US4994218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing gelled green compact for thin sintered body
Assignee: Niterra Co Ltd
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Filing: 1989-06-28
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Granted: 1991-02-19
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Expires: 2009-06-28
Abstract
Abstract A method of producing a gelled green compact for a thin sintered body is disclosed. The method comprises by steps (a) adding an acid to a solution of metal alkoxide to produce a sol which has the pH controlled within the range from approximately 2 to approximately 3; (b) adding an acid to the sol to lower the pH of the same; (c) adding an alkali to the sol to increase the pH of the same and control the pH within a range from approximately 1.5 to approximately 3; (d) drying the sol; and (e) molding the sol into a gelled green compact. The gelled green compact has a satisfied plasticity.
Inventors
- 👤 Junichi Tokumoto
- 👤 Minato Ando
- 👤 Takashi Katoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:06
CPC Classifications
C; C01; C01B; C01B13/00; C01B13/14; C01B13/32; C04; C04B; C04B35/00; C04B35/622; C04B35/624; C01P; C01P2004/00; C01P2004/01; C01P2004/03
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
94 words
A method for producing a gelled green compact for a thin sintered body, comprising the steps of: (a) adding an acid to a solution of metal alkoxide to produce a sol which has a pH of from approximately 2 to approximately 3; (b) adding an acid to said sol to lower the pH of said sol; (c) adding an alkali to said sol to increase the pH of said sol to within a range from approximately 1.5 to approximately 3; (d) drying said sol; and (e) molding said sol into the gelled green compact.
Claim 2
Independent Claim
94 words
A method for producing a gelled green compact for a thin sintered body, comprising the steps of: (a) adding an acid to a solution of metal alkoxide to produce a sol which has a pH of from approximately 2 to approximately 3; (b) adding an acid to said sol to lower the pH of said sol; (c) adding an alkali to said sol to increase the pH of said sol to within a range from approximately 1.5 to approximately 3; (d) drying said sol; and (e) molding said sol into the gelled green compact.
Claim 3
Dependent Claim
23 words
A method as claimed in claim 1, wherein step (a) further comprises adding a concentrated acid to control the pH of said sol.
Claim 4
Dependent Claim
19 words
A method as claimed in claim 2, wherein said acids used in steps (a) and (b) are the same.
Claim 5
Dependent Claim
16 words
A method as claimed in claim 3, wherein said acid is nitric acid or hydrochloric acid.
Claim 6
Dependent Claim
23 words
A method as claimed in claim 1, wherein said alkali used in the step (c) is an ammonia solution or a caustic soda.
Claim 7
Dependent Claim
25 words
A method as claimed in claim 1, wherein step (b) comprises adding said acid until the pH of said sol is lowered to approximately 1.4.
Claim 8
Independent Claim
142 words
A method of producing a thin sintered body, comprising the steps of: (a) adding aluminum isopropoxide to isopropyl alcohol so as to keep a total reflux of the alcohol at its boiling point and thereby produce a solution of metal alkoxide; (b) adding a solution of nitric acid to said metal alkoxide solution to hydrolyze the aluminum isopropoxide and thereby produce a sol; (c) cooling said sol and removing any remaining alcohol therefrom; (d) adding concentrated nitric acid to said sol so that said sol has a pH of 2.0; (e) adding said concentrated nitric acid to said sol to lower the pH to 1.4; (f) adding a concentrated ammonia solution to said sol to raise the pH to 2.0; (g) drying said sol; (h) molding said sol into a thin gelled green compact; and (i) baking said thin gelled green compact.
Claim 9
Independent Claim
142 words
A method of producing a thin sintered body, comprising the steps of: (a) adding aluminum isopropoxide to isopropyl alcohol so as to keep a total reflux of the alcohol at its boiling point and thereby produce a solution of metal alkoxide; (b) adding a solution of nitric acid to said metal alkoxide solution to hydrolyze the aluminum isopropoxide and thereby produce a sol; (c) cooling said sol and removing any remaining alcohol therefrom; (d) adding concentrated nitric acid to said sol so that said sol has a pH of 2.0; (e) adding said concentrated nitric acid to said sol to lower the pH to 1.4; (f) adding a concentrated ammonia solution to said sol to raise the pH to 2.0; (g) drying said sol; (h) molding said sol into a thin gelled green compact; and (i) baking said thin gelled green compact.
Claim 10
Dependent Claim
25 words
A method as claimed in claim 7, wherein step (a) comprises adding 0.2 mole of said aluminum isopropoxide to 6 mole of said isopropyl alcohol.
Claim 11
Dependent Claim
29 words
A method as claimed in claim 8, wherein step (b) comprises adding a solution of nitric acid comprising 20 mole of water and 2.5×10 -5 mole of nitric acid.
Claim 12
Dependent Claim
19 words
A method as claimed in claim 9, wherein step (i) is carried out at 1100° C. for 6 hours.
Claim 13
Independent Claim
94 words
A method for producing a gelled green compact for a thin sintered body, comprising the steps of: (a) adding an acid to a solution of aluminium alkoxide to produce a sol which has a pH of from approximately 2 to approximately 3; (b) adding an acid to said sol to lower the pH of said sol; (c) adding an alkali to said sol to increase the pH of said sol to within a range from approximately 1.5 to approximately 3; (d) drying said sol; and (e) molding said sol into the gelled green compact.
Claim 14
Independent Claim
94 words
A method for producing a gelled green compact for a thin sintered body, comprising the steps of: (a) adding an acid to a solution of aluminium alkoxide to produce a sol which has a pH of from approximately 2 to approximately 3; (b) adding an acid to said sol to lower the pH of said sol; (c) adding an alkali to said sol to increase the pH of said sol to within a range from approximately 1.5 to approximately 3; (d) drying said sol; and (e) molding said sol into the gelled green compact.
Claim 15
Dependent Claim
23 words
A method as claimed in claim 11, wherein step (a) further comprises adding a concentrated acid to control the pH of said sol.
Claim 16
Dependent Claim
19 words
A method as claimed in claim 12, wherein said acids used in steps (a) and (b) are the same.
Claim 17
Dependent Claim
16 words
A method as claimed in claim 13, wherein said acid is nitric acid or hydrochloric acid.
Claim 18
Dependent Claim
23 words
A method as claimed in claim 11, wherein said alkali used in the step (c) is an ammonia solution or a caustic soda.
Claim 19
Dependent Claim
25 words
A method as claimed in claim 11, wherein step (b) comprises adding said acid until the pH of said sol is lowered to approximately 1.4.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1994-02-18 | 1994-08-20 | 1995-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-18 | 1998-08-20 | 1999-02-19 | $3760.00 | Window Closed / Lapsed |
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