Factory Supply Pigment Cobalt Blue 28 Inorganic Pigment

Product Name

Cobalt Blue JHM-2811

CAS

1345-16-0

EINECS

310-193-6

Density

4.26[at 20℃]

Physical and Chemical Properties

The main components of cobalt blue are CoO, Al2O3, or cobalt aluminate [CoAl2O4]. According to the chemical formula theory, the
content of Al2O3 is 57.63%, the content of CoO is 42.36%, or the content of Co is 33.31%. However, the actual composition of
cobalt blue pigments is between 65% -70%, and the content of CoO is between 30% -35%. Some cobalt blue pigments have a cobalt
oxide content that is even 10% or half lower, as there may be oxides containing small amounts of other elements, such as Ti, Li,
Cr, Fe, Sn, Mg, Zn, etc. The analysis of a certain cobalt blue pigment variety shows that its CoO is 34%, Al2O3 is 62%, ZnO is 2%,
and P2O5 is 2%. In addition to the main components, cobalt blue may also contain a small amount of alumina, cobalt green (CoO ·
ZnO), and cobalt purple [CO2 (PO4) 2] to change the color phase of cobalt blue pigments. This type of pigment belongs to the
spinel category and is a cube with spinel crystals. The relative density is 3.8-4.54, the covering power is very weak, only
75-80g/m2, the oil absorption is 31% -37%, and the apparent specific volume is 630-740g/L. The quality of cobalt blue produced in
modern times is fundamentally different from that of early products. Cobalt blue pigment has a bright color, excellent weather and
alkali resistance, can withstand various solvents, and can withstand heat up to 1200 ℃. Its main weakness is that its coloring
power is not as strong as that of phthalocyanine blue pigment. Due to its high-temperature calcination, although finely ground,
the particles still have a certain degree of hardness.