US3900604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a magnetic recording material
Assignee: Teijin Ltd
•
Filing: 1973-11-05
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Granted: 1975-08-19
•
Expires: 1993-11-05
Abstract
Abstract A method of producing a magnetic recording material which comprises preparing an unstretched film of a crystalline polymer, stretching it and coating a magnetic layer on one surface of the film, wherein the film is crystallized so that the degree of crystallization of one surface of the film becomes at least 5% higher than that of the other surface, then the film is stretched in at least one direction, and then a magnetic layer is coated on said other surface. In an alternate embodiment a crystalline polymer is stretched in one direction, subjected to a differential crystallization treatment and stretched in a direction at right angles to the first stretch before application of the magnetic coating.
Inventors
- 👤 Takashi Tanabe
- 👤 Tomio Adachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:07
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/62; G11B5/73; G11B5/739; G11B5/73923; G11B5/73927; G11B5/73929; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24471; Y10T428/24942; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/26; Y10T428/261; Y10T428/263; Y10T428/269; Y10T428/31504; Y10T428/31678; Y10T428/31681; Y10T428/31725; Y10T428/31765; Y10T428/31786; Y10T428/31855; Y10T428/31938
Claims Analysis
Total Claims: 52
Claim 1
Independent Claim
16 words
PREPARING AN UNSTRETCHED FILM OF A CRYSTALLINE POLYMER SELECTED FROM THE GROUP CONSISTING OF AROMATIC LINEAR
Claim 2
Dependent Claim
16 words
PREPARING AN UNSTRETCHED FILM OF A CRYSTALLINE POLYMER SELECTED FROM THE GROUP CONSISTING OF AROMATIC LINEAR
Claim 3
Dependent Claim
61 words
PREPARING AN UNSTRETCHED FILM OF A CRYSTALLINE POLYMER SELECTED FROM THE GROUP CONSISTING OF AROMATIC LINEAR POLYESTERS, AROMATIC LINEAR CO-POLYESTERS, POLYAMIDES, AND POLYPROPYLENE, I. SUBJECTING THE UNSTRETCHED FILM TO A DIFFERENTIAL CRYSTALLIZATION TREATMENT SUCH THAT ONE SURFACE OF THE FILM WILL POSSESS A DEGREE OF CRYSTALLIZATION WHICH IS AT LEAST 5% HIGHER THAN THAT OF THE OTHER SURFACE OF THE FILM,
Claim 4
Dependent Claim
61 words
PREPARING AN UNSTRETCHED FILM OF A CRYSTALLINE POLYMER SELECTED FROM THE GROUP CONSISTING OF AROMATIC LINEAR POLYESTERS, AROMATIC LINEAR CO-POLYESTERS, POLYAMIDES, AND POLYPROPYLENE, I. SUBJECTING THE UNSTRETCHED FILM TO A DIFFERENTIAL CRYSTALLIZATION TREATMENT SUCH THAT ONE SURFACE OF THE FILM WILL POSSESS A DEGREE OF CRYSTALLIZATION WHICH IS AT LEAST 5% HIGHER THAN THAT OF THE OTHER SURFACE OF THE FILM,
Claim 5
Independent Claim
9 words
A METHOD FOR PRODUCING A MAGNETIC RECORDING MATERIAL COMPRISING:
Claim 6
Independent Claim
9 words
A METHOD FOR PRODUCING A MAGNETIC RECORDING MATERIAL COMPRISING:
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein said crystallization is performed by heating said one surface of the film more strongly than said other surface.
Claim 8
Dependent Claim
37 words
subjecting The unstretched film to a differential crystallization treatment such that one surface of the film will possess a degree of crystallization which is at least 5% higher than that of the other surface of the film,
Claim 9
Dependent Claim
37 words
subjecting The unstretched film to a differential crystallization treatment such that one surface of the film will possess a degree of crystallization which is at least 5% higher than that of the other surface of the film,
Claim 10
Dependent Claim
8 words
UNIAXIALLY, STRETCHING THE UNSTRETCHED FILM IN ONE DIRECTION,
Claim 11
Dependent Claim
8 words
UNIAXIALLY, STRETCHING THE UNSTRETCHED FILM IN ONE DIRECTION,
Claim 12
Dependent Claim
8 words
uniaxially, stretching the unstretched film in one direction,
Claim 13
Dependent Claim
8 words
uniaxially, stretching the unstretched film in one direction,
Claim 14
Dependent Claim
43 words
subjecting the uniaxially stretched film of step 2 to a differential crystallization treatment such that one surface of said film obtains a degree of crystallization which is at least 5% higher than the degree of crystallization of the other surface of the film,
Claim 15
Dependent Claim
43 words
subjecting the uniaxially stretched film of step 2 to a differential crystallization treatment such that one surface of said film obtains a degree of crystallization which is at least 5% higher than the degree of crystallization of the other surface of the film,
Claim 16
Dependent Claim
25 words
The method of claim 1 wherein said crystallization is performed by allowing a crystallization promotor to act only on said one surface of the film.
Claim 17
Dependent Claim
43 words
SUBJECTING THE UNIAXIALLY STRETCHED FILM OF STEP 2 TO A DIFFERENTIAL CRYSTALLIZATION TREATMENT SUCH THAT ONE SURFACE OF SAID FILM OBTAINS A DEGREE OF CRYSTALLIZATION WHICH IS AT LEAST 5% HIGHER THAN THE DEGREE OF CRYSTALLIZATION OF THE OTHER SURFACE OF THE FILM,
Claim 18
Dependent Claim
43 words
SUBJECTING THE UNIAXIALLY STRETCHED FILM OF STEP 2 TO A DIFFERENTIAL CRYSTALLIZATION TREATMENT SUCH THAT ONE SURFACE OF SAID FILM OBTAINS A DEGREE OF CRYSTALLIZATION WHICH IS AT LEAST 5% HIGHER THAN THE DEGREE OF CRYSTALLIZATION OF THE OTHER SURFACE OF THE FILM,
Claim 19
Dependent Claim
13 words
stretching the treated film from step 2 in at least one direction, and
Claim 20
Dependent Claim
13 words
stretching the treated film from step 2 in at least one direction, and
Claim 21
Dependent Claim
13 words
STRETCHING THE TREATED FILM FROM STEP 2 IN AT LEAST ONE DIRECTION, AND
Claim 22
Dependent Claim
13 words
STRETCHING THE TREATED FILM FROM STEP 2 IN AT LEAST ONE DIRECTION, AND
Claim 23
Dependent Claim
9 words
THEREAFTER COATING A MAGNETIC LAYER ON SAID OTHER SURFACE
Claim 24
Dependent Claim
9 words
THEREAFTER COATING A MAGNETIC LAYER ON SAID OTHER SURFACE
Claim 25
Dependent Claim
21 words
STRETCHING THE TREATED FILM OF STEP 3 IN A DIRECTION AT RIGHT ANGLES TO THE DIRECTION OF THE UNIAXIAL STRETCHING SAID,
Claim 26
Dependent Claim
21 words
STRETCHING THE TREATED FILM OF STEP 3 IN A DIRECTION AT RIGHT ANGLES TO THE DIRECTION OF THE UNIAXIAL STRETCHING SAID,
Claim 27
Dependent Claim
9 words
thereafter coating a magnetic layer on said other surface.
Claim 28
Dependent Claim
9 words
thereafter coating a magnetic layer on said other surface.
Claim 29
Dependent Claim
39 words
The method of claim 1 wherein the crystallization is carried out by simultaneously heating said one surface of the film more strongly than said other surface and by allowing a crystallization promotor to act only on said one surface.
Claim 30
Dependent Claim
21 words
stretching the treated film of step 3 in a direction at right angles to the direction of the uniaxial stretching and,
Claim 31
Dependent Claim
21 words
stretching the treated film of step 3 in a direction at right angles to the direction of the uniaxial stretching and,
Claim 32
Dependent Claim
9 words
thereafter coating a magnetic layer on said other surface.
Claim 33
Dependent Claim
9 words
thereafter coating a magnetic layer on said other surface.
Claim 34
Dependent Claim
20 words
The method of claim 1 wherein after stretching the film subsequent to the differential crystallization treatment, the film is heat-treated.
Claim 35
Dependent Claim
9 words
THEREAFTER COATING A MAGNETIC LAYER ON SAID OTHER SURFACE.
Claim 36
Dependent Claim
9 words
THEREAFTER COATING A MAGNETIC LAYER ON SAID OTHER SURFACE.
Claim 37
Dependent Claim
11 words
The method of claim 3 wherein said crystallization promotor is water.
Claim 38
Dependent Claim
14 words
The method of claim 1 wherein the crystalline polymer is a linear aromatic polyester.
Claim 39
Dependent Claim
11 words
The method of claim 7 wherein the polyester is polyethylene terephthalate.
Claim 40
Dependent Claim
27 words
The method of claim 1 wherein said crystalline polymer is an aromatic linear polyester selected from the group consisting of polymethylene terephthalate, polymethylene-2,6-naphthalate and the copolyesters thereof.
Claim 41
Dependent Claim
23 words
The method of claim 1 wherein said crystalline polymer is a polyamide selected from the group consisting of nylon 6 and nylon 66.
Claim 42
Independent Claim
10 words
A METHOD FOR PRODUCING A MAGNETIC RECORDING MATERIAL WHICH COMPRISES
Claim 43
Independent Claim
10 words
A METHOD FOR PRODUCING A MAGNETIC RECORDING MATERIAL WHICH COMPRISES
Claim 44
Dependent Claim
24 words
The method of claim 1 wherein said crystallization is performed by heating said one surface of the film more strongly than said other surface.
Claim 45
Dependent Claim
25 words
The method of claim 1 wherein said crystallization is performed by allowing a crystallization promotor to act only on said one surface of the film.
Claim 46
Dependent Claim
39 words
The method of claim 1 wherein the crystallization is carried out by simultaneously heating said one surface of the film more strongly than said other surface and by allowing a crystallization promotor to act only on said one surface.
Claim 47
Dependent Claim
20 words
The method of claim 1 wherein after stretching the film subsequent to the differential crystallization treatment, the film is heat-treated.
Claim 48
Dependent Claim
11 words
The method of claim 13 wherein said crystallization promotor is water.
Claim 49
Dependent Claim
14 words
The method of claim 11 wherein the crystalline polymer is a linear aromatic polyester.
Claim 50
Dependent Claim
11 words
The method of claim 17 wherein the polyester is polyethylene terephthalate.
Claim 51
Dependent Claim
27 words
The method of claim 11 wherein said crystalline polymer is an aromatic linear polyester selected from the group consisting of polymethylene terephthalate, polymethylene-2,6-naphthalate and the copolyesters thereof.
Claim 52
Dependent Claim
23 words
The method of claim 11 wherein said crystalline polymer is a polyamide selected from the group consisting of nylon 6 and nylon 66.
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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |