Comparison of the Lithographic Ink Properties of Various Types of Acrylated Binders

Raw materials'for lithographic offset printing must meet, apart
from viscosity and rheology,a number of requirémeñts related to
the printing process. The process is based on a chemical
difference between image and non image areas (in contrast to
printing 'systems with a physical 'relief differentiation). To
obtain an the lithographic ink is in competition with the
water or fountain, solution. The ink or varnish will go'
preferentially on to the image area and will be repelled from the
non image area by the fountain solution. The ink image on the
lithographic plate is transferred to a rubber roll which,is in
contact with.the.substrate. The requirements for a lithographic
binder therefore are:

- Right balance between hydrophilic and hydrophobic properties :
the hydrophobic' character must be high enough to avoid mixing
of the fountain solution with the ink. The binder must however
be able to emulsify'small droplets of fountain solution on the ink
surface.
- Good pigment wetting
- Low misting (= microscopic ink particles in the atmosphere
surrounding rotating rollers)