US3754916A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat developable diazo type sheets
Assignee: 3M Co
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Filing: 1971-11-29
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Granted: 1973-08-28
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Expires: 1991-11-29
Abstract
Abstract A heat-developable diazo type sheet containing an acidstabilized diazonium salt in one layer thereof and an acidneutralizing component in another layer thereof is shown wherein at least half of the basic equivalents of the acid-neutralizing component are provided by at least one weakly basic benzimidazole acid-neutralizer compound.
Inventors
- 👤 J Winslow
- 👤 B Sagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:19
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/52; G03C1/60; G03C1/61
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
135 words
A heat reactive diazotype sheet having at least three layers, one of said layers comprising a heat-softenable binder material and an acid-stabilized diazonium salt capable of reacting with an azo-coupler compound to form a dye, another of said layers comprising a heat-softenable binder material and an acid-neutralizer component capable of providing basic equivalents in an amount at least sufficient to neutralize said acid stabilization of said diazonium salt to render said diazonium salt reactive with said azo-coupler compound by providing a weakly basic environment for the diazonium salt in the sheet, greater than 75% of said basic equivalents being provided by benzimidazole, at least one of said heat softenable binder layers additionally including an azo-coupler compound, and between said diazonium salt containing layer and said benzimidazole-containing layer a barrier layer, permeable, upon heating, to benzimidazole.
Claim 2
Dependent Claim
122 words
A light-sensitive, storage-stable diazotype sheet capable of rapid heat development, said sheet comprising a support bearing at least two layers, one of said layers comprising a heat-softenable polymeric binder and a dye-forming composition including an azo-coupler compound and a light-sensitive acid-stabilized diazonium salt capable of reacting with said coupler compound to form a dye, and another of said layers comprising a heat-softenable polymeric binder and an acid neutralizer capable of neutralizing said acid stabilization of said acid-stabilized diazonium salt in sufficient quantity to provide a weakly basic environment for the diazonium salt in the sheet, and to render said dia-zonium salt reactive with said coupler compound, greater than 75 percent of the basic equivalents of said acid neutralizer being provided by benzimidazole.
Claim 3
Dependent Claim
17 words
The sheet of claim 3 wherein said dye-forming composition comprises p-diazomorpholino-2,5-dibutoxy benzene borofluoride, acetoacetanilide, 2,7-dihydroxynaphthalene and 3-hydroxy-2-naphtho-o-toluidine.
Claim 4
Dependent Claim
112 words
A light-sensitive, storage-stable diazotype sheet capable of rapid heat development comprising a support bearing at least two layers, one of said layers comprising a first heat-softenable polymeric binder containing a dye-forming composition including an azo coupler compound and a light-sensitive acid-stablized diazonium salt capable of reacting therewith to form a dye, and another of said layers comprising a second heat-softenable polymeric binder which contains, as the sole acid neutralizer component of said sheet, a sufficient quantity of benzimidazole to neutralize said acid stabilization of said diazonium salt and to render said diazonium salt reactive with said azo coupler compound, by providing a weakly basic environment for the diazonium salt in the sheet.
Claim 5
Dependent Claim
21 words
The sheet of claim 5 wherein said second heat-softenable polymeric binder is soluble in a non-solvent for said first polymeric binder.
Claim 6
Dependent Claim
114 words
A heat-reactive diazotype sheet having at least two layers, one of said layers comprising a heat-softenable binder material and an acid-stabilized diazonium salt capable of reacting with an azo-coupler compound to form a dye, and another of said layers comprising a heat-softenable binder material and an acid-neutralizer component capable of providing basic equivalents in an amount at least sufficient to neutralize said acid stabilization of said diazonium salt and to render said diazonium salt reactive with said azo-coupler compound by providing a weakly basic environment for the diazonium salt in the sheet, greater than 75% of said basic equivalents being provided by benzimidazole, at least one of said layers additionally including an azo-coupler compound.
Claim 7
Dependent Claim
18 words
The sheet of claim 7 additionally comprising, in said layer containing said diazonium salt, an acid stabilizing compound.
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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |