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US4171406A
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1978-07-06
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Granted: 1979-10-16
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Expires: 1998-07-06
Abstract
Abstract A magnetic recording medium with a greatly reduced coefficient of friction comprising a non-magnetic support having thereon a magnetic recording layer comprising finely divided ferromagnetic powders in a binder, wherein (1) at least one alkylpolysiloxane having a hydrophilic group in the side chain thereof and represented by the formula (I) ##STR1## wherein R 1 and R 2 , which may be the same or different, each represents ##STR2## provided that R 1 and R 2 are not simultaneously --CH 3 ; R 3 represents --CH 3 or the aliphatic chain having 10 to 18 carbon atoms of a saturated or unsaturated fatty acid; R 4 represents --H or --CH 3 ; Z represents an ionic group, which renders the alkylpolysiloxane water-soluble, selected from the group consisting of --OSO 3 Na, --COOR 5 wherein R 5 is H, Na or K, and ##STR3## X REPRESENTS A NUMBER OF FROM 3 TO 50; Y REPRESENTS A NUMBER OF FROM 2 TO 50; Z REPRESENTS 0 OR A NUMBER OF FROM 1 TO 10; X+Y+Z IS A NUMBER OF FROM 5 TO 100; N IS 0 OR A NUMBER OF FROM 1 TO 5; P IS 0 OR A NUMBER OF FROM 1 TO 50; AND Q IS 0 OR A NUMBER OF FROM 1 TO 50; IS PRESENT IN THE MAGNETIC RECORDING LAYER IN AN AMOUNT OF ABOUT 5 WT% OR LESS BASED ON THE WEIGHT OF THE FERROMAGNETIC POWDERS AND (2) the magnetic layer has a Young's modulus of at least 1×10 10 dyne/cm 2 .
Inventors
- 👤 Nobutaka Yamaguchi
- 👤 Masahiro Utumi
- 👤 Masaaki Fujiyama
- 👤 Masakazu Yoneyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:00
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7023; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
258 words
A magnetic recording medium having a running speed below 5 cm/sec comprising a non-magnetic support having thereon a magnetic recording layer comprising finely divided ferromagnetic powders in a binder, wherein (1) the magnetic recording layer contains about 0.1 to about 5% by weight based on the weight of said finely divided ferromagnetic powder of at least one alkylpolysiloxane having a hydrophilic group in the side chain thereof, represented by the formula (I) below ##STR9## wherein R 1 and R 2 , which may be the same or different, each represents --CH 3 or ##STR10## provided that R 1 and R 2 are not simultaneously --CH 3 ; R 3 represents --CH 3 or the aliphatic chain having 10 to 18 carbon atoms of a saturated or unsaturated fatty acid; R 4 represents --H or --CH 3 ; Z represents an ionic group, which renders the alkylpolysiloxane water-soluble, selected from the group consisting of --OSO 3 Na, --COOR 5 wherein R 5 is H, Na or K, and ##STR11## x represents a number of from 3 to 50; y represents a number of from 2 to 50; z represents 0 or a number of from 1 to 10; x+y+z is a number of from 5 to 100; n is 0 or a number of from 1 to 5; p is 0 or a number of from 1 to 50; and q is 0 or a number of from 1 to 50, and (2) the magentic recording layer has a Young's modulus of at least 1×10 10 dyne/cm 2 .
Claim 2
Dependent Claim
258 words
A magnetic recording medium having a running speed below 5 cm/sec comprising a non-magnetic support having thereon a magnetic recording layer comprising finely divided ferromagnetic powders in a binder, wherein (1) the magnetic recording layer contains about 0.1 to about 5% by weight based on the weight of said finely divided ferromagnetic powder of at least one alkylpolysiloxane having a hydrophilic group in the side chain thereof, represented by the formula (I) below ##STR9## wherein R 1 and R 2 , which may be the same or different, each represents --CH 3 or ##STR10## provided that R 1 and R 2 are not simultaneously --CH 3 ; R 3 represents --CH 3 or the aliphatic chain having 10 to 18 carbon atoms of a saturated or unsaturated fatty acid; R 4 represents --H or --CH 3 ; Z represents an ionic group, which renders the alkylpolysiloxane water-soluble, selected from the group consisting of --OSO 3 Na, --COOR 5 wherein R 5 is H, Na or K, and ##STR11## x represents a number of from 3 to 50; y represents a number of from 2 to 50; z represents 0 or a number of from 1 to 10; x+y+z is a number of from 5 to 100; n is 0 or a number of from 1 to 5; p is 0 or a number of from 1 to 50; and q is 0 or a number of from 1 to 50, and (2) the magentic recording layer has a Young's modulus of at least 1×10 10 dyne/cm 2 .
Claim 3
Dependent Claim
82 words
The magnetic recording layer of claim 1, wherein said aliphatic chain having 10 to 18 carbon atoms for R 3 is a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an 8-undecenyl group, a 3-tridecenyl group, a 4-tridecenyl group, an 8-pentadecenyl group, a 5-heptadecenyl group, an 8-cis-heptadecenyl group, an 8-trans-heptadecenyl group, a 10-heptadecenyl group, an 8,11-heptadecadienyl group, an 8,10,12-heptadecatrienyl group, an 8,11,14-heptadecatrienyl group or an 8,10,12,14-heptadecatetraenyl group.
Claim 4
Dependent Claim
74 words
The magnetic recording medium of claim 1, wherein x is a number of from 5 to 30; y is a number of from 4 to 30; z is 0 or a number of 1 to 5; x+y+z is a number of from 5 to 50; n is 0 or a number of 1 to 3; p is a number of from 1 to 20; and q is a number of from 1 to 10.
Claim 5
Dependent Claim
12 words
The magnetic recording member of claim 1, wherein said alkylpolysiloxane is: ##STR12##
Claim 6
Dependent Claim
12 words
The magnetic recording medium of claim 1, wherein said alkylpolysiloxane is: ##STR13##
Claim 7
Dependent Claim
12 words
The magnetic recording medium of claim 1, wherein said alkylpolysiloxane is ##STR14##
Claim 8
Dependent Claim
12 words
The magnetic recording medium of claim 1, wherein said alkylpolysiloxane is: ##STR15##
Claim 9
Dependent Claim
12 words
The magnetic recording medium of claim 1, wherein said alkylpolysiloxane is: ##STR16##
Claim 10
Dependent Claim
36 words
The magnetic recording medium of claim 1, wherein said alkylpolysiloxane is present in said magnetic recording layer in an amount of 0.1 to 2% by weight, based on the weight of said finely divided ferromagnetic powders.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-15 | 1983-04-16 | 1983-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-15 | 1987-04-16 | 1987-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-15 | 1991-04-16 | 1991-10-16 | $7700.00 | Window Closed / Lapsed |