US4252674A
Expired / Lapsed
US
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Preparation of colloidal cobalt dispersions by the polymer-catalyzed decomposition of cobalt carbonyl and cobalt organocarbonyl compounds
Assignee: Xerox Corp
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Filing: 1979-12-04
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Granted: 1981-02-24
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Expires: 1999-12-04
Abstract
Abstract There is disclosed a method for the preparation of a homogeneous physically stable colloidal elemental cobalt dispersion of colloidal cobalt particles having a size in the range of from about 10 Angstrom units to about 200 Angstrom units. The method comprises preparing a solution of a passive polymer in an inert solvent, and incrementally adding thereto a cobalt precursor, at a temperature at which the cobalt precursor will lose at least one ligand and become bound to the passive polymer and thermally decompose to produce elemental cobalt particles, the process being carried out in an inert atmosphere. Such dispersions may be used per se as catalysts, or may be used for the preparation of supported colloidal cobalt catalysts. The dispersions may also be used for the preparation of ablative optical recording media.
Inventors
- 👤 Thomas W. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:56
CPC Classifications
B; B01; B01J; B01J31/00; B01J31/02; B01J31/06; B01J23/00; B01J23/70; B01J23/74; B01J23/75; B01J31/16; B01J31/165; B01J31/20; B01J35/00; B01J35/20; B01J35/23; B01J35/40; B01J35/45; G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/251; B01J2231/00; B01J2231/30; B01J2231/32; B01J2231/321; B01J2231/40; B01J2231/42; B01J2231/60; B01J2231/64; B01J2231/641; B01J2231/645; B01J2531/00; B01J2531/02; B01J2531/0202; B01J2531/0208; B01J2531/0211; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
180 words
A method for the preparation of a homogeneous, physically stable colloidal elemental cobalt dispersion comprising: (a) preparing a solution in an inert solvent of a passive polymer, the concentration of the polymer being below its critical entanglement concentration, to provide discrete reactive binding sites to which cobalt precursor molecules can become bound upon loss of at least one ligand from the cobalt precursor; (b) incrementally adding, at suitable time intervals, a labile cobalt precursor, the molecules of which lose at least one ligand and rapidly become bound to the reactive sites of the polymer; (c) maintaining a temperature which is sufficiently high to decompose the polymer-bound cobalt precursor much more rapidly than any cobalt precursor which may remain unbound in the solution decomposes to cobalt; (d) continuing the addition of increments of cobalt precursor to yield colloidal cobalt particles of the desired size within the range of from about 10 Angstrom units to about 200 Angstrom units, the cobalt particles being bound to the polymer molecules; and (e) steps (b), (c) and (d) being carried out in an inert atmosphere.
Claim 2
Independent Claim
180 words
A method for the preparation of a homogeneous, physically stable colloidal elemental cobalt dispersion comprising: (a) preparing a solution in an inert solvent of a passive polymer, the concentration of the polymer being below its critical entanglement concentration, to provide discrete reactive binding sites to which cobalt precursor molecules can become bound upon loss of at least one ligand from the cobalt precursor; (b) incrementally adding, at suitable time intervals, a labile cobalt precursor, the molecules of which lose at least one ligand and rapidly become bound to the reactive sites of the polymer; (c) maintaining a temperature which is sufficiently high to decompose the polymer-bound cobalt precursor much more rapidly than any cobalt precursor which may remain unbound in the solution decomposes to cobalt; (d) continuing the addition of increments of cobalt precursor to yield colloidal cobalt particles of the desired size within the range of from about 10 Angstrom units to about 200 Angstrom units, the cobalt particles being bound to the polymer molecules; and (e) steps (b), (c) and (d) being carried out in an inert atmosphere.
Claim 3
Dependent Claim
27 words
A method as set forth in claim 1 wherein the final increment, after decomposition, yields colloidal cobalt particles having a maximum size of about 150 Angstrom units.
Claim 4
Dependent Claim
30 words
A method as set forth in claim 1 wherein the final increment, after decomposition, yields colloidal cobalt particles, some of which have a maximum size of about 100 Angstrom units.
Claim 5
Dependent Claim
35 words
A method as set forth in claim 1 wherein the cobalt precursor increments are added in an amount of from about 5 to about 10 moles of cobalt precursor per mole of reactive binding sites.
Claim 6
Dependent Claim
26 words
A method as set forth in claim 1 wherein the cobalt precursor increments are added when only a little or no carbon monoxide is being generated.
Claim 7
Dependent Claim
23 words
A method as set forth in claim 1 wherein the cobalt precursor increments are added from about 2 to about 4 hours apart.
Claim 8
Dependent Claim
16 words
A method as set forth in claim 1 which is carried out at about atmospheric pressure.
Claim 9
Dependent Claim
34 words
A method as set forth in claim 1 wherein the addition of increments of the cobalt precursor is continuous, at a rate sufficient to compensate for the consumption of the cobalt precursor already added.
Claim 10
Dependent Claim
16 words
A method as set forth in claim 1 wherein the sufficiently high temperature is reflux temperature.
Claim 11
Dependent Claim
26 words
A method as set forth in claim 1 wherein the sufficiently high temperature is within the range of from about 100° C. to about 170° C.
Claim 12
Dependent Claim
24 words
A method as set forth in claim 10 wherein the temperature is within the range of from about 130° C. to about 150° C.
Claim 13
Dependent Claim
29 words
A method as set forth in claim 1 wherein the sufficiently high temperature is the minimum temperature that will cause a significant rate of decomposition of the polymer-cobalt precursor.
Claim 14
Dependent Claim
25 words
A method as set forth in claim 1 wherein decomposition of the polymer-bound cobalt precursor to cobalt is effected by actinic radiation instead of heat.
Claim 15
Dependent Claim
24 words
A method as set forth in claim 1 wherein the binding of the cobalt precursor to the passive polymer is effected by actinic radiation.
Claim 16
Dependent Claim
16 words
A method as set forth in claim 1 wherein additional polymer is added during the reaction.
Claim 17
Dependent Claim
18 words
A method as set forth in claim 1 wherein additional polymer is added after the reaction is complete.
Claim 18
Dependent Claim
22 words
A method as set forth in claim 1 wherein the passive polymer is soluble in the inert solvent at about ambient temperature.
Claim 19
Dependent Claim
15 words
A method as set forth in claim 1 wherein the passive polymer is a homopolymer.
Claim 20
Dependent Claim
23 words
A method as set forth in claim 1 wherein the passive polymer is a copolymer of a reactive monomer and an inert monomer.
Claim 21
Dependent Claim
19 words
A method as set forth in claim 19 wherein said copolymer is prepared by polymerization of vinyl type monomers.
Claim 22
Dependent Claim
24 words
A method as set forth in claim 1 wherein said passive polymer has a molecular weight of from about 1000 to about 1 million.
Claim 23
Dependent Claim
37 words
A method as set forth in claim 21 wherein the passive polymer concentration in the solution is, respectively, from about 10 percent or more to about 0.2-0.5 percent by weight based upon the weight of the solvent.
Claim 24
Dependent Claim
23 words
A method as set forth in claim 1 wherein said passive polymer has a molecular weight of from about 10,000 to about 100,000.
Claim 25
Dependent Claim
35 words
A method as set forth in claim 23 wherein the passive polymer concentration in the solution is, respectively, from about 5 percent to about 2 percent by weight based upon the weight of the solvent.
Claim 26
Dependent Claim
19 words
A method as set forth in claim 1 wherein said inert solvent is a liquid at about ambient temperature.
Claim 27
Dependent Claim
16 words
A method as set forth in claim 1 wherein said cobalt precursor is a cobalt carbonyl.
Claim 28
Dependent Claim
15 words
A method as set forth in claim 26 wherein said cobalt carbonyl is dicobalt octacarbonyl.
Claim 29
Dependent Claim
16 words
A method as set forth in claim 1 wherein said cobalt precursor is a cobalt alkylcarbonyl.
Claim 30
Dependent Claim
16 words
A method as set forth in claim 1 wherein said cobalt precursor is a cobalt alkenylcarbonyl.
Claim 31
Dependent Claim
16 words
A method as set forth in claim 1 wherein said cobalt precursor is a cobalt nitrosyl.
Claim 32
Dependent Claim
16 words
A method as set forth in claim 1 wherein said cobalt precursor is a cobalt acylcarbonyl.
Claim 33
Dependent Claim
71 words
A homogenous, physically stable colloidal elemental cobalt dispersion, suitable for use as a catalyst, comprising colloidal cobalt particles having a particle size within the range of from about 10 Angstrom units to about 200 Angstrom units dispersed in an inert liquid and stabilized by the presence of a passive polymer to the reactive sites of which the cobalt particles are bound, said dispersion being prepared by the method of claim 1.
Claim 34
Dependent Claim
19 words
A dispersion as set forth in claim 32 having a maximum colloidal cobalt particle of about 150 Angstrom units.
Claim 35
Dependent Claim
19 words
A dispersion as set forth in claim 32 having a maximum colloidal particle size of about 100 Angstrom units.
Claim 36
Dependent Claim
27 words
A dispersion as set forth in claim 32 wherein the weight ratio of cobalt to polymer is within the range of from about 90:100 to about 90:10.
Claim 37
Dependent Claim
84 words
A method for the preparation of a bead-supported catalyst comprising colloidal cobalt particles having a particle size within the range of from about 10 Angstrom units to about 200 Angstrom units, said particles being bound to the reactive sites of a passive polymer, and said particles and polymer being supported in the beads, said method comprising supporting a liquid-dispersed colloidal elemental cobalt catalyst as set forth in claim 34 in beads, said beads being produced by suspension polymerization of at least one polymerizable monomer.
Claim 38
Dependent Claim
15 words
A bead-supported catalyst as set forth in claim 36 wherein the beads comprise cross-linked polystyrene.
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) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |