| 摘要 |
A reversible thermochromic system comprising a) a compound of the formula (IA) or a tautomer thereof or a compound of the formula (IB) or a tautomer thereof (IA) (IB) wherein R1 is C1-C18alkyl, C2-C18alkenyl, C3-C12cycloalkyl, C3-C12cycloalkyl substituted by 1, 2 or 3 C1-C4alkyl; phenyl, phenyl substituted by 1, 2 or 3 C1-C4alkyl; or C7-C12phenylalkyl; R2 is hydrogen or a group —SO2—R; R3 and R4 independently of one another are hydrogen, C1-C18alkyl, C2-C18alkenyl, C3-C12cycloalkyl, C3-C12cycloalkyl substituted by 1, 2 or 3 C1-C4alkyl; phenyl, phenyl substituted by 1, 2 or 3 C1-C4alkyl; or C7-C12phenylalkyl; and R is C1-C18alkyl, C2-C18alkenyl, C3-C12cycloalkyl, C3-C12cycloalkyl substituted by 1, 2 or 3 C1-C4alkyl; phenyl, phenyl substituted by 1, 2 or 3 C1-C4alkyl; or C7-C12phenylalkyl; and b) a compound containing a group of the formula (III). |
