Appeal No. 2006-3224 Page 6 Application No. 10/063,656 1 to about 15 microns,” the Examiner cites Callegaro and Grinstaff for teaching particles of the claimed size which are utilized in a biomedical environment. Id. Appellants argue that “Rembaum is directed to a conventional emulsion polymerization process for forming the polymer microsphere, not an emulsion/ aggregation process as required in the claimed invention.” Brief, page 9. The claimed emulsion/aggregation process, on the other hand, is a materially different process that takes polymer particles prepared by standard emulsion polymerization techniques (such as disclosed in Rembaum), in the general 50-500 nm size range, and aggregates them under controlled particle growth conditions to make larger particles that are in the size range of 1 to 15 microns (1,000-15,000 nm) with a narrow particle geometric size distribution. The result of the claimed emulsion/aggregation process is thus relatively larger sized particles, but which have a narrow particle geometric size distribution, such as less than about 1.25. Nowhere does Rembaum teach or suggest that an emulsion/aggregation process could or should be used in place of the disclosed conventional emulsion polymerization process. Brief, page 12. Rembaum describes a method of making uniformly-sized polymeric microspheres having a selected uniform diameter below 3500 Å. Rembaum, column 1, lines 14-16; column 2, lines 13-16. The microspheres are produced by “emulsion polymerization.” Id., column 2, line 41. This process is described to include a step of forming a polymerization mixture comprising monomers, catalyst, and a surface active agent. Id., column 4, lines 10-60. The mixture is “tumbled,” and then polymerization is initiated by applying heat to the mixture, which results in the formation of the microspheres. Id., column 4, lines 53-65; column 10, claims 9-11. We agree with Appellants that Rembaum’s process does not carry out “aggregating and coalescing said polymeric resin into polymeric microspheres” as required by claim 1. PolymericPage: Previous 1 2 3 4 5 6 7 8 9 10 11 NextLast modified: November 3, 2007