Pigment red 53

Structural formula
General
Surname	Pigment red 53
other names	5-chloro-2 - [(2-hydroxy-1-naphthyl) diazenyl] -4-methylbenzenesulfonic acid ( IUPAC ) Lacquer red C
Molecular formula	C 17 H 13 ClN 2 O 4 S
External identifiers / databases
CAS number 15958-19-7 EC number 240-089-5 ECHA InfoCard 100.036.429 PubChem 21239 ChemSpider 13902209 Wikidata Q27291560
properties
Molar mass	376.8 g mol −1
Physical state	firmly
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

CI Pigment Red 53 is an azo compound from the group of β-naphthol pigments . In particular, the barium- lacquered compound Pigment Red 53: 1 plays an economically important role in printing pigments .

history

Pigment Red 53 was at Meister Lucius & Brüning, the later 1902 Hoechst AG , invented under the name Lake Red C markets. In the past, pigment processors, especially printing ink manufacturers in Central Europe, were often supplied with the sodium salt of the compound. The varnishing was then carried out by these ink factories themselves.

Manufacturing

The preparation of Pigment Red 53 by diazotization of 2-amino-5-chloro-4-methylbenzenesulfonic acid with sodium nitrite and hydrochloric acid followed by coupling with β-naphthol . The primarily obtained sodium salt of Pigment Red 53 can be laked by reaction with barium, calcium or strontium salts . Further post-treatment - for example heating in various solvents - results in crystal modifications suitable for further applications .

use

While Pigment Red 53 is of no economic importance as a free sulfonic acid, the barium salt Pigment Red 53: 1 is one of the most widely used red pigments for printing inks. It is used in particular as an inexpensive pigment for short-lived printed matter in various printing processes (e.g. flexographic printing , offset printing ). Various fastness properties ( light fastness , alkali and acid fastness) are comparatively poor, but the prints show good resistance to various organic solvents. Pigment Red 53: 1 shows good heat stability and is also used as a red pigment for various plastics, for example PVC and polystyrene . The use of Pigment Red 53: 1 in cosmetic articles is prohibited by EC Regulation No. 1223/2009, Annex 2 .

The use of Pigment Red 53, sodium salt is occasionally due to its significantly more yellow color, despite the poorer solvent and usage fastness properties.

The calcium salt, Pigment Red 53: 2 and the strontium salt, Pigment Red 53: 3, are of rather subordinate importance.

Individual evidence

1. ↑ Data sheet Pigment Red 53 from Sigma-Aldrich , accessed on December 11, 2019 ( PDF ).
2. ↑ External identifiers or database links for Pigment Red 53: 1, barium salt : CAS number: 5160-02-1, EC number: 225-935-3, ECHA InfoCard: 100.023.578 , PubChem : 21238 , ChemSpider : 17215143 , Wikidata : Q27155937 .
3. ↑ ^{a b} Willy Herbst, Klaus Hunger: Industrial Organic Pigments . Production, properties, application. VCH Verlagsgesellschaft, Weinheim 1995, ISBN 3-527-28744-2 , pp. 325 ff . ( limited preview in Google Book search).
4. ↑ Patent DE19827272 : New crystal modification of the pigment CI Pigment Red 53: 2 (gamma phase). Registered on June 19, 1998 , published on December 23, 1999 , applicant: Clariant GmbH, inventor: Martin U. Schmidt, Hans Joachim Metz. ‌
5. ↑ Regulation (EC) No. 1223/2009 (PDF)
6. ↑ External identifiers or database links for Pigment Red 53, sodium salt : CAS number: 2092-56-0, EC number: 218-248-5, ECHA InfoCard: 100.016.589 , PubChem : 135565346 , ChemSpider : 20127074 , Wikidata : Q27282927 .
7. ↑ External identifiers or database links to Pigment Red 53: 2, calcium salt : CAS number: 67990-35-6, EC number: 268-057-6, ECHA InfoCard: 100.061.852 , PubChem : 106331 , ChemSpider : 21162567 , Wikidata : Q72499686 .
8. ↑ External identifiers or database links for Pigment Red 53: 3, strontium salt : CAS number: 73263-40-8, EC number: 277-335-6, ECHA InfoCard: 100.070.284 , PubChem : 175420 , ChemSpider : 21162904 , Wikidata : Q72499684 .