JPS57176549A - Disc type recording medium and its manufacture - Google Patents

Disc type recording medium and its manufacture

Info

Publication number
JPS57176549A
JPS57176549A JP6021781A JP6021781A JPS57176549A JP S57176549 A JPS57176549 A JP S57176549A JP 6021781 A JP6021781 A JP 6021781A JP 6021781 A JP6021781 A JP 6021781A JP S57176549 A JPS57176549 A JP S57176549A
Authority
JP
Japan
Prior art keywords
carbon black
vinyl chloride
dried
heated
raw material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP6021781A
Other languages
Japanese (ja)
Other versions
JPH024063B2 (en
Inventor
Yoshio Enoki
Kazuhisa Morimoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP6021781A priority Critical patent/JPS57176549A/en
Priority to US06/369,107 priority patent/US4472336A/en
Priority to GB8211134A priority patent/GB2098221B/en
Priority to FR8206672A priority patent/FR2504298B1/en
Priority to DE19823214344 priority patent/DE3214344A1/en
Publication of JPS57176549A publication Critical patent/JPS57176549A/en
Publication of JPH024063B2 publication Critical patent/JPH024063B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B9/00—Recording or reproducing using a method not covered by one of the main groups G11B3/00 - G11B7/00; Record carriers therefor
    • G11B9/06—Recording or reproducing using a method not covered by one of the main groups G11B3/00 - G11B7/00; Record carriers therefor using record carriers having variable electrical capacitance; Record carriers therefor
    • G11B9/061—Record carriers characterised by their structure or form or by the selection of the material; Apparatus or processes specially adapted for the manufacture of record carriers

Landscapes

  • Compositions Of Macromolecular Compounds (AREA)

Abstract

PURPOSE:To obtain a static capacitance type video disc with good quality and yield, by using vinyl chloride as a main content, purifying a conductive carbon black prepared for the vinyl chloride with a specific method and increasing the purity, and using the result. CONSTITUTION:A conductive carbon black raw material is heated and dried to >=70 deg.C, stirred in a dilute hydrochloric acid, filtered under suction and neutralized with ammonium water and heated and dried in an inactive gas or under reduced pressure. Thus, the ash content in the raw material (Na, Ca and Al and the like) can be eliminated in >=95%. Next, 10-40pts.wt. of the purified carbon black is included in 100pts.wt. resin (vinyl chloride) to constitute a disc main body 1, and a center hole 2 is provided. Pits 3 corresponding to information signals are remarkably less in the surface deficiency in comparison with unpurified material.
JP6021781A 1981-04-17 1981-04-20 Disc type recording medium and its manufacture Granted JPS57176549A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP6021781A JPS57176549A (en) 1981-04-20 1981-04-20 Disc type recording medium and its manufacture
US06/369,107 US4472336A (en) 1981-04-17 1982-04-16 Method of manufacturing video disc
GB8211134A GB2098221B (en) 1981-04-17 1982-04-16 Method of producing video discs
FR8206672A FR2504298B1 (en) 1981-04-17 1982-04-19 METHOD OF MANUFACTURING VIDEO DISCS
DE19823214344 DE3214344A1 (en) 1981-04-17 1982-04-19 METHOD FOR PRODUCING VIDEO DISKS

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6021781A JPS57176549A (en) 1981-04-20 1981-04-20 Disc type recording medium and its manufacture

Publications (2)

Publication Number Publication Date
JPS57176549A true JPS57176549A (en) 1982-10-29
JPH024063B2 JPH024063B2 (en) 1990-01-25

Family

ID=13135769

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6021781A Granted JPS57176549A (en) 1981-04-17 1981-04-20 Disc type recording medium and its manufacture

Country Status (1)

Country Link
JP (1) JPS57176549A (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03288067A (en) * 1990-04-04 1991-12-18 Ketsuto & Ketsuto:Kk Metal gasket
JPH04191569A (en) * 1990-11-27 1992-07-09 Nippon Riikuresu Kogyo Kk Metal gasket

Also Published As

Publication number Publication date
JPH024063B2 (en) 1990-01-25

Similar Documents

Publication Publication Date Title
EP0136905A3 (en) Method of purification of phosphoric acid
NZ335392A (en) Method for the recombinant production of 1,3-propanediol
AU560614B2 (en) Biogas production by anaerobic digestion of organic waste
ES8202861A1 (en) Process for obtaining corn oil from corn germs and corn oil thus obtained.
AU6480186A (en) Recovery of lignin
CA2171712A1 (en) Natamycin Recovery
US5032686A (en) Method for the recovery of citric acid from a liquor containing the same
JPS57176549A (en) Disc type recording medium and its manufacture
KR850001284A (en) Antibiotics produced by KIBDELOSPORANGIUM ARIDUM SHEARER GEN.NOV., GEN.NOV., SP.NOV.ATCC 39323
IE44193L (en) Active carbon
JPS57172555A (en) Disk type recording medium and its manufacture
ATE20761T1 (en) PROCESS FOR PRODUCTION OF ACIDIC PROTEASE.
GB2047710A (en) Enhanced cellulase production
AU4846196A (en) Process for the recovery of cephalexin
FR2526442B1 (en) PRODUCTION OF GLUCOSE DEHYDROGENASE AND USE OF THE ENZYME OBTAINED IN THE ENZYMATIC SYNTHESIS OF L-CARNITINE
IE802291L (en) FERMENTATIVE PRODUCTION OF D(-)-ß-HYDROXY ISOBUTYRIC ACID
JPS5675095A (en) Preparation of heat-resistant acetic acid kinase
JPS56106597A (en) Preparation of coenzyme q10
JPS557A (en) Production of ceftezole
JPS56137893A (en) Production of itaconic acid by fermentation
JPS54141794A (en) Preparation of n-acylcephamycin c and its salt with organic base
SU1298221A1 (en) Method for producing carbon black
FR2630751B1 (en) PROCESS FOR PRODUCING ITACONIC ACID
EP0059669A3 (en) Purification of sugar liquors with activated carbon
JPS5783283A (en) Novel yeast