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IPR2018-01768

Hubei Grand Life Science Technology Co Ltd v. Vitaworks IP LLC

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petition

1. Case Identification

2. Patent Overview

  • Title: Process for Producing Taurine
  • Brief Description: The ’890 patent describes a process for producing taurine through the ammonolysis of alkali isethionate. The purported novelty involves improving taurine yield by mixing the alkali isethionate with a solution containing byproducts of the reaction (alkali ditaurinate or tritaurinate) before subjecting the mixture to ammonolysis.

3. Grounds for Unpatentability

Ground I: Obviousness over Liu 2013 and DD 023 - Claims 1, 3-10 are obvious over Liu 2013 in view of DD 023.

  • Prior Art Relied Upon: Liu 2013 (a journal article titled "Process Design of Taurine Ammonolysis" published in China Chemical Trade, Aug. 2013) and DD 023 (German Patent No. DD 219 023).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Liu 2013 teaches the core process of claim 1: producing taurine via the ammonolysis of sodium isethionate. Critically, Liu 2013 disclosed recycling the "mother liquor" remaining after taurine extraction back into the reaction. Component analysis in Liu 2013 showed this mother liquor contains sodium ditaurinate, a claimed byproduct. Therefore, Liu 2013's process involved mixing alkali isethionate with a solution of alkali ditaurinate before ammonolysis. DD 023, which discloses the same ammonolysis method, was cited to confirm that ditaurinate and tritaurinate are well-known, inevitable byproducts of the reaction. The remaining steps of claim 1, such as using a catalyst (sodium hydroxide), adding excess ammonia, neutralizing with acid, and separating the final product, were all disclosed in Liu 2013 as part of this standard process.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) seeking to improve taurine yield—the same problem addressed by the ’890 patent and Liu 2013—would combine these references. Liu 2013 explicitly stated that recycling the mother liquor containing ditaurinate would increase the taurine yield. A POSA would also be motivated by fundamental chemical principles, such as Le Châtelier's Principle, to add known byproducts (ditaurinate and tritaurinate, identified by DD 023) at the start of the reversible ammonolysis reaction to shift the equilibrium toward the desired product, taurine.
    • Expectation of Success: A POSA would have a reasonable expectation of success because the combination involved applying a predictable chemical principle to a well-established industrial process to achieve the known goal of increased yield, as suggested by Liu 2013.

Ground II: Obviousness over Wu 2004, DD 023, and Liu 2013 - Claims 1, 3-10 are obvious over Wu 2004 in view of DD 023 and Liu 2013.

  • Prior Art Relied Upon: Wu 2004 (a journal article titled "Optimization on Ammonolysis in Manufacturing Method of Taurine" published in Journal of Hubei Polytechnic University, Feb. 2004), DD 023 (German Patent), and Liu 2013 (journal article).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Wu 2004 taught the same process of producing taurine from sodium isethionate. Wu 2004 explicitly disclosed that the reaction produces sodium ditaurinate as a byproduct and taught that after taurine is separated, the resulting byproducts "are fed again into the ammonolysis system," whereby the total yield "may very well increase" to over 97%. This directly taught mixing the starting material (a new batch of sodium isethionate) with the byproduct ditaurinate. As in Ground I, DD 023 confirmed the identities of the byproducts. The combination also taught the remaining process steps, including using a catalyst (sodium carbonate), neutralization, and product separation. Liu 2013 was cited to support arguments for dependent claims related to the cyclic process.
    • Motivation to Combine: The motivation was to improve the yield of the taurine production process, a goal explicitly stated in Wu 2004. A POSA would be motivated by Wu 2004's clear disclosure that recycling ditaurinate increases the overall taurine yield to levels exceeding 97%, which directly addresses the objective of the ’890 patent.
    • Expectation of Success: A POSA would have a high expectation of success because Wu 2004 provided experimental examples and data demonstrating that its process, including the recycling of ditaurinate, successfully achieves high yields.

Ground III: Obviousness over Chen, DD 023, and Wu 2004 - Claims 1, 3-10 are obvious over Chen in view of DD 023 and Wu 2004.

  • Prior Art Relied Upon: Chen (Application # 2014/0121405), DD 023 (German Patent), and Wu 2004 (journal article).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Chen disclosed two cyclic processes for producing taurine that included ammonolysis of sodium isethionate as a fundamental step. In these cyclic processes, the mother liquor was recycled to form additional taurine. Petitioner asserted that because the ammonolysis reaction invariably produces ditaurinate and tritaurinate (as confirmed by DD 023 and the ’890 patent itself), these byproducts would necessarily be present in Chen's recycled mother liquor. Therefore, Chen's cyclic process inherently taught mixing isethionate with its byproducts. Wu 2004 was cited to provide the explicit teaching that this recycling method could achieve yields above 97%.
    • Motivation to Combine: A POSA reviewing Chen's cyclic process would be motivated to optimize its yield. Wu 2004, which addressed the same technical problem, provided the blueprint for achieving very high yields by demonstrating the effectiveness of recycling ditaurinate. A POSA would therefore combine the teachings to implement the cyclic process of Chen with the yield-optimizing knowledge from Wu 2004.
    • Expectation of Success: A POSA would reasonably expect success because both Chen and Wu 2004 teach cyclic taurine production processes. Combining them would involve using Wu 2004's established optimization techniques to enhance Chen's known process, a predictable path to improvement.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1 and 3-10 of the ’890 patent as unpatentable.