PROCESS FOR THE MODIFICATION OF STARCH IN AN AQUEOUS MEDIUM

摘要

The present invention is concerned with the modification of starch by means of silanes. The modification takes place in such manner that the starch is brought into intimate contact with the hydrolysates of the silanes in the presence of alkali aluminates. Preferably this takes place in the aqueous solution of the silane hydrolysate; in which case the additives can be used either in aqueous solution or in solid form. The aluminate and the alkali hydroxide must be present in such amounts that 0.4 mol of aluminate is present per mol of silane. The modification is not only possible with alkylalkoxy silanes, but also with organofunctional alkoxysilanes. The starch modified with the silanes shows better working properties than corresponding unmodified starch. It can be used, for instance for the hydrophobation and oleophobation of cellulose containing material.