EP0074750A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Polyester film for magnetic recording medium and magnetic recording medium made therewith
Assignee: Toray Industries Inc
•
Filing: 1982-08-31
•
Granted: —
•
Expires: 2002-08-31
Abstract
Abstract A polyester based film for a magnetic recording medium is provided, which comprises a polyester. film (2) and a discontinuous film (1) formed on at least one surface of the polyester film. The discontinuous film (1) has a thickness of smaller than 500 angstroms and is composed mainly of a water-soluble polymer, a silane coupling agent, and if desired, a silicone resin. A high density magnetic recording medium is also provided, which comprises a ferromagnetic metal thin film formed on the discontinuous film layer (1, 2) of the polyester base film. The polyester base film is especially suitable for formation of a metallized video tape, and this tape is excellent in the slip characteristics and abrasion resistance and advantageous in that noises and drop-out are reduced.
Inventors
- 👤 Masaaki Ono
- 👤 Masahiko Motegi
- 👤 Kazuo Okabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 11:27
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/2438; Y10T428/24388; Y10T428/24405; Y10T428/24421; Y10T428/24446; Y10T428/24802; Y10T428/24851; Y10T428/31504; Y10T428/31652; Y10T428/31663; Y10T428/31678; Y10T428/31786; Y10T428/3179; Y10T428/31797
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
50 words
A polyester film for a magnetic recording medium, which comprises a polyester film and a discontinuous film formed on at least one surface of the polyester film, said discontinuous film having a thickness of not larger than 500 angstroms and comprised of a water-soluble polymer and a silane coupling reagent.
Claim 2
Dependent Claim
50 words
A polyester film for a magnetic recording medium, which comprises a polyester film and a discontinuous film formed on at least one surface of the polyester film, said discontinuous film having a thickness of not larger than 500 angstroms and comprised of a water-soluble polymer and a silane coupling reagent.
Claim 3
Dependent Claim
28 words
A polyester film as set forth in claim 1, wherein the weight ratio of the water-soluble polymer to the silane coupling reagent is in the range of (10-200):(2-50).
Claim 4
Dependent Claim
28 words
A polyester film as set forth in claim 2, wherein the weight ratio of the water-soluble polymer to the silane coupling reagent is in the range of 100:(1-10).
Claim 5
Dependent Claim
28 words
A polyester film as set forth in claim 1, wherein the discontinuous film comprises a silicone resin in addition to the water-soluble polymer and the silane coupling reagent.
Claim 6
Dependent Claim
25 words
A polyester film as set forth in claim 4, wherein the water-soluble polymer:silane coupling reagent:silicone resin weight ratio is in the range of (10-300):(2-50):_ (10-100).
Claim 7
Dependent Claim
20 words
A polyester film as set forth in claim 4, wherein the water-soluble polymer:silane coupling reagent:silicone resin weight ratio is (50-250):(5-30):(20-80).
Claim 8
Dependent Claim
29 words
A polyester film as set forth in any one of claims 4 to 6, wherein the silicone resin is a polysiloxane having a molecular weight of 30,000 to 300,000.
Claim 9
Dependent Claim
94 words
A polyester film as set forth in any one of claims 4 to 6, wherein the silicone resin is a compound having a structure represented by the following formula : wherein R 1 stands for a methyl group, a phenyl group or a hydrogen atom, R 2 stands for a methyl group, a phenyl group, a hydrogen atom, an epoxy group, an amino group or a hydroxyl group, and n is a number of from 100 to 7,000, and containing functional terminal groups selected from the group consisting of epoxy, amino and hydroxyl groups.
Claim 10
Dependent Claim
26 words
A polyester film as set forth in any preceding claim wherein the thickness of the discontinuous film is in the range of 50 to 500 angstroms.
Claim 11
Dependent Claim
25 words
A polyester film as set forth in claim 9, wherein the thickness of the discontinuous film is in the range of 50 to 300 angstroms.
Claim 12
Dependent Claim
45 words
A polyester film as set forth in claim 9 or claim 10, wherein the discontinuous film has a short axis length of 0.05 to 10 µ, a long axis length/short axis length ratio of at least 1.7 and an area ratio of 10 to 90%.
Claim 13
Dependent Claim
18 words
A polyester film as set forth in any preceding claim wherein the discontinuous film has a net-like shape.
Claim 14
Dependent Claim
23 words
A polyester film as set forth in any one of claims 1 to 11, wherein the discontinuous film has a node-broken net-like shape.
Claim 15
Dependent Claim
46 words
A polyester film as set forth in any preceding claim wherein the polyester film is a smooth polyester film having a surface roughness value Ra of not larger than 0.015 µ at a cut-off value of 0.08 mm as measured by a stylus-type surface roughness tester.
Claim 16
Dependent Claim
43 words
A polyester film as set forth in claim 14, wherein the polyester film is a smooth polyester film having a surface roughness value Ra of 0.010 to 0.002 µ at a cut-off value of 0.08 mm as measured by a stylus-type surface tester.
Claim 17
Dependent Claim
24 words
A polyester film as set forth in any preceding claim wherein the discontinuous film is formed on both the surfaces of the polyester film.
Claim 18
Dependent Claim
38 words
A polyester film as set forth in any preceding claim wherein the polyester is at least one polyester selected from the group consisting of polyethylene terephthalate, polytetramethylene terephthalate, poly-1, 4-cyclohexylene-dimethylene terephthalate, polyethylene 2,6-naphthalene-dicarboxylate, polyethylene p-hydroxybenzoate and copolymers thereof.
Claim 19
Dependent Claim
15 words
A polyester film as set forth in claim 17, wherein the polyester is polyethylene terephthalate.
Claim 20
Dependent Claim
26 words
A polyester film as set forth in any preceding claim wherein the water-soluble polymer is a water-soluble polymer having a molecular weight of 10,000 to 2,000,000.
Claim 21
Dependent Claim
25 words
A polyester film as set forth in claim 19, wherein the water-soluble polymer is a water-soluble polymer having a molecular weight of 100,000 to 1,000,000.
Claim 22
Dependent Claim
39 words
A polyester film as set forth in any preceding claim wherein the water-soluble polymer is at least one member selected from the group consisting of polyvinyl alcohol, tragacanth gum, gum arabic, casein, gelatin, methylcellulose, hydroxyethyl cellulose and carboxymethyl cellulose.
Claim 23
Dependent Claim
31 words
A polyester film as set forth in claim 21, wherein the water-soluble polymer is at least one member selected from the group consisting of methyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose.
Claim 24
Dependent Claim
30 words
A polyester film as set forth in any preceding claim wherein the silane coupling reagent is an organic silicon monomer having at least two different reactive groups in the molecule.
Claim 25
Dependent Claim
20 words
A polyester film as set forth in any preceding claim, wherein the silane coupling reagent is a mono- or di-organo-alkoxysilane.
Claim 26
Dependent Claim
46 words
A polyester film as set forth in claim 23, wherein one of the reactive groups is selected from the group consisting of methoxy, ethoxy and silanol groups and the other reactive group is selected from the group consisting of vinyl, epoxy, methacryl, amino and mercapto groups.
Claim 27
Dependent Claim
24 words
A polyester film as set forth in any one of claims 1 to 22, wherein the silane coupling reagent is an amino-silane type compound.
Claim 28
Dependent Claim
52 words
A polyester film as set forth in any one of claims 1 to 22, wherein the silane coupling reagent is at least one organic silane compound selected from the group consisting of vinyltrichlorosilane, vinyltriethoxysilane, vinyl-tris(β-methoxyethoxy) silane, γ-glycidoxypropyltrimethoxysilane, γ -methacryloxy propyltrimethoxysilane, N-β-(aminoethyl)-γ- aminopropyltrimethoxysilane, N-β-(aminoethyl)- γ - aminopropylmethyldimethoxysilane, γ -chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane and γ -aminopropyltriethoxysilane.
Claim 29
Dependent Claim
20 words
A polyester film as set forth in any preceding claim wherein the polyester film is a biaxially oriented polyester film.
Claim 30
Dependent Claim
39 words
A polyester film as set forth in any one of claims 1 to 27, wherein the polyester film is a biaxially oriented polyester film which is tensilized in at least one of the longitudinal direction and the transverse direction.
Claim 31
Dependent Claim
24 words
A polyester film as set forth in any one of claims 1 to 27, wherein the polyester film is a biaxially tensilized polyester film.
Claim 32
Dependent Claim
30 words
A super high density magnetic recording medium which comprises a ferromagnetic metal thin film formed on said discontinuous film of a polyester film as set forth in any preceding claim.
Claim 33
Dependent Claim
26 words
A super high density magnetic recording medium as set forth in claim 31, wherein the ferromagnetic metal thin film is a vacuum-deposited ferromagnetic metal thin film.
Claim 34
Dependent Claim
34 words
A super high density magnetic recording medium as set forth in claim 31 or claim 32, wherein the thickness of the ferromagnetic metal thin film is in the range of 500 to 2,000 angstroms.
Claim 35
Dependent Claim
39 words
A super high density magnetic recording medium as set forth in any one of claims 31 to 33, wherein the ferromagnetic metal is at least one member selected from the group consisting of Fe, Co, Ni and alloys thereof.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.