SU28434A1 - The method of preparation of the viscous dope solution - Google Patents

Description

The present invention relates to the manufacture of viscose, which is used for the production of artificial silk. I.

Viscose used for this purpose is usually prepared by the mercerization of cellulose in a solution of caustic soda followed by treatment with carbon disulfide, during which the viscose goes through a bath containing sulfuric acid, glucose and pure sulfuric acid salts. At the same time, some gases that are unpleasant and healthy for health, such as hydrogen sulfide, sulfur dioxide and carbon disulfide, which are extremely undesirable in the production process, are formed during the forwarding. Removal of these gases in the set. G-13213 obtains a-BToipOM by adding nitrous acid to the quicose salt, while the catalytic oxidative effect of sodium nitrite or other nitrous acid has a certain amount and decreases to zero when the amount of nitrous salts in the bath reaches 0.8% by weight of the viscose. The solution of viscose in a medium containing sulfuric acid (25 cm of sulfuric acid and 800 water) loses its stability and the xanthate solution is destroyed; cellulose falls out, developing the smell of sepgg. tgrto tt otstltsi zpt TTK ptptpy

sulfuric acid occurs almost instantly when the content of nitrogen-acid salts and, in particular, nitrous sodium soda in viscose reaches one percent. At the present time, according to the proposed method, the author has found that when viscose is limited to a 0.3–0.4% sodium nitrite sour solution of such viscose in dilute sulfuric acid, the same concentration remains stable: xanthate is not destroyed, cellulose does not fall out, does not no odor of carbon disulfide or nitrogen oxides is observed, and such a solution of viscose in an acidic medium can remain stable for several days or even a week. Viscose with a content of 0.6% sodium nitrite, i.e. as the catalytic oxidative effect of nitrite (O, 8%) approaches its limit, its oxidative effect on hydrogen sulfide decreases. Thus, for example, 2.5 g of viscose in dilute sulfuric acid to bind the hydrogen sulfide released at the same time consumes 1, 4 cm of decinormal ice, if the viscose contains 0.3-0.4% nitrite. Thats The same amount of viscose of the same maturity with a content of 0.6% nitrite in diluted sulfuric acid of the same concentration binds 3.2 cm of detsional normal iodine. Consequently, the proportion is ttttt. .R -ctttel l -R kl.tscheon.1te 0.3-0.4%

Further, the author found that by adding dry nitrocellulose to viscose to 1.5% by weight of viscose, the stability of the viscose solution in diluted weed acid is greatly increased. Dry nitrocellulose (double nitrocellulose) with a content of 11% nitrogen can be added to an ordinary viscose solution and a slight stirring of this mixture — viscose and ditrocellular tissue — after 18 hours, a uniform viscose solution is obtained that is suitable for artificial silk on an ordinary sedimentary bath.

For the production of industrial purposes, dry nitrocellulose together with cellulose xanthate: in a rastoreor; The caustic soda is dissolved in the mixer for 4-5 hours, after which a homogeneous viscose solution is obtained. The nitrocellulose, in the presence of sulfur salts 1x in viscose, such as sulfurous acid and sodium thiocarbonate, is washed by breaking up into sodium nitrite and fiber; in the result of dissolving nitro, rokletchatka in viscose, it turns out that viscose is more mature and the process of maturation of viscose is accelerated unlike viscose containing 0.3-0.4% sodium nitrite, which in this case does not have any chemical effect acceleration or deceleration of viscose ripening. Thus, a homogeneous, viscose solution obtained by the method of mixing cellulose xanthate with nitrocellulose in a solution of caustic soda consists of cellulose xanthate, cellulose, and sodium nitrite. At the same time, viscose, in which 1 %% of nitrocellulose containing 11% nitrogen is dissolved, contains 0.8% nitrite. This viscose is contained, and 0.8% nitrite, blashd dissolve the amount of nitrocellulose mentioned in it, c. diluted sulfuric acid retains its stability (xanthate is not destroyed), its catalytic oxidative effect on hydrogen sulfide. The highest, for example, 2.5 g of viscose in diluted sulfuric acid, accounts for only 0.4 cm of detsin-normal iodine. This observation shows that the limit of the oxidative effect of nitrite on hydrogen sulphide is greatly increased by spinning the viscose obtained by injecting nitrocellulose into it, compared with viscose, in which only Nitrogen Sodium has been absorbed. Of course, when spinning viscose, obtained by introducing into it the above method

1.5% nitrocellulose, there is an even greater decrease in the concentration of excreted yush; their harmful gases (hydrogen sulfide, carbon disulfide and sulfur dioxide) are compared with the Method described in the patent 13213, while abundantly deposited sulfur is not inside the fiber, but on its surface, and during further processing, it is easier to remove from it. At the same time, silk is of better quality, good tensile strength, elasticity and luster, and these qualities it ooh-ranks for a long time. With this method, as mentioned above, the maturation process of the viscose solution is accelerated and therefore such viscose solution, without ears; quality for silk can be mapped after 24 hours it can withstand baths, whereas in normal processes viscose should mature, approximately, for four days.

With the described joint venture (Part No. (Mixing viscose with nitrocellulose, it becomes possible to obtain highly concentrated cellulose solutions for artificial silk / top grades, since the fiber consists in this case of α-sulfite pulp to a certain extent of cotton cellulose.

The author tested at the same time viscose of one solid origin with only 0.3% nitrite in the one case, 0.3% nitrite and 0.1% nitrocellulose containing 11.0% nitrogen in the second case, and 0 in the third case. , 3% nitrite and 0.5% of tshcherocellulose, containing also 11.0% of nitrogen. The results, based on the determination of: - the relative capacity of nitrite, showed the following: in the first case, 3.5 a decade of normal iodine was bound in the airs layer of the diluted medium, in the second - 2.5 cm of detsional normal Iodine I1 in the third case - 1 , 8 cm decinormal iodine. Thus, with the addition of 0.5% bicarbonate, the oxidative effect of nitrite is the highest. In addition to all the qualities described, with the method of introducing nitrocellulose into viscose, the percentage of cellulose from the uptake of microcellulose is increased in it. So, for example, 3 g of dry nitrocellulose (dinitrocellulose) was added to 200 g of VISK105Y containing 7.7% cellulose and 7% of caustic soda, and the mixture was left for the entire note. Acceleration of the dissolution of nitrocellulose in viscose is achieved by stirring the mixture in a mixer for four

hours And the viscose content after filtration shows that the cellulose content in the solution rises from 7.7% to

800 /

, / 0.

A viscose solution with nitrocellulose is prepared as follows. Cellulose xanthate in the mixer is dissolved for four hours together with nitrocellulose in a solution of caustic soda in a proportion of 20% nitrocellulose to the amount of cellulose in xanthogenate, until a homogeneous solution of viscose is obtained; in another case, the xanthate is dissolved with the addition of 0.3% sodium nitrite, and 7% nitrocellulose to the amount of cellulose in the x-santogenate in a solution of caouthenic soda.

During the spinning of an isklaze containing nitrite in a reducing bath, by the side reduction of nitrous acid, partly a small amount of hydrazine is formed, which accumulates in the bath in the form of hydrazine sulfate (NH2. NHz. HZ SO J. In the presence of anhydrous ferrous ferrous sulfate (in at least 0.11% of the bath; hydrazine precipitates as a precipitate, bound to ferrous sulphate and form the double salt Pe S 0 (N HJ SOJ). Hydrazine remains in the bath and the precipitated sulfur to the sulfurous iron is partially deposited on a surface olokla, I gave him a brown color. When sequential processing fiber again becomes a marketing natural dvet as

usually, freeing from this osadAc, and, Chemical reactions of hydrazine formation can be represented; in the following form:

20H-NO + + 2NO + 2H2O;

2NO + -f S -f HjO HaS H- + HaSOs + HgO;

Ы2О + ЗН25Оз + 2НгО NH2-NH2-H2SO4 + 2H2SO4

In the presence of iron in the reducing bath, the reaction can flow as follows: 2 (N2H4) H2SO4 + 2FeS044-2OHNO + -Ь 2H2S + HoSO4 FeSO4 (N2H) 2SO4 + H- FeS + S -f 2NO + ЗНгЗО + 2Н2р.

The subject matter of the invention.

1. A method for preparing an irregular viscose solution, characterized in that nitrocellulose is added to the xanthox solution.

2. A variation of the method according to p. 1, characterized in that from 0.3 to 0.4% sodium nitrite is added to the xanthate solution, in addition to nitrocellulose.

3. A method of using a spinning dope, prepared according to items 1 and 2, characterized in that the viscose is aged for 24 hours.

4. A method for preparing a reducing bath for precipitating viscose, obtained according to items 1 and 2, characterized in that at least 0.11% anhydrous liquids are added to the reducing bath. ferrous sulfate.