| 摘要 |
A compound of formula: wherein R1, R2 are selected from an alkyl, alkenyl, alkoxy, aryl and alkylene aryl group having from 6-22 carbon atoms; X1, X2 selected from -OC(O)-, -CO2- and O; R3, R4 and R5 are selected from hydrogen, alkyl, cycloalkyl, alkenyl, alkoxy, aryl and alkylene aryl group; R6 is selected from hydrogen, R3, -X1R1, aryl and halogen; Y1, Y2, Y3 and Y4 are selected from hydrogen, R3, -OR3 and halogen; a is 0-4; b is 0 or 1; x and y are independently 0 or 1 provided that where x and y are 0, a is 0 and b is 1 and R6 is -CO2R1; and wherein when a is 0 and b is 1 and R5 or R6 is phenyl, R6 and R5 respectively are not hydrogen or C1-7 alkyl. A thermochromic composition is disclosed, comprising said compound, an electron-donating organic colouring compound and an electron-accepting compound. Further disclosed is a thermochromic microencapsulated pigment and an ink composition for a writing implement. Also disclosed is an indicator comprising a portion of thermochromic composition, pigment or ink in its coloured state and a portion of the same composition, pigment or ink in its discoloured state. |
