Process for the preparation of organic pigments
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Feb 13, 1996
Grant Date -
N/A
app pub date -
May 6, 1994
filing date -
May 6, 1994
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
This invention relates to a process for the preparation of quinacridone pigments comprising (a) heating, at a temperature of about 80.degree. C. to about 145.degree. C., a reaction mixture comprising (i) 2,5-dianilinoterephthalic acid or a 2,5-dianilinoterephthalic acid derivative having one or more substituents in at least one aniline ring, (ii) about 2 to about 10 parts by weight, relative to component (i), of a strong acid, and (iii) at least about 0.4 mole percent, relative to component (i), of iron in the form of an iron salt; (b) drowning the reaction mixture from step (a) by adding said reaction mixture to about 3 to about 15 pads by weight, relative to component (i), of a liquid in which the pigment is substantially insoluble; (c) isolating the quinacridone pigment; and (d) optionally, conditioning the quinacridone pigment.
First Claim
Family
International Classification(s)
- [Classification Symbol]
- [Patents Count]
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully