Abstract: The present invention relates to a process for the preparation of a water-moist cellulose ether composition, characterized in that water-soluble polymeric additives which contain anionic groups (WSAP), or corresponding additive mixtures, are added to the cellulose ether composition. The invention furthermore relates to water-moist cellulose ether compositions which can be prepared by such a process, and to corresponding milled and dried cellulose ether compositions. The invention also relates to the use of these WSAP or corresponding WSAP mixtures for improving the transportability of water-moist cellulose ether compositions in conveying units.

Abstract: The present invention describes a process for preparing methylhydroxyalkylcellulose having a small number of colored particles by separation of methylhydroxyalkylcellulose from aqueous suspension with subsequent washing of the methylhydroxyalkylcellulose using a specially equipped rotary pressure filter.

Abstract: A description is given of glyoxal-treated polysaccharide derivatives which, to decrease the unbound glyoxal, are treated with an aqueous solution of one or more water-soluble aluminium salts, or one or more water-soluble borates, or a combination of one or more water-soluble aluminium salts and one or more water-soluble borates, and, if appropriate, with suitable buffer substances to set the pH, and then dried. A description is likewise given of a process for decreasing the content of unbound glyoxal in glyoxal-treated polysaccharide derivatives.

Abstract: The present invention relates to a process for the preparation of a water-moist cellulose ether composition, characterized in that water-soluble polymeric additives which contain anionic groups (WSAP), or corresponding additive mixtures, are added to the cellulose ether composition. The invention furthermore relates to water-moist cellulose ether compositions which can be prepared by such a process, and to corresponding milled and dried cellulose ether compositions. The invention also relates to the use of these WSAP or corresponding WSAP mixtures for improving the transportability of water-moist cellulose ether compositions in conveying units.

Abstract: The present invention relates to the preparation of methylhydroxypropylcellulose (MHPC) and the use thereof in mineral-bound building material systems, preferably in gypsum-bound building material systems, particularly preferably in gypsum machine plaster.

Abstract: The invention relates to innovative cellulose derivatives with low surface swelling in aqueous suspension, with high relative high-shear viscosity, and with high thermal flocculation point in water, and also to their use in building-material systems.

Abstract: A description is given of glyoxal-treated polysaccharide derivatives which, to decrease the unbound glyoxal, are treated with an aqueous solution of one or more water-soluble aluminium salts, or one or more water-soluble borates, or a combination of one or more water-soluble aluminium salts and one or more water-soluble borates, and, if appropriate, with suitable buffer substances to set the pH, and then dried. A description is likewise given of a process for decreasing the content of unbound glyoxal in glyoxal-treated polysaccharide derivatives.

Abstract: The present invention relates to a process for preparing cellulose ether products which is characterized in that superabsorbent polymers (SAPs) are dried and milled, or mill-dried, conjointly with moist cellulose ether and also to the cellulose ether products resulting from this process.

Abstract: A description is given of a cellulose ether composition as additive for the extrusion of mineral masses which comprises 70 to 99.9% by weight of cellulose ether and 0.1 to 30% by weight of superabsorbent polymer, as well as a process for the extrusion of mineral masses using these compositions as additive.

Abstract: A process of preparing alkylhydroxyalkylcellulose (e.g., methylhydroxyethylcellulose and methylhydroxypropylcellulose) by reaction of cellulose in the presence of alkali metal hydroxide with an alkylating agent and a hydroxyalkylating agent is described. The process includes: (a) alkalizing cellulose by means of 0.9 to 2.9 equivalents of an alkali metal hydroxide I/AGU of the cellulose in the form of an aqueous alkali metal hydroxide solution, in the presence of a suspension medium containing at least 0.2 equivalents of an alkylating agent I/AGU of the cellulose; (b) reacting the alkalized cellulose of step (a) with alkylating agent I and a hydroxyalkylating agent at a temperature above 65° C.

Abstract: A composition comprising cellulose ether, a superplasticizer and defoamer suitable for use as an additive in extruding inorganic compositions is disclosed. The inventive composition functions as a water retention agent, plasticizer and lubricant in the extrusion of inorganic compositions. The use of the inventive composition in the extrusion of building materials leads to improved processing properties, to a higher surface quality and product properties of the extruded article.

Abstract: The present invention describes a process for preparing methylhydroxyalkylcellulose having a small number of coloured particles by separation of methylhydroxyalkylcellulose from aqueous suspension with subsequent washing of the methylhydroxyalkylcellulose using a specially equipped rotary pressure filter.

Abstract: The present invention relates to a new, particularly economical process for preparing particulate water-soluble cellulose derivatives. The process involves forming a feed composition of swollen and/or dissolved cellulose derivative, and water. The feed composition is contacted with a superheated gas mixture, in a sieve-free high rotational speed gas jet impact mill, and the cellulose derivative of the feed composition is converted into a solid state form of finely particulate particles. The superheated gas mixture, with which the feed composition is contacted, is selected from: (i) a superheated gaseous mixture of steam and an inert gas; and (ii) a superheated gas mixture of steam and air. The superheated gas mixture has a steam content of 40 wt. % to 99 wt. %, based on the total weight of the superheated gas mixture.

Abstract: The present invention relates to a process for preparing cellulose ether products which is characterized in that superabsorbent polymers (SAPs) are dried and milled, or mill-dried, conjointly with moist cellulose ether and also to the cellulose ether products resulting from this process.

Abstract: A description is given of glyoxal-treated polysaccharide derivatives which, to decrease the unbound glyoxal, are treated with an aqueous solution of one or more water-soluble aluminium salts, or one or more water-soluble borates, or a combination of one or more water-soluble aluminium salts and one or more water-soluble borates, and, if appropriate, with suitable buffer substances to set the pH, and then dried. A description is likewise given of a process for decreasing the content of unbound glyoxal in glyoxal-treated polysaccharide derivatives.

Abstract: A composition comprising cellulose ether, a superplasticizer and defoamer suitable for use as an additive in extruding inorganic compositions is disclosed. The inventive composition functions as a water retention agent, plasticizer and lubricant in the extrusion of inorganic compositions. The use of the inventive composition in the extrusion of building materials leads to improved processing properties, to a higher surface quality and product properties of the extruded article.

Abstract: A method of preparing construction material systems is described. The process includes extruding a composition of construction materials and an irreversibly crosslinked cellulose derivative that is prepared by a particular process.

Abstract: A process for preparing cellulose ethers having delayed dissolution in water is described. The process comprises: (a) treating a moist cellulose ether with a solution comprising a dialdehyde; (b) adding an aqueous salt solution to the moist cellulose ether, such that said cellulose ether has a pH of from 6.0 to 8.0, the aqueous salt addition being performed at least one of, (i) prior to step (a), (ii) concurrently with step (a), and (iii) subsequent to step (a); and (c) drying and comminuting the treated cellulose ether of step (b). The cellulose ether, or mixtures of cellulose ethers, prepared by the method of the present invention may be used as protective colloids, thickeners and adhesives.

Abstract: A description is given of particle compositions of polysaccharides and/or polysaccharide derivatives and at least one synthetic polymer and if appropriate other aids, characterized in that I. the particles contain a plurality of solid phases, II. the solid phase of the synthetic polymer being contained in the solid phase of the polysaccharide and/or polysaccharide derivative. Likewise a description is given of a process for producing these particle compositions and also of their use in construction material mixtures, for example mortars, plasters, fillers or thin-bed adhesives.

Abstract: A process of producing methylhydroxyalkyl cellulose (MHAC) is described and involves in a first step (a), (i) introducing cellulose and a suspension medium into an autoclave, the suspension medium comprising 20 wt. % to 50 wt. % of chloromethane, based on the total weight of the said suspension medium, and (ii) spraying the cellulose in the autoclave with an aqueous alkali metal hydroxide solution, thereby alkalizing the cellulose and reacting the cellulose with chloromethane. In a second step (b), hydroxyalkylating agent is optionally introduced into the autoclave at a temperature above 60° C. In a third step (c) alkali metal hydroxide is introduced into the autoclave in a hyperstoichiometric quantity of at least +0.1 mol eq., relative to the chloromethane utilised. In a fourth step (d), at least one hydroxyalkylating agent is optionally introduced into the autoclave at a temperature above 60° C., and the introduced hydroxyalkylating agent is allowed to react for at least 20 min.