Hoechst Aktiengesellschaft

Edgar Fischer

Siegfried Noetzel

Horst Jastrow

Johannes Brandrup

Jurgen Weinlich

Merten Schlingmann

Gerhard Pfahler

Norbert Mayer

Otto Mauz

Hartmut Voelskow

Manfred Engelmann

Walter Luders

Wolfgang Sittig

Karl Eberl

Microbial polysaccharides can be liberated from their fatty amine adducts by treating these adducts in the presence of an alcohol with a salt of ammonia or of a highly volatile amine which is soluble in this alcohol or thermally readily dissociated. It is preferable to use alcohols which have a boiling point under atmospheric pressure of up to about 100.degree. C., and salts of ammonia or of an amine which has a boiling point of less than 150.degree. C. under atmospheric pressure.

Process for isolating microbial polysaccharides from their fatty amine

Microbial polysaccharides can be quantitatively precipitated from their aqueous solutions, in particular directly from the fermentation solutions, in an acidic medium in the form of an adduct with a tertiary amine which has a long-chain alkyl radical. It is advantageous to add the amine to the polysaccharide solution and then to carry out the precipitation, in particular by adding the dispersion obtained to an acidic coagulation bath. The adducts are suitable for use as thickeners and for preparing the free polysaccharides.

Microbial polysaccharide amine adducts

Microbial polysaccharides can be liberated from their amine adducts by treating them with ammonia or a highly volatile amine in the presence of monohydric alkanols having 1 to 3 carbon atoms. It is advantageous to use the amine adduct in the form of a moist press cake in which it is isolated from fermenter broths. The free polysaccharides are obtained in a virtually quantitative yield.

Process for isolating microbial polysaccharides from their amine adducts

A device for dispersing a second phase in a first phase is provided, wherein gas inlet means are arranged at the bottom of a vessel. The outlet parts of these inlet elements have a varying distance to the bottom, this distance decreasing towards the center of the bottom. The distance of the outer outlet parts of the elements to the bottom, for those located near to the periphery, is from 15 to 40% of the diameter of the bottom.

Device for dispersing a second phase in a first phase

A process is described for preparing vinyl chloride polymers. The polymerization is carried out in an apparatus the inside walls and internal fitments of which have been coated with a reaction product which forms on reacting certain silanes with inhibitors for free-radical polymerizations and which contain in the molecule at least one aromatic or at least one quinonoid ring and at least one hydrogen atom which is bonded to an oxygen, sulfur or nitrogen atom with subsequent reaction with water, drying and heat treatment. The wall-deposit formation observed with the new process is markedly smaller, in particular after several polymerization batches, than in the case of known processes.

Process for preparing vinyl chloride polymers

A process for the manufacture of vinyl chloride polymers by polymerization of the monomer or monomer mixture in a reactor in which the internal walls, and the other parts on which polymer deposits can form, have a covering which contains a representative compound such as depicted by the formula ##STR1## extensive suppression of polymer crusts is thereby obtained.

Process for the manufacture of vinyl chloride polymers by coating

The present invention provides a process for the manufacture of vinyl chloride polymers by polymerization of the monomer or monomer mixture in aqueous dispersion in the presence of radical-forming catalysts and optionally suspension stabilizers, emulsifiers and further polymerization auxiliaries, which comprises carrying out the polymerization in a reactor the inner walls of which and other parts where polymer deposits may form are coated partially or entirely with a coating containing determined compounds of the formula ##STR1## In accordance with this invention, a substantial suppression of polymer deposit formation is achieved especially in the case of vinyl chloride copolymers.

Polymerization of vinylic monomer in presence of benzothiazol-hydrazones

There is provided a process for the manufacture of vinyl chloride homopolymers, copolymers or graft polymers by carrying out the polymerization in a reactor the inner parts and inserts of which are coated with a coating consisting of defined hydrazine derivatives and, preferably, a film-forming material as carrier substance.

Process for the manufacture of vinyl chloride polymers

Bromine-containing phosphonic acid esters of the formula ##STR1## in which R represents a halogen-containing linear or branched aliphatic or cycloaliphatic hydrocarbon radical having from 1 to 8 carbon atoms and R' and R' are hydrogen, halogen or alkyl groups having from 1 to 4 carbon atoms which may be closed to form a ring and/or substituted by halogen, at least one substituent being a bromine atom, are suitable as flame retardants for plastic materials, especially polystyrene and styrene copolymers.

Bromine-containing cyclic phosphonic acid esters

Acetoacetic acid pentaerythrite phosphite ester may be easily mixed with polymers and improves their processing, color and weather stability.

Acetoacetic acid pentaerythrite phosphite ester

Bromine containing telomeric phosphonic acid esters of the formula ##STR1## which are used as flameproofing agent for the preparation of flame-repellent thermoplastic compositions.

Bromine containing telomeric phosphonic acid esters as flame retardant

The present invention relates to 1,2-dibromoethane phosphonic acid bis-(2,3-dibromopropyl) ester, to a method for preparing the same, and to moldable plastics materials with improved flame retarding characteristics containing 1,2-dibromoethane phosphonic acid bis-(2,3-dibromopropyl) ester as the flame proofing agent.

Process for preparing flame resistant plastics materials

Bromine-containing phosphonic acid esters of the formula ##EQU1## in which R represents a halogen-containing linear or branched aliphatic or cycloaliphatic hydrocarbon radical having from 1 to 8 carbon atoms and R' and R' are hydrogen, halogen or alkyl groups having from 1 to 4 carbon atoms which may be closed to form a ring and/or substituted by halogen, at least one substituent being a bromine atom, are suitable as flame retardants for plastic materials, especially polystyrene and styrene copolymers.

Bromine containing telomeric phosphonic acid esters of the formula ##EQU1## which are used as flameproofing agent for the preparation of flame-repellent thermoplastic compositions.

Bromine containing telomeric phosphonic acid esters

Thermoplastic polymers are stabilized against ultra-violet radiation by incorporating therein as a stabilizer a stabilizing amount, e.g., 0.1 to 5% by weight of a tertiary phosphine oxide or sulfide of the general formula: ##EQU1## in which X is oxygen or sulfur and R.sub.1, R.sub.2 and R.sub.3 are each selected from hydroxyalkyl, haloalkyl, carbalkoxyalkyl, acyloxyalkyl, phenylhydroxyalkyl wherein the phenyl radical may be substituted by one or more halogens, and cyanoalkyl wherein the alkyl radical has 1 to 6 carbon atoms.

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Frankfurt am Main, Germany

Edgar Fischer