SILICONE TYPE CINNAMIC ACID DERIVATIVE, PREPARATION METHOD THEREOF, UV-RAY ABSORBER, AND EXTERNAL SKIN TREATMENT AGENT

摘要

SILICONE TYPE CINNAMIC ACID DERIVATIVE,PREPARATION METHOD THEREOF, UV-RAYABSORBER, AND EXTERNAL SKINTREATMENT AGENTABSTRACT OF THE DISCLOSUREA silicone type cinnamic acid derivative which is asiloxane having at least one unit represented by theformula (I): (I)and having the other units which may exist in thesiloxane being represented by the formula:O(4-m)/2SiR3mwherein R1 represents an alkyl group having 1 to 4carbon atoms, a phenyl group, or a trimethylsiloxygroup, R2 is a divalent hydrocarbon group having atleast two carbon atoms, which may include aheteroatom O, X is an alkoxy group, n is an integer of 0to 3, a is an integer of 2 or 3, R3 is an alkyl grouphaving 1 to 4 carbon atoms, a phenyl group, or atrimethylsiloxy group, and m is an integer of 0 to 3.The novel derivatives of the invention are useful inexternal skin treatment compositions, especially forUV-ray absorption to prevent sunburn.