Ex parte Verbeeck

Board of Patent Appeals and Interferences

Mar 29, 2001

08608321 (B.P.A.I. Mar. 29, 2001)

-1-
The opinion in support of the decision being entered
today was not written for publication and is not binding
precedent of the Board.
Paper No. 17
UNITED STATES PATENT AND TRADEMARK OFFICE
________________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
________________
Ex parte ANN VERBEECK
________________
Appeal No. 1998-1732
Application 08/608,321
________________
HEARD: MARCH 20, 2001
________________
Before JOHN D. SMITH, WARREN, OWENS, Administrative Patent
Judges.
OWENS, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal from the examiner’s refusal to allow
claims 1-12 and 15-17 as amended after final rejection. These
are all of the claims remaining in the application.
Appeal No. 1998-1732
Application 08/608,321
-2-
THE INVENTION
The appellants’ claimed invention is directed toward a
method for making a light sensitive silver halide emulsion
comprising tabular grains having colloidal silica sol as a
protective colloid. Claim 1 is illustrative:
1. Method for preparing a light-sensitive silver halide
emulsion comprising tabular grains containing colloidal silica
sol as a protective colloid, said tabular grains having an
average grain thickness of not more than 0.3 Fm, an average
aspect ratio of more than 12:1, a total projective area of
said tabular grains of at least 90% and a coverage degree by
silica sol particles within the range from 50 to 2000%,
comprising the following steps:
precipitating in a reaction medium silver halide by means
of a double-jet or triple-jet technique applied to aqueous
solutions of silver nitrate and halide salts in colloidal
silica having an average particle size in the range from 0.003
Fm to 0.30 Fm as a protective colloid, in the presence as an
onium compound of a phosphonium compound; but in the absence
of gelatin, wherein a ratio by weight of said colloidal silica
to said phosphonium compound is obtained between 3 and 400;
controlling nucleation and growth steps by means of
variable flow rate(s) of aqueous solutions of silver nitrate
and halide salts and/or by means of constant pAg-values during
said steps;
subjecting the reaction medium to at least one physical
ripening step;
desalting the reaction medium and redispensing the silver
halide obtained;
Appeal No. 1998-1732
Application 08/608,321
The examiner relies upon pages from an Aldrich catalog1
(answer, page 6). This reference is not included in the
statement of the rejection and, therefore, is not properly
before us. See In re Hoch, 428 F.2d 1341, 1342 n.3, 166 USPQ
406, 407 n.3 (CCPA 1970). Consequently, we do not consider
this reference in reaching our decision.
-3-
chemically ripening the silver halide and
adjusting a ratio by weight of colloidal silica sol to
amount of silver halide, expressed as an equivalent amount of
silver nitrate, to a value of at least 0.03 at all times
during precipitation in a reaction vessel.
THE REFERENCES
Vandenabeele et al. (EP ‘092) 0 392 092 Oct. 17,
1990
(European patent application)
Vandenabeele (EP ‘961) 0 517 961 Dec. 16,
1992
(European patent application)
THE REJECTION
Claims 1-12 and 15-17 stand rejected under 35 U.S.C.
§ 103 as being unpatentable over EP ‘092 in view of EP ‘961.1
OPINION
We reverse the aforementioned rejection. We need to
address only claim 1, the subject matter of which is included
in all of the claims.
Appeal No. 1998-1732
Application 08/608,321
-4-
EP ‘092 discloses a method for making a light sensitive
silver halide emulsion comprising grains which contain
colloidal silica sol as a protective colloid and which may be
tabular grains (abstract; page 4, line 26). The size of the
grains may be 0.01 to 7 µm (page 4, lines 36-37). In an
example, the aspect ratio of the grains is up to 12 (page 9,
line 56). The degree of coverage by silica sol particles is
50-100% (page 5, line 55).
The method includes precipitating silver halide in a
reaction medium comprising an aqueous solution of silver
nitrate and a halide salt in colloidal silica, by means of a
technique which can be a double-jet method (page 4, lines 18-
19) (page 6, lines 41-46). Suitable colloidal silicas include
Syton , Ludox , Nalco , Nalcoag , and Kieselsol Types 100, 200® ® ® ® ®
and 600 (page 4, lines 2-5), which are among the colloidal
silicas used by the appellants (specification, page 5, lines
10-18) and, therefore, include particles within the average
particle size limitation of claim 29. The precipitation takes
place in the presence of an onium compound which can be a
phosphonium compound (page 3, lines 25-54). The teaching that
in the precipitation “the protective colloid can comprise
Appeal No. 1998-1732
Application 08/608,321
-5-
silicic acid sol and gelatin” (page 3, line 15) indicates that
gelatin may be present or absent, and EP ‘961 discloses such a
precipitation in the absence of gelatin (page 3, line 48).
The ratio of onium compound to colloidal silica is preferably
0.5x10- to 5x10- mol of onium compound per 90g of SiO (page3 3 2
3, lines 55-57). The examiner calculates that the EP ‘092
examples include colloidal silica:onium ratios within the
appellants’ range of 3-400 (answer, pages 5-6), and in their
reply brief the appellants do not challenge the examiner’s
calculations. The silver halide emulsions can be prepared
under conditions of controlled flow rates (page 4, lines 16-
18). Steps of physical ripening (page 6, lines 52-53),
desalting the reaction medium and redispersing the silver
halide obtained (page 4, lines 41-43), chemically ripening the
silver halide (page 4, lines 44-56; page 7, line 7), and
adjusting the ratio of colloidal sol to silver halide,
apparently to keep it in the 0.5-1.0 weight ratio range (page
5, lines 51-58), can be used.
Thus, it is seen that there is substantial overlap
between the EP ‘092 method and that recited in the appellants’
claim 1. The appellants’ claim 1, however, requires that the
Appeal No. 1998-1732
Application 08/608,321
-6-
steps be carried out such that the total projective area of
the tabular grains is at least 90%. The examiner does not
point out, and we do not find, a disclosed total projective
area in the applied references. In their specification (pages
20-21), the appellants coat a support with the photographic
tabular grain emulsion of example XVIII of EP ‘092, and
report that the total projective area of the tabular grains is
less than 50%. This example indicates that the total
projective area of the tabular grains in EP ‘092 is not
necessarily at least 90% as required by the appellants’ claim
1, and the examiner has given no reason as to why the applied
references would have led one of ordinary skill in the art to
prepare an emulsion having tabular grains with such a total
projective area.
The examiner argues that “[t]he ranges claimed by
Appellant appear to be quite broad to the Examiner and thus
are not very narrow limitations. This is especially true of
the independent claim” (answer, page 5). Merely arguing that
the limitations are not very narrow, however, is not
sufficient for carrying the burden of establishing that the
claimed invention would have been prima facie obvious to one
Appeal No. 1998-1732
Application 08/608,321
-7-
of ordinary skill in the art over the applied prior art.
Because the examiner has not pointed out where a total
projective area of the tabular grains of at least 90% is
disclosed in the applied references, or explained why the
applied references would have led one of ordinary skill in the
art to prepare a silver halide emulsion having tabular grains
with such a total projective area, the examiner has not
carried the burden of establishing a prima facie case of
obviousness of the appellants’ claimed invention.
Consequently, we reverse the examiner’s rejection.
DECISION
The rejection of claims 1-12 and 15-17 under 35 U.S.C.
§ 103 over EP ‘092 in view of EP ‘961 is reversed.
REVERSED
JOHN D. SMITH )
Administrative Patent Judge )
)
Appeal No. 1998-1732
Application 08/608,321
-8-
)
)
CHARLES F. WARREN ) BOARD OF PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
)
)
TERRY J. OWENS )
Administrative Patent Judge )
TJO/ki
Appeal No. 1998-1732
Application 08/608,321
-9-
Breiner and Breiner
115 North Hanry Street
P. O. Box 19290
Alexandria, VA 22320-0290