DD158656A1 - METHOD FOR REDUCING CELLULOSE ABBAUS IN AMINOXIDE-CONTAINING CELLULOSE SOLUTIONS - Google Patents

Abstract

The method for reducing cellulose degradation in aminoxide-containing cellulosic solutions involves the preparation of aminoxide-containing cellulosic compositions for the purpose of cellulose deformation, wherein to reduce the cellulose degradation occurring at elevated temperatures in the solution, the solution contains amine oxide reducing agents.

Description

2295

Dr. Brigitte Lukanoff Teltow, 16.04 * 1981

Dr. Harry Schleicher

Title of the invention

A method for reducing cellulose degradation in aminoxide-containing cellulosics

Field of application of the invention

The invention includes the preparation of Oelluloselösungen ₅ su the formations ₅ such . B, fibers or films, can be processed,

Characteristic of the known technical solutions

It is known that. be certain amine oxides such as ζ «3, IT-IvIe thylmorpholin-lT-oxide, iTjl'-dimethylethanolamine il-oxide or triethylamine H-oxide bsw. aminoxidhaltige mixtures dissolve cellulose assets. The aminosocid-containing cellulose solutions can be processed into molds by precipitating the cellulose back out of the solutions by means of precipitants after appropriate shaping. the amine oxide is dissolved out of the solidified melt (DD-AP 140 257, 140 258, 140 356, 142 898).

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The Auflösimg of the cellulose in the amine oxide cellulose solvent and the processing of Gelluloselösungen has up to about 110 ⁰ G are generally carried out at elevated temperatures. However, with increasing temperature and increasing residence time of the cellulose in the heated aminoxide-containing cellulose solution, an increasingly stronger degradation of the cellulose takes place, which manifests itself in a reduction in the average degree of polymerisation of the cellulose (Chanzy, H., Pegny, A., Chaunis , S. and Monzie, P .: Tappi Conference Papers 1980, p. 105). Too much cellulose degradation has a negative effect on the properties of the organ structures produced from the cellulose solutions.

Object of the invention

The object of the invention is the development of a process which enables the production and processing of aminoxide-containing cellulose solutions with reduced elimination of cellulose.

Explanation of the essence of the invention

- Task

The object of the invention is to develop a method for reducing the degradation of cellulose in amine oxide cellulose solutions in which, by means of suitable additives to L ₀ -Sung the drop of Durchschnittspolymerisationsgrades the cellulose during the manufacture and processing of the cellulose solution is limited.

- T _{U R} ES of the invention

It has been found that by addition of aminoxides reducing substances to the aminoside solutions of the melts, the dissolution of the cellulose and

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cellulose degradation occurring during processing of the cellulose solution under elevated temperatures can be substantially reduced.

As the cellulose degradation-reducing additives to the amine oxide-containing solutions or melts are mainly considered:

nitrogen-containing substances such as imine, urea, hydroxylamine, hydrazine or compounds of these substances;

- Sulfur-containing reducing substances, such as. Sulfites, thiosulfates, dithionites, thiourea or sulfur;

- fertilize reducing compounds containing C, H and O, such. B. aldehydes or reducing sugars,

However, they can also be added to the cellulose solution already present. In general, the amount of cellulose degrading additives is less than 10 %, based on the amount of amine oxide used amount, but with some substances larger amounts are possible »

The invention will be explained in more detail in the following exemplary embodiments »

1st comparative example

Pichtensulfitzellstoff (D? 720) for 30 min was dissolved with stirring in a molten ΪΤ-Hethylmorpholinoxid at 85 ⁰ C, the cellulose concentration was 5%. The cellulose was precipitated by pouring the solution in water

 The D? determined by the Cuoxammethode was 4-05.

Spruce sulphite pulp (DP 720) was dissolved in molten N-methylmorpholine N-oxide containing 5 % H-methylmorpholine at 85 ^° C. for 30 minutes. The cellulose concentration was 5 %. The regeneration of the cellulose was carried out as described in Example 1. DP = 644

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Pichensulfite pulp (DP 720) was added in molten H-methylmorpholine EF oxide with addition of 2 % ITa ₂ SO ₂

85 ⁰ C dissolved for 30 minutes. The cellulose concentration was 5 % <y The regeneration of the cellulose was carried out as described in Example 1. DP = 482 «

4. Pichensulfitzellstoff (DP 720) was dissolved in molten N-methylmorpholine N-oxide with the addition of 2 % glucose at 85 ⁰ G for 30 minutes. The cellulose concentration was 5 %. The regeneration of the cellulose was carried out as described in Example 1. DP = 487 *

5th Comparative Example

Pichtensulfitzellstoff (DP 300) .120 minutes was dissolved in a molten IT-methylmorpholine-K OSD d at 85 ⁰ C. Cellulase concentration-b was 4j5%. The. Regeneration of the C _e llulose carried out as described in Example. 1 DP = 240.

6. Pichensulfitzellstoff was dissolved in molten UT-methylmorpholine H-oxide with the addition of 10 % urea based on Rl-methylmorpholine-H-ozid at 85 ⁰ C for 120 minutes. The cellulose concentration was 4.5. / S The regeneration of the cellulose was carried out as described in Example 1. DP = 290.

Claims (1)

229503 0 Brfindungsanspruch Process for reducing cellulose degradation in cellulose solutions containing aminoxides, characterized in that the cellulose used for the preparation of the gelulose solution. Solvents Amine, urea, hydroxylamine, hydrazine, sulfites, thiosulfates, dithionites, thiourea, sulfur, aldehydes,
reducing sugars or theirs. Derivatives alone or in
Containing mixtures and / or these are added during the preparation and / or processing of the cellulose solution