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US3635890A Expired / Lapsed US ⏱️ 0.0 years remaining

Stabilization of polyphenylene oxides

Assignee: Sumitomo Chemical Co Ltd
•
Filing: 1970-09-08
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Granted: 1972-01-18
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Expires: 1990-09-08
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Abstract

Abstract POLYPHENYLENE OXIDES ARE STABILIZED TO THERMAL OXIDATION BY REACTING THE POLYMERS WITH A HALOGENATED PHOSPHORUS COMPOUND IN THE PRESENCE OR ABSENCE OF A BASIC COMPOUND.

Inventors

  • 👤 Toshio Takemura
  • 👤 Isamu Nakagawa
  • 👤 Seizo Nakashio

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 02:38
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/34; C08G65/48; C08G65/485; C08K; C08K5/00; C08K5/49

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-01-17 1975-07-19 1976-01-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-01-17 1979-07-19 1980-01-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-01-17 1983-07-19 1984-01-18 $7700.00 Window Closed / Lapsed

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