Description
C.I. Pigment Red 3, 12120 [2425-85-6] is a good representative of
monoazopigments of the β-naphthol type and is one of the most important
organic pigments.
Chemical Properties
red to orange powder
Uses
Toluidine Red is a oil soluble dye. Toluidine Red has been shown to cause hematopoietic cell proliferation in the spleen, liver, and bone marrow of rats. Dyes and metabolites, Environmental Testing
Definition
ChEBI: CI Pigment Red 3 is a member of azobenzenes.
General Description
Yellowish-red to red powder or solid.
Air & Water Reactions
Sensitive to moisture Dust suspensions in air can be explosive at certain concentrations. Insoluble in water.
Reactivity Profile
Pigment Red 3 may form toxic gases with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. May form flammable gases with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides.
Fire Hazard
Flash point data for Pigment Red 3 are not available; however, Pigment Red 3 is probably combustible.
Flammability and Explosibility
Non flammable
Synthesis
Using the coupling component 2-naphthol in acidic or neutral pH aqueous solution, at a temperature of 65 C or below the characteristics of low solubility, so that the coupling reaction of diazoxide and 2-naphthol in below 65 C conditions, the pH value of the control of 2 ~ 9, and then the unreacted 2-naphthol in the form of reactant crystals precipitation, and then the coupling reaction to prepare toluidine red.
Properties and Applications
|
TEST ITEMS
|
SPECIFICATION
|
|
APPEARANCE
|
DARK RED POWDER
|
|
SHADE
|
BLUISH
|
|
HEAT RESISTANCE
|
140 °C min
|
|
LIGHT FASTNESS
|
7
|
|
ACID RESISTANCE
|
5
|
|
ALKALI RESISTANCE
|
5
|
|
FASTNESS TO BLEEDING
|
4
|
|
OIL ABSORPTION
|
40-45%
|
|
SPECIFIC SURFACE
|
28 m
2
/g
|
|
DENSITY
|
1.60 g/cm
3
|
|
RESIDUE ON 80 MESH
|
5.0% max
|
|
WATER SOLUBLE
|
1.0% max
|
|
VOLATITE 105 °C
|
1.0% max
|
|
TINTING STRENGTH
|
100-105 %
|
