US1717322A - Treating cotton fibers to produce woollike effects - Google Patents

Description

Patented June 11, 1929. I

' UNITED STATES ALBERT BODMER, F WATTWIL, SWITZERLAND, ASSIGNOR TO HEBERLEIN & CO. A.

OF WATTWIL, SWITZERLAND, A CORPORATION OF SWITZERLAND.

PATENT OFFICE.

TREATING COTTON FIBERS TO nonucn WOOLLIKE EFF'EcTs.

No Drawing. Application filed September 8, 1926, Serial N'o..134,332,' and in Germany September 16, 1925.

My invention relates to process of treating cotton goods, and more particularly the 1nvention relates to a process of producing cotton goods with a wool-like finish.

5 It is well known that cotton may be treated with (concentrated) nitric acid to thereby produce a good permanent finish Wool-like effect resembling wool in looks, feel and in caloric quality. This treatment as is now well known in the art, may be produced with or without a preliminary mercerization treatment. As an example of a treatment of cotton goods by nitric acid to produce a woollike effect, reference is made to United States Letters Patent, No. 1,439,515, to Georges Heberlein, patented. December 19, 1922, wherein such a process is described and claimed.

However, when cotton is processed with nitric acid to produce said-permanent finish wool effect, certain properties are attendant in the resultant product which are highly undesirable in textile materials. For example, vegetable fibrous material, such as cotton,

2 which has been modified in this manner, possesses a yellowish color, and it also has a very great aflinity for dyes. and consequently the uniform coloring of such a product isextremely difficult. In addition, these products are very sentive to alkali, so much so that even a washing with soda is attended with injury to the fibers, so that when one cannot bleach the goods to remove the yellow color without damage to the goods. Dyeing with vat dyes in an alkali bath likewise brings about a weakening of .the material.

The object of this invention is to improve such nitrated permanent finish textile ma-. terial's, by overcoming these objectionable 40 characteristics.

The invention comprises the improved product and also the process of producing same. The-invention will be more readily understood from the following description; including one or more examples of how the product may be produced; and the invention will be more fully set forth in the appended claims. I 1

Upon making. investigations, I have observed that small quantities of nitrogen are always absorbed and retained by the fibers in the treatment of the cotton with nitric acid. And I have discovered that if the fibers that have been thus treated are denitrated, the surprising fact becomes manifest, that the afiinity for dyes has reverted to a normal amount and that at the same time the sensitiveness to alkali has disappeared. Besides this, a more extensive modification in the structure of the fiber has taken place whichmanifests itself in a considerable heightening of the fiber. The resistance to alkali that is attained also results in greatly increasing the fastness as to color; and the permanence of textiles thathave been improved in this manner.

While nitrated cotton wool eflects, i. e., those produced by treatment with nitric acid, have been very excellent as to their wool qualities, yet the above-mentioned detrimental characteristics have been such as to greatly curb an extensive commercial use of the same; but by the simple treatment according to this invention, .not only have all of these objections been overcome, but the wool effect itself is actually improved.

. This denitration may be carried out in any suitable manner. For example, I have'found it to be satisfactory to denitrate in a manner similar to the method used in the production of artificial silk from cellulose nitrate; and furthermore, the denitrating agents that are in use or are suitable for use in the production of artificial silk from-cellulose nitrate.

are likewise satisfactory in connection with my invention. Thus by way of example, there are found to he satisfacto especially the sulfides and sulfohydrates 0 the alkalis, alkaline earths and ammonium, in which connection these agents may be used singly.

Also the salts of the low stages of oxidation of multivalent While any suitable denitrating treatment andwashing,

may be used, I give by way of example only, the following treatments that have been found to give satisfactory results:

Example No; 1.

and are washed out, soured, washed and dried. Goods thus pretreated are ex osedfi to the action of nitric acid with an aci content of about 72% for about 8 minutes, and are washed out in denitrating bath tion of NaSH and goods may remain in the bath at room temperature for instance for i 30 to 60 minutes, then bleached and dyedof cotton fabrics, for the invention is also Example 2.

a denitrating bath This may consist of a% solu-' applicable to the treatment of yarns and threads made of cotton fiber, and by the term goods I wish to be understood as including cotton fabrics and yarns nor to any particular denitrating treatment; and while the dewith nitrated wool efl'ects on cotton fibers, it may also be useful in connection with other uitrated effects on cotton goods having some of the foregoing objections.

Having thus described myinvention, what i I claim as new anddesire to secure by Letters Patent, is:

nitration is especially useful in connection 1. Method of treatin cotton goods which comprises producing t ereon a permanent finish wool-like effect by treating the goods with nitric acid, denitrating the goods to render them less sensitive to alkali prior to any finishingtreatment involvin alkali, and subsequently treating the goods with an alkali substance to further finish the same.

2. Method of treating cotton goods which comprises producing thereon a permanent finish wool-like effect by treatin the goods with nitric acid, reducing the afl iity of the goods for dyes and increasing the fastnes's of the color by denitrating the goods, prior to any dyeing or other treatment involving an alkali, and subsequently dyeing the goods with a dye containing alkali.

In testimony whereof I name to this specification,

ALBERT BODMER.

have signed I