Tickener, cosmetic preparation containing the same, and process for producing the same

Abstract

The present invention is a thickener consisting of a microgel obtained by radical polymerization of water soluble ethylene-type unsaturated monomers dissolved in the dispersion phase in a composition having an organic solvent or an oil component as the dispersion medium and water as the dispersion phase, as well as a cosmetic containing said thickener. Also, the present invention is a method of manufacturing a water-swelling polymer in a radical polymerization system consisting of a composition having an organic solvent or oil component as the dispersion medium and an aqueous solution of a water soluble ethylene type unsaturated monomer as the dispersion phase wherein said system contains a surfactant chosen in such a way that the aforementioned composition forms a single phase W/O microemulsion or fine W/O emulsion at a thermal radical polymerization temperature and said thermal radical polymerization is carried out at a temperature equal to or higher than the phase transition temperature of the radical polymerization system, yet not higher than the phase transition temperature by 20° C. or more.

1 . A thickener consisting of a microgel obtained by radical polymerization of water soluble ethylene-type unsaturated monomers dissolved in the dispersion phase in a composition having an organic solvent or an oil component as the dispersion medium and water as the dispersion phase.  
     
     
         2 . A thickener consisting of a microgel obtained by radical polymerization of water soluble ethylene-type unsaturated monomers dissolved in the dispersion phase in a composition having an organic solvent or an oil component as the dispersion medium and water as the dispersion phase wherein said composition contains a surfactant and forms a single phase microemulsion or fine W/O emulsion.  
     
     
         3 . A thickener consisting of a microgel wherein the apparent viscosity of the microgel aqueous dispersion having 0.5% (mass percentage) of the microgel at 25° C. is 10,000 mPa·s or higher at a shear rate of 1.0 s −1 .  
     
     
         4 . A thickener consisting of a microgel wherein the apparent viscosity of the microgel ethanol dispersion having 0.5% (mass percentage) of the microgel at 25° C. is 5,000 mPa·s or higher at a shear rate of 1.0 s −1 .  
     
     
         5 . The thickener consisting of said microgel of  claim 3 , wherein the dynamic elastic modulus of the microgel aqueous or ethanol dispersion having 0.5% (mass percentage) of it at 25° C. satisfies the relationship G′ (stored elastic modulus)>G″ (loss elastic modulus) at a strain of 1% or less and a frequency range of 0.01-10 Hz.  
     
     
         6 . The thickener of  claim 1 , wherein said water soluble ethylene-type unsaturated monomer is an ionic acrylamide derivative and dialkylacrylamide represented by general formula (1) as follows:  
       
         
           
           
               
               
           
         
       
       (R 1  denotes a H or methyl group; R 2  and R 3 , independent of each other, denote a methyl, ethyl, propyl, or isopropyl group[[.]]).  
     
     
         7 . The thickener of  claim 1 , wherein said water soluble ethylene-type unsaturated monomer is a dialkylacrylamide represented by general formula (1) and an anionic acrylamide derivative represented by general formula (2) as follows:  
       
         
           
           
               
               
           
         
       
       (R 1  denotes a H or methyl group; R 2  and R 3 , independent of each other, denote a methyl, ethyl, propyl, or isopropyl group);  
       
         
           
           
               
               
           
         
       
       (R 4  and R 5 , independent of each other, denote a H or methyl group, R 6  denotes a straight chain or branched alkyl group having 1-6 carbon atoms, and X denotes a metal ion or NH 3 ).  
     
     
         8 . The thickener of  claim 1 , wherein said water soluble ethylene-type unsaturated monomer is a dialkylacrylamide represented by general formula (1) and an cationic acrylamide derivative represented by general formula (3) as follows:  
       
         
           
           
               
               
           
         
       
       (R 1  denotes a H or methyl group; R 2  and R 3 , independent of each other, denote a methyl, ethyl, propyl, or isopropyl group);  
       
         
           
           
               
               
           
         
       
       (R 7  denotes a H or methyl group, R 8  denotes a H or straight chain or branched alkyl group having 1-6 carbon atoms, R 9  denotes a straight chain or branched alkyl group having 1-6 carbon atoms, R 10 , R 11 , and R 12  denote a methyl group or ethyl group, and Y denotes a metal ion).  
     
     
         9 . The thickener of  claim 1 , wherein said water soluble ethylene-type unsaturated monomer is a dialkylacrylamide represented by general formula (1), an anionic acrylamide derivative represented by general formula (2), and a cross-linking monomer represented by general formula (4) as follows:  
       
         
           
           
               
               
           
         
       
       (R 1  denotes a H or methyl group; R 2  and R 3 , independent of each other, denote a methyl, ethyl, propyl, or isopropyl group);  
       
         
           
           
               
               
           
         
       
       (R 4  and R 5 , independent of each other, denote a H or methyl group, R 6  denotes a straight chain or branched alkyl group having 1-6 carbon atoms, and X denotes a metal ion or NH 3 );  
       
         
           
           
               
               
           
         
       
     
     
         10 . The thickener of  claim 1 , wherein said water soluble ethylene-type unsaturated monomer is a dialkylacrylamide represented by general formula (1), an cationic acrylamide derivative represented by general formula (3), and a cross-linking monomer represented by general formula (4) as follows:  
       
         
           
           
               
               
           
         
       
       (R 1  denotes a H or methyl group; R 2  and R 3 , independent of each other, denote a methyl, ethyl, propyl, or isopropyl group);  
       
         
           
           
               
               
           
         
       
       (R 7  denotes a H or methyl group, R 8  denotes a H or straight chain or branched alkyl group having 1-6 carbon atoms, R 9  denotes a straight chain or branched alkyl group having 1-6 carbon atoms, R 10 , R 11 , and R 12  denote a methyl group or ethyl group, and Y denotes a metal ion); and  
       
         
           
           
               
               
           
         
       
     
     
         11 . A method of manufacturing the thickener of  claim 1 , comprising radical polymerization of water soluble ethylene-type unsaturated monomers dissolved in the dispersion phase in a composition having an organic solvent or an oil component as the dispersion medium and water as the dispersion phase.  
     
     
         12 . A cosmetic containing the thickener of  claim 1 .  
     
     
         13 . A cosmetic containing the thickener of  claim 1 , and a medically acceptable carrier.  
     
     
         14 . A cosmetic containing the thickener of  claim 1 , and a cosmetically acceptable carrier.  
     
     
         15 . A method of manufacturing a water-swelling polymer in a radical polymerization system consisting of a composition having an organic solvent or oil component as the dispersion medium and an aqueous solution of a water soluble ethylene type unsaturated monomer as the dispersion phase wherein said system contains a surfactant chosen in such a way that the aforementioned composition forms a single phase W/O microemulsion or fine W/O emulsion at a thermal radical polymerization temperature and said thermal radical polymerization is carried out at a temperature equal to or higher than the phase transition temperature of the radical polymerization system, yet not higher than the phase transition temperature by 20° C. or more.  
     
     
         16 . The method of manufacturing a water-swelling polymer described in  claim 15  wherein said surfactant is a nonionic surfactant.  
     
     
         17 . The method of manufacturing the water-swelling polymer described in  claim 15  wherein the mass ratio between the water phase and the surfactant is water phase/surfactant=0.5-20 in said radical polymerization system.  
     
     
         18 . The method of manufacturing the water-swelling polymer described in  claim 15 , wherein the concentration of the surfactant is 1 mass % or more and 30 mass % or less in said radical polymerization system.  
     
     
         19 . The method of manufacturing the water-swelling polymer described in  claim 15 , wherein the apparent viscosity of the microgel aqueous dispersion having 0.5% of the aforementioned water-swelling polymer at 25° C. is 10,000 mPa·s or higher at a shear rate of 1.0 s −1 .  
     
     
         20 . The method of manufacturing the water-swelling polymer described in  claim 15 , wherein the dynamic elastic modulus of the water dispersion having 0.5% of the aforementioned water-swelling polymer at 25° C. satisfies the relationship G′ (stored elastic modulus)>G″ (loss elastic modulus) at a strain of 1% or less and a frequency range of 0.01-10 Hz.  
     
     
         21 . The method of manufacturing the water-swelling polymer described in  claim 15 , wherein said water soluble ethylene-type unsaturated monomer is a dimethylacrylamide and 2-acrylamido-2-methylpropanesulfonic acid.