Abstract: The present invention relates to a process for the preparation and work-up of N-hydroxyalkylchitosans soluble in aqueous media, comprising the measuresdispersion of chitosan in an aqueous medium,subsequent hydroxyalkylation of the dispersed chitosan andsubsequent work-up of the N-hydroxyalkylchitosan, which comprises carrying out the hydroxyalkylation up to an average degree of substitution (DS) of 2.0, preferably 1.5 to 2.0, if desired removing some of the aqueous medium after the hydroxyalkylation and before the work-up and performing the work-up of the N-hydroxyalkylchitosan by drying.

Abstract: Cationic unsaturated saccharides of the formula IR.sup.5 R.sup.4 C.dbd.CHR.sup.3 --CH.sub.2 --N.sup..sym. R.sup.1 R.sup.2 --CH.sub.2 --CHR.sup.3 .dbd.CR.sup.4 R.sup.5 X.sup..crclbar.(I)in whichR.sup.1 is a deoxysaccharide radical having 1 to 20 monomer units,R.sup.2 has the same meaning as R.sup.1 or is C.sub.1 -C.sub.20 -alkyl, C.sub.2 -C.sub.20,-alkenyl, C.sub.1 -C.sub.4 -hydroxyalkyl, C.sub.1 -C.sub.4 -alkylphenyl or a polyoxyethylene, polyoxypropylene or polyethyleneimine group having in each case 1 to 10 ethylene oxide, propylene oxide or ethyleneimine units,R.sup.3, R.sup.4 and R.sup.5 are hydrogen or methyl andX is a halogen, tosylate or allyl-sulfate ion.These compounds are obtained by reaction of deoxyaminosaccharides with allyl compounds. Polymers which are built up from these compounds or comprise these compounds as monomer units are suitable as flocculating and thickening agents.

Abstract: The invention relates to a process for the purifying working-up of liquid reaction media and/or wash media obtained during preparation of cellulose ethers, which are insoluble in hot water, from cellulose, an alkali metal hydroxide and at least one etherifying agent in a medium containing water and if appropriate at least one organic solvent, by ultrafiltration of the media into a permeate and concentrate, which comprises carrying out the ultrafiltration of the reaction media and/or wash media at a temperature at or above the flocculation temperature of the cellulose ethers.

Abstract: The invention relates to a process for the preparation of activated chitosans, in which process a chitosan is reacted with an acid for salt formation, preferably followed by a reaction with a base. The addition of acid and the addition of bases which is preferably to be effected in the activation are carried out in a suspending agent which largely prevents the chitosan salts from dissolving, suitable suspending agents can be both aqueous solutions of inorganic salts and organic or aqueous-organic solvents. The invention also relates to a process for the preparation of both water-soluble and water-insoluble chitosan derivatives by reacting the activated chitosans with reagents which are generally suitable for the reaction of polysaccharides or amines.

Abstract: The present invention relates to alkyl hydroxyalkyl cellulose ethers which contain a sulfoalkyl group as a further substituent, to a process for the preparation of these cellulose ethers and to building material mixtures which are based on gypsum, hydrated lime or cement and contain alkyl hydroxyalkyl cellulose ethers containing sulfoalkyl groups.

Abstract: The present invention relates to the use of carboxymethylated methyl hydroxyethyl cellulose ethers or methyl hydroxypropyl cellulose ethers having a DS.sub.alkyl from 1.0 to 2.0, a DS.sub.carboxyalkyl from 0.005 to 0.6 and an MS.sub.hydroxyalkyl from 0.05 to 1 as an additive to mixtures of hydrated lime and cement, and to the mixtures of hydrated lime and cement obtained in this way.

Abstract: The invention relates to water-soluble cellulose ethers, containing at least one fluorine-free radical attached via an ether link and selected from the group hydroxyethyl, hydroxypropyl, methyl, ethyl and carboxymethyl, and a hydrophobic substituent which comprises one fluorine-containing alkyl radical of 3 to 24, in particular 5 to 18, carbon atoms, the fluorine content being 0.05 to 5, in particular 0.1 to 1% by weight, based on the dry weight of the cellulose ether.

Abstract: The present invention relates to a process for careful grinding and simultaneous drying of moist cellulose ether products wherein a moist cellulose ether is introduced by means of a transport gas into a circular space. The moist cellulose ether is impact-comminuted while being circulated in that space, and the product is simultaneously friction-comminuted in a direction opposite to that of the impact comminution. The peripheral speed of the comminution stages, which operate in opposite directions, is regulated to such a value that the resulting grinding energy dries the product to a predetermined residual moisture content. The ground material is conveyed by the gas stream introduced into the comminution space, and the ground material is then separated from the gas stream. If desired, the ground material is subjected to selective screening.

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: Disclosed are a photopolymerizable mixture and photopolymerizable copy materials made therefrom. The mixture contains a polymerizable compound having terminal acrylic or methacrylic acid ester groups, selected from a compound of one of the general formulas ##STR1## wherein R.sub.1 is a phenylene group or a biphenyldiyl group or a group formed by two phenylene groups which are linked by a bridge comprising an oxygen atom, a sulphur atom, a sulfone group, a substituted or unsubstituted alkylene group or cycloalkylene group, or a group of the formula --(O-alkylene).sub.n O-- with n=1-3,R.sub.2 is an oxygen atom or the group CH.sub.2 --CH.sub.2 --CO;R.sub.3 is a hydrogen atom or a methyl radical; andR.sub.

Abstract: Disclosed are a photopolymerizable mixture and photopolymerizable copy materials made therefrom. The mixture contains a polymerizable compound having terminal acrylic or methacrylic acid ester groups and being selected from a compound of the formula I ##STR1## wherein R.sub.1 is a naphthylene group, a biphenyldiyl group or a dinaphthyl-methanediyl group or a group formed by two phenylene groups which are linked by a bridge comprised of an oxygen atom, a sulphur atom, a sulfone group or an alkylene group which is substituted by at least one carboxylic acid group, carboxylic acid alkyl ester groups, halogen atom or phenyl group, or by such a substituted alkylene group which is connected to the group R.sub.1 of another molecule via said substituent;R.sub.2 is a hydrogen atom or a methyl group; andm is 0 or 1, m being 1 if R.sub.1 is a naphthylene group or a biphenyldiyl group.

Abstract: This invention relates to a novel 2-(halogenomethyl-phenyl)-4-halogeno-oxazole derivative; to a radiation-sensitive composition which, as the radiation-sensitive compound, contains a 2-halogenomethyl-phenyl)-4-halogeno-oxazole derivative; and to a process for the preparation of the novel 2-(halogenomethyl-phenyl)-4-halogeno-oxazole derivatives.

Abstract: This invention relates to a novel 4-halogeno-5-(halogenomethyl-phenyl)-oxazole derivative; to a radiation-sensitive composition which, as the radiation-sensitive compound, contains a 4-halogeno-5-(halogenomethyl-phenyl)-oxazole derivative; and to a process for the preparation of the novel 4-halogeno-5-(halogenomethyl-phenyl)-oxazole derivatives.