PTAB

IPR2015-01402

Johns Manville Corp v. Knauf Insulation Inc

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1. Case Identification

2. Patent Overview

  • Title: Binders for Insulation Products
  • Brief Description: The ’210 patent discloses substantially formaldehyde-free aqueous binders for manufacturing insulation products from loose matter like mineral fibers. The binders consist essentially of an aqueous solution containing a reducing sugar and one or more specified ammonium salts.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 2, 6, 8, and 10 by Gogek

  • Prior Art Relied Upon: Gogek (Patent 2,965,504).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Gogek, a 1960 patent not cited during prosecution, discloses every limitation of independent claims 1 and 10. Gogek teaches a formaldehyde-free binder for insulating refractory blocks that "consists essentially of a sugar and a chemical adjunct." It expressly identifies dextrose as a suitable sugar (a reducing sugar) and ammonium sulfate as the preferred adjunct (an ammonium sulfate salt). Gogek’s Example 1 discloses a binder with 2.82 parts dextrose and 0.18 parts ammonium sulfate, which calculates to 6.38% ammonium sulfate by weight with respect to the reducing sugar, satisfying the "at least 2.5%" limitation of claim 1. Furthermore, Gogek describes a method of manufacturing insulating blocks that meets the steps of claim 10, including slurrying loose matter (rock wool) with the binder, forming it into shape, and curing it in a kiln.

Ground 2: Obviousness of Claims 3-5, 7, 9, and 11-17 over Gogek in view of Swift

  • Prior Art Relied Upon: Gogek (Patent 2,965,504) and Swift (Application # 2007/0027283).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Gogek provides the foundational binder composition of a reducing sugar and an ammonium salt. Swift, which is directed to the same subject matter of thermally-curable binders for fiberglass, teaches specific modifications that render the dependent claims obvious. For claims 4 and 5, which require an alkaline pH (construed as pH > 7), Swift teaches formulating such binders in an alkaline range (pH 7-10) to inhibit corrosion of manufacturing equipment. For claim 9, which requires 0.1% to 1% of a silane coupling agent, Swift explicitly teaches adding a silicone-containing coupling agent in this exact range to improve the binder’s adhesion to fibers. For claims related to curing parameters, such as claim 11 (curing at 230-300°C for 30 seconds to 20 minutes), Swift discloses curing its analogous Maillard-reactant binder under conditions (e.g., ~232°C for 0.75-1.5 minutes) that align with the claimed ranges and would be directly applicable to Gogek’s process.
    • Motivation to Combine: A POSITA would combine the teachings because both references address the same technical problem—creating binders for insulating materials using the same core Maillard reaction chemistry. Swift provides solutions to well-known problems in the field. A POSITA would have been motivated to modify Gogek’s binder with Swift’s teachings to achieve predictable benefits, such as reducing manufacturing costs by preventing equipment corrosion (by raising the pH) and improving final product cohesion and water resistance (by adding a silane agent).
    • Expectation of Success: The results of implementing Swift’s teachings into Gogek’s system were well-known and predictable. A POSITA would have had a high expectation of success in combining these known elements to achieve their established functions.

Ground 3: Anticipation of Claims 13 and 14 by Helbing

  • Prior Art Relied Upon: Helbing (WO 2006/044302).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Helbing’s Example 4 anticipates every limitation of claim 13. Helbing describes a "formaldehyde-free, thermally-curable, alkaline, aqueous binder" for use with non-woven fibers. This example explicitly discloses a binder solution with a pH of 10.49 (satisfying the claimed pH of >6), using corn syrup (which contains the reducing sugar glucose) and ammonium sulfate. The calculated dry weight ratio of ammonium sulfate to corn syrup solids in this example is 250%, which is well above the "at least 2.5%" required by claim 13. For dependent claim 14, which requires the loose matter to comprise "mineral fibers," Helbing teaches that its binder is suitable for "fiberglass," which Helbing expressly defines as a type of "mineral fiber," thereby anticipating the claim.

4. Key Claim Construction Positions

  • For claim 5, Petitioner argued the phrase "a pH which, in its conditions of use, prevents precipitation of sulphates, phosphates, nitrates or carbonates" should be construed to mean a pH that is neutral or alkaline (i.e., greater than or equal to 7). This construction was asserted to be required by the ’210 patent’s specification, which repeatedly characterizes the invention as having a "neutral or alkaline pH" to solve problems associated with prior art acidic binder systems.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-17 of Patent 8,114,210 as unpatentable.