Printing inks Luwax A Granules can be added to lithographic and gravure inks to
improve the rub resistance and scratch resistance of the printed image.
Luwax A Granules are added to lithographic inks by stirring 20 – 30% wax
into mineral oil heated to 110 –130 °C. A finely divided crystalline paste is
formed on cooling, which can then be added to the ink. The wax can also
be dissolved in varnishes that do not contain any mineral oil. Luwax A
Granules are added to gravure inks by dispersing them in toluene. It is
usually advisable to add wax dispersions before the pigments are dispersed,
but they can be added to the made-up ink if it is subsequently
homogenized with a high-speed mixer.
The amount of wax required to obtain high rub resistance depends on the
substrate and the type of pigments that the ink contains. The required wax
concentration is usually between 1% and 2.5 %, expressed as a proportion
of the made-up ink.
Masterbatches Luwax A Granules and Luwax A Powder are effective dispersing agent for
pigments, they are themselves easy to disperse, and they have a relatively
low melt viscosity. They are used to disperse pigments in masterbatches
for colouring polyethylene, polypropylene, PVC and polystyrene. They
allow pigments to be dispersed quickly and homogeneously, with no
detrimental effects on the mechanical properties of the plastic.
Colour masterbatch – Suggested formulation
(All figures in % w/w)
30 Organic pigment
5 –15 Luwax A Powder or Luwax A Granules
54 – 64 Lupolen 1800 S
0.5 – 1 Antioxidant
PVC processing Hydrocarbon waxes such as Luwax A Powder are only sparingly soluble in
PVC, with the result that they have a pronounced external lubricant effect.
Luwax A Powder can be used as a lubricant for rigid and plasticized PVC.
It prevents the melt from adhering to the hot metal surfaces of processing
machinery and decomposing. Adding wax improves the gloss, smoothness
and water repellancy of surfaces, as well as making the plastic easier
to process. Between 0.1 phr and 0.6 phr normally needs to be added.
Luwax A Powder is often used in combination with montanic ester waxes
such as Luwax E Powder or Luwax OP Powder, which have both an
internal and external lubricant effect, or other internal lubricants.