Wolff Walsrode Ag

Dow Global Technolgoies LLC

Dow Wolff Cellulosics Gmbh

Wolff Cellulosics Gmbh & Co. Kf

Wolfgang Dannhorn

Lutz Hoppe

Erhard Luhmann

Hartwig Schlesiger

Jörn-Bernd Pannek

Erik-Andreas Klohr

Burkhard Kressdorf

Martin Kowollik

Hans-Jurgen Juhl

Gerd Sonnenberg

Frank Höhl

Reinhold Hecht

Hans-J Urgen Juhl

Helmut Holste

Erhard L Uhmann

Volkhardt Müller

Gerolf Weissach

Bernhard Kranz

Marc Oliver Schmidt

Gerd Sonneneberg

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.

Process for preparing methylhydroxyalkylcellulose having a small number of coloured particles

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&#xb0; C.; (c) adding additional alkali metal hydroxide 11 in the form of an aqueous alkali metal hydroxide solution; and (d) adding additional alkylating agent 11 in an amount of at least the absolute value of the difference between (i) the number of equivalents of alkylating agent I/AGU of the cellulose already added, and (ii) the total number of equivalents of alkali metal hydroxide/AGU of the cellulose added. Additional alkylating agent 11 is not added in step (d) if (i) the number of equivalents of alkylating agent I/AGU of the cellulose already added exceeds (ii) the total number of equivalents of alkali metal hydroxide/AGU of the cellulose already added. In a further step (e), the alkylhydroxyalkylcellulose is isolated from the reaction mixture. The isolated alkylhydroxyalkylcellulose may be optionally purified.

Process of preparing alkylhydroxyalkylcellulose

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.

Process of preparing delayed-dissolution cellulose ethers

Described is a process of preparing alkylhydroxyalkyl cellulose, e.g., methylhydroxypropyl cellulose (MHPC). The process includes: (a) alkylating cellulose with an aqueous caustic solution containing from 1.5 to 5.5 equivalents of alkali metal hydroxide, e.g., NaOH, per anhydroglucose unit (AGU) of said cellulose, in the presence of a suspension agent, e.g., dimethyl ether, which contains alkyl halide, e.g., methyl chloride, in an amount of from (equivalents of alkali metal hydroxide per AGU minus 1.4) to (equivalents of alkali metal hydroxide per AGU plus 0.8); (b) reacting the alkalised cellulose of step (a) with one or more alkylene oxides, e.g., propylene oxide, at a temperature higher than 65&#xb0; C., e.g., 85&#xb0; C.; (c) adding alkyl halide, to the product of step (b), in an amount of at least the difference between (i) the equivalents of alkyl halide per AGU in step a) and (ii) the equivalents of alkali metal hydroxide added per AGU in step (a), provided that the amount of additionally added alkyl halide is at least 0.2 equivalents per AGU; and (d) isolating alkylhydroxyalkyl cellulose from the reaction mixture of step (c). Optionally the isolated alkylhydroxyalkyl cellulose may be purified.

Process for preparing alkylhydroxyalkyl cellulose

Lacquer vehicles in granular form, wherein the lacquer vehicles in granular form are composed of 10-82 weight % cellulose ester and 18-90 weight % resin and/or plasticizer as an explosive stabilizer.

Lacquer vehicles in granular form and free from emulsifying agents, and

The present invention relates to polyester acrylate/urethane dispersions based on polyester acrylate prepolymers containing hydroxyl groups, obtainable by polyaddition of A. 40-90 wt. % of one or more polyester acrylate prepolymers containing hydroxyl groups and having an OH content of 40-120 mg of KOH/g and B. 0.1-20 wt. % of one or more mono- and/or difunctional compounds reactive towards isocyanate groups, which compounds contain groups which are cationic, artionic and/or have a dispersant action due to ether groups with C. 10-50 wt. % of one or more polyisocyanates D. 0.0-30 wt. % of polyols together with a subsequent reaction with E. 0.1-10 wt. % of one or more di- and/or polyamines.

Radiation-curable, aqueous dispersions, production and use thereof

The present Application relates to an aqueous, reactive microgel dispersion, wherein the microgel particles have an average particle diameter of 0.01 to 1 .mu.m, are insoluble but are capable of swelling in the usual organic solvents, dry without additional film-forming agents to form uniform, transparent, reactive films, and have iodine numbers of 2 to 100.

Aqueous reactive microgel dispersions, a method of preparing them and

The present Application relates to a polymer dispersion comprising an aqueous continuous phase and dispersed particles, which consist of a polymerized, water-soluble, urethane-modified allyl ether polyester and polymerized monomers, wherein at least two polymerized monomers A and B together with a water-soluble urethane-modified allyl ether polyester constitute the dispersion particle and are produced according to the core-shell model (multiphase).

Polymer dispersion

The invention relates to novel branched polyesters containing allyl groups, which polyesters are water-emulsifiable, and their use as raw materials for lacquers.

Polymerizable, highly crosslinking lacquer binders and their use for the

This invention relates to new water-emulsifiable polyester resins, a process for their production and their use as a lacquer row material. These lacquer binders are produced by the reaction of at least one prepolymer A which contains (meth)acryloyl groups and at least one unsaturated water-emulsifiable polyester B with at least one polyisocynate C.

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Walsrode, Germany

Wolfgang Dannhorn