PTAB

IPR2021-00192

GAF Materials LLC v. Kirsch Research Development LLC

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1. Case Identification

2. Patent Overview

  • Title: Reinforced Roof Underlayment And Method Of Making The Same
  • Brief Description: The ’482 patent relates to a multi-layer, reinforced roofing underlayment intended to provide a durable and waterproof alternative to traditional paper-based felt. The invention comprises a reinforcing scrim of interwoven strands coated on at least one side with a layer of thermoplastic material affixed by extrusion lamination.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 8-12, and 19 by Lou

  • Prior Art Relied Upon: Lou (Patent 4,684,568).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Lou anticipates every limitation of independent claim 1 and several dependent claims under 35 U.S.C. §102. Lou was shown to disclose a multi-layered thermoplastic fabric for use as a "roofing-tile underlayment" that is both vapor-permeable and liquid-impermeable. Petitioner contended that Lou’s "fibrous base sheet" made of woven polypropylene or polyester slit films is a "reinforcing scrim of interwoven strands." Further, Lou was shown to explicitly teach applying a polypropylene polymer coating onto this scrim using an extrusion lamination process to form a weather-resistant barrier, directly mapping to the product-by-process limitations of claim 1. Dependent claims reciting film-forming polymers (claim 8), specific thermoplastics like polypropylene (claim 10), and passive ventilation (claim 19) were also argued to be disclosed by Lou.

Ground 2: Obviousness of Claims 4-6 and 18 over Lou in view of Simpson

  • Prior Art Relied Upon: Lou (Patent 4,684,568) and Simpson (Patent 5,142,837).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that claims 4-6 and 18, which add a "radiant barrier layer" to the base invention of claim 1, are obvious over Lou in view of Simpson under 35 U.S.C. §103. While Lou provided the base roofing underlayment structure, Simpson was presented as teaching a multi-layered roofing material containing an aluminum foil sheet specifically to "reflect infrared and ultraviolet rays." Simpson explicitly noted that UV rays are well-recognized as destructive to roofing surfaces. Petitioner argued that combining Simpson’s aluminum radiant barrier with Lou’s thermoplastic underlayment was a simple combination of known elements.
    • Motivation to Combine: A person of ordinary skill in the art (POSA) would combine Lou and Simpson to incorporate the well-known benefits of a radiant barrier into a roofing underlayment. The motivation was to improve the product by preventing UV degradation and reducing heat transmission into the building, which were recognized problems with known solutions.
    • Expectation of Success: A POSA would have had a reasonable expectation of success because combining a known radiant barrier (Simpson) with a known underlayment structure (Lou) would predictably result in an underlayment with enhanced preservation and cooling features.

Ground 3: Anticipation of Claims 1-12, 15, 16, and 18 by Howells

  • Prior Art Relied Upon: Howells (WO 96/26067).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Howells independently anticipates the same set of claims as Lou. Howells was shown to disclose a "fabric mesh reinforced monolithic thermoplastic membrane" for use as a "roofing membrane." This membrane comprises an "open mesh fabric" (the scrim) made of woven polymers like polyester or nylon. Howells taught an extrusion lamination process where nozzles dispense molten thermoplastic onto opposing surfaces of the scrim to fully encapsulate it, thereby creating an integrated, weather-resistant membrane. Petitioner contended this directly taught the limitations of claim 1, including the interwoven scrim and thermoplastic layer affixed by extrusion. Howells was also argued to disclose a slip-resistant roughened surface (claim 2), the use of polypropylene (claim 3), and an aluminum-pigmented radiant barrier layer (claims 4-6).

  • Additional Grounds: Petitioner asserted numerous other obviousness grounds based on Lou and Howells. These included combining Lou or Howells with:

    • Buesscher (Austrian Utility Model AT1731U2) to add a distinct polypropylene slip-resistant layer for roofer safety.
    • Ellison (Patent 4,615,934) to teach the full encapsulation of the scrim on both sides to maximize strength and prevent delamination.
    • Goodacre (Patent 4,656,082) to teach using cross-laminated and/or biaxially oriented polypropylene strands in the scrim for increased tensile strength.
    • Curran (Patent 5,291,712) to add micro-perforations to the thermoplastic layer to provide adjustable breathability and prevent moisture damage.
    • Various multi-reference combinations (e.g., Lou in view of Goodacre, Ellison, and Buesscher) were asserted against the remaining dependent claims.

4. Relief Requested

  • Petitioner requested institution of an inter partes review (IPR) and cancellation of claims 1-34 of the ’482 patent as unpatentable.