CS256750B1 - A method of permanent treatment of polymers, to increase their electrical conductivity - Google Patents

Abstract

Method for permanent treatment of polymers to increase their electrical conductivity. The essence of the solution lies in the fact that a polymer material containing — Cl groups is treated with a cuprous compound in the presence of a reducing agent at a temperature of 5 to 200 °C in a polar solvent bath, and the thus prepared surface is treated with an organic and/or inorganic compound releasing or containing sulfite ions.

Description

236750

BACKGROUND OF THE INVENTION The present invention relates to a process for the preparation of polymers. in order to increase their efficiency conductivity, the condition being that the products of the base polymers obtained achieve the desired chemical resistance against physico-chemical stress.

It is known that pure synthetic polymers are isolators with a specific resistance of the order of 1012 to 1018 Ω. cm. As the limit of electrical resistance below which the materials are virtually non-electrostatic, i.e., do not form a static charge, a value less than ΙΟ9 Ω is given. . cm - antistatic materials. At present, we are familiar with several methods for the polymeric materials by which they increase the electrical conductivity, for example metallization, respectively. application to the surface of ionized and hygroscopic substances, filling with metal or carbon particles and the like.

The most important methods of applying metal layers to polymers can be physically, electrochemically and chemically separated, while the metal is applied in the gas phase or in solution.

The chemical metallization of the polymer in the solution consists of coating the surface with a metal-soluble soluble reducible agent. The driving force behind the autocatalytic process of incorporating metal ions on the surface of the polymer is the catalytic oxidation of a reducible agent which, with sufficient intensity, takes place on some metals with catalytic properties. The deposition of these agents on the surface of the polymeric material is activated by activation which may consist of two stages, namely sensitization and activation. The sensitization is generally carried out in the divalent tin salt solutions. Activation of sensitization is done in solutions of salts and complex noble metal compounds with palladium or silver.

According to JAP PAT 3 337 912, the metal is introduced into the polymer surface so that the polymeric clad material is comminuted by particles which are subsequently applied to the base polymeric material. U.S. Pat. No. 4,405,394 discloses a coating method for coating a thermoplastic laminate surface polymeric coating on a copper or aluminum epoxy substrate. U.S. Pat. No. 3,962,497 discloses a method for improving the electrical properties of polymers by reducing hexavalent chromium ions on a triple-acting effect of a ferrous sulfate solution or hydroxylamine salt in an acidic medium. USSR A0 425 985 discloses metallization of polymeric surfaces with nickel, iron. at least 300 ° C with cobalt, vanadium, manganese, zinc and cadmium carbonyl. The processes of chemical metallization in vacuum chambers are the USSR 699,031, US PAT No. 3,355,318 and French. PAT 2 348 941. The further formation of the metallopolymer-boron of the polymer surfaces is the formation of co-metal particles in the polymer mass (Kor-jukinA. In Metallopolymery is covered by polyareaw, Meslkw, Izdat. Chimija 1983 J. USA PAT 4). U.S. Patent No. 566,991 discloses obtaining good antistatic properties of 4.6-110-8.7.1011 cm, versus untreated PA-6.1-15 cm, to form a polymer composite by mixing the polymer and the cobalt salt in the mass and followed by carbonate, sulphide, or aqueous or gas phase oxidation.

Franc. PAT 2 181 482 and U.S. Pat. No. 3,910,533 disclose a process for fixing metal compounds in textile materials from synthetic polymers by treatment with hydrogen sulfide gas or aqueous sulphate compounds containing a reactive sulfur atom and subsequent treatment of metal salt solutions.

Franc. PAT 2 264 482 and US PAT 3 983 286 disclose a process as in the previous two patents, in which, in addition to the metal salt solution, an opaque suitable for the treated material is used in a modified bath. U.S. Pat. No. 4,374,893 discloses antistatic textiles having permanent electrical conductivity properties which are achieved by the use of fibers having a surface layer comprising at least 3% of the sulfur sulfides formed by the action of hydrogen sulfide gas under pressure, followed by the action of an aqueous copper sulfate solution and a reducing agent. GB PAT 2 078 545 also describes the same modification principle. U.S. Pat. wherein the modified polymer is a different form of polymerisation of the incorporated nitrile group. Further modifications of the polymers to reduce electrical resistance are described in numerous patents, for example, U.S. Pat. No. 4,362,779; 4,287,254; 4,310-028; 4,410-593; lEurop. .PAT .35 406, JAP PAT No.5Ι2.358Ό00; 58-018 445; 59Ό21 722, Franc. PAT2 272,567.

A disadvantage of the present state of the metallized surfaces is the relatively complicated and expensive methods, the questionable adhesion layer mainly at the locations exposed to dynamic stress. In the carbonyl method, a temperature of at least 300 ° C is required, which is beyond the decomposition temperature of conventional -Cl-containing polymeric materials. The presence of metal or carbon particles in the polymer mass mostly affects the important properties of the polymer and requires a high concentration of water particles in the mass to achieve the desired effect. Surface treatments with the addition of ionized and hygroscopic substances are often sensitive and unstable at higher temperatures. Some of these procedures are limited to polymers containing CN

Claims (1)

5 256750 pins, respectively. I bear the risks of living and working environment. The aforementioned and other disadvantages of the known state of the art are solved by the present invention, according to which the process of permanent treatment of polymers, the increase of their electrical conductivity, makes it possible for the polymeric material containing Cl to be at a temperature of 5 to 200 ° C. The polar solvent, preferably water, is treated with a copper compound in the presence of a reducing agent, and the surface so treated is treated with an organic and / or sulfite-releasing or containing sulfite ion. Advantages of the process according to the invention are in the high variability of the state and form of the polymer-containing treated -Cl-powder, granulate, fiber, fibrous particle, film, sheet, spatial product, etc. Another advantage of the process is the fact that it binds electrically actively ] the compound polymerizes to a high degree of treatment stability to the mechanical, chemical and thermal load of the product. The principle of surface treatment of polymeric materials containing —C1 groups consists in the binding of a two-, but preferably monovalent, medium co-ordinating to said group, which as a ligand co-ordinating compound, promotes the reduction of Cu2 + to Cu +. In addition, sulfide ions bind to the media-bound ions in the medium to form sulfides of the medium with pKs of 35.2 (CuS) to 47.6 (CU2S), except for the preparation of the polar solvent bath. distilled] and demineralized water are used and the spring water, since the salt additives do not reduce its effect. When water is used as a bath, it can be filled with another solvent, e.g. dilute acid solutions, ionic or non-ionic thinners, or a mixture of solvents, may be a single compound, such as thioacetamide, thio-sodium sulfate, etc., but also a more preferred two-step process in this case. The following examples illustrate the invention but do not limit it in any way: Example 1 To a 20 ° C water pH pH bath with 4 moles containing 0.05 mol / l of copper (II) sulphate and 0.005 moles, polyvinylchloride was introduced in thio-sodium sulphate (PVC powder in a ratio of 1: 15a and heated to 70 ° C with stirring). At this temperature, additional sodium thiosulphate was added to a total concentration of 0.01 mol. 11 and the temperature is raised to 100 ° C. At this temperature, the powder is adjusted with stirring over a period of 60 minutes. The modified PVC powder is olive-green and is suitable for processing by conventional techniques. The electrical resistance of the product was ΙΟ6 Ω. Example 2 To a 20 ° C water bath containing 0.06 moles of sodium dithionite. Polyvinylchloride (PVC powder at a ratio of 1: 10a with stirring is heated to 40 ° C for 10 minutes), then copper sulfate is added to a concentration of 0.2 mole. The temperature of the PVC powder is adjusted to 30 minutes, followed by cooling to 50 ° C and sodium thiosulphate is added, resulting in a concentration of 0.13 mol / l. This treatment phase lasts for 30 minutes The treated powder is dark brown and is suitable for processing by conventional techniques The electrical resistance of the finished product is ΙΟ5 Příklad Example 3 As in Example 1, with the difference that instead of 0.1 mole of thioacetamide is used in sodium thiosulphate Example 4. The procedure is as in Example 1, except that copper (II) sulphate is used instead of copper (II) nitric acid at a concentration of 0.1 mole. OBJECTIVE A method of permanently treating a polymer to increase its electrical conductivity, characterized in that the polymeric material containing the —Cl groups is treated with a copper compound in the presence of a reducing agent in a polar solvent bath, preferably water, at a temperature of 5 to 200 ° C; such a surface to be treated is organic and / or inorganic with a sulfide-releasing or releasing compound,