Invalidity dossier
US 5225473
Pressure-sensitive adhesives
Current assignee: 3M Co
Added 9/23/2026, 5:34:20 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US5225473A — Pressure-Sensitive Adhesives
Title: Pressure-sensitive adhesives
Patent number: US5225473A
Application number: US07/866,207
Inventor: Daniel C. Duan
Original assignee: Minnesota Mining and Manufacturing Co. (current assignee listed as 3M Co)
Priority date: 1987-11-25 | Filing date: 1992-04-09 | Publication/grant date: 1993-07-06 | Anticipated expiration: 2010-07-06 | Status: Expired – Lifetime
Purpose (plain language): The patent concerns pressure-sensitive adhesive compositions made of a crosslinked hydrophilic polymer. The invention relates more specifically to pressure-sensitive adhesives made with N-vinyl-2-pyrrolidone crosslinked with controlled amounts of specific crosslinkers. Adhesives are needed that can tolerate substantial amounts of water or other polar liquids without unacceptable phase separation, loss of tack, or loss of cohesive strength. One aspect covers compositions made electrically conductive for use as the skin-interfacing material in a disposable bioelectrode; another contemplates an adhesive that can be made electrochemically reactive for use with galvanically inert graphite conductors.
Background described: Prior adhesives include polyvinyl ethers and copolymers of hydrophobic water-insoluble monomers (e.g., isooctyl acrylate) with small amounts of water-soluble monomers (e.g., acrylic acid or N-vinyl-2-pyrrolidone); the excerpt states that incorporating substantial ionic or highly polar solutions causes phase separation in those formulations. The patent text also discusses Larimore et al. patents (e.g., U.S. Pat. No. 4,273,135), U.S. Pat. No. 4,554,924, U.S. Pat. No. 3,294,765, U.S. Pat. No. 4,536,554, and hydrogels based on poly(N-vinyl-2-pyrrolidone), including an EPO application (publication 0107376).
What the excerpt does not establish: The supplied text is an excerpt with omitted portions. It does not provide the full claims, the complete list of crosslinkers, quantitative formulation ranges, examples, or the full specification. The prior-art summary above reflects only characterizations stated in the excerpt, not an independent analysis. Legal status shown is an assumption per the source and is not a legal conclusion; no litigation, ownership-transfer, validity, or prior-art conclusions are drawn here.
Source: https://patents.google.com/patent/[US5225473](/patent/US5225473)/en
Generated 10/1/2026, 9:43:29 PM
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Litigation summary
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PTAB challenges
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Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
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Obviousness
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Extensions
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Derivative works
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