| 摘要 |
PROBLEM TO BE SOLVED: To obtain a benzylidene-gamma-butyrolactone compound useful as a UV absorbent. SOLUTION: A compound of the formula (R is H, a 1-6C alkyl or a cycloalkyl; R1-R5 are each H, provided that at most four of R1-R5 are simultaneously H, a 1-8C alkyl or a cycloalkyl; R1/R2 and/or R3/R4 mar form a carbon ring having five to seven ring carbon atoms). For example, p- methoxybenzylidene-3-ethyl-4,4-dimethyl-γ-butyrolactone. The compound of the formula, for example, by subjecting the corresponding substitutedγ-butyrolactone (for example,β-ethyl-γ,γ-dimethyl-γ-butyroaldehyde) to an aldol condensation reaction with a substituted benzaldehyde (for example, anisaldehyde). The compound of the formula is added in an amount of 0.1-15 wt.% to obtain a composition suitable for shielding injurious UV light.
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