Abstract: A method for oven drying chemically modified cellulosic materials, especially fibers, having improved fluid absorbency involves incorporating into the cellulose structure while swollen an amphiphilic compound miscible with water which will not evaporate when the fiber is oven dried and will remain in the fiber to prevent collapse of the fiber as the water is removed. The improved method of drying the fibrous cellulosic material produces a product having saline absorbency about equal to that produced when the fibers are dried with a water-miscible solvent and avoids the use of volatile solvents and the disadvantages inherent therewith. The fibers provided by the invention are especially suitable for use in pads which are to be used for absorbing water and body fluids.

Abstract: An absorbent cellulose material is disclosed which comprises a substituted cellulose having an average degree of substitution sufficiently low to render the material insoluble and in which the fibers have an increased surface area formed by bursting the fibers during drying. In addition, a method of manufacturing such absorbent material is also disclosed which comprises providing an insoluble substituted cellulose material having an average degree of substitution sufficiently low to render the material insoluble, swelling the material to its maximum swelled state, fixing the material in that state, and drying the material while maintaining the material in its swelled state to thereby prevent shrinkage of the material during drying and to cause the fibers to burst during drying.

Abstract: This invention relates to a process for preparing swellable cross-linked carboxyalkylcelluloses by reacting cellulose, a carboxyalkylating etherifying agent, and a cross-linking agent in an aqueous alkaline medium, comprising effecting alkalizing, etherifying, and cross-linking simultaneously in one reaction step using fibers, textile sheet materials containing these fibers, or sheet materials of other kinds, having a base of cellulose hydrate or of natural cellulose, by contacting said fibers or sheet materials with an ample quantity of an aqueous alkaline reaction mixture, removing part of the reaction mixture from the fibers or sheet materials contacted therewith, so that at least the quantity required for reaction is still present, and treating the fibers or sheet materials containing the remainder of the aqueous alkaline reaction mixture with heat energy. The invention also relates to equipment for performing the process.

Abstract: This invention relates to a process for preparing swellable cross-linked carboxyalkylcelluloses in the form of fibers, by reacting cellulose, a carboxyalkylating etherifying agent, and a cross-linking agent in an aqueous alkaline medium, comprising effecting alkalizing, etherifying, and cross-linking simultaneously in one reaction step using fibers of cellulose hydrate or fiber-based textile sheet materials which contain these fibers, by contacting said fibers or textile sheet materials which contain these fibers with an ample quantity of an aqueous alkaline reaction mixture, removing part of the reaction mixture from the fibers or the textile sheet materials contacted therewith, so that at least the quantity required for reaction is still present, and treating the fibers or the textile sheet materials containing the remainder of the aqueous alkaline reaction mixture with heat energy.

Abstract: Cellulose ethers containing an amount of hydroxypropyl, hydroxyethyl, or methyl radicals such that they are normally water soluble are further modified with C.sub.12 to C.sub.24 hydrocarbon radicals to a level at which they are water insoluble. These modified ethers are soluble in surfactants and effect substantial viscosity increases in solutions of surfactants. They also are highly effective emulsifiers in aqueous systems.

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.

Abstract: A process for the preparation of a substantially water-insoluble, particulate sodium salt of carboxymethyl cellulose, suitable for use as an absorbent in tampons and other catamenial devices or the like. The process involves heating solid, water-soluble sodium carboxymethyl cellulose, having a degree of substitution of at least 0.4, with carbon dioxide gas to substantially insolubilize the carboxymethyl cellulose and convert it to a form suitable for absorbent applications.

Abstract: The invention relates to a novel water insoluble hydroxyalkylated cross-linked regenerated cellulose and a method for its preparation. The product is characterized by having outstanding swelling characteristics and high chemical reactivity. A method of preparing the product using near stoichiometric proportions of reagents is described. Use of the product directly in gel chromatography and as an intermediate in the preparation of ion exchangers is described.

Abstract: This invention comprises a gas-permeable contact lens consisting essentially of a plasticized cellulose resin selected from a partially esterified or partially etherified cellulose polymer plasticized with a compatible plasticizer in an amount sufficient to increase the gas permeability of the cellulose resin.

Abstract: A water-repellent cellulose and articles comprising the water-repellent cellulose are disclosed together with a process and apparatus for preparing the same. The water-repellent cellulose is prepared by exposing one or more sides and edges of a cellulose sheet, pad, or cloth to aliphatic acid chloride vapors. The resulting product is water-repellent along the treated sides and edges and, in general, water-permeable along the untreated sides and edges. Therefore, the treated cellulose products of this invention are especially suitable for disposable articles of sanitary clothing, sanitary napkins, bandaging materials, paper cups, bags and the like.

Abstract: Disclosed is a process for the chemical modification of a water-soluble cellulose ether, which comprises reacting the ether with a chloroformic acid ester in an aqueous organic medium containing alkali hydroxide, whereby the cellulose ether is rendered at least partially insoluble in water. The modified cellulose ether may be easily dispersed in water and redissolved to form a smooth solution of the original water-soluble ether by adding sufficient alkali to the dispersion to reuse its pH to at least about 11, preferably to about 12.

Abstract: This invention relates to an improvement in the process for the manufacture of water-absorbing, but largely water-insoluble cellulose ethers, wherein cellulose is etherified with a halogen fatty acid in an alkaline medium to which organic solvents may be added, to such an extent that without a further reaction a water-soluble cellulose ether would be produced, and wherein, prior to, during, or after etherification, a further reaction is carried out with a cross-linking agent which is polyfunctional towards cellulose in an alkaline reaction medium, the improvement comprising that chips of regenerated cellulose film are used as cellulose.

Abstract: This invention relates to an improvement in the process for the production of water-adsorbing, but at least partially water-insoluble cellulose ethers in which cellulose is alkalized in a liquid reaction medium and etherified in a manner such that by etherification only an at least largely water-soluble carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose or methyl hydroxyethyl cellulose is produced, and in which the cellulose is reacted in an alkaline reaction medium before, during, or after the etherification with a modification agent reactive with the still free hydroxyl groups of the cellulose anhydro glucose groups, said modification agent having one of the formulae ##STR1## in which R.sub.1 is hydroxyl, an acylamino or esterified carbamino group, andR.sub.2 is hydrogen or a carboxyl group,The improvement comprising effecting alkalization, etherification, and modification in a liquid reaction medium other than isopropyl alcohol.

Abstract: This invention relates to an improvement in the process for the manufacture of water-adsorbing but at least partially water-insoluble cellulose ethers in which cellulose is alkalized in a liquid reaction medium and reacted with an etherification agent in a manner such that an at least preponderantly water-soluble cellulose ether would be obtained in the case of a mere etherification process and in which, prior to, simultaneously with, or after the etherification process, a reaction is effected with a crosslinking agent which is polyfunctional towards cellulose in an alkaline reaction medium,The improvement comprising employing bis(acrylamido)-acetic acid as the crosslinking agent.

Abstract: This invention relates to an improvement in the process for the production of water-adsorbing, but at least partially water-insoluble, cellulose ethers in which cellulose is alkalized in a liquid reaction medium and etherified in a manner such that by etherification only an at least largely water-soluble carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose or methyl hydroxyethyl cellulose is produced, and in which the cellulose is reacted in an alkaline reaction medium before, during, or after the etherification with a cross-linking agent which is polyfunctional towards cellulose and selected from the group consisting of acrylamido methylene chloroacetamide, dichloroacetic acid, phosphorous oxychloride, or a compound in which at least two groups functional towards cellulose are ##STR1## the improvement comprising effecting alkalization, etherification, and cross-linking in a liquid reaction medium other than isopropyl alcohol.

Abstract: This invention is directed to a compressed catamenial tampon made up of a mass of absorbent fibers having intermixed therein a quantity of carboxymethylcellulose fibers containing free-acid carboxyl radicals and characterized by a high capacity for absorbing and retaining menstrual fluids. These carboxymethylcellulose fibers are modified by heat treatment to shorten the time it takes for such fibers to absorb a specified amount of fluid and thereby more effectively utilize their high capacity. The particular high capacity fibers are defined as carboxymethylcellulose fibers having a degree of substitution in the normally soluble range of about 0.4 to about 2.0 in which a part of the carboxyl groups are in free-acid form with the remainder in salt form.

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.

Abstract: This invention comprises a gas-permeable contact lens consisting essentially of a plasticized cellulose resin selected from a partially esterified or partially etherified cellulose polymer plasticized with a compatible plasticizer in an amount sufficient to increase the gas permeability of the cellulose resin.