Phosphorescent screens
AssigneeEastman Kodak Company
InventorsChen-i Lu, Harry J. Krall, Herman R. Osmers
Life of this patent
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Abstract
Phosphorescent screens which are useful for such purposes as intensifying screens for radiographs are comprised of a support on which is coated a layer of finely-divided particles of a phosphor dispersed in a polymeric binder which has been cured by radiation. The phosphor layer includes voids formed by evaporation of a component which is present in the coating composition from which such layer is formed. Curing of the binder is carried out by use of suitable radiation, such as ultraviolet light or high energy ionizing radiation, and evaporation of the void forming component is carried out simultaneously with or subsequent to the radiation-curing of the binder.
Claims35
A phosphorescent screen comprising a support and a layer of finely-divided particles of a phosphor dispersed in a cross-linked, void-containing polymeric matrix, said layer having been formed by:
- (1) coating said support with a radiation-curable composition comprising a suspension of said finely-divided phosphor particles in a viscous liquid composition, said viscous liquid composition comprising a first component that is capable of being radiation-cured to form a cross-linked polymeric matrix surrounding said phosphor particles and a second component that is capable of being evaporated to generate voids within said matrix,
- (2) irradiating said coating to cure said first component and form thereby a cross-linked polymeric matrix surrounding said phosphor particles, and
- (3) evaporating said second component simultaneously with or subsequent to said irradiating to thereby generate voids within said matrix.
A phosphorescent screen comprising a support and a layer of finely-divided particles of a phospor dispersed in a cross-linked void-containing polymeric matrix, said layer having been formed by:
- (1) coating said support with a radiation-curable composition comprising a suspension of said finely-divided phosphor particles in a viscous liquid composition, said viscous liquid composition comprising a first component that is capable of being radiation-cured to form a cross-linked polymeric matrix surrounding said phosphor particles and a second component that is capable of being evaporated to generate voids within said matrix, said phosphor being europium-activated barium strontium sulfate, said first component comprising a solution of an acrylated epoxy resin in butyl acrylate, said second component being methyl ethyl ketone, and said viscous liquid composition additionally comprising a photoinitiator,
- (2) irradiating said coating with ultraviolet light to cure said first component and form thereby a cross-linked polymeric matrix surrounding said phosphor particles, and
- (3) evaporating said second component simultaneously with or subsequent to said irradiating to thereby generate voids within said matrix.
A method for the manufacture of a phosphorescent screen, said method comprising the steps of:
- (1) coating a support with a radiation-curable composition comprising a suspension of finely-divided phosphor particles in a viscous liquid composition, said viscous liquid composition comprising a first component that is capable of being radiation-cured to form a cross-linked polymeric matrix surrounding said phosphor particles and a second component that is capable of being evaporated to generate voids within said matrix,
- (2) irradiating said coating to cure said first component and form thereby a cross-linked polymeric matrix surrounding said phosphor particles, and
- (3) evaporating said second component simultaneously with or subsequent to said irradiating to thereby generate voids within said matrix.
Dependencies are inferred from the claim text.