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: The present invention relates to a novel process for removing and purifying polysaccharide derivatives, preferably cellulose ethers, from a suspension using a continuous filter device with a multitude of working zones with intermediate resuspension of the filtercake.

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 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: The present invention relates to a novel double-cone mixer, if necessary of enamelled construction, and its use in the production and/or processing of polysaccharide products, preferably based on cellulose.

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 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 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.

Abstract: A description is given of cellulose derivatives having gel-like rheological properties in aqueous solution characterized in that: a) cellulose is alkalized with aqueous alkali metal hydroxide solution in the presence of a suspension medium, b) the alkalized cellulose is reacted with one or more alkylene oxides, c) then reacted with an alkyl halide present in the suspension medium d) subsequently or simultaneously the alkalized cellulose is reacted with a crosslinking agent in an amount of 0.0001 to 0.05 eq, where the unit “eq” represents the molar ratio of crosslinking agent relative to the anhydroglucose unit (AGU) of the cellulose used, and e) after, if appropriate, further addition of alkali metal hydroxide and/or alkylating agent, the resultant irreversibly crosslinked cellulose derivative is separated off from the reaction mixture, if appropriate purified and dried.

Abstract: A cellulose ether that is predominantly substituted in the C3 position of the anhydroglucose unit of the cellulose is described. In an embodiment of the present invention, the partial degree of substitution in the C3 position of the cellulose ether is ?60%, based on the total degree of substitution.

Abstract: A method of producing a cellueose ether that is predominantly substituted in the C2 position of the anhydroglucose unit of the cellulose is described. The regioselectively substituted saccharide ester produced according to the method of the present invention is selected from the group consisting of oligo-saccharide ester and polysaccharide ester, having a partial average degree of substitution (AS) at the C2 position of its anhydroglucose unit of at least 90% relative to the total AS. Also described is a blood plasma expander comprising the regioselectively substituted ester.

Abstract: The present invention encompasses cellulose ether blends comprising

Abstract: A description is given of cellulose derivatives having gel-like rheological properties in aqueous solution characterized in that:

Abstract: A regioselectively substituted member selected from the group consisting of oligo-saccharide ester and polysaccharide ester is disclosed. The ester has a partial average degree of substitution AS at the C2 position of its anhydroglucose unit of at least 90% relative to the total AS. Also disclosed is a method of producing the regioselectively substituted ester. The method entails reacting in the presence of a catalyst a dissolved or a highly swollen oligo-saccharide or polysaccharide with an esterification reagent.

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: Cellulose ethers with a specific substitution pattern, wherein they are substituted predominantly in the C3 position of the anhydroglucose unit of the cellulose.

Abstract: A regioselectively substituted member selected from the group consisting of oligo-saccharide ester and polysaccharide ester is disclosed. The ester has a partial average degree of substitution AS at the C2 position of its anhydroglucose unit of at least 90% relative to the total AS. Also disclosed is a method of producing the regioselectively substituted ester. The method entails reacting in the presence of a catalyst a dissolved or a highly swollen oligo-saccharide or polysaccharide with an esterification reagent.

Abstract: A cellulose ether that is predominantly substituted in the C3 position of the anhydroglucose unit of the cellulose is described. In an embodiment of the present invention, the partial degree of substitution in the C3 position of the cellulose ether is ≧60%, based on the total degree of substitution. Also described is a process for preparing the cellulose ether of the present invention. The process involves, reacting cellulose, dissolved in N-methylmorpholine-N-oxide monohydrate (NMMNO) and optionally other inert organic solvents, with alkylation reagents. The reaction takes place in the presence of: (i) an insoluble solid phase catalyst, e.g., solid ion exchange resins based on polystyrene having quaternary ammonium groups; (ii) stabilizers, e.g., propyl gallate; and (iii) optionally additional soluble co-catalysts, e.g., trimethylbenzylammonium hydroxide.