Patent US4677082A successfully refreshed from Google Patents.
US4677082A
Expired / Lapsed
US
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Composition comprising ceramic particles
Assignee: Ceram Research Ltd
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Filing: 1985-11-14
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Granted: 1987-06-30
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Expires: 2005-11-14
Abstract
Abstract A homogeneous composition comprising (1) at least one particulate ceramic material, and (2) a liquid medium, in which the composition comprises at least 50% by volume of particulate ceramic material, in which the particulate ceramic material and liquid medium are selected such that a test composition has a friction coefficient of less than 0.2, and in which the particulate ceramic material has a mean aspect ratio of less than 1.70, a shaped article produced from the composition, a shaped article from which the liquid medium has been removed, and a product in which the particles of ceramic material have been sintered.
Inventors
- 👤 Neil M. Alford
- 👤 James D. Birchall
- 👤 Anthony J. Howard
- 👤 Kevin Kendall
- 👤 James H. Raistrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:06
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/626; C04B35/63; C04B35/632; C04B35/634; C04B35/63404; C04B35/63416
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
71 words
A homogeneous composition comprising (1) at least one particulate sinterable ceramic material, and (2) a liquid medium, in which the composition comprises at least 50% by volume of particulate ceramic material, in which the particulate ceramic material and liquid medium are selected such that a test composition has a friction coefficient of less than 0.2, and in which the particulate ceramic material has a mean aspect ratio of less than 1.70.
Claim 2
Dependent Claim
71 words
A homogeneous composition comprising (1) at least one particulate sinterable ceramic material, and (2) a liquid medium, in which the composition comprises at least 50% by volume of particulate ceramic material, in which the particulate ceramic material and liquid medium are selected such that a test composition has a friction coefficient of less than 0.2, and in which the particulate ceramic material has a mean aspect ratio of less than 1.70.
Claim 3
Dependent Claim
22 words
A homogeneous composition as claimed in claim 1 in which the particles of ceramic material have a size less than 5 microns.
Claim 4
Dependent Claim
22 words
A homogeneous composition as claimed in claim 2 in which the particles of ceramic material have a size less than 1 micron.
Claim 5
Dependent Claim
65 words
A homogeneous composition as claimed in claim 1 in which the coefficient of variation in the size of the particles of ceramic material, V s , lies in the range 0 to 0.5, where ##EQU4## where V s is the coefficient of variation of size, S s is the standard deviation about the mean size, and x s is the mean size of the particles.
Claim 6
Dependent Claim
24 words
A homogeneous composition as claimed in claim 4 in which the mean aspect ratio of the particles of ceramic material is less than 1.50.
Claim 7
Dependent Claim
72 words
A homogeneous composition as claimed in any one of claims 1, 2 or 4 in which the coefficient of variation in the aspect ratio of the particles of ceramic material, V a , lies in the range 0 to 0.5, where ##EQU5## where V a is the coefficient of variation of aspect ratio, S a is the standard deviation about the mean aspect ratio, and x a is the mean aspect ratio.
Claim 8
Dependent Claim
18 words
A homogeneous composition as claimed in claim 1 in which the liquid medium is liquid at ambient temperature.
Claim 9
Dependent Claim
17 words
A homogeneous composition as claimed in claim 7 in which the liquid medium is an aqueous medium.
Claim 10
Dependent Claim
26 words
A homogeneous composition as claimed in claim 8 in which the liquid medium comprises a solution or dispersion of an organic polymeric material in a liquid.
Claim 11
Dependent Claim
27 words
A homogeneous composition as claimed in claim 9 in which the liquid medium comprises an aqueous solution of a hydrolysed polymer or copolymer of a vinyl ester.
Claim 12
Dependent Claim
39 words
A homogeneous composition as claimed in claim 10 in which the hyrolysed polymer or copolymer of a vinyl ester is a hydrolysed polymer or copolymer of vinyl acetate having a degree of hydrolysis in the range 70% to 90%.
Claim 13
Dependent Claim
35 words
A homogeneous composition as claimed in any one of claims 9, 10 or 11 in which the concentration of organic polymeric material in the liquid medium is in the range 5% to 60% by volume.
Claim 14
Dependent Claim
16 words
A homogeneous composition as claimed in claim 8 in which the liquid medium comprises a surfactant.
Claim 15
Dependent Claim
28 words
A homogeneous composition as claimed in claim 1 in which the particulate ceramic material comprises an oxide or a mixture of oxides of a metallic or non-metallic element.
Claim 16
Dependent Claim
25 words
A homogeneous composition as claimed in claim 14 in which the particulate ceramic material is selected from an oxide of aluminium, silicon, titanium an zirconium.
Claim 17
Dependent Claim
22 words
A homogeneous composition as claimed in any one of claims 1 to 13 in which the particulate ceramic material comprises silicon carbide.
Claim 18
Dependent Claim
25 words
A homogeneous composition as claimed in any one of claims 1, 2 or 4 which comprises more than 60% by volume of particulate ceramic material.
Claim 19
Dependent Claim
23 words
A homogeneous composition as claimed in any one of claims 1, 2 or 4 in which the friction coefficient is less than 0.10.
Claim 20
Dependent Claim
17 words
A homogeneous composition as claimed in claim 1 in which the friction coefficient is less than 0.05.
Claim 21
Dependent Claim
11 words
A shaped article of a composition as claimed in claim 1.
Claim 22
Dependent Claim
19 words
A shaped article as claimed in claim 20 from which the liquid of the liquid medium has been removed.
Claim 23
Dependent Claim
16 words
A shaped article as claimed in claim 21 from which the liquid medium has been removed.
Claim 24
Dependent Claim
21 words
A product in which the particles of ceramic material in a shaped article as claimed in claim 22 have been sintered.
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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) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |