JPS6147738A - Transparent antistatic film or sheet - Google Patents

Abstract

PURPOSE:A film or sheet, obtained by laminating an electrically conductive resin layer containing a resin binder and a tin oxide and a surface layer one after another on a synthetic resin layer, and suitable for curtains of clean rooms or packaging materials having improved transparency, abrasion resistance and antistatic properties. CONSTITUTION:A transparent film or sheet obtained by laminating an electrically conductive layer consisting of 100pts.wt. resin binder and 70-350pts.wt. electrically conductive powder consisting essentially of tin oxide and a surface layer consisting of 100pts.wt. resin binder and <=20pts.wt. electrically conductive powder consisting essentially of tin oxide powder one after another on a synthetic resin layer. Acrylic or vinyl based binders, etc., are used as the resin binder. The electrically conductive powder preferably contains 0.1-20wt% antimony, and the shape is the spherical form having <=0.2mu average particle diameter, etc. The thickness of the electrically conductive resin layer is 0.5-4mu, and that of the surface layer is 0.2-1mu.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to transparent antistatic films or sheets.

[Conventional technology]

In general, synthetic resin films or sheets are very easily charged with electricity, and when used in clean room curtains, etc., they become charged and dirt tends to stick to them, and when 9 IC products are packaged, there are many problems such as TTLC being destroyed. there were.

Conventionally, surfactants were laminated onto synthetic resin films to improve the above-mentioned drawbacks, but the antistatic effect of surfactants varies greatly depending on humidity, and they easily detach due to friction, preventing static build-up. Since the effect is lost, paints in which conductive powder containing tin oxide as a main component is mixed into a resin binder have recently been developed (Japanese Patent Application Laid-Open No. 57-858668).
It has been proposed to laminate this onto a synthetic resin film.

[Problem that the invention seeks to solve]

However, these paints had the drawbacks of low transparency due to the addition of a large amount of conductive powder containing copper oxide as a main component, and low abrasion resistance because the surface of the paint film was not smooth.

In view of the above-mentioned drawbacks, the present invention has developed transparent E! which has excellent antistatic properties, has a smooth surface, and has high abrasion resistance. The purpose of the present invention is to provide an antistatic film or sheet.

[Means for solving problems]

Examples of the synthetic resin used in the present invention include polyester, polycarbonate, polyethylene, polypropylene, polyvinyl chloride, etc., and can be made into a transparent film or sheet.

The resin binder used in the present invention can be a resin that can bind conductive powder and is generally used as a paint, such as acrylic, vinyl, carbonate, polyester, phrethane, epoxy, etc. of resin can be opened.

The conductive powder used in the present invention is mainly composed of oxidized steel, and preferably tin oxide containing a1 to 20% by weight of antimony. Also, the powder becomes larger (!-
Since the transparency of the conductive resin layer decreases, the average particle size (L2
Spherical objects with a diameter of less than μ or a thickness of less than Qlμ and a major axis of 2μ
The following scale-like ones are preferable. The conductive resin layer in the present invention is a transparent layer formed from the above resin binder and conductive powder. The antistatic effect disappears, and conversely if the amount increases, the moldability of the sheet and the surface smoothness and transparency of the resin layer will decrease, and the antistatic effect will not improve, so for 100 parts by weight of the resin binder,
It is added in an amount of 70 to 350 parts by weight, preferably 100 to 300 parts by weight. Further, the thickness Fi (L6 to 4 μm is preferable) of the conductive resin layer.

The surface layer in the present invention is a transparent layer formed from the resin binder and conductive powder, and has the ability to improve the transparency and abrasion resistance of the S, antistatic film or sheet.

When the amount of conductive powder added increases, the effect of improving transparency disappears, and when it decreases, the antistatic effect decreases.
If the surface layer is thinned so as not to reduce the antistatic effect, the abrasion resistance will decrease, so the amount is 20 parts by weight or less, preferably 2 to 15 parts by weight, based on 100 parts by weight of the resin binder. Further, the thickness of the surface layer is preferably α2 to 1μ.

Silane coupling agents, titanate coupling agents, surfactants, dispersion aids such as oleic acid and lecithin, and ultraviolet absorbers to improve heat resistance, weather resistance, stability, etc. in the conductive resin layer and surface layer. , stabilizers, fillers, etc. may be added.

Any method may be used to form the conductive resin layer and the surface layer, such as dispersing conductive powder in a resin powder solution or emulsion, and forming the mixture for the conductive resin layer and surface layer. Examples include a method in which the synthetic resin layer is prepared and the resulting compound is sequentially applied to the synthetic resin layer by a method such as a spray method, a roll coating method, a barcoding method, a gravure printing method, and the like, and then dried.

In order to improve the adhesion between the synthetic resin layer and the conductive resin layer, a primer layer may be formed on the synthetic resin layer, or the synthetic resin layer may be subjected to surface treatment such as corona treatment.

〔Effect of the invention〕

The structure of the antistatic film or sheet of the present invention is as described above, in which a surface layer consisting of 100 parts by weight of a resin binder and 20 parts by weight or less of a conductive powder containing tin oxide as a main component is laminated on the conductive resin layer. It has excellent transparency, abrasion resistance, and antistatic effect, and can be suitably used as curtains for clean rooms and packaging materials for IC products.

Example〕 Next, the present invention will be explained in detail.

Example 1.2, Comparative Examples 1 to 4 A conductive resin layer composition having the composition shown in Table 4E1 was dispersed in a ball mill for 36 hours, then coated on one side of a polyester film (thickness 25 μm) with a Quier Per coater and dried. death,
A conductive resin layer having a thickness of 1 μm was formed. Next, the composition for the surface layer having the composition shown in Table 1 was dispersed for 30 minutes using a high-speed stirrer, and then coated on the conductive fat layer with a wire percoke and dried to obtain the thickness shown in Table 1. An antistatic film was obtained by forming a surface layer of .

Surface resistivity (ASTM
D-257), total light transmittance (ASTM D-
1003), Haze (ASTM D-1003)
) and wear weight loss (based on JIS K-7204, worn wheel C5-10-1 weight load 250jl) were measured, and the results are shown in Table 1.

+1) Byron 200 (2) manufactured by Toyobo Co., Ltd. T-1 manufactured by Mitsubishi Metals Co., Ltd. (tin oxide doped with antimony, average particle size o, 1 μ) (3) Nippokun 2032 manufactured by Nippon Polycrethane Co., Ltd.
(Tetrahydrofuran 35% by weight solution)

Claims (1)

[Claims] 1. A conductive resin layer consisting of 100 parts by weight of a resin binder and 70 to 350 parts by weight of a conductive powder whose main components are tin oxide, and a conductive resin layer whose main components are 100 parts by weight of a resin binder and tin oxide. A transparent antistatic film or sheet formed by sequentially laminating surface layers containing 20 parts by weight or less of powder.