Method of pretreatment of cellulose containing textiles

Abstract

A method for pretreatment of cellulose-containing textiles characterized by applying an aqueous solution with a pH between 1 and 7 and containing at least one agent for durably changing the surface morphology of the cellulose, preferably a neutral salt.

Description

BACKGROUNDField of the Invention[0001]The present invention relates to a method for pretreatment of cellulose containing textiles by applying an aqueous solution having a pH between about 1 and 7 and comprising at least one agent for durably changing the surface morphology of the cellulose.Background Art[0002]Enzymatic processes have been widely used in the treatment of textile substrates. In recent years, cellulose-cleaving enzymes (cellulases) have gained great importance in the textile-chemical treatment of materials containing cellulose fibers. The technically most frequently used “total crude” cellulases are a mixture of microbiologically produced endo-, exocellulases and cellobiohydrolases. The main task of the cellulases is to hydrolytically degrade cellulose by selective cleavage of the β-1,4-glycosidic bond, so that soluble debris is removed from the polymers and taken up by the treatment solution, where further hydrolysis to glucose takes place. Usually, this is done to ch...

AI Technical Summary

Benefits of technology

The patent proposes a method for improving the performance of cellulases in treating cellulosic materials, but it has several disadvantages. The use of concentrated alkaline solutions involves a risk potential and requires extensive measures for occupational safety. There is also a risk of uncontrolled carry-over of caustic soda into cellulase treatment baths, which may affect the effect of the treatment. The method requires large amounts of water for intermediate washing, leading to additional costs for both fresh water and waste water.

Problems solved by technology

In all processes, the textiles are exposed to cellulase treatments in large scale washing machines, which treatments weaken the textile through hydrolytic attack and thus support, in combination with the washing mechanics, wear of any dyes present, which leads to the development of a wash-down.

Cellulase treatments always lead to a loss of mechanical resistance of the textile, which leads to reduced strength and lower abrasion resistance of treated products compared to non-treated products.

This reduction of the use-value is an undesired result of cellulase treatment.

However, the positive effect in this case is based on pure swelling of the cellulosic backbone material and is not of durable nature (especially after drying, which eventually leads to hornification of the cellulose material and a dramatic decrease of accessible sites for further enzymatic action).

However, the working method proposed in EP2000583A1 has several disadvantages resulting from the use of concentrated alkaline preparations:From the point of view of industrial hygiene, handling of concentrated alkaline solutions involves a considerable risk potential.

Consequently, corresponding extensive measures for guaranteeing occupational safety are required to guarantee safe handling.Intermediate storage of treated materials stably over time is not possible because carbon dioxide (CO2) taken up from the air results in partial neutralization of the working solution, which may change the effect of the applied base in an indefinable, unreproducible and locally diverse way.Before the actual enzyme treatment, careful neutralization of the solutions and the treated goods is required because uncontrolled carry-over of caustic soda into cellulase treatment baths may affect or possibly even stop the effect thereof.

In that case, large amounts of buffer substances have to be used to safely intercept possible carry-over of caustic soda.The necessary intermediate washing requires large amounts of water, which leads to additional costs for both, fresh as well as resulting waste water.

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