摘要:
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.
摘要:
Described is a building material composition prepared from or having added thereto a particulate material selected from particulate polysaccharides or particulate polysaccharide derivatives. The particulate material of the building material composition is prepared by a method comprising: (a) forming a feed composition comprising a member selected from the group consisting of polysaccharides and polysaccharide derivatives, and 35 wt. % to 99 wt. % of water, based on the total weight of the feed composition, wherein said member is at least one of swelled and dissolved in the feed composition; (b) contacting, in a mill, the feed composition with a gas stream, thereby converting simultaneously the water of said feed composition into water vapor, and said member of said feed composition into a solid state form of finely particulate material; (c) separating the particulate material from the gas stream; and (d) optionally drying the particulate material. Examples of building material compositions according to the present invention include tile adhesives and joint fillers.
摘要:
The present invention relates to a new, particularly economical process for producing 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 carrier and heat exchange gas, 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 particulate cellulose derivative is then separated from the heat exchange gas and carrier gas, and optionally dried. The mill drying and the particulate cellulose derivative product are influenced by establishing a specific water content in the swollen and/or dissolved cellulose derivative.
摘要:
A process of both milling and drying a solvent-moist material (e.g., water-moist methylhydroxyethylcellulose) is described. The process includes, (a) providing a mill-dryer (100) which includes, in series, a heat exchanger (1), a mill (2) and a particulate separating apparatus (105) connected by conduits (8), (9) and (11, 12), which together define a mill-dryer circuit (103). The mill-dryer (100) also includes a bypass conduit (14), which provides optionally at least partial gaseous bypass of the heat exchanger (1). The process further includes: (b) introducing the solvent-moist material into the mill (2); (c) circulating a vapor stream (e.g., a steam/air stream) throughout the mill-dryer circuit (103); (d) heating the vapor stream by means of passage through the heat-exchanger (1); (e) forwarding milled particulate material from the mill (2) to the particulate separating apparatus (105) by means of conduit (9); (f) separating the particulate material from the vapor stream in the particulate separating apparatus (105); (g) forwarding the vapor stream from the particulate separating apparatus (105) through conduits (11, 12); and (h) controlling the temperature of the vapor stream by optionally forwarding at least some of the vapor stream through the bypass line (14).
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.