Abstract: Process for the preparation of low molecular weight polysaccharide ethers which can be employed in binders for improving adhesive power and film-forming properties, by oxidative degradation of relatively high molecular weight polysaccharide ethers, which comprises initially introducing a relatively high molecular weight polysaccharide ether in suspension (e.g. in a slurry), adding a perborate or a mixture of perborate and perborate activator, and carrying out the oxidative degradation at a temperature of between 25.degree. and 90.degree. C.

Abstract: The present invention relates to a process and a device for selectively separating the solvents employed in the preparation and purification of products. In this connection the different solvents are removed from the product to be treated by means of mechanical separation and subsequent admission of steam, and are collected separately. As a result of this, mixing of solvents from the preparation and from the purification is avoided, so that the working up of a solvent mixture is superfluous. The proces and the device are preferably used in the process for producing starch ethers and cellulose ethers.

Abstract: A polymer hydrogel substantially free from monomers and oligomers is prepared by contacting a previously prepared polymer hydrogel with a single-phase mixture of water and a solvent and then separating the mixture of water and solvent from the hydrogel.

Abstract: 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.

Abstract: Apparatus for continuously producing water-soluble hydroxyalkyl cellulose and related ethers comprising, in combination, the following elements connected in series: a stirred kettle for alkalizing cellulose at atmospheric pressure, at least one stirred autoclave for partially etherifying the alkalized cellulose, individual homogenizing pumps at the outlet of the stirred kettle and at the outlet of each stirred autoclave, individual bypass lines leading from the bottom of the stirred kettle to the upper end thereof and from the bottom of each stirred autoclave to the upper end of the same autoclave for circulating slurry from each vessel in a loop, a tubular reactor comprising a plurality of serially-connected, horizontal tubes for completing the etherification of the cellulose slurry, the first tube of the tubular reactor being provided with a non-conveying, homogenizing agitator, and each subsequent tube being provided with a conveying agitator such as an impeller, means such as a jacket for each section of

Abstract: A continuous process for manufacturing water-soluble hydroxyalkyl cellulose, and water-soluble mixed ethers based on hydroxyalkyl cellulose, comprising producing a slurry comprising (by weight) 1 part cellulose, 0.02 to 0.6 parts alkali metal hydroxide, 5 to 10 parts inert organic solvent, and 0.4 to 2.5 parts water; continuously feeding the slurry to a first elevated pressure reactor and mixing the slurry therein with at least one normally gaseous etherifying agent which has been liquified under pressure; maintaining the slurry at a temperature up to 40.degree. C., and a gauge pressure up to 3 bars, for 15 to 90 minutes, to give a degree of substitution from 0.2 to 1.