Patent US4280925A successfully refreshed from Google Patents.
US4280925A
Expired / Lapsed
US
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Filter for sorption of heavy metals
Assignee: Eastman Chemical Co
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Filing: 1980-06-30
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Granted: 1981-07-28
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Expires: 2000-06-30
Abstract
Abstract A hydrophilic, cellulose ester material that may be used as a filter or ion exchanger to sorb heavy metal ions, such as silver, mercury, lead, copper and cadmium, from aqueous solutions, the material having incorporated therein a high surface area zinc sulfide of at least 15 square meters per gram, and preferably at least 24 square meters per gram; and method for incorporating high surface area zinc oxide into a cellulose ester material by slurry process or solution process and converting the zinc oxide so incorporated into high surface area zinc sulfide; and product of the method.
Inventors
- 👤 John E. Kiefer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:37
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/28; B01J20/28054; B01J20/28057; B01J20/28059; B01J20/28014; B01J20/28023; C; C01; C01G; C01G9/00; C01G9/08; C02; C02F; C02F1/00; C02F1/28; C02F1/286; C02F1/288; C22; C22B; C22B3/00; C22B3/20; C22B3/42; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
52 words
The method of making a sorbent for heavy metals comprising: incorporating in a hydrophilic material a zinc sulfide having a high surface area of at least about 15 m 2 /g, said hydrophilic material being formed from a cellulose ester selected from cellulose acetate, cellulose butyrate, cellulose propionate or mixed esters thereof.
Claim 2
Independent Claim
52 words
The method of making a sorbent for heavy metals comprising: incorporating in a hydrophilic material a zinc sulfide having a high surface area of at least about 15 m 2 /g, said hydrophilic material being formed from a cellulose ester selected from cellulose acetate, cellulose butyrate, cellulose propionate or mixed esters thereof.
Claim 3
Dependent Claim
29 words
The method as defined in claim 1 wherein said zinc sulfide incorporated in said hydrophilic material has a high surface area of at least about 24 m 2 /g.
Claim 4
Dependent Claim
69 words
The method as defined in claim 1, wherein said high surface area zinc sulfide is incorporated in the amount of about 5% to about 10% by weight in said hydrophilic material by treating in such manner said hydrophilic material with a slurry comprising said zinc sulfide and a nonvolatile solvent for said hydrophilic material so that said zinc sulfide becomes encapsulated just within the surface of said hydrophilic material.
Claim 5
Dependent Claim
49 words
The method as defined in claim 3, wherein said high surface area zinc sulfide is formed from zinc oxide having a high surface area of at least about 15 m 2 /g by treating said zinc oxide with a sulfide to convert the zinc oxide into said zinc sulfide.
Claim 6
Dependent Claim
49 words
The method as defined in claim 3, wherein said high surface area zinc sulfide is formed from zinc oxide having a high surface area of at least about 24 m 2 /g by treating said zinc oxide with a sulfide to convert the zinc oxide into said zinc sulfide.
Claim 7
Dependent Claim
24 words
The method as defined in claim 4, wherein the sulfide in said sulfide treatment is selected from hydrogen sulfide, ammonium sulfide or sodium sulfide.
Claim 8
Dependent Claim
24 words
The method as defined in claim 5, wherein the sulfide in said sulfide treatment is selected from hydrogen sulfide, ammonium sulfide or sodium sulfide.
Claim 9
Dependent Claim
31 words
The method as defined in claim 3, wherein said nonvolatile solvent for said hydrophilic material is selected from triacetin, glycol esters, or phthalate esters that are plasticizers for said cellulose esters.
Claim 10
Dependent Claim
56 words
The method as defined in claim 1, wherein the high surface area zinc sulfide is incorporated in the amount of about 5% to about 10% by weight in said hydrophilic material by being introduced into a spinning solution comprising said cellulose ester and a volatile solvent for said cellulose ester, and then spinning said hydrophilic material.
Claim 11
Dependent Claim
23 words
The method as defined in claim 9, wherein said volatile solvent for said cellulose ester is selected from acetone, methylene chloride or chloroform.
Claim 12
Dependent Claim
47 words
The method as defined in claim 1, wherein said high surface area zinc sulfide is incorporated in said hydrophilic material by incorporating a zinc oxide having a high surface area of at least about 15 m 2 /g and then treating said zinc oxide with a sulfide.
Claim 13
Dependent Claim
24 words
The method as defined in claim 11, wherein the sulfide in said sulfide treatment is selected from hydrogen sulfide, ammonium sulfide or sodium sulfide.
Claim 14
Dependent Claim
37 words
The method as defined in claim 11, wherein said zinc oxide is incorporated in said hydrophilic material by treating said hydrophilic material with a slurry comprising said zinc oxide and a nonvolatile solvent for said hydrophilic material.
Claim 15
Dependent Claim
31 words
The method as defined in claim 13, wherein said nonvolatile solvent for said hydrophilic material is selected from triacetin, glycol esters, or phthalate esters that are plasticizers for said cellulose esters.
Claim 16
Dependent Claim
35 words
The method as defined in claim 11, wherein said zinc oxide is incorporated in a spinning solution comprising said cellulose ester and a volatile solvent for said cellulose ester, and then spinning said hydrophilic material.
Claim 17
Dependent Claim
23 words
The method as defined in claim 15, wherein said volatile solvent for said cellulose ester is selected from acetone, methylene chloride or chloroform.
Claim 18
Dependent Claim
18 words
A hydrophilic material for sorbing heavy metals and made in accordance with the method defined in claim 3.
Claim 19
Dependent Claim
18 words
A hydrophilic material for sorbing heavy metals and made in accordance with the method defined in claim 9.
Claim 20
Dependent Claim
18 words
A hydrophilic material for sorbing heavy metals and made in accordance with the method defined in claim 13.
Claim 21
Dependent Claim
18 words
A hydrophilic material for sorbing heavy metals and made in accordance with the method defined in claim 15.
Claim 22
Dependent Claim
54 words
A hydrophilic material for sorbing heavy metals comprising a material formed from a cellulose ester selected from cellulose acetate, cellulose butyrate, cellulose propionate or mixed esters thereof, and having incorporated therein about 5% to about 10% by weight a zinc sulfide having a high surface area of at least about 15 m 2 /g.
Claim 23
Dependent Claim
54 words
A hydrophilic material for sorbing heavy metals comprising a material formed from a cellulose ester selected from cellulose acetate, cellulose butyrate, cellulose propionate or mixed esters thereof, and having incorporated therein about 5% to about 10% by weight a zinc sulfide having a high surface area of at least about 15 m 2 /g.
Claim 24
Dependent Claim
29 words
A hydrophilic material as defined in claim 21, wherein said zinc sulfide incorporated in said material has a high surface area of at least about 24 m 2 /g.
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) | 1984-07-27 | 1985-01-26 | 1985-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-27 | 1989-01-26 | 1989-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-27 | 1993-01-26 | 1993-07-28 | $7700.00 | Window Closed / Lapsed |