Spirodipyrans useful as dye precursors for copying processes
US4029677A · kind A · utility
6Cited by
7References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 5, 1975 |
| Grant date | Jun 14, 1977 |
| Priority date | — |
| Expiry date | Jun 5, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D311/78
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
New spirodipyrans of the formula ##STR1## in which A is an optionally substituted benzene or naphthalene nucleus, B is dimethylene, trimethylene or tetramethylene substituted by from 1 to 3 alkyl groups and R.sup.1 and R.sup.2 are each alkyl of 1 to 6 carbon atoms, which may be substituted by cyano. The compounds (I) give deep blue to violet colorations with acid materials. They may be used for the manufacture of pressure-sensitive recording materials. The compounds (I) exhibit improved solubility in the solvents used for the manufacture of microcapsules.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.