Oil and water emulsions and emulsification systems

Abstract

Disclosed are improved oil and water emulsions and improved oil and water emulsification systems. Also disclosed are methods and compositions for increasing the sun protection factor of oil and water sunscreen emulsions comprising adding a phthalic acid derivative to an oil and water sunscreen emulsion in an amount effective to increase the sun protection factor of the emulsion, the phthalic acid derivative having the general formula: where R represents an organic substituent, X represents a cation; and m is an integer satisfying the valency of X.

What is claimed is:  
     
         1 . A water and oil emulsification system comprising: 
 (a) a phthalic acid derivative having the formula:                          where    represents C 8 -C 40  alkyl, C 8 -C 40  alkenyl, alkylaryl where the alkyl portion is C 8 -C 40  alkyl, aryl, C 3 -C 7  cycloalkyl, or R 1 —O—R 2  where R 1  and R 2  independently represent C 1 -C 22  alkyl, C 1 -C 22 alkenyl, alkylaryl where the alkyl portion is C 1 -C 22  alkyl, aryl, or C 3 -C 7  cycloalkyl;    X represents a cation; and    m is an integer satisfying the valency of X; and    (b) a secondary emulsifier selected from 
 (1) polyacrylic acid-based emulsifiers;  
 (2) polyglycerol esters;  
 (3) phospholipids; or  
 (4) carboxylic copolymers containing a crosslinking monomer selected from the group consisting of triallylisocyanurate, triallyl trimellitate and glyoxal bis(diallyl acetal) in combination with an ethoxylated glyceride surfactant ester with an HLB value greater than 10; or  
 (5) mixture thereofs.  
   
     
     
         2 . An oil in water emulsion comprising water, at least one oil, and an effective emulsifying amount of the emulsification system of  claim 1 .  
     
     
         3 . An emulsion according to  claim 2 , wherein X is a cation selected from the group consisting of sodium, potassium, triethanolammonium, and ammonium.  
     
     
         4 . An emulsion according to  claim 2 , wherein R is C 10 -C 22  alkyl.  
     
     
         5 . An emulsion according to  claim 2 , where X is a sodium ion and R represents an alkyl group having an average of from 16-18 carbon atoms.  
     
     
         6 . An emulsion according to  claim 2 , where X is a sodium ion and R represents stearyl.  
     
     
         7 . An emulsion according to  claim 2 , where the composition comprises at least about 0.5% by weight of the phthalic acid derivative and at least about 0.05% by weight of the polyacrylic acid-based emulsifier.  
     
     
         8 . An emulsion according to  claim 7 , where the emulsification system is from about 0.5 to 5 % by weight of the emulsion.  
     
     
         9 . An emulsion according to  claim 8 , where X is sodium and R is stearyl.  
     
     
         10 . An emulsion according to  claim 9 , where the oil phase is from about 10-50% by weight of the composition.  
     
     
         11 . An emulsion according to  claim 10 , where the oil phase comprises at least one oil selected from the group of dimethicones, C 12 -C 18  alcohols, and C 5 -C 10  alkyl esters of C 8 -C 18  fatty acids.  
     
     
         12 . A sunscreen composition comprising an emulsion of oil and water, a sunscreen compound and an effective emulsifying amount of the water and oil emulsification system of  claim 1 .  
     
     
         13 . A composition according to  claim 12 , wherein X is a cation selected from the group consisting of sodium, potassium, triethanolammonium, and ammonium.  
     
     
         14 . A composition according to  claim 12 , wherein R is C 10 -C 22  alkyl.  
     
     
         15 . A composition according to  claim 12 , where X is a sodium ion and R represents an alkyl group having an average of from 16-18 carbon atoms.  
     
     
         16 . A composition according to  claim 12 , where X is a sodium ion and R represents stearyl.  
     
     
         17 . An emulsion according to  claim 6 , where the carboxylic copolymer is a crosslinked carboxylic copolymer comprising 
 (i) an unsaturated carboxylic acid;    (ii) an additional comonomer containing a polymerizable ethylenically unsaturated group;    (iii) a crosslinking monomer selected from the group consisting of triallylisocyanurate, triallyl trimellitate, and glyoxal bis(diallyl acetal); and    (iv) an ethoxylated glyceride compound of the formula                          wherein R represents an alkyl group of from C 8  to C 18  and the sum of x+y is from 20 to 300.    
     
     
         18 . An emulsion according to  claim 6 , where the polyacrylic acid-based emulsifier is an acrylates/C 10-30  alkyl acrylate crosspolymer.  
     
     
         19 . A method for increasing the sun protection factor of an oil and water sunscreen emulsion comprising adding a phthalic acid derivative to an oil and water sunscreen emulsion in an amount effective to increase the sun protection factor of the emulsion, the phthalic acid derivative of the formula:  
       
         
           
           
               
               
           
         
       
       where 
 R represents C 8 -C 40  alkyl, C 8 -C 40  alkenyl, alkyl where the alkyl portion is C 8 -C 40  alkyl, aryl, C 3 -C 7  cycloalkyl, or R 1 —O—R 2  where R 1  and R 2  independently represent C 1 -C 22  alkyl, C 1 -C 22  alkenyl, alkylaryl where the alkyl portion is C 1 -C 22  alkyl, aryl, or C 3 -C 7  cycoalkyl;  
 X represents a cation; and m is an integer satisfying the valency of X.  
 
     
     
         20 . A method according to  claim 19 , wherein the amount of phthalic acid derivative is about 0.1 to 15% by weight of the emulsion.  
     
     
         21 . A method according to  claim 20 , wherein the phthalic acid derivative is added to the emulsion with a low hydrophilic/lipophilic balance emulsifier.  
     
     
         22 . A method according to  claim 21 , wherein the amount of phthalic acid derivative is about 1% to 5% by weight of the emulsion.  
     
     
         23 . A method according to  claim 22 , wherein the amount of oil in the emulsion is from about 1 to 65% by weight of the emulsion.  
     
     
         24 . A method according to  claim 23 , wherein the emulsion comprises at least one sunscreen compound and the oil comprises at least one hydrophobic oil.  
     
     
         25 . A method according to  claim 24 , wherein the sunscreen compound absorbs UV-A or UV-B radiation, or UV-A and UV-B radiation.  
     
     
         26 . A method according to  claim 25 , further comprising at least one inorganic sunscreen capable of scattering, reflecting or absorbing UV radiation.  
     
     
         27 . A method according to  claim 26 , wherein the emulsion is an oil-in-water emulsion.  
     
     
         28 . A sunscreen composition comprising an emulsion of an oil, water, a sunscreen compound, and a sun protection factor enhancement system, the sun protection factor enhancement system consisting essentially of a low hydrophilic/lipophilic balance emulsifier plus a phthalic acid derivative in an amount effective to enhance the sun protection factor having the formula:  
       
         
           
           
               
               
           
         
       
       where 
 represents C 8 -C 40  alkyl, C 8 -C 40  alkenyl, alkylaryl where the alkyl portion is C 8 -C 40  alkyl, aryl, C 3 -C 7  cycloalkyl, or R 1 —O—R 2  where R 1  and R 2  independently represent C 1 -C 22  alkyl C 1 -C 22  alkenyl, alkylaryl where the alkyl portion is C 1 -C 22  alkyl, aryl, or C 3 -C 7  cycloalkyl;  
 X represents a cation; and  
 m is an integer satisfying the valency of X.  
 
     
     
         29 . A composition according to  claim 28 , wherein the amount of phthalic acid derivative is about 0.1 to 15% by weight of the emulsion.  
     
     
         30 . A composition according to  claim 29 , wherein the emulsifier is a low hydrophilic/lipophilic balance emulsifier.  
     
     
         31 . A composition according to  claim 30 , wherein the amount of phthalic acid derivative is about 1% to 5% by weight of the emulsion.  
     
     
         32 . A composition according to  claim 31 , wherein the amount of oil in the emulsion is from about 1 to 65% by weight of the emulsion.  
     
     
         33 . A composition according to  claim 32 , wherein the oil phase comprises at least one oil.  
     
     
         34 . A composition according to  claim 33 , wherein the sunscreen compound absorbs UVA and UVB radiation or UVA or UVB radiation.  
     
     
         35 . A composition according to  claim 34 , further comprising at least one inorganic sunscreen capable of scattering, reflecting and absorbing UV radiation.  
     
     
         36 . A composition according to  claim 35 , wherein the emulsion is an oil-in-water emulsion.