Appeal No. 95-0562
Application 07/878,940
Mosier 3,676,363 Jul. 11, 1972
Hen 5,068,042 Nov. 26, 1991
Jacobs et al. (Jacobs) 5,112,505 May 12, 1992
(filed Sep. 13, 1990)
The appealed claims stand rejected for obviousness (35
USC
§ 103) over Mosier in view of either Hen or Jacobs.
The subject matter on appeal is directed to oil field
chemical microcapsules having a gelatin wall stabilized by a
strong chelating agent such as EDTA. The microcapsules
contain oil well chemicals such as scale inhibitors or
corrosion agents. Appellants allegedly have discovered that
premature microcapsule destruction by brine solutions
containing 20,000 mg/ml of chloride ion (as commonly found in
oil wells) may be avoided by incorporation of certain classes
of strong chelating agents which stabilize the capsule wall
and thus allegedly provide for an extended time release of the
oil well chemical.
As evidence of obviousness, the examiner principally
relies on Mosier. This reference discloses a microcapsule
with a gelatin wall containing droplets of an oil well
chemical treating agent such as a corrosion inhibitor. An
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