Preparation of water-insoluble carboxymethyl cellulose absorbents
AssigneeInternational Playtex, Inc.
InventorsHerman L. Marder, Nathan D. Field, Makoto Shinohara
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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.
Claims7
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.degree. 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.
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.degree. 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.degree. to 165.degree. 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.
Dependencies are inferred from the claim text.