Patent US5021376A successfully refreshed from Google Patents.
US5021376A
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Method for preparing a ceramic suspension
Assignee: ABB AG
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Filing: 1989-01-19
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Granted: 1991-06-04
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Expires: 2009-01-19
Abstract
Abstract A method for preparing a ceramic suspension using alpha-Al 2 O 3 powder containing agglomerated powder particles includes dissolving ionic or polymeric reagents as additional dispersing agents in water or an organic solvent as a dispersion medium. Alpha-Al 2 O 3 powder is added thereto while being stirred. Ceramic molded articles may be produced from the suspension.
Inventors
- 👤 Hans Nienburg
- 👤 Friedrich Harbach
- 👤 Peter Stein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:28
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
232 words
A method for preparing a suspension of 30-90 wt. % alpha-Al 2 O 3 in deagglomerated form from alpha-Al 2 O 3 having a mean grain size under 1 μm which comprises the steps of forming a dispersion by dissolving 0.1 to 2% by weight, with respect to the alpha-Al 2 O 3 , of a dispersing agent in a dispersion medium, wherein the medium is selected from the group consisting of (a) water and (b) a lower alkanol of up to three carbon atoms and when the medium is (a) water, the dispersing agent is an electrolyte selected from the group consisting of ammonium hydroxide, lower organic amines, nitric acid and carboxylic acids and at least one complex water-soluble polyelectrolyte selected from the group consisting of 3,6,9-trioxaundecane diacid, polyglycol diacid, naphthalene sulfonic acid condensate, polyacrylic acid, partially esterified polyacrylic acid and the ammonium salts of the complex acids; and when the dispersion medium is the (b) alkanol the dispersing agent is selected from the group consisting of triethylamine and tetrabutyl ammonium hydroxide strong organic bases; acetic acid, p-hydroxy-benzoic acid and 3,6,9-trioxaundecane diacid carbolic acids; and polyvinyl pyrrolidone, nitrocellulose, polyacrylic acid, partially esterified polyacrylic acid and polyvinyl butyral polymers and a mixture thereof; then adding the alpha Al 2 O 3 to the solution and agitating for a time sufficient to deagglomerate the alpha-Al 2 O 3 to the mean grain size.
Claim 2
Independent Claim
232 words
A method for preparing a suspension of 30-90 wt. % alpha-Al 2 O 3 in deagglomerated form from alpha-Al 2 O 3 having a mean grain size under 1 μm which comprises the steps of forming a dispersion by dissolving 0.1 to 2% by weight, with respect to the alpha-Al 2 O 3 , of a dispersing agent in a dispersion medium, wherein the medium is selected from the group consisting of (a) water and (b) a lower alkanol of up to three carbon atoms and when the medium is (a) water, the dispersing agent is an electrolyte selected from the group consisting of ammonium hydroxide, lower organic amines, nitric acid and carboxylic acids and at least one complex water-soluble polyelectrolyte selected from the group consisting of 3,6,9-trioxaundecane diacid, polyglycol diacid, naphthalene sulfonic acid condensate, polyacrylic acid, partially esterified polyacrylic acid and the ammonium salts of the complex acids; and when the dispersion medium is the (b) alkanol the dispersing agent is selected from the group consisting of triethylamine and tetrabutyl ammonium hydroxide strong organic bases; acetic acid, p-hydroxy-benzoic acid and 3,6,9-trioxaundecane diacid carbolic acids; and polyvinyl pyrrolidone, nitrocellulose, polyacrylic acid, partially esterified polyacrylic acid and polyvinyl butyral polymers and a mixture thereof; then adding the alpha Al 2 O 3 to the solution and agitating for a time sufficient to deagglomerate the alpha-Al 2 O 3 to the mean grain size.
Claim 3
Dependent Claim
41 words
The method according to claim 1 wherein the agitation is continued until the deagglomeration results in a distribution of 30 to 90% by weight of the alpha-Al 2 O 3 having a mean particle size range of 0.1 to 0.6 μm.
Claim 4
Dependent Claim
12 words
The method according to claim 1, wherein the agitation includes ultrasound agitation.
Claim 5
Dependent Claim
41 words
The method according to claim 1, wherein the medium is water and the agent is selected from the group consisting of ammonium hydroxide, lower organic amines, nitric acid and carboxylic acids from the group consisting of acetic acid and p-hydroxy-benzoic acid.
Claim 6
Dependent Claim
42 words
The method according to claim 1, wherein the medium is water and the agent is selected from the group consisting of 3,6,9-trioxaundecane diacid, polyglycol diacid, naphthalene sulfonic acid condensate, polyacrylic acid, partially esterified polyacrylic acid complex water-soluble polyelectrolytes and their ammonium salts.
Claim 7
Dependent Claim
72 words
The method according to claim 1, wherein the medium is an alkanol selected from the group consisting of methanol, ethanol and propanol and the agent is selected from the group consisting of organic bases and acids, the bases being selected from the group consisting of triethylamine, tetrabutyl ammonium hydroxide and the acid is selected from the group of carboxylic acids consisting of acetic acid, p-hydroxy-benzoic acid, and 3,6,9-trioxaundecane diacid and mixture thereof.
Claim 8
Dependent Claim
43 words
The method according to claim 1, wherein the medium is an alkanol selected from the group consisting of methanol, ethanol and propanol and the agent is selected from the group of water-soluble polymers consisting of polyvinyl pyrrolidone, nitrocellulose, polyacrylic acid and polyvinyl butyral.
Claim 9
Dependent Claim
26 words
The method according to claim 1, which comprises subsequently producing shaped ceramic articles by one of electrodeposition and slip casting with the suspension as a vehicle.
Claim 10
Dependent Claim
26 words
The method according to claim 2, which comprises subsequently producing shaped ceramic articles by one of electrodeposition and slip casting with the suspension as a vehicle.
Claim 11
Dependent Claim
26 words
The method according to claim 3, which comprises subsequently producing shaped ceramic articles by one of electrodeposition and slip casting with the suspension as a vehicle.
Claim 12
Dependent Claim
26 words
The method according to claim 4, which comprises subsequently producing shaped ceramic articles by one of electrodeposition and slip casting with the suspension as a vehicle.
Claim 13
Dependent Claim
26 words
The method according to claim 5, which comprises subsequently producing shaped ceramic articles by one of electrodeposition and slip casting with the suspension as a vehicle.
Claim 14
Dependent Claim
26 words
The method according to claim 6, which comprises subsequently producing shaped ceramic articles by one of electrodeposition and slip casting with the suspension as a vehicle.
Claim 15
Dependent Claim
26 words
The method according to claim 7, which comprises subsequently producing shaped ceramic articles by one of electrodeposition and slip casting with the suspension as a vehicle.
Claim 16
Dependent Claim
28 words
The method according to claim 1, which comprises subsequently producing shaped ceramic articles by electrodeposition with the suspension as a vehicle and the alkanol as the dispersion medium.
Claim 17
Dependent Claim
28 words
The method according to claim 2, which comprises subsequently producing shaped ceramic articles by electrodeposition with the suspension as a vehicle and the alkanol as the dispersion medium.
Claim 18
Dependent Claim
28 words
The method according to claim 3, which comprises subsequently producing shaped ceramic articles by electrodeposition with the suspension as a vehicle and the alkanol as the dispersion medium.
Claim 19
Dependent Claim
28 words
The method according to claim 4, which comprises subsequently producing shaped ceramic articles by electrodeposition with the suspension as a vehicle and the alkanol as the dispersion medium.
Claim 20
Dependent Claim
28 words
The method according to claim 5, which comprises subsequently producing shaped ceramic articles by electrodeposition with the suspension as a vehicle and the alkanol as the dispersion medium.
Claim 21
Dependent Claim
28 words
The method according to claim 6, which comprises subsequently producing shaped ceramic articles by electrodeposition with the suspension as a vehicle and the alkanol as the dispersion medium.
Claim 22
Dependent Claim
28 words
The method according to claim 7, which comprises subsequently producing shaped ceramic articles by electrodeposition with the suspension as a vehicle and the alkanol as the dispersion medium.
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