Appeal No. 95-1360
Application No. 08/134,002
'127.
The claimed invention
The claims relate to a controlled set cement product
comprising rapid hardening hydraulic cement and an additive
package. The additive package “consists essentially of” a
specific amount of each of a pozzolan, set retarder, and
plasticizer. Pozzolans include silica fume, set retarders
include citric acid, and plasticizers include “a modified
lignosulphonate or other material” (Specification, p. 3, lines
25-28). Appellants’ claimed controlled set cement products
may further comprise alkali-resistant glass fiber
reinforcements (claim 7).
Discussion
Watanabe discloses a cement additive comprising a
superplasticizer, bentonite, and an inorganic strength
improving agent (col. 2, lines 46-48). Inorganic strength
improving agents include calcium sulfates, silica fume and
mixtures thereof (col. 3, lines 43-46). The cement
additive may further comprise organic acids and salts,
including citric acid (col. 4, line 62-col. 5, line 33).
Appellants argue that Watanabe does not suggest adding
3
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