← Back to Patent Explorer
US4258644A Expired / Lapsed US ⏱️ 0.0 years remaining

Depositing latent fingerprints and development thereof

Assignee: 3M Co
•
Filing: 1979-07-23
•
Granted: 1981-03-31
•
Expires: 1999-07-23
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Latent fingerprints having a latency of several weeks are applied to paper substrates using compositions comprising trimeric aliphatic acids of at least 30 carbon atoms which are substantive to paper fibers are substantially non-volatile, and are non-hardening, non-toxic and non-hygroscopic. The latent fingerprints are developed as desired by dusting in the conventional manner with toner particles, suitably, comprising magnetic particles in oleophilic matrix.

Inventors

  • 👤 Edward J. Goettert
  • 👤 George V. D. Tiers

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 00:55
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/117; A61B5/1171; A61B5/1172

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 65 words
A fingerprinting pad consisting essentially of an absorbent pad at least partly saturated with a composition comprising polymeric acid of the general formula (C n H 2n-x CO 2 H) y where n is from 10 to 20, x is 1, 3 or 5 and y is 2 to 4 inclusive, wherein said composition moistens a finger upon contact of said finger with said pad.
Claim 2
Dependent Claim 65 words
A fingerprinting pad consisting essentially of an absorbent pad at least partly saturated with a composition comprising polymeric acid of the general formula (C n H 2n-x CO 2 H) y where n is from 10 to 20, x is 1, 3 or 5 and y is 2 to 4 inclusive, wherein said composition moistens a finger upon contact of said finger with said pad.
Claim 3
Dependent Claim 24 words
The fingerprinting pad according to claim 1 wherein the trimeric acid is of the formula (C 17 H 31 CO 2 H) 3 .
Claim 4
Dependent Claim 39 words
A fingerprinting pad comprising an absorbent pad impregnated with a composition comprising a non-hardenable, substantially non-volatilizable, non-hygroscopic, non-toxic higher fatty polybasic acid substantive to paper, wherein said composition moistens a finger upon contact of said finger with said pad.
Claim 5
Dependent Claim 39 words
A fingerprinting pad comprising an absorbent pad impregnated with a composition comprising a non-hardenable, substantially non-volatilizable, non-hygroscopic, non-toxic higher fatty polybasic acid substantive to paper, wherein said composition moistens a finger upon contact of said finger with said pad.
Claim 6
Dependent Claim 13 words
A fingerprinting pad according to claim 3 wherein said absorbent pad comprises paper.

References Cited (Backward Citations)

US2341239A Cited
US2334850A Cited
US3251869A Cited
US3239545A Cited
US3377286A Cited
US3639245A Cited
US3823022A Cited
US3776865A Cited
US4069235A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-03-30 1984-09-29 1985-03-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-03-30 1988-09-29 1989-03-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-03-30 1992-09-29 1993-03-31 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag