Daikin Indus. v. Chemours Co. (Fed. Cir. 2021) (non-precedential)
The PTAB sided with the patent challenger Chemours — finding claims 1-5 of Daikin’s U.S. Patent No. 9,574,123 unpatentable as obvious. On appeal, the Federal Circuit has affirmed.
The patent here is covers a refrigerant mixture of three compounds that I have labeled A, B, and C.
- A: hydrofluorocarbons (HFCs);
- B: hydrofluoroolefins (HFOs) (such as HFO-1234yf); and
- C: a chlorine-containing hydrocarbon refrigerant (such as chlorofluorocarbon (CFC)).
The HFCs and HFOs apparently have lower global environmental impact, but lack the lubricant-performance of chlorine-containing CFCs. The invention balances these factors by mixing them all together. The prior art disclosed the combination of A&B and also the combination of B&C, but did not expressly disclose the full three-way combination.
Substitution: In its discussion, the court focused on the obviousness of a substitution because the prior art spoke of two forms HFO-1234yf. One form that only contains HFOs (B only); and another form that includes small amounts of CFCs (B and C). The PTAB and FedCir agreed that, in this case it would have been obvious to start with the A&B combination and then substitute the B&C version of HFO-1234yf in place of the B only version found in the primary reference.
The US Supreme Court most recently wrote about obviousness substitutions in KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007). There, the court explained:
[W]hen a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result. . . . [W]hen a patent simply arranges old elements with each performing the same function it had been known to perform and yields no more than one would expect from such an arrangement, the combination is obvious.”
KSR. Here, there is no question that all of the elements were known in the art, the but the patentee argued unpredictability of results especially because the proposed substitution disclosed in the prior art also included other contaminants that could impact performance.
On appeal, the Federal Circuit gave deference to the PTAB’s fact finding — and concluded that it was supported by substantial evidence. In particular, the Board had relied upon expert testimony that the result was predictable and that “trivial
increase [in the contaminants] would not have prevented a [skilled artisan] from making such a substitution.”
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1. A composition comprising HFC and HFO, wherein the composition comprises:
- HFC-32, HFC-125, HFC-134a, and HFC-134 as the HFC;
- at least one of HFO-1234yf and HFO-1234ze as the HFO; and
- at least one member selected from the group consisting of HCC-40, HCFC-22, HCFC-124, CFC-115, HCFC-1122, CFC-1113, and 3,3,3-trifluoropropyne as a third component.