← Back to Patent Explorer
US4067740A Expired / Lapsed US ⏱️ 0.0 years remaining

Trithiocarbonates as sensitizers for silver halide emulsions

Assignee: EIDP Inc
•
Filing: 1976-12-21
•
Granted: 1978-01-10
•
Expires: 1996-12-21
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Photographic colloid-silver halide emulsions are chemically sensitized by the addition prior to or during digestion of at least one trithiocarbonate compound of the general formula: ##STR1## wherein R is a tertiary alkyl radical having from 4 to 16 carbon atoms and R' may be the same as R or an aryl or an alphyl radical containing 1 to 3 aryl groups which may be substituted or unsubstituted.

Inventors

  • 👤 John Howard Bigelow

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 18:55
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/08; G03C1/09

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 71 words
A photographic element comprising a support bearing at least one layer of a photographic silver halide emulsion which is chemically sensitized by the addition thereto prior to or during digestion of at least one trithiocarbonate of the general formula: ##STR9##wherein R is a tertiary alkyl radical having from 4 to 16 carbon atoms, and wherein R' is R or an aryl or an alphyl radical containing 1 to 3 phenyl groups.
Claim 2
Dependent Claim 71 words
A photographic element comprising a support bearing at least one layer of a photographic silver halide emulsion which is chemically sensitized by the addition thereto prior to or during digestion of at least one trithiocarbonate of the general formula: ##STR9##wherein R is a tertiary alkyl radical having from 4 to 16 carbon atoms, and wherein R' is R or an aryl or an alphyl radical containing 1 to 3 phenyl groups.
Claim 3
Dependent Claim 13 words
The composition of claim 1 wherein the trithiocarbonate is tert.-butyl triphenyl methyl-trithiocarbonate ##STR10##
Claim 4
Dependent Claim 11 words
The composition of claim 1 wherein the trithiocarbonate is di-tert.-butyl trithiocarbonate
Claim 5
Dependent Claim 14 words
The composition of claim 1 wherein the trithiocarbonate is 1,1-dimethyl propyl triphenyl methyl trithiocarbonate
Claim 6
Dependent Claim 13 words
The composition of claim 1 wherein the trithiocarbonate is tert.-butyl diphenyl methyl trithiocarbonate.
Claim 7
Dependent Claim 14 words
The composition of claim 1 wherein the trithiocarbonate is tert.-butyl phenol methyl trithiocarbonate ##STR11##
Claim 8
Dependent Claim 12 words
The composition of claim 1 wherein the trithiocarbonate is tert.-butyl phenyl trithiocarbonate

References Cited (Backward Citations)

US1678832A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-01-09 1981-07-11 1982-01-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-01-09 1985-07-11 1986-01-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-01-09 1989-07-11 1990-01-10 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag