Image display panel having antistatic film with transparent and electroconductive properties and process for processing same

• US 4,945,282 A
• Filed: 12/08/1988
• Issued: 07/31/1990
• Est. Priority Date: 12/10/1987
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Endo, Yoshishige, Kobara, Katsumi, Kawamura, Takao, Kawamura, Hiromitsu
• Primary Examiner(s): Wieder, Kenneth
• Application Number:
  US07/281,213
• Time in Patent Office: 600 Days
• Field of Search: 313/478, 313/479, 358/252, 427/61, 427/106, 427/126.2, 427/126.3
• US Class Current: 313/479
• CPC Class Codes: C03C 17/007 containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• CPC Class Codes: C03C 2217/211 SnO2
• CPC Class Codes: C03C 2217/213 SiO2
• CPC Class Codes: C03C 2217/215 In2O3
• CPC Class Codes: C03C 2217/452 Glass
• CPC Class Codes: C03C 2217/465 having a specific shape
• CPC Class Codes: C03C 2217/476 Tin oxide or doped tin oxide
• CPC Class Codes: C03C 2217/478 Silica
• CPC Class Codes: C03C 2217/48 having a specific function
• CPC Class Codes: C03C 2217/732 made of a single layer
• CPC Class Codes: C03C 2217/734 comprising an alternation of high and low refractive indexes
• CPC Class Codes: C03C 2217/77 Coatings having a rough surface
• CPC Class Codes: C03C 2218/113 by sol-gel processes
• CPC Class Codes: C03C 2218/116 by spin-coating, centrifugation
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: H01J 2229/8913 Anti-reflection, anti-glare, viewing angle and contrast improving treatments or devices
• CPC Class Codes: H01J 29/28 with protective, conductive or reflective layers
• CPC Class Codes: H01J 29/868 Screens covering the input or output face of the vessel, e.g. transparent anti-static coatings, X-ray absorbing layers

Abstract

There are disclosed an image display panel having an antistatic film comprising a SiO₂ coat of transparent and electroconductive properties on the front surface of said panel; the coat containing fine particles of at least one compound selected from electroconductive metal oxides and hygroscopic metal salts; and a process for producing the same.

Claims

1. An image display panel having an antistatic film comprising a SiO₂ coat of transparent and electroconductive properties on the front surface of said panel;

said coat containing fine particles of at least one compound selected from electroconductive metal oxides and hygroscopic metal salts capable of absorbing moisture to impart electroconductivity to said coat.

2. The image display panel of claim 1, wherein the antistatic coat itself either has the non-glare function or is overlaid with a non-glare coat.

3. The image display panel of claim 2, wherein said non-glare coat overlaid on said antistatic coat comprises a thin SiO₂ film which contains fine SiO₂ particles of 100-10,000 Å

in diameter;

said particles being coated by said film so as to fix on the surface of said panel.

4. The image display panel of claim 3, wherein the thickness of said antistatic coat is up to 2000 Å

and the amount of fine SiO₂ particles contained in the non-glare coat is in a range of 0.01-1 mg/cm².

5. The image display panel of claim 4, wherein the thickness of the antistatic coat is 50-500 Å

and the amount of said fine SiO₂ particles is in a range of 0.1-0.3 mg/cm².

6. The image display panel of claim 1, wherein said at least one compound is one selected from the group consisting of tin oxide, indium oxide, antimony oxide, chlorides, nitrates, sulfates, and carboxylates of metals of groups II and III of the periodic table.

7. The image display panel of claim 1, wherein the content of said at least one compound in said SiO₂ film is in a range of 0.01-1.0 mg/cm² area of the film.

8. The image display panel of claim 1, wherein the antistatic coat is formed as a thin SiO₂ film having also reflection inhibitory function and containing further fine SiO₂ particles of 100-10,000 Å

in diameter in addition to said at least one compound.

9. The image display panel of claim 8, wherein said at least one compound is one selected from the group consisting of salts of metals of the groups II and III of the periodic table, tin oxide, indium oxide and antimony oxide.

10. The image display panel of claim 8, wherein said SiO₂ film contains 0.01 to 1.0 mg/cm² of said fine SiO₂ particles and 0.01 to 1.0 mg/cm² of said compound, respectively.

11. The image display panel of claim 10, wherein the amount of said fine SiO₂ particles contained is 0.1-0.3 mg/cm² and the amount of said at least one compound of fine particles contained is 0.15-0.3 mg/cm².

12. The image display panel of claim 2, wherein said antistatic coat has itself a non-glare function, and said antistatic coat has fine projections on its surface and contains fine particles of at least one metal oxide selected from SnO₂, In₂ O₃ and Sb₂ O₃.

13. The image display panel of claim 1, wherein said antistatic coat contains fine particles of at least one electroconductive metal oxide selected from SnO₂, In₂ O₃, and Sb₂ O₃ and said SiO₂ coat is formed by applying an alcoholic solution of alkoxysilane [Si(OR₁)₄, wherein R₁ is alkyl] on the front surface of panel, followed by heat treatment of the resulting coat at temperatures of up to 200°

C.

14. The image display panel of claim 1, wherein said at least one compound is selected from the group consisting of tin oxide, indium oxide and antimony oxide.

15. The image display panel of claim 1, wherein said at least one compound is selected from the group consisting of chlorides, nitrates, sulfates and carboxylates of metals of groups II and III of the Periodic Table.

35. The process of claim 6, wherein said suspension includes an electroconductive metal oxide selected from the group consisting of tin oxide, indium oxide and antimony oxide.

16. A process for producing image display panels which comprises applying a suspension of fine particles of at least one of electroconductive metal oxides and hygroscopic metal salts in an alcoholic solution of alkoxysilane on the front surface of panel, followed by heat treatment of the resulting coat to form an antistatic film comprising a transparent electroconductive SiO₂ coat on the front surface.

17. The process of claim 16 which comprises forming further a non-glare film on the antistatic film.

18. The process of claim 17, wherein the formation of a non-glare film comprises the steps of;

dispersing fine SiO₂ particles of 100-10,000 Å

in diameter in an alcoholic solution of alkoxysilane Si(OR₁)₄, wherein R₁ is alkyl, applying the suspension on the antistatic film which is the transparent substrate formed on the panel; and

heating the resulting coat to decompose the Si(OR₁)₄, forming a thin SiO₂ film, therewith covering and fixing the fine SiO₂ particles.

19. The process of claim 18 wherein the hygroscopic metal salts are chlorides, nitrates, sulfates, and carboxylates of metals of groups II and III of the periodic table and the transparent conductive metal oxides are of tin, indium, and antimony.

20. The process of claim 16, wherein said suspension is prepared by dissolving or dispersing 0.05-7% by weight of the metal oxide or metal salt in the alcoholic solution of alkoxysilane.

21. The process of claim 16, wherein the first step comprises applying the suspension prepared by further adding a ketone or ethyl Cellosolve as a dispersing medium for the metal salt and metal oxide to the alcoholic solution and also adding water and, as a catalyst, an inorganic acid for facilitating the hydrolysis of Si(OR₁)₄.

22. The process of claim 18, wherein said suspension is prepared by dispersing 0.1-10% by weight of the fine SiO₂ particles in the alcoholic solution of Si(OR₁)₄.

23. The process of claim 18 or 22, wherein R₁ of the Si(OR₁)₄ is ethyl and the alcohol component of the alcoholic solution is ethyl alcohol.

24. The process of claim 22, wherein said suspension is prepared by further adding a ketone or ethyl Cellosolve as a dispersing medium for the fine SiO₂ particles and also adding water and an inorganic acid for facilitating the hydrolysis of Si(OR₁)₄.

25. The process of claim 16, which said suspension is applied by spin coating, dip coating, spray coating, or combination of these coating methods and the heat treatment of coating surface is conducted at 50°

-200°

C.

26. The process of claim 16, wherein said antistatic film is formed by the steps which comprises dispersing fine SiO₂ particles of 100-10,000 Å

in diameter in an alcoholic solution of Si(OR₁)₄ wherein R₁ is alkyl; and

also dispersing particles of at least one compound selected from hygroscopic metal salts and electroconductive metal oxides, applying the resulting suspension on the antistatic film, heating the resulting coat to decompose the Si(OR₁)₄ and forming a thin SiO₂ film to coat fine SiO₂ particles in order to fix them on the surface of said panel, whereby said antistatic film also has a non-glare function.

27. The process of claim 26, wherein said at least one compound is one selected from the group consisting of chlorides, nitrates, sulfates, carboxylates of metals of groups II and III of the periodic table and the oxides of tin, indium, and antimony.

28. The process of claim 27 the said fine SiO₂ particles in the alcoholic solution of Si(OR₁)₄ is contained from 0.1 to 10% by weight and said at least one compound in that solution is from 0.05 to 7% by weight.

29. The process of claim 28, wherein said fine SiO₂ particles is contained in a range of from 1 to 3% by weight and said at least one compound from 1.0 to 2.0% by weight.

30. The process of claim 26, wherein R₁ of the Si(OR₁)₄ is ethyl and the alcohol component of the alcoholic solution consists mainly of ethyl alcohol.

31. The process of claim 30, wherein said suspension is prepared by further adding a ketone as a dispersing medium for the fine SiO₂ particles to the alcoholic solution, water and an inorganic acid, as a catalyst, for facilitating the hydrolysis of Si(OR₁)₄.

32. The process of claim 26, wherein said suspension is applied by spin coating, dip coating, spray coating, or combination of these coating methods and the heat treatment of coating surface is conducted at 50°

-200°

C.

33. The process of claim 17, wherein said antistatic film is formed on the front surface of an image display panel by applying an alcoholic Si(OR₁)₄ solution, wherein R₁ is alkyl, containing at least one of SnO₂, In₂ O₃, and Sb₂ O₃ on the front surface, and burning the coat preliminarily, and further said nonglare film is formed on the preliminarily burnt coat by applying an alcoholic solution of Si(OR₁)₄ by spray coating, and burning the whole coat fully, thereby forming film projections of SiO₂ at the outermost surface.

34. The process of claim 16, wherein the suspension is a dispersion of fine particles of at least one of SnO₂, In₂ O₃, and Sb₂ O₃ in an alcoholic solution of alkoxysilane Si(OR₁)₄, wherein R₁ is alkyl, and the heat treatment is carried out at temperatures of up to 200°

C.

36. The process of claim 16, wherein said suspension includes a hygroscopic metal salt selected from the group consisting of chlorides, nitrates, sulfates and carboxylates of metals of groups II and III of the Periodic Table.