Back to results
US 4,061,529 AGranted
Method for making etch-resistant stencil with dichromate-sensitized casein coating
AssigneeRCA Corporation
InventorsAbraham Goldman, Pabitra Datta
Life of this patent
Estimating the term…
Abstract
The method comprises applying to a surface to be etched a coating of a liquid composition comprising an acid-precipitated casein, alkali dichromate photosensitizer, sodium borate and water. The layer is dried, photoexposed, developed and baked to produce an etch-resistant stencil.
Claims10
A method for producing an etch-resistant stencil upon a surface comprising applying to said surface a coating of a liquid composition comprising
- i. acid precipitated casein, as the sole sensitizable protein material in said liquid composition,
- ii. alkali dichromate photosensitizer for said casein,
- iii. sodium borate, as the sole alkalizing agent in said liquid composition,
- iv. and water, drying said coating, photoexposing said dry coating to a light image, developing said exposed coating to produce said stencil, and then baking said stencil in air to render said stencil etch resistant.
1 more element
In a method for producing an apertured mask for a cathode-ray tube, the steps comprising
- a. applying to each major surface of a metal sheet a coating of a liquid, water-based coating composition having a pH of about 6.7 to 7.3 and consisting essentially of
- i. acid-precipitated casein as the sole photosensitizable protein material present,
- ii. alkali dichromate photosensitizer for said casein,
- iii. anhydrous sodium borate, as the sole alkalizing agent in said coating composition, said sodium borate comprising about 0.05 to 0.20 of the weight of said casein,
- iv. and water,
- b. drying said coatings,
- c. exposing said dry coatings to light images,
- d. developing said exposed coatings to produce stencils on each of said major surfaces,
- e. baking said stencils in air to render said stencils etch resistant,
- f. and then applying an etchant for said metal sheet to both of said surfaces until said sheet is etched a desired amount.
7 more elements
Dependencies are inferred from the claim text.