PTAB

IPR2020-01730

SNF SA v. Solenis Technologies LP

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: High Molecular Weight and High Cationic Charge Glyoxalated Polyacrylamide Copolymers and Their Methods of Manufacture and Use
  • Brief Description: The ’320 patent relates to cellulose reactive glyoxalated copolymer compositions used in papermaking. The technology claims to improve paper properties such as wet-strength, dry-strength, and dewatering rates during the manufacturing process by using a specific ratio of copolymer molecular weight to cationic monomer content.

3. Grounds for Unpatentability

Ground I: Claims 1-21 are obvious over Wright ’343 in view of Coscia ’932, Lu ’382, Dauplaise ’022, or Cyr ’934.

  • Prior Art Relied Upon: Wright ’343 (Patent 8,222,343), Coscia ’932 (Patent 3,556,932), Lu ’382 (Patent 8,435,382), Dauplaise ’022 (Patent 5,723,022), and Cyr ’934 (Patent 7,828,934).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Wright ’343, the primary reference, teaches glyoxalated cationic copolymers for improving paper strength and discloses ranges for Weight-Average Molecular Weight (WAMW) and diallyldimethylammonium chloride (DADMAC) monomer content that overlap or encompass those in the challenged claims. The secondary references were asserted to teach the remaining limitations, such as the specific dry-weight ratio of glyoxal to cationic copolymer, which Wright ’343 does not explicitly disclose. For example, Coscia ’932 and Lu ’382 were cited as teaching dry-weight ratios that fall within the claimed range.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references as they all operate in the same field of papermaking additives and seek to achieve the same goals. Petitioner noted that Wright ’343 itself references the glyoxalation procedure of Coscia ’932, providing an explicit reason to combine their teachings.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success because combining the teachings involved the routine optimization of known result-effective variables (e.g., WAMW, %DADMAC, glyoxal ratio) to predictably improve the known properties of paper strength and dewatering.

Ground II: Claims 1-21 are obvious over Lu ’382 alone or in view of Dauplaise ’022, Coscia ’932, Wright ’343, or Cyr ’934.

  • Prior Art Relied Upon: Lu ’382 (Patent 8,435,382) as the primary reference, with Dauplaise ’022, Coscia ’932, Wright ’343, and Cyr ’934 as secondary references.
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Lu ’382 alone teaches most claimed features, including acrylamide/DADMAC copolymers for improving paper strength and dewatering rates, overlapping monomer concentration ranges, and specific dry-weight glyoxal ratios. Although Lu ’382 teaches a WAMW of ≤100,000 Daltons (just below the claimed lower limit of 120,000), the secondary references (Dauplaise, Coscia, and Wright) were argued to explicitly teach WAMW ranges that fully encompass the claimed range of 120,000-1,000,000 Daltons.
    • Motivation to Combine: A POSITA would look to the secondary references to modify the copolymer taught in Lu ’382. It was well-known in the art that using higher WAMW copolymers improved paper strength and drainage, providing a clear motivation to increase the WAMW of the Lu ’382 copolymer into the ranges taught by Dauplaise, Coscia, and Wright.
    • Expectation of Success: Success was expected because adjusting the WAMW upward was a predictable modification of a known result-effective variable. The resulting copolymer would have been expected to exhibit the known benefits of both the higher charge taught by Lu ’382 and the higher molecular weight taught by the other references.

Ground III: Claims 1-21 are obvious over Dauplaise ’022 alone or in view of Coscia ’932, Lu ’382, or Cyr ’934.

  • Prior Art Relied Upon: Dauplaise ’022 (Patent 5,723,022) as the primary reference, with Coscia ’932, Lu ’382, and Cyr ’934 as secondary references.
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Dauplaise ’022 discloses glyoxalated cationic copolymers for paper strengthening with key parameters that overlap the challenged claims, including a WAMW range of 200,000-2,000,000 Daltons and a molar ratio of acrylamide to DADMAC that corresponds to the claimed weight percentages. Dauplaise ’022 also teaches a dry-weight ratio of glyoxal to copolymer and a solids solution percentage within the claimed ranges.
    • Motivation to Combine: A POSITA would have been motivated to look to the secondary references to optimize the formulation taught by Dauplaise ’022. For instance, a POSITA could have looked to Coscia ’932 or Cyr ’934 for alternative dry-weight ratios or to Lu ’382 to optimize viscosity, all of which were known techniques for improving the performance of such additives.
    • Expectation of Success: Modifying the Dauplaise ’022 composition based on the other references would have been a routine optimization with a high expectation of success. The art already established that adjusting these parameters predictably affected the final product’s performance in papermaking applications.

4. Key Claim Construction Positions

  • Claimed Ranges: Petitioner argued that, according to the ’320 patent's own specification, a recited range "specifically discloses all the possible subranges as well as individual numbers within that range." This construction was central to Petitioner's obviousness arguments, as it allowed prior art disclosing point values or overlapping ranges to anticipate or render obvious the full scope of the claimed ranges.

5. Key Technical Contentions (Beyond Claim Construction)

  • Ratio as Routine Optimization: The petition’s central technical contention was that the claimed ratio of WAMW to wt.% DADMAC (≥4000 Daltons/wt.%) is not a critical limitation that yields unexpected results. Petitioner argued that both WAMW and %DADMAC were well-known "result-effective variables" in the art. A POSITA would have been motivated to routinely optimize these known variables to enhance paper strength and drainage, and the claimed ratio is merely a mathematical expression of this obvious optimization, not a patentable invention.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-21 of Patent 9,644,320 as unpatentable.