Appeal No. 2004-0495 Paper 22
Application No. 09/503,599 Page 5
continuous process (c. 3, ll. 38-39). Kurian Example 1 is illustrative.
A 250 ml flask equipped with a stirrer and distillation column was
charged with 58.5 g of dimethyl terephthalate (DMT) and 41 g of 1,3-
propanediol ... for a mole ratio of 1,3-propanediol:DMT of 1.8:1. The flask
was then purged with nitrogen and the contents of the flask were heated.
When the temperature inside the flask reached about 150oC and all of the
DMT had melted, the stirrer was started. When the temperature reached
210oC, 30 mg of lanthanum tris(acetylacetonate) hydrate ... was added.
... Upon addition of the lanthanum tris(acetylacetonate) hydrate,
methanol was evolved [i.e., a gaseous reaction product]. The methanol
was removed as a liquid condensate by distillation. The total liquid
condensate was assumed to be methanol for purposes of this Example
because the amount of methanol is more than 99% of the condensate in
such a procedure. The temperature was held at 210o C. and the amount
of liquid methanol collected was measured every ten minutes until no
more methanol was evolved. ...
After evolution of methanol, the resulting monomer, bis(3-
hydroxypropyl) terephthalate, was polymerized in the same reaction
vessel at a temperature of 250o C. and a pressure of 0.4 mm Hg, using a
titanate compound as the polycondensate. ... [c. 4, l. 55 - c. 5, l. 25.]
As noted by the examiner, Kurian "does not teach the preheating of the starting
material" (Answer, p. 4, ¶ 2). As noted by appellants, Kurian "does not provide details
regarding the reactors used to make his product" (Brief, p. 10, ¶ 3) or "any suggestion
whatsoever to feed reactants at or below the midpoint of an ester exchange vessel" (id.,
p. 11, ¶ 2).
Armstrong discloses continuous production of bis(2-hydroxylethyl) terephthalate
by reacting ethylene glycol and dimethyl terephthalate in a vessel and then completing
the reaction in a bubble cap column (c. 1, ll. 15-20). As described in Example 1,
An apparatus is used of the type illustrated in the drawing. Vessel
3 is a stainless steel pot heated by means of electric heating coils 4, with
dimensions such that the liquid content is approximately 40 liters (1.4 cu.
ft.). Vessel 7 is a conventional bubble-cap distillation column
approximately 30 cm. (12 inches) in diameter with 20 bubble-cap plates
and with the liquid level on each plate being about 4.75 cm. (1.875 inches)
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