top of page

CAFC Vacates and Remands ITC Ruling on Sinorgchem’s Infringement of Flexsys 4-ADPA Process Pat

There was a major development on Friday in the ongoing patent infringement dispute between Flexsys and Shandong Sinorgchem regarding process technology for the manufacture of 4-ADPA (4-aminodiphenylamine), the precursor to 6PPD rubber antidegradants. On December 21, 2007, the US Federal Appeals Court (CAFC) issued a ruling that vacated and remanded a February 2006 decision by the US International Trade Commission that found that Sinorgchem had infringed on the Flexsys patents (Flexys America’s U.S. Pat. Nos. 5,117,063 and 5,608,111). Here is a copy of the decision.

Here is some background on the case: In February 2005, Flexsys America LP (then a joint venture between Solutia and Akzo Nobel, now a subsidiary of Solutia) filed a complaint with the US International Trade Commission alleging that Sinorgchem was violating its patents for 4-ADPA production under Section 337 of the Tariff Act of 1930. The process in question is a continuous catalytic hydrogenation technology, which involves reacting nitrobenzene with a solvent (aniline) in the presence of a suitable base (tetramethylammonium hydroxide, or TMAH) and a controlled amount of protic material (or proton donor — in this case water).

Given that there is no dispute that the two processes utilize the same materials and basic steps, the initial finding and the most recent appeal focussed on the definition of the term “controlled amount of protic material” in the original patent descriptions. The central question is whether the Flexsys patents require a specific amount of protic material (defined as “at most 4% when aniline is the solvent”) or whether the quantity required is variable between upper and lower limits. Sinorgchem argued that its process uses more protic material than is described in the Flexsys patent (i.e., more then 4%), meaning its process does not infringe. Flexsys argued that the amount of protic material is variable, meaning that the Sinorgchem process does infringe.

The initial February 2006 ITC ruling sided with Flexsys on this issue, but on appeal a majority of the CaFC’s three-judge panel agreed with Sinorgchem’s definition and therefore concluded that Sinorgchem had not literally infringed on the Flexsys patents. It therefore vacated and remanded the ITC decision. One member of the three member panel, District Judge Newman, dissented, stating in part,

“. . . my colleagues have made finding contrary to the detailed and unchallenged text of the patent specifications, and have construed the claims so that they exclude a major part of the invention described in the patents.”

Note that the finding addressed only literal infringement; it did not reach the question of whether Sinorgchem’s process would infringe under the doctrine of equivalents. The decision stated,

“On remand, the ITC should address the claim of doctrine of equivalents infringement in light of our holding that there was no literal infringement.”

Here is some commentary on the CAFC ruling.

From Anticipate This!, a patent and trademark law blog, comes an interesting and well considered commentary on the decision. Here is the link.

The Patent Prospector, a forum on patent information and opinion, also has a commentary. Here is the link.

For an overview of recent restructuring at Flexsys following the acquisition by Soluia, click here.

Update: A source at Flexsys notes that despite the ruling the patent is valid and the Exclusion Order against Sinorgchem 6PPD and other 4-APDA derivatives remains in effect. Flexsys plans to appeal the ruling.

0 views0 comments

Recent Posts

See All

Emerald closing Illinois accelerator site

Emerald Performance Materials L.L.C. is closing a chemical plant in Henry, Illinois, a move that will impact more than 50 workers at the facility. Layoffs at the plant will begin April 6 and be comple

Comments


bottom of page