Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase, wherein the monomer solution comprises at least 0.0002% by weight of oxygen and the oxygen content of the gas phase is at least 0.5% by volume.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets and postcrosslinking the polymer particles, wherein the postcrosslinked polymer particles are at least partly coated.

Abstract: A process for producing water-absorbing polymer particles, wherein the water-absorbing polymer particles are surface postcrosslinked with unsaturated fatty acids or derivatives thereof.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase in a reaction chamber, wherein the monomer solution is metered into the reaction chamber via at least one bore, and the diameter is from 210 to 290 ?m per bore and the metering rate is from 0.9 to 5 kg/h per bore.

Abstract: A process for thermally surface postcrosslinking water-absorbing polymer particles in a fluidized bed generated by means of a carrier gas, wherein the surface postcrosslinker is supplied to the fluidized bed in gaseous form.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase, wherein the monomer solution comprises at least 0.0002% by weight of oxygen and the oxygen content of the gas phase is at least 0.5% by volume.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets, wherein the particle surface is coated at least partly with at least one polymer and/or wax.

Abstract: A process for continuously producing water-absorbing polymer particles, wherein the monomer stems from at least two different sources and the monomer from one source differs from the monomer from at least one other source in the content of at least one secondary component.

Abstract: What is described is a process for producing water-absorbing resins, in which a) acrylic acid is prepared at an acrylic acid production site, b) the acrylic acid prepared is dissolved in water at the acrylic acid production site to obtain an aqueous acrylic acid solution, c) the aqueous acrylic acid solution is fed into a pipeline at the acrylic acid production site and passed through the pipeline to an acrylic acid processing site and d) the aqueous acrylic acid solution is subjected to a free-radical polymerization at the acrylic acid processing site. The process ensures safe transport of the highly reactive acrylic acid. Endangerment as a result of premature polymerization, as in the case of glacial acrylic acid, is ruled out, since the acrylic acid is “diluted” by the aqueous solvent and the specific heat capacity and the evaporation enthalpy of the water limit the maximum temperature rise.

Abstract: The invention relates to a method for monitoring the bending of a shaft, particularly a shaft in a mixing kneader, the shaft having a bearing at least on one side. In a first step, the deviation of the shaft from the radial position is measured on at least one position different from the bearing of the shaft. In a further step, a reference value is optionally determined from the measured deviation from the radial position. In a third step, the deviation from the radial position as measured in the first step or the reference value found in the second step is compared with a predetermined limit value.

Abstract: A process for producing water-absorbing polymeric particles by dropletization polymerization in the gas phase, which comprises drying the polymeric particles after the polymerization in a fluidized bed, the water-absorbing polymeric particles themselves, hygiene articles comprising these water-absorbing polymeric particles and also apparatus for implementing the process.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase, said monomer solution comprising at least one azo compound and at least one persulfate, the resulting polymer particles having a water content of at least 5% by weight, and being aftertreated thermally at a temperature of at least 100° C. for at least 5 minutes.

Abstract: The invention relates to a method for the transportation of a monomer composition in which a composition comprising an aqueous solution of partially or entirely neutralized acrylic acid or overneutralized acrylic acid is placed in a transport means or sent through a pipe. The method according to the invention is characterized in that it has an increased level of safety during the transportation of acrylic acid monomers, an improved quality of the resulting product, and a high degree of efficiency. The method ensures safe transport of the highly reactive acrylic acid. The amount of polymerization inhibitors added to said acrylic acid may be reduced. An additional advantage is the minimization of the formation of dimeric acrylic acid. Tempering of containers, pipes, and pipelines may be omitted.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase, the resulting polymer particles having a water content of at least 5% by weight, and being aftertreated thermally in the fluidized state in the presence of steam at a temperature of at least 60° C.

Abstract: In a process for producing water-absorbing polymeric particles which comprises generating droplets comprising monomers, polymerizing the monomers in a heated gas phase surrounding the droplets and flowing the gas through the polymerization reactor, the temperature of the gas leaving the polymerization reactor is closed-loop controlled.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets and postcrosslinking the polymer particles, wherein the postcrosslinked polymer particles are at least partly coated.

Abstract: A process for producing polymer particles by polymerizing liquid droplets in a gas phase surrounding the droplets, said droplets comprising at least one monomer and being coated with particulate solids during the polymerization.

Abstract: A process for preparing postcrosslinked water-absorbing polymer beads with high absorption by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets, wherein the solids content of the monomer solution is at least 35% by weight and the polymer beads have a mean diameter of at least 150 ?m.

Abstract: A process for preparing water-absorbing polymer beads with high permeability by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets, wherein a water-insoluble inorganic salt is suspended in the monomer solution and the polymer beads have a mean diameter of at least 150 ?m.

Abstract: A process for producing water-absorbing polymeric particles by dropletization polymerization in the gas phase, which comprises drying the polymeric particles after the polymerization in a fluidized bed, the water-absorbing polymeric particles themselves, hygiene articles comprising these water-absorbing polymeric particles and also apparatus for implementing the process.