Patent ID: 9156919
Filing Date: 2015-10-13
Classification: C08B,C08L

Abstract:
1. A method of making a hydroxyalkyl alkylcellulose with a reduced concentration of alkylene halogenohydrin comprising the steps of: a) providing a hydroxyalkyl alkylcellulose; and b) contacting the hydroxyalkyl alkylcellulose with an acid to partially depolymerize the hydroxyalkyl alkylcellulose to a hydroxyalkyl alkylcellulose having a lower molecular weight and a lower viscosity; characterized in that after the depolymerization step b) the method comprises the following steps: c) adding water to the reaction mixture of the hydroxyalkyl alkylcellulose having the lower molecular weight and the lower viscosity, and d) removing alkylene halogenohydrin and water from the reaction mixture by evaporating.