Microcapsules with uv filter activity and process for producing them

Abstract

The invention provides a process for producing microcapsules with UV filter activity, wherein at least one type of crosslinkable chromophore with UV-A and/or UV-B and/or UV-C filter activity and optionally at least one type of crosslinkable monomer which does not have UV-A and/or UV-B and/or UV-C filter activity are subjected to a crosslinking reaction in the absence of non-crosslinkable chromophores with UV-A and/or UV-B and/or UV-C filter activity and microcapsules obtainable by this process.

1 . Process for producing microcapsules with UV filter activity, wherein at least one type of crosslinkable chromophore with UV-A and/or UV-B and/or UV-C filter activity and optionally at least one type of crosslinkable monomer which does not have UV-A and/or UV-B and/or UV-C filter activity are subjected to a crosslinking reaction in the absence of non-crosslinkable chromophores with UV-A and/or UV-B and/or UV-C filter activity.  
     
     
         2 . Process for producing microcapsules with UV filter activity according to  claim 1 , wherein at least one type of crosslinkable chromophores with UV-A and/or UV-B and/or UV-C filter activity and at least one type of crosslinkable monomer which does not have UV-A and/or UV-B and/or UV-C filter activity are subjected to a crosslinking reaction in the absence of non-crosslinkable chromophores with UV-A and/or UV-B and/or UV-C filter activity.  
     
     
         3 . Process for producing microcapsules with UV filter activity according to  claim 1 , wherein the microcapsules are produced by the sol-gel method.  
     
     
         4 . Process for producing microcapsules with UV filter activity according to  claim 1 , wherein the at least one type of crosslinkable chromophore with UV-A and/or UV-B and/or UV-C filter activity is a monomer of the formula M(R) n (P) m (Q) q , wherein M is a metallic or semi-metallic element, R is a hydrolysable group, P is a chromophore with UV-A, UV-B and/or UV-C filter activity, Q is a non-hydrolysable group, n is 2 or 3, m is 1 or 2 and q is 0 or 1, wherein n+m+q=4.  
     
     
         5 . Process for producing microcapsules with UV filter activity according to  claim 4 , wherein the chromophore P has the general formula A—(B) b (C) c (D) d (E) e — which is chemically bonded to M  
       wherein 
 A is a chromophore with UV-A and/or UV-B filter activity and —(B) b (C) c (D) d (E) e — is a spacer group in which  
 B is a linear or branched alkylene group with up to 20 carbon atoms  
 C is O, S or NH  
 D is a CONH— group  
 E is a linear or branched alkylene or alkenylene group with up to 20 carbon atoms and  
 b is 0 or 1,  
 c is 0 or 1,  
 d is 0 or 1 and  
 e is 0 or 1.  
 
     
     
         6 . Process for producing microcapsules with UV filter activity according to  claim 4 , wherein the metallic or semi-metallic element M is silicon.  
     
     
         7 . Process for producing microcapsules with UV filter activity according to  claim 4 , wherein all crosslinkable compounds used for producing the microcapsules are silicon-containing monomers.  
     
     
         8 . Process for producing microcapsules with UV filter activity according to  claim 1 , wherein the at least one type of crosslinkable chromophore with UV-A and/or UV-B and/or UV-C filter activity is a silane monomer comprising at least two C 1-6 -alkoxy groups.  
     
     
         9 . Process for producing microcapsules with UV filter activity according to  claim 8 , wherein all monomers which are used for producing the microcapsules are silane monomers comprising at least two C 1-6 -alkoxy groups.  
     
     
         10 . Process for producing microcapsules with UV filter activity according to  claim 1 , wherein the microcapsules have a particle size of 0.01-100 μm.  
     
     
         11 . Process for producing microcapsules with UV filter activity according to  claim 1 , wherein the amount of crosslinkable chromophores with UV-A and/or UV-B and/or UV-C filter activity is such that the concentration of UV absorber moieties in the final microcapsule is 10-80 w/w %.  
     
     
         12 . Microcapsules with UV filter activity made according to the process of  claim 1 .  
     
     
         13 . Sunscreen composition comprising the microcapsules as defined in  claim 12 .  
     
     
         14 . (canceled)  
     
     
         15 . Crosslinkable chromophore with UV-A and/or UV-B and/or UV-C filter activity which is a monomer of the formula 
         M(R) n (P) m (Q) q   
       wherein 
 M is a metallic or semi-metallic element,  
 R is a hydrolysable group,  
 Q is a non-hydrolysable group,  
 n is 2 or 3, m is 1 or 2 and q is 0 or 1, and wherein n+m+q=4 and P is a chromophore with UV-A, UV-B and/or UV-C filter activity with the general formula A—(B) b (C) c (D) d (E) e — which is chemically bonded to M  
 wherein  
 A is a chromophore with UV-A and/or UV-B filter activity and —(B) b (C) c (D) d (E) e — is a spacer group in which  
 B is a linear or branched alkylene group with up to 20 carbon atoms  
 C is O, S or NH  
 D is a CONH— group  
 E is a linear or branched alkylene or alkenylene group with up to 20 carbon atoms and  
 b is 0 or 1,  
 c is 0 or 1,  
 d is 0 or 1 and  
 e is 0 or 1.  
 
     
     
         16 . Crosslinkable chromophore according to  claim 15 , wherein the metallic or semi-metallic element M is silicon.  
     
     
         17 . Crosslinkable chromophore according to  claim 15 , wherein moiety A is a chromophore selected from the group consisting of acrylates, p-aminobenzoates, camphor derivatives, cinnamates, benzophenones, esters of benzalmalonic acid, esters of 2-(4-ethoxy anilinomethylene)propandioic, imidazole derivatives, salicylates, triazone derivatives, triazol derivatives, dibenzoylmethanes, amino substituted hydroxybenzophenones, phenylbenzimidazoles, anthranilates, phenyl-benzoxazoles and 1,4-dihydropyranes.  
     
     
         18 . Crosslinkable chromophore according to  claim 15 , wherein moiety A is selected from the group consisting of  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein R′ is hydrogen, hydroxy, straight or branched chain C 1-20 -alkyl, -alkoxy or C 2-20 -alkenyl.  
     
     
         19 . Crosslinkable chromophore according to  claim 15 , made by reaction of a silene of the formula Si(R) r (Q) q S, wherein R and Q are as defined in  claim 15 , S is a hydrogen atom, a —(CH 2 ) o —NCO group or a —(CH 2 ) o —NH 2  group, r is 2 or 3, q is 0 or 1 and o is 1 to 6 with a chromophore with UV-A, UV-B and/or UV-C filter activity.  
     
     
         20 . Crosslinkable chromophore according to  claim 19 , wherein the silane is selected from the group consisting of  
       
         
           
           
               
               
           
         
       
       wherein Alk is a C 1 -C 6  alkyl group.  
     
     
         21 . Crosslinkable chromophore according to  claim 19 , wherein the chromophore with UV-A, UV-B and/or UV/C filter activity is selected from the group consisting of  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein R′ is hydrogen, hydroxy, straight or branched chain C 1-20 -alkyl, -alkoxy or C 2-20 -alkenyl.  
     
     
         22 . Chromophore selected from the group consisting of  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein R′ is hydrogen, hydroxy, straight or branched chain C 1-20 -alkyl, -alkoxy or C 2-20 -alkenyl.  
     
     
         23 . Process for producing a crosslinkable monomer as defined in  claim 15  comprising the step of reacting a silane molecule with a chromophore.  
     
     
         24 . Process for producing a crosslinkable monomer according to  claim 23 , wherein the silane molecule is as defined in  claim 19 .  
     
     
         25 . Process for producing a crosslinkable monomer as defined in  claim 23 , wherein the chromophore is as defined in  claim 22.