LITHIUM SILICATE GLARE-REDUCING COATING AND METHOD OF FABRICATION ON A GLASS SURFACE

• US 3,635,751 A
• Filed: 04/03/1969
• Issued: 01/18/1972
• Est. Priority Date: 04/03/1969
• Status: Expired due to Term

• Current Assignee: RCA Corporation
• Original Assignee: Donald W. Bartch, Francis D. Grove, George E. Long III
• Inventors: Long, George E. III, Grove, Francis D., Bartch, Donald W.
• Primary Examiner(s): Leavitt, Alfred L.
• Assistant Examiner(s): Whitby, Edward G.
• Application Number:
  US04/813,043
• Time in Patent Office: 1,020 Days
• Field of Search: 117/69,33.5C,35,33.3,94 313/65T 23/110 161/116 252/313S
• US Class Current: 220/2.10A
• CPC Class Codes: C03C 17/22 with other inorganic material C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 17/3411 with at least two coatings of inorganic materials C03C17/36, C03C17/42 take precedence
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 2217/28 Other inorganic materials
• CPC Class Codes: C03C 2218/113 by sol-gel processes
• CPC Class Codes: H01J 29/896 Anti-reflection means, e.g. eliminating glare due to ambient light

Abstract

A novel optical screen comprises, as its viewing surface, a hard, abrasion-resistant coating having a rough, glare-reducing surface and composed of a lithium silicate material. The screen may be prepared by a novel method comprising: (a) warming the surface of a glass support to about 30* to 100* C., (b) coating the warm surface with an aqueous solution containing about 1 to 10 weight percent of a lithium-stabilized silica sol, (c) drying the coating, and then (d) heating the dry coating at about 150* C. to 450* C.

Claims

2. The screen defined in claim 1 wherein said lithium silicate has an Si02:

Li20 ratio of about 4;

1 to 25;

1.

3. A cathode-ray tube having a faceplate comprising the viewing screen defined in claim 2.

4. In a method for preparing an optical viewing screen having a glare-reducing viewing surface, the steps including a. warming the surface of a glass support to about 30* C. to 100* C., b. coating said surface with an aqueous solution containing about 1 to 10 weight percent of a lithium-stabilized silica sol, said sol having an Si02:

Li20 ratio of about 4;

1 to 25;

1, c. drying said coating, d. and then heating said dry coating at about 100* C. to 450* C. for about 10 to 60 minutes.

5. The method defined in claim 4 wherein said glass support is the faceplate of a cathode-ray tube and said surface is the external surface thereof.

6. The method defined in claim 5 wherein said steps are carried out after said cathode ray tube has been evacuated and sealed.

7. The method defined in claim 5 wherein said steps are carried out before said cathode-ray tube has been evacuated and sealed.