Hoechst Aktiengesellschaft

Michael Kostrzewa

Arno Holst

Helmut Lask

Gerhard Buchberger

Karl-Friedrich Muck

Ehrenfried Nischwitz

Heinz Wallisch

Uth H Felcht

Ottokar Smerz

Disclosed is a process for the purification treatment of liquid reaction and/or washing media obtained in the preparation of cellulose ethers which comprises distilling and subsequently ultrafiltering the media. In the distilling step, the low-boiling organic by-products of the reaction, the residual, non-reacted, low-boiling organic reaction components and/or the optionally used organic solvents are separated in the form of a distillate. The aqueous distillation residue, which particularly comprises salts, a cellulose constituent and possibly medium and/or high-boiling organic by-products of the reaction and/or non-reacted organic reaction components, is thereafter subjected to ultrafiltration. Ultrafiltration results in a permeate, in which the COD values are, for example, reduced by about 20% by weight.

Process for purifying aqueous distillation residues during the treatment

Hydrophilic films, fibers and spongy articles of a water-insoluble polymer selected from the group consisting of regenerated cellulose, cellulose ether, cellulose ester and polyalkylene, and capable of forming fibers and films, are produced by distributing in a mass of the polymer up to 50% of pulverulent or granular amorphous particles of an originally water-soluble cellulose ether prepared from natural cellulose and rendered by chemical modification at least partly water-insoluble while remaining water-absorbent. The resulting mixture is then processed by conventional methods into the desired article.

Method of producing hydrophilic articles of water-insoluble polymers

This invention relates to a hydrophilic shaped article of a water-insoluble polymer selected from the group consisting of regenerated cellulose, cellulose ether, cellulose ester and polyalkylene, and capable of forming fibers and films, said article containing amorphous particles of an originally water-soluble cellulose ether prepared from natural cellulose and rendered by chemical modification at least partly water-insoluble while remaining water-absorbent.

Method of making hydrophilic articles of water-insoluble polymers

Hydrophilic articles of water-insoluble polymers

This invention relates to a cigarette filter of cellulosic material composed at least partially of modified cellulose modified with at least one fatty acid group containing at least 14 carbon atoms in the molecule selected from the group consisting of a complex compound of a fatty acid containing basic chromium chloride and a melamine resin precondensate containing a fatty acid group.

Cigarette filter

Process for improving the water-absorbing capacity and absorptivity of fibrous materials consisting of, or containing, synthetic fibers or filaments, which comprises applying modified, highly absorbing cellulose ethers onto the fibrous materials and fixing these cellulose ethers on the fibrous material with the aid of finishing agents, resins or binders.

Process for the improvement of the water-absorbing capacity and the

This invention relates to an improvement in the process for the manufacture of modified starch ethers in which, prior to, during, or after etherification, a reaction with a modifying agent is conducted in a wet alkaline medium, the improvement comprising that, if etherification were the only reaction conducted, an at least preponderantly water-soluble starch ether would be formed, and the modification results in an absorbent modified starch ether more than 40 per cent by weight of which is insoluble in water.

Process for the manufacture of absorbent, modified starch ethers and

This invention relates to an improvement in the process for the preparation of a polyhydroxy methylene ether in which polyhydroxy methylene is reacted with an alkylating agent in an aqueous alkaline medium, the improvement comprising that the alkylating agent has at least one ionic or ionizable carboxyl group, phospho group, quaternary ammonium group, or substituted amino group. The invention also relates to ion exchangers composed of the polyhydroxy methylene ethers.

Process for the preparation of polyhydroxy methylene ethers and ion

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.

Hydroxyalkyl cellulose ethers

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.

Process for the manufacture of swellable cellulose ethers

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.

Process for the manufacture of water-absorbing cellulose ethers

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, and R.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.

Process for the production of water-adsorbing cellulose ethers

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.

This invention relates to a process for the manufacture of absorptive polymers which are at least preponderantly insoluble in water, but capable of swelling in water, which comprises etherifying polyhydroxy methylene in a homogeneous phase in an aqueous alkaline solution with an .alpha.-halogen carboxylic acid, and prior to, during, or after the etherification process performing a further reaction with a cross-linking agent which is polyfunctional towards polyhydroxy methylene in an alkaline medium.

Process for the manufacture of swellable, absorptive polymers of

This invention relates to an improvement in the method for the cold-milling of a cellulose derivative, in which the cellulose derivative is cooled by means of liquid nitrogen until it becomes brittle and the thus cooled cellulose derivative is milled in a mill, the improvement comprising cold-milling a cellulose derivative which is soluble or swellable in water and has a water content of between 40 and 150 percent by weight, based on its dry weight, and which is, at 20.degree. C, able to absorb, during swelling, more than 150 percent by weight of water, based on its dry weight.

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Wiesbaden, Germany

Michael Kostrzewa