AfTon Chemical Corp v. Infineum Intl Ltd

1. Case Identification

• Case #: IPR2017-01321
• Patent #: 8,076,274
• Filed: April 25, 2017
• Petitioner(s): Afton Chemical Corporation
• Patent Owner(s): Infineum International Limited
• Challenged Claims: 1-13

2. Patent Overview

• Title: Lubricating Oil Compositions
• Brief Description: The ’274 patent relates to lubricating oil compositions for diesel engines. The technology centers on using an overbased magnesium detergent with a high total base number (TBN) in combination with a specified amount of ash-free aminic and/or sulfur-free phenolic antioxidants to reduce engine bore polishing and control sulfated ash levels.

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 of Colclough each explicitly disclose every limitation of claims 1-11. Colclough teaches lubricating compositions for diesel engines containing an overbased magnesium sulfonate detergent with a TBN of 400 (exceeding the claimed >350 mg/g KOH), which provides 0.15 mass% magnesium (Mg) to the composition (meeting the >0.05 mass% and other dependent claim limitations). The examples also include a combination of an ash-free aminic antioxidant and a sulfur-free phenolic antioxidant at 0.7 wt.% (meeting the claimed 0.6-3.0 mass% range). Petitioner asserted that both measured and calculated sulfated ash (SASH) content for Colclough’s examples (0.89-1.28 mass%) fall squarely within the claimed range of 0.6-2.0 mass%.

Ground 2: Obviousness over Nicholson and ACEA 2004 - 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 Example IV of Nicholson discloses a lubricating oil for heavy-duty diesel engines containing the key claimed components: an overbased magnesium sulfonate detergent with a TBN of 400 and a mixture of ash-free aminic and sulfur-free phenolic antioxidants. Although Nicholson does not explicitly state the final Mg or SASH content, Petitioner argued that the disclosed components and their concentrations inherently or obviously lead to a composition meeting the claim limitations. For example, the phosphorus content from the zinc dialkyldithiophosphate in Nicholson’s Example IV meets the range required by claim 12.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to formulate the composition of Nicholson to meet prevailing industry standards, such as the ACEA 2004 specifications. ACEA 2004, which defined performance requirements for heavy-duty diesel engine oils, provided explicit upper limits for SASH (e.g., 2.0 mass% for the E7 category) that directly align with the claimed SASH range. This standard would have guided a POSITA to select a commercially available magnesium detergent for Nicholson’s formulation that would result in Mg and SASH levels meeting all limitations of the challenged claims.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success in formulating Nicholson’s composition to meet ACEA 2004 standards, as it involved the routine optimization of known additives to satisfy well-defined performance criteria.

Ground 3: Obviousness over Fetterman and Arrowsmith ‘371 - 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 Examples A and B of Fetterman disclose lubricating oil compositions for diesel engines that satisfy nearly all limitations of claim 1, including an overbased magnesium sulfonate detergent (TBN 400), Mg content around 0.11-0.13 mass%, and SASH content of 0.84-0.85 mass%. The key difference is that Fetterman employs a sulfurized phenol antioxidant.
  • Motivation to Combine: A POSITA would have been motivated to replace Fetterman’s sulfurized antioxidant with a sulfur-free alternative as taught by Arrowsmith ‘371. This motivation arose from the well-established industry trend at the time to reduce sulfated ash, phosphorus, and sulfur (SAPS) levels in lubricants. Arrowsmith ‘371 explicitly teaches minimizing or avoiding sulfur-containing additives to ensure compatibility with modern exhaust after-treatment systems, such as catalytic converters, which are poisoned by sulfur.
  • Expectation of Success: A POSITA would have expected success in substituting the antioxidant, as it was a predictable design choice to replace a known component with a functionally similar, sulfur-free alternative to meet pressing industry demands for lower SAPS lubricants.
• Additional Grounds: Petitioner asserted additional obviousness challenges against claim 13, which requires a salicylate detergent. These grounds argued a POSITA would have been motivated to combine the compositions of Colclough (Ground 4) or Nicholson/ACEA 2004 (Ground 5) with the teachings of Arrowsmith ‘371, which explicitly discloses salicylate detergents as a preferred, sulfur-free option.

4. Key Claim Construction Positions

• Petitioner argued that the claim term "selected from one or more ash-free aminic and/or sulfur-free phenolic compounds" should be interpreted in light of the open-ended "comprising" transition phrase of claim 1. This construction means the claimed antioxidant component must include at least one of the specified types, but does not exclude the presence of other, additional antioxidants in the composition.

5. Key Technical Contentions (Beyond Claim Construction)

• A central technical contention was that a POSITA could and would determine the SASH content of a prior art composition even if it was not explicitly reported. Petitioner argued that because the prior art compositions (e.g., in Colclough and Nicholson) contain metal-containing additives, they necessarily have a measurable SASH content. Petitioner supported its anticipation and obviousness arguments by providing expert declarations with both measured SASH values (from recreated compositions) and calculated SASH values based on widely known elemental weighting factors, asserting both methods confirm the prior art falls within the claimed ranges.

6. Relief Requested

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