SU64593A1 - Wood dyeing method using oxidative dyes - Google Patents

Description

When dyeing wood products, it is sometimes important to obtain a sufficiently deep penetration of the color into the pores of the wood.

In a number of cases, when the facial finish of a tree is for some reason carried out directly by grinding painted finished products without applying a lacquer coating, wood stains must penetrate to a considerable depth, so that subsequent polishing of the product will not wipe the (etched) layer of pickled wood until the unpainted layers are exposed.

For example, for aesthetic reasons, smoking pipes, due to the insufficient fire resistance of most varnish coatings and due to the difficulty of obtaining deep coloring, are usually finished by direct polishing to the shine of the wood, without coloring.

The deepened color of the tree can be achieved by etching by prolonged soaking in solutions of cr with sh; their substances or, so-called, mordant by fumigation (smokehouse mordant) with ammonia.

Soaking staining is applicable only for staining.

unprocessed forest materials and unsuitable for coloring finished products, since the latter, when soaked, are significantly deformed due to swelling.

The method of mordant fumigation is. that a tree containing naturally tannins, such as oak, or pretreated with a solution of a dubitel - pyrogallic acid, for the purpose of artificially introducing it, is exposed to gaseous ammonia in a closed chamber for a certain time. As a result of prolonged exposure to ammonia in the presence of moisture and air, the dubbing substances form a coloring penetrating to a considerable depth. It is possible to paint a tree, having previously treated it with solutions of salts, which give colored precipitates during subsequent exposure to ammonia, which, deposited in the pores of wood, give it a particular color.

U.S. Patent No. 1, 714701 dated May 1928, proposes a method of painting wood by pre-coating it with solutions of acid salts of 2,4-diaminophenol or other commercial products capable of producing a color upon oxidation in a neutral or alkaline medium. During the subsequent treatment of wood with aqueous ammonia, oxidation is caused and a corresponding color develops. Such a method makes it impossible to obtain a sufficiently deep coloration allowing the use of the finish by direct grinding.

The author of the present invention proposes to dye wood with oxidation dyes so that the color penetrates deep into the wood layer.

This is done as follows.

A product made of beech, birch or other wood to open the pores is preheated to 50-60 ° and in a warm condition is covered with a freshly prepared cold solution containing 1 liter:

paraamidophenol sulfate 15 g

copper sulfate. . . . 1 g

10% solution of permanganate 1.5 ml

The products covered with this solution for the first time are kept in air until the traces of visible moisture disappear, after which they are again covered with the same solution, but heated to 60-75 °. Immediately after the second coating, the wet products are placed in a hermetic gas chamber, where they process the calculated amount of gaseous ammonia for at least 16 hours, based on the NHg concentration relative to the wood moisture content of about 15-20%. The color of the color of the tree from the original light yellow after being in the atmosphere of gaseous ammonia and air gradually turns into reddish-brown. Color penetrates to a greater depth than when dyeing directly. The depth and intensity of the mordant depend mainly on the duration of exposure, the concentration of ammonia and the density of the wood.

Products painted in this way are then placed in a substance at a temperature of 60 - 75 ° to remove the smell of amyiac and excess moisture, after which they can be directly grinded using polishing agents, such as crocus, etc.

Subject invention

Claims (2)

1. Wood dyeing method using oxidative dyes, characterized in that the wood is preheated to 50-60 and then coated successively with cold and hot paraamidophenol solution or similar intermediate products, an oxidizer, such as potassium permanganate, and a copper oxygen-oxygen transmitter, copper sulphate and when wet it is treated with ammonia gas. 2. A method according to claim 1, wherein the wood is treated with ammonia gas mixed with air.