Appeal 1997-1635
Application 08/319,667
contaminated with aldehydes, before the treatment by
distillation.[3]
The invention described in the specification
4. "(Meth)acrylic acid" means acrylic acid or
methacrylic acid (specification, page 1, lines 13-14). For
convenience, we will limit our discussion to methacrylic acid.
5. Methacrylic acid can be made by a catalytic gas-
phase oxidation process (specification, page 3, lines 35-36).
6. Methacrylic acid produced by the process
contains impurities including aldehydes (specification, page
2, lines 5-9).
7. The presence of impurities is often not
desirable (specification, page 2, lines 17-18).
8. A prior art method for removing the impurities,
particularly aldehydes, involves mixing (1) impure methacrylic
acid containing aldehydes with (2) an amine followed by
distillation (specification, page 2, lines 41-46; see also
European Patent Application 0 270 999 A1 (published 15 June
1988), discussed infra).
There is no antecedent in the claim for "the treatment by distillation".3
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