Appeal No. 2002-0751 Page 3
Application No. 09/336,051
the product is placed in a toilet bowl. The claimed process has essentially five
sequential steps:
(1) extruding a mixture of polyvinyl alcohol (PVA)1 and a plasticizer to
form an extrudate, which is then cooled and pelletized;
(2) cryogenically grinding the pellets to particles in the size range of 10 to
500 microns;
(3) comminuting the particles to form a powder;
(4) mixing the powder with at least a surfactant and a water-soluble filler;
and
(5) molding the resulting mixture into a toilet block.
The fragrance can be added either in the first step (in claim 38) or in the mixing
step (in claim 37). Claims 39 and 40 are directed to the toilet blocks made in the
process of claims 37 and 38, respectively.
The examiner rejected the claims as obvious in view of McDermott. The
examiner characterized McDermott as teaching a method of making toilet blocks
that uses essentially the same combination of ingredients as recited in the instant
claims, and differs only in two ways: (1) McDermott does not specify a particle
size for the treated extrudate, and (2) the “cryogenic step” occupies a different
place in McDermott’s process than in the claims. See the Examiner’s Answer,
pages 3-4. The examiner concluded that these differences did not distinguish
the instant claims from the prior art because “one of ordinary skill in the art would
have been motivated to create a toilet rim block using the process disclosed by
McDermott, regardless of the specific order of the method steps, and the specific
particle size.” Id., page 4.
1 Instead of PVA, a partially hydrolyzed polyvinyl acetate can also be used.
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