PTAB

PGR2019-00046

Solvay USA Inc v. World Sources Enterprises LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Liquid Formulations of Urease Inhibitors for Fertilizers
  • Brief Description: The ’108 patent relates to solvent formulations for incorporating the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) into urea-based fertilizers. The technology focuses on using the polar aprotic solvent dimethyl sulfoxide (DMSO) to create stable, effective, and less toxic fertilizer compositions compared to prior art formulations.

3. Grounds for Unpatentability

Ground 1: Claims 1-20 are obvious over Iannotta in view of the CN 400 Patent.

  • Prior Art Relied Upon: Iannotta (Application # 2013/0145806) and CN 400 Patent (Chinese Patent No. 101200400 B).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Iannotta disclosed all elements of the independent claims except for the specific use of dimethyl sulfoxide (DMSO). Iannotta taught liquid fertilizer compositions comprising urea and a urease inhibitor, specifically NBPT, solubilized within an aprotic solvent. Petitioner asserted that Iannotta’s disclosure of NBPT concentrations up to 50% by weight rendered the claimed range of "45-5%" in claim 1 obvious. The CN 400 Patent supplied the missing element by explicitly teaching a "fertilizer core" that includes urea, the urease inhibitor NBPT, and an organic solvent, which can be DMSO. The combination of Iannotta’s solvent system and the specific disclosure of DMSO from the CN 400 Patent rendered the limitations of independent claims 1, 6, and 18 obvious. For dependent claims, Petitioner contended that Iannotta also disclosed the use of co-solvents, including protic solvents (e.g., glycerine) and other aprotic solvents (e.g., alkylene carbonates), as well as additives like surfactants and dyes, meeting the limitations of claims 2-5 and 10-14.
    • Motivation to Combine: A POSITA would combine these analogous art references to solve a known problem. Petitioner asserted that Iannotta expressly stated an objective to create a low-cost solvent system with a "favorable toxicological and/or ecological profile." At the time of the invention, DMSO was widely known in the art as a preeminent, low-toxicity, and highly effective solvent for NBPT, making it particularly suitable for agrochemical use. The CN 400 Patent provided the explicit suggestion to use DMSO for this exact purpose. Therefore, a POSITA, guided by Iannotta's objective, would have been motivated to consult the CN 400 Patent and incorporate its teaching of DMSO to create an improved, less toxic formulation.
    • Expectation of Success: A POSITA would have had a high expectation of success. The combination involved using a well-known solvent (DMSO) with a known high solubility for NBPT in a fertilizer application where both were known to be effective. The result would be a predictable improvement in the toxicological profile of the formulation without compromising performance.

Ground 2: Claims 1, 3-9, and 11-20 are obvious over Kolc in view of the CN 400 Patent.

  • Prior Art Relied Upon: Kolc (Patent 4,530,714) and CN 400 Patent (Chinese Patent No. 101200400 B).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that the older Kolc reference taught foundational urease-inhibited fertilizer compositions containing urea, NBPT, and an organic aprotic solvent. Kolc’s disclosure of using up to 20 wt% NBPT in a solution fell squarely within the claimed range of "45-5%" inhibitor, which would inherently comprise "55-95%" solvent, thus meeting the concentration limitations of the independent claims. The CN 400 Patent supplied the teaching of using DMSO as the specific aprotic solvent for NBPT. Regarding dependent claims, Petitioner argued Kolc taught using surfactants and protic solvents (water, alcohols), while the CN 400 Patent taught using co-solvents like ethylene glycol. The combination of these teachings rendered the additional limitations of the dependent claims obvious.
    • Motivation to Combine: The motivation was presented as a simple and predictable substitution of one known solvent for another to achieve known benefits. Kolc taught general organic solvents, but also disclosed using deuterated DMSO to dissolve NBPT for NMR analysis, confirming the art's awareness that DMSO was an excellent solvent for NBPT. A POSITA seeking to improve Kolc's decades-old formulation would have been motivated by the well-known low toxicity and superior solvency of DMSO, as explicitly taught for the same purpose in the CN 400 Patent, to substitute it for the solvents in Kolc.
    • Expectation of Success: Success was predictable because the combination involved replacing a generic organic solvent with a specific, known-superior solvent from a finite list of candidates for use with NBPT. This would predictably yield a more desirable formulation with known characteristics.

  • Additional Grounds: Petitioner asserted that claims 2 and 10 are obvious over the combination of Kolc and the CN 400 Patent in further view of Iannotta. This ground argued that Iannotta provided the specific teachings for adding co-solvents (e.g., alkylene carbonates) to the base composition established by Kolc and the CN 400 Patent.

4. Key Arguments on PGR Eligibility

  • Petitioner contended that the ’108 patent was eligible for Post-Grant Review (PGR), which requires at least one claim to have an effective filing date on or after March 16, 2013, despite the patent claiming priority to earlier applications.
  • The core of the argument was that the earliest priority document, U.S. Provisional Application No. 61/708,105 (the 105 Provisional), failed to provide adequate written description support under 35 U.S.C. §112 for at least claims 6-20 of the issued patent.
  • Specifically, Petitioner argued the '105 Provisional only disclosed a solubility concentration of NBPT in DMSO of "about 5-45% by weight," whereas issued claims 6 and 18 required compositions with significantly higher urease inhibitor concentrations (e.g., "75-5%" and "58.9-5%"). Because these claimed concentrations were not possessed by the inventor as of the provisional filing date, claims 6-20 were not entitled to the earlier, pre-AIA priority date, making the entire patent eligible for PGR.

5. Relief Requested

  • Petitioner requested institution of a post-grant review and cancellation of claims 1-20 of the ’108 patent as unpatentable.