How does criticality affect anticipation of ranges?

Criticality can play a significant role in determining whether a prior art range anticipates a claimed range, especially when the ranges overlap or are close. If an applicant can demonstrate that the claimed range is critical to the invention’s function or produces unexpected results, it may overcome an anticipation rejection.

The MPEP 2131.03 discusses this concept in relation to the case of Atofina v. Great Lakes Chem. Corp:

“Patentee described claimed temperature range as ‘critical’ to enable the process to operate effectively, and showed that one of ordinary skill would have expected the synthesis process to operate differently outside the claimed range.”

In this case, the court held that a reference temperature range of 100-500 degrees C did not anticipate the claimed range of 330-450 degrees C, despite some overlap, because the patentee had demonstrated the criticality of the narrower range.

If criticality is established, it may render the claims nonobvious even if the prior art discloses an overlapping range. The MPEP states:

“If the prior art disclosure does not disclose a claimed range with ‘sufficient specificity’ to anticipate a claimed invention, any evidence of unexpected results within the narrow range may render the claims nonobvious.”

Therefore, demonstrating criticality can be a powerful tool for overcoming both anticipation and obviousness rejections based on overlapping ranges.

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Topics: MPEP 2100 - Patentability, MPEP 2131.03 - Anticipation Of Ranges, Patent Law, Patent Procedure
Tags: Anticipation, Criticality, Ranges, unexpected results