SU43733A1 - Electrodeposition of non-porous films on iron - Google Patents

Description

When rubber is electrically deposited from natural or artificial water dispersion, electrolysis of water occurs simultaneously with cataphoresis of rubber particles and ingredients, and gaseous oxygen is released at the anode. As a result, a porous rubber film is deposited on the anode.

To eliminate this phenomenon, rubber can be electrically deposited at a voltage below the water decomposition potential, but the rate of rubber deposition is very low.

Another way to eliminate the porosity of a deposited rubber layer is to use anodes of an easily oxidizing metal, such as zinc. The deposit then becomes completely non-porous.

The use of an electrical deposition method for coating an iron chemical apparatus with a protective layer of rubber or ebonite is possible only if non-porous deposition is obtained on the anode. Under normal conditions, during the deposition of natural or artificial dispersion of rubber and similar materials, the anode iron is passivated and oxygen is released.

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in free form, causing the formation of an unsuitable porous film.

The proposed method is based on the introduction of some electrolytes into the natural or artificial dispersion of rubber and the like materials, which destroys the passivity of iron and gives it soluble compounds, resulting in a non-porous rubber layer that is fully satisfied to such coatings

An example of such electrolytes is sodium sulphate, rhodium ammonium, and other alkaline salts of rhodian hydrosulfuric acid. These salts are introduced into the bath in an amount of 0.5-U / o (calculated on the dry matter), depending on the composition of the latter.

The following examples illustrate the implementation of the proposed method.

Example. To 70 cu. see a concentrated latex containing 50 g of rubber, add 5 g of a 50% solution of rhodium potassium and 35 cu. see water When DC is passed through this bath with a voltage of 12 V

and a density of 4 KJKs. dm on the iron anode a non-porous rubber layer is formed.

Example 2. In a 100 I latex mixture containing 40% rubber, 20%, sulfur and 40% kaolin, an L 50% solution of rhodium ammonium and 40 cu. see water

When DC is passed through this bath, the voltage is 100 V and the density is 2A / sq. dm on the iron anode is deposited a non-porous layer consisting of rubber, sulfur and kaolin, which, when dried and zoned, produces ebonite.

Example 3. To 100 g of an artificial dispersion of rubber containing 43% rubber and 57% of ingredients, add 2.5 g of a 50% solution of roentan

ammonium and 10 cu. see water When a direct current is passed through this bath with a voltage of 80 V and a density of 2 A 1k8. (A JM layer of rubber compound is deposited on the iron anode, which gives acid-resistant soft rubber after vulcanization.

The subject matter of the invention.

The method of electro-deposition of non-porous rubber films on iron, characterized by the introduction of rodanist or thiomeric salts into the natural or artificial dispersion of rubber, in order to eliminate the passivity of iron and the formation of soluble compounds with it, and electrical deposition is carried out according to known methods.