US4200737A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of water-insoluble carboxymethyl cellulose absorbents
Assignee: International Playtex Inc
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Filing: 1978-05-17
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Granted: 1980-04-29
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Expires: 1998-05-17
Abstract
Abstract A process for the preparation of substantially water-insoluble, particulate sodium carboxymethyl cellulose, suitable for use as an absorbent in tampons and other catamenial devices, or the like. The process involves treating solid, water-soluble sodium carboxymethyl cellulose having a degree of substitution of at least 0.4 with hydrogen chloride gas and heating the carboxymethyl cellulose, either after the hydrogen chloride treatment or concurrently therewith, to produce a cross-linked, insoluble, partially acid form carboxymethyl cellulose suitable for absorbent applications.
Inventors
- 👤 Herman L. Marder
- 👤 Nathan D. Field
- 👤 Makoto Shinohara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:04
CPC Classifications
C; C08; C08B; C08B15/00; C08B15/005; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/28; C08B11/00; C08B11/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
69 words
A process for the preparation of substantially water-insoluble, particulate carboxymethyl cellulose, which comprises treating a solid, water-soluble particulate sodium carboxymethyl cellulose having a degree of substitution of at least 0.4 with hydrogen chloride gas, and heating the carboxymethyl cellulose at temperatures in excess of 100° C. to convert the same to a partially acid form, cross-linked and substantially insolubilized material exhibiting a swell ratio of from 5 to 50.
Claim 2
Dependent Claim
69 words
A process for the preparation of substantially water-insoluble, particulate carboxymethyl cellulose, which comprises treating a solid, water-soluble particulate sodium carboxymethyl cellulose having a degree of substitution of at least 0.4 with hydrogen chloride gas, and heating the carboxymethyl cellulose at temperatures in excess of 100° C. to convert the same to a partially acid form, cross-linked and substantially insolubilized material exhibiting a swell ratio of from 5 to 50.
Claim 3
Dependent Claim
46 words
The process of claim 1, wherein the sodium carboxymethyl cellulose is heated at temperatures of up to 200° C. to convert the same to a partially acid form having a degree of acidification of as much as 80% and an extractables content of less than 40%.
Claim 4
Dependent Claim
49 words
The process of claim 1, wherein the solid sodium carboxymethyl cellulose is initially contacted by the hydrogen chloride gas at temperatures of up to 100° C. and the thus partially acidified particulate material is thereafter heated to temperatures of from 105°to 200° C. to cross-link and insolubilize the same.
Claim 5
Dependent Claim
61 words
The process of claim 3, wherein the soluble sodium carboxymethyl cellulose reacted has a degree of substitution of from 0.5 to 1.2 and the insoluble partially acid form carboxymethyl cellulose produced has a degree of acidification of from 1 to 30 percent and exhibits a swell ratio of from 5 to 40 and a percent extractables of less than 35 percent.
Claim 6
Dependent Claim
40 words
The process of claim 1, wherein the sodium carboxymethyl cellulose is simultaneously contacted by the hydrogen chloride gas and heated to temperatures of from 105° to 200° C. to produce the cross-linked, insolubilized partially acid form sodium carboxymethyl cellulose product.
Claim 7
Dependent Claim
61 words
The process of claim 5, wherein the soluble sodium carboxymethyl cellulose reacted has a degree of substitution of from 0.5 to 1.2 and the insoluble partially acid form carboxymethyl cellulose produced has a degree of acidification of from 1 to 30 percent and exhibits a swell ratio of from 5 to 40 and a percent extractables of less than 35 percent.
Claim 8
Dependent Claim
111 words
A process for the preparation of substantially water-insoluble particulate carboxymethyl cellulose, which comprises treating a solid, water-soluble particulate sodium carboxymethyl cellulose having a degree of substitution of from 0.5 to 1.2 with hydrogen chloride gas at a temperature of up to 100° C. to convert the same to a partially acid form carboxymethyl cellulose having a degree of acidification of from 1 to 30 percent; and thereafter heating the carboxymethyl cellulose at temperatures of from 125° to 165° C. to convert the same to a partially acid form, cross-linked and substantially insolubilized material exhibiting a swell ratio of from 5 to 40 and an extractables content of less than 35 percent.
Claim 9
Dependent Claim
111 words
A process for the preparation of substantially water-insoluble particulate carboxymethyl cellulose, which comprises treating a solid, water-soluble particulate sodium carboxymethyl cellulose having a degree of substitution of from 0.5 to 1.2 with hydrogen chloride gas at a temperature of up to 100° C. to convert the same to a partially acid form carboxymethyl cellulose having a degree of acidification of from 1 to 30 percent; and thereafter heating the carboxymethyl cellulose at temperatures of from 125° to 165° C. to convert the same to a partially acid form, cross-linked and substantially insolubilized material exhibiting a swell ratio of from 5 to 40 and an extractables content of less than 35 percent.
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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) | 1983-04-29 | 1983-10-29 | 1984-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-29 | 1987-10-29 | 1988-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-29 | 1991-10-29 | 1992-04-29 | $7700.00 | Window Closed / Lapsed |