Novel spiro-heterocyclic compounds, their preparation, and use thereof in a thermographic recording material
AssigneeLaboratoires de Physicochimie Appliquee I S S E C
InventorsAndre Samat, Robert Guglielmetti, Jacques Metzger
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Abstract
The invention relates to novel thermochromic spiro heterocyclic compounds having one or the other of the following formulae: ##STR1## where R.sub.1 denotes hydrogen atoms or one or more electron-donor groups in positions 5, 6, 7 and 8 in formula (1); R.sub.i ' denotes hydrogen atoms or one or more electron-donor or electron-acceptor groups in positions 4', 5', 6' and 7' and 4", 5", 6" and 7" in formulae (1) and (2); and R.sub.j denotes hydrogen atoms or one or more electron-donor groups in positions 5, 6, 7, 8, 9 and 10 in formula (2). Use in thermographic recording material.
Claims7
Thermochromic spiro heterocyclic compounds, selected from the group consisting of the following formulae;
- ##STR8## where R.sub.i is a substituent in positions 5, 6, 7 and 8 in formula (1);
- R.sub.i ' is a substituent in positions 4', 5', 6' and 7' and 4", 5", 6" and 7" in formulae (1) and (2);
- and R.sub.j is a substituent in positions 5, 6, 7, 8, 9 and 10 in formula (2);
- wherein R.sub.i and R.sub.j are selected from the group consisting of hydrogen, alkyl, OH, OR, NH.sub.2, NR.sub.1 R.sub.2 and NHCOR, where R, R.sub.1 and R.sub.2 each denotes an alkyl radical;
- and wherein R.sub.i ' is selected from the group consisting of hydrogen, alkyl, OH, OR, NH.sub.2, NR.sub.1 R.sub.2, NHCOR, NO.sub.2, C.tbd.N, HSO.sub.3, CHO, COR, COOH, COOR, and halogen, where R, R.sub.1 and R.sub.2 each denotes an alkyl radical.
A thermographic recording element comprising a support having thereon a layer of a thermochromic composition containing at least one thermochromic compound selected from the group consisting of those having the formula:
- ##STR10## where R.sub.i is a substituent in positions 5, 6, 7 and 8 in formula (1);
- R.sub.i ' is a substituent in positions 4', 5', 6' and 7' and 4", 5", 6" and 7" in formulae (1) and (2);
- and R.sub.j is a substituent in positions 5, 6, 7, 8, 9 and 10 in formula (2);
- wherein R.sub.i and R.sub.j are selected from the group consisting of hydrogen, alkyl, OH, OR, NH.sub.2, NR.sub.1 R.sub.2 and NHCOR, where R, R.sub.1 and R.sub.2 each denotes an alkyl radical;
- and wherein R.sub.i ' is selected from the group consisting of hydrogen, alkyl, OH, OR, NH.sub.2, NR.sub.1 R.sub.2, NHCOR, NO.sub.2, C.tbd.N, HSO.sub.3, CHO, COR, COOH, COOR, and halogen, where R, R.sub.1 and R.sub.2 each denotes an alkyl radical.
Dependencies are inferred from the claim text.