SU35814A1 - The method of obtaining dyed viscose silk - Google Patents

Description

The object of the present invention is to obtain colored viscose silk by introducing dyes into a viscose mass before the silk is spun. According to the usual methods currently adopted in production, the fabric or yarn is dyed in finished form, which entails an excessive consumption of materials, reduces the quality and strength of viscose fiber.

The proposed method eliminates all operations associated with post / dying dyeing excessive consumption of chemical reagents, gives a complete evenness of the color of the thread, regardless of the batch, gives strength to the color to light and other physicochemical effects, makes the viscose more durable and silky and cheapened the cost of painting almost twice.

When making a viscose solution for the spinning process, cellulose xanthate is usually dissolved in 3% sodium hydroxide solution. In a solution of caustic soda, applicants suggest adding dye solutions (substantive for cotton, bottoms or sulphurous) and then adding cellulose xanthate. As the xanthate disperses and matures, the dye is adsorbed and firmly attached to the fiber elements. A uniformly colored viscose is obtained, which

filtered to remove air from conventional processes. Spreading viscose is produced by squeezing into a precipitation bath of conventional composition which does not stain. Further processing is no different from processing unpainted silk. Desulphonation is not sulphurous sodium, as usual, but with medium sulphate at a temperature of 20–20 minutes with the addition of table salt (20 g per 1 liter), which makes viscose silk more silky and more resistant to desulfurization and soap.

To obtain full colors, dyes are taken (by weight of a-cellulose): Substantive for cotton. . 3-4%

Kubovy3-5%

Sulfur 8-10%

Cotton substantive dyes are dissolved in distilled water (25-30 g in 1 liter) with the addition of caustic soda (up to 3 e in 1 liter) and then the solution is filtered through a pre-mercerized calico. Sulfur and vat dyes are dissolved by glucose reduction in a strongly alkaline solution, with heating. After cooling and filtering, sodium hydroxide solution, necessary for dissolving the xanthate, is added to the solution. In order to preserve the color and completeness of the shade, it is useful to add Tnatri nitrite in a 1-2-fold amount of the weight of the dyes taken.

Example 1. 4% Anil pure blue FF or 3% Anil Sharlach 4 BS {weight of cellulose) is dissolved in 3% sodium hydroxide solution, measured to dissolve xanthate. Then, the xanthate is added and, after stirring and dissolving, the solution is subjected to the usual treatments (dispersing, filtering, aging, etc.).

Example 2. Desulfurization is carried out in a bath having the following composition:

20 g sodium sulfate

20 g of salt per 1000 cubic meters. cm of water at a temperature of .75-80 for 20 minutes. Then the product is washed with cold trouble and, if necessary, washed.

The subject matter of the invention.

A method for producing dyed viscose silk, characterized by those; that in the usual way the prepared solutions substantive for cotton, or sulphurous or vat dyes are mixed with caustic soda solution, then after the dye has completely dissolved, the prepared cellulose xanthate is introduced into the filtered solution in the usual way and the resulting solution is processed into artificial silk.

2. With the use of medium sulfur acid salts for the desulfurization of the obtained yarn of viscose silk, as indicated in paragraph 1 of the method.