Appeal No. 94-2441
Application 07/821,314
Specification, page 6.
As evidence of obviousness of the claimed subject matter,
the examiner relies on El-Sayed. This reference discloses a
positive-working liquid developer for use in electrophotography
comprising a toner dispersed in an aliphatic hydrocarbon carrier
liquid. El-Sayed’s toner is comprised of a colorant (column 5,
line 62 to column 6, line 18) and a polyolefin resin (column 4,
line 48 to column 5, line 50). Especially preferred polyolefin
resins are copolymers of ethylene with acrylic acid/ester or
methacrylic acid/ester. At column 5, line 21, El-Sayed indicates
that the acid number of the copolymers range from 1 to 120,
preferably 54 to 90 wherein the acid number is defined as the
milligrams of potassium hydroxide required to neutralize one gram
of polymer. At column 5, line 24, El-Sayed teaches that these
copolymers have a melt index of 10 to 500 as defined by the ASTM4
D1238 procedure A.
4Melt index is a measure of the viscosity of a
thermoplastic polymer at a specified temperature and pressure and
is a function of the molecular weight of the polymer.
Specifically, melt index is defined as the number of grams of
such a polymer that can be forced through a standard orifice
under a standard applied force in ten minutes at 190EC. See the
Condensed Chemical Dictionary, page 649, copyright 1981 and Kirk-
Othmer Encyclopedia of Chemical Technology, Third Edit., Vol. 16,
pages 425 and 426, copyright 1981, copies attached. As evident
from Table 1 in Kirk-Othmer, melt index and molecular weight are
inversely related.
4
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