Patent USH626H successfully refreshed from Google Patents.
USH626H
Expired / Lapsed
US
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Sol-gel ceramic oxides
Assignee: United States Department of the Navy
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Filing: 1986-08-04
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Granted: 1989-04-04
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Expires: 2006-08-04
Abstract
Abstract A method of synthesizing ceramic oxides using the Sol-Gel process to control particle size distribution, crystal structure and to achieve the selective incorporation of transition metals within a ceramic oxide matrix in order to produce tailored oxides with specific particle morphology and near zero expansion optical ceramics.
Inventors
- 👤 Josephine Covino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:53
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/19; C04B35/10; C04B35/111
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
126 words
A method for selectively incorporating transition metals within a ceramic oxide matrix and for producing a ceramic oxide product having a particular particle size distribution and crystal structure, said method comprising the steps of: forming a solution of hydrolyzable transition metal organic compounds in an organic solvent; lowering the pH of said solution with an acid to a range that allows growth of metal oxide chains and networks through hydrolysis and condensation reactions without the formation of colloidal silica; initiating a hydrolytic polycondensation reaction in said solution by adding water to produce a gel containing three-dimensionally cross-linked polymers having a controlled cross-linked matrix; and heating said gel so as to substantially remove organic and free liquid components and convert said gel to a particulate oxide product.
Claim 2
Independent Claim
126 words
A method for selectively incorporating transition metals within a ceramic oxide matrix and for producing a ceramic oxide product having a particular particle size distribution and crystal structure, said method comprising the steps of: forming a solution of hydrolyzable transition metal organic compounds in an organic solvent; lowering the pH of said solution with an acid to a range that allows growth of metal oxide chains and networks through hydrolysis and condensation reactions without the formation of colloidal silica; initiating a hydrolytic polycondensation reaction in said solution by adding water to produce a gel containing three-dimensionally cross-linked polymers having a controlled cross-linked matrix; and heating said gel so as to substantially remove organic and free liquid components and convert said gel to a particulate oxide product.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein said hydrolyzable transition metal organic compunds contain transition metals selected from the group consisting of aluminum, titanium, zirconium, magnesium, zinc and lithium.
Claim 4
Dependent Claim
32 words
The method of claim 2 wherein said hydrolyzable transition metal organic compounds are selected from the group consisting of aluminum butoxide, titanium isopropoxide, zirconium 2,4-pentanedionate, magnesium 2,4-pentanedionate, zinc 2,4-pentanedionate, and lithium 2,4-pentanedionate.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein said organic solvent or mixture of solvents is selected from the group consisting of tetraethoxysilane, isopropyl alcohol, methanol and tributyl phosphate.
Claim 6
Dependent Claim
20 words
The method of claim 1 wherein said acid adjusted pH range is between the pH values of 3 and 4.
Claim 7
Dependent Claim
23 words
The method of claim 5 wherein said acid is a mineral acid selected from the group consisting of nitric acid and hydrochloric acid.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein said oxide product is a composition corresponding to a lithium aluminum silicate composition having the beta-quartz structure.
Claim 9
Dependent Claim
19 words
The method of claim 7 wherein said beta-quartz lithium aluminum silicate has a coefficient of thermal expansion near zero.
Claim 10
Independent Claim
69 words
A method of producing an aluminum oxide product having the gamma-Al 2 O 3 structure comprising the steps of: forming a solution of aluminum propionate and distilled water; adding concentrated hydrochloric acid to said solution to lower the pH of said solution to about 0.7; adding methanol to dilute said solution; sonicating said solution for about ten minutes; and dehydrating said solution to recover a crystalline ceramic oxide powder.
Claim 11
Independent Claim
69 words
A method of producing an aluminum oxide product having the gamma-Al 2 O 3 structure comprising the steps of: forming a solution of aluminum propionate and distilled water; adding concentrated hydrochloric acid to said solution to lower the pH of said solution to about 0.7; adding methanol to dilute said solution; sonicating said solution for about ten minutes; and dehydrating said solution to recover a crystalline ceramic oxide powder.
Claim 12
Dependent Claim
77 words
In the method of preparing a desired ceramic oxide product by forming metal oxide chain and network structures by hydrolysis and polymerization of a solution of at least one metal-organic compound followed by drying the solution to recover the product where the product is determined by controlling said structure by selection of the pH of the solution and by selective dilution of the solution, the improvement comprising further control of said structure by sonication of the solution.
Claim 13
Dependent Claim
77 words
In the method of preparing a desired ceramic oxide product by forming metal oxide chain and network structures by hydrolysis and polymerization of a solution of at least one metal-organic compound followed by drying the solution to recover the product where the product is determined by controlling said structure by selection of the pH of the solution and by selective dilution of the solution, the improvement comprising further control of said structure by sonication of the solution.
Claim 14
Dependent Claim
82 words
The method of claim 10 wherein the desired product is aluminum oxide having the gamma structure; wherein the solution is an aqueous solution of aluminum propionate; wherein said selection of the pH of the solution is by the addition of hydrochloric acid to give a pH of about 0.7 and said dilution is by methanol; and wherein the solution is sonicated for about ten minutes with the solution at a temperature in the range of about 34° C. to about 60° C.
Claim 15
Independent Claim
97 words
A method for producing a lithium aluminum silicate-like ceramic oxide product incorporating desired metal oxides, the method comprising: forming a solution in an organic solvent of hydrolyzable organic compounds of said metals; adding sufficient water to said solution to initiate and to maintain hydrolysis of said compounds and growth of metal oxide chains and networks in the solution by polymerization; and selecting the pH of said solution so that said hydrolysis and polymerization proceeds without the formation of colloidal oxides which detach from said chains and networks but are desired to remain therein to form said product.
Claim 16
Independent Claim
97 words
A method for producing a lithium aluminum silicate-like ceramic oxide product incorporating desired metal oxides, the method comprising: forming a solution in an organic solvent of hydrolyzable organic compounds of said metals; adding sufficient water to said solution to initiate and to maintain hydrolysis of said compounds and growth of metal oxide chains and networks in the solution by polymerization; and selecting the pH of said solution so that said hydrolysis and polymerization proceeds without the formation of colloidal oxides which detach from said chains and networks but are desired to remain therein to form said product.
Claim 17
Dependent Claim
105 words
The method of claim 12 wherein said oxides include oxides of aluminum, titanium, zirconium, magnesium, zinc, and lithium having as respective precursors dissolved in said solution, aluminum butoxide, titanium isopropoxide, zirconium 2,4-pentanedionate, magnesium 2,4-pentanedionate, zinc 2,4-pentanedionate, and lithium 2,4-pentanedionate with tetraethoxysilane, isopropyl alcohol, and methanol as solvents, and wherein during hydrolysis and polymerization the temperature of said solution is maintained at substantially room temperature and the pH of said solution is selected in the range of about 3 to about 4 so that silica in colloidal form does not detach from said chains and networks and so that the product has the beta quartz structure.
Claim 18
Dependent Claim
44 words
The method of claim 13 wherein, to form said solution, the aluminum butoxide and the titanium isopropoxide are dissolved is said tetraethoxysilane; the zirconium, magnesium, and the zinc 2,4-pentanedionates are dissolved in said isopropyl alcohol; and the lithium 2,4-pentanedionate to be dissolved in methanol.
Claim 19
Dependent Claim
62 words
The method of claim 13 wherein, to form said solution, the aluminum butoxide is dissolved in said tetraethoxysilane; the zirconium, magnesium, and zinc 2,4-pentanedionates are dissolved in said isopropyl alcohol; and the lithium 2,4-pentanedionates is dissolved in methanol, and wherein the product further includes phosphorus having as a precursor tributyl phosphate utilized is said solution as a solvent for the titanium isoproxide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-03 | 2000-10-03 | 2001-04-04 | $7700.00 | Window Closed / Lapsed |