker than necessary, the conductive layer on the rough surface convex portions will also be coated with the polymer, impairing the surface conductivity. .

The sheet of the present invention has excellent conductivity, translucency, and abrasion resistance, so it is useful, for example, as a mat for antistatic work in the IC assembly process, a lighting cover that requires antistatic properties, etc. However, since it has excellent writability, it is also useful as a film for second original images of electrophotography.

The present invention will be illustrated below with examples.

Note that all figures in the middle part of the examples are parts by weight. In addition, the amount of application is
It is calculated in terms of resin solid content. Friction test method is JI
The same method was used except that the "Krotsukmeter type 1 friction test device" specified in SL-1048 "Rubbing fastness test method for dyed products and dyes" was used, and the rubbing speed of the friction element was 3.7 seconds per round trip. The method specifications were followed.

Fruit surface resistance was measured at three locations on the rubbed surface, and the average value was shown.

Example 1 A metal oxide mainly composed of indium oxide was applied to the rough surface of a polyethylene terephthalate Sambimat film with a thickness of 50 μm and a roughness width of 1.0 to 4.0 μ and a period of 10 to 60 μ. 0.5 of polyvinyl alcohol (trade name: Kuraray Poval-1110) was applied on the conductive surface of surface-conductive pine finum obtained by vacuum deposition and thermal oxidation.
A weight % aqueous solution was applied at a coating amount of 1.5 y/d' (-) using a No. 3 percoater (also called a wire coater), and heat treated at 120°C for 30 minutes.

Friction test results for plastic sheets with these layers are shown in Table 1. For comparison, Table 1 also shows the results of the rub test for the above sample without the protective coating. Example 2 A metal oxide containing indium oxide as a main component was prepared with a rough surface having an unevenness width of 1.0 to 4.0μ and a period of 10 to 60μ.
A polyvinylidene chloride-acrylonitrile copolymer (trade name: Tau A 5% by weight methyl ethyl ketone solution of Saran Resin (Fl2O) by Chemical Co., Ltd. was applied at a coating weight of 1.09/M2 using a No. 3 Percog and heat treated at 1000C for 15 minutes.

The friction test results are shown in Table 1.

Example 3 A metal oxide containing indium oxide as the main component was applied to the rough surface of a polyethylene terephthalate sand mat film with a thickness of 50 μm and a roughness width of 1.0 to 4.0 μ and a period of 10 to 60 μ. On the conductive surface of a surface conductive matte film obtained by vacuum deposition and thermal oxidation, 10 parts of diethylene triamine, 0.5 part of a silane coupling agent, and 9 parts of epoxy resin (trade name: Ciel Chemical, Ebicoat 828) were applied.
0 parts of the mixture was dissolved in 500 parts of toluene, and this solution was coated with a No. 3 percoater in a coating amount of 1.39/1.
It was coated in step A and heat treated at 130 taC for 1 hour.

The friction test results are shown in Table 1.

Example 4 A metal oxide containing indium chloride as a main component was prepared so that the amplitude of the roughness of the rough surface was 0.5 to 6.0μ and the period was 20 to 200μ.
A triazine-based resin (trade name: Ziatrac PL from Ziart Co., Ltd. , resin content of about 20% by weight) was applied at a coating amount of 0.99/m' using a No. 3 percoater, and heat treated at 800C for 30 minutes.

The friction test results are shown in Table 1. Note that Comparative Example 2 is the same sample without a protective coating. Example 5 A metal oxide containing indium oxide as the main component was prepared with a rough surface having an unevenness width of 0.5 to 3.0μ and a period of the amplitude of 20 to 3.0μ.
A triazine resin (Ziatrack PL) number 3 was deposited on the conductive surface of a surface conductive matte film obtained by vacuum evaporation and thermal oxidation on the rough surface of a polyethylene terephthalate sandmat film with a thickness of 10μ and 31μ. Coated with a coating amount of 0.99/I using a No. 1 bar coater, 800C, 3
Heat treatment was performed for 0 minutes.

The friction test results are shown in Table 1.

Note that Comparative Example 3 is the same sample without a protective coating. Example 6 Chromium was vacuum-deposited on the rough surface of a polyethylene terephthalate sand mat film with a thickness of 50 μ and the amplitude of the unevenness of the rough surface was 1.0 to 4.0 μ and the period of the vibration was 10 to 60 μ. On the conductive surface of the surface-conductive matte film, a triazine-based resin (trade name of Zeatrack PL Ziart) was applied in an amount of 1. ．． 09/
It was coated with Tff and heat treated at 80°C for 30 minutes.

The friction test results are shown in Table 1.

Claims (1)

[Claims] 1. A conductive layer is provided on the roughened surface of a plastic sheet with at least one surface roughened, and a polymer protective layer is further applied thereon so that a portion of the conductive layer on the convex portions of the rough surface is exposed. A conductive plastic sheet having abrasion resistance.