Patent ID: 7041168
Filing Date: 2006-05-09
Classification: C04B,C08B

Abstract:
1. A process of preparing a construction material system, comprising extruding a construction material with an additive comprising an irreversibly crosslinked cellulose derivative, wherein the irreversibly crosslinked cellulose derivative is prepared by a process comprising, (a) alkalizing cellulose with aqueous alkali metal hydroxide solution in the presence of a suspension medium, (b) reacting the alkalized cellulose with one or more alkylene oxides, (c) reacting the alkalized cellulose of step-(b) with an alkyl halide present in the suspension medium, (d) subsequently or simultaneously reacting the alkalized cellulose with a crosslinker in an amount of 0.0001to 0.05 eq, where the unit “eq” represents the molar ratio of the crosslinker relative to the anhydroglucose unit (AGU) of the cellulose used, and (e) optionally performing at least one of steps (i), (ii), (iii) and (iv),