Microcapsules containing a hydrophobic, volatile core substance and their production
AssigneeKureha Kagaku Kogyo Kabushiki Kaisha
InventorsYuriko Igarashi, Masaaki Takahashi
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Abstract
Disclosed herein are microcapsules containing a hydrophobic, volatile substance as the core substance, a wall membrane of the microcapsule comprising a polymer made by interfacial polymerization of a polyvalent isocyanate with a water-soluble cationic urea resin and/or a prepolymer of aminoresin, and a resin made by polycondensing the water-soluble cationic urea resin with the prepolymer of aminoresin in the presence of a low-molecular anionic surfactant, and a process for producing the microcapsules.
Claims7
A microcapsule containing a hydrophobic, volatile substance as the core substance, wherein a wall membrane of the microcapsule comprises a polymeric material formed by the interfacial polymerization of a polyvalent isocyanate which is at least one member selected from the group consisting of tolylene diisocyanates, diisocyanate diphenylmethanes, hexamethylene diisocyanates, polymethylene polyphenyl isocyanates, triisocyanatotriphenylmethanes, dimers of tolylene diisocyanates and trimers of tolylene diisocyanates, with a water-soluble cationic urea resin and a prepolymer of an aminoresin, and a polymeric material formed by the polycondensation of the water-soluble cationic urea resin with the prepolymer of an aminoresin in the presence of a low-molecular anionic surfactant.
A process for producing a microcapsule containing a hydrophobic, volatile substance as the core substance, comprising dispersing the said hydrophobic, volatile substance containing a polyvalent isocyanate which is at least one member selected from the group consiting of tolylene diisocyanates, diisocyanate diphenylmethanes, hexamethylene diisocyanates, polymethylene polyphenyl isocyanates, triisocyanatotriphenylmethanes, dimers of tolylene diisocyanates and trimers of tolylene diisocyanates in an aqueous medium containing a water-soluble cationic urea resin, a low-molecular anionic surfactant and at least one prepolymer of aminoresin, and maintaining the pH of the resultant dispersion within an acidic range by adding an acid catalyst to interfacially polymerize the polyvalent isocyanate with the water-soluble cationic urea resin and the at least one prepolymer and to precondense the water-soluble cationic urea resin with at least one prepolymer.
The process of 13, comprising using 0.1 to 50 parts by weight of the polyvalent isocyanate contained in 100 parts by weight of the hydrophobic, volatile substance.
Dependencies are inferred from the claim text.