US4917857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing metallic or ceramic hollow-sphere bodies
Assignee: Aurubis AG
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Filing: 1988-07-12
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Granted: 1990-04-17
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Expires: 2008-07-12
Abstract
Abstract Metallic or ceramic hollow spheres are produced by applying a solid layer to a substantially spherical particle of foamed polymer and the coated polymer cores are pyrolyzed with formation of vapor. In order to permit an economical production of the hollow spheres and a wide selection from a wide range of metallic or ceramic materials, the particles consisting of foamed polymer are treated in a state of agitation with an aqueous suspension which contains dissolved or suspended binder and metallic and/or ceramic powder particles, whereby a coating is formed on said polymer particles. The coating is dried, the polymer particles and least part of the binder are subsequently pyrolyzed at temperatures from 400° to 500° C. with formation of vapor while they are agitated and the resulting metallic and/or ceramic hollow spheres are sintered at temperatures from 1000° to 1500° C. while they are agitated.
Inventors
- 👤 Manfred Jaeckel
- 👤 Hartmuth Smigilski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:17
CPC Classifications
C; C04; C04B; C04B38/00; C04B38/009; B; B01; B01J; B01J37/00; B01J37/0009; B01J37/0018; B22; B22F; B22F1/00; B22F1/06; B22F1/065; B22F1/0655; B22F3/00; B22F3/10; B22F3/1017; B22F3/11; B22F3/1103; B22F3/1112; B01J21/00; B01J21/02; B01J21/04; B01J23/00; B01J23/70; B01J23/72; B01J23/74; B01J23/745; B01J35/00; B01J35/50; B01J35/51; B01J35/52; B01J37/02; B01J37/0215; B01J37/0221; B29; B29C; B29C43/00; B29C43/006
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
100 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) agitating, in a fluidized bed reactor, particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended or organic binder and metallic and/or ceramic powder particles, whereby a coating is formed on said expanded polystyrene particles; (b) drying said coating; (c) pyrolyzing the expanded polystyrene of said particles and at least part of the binder at a temperature from 400° to 500° C. form hollow spheres; and (d) sintering the metallic or ceramic hollow spheres at a temperature from 1000° to 1500° C.
Claim 2
Dependent Claim
100 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) agitating, in a fluidized bed reactor, particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended or organic binder and metallic and/or ceramic powder particles, whereby a coating is formed on said expanded polystyrene particles; (b) drying said coating; (c) pyrolyzing the expanded polystyrene of said particles and at least part of the binder at a temperature from 400° to 500° C. form hollow spheres; and (d) sintering the metallic or ceramic hollow spheres at a temperature from 1000° to 1500° C.
Claim 3
Dependent Claim
43 words
The process defined in claim 1 wherein said powder particles are selected from materials or the group which consists of A1 2 O 3 , SiO 2 , CR 2 O 3 , ZrO 2 , SiC and Si 3 N 4 .
Claim 4
Dependent Claim
29 words
The process defined in claim 1 wherein said powder particles are selected from the group which consists of Fe, Co, Ni, Cu, W, Mo, noble metals and hard metals.
Claim 5
Dependent Claim
37 words
The process defined in claim 1 wherein said organic binder is selected from the group which consists of polyethylene, polyacrylate, polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polybutyral, polyamide, cellulose ester, phenol resin, amino resin and epoxy resins.
Claim 6
Dependent Claim
18 words
The process defined in claim 1 wherein said powder has a particle size from 0.0001 to 0.2 mm.
Claim 7
Dependent Claim
21 words
The process defined in claim 1 wherein said coating has a thickness from 0.01 to 0.2 mm in a dry state.
Claim 8
Dependent Claim
101 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) agitating particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended binder and metallic and/or ceramic powder particles, whereby a coating is formed on said expanded polystyrene particles; (b) drying said coating; (c) pyrolyzing the expanded polystyrene of said particles and at least part of the binder at a temperature from 400° to 500° C. to form hollow spheres; and (d) sintering the metallic or ceramic hollow spheres at a temperature from 1000° to 1500° C., the hollow spheres being agitated during sintering.
Claim 9
Dependent Claim
101 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) agitating particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended binder and metallic and/or ceramic powder particles, whereby a coating is formed on said expanded polystyrene particles; (b) drying said coating; (c) pyrolyzing the expanded polystyrene of said particles and at least part of the binder at a temperature from 400° to 500° C. to form hollow spheres; and (d) sintering the metallic or ceramic hollow spheres at a temperature from 1000° to 1500° C., the hollow spheres being agitated during sintering.
Claim 10
Dependent Claim
103 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) agitating particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended binder and metallic and/or ceramic powder particles, whereby a coating is formed on said expanded polystyrene particles; (b) drying said coating; (c) pyrolyzing the expanded polystyrene of said particles and at least part of the binder at a temperature from 400° to 500° C. to form hollow spheres; and (d) sintering the metallic or ceramic hollow spheres at a temperature from 1000° to 1500° C., the particles being agitated in step (c) during pyrolysis.
Claim 11
Dependent Claim
103 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) agitating particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended binder and metallic and/or ceramic powder particles, whereby a coating is formed on said expanded polystyrene particles; (b) drying said coating; (c) pyrolyzing the expanded polystyrene of said particles and at least part of the binder at a temperature from 400° to 500° C. to form hollow spheres; and (d) sintering the metallic or ceramic hollow spheres at a temperature from 1000° to 1500° C., the particles being agitated in step (c) during pyrolysis.
Claim 12
Dependent Claim
111 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) agitating particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended binder and metallic and/or ceramic powder particles, whereby a coating is formed on said expanded polystyrene particles; (b) drying said coating; (c) pyrolyzing the expanded polystyrene of said particles and at least part of the binder at a temperature from 400° to 500° C. to form hollow spheres; and (d) sintering the metallic or ceramic hollow spheres at a temperature from 1000° to 1500° C., said aqueous dispersion having a binder content from 3 to 15% by weight relative to said powder.
Claim 13
Dependent Claim
111 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) agitating particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended binder and metallic and/or ceramic powder particles, whereby a coating is formed on said expanded polystyrene particles; (b) drying said coating; (c) pyrolyzing the expanded polystyrene of said particles and at least part of the binder at a temperature from 400° to 500° C. to form hollow spheres; and (d) sintering the metallic or ceramic hollow spheres at a temperature from 1000° to 1500° C., said aqueous dispersion having a binder content from 3 to 15% by weight relative to said powder.
Claim 14
Dependent Claim
123 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) in a fluidized bed reactor agitating particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended organic binder and metal oxide powder particles selected from easily reducible oxides of metals of the group Fe, Ni, Co, Cu, noble metals, W and Mo, whereby a coating is formed on said polymer particles of expanded polystyrene; (b) drying said coating; (c) pyrolyzing the polymer of said coated particles and at least part of the organic binder at a temperature from 400° to 500° C. to form hollow spheres; and (d) sintering the metal oxide hollow spheres at a temperature from 1000° to 1500° C. under reducing conditions.
Claim 15
Dependent Claim
123 words
A process for producing metallic or ceramic hollow spheres which comprises the steps of: (a) in a fluidized bed reactor agitating particles of expanded polystyrene with an aqueous suspension which contains dissolved or suspended organic binder and metal oxide powder particles selected from easily reducible oxides of metals of the group Fe, Ni, Co, Cu, noble metals, W and Mo, whereby a coating is formed on said polymer particles of expanded polystyrene; (b) drying said coating; (c) pyrolyzing the polymer of said coated particles and at least part of the organic binder at a temperature from 400° to 500° C. to form hollow spheres; and (d) sintering the metal oxide hollow spheres at a temperature from 1000° to 1500° C. under reducing conditions.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
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