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Board’s Finding of Obviousness Reversed Because Prior Art Rigid Foam That Is Crushed Could Not Reasonably Be Construed to Be a Flexible Foam Reaction Mixture

September 27, 2007

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Last Month at the Federal Circuit - October 2007

Judges: Newman (author), Friedman, Prost (dissenting)

[Appealed from: Board]

In In re Buszard, No. 06-1489 (Fed. Cir. Sept. 27, 2007), the Federal Circuit reversed the Board’s decision regarding anticipation and remanded for completion of examination, holding that the reference applied by the Board could not be reasonably construed to describe claims of the patent application at issue.

The patent application at issue, U.S. Patent Application Serial No. 10/429,429 (“the ’429 application”), claims a flame retardant composition that produces a flexible polyurethane foam, and the flexible foamed article made from the composition. In the Board’s view, a patent to Eling anticipated the claims of the ’429 application.The Eling patent discloses a rigid foam produced by chemical reaction of compounds and a flexible foam produced by crushing the rigid foam. The Board interpreted patentees’ claimed reaction mixture to include “any reaction mixture which produces, at least ultimately, a flexible polyurethane foam.” The patentees disagreed and appealed, contending that their claims explicitly require a “flexible polyurethane foam reaction mixture,” which the Eling patent fails to disclose.

On appeal, the patentees argued that the Eling patent discloses only a rigid polyurethane foam, which, when mechanically crushed, loses its rigidity because it is in small particles. The patentees further asserted that the rigid foam product disclosed by the Eling patent is chemically different from a flexible polyurethane foam that is directly produced by polymerization, without crushing, and that this difference is readily understood by a person of ordinary skill in the field of polyurethane foams. According to the patentees, whether or not the rigid polyurethane foam disclosed by the Eling patent is subsequently crushed is of no consequence because the flexible foam mixture required by their claims is different in kind from the rigid foam mixture described by Eling.

The PTO, on the other hand, stated that Buszard’s claims, when given their broadest interpretation, read on the Eling product and thus were anticipated by Eling. Buszard responded that the Board’s construction of the claims to read on, and thus be anticipated by, Eling’s crushed solid foam was not reasonable. More specifically, Buzsard contended that persons experienced in the field of polyurethane foams know that a “flexible polyurethane foam reaction mixture” is different from a rigid polyurethane foam reaction mixture, and that this process limitation cannot be found in Eling, no matter how broadly that reference is read.

The Federal Circuit rejected the PTO’s argument. The Court noted that the PTO Solicitor agreed at the oral argument that the flexibility or rigidity of foamed polyurethane depends on the composition of the reaction mixture, which controls the degree of chemical cross-linking and, thus, the flexibility of the polymer. The Court further noted the Solicitor’s agreement that a person of ordinary skill in the field of polyurethane foams knows that a flexible foam and a rigid foam have different chemical structures and are produced from different chemical reactants.

The Court next considered the Solicitor’s proposal at oral argument that when a rigid foam is mechanically crushed, the chemical bonds are broken and the product is the same as the flexible product of a flexible foam reaction mixture. The Court dismissed this argument, noting that “[t]here was no rejection on this ground, there is no evidence or argument to this effect in the record, this theory was not mentioned by any examiner or in the Board’s opinion, and it appears to be contrary to science.” Slip op. at 5.

The Court thus concluded that the Eling patent did not anticipate the ’429 application because “[n]o matter how broadly ‘flexible foam reaction mixture’ is construed, it is not a rigid foam reaction mixture.” Id. at 6. As explained by the Court, while the ’429 application requires a flexible polyurethane foam reaction mixture, the Eling patent only discloses a rigid foam reaction mixture that produces a rigid product. Furthermore, “[o]nly by mechanically crushing the rigid product into small particles is it rendered flexible, as a rock can be mechanically crushed to produce particles of sand.” Id. In the Court’s view, “[t]his description cannot reasonably be construed to describe, and thus to ‘anticipate,’ the flexible foam product of a flexible foam reaction mixture.” Id. Having agreed with the patentees that “it is not a reasonable claim interpretation to equate ‘flexible’ with ‘rigid,’ or to equate a crushed rigid polyurethane foam with a flexible polyurethane foam,” the Court reversed the Board’s decision and remanded for completion of examination.

Judge Prost dissented. In her view, the Board reasonably interpreted the claims of the ’429 application, and under the Board’s interpretation, substantial evidence supported its finding that the Eling patent anticipated the claims of the ’429 application. Judge Prost noted that the Board does not engage in the same claim construction process during patent prosecution as a district court would in an infringement suit. Instead, the Board gives claim language its broadest reasonable interpretation consistent with the specification. If a claim term is ambiguous or confusing, the application can (and should) clarify it.

Because the Board must give claim language its broadest reasonable interpretation, Judge Prost would affirm the Board’s construction of “flexible polyurethane foam reaction mixture” to mean “any reaction mixture which produces, at least ultimately, a flexible polyurethane foam.” And such a construction, she concluded, encompasses mixtures that produce polyurethane foams that are made flexible upon crushing, such as the mixture disclosed in the Eling reference. She noted that Buszard’s specification did not define the term, and the Board’s interpretation, while broad, was not unreasonable. Although Buszard alleged that the term “flexible polyurethane foam mixture” has a specific meaning to one of ordinary skill in the art, neither Buszard’s specification nor his briefs provided such a definition.