Chinta & Fratangelo LLP

Wellman, Inc. v. Eastman Chemical Co. – A Trade Secret Does Not Excuse Best Mode

Wellman lost a patent infringement claim on the grounds that it failed to disclose a specific preferred formulation known at the time the patent was filed, and also because it attempted to hold back part of the invention as a trade secret.   Wellman, Inc. v. Eastman Chemical Co., No. 2010-1249 (Fed. Cir. 4/29/2011).

Wellman had two patents on PET resins for beverage bottles that had favorable characteristics. Wellman had a specific formula at the time the patents were filed, but the patents did not disclose the preferred formula (“Ti818”) or any other specific formulae.  Claim 1 of the ‘317 patent, stated to be exemplary, had generic chemical limitations and functional elements to a “crystallization exotherm peak temperature” and an “L* luminosity value.”  Wellman alleged that Eastman infringed its patents. Eastman responded that the patents were indefinite and didn’t meet the best mode requirement.

The district court granted-in-part Eastman’s motion for lack of best mode, holding that key claims were invalid for want of best mode. The district ct found that Ti818 was a preferred formula that the time of filing.  The district ct also found that the patents did not disclose the use of carbon black, and that Wellman sought to retain that as a trade secret.

The Federal Circuit panel (opinion by Rader) affirmed on the best mode holding.  The panel noted that the actual formula of Ti818 was outside the claimed ranges for some ingredients. The panel concluded that Wellman concealed its invention. “By masking what at least one inventor considered the best of these slow-crystallizing resins, Wellman effectively concealed its recipe for Ti818.” Slip op. at 18.  The attempt to hold back the carbon black additive as a trade secret was condemned as an intentional concealment. Slip op. at 18–19. Choosing to maintain part of the invention as a trade secret “does not excuse Wellman’s compliance with the best mode requirement.” Slip op. at 19. The indefiniteness claim was rejected by the panel.

Comment: mixing trade secrets and patented inventions is not a good idea.  Especially in this case where the carbon black appeared to be essential for practicing the invention to get PET with the desired characteristics.