US4308311A
Expired / Lapsed
US
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Magnetic recording material
Assignee: Fujifilm Holdings Corp
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Filing: 1979-07-18
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Granted: 1981-12-29
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Expires: 1999-07-18
Abstract
Abstract A magnetic recording material, and, more particularly, a high density magnetic recording material is disclosed having an aromatic polyamide support in which the adhesion between the support and the magnetic recording layer is improved by an undercoating of an alcohol-soluble polyamide resin.
Inventors
- 👤 Hiroshi Ogawa
- 👤 Masashi Aonuma
- 👤 Yasuo Tamai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:04
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/739; G11B5/73923; G11B5/73937; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/266; Y10T428/31; Y10T428/31504; Y10T428/31725; Y10T428/31728; Y10T428/31732; Y10T428/31739; Y10T428/31743
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
167 words
A magnetic recording material comprising a nonmagnetizable flexible support of an aromatic polyamide resin having provided thereon a magnetic recording layer containing a ferromagnetic fine powder dispersed in a binder, and between said support and said magnetic recording layer an alcoholsoluble polyamide resin layer, wherein said aromatic polyamide resin is a polyamide resin represented by the formulae (I) or (II): ##STR11## wherein R 1 , R 2 and R 3 each represents ##STR12## R 4 represents ##STR13## and --S 2 --, X and X' which may be the same or different each represents a hydrogen atom, a halogen atom and nitro group, and m and m' each is an integer of from about 100 to about 1,000, provided that the polyamide resin contains at least 70% p-arylene groups based on the total number of arylene groups in the resin; or a polyamide resin containing units of both the formulae (I) and (II) in a molar ratio of (I) to (II) of from about 1:9 to about 9:1.
Claim 2
Dependent Claim
167 words
A magnetic recording material comprising a nonmagnetizable flexible support of an aromatic polyamide resin having provided thereon a magnetic recording layer containing a ferromagnetic fine powder dispersed in a binder, and between said support and said magnetic recording layer an alcoholsoluble polyamide resin layer, wherein said aromatic polyamide resin is a polyamide resin represented by the formulae (I) or (II): ##STR11## wherein R 1 , R 2 and R 3 each represents ##STR12## R 4 represents ##STR13## and --S 2 --, X and X' which may be the same or different each represents a hydrogen atom, a halogen atom and nitro group, and m and m' each is an integer of from about 100 to about 1,000, provided that the polyamide resin contains at least 70% p-arylene groups based on the total number of arylene groups in the resin; or a polyamide resin containing units of both the formulae (I) and (II) in a molar ratio of (I) to (II) of from about 1:9 to about 9:1.
Claim 3
Dependent Claim
47 words
The magnetic recording material of claim 1, wherein said aromatic polyamide resin contains at least 70% based on the total number of arylene units in the resin of one or more of a unit selected from the group consisting of terephthalhydrazide unit, p-benzamide unit and p-phenyleneterephthalamide unit.
Claim 4
Dependent Claim
24 words
The magnetic recording material of claim 2, wherein said aromatic polyamide resin has a weight average molecular weight of from about 10,000 to 100,000.
Claim 5
Dependent Claim
17 words
The magnetic recording material of claim 1, wherein said support is about 3 to 10 μm thick.
Claim 6
Dependent Claim
21 words
The magnetic recording material of claim 4, wherein the surface roughness of said support is not more than about 0.1 μm.
Claim 7
Dependent Claim
20 words
The magnetic recording material of claim 1, wherein the alcohol-soluble polyamide resin is a nylon copolymer or an N-alkoxymethyl-modified nylon.
Claim 8
Dependent Claim
27 words
The magnetic recording material of claim 6, wherein said nylon copolymer is a terpolymer of 6-nylon, 6/6-nylon and 6/10-nylon or a terpolymer of 6-nylon, 6/6-nylon and bis(4-aminocyclohexyl)methane-6-nylon.
Claim 9
Dependent Claim
49 words
The magnetic recording material of claim 6, wherein said N-alkoxymethyl-modified nylon has the molecular structure represented by the formula (VIII): ##STR14## wherein R 9 represents a hydrogen atom and an alkyl group having from 1 to 5 carbon atoms, p is an integer of from about 1 to 50.
Claim 10
Dependent Claim
20 words
The magnetic recording material of claim 1, wherein said alcohol-soluble polyamide resin layer is about 0.03 to 0.3 μm thick.
Claim 11
Dependent Claim
20 words
The magnetic recording material of claim 9, wherein said alcohol-soluble polyamide resin layer is about 0.05 to 0.2 μm thick.
Claim 12
Dependent Claim
27 words
The magnetic recording material of claim 1, wherein said alcohol-soluble polyamide resin layer is provided using a solvent of an alcohol having 1 to 5 carbon atoms.
Claim 13
Dependent Claim
26 words
The magnetic recording material of claim 11, wherein said solvent is at least one selected from the group consisting of methanol, ethanol, isopropanol, butanol and pentanol.
Claim 14
Dependent Claim
30 words
The magnetic recording material of claims 11 or 12, wherein said solvent contains 0 to about 50 wt% of a chlorine-series solvent based on the total weight of said solvent.
Claim 15
Dependent Claim
17 words
The magnetic recording material of claim 13, wherein said chlorine-series solvent is chloroform, trichloroethylene or ethylene dichloride.
Claim 16
Dependent Claim
20 words
The magnetic recording material of claim 1, wherein said magnetic recording layer is from about 0.8 to 10 μm thick.
Claim 17
Dependent Claim
19 words
The magnetic recording material of claim 15, wherein said magnetic recording layer is from 1 to 5 μm thick.
Claim 18
Dependent Claim
44 words
The magnetic recording material of claim 1, wherein the surface of said support opposite said magnetic recording layer is provided with a back-coating layer capable of preventing electrostatic charge, preventing transfer, preventing flutter, improving the strength of the magnetic recording material, or a matting.
Claim 19
Dependent Claim
22 words
The magnetic recording material of claim 17, wherein an alcohol-soluble polyamide resin layer is provided between said support and said back-coating layer.
Claim 20
Dependent Claim
20 words
the magnetic recording material of claim 18, wherein the alcohol-soluble polyamide resin is a nylon copolymer or an N-alkoxymethyl-modified nylon.
Claim 21
Dependent Claim
27 words
The magnetic recording material of claim 19, wherein said nylon copolymer is a terpolymer of 6-nylon, 6/6-nylon and 6/10-nylon, or a terpolymer of 6-nylon, 6/6-nylon and bis(4-aminocyclohexyl)methane-6-nylon.
Claim 22
Dependent Claim
47 words
The magnetic recording material of claim 19, wherein said N-alkoxymethyl-modified nylon has the molecular structure represented by the formula (VIII): ##STR15## wherein R 9 represents hydrogen atom or alkyl group having from 1 to 5 carbon atoms, p is an integer of from about 1 to 50.
Claim 23
Dependent Claim
20 words
The magnetic recording material of claim 18, wherein said alcohol-soluble polyamide resin layer is about 0.03 to 0.3 μm thick.
Claim 24
Dependent Claim
20 words
The magnetic recording material of claim 22, wherein said alcohol-soluble polyamide resin layer is about 0.05 to 0.2 μm thick.
Claim 25
Dependent Claim
28 words
The magnetic recording material of claim 18, wherein said alcohol-soluble polyamide resin layer is provided using to a solvent of an alcohol having 1 to 5 carbon atoms.
Claim 26
Dependent Claim
26 words
The magnetic recording material of claim 24, wherein said solvent is at least one selected from the group consisting of methanol, ethanol, isopropanol, butanol and pentanol.
Claim 27
Dependent Claim
30 words
The magnetic recording material of claims 24 or 25, wherein said solvent contains 0 to about 50 wt% of a chlorine-series solvent based on the total weight of said solvent.
Claim 28
Dependent Claim
22 words
The magnetic recording material of claim 17, wherein said back-coating layer comprises thermosetting resins or reaction-type resins and inorganic or organic additives.
Claim 29
Dependent Claim
27 words
The magnetic recording material of claim 27, wherein said additive is carbon black, graphite, talc, Cr 2 O 3 , α--Fe 2 O 3 or silicone oil.
Claim 30
Dependent Claim
43 words
The magnetic recording material of claim 27, wherein the amount of said inorganic additives is about 30 to 85 wt%, and the amount of said organic additives is about 0.1 to 30 wt%, based on the total solid ingredients of the back-coating layer.
Claim 31
Dependent Claim
18 words
The magnetic recording material of claim 17, wherein said back-coating layer is about 0.5 to 3 μm thick.
Claim 32
Dependent Claim
24 words
The magnetic recording material of claims 1 or 17, wherein said magnetic recording material is an audio cassette tape or a video cassette tape.
Claim 33
Dependent Claim
25 words
The magnetic recording material of claim 1, wherein said alcohol-soluble polyamide resin layer increases adhesion between the aromatic polyamide support and the magnetic recording layer.
Claim 34
Dependent Claim
14 words
The magnetic recording material of claim 32, wherein said binder is an organic polymer.
Claim 35
Dependent Claim
41 words
The magnetic recording material of claim 33, wherein the ratio of the ferromagnetic powder to binder in the magnetic recording layer is about 8 to 400 parts by weight of the binder per 100 parts by weight of the ferromagnetic powder.
Claim 36
Dependent Claim
41 words
The magnetic recording material of claim 33, wherein the ratio of the ferromagnetic powder to binder in the magnetic recording layer is about 10 to 20 parts by weight of the binder per 100 parts by weight of the ferromagnetic powder.
Claim 37
Dependent Claim
24 words
The magnetic recording material of claim 34, wherein the binder is selected from the group consisting of thermoplastic resins, thermosetting resins and reaction resins.
Claim 38
Dependent Claim
45 words
The magnetic recording material of claim 36, wherein said binder is said thermoplastic resin and said thermoplastic resin has a sotening point of not higher than 150° C., a mean molecular weight of 10,000 to 200,000 and a polymerization degree of about 200 to 2,000.
Claim 39
Dependent Claim
32 words
The magnetic recording material of claim 36, wherein said binder is said thermosetting resin or said reaction resin and said binder has a molecular weight of not more than 200,000 in solution.
Claim 40
Dependent Claim
26 words
The magnetic recording material of claim 1, wherein said alcohol-soluble polyamide resin layer is the only layer present between said magnetic recording layer and said support.
Claim 41
Dependent Claim
69 words
The magnetic recording material of claim 1, wherein said aromatic polyamide resin contains at least 70% based on the total number of arylene units in the resin of one or more of a unit selected from the group consisting of terephthalhydrazide unit, p-benzamide unit and p-phenyleneterephthalamide unit, and wherein the alcohol-soluble polyamide resin is a terpolymer of 6-nylon, 6/6-nylon and 6/10-nylon or a terpolymer of 6-nylon, 6/6-nylon and bis(4-aminocyclohexyl)methane-6-nylon.
Claim 42
Dependent Claim
133 words
The magnetic recording material of claim 1, wherein said aromatic polyamide resin contains at least 70%, based on the total number of arylene units in the resin, of p-phenyleneterephthalamide units, and wherein the alcohol-soluble polyamide resin is an N-alkoxymethyl-modified nylon prepared by reacting nylon with formalin and nylon and having the molecular structure represented by formula (VIII): ##STR16## wherein R 9 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms and p is an integer of about 1 to 50, the modification degree of the nylon being more than 20% based on the total number of repeating units in the nylon, said support having a thickness of about 2 to 80 μm and said alcohol-soluble polyamide resin layer having a dry thickness of about 0.03 to 0.3 μm.
Claim 43
Dependent Claim
35 words
The magnetic recording material of claim 41, wherein said support has a thickness of about 3 to 10 μm and said alcohol-soluble polyamide resin layer has a dry thickness of about 0.05 to 0.2 μm.
Claim 44
Dependent Claim
16 words
The magnetic recording material of claim 41 or claim 42, wherein said nylon is 6/6 nylon.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-28 | 1985-06-29 | 1985-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-28 | 1989-06-29 | 1989-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-28 | 1993-06-29 | 1993-12-29 | $7700.00 | Window Closed / Lapsed |