Inorganic compound-coated pigments and cosmetics using the same

Abstract

White or colored pigments which do not suffer from color tone or hiding performances thereof even when the surface is moistened with water or oil, without spoiling coloring performance or hiding performance of the pigments themselves. These pigments are surface-coated with an inorganic compound having the refractive index of 1.8 or below. The inorganic compound is preferably silicon oxide, and the pigments are preferably inorganic pigments comprising titanium oxide, zinc oxide, or iron oxide. The cosmetics of the invention are blended the pigments therein.

1 . A method of manufacturing pigments, comprising: 
 preparing a dispersion of pigment particles, and    adding a silicic acid solution to the dispersion of the pigment particles to have silicic acid polymer deposited on surfaces of the pigment particles so that the surfaces of the pigment particles are coated homogeneously with the silicic acid polymer having refractive index of at most 1.8.    
     
     
         2 . A method of manufacturing pigments according to  claim 1 , wherein said pigment particles have a decrease rate of a color difference defined by Hunter's color difference formula defined in 6.3.2 of JIS Z 8730 in a range from 55 to 84% when caprylic triglyceride is mixed at a (pigments)/(caprylic triglyceride) mixing ratio of 84/16 by weight so that a change of color of the pigment particles when caprylic triglyceride is added to the pigment particles is reduced.  
     
     
         3 . A method of manufacturing pigments according to  claim 1 , wherein said pigment particles have a decrease rate of a color difference defined by Hunter's color difference formula defined in 6.3.2 of JIS Z 8730 in a range from 70 to 89% when water is mixed at a (pigments) / (water) mixing ratio of 84/16 by weight so that a change of color of the pigments when water is added to the pigments is reduced.  
     
     
         4 . A method of manufacturing pigments according to  claim 1 , wherein said pigment particles are selected from the group consisting of, as inorganic pigments, titaniumoxide, zincoxide, zirconiumoxide, cerium oxide, Indian red, yellow iron oxide, black iron oxide, ultramarine blue, darkblue, bariumsulfate, titanatedmica, mica, sericite, talc, bentonite, kaolin and mixed pigments with a color of human skin formed of titanium oxide and iron oxide, and as organic pigments, Red No. 202, Red No. 203, Red No. 204, Red No. 205, Red No. 207, Orange No. 203, Orange No. 204, Yellow No. 205, Blue No. 201 and Blue No. 204.  
     
     
         5 . A method of manufacturing pigments according to  claim 1 , wherein said silicic acid polymer is coated onto the pigment particles in a range of 1-40 weight parts relative to 100 weight parts of the pigment particles.  
     
     
         6 . A method of manufacturing pigments according to  claim 1 , wherein said pigment particles have an average diameter between 0.1 and 1 μm.  
     
     
         7 . A method of manufacturing cosmetics comprising adding the pigment particles with the silicic acid polymer thereon according to  claim 1  to the cosmetics.  
     
     
         8 . A method of manufacturing cosmetics according to  claim 7 , wherein said pigment particles with the silicic acid polymer are included in the cosmetics in a range of 1-80 wt %.  
     
     
         9 . A method of manufacturing pigments, comprising: 
 preparing a dispersion of pigment particles, and    adding a hydrolytic organic silicon compound or organic aluminum compound to the dispersion of the pigment particles so that the organic compound is hydrolyzed to form inorganic coating films on surfaces of the pigment particles, said surfaces of the pigment particles being coated homogeneously with the inorganic compound films having refractive index of at most 1.8.    
     
     
         10 . A method of manufacturing pigments according to  claim 9 , wherein said pigment particles have a decrease rate of a color difference defined by Hunter's color difference formula defined in 6.3.2 of JIS Z 8730 in a range from 55 to 84% when caprylic triglyceride is mixed at a (pigments)/(caprylic triglyceride) mixing ratio of 84/16 by weight so that a change of color of the pigment particles when caprylic triglyceride is added to the pigment particles is reduced.  
     
     
         11 . A method of manufacturing pigments according to  claim 9 , wherein said pigment particles have a decrease rate of a color difference defined by Hunter's color difference formula defined in 6.3.2 of JIS Z 8730 in a range from 70 to 89% when water is mixed at a (pigments) / (water) mixing ratio of 84/16 by weight so that a change of color of the pigments when water is added to the pigments is reduced.  
     
     
         12 . A method of manufacturing pigments according to  claim 9 , wherein said pigment particles are selected from the group consisting of, as inorganicpigments, titaniumoxide, zincoxide, zirconiumoxide, cerium oxide, Indian red, yellow iron oxide, black iron oxide, ultramarine blue, darkblue, bariumsulfate, titanatedmica, mica, sericite, talc, bentonite, kaolin and mixed pigments with a color of human skin formed of titanium oxide and iron oxide, and as organic pigments, Red No. 5 202, Red No. 203, Red No. 204, Red No. 205, Red No. 207, Orange No. 203, Orange No. 204, Yellow No. 205, Blue No. 201 and Blue No. 204.  
     
     
         13 . A method of manufacturing pigments according to  claim 9 , wherein said inorganic compound films are coated onto the pigment particles in a range of 1-40 weight parts relative to 100 weight parts of the pigment particles.  
     
     
         14 . A method of manufacturing pigments according to  claim 9 , wherein said pigment particles have an average diameter between 0. 1 and 1 μm.  
     
     
         15 . A method of manufacturing cosmetics comprising adding the pigment particles with the inorganic compound films thereon according to  claim 9  to the cosmetics.  
     
     
         16 . A method of manufacturing cosmetics according to  claim 15 , wherein said pigment particles with the inorganic compound films are included in the cosmetics in a range of 1-80 wt %.