| 摘要 |
The present invention relates to certain novel bis-oxalic acid diamide derivatives which are especially useful as ultraviolet absorbers for organic materials. Said new bis-oxalic acid diamides correspond to the formula A1-NH-CO-CO-NH-B1-NH-CO-CO-NH-A1 wherein A1 each represents an alkyl, alkenyl, cycloalkyl, aralkyl, aryl or amino group, with these groups optionally containing further substituents, and B1 represents an alkylene or arylene grouping which is free of ethylene double bonds and may be interrupted by hetero-atoms, wherein the groups A1 and B1 must not displace the absorption maximum of these compounds to above 370m mu , and wherein at least one of the groups A1 and B1 must contain a benzene ring which is directly bonded to a -NH- group according to the above formula.
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