US4020271A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crosslinked phosphonoalkyl cellulose and absorbent devices incorporating same
Assignee: Personal Products Co
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Filing: 1975-01-13
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Granted: 1977-04-26
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Expires: 1995-01-13
Abstract
Abstract Alkali metal and ammonium salts of crosslinked phosphonoalkyl cellulose are described which have a phosphorous content of from about 1.5% to about 4.0% by weight and a degree of crosslinking sufficient to make the modified cellulose salts essentially insoluble in aqueous media. These crosslinked phosphonoalkyl cellulose salts have significantly increased fluid absorption capacities as compared to unmodified cellulose and may be incorporated alone or in combination with other absorbent materials into catamenial tampons, sanitary napkins, diapers, and like absorbent devices.
Inventors
- 👤 Pronoy Kumar Chatterjee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:22
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/02; C08B11/04; C08B11/10; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/28; Y; Y10; Y10S; Y10S604/00; Y10S604/904
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
67 words
A crosslinked phosphonoalkyl cellulose having a degree of crosslinking sufficient to make said cellulose essentially insoluble in aqueous media, said cellulose containing ##STR3## groups wherein R is an alkylene radical of no more than 5 carbon atoms and wherein M is a member selected from the group consisting of alkali metal ions and ammonium ions, said cellulose containing from about 1.5% to about 4.0% phosphorous by weight.
Claim 2
Dependent Claim
67 words
A crosslinked phosphonoalkyl cellulose having a degree of crosslinking sufficient to make said cellulose essentially insoluble in aqueous media, said cellulose containing ##STR3## groups wherein R is an alkylene radical of no more than 5 carbon atoms and wherein M is a member selected from the group consisting of alkali metal ions and ammonium ions, said cellulose containing from about 1.5% to about 4.0% phosphorous by weight.
Claim 3
Dependent Claim
23 words
A crosslinked phosphonoalkyl cellulose as described in claim 1 wherein R is a member selected from the group consisting of methylene and ethylene.
Claim 4
Dependent Claim
30 words
A crosslinked phosphonoalkyl cellulose as described in claim 2 which has a degree of crosslinking from about 0.005 to about 0.190 mole of crosslinking unit per mole of anhydroglucose unit.
Claim 5
Dependent Claim
15 words
A crosslinked phosphonoalkyl cellulose as described in claim 2 which is crosslinked by alkyleneoxy chains.
Claim 6
Dependent Claim
17 words
A crosslinked phosphonoalkyl cellulose as described in claim 1 wherein R is methylene and M is sodium.
Claim 7
Dependent Claim
18 words
A crosslinked phosphonomethyl cellulose as described in claim 5 wherein said cellulose contains about 2% phosphorous by weight.
Claim 8
Dependent Claim
31 words
A crosslinked phosphonomethyl cellulose as described in claim 5 which has a degree of crosslinking of from about 0.015 to about 0.110 mole of crosslinking unit per mole of anhydroglucose unit.
Claim 9
Dependent Claim
12 words
A crosslinked phosphonoalkyl cellulose as described in claim 1 which is fibrous.
Claim 10
Dependent Claim
12 words
A crosslinked phosphonoalkyl cellulose as described in claim 3 which is fibrous.
Claim 11
Dependent Claim
12 words
A crosslinked phosphonomethyl cellulose as described in claim 6 which is fibrous.
Claim 12
Dependent Claim
20 words
An absorbent product having an absorbent mass comprising at least about 10% of the crosslinked phosphonoalkyl cellulose of claim 1.
Claim 13
Dependent Claim
20 words
An absorbent product having an absorbent mass comprising at least about 5% of the crosslinked phosphonomethyl cellulose of claim 6.
Claim 14
Dependent Claim
20 words
An absorbent product having an absorbent mass comprising at least about 10% of the crosslinked phosphonomethyl cellulose of claim 6.
Claim 15
Dependent Claim
20 words
An absorbent product having an absorbent mass comprising at least about 5% of the crosslinked phosphonomethyl cellulose of claim 10.
Claim 16
Dependent Claim
15 words
A sanitary napkin comprising at least about 5% of the crosslinked phosphonoalkylcellulose of claim 1.
Claim 17
Dependent Claim
16 words
A sanitary napkin comprising at least about 5% of the crosslinked phosphonomethyl cellulose of claim 10.
Claim 18
Dependent Claim
15 words
A diaper comprising at least about 5% of the crosslinked phosphonoalkyl cellulose of claim 1.
Claim 19
Dependent Claim
15 words
A diaper comprising at least about 5% of the crosslinked phosphonomethyl cellulose of claim 10.
Claim 20
Dependent Claim
16 words
A catamenial tampon comprising at least about 5% of the crosslinked phosphonoalkyl cellulose of claim 1.
Claim 21
Dependent Claim
16 words
A catamenial tampon comprising at least about 5% of the crosslinked phosphonomethyl cellulose of claim 10.
Claim 22
Dependent Claim
100 words
An absorbent product having an absorbent mass comprising at least about 5% by weight crosslinked phosphonoalkyl cellulose having a degree of crosslinking sufficient to make said crosslinked phosphonoalkyl cellulose essentially insoluble in aqueous media, said crosslinked phosphonoalkyl cellulose containing ##STR4## groups wherein R is an alkylene radical of no more than 5 carbon atoms and wherein M is a member selected from the group consisting of alkali metal ions and ammonium ions, said crosslinked phosphonoalkyl cellulose containing from about 1.5% to about 4.0% phosphorous by weight, and said crosslinked phosphonoalkyl cellulose having significantly greater fluid absorption capacity than unmodified cellulose.
Claim 23
Dependent Claim
100 words
An absorbent product having an absorbent mass comprising at least about 5% by weight crosslinked phosphonoalkyl cellulose having a degree of crosslinking sufficient to make said crosslinked phosphonoalkyl cellulose essentially insoluble in aqueous media, said crosslinked phosphonoalkyl cellulose containing ##STR4## groups wherein R is an alkylene radical of no more than 5 carbon atoms and wherein M is a member selected from the group consisting of alkali metal ions and ammonium ions, said crosslinked phosphonoalkyl cellulose containing from about 1.5% to about 4.0% phosphorous by weight, and said crosslinked phosphonoalkyl cellulose having significantly greater fluid absorption capacity than unmodified cellulose.
Claim 24
Dependent Claim
100 words
An absorbent product having an absorbent mass comprising at least about 15% by weight crosslinked phosphonoalkyl cellulose having a degree of crosslinking sufficient to make said crosslinked phosphonoalkyl cellulose essentially insoluble in aqueous media, said crosslinked phosphonoalkyl cellulose containing ##STR5## groups wherein R is an alkylene radical of no more than 5 carbon atoms and wherein M is a member selected from the group consisting of alkali metal ions and ammonium ions, said crosslinked phosphonoalkyl cellulose containing from about 1.5% to about 4.0% phosphorous by weight, and said crosslinked phosphonoalkyl cellulose having significantly greater fluid absorption capacity than unmodified cellulose.
Claim 25
Dependent Claim
100 words
An absorbent product having an absorbent mass comprising at least about 15% by weight crosslinked phosphonoalkyl cellulose having a degree of crosslinking sufficient to make said crosslinked phosphonoalkyl cellulose essentially insoluble in aqueous media, said crosslinked phosphonoalkyl cellulose containing ##STR5## groups wherein R is an alkylene radical of no more than 5 carbon atoms and wherein M is a member selected from the group consisting of alkali metal ions and ammonium ions, said crosslinked phosphonoalkyl cellulose containing from about 1.5% to about 4.0% phosphorous by weight, and said crosslinked phosphonoalkyl cellulose having significantly greater fluid absorption capacity than unmodified cellulose.
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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) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |