How does combining equivalents affect patent obviousness?
Combining equivalents can affect patent obviousness by making a new composition or method prima facie obvious. According to MPEP 2144.06:
“It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose…. [T]he idea of combining them flows logically from their having been individually taught in the prior art.”
This principle is based on the In re Kerkhoven case, where claims to a process of preparing a spray-dried detergent by mixing two conventional spray-dried detergents were held to be prima facie obvious. The rationale is that if two components are known to serve the same purpose individually, combining them for that same purpose would be logical and potentially obvious to a person skilled in the art.
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