Appeal No. 2004-0448
Application No. 09/636,311
1. In the method of producing a hydrophobic particulate
inorganic oxide by contacting an acidic aqueous suspension
of a particulate inorganic oxide selected from the group
consisting of precipitated silica, colloidal silica and
mixtures of such inorganic oxides, with an organometallic
compound to form an acidic aqueous suspension of hydrophobic
particulate inorganic oxide, optionally in the presence of a
surfactant and/or a water miscible solvent, and recovering
said hydrophobic particulate inorganic oxide, the
improvement comprises using said organometallic compound in
an amount sufficient to hydrophobize the inorganic oxide,
such that the inorganic oxide has a hydroxyl content of from
2 to 15 OH/nm2, a carbon content of from 0.1 to 6 weight
percent, and a methanol wettability of from 15 to 45
percent, in an aqueous suspension of inorganic oxide having
a pH of 2.5 or less, and treating the acidic aqueous
suspension of the hydrophobic particulate inorganic oxide
with acid neutralizing agents to produce a hydrophobic
particulate inorganic oxide having a pH of from 3 to 10, a
carbon content that is substantially non-extractable and an
M1 Standard White Area of less than 0.4 percent.
THE REFERENCES
Griffith et al. (Griffith) 5,908,660 Jun. 1, 1999
Lightsey et al. (Lightsey) 5,985,953 Nov. 16, 1999
Burns et al. (Burns) 6,051,672 Apr. 18, 2000
THE REJECTIONS
Claims 1-17 stand rejected under 35 U.S.C. § 103 as being
unpatentable over Griffith in view of Lightsey and/or Burns.
OPINION
We reverse the aforementioned rejection. We need to address
only the sole independent claim, i.e., claim 1.
The appellants’ claim 1 requires that the hydrophobic
particulate inorganic oxide has an M1 Standard White Area of less
2
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