US6328894B1
Expired / Lapsed
US
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Processes of purifying a dispersion and making inkjet inks
Assignee: Cabot Corp
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Filing: 1999-01-29
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Granted: 2001-12-11
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Expires: 2019-01-29
Abstract
Abstract A process to purify and classify a dispersion containing stabilized particles having counterions and ions as well as free species is disclosed. The solution may comprise an aqueous media, a solvent media, or a combination of both and can include more than one type of aqueous and/or solvent solutions. The process includes at least the steps, in any order, of substantially removing the particles having sizes above about 1 micron, preferably above 0.5 micron; substantially removing the free species; and exchanging at least a portion of the counterions that are a part of the stabilized particles. The process disclosed is especially useful in purifying dispersions where the ionic stabilized colloidal particles are carbon black having attached organic groups comprising at least one ionic group, or at least one ionizable group, or mixtures thereof.
Inventors
- 👤 Michael K. Chan
- 👤 Joseph E. Johnson
- 👤 John Mathew
- 👤 Friedrich K. von Gottberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:37
CPC Classifications
C; C09; C09D; C09D11/00; C09D11/30; C09D11/32; C09D11/324; Y; Y10; Y10S; Y10S516/00; Y10S516/921
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
81 words
A process to purify a dispersion comprising a) ionic stabilized colloidal particles having cations and anions, wherein either the cations or anions are counterions, and b) free species in a solution, said process comprising, in any order, the following steps: (a) substantially removing particles having a particle size above about 1 micron; (b) substantially removing the free species; and (c) exchanging at least a portion of said counterions that form a part of the ionic stabilized colloidal particles with alternate counterions.
Claim 2
Dependent Claim
81 words
A process to purify a dispersion comprising a) ionic stabilized colloidal particles having cations and anions, wherein either the cations or anions are counterions, and b) free species in a solution, said process comprising, in any order, the following steps: (a) substantially removing particles having a particle size above about 1 micron; (b) substantially removing the free species; and (c) exchanging at least a portion of said counterions that form a part of the ionic stabilized colloidal particles with alternate counterions.
Claim 3
Dependent Claim
22 words
The process of claim 1 , wherein particles having a particle size above about 0.5 micron are substantially removed in step (a).
Claim 4
Dependent Claim
13 words
The process of claim 1 , wherein step (a) is accomplished by centrifugation.
Claim 5
Dependent Claim
20 words
The process of claim 3 , wherein said centrifugation occurs at a centrifugal force of at least about 5,000 Gs.
Claim 6
Dependent Claim
20 words
The process of claim 3 , wherein said centrifugation occurs at a G force of at least about 15,000 Gs.
Claim 7
Dependent Claim
22 words
The process of claim 3 , wherein said centrifugation occurs at a G force of from about 15,000 to about 20,000 Gs.
Claim 8
Dependent Claim
13 words
The process of claim 3 , wherein said centrifugation is a solid-bowl centrifugation.
Claim 9
Dependent Claim
13 words
The process of claim 3 , wherein said centrifugation is a tubular-bow centrifugation.
Claim 10
Dependent Claim
15 words
The process of claim 3 , wherein said centrifugation is with a semi-continuous feed rate.
Claim 11
Dependent Claim
18 words
The process of claim 9 wherein said feed rate is from about 500 ml/min to about 10 L/min.
Claim 12
Dependent Claim
14 words
The process of claim 3 , wherein said centrifugation is conducted at ambient temperatures.
Claim 13
Dependent Claim
13 words
The process of claim 3 , wherein said centrifugation includes a recirculating bath.
Claim 14
Dependent Claim
23 words
The process of claim 3 wherein said dispersion during said centrifugation has a viscosity of from about 1 cP to about 8 cP.
Claim 15
Dependent Claim
16 words
The process of claim 1 , wherein step (a) occurs before the steps (b) and (c).
Claim 16
Dependent Claim
16 words
The process of claim 1 , wherein step (a) occurs after step (b) or step (c).
Claim 17
Dependent Claim
20 words
The process of claim 1 , wherein step (a), step (b) or step (c) is repeated one or more times.
Claim 18
Dependent Claim
13 words
The process of claim 1 , wherein step (a) is accomplished by filtration.
Claim 19
Dependent Claim
28 words
The process of claim 17 , wherein said filtration uses one or more filters having a pore size of from about 0. 1 microns to about 100 microns.
Claim 20
Dependent Claim
26 words
The process of claim 17 , wherein said filtration has a flow rate of from about 0.14 L/m 2 s to about 0.47 L/m 2 s.
Claim 21
Dependent Claim
18 words
The process of claim 1 , wherein step (b) is accomplished by ultrafiltration or diafiltration having a membrane.
Claim 22
Dependent Claim
18 words
The process of claim 20 , wherein said membrane has a molecular weight cutoff of at least 10,000.
Claim 23
Dependent Claim
20 words
The process of claim 21 , wherein said membrane has a molecular weight cutoff from about 10,000 to about 50,000.
Claim 24
Dependent Claim
22 words
The process of claim 20 , wherein said membrane has a channel size of from about 0.5 mm to about 1.5 mm.
Claim 25
Dependent Claim
22 words
The process of claim 20 , wherein said membrane has a permeate flux of at least about 5 gal./ft 2 per day.
Claim 26
Dependent Claim
24 words
The process of claim 20 , wherein said membrane has a permeate flux of from about 5 to about 30 gal./ft 2 per day.
Claim 27
Dependent Claim
26 words
The process of claim 20 , wherein said membrane has a sufficient surface area to substantially remove the free ionic species in one or more passes.
Claim 28
Dependent Claim
16 words
The process of claim 20 , wherein said ultrafiltration or diafiltration is a cross-flow membrane separation.
Claim 29
Dependent Claim
12 words
The process of claim 1 , wherein said colloidal particles are pigments.
Claim 30
Dependent Claim
12 words
The process of claim 28 , wherein said pigments are carbon pigments.
Claim 31
Dependent Claim
23 words
The process of claim 29 , wherein said carbon pigments are carbon black, graphite, vitreous carbon, activated charcoal, activated carbon, or mixtures thereof.
Claim 32
Dependent Claim
15 words
The process of claim 30 , wherein said carbon black has an attached organic group.
Claim 33
Dependent Claim
20 words
The process of claim 31 , wherein said organic group comprises an aromatic group directly attached to said carbon black.
Claim 34
Dependent Claim
178 words
The process of claim 32 , wherein said organic group is selected from the group consisting of: —C 6 H 4 —COO − X + ; —C 6 H 4 —SO 3 − X + ; —C 6 H 2 —(COO − X + ) 3 ; —C 6 H 3 —(COO − X + ) 2 ; —C 6 H 3 —(CF 3 ) 2 ; —C 6 H 4 —(CF 3 ); —(CH 2 ) z —(COO − X + ); —C 6 H 4 —(CH 2 ) z —(COO − X + ); —C 6 H 4 —(NC 5 H 5 ) + Y − , and combinations thereof, wherein X is a cation selected from the group consisting of Na + , H + , K + , NH 4 + , Li + , Ca 2+ , and Mg 2+ , z is an integer from 1 to 18, and Y is an anion selected from the group consisting of NO 3 − , OH − , and CH 3 COO − .
Claim 35
Dependent Claim
21 words
The process of claim 1 , wherein said counterions are Na + and said alternate counterions are NH 4 + .
Claim 36
Dependent Claim
13 words
The process of claim 1 , wherein said solution is an aqueous solution.
Claim 37
Dependent Claim
16 words
The process of claim 1 , wherein step (c) is accomplished by an ion exchange process.
Claim 38
Dependent Claim
18 words
The process of claim 1 , wherein step (c) is accomplished by a modified three compartment electrodialysis process.
Claim 39
Dependent Claim
57 words
A process for purifying and classifying an ink dispersion comprising a) stabilized colloidal particles having cations and anions and b) free species in a solution comprising the following steps: (a) substantially removing the free species by ultrafiltration or diafiltration having a membrane; and (b) substantially removing particles having a particle size above about 0.5 micron by centrifugation.
Claim 40
Dependent Claim
57 words
A process for purifying and classifying an ink dispersion comprising a) stabilized colloidal particles having cations and anions and b) free species in a solution comprising the following steps: (a) substantially removing the free species by ultrafiltration or diafiltration having a membrane; and (b) substantially removing particles having a particle size above about 0.5 micron by centrifugation.
Claim 41
Dependent Claim
37 words
The process of claim 38 , wherein said dispersion is subject to the further step of exchanging at least a portion of said counterions that form a part of the ionic stabilized colloidal particles with alternate counterions.
Claim 42
Dependent Claim
21 words
The process of claim 39 , wherein said counterions are Na + and said alternate counterions are NH 4 + .
Claim 43
Dependent Claim
28 words
The process of claim 38 wherein, substantially all of the particles in said dispersion having a particle size above about 1 micron are removed prior to step (a).
Claim 44
Dependent Claim
13 words
The process of claim 41 , wherein, said particles are removed by centrifugation.
Claim 45
Dependent Claim
12 words
The process of claim 38 , wherein said colloidal particles are pigments.
Claim 46
Dependent Claim
12 words
The process of claim 43 , wherein said pigments are carbon black.
Claim 47
Dependent Claim
15 words
The process of claim 44 , wherein said carbon black has an attached organic group.
Claim 48
Dependent Claim
178 words
The process of claim 45 , wherein said organic group is selected from the group consisting of: —C 6 H 4 —COO − X + ; —C 6 H 4 —SO 3 − X + ; —C 6 H 2 —(COO − X + ) 3 ; —C 6 H 3 —(COO − X + ) 2 ; —C 6 H 3 —(CF 3 ) 2 ; —C 6 H 4 —(CF 3 ); —(CH 2 ) z —(COO − X + ); —C 6 H 4 —(CH 2 ) z —(COO − X + ); —C 6 H 4 —(NC 5 H 5 ) + Y − , and combinations thereof, wherein X is a cation selected from the group consisting of Na + , H + , K + , NH 4 + , Li + , Ca 2+ , and Mg 2+ , z is an integer from 1 to 18, and Y is an anion selected from the group consisting of NO 3 − , OH − , and CH 3 COO − .
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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) | 2004-12-10 | 2005-06-11 | 2005-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-12-10 | 2009-06-11 | 2009-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-12-10 | 2013-06-11 | 2013-12-11 | $7700.00 | Window Closed / Lapsed |