INTRODUCTION OF ACID GROUPS AND HYDROPHOBIC GROUPS INTO VISCOSE RAYON AND FASTNESS TO WASHING OF THE FABRICS DYED WITH CATIONIC DYES

Abstract

In order to improve dyeing property with cationic dyes and fastness to washing, acid and hydrophobic groups were introduced into a viscose rayon fabric.Acid groups were introduced by oxidizing the fabric with sodium metaperiodate and further treating with sodium bisulfite. Hydrophobic groups were introduced by treating with various isocyanate.The relations between chemical structure of alkyl groups introduced into the fabric and washing fastness of dyed products were studied.Results were as follows:(1) The fabric being introduced the acid groups indicates good dyeing property for cationic dyes, but it shows poor fastness to washing.(2) By introducing acid and hydrophobic groups simultaneously the fabric is dyed with cationic dyes in high yield and the fastness to washing is much improved.(3) The fastness to washing is increased with carbon numbers of linear alkyl groups of the isocyanates.(4) Methyl and ethyl groups are not effective to improve the fastness to washing but propyl and buthyl groups are effective.