PTAB

IPR2017-01321

Afton Chemical Corporation v. Infineum International Limited

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1. Case Identification

2. Patent Overview

  • Title: Lubricating Oil Compositions
  • Brief Description: The ’274 patent relates to lubricating oil compositions for diesel engines. The invention is described as a formulation containing relatively high concentrations of magnesium from magnesium-containing detergents without causing unacceptable levels of engine bore polishing or ash, purportedly by including a specific amount of an antioxidant component.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-11 - Claims 1-11 are anticipated under 35 U.S.C. §102(b) by Colclough.

  • Prior Art Relied Upon: Colclough (E.P. Publication No. 0 280 579 A2).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Examples V and VI in Colclough expressly disclose every element of the challenged claims. Colclough describes lubricating compositions for diesel engines containing a base oil, an overbased magnesium sulfonate detergent with a Total Base Number (TBN) of 400 (exceeding the claimed >350 mg/g KOH), and a magnesium content of 0.15 wt.% (exceeding the claimed >0.05 wt.%). Petitioner asserted that Colclough’s examples also disclose the claimed antioxidant component—a combination of ash-free aminic and sulfur-free phenolic antioxidants—at a concentration of 0.7 wt.% (within the claimed 0.6 to 3.0 wt.% range). Finally, Petitioner provided measured and calculated sulfated ash (SASH) content for Colclough’s examples (e.g., 1.18 mass% for Ex. VI), which falls squarely within the claimed range of 0.6 to 2.0 mass%.

Ground 2: Obviousness of Claims 1-12 - Claims 1-12 are obvious over Nicholson in view of ACEA 2004.

  • Prior Art Relied Upon: Nicholson (E.P. Publication No. 0 663 436 A1) and ACEA 2004 (European Oil Sequences 2004).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Nicholson's Example IV discloses a lubricating oil for heavy-duty diesel engines that contains all the major components of claim 1: a base oil, antioxidants (including ash-free aminic and sulfur-free phenolic types), and an overbased magnesium sulfonate detergent with a TBN of 400. While Nicholson did not expressly state the final magnesium or SASH concentrations, Petitioner argued these properties would have been obvious or were inherently disclosed. A reconstruction and testing of Nicholson's Example IV allegedly yielded a magnesium content of 0.2 wt.% and a SASH content of 1.12 mass%, both meeting the limitations of claim 1.
    • Motivation to Combine: ACEA 2004 is an industry standard that defines performance specifications for lubricants, including maximum SASH levels for different engine categories (e.g., a 2.0 mass% limit for the E7 specification). Petitioner argued a person of ordinary skill in the art (POSITA) would have been motivated to formulate the composition of Nicholson to meet the well-known ACEA 2004 standards. This routine optimization to meet industry requirements would have naturally led to a composition with the SASH and magnesium content recited in the ’274 patent claims.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because combining known additives according to established industry standards like ACEA 2004 was a common and predictable formulation practice.

Ground 3: Obviousness of Claims 1-12 - Claims 1-12 are obvious over Fetterman in view of Arrowsmith ‘371.

  • Prior Art Relied Upon: Fetterman (E.P. Publication No. 0 311 318 A1) and Arrowsmith ‘371 (Application # 2004/0127371).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Fetterman's Examples A and B disclose heavy-duty diesel lubricating oils that meet most limitations of claim 1, including an overbased magnesium sulfonate detergent (TBN 400) providing sufficient magnesium (0.11-0.13 wt.%) and SASH levels (0.84-0.85 mass%). However, Fetterman used a sulfurized phenol antioxidant. Fetterman itself suggests that other oxidation inhibitors, including ash-free aminic and sulfur-free phenolic compounds, could be used.
    • Motivation to Combine: Arrowsmith ‘371, which addresses the industry-wide trend toward low-SAPS (Sulfated Ash, Phosphorus, Sulfur) lubricants, explicitly teaches that "the use of sulphur-containing additives should be minimized or avoided" to ensure compatibility with modern exhaust after-treatment systems. A POSITA, aware of this strong industry pressure, would have been motivated to modify Fetterman’s composition by replacing the sulfurized antioxidant with a known sulfur-free alternative, as taught by both Fetterman and Arrowsmith ‘371.
    • Expectation of Success: The substitution of one known type of antioxidant for another to achieve a known benefit (reduced sulfur) was a predictable design choice for a POSITA, who would have reasonably expected the resulting low-SAPS composition to function as intended.

  • Additional Grounds: Petitioner asserted that claim 13, which requires a salicylate detergent, is obvious over Colclough in view of Arrowsmith ‘371, and also over Nicholson/ACEA 2004 in further view of Arrowsmith ‘371. The core of these arguments was that Arrowsmith ‘371 teaches that sulfur-free salicylate detergents are preferred, providing the motivation to modify the primary reference compositions accordingly to reduce sulfur content.

4. Key Claim Construction Positions

  • “selected from one or more ash-free aminic and/or sulfur-free phenolic compounds”: Petitioner argued that because independent claim 1 uses the open-ended transitional phrase "comprising," this limitation should be interpreted to mean the antioxidant component must include at least one of the listed compounds, but does not exclude the presence of other types of antioxidants.
  • “optionally”: Petitioner contended that this term, applied to the metal hydrocarbyl dithiophosphate (d) and calcium detergent (e) components, should be construed to mean that these components may or may not be part of the final composition. The inclusion of 0.0 mass% as a lower limit for component (d) was cited as further evidence of its optional nature.

5. Arguments Regarding Secondary Considerations

  • Petitioner preemptively argued that any secondary considerations of non-obviousness, such as the "surprising and unexpected effects" (i.e., reduced bore polishing) argued by the Patent Owner during prosecution, are insufficient to overcome the obviousness grounds. Petitioner asserted that:
    • The alleged benefit is merely the discovery of a new property of a previously known composition, which cannot confer patentability on the known composition itself.
    • The Patent Owner’s test data is not commensurate with the full scope of the claims, as the examples only cover a narrow range of the claimed magnesium and antioxidant concentrations and do not show the entire range is effective.
    • The improved performance is not unexpected, as the prior art already showed acceptable bore polishing results, and the lower SASH content in the patent's examples is an expected result of using less calcium detergent.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-13 of the ’274 patent as unpatentable.