| Patent application number | Description | Published |
|---|
| 20100272998 | Method for Producing Water-Absorbent Polymer Particles - A process for producing water-absorbing polymer particles, wherein a product stream comprising water-absorbing polymer particles is tested for nonferritic metallic impurities by means of an eddy current detector. | 10-28-2010 |
| 20100273942 | Method for Producing Water-Absorbing Polymer Particles - A process for producing water-absorbing polymer particles, comprising the addition of a solid additive to a polymer gel by means of a conveying screw ( | 10-28-2010 |
| 20100324212 | Production of a Water-Absorbing Resin to Which a Particulate Additive is Admixed - The invention relates to a process for producing a water-absorbing resin by polymerization of a reaction mixture comprising at least one hydrophilic monomer and, if appropriate, at least one crosslinker in a reactor, which comprises admixing the reaction mixture with at least one first portion of a particulate additive before the reaction mixture has reached a residence time of 40% of the overall residence time in the reactor and with at least one second portion of a particulate additive when the reaction mixture has reached a residence time of 45% or more of the overall residence time in the reactor, the additive being selected from water-absorbing resin powders, fillers and mixtures thereof, the total solids content of monomer and additive being in the range from 30% to 60% by weight, the amount of additive being in the range from 5% to 50% by weight, based on the monomers, and the weight ratio of the first portion to the second portion of the additive being in the range from 10:1 to 1:5. The resin powder is recycled fine-sized material for example. Not only the residual monomer content, specifically the residual crosslinker content, but also the level of extractables in the water-absorbing resin are reduced by the method of addition described. A high fraction of additives can be incorporated without the properties of the water-absorbing resin obtained being adversely affected. The additives enter a sufficiently firm bond with the resin, so that no excessive dusting occurs on exposure to mechanical stress. | 12-23-2010 |
| Patent application number | Description | Published |
|---|
| 20080200623 | Polymerization Process - The invention relates to a process for preparing water-absorbing polymer particles, comprising the inertization of monomer solutions, wherein the monomer solution, based on the dissolved monomer, comprises from 0.001 to 0.016% by weight of at least one polymerization inhibitor and at least 50% by volume of the inert gas used to inertize the monomer solution is transferred into the polymerization reactor together with the inertized monomer solution, and also to apparatus for performing the process. | 08-21-2008 |
| 20080214749 | Method for the Production of Water Absorbing Polymers - A process for producing a water-absorbing polymer by polymerizing a monomer solution and drying the resulting hydrogel by means of a heated gas stream comprises
| 09-04-2008 |
| 20080275195 | Polymerization Process - The present invention relates to a process for continuously preparing water-absorbing polymers by mixing a monomer solution with at least one crosslinker and polymerizing the resulting mixture, wherein the residence time of the mixture between the addition of the at least one crosslinker and the entry into the polymerization reactor is less than 180 seconds, and also to an apparatus for performing the process. | 11-06-2008 |
| 20080306209 | Production of a Water-Absorbing Resin to Which a Particulate Additive is Admixed - The invention relates to a process for producing a water-absorbing resin by polymerization of a reaction mixture comprising at least one hydrophilic monomer and, if appropriate, at least one crosslinker in a reactor, which comprises admixing the reaction mixture with at least one first portion of a particulate additive before the reaction mixture has reached a residence time of 40% of the overall residence time in the reactor and with at least one second portion of a particulate additive when the reaction mixture has reached a residence time of 45% or more of the overall residence time in the reactor, the additive being selected from water-absorbing resin powders, fillers and mixtures thereof, the total solids content of monomer and additive being in the range from 30% to 60% by weight, the amount of additive being in the range from 5% to 50% by weight, based on the monomers, and the weight ratio of the first portion to the second portion of the additive being in the range from 10:1 to 1:5. The resin powder is recycled fine-sized material for example. Not only the residual monomer content, specifically the residual crosslinker content, but also the level of extractables in the water-absorbing resin are reduced by the method of addition described. A high fraction of additives can be incorporated without the properties of the water-absorbing resin obtained being adversely affected. The additives enter a sufficiently firm bond with the resin, so that no excessive dusting occurs on exposure to mechanical stress. | 12-11-2008 |
