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Celanese v. ITC: Secret Process, Public Sales

Federal Circuit, decided 12 August 2024. Read from the opinion; quotations verified against the court's text.

Holding

On August 12, 2024 the Federal Circuit affirmed that Celanese's patents on a manufacturing process were invalid under the on-sale bar because it had sold products made by that secret process in the United States more than a year before filing, and held that the America Invents Act did not change the long-standing rule that such sales trigger the bar.

Celanese made an artificial sweetener using a process it kept secret, sold the sweetener in the United States for years, and then filed patents on the process. The Federal Circuit held the patents invalid.

Under long-standing law, selling the product of a secret process starts the clock on patenting the process, and the America Invents Act did not change that.

The commercial decision that felt safe, keep the method confidential and sell the output, is the decision that forfeited the patent.

What This Case Is Not

This page does not compute your deadline. The useful takeaway, talk to counsel before you sell, sits one step away from "you have a year from your first sale," which is a legal deadline stated to someone whose facts nobody has assessed. What happened to Celanese is described here. What it means for a particular product and a particular sale is not.
  • It does not tell you when your clock started, or whether one did.
  • It does not mean keeping a process secret is a mistake. It means secrecy and selling the output are a combination worth talking through before, not after.
  • It does not disturb the ordinary on-sale analysis for product claims, which raises its own questions independently. What is distinctive here is the combination: claims to a process that stayed secret, and commercial sales of what that process made.

Educational, not legal advice. Consult a qualified patent attorney about your own timing, disclosure and claims.

Sources

  • Celanese International Corp. v. International Trade Commission, No. 22-1827 (Fed. Cir. Aug. 12, 2024)
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