DEV0000363MA - Process for refining artificial structures, such as threads or, in particular, rayon from cellulose hydrate - Google Patents

Description

Process for finishing ..iron artificial / threads or icell-

United Glanzstoff-Fahriken AG Wuppertal-Elberfeld

It is already known _: Cellulose and CeTlulo.sehydratgutV such as rayon / and "cotton wool" with a fatty acid anhydride at elevated temperature using alkali salts of weak acids as a catalyst. As a result of this esterification, the properties of the 'output! ¹ aser greatly changed, for example reserve against substantive dyes, insolubility in organic _: solvents , higher inflexibility, change in handle and, appearance, etc., achieved. with '■■■■'. application - from easlgic acid ahydride a, .B.>'to; the. stage of the .2 - / 2-acetate ,.

A major disadvantage of the largely ulcerated,. a "E .. '-acetyl-Xi he th' goods, it is now a 'that." the acetate CelluloEen not b u s obtained'tä'ndi g. ge gen _Λ the washing e ,, s al ο "counter- , S ei ι e and _{soda. are:>} what si ch in my. erheblichen- Quellungsans ti eg d.er .ursprung-Iich strong deswollen product indicates .. at ^{1/2-l-stünäiger} decoction with a solution von'5 gSei'fe _Uend; 3 g soda per / liter increases .aB- the; Swelling value of a "cell wool '·" acetylated by known processes of'; 31 f " on.: 5o '. #' · .. In the case of. Repeated washing, further. Vex sole increase in the swelling value. Also goods. That are still, more strongly esterified 1; βϊ, and a swelling value of nar 2 5 $>'has., this harmful interference is subject to .. and that is for the fact that when cooking mit.Seife and soda a saponification uiig de.s Celluloseacetäts and source value increase occurs, not surprising for use in the laundry sector but where it is appreciated that the swelling of the fiber, B3W also during the washing process in the size of the _{Baumwollquellung:..} darun- • ter remains, however, is one that Vare virtually 'useless, at least ^nar. conditionally usable form .

The surprising finding was made that it is' possible to produce largely esterified goods which greatly reduce swelling down to. .73 of the initial swelling, but which is resistant to hot soap and soda solution, can be achieved by the fact that the cellulose, which has been pretreated in a very specific way, is "post-treated" with aromatic acid anhydrides. The pretreatment is done in such a way that the cellulose is immersed in concentrated solutions of alkali salts of salicylic acid and then dried well. Although the new type of process is also an esterification of the cellulose In addition, the cellulose esters formed according to it are not practical against alkaline saponification with soap and soda Impairment of the swelling value surprisingly constant * Goods made from it can therefore be harmless in the important Linen sector are used, the favorable properties achieved by the strong reduction in value being fully retained remain.

Those aromatic acid anhydrides which contain an aliphatic before group in the molecule, z. 3. Benzoic acid-acetic anhydride, cinnamic acid-acetic anhydride and similar compounds. These substances result in an extraordinarily strong reduction in the swelling value down to V 3 of the initial value. Nevertheless, the goods treated with it are resistant to swelling against hot soap or soda solutions. The simple aromatic acid anhydrides, such as benzoic acid anhydride and cinnamic acid anhydride, do not cause so much de-swelling. The initial source value is reduced by about V3, but this source is also resistant to soap soia. The advantage thereby achieved over that achieved with aliphatic acid anhyarids is evident. As working examples, the following may be given;

Example 1),

5oo g moist, never dried, unavivated rayon from Vls £ o-

Se with about 7o % water content w4ra * s- 30 minutes in one

50% sodium precipitate solution is immersed, whereupon it is centrifuged to a weight of 92o.g. The goods pre-impregnated in this way are dried for 9.0 minutes at 90 ° with good air circulation to a weight of 50 g. This is followed by a follow-up treatment in a bath. from 6.6 l of chlorobenzene, in which 1.5 kg of benzoic acid-acetic acid-anhydride are dissolved, '. for "12.0 min. at 100 instead of .. Ss is spun off; with acetone, then washed with water, - spun off again' and normally dried .. After conditioning, the weight of the goods is -435 g, so it has increased considerably ... The water retention capacity is 23 ° compared to 74 ° for the untreated tares .. In addition, the goods show , water-repellent properties; it floats on water. After a long period of soaping, the swelling value was -2.4.8., i.e. practically unchanged.

Example 2).

150 g of moist viscose rayon as in Example 1 is dipped for 15 minutes .2., 5 9. "P ^J on a weight of 165 g of dried viscose wool is then treated at 90 ° in a plot of .1.7 1 chlorobensol and 35o g of benzoic anhydride and worked up as above . The rayon obtained has a WaoS retention capacity of 51.7 "# .. Kach ■ one hour simmering with a solution of 5 g of soap and .3 g of soda, per liter the swelling value was 52.9 * f °, that is practical ■ g.1 ei ch g 8b 1 ieb en ■.

Example 3)

if you act against it. de:;: DRP 7o "6 S'7o manufactured., 'achv / er dried viscose wool with a 5o ^ strength potassium acetate solution tro-e.kn.et and treated in acetic anhydride afterwards, a swelling value of 37.3% is obtained (unbahanielt $ 36 '). strongly lowered in this way in their swelling viscose staple becomes long boiling soaping 1 hours' with a solution of 5 g soap and 3 g of sodium carbonate / l, and it wiederum.der _H uellwert determined so · it turns out that the goods besügi, their -Quellwert has suffered greatly and moreover

Claims (1)

has become very even. The swelling values are between 4 5 - and 54 -. # ·. P at a nt ansp.r αch: _ A method of refining artificial structures, such as threads or, in particular, "rayon from cellulose hydrate, characterized in that" that the freshly produced., washed, post-treated, but not yet dried, unavivated threads with a concentrated Älkalisalicylatlösung pretreated, 'after removal' of the excess dries the goods and now an aromatic Acid anhydride acts at an elevated temperature, whereupon I with an organic solvent such as acetone and the like. and then washed with water and. then is dried.