Microemulsion-type cosmetic and method for manufacturing same

Abstract

A fine emulsion-type cosmetic comprises a finely-emulsified oil phase mainly based on a silicone oil or hydrocarbon oil without use of a high-pressure emulsifying apparatus, and optionally has an average emulsion particle size of 150 nm or less comprising: an aqueous phase as a continuous layer; an oil phase dispersed in the aqueous phase and comprising 82% by mass or more of a silicone oil and a hydrocarbon oil therein; a carboxy-modified silicone represented by the following formula (1); a C16 to 22 higher alcohol; a nonionic surfactant having a POE chain and an HLB of 5 to 10; and a dihydric glycol; wherein R 1 and R 2 are respectively a functional group represented by —O—Si(R 4 ) 3 in which R 4 is an alkyl group having 1 to 6 carbon atoms; R 3 is a monovalent hydrocarbon group having 1 to 10 carbon atoms; M is a hydrogen atom, metal atom, or organic cation; A is a linear or branched alkylene group represented by C q H 2q ; and q is an integer of 6 to 20.

1 .- 4 . (canceled) 
     
     
         5 . A fine emulsion cosmetic, comprising:
 an aqueous phase that is a continuous layer;   an oil phase that is dispersed in said aqueous phase and comprises at least 82% by mass of a silicone oil and a hydrocarbon oil;   a carboxy-modified silicone;   a higher alcohol having 16 to 22 carbon atoms;   a nonionic surfactant having a POE chain and an HLB of 5 to 10; and   a dihydric glycol;   said fine emulsion has an average emulsion particle size at largest 150 nm; said carboxy-modified silicone is represented by a formula (1)   
       
         
           
           
               
               
           
         
         wherein each of R 1  and R 2  is a functional group represented by —O—Si(R 4 ) 3  in which R 4  is an alkyl group having 1 to 6 carbon atoms; R 3  is a monovalent hydrocarbon group having 1 to 10 carbon atoms; M is a hydrogen atom, a metal atom, or an organic cation; A is one of a linear and a branched alkylene group represented by C q H 2q ; and q is an integer of 6 to 20. 
       
     
     
         6 . The cosmetic according to claim  1 , wherein:
 a mass ratio of an amount of said silicone to an amount of said hydrocarbon oil in said oil phase is 1:9 to 9:1.   
     
     
         7 . The cosmetic according to claim  1 , wherein:
 a mass ratio of an amount of an oil agent to a combined amount of said carboxy-modified silicone, said higher alcohol and said nonionic surfactant 1.5 or less.   
     
     
         8 . A method of producing a fine emulsion-type cosmetic comprising the steps of:
 preparing a microemulsion by mixing an acid moiety of a carboxy-modified silicone represented by a formula (1), a higher alcohol, a nonionic surfactant, an oil phase, at least one of an organic amine and alkali metal, a first portion of an aqueous phase, and a dihydric glycol; and   diluting by adding a second portion of said aqueous phase to said microemulsion;   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are respectively a functional group represented by —O—Si(R 4 ) 3  in which R 4  is an alkyl group having 1 to 6 carbon atoms; R 3  is a monovalent hydrocarbon group having 1 to 10 carbon atoms; M is a hydrogen atom, metal atom, or organic cation; A is a linear or branched alkylene group represented by C q H 2q ; and q is an integer of 6 to 20. 
       
     
     
         9 . The method, according to  claim 8 , wherein:
 a mass ratio of an amount of an oil agent to a combined amount of said carboxy-modified silicone, said higher alcohol and said nonionic surfactant 1.5 or less.