Hoechst Aktiengesellschaft

Se Tylose Gmbh & Co. Kg

Eberhard Perplies

Arno Holst

Utz-Hellmuth Felcht

Josef Hilbig

Gerhard Buchberger

Utz H Felcht

Wolfgang Kornrumpf

Manfred Erdler

Disclosed are a method and a device for grinding cellulose, in which a raw cellulose material () is uniformly moistened with a given quantity of liquid by means of a moistening unit () before being ground in a grinding mill (). A first conveying mechanism () conveys the raw cellulose material () to the moistening unit () while a second conveying mechanism () conveys the moist raw cellulose material on the grinding mill ().

Method and device for grinding cellulose

Disclosed is a process for preparing water-soluble sodium carboxymethyl cellulose (NaCMC), including mixed ethers of NaCMC, by etherifying cellulose with alkyl monochloroacetates in an aqueous-alkaline dispersion containing at least one organic solvent. In the process, cellulose is first alkalized in an aqueous-alkaline dispersion, which optionally already contains the organic solvent. Subsequently, the alkali cellulose is reacted essentially with an alkyl monochloroacetate as the etherifying agent, in the presence of the organic solvent.

Process for etherifying cellulose with alkyl monochloroacetates

In modern processes for the preparation of cellulose ethers containing one or more types of substituents (such as MC, CMC, HEC, HPC, MHEC or EHEC), cellulose is reacted with etherifying agents in the presence of water, base and a mixture of preferably inert organic solvents (as a dispersing auxiliary). Dimethoxyethane (ethylene glycol dimethyl ether) and at least one organic solvent selected from the group including alkanols, alkane diols and alkoxy alkanols (for example, methanol and/or isopropanol) are employed in the mixture of organic solvents used for these syntheses, particularly in quantities of 1 to 30 parts by weight per 1 part by weight of cellulose.

Preparing cellulose ethers in a dimethoxyethane/(dispersing auxiliary)

In modern processes for preparing cellulose ethers containing one or more types of substituents, such as MC, CMC, HEC, HPC, MHEC or EHEC, cellulose is reacted with an etherifying agent in the presence of water, base and at least one inert organic solvent (as a dispersing auxiliary). Dimethoxyethane (ethylene glycol dimethyl ether) is employed as a new organic solvent for these syntheses, particularly in quantities of 1 to 30 parts by weight per part by weight of cellulose.

Dispersing auxiliary for preparing cellulose ethers

A process for purifying or working-up a mixture containing water, water-soluble salts, organic ions and organic solvents, particularly mixtures of water, NaCl, Na glycolate and aliphatic alcohols such as methanol or isopropanol, by separating the mixture into its components using acidic and/or basic ion exchangers, in particular, using weakly basic anion exchangers after optionally adjusting the pH of the mixture to an acid value. The process is especially suited for purifying liquid reaction media and/or washing media from the production of polysaccharides, such as cellulose ethers or starch ethers containing sodium-carboxymethyl group substituents, which are prepared from polysaccharides, an alkali metal hydroxide and monochloroacetate ions in a medium containing water and at least one organic solvent.

Process for purification of mixtures containing water, salts, glycolate

This invention relates to a process for the preparation of acrylic polymers which are at least for the most part insoluble in water and have a high swellability in water, by reacting polyacrylonitrile or copolymers based on acrylonitrile at a temperature exceeding 100.degree. C. with aqueous-alkaline solutions which may contain an organic solvent which is miscible with water.

Acrylic polymers having a high swellability in water

This invention relates to a process for reducing the viscosity of cellulose ethers by reacting a water-soluble cellulose ether with ozone in the presence of water, wherein said cellulose ether which is moist with water and has a dry content of from 20 to 95% by weight is reacted with an ozone/oxygen mixture or with an ozone/air mixture at a temperature of about 0.degree. to 60.degree. C.

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Walluf, Germany

Eberhard Perplies