JPS58104930A - Antistatic plastic sheet or film - Google Patents

Abstract

PURPOSE:To obtain titled sheet or film of excellent durability, capable of clear desired coloring, suitable for floorings of laboratories or operating rooms, covering materials for assembly tables for electronic equipment, etc., by incorporating the original sheet or film with a conductive zinc oxide. CONSTITUTION:A plastic sheet or film composed of PVC, PE, PMMA, etc. is incorporated with pref. 70-90wt% of a conductive zinc oxide to obtain the objective product having, e.g. a resistivity of 10<5>-10<7>ohm.cm.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to plastic sheets or films (hereinafter referred to as plastic sheets) having excellent antistatic properties, colorability, durability, etc.

As is well known, plastic sheets such as polyvinyl chloride resin sheets and films are extremely susceptible to being charged with electricity, so they attract a lot of dust, and when the amount of charge becomes large, discharge occurs through conductors such as the human body. Therefore, there are various problems such as giving an electric shock.

In order to deal with such problems, conventional methods have been used: (2) A method of applying an antistatic agent to the surface of plastic sheets, (B) A method of incorporating an antistatic agent into plastic sheets, (C) A method of incorporating an antistatic agent into plastic sheets. A method of incorporating carbon black, which is a conductive material, has generally been adopted.

However, the above method (b) has the disadvantage of durability in that the coating layer of the antistatic agent wears out in a relatively short period of time and loses its antistatic effect. ′ has good durability, but there are severe restrictions on the type and amount of antistatic agent used from the aspect of moldability, so the actual version is one that does not sufficiently reduce the volume resistivity of plastic sheets. It has the disadvantage that it is difficult and a satisfactory antistatic effect cannot be expected, and in addition, method (C) has a high content of carbon black, so there is no problem when producing black plastic sheets. When colored with other colors, the color becomes dark and dirty, and the color becomes bright and pale (for example, light yellow, pale yellow, etc.).
It had the disadvantage that it was impossible to color it in yellow, yellow-green, pale green, pale blue, pale pink, pink, pale red, white, etc.).

In view of the above-mentioned circumstances, the present invention has been made to provide antistatic plastic sheets that have excellent antistatic properties and durability, and can be colored in a desired bright color.

That is, the present invention relates to antistatic plastic sheets containing preferably 7G-90% by weight of conductive zinc oxide, the conductive zinc oxide contained therein. The particles form a complete chain or an incomplete chain with a partially missing part within a few angstroms, and this complete or incomplete chain is used as a conductive path to release static electricity to the outside, resulting in a good It is thought that it exhibits an antistatic effect.

The conductive zinc oxide used in the present invention is an organic aluminum compound containing an aluminum atom (for example, aluminum salt of carboxylic acid, aluminum alkoxide, aluminum complex salt, etc.) in a ratio of 0.05 to 5 moles, is heated and calcined at a temperature of approximately 800 to 1100°C, and then finely pulverized, or a similar product is produced. The conductive zinc oxide is a white powder with a low specific resistance of several grams to several tens of grams (j-ts).In this way, conductive zinc oxide is a white powder that does not have a negative effect on coloring. Since the antistatic plastic sheets of the present invention are powder particles, by kneading an appropriate amount of coloring agent, it is possible to color them not only in bright pale colors but also in a desired bright color. As mentioned above, the content of conductive zinc oxide in a certain type of antistatic plastic sheet is preferably about 701:11 to 90% by weight of the entire antistatic plastic sheet.In general, plastic sheet leprosy is Its volume resistivity is to'~10
If it is about 7g/kg, it will exhibit a good antistatic effect, but if the content of conductive zinc oxide is less than 70% by weight,
If the volume resistivity of plastic sheets becomes larger than the above range, it becomes difficult to exhibit a good antistatic effect, and conversely, if it exceeds 90% by weight, conductive zinc oxide becomes excessive and the strength of the plastic sheets decreases. This is because it causes Note that when the content of conductive zinc oxide is less than 70% by weight, the volume resistivity increases and a good antistatic effect cannot be obtained because of the lack of conductive zinc oxide, which acts as a conductive path for static electricity. It is thought that this is because a complete or incomplete chain of 2 is not sufficiently formed inside the plastic sheet.

The antistatic plastic sheets of the present invention are produced by blending appropriate amounts of various auxiliary materials such as a binder, a stabilizer, and a coloring agent with the thermoplastic resin as the main material, and also containing conductive zinc oxide at the above-mentioned content. It is manufactured by mixing and kneading to prepare a material, and then molding this material into a sheet or film using a desired molding method such as extrusion molding, calendar molding, press molding, etc. In this case, As the main thermoplastic resin, any thermoplastic resin that is easily charged can be used, such as polyvinyl chloride resin, polyethylene resin, polypropylene resin, ethylene vinyl acetate copolymer resin, polymethyl methacrylate resin, polycarbonate resin, cellulose resin, etc. Moreover, it goes without saying that all of the various auxiliary materials commonly used in conventional plastic ivy sheets can be used as auxiliary materials such as plasticizers, stabilizers, and colorants. .

As described above, the antistatic plastic sheets of the present invention contain highly conductive zinc oxide, which is thought to form a complete or incomplete chain as a conductive path for static electricity, throughout the inside of the plastic sheets. , it is extremely durable and does not lose its antistatic effect even if wear progresses from the surface, especially when the content of conductive zinc oxide is 70-90% by weight, the antistatic effect is maintained. However, conductive zinc oxide is a white powder that does not have a negative effect on coloring. It can be colored in a desired color, and all the drawbacks of conventional antistatic plastic sheets can be overcome. Therefore, the antistatic plastic sheets of the present invention can be used as flooring materials in laboratories of chemical factories, operating rooms in hospitals, etc., or as covering materials for assembly workbenches of electronic equipment and precision equipment, etc. due to their durability and durability. It is extremely suitable for applications that require good antistatic properties, as well as for decorative floor coverings and wall coverings for various buildings.

Next, examples will be given.

(Example 1) Too parts of polyvinyl chloride resin (parts by weight, the same applies hereinafter),
50 parts of DOP, 8 parts of stabilizer, 400 parts of conductive zinc oxide,
One part of a pigment (a phthalocyanine-based pigment) was kneaded and roll-molded to produce an antistatic polyvinyl chloride resin sheet (thickness: 2 m+) containing about 72% by weight of conductive zinc oxide.

The obtained sheet was colored in a bright blue-green color with no dullness, and had a volume resistivity of about 1079·1 and good antistatic property.

(Example 2) An antistatic polyvinyl chloride resin sheet containing about 80 parts by weight of conductive zinc oxide was produced in the same manner as in Example 1 except that the amount of conductive zinc oxide was changed to 600 parts.

As in Example 1, the obtained sheet exhibited a bright blue-green color without turbidity, and had a volume resistivity of about 106 Ω and good antistatic properties.

(Example 8) The conductive zinc oxide content was about 84% by weight in the same manner as in Example 1 except that the amount of conductive zinc oxide was changed to 800 parts and 1 part of Bengara pigment was added as a coloring agent. An antistatic polyvinyl chloride resin sheet was manufactured.

The obtained sheet had a bright red color with no turbidity, and its volume resistivity was 105Ω, and it had excellent antistatic properties in Japan.

”'□ -End- Patent Applicant Takiron Co., Ltd. Representative Ryuta Yagi Part Procedural Amendment (Method) % Formula % 1. Indication of Case 1982 Patent Application No. 206624 8. Related: Patent applicant postal code: 641 Address: 2-80 Azuchi-cho, Higashi-ku, Osaka [Telephone: 06-267-2648 Patent Division] 4. Date of amendment order: April 27, 1980 (shipment date) 5. Subject of amendment Specification

Claims (1)

[Claims] 1. An antistatic plastic sheet or film characterized by containing conductive zinc oxide in the plastic sheet or film. 2. The sheet or film according to claim 1, wherein the content of conductive zinc oxide is 70 to 90% by weight.