| abstract |
Compounds of the general formula I (see formula I) wherein R1 and R2 each independently are C2-C18 alkyl or C5-C7 cycloalkyl, or C2-C18 alkyl in which at least one methylene group is replaced by oxygen; R3 is hydrogen, C1-C18 alkyl or C2-C18 alkyl in which at least one methylene group is replaced by oxygen, or is C1-C18 alkyl carbonyl, C3-C18 alkenyl, C3- C18 alkynyl or a group YS; R4 is hydrogen, C1-C8 alkyl or a group OR3; Y is a linker group; Z is a silane-, an oligosiloxane- or a polysiloxane-moiety. are effective in absorbing ultra violet radiation and can be used as sunscreen agents. |