Abstract: The invention relates to a process for continuously preparing polyamide oligomers. This comprises continuous conveying of an aqueous solution of polyamide-forming monomers from a reservoir vessel into an oligomerization reactor, heating of the aqueous solution beyond a dissolution or storage temperature, the residence time of the monomer solution in the oligomerization reactor being limited and the pressure or the partial vapor pressure of the water being adjusted such that a conversion of monomers to polyamide oligomers does not exceed a maximum value and/or the polyamide oligomers formed do not phase-separate or spontaneously crystallize in solid form, and continuous discharge of the polyamide oligomers from the oligomerization reactor. A polyamide oligomer preparable by this process can be provided continuously in a mixture with water in a process for preparing a semicrystalline or amorphous, thermoplastically processible polyamide and then postcondensed to give a polyamide.

Abstract: The present invention relates to a process for preparing an aliphatic or semiaromatic polyamide oligomer, in which an aqueous composition of the monomers is subjected to an oligomerization at elevated temperature and elevated pressure and the oligomerization output is preferably subjected to an expansion.

Abstract: The invention relates to a method for producing polyamides by means of a spray nozzle arrangement for the collision of spray jets, comprising at least one spray nozzle forming a first spray jet having a first spray jet cross-sectional surface and a first spray jet longitudinal extension axis, and comprising a second spray jet forming a second spray jet having a second spray jet cross-sectional surface and a second spray jet longitudinal extension axis, wherein the first and second spray jets have a spray direction that is facing the gravitational field, and are arranged opposite one another such that in a spray direction facing the gravitational field, the formed spray jets collide in a collision area.

Abstract: The present invention relates to a process for preparing an aliphatic or semiaromatic polyamide oligomer, in which an aqueous composition of the monomers is subjected to an oligomerization at elevated temperature and elevated pressure and the oligomerization output is preferably subjected to an expansion.

Abstract: The invention relates to a process for continuously preparing polyamide oligomers. This comprises continuous conveying of an aqueous solution of polyamide-forming monomers from a reservoir vessel into an oligomerization reactor, heating of the aqueous solution beyond a dissolution or storage temperature, the residence time of the monomer solution in the oligomerization reactor being limited and the pressure or the partial vapor pressure of the water being adjusted such that a conversion of monomers to polyamide oligomers does not exceed a maximum value and/or the polyamide oligomers formed do not phase-separate or spontaneously crystallize in solid form, and continuous discharge of the polyamide oligomers from the oligomerization reactor. A polyamide oligomer preparable by this process can be provided continuously in a mixture with water in a process for preparing a semicrystalline or amorphous, thermoplastically processible polyamide and then postcondensed to give a polyamide.

Abstract: The invention relates to excipients in powder form for use in solid pharmaceutical presentations, comprising a pharmaceutically acceptable polymer and a liquid or semisolid solubilizing surface-active substance.

Abstract: A process for the preparation of a readily water-redispersible polymer powder by spray drying of an aqueous polymer dispersion in the presence of a novel spray drying assistant.

Abstract: A process for preparing a polymer powder by evaporating the volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion still comprises drying assistants T, present in an amount of from 0.1 to 80% by weight, based on the polymer P of the dispersion, and there being used as drying assistant T polyvinylformamide. The polyvinylformamide used preferably has a K value (KW), determined by the method of Fikentscher in accordance with DIN 53726, of from 5 to 50.

Abstract: A process for the preparation of a readily water-redispersible polymer powder by spray drying of an aqueous polymer dispersion in the presence of a novel spray drying assistant.

Abstract: In a spray condensation process for the preparation of dried resins in powder form, the condensation of at least one crosslinkable starting material which is liquid or dissolved in a liquid phase with at least one aldehyde is carried out in a spray reactor.

Abstract: A process for preparing a polymer powder by evaporating the volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion still comprises drying assistants T, present in an amount of from 0.1 to 80% by weight, based on the polymer P of the dispersion, and there being used as drying assistant T polyvinylformamide. The polyvinylformamide used preferably has a K value (KW), determined by the method of Fikentscher in accordance with DIN 53726, of from 5 to 50.

Abstract: A readily water-redispersible and water-wettable polymer powder is prepared by spray-drying of an aqueous dispersion of polymer particles with admixing of a hydrophilic and of a hydrophobic antiblocking agent.

Abstract: A readily water-redispersible and water-wettable polymer powder is prepared by spray-drying of an aqueous dispersion of polymer particles with admixing of a hydrophilic and of a hydrophobic antiblocking agent.

Abstract: Naphthalenesulfonic acid-formaldehyde condensates are used as assistants in the drying of aqueous polymer dispersions. Also described is a process for preparing polymer powders by drying, using these condensates; the polymer powders obtainable by the process; and their use as binders.

Abstract: The invention relates to a thermally hardenable polymer dispersion powder and the use of said powder as a binding agent in particular for fibrous and grainy materials. The binding agent in powder form is obtained by drying a polymer dispersion which comprises a carboxyl-group-containing polymerization component in addition to, optionally, a hydroxy-alkylated amine.

Abstract: The present invention provides a process for preparing polymer powders by evaporating the volatile constituents from aqueous dispersions of film-forming polymers P in the presence of drying assistants T selected from the salts of oligomeric arylsulfonic acid-formaldehyde condensates wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion comprises at least 1.5% by weight, preferably at least 1.7% by weight, based on the polymer in the dispersion, of at least one anionic surface-active compound AO having at least one C6-C32 alkyl group; the polymer powders obtainable by the process; and their use in binding mineral building materials.

Abstract: The present invention provides a process for preparing polymer powders by evaporating the volatile constituents from aqueous dispersions of film-forming polymers P in the presence of drying assistants T selected from the salts of oligomeric arylsulfonic acid-formaldehyde condensates wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion comprises at least 1.5% by weight, preferably at least 1.7% by weight, based on the polymer in the dispersion, of at least one anionic surface-active compound AO having at least one C6-C32 alkyl group; the polymer powders obtainable by the process; and their use in binding mineral building materials.

Abstract: A polymer is obtained by removing the medium from a polymer dispersion or polymer solution containing at least one polymeric phase and at least one stabilizer suitable to protect against the damaging effect of light, heat and/or oxidation.

Abstract: The invention relates to a pulverulent polymer composition comprisinga) a particulate mineral carrier of high specific surface area andb) a polymer dispersion applied to the carrier, andto a process for preparing this pulverulent polymer composition, to its use for preparing building materials, and to polymer-modified building materials, such as bitumen, dry mortars, powder adhesives, pulverulent coating formulations and filling compounds, all of which comprise such polymer compositions.

Abstract: Pulverulent adhesives comprise a redispersible polymer powder based on a polymer which can be obtained in the presence of a protective colloid, and additionally comprise a filler, an alkaline additive and, if desired, an emulsifier and other additives.