US4820681A
Expired / Lapsed
US
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Preparation of hydrophobic carbon molecular sieves
Assignee: Honeywell International Inc
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Filing: 1987-12-24
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Granted: 1989-04-11
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Expires: 2007-12-24
Abstract
Abstract A method is described for producing hydrophobic carbon molecular sieves. The method does not employ a binder to form or shape previously carbonized materials. Instead, a cross-linked oxygen-free polymer is first produced. Fine particles of this polymer are then pelletized or shaped as by simple extrusion. The extruded pellets are then carbonized in an oxygen-free atmosphere to yield binderless homogeneous particles of similar shape comprised of carbon sieves.
Inventors
- 👤 Chin-Hsiung Chang
- 👤 Gary J. Seminara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:58
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
98 words
A method of producing shaped products comprising a homogeneous hydrophobic molecular sieve material which comprises the steps: (a) performing a bulk or solution polymerization of an oxygen-free monomer in the presence of 0.5-0.9 wt. percent of an oxygen-free cross-linking agent, and producing free flow granules of a cross-linked polymer; (b) producing shaped articles from a quantity of said granules without a binder material; and, (c) carbonizing the resultant shaped articles in an oxygen-free environment in the presence of an inert gas into shaped products having a density of 0.7-1.05 gm/ml and an average pore volume of 0.4-0.8 cc/gm.
Claim 2
Independent Claim
98 words
A method of producing shaped products comprising a homogeneous hydrophobic molecular sieve material which comprises the steps: (a) performing a bulk or solution polymerization of an oxygen-free monomer in the presence of 0.5-0.9 wt. percent of an oxygen-free cross-linking agent, and producing free flow granules of a cross-linked polymer; (b) producing shaped articles from a quantity of said granules without a binder material; and, (c) carbonizing the resultant shaped articles in an oxygen-free environment in the presence of an inert gas into shaped products having a density of 0.7-1.05 gm/ml and an average pore volume of 0.4-0.8 cc/gm.
Claim 3
Dependent Claim
14 words
The method of claim 1 further characterized in that the monomer is vinylidene chloride.
Claim 4
Dependent Claim
29 words
The method of claim 1 further characterized in that the article is held at a temperature above 800 degrees C. for at least one hour during the carbonization step.
Claim 5
Dependent Claim
25 words
The method of claim 3 further characterized in that the weight of the article is reduced by at least 60 percent during the carbonization step.
Claim 6
Dependent Claim
14 words
The method of claim 3 further characterized in that the monomer comprises a halogen.
Claim 7
Dependent Claim
16 words
The method of claim 4 further characterized in that the monomer is a vinyl chloride monomer.
Claim 8
Dependent Claim
17 words
The method of claim 4 further characterized in that divinyl benzene is employed as the cross-linking agent.
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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) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |