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Title:
MAGNETIC RECORDING BODY
Document Type and Number:
Japanese Patent JPS5919233
Kind Code:
A
Abstract:

PURPOSE: To provide excellent recovering power for video heads and durability by forming a titled recording body with a nonmagnetic substrate and a magnetic layer, and incorporating carbon black having ≥90mμ average primary particle size and ≥8pH.

CONSTITUTION: The average primary particle sizes of carbon black are larger than 90mμ, preferably ≥100mμ, more preferably 100W350mμ. If the particle sizes are smaller than the above-mentioned sizes, the durability of the magnetic layer is insufficient, and the carbon black of large sizes is hardly available on the market. The pH of the carbon black is larger than 8, more particularly preferably 9 or larger than 9. If the pH is ≤8, the durability of the magnetic layer deteriorates. The amt. of the carbon black to be added is 1W20pts.wt., more particularly, 3W15pts.wt., based on 100pts.wt. a magnetic material. If the amt. is too small, the antistat effect decreases and if the amt. is too large, the degree of filling of the magnetic material decreases and an electromagnetic conversion characteristic deteriorates.


Inventors:
YAMAGUCHI NOBUTAKA
FUJIYAMA MASAAKI
Application Number:
JP12806082A
Publication Date:
January 31, 1984
Filing Date:
July 22, 1982
Export Citation:
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Assignee:
FUJI PHOTO FILM CO LTD
International Classes:
G11B5/71; C09C1/48; C09D5/23; C09D7/12; G11B5/708; (IPC1-7): G11B5/70