| 摘要 |
<p>Compounds having the formula wherein R1 and R2 are alkyl, cycloalkyl, phenyl, alkyl substituted phenyl, benzyl or alkyl substituted benzyl, R3 and R4 are both independently hydrogen or lower alkyl M is a metal, and n has a value of from 1 to 4, are good light stabilizers. The metal salts of this invention are prepared by reacting the appropriate amino acid or its alkali metal salt with a reactive form of the metal or metal complex.</p> |
