PTAB

IPR2017-01086

New NGC Inc v. United States Gypsum Co

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Producing Set Gypsum-Containing Product
  • Brief Description: The ’550 patent discloses methods for producing set gypsum-containing products, such as gypsum boards, with improved physical properties. The methods involve forming a mixture of calcined gypsum, water, an accelerator, and one or more “enhancing materials” chosen from condensed phosphoric acids or condensed phosphates, which allegedly provide greater strength and resistance to permanent deformation (sag).

3. Grounds for Unpatentability

Ground 1: Claims 1, 2, 5, 7-9, and 54-57 are obvious over Graux in view of ASTM C473-95 and Hjelmeland.

  • Prior Art Relied Upon: Graux (Patent 5,932,001), ASTM C473-95 (an industry testing standard), and Hjelmeland (Patent 5,980,628).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Graux taught the core components of the claimed method, including a plaster composition containing calcined gypsum, water, accelerators, and starch "crosslinked with sodium trimetaphosphate" (STMP). STMP is a condensed phosphate that falls within the ’550 patent's definition of an "enhancing material." ASTM C473-95 was the well-known, industry-standard test method for measuring the sag resistance recited in the claims. Hjelmeland disclosed using polyphosphates (such as STMP) as a set-retarding substance in gypsum compositions within a concentration range of 0.01-0.2% by weight, which Petitioner asserted overlaps with and renders obvious the concentration range recited in claim 2.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Graux and ASTM C473-95 because it was standard practice to use the ASTM test to measure the physical properties, like sag resistance, of gypsum products such as those disclosed in Graux. A POSITA would have been motivated to consult Hjelmeland to determine an effective and conventional concentration range for the polyphosphate (STMP) used in Graux’s composition, as Hjelmeland provided specific guidance on such ranges for gypsum products.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because all references operate in the predictable field of gypsum chemistry. Combining Graux's known composition with the standard ASTM test would predictably yield the claimed sag resistance values, and applying the concentration ranges from Hjelmeland to the STMP in Graux's composition would predictably influence the product's properties as described.

Ground 2: Claims 1, 2, 5, 7-9, and 54-57 are obvious over Satterthwaite in view of ASTM C473-95 and Hjelmeland.

  • Prior Art Relied Upon: Satterthwaite (Patent 3,234,037), ASTM C473-95, and Hjelmeland (Patent 5,980,628).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Satterthwaite disclosed manufacturing acoustical ceiling tiles from a mixture of water, gypsum, and a starch binder treated with STMP specifically to provide "increased resistance to warp or sag." While Satterthwaite did not explicitly require an accelerator, its inclusion was admitted prior art in the ’550 patent’s own specification and was also taught by Hjelmeland. As in Ground 1, ASTM C473-95 provided the standard method for measuring the claimed sag resistance, and Hjelmeland provided the concentration ranges for the STMP enhancing material.
    • Motivation to Combine: A POSITA looking to create the sag-resistant gypsum tiles of Satterthwaite would naturally use the industry-standard ASTM C473-95 test to quantify that sag resistance. To optimize the formulation, the POSITA would be motivated to include a conventional accelerator to control the hardening process and improve strength, as taught by Hjelmeland or known in the art. The POSITA would also look to references like Hjelmeland for guidance on appropriate concentration levels of STMP to achieve the desired properties taught by Satterthwaite.
    • Expectation of Success: The combination involved applying known additives (accelerators, STMP) at conventional concentrations (Hjelmeland) to a known base material (Satterthwaite's gypsum composition) and measuring the result with a standard industry test (ASTM). Petitioner argued this represented a predictable application of known technologies to achieve a desired, known result, leading to a high expectation of success.

4. Key Claim Construction Positions

  • "enhancing material(s)": Petitioner argued that this term should be construed as "an additive that improves at least one of resistance to permanent deformation, strength, and dimensional stability in set gypsum-containing products." This construction was asserted to be consistent with the patent’s specification, which explicitly states that an enhancing material meets "one or more of these needs." This construction was critical to Petitioner's arguments because prior art references like Graux and Satterthwaite disclosed additives (specifically STMP) for the express purpose of improving these exact properties, thereby meeting the definition of an enhancing material.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 2, 5, 7-9, and 54-57 of Patent 6,632,550 as unpatentable.