Tensio-active glucoside urethanes

A glucoside alkyl urethane (I) which is composed of units of formula (II)

• A(O—CO—NH—R)s (II)
• wherein
• A represents a glucosyl unit of a starch hydrolysate molecule, the starch hydrolysate having a Dextrose Equivalent (D.E.) ranging from 1 to 47,
• (O—CO—NH—R) represents an N-alkyl aminocarbonyloxy group replacing a hydroxyl group of the glucosyl unit A, and wherein R represents a linear or branched, saturated or unsaturated alkyl group containing from 3 to 22 carbon atoms, and
• s represents the number of alkyl carbamate groups per glucosyl unit which number is expressed as a degree of substitution (DS) with said DS value ranging from about 0.01 to about 0.2.

A process for the manufacture of a glucoside alkyl urethane (I) which is composed of units of formula (II)

• A(O—CO—NH—R)s (II)
• wherein
• A represents a glucosyl unit of a starch hydrolysate molecule, the starch hydrolysate having a Dextrose Equivalent (D.E.) ranging from 1 to 47,
• (O—CO—NH—R) represents an N-alkyl aminocarbonyloxy group replacing a hydroxyl group of the glucosyl unit A, and wherein R represents a linear or branched, saturated or unsaturated alkyl group containing from 3 to 22 carbon atoms, and
• s represents the number of alkyl carbamate groups per glucosyl unit which number is expressed as a degree of substitution (DS) with said DS value ranging from about 0.01 to about 0.2, which comprises
• reacting, under anhydrous conditions, a starch hydrolysate with a D.E. between 1 and 47, dissolved in a first solvent, with such an amount of alkyl isocyanate that an urethane (I) is produced having a degree of substitution (DS) ranging from 0.01 to 0.2, the first solvent being inert with respect to the glucoside, the isocyanate and the urethane (I), followed (i) by precipitation of the formed urethane (I), optionally after partial removal of the first solvent by evaporation under reduced pressure, either by addition under stirring of a precipitant solvent to the reaction mixture or by slowly pouring under stirring the, optionally concentrated, reaction mixture into a precipitant solvent, followed by isolation of the precipitated urethane (I), treating or washing of the urethane (I) with a precipitant solvent, and drying of the urethane (I) to a water content of less than 0.5 wt. %, or (ii) by spraying the reaction mixture in a stream of CO2 under about 200 bar, with subsequent isolation, optionally washing with a precipitant solvent, and drying of the obtained urethane (I) wherein the temperature is maintained below 80° C. throughout the entire process.