Toluidine red
Description
Toluidine Red (CAS 2425-85-6), also sold under the designations C.I. Pigment Red 3, Hansa Red B, and PR3, is a monoazo organic pigment delivering a bright, clean red shade across a broad range of industrial colorant applications.
Permanent Red 4R is another commercially recognized name buyers encounter across supplier catalogs and technical datasheets. In solvent-based and water-based paints and industrial coatings, PR3 provides strong tinting strength and good opacity.
This makes it a preferred red pigment for decorative and protective finishes. Plastics compounders incorporate it into polyolefins and PVC to achieve vivid red coloration in consumer goods, packaging, and automotive interior components.
Printing ink manufacturers use it in flexographic and offset formulations where cost-effective red hues are required for packaging and label printing. Leather finishes and paper colorants also rely on this pigment for surface dyeing.
Consistent shade and batch-to-batch reproducibility are critical procurement criteria for these industries. Toluidine Red is supplied as a dry powder, typically in press cake form for wet-process applications or as a flushed pigment paste.
This allows for direct ink and coating incorporation. Standard commercial grades are available at varying pigment concentrations to suit different dispersion and end-use requirements across the global chemical market.
Technical grade is the predominant market offering, with specifications aligned to standard colorant industry benchmarks. Our supply chain ensures that all batches meet the necessary performance metrics for industrial manufacturing.
Physical Properties
| Melting Point | 270-272 °C(lit.) |
| Boiling Point | 447.81°C (rough estimate) |
| Density | 1.1873 (rough estimate) |
| Appearance | red to orange powder |
| Form | neat |
| Water Solubility | 211μg/L at 20℃ |
| Refractive Index | 1.6500 (estimate) |
| Log P | 5.4 at 25℃ |
Safety & Handling (Learn More)
Trade & Regulatory
| UN Number | 3077 |
| ADR Class | 9 |
| Packing Group | III |
| WGK (Germany) | 3 |
Documentation
Other Names
C.I. Pigment Red 3|Hansa Red B|Permanent Red 4R|Fast Red R|Toluidine Toner|Independence Red|Helio Fast Red RN|Chromatex Red J|PR3
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