US5082811A
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Ceramic dielectric compositions and method for enhancing dielectric properties
Assignee: EIDP Inc
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Filing: 1990-02-28
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Granted: 1992-01-21
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Expires: 2010-02-28
Abstract
Abstract An improved ceramic dielectric composition comprising a plurality of mixed metal oxide dopants distributed homogeneously on the surface of ceramic powder particles, and a method for enhancing dielectric properties of such compositions by improving the chemical homogeneity of the particles.
Inventors
- 👤 Salvatore A. Bruno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:28
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/628; C04B35/62802; C04B35/62805; C04B35/62818; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; C04B35/6281; C04B35/62815; C04B35/62826; C04B35/62886; H; H01; H01B; H01B3/00; H01B3/02; H01B3/12; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1209; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3224; C04B2235/3231; C04B2235/3232; C04B2235/3234; C04B2235/3236; C04B2235/3251; C04B2235/3262; C04B2235/327; C04B2235/3279; C04B2235/3284; C04B2235/34; C04B2235/3418; C04B2235/44; C04B2235/444; C04B2235/449; C04B2235/50; C04B2235/54; C04B2235/5409; C04B2235/70; C04B2235/72; C04B2235/74; C04B2235/79
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
120 words
A process for preparing a ceramic dielectric composition having a chemically homogeneous coating of secondary metal oxide or hydrous metal oxide components on the surface of a primary ceramic particle component comprising the steps of: (a) adding a stable solution of metal chelates to a slurry of fine particle of primary ceramic component with an aqueous solvent with agitation; (b) adding a strong base to said slurry with metal chelates of step (a) while maintaining a sufficient temperature for a sufficient time to decompose said metal chelates and to deposit a homogeneous coating of secondary metal oxide or hydrous metal oxides components on the surface of the primary ceramic particle component; and (c) recovering an washing the homogeneously coated particles.
Claim 2
Dependent Claim
120 words
A process for preparing a ceramic dielectric composition having a chemically homogeneous coating of secondary metal oxide or hydrous metal oxide components on the surface of a primary ceramic particle component comprising the steps of: (a) adding a stable solution of metal chelates to a slurry of fine particle of primary ceramic component with an aqueous solvent with agitation; (b) adding a strong base to said slurry with metal chelates of step (a) while maintaining a sufficient temperature for a sufficient time to decompose said metal chelates and to deposit a homogeneous coating of secondary metal oxide or hydrous metal oxides components on the surface of the primary ceramic particle component; and (c) recovering an washing the homogeneously coated particles.
Claim 3
Dependent Claim
37 words
The process of claim 1 wherein the primary ceramic component is of a formula ABO 3 wherein A is predominately an alkaline earth metal, lead or mixtures thereof, and B is predominately titanium, zirconium or mixtures thereof.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein the primary ceramic components comprise alumina, silica and silicates.
Claim 5
Dependent Claim
27 words
The process of claim 1 or claim 2 or claim 3 wherein the solution of metal chelates comprises metal compounds in a solvent with a chelating agent.
Claim 6
Dependent Claim
107 words
The process of claim 4 wherein the metal compounds are of the general formula, MXn, wherein M is a metal cation selected from magnesium, lead, titanium, zirconium, tin, niobium, tantalum, tungsten, antimony, bismuth, manganese, iron, cobalt, chromium, zinc, copper, neodymium, samarium, nickel, praseodymium, aluminum and mixtures thereof; X is an anion or a radical selected from HCO 2 -- , CH 3 CO 2 -- , 13 O 2 C--CO 2 -- , -- OH, --OR, -- NO 3 and -- Cl and mixtures thereof; and n is a whole number from 2 to 6 depending on the valence state of the metal cation, M +n .
Claim 7
Dependent Claim
45 words
The process of claim 1 or claim 4 wherein the solvent is selected from the group consisting essentially of deionized water or mixtures of deionized water and water miscible organic solvents, with the optional presence of a small amount of a wetting agent or surfactant.
Claim 8
Dependent Claim
36 words
The process of claim 4 wherein the chelating agent is selected from a group capable of forming soluble chelates with the metal cation after adjustment of the pH in the range of from 5 to 10.
Claim 9
Dependent Claim
22 words
The process of claim 7 wherein the chelating agent is selected from the group consisting essentially of alpha-hydroxycarboxylic acid or alpha-aminocarboxylic acid.
Claim 10
Dependent Claim
26 words
The process of claim 8 wherein the alpha-hydroxycarboxylic acid is selected from the group consisting essentially of glycolic acid, lactic acid, malic acid and citric acid.
Claim 11
Dependent Claim
47 words
The process of claim 4 wherein the pH of the solution of metal chelates is adjusted to a value in the range of from 5 to 10 by adding a base selected from the group consisting essentially of ammonium hydroxide, tetramethylammonium hydroxide, sodium hydroxide and potassium hydroxide.
Claim 12
Dependent Claim
25 words
The process of claim 1 wherein said slurry of fine particles of an aqueous ceramic powder in a solvent contains a small amount of silica.
Claim 13
Dependent Claim
36 words
The process of claim 1 wherein said strong base is selected from the group consisting essentially of potassium hydroxide and sodium hydroxide and the pH of the resulting mixture is adjusted to a value above 8.5
Claim 14
Dependent Claim
26 words
The process of claim 1 wherein the resulting mixture is heated in the range of 50° C. and the reflux temperature for 1 to 8 hours.
Claim 15
Dependent Claim
36 words
A process for preparing dielectric powder compositions comprising particles of ceramic powder by distributing a mixture of secondary metal oxide or hydrous metal oxide components surface of the particles to form a chemically homogeneous coating layer.
Claim 16
Dependent Claim
36 words
A process for preparing dielectric powder compositions comprising particles of ceramic powder by distributing a mixture of secondary metal oxide or hydrous metal oxide components surface of the particles to form a chemically homogeneous coating layer.
Claim 17
Dependent Claim
22 words
The process of claim 1 wherein said recovering and washing of homogeneously coated particles further comprises: (d) drying said homogeneously coated particles.
Claim 18
Dependent Claim
15 words
The process of claim 15 further comprising the step of calcining said homogeneously coated particles.
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) | 1995-01-20 | 1995-07-22 | 1996-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-20 | 1999-07-22 | 2000-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-20 | 2003-07-22 | 2004-01-21 | $7700.00 | Window Closed / Lapsed |