Benefit delivery particle, process for preparing said particle, compositions comprising said particles and a method for treating substrates

Abstract

The invention provides a benefit agent delivery particle having an average diameter of less than 50 micron comprising; at least one shell formed by a step-growth polymerisation reaction, preferably involving an isocyanate monomer, more preferably a urethane and/or a urea, interior said shell, at least one region formed by chain-growth polymerisation reaction (preferably a free-radical polymerisation) which does not involve an isocyanate, c) optionally, a benefit agent interior to said shell, and/or a deposition aid exterior to said shell. The invention further provides a process for the preparation of such particles wherein the shell is formed prior to the chain-growth polymerisation of the at least one region interior of the shell, preferably be forming the shell at a temperature at which the chain-growth reaction is inhibited. The invention further provides fully formulated products, preferably liquids and gels, which contain said benefit agent delivery particles and a method of treating substrates using said products.

1 . A particle having an average diameter of less than 50 micron comprising;
 a) at least one shell formed by a step-growth polymerisation reaction,   b) interior said shell, at least one region formed by chain-growth polymerisation reaction which does not involve an isocyanate,   c) a benefit agent interior to said shell and a deposition aid exterior to said shell.   
     
     
         2 . The particle according to  claim 1  wherein the step-growth polymerisation reaction is not condensation polymerisation, preferably involving an isocyanate monomer, preferably a urethane and/or a urea. 
     
     
         3 . The particle according to  claim 1  wherein the chain-growth polymerisation reaction is a radical polymerisation reaction, preferably of at least one ethylenically unsaturated, preferably vinyllic, monomer, preferably selected from acrylate or methacryate. 
     
     
         4 . The particle according to  claim 1  which comprises a surface decoration, which is a deposition aid, substantive to proteinaceous, cellulosic, polyester or polyamide surfaces, wherein the decoration comprises a polysaccharide. 
     
     
         5 . The particle according to  claim 1  having an average diameter of less than 10 micron. 
     
     
         6 . The particle according to  claim 1  having an average diameter of less than 1 micron. 
     
     
         7 . The particle according to  claim 1  comprising a hydrophobic benefit agent, preferably an organoleptic benefit agent, preferably a flavour or fragrance. 
     
     
         8 . The particle according to  claim 1  obtainable by a method comprising;
 providing an emulsion, preferably having a mean dispersed particle size diameter of less than 1000 nm, more preferably less than 500 nm and having a dispersed non-aqueous phase comprising:
 i) a first co-monomer, capable of step-growth polymeriation with a suitable second co-monomer, said first co-monomer preferably being an isocyanate; 
 ii) an optional benefit agent, preferably an organoleptic benefit agent; 
 iii) at east one monomer capable of chain-growth polymerisation; and, 
 iv) a radical initiator, preferably peroxide or azo-, which is not significantly active at the temperature at which the first and second co-monomer undergoes step-growth polymerisation, 
 
 and, a continuous aqueous phase comprising:
 i) water, 
 ii) emulsifying agent, 
 iii) a second co-monomer, preferably a diol or diamine, 
 preferably to form a polyurethane or polyurea on reaction with the first co-monomer, 
 
 b) maintaining the emulsion at a temperature at which the step-growth polymerisation occurs but not the chain growth polymerisation, and, subsequently, 
 c) maintaining the emulsion at a temperature at which the chain-growth polymerisation proceeds, and 
 d) adding a deposition aid at the end of phase (c). 
 
     
     
         9 . A The particle according to  claim 8  wherein the at least one monomer capable of chain growth polymerisation comprises an ethylenically unsaturated, preferably vinyllic monomer, preferably acrylate or methacryate. 
     
     
         10 . The particle according to  claim 1  which further comprises at least one cross-linking agent, derived from:
 i) a more than di-functional agent having isocyanate, alcohol, or amine functionality, and/or 
 ii) a more than mono-functional vinyllic monomer, 
 
     
     
         11 . A method of treatment of a substrate, wherein the substrate is selected from skin, hair and/or textile material, the method comprising the step of treating the substrate with a composition comprising particles according to  claim 1 . 
     
     
         12 . A composition comprising a dispersion of particles according to  claim 1 , wherein the composition is a laundry detergent, laundry conditioner, deodorant, antiperspirant, shampoo, hair conditioner or skin care or skin cleansing product. 
     
     
         13 . A method of preparing the composition according to  claim 12  in which the particles and the benefit agent are added separately such that the particles take up the benefit agent in the composition. 
     
     
         14 . A particle having an average diameter of less than 50 micron comprising;
 at least one polyurethane shell;   b) interior to said shell, a solid core formed by chain growth polymerisation of ethylenically unsaturated species, preferably comprising acrylates and/or methacrylates;   c) a polysaccharide deposition aid exterior to the shell, and   d) a fragrance absorbed in the core.   
     
     
         15 . The particle according to  claim 14  haying a particle size of 50-500 nm. 
     
     
         16 . (canceled) 
     
     
         17 . (canceled)