Patent application number | Description | Published |
20080221229 | WATER-ABSORBING AGENT AND PRODUCTION METHOD THEREOF - To provide a water absorbing agent which is excellent in balance between absorbency and liquid permeability against pressure and is excellent in flowability at the time of moisture absorption. The water absorbing agent comprises water absorbent resin particles and an organic surface additive, wherein: the organic surface additive having (i) a reactive group for a functional group of a surface of each water absorbent resin particle and (ii) a hydrophobic group exists on the surface of the water absorbent resin particle, and the hydrophobic group has a hydrocarbon group whose carbon number is 8 or more, and a ratio of an oxyalkylene group in a molecular mass of the organic surface additive is 0 or more and 25 mass % or less. | 09-11-2008 |
20100308263 | WATER ABSORBENT AND PRODUCING METHOD OF SAME - An object of the present invention is to provide a water absorbent having excellent gel properties and showing excellent properties when used in a water-absorbing material of a sanitary/hygienic material such as paper diaper. Moreover, another object of the present invention is to provide a water absorbent which is safe and excellent in liquid permeability, and in which an amount of liquid permeability improver for improving the liquid permeability is reduced. The water absorbent is made from a water-absorbing resin prepared by a specific polymerization method and having a high degree of cross-linking, a high liquid holding property and a high gel strength (its swelling pressure of gel layer of is 35 kdyne/cm2 or more). This water absorbent is further processed to have a particular particle size distribution (95 wt % or more of its particles are less than 850ƒÊm but not less than 106ƒÊm, and logarithmic standard deviation (ƒĐƒÄ) is in a range of 0.25 to 0.45) and then surface cross-linked. After that, a liquid permeability improver is added therein. | 12-09-2010 |
20120220733 | PRODUCTION METHOD FOR WATER-ABSORBING RESIN POWDER | 08-30-2012 |
20120220745 | PRODUCTION METHOD FOR WATER-ABSORBING RESIN POWDER | 08-30-2012 |
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 |
20130026412 | METHOD FOR PRODUCING WATER ABSORBENT POLYACRYLIC ACID (SALT) RESIN POWDER, AND WATER ABSORBENT POLYACRYLIC ACID (SALT) RESIN POWDER - An object of the present invention is to provide a method for producing water absorbent resin powder in which permeability potential (SFC) is improved while a water absorbing rate (FSR) is being kept. The method is a method for producing water absorbent polyacrylic acid (salt) resin powder including the steps of: (i) polymerizing an acrylic acid (salt) monomer aqueous solution; (ii) during or after the step of (i), performing gel grinding of a hydrogel crosslinked polymer obtained by the polymerization, wherein the hydrogel crosslinked polymer has resin solid content of 10 wt % to 80 wt %, and the gel grinding is carried out with gel grinding energy (GGE) of 18 [J/g] to 60 [J/g]; (iii) drying a particulate hydrogel crosslinked polymer obtained by the gel grinding, wherein the drying is performed at 150° C. to 250° C.; and (iv) carrying out a surface treatment to the particulate hydrogel crosslinked polymer thus dried. | 01-31-2013 |
20130102750 | METHOD FOR PRODUCING POLYACRYLIC ACID (SALT)-BASED WATER ABSORBENT RESIN POWDER - A water absorbent resin having less fine powder or powdery dust and a controlled particle size is provided, and the water absorption rate of the water absorbent resin is increased by a simple method at low cost, while maintaining or improving other physical properties such as liquid permeability. Disclosed is a method for producing a polyacrylic acid (salt)-type water absorbent resin powder, which includes, in sequence, a step of polymerizing an aqueous solution of acrylic acid (salt)-type monomer; a step of gel-crushing a gel of a water-containing gel-like crosslinked polymer during polymerization or after polymerization; a step of drying the water-containing gel-like crosslinked polymer; and a step of pulverizing and classifying the dried polymer, wherein water absorbent resin fine particles having a particle size of less than 150 μm or a hydrated-particles thereof is added to a step prior to the drying step, and in the drying step, hot air drying is carried out with a hot air having an average flow velocity of 1.0 to 3.0 [m/s], a dew point of 30° C. to 100° C., and a hot air temperature of 140° C. to 235° C. | 04-25-2013 |
20140371400 | METHOD FOR PRODUCING POLYACRYLIC ACID (SALT)-BASED WATER ABSORBENT RESIN - The purpose of the present invention is to provide a method for producing a water absorbent resin having improved physical properties, particularly, improved saline flow conductivity (SFC) and less amount of fine powder. The present invention provides a method for producing a polyacrylic acid (salt)-based water absorbent resin, the method comprising: a polymerization step of supplying as a base material an aqueous solution containing an acrylic acid and/or an acrylic acid salt as a monomer component and polymerizing the monomer in the presence of a polymerization initiator, wherein in the polymerization step, there is used a polymerization apparatus which comprises a polymerization part covered with a case, said polymerization part comprising at least a supply line for supplying the aqueous solution, an external gas supply port, and a gas discharge port, and has a structure that a liquid contact part in contact with the aqueous solution and a gas supplied from the outside of the polymerization apparatus are brought into contact with the aqueous solution during a polymerization, and assuming that a controlled temperature of the liquid contact part is set as TS, a temperature of the gas part is set as TG, and TT is (TS+TG)/2, the polymerization is carried out under temperature conditions satisfying the following Equations 1 to 3: Equation 1: 35° C.≦TS≦85° C., Equation 2: 40° C.≦TG≦90° C., Equation 3: 47° C.≦TT≦73° C. | 12-18-2014 |