Amine modified polysaccharide urethane/urea microcapsules

An oil-in water microencapsulation process comprising dispersing an oil phase composition comprising a core material and an isocyanate wall forming material comprising one or more di- or poly-isocyanates, in an aqueous phase composition and subjecting the dispersion to polymerization conditions;

• said aqueous phase composition, prior to subjecting the dispersion to polymerization conditions, comprising an amine modified polysaccharide wall forming material, whereby the isocyanate and the amine modified polysaccharide form a cross-linked shell wall encapsulating the core material;
• wherein i) the amine modified polysaccharide is characterized as having from 0.005 up to 8 mole percent of the hydroxy groups substituted with a moiety having a free or reactive amino group, provided that, in the case wherein the amine modified polysaccharide is a maltodextrin the amine modified polysaccharide has at least 1 amino functional group per molecule, and ii) the weight ratio of the polysaccharide to isocyanate is from 40:60 to 99:1.

Polyurea/polyurethane microcapsules comprising the reaction product of a) one or more polysaccharides, b) one or more di- or poly-isocyanates, and c) one or more di- or poly-functional amines or aminating agents wherein the weight ratio of the polysaccharide to isocyanate is from 40:60 to 99:1 and the mole ratio of the amine or aminating agent to the isocyanate of from 15:1 to 1:7.

A microencapsulation process comprising dispersing a) an oil phase comprising a core material and an isocyanate wall forming material comprising one or more di- and/or polyisocyanates in b) an aqueous phase comprising a polysaccharide wall forming material and an amine or aminating agent of at least di-functionality wherein at least one of the functional groups is an amino functional group, and subjecting the dispersion to polymerization conditions whereby the isocyanate, the polysaccharide and the amine or aminating agent form a shell wall wherein the weight ratio of the polysaccharide to isocyanate is from 40:60 to 99:1 and the mole ratio of the amine or aminating agent to the isocyanate of from 15:1 to 1:7.