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Description and features

Vicura MC-55 (Pyrromelletic Acid Diphenyl Imidazoline Salt 1:2) is an off-white powder with the following chemical formula: C10H6O8.2C9H10N2

The curing mechanism between Vicura MC-55 (Pyrromelletic Acid Diphenyl Imidazoline Salt 1:2) and the epoxy resin is complex. Two parallel processes are taking place; direct reaction between the imidazoline and the epoxy group and homopolymerization of the epoxy resin that is catalyzed by Vicura MC- 55. Compared to most of the powder coating systems where the optimal ratio between the crosslinker and the binder is close to the stoichiometric one, in the case of Vicura MC-55 the optimal ratio is generally determined empirically. For epoxy resins that are typically used for powder coatings (epoxy equivalent weights between 700 – 1000) amounts of 6,0 – 9,0 % of Vicura MC-31 are recommended as good starting.

Benzene-1,2,4,5-tetracarboxylic acid, compound with 4,5-dihydro-2-phenyl-1H-imidazole (1:2) is also known as Pyromellitic acid di(2-phenyl-2-imidazoline) salt (1:2).


Europe: Vicura MC-55 is ➔ on stock in our local warehouses. Our lead time is about one week if delivered in 20 KG paper bags.

United States, Canada, South America, South Africa and other markets can also be served, please contact our sales department for more details.

This substance (CAS: 54553-91-2) has been registered under
REACH (EC) 1907/2006.

Product Identification

CAS number54553-91-2
EC number259-226-5
HS code2933 2990


AppearanceWhite or yellow fine powder
Assay≥99 %
Melting range220 – 245 ºC


Vicura MC-55 (Pyromellitic Acid Diphenyl Imidazoline Salt) is an organic salt of polycarboxylic acid and cyclic amidine. It is used as a crosslinker in manufacturing of matt epoxy and polyester/epoxy hybrid powder coatings. Vicura MC-55 can be used as a single crosslinker in formulating matt epoxy powder coatings where gloss of 20-25 (Gardner 600) is obtained. The gloss level can be increased by partially replacing Vicura MC-55 with the “high gloss crosslinker” Vicura MC-31. The desired ratio between the two crosslinkers should be determined experimentally. In polyester/epoxy powder coatings the gloss level is controlled by replacing part of the polyester with Vicura MC-55, while at the same time increasing the amount of epoxy resin. The curing reaction between Vicura MC-55 and the epoxy groups starts at temperatures above 180 ºC. ͦ By increasing the temperature the curing cycles are getting quickly in the range typical for other thermosetting powder coatings.


Available packaging: 20 KG paper bags.
Special packaging is available on request.


Store Pyrromelletic Acid Diphenyl Imidazoline Salt (1:2)  cool, dry and well-ventilated area and in line with legal requirements.


A Material Safety Data Sheets (MSDS) is available for Vicura MC-55 and all other products supplied by Vesta Chemicals BV.

An MSDS describes the hazards of a product and explains how a product can be safely handled, used and stored. Besides it provides important regulatory and emergency response information for the purchased product.

Molecular and structural information

Molecular formula C10H6O8.2C9H10N2
Molecular weight 546.54 g/mol
Smiles notation

Structural formula:
Pyrromelletic Acid Diphenyl Imidazoline Salt 1:2, 54553-91-2

Physicochemical information

Boiling point >201 ºC
Bulk density1.38 g/cm3 @ 20 ºC
Flash point >250 ºC @ 1 atm
Melting point±240 ºC at ± 1 atm
Partition coefficient (log Pow) 6.45 @ 25 ºC
Solubility in water 6 g/l @ 20 ºC / pH 3.8
Vapor pressure (MGM) 0 Pa @ 25 ºC

Pyrromelletic Acid Diphenyl Imidazoline Salt | CAS: 54553-91-2 | Disclaimer. This information is supplied solely for informational purposes and Vesta Chemicals bv makes no guarantees or warranties, either expressed or implied, with respect to the accuracy and use of this data. All product warranties and guarantees shall be governed by the Standard Terms of Sale. Nothing in this document is legal advice or is a substitute for competent legal advice.