Patent US5077241A successfully refreshed from Google Patents.
US5077241A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sol gel-derived ceramic bubbles
Assignee: 3M Co
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Filing: 1988-11-17
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Granted: 1991-12-31
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Expires: 2008-11-17
Abstract
Abstract Discrete, free-flowing, ceramic microbubbles consist essentially of at least one of a non-oxide component and an oxide component having diameters in the range of 1 to 300 micrometers and each having a wall thickness of less than 10 percent of the diameter of the bubble. In the process of the invention, a sol precursor and a suitable liquid, referred to as a bloating agent, when added to a bubble promoting medium under proper conditions, provide green gelled microbubbles which after firing are ceramic microbubbles having wall thicknesses less than 10 percent of the diameter of the bubbles. The microbubbles are non-vitreous, sol-gel derived, fine microstructured, uniform, hollow, smooth, and are either essentially all oxide or non-oxide or combinations of both.
Inventors
- 👤 Kyung H. Moh
- 👤 Harold G. Sowman
- 👤 Thomas E. Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:17
CPC Classifications
C; C04; C04B; C04B35/00; C04B38/00; C04B38/009; B; B01; B01J; B01J2/00; B01J2/02; B01J2/06; B01J2/08
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
92 words
A method of preparing green microbubbles comprising the steps of: a) adding droplets of a mixture comprising at least one of an oxide and a non-oxide sol precursor and a volatile liquid bloating agent, said sol precursor and bloating agent being miscible, to a bubble promoting medium, said bubble promoting medium being maintained at a temperature in the range of 50° to 150° C., said bloating agent having a boiling point below the temperature of the bubble promoting medium to provide green, hollow, gas-filled microbubbles, and b) isolating the resulting green microbubbles.
Claim 2
Independent Claim
92 words
A method of preparing green microbubbles comprising the steps of: a) adding droplets of a mixture comprising at least one of an oxide and a non-oxide sol precursor and a volatile liquid bloating agent, said sol precursor and bloating agent being miscible, to a bubble promoting medium, said bubble promoting medium being maintained at a temperature in the range of 50° to 150° C., said bloating agent having a boiling point below the temperature of the bubble promoting medium to provide green, hollow, gas-filled microbubbles, and b) isolating the resulting green microbubbles.
Claim 3
Dependent Claim
19 words
The method according to claim 1 further comprising the step of firing said green microbubbles to provide ceramic microbubbles.
Claim 4
Dependent Claim
20 words
The method according to claim 2 wherein said firing step takes place in the presence of an agglomeration preventative agent.
Claim 5
Dependent Claim
21 words
The method according to claim 2 wherein said ceramic microbubbles comprise at least one of oxide- and non-oxide phases or components.
Claim 6
Dependent Claim
25 words
The method according to claim 2 wherein said bloating agent has a boiling point in the range of 25° to 100° C. at atmospheric pressure.
Claim 7
Dependent Claim
25 words
The method according to claim 5 wherein said bloating agent is selected from the group consisting of halocarbons, aldehydes, alcohols, ethers, ketones, and combinations thereof.
Claim 8
Dependent Claim
27 words
The method according to claim 2 wherein said bloating agent is selected from the group consisting of 1) acetone, and 2) 1/1 vol/vol liquid halocarbon and methanol.
Claim 9
Dependent Claim
34 words
The method according to claim 2 wherein said bubble promoting medium is selected from the group consisting of esters of long chain fatty acids and derivatives thereof and long chain alcohols and combinations thereof.
Claim 10
Dependent Claim
15 words
The method according to claim 8 wherein said bubble promoting medium comprises a vegetable oil.
Claim 11
Dependent Claim
14 words
The method according to claim 8 wherein said bubble promoting medium comprises oleyl alcohol.
Claim 12
Dependent Claim
15 words
The method according to claim 3 wherein said agglomeration preventative agent is a carbon-containing material.
Claim 13
Dependent Claim
26 words
The method according to claim 2 wherein said firing step takes place in an atmosphere selected from the group consisting of reducing, inert, and oxygen-containing atmospheres.
Claim 14
Dependent Claim
25 words
The method according to claim 12 wherein said firing step takes place in an atmosphere at a pressure in the range of sub-atmospheric to super-atmospheric.
Claim 15
Dependent Claim
18 words
The method according to claim 1 wherein said temperature is in the range of 90° to 97° C.
Claim 16
Dependent Claim
18 words
The method according to claim 2 wherein said firing step takes place at a temperature above 400° C.
Claim 17
Dependent Claim
72 words
Free-flowing, discrete ceramic microbubbles consisting essentially of 1) a non-oxide component selected from metal nitrides and metal carbides or 2) said non-oxide component in combination with a metal oxide component, each microbubble having a fine microstructured ceramic wall and a single central gas-filled cavity, said microbubbles having a diameter in the range of 1 to 300 micrometers and a wall thickness of less than 10 percent of the diameter of the microbubbles.
Claim 18
Dependent Claim
72 words
Free-flowing, discrete ceramic microbubbles consisting essentially of 1) a non-oxide component selected from metal nitrides and metal carbides or 2) said non-oxide component in combination with a metal oxide component, each microbubble having a fine microstructured ceramic wall and a single central gas-filled cavity, said microbubbles having a diameter in the range of 1 to 300 micrometers and a wall thickness of less than 10 percent of the diameter of the microbubbles.
Claim 19
Dependent Claim
25 words
The microbubbles according to claim 16 wherein said non-oxide component and oxide components are present in the range of 95:5 to 5:95 parts by weight.
Claim 20
Dependent Claim
14 words
The microbubbles according to claim 16 which are essentially 100 weight percent non-oxide containing.
Claim 21
Dependent Claim
12 words
The microbubbles according to claim 16 wherein said walls are fully dense.
Claim 22
Dependent Claim
13 words
The microbubbles according to claim 16 wherein said microbubble cavities contain a gas.
Claim 23
Dependent Claim
17 words
The microbubbles according to claim 20 wherein said gas is an inert or reducing gas or air.
Claim 24
Dependent Claim
12 words
The microbubbles according to claim 16 wherein said cavities contain a vacuum.
Claim 25
Dependent Claim
23 words
The microbubbles according to claim 16 wherein said ceramic walls are selected from the group consisting of aluminum-, titanium-, zirconium-, and silicon-containing ceramics.
Claim 26
Dependent Claim
25 words
The microbubbles according to claim 16 wherein said ceramic comprises a metal oxide and at least one of a metal nitride and a metal carbide.
Claim 27
Dependent Claim
10 words
The microbubbles according to claim 16 which are electrically conductive.
Claim 28
Dependent Claim
9 words
A shaped article comprising microbubbles according to claim 16.
References Cited (Backward Citations)
US2978340A
Cited
US3709706A
Cited
US3792136A
Cited
US3975194A
Cited
US4039480A
Cited
US4290847A
Cited
US4349456A
Cited
US4637990A
Cited
US4777154A
Cited
US4279632A
Cited
US4421562A
Cited
US4772511A
Cited
JPS62191426A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |