DE870430C - Process for the production of a coating on a dielectric material - Google Patents

Description

Process for the preparation of a coating on a dielectric Substances The invention relates to a process for the production of metallized materials dielectric materials, their metal coating, applied by a vacuum process is, prior to the deposition of the metal in a vacuum on, diene, dielectric First of all, an insulating coating is applied to the fabric, covering the pores and cavities this fills dielectric material.

To produce this coating, paints have generally been used up to now, mainly nitrocellulose lacquers, but because of their chemical properties Cellulose paper, which normally builds up at higher temperatures served as a dielectric, heavily attacked. By splitting off acids from the paints if the paper aged quickly, its mechanical strength was considerable Dimensions decreased. The use of special varnishes that do not split off acids, especially of styrene lacquers, was because of the greater brittleness of these lacquers night to recommend. In order to avoid the greater brittleness, one would have the styrene lacquer Have to add plasticizers that increase the elasticity of the paint layers, when applying this metal coating, however, caused considerable difficulties. By namely, the vapors emerging from the plasticizers in a vacuum became a metal precipitate prevented on the styrene lacquer layers, or at least it turned out to be very bad adhesive metal layers. According to the invention, these N.achte@le thereby eliminated; .that applied and dried as a coating material in aqueous solution Methyl cellulose is used. This coating is in a manner similar to with a lacquer coating: the insulation resistance of the dielectric is considerably increased.

As with the use of varnishes, you can also use several layers of methyl cellulose a further improvement in dielectric strength and improvement achieve this insulation resistance of the dielectric material. The , later layers must be thinner than the layer applied first.

If subsequent impregnation of the paper tape is not necessary is; so it can be practiced on both ropes with methyl cellulose.

Methyl cellulose is commercially available as woolly. fibrous web available, This can be seen in boiling water during the cooling down of the Water dissolves and one that can be spread or sprayed in a similar way to paint Fabric supplies. In contrast, the dried methylcellulose is in water no longer solvable.

Advantages of the method according to the invention are other than those already mentioned Increased resistance to aging by using water instead Another solvent made the production of the coating material much cheaper And the absolute harmlessness of the production, the aqueous solution and the Spread on. The usual paint solution tools are all highly flammable and much more expensive than water. They do not require weaving their party danger only in the preparation of the lacquer solution, but also in the processing special Precautions. and facilities of a fire protection type, which when using Methyl cellulose become superfluous.

Claims (4)

PATENT CLAIMS: r. Process for the production of a coating a dielectric material, in particular one serving as a metallization carrier Paper, characterized in that the pores and depressions on the surface of the dielectric material by an insulating coating in aqueous solution applied and dried methyl cellulose are sealed. 2. Procedure according to claim z, characterized in that the coating is made of methyl cellulose applied to both sides of the dielectric tape. 3. The method according to claim r or 2, characterized ,, that several layers of methyl cellulose on top of each other be applied. 4. The method according to claim 3, characterized in that the later layers are thinner than the first applied layer.