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US2228033A Expired / Lapsed US ⏱️ 0.0 years remaining

Sympathetic ink

Assignee: EIDP Inc
•
Filing: 1938-01-06
•
Granted: 1941-01-07
•
Expires: 1958-01-06
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Abstract

No abstract record available.

Inventors

  • 👤 Thomas A Martone

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 10:07
CPC Classifications
C; C09; C09D; C09D11/00; C09D11/50; D; D06; D06P; D06P1/00; D06P1/44; D06P1/46; D06P1/48; D06P1/50; D21; D21H; D21H21/00; D21H21/14; D21H21/40; D21H21/44; D21H21/46

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1944-01-07 1944-07-08 1945-01-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1948-01-07 1948-07-08 1949-01-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1952-01-07 1952-07-08 1953-01-07 $7700.00 Window Closed / Lapsed

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