Photosensitive composition for making repeatably tonable layers
AssigneeE. I. Du Pont de Nemours and Company
InventorMario Grossa
Life of this patent
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Abstract
Photosensitive composition for production of repeatably tonable layers for the manufacture of fluorescent screens with a black matrix for color picture tubes, said composition comprising at least one light sensitive 4-(2'-nitrophenyl)-1,4-dihydropyridine compound and at least one organic sulfonic acid.
Claims14
A photosensitive composition for the production of repeatedly tonable layers for the manufacture of fluorescent screens with a black matrix for color picture tubes, said composition comprising at least one 1,4-dihydropyridine compound substituted in the 4 position with a 2'-nitrophenyl ring, the improvement wherein the composition also comprises at least one organic sulfonic acid in an amount such that the photosensitive composition is tacky at the temperature of toner application.
A process for the production of a fluorescent screen with a black matrix for color television tubes comprising the steps of:
- (1) applying a photosensitive, repeatably tonable layer of a photosensitive composition comprising at least one 1,4-dihydropyridine compound substituted in the 4 position with a 2'-nitrophenyl ring and at least one organic sulfonic acid on the inner surface of the screen,
- (2) exposing the layer successively through a shadow mask in the green, blue and red positions,
- (3) toning the unexposed tacky areas with a black pigment,
- (4) exposing imagewise to produce tacky areas in the green, blue, or red position,
- (5) toning the resulting tacky areas with a fluorescent powder of the corresponding color, and
- (6) repeating the imagewise exposing and toning steps twice, each time in a different color position, and after each exposure, toning with a fluorescent powder of the corresponding second or third color.
Dependencies are inferred from the claim text.