Appeal No. 94-2441
Application 07/821,314
The subject matter on appeal is directed to a liquid
developer for use in electrophotography comprising a toner which
is dispersed into an aliphatic hydrocarbon carrier liquid. The
toner is comprised of a colorant and a polyolefin resin.
Importantly, the polyolefin resin is defined as having an acid
value of from 5 to 50 and a melt viscosity at 200EC of from 100
to 15,000 cps. When the polyolefin resin component of the toner
has an acid value of less than 5, allegedly the toner does not
exhibit sufficient adhesiveness. When the toner component has an
acid value of greater than 50, it is said that the toner
particles tend to coagulate and thereby affect the storage
stability (the “preservability”) of the composition. With
respect to the melt viscosity parameter of the claimed polyolefin
resin, appellants indicate (Specification, pages 5 and 6) that
when a polyolefin having a melt viscosity of below 100 cps is
used, the toner layer permeates through a transfer sheet to the
reverse side upon application of heat, thus resulting in images
which are fixed to both sides of the transfer sheet. Further, it
is stated that when a polyolefin having a melt viscosity of more
than 15,000 cps is employed, the toner cannot be easily melted
upon application of heat. Therefore, it is difficult to fix the
toner image to a transfer sheet at a low temperature. See the
3
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007