PTAB

IPR2015-00737

Nestlé Purina PetCare Company v. Oil-Dri Corporation of America

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1. Case Identification

2. Patent Overview

  • Title: Clumping Animal Litter
  • Brief Description: The ’019 patent discloses a clumping animal litter composed of a free-flowing mixture of particulate swelling and non-swelling clay. The invention is based on the principle that having the mean particle size of the non-swelling clay be greater than that of the swelling clay allows for a more effective clumping litter using less than 60% swelling clay by weight.

3. Grounds for Unpatentability

Ground 1: Claims 1-4, 6-13, 30, and 32 are anticipated under 35 U.S.C. §102 by Hughes.

  • Prior Art Relied Upon: Hughes (Patent 5,386,803).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hughes, titled "Animal Dross Absorbent and Method," discloses every element of the challenged claims. Hughes teaches a clumping litter comprising a mix of discrete, free-flowing particles of non-swelling clay (calcium bentonite) and swelling clay (sodium bentonite). Petitioner asserted that Hughes expressly discloses particle size ranges that meet the limitations of claim 1. Specifically, Hughes discloses non-swelling clay with a mean particle size of 1.975 mm (less than the claimed 4 mm) and swelling clay with a mean size of 1.7 mm or 1.975 mm (less than the claimed 2 mm). Crucially, Hughes teaches embodiments where the mean size of the non-swelling clay (1.975 mm) is greater than that of the swelling clay (1.7 mm). Petitioner further contended Hughes anticipates the dependent claims by disclosing the use of sodium bentonite (claim 2) and smectite (claim 3), a particle size ratio of 1.16:1 that falls within the claimed 1.1:1 to 4:1 range (claim 4), and various weight percentages of non-swelling clay (e.g., "50% to about 89%") and swelling clay (e.g., "about 1% to about 50%") that meet the limitations of claims 6-10 and 32.

Ground 2: Claims 1-4, 6-13, 30, and 32 are anticipated under 35 U.S.C. §102 by Pattengill.

  • Prior Art Relied Upon: Pattengill (Patent 5,458,091).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Pattengill, titled "Clumpable Animal Litter Mixture," independently anticipates all challenged claims. The reference explicitly discloses clumping litters made from mixtures of swelling and non-swelling clays. Petitioner focused on Pattengill's "Mixture 11," which combines non-swelling clay ("Tidy Cat") and swelling clay ("Scoop Fresh"). Calculations based on the disclosed particle size ranges in Mixture 11 show a mean particle size for non-swelling clay of 1.52 mm (below the claimed 4 mm) and a mean particle size for swelling clay of 0.89 mm (below the claimed 2 mm). This embodiment directly teaches the core limitation where the non-swelling particles are larger than the swelling particles. Petitioner also argued that Pattengill's Mixture 11 anticipates dependent claims by disclosing sodium bentonite (claim 2), smectite (claim 3), a particle size ratio of 1.7:1 (within the claimed range of claim 4), a non-swelling clay content of 69.2% (meeting claims 6-7), and the addition of an organic clumping agent, Plantago (claim 13).

Ground 3: Claims 1-13, 30, and 32 are obvious under 35 U.S.C. §103 over Hughes and/or Pattengill.

  • Prior Art Relied Upon: Hughes (Patent 5,386,803) and Pattengill (Patent 5,458,091).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that, even if not anticipated, the claims would have been obvious over Hughes, Pattengill, or a combination of the two. Both references are in the identical field of clumping animal litter and teach using blends of swelling and non-swelling clays. They both disclose the key concept of using larger non-swelling particles with smaller swelling particles, as well as the particle sizes, ratios, and compositions recited in the claims. Method steps in claim 30, such as mixing for "substantially uniform distribution" and "packaging," were argued to be inherently obvious steps for creating and selling a commercial litter product, as taught in both references.
    • Motivation to Combine: A person of ordinary skill in the art (POSA) would combine the teachings of Hughes and Pattengill because both address the same problem (creating effective clumping litter) using the same well-known components (bentonite clays). A POSA would have looked to both references to optimize particle size distributions and component ratios to improve clumping performance, a known goal in the art.
    • Expectation of Success: A POSA would have a high expectation of success. Both Hughes and Pattengill demonstrate that their respective compositions of blended clays work for their intended purpose. Combining or modifying their disclosed ranges and ratios was a matter of simple and predictable optimization, not an inventive leap.

4. Key Claim Construction Positions

  • "Mean Particle Size": Petitioner proposed that under the broadest reasonable construction, this term means the mathematical average of a known range of particle sizes. This construction is critical because both Hughes and Pattengill disclose particle sizes as ranges (e.g., 600µ to 3350µ). By calculating the mean of these disclosed ranges, Petitioner argued the prior art explicitly teaches values that fall within the limitations of the ’019 patent.
  • "Particulate Non-Swelling Clay" & "Particulate Swelling Clay": Petitioner argued these terms should be construed to mean separate, discrete, free-flowing particles of the respective clays. This construction is based on the ’019 patent's specification, which repeatedly describes the invention as a "free-flowing admixture" of "discrete particles." This interpretation is important to establish that the mixtures of discrete particles described in Hughes and Pattengill are the same form as that claimed in the ’019 patent.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-13, 30, and 32 of Patent 5,975,019 as unpatentable.