PHTHALOCYANINE PIGMENT POWDERS
These Phthalocyanine Pigment find wide application in
paints , Textiles , Rubber , Plastics , Artist Colours , Ink Industries etc.
They Have excellent dispersion and rheological characteristics required for
printing inks with good transparency , gloss and tone. These pigments are
homogeneous belonging to Azo Phthalocyanine groups. The physical, chemical,
colouristic as well as fastness properties of the pigments depend to a large
extent on the type of binders used, presence of driers, hardeners,the
substrate and film thickness etc.
Specific gravity has been determined in an inert liquid at 20°C
Oil Absorption :
10gm. Of pigment is placed on the glass plate and acid refined linseed oil
is added from a burette in drop and the paste rubbed at get a spreadable
paste. The quantity of oil required for 100gms. Of pigment is then
calculated and expressed as ml. Oil/100 gms. Pigment.
The prints of the pigments dispersed in printing ink medium is expressed
along with Standard Blue Scale and rating expressed in 1 to 8 scale. 8
denotes excellence and 1 denotes poor fastness.
A stove paint of the pigment is prepared in non-yellowing medium and
applied to a tin panel.The temperature upto which there is negligible change
in the shade after for 30min. Noted.
Fastness to Solvents and Chemicals:
The test is carried out by placing 0.5gms. Of pigments in a folded paper,
sealed at the top and suspended in 20 CC of solvent in a stoppered test tube
at room temperature for 24hours. The staining noted and expressed in 1 to 5
scale. In case of water, Acid or Alkali 0.5gm. Of pigments is mixed with 10
ml. each and these liquids heated in water bath for 10 minutes cooled and
filtered. The filterate is assessed for colouration.
Soap Bleeding :
The test is carried out by placing completely dried draw down /
print of 20% jelly made with neutral white soap for 24 hours. Extent of
bleeding noted expressed in 1 to 5 scale.