Appeal No. 2004-0375
Application 09/841,926
Takagi discloses a developing roller having a highly
conductive shaft (2) and, around the outer periphery of the
shaft, an elastic layer (3) (col. 3, lines 57-62). The elastic
layer is covered, optionally over its entire surface, with a high
resistivity surface layer which can be a urea resin or a melamine
resin (col. 6, lines 34-41; col. 8, lines 9-11). Urea resin and
melamine resin are among Takagi’s preferred surface layer
materials (col. 6, lines 47-48). In an example, a melamine resin
is mixed with an oil free alkyd resin in a 1:4 ratio (col. 10,
lines 54-57). There is no dispute as to whether the oil free
alkyd resin is a crosslinking component. The disclosed elastic
layer materials include silicon rubber (col. 4, lines 11-14).
For resistivity adjustment, the elastic layer includes 0.01-1
parts by weight of an ionically conductive material and can
include a suitable amount of an electronically conductive
material (col. 5, lines 11-55). The disclosed electronically
conductive materials include carbon black (col. 5, lines 55-56).
Takagi does not disclose a coupling layer between the
elastic layer and the high resistivity surface layer. Ishii,
however, teaches that a coupling layer between a carbon black-
containing silicone rubber layer and a polyurethane outer layer
of a semiconductive roller improves the adhesion between the
3
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