Appeal No. 2000-1860 2
Application No. 08/679,243
lithographic printing process. The solution has a pH of 3 to 6 and comprises a water
soluble organic solvent, a phosphate salt and a modified silica transparent pigment having
specified characteristics. Additional limitations are provided in the following illustrative
claim.
THE CLAIM
Claims 1 is illustrative of appellants’ invention and is reproduced below:
1. A concentrated dampening solution for use in a lithographic printing
process having a pH between 3 and 6 and comprising a water-soluble organic
solvent, a phosphate salt in an amount, expressed as NaH PO between 4 and 30
2 4
g/l and a transparent pigment, characterized in that said transparent pigment is a
modified silica in which the silica particles have a number average size of 0.003 to
0.100 Fm and in which the silica particles are coated with chemically combined
atoms of an amphoteric metal which forms an insoluble silicate at a pH between 5
and 12, said metal atoms being chemically bound through oxygen atoms to silicon
atoms in the surface of said particles, and the amount of said metal being such
that: Gram atoms M/ Gram atoms Si = A/1250 to A/250000 where M is the
2
metal and A is the surface area of the particles of the silica sol expressed in m /g.
THE REFERENCE OF RECORD
As evidence of obviousness, the examiner relies upon the following reference:
Kinderman et al. (Kinderman) 4,530,721 Jul. 23,
1985
THE REJECTION
Claims 1 through 7 and 9 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Kinderman.
OPINION
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