Patent ID: 6645479
Filing Date: 2003-11-11
Classification: A61K,A61Q,G01N

Abstract:
A fragranced hair care composition comprising an unfragranced hair care base and intimately admixed therewith a perfuming quantity and concentration of a microparticulate encapsulated fragrance composition comprising substantially ellipsoidal hydrophobic particles, each of which has a continuous outer surface and an internal matrix volume consisting essentially of:i. a single phase solid solution of a matrix material selected from the group consisting of at least one hydrophobic polymer selected from the group consisting of a polyamide having a molecular weight in the range of from about 6,000 up to about 12,000 and at least one hydrophobic wax selected from the group consisting of carnauba wax, candelilla wax, mixtures of cetyl palmitate with carnauba wax, mixtures of cetyl palmitate with candelilla wax, ozokerite wax, ceresin wax low density polyethylene wax having a molecular weight in the range of from about 500 up to about 6,000, each of which polymer and wax has a melting point in the range of from about 35Â° C. up to about 120Â° C. at 1 atmosphere pressure, having dissolved therein at least one hydrophobic fragrance material, each of said substantially ellipsoidal hydrophobic particles having an outer surface and an internal matrix volume; and ii. a substantially hydrophilic surfactant which is either a cationic surfactant, an anionic surfactant, a nonionic surfactant or a zwitterionic surfactant and which is selected from the group consisting of a cationic modified starch in admixture with a partially-hydrolyzed polyvinyl acetate having a degree of hydrolysis of between about 73% up to about 99% and having a molecular weight in the range of from about 5,000 up to about 67,000, tetra(2-hydroxypropyl)ethylenediamine, a cetyl trimethylammonium halide, a quaternary ammonium polysilane derivative in admixture with a partially-hydrolyzed polyvinyl acetate having a degree of hydrolysis of between about 73% up to about 99% and having a molecular weight in the range of from about 5,000 up to about 67,000, and a cationic polysaccharide derivative, said hydrophilic surfactant: (a) being substantially entirely coated on and fixedly bonded to the entirety of the outer surface of the single phase solid solution in the form of a submicron layer of surfactant, or (b) being located proximate to and immediately, substantially beneath the entirety of the outer surface of the solid solution and substantially within the said internal matrix volume, or (c) being both substantially entirely coated on and fixedly bonded to the entirety of the outer surface of the single phase solid solution in the form of a submicron layer of surfactant, and being located proximate to and immediately, substantially beneath the entirety of the outer surface of the solid solution and substantially within the said internal matrix volume, whereby when the surfactant is a cationic surfactant, the particle is positively charged, when the surfactant is an anionic surfactant, the particle is negatively charged, when the surfactant is a nonionic surfactant, the particle has a neutral charge and when the surfactant is a zwitterionic surfactant, the particle has a variable charge, each of the components of said fragrance material having a vapor pressure in the range of from 0.0001 mm/Hg up to 2.0 mm/Hg at 25Â° C. and a calculated log10P in the range of from about 1 up to about 8 wherein P is the partition coefficient of the fragrance material between n-octanol and water, said hydrophobic particle having an outside diameter in the range of from about 0.50 up to about 20 microns, the concentration of fragrance material in said polymer or said wax being from about 5% up to about 60% by weight of said particle, the weight percent of said surfactant being from about 0.01% up to about 5% by weight of said particle, with said wax, said surfactant and said polymer each being non-reactive with said fragrance material and one another, prepared by means of a process comprising the steps of: (1) intimately admixing at least one hydrophobic fragrance material with at least one hydrophobic polymer and/or at least one hydrophobic wax to form a first liquid single phase mixture at a temperature greater than or equal to the melting point of said polymer, said wax, or in the case of mixtures, the melting point of the highest melting point component of the materials in the mixture; (2) intimately admixing a surfactant with an aqueous composition comprising water to form a second mixture which is an aqueous solution; (3) blending said first mixture and said second mixture at a temperature of between 60Â° C. and the boiling point of said aqueous composition whereby a micro emulsion is formed; and (4) causing the hydrophobic perfume-containing composition in the solid phase to form as an aqueous suspension of solid-phase particles wherein the weight percent for forming said first mixture is in the range of from about 5% up to about 60% by weight of said first mixture; and wherein the weight percent of surfactant in the second mixture is from about 0.01% up to about 5% by weight of said second mixture.