| Patent application number | Description | Published |
|---|
| 20090221746 | Neutralization Process - The invention relates to a neutralization process in which at least one ethylenically unsaturated carboxylic acid is preneutralized at least partly with a base, wherein the preneutralized solution is divided into at least two part-solutions and at least one part-solution is aftertreated so as to form part-solutions with different degree of neutralization and/or solids content, and also to an apparatus for carrying out the process. | 09-03-2009 |
| 20100016522 | Method for the Continuous Production of Water Absorbent Polymer Particles - A process for continuously preparing water-absorbing polymer beads, comprising the drying of a polymer gel on a forced-air belt dryer, the water content of the polymer gel being used to control the forced-air belt dryer during or after the drying. | 01-21-2010 |
| 20100298513 | Method for the Production of Water-Absorbing Polymer Particles - 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. | 11-25-2010 |
| 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 |
| 20110015362 | Method for Manufacturing Water-Absorbing Polymer Particles with a Low Centrifuge Retention Capacity - A process for producing water-absorbing polymer particles with a low centrifuge retention capacity by polymerizing in a continuous kneading reactor under an inert gas volume flow of at most 10 m | 01-20-2011 |
| 20110098416 | Method for the Continuous Thermal Secondary Surface Cross-Linking of Water-Absorbing Polymer Particles - A process for continuous thermal postcrosslinking of water-absorbing polymer particles, wherein the postcrosslinker is applied to the water-absorbing polymer particles by means of suitable nozzles and the nozzles are exchanged or cleaned via the interior of a glovebox adjoining the plant section comprising the nozzle. | 04-28-2011 |
| Patent application number | Description | Published |
|---|
| 20080221282 | Polymerization Process - The invention relates to a process for continuously preparing water-absorbing polymer particles by mixing a monomer solution with a redox initiator consisting of at least one oxidizing agent and at least one reducing agent and polymerizing it, wherein the monomer solution is mixed with at least one oxidizing agent upstream of the polymerization reactor and the at least one reducing agent is metered into the polymerization reactor, and also to an apparatus for performing the process. | 09-11-2008 |
| 20080242816 | Neutralization Process - The invention relates to a neutralization process in which at least one ethylenically unsaturated carboxylic acid is neutralized at least partly with a base and at least one stream of the neutralization is determined continuously, and also to an apparatus for carrying out the process. | 10-02-2008 |
| 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 |
| 20090194462 | Method for Grading Water-Absorbent Polymer Particles - A process for classifying water-absorbing polymer beads, wherein screens having different mesh sizes are used before and after the postcrosslinking to remove the oversize. | 08-06-2009 |
