Method for dissolving cellulose and method for preparing regenerated fiber

A technology of regenerated cellulose and cellulose, applied in the direction of artificial filaments in cellulose solution, can solve the problems of lower quality of cellulose products, short time, uneven solution, etc., to avoid cellulose degradation and increase cellulose concentration , The effect of environmental protection in the manufacturing process

Active Publication Date: 2013-06-12
CHINESE TEXTILE ACAD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The above-mentioned sodium hydroxide / sodium zincate / urea mixed aqueous solution solvent system, because zinc ions are toxic, has strong toxicity to freshwater plants and plankton, and is not suitable for industrial applications; the above-mentioned freezing-thawing technical scheme has been proved by practice. Keep the mixed slurry of cellulose and solvent under freezing conditions (-20°C) for 3 to 8 hours to freeze into ice, and then thaw to dissolve the cellulose to obtain a cellulose solution, which is not easy to industrialize; Pretreat cellulose with sodium oxide or lithium hydroxide aqueous solution, then add urea or thiourea aqueous solution to dissolve, or directly dissolve cellulose in a cooled alkali (sodium hydroxide or lithium hydroxide) / urea or (and) thiourea mixed aqueous solution The method of dissolving and preparing regenerated cellulose fibers has the following disadvantages: the time for maintaining a stable solution state is short, and irreversible gels are easily formed, and high or low temperatures will lead to gelation, especially in terms of cellulose concentration or molecular weight. Higher solution stability is worse; the solvent system still lacks strong dissolving power, and the cellulose concentration that can reach a uniform solution is low; When alkali cellulose is used, it is easy to cause rapid degradation of cellulose, which will significantly reduce the quality of cellulose products made from this cellulose solution.
Disclosed in the publication number CN 101397369A is a sodium hydroxide / polyethylene glycol aqueous solution solvent system and a method for directly dissolving cellulose by freezing-thawing or in a pre-cooled solvent system, but practice has proved that the solvent system can dissolve Microcrystalline cellulose and regenerated cellulose, but the ability to dissolve natural cellulose such as cotton pulp and wood pulp is limited

Method used

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  • Method for dissolving cellulose and method for preparing regenerated fiber

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0052] 3.6g of dried wood pulp (polymerization degree 400) and 40g of 7.5 wt% sodium hydroxide / 11.0 wt% urea / 1.5 wt% polyethylene glycol (molecular weight 800) mixed aqueous solution were kneaded and sheared at 8 °C to mix evenly, Then add 60g of 7.5 wt% sodium hydroxide / 11.0 wt% urea / 1.5 wt% polyethylene glycol (molecular weight 800) mixed aqueous solution with a temperature of -15°C, and place it at 25°C for kneading and shearing to mix evenly, and the fibers The element can be completely dissolved to obtain a uniform and transparent cellulose solution. The cellulose solution was stored at room temperature for 35 days without significant gelation.

Embodiment 2

[0054] 3.8g dry bamboo pulp (polymerization degree 400) and 30g 9.2 wt% sodium hydroxide / 4.5 wt% thiourea / 0.4 wt% polyethylene glycol (molecular weight 4000) mixed aqueous solution were kneaded and sheared at 25°C , and then add 70g of 9.2wt% sodium hydroxide / 4.5wt% thiourea / 0.4wt% polyethylene glycol (molecular weight 4000) mixed aqueous solution at a temperature of -8°C, and place it at -2°C for kneading and shear mixing Evenly, the cellulose can be completely dissolved to obtain a uniform and transparent cellulose solution. The cellulose solution was stored at room temperature for 35 days without significant gelation.

Embodiment 3

[0056] 5.0 g of dry cotton pulp (polymerization degree 500) and 70 g of 5.0 wt% lithium hydroxide / 12.0 wt% urea / 5.5 wt% polyethylene glycol (molecular weight 150) mixed aqueous solution were kneaded and sheared at 0 °C to mix evenly, Then add 30g of 5.0wt% lithium hydroxide / 12.0wt% urea / 5.5wt% polyethylene glycol (molecular weight 150) mixed aqueous solution at a temperature of -15°C, and knead and shear at -8°C to mix evenly. The cellulose can be completely dissolved to obtain a uniform and transparent cellulose solution. The cellulose solution was stored at room temperature for 35 days without significant gelation.

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Abstract

The invention discloses a method for dissolving cellulose. The method comprises the following steps: at the temperature of 0-25 DEG C, firstly mixing the cellulose and solvent uniformly through kneading and shearing, wherein the solvent accounts for 30-70% of total weight of the solvent with dissolved cellulose; then adding the remaining solvent with dissolved cellulose at the temperature of -15 DEG C to 5 DEG C, and mixing uniformly at the temperature of -8 DEG C to 25 DEG C through kneading and shearing to obtain cellulose solution, wherein the solvent is aqueous solution containing alkali, urea / thiurea and polyethylene glycol. The method can prevent the formation of colloidal particles, micelles and white cores in the dissolving of the cellulose, thereby well dissolving the cellulose and obtaining the uniform solution; spinning solution obtained from deaerating the cellulose solution is subjected to secondary coagulating bath the saline solution of which is coagulating solution to obtain cellulosic fiber, the recycling cost of the solvent and coagulator can be greatly lowered, fast coagulation can be avoided, the drawing orientation degree can be improved, and the regenerated cellulosic fiber with better strength can be manufactured.

Description

[0001] The present invention is a divisional application of the invention patent application number 201110223103.0 and the title of the invention is "a method for dissolving cellulose and a method for preparing regenerated fiber". The filing date of the original application is August 4, 2011. technical field [0002] The present invention relates to a method of dissolving cellulose, and a method of producing regenerated cellulose fibers. Background technique [0003] Cellulose is a natural biopolymer material with abundant reserves in nature. It has the characteristics of renewability, biodegradability, biocompatibility, and derivatization. It is widely used in textiles, papermaking, medical treatment, hygiene, and environmental engineering. It is a regenerated cellulose fiber, with its unique luster, good hygroscopicity and textile processability, it has always been an important textile fiber. However, due to the presence of strong intramolecular and intermolecular hydrogen...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F2/02
Inventor 朱庆松程春祖孙玉山李晓俊
Owner CHINESE TEXTILE ACAD
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