DE485305C - Production of soft transparent effects on cotton while increasing the affinity to basic dyes - Google Patents

Description

Production of soft transparent effects on cotton while at the same time Increasing the affinity for basic dyes It has been done on various occasions. - Attempts have been made to bypass the usual tannin or metal oxide heating cotton through chemical treatment capable of direct absorption of basic dyes to make or the low existing affinity for such. Dyes, to increase, and attempts have been made to do this by treating the cotton with it Acids to achieve. -But so far it has not been possible to increase this affinity as follows :, that it could technically have been used, be it to replace the pretreatment or to create new effects. The reason the acid treatment fails led to a technically usable success lies in the fact that to achieve a Somewhat usable dyeability of cotton with basic dyes like this 'High acid concentrations were used: the treated fabric had to be straw-stiff and was parchment hard. It has now been shown that in the treatment of Cotton fabrics with sulphuric acid with the addition of ammonium sulphate do not affect the fibers only remains soft and gets a pleasant grip, but that another, new effect is achieved, namely a striking increase in the affinity of the sun treated; Cotton to basic dyes. This unexpected property of the according to the present process soft transparent cotton can be easily demonstrate on tissues that before treatment with the acid containing ammonium bisulfate received a patterned print of a reserve; when dyeing such a soft transparent and then neutral washed fabric with a suitable basic Only those tissue parts that came into contact with the acid become dye colored.

The present method also leads to a change in affinity cotton to organic dyes, also to soft transparent effects of cotton.

To carry out the process, an a @ -nmoniumbisulfathaltige is used Sulfuric acid to act on the cotton as it is by adding ammonium sulfate or other ammonium salts are converted into sulfuric acid. The behavior of a Such an acid mixture is quite surprising and could not be foreseen.

Usable solutions are e.g. B. those with a content of 69% sulfuric acid, 5 o; 'o ammonium sulphate and 26 0lo water, or 72 o-o sulfuric acid, i o o, o ammonium sulphate (dissolved as such) and i8lolo water, or 82% sulfuric acid, 120% ammonium sulphate and 6 ° ö water. Solutions with an even higher content of sulfuric acid and ammonium sulfate Correspondingly lower water content can otherwise be used for the present Use procedure. It is particularly important to emphasize that one as a result the addition of ammonium sulphate to the acid, these in considerably higher concentrations can act on the cotton, in contrast to previously known Transparent processes without weakening the fibers.

This creates an all the more soft transparent effect on the treated geo-floors achieved, the greater the ammonium sulfate content of the baths and the smaller their water content is. The acid containing ammonium bisulfate is expediently used at temperatures from: io to i8 ° C during, for example, 5 to. 10 seconds on the cotton to be treated allowed to act; but can. one even at lower temperatures and for longer Work exposure time.

A cotton fabric treated with such an acid mixture has when wet, a characteristic silky, glutinous handle, after washing and drying a velvety soft handle; when wetting the fabric feels this again soapy.

The acid mixtures required to carry out the process can be can be made by putting in a sulfuric acid that has the desired water content sits, dissolves ammonium sulfate. Instead of ammonium, sulphate can also be used Add cranium salt or another ammonium carb (onate) to sulfuric acid and the Use the obtained hot solution for transport after cooling :; included the action of the sulfuric acid on these ammonium salts - water is formed this fact in the production of an acid containing ammonium bisulfite from a certain one Concentration of course to be considered. Also with salmia, ammonium acetate, ammonium isphate etc. and sulfuric acid can be useful transparency solutions for the present Process.

To carry out the procedure, it is best to use well-bleached meroerisnertes Tissue used that has been dried under tension. Immediately after the treatment with then S, äuregemi: sch is squeezed, washed out and dried under tension. The transparent effect! Can be increased by subsequent mercerization with caustic soda be e.g. B. by lye of a8 ° Be, being dried under tension after washing will. Here. afterwards, a further soft transparent layer may be required made, washed and dried under tension.

By printing suitable acid-proof reserves, such as rubber solution, Paste etc. on the fabric, drying and treating with ammonsulfaübaltigen Acid patterned effects can be achieved on the fabric.

Claims (1)

PATENT CLAIM: Process for the production of soft transparent effects on cotton with the help of sulfuric acid, characterized in that for the purpose at the same time increasing the affinity of the cotton for basic dyes and to prevent fiber weakening, sulfuric acid with the addition of ammonium; sulphate or another ammonium salt converted into ammonium bisulphate for action brings.