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 |
20090036855 | Particulate water-absorbing agent with water-absorbing resin as main component, method for production of the same, and absorbing article - Reversed phase suspension polymerization is allowed while controlling content of minor components in monomer, particularly controlling a content of acetic acid and propionic acid being not higher than 500 ppm, controlling a content of acrylic acid dimer being not higher than 1000 ppm, in acrylic acid. Cross-linked polymer obtained by the polymerization is subjected to a surface crosslinking treatment without substantially using an organic solvent, and under heating at high temperature (150° C. or higher and 250° C. or lower). Thereafter, agglomeration is carried out without substantially using an organic solvent. Accordingly, a particulate water-absorbing agent including a water-absorbing resin having superior property, and being suited for practical applications at high concentrations in absorbing cores such as a diaper and the like without generation of any odor of the organic solvent can be obtained because no volatile organic compound is included. | 02-05-2009 |
20090182294 | Water absorbing agent and production method thereof - A water absorbing agent includes water absorbent resin particles which are obtained by polymerizing a water-soluble ethylenic unsaturated monomer and which internally include a cross-linked structure, wherein a pressurized void average radius index is 140 or more. As a result, it is possible to provide a water absorbing agent which essentially includes water absorbent resin particles and is suitable for use in a sanitary material. Specifically, it is possible to improve not only a performance for absorbing and retaining aqueous liquid without pressure or under pressure but also (i) a performance for quickly absorbing aqueous liquid with a great help of a performance of a fibrous material, (ii) a performance for dispersing the aqueous liquid after absorbing the aqueous liquid, and (iii) a performance for retaining the aqueous liquid after absorbing the aqueous liquid. | 07-16-2009 |
20090298685 | WATER ABSORBING AGENT, WATER ABSORBENT CORE USING THE AGENT, AND MANUFACTURING METHOD FOR WATER ABSORBING AGENT - A water absorbing agent of the present invention has an internal crosslinking structure obtained by polymerization of a water-soluble unsaturated monomer. The agent satisfies conditions (a) to (d): (a) the agent contains water-insoluble inorganic particles at an amount of from 10 ppm to 1,900 ppm inclusive; (b) the agent contains 5 mass % or less particles which have such a size that they can pass through a sieve having a mesh opening size of 150 μm; (c) the agent has an absorbency against a pressure of 4.83 kPa (AAP) of 18 g/g or more; and (d) the water-insoluble inorganic particles reside on a surface of the water absorbing resin or near the surface. | 12-03-2009 |
20100062252 | Water absorbing agent, water absorbing article and method for production of water absorbing agent - An object of the present invention is to provide a water absorbing agent having a low amount of residual monomer, small variance of the amount of residual monomer among ranges of particle size distribution and favorable absorption properties, and being sanitary; an absorbing article; and a method for the production of a water absorbing agent. The water absorbing agent of the present invention has the amount of residual monomer of not higher than 500 ppm, and a residual monomer index of not greater than 0.30. The method for the production includes a first step of obtaining a hydrogel polymer by polymerizing an aqueous solution of a monomer including an unsaturated carboxylic acid and/or a salt thereof in the presence of a crosslinking agent; a second step of obtaining a water absorbent resin precursor which is in powder form and includes particles having a particle size of 300 to 850 μm and particles having a particle size of smaller than 300 μm as main components by drying said hydrogel polymer followed by pulverization and classification to adjust the particle size distribution, a third step of obtaining a water absorbent resin by heating a mixture of said water absorbent resin precursor and a surface crosslinking agent, which can form an ester bond around the surface of said water absorbent resin precursor, a fourth step of adding by spraying an aqueous solution that includes a sulfur-containing reducing agent to said water absorbent resin, and a fifth step of subjecting the mixture of the water absorbent resin and said aqueous solution to a heat treatment under an airflow of not lower than 40° C. but not higher than 120° C. | 03-11-2010 |
20100072421 | PARTICULAR WATER-ABSORBENT AGENT HAVING WATER-ABSORBENT RESIN AS MAIN COMPONENT - A particulate water-absorbent agent containing a polyacrylate salt-type water-absorbent resin. The agent has an absorption capacity without load of 28 g/g or higher and has a diffusion absorption index of 1.40 to 10.0 g/g min. The amount of water-soluble components in the agent, with stirring, is 15-60% by mass. The difference between this amount and the amount of water-soluble components, without stirring, is 15-50% by mass. Also disclosed is a method of making the above-identified agent. | 03-25-2010 |
20100120940 | PARTICULATE WATER-ABSORBING AGENT HAVING WATER-ABSORBING RESIN AS MAIN COMPONENT - A water-absorbing goods having excellent absorption performance in practical use is to be provided at low price. A particulate water-absorbing agent provided by one aspect of the present invention is a particulate water-absorbing agent comprising a polyacrylate salt-type water-absorbing resin as a main component, and satisfying the following (a) and (b):
| 05-13-2010 |
20100240808 | WATER-ABSORBING RESIN COMPOSITION AND PROCESS FOR PRODUCTION OF THE SAME - An object is to provide a water absorbent resin composition containing a water absorbent resin as a main component, with excellent deodorant property and antimicrobial property without impairing appearance and absorption characteristics of the water absorbent resin. The water absorbent resin composition according to the first aspect includes a water absorbent resin containing a polyacrylic acid (salt)-based water absorbent resin as a main component, and an extract of bamboo and an extract of tea. The water absorbent resin composition according to the second aspect includes a water absorbent resin containing a polyacrylic acid (salt)-based water absorbent resin as a main component, and at least two kinds of compounds selected from a group consisting of hexanoic acid (salt), ethyl butyrate, and 3-methyl-2-cyclopenten-1-one. In addition, the method for producing the water absorbent resin composition according to the third aspect includes the step of adding an alcoholic solution of an extract of bamboo, before or after polymerization of an unsaturated monomer containing an acrylic acid (salt) as a main component. | 09-23-2010 |
20120172536 | POLYACRYLIC ACID (SALT)-TYPE WATER ABSORBENT RESIN AND METHOD FOR PRODUCING OF SAME - Disclosed is a method for producing a water absorbent resin, by which a surface-crosslinked water absorbent resin having excellent physical properties can be efficiently obtained at low cost, while assuring high productivity. When the production scale is increased to a continuous production on a huge scale (for example, 1 t/hr or more), the physical properties are improved and stabilized (for example, standard deviation of the physical properties is reduced) by a surface-crosslinking treatment, and the absorption against pressure (AAP) and liquid permeability (SFC) are further improved. Specifically disclosed is a method for continuously producing a polyacrylic acid (salt)-type water absorbent resin powder, which comprises: a step of preparing an aqueous monomer solution using an acrylic acid (salt); a step of polymerizing the aqueous monomer solution; a shredding step of a hydrous gel-like crosslinked polymer during or after the polymerization; a step of drying the thus-obtained particulate hydrous gel-like crosslinked polymer; a step of crushing and classifying the dried product; a step of heating and surface-crosslinking after the classification; and a step of cooling after the surface-crosslinking. In the method for producing a polyacrylic acid (salt)-type water absorbent resin, the internal area of the cooling device that is used in the cooling step is 0.25-0.95 times the internal area of the heating device that is used in the surface-crosslinking step. | 07-05-2012 |
20120184670 | PARTICULATE WATER ABSORBENT AND PROCESS FOR PRODUCTION THEREOF - A particulate water absorbing agent of the present invention is a water absorbing agent containing a water absorbing resin as a main component, the particulate water absorbing agent containing a polyvalent metal cation and satisfying: (1) the polyvalent metal cation is contained in an amount between 0.001 wt % and 5 wt % relative to the amount of the water absorbing agent; (2) an absorbency without pressure (CRC) is not less than 28 (g/g) and an absorbency against pressure (AAP 4.83 kPa) is not less than 10 (g/g); (3) the absorbency against pressure and the absorbency without pressure satisfy 77≦AAP (4.83 kPa)+1.8×CRC≦100; and (4) a moisture content of the water absorbing agent is between 5 wt % and 20 wt %. This provides a water absorbing agent which has blocking resistance after moisture absorption, is excellent in stability to shock and suppresses Re-Wet when used in a diaper. | 07-19-2012 |
20120305842 | WATER ABSORBING AGENT, WATER ABSORBENT CORE USING THE AGENT, AND MANUFACTURING METHOD FOR WATER ABSORBING AGENT - A water absorbing agent of the present invention has an internal crosslinking structure obtained by polymerization of a water-soluble unsaturated monomer. The agent satisfies conditions (a) to (d): (a) the agent contains water-insoluble inorganic particles at an amount of from 10 ppm to 1,900 ppm inclusive; (b) the agent contains 5 mass % or less particles which have such a size that they can pass through a sieve having a mesh opening size of 150 μm; (c) the agent has an absorbency against a pressure of 4.83 kPa (AAP) of 18 g/g or more; and (d) the water-insoluble inorganic particles reside on a surface of the water absorbing resin or near the surface. | 12-06-2012 |
20140193641 | Polyacrylic Acid (Salt)-Based Water Absorbent Resin Powder and Method for Producing the Same - Provided is a water absorbent resin having excellent liquid permeability, water absorbent speed, anti-impact stability, and weather resistance. Provided is a polyacrylic acid (salt)-based water absorbent resin powder in which the water absorption capacity without load (CRC) is 30 to 45 [g/g], the water absorption capacity under load (AAP 0.3) is 20 to 35 [g/g], the water absorption capacity under load (AAP 0.7) is 10 to 28 [g/g], and the weight average particle diameter (D50) is 300 to 500 μm, characterized by including p-methoxyphenol; having a degradable soluble component (0.05% L-A (saline) for 2 hours/60° C., one hour extraction rinse/room temperature) of 40% by weight or less; and having a internal gas bubbles ratio of 0.1 to 2.5%, as specified by the following equation. | 07-10-2014 |