PTAB

IPR2014-00606

Henkel Corp v. HB Fuller Co

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1. Case Identification

2. Patent Overview

  • Title: Hot Melt Adhesive Compositions
  • Brief Description: The ’404 patent relates to hot melt adhesive compositions that utilize a hydrogenated, substantially aliphatic tackifying resin having a high glass transition temperature (Tg). The claimed compositions comprise this tackifying resin and a thermoplastic base polymer, such as an ethylene copolymer or an amorphous polyalphaolefin.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 22, 23, 25, 28, 31, and 32 by the Eastotac Brochure

  • Prior Art Relied Upon: Eastotac Brochure (an Aug. 1992 publication by Eastman Company).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the Eastotac Brochure discloses two distinct hot melt adhesive compositions that each anticipate the challenged claims. The first, an "Amorphous Polyolefin Composition," comprises 30-50% Eastotac® hydrocarbon tackifying resin and 50-70% amorphous polyolefin. The second, an "EVA Composition," comprises 30-60% Eastotac® resin and 30-50% ethylene-vinyl acetate (EVA) copolymer. Petitioner asserted that the brochure’s specific tackifier, Eastotac® H-142, is a dicyclopentadiene-derived hydrocarbon resin with a Tg of 82°C, which satisfies the limitations of independent claims 22 and 28 requiring a Tg greater than 65°C. This 82°C Tg also meets the greater than 68°C limitation of dependent claim 23. The known low bromine number of H-142 indicates it is hydrogenated, meeting claim 25. For claims 31 and 32, Petitioner argued the Amorphous Polyolefin Composition’s 30-50% tackifier concentration is inherently less than its 50-70% base polymer concentration.

Ground 2: Anticipation of Claims 22-25 and 28 by the Exxon Reference

  • Prior Art Relied Upon: Exxon Reference (an Oct. 1990 publication on specialty polymers by Exxon Chemical Company).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that the Exxon Reference discloses a hot melt composition comprising 40% hydrocarbon tackifying resin (Escorez® 5340), 20% thermoplastic base polymer (Escorene UL 7750), and 40% paraffin wax, which anticipates the claims. Petitioner identified Escorez® 5340 as a dicyclopentadiene-based tackifier with a Tg of 76°C, satisfying the limitations of independent claim 22. The reference's Escorene UL 7750 was identified as an EVA copolymer, meeting the thermoplastic base polymer limitation. The known properties of the Escorez® 5340 resin were also used to show it meets the dependent claim limitations of having greater than 80 wt-% of its units derived from dicyclopentadiene (claim 24) and being hydrogenated (claim 25).

Ground 3: Obviousness of Claim 26 over the Eastotac Brochure and Exxon Reference in view of the ’717 Patent

  • Prior Art Relied Upon: Eastotac Brochure, Exxon Reference, and the ’717 patent (Patent 5,256,717).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner asserted that the Eastotac Brochure and Exxon Reference disclose the base compositions of claim 22. Dependent claim 26 adds the limitation of "up to about 40% by weight of a solid benzoate plasticizer." Petitioner argued the ’717 patent explicitly teaches hot melt adhesive compositions containing such plasticizers.
    • Motivation to Combine: A POSITA would combine the ’717 patent's teaching with the base compositions from Eastotac or Exxon because adding a benzoate plasticizer was a well-known and routine technique for improving adhesive properties. Specifically, it was known to increase the "open time" of hot melt adhesives while maintaining high crystallinity.
    • Expectation of Success: The ’717 patent demonstrates that benzoate plasticizers are compatible with adhesive components analogous to those in the primary references (e.g., aliphatic hydrocarbon tackifiers and ethylene copolymers), providing a clear and reasonable expectation of success.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including for claim 27 over the Eastotac Brochure and Exxon Reference in view of Litz (a 1974 article), arguing that achieving peel values greater than 70°C was a routine modification. Petitioner also presented, as an alternative to anticipation, that all challenged claims are obvious over the combination of the Eastotac Brochure and the Exxon Reference.

4. Key Claim Construction Positions

  • "Hydrocarbon tackifying resin" (claim 22): Petitioner proposed this term be construed as "a chemical compound consisting of hydrogen and carbon that is used in adhesives to increase the tack," which may be aliphatic or aromatic, and exemplified by the specific resins Eastotac® H-142 and Escorez® 5340 mentioned in the ’404 patent.
  • "derived, at least in part, from dicyclopentadiene" (claim 22): Proposed construction was "resins where at least part of the total unit is derived from dicyclopentadiene," such as the aforementioned resins.
  • "Glass transition temperature" (Tg) (claims 22, 28): Proposed construction was "the onset temperature as determined using Dynamic Mechanical Analysis," as defined in the ’404 patent’s specification.
  • These constructions were central to Petitioner's arguments, as they allowed for a direct mapping of the known properties of commercially available resins disclosed in the prior art (Eastotac® H-142 and Escorez® 5340) to the specific limitations recited in the challenged claims.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 22-28, 31, and 32 of Patent 6,833,404 as unpatentable.