Microcapsules comprising hydroxyalkyl cellulose

Abstract

The application describes an aqueous dispersion of microcapsules, wherein the shell of the microcapsules comprises at least one polyuria and the core comprises one or more lipophilic components with the proviso that the core does not contain a fragrance, and having a percentage of the shell weight with reference to the total weight of the capsules of 5 to 40% and wherein the microcapsules have a volume average diameter of 15 to 90 μm and the dispersion comprises hydroxyalkylcellulose and the use of such a dispersion.

1 . An aqueous dispersion of microcapsules, wherein:
 a shell of the microcapsules comprises at least one polyurea and a core comprises one or more lipophilic components with the proviso that the core does not contain a fragrance, and having a percentage of the shell weight with reference to a total weight of the microcapsules of 5 to 40%;   the microcapsules have a volume average diameter of 15 to 90 μm;   the dispersion comprises hydroxyalkylcellulose as a stabilizing agent; and   a ratio of the shell weight percentage to the volume average diameter of the microcapsules is at most 0.7 μm −1 .   
     
     
         2 . The microcapsule dispersion according to  claim 1 , wherein a ratio of the shell weight percentage to the volume average diameter of the capsules is at most 0.5 μm −1 . 
     
     
         3 . The microcapsule dispersion according to  claim 1 , wherein a nominal rupture stress of the capsules is in a range of 0.1 to 2 MPa. 
     
     
         4 . The microcapsule dispersion according to  claim 1 , wherein the lipophilic components are selected from components having a solubility in water of ≤10 mg/mL at 20° C. 
     
     
         5 . The microcapsule dispersion according to  claim 1 , wherein a viscosity of the dispersion is ≤4 Pa s, measured on a rheometer with rotating discs at a shear rate of 21 s −1  and at a temperature of 25° C. 
     
     
         6 . The microcapsule dispersion according to  claim 1 , wherein an amount of the hydroxyalkylcellulose is 0.05 to 1.2% by weight based on the total weight of the dispersion. 
     
     
         7 . The microcapsule dispersion according to  claim 1 , wherein the hydroxyalkylcellulose comprises at least one hydroxyethylcellulose. 
     
     
         8 . The microcapsule dispersion according to  claim 1 , wherein the lipophilic component is selected from the group consisting of oil bodies, UV-filters, biocides, dyes, emollients, vitamins, cosmetically active ingredients, pharmaceutically active ingredient, cosmetically and pharmaceutically acceptable auxiliaries, detergents, and mixtures thereof. 
     
     
         9 .- 12 . (canceled) 
     
     
         13 . The microcapsule dispersion according to  claim 3 , wherein the nominal rupture stress of the capsules is in a range of 0.2 to 1.5 mPa. 
     
     
         14 . The microcapsule dispersion according to  claim 3 , wherein the nominal rupture stress of the capsules is in a range of 0.4 to 1 mPa. 
     
     
         15 . The microcapsule dispersion according to  claim 1 , wherein the microcapsules have a percentage of the shell weight with reference to a total weight of the microcapsules of 10 to 20%. 
     
     
         16 . The microcapsule dispersion according to  claim 1 , wherein a ratio of the shell weight percentage to the volume average diameter of the capsules is in a range from 0.2 μm −1 . 
     
     
         17 . The microcapsule dispersion according to  claim 1 , wherein a ratio of the shell weight percentage to the volume average diameter of the capsules is in a range from 0.2 μm −1  to 0.6 μm −1 .