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EP0962814A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Recording material with improved shelf-life producing prints upon thermal development with improved archivability

Assignee: Agfa Gevaert NV
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Filing: 1999-05-25
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Granted: —
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Expires: 2019-05-25
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Abstract

Abstract A recording material comprising a support and a thermosensitive element containing silver stearate, an organic reducing agent therefor in thermal working relationship therewith and a binder, characterized in that the silver stearate is not associated with mercury and/or lead ions and when the recording material is irradiated with a copper Kα 1 X-ray source the ratio of the sum of the peak heights of the X-ray diffraction lines attributable to silver stearate at Bragg angles, 2Θ, of 2Θ, of 3.62°, 5.45°, 7.30°, 9.04°, 10.97° and 12.71° to the sum of the peak heights of the X-ray diffraction lines at Bragg angles, 2Θ, of 25.60°, 35.16° and 43.40° of NIST standard 1976, rhombohedral Al 2 O 3 , determined with the same X-ray diffractometer in the same state of adjustment on a sample of the recording material and a sample of the NIST standard 1976 cut to fit a sample holder of the X-ray diffractometer, divided by the square root of the quantity of silver in the recording material, expressed in g per m 2 , is greater than 2.2m/g 0.5 ; and a process for producing particles of substantially light-insensitive organic silver salt comprising silver stearate with these X-ray characteristics in the substantial absence of organic solvent.

Inventors

  • 👤 Ingrid Geuens
  • 👤 Yvan Gilliams
  • 👤 Dirk Bollen
  • 👤 Yvan Hoogmartens
  • 👤 André Bellens

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-03 17:35
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/494; G03C1/498; G03C1/49809; C; C07; C07C; C07C51/00; C07C51/41; C07C51/412; G03C1/49872; G03C1/76; G03C1/7614; G03C2001/7635; G03C7/00; G03C7/30; G03C7/3022; G03C2007/3025; G03C2200/00; G03C2200/43

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 179 words
A recording material comprising a support and a thermosensitive element comprising silver stearate, an organic reducing agent therefor in thermal working relationship therewith and a binder, characterized in that said silver stearate is not associated with mercury and/or lead ions and when said recording material is irradiated with a copper Kα 1 X-ray source the ratio of the sum of the peak heights of the X-ray diffraction lines attributable to silver stearate at Bragg angles, 2Θ, of 3.62°, 5.45°, 7.30°, 9.04°, 10.97° and 12.71° to the sum of the peak heights of the X-ray diffraction lines at Bragg angles, 2Θ, of 25.60°, 35.16° and 43.40° of NIST standard 1976, rhombohedral Al 2 O 3 , determined with the same X-ray diffractometer in the same state of adjustment on a sample of said recording material and a sample of said NIST standard 1976 cut to fit a sample holder of said X-ray diffractometer, divided by the square root of the quantity of silver in said recording material, expressed in g per m 2 , is greater than 2.2m/g 0.5 .
Claim 2
Dependent Claim 35 words
Recording material according to claim 1, wherein said ratio divided by the square root of the quantity of silver in said recording material expressed in g per m 2 is greater than 3.0m/g 0.5 .
Claim 3
Dependent Claim 18 words
Recording material according to claim 1 or 2, wherein said thermosensitive element is provided with a protective layer.
Claim 4
Dependent Claim 33 words
Recording material according to any of the preceding claims, wherein said thermosensitive element further comprises a photosensitive species capable upon exposure of forming a species capable of catalyzing reduction of said silver stearate.
Claim 5
Dependent Claim 135 words
A production process for a dispersion of particles of substantially light-insensitive organic silver salt containing silver stearate in a substantially solvent-free aqueous medium comprising the steps of: i) producing an aqueous dispersion of one or more organic acids containing stearic acid and an anionic surfactant; ii) substantially neutralizing said organic acids with aqueous alkali thereby forming organic acid salts containing a stearic acid salt; (iii) adding an aqueous solution of a silver salt to convert completely said organic acid salts into their silver salts containing silver stearate, characterized in that said anionic surfactant is present in a molar ratio with respect to organic acid greater than 0.15 and said silver salt is added to produce organic silver salt(s) at a rate between 0.025mol/mol organic silver salt(s) · min and 2.25mol/mol organic silver salt(s) · min.
Claim 6
Dependent Claim 21 words
Production process according to claim 5, wherein said anionic surfactant is an alkali or ammonium salt of an alkaryl sulfonic acid.
Claim 7
Dependent Claim 27 words
Production process according to claim 6, wherein said alkali or ammonium salt of an alkylarylsulfonic acid is an alkali or ammonium salt of an alkylbenzene sulfonic acid.
Claim 8
Dependent Claim 31 words
Production process according to any of claims 5 to 7 further comprising the step of subjecting said dispersion of particles of substantially light-insensitive organic silver salt(s) containing silver stearate to ultrafiltration.
Claim 9
Dependent Claim 19 words
Particles of substantially light-insensitive organic silver salt containing silver stearate producible according to any of claims 5 to 8.
Claim 10
Dependent Claim 64 words
A recording process comprising the steps of: (i) bringing an outermost layer of a recording material according to any of claims 1 to 3 into proximity with a heat source; and (ii) applying heat from said heat source imagewise to said recording material while maintaining proximity to said heat source to produce an image; and (iii) removing said recording material from said heat source.
Claim 11
Dependent Claim 16 words
Recording process according to claim 10, wherein said heat source is a thin film thermal head.

References Cited (Backward Citations)

EP0754969A2 Cited
EP0848286A1 Cited

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