Patent US4634633A successfully refreshed from Google Patents.
US4634633A
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Magnetic recording medium
Assignee: Sony Corp
•
Filing: 1984-12-06
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Granted: 1987-01-06
•
Expires: 2004-12-06
Abstract
Abstract A magnetic recording medium has a magnetic layer consisting essentially of a binder and magnetic particles on one surface of a non-magnetic substrate. The thermoplastic polyurethane-urea resin in which unsaturated bonds sensitive to radiation are introduced is used as the binder. The thermoplastic polyurethane-urea resin in which the radiation-sensitive unsaturated bonds are introduced has both urethane and urea bonds in the molecular structure thereof. It is synthesized from long chain diol with a molecular weight of approximately 500 to 5000, a short chain diol with a molecular weight of approximately 50 to 500, an organic diisocyanate, an organic diamine, and a compound containing radiation-sensitive unsaturated double bonds, and cured by radiation. The thermoplastic polyurethane-urea resin in which not only the radiation-sensitive double bonds but also hydrophilic polar groups are introduced may also be used as the binder. These hydrophilic polar groups may for example include -SO3M, -OSO3M, -COOM, and <IMAGE>
Inventors
- 👤 Yoshinobu Ninomiya
- 👤 Masashi Somezawa
- 👤 Kiyokazu Oiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:26
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/0804; C08G18/0819; C08G18/28; C08G18/67; C08G18/671; C08G18/675; C08G18/70; C08G18/81; C08G18/8141; C08G18/815; C08G18/8158; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31609
Claims Analysis
Total Claims: 105
Claim 1
Independent Claim
107 words
A magnetic recording medium comprising a non-magnetic substrate and a magnetic layer formed thereon composed mainly of magnetic powder and an irradiation hardened binder, said binder containing a thermoplastic polyurethane-urea resin obtained by the polyaddition reaction of (A) a long chain diol having a molecular weight in the range of about 500 to 5000; (B) a short chain diol having a molecular weight in the range of about 50 to 500; (C) an organic diamine; (D) an organic diisocyanate; and (E) a compound having unsaturated bonds sensitive to irradiation, said resin having a total concentration of urea groups and urethane groups between 1.8 and 3.0 m mol/g.
Claim 2
Dependent Claim
107 words
A magnetic recording medium comprising a non-magnetic substrate and a magnetic layer formed thereon composed mainly of magnetic powder and an irradiation hardened binder, said binder containing a thermoplastic polyurethane-urea resin obtained by the polyaddition reaction of (A) a long chain diol having a molecular weight in the range of about 500 to 5000; (B) a short chain diol having a molecular weight in the range of about 50 to 500; (C) an organic diamine; (D) an organic diisocyanate; and (E) a compound having unsaturated bonds sensitive to irradiation, said resin having a total concentration of urea groups and urethane groups between 1.8 and 3.0 m mol/g.
Claim 3
Dependent Claim
26 words
The magnetic recording medium according to claim 1, wherein the concentration ratio of urea group to urethane group in said resin is between 0.3 and 1.6.
Claim 4
Dependent Claim
26 words
The magnetic recording medium according to claim 1, wherein the concentration of unsaturated bonds sensitive to irradiation in said resin is between 0.1 and 1.0 mmol/g.
Claim 5
Dependent Claim
21 words
The magnetic recording medium according to claim 1, wherein the number-average molecular weight of said resin is between 2000 and 60000.
Claim 6
Dependent Claim
21 words
The magnetic recording medium according to claim 4, wherein the number-average molecular weight of said resin is between 5000 and 40000.
Claim 7
Dependent Claim
21 words
The magnetic recording medium according to claim 1, wherein the softening point of said resin is not less than 80° C.
Claim 8
Dependent Claim
21 words
The magnetic recording medium according to claim 6, wherein the softening point of said resin is not less than 100° C.
Claim 9
Dependent Claim
22 words
The magnetic recording medium according to claim 1, wherein the glass transition point of said resin is not more than 0° C.
Claim 10
Dependent Claim
22 words
The magnetic recording medium according to claim 8, wherein the glass transition point of said resin is not more than -10° C.
Claim 11
Dependent Claim
27 words
The magnetic recording medium according to claim 1, wherein the weight ratio of the short chain diol to the long chain diol is not more than 3.
Claim 12
Dependent Claim
25 words
The magnetic recording medium according to claim 1, wherein the long chain diol is a polyester diol, a polyether diol or a polyether ester diol.
Claim 13
Dependent Claim
38 words
The magnetic recording medium according to claim 11, wherein the polyester diol is obtained by the reaction of an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid or a lower alcohol ester of the dicarboxylic acid with a glycol.
Claim 14
Dependent Claim
23 words
The magnetic recording medium according to claim 12, wherein the aliphatic dicarboxylic acid is succinic acid, adipic acid, sebasic acid or azelaic acid.
Claim 15
Dependent Claim
19 words
The magnetic recording medium according to claim 12, wherein the aromatic dicarboxylic acid is terephthalic acid or isophthalic acid.
Claim 16
Dependent Claim
22 words
The magnetic recording medium according to claim 12, wherein the lower alcohol ester of dicarboxylic acid is a methyl or ethyl ester.
Claim 17
Dependent Claim
35 words
The magnetic recording medium according to claim 12, wherein the glycol is ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexane glycol, diethylene glycol, neopentyl glycol or an ethylene oxide or propylene oxide adduct of bisphenol A.
Claim 18
Dependent Claim
25 words
The magnetic recording medium according to claim 1, wherein the long chain diol is a polyester diol, a polyether diol or a polyether ester glycol.
Claim 19
Dependent Claim
38 words
The magnetic recording medium according to claim 17, wherein the polyester diol is obtained by the reaction of an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid or a lower alcohol ester of the dicarboxylic acid with a glycol.
Claim 20
Dependent Claim
23 words
The magnetic recording medium according to claim 18, wherein the aliphatic dicarboxylic acid is succinic acid, adipic acid, sebacic acid or azelaic acid.
Claim 21
Dependent Claim
19 words
The magnetic recording medium according to claim 18, wherein the aromatic dicarboxylic acid is terephthalic acid or isophthalic acid.
Claim 22
Dependent Claim
19 words
The magnetic recording medium according to claim 18, wherein the lower alcohol ester is a methyl or ethyl ester.
Claim 23
Dependent Claim
35 words
The magnetic recording medium according to claim 18, wherein the glycol is ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexane glycol, diethylene glycol, neopentyl glycol or an ethylene oxide or propylene oxide adduct of bisphenol A.
Claim 24
Dependent Claim
21 words
The magnetic recording medium according to claim 17, wherein the polyether diol is obtained by the cleavage polymerization of a lactone.
Claim 25
Dependent Claim
13 words
The magnetic recording medium according to claim 23, wherein the lactone is ε-caprolactone.
Claim 26
Dependent Claim
15 words
The magnetic recording medium according to claim 17, wherein the polyether diol is polyether glycol.
Claim 27
Dependent Claim
22 words
The magnetic recording medium according to claim 25, wherein the polyether glycol is polyethylene glycol, polypropylene ether glycol or polytetramethylene ether glycol.
Claim 28
Dependent Claim
36 words
The magnetic recording medium according to claim 17, wherein the polyether ester glycol is a polyester glycol obtained by the reaction of a polyalkylene ether glycol with an aliphatic dicarboxylic acid or an aromatic dicarboxylic acid.
Claim 29
Dependent Claim
23 words
The magnetic recording medium according to claim 27, wherein the polyalkylene ether glycol is polyethylene glycol, polypropylene ether glycol or polytetramethylene ether glycol.
Claim 30
Dependent Claim
22 words
The magnetic recording medium according to claim 27, wherein the aliphatic acid is succinic acid, adipic acid, sebacic acid or azelaic acid.
Claim 31
Dependent Claim
18 words
The magnetic recording medium according to claim 27, wherein the aromatic acid is terephthalic acid or isophthalic acid.
Claim 32
Dependent Claim
21 words
The magnetic recording medium according to claim 1, wherein the short chain diol is an aliphatic glycol or an aromatic diol.
Claim 33
Dependent Claim
24 words
The magnetic recording medium according to claim 1, wherein the aliphatic glycol is ethylene glycol, propylene glycol, 1,4-butylene glycol, 1,6-hexane glycol or neopentyl glycol.
Claim 34
Dependent Claim
30 words
The magnetic recording medium according to claim 31, wherein the aromatic diol is an ethylene oxide or propylene oxide adduct of biophenol A or an ethylene oxide adduct of hydroquinone.
Claim 35
Dependent Claim
23 words
The magnetic recording medium according to claim 1, wherein the organic diamine is an aliphatic diamine, an aromatic diamine or an alicyclic diamine.
Claim 36
Dependent Claim
23 words
The magnetic recording medium according to claim 1, wherein the organic diisocyanate is an aliphatic diisocyanate, an aromatic diisocyanate or an alicyclic diisocyanate.
Claim 37
Dependent Claim
43 words
The magnetic recording medium according to claim 1, wherein the compound having unsaturated bonds sensitive to irradiation is a diol having unsaturated bonds sensitive to irradiation, a diamine having unsaturated bonds sensitive to irradiation or a diisocyanate having unsaturated bonds sensitive to irradiation.
Claim 38
Dependent Claim
169 words
A magnetic recording medium comprising a non-magnetic substrate and a magnetic layer formed thereon composed mainly of magnetic powder and a binder, said binder containing a thermoplastic polyurethane-urea resin having unsaturated bonds sensitive to irradiation and being obtained by the polyaddition reaction of (A) a long chain diol having a molecular weight in the range of about 500 to 5000; (B) a short chain diol having a molecular weight in the range of about 50 to 500; (C) an organic diamine; (D) an organic diisocyanate; (E) a compound having unsaturated bonds sensitive to (F) a compound having at least one hydrophilic polar group selected from the group consisting of the groups represented by the following formulas: --SO 3 M, --OSO 3 M, --COOM and ##STR61## wherein M is hydrogen or alkali metal and M' is hydrogen, alkali metal or a hydrocarbon group, said thermoplastic polyurethane-urea resin being hardened under irradiation, the total concentration of urea groups and urethane groups in said resin being between 1.8 and 3.0 m mol/g.
Claim 39
Dependent Claim
169 words
A magnetic recording medium comprising a non-magnetic substrate and a magnetic layer formed thereon composed mainly of magnetic powder and a binder, said binder containing a thermoplastic polyurethane-urea resin having unsaturated bonds sensitive to irradiation and being obtained by the polyaddition reaction of (A) a long chain diol having a molecular weight in the range of about 500 to 5000; (B) a short chain diol having a molecular weight in the range of about 50 to 500; (C) an organic diamine; (D) an organic diisocyanate; (E) a compound having unsaturated bonds sensitive to (F) a compound having at least one hydrophilic polar group selected from the group consisting of the groups represented by the following formulas: --SO 3 M, --OSO 3 M, --COOM and ##STR61## wherein M is hydrogen or alkali metal and M' is hydrogen, alkali metal or a hydrocarbon group, said thermoplastic polyurethane-urea resin being hardened under irradiation, the total concentration of urea groups and urethane groups in said resin being between 1.8 and 3.0 m mol/g.
Claim 40
Dependent Claim
26 words
The magnetic recording medium according to claim 37, wherein the concentration ratio of urea group to urethane group in said resin is between 0.3 and 1.6.
Claim 41
Dependent Claim
27 words
The magnetic recording medium according to claim 37, wherein the concentration of unsaturated bonds sensitive to irradiation in said resin is between 0.1 and 1.0 m mol/g.
Claim 42
Dependent Claim
25 words
The magnetic recording medium according to claim 37, wherein the concentration of hydrophilic polar group in said resin is between 0.01 and 1.0 m mol/g.
Claim 43
Dependent Claim
25 words
The magnetic recording medium according to claim 40, wherein the concentration of hydrophilic polar group in said resin is between 0.1 and 0.5 m mol/g.
Claim 44
Dependent Claim
21 words
The magnetic recording medium according to claim 37, wherein the number-average molecular weight of said resin is between 2000 and 60000.
Claim 45
Dependent Claim
21 words
The magnetic recording medium according to claim 42, wherein the number-average molecular weight of said resin is between 5000 and 40000.
Claim 46
Dependent Claim
21 words
The magnetic recording medium according to claim 37, wherein the softening point of said resin is not less than 80° C.
Claim 47
Dependent Claim
21 words
The magnetic recording medium according to claim 44, wherein the softening point of said resin is not less than 100° C.
Claim 48
Dependent Claim
22 words
The magnetic recording medium according to claim 37, wherein the glass transition point of said resin is not more than 0° C.
Claim 49
Dependent Claim
22 words
The magnetic recording medium according to claim 46, wherein the glass transition point of said resin is not more than -10° C.
Claim 50
Dependent Claim
27 words
The magnetic recording medium according to claim 37, wherein the weight ratio of the short chain diol to the long chain diol is not more than 3.
Claim 51
Dependent Claim
25 words
The magnetic recording medium according to claim 37, wherein the long chain diol is a polyester diol, a polyether diol or a polyether ester diol.
Claim 52
Dependent Claim
38 words
The magnetic recording medium according to claim 49, wherein the polyester diol is obtained by the reaction of an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid or a lower alcohol ester of the carboxylic acid with a glycol.
Claim 53
Dependent Claim
23 words
The magnetic recording medium according to claim 50, wherein the aliphatic dicarboxylic acid is succinic acid, adipic acid, sebacic acid or azelaic acid.
Claim 54
Dependent Claim
18 words
The magnetic recording medium according to claim 50, wherein the aromatic dicarboxylic acid is terephthalic acid isophthalic acid.
Claim 55
Dependent Claim
22 words
The magnetic recording medium according to claim 50, wherein the lower alcohol ester of dicarboxylic acid is a methyl or ethyl ester.
Claim 56
Dependent Claim
35 words
The magnetic recording medium according to claim 50, wherein the glycol is ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexane glycol, diethylene glycol, neopentyl glycol or an ethylene oxide or propylene oxide adduct of bisphenol A.
Claim 57
Dependent Claim
25 words
The magnetic recording medium according to claim 37, wherein the long chain diol is a polyester diol, a polyether diol or a polyether ester glycol.
Claim 58
Dependent Claim
38 words
The magnetic recording medium according to claim 55, wherein the polyester diol is obtained by the reaction of an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid or a lower alcohol ester of the dicarboxylic acid with a glycol.
Claim 59
Dependent Claim
23 words
The magnetic recording medium according to claim 56, wherein the aliphatic dicarboxylic acid is succinic acid, adipic acid, sebacic acid or azelaic acid.
Claim 60
Dependent Claim
19 words
The magnetic recording medium according to claim 56, wherein the aromatic dicarboxylic acid is terephthalic acid or isophthalic acid.
Claim 61
Dependent Claim
19 words
The magnetic recording medium according to claim 56, wherein the lower alcohol ester is a methyl or ethyl ester.
Claim 62
Dependent Claim
35 words
The magnetic recording medium according to claim 52, wherein the glycol is ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexane glycol, diethylene glycol, neopentyl glycol or an ethylene oxide or propylene oxide adduct of bisphenol A.
Claim 63
Dependent Claim
21 words
The magnetic recording medium according to claim 55, wherein the polyether diol is obtained by the cleavage polymerization of a lactone.
Claim 64
Dependent Claim
13 words
The magnetic recording medium according to claim 61, wherein the lactone is ε-caprolactone.
Claim 65
Dependent Claim
15 words
The magnetic recording medium according to claim 55, wherein the polyether diol is polyether glycol.
Claim 66
Dependent Claim
22 words
The magnetic recording medium according to claim 63, wherein the polyether glycol is polyethylene glycol, polypropylene ether glycol or polytetramethylene ether glycol.
Claim 67
Dependent Claim
36 words
The magnetic recording medium according to claim 55, wherein the polyether ester glycol is a polyester glycol obtained by the reaction of a polyalkylene ether glycol with an aliphatic dicarboxylic acid or an aromatic dicarboxylic acid.
Claim 68
Dependent Claim
23 words
The magnetic recording medium according to claim 65, wherein the polyalkylene ether glycol is polyethylene glycol, polypropylene ether glycol or polytetramethylene ether glycol.
Claim 69
Dependent Claim
23 words
The magnetic recording medium according to claim 65, wherein the aliphatic dicarboxylic acid is succinic acid, adipic acid, sebacic acid or azelaic acid.
Claim 70
Dependent Claim
19 words
The magnetic recording medium according to claim 65, wherein the aromatic dicarboxylic acid is terephthalic acid or isophthalic acid.
Claim 71
Dependent Claim
21 words
The magnetic recording medium according to claim 37, wherein the short chain diol is an aliphatic glycol or an aromatic diol.
Claim 72
Dependent Claim
24 words
The magnetic recording medium according to claim 69, wherein the aliphatic glycol is ethylene glycol, propylene glycol, 1,4-butylene glycol, 1,6-hexane glycol or neopentyl glycol.
Claim 73
Dependent Claim
30 words
The magnetic recording medium according to claim 69, wherein the aromatic diol is an ethylene oxide or propylene oxide adduct of bisphenol A or an ethylene oxide adduct of hydroquinone.
Claim 74
Dependent Claim
23 words
The magnetic recording medium according to claim 37, wherein the organic diamine is an aliphatic diamine, an aromatic diamine or an alicyclic diamine.
Claim 75
Dependent Claim
23 words
The magnetic recording medium according to claim 37, wherein the organic diisocyanate is an aliphatic diisocyanate, an aromatic diisocyanate or an alicyclic diisocyanate.
Claim 76
Dependent Claim
43 words
The magnetic recording medium according to claim 57, wherein the compound having unsaturated bonds sensitive to irradiation is a diol having unsaturated bonds sensitive to irradiation, a diamine having unsaturated bonds sensitive to irradiation or a diisocyanate having unsaturated bonds sensitive to irradiation.
Claim 77
Dependent Claim
35 words
The magnetic recording medium according to claim 37, wherein the compound having hydrophilic polar group is a diol having hydrophilic polar group, a diamine having hydrophilic polar group or a diisocyanate having hydrophilic polar group.
Claim 78
Dependent Claim
125 words
A magnetic recording medium comprising a non-magnetic substrate, a magnetic layer formed on one surface of said non-magnetic substrate and a back coating layer composed of an irradiation hardened binder and non-magnetic pigment formed on the other surface of said non-magnetic substrate, said binder containing a thermoplastic polyurethane-urea resin obtained by the polyaddition reaction of (A) a long chain diol having a molecular weight in the range of about 500 to 5000; (B) a short chain diol having a molecular weight in the range of about 50 to 500; (C) an organic diamine; (D) an organic diisocyanate; and (E) a compound having unsaturated bonds sensitive to irradiation, said resin having a total concentration of urea groups and urethane groups between 1.8 and 3.0 m mol/g.
Claim 79
Dependent Claim
125 words
A magnetic recording medium comprising a non-magnetic substrate, a magnetic layer formed on one surface of said non-magnetic substrate and a back coating layer composed of an irradiation hardened binder and non-magnetic pigment formed on the other surface of said non-magnetic substrate, said binder containing a thermoplastic polyurethane-urea resin obtained by the polyaddition reaction of (A) a long chain diol having a molecular weight in the range of about 500 to 5000; (B) a short chain diol having a molecular weight in the range of about 50 to 500; (C) an organic diamine; (D) an organic diisocyanate; and (E) a compound having unsaturated bonds sensitive to irradiation, said resin having a total concentration of urea groups and urethane groups between 1.8 and 3.0 m mol/g.
Claim 80
Dependent Claim
26 words
The magnetic recording medium according to claim 76, wherein the concentration ratio of urea group to urethane group in said resin is between 0.3 and 1.6.
Claim 81
Dependent Claim
27 words
The magnetic recording medium according to claim 76, wherein the concentration of unsaturated bonds sensitive to irradiation in said resin is between 0.1 and 1.0 m mol/g.
Claim 82
Dependent Claim
21 words
The magnetic recording medium according to claim 76, wherein the number-average molecular weight of said resin is between 2000 and 60000.
Claim 83
Dependent Claim
21 words
The magnetic recording medium according to claim 79, wherein the number-average molecular weight of said resin is between 5000 and 40000.
Claim 84
Dependent Claim
21 words
The magnetic recording medium according to claim 76, wherein the softening point of said resin is not less than 80° C.
Claim 85
Dependent Claim
21 words
The magnetic recording medium according to claim 81, wherein the softening point of said resin is not less than 100° C.
Claim 86
Dependent Claim
22 words
The magnetic recording medium according to claim 76, wherein the glass transition point of said resin is not more than 0° C.
Claim 87
Dependent Claim
22 words
The magnetic recording medium according to claim 83, wherein the glass transition point of said resin is not more than -10° C.
Claim 88
Dependent Claim
27 words
The magnetic recording medium according to claim 76, wherein the weight ratio of the short chain diol to the long chain diol is not more than 3.
Claim 89
Dependent Claim
21 words
The magnetic recording medium according to claim 76, wherein the magnetic layer is composed mainly of magnetic powder and a binder.
Claim 90
Dependent Claim
19 words
The magnetic recording medium according to claim 76, wherein the magnetic layer is composed of ferromagnetic metal thin film.
Claim 91
Dependent Claim
187 words
The magnetic recording medium comprising a non-magnetic substrate, a magnetic layer formed on one surface of said non-magnetic substrate and a back coating layer composed of a binder and non-magnetic pigment formed on the other surface of said non-magnetic substrate, said binder containing a thermoplastic polyurethane-urea resin having unsaturated bonds sensitive to irradiation and being obtained by the polyaddition reaction of (A) a long chain diol having a molecular weight in the range of about 500 to 5000; (B) a short chain diol having a molecular weight in the range of about 50 to 500; (C) an organic diamine; (D) an organic diisocyanate; (E) a compound having unsaturated bonds sensitive to irradiation; and (F) a compound having at least one hydrophilic polar group selected from the group consisting of the groups represented by general formulas: --SO 3 M, --OSO 3 M, --COOM and ##STR62## wherein M is hydrogen or alkali metal and M' is hydrogen, alkali metal or hydrocarbon group, said thermoplastic polyurethane-urea resin being hardened under irradiation, the total concentration of urea groups and urethane groups in said resin being between 1.8 and 3.0 m mol/g.
Claim 92
Dependent Claim
187 words
The magnetic recording medium comprising a non-magnetic substrate, a magnetic layer formed on one surface of said non-magnetic substrate and a back coating layer composed of a binder and non-magnetic pigment formed on the other surface of said non-magnetic substrate, said binder containing a thermoplastic polyurethane-urea resin having unsaturated bonds sensitive to irradiation and being obtained by the polyaddition reaction of (A) a long chain diol having a molecular weight in the range of about 500 to 5000; (B) a short chain diol having a molecular weight in the range of about 50 to 500; (C) an organic diamine; (D) an organic diisocyanate; (E) a compound having unsaturated bonds sensitive to irradiation; and (F) a compound having at least one hydrophilic polar group selected from the group consisting of the groups represented by general formulas: --SO 3 M, --OSO 3 M, --COOM and ##STR62## wherein M is hydrogen or alkali metal and M' is hydrogen, alkali metal or hydrocarbon group, said thermoplastic polyurethane-urea resin being hardened under irradiation, the total concentration of urea groups and urethane groups in said resin being between 1.8 and 3.0 m mol/g.
Claim 93
Dependent Claim
26 words
The magnetic recording medium according to claim 88, wherein the concentration ratio of urea group to urethane group in said resin is between 0.3 and 1.6.
Claim 94
Dependent Claim
27 words
The magnetic recording medium according to claim 88, wherein the concentration of unsaturated bonds sensitive to irradiation in said resin is between 0.1 and 1.0 m mol/g.
Claim 95
Dependent Claim
25 words
The magnetic recording medium according to claim 88, wherein the concentration of hydrophilic polar group in said resin is between 0.01 and 1.0 m mol/g.
Claim 96
Dependent Claim
25 words
The magnetic recording medium according to claim 91, wherein the concentration of hydrophilic polar group in said resin is between 0.1 and 0.5 m mol/g.
Claim 97
Dependent Claim
21 words
The magnetic recording medium according to claim 88, wherein the number-average molecular weight of said resin is between 2000 and 60000.
Claim 98
Dependent Claim
21 words
The magnetic recording medium according to claim 93, wherein the number-average molecular weight of said resin is between 5000 and 40000.
Claim 99
Dependent Claim
21 words
The magnetic recording medium according to claim 88, wherein the softening point of said resin is not less than 80° C.
Claim 100
Dependent Claim
21 words
The magnetic recording medium according to claim 95, wherein the softening point of said resin is not less than 100° C.
Claim 101
Dependent Claim
22 words
The magnetic recording medium according to claim 88, wherein the glass transition point of said resin is not more than 0° C.
Claim 102
Dependent Claim
22 words
The magnetic recording medium according to claim 97, wherein the glass transition point of said resin is not more than -10° C.
Claim 103
Dependent Claim
27 words
The magnetic recording medium according to claim 97, wherein the weight ratio of the short chain diol to the long chain diol is not more than 3.
Claim 104
Dependent Claim
21 words
The magnetic recording medium according to claim 88, wherein the magnetic layer is composed mainly of magnetic powder and a binder.
Claim 105
Dependent Claim
19 words
The magnetic recording medium according to claim 88, wherein the magnetic layer is composed of ferromagnetic metal thin film.
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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) | 1990-01-05 | 1990-07-07 | 1991-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-05 | 1994-07-07 | 1995-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-05 | 1998-07-07 | 1999-01-06 | $7700.00 | Window Closed / Lapsed |