| abstract |
The present invention provides compounds of formula I, which are effective in absorbing ultraviolet radiation and can be used as sunscreen agents:whereinR1 and R2 are each independently C2-C18 alkyl, C5-C7 cycloalkyl, or C2-C18 alkyl in which at least one methylene group is replaced by oxygen;R3 is hydrogen, C1-C18 alkyl, C2-C18 alkyl in which at least one methylene group is replaced by oxygen, 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; andS is a silane-, an oligosiloxane- or a polysiloxane-moiety. |