PTAB

IPR2018-00576

3M Co v. Westech AeroSol Co

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Aerosol Adhesive and Canister-Based Aerosol Adhesive System
  • Brief Description: The ’056 patent discloses a canister-based aerosol adhesive system, dispensed via a hose and gun, that uses a combination of a liquefied hydrocarbon propellant and a compressed inert gas propellant. This dual-propellant system is purported to enable the delivery of low volatile organic compound (VOC) adhesives with a consistent spray pattern.

3. Grounds for Unpatentability

Ground 1: Obviousness over Takashima and Braud - Claims 1, 2, 14-19, 21, and 24-27 are obvious over Takashima in view of Braud.

  • Prior Art Relied Upon: Takashima (Japanese Application Publication No. H11-349917) and Braud (Patent 5,931,354).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Takashima disclosed a can-based aerosol adhesive comprising all the key chemical components of claim 1: a polymeric base (SBR), a solvent, a liquefied hydrocarbon propellant (isobutane), and a compressed inert gas (nitrogen or carbon dioxide) used as an "auxiliary gas." However, Takashima taught a small, can-based system. Braud disclosed a larger, canister-based system for high-solids, low-VOC adhesives, complete with the hose and spray gun recited in claim 1, and also taught the combination of a liquefied propellant with a compressed inert gas to boost pressure and ensure proper spraying.
    • Motivation to Combine: A POSITA would combine these references to scale up Takashima's adhesive formulation for more cost-effective, larger-scale applications (e.g., on an assembly line) by employing the well-known larger canister, hose, and gun configuration taught by Braud. Both references address similar technical fields and use a dual-propellant system to achieve desired spray characteristics.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because the behavior of the combined system was predictable. The properties of the gaseous phase, liquid phase, and rheology of the polymer base were well-understood and could be predicted using established principles like the ideal gas law and Henry's law.

Ground 2: Obviousness over Carnahan and Braud - Claims 1, 2, 5, 6, 8, 12, 14-22, and 24-27 are obvious over the Carnahan Publication in view of Braud.

  • Prior Art Relied Upon: Carnahan Publication (Application # 2002/0161056) and Braud (Patent 5,931,354).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground is predicated on Petitioner's argument that the ’056 patent is not entitled to its claimed 2001 priority date, making its published parent application, Carnahan, prior art. Carnahan disclosed the canister-based aerosol adhesive system with a hose and gun, a polymeric base, a solvent, and a compressed gas propellant. Critically, Carnahan did not disclose the combination with a liquefied propellant and acknowledged that compressed gases like nitrogen have low solubility, leading to inconsistent spray pressure as the canister empties. Braud taught a known solution to this exact problem by combining a compressed inert gas with a liquefied propellant to maintain consistent pressure for spraying adhesives.
    • Motivation to Combine: A POSITA would combine Carnahan with Braud to solve the known performance problem inherent in Carnahan's compressed-gas-only system. To improve the inconsistent spray characteristics of the Carnahan system, a POSITA would have looked to known techniques and found Braud's teaching of a dual-propellant system to be a direct and suitable solution.
    • Expectation of Success: Applying the known technique from Braud to improve the known deficiency in the Carnahan system would yield the predictable result of a more consistent spray pressure and better performance, providing a strong expectation of success.

  • Additional Grounds: Petitioner asserted additional obviousness challenges (Grounds 2 and 4) against the remaining dependent claims. These grounds argued that the specific claimed ranges for pressure, solids concentration, solvent ratios, and viscosity were the result of simple and routine optimization over the primary combinations of Takashima/Braud and Carnahan/Braud, respectively, and were well within the ordinary skill of a POSITA.

4. Key Claim Construction Positions

  • "polymeric base in said solvent mixture" (Claims 1-27): Petitioner proposed this term be construed as the "polymeric base suspended, dissolved, emulsified, or otherwise dispersed in said solvent mixture," arguing this aligns with disclosures in the specification and the prior art.
  • "wherein the relative volume and concentration of liquefied propellant is minimal relative to the relative volume and concentration of compressed inert gas" (Claim 28): Petitioner argued this term is indefinite. However, for the purposes of the IPR, Petitioner proposed it be construed as "wherein the amount of liquefied propellant is small relative to the amount of compressed inert gas," based on a disclosure in the specification.

5. Key Technical Contentions (Beyond Claim Construction)

  • Priority Date Entitlement: A central contention of the petition was that the challenged claims are not entitled to a priority date earlier than November 2, 2004. Petitioner argued that the purported inventive concept—the combination of a liquefied propellant with a compressed inert gas—was first disclosed in the Continuation-in-Part application filed on that date and was absent from the parent application. This argument was critical for establishing the Carnahan Publication (the published parent application from 2002) as prior art for Grounds 3 and 4.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review (IPR) and the cancellation of claims 1-28 of the ’056 patent as unpatentable under 35 U.S.C. §103.