Appeal No. 2005-0528 Page 2
Application No. 10/178,143
INTRODUCTION
According to the specification, the invention relates to polyol compositions which can be
used to prepare dimensionally stable, low density water-blown rigid foams having acceptable
compressive strength, foams made from the polyol compositions, and processes for preparing the
foams (specification, p. 1, ll. 6-14).
According to the “Background of the Invention” section of the specification, rigid foam
is produced by reacting a polyisocyanate with a polyol in the presence of a blowing agent
(specification, p. 1, ll. 19-20). Typically, chlorofluorocarbons (CFCs) have been used as
blowing agents, but effort has been directed to replacing CFCs with water because water is more
environmentally friendly (specification, p. 1, ll. 21-28). The use of water as the blowing agent,
however, has resulted in a shrinkage problem in the foam product (specification, p. 1, l. 29 to
p. 2, l. 7). This shrinkage problem has been addressed in several ways, but each has deficiencies
(specification, p. 2, 8-27). One approach has been to produce open-cell rigid polyurethane
foams. However, unlike closed-cell water blown foams, open-cell foams are poor insulators
(specification, p. 2, ll. 8-13). Appellants’ foams are closed-cell foams yet are dimensionally
stable, i.e., do not shrink, and have acceptable compressive strength. Claims 6 and 11 are further
illustrative of the subject matter on appeal:
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