## Facts

- Celanese International Corp. and affiliates (collectively, “Celanese”) owned U.S. patents claiming a chemical **process** for manufacturing the artificial sweetener **acesulfame potassium (Ace‑K)**.
- Celanese filed a petition at the U.S. International Trade Commission (ITC) under **19 U.S.C. § 1337**, alleging that Anhui Jinhe Industrial Co. and related entities (collectively, “Jinhe”) imported Ace‑K made using a process that infringed Celanese’s process patents.
- The asserted claims were **process claims**; Ace‑K as a product was not claimed.
- Jinhe moved for **summary determination** that there was no Section 337 violation because the asserted claims were invalid under the **AIA on‑sale bar**, **35 U.S.C. § 102(a)(1)**.
- It was undisputed that Celanese had been **selling products made using the claimed process for more than one year before** the patents’ **effective filing date of September 1, 2016**.
- Celanese argued the on‑sale bar should not apply because the **process itself remained secret** and was **not sold or disclosed** to third parties before the effective filing date; only goods made using the process were sold.
- The ITC Administrative Law Judge granted Jinhe’s motion for summary determination.
- The Commission denied Celanese’s petition for review, making the ALJ’s determination the Commission’s final decision.
- Celanese appealed to the U.S. Court of Appeals for the Federal Circuit.

## Issues

1. Whether, under **AIA 35 U.S.C. § 102(a)(1)**, pre‑critical‑date sales of **products made by a secret process** can place the claimed **process** “on sale,” barring patentability.
2. Whether the phrase **“or otherwise available to the public”** in § 102(a)(1) limits “on sale” to transactions that publicly disclose the claimed invention.

## Decision

- The Federal Circuit **affirmed** the ITC’s final decision of **no Section 337 violation**.
- The court held that the **AIA did not change** the meaning of “on sale” for purposes of § 102(a)(1).
- Celanese’s **pre‑critical‑date commercial sales** of Ace‑K made by the claimed process triggered the **on‑sale bar**, rendering the asserted process claims **invalid**, even though the process details were kept secret.

## Legal Principles

- Under **35 U.S.C. § 102(a)(1)**, a claimed invention is unpatentable if, before the effective filing date, it was **on sale** in a manner that qualifies under the statute as interpreted by controlling precedent.
- For **process claims**, commercial exploitation may occur through **sales of products made by the process**; the process need not be sold, licensed, or revealed to customers for the on‑sale bar to apply.
- The AIA’s inclusion of **“or otherwise available to the public”** does not impose a blanket requirement that an “on sale” event must itself make the claimed invention publicly available.
- When Congress reenacts statutory language with an established judicial meaning (including “on sale”), courts generally presume continuity absent a clear indication of change.
- Supreme Court guidance interpreting the AIA on‑sale bar (including **Helsinn**) supports that a sale can trigger the bar even if the transaction does not disclose the invention’s details.

## Conclusion

Because Celanese commercially sold Ace‑K made using its claimed (but undisclosed) manufacturing process more than one year before the patents’ effective filing date, the AIA on‑sale bar invalidated the asserted process claims, leaving no basis for Section 337 relief at the ITC.


Celanese International Corp. v. International Trade Commission, 111 F.4th 1338 (Fed. Cir. 2024)