Patent application number | Description | Published |
20090008604 | Particulate Water Absorbing Agent, Water-Absorbent Core and Absorbing Article - The present invention provides a particulate water absorbing agent for absorbent cores which is excellent in powder conveying property, and achieves sufficient absorption performances for use in absorbent cores in particulate water absorbing agents including a water absorbing resin as a principal component, and which further is suitable for practical applications. In the present invention, characteristics that had not been known conventionally at all, i.e., “permeability potential under pressure (PPUP)” and “frictional charge being a positive charge” of the particulate water absorbing agent are regulated at a time, and furthermore, regulation of the “moisture content of 2 to 10% by weight” is perfected. Also, the particulate water absorbing agent including (A) a water-swelling crosslinked polymer having a constitutional unit derived from an unsaturated monomer containing an acid group and/or a salt thereof; and (B) water fulfills certain requirements. | 01-08-2009 |
20100249320 | Process for producing water-absorbing resin - Drying is performed in a continuous fluidized bed having at least two drying rooms. Drying is performed after pulverization is performed between drying in a first drying room and drying in a second or subsequent room. Drying is performed in a continuous fluidized bed whose fluidized bed contains a heat transfer tube. The second or subsequent drying room has a higher drying temperature than the first drying room. Drying is performed with the drying temperature of the first drying room falling within a range of not less than 80° C. to not more than 200° C. and with the drying temperature of the second or subsequent drying room falling within a range of not less than 100° C. to not more than 220° C. Further, a method for producing a water absorbent resin includes: a sequence of the steps of: (1) polymerizing a monomer aqueous solution; (2) drying a hydrogel polymer obtained in the step (1); (3) performing particle size control by either pulverizing or pulverizing and classifying a dry polymer obtained in the step (2); and (5) performing surface crosslinking on water absorbent resin powder whose particle size has been controlled in the step (3), the method further including the step (4) of performing second heat drying on the water absorbent resin powder whose particle size has been controlled in the step (3), the step (4) preceding the step (5). Further, the water absorbent resin has a moisture content (defined by a loss on drying performed for three hours at 180° C.) of 0 wt % to 3 wt % before it is supplied to the step (5). (This makes it possible to provide a method for producing a water absorbent resin which method makes it possible to obtain a particulate water absorbent resin of excellent properties at low cost with high productivity. | 09-30-2010 |
20110021725 | Production method and production apparatus of particulate water absorbing agent containing water absorbent resin as main component - An apparatus ( | 01-27-2011 |
Patent application number | Description | Published |
20120016084 | Method for Producing Particulate Water-Absorbent Resin - A production of a water-absorbent resin by which a particle diameter of the water-absorbent resin can be controlled simply and conveniently, and a content of fine powder can be decreased, without necessity of change of raw materials or expensive facility investment is to be provided. The method is a continuous production method of a polyacrylic acid (salt)-based water-absorbent resin, comprising a polymerization step of an aqueous solution containing acrylic acid (salt), a drying step of the resultant hydrogel-like polymer, a pulverization step of the dried substance, a classification step of the pulverized substance, and optionally a surface cross-linking step of the classified substance, wherein (a) the drying step and the pulverization step are connected via a storage step and a transportation step; and (b) a time of holding the dried substance from a time of completing the drying step to a time of starting the pulverization step is set at 3 minutes or longer. | 01-19-2012 |
20120258851 | WATER-ABSORBABLE POLYACRYLIC ACID RESIN POWDER, AND PROCESS FOR PRODUCTION THEREOF - A process according to the present invention for production of water-absorbable polyacrylic acid resin powder, including: (a) polymerizing an acrylic acid-based monomer aqueous solution containing bubbles, and (b) drying a hydrogel crosslinked polymer thus obtained in the step of polymerizing, further includes (c) lowering solubility of dissolved gas in a monomer aqueous solution in the presence of a surfactant and/or a dispersing agent, so as to generate the bubbles in the acrylic acid-based monomer aqueous solution. With this arrangement, it is possible to provide white water-absorbable resin with better water absorbing rate, keeping or without significantly losing the other properties (permeability potential, bulk specific gravity, surface tension, absorbency against pressure, impact resistance, etc.) | 10-11-2012 |
20120289671 | METHOD FOR PRODUCING WATER ABSORBENT RESIN - With regard to a method for producing a water absorbent resin by drying a particulate hydrogel crosslinked polymer having a high solid content concentration (of 45% by weight or more, further 50% by weight or more, and particularly 55% by weight or more), to provide a method for efficient drying of a water absorbent resin having maintained/improved physical properties. | 11-15-2012 |
20120296057 | METHOD FOR PRODUCING WATER ABSORBENT RESIN - In a method for producing a water absorbent resin by drying a particulate hydrogel having a high solid content concentration (of 45% by weight or more, preferably 50% by weight or more, and more preferably 55% by weight or more), a method for efficient drying water absorbent resin having maintained/improved physical properties is provided. | 11-22-2012 |
20130101851 | POLYACRYLIC ACID-TYPE WATER ABSORBENT RESIN AND METHOD FOR PRODUCING SAME - Provided is a method for producing a water absorbent resin, which promotes the formation of interconnected voids (continuous gas bubbles) in a foamed polymer (foam-like water absorbent resin) by a more convenient method, and produces with high efficiency a water absorbent resin which exhibits a high water absorption rate even when stepped into a sheet form or a powder form in hygiene articles and the like. Disclosed is a a method for producing a polyacrylic acid-type water absorbent resin, comprising (A) a step of obtaining an aqueous solution of acrylic acid-type monomers containing gas bubbles dispersed therein; (B) a step of polymerizing the aqueous monomer solution and thereby obtaining a foamed polymer; and (C) a step of heating and drying the foamed polymer,
| 04-25-2013 |