PTAB

IPR2017-01011

New NGC Inc v. United States Gypsum Co

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Set Gypsum-Containing Product and Method for Preparing Same
  • Brief Description: The ’034 patent discloses methods for producing set gypsum-containing products, such as gypsum boards and tiles. The invention involves forming a mixture of calcined gypsum, water, an accelerator, and one or more specified "enhancing materials" (condensed phosphates) to achieve improved strength and resistance to permanent deformation (sag).

3. Grounds for Unpatentability

Ground 1: Obviousness over Graux, ASTM C473-95, and Hjelmeland - Claims 1, 2, 4, 5, and 7-9 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 standard), and Hjelmeland (Patent 5,980,628).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Graux disclosed all key components claimed in the ’034 patent. Graux taught a method for producing a set gypsum product comprising calcined gypsum, water, accelerators, and a starch crosslinked with sodium trimetaphosphate (STMP), which is one of the specific "enhancing materials" recited in the challenged claims. Petitioner asserted that ASTM C473-95 was the well-known, admitted prior art standard for measuring the claimed sag resistance property. Finally, Hjelmeland was cited for its disclosure of using polyphosphates (like STMP) as a "set retarding substance" in a concentration range (0.01-0.2% by weight) that overlaps with the range claimed in dependent claim 2.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would have been motivated to combine these references because they all address the same field of gypsum product manufacturing. A POSITA reviewing Graux's composition, which included the claimed enhancing material STMP, would naturally use the industry-standard ASTM C473-95 test to measure and confirm the resulting product's sag resistance. Furthermore, a POSITA seeking to optimize the formulation in Graux would have looked to references like Hjelmeland, which taught specific concentration ranges for similar phosphate additives to achieve desired properties.
    • Expectation of Success: Petitioner contended a POSITA would have had a reasonable expectation of success. The use of STMP to improve sag resistance and accelerators to improve strength were known, predictable solutions in the art. Combining Graux's composition with Hjelmeland's concentration teachings to achieve the claimed functional outcomes was argued to be nothing more than the predictable application of known technologies to obtain an expected result.

Ground 2: Obviousness over Satterthwaite, ASTM C473-95, and Hjelmeland - Claims 1, 2, 4, 5, and 7-9 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: This ground presented an alternative primary reference. Petitioner argued that Satterthwaite disclosed a method for making acoustical ceiling tiles from a mixture of water, gypsum, and a starch binder treated with STMP, explicitly for the purpose of increasing "resistance to warp or sag." While Satterthwaite did not explicitly require an accelerator, Petitioner noted that the ’034 patent itself admitted the use of accelerators in gypsum products was conventional and well-known. Hjelmeland was again relied upon to teach the inclusion of accelerators to "accelerate the hardening process" and to provide an exemplary concentration range for the STMP. ASTM C473-95 was again presented as the standard for measuring the claimed sag resistance.
    • Motivation to Combine: A POSITA starting with Satterthwaite's sag-resistant gypsum composition would be motivated to add an accelerator, as taught by Hjelmeland or known from common industry practice, to increase strength and control the setting time, which are routine objectives in gypsum board manufacturing. The motivation to consult the ASTM C473-95 standard was the same as in Ground 1: to verify the very property Satterthwaite sought to improve. The combination was presented as a straightforward integration of known elements to solve a known problem.
    • Expectation of Success: The expectation of success was argued to be high. A POSITA would reasonably expect that adding a conventional accelerator to Satterthwaite's STMP-containing gypsum mixture would predictably increase its strength without negatively affecting the known sag-resistance benefits imparted by the STMP.

4. Key Claim Construction Positions

  • Enhancing Material(s): Petitioner argued 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 critical because the specification explicitly stated that an enhancing material need not improve all three properties, meaning prior art teaching improvement in any one of these known areas would qualify.
  • Accelerator: Petitioner proposed that "accelerator" should be construed as any "reagent or combination of reagents known to be useful to influence the rate of formation of set gypsum." This broad construction was based on language from a related patent in the same family and was intended to encompass the wide variety of accelerators known in the prior art.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1, 2, 4, 5, and 7-9 of the ’034 patent as unpatentable under 35 U.S.C. §103.