Appeal No. 1997-4365
Application 08/469,726
capped, and further that where “2,4,6-tris(á-pyrrolidonyl)-1,3,5-triazine (TpT)” is employed, at least
some of the chain extension product would reasonable involve all three pyrrolidonyl moieties, thus
resulting in a branched prepolymer which is reactive with caprolactam in a ring opening reaction (pages
315 and 318-319). We find no disclosure in Akkapeddi that would suggest that the prepolymers and
polymers form a “film or object.”
Accordingly, we find that the combined teachings of Kajiura and Akkapeddi would have
reasonably suggested to one of ordinary skill in this art that tris-pyrrolidonyl triazine can be used as a
cross linking or hardening agent for epoxy and phenolic resins as well as in reactions with ether and
amido containing prepolymers and compounds. The examiner relies on these teaching along with the
contention that Macholdt, Iwasawa and Wooten “establish the conventional expedient in the art of
curing powder coatings produced from hydroxyl-functional resins with melamines” to allege that the
“combined teachings of the references clearly establish the use of tris-pyrrolidonyl triazine as a hardener
for hydroxyl-functional resins based on the reactivity of the pyrrolidonyl with the hydroxyl groups” and
thus one of ordinary skill in this art would have been motivated to “harden the hydroxyl-functional resins
of [Macholdt], [Iwasawa] and [Wooten] with tris-pyrrolidonyl triazine of [Kajiura]” in expectation of
enhancing the “heat resistance of the crosslinked films” (answer, pages 5 and 6). Appellants submit that
there is no disclosure in Macholdt that melamine resins are curing agents for epoxy resins shown in
Kajiura and that Kajiura does not “support a general interchangeability of tris-pyrrolidonyl triazine . . .
with ‘other compounds having a triazine ring’ for all applications’ or for “producing crosslinked films
and objects by reaction with a polyfunctional active hydrogen containing material” (brief, page 4;
emphasis in original deleted). In view of the evidence in Macholdt, Iwasawa, Wooten and Kajiura, we
find ourselves in agreement with appellants.
We agree with the examiner and appellants that each of Macholdt, Iwasawa and Wooten
discloses preparing a film with a powder coating composition using a hydroxy-functional resin and a
cross-linking agent and find, as pointed out by appellants, that a “variety of crosslinking agents” are
used, including, inter alia, melamine resins (e.g., answer, page 4; brief, pages 3-4). Indeed, we find
that Iwasawa discloses that thermosetting powder coating compositions “containing an acrylic resin and
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