Patent US2935592A successfully refreshed from Google Patents.
US4020134A
Expired / Lapsed
US
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Method for preparing shaped, green ceramic compacts
Assignee: Ford Motor Co
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Filing: 1975-01-29
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Granted: 1977-04-26
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Expires: 1995-01-29
Abstract
Abstract A method for preparing shaped, green ceramic compacts suitable for firing to form high density β"-alumina containing ceramic bodies comprising: (1) mixing between about 2.5 parts by weight and about 4.5 parts by weight of a ceramic composition comprising at least about 80 weight percent of aluminum oxide and from about 5 to about 15 weight percent of sodium oxide with 1 part by weight of a binder composition consisting essentially of between about 20 weight percent and about 35 weight percent of polyvinyl pyrrolidone having a number average molecular weight (M n ) between about 20,000 and about 160,000 and between about 80 weight percent and about 65 weight percent of ethylene glycol; (2) extruding the mixture so formed through a die of desired configuration; and (3) heating the extrudate at temperatures and for periods of time necessary to evaporate the ethylene glycol solvent and burn off the polyvinyl pyrrolidone.
Inventors
- 👤 Ronald S. Gordon
- 👤 Ralph W. Sutton
- 👤 Gerald J. Tennenhouse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:19
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/638; C04B35/01; C04B35/10; C04B35/111; C04B35/113; C04B35/632; C04B35/634; C04B35/63404; C04B35/63444; Y; Y10; Y10S; Y10S264/00; Y10S264/25
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
152 words
A method for preparing shaped, green ceramic compacts suitable for firing to form high density β"-alumina containing ceramic bodies comprising: 1. mixing between about 2.5 parts by weight and about 4.5 parts by weight of a ceramic composition comprising at least about 80 weight percent of aluminum oxide and from about 5 to about 15 weight percent of sodium oxide with 1 part by weight of a binder composition consisting essentially of between about 20 weight percent and about 35 weight percent of polyvinyl pyrrolidone having a number average molecular weight between about 20,000 and about 160,000 and between about 80 weight percent and about 65 weight percent of ethylene glycol; 2. extruding the mixture so formed through a die of the desired configuration; and 3. heating the extrudate at a temperature and for a time so as to evaporate the ethylene glycol solvent therefrom and to burn off the polyvinyl pyrrolidone.
Claim 2
Independent Claim
152 words
A method for preparing shaped, green ceramic compacts suitable for firing to form high density β"-alumina containing ceramic bodies comprising: 1. mixing between about 2.5 parts by weight and about 4.5 parts by weight of a ceramic composition comprising at least about 80 weight percent of aluminum oxide and from about 5 to about 15 weight percent of sodium oxide with 1 part by weight of a binder composition consisting essentially of between about 20 weight percent and about 35 weight percent of polyvinyl pyrrolidone having a number average molecular weight between about 20,000 and about 160,000 and between about 80 weight percent and about 65 weight percent of ethylene glycol; 2. extruding the mixture so formed through a die of the desired configuration; and 3. heating the extrudate at a temperature and for a time so as to evaporate the ethylene glycol solvent therefrom and to burn off the polyvinyl pyrrolidone.
Claim 3
Dependent Claim
23 words
A method in accordance with claim 1, wherein said polyvinyl pyrrolidone has a number average molecular weight between about 30,000 and about 50,000.
Claim 4
Dependent Claim
20 words
A method in accordance with claim 1, wherein said polyvinyl pyrrolidone has a number average molecular weight of about 40,000.
Claim 5
Dependent Claim
47 words
A method in accordance with claim 1, wherein the mixture of said ceramic composition and said binder composition is extruded through said die at a pressure of between about 3000 psi and about 50,000 psi at a rate of between about 0.25 inches/min. and about 50 in./min.
Claim 6
Dependent Claim
24 words
A method in accordance with claim 4, wherein said mixture is extruded at a pressure of between about 8000 psi and about 40,000 psi.
Claim 7
Dependent Claim
31 words
A method in accordance with claim 1, wherein the density of said shaped, green ceramic compact is between about 45 and about 60 weight percent of the theoretical density for β"-alumina.
Claim 8
Dependent Claim
80 words
A method in accordance with claim 1, wherein between about 2.8 parts by weight and about 3.8 parts by weight of said composition is mixed with 1 parts by weight of a binder composition consisting esssentially of a solution of about 75 weight percent ethylene glycol and about 25 weight percent of polyvinyl pyrrolidone having a molecular weight of about 40,000 and wherein the extrudate formed has a green density greater than 50 percent of the theoretical density for β"-alumina.
Claim 9
Dependent Claim
47 words
A method in accordance with claim 1, wherein said ethylene glycol solvent is evaporated by heating to a temperature of between about 75° and about 180° C and said polyvinyl pyrrolidone is subsequently burned off by heating to a temperature between about 250° and about 400° C.
Claim 10
Dependent Claim
22 words
A method in accordance with claim 1, wherein said composition includes from about 0.1 to about 1 weight percent of boron oxide.
Claim 11
Dependent Claim
28 words
A method in accordance with claim 1, wherein said composition includes from about 0.1 to about 1.5 weight percent of lithium oxide, magnesium oxide or a mixture thereof.
Claim 12
Dependent Claim
22 words
A method in accordance with claim 10, wherein said composition contains between about 0.1 and about 1.5 weight percent of lithium oxide.
Claim 13
Dependent Claim
20 words
A method in accordance with claim 1, wherein said die is shaped such that the extrudate has a rod form.
Claim 14
Dependent Claim
20 words
A method in accordance with claim 1, wherein said die is shaped such that the extrudate has a tubular form.
Claim 15
Independent Claim
181 words
A method for preparing shaped, green ceramic compacts suitable for firing to form high density β"-alumina containing ceramic bodies having a density of between about 45 and about 60 percent of the theoretical density for β"-alumina comprising: 1. mixing between about 2.5 parts by weight and about 4.5 parts by weight of a ceramic composition comprising at least about 80 weight percent of aluminum oxide, between about 5 and about 15 weight percent of sodium oxide and between about 0.1 and 5 weight percent of lithium oxide, magnesium oxide or a mixture thereof with 1 part by weight of a binder composition consisting essentially of between about 20 weight percent and about 35 weight percent of polyvinyl pyrrolidone having a molecular weight of between about 30,000 and about 50,000 and between about 80 weight percent and about 65 weight percent of ethylene glycol; 2. extruding the mixture so formed through a die of the desired configuration at a pressure of between about 3000 psi and about 50,000 psi at a rate of between about 0.25 inch/min. and for about 50 inch/min.
Claim 16
Independent Claim
181 words
A method for preparing shaped, green ceramic compacts suitable for firing to form high density β"-alumina containing ceramic bodies having a density of between about 45 and about 60 percent of the theoretical density for β"-alumina comprising: 1. mixing between about 2.5 parts by weight and about 4.5 parts by weight of a ceramic composition comprising at least about 80 weight percent of aluminum oxide, between about 5 and about 15 weight percent of sodium oxide and between about 0.1 and 5 weight percent of lithium oxide, magnesium oxide or a mixture thereof with 1 part by weight of a binder composition consisting essentially of between about 20 weight percent and about 35 weight percent of polyvinyl pyrrolidone having a molecular weight of between about 30,000 and about 50,000 and between about 80 weight percent and about 65 weight percent of ethylene glycol; 2. extruding the mixture so formed through a die of the desired configuration at a pressure of between about 3000 psi and about 50,000 psi at a rate of between about 0.25 inch/min. and for about 50 inch/min.
Claim 17
Dependent Claim
24 words
A method in accordance to claim 14, wherein said mixture is extruded at a pressure of between about 8000 psi and about 40,000 psi.
Claim 18
Dependent Claim
72 words
A method in accordance with claim 14, wherein between about 2.8 parts by weight and about 3.8 parts by weight of said composition is mixed with a binder composition consisting essentially of about 25 weight percent of polyvinyl pyrrolidone having a molecular weight of about 40,000 and about 75 weight percent of ethylene glycol and wherein said extrudate has a density greater than about 50 percent of the theoretical density for β"-alumina.
Claim 19
Dependent Claim
24 words
A method in accordance with claim 14, wherein said composition contains between about 0.1 weight percent and about 1.5 weight percent of lithium oxide.
Claim 20
Dependent Claim
21 words
A method in accordance with claim 14, wherein said die is shaped such that the extrudate is in a rod form.
Claim 21
Dependent Claim
21 words
A method in accordance with claim 14, wherein said die is shaped such that the extrudate is in a tubular form.
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) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |