JPH02295732A - Antistatic plastic sheet - Google Patents

Abstract

PURPOSE:To impart lasting antistatic properties not affected by a humidity condition without exerting an adverse effect on the appearance of a molded product by providing a thin conductive layer composed of a metal or metal oxide to the single surface of a base film and providing a protective coating layer mixed with an antistatic substance on said thin conductive layer. CONSTITUTION:As a base film 1, for example, a film composed of polyester, polyamide or polyolefin is used and a thin conductive layer 2 composed of a metal or metal oxide is provided on the single surface of the base film 1 and indium-tin composite oxide is especially pref. among a metal and metal oxide. A protective coating layer 3 mixed with an antistatic substance is provided on the thin conductive layer 2 but pref. composed of a hard coating layer. An adhesive layer 4 is provided to the other surface of the base film 1 and a decorative layer 5 is pref. provided to the surface of the base film 1 on the side of the adhesive layer 4. Further, an earth terminal 6 is usually provided to a sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of Industry 1F The present invention relates to a plastic sheet for imparting antistatic properties to plastic molded products. Conventional technology Plastic molded products, except for those made of special materials, are generally susceptible to static electricity, and their surfaces can absorb dust and fine particles in the air during the manufacturing process, during storage/transportation, and during use. Easily contaminated. In addition, if there is friction with packaging materials during handling, or if the surface of home appliances with a built-in drive unit is particularly charged, electrostatic damage may occur in the electronic circuit system, and unpleasant electric shocks may occur to the human body. I often give. Therefore, in order to impart antistatic properties to plastic molded products, there are two methods: (a) coating the surface of the molded product with a water-absorbing polymer, and (b) applying a paint containing a surfactant to the surface of the molded product. (C) A method of applying a paint containing conductive powder such as carbon black or metal powder to the surface of the molded product; (d) A method of mixing a conductive material into the molded product manufacturing raw material itself and subjecting it to molding. methods are being adopted.

Problems to be Solved by the Invention However, in the method (a) above, the molded product loses its aqueous properties and its surface characteristics change.
The problem is that the antistatic properties are significantly reduced when the relative humidity is low. In the method (b) above, (a)
Similarly, there is a problem in that the antistatic properties are significantly reduced when the relative humidity is low. The above methods (C) and (d) have the disadvantage that the hue of the molded product is limited, and when trying to obtain a transparent molded product made of polycarbonate, polymethyl methacrylate, etc. However, this method is difficult to apply and has aesthetic problems. In view of these circumstances, the present invention aims to provide an antistatic plastic sheet that does not adversely affect the appearance of molded products, is unaffected by humidity conditions, and can provide permanent antistatic properties. It was done for a purpose. Means for Solving the Problems The antistatic plastic sheet of the present invention has a conductive thin layer (2) of a metal or metal oxide on one side of a base film (1), and a conductive thin layer (2) of a metal or metal oxide. 2) A protective coating layer (3) containing an antistatic substance is provided on top. The present invention will be explained in detail below. Examples of the base film (1) include polyester films, polyamide films, polyolefin films, polyvinyl chloride films, polyvinylidene chloride films, polystyrene films, and polyurethane films. , cellulose-based films, etc. are used. It is desirable that the base film (1) be transparent. Furthermore, it may be stretched or may be a laminate film with two or more layers. There is no particular limitation on the thickness of the base film (+), but the thickness is between 5 and
Something around 200 JLI is often used. prefecture! 1st Section D A conductive S layer (2) made of metal or metal oxide is provided on one side of the base film (1). Conductive thin R (2
) is particularly desirable to be transparent. The above metals or metal oxides include indium, iridium, aluminum, gold, silver, copper, nickel, chromium, titanium, stainless steel, iron, cobalt, molybdenum, rhodium, palladium, gallium, lead, tin, tantalum, Examples include metals such as platinum and metal oxides, which are used alone, in alloys, or in mixtures. Among these, ITO (indium-tin composite oxide) is particularly important. The conductive thin layer (2) is formed by means such as ion plating, sputtering, vacuum deposition, plating, etc., and its thickness is often 50 to 2000 A or more. A protective film layer (3) containing an antistatic substance is provided on the conductive thin film layer (2). Examples of antistatic substances include surfactants such as nonionic, anionic, cationic, or amphoteric surfactants; metals or I
Metal oxides such as TO; carbon black; organometallic compounds including organotin compounds; organic compounds such as polyaniline, polypyrrole, polythiophene, polyacetylene, polyphenylene vinylene, etc. as 7 receptors;
A combination of this with an appropriate donor is used,
Among these, those in which the formed conductive film layer (2) is transparent are preferred. The matrix components forming the protected M layer (3) include acrylic resin, urethane resin, epoxy resin, polyester resin, silicone resin, fluorine resin, melamine resin, phenol resin, and urea resin. , diallylphthalate resin, alkyd resin, maleated rosin, polyvinyl butyral, cellulose polymer, polyamide resin, vinyl chloride-vinyl acetate copolymer, and various other thermosetting resins.
Thermoplastic or active energy ray-curable polymers are used. The protective coating layer (3) is particularly preferably a hard coating layer, that is, a scratch-resistant coating layer. Examples of hard coating agents include ultraviolet curable hard coating agents that use acrylic resin or urethane-modified acrylic resin as the main ingredient, and thermosetting hard coating agents that use silicone resin as the main ingredient. The amount of antistatic substance mixed in the protective coating layer (3) is:
Although it cannot be determined unconditionally because it varies greatly depending on the type of antistatic substance, it is often set to, for example, 0.1 to 50% by weight. The protective coating layer (3) is usually formed by a solution coating method, a dispersion coating method, or an extrusion coating method, but in some cases, a dry lamination method may be employed. The thickness of the protective coating layer (3) is set to, for example, 0.5 to 50 μm. An adhesive layer (4) is provided on the other side of the skin shin area base material film (1),
Try to ensure close contact with the target object, the molded product. However, when providing an adhesive layer on the molded product side, or when attempting to bond at the same time as in-mold molding,
The installation of the adhesive layer (0) on the other side of the base film (1) can be omitted. glue,
Adhesives such as epoxy adhesives, vinyl adhesives, natural adhesives, etc.: Rubber pressure sensitive adhesives, acrylic pressure sensitive adhesives, silicone pressure sensitive adhesives, vinyl pressure sensitive adhesives, etc. Pressure adhesives; hot melt adhesives such as ethylene-vinyl acetate copolymer hot melt adhesives, acrylic hot melt adhesives, and polyester hot melt adhesives; rewetting adhesives; etc. are used. There is no limit to the thickness of the adhesive layer (4), but it is often about 3 to 100 gm, for example. The other side of the base film (1) (when the adhesive layer (4) is provided, the base film (1) side on the side where the adhesive layer (4) is installed)
In this case, Ill! It is preferable to provide one layer (5). Dressing f! Examples of li R(5) include printed layers and colored layers. The thickness of the decorative layer (5) is also not particularly limited, but may be 3 to 50.
It is often at the stage of terminal pus. Antistatic Plastic Sheet The antistatic plastic sheet of the present invention has a basic layer structure consisting of a protective film layer (3), a conductive thin layer (2), and a base film (1). Adhesive layer (protective coating layer (3) / conductive thin layer (2) / base film (1) by adding 0, adhesive layer (0) layer structure, or base film (1) etc. A decorative layer (5) is provided on the surface side, and a protective coating layer (3) / conductive thin layer (2) / base film (1) / protective coating layer (5) or protective coating layer (3) / conductive As mentioned above, the layer structure of thin layer (2) / base film (1) / decoration layer (5) / adhesive layer (0) can be used. It is also possible to add other layers as long as it does not impair the spirit of the invention. A grounding terminal (6) is usually attached to a sheet with the above layer structure of 222 and IL5k. (6) can be attached to one end of the sheet by making a hole, or by pulling out a conductive piece from the conductive thin layer (2) and attaching it there. , connect the ground wire when in use.Toriko Shitoj Applicable molded products include housing divider covers for home appliances, covers for audio products, display power bars, furniture, interior materials for construction, automobile parts, There are various types including windshields, see-through windows for instruments, light windows, and windshields. Materials for molded products include polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, ABS resin, nylon, polyacetal, Examples include polycarbonate, polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, phenolic resin, unsaturated polyester, epoxy resin, etc. Function: The sheet of the invention with the above layer structure is installed on the surface of a molded product. The sheet can be installed by pasting, or if the molded product is obtained by injection molding or vacuum forming, it can be inserted into the mold in advance and integrated into the surface of the molded product at the same time as molding. Ground terminal attached to the seat (6
) By connecting a ground wire to the ground wire, molded products can be effectively prevented from being charged. EXAMPLE Next, the tree invention will be further explained by giving an example. Example 1 <<Manufacture of Sheet>> FIG. 1 is a sectional view showing an example of the antistatic plastic sheet of the present invention. ITO was deposited by ion plating on one side of a base film (1) made of polyethylene terephthalate film with a thickness of 150 JLm to form a conductive thin layer (2) with a thickness of 400 A. Next, on this conductive thin layer (2), an acrylic UV-curable hard coating agent containing a surfactant-based antistatic substance containing 1% by weight each of sorbitan monolaurate and stearic acid monoglyceride is applied. Irradiation was performed to form a protective coating layer (3) with a thickness of approximately 31 Lm. Next, acrylic ink containing dye is printed on the other side of the base film (1), and then dried and mounted.
Layer (5) was formed, and then an acrylic pressure-sensitive adhesive solution was coated thereon and dried at 80°C to form adhesive layer (4) with a thickness of about 251 L. As a result, the transparent electrically charged layer shown in FIG. A protective plastic sheet was obtained. Drill a hole at one end of this sheet and connect the ground terminal (6).
has been added. This sheet was pasted on the surface of a 1-inch thick plate obtained by injection molding polymethyl methacrylate, with the adhesive layer (0 side being biased), and a ground wire was connected to the terminal (6) of the sheet. <Test method and results> For the above bonded molded product, the electrostatic charge attenuation and surface resistance were measured using an electrostatic field meter, electrostatic charge applicator, X-Y recorder, and surface resistance meter. The prevention property was evaluated. The application time was 5 seconds, and the environmental conditions were a temperature of 18.8
Drying conditions of 0. Humidity and 37.1% RH were adopted. The results were as follows. Charge amount During application -2.4 Immediately after KV application -
〇． 7 KV 5 seconds% -Q. 5 KV after 10 seconds -0.5 KV after 15 seconds -0.8 KV Surface resistance io3~104Ω As mentioned above, the adhesive molded product of Example 1 has a humidity of 37.1
Despite the drying conditions of % RH, it can be seen that it definitely has antistatic properties. Comparative Examples 1 to 2 In the same manner as in Example 1, base film (l)/decoration layer (
5)/Sheet with layer configuration of adhesive layer (4) (Comparative Example 1),
And, protective coating layer (3) 7 base film (1) decoration layer (5)/adhesive layer (0 sheet (comparative example 2)
It was created. The results were as follows. Comparative example l Charge amount During application -3.2 Immediately after KV application -
3.8 KV After 5 seconds -3.7 KV After 15 seconds -3.8 KV Surface resistance lO'3~1o''Ω Comparative example 2 Band''ttL amount During application -3.8 KV Immediately after application -1.2 KV After 5 seconds -1.2 KV After 15 seconds -1. I KV Surface resistance 109 to 10 Ω As mentioned above, it can be seen that even the adhesive molded product of Comparative Example 2 lacks antistatic properties under dry conditions of humidity 37.1% RH. Example 2 FIG. 2 is a sectional view showing another example of the antistatic plastic sheet of the present invention. Example 1 was repeated except that only the installation of the decorative layer (5) was omitted. As a result, the protective coating layer (3)/conductive thin layer (2)
A transparent antistatic plastic sheet shown in FIG. 2 having a layer structure of /base film (1)/adhesive layer (0) was obtained.The conductive thin layer (2) of this sheet The conductive piece was pulled out and a grounding terminal (6) was attached to it. The antistatic property was as good as in Example 1. Example 3 Biaxially oriented polypropylene with a loog thickness layer ITO was deposited on one side of the base film (1) by sputtering to form a conductive thin layer (300A thick).
2) was formed. Next, this conductive thin layer (2) is coated with an acrylic urethane resin solution mixed with 3% by weight of an organic tin antistatic substance, dried and aged to form a protective coating layer with a thickness of about 5 Bm. (3) was formed. Next, the other side of the base film (1) is entirely coated with an acrylic coating agent containing pigments, dried to form a decorative layer (5), and then a urethane adhesive is applied on top of the decorative layer (5). By drying, most of the solvent was evaporated to form an adhesive layer (0) with some turquoise and a thickness of about 25 mm. This created a protective coating (3)/ Conductive thin layer (
2) Base film (1)/Decorative layer (5) Adhesive layer (
A transparent antistatic plastic sheet having a layer structure of 0 was obtained. This sheet was attached to the surface of a 1-inch thick plate obtained by injection molding polypropylene so that the adhesive layer (4) side was biased, and heat aging was performed. A ground wire was connected to the terminal (6) on the seat. The antistatic properties were as favorable as in Example 1. Effects of the Invention If the antistatic plastic sheet of the present invention is attached and integrated with a molded product, it will not adversely affect the appearance of the molded product, and will provide permanent antistatic properties that are not affected by humidity conditions. sell. Furthermore, by providing a decorative layer (5) on the other side of the base film (1), it is possible to actively improve the aesthetic appearance of the molded product while also providing antistatic properties.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the antistatic plastic sheet of the present invention.

Claims (5)

[Claims] 1. A conductive thin layer (2) made of metal or metal oxide is provided on one side of the base film (1), and a protective coating layer (3) containing an antistatic substance is provided on the conductive thin film layer (2).
) is an antistatic plastic sheet. 2. The sheet according to claim 1, characterized in that an adhesive layer (4) is provided on the other surface of the base film (1). 3. The sheet according to claim 1, wherein the protective coating layer (3) is a hard coating layer. 4. The sheet according to claim 1, characterized in that a decorative layer (5) is provided on the other surface of the base film (1). 5. The seat according to claim 1, wherein the seat is provided with a grounding terminal (6).