JPH0260939A - Surface conductivity method for rubber materials - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for making the surface of a rubber material electrically conductive.

[Conventional technology] Conventionally, a method of imparting appropriate conductivity to the surface of highly insulating rubber materials for the purpose of preventing static electricity and preventing static electricity damage was to add conductive fillers such as carbon black or metal powder to rubber. A method of mixing an ionic surfactant into a rubber material, a method of mixing an ionic surfactant into a rubber material, or a method of coating it on the surface of a rubber material are known.

[Problems to be Solved by the Invention] However, although only the surface of the rubber material is required to be conductive, the conventional method of kneading conductive fillers and surfactants does not make the entire rubber material conductive. In addition to the drawback that the rubber material itself contains foreign matter, there is a problem that as the amount of foreign matter increases, the excellent elasticity inherent to the rubber material decreases.

On the other hand, the method of applying surfactant to the surface of rubber material is
Because the compatibility of the two materials is small, the secret stone sword is weak and has problems with durability.

Therefore, in order to impart appropriate conductivity only to the surface without impairing the original properties of the rubber material, a material that can be strongly bonded to the rubber material and has appropriate conductivity is added to the surface of the rubber material. It is necessary to form only

The present invention has been made in view of the above circumstances, and its purpose is to eliminate the drawbacks of the prior art described above,
An object of the present invention is to provide a method for imparting highly durable surface conductivity to a rubber material.

[Means for Solving the Problems] The gist of the present invention is to treat the surface of a rubber material with low-temperature plasma, thereby imparting durable surface conductivity to the rubber material.

Rubber base materials to which the present invention is applied include natural rubber, butyl rubber, butadiene rubber, butadiene styrene rubber, butadiene acrylonitrile rubber, chloroprene rubber, urethane rubber, silicon rubber, fluororubber, ethylene propylene rubber, and the like.

Gases used for low-temperature plasma treatment include hydrocarbons such as methane, ethylene, and propylene, fluorine-containing carbon compounds such as hexafluoroethane and occufluorocyclobutane, organometallic compounds such as tetramethylsilicon and tetramethyltin, ammonia, trimethylamine, Nitrogen-containing compounds such as ethanolamine can be used.

Note that low-temperature plasma treatment greatly reduces the surface friction coefficient, but if you want to reduce the surface electrical resistance without reducing the surface friction coefficient, use silica, talc, clay, etc. for the rubber material to be subjected to low-temperature plasma treatment. An inorganic filler may be added.

[Effect] It is thought that the low-temperature plasma treatment forms a plasma polymer on the surface of the rubber material that forms a strong bond with the comb base material and has appropriate conductivity.

[Example] Iodine value 15, Mooney viscosity ML1+4 (100°C) 5
5 parts of zinc white, 1 part of stearic acid, 10 parts of titanium white, T
Add 5 parts of Sl, 5 parts of Mo, and 1.5 parts of sulfur, cross-wire with rolls, form a sheet with a thickness of 2 cm, and heat at 160°C for 30 minutes.
A rubber material was prepared by vulcanization for a minute.

Next, this rubber material was placed in a reaction vessel of a low-temperature plasma device and after exhausting, tetramethylsilane and ammonia were added in a ratio of 1:2.
When a mixed gas of 201 is flowing per minute, the pressure is I
It was adjusted so that it was Torr.

The low-temperature plasma device used was a capacitively coupled, external electrode type, and generated low-temperature plasma at a high frequency of 13°56 MHz and an output of 50 W, and treated the rubber material for 20 minutes.

Thereafter, the rubber material was taken out into the air, and heat treatment was performed at 80° C. for 24 hours to stabilize the plasma-treated surface.

The surface electrical resistance of the low-temperature plasma treated surface of the rubber material after heat treatment was measured and found to be 3×10 5 Ω under conditions of temperature 20° C. and humidity 60%.

On the other hand, as a comparative example, the surface electrical resistance of the surface not treated with low-temperature plasma was 2×10''Ω.

[Effects of the Invention] As explained above, according to the present invention, highly durable conductivity can be imparted only to the surface of the rubber material, which is inherently highly insulating, without changing its overall properties.

Claims (2)

[Claims] 1. A method for making the surface of a rubber material electrically conductive, which is characterized by treating the surface of the rubber material with low-temperature plasma. 2. The surface of the rubber material according to claim 1, characterized in that a mixed gas of a nitrogen-containing compound and at least one of hydrocarbons, fluorine-containing carbon compounds, and organometallic compounds is used as the low-temperature plasma treatment gas. Conductivity method.