EP0232941A2
Expired / Lapsed
EP
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Sol-gel process for producing luminescent thin film, and film so produced, and devices utilizing same
Assignee: Koninklijke Philips NV
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Filing: 1987-02-03
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Granted: —
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Expires: 2007-02-03
Abstract
Abstract Luminescent thin films are produced by a sol-gel process in which a gellable liquid is applied to a substrate to form a thin film, gelled and heated to remove volatile constituents and form a polycrystalline luminescent material.
Inventors
- 👤 Dagobert Michel De Leeuw
- 👤 Walter Karl Zwicker
- 👤 Rameshwar Nath Bhargava
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 14:43
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/20; H01J9/22; H01J9/221; H01J9/223; C; C09; C09K; C09K11/00; C09K11/08
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
135 words
A sol-gel process for producing a thin film of luminescent material on a substrate, the process comprising: (a) applying a gellable liquid on a substrate to form a thin film, the liquid comprising: (1) at least a portion of the constituents or precursors of the constituents of the luminescent material in the proportions required to form the desired luminescent material composition; and (2) at least one liquid vehicle; the constituents or precursors being present in the vehicle in solution or in colloidal suspension, or partly in solution and partly in colloidal suspension; (b) gelling the film by allowing the film to air dry; and (c) heating the gelled film to decompose the precursors into non-volatile constituents and volatile components, to remove the volatile components, and to convert the non-volatile, non-luminescent constituents into a luminescent material.
Claim 2
Dependent Claim
135 words
A sol-gel process for producing a thin film of luminescent material on a substrate, the process comprising: (a) applying a gellable liquid on a substrate to form a thin film, the liquid comprising: (1) at least a portion of the constituents or precursors of the constituents of the luminescent material in the proportions required to form the desired luminescent material composition; and (2) at least one liquid vehicle; the constituents or precursors being present in the vehicle in solution or in colloidal suspension, or partly in solution and partly in colloidal suspension; (b) gelling the film by allowing the film to air dry; and (c) heating the gelled film to decompose the precursors into non-volatile constituents and volatile components, to remove the volatile components, and to convert the non-volatile, non-luminescent constituents into a luminescent material.
Claim 3
Dependent Claim
43 words
The sol-gel process of Claim 1 in which the gellable liquid is formed by first dissolving at least one metal alkoxide precursor in a water-miscible non-polar solvent, and then adding sufficient water to at least partially hydrolize the alkoxide without gelling the solution.
Claim 4
Dependent Claim
21 words
The sol-gel process of Claim 2 in which water is added in excess of the stoichiometric amount needed for complete hydrolysis.
Claim 5
Dependent Claim
24 words
The sol-gel process of Claim 3 in which water is added in the amount of from about 2 to 4 times the stoichiometric amount.
Claim 6
Dependent Claim
32 words
The sol-gel process of Claim 2 in which the hydrolysis is catalyzed by the addition of sufficient hydrogen ions to reduce the pH of the solution to a level below about 4.
Claim 7
Dependent Claim
13 words
The sol-gel process of Claim 3 in which the pH is about 2.
Claim 8
Dependent Claim
18 words
The sol-gel process of Claim 2 in which hydrolysis is accelerated by refluxing the solution at atmospheric pressure.
Claim 9
Dependent Claim
14 words
The sol-gel process of Claim 2 in which the precursor is a metal alcoholate.
Claim 10
Dependent Claim
14 words
The sol-gel process of Claim 8 in which the precursor is a metal ethylate.
Claim 11
Dependent Claim
33 words
The sol-gel process of Claim 1 in which the gellable liquid is formed by co-precipitating at least two metal hydroxides from a solution, washing the co-precipitate, and suspending the co-precipitate in the vehicle.
Claim 12
Dependent Claim
51 words
The sol-gel process of Claim 1 in which prior to heating of the gelled film to convert the film to a luminescent material, the steps of forming a thin film of gellable liquid and gelling the film are sequentially repeated one or more times to increase the thickness of the film.
Claim 13
Dependent Claim
31 words
The sol-gel process of Claim 1 in which the gelled thin film is heated to a temperature below that necessary to achieve solid state reaction of the constituents in powder form.
Claim 14
Dependent Claim
24 words
The sol-gel process of Claim 12 in which during heating, the substrate is maintained at a temperature substantially below the temperature of the film.
Claim 15
Dependent Claim
35 words
The sol-gel process of Claim 1 in which a portion of the heating is carried out in an atmosphere containing a gaseous reactant in order to promote incorporation of the reactant into the luminescent material.
Claim 16
Dependent Claim
12 words
The product produced by the method of any of the previous Claims.
Claim 17
Dependent Claim
15 words
A thin film of a luminescent material having the polycrystalline microstructure shown in Fig. 1.
Claim 18
Dependent Claim
15 words
A thin film of a luminescent material having the polycrystalline microstructure shown in Fig. 1.
Claim 19
Dependent Claim
24 words
A luminescent device comprising at least one layer of luminescent material supported by a transparent substrate, and produced by the method of Claim 1.
Claim 20
Dependent Claim
26 words
The device of Claim 17 in which a first layer of a first luminescent material is superposed on a second layer of a second luminescent material.
Claim 21
Dependent Claim
21 words
The device of Claim 18 in which a layer of non-luminescent material is positioned between the first and second luminescent layers.
References Cited (Backward Citations)
No citation records indexed.
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