Appeal No. 95-5080 Application 07/952,122 inconclusive to establish that the claimed epoxy resin exhibits a difference, that the difference actually obtained is unexpected and of a practical advantage. In re Freeman 474 F.2d 1318, 1324, 177 USPQ 139, 143 (CCPA 1973), citing In re Klosak, 455 F.2d 1077, 1080, 173 USPQ 14, 16 (CCPA 1972). See also In re D'Ancicco, 439 F.2d 1244, 1248, 169 USPQ 303, 306 (CCPA 1971). Eldin’s test composition B which is allegedly based upon Henton, employs an epoxy resin, toughener and amine curing agent but does not include a hardener, as disclosed and claimed by Henton. Test composition A based upon the instant claims, employs an epoxy resin, a toughener, a hardener-amine accelerator combination and bisphenol A. Eldin concludes that the results show the unexpected superiority of the claimed composition over those of Henton with respect to fracture toughness--the products according to the invention are said to exhibit an improvement of about 70% over those of Henton. As noted, composition A includes components b and d whereas test composition B contains neither. Hence, the two tested compositions differ by more than the addition of the component having two active hydrogen atoms. Since Henton discloses and claims the addition of a hardener, and the hardener is not part of test composition B, the comparison is not truly 11Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 NextLast modified: November 3, 2007