Linear salicylic acid copolymers and their metal salts, production process thereof, color-developing agents comprising metal-resins of the copolymers
US4783521A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 1987 |
| Grant date | Nov 8, 1988 |
| Priority date | — |
| Expiry date | Jan 16, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G61/10
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed herein are novel linear copolymers having weight average molecular weight of 500-30,000 and comprising structural units represented by the following formulae (I), (II), (III) and (IV): ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 mean individually an alkyl group having 4 or fewer carbon atoms and R.sub.4 denotes an alkyl, cycloalkyl, aralkyl or phenyl group, and multivalent metal salts thereof in each of which the multivalent metal forms the multivalent metal salt between carboxyl groups within the same molecule of the copolymer or between different molecules of the copolymer; color-developing agents comprising multivalent metal-modified resins of the copolymers; and color-developing sheets obtained by coating the color-developing agents on their surfaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.