Judges: Rader, Friedman, Bryson (author)

[Appealed from W.D. Ky., Judge Simpson]

In Süd-Chemie, Inc. v. Multisorb Technologies, Inc., No. 08-1247 (Fed. Cir. Jan. 30, 2009), the Federal Circuit vacated the district court’s grant of SJ that U.S. Patent No. 5,743,942 (“the ’942 patent”) was invalid due to obviousness and remanded. The Court found that the evidence before the district court did not support its conclusion that the prior art disclosed every claim limitation.

Süd-Chemie, Inc. (“Süd-Chemie”) owns the ’942 patent. The ’942 patent is directed to desiccant containers, which are frequently used to maintain a dry environment for products during storage or shipping. Some desiccants function by absorbing water vapor and undergoing a phase change into liquid form. Leakage of the liquid from the desiccant container would defeat the purpose of the desiccant and could damage either the products that are maintained in a dry environment or the container in which the products are shipped. The ’942 patent discloses a desiccant container made from a water-vapor-permeable, multilayered packaging material. The ’942 patent, contrary to the prior art, sought to solve the problem of water leakage by requiring the use of packaging films that are not coated with adhesives but that are “compatible” with each other.

Süd-Chemie sued Multisorb Technologies, Inc. (“Multisorb”) for infringement. After the district court issued an order construing claim 1, the only independent claim of the ’942 patent, both parties filed cross-motions for SJ on the issues of infringement and validity. The central issue with respect to validity was whether U.S. Patent No. 4,487,791 (“Komatsu”) rendered the ’942 patent invalid for obviousness. The district court granted SJ that the ’942 patent was invalid for obviousness in view of Komatsu. Süd-Chemie appealed.

Süd-Chemie asserted that Komatsu failed to teach three of the limitations pertaining to the desiccant container recited in claim 1. The Federal Circuit agreed with Multisorb that Komatsu taught two of those limitations, but concluded that the evidence before the district court did not support its conclusion that Komatsu disclosed the third limitation. Specifically, claim 1 of the ’942 patent requires that the inner surfaces of the microporous and laminate films recited in the claim be “comprised of compatible polymeric materials.” The district court concluded that Komatsu taught the use of compatible films because “[t]he Komatsu patent suggest[ed] the employment of the same materials claimed by the ’942 patent to be ‘compatible polymeric materials.’” Slip op. at 8 (first alteration in original).

The Federal Circuit found that Komatsu disclosed the same general classes of materials that were identified in the ’942 patent. The Court, however, noted that the district court failed to acknowledge that the specified classes of materials comprised a large number of substances with quite different properties, and that various combinations of those materials could be compatible or incompatible, depending on how they are assembled in layers to form the container. Relying on the definition of “compatible” given in the specification of the ’942 patent, the Federal Circuit found that Komatsu taught the use of incompatible materials, not compatible materials as claimed in the ’942 patent. The Court observed that the district court failed to recognize that Komatsu disclosed the use of incompatible materials, whereas the ’942 patent required compatible materials. As such, the Court vacated the district court’s grant of SJ of invalidity for obviousness and remanded.

In so doing, the Federal Circuit reiterated that evidence relating to secondary considerations “can be quite instructive in the obviousness inquiry.” Id. at 12. While the Court made no judgment as to the probative value of Süd-Chemie’s evidence regarding the asserted secondary considerations, it emphasized that the district court should take such evidence into account when conducting obviousness analysis.