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Patent US4944802A successfully refreshed from Google Patents.
US4944802A
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High coercivity magnetic inks and method for making same
Assignee: Molecular BioQuest Inc
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Filing: 1988-09-16
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Granted: 1990-07-31
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Expires: 2008-09-16
Abstract
Abstract Magnetic inks useful for the production of magnetic recording products are disclosed. The present magnetic inks contain ferromagnetic barium ferrite particles dispersed in a flexible polymer medium.
Inventors
- 👤 Mark S. Chagnon
- 👤 John R. Ferris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:05
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/14; H01F41/16; G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70642; G11B5/70678
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
104 words
A method for producing a magnetic ink comprising: combining barium ferrite powder, an inorganic oxide, a blend of a polyurethane polymer and a vinylchloride-vinyl acetate copolymer, an organic solvent and a surface active agent of the general structure R"--R'--R--YH wherein: R" is a solubilizing tail of similar solubility parameter to a mixture of the organic solvent and the polymer blend; R' is a double bond, ether linkage, secondary amine, phenyl ring, phosphate ester or sulfide linkage; R is an aliphatic chain about C 4 to C 20 in length; and YH is COOH, NH 2 , PO 3 H, SO 3 H or OH.
Claim 2
Independent Claim
104 words
A method for producing a magnetic ink comprising: combining barium ferrite powder, an inorganic oxide, a blend of a polyurethane polymer and a vinylchloride-vinyl acetate copolymer, an organic solvent and a surface active agent of the general structure R"--R'--R--YH wherein: R" is a solubilizing tail of similar solubility parameter to a mixture of the organic solvent and the polymer blend; R' is a double bond, ether linkage, secondary amine, phenyl ring, phosphate ester or sulfide linkage; R is an aliphatic chain about C 4 to C 20 in length; and YH is COOH, NH 2 , PO 3 H, SO 3 H or OH.
Claim 3
Dependent Claim
24 words
A method of claim 1 wherein the inorganic oxide comprises zinc oxide having a particle size of about 0.015 to 0.15 microns in diameter.
Claim 4
Dependent Claim
12 words
A method of claim 1 wherein the inorganic oxide is titanium dioxide.
Claim 5
Dependent Claim
18 words
A method of claim 3 wherein the titanium dioxide is made by in situ oxidation of titanium tetraisopropoxide.
Claim 6
Dependent Claim
20 words
A method of claim 1 wherein the barium ferrite has a particle size of from about 0.01-0.1 microns in diameter.
Claim 7
Dependent Claim
18 words
A method of claim 1 wherein the barium ferrite has an aspect ratio of from 1:1 to 10:1.
Claim 8
Dependent Claim
27 words
A method of claim 1 wherein the inorganic oxide is selected from the group consisting of tin oxide, hafnium oxide, zirconium dioxide, iron oxide and silicon dioxide.
Claim 9
Dependent Claim
11 words
A method of claim 1 wherein the organic solvent is tetrahydrofuran.
Claim 10
Dependent Claim
28 words
A method of claim 1 wherein the surface active agent is selected from the group consisting of: lecithin, 11-phenoxy-undecanoic acid, polyoxyethylene nonylphenyl ether phosphate and N-tallow-1,3-diamino propane dioleate.
Claim 11
Independent Claim
41 words
A method for producing a magnetic ink having a coercivity greater than 600 oersteads comprising combining barium ferrite, an organic oxide, a blend of a polyurethane polymer and a vinyl chloride-vinyl acetate copolymer, an organic solvent and a surface active agent.
Claim 12
Independent Claim
41 words
A method for producing a magnetic ink having a coercivity greater than 600 oersteads comprising combining barium ferrite, an organic oxide, a blend of a polyurethane polymer and a vinyl chloride-vinyl acetate copolymer, an organic solvent and a surface active agent.
Claim 13
Dependent Claim
33 words
A method for claim 10 wherein the inorganic oxide is selected from the group consisting of: zinc oxide, iron oxide, titanium dioxide, tin oxide, hafnium oxide, zirconium dioxide, titanium tetraisopropoxide and silicon dioxide.
Claim 14
Dependent Claim
24 words
A method of claim 11 wherein the inorganic oxide comprises zinc oxide having a particle size of from about 0.015 microns to 0.15 microns.
Claim 15
Dependent Claim
11 words
A method of claim 10 wherein the organic solvent comprises tetrahydrofuran.
Claim 16
Dependent Claim
28 words
A method of claim 10 wherein the surface active agent is selected from the group consisting of: lecithin, 11-phenoxy-unecanoic acid, polyoxyethylene nonylphenyl ether phosphate and N-tallow-1,3-diamino propane dioleate.
Claim 17
Dependent Claim
34 words
A magnetic ink composition comprising: (a) barium ferrite; (b) an inorganic oxide; (c) a blend of a polyurethane polymer and vinyl chloride-vinyl acetate copolymer; (d) an organic solvent; and (e) a surface active agent.
Claim 18
Dependent Claim
34 words
A magnetic ink composition comprising: (a) barium ferrite; (b) an inorganic oxide; (c) a blend of a polyurethane polymer and vinyl chloride-vinyl acetate copolymer; (d) an organic solvent; and (e) a surface active agent.
Claim 19
Dependent Claim
25 words
A magnetic ink composition of claim 15 wherein the barium ferrite has a particle size of from about 0.01 to about 1.0 microns in diameter.
Claim 20
Dependent Claim
35 words
A magnetic ink composition of claim 15 wherein the inorganic oxide is selected from the group consisting of: zinc oxide, iron oxide, titanium dioxide, tin oxide, hafnium oxide, zirconium dioxide, titanium tetraisopropoxide and silicon dioxide.
Claim 21
Dependent Claim
24 words
A magnetic ink composition of claim 17 wherein the inorganic oxide comprises zinc oxide having a particle size of about 0.015 to 0.15 microns.
Claim 22
Dependent Claim
13 words
A magnetic ink composition of claim 15 wherein the organic solvent comprises tetrahydrofuran.
Claim 23
Dependent Claim
29 words
A magnetic ink composition of claim 15 wherein the surface active agent is selected from the group consisting of: lecithin, 11-phenoxyundecanoic acid, polyoxyethylene nonylphenyl ether phosphate and N-tallow-1,3-diaminopropane dioleate.
Claim 24
Dependent Claim
29 words
A magnetic ink composition comprising: (a) barium ferrite powder; (b) zinc oxide; (c) a blend of a polyurethane and a vinyl chloride/vinyl acetate copolymer; (d) tetrahydrofuran; and (e) lecithin.
Claim 25
Dependent Claim
29 words
A magnetic ink composition comprising: (a) barium ferrite powder; (b) zinc oxide; (c) a blend of a polyurethane and a vinyl chloride/vinyl acetate copolymer; (d) tetrahydrofuran; and (e) lecithin.
Claim 26
Dependent Claim
14 words
A magnetic ink composition of claim 21 having a coercivity greater than 600 oersteads.
Claim 27
Dependent Claim
19 words
A magnetic ink composition of claim 21 having a surface roughness of less than 100 microinches peak to peak.
Claim 28
Dependent Claim
25 words
A magnetic ink composition of claim 21 wherein the barium ferrite has a particle size of from about 0.01 to about 1.0 microns in diameter.
Claim 29
Dependent Claim
17 words
A magnetic film coated on a plastic or paper substate comprising a magnetic ink of claim 15.
Claim 30
Dependent Claim
17 words
A magnetic film coated on a plastic or paper substrate comprising a magnetic ink of claim 21.
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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) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |