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EP1069162A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Process for the continuous preparation of quinacridones

Assignee: Sun Chemical Corp
•
Filing: 2000-07-03
•
Granted: —
•
Expires: 2020-07-03
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Abstract

Abstract This invention relates to a continuous process for the preparation of quinacridone pigments by (a) preparing a reaction mixture by mixing (i) a 2,5-dianilinoterephthalic acid or ester thereof, and (ii) at least about 0.5 parts by weight, per part of component (a)(i), of a dehydrating agent; (b) passing the reaction mixture through a continuous reactor having one or more heated zones at a temperature of about 80°C to about 300°C to form a crude quinacridone composition; and (c) mixing a continuous stream of the crude quinacridone composition with a liquid in which the quinacridone pigment is substantially insoluble at a ratio of about 0.5 to about 15 parts by weight of the liquid per part by weight of the crude quinacridone composition.

Inventors

  • 👤 Thomas R. Flatt
  • 👤 Mark A. Putnam
  • 👤 Ulrich Dr. Feldhues

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-05 00:06
CPC Classifications
C; C09; C09B; C09B48/00

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 138 words
A continuous process for the preparation of quinacridone pigments comprising (a) preparing a reaction mixture by mixing (i) a 2,5-dianilinoterephthalic acid or ester thereof, and (ii) at least about 0.5 parts by weight, per part of component (a)(i), of a dehydrating agent; (b) passing the reaction mixture through a continuous reactor having one or more heated zones at a temperature of about 80°C to about 300°C to form a crude quinacridone composition; (c) mixing a continuous stream of the crude quinacridone composition with a liquid in which the quinacridone pigment is substantially insoluble at a ratio of about 0.5 to about 15 parts by weight of the liquid per part by weight of the crude quinacridone composition; (d) optionally, conditioning the resultant quinacridone pigment; and (e) optionally, blending the resultant quinacridone pigment with one or more quinacridone derivatives.
Claim 2
Dependent Claim 39 words
A process according to Claim 1 wherein the 2,5-dianilinoterephthalic acid or ester thereof is 2,5-dianilinoterephthalic acid or an ester thereof, 2,5-di(4-chloroanilino)terephthalic acid or an ester thereof, 2,5-di(4-methylanilino)terephthalic acid or an ester thereof, or 2,5-di(4-methoxyanilino)terephthalic acid or an ester thereof.
Claim 3
Dependent Claim 38 words
A process according to Claim 1 wherein in step (c) the continuous stream of the crude quinacridone composition from step (b) is mixed with a continuous stream of the liquid in which the quinacridone pigment is substantially insoluble.
Claim 4
Dependent Claim 19 words
A process according to Claim 1 wherein the dehydrating agent is polyphosphoric acid or 70 to 100% sulfuric acid.
Claim 5
Dependent Claim 16 words
A process according to Claim 1 wherein in step (c) the liquid is water and/or methanol.
Claim 6
Dependent Claim 29 words
A process according to Claim 1 wherein in step (c) the liquid is water and/or methanol containing an alkali metal hydroxide in sufficient quantities to maintain an alkaline medium.

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