Salicylic acid copolymers and their metal salts, production process thereof, color-developing agents comprising metal salts of the copolymers, and color-developing sheets employing the agents
US5023366A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1987 |
| Grant date | Jun 11, 1991 |
| Priority date | — |
| Expiry date | Oct 23, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41M5/155
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed herein are salicylic acid copolymers having a weight average molecular weight of 500-10,000 and obtained (a) by condensing salicylic acid (i) with a benzyl alcohol (ii) and/or benzyl ether (iii) or a benzyl halide (iv) in the presence of an acid catalyst or (b) by reacting a co-condensation resin of (i) and (ii) and/or (iii) with (iv) or (c) by reacting a co-condensation resin of (i) and (ii) and/or (iii) or (iv) with a styrene derivative in the presence of an acid catalyst; multivalent metal salts of the salicylic acid copolymers; color-developing agents comprising the multivalent metal salts; and color-developing sheets suited for pressure-sensitive copying paper and comprising the color-developing agents. Their production processes are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.