Appeal No. 95-2644
Application 07/818,852
Claims 1 to 24 stand rejected under 35 U.S.C. § 103 as being unpatentable over
Homola in view of Kratohvil.
In their brief, appellants state that the claims stand or fall together. Claim 1, the only
independent claim, reads as follows:
1. A process of making coated magnetic particles, comprising the steps of:
a) providing an aqueous suspension of magnetic particles;
b) providing an aqueous sol comprising amorphous, hydrolyzed,
aluminous, colloidal particles, wherein the amorphous, hydrolyzed,
aluminous, colloidal particles have a mean particle diameter in the
range from about 0.5 to about 5 nanometers and have an average
degree of hydrolysis in the range from about 1.5 to about 3 and
wherein said colloidal particles have a positive surface charge;
c) mixing the aqueous sol with the aqueous suspension of magnetic
particles, whereby the amorphous, hydrolyzed, aluminous, colloidal
particles form a continuous, amorphous, aluminum hydrous oxide
coating on the magnetic particles, said coating having an average
thickness in the range from about 0.5 to about 5 nanometers.
The references relied upon by the Examiner are:
Homola et al. (Homolo) 4,280,918 Jul. 28, 1981
Advanced Ceramic Materials, Vol. 2, No. 4, issued 1987, Kratohvil et al.,
"Preparation and Properties of Coated Uniform, Inorganic Colloidal Particles: I,
Aluminum (Hydrous) Oxide on Hematite, Chromia, and Titania", pp. 798-803.
(Kratohvil)
After having reviewed the references in light of the arguments raised by appellants,
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