Influences of Reactive Capping Rate of Cationic Hydrophilic Polyurethane Capped with Coupling Agent on its Color Fixing Properties

A sort of special cationic hydrophilic polyurethane with moderate chemical reactivity is prepared as anti-crocking agent of fabric dyed with reactive dyes. Influences of chemical reactivity and processing parameters such as quaterization and end-group capping conditions of auxiliaries on its application properties are studied. The results imply that moderate reactive capping rate of cationic hydrophilic polyurethane (about 13%), quaterization conditions of 55-60°C ×30-40min and end-group capping conditions of 50°C×40min are optimum. The deep color fabric treated with our auxiliary takes on a higher wet rubbing fastness than the untreated one by 1-1.5 grade and the hydrophility and soft handle of the fabric are better than the fabric treated with traditional color fixing agent.