US4794483A
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Magnetic head having layers of amorphous magnetic alloy bonded together with a glass containing vandium oxide phosphorus oxide and antimony oxide
Assignee: Hitachi Ltd
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Filing: 1986-10-14
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Granted: 1988-12-27
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Expires: 2006-10-14
Abstract
Abstract A magnetic head has a layer of amorphous magnetic alloy arranged to define a magnetic gap therebetween, the layer being bonded with a bonding glass having a viscosity of 105 poises or less at a temperature by at least 50 DEG C. lower than the crystallization temperature of the amorphous magnetic alloy, a good water resistance after sintering and a low coefficient of thermal expansion such as 100x10-7/ DEG C. or less. The bonding glass contains 55 to 70% by weight of V2O5, 17 to 25% by weight of P2O5, 3 to 20% by weight of Sb2O3, 0 to 20% by weight of PbO, 0 to 15% by weight of Tl2O, and 0 to 5% by weight of Nb2O5.
Inventors
- 👤 Takashi Naitoh
- 👤 Takashi Namekawa
- 👤 Seiichi Yamada
- 👤 Satoru Ogihara
- 👤 Juichi Morikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:56
CPC Classifications
C; C22; C22C; C22C45/00; C22C45/04; C03; C03C; C03C8/00; C03C8/24; G; G11; G11B; G11B5/00; G11B5/10; G11B5/105; G11B5/127; G11B5/1272; G11B5/147; G11B5/1475
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
111 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate having an amorphous magnetic alloy layer on said substrate, counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising vanadium oxide as a major component and phosphorus oxide and antimony oxide as minor components and, having a viscosity of not more than 10 5 poises at the bonding temperature; said bonding temperature being at least 50° C. lower than the crystallization temperature of the amorphous magnetic alloy layer.
Claim 2
Dependent Claim
111 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate having an amorphous magnetic alloy layer on said substrate, counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising vanadium oxide as a major component and phosphorus oxide and antimony oxide as minor components and, having a viscosity of not more than 10 5 poises at the bonding temperature; said bonding temperature being at least 50° C. lower than the crystallization temperature of the amorphous magnetic alloy layer.
Claim 3
Dependent Claim
142 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate having an amorphous magnetic alloy layer on said substrate, counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 70% by weight of V 2 O 5 , 17 to 25% of P 2 O 5 , 3 to 20% by weight of Sb 2 O 3 , 0 to 20% by weight of PbO, 0 to 15% by weight of Tl 2 O and 0 to 5% by weight of Nb 2 O 5 in terms of oxides; said bonding temperature being at least 50° C. lower than the crystallization temperature of the amorphous magnetic alloy.
Claim 4
Dependent Claim
142 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate having an amorphous magnetic alloy layer on said substrate, counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 70% by weight of V 2 O 5 , 17 to 25% of P 2 O 5 , 3 to 20% by weight of Sb 2 O 3 , 0 to 20% by weight of PbO, 0 to 15% by weight of Tl 2 O and 0 to 5% by weight of Nb 2 O 5 in terms of oxides; said bonding temperature being at least 50° C. lower than the crystallization temperature of the amorphous magnetic alloy.
Claim 5
Dependent Claim
142 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate having an amorphous magnetic layer on said substrate, counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 0 to 15% by weight of Tl 2 O and 0 to 5% by weight of Nb 2 O 5 in terms of oxides; the bonding temperature being at least 50° C. lower than the crystallization temperature of the amorphous magnetic alloy layer.
Claim 6
Dependent Claim
142 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate having an amorphous magnetic layer on said substrate, counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 0 to 15% by weight of Tl 2 O and 0 to 5% by weight of Nb 2 O 5 in terms of oxides; the bonding temperature being at least 50° C. lower than the crystallization temperature of the amorphous magnetic alloy layer.
Claim 7
Dependent Claim
24 words
A magnetic head of amorphous magnetic alloy according to claim 1, wherein the amorphous magnetic alloy comprises an alloy of Co--Nb--Zr as main components.
Claim 8
Dependent Claim
152 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate having an amorphous magnetic alloy layer on said substrate, counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 and having a coefficient of thermal expansion of (70 to 100)×10 -7 /°C.; the bonding temperature being at least 50° C. lower than the crystallization temperature of the amorphous magnetic alloy layer.
Claim 9
Dependent Claim
152 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate having an amorphous magnetic alloy layer on said substrate, counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 and having a coefficient of thermal expansion of (70 to 100)×10 -7 /°C.; the bonding temperature being at least 50° C. lower than the crystallization temperature of the amorphous magnetic alloy layer.
Claim 10
Dependent Claim
128 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate counterposed to each other, an amorphous magnetic alloy layer being provided on each of the counterposed surfaces of said substrates, a non-magnetic layer being formed on each of the amorphous magnetic alloy layers on the counterposed surfaces of said substrates to serve as a small magnetic gap of desired thickness, both the magnetic cores being bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising vanadium oxide as a major component and phosphorus oxide and antimony oxide as minor components and having a viscosity of not more than 10 5 poises at the bonding temperature.
Claim 11
Dependent Claim
128 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate counterposed to each other, an amorphous magnetic alloy layer being provided on each of the counterposed surfaces of said substrates, a non-magnetic layer being formed on each of the amorphous magnetic alloy layers on the counterposed surfaces of said substrates to serve as a small magnetic gap of desired thickness, both the magnetic cores being bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising vanadium oxide as a major component and phosphorus oxide and antimony oxide as minor components and having a viscosity of not more than 10 5 poises at the bonding temperature.
Claim 12
Dependent Claim
142 words
A magnetic head which comprises a pair of magnetic cores each core comprising or non-magnetic substrate counterposed to each other, an amorphous alloy layer being provided on each of the counterposed surfaces of said substrates, a non-magnetic layer being formed on each of the amorphous magnetic alloy layers on the counterposed surfaces of said substrates to serve as a small magnetic gap of desired thickness, both the magnetic cores being bonded to each other by fusion of a glass comprising 55 to 70% by weight of V 2 O 5 , 17 to 25% of P 2 O 5 , 3 to 20% by weight of Sb 2 O 3 , 0 to 20% by weight of PbO, 0 to 15% by weight of Tl 2 O and 0 to 5% by weight of Nb 2 O 5 in terms of oxides.
Claim 13
Dependent Claim
142 words
A magnetic head which comprises a pair of magnetic cores each core comprising or non-magnetic substrate counterposed to each other, an amorphous alloy layer being provided on each of the counterposed surfaces of said substrates, a non-magnetic layer being formed on each of the amorphous magnetic alloy layers on the counterposed surfaces of said substrates to serve as a small magnetic gap of desired thickness, both the magnetic cores being bonded to each other by fusion of a glass comprising 55 to 70% by weight of V 2 O 5 , 17 to 25% of P 2 O 5 , 3 to 20% by weight of Sb 2 O 3 , 0 to 20% by weight of PbO, 0 to 15% by weight of Tl 2 O and 0 to 5% by weight of Nb 2 O 5 in terms of oxides.
Claim 14
Dependent Claim
160 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate counterposed to each other, an amorphous magnetic alloy layer being provided on each of the counterposed surfaces of said substrates, a non-magnetic layer being formed on each of the amorphous magnetic alloy layers on the counterposed surfaces of said substrates to serve as a small magnetic gap of desired thickness, both the magnetic cores being bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 in terms of oxides.
Claim 15
Dependent Claim
160 words
A magnetic head which comprises a pair of magnetic cores each core comprising a non-magnetic substrate counterposed to each other, an amorphous magnetic alloy layer being provided on each of the counterposed surfaces of said substrates, a non-magnetic layer being formed on each of the amorphous magnetic alloy layers on the counterposed surfaces of said substrates to serve as a small magnetic gap of desired thickness, both the magnetic cores being bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 in terms of oxides.
Claim 16
Dependent Claim
169 words
A magnetic head which comprises a pair of magnetic cores counterposed to each other each core comprising a non-magnetic substrate, an amorphous magnetic alloy layer being provided on each of the counterposed surfaces of said substrates, a non-magnetic layer being formed on each of the amorphous magnetic alloy layers on the counterposed surfaces of said substrates to serve as a small magnetic gap of desired thickness, both the magnetic cores being bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 and having a coefficient of thermal expansion of (70 to 100)×10 -7 /°C.
Claim 17
Dependent Claim
169 words
A magnetic head which comprises a pair of magnetic cores counterposed to each other each core comprising a non-magnetic substrate, an amorphous magnetic alloy layer being provided on each of the counterposed surfaces of said substrates, a non-magnetic layer being formed on each of the amorphous magnetic alloy layers on the counterposed surfaces of said substrates to serve as a small magnetic gap of desired thickness, both the magnetic cores being bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 and having a coefficient of thermal expansion of (70 to 100)×10 -7 /°C.
Claim 18
Dependent Claim
98 words
A magnetic head which comprises a pair of magnetic cores arranged counterposed to each other through a small magnetic gap, an amorphous magnetic alloy layer located between non-magnetic elements forming each of the pair of the magnetic cores, the magnetic cores being bonded to each other by fusion of a glass at bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layer, the glass comprising vanadium oxide as a major component and phosphorus oxide and antimony oxide as minor components and having a viscosity of not more than 10 5 poises at the bonding temperature.
Claim 19
Dependent Claim
98 words
A magnetic head which comprises a pair of magnetic cores arranged counterposed to each other through a small magnetic gap, an amorphous magnetic alloy layer located between non-magnetic elements forming each of the pair of the magnetic cores, the magnetic cores being bonded to each other by fusion of a glass at bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layer, the glass comprising vanadium oxide as a major component and phosphorus oxide and antimony oxide as minor components and having a viscosity of not more than 10 5 poises at the bonding temperature.
Claim 20
Dependent Claim
131 words
A magnetic head which comprises a pair of magnetic cores arranged counterposed to each other through a small magnetic gap, an amorphous magnetic alloy layer located between non-magnetic elements forming each of the pair of the magnetic cores, the magnetic cores being bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layer, the glass comprising 55 to 70% by weight of V 2 O 5 , 17 to 25% of P 2 O 5 , 3 to 20% by weight of Sb 2 O 3 , 0 to 20% by weight of PbO, 0 to 15% by weight of Tl 2 O and 0 to 5% by weight of Nb 2 O 5 in terms of oxides.
Claim 21
Dependent Claim
131 words
A magnetic head which comprises a pair of magnetic cores arranged counterposed to each other through a small magnetic gap, an amorphous magnetic alloy layer located between non-magnetic elements forming each of the pair of the magnetic cores, the magnetic cores being bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layer, the glass comprising 55 to 70% by weight of V 2 O 5 , 17 to 25% of P 2 O 5 , 3 to 20% by weight of Sb 2 O 3 , 0 to 20% by weight of PbO, 0 to 15% by weight of Tl 2 O and 0 to 5% by weight of Nb 2 O 5 in terms of oxides.
Claim 22
Dependent Claim
130 words
A magnetic head which comprises a pair of magnetic cores arranged counterposed to each other through a small magnetic gap, an amorphous magnetic alloy layer located between non-magnetic elements forming each of the pair of the magnetic cores, the magnetic cores being bonded to each other by fusion of a glass at bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layer, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 in terms of oxides.
Claim 23
Dependent Claim
130 words
A magnetic head which comprises a pair of magnetic cores arranged counterposed to each other through a small magnetic gap, an amorphous magnetic alloy layer located between non-magnetic elements forming each of the pair of the magnetic cores, the magnetic cores being bonded to each other by fusion of a glass at bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layer, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 in terms of oxides.
Claim 24
Dependent Claim
139 words
A magnetic head which comprises a pair of magnetic cores arranged counterposed to each other through a small magnetic gap, an amorphous magnetic alloy layer located between non-magnetic elements forming each of the pair of the magnetic cores, the magnetic cores being bonded to each other by fusion of a glass at bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layer, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 and having a coefficient of thermal expansion of (70 to 100)×10 -7 /°C.
Claim 25
Dependent Claim
139 words
A magnetic head which comprises a pair of magnetic cores arranged counterposed to each other through a small magnetic gap, an amorphous magnetic alloy layer located between non-magnetic elements forming each of the pair of the magnetic cores, the magnetic cores being bonded to each other by fusion of a glass at bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layer, the glass comprising 55 to 65% by weight of V 2 O 5 , 18 to 22% of P 2 O 5 , 5 to 12% by weight of Sb 2 O 3 , 3 to 10% by weight of PbO, 3 to 10% by weight of Tl 2 O and 0.5 to 2% by weight of Nb 2 O 5 and having a coefficient of thermal expansion of (70 to 100)×10 -7 /°C.
Claim 26
Dependent Claim
137 words
A magnetic head which comprises a pair of magnetic cores each having an amorphous magnetic alloy layer on the core surface, arranged counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass having a viscosity of not more than 10 5 poises at the bonding temperature, a water resistance in terms of weight reduction not more than 1.8 mg per gram when 5 mm cube of the glass is dipped in distilled water at 70° C. for 2 hours, a 4-point bending strength of not less than 4.6 Kgf/mm 2 , a Microvickers hardness of not less than 339 and a coefficient of thermal expansion of (70 to 100)×10 -7 /°C.
Claim 27
Dependent Claim
137 words
A magnetic head which comprises a pair of magnetic cores each having an amorphous magnetic alloy layer on the core surface, arranged counterposed to each other through a small magnetic gap and bonded to each other by fusion of a glass at a bonding temperature lower than the crystallization temperature of the amorphous magnetic alloy layers, the glass having a viscosity of not more than 10 5 poises at the bonding temperature, a water resistance in terms of weight reduction not more than 1.8 mg per gram when 5 mm cube of the glass is dipped in distilled water at 70° C. for 2 hours, a 4-point bending strength of not less than 4.6 Kgf/mm 2 , a Microvickers hardness of not less than 339 and a coefficient of thermal expansion of (70 to 100)×10 -7 /°C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |