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US005147460A
United States Patent [19] [ii] Patent Number: 5,147,460
Otaki [45] Date of Patent: Sep. 15,1992
U.S. Patent Sep. 15,1992 sheet 2 of 3 5,147,460
[54] INTERNAL COATING MATERIALS FOR A CATHODE RAY TUBE
[75] Inventor: Shiro Otaki, Tokyo, Japan
[73] Assignee: Acheson Industries, Inc., Port Huron, Mich.
[21] Appl. No.: 702,749
[22] Filed: May 20,1991
[30] Foreign Application Priority Data
May 21, 1990 [JP] Japan 2-130549
[51] Int. CI.* C04B 28/20; C04B 14/04;
C09C 1/02
[52] U.S. CI 106/626; 106/618;
106/467
[58] Field of Search 106/618, 626, 467, 14.21
[56] References Cited
U.S. PATENT DOCUMENTS
2,951,773 9/1960 Helle et al 106/626
4,085,235 4/1978 Compen 106/626
4,741,779 5/1988 Mita et al 106/467
FOREIGN PATENT DOCUMENTS
3842837 6/1990 Fed. Rep. of Germany 106/626
Primary Examiner—Helane Myers
Assistant Examiner—David M. Brunsman
Attorney, Agent, or Firm—Dinnin & Dunn
[57] ABSTRACT
Internal coating materials for a cathode ray tube which are characterized by the fact that, in order to increase the electric resistivity of the internal coating, synthetic zeolite powder with a primary particle size of 0.5 to 20 microns, and more preferably 1 to 7 microns, is used together with electrically conductive graphite powder.
9 Claims, 3 Drawing Sheets
