Nippon Shokubai Co., Ltd.

Other

Nippon Shokubai Kagaku Kogyo Co., Ltd.

Kozo Nogi

Kunihiko Ishizaki

Shigeru Sakamoto

Yorimichi Dairoku

Kenji Kadonaga

Masazumi Sasabe

Shinichi Fujino

Masatoshi Nakamura

Motohiro Imura

Katsuhiko Sakamoto

Koji Matsumoto

Yoshio Irie

Katsuyuki Wada

Yusuke Watanabe

Sumio Okuda

Syuji Kanzaki

Koji Honda

Koji Miyake

Taku Iwamura

Yoshiro Mitsukami

Takahiro Kitano

Kazushi Torii

Satoshi Matsumoto

Hirotama Fujimaru

Yoshifumi Adachi

Hiroki Inoue

Kenji Minami

Hirofumi Shibata

Reiko Nakatsuru

Kinya Nagasuna

Sayaka Machida

Kazuki Kimura

Hiroko Ueda

Taishi Kobayashi

Kazumasa Konishi

Motohiro Arakawa

Nobuhiko Yukawa

Masato Abe

Kazuma Awai

Hiroshi Yamazaki

Yasuhiro Fujita

Toshimasa Kitayama

Shin-Ichi Fujino

Ryota Wakabayashi

Koichi Yonemura

Akiko Mitsuhashi

Terukuni Hashimoto

Kazutomo Takahashi

Toru Nishioka

Noriaki Mizutani

Sachie Kitabata

Tomoyuki Arake

Chihiro Tani

Erina Minami

Yoshiki Katada

Teruhisa Nagashima

Sumito Kumagai

Keiji Inoue

Akihiro Morita

Hiroaki Hattori

Naofumi Tsujino

Koji Shibata

An object of the present invention is to provide a water absorbent resin powder for a heat-generating element composition, which suppresses the generation of the aggregates derived from the water absorbent resin and the adhesion of the water absorbent resin in the production of a heat-generating element composition. A present inventive water absorbent resin powder for a heat-generating element composition includes polyacrylic acid (salt)-based water absorbent resin powder which have a bulk specific gravity (specified by JIS K3362) of 0.630 g/cmor less, fluid retention capacity without load (CRC) for a 0.9% by weight aqueous solution of sodium chloride (specified by ERT441.01-2) of 32.0 g/g or less, a weight-average particle diameter (specified by sieve classification) of 250 μm or more, and an amount of a residual glycidyl-based crosslinking agent of 10 ppm or less.

Water absorbent resin powder for heat-generating element composition, and heat-generating element composition

The present invention provides a novel acrylic acid crosslinked polymer and the use thereof. The present invention provides the acrylic acid crosslinked polymer in which the content of soluble components is 40 wt. % or higher. The present invention also provides a method for adjusting the viscosity of a fracturing fluid in a hydraulic fracturing method, the viscosity adjustment method including: A) a step of measuring the types and quantities of metal cations which are in water and which are the object of viscosity adjustment; B) a step of selecting the type and quantity of an acrylic acid crosslinked polymer on the basis of the types and quantities of metal cations and the pH so as to achieve a viscosity that is required for fracturing in a hydraulic fracturing method; and C) a step of adjusting the viscosity of the fracturing fluid using the acrylic acid crosslinked polymer of the selected type and quantity.

Acrylic acid crosslinked polymer and use thereof

[Object] To provide a method for stably producing a water-absorbent resin in powder form or particle form, which has excellent physical properties such as water absorption performance and the like, without any production trouble. [Solution] A method for producing a water-absorbent resin includes mixing a monomer composition, which contains at least a monomer and a pyrolytic polymerization initiator, with an organic solvent, a temperature of the organic solvent is not lower than 70&#xb0; C. at time of mixing, and when a mass per unit time of the monomer in the monomer composition to be mixed with the organic solvent is expressed as an amount per unit volume of the organic solvent, a lower limit is 0.01 g/ml/min, and an upper limit is 0.2 g/ml/min.

Method for producing water-absorbent resin

From a view pint of decreasing an out of spec product after surface crosslinking, particularly, when an alkylene carbonate compound is used as a surface crosslinking agent, influence due to an air temperature is great, and it is necessary to reduce ethylene glycol which is produced as a byproduct. There is provided a process for producing a polyacrylic acid (salt)-based water absorbent resin powder, comprising storing a non-polymerized organic compound being a raw material (modified raw material) of a water absorbent resin powder in a heated state, thereafter, mixing the non-polymerized organic compound with other compound at a predetermined ratio and, further, mixing the mixture into a water absorbent resin powder.

Method for producing polyacrylic acid (salt)-based water absorbent resin powder

A water-absorbing resin composition including 100 parts by weight of water-absorbing resin particles and 0.01 to 1 part by weight of additive particles, wherein a percent by weight of the additive particles, (x [%]), based on 100% by weight of the water-absorbing resin particles in the composition, and weight ratio of free additive particles, (y), relative to the percent by weight, (x [%]), satisfy the following formula:0.04()0.2().

Production method for water-absorbing resin composition

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 &#x2266;AAP (4.83 kPa)+1.8&#xd7;CRC&#x2266;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.

Particulate water absorbent and process for production thereof

A method for producing a water absorbent resin, the method including a polymerization step, a drying step, a classification step, and a surface crosslinking step. The classification step carried out before or after the surface crosslinking step requires use of a tapping material and a metal sieve mesh, in which the tapping material being heated at 40&#xb0; C. to 100&#xb0; C. is installed below the metal sieve mesh, and the metal sieve mesh has an area of 1 to 10 m/sheet. The classification step further requires introducing a classification aid particle, which has a specific gravity different from that of the water absorbent resin, to the metal sieve mesh; and monitoring the presence or absence of damage to the metal sieve mesh.

Method of producing water absorbent resin

The purpose of the present invention is to provide a method for producing a water absorbent resin in which a water absorbent resin having excellent properties can be obtained effectively. The present invention relates to a method for producing a polyacrylic acid (salt)-based water absorbent resin, which includes a polymerization step of polymerizing an aqueous monomer solution containing a polymerization inhibitor, acrylic acid (salt) and an internal cross-linking agent to produce a water-containing gel-like cross-linked polymer, a gel-crushing step of performing the gel-crushing of the water-containing gel-like cross-linked polymer simultaneously with or subsequent to the polymerization to produce a particulate water-containing gel-like cross-linked polymer, and a drying step of supplying the particulate water-containing gel-like cross-linked polymer to a continuous through-flow belt-type dryer by a traverse conveyor to dry the particulate water-containing gel-like cross-linked polymer, in which the belt temperature of the traverse conveyor is 40 to 120&#xb0; C. and/or the water soluble component in the particulate water-containing gel-like cross-linked polymer on the traverse conveyor is 10% by weight or less and the water soluble component is increased after the drying step.

Method and apparatus for producing polyacrylic acid (salt)-based water absorbent resin

From a view point of reduction in an out of spec product after surface crosslinking, particularly, when an alkylene carbonate compound is used as a surface crosslinking agent, influence by an air temperature is great, and it is necessary to reduce ethylene glycol which is produced as a byproduct, and there is provided a process for producing a polyacrylic acid (salt)-based water absorbent resin powder, comprising

A method for producing a water absorbent resin, the method including a polymerization step, a drying step, a classification step, and a surface crosslinking step. The classification step carried out before or after the surface crosslinking step requires use of a metal sieve mesh having stretch tension from 35 to 100 N/cm, in which an air jet cleaner or an air jet brush cleaner and plural tapping balls or tapping blocks are installed below the metal sieve mesh, a classification aid particle having specific gravity different from that of the water absorbent resin powder is added, and a fine powder of the water absorbent resin and the classification aid particle are removed.

A method for producing a polyacrylic water-absorbent resin powder includes the steps of: producing an acrylic monomer solution in which gas is dissolved and/or dispersed; polymerizing the monomer solution in the absence of a surface active agent or in the presence of not more than 300 ppm of a surface active agent; during or after polymerizing, fragmenting the resulting hydrated gel crosslinked polymer; and drying the fragmented hydrated gel crosslinked polymer. The gas is dissolved and/or dispersed in the monomer solution by (a) applying pressure to the acrylic monomer solution and the gas; (b) creating swirling flows of the acrylic monomer solution and the gas; or (c) introducing the gas with the acrylic monomer solution via fine holes. The production method efficiently produces a water-absorbent resin having an excellent water-absorption rate without deteriorating a liquid-absorbent property of a sanitary product or the like.

Polyacrylic acid-based water-absorbing resin powder and method for producing the same

[PROBLEM] Provided is a transportation method for a water-absorbing resin powder substance, which is capable of suppressing property decrease of the water-absorbing resin powder substance while suppressing blocking phenomenon and is suitable for long distance transportation. [SOLUTION] The present invention is a transportation method for a water-absorbing resin powder substance during a production step by pneumatic transportation via a transportation pipeline. In this transportation method, two or more pneumatic transportation apparatuses (A, B, C) are provided in one transportation section, and these pneumatic transportation apparatuses (A, B, C) are connected by the transportation pipelines (P, P, P) in series.

Transportation method for water-absorbing resin powder substance

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.

Polyacrylic acid (salt)-type water absorbent resin and method for producing of same

[Problem] To provide a pneumatic conveyance method for a water-absorbing resin powder substance, which is capable of suppressing property decrease of the water-absorbing resin powder substance, while suppressing obstruction phenomenon. [Solution] A conveyance method for a water-absorbing resin powder substance by pneumatic conveyance of the water-absorbing resin powder substance during a production step via a transportation pipeline, wherein a variation of a solid-gas ratio (R/R) exceeds 1 and is equal to or smaller than 7, provided that R(kg-resin/kg-air) stands for an initial solid-gas ratio at a start point of the transportation pipeline, and R(kg-resin/kg-air) stands for a terminal solid-gas ratio at a terminal point of the transportation pipeline is provided.

Conveyance method for water-absorbing resin powder substance

Provided is a production method for the particulate water-absorbing agent, which can collecting the fine powders generated during the producing process efficiently without worsening working environment, and also the particulate water-absorbing agent produced by the production method thereof. This production method includes (1) a polymerization step for obtaining a polymer gel, (2) a drying step for drying said polymer gel to obtain a particulate water-absorbing resin, (3) a classification step for sieving said particulate water-absorbing resin, (4) a surface cross-linking step for cross-linking the neighborhood of the surface of said particulate water-absorbing resin (5) a packaging step for filling a packaging material container with said particulate water-absorbing agent for packaging and (6) a transportation step for transporting the products produced in each of the steps to the other steps. In this production method, the fine powders contained in gas composed principally of air, in any of the steps, can be collected by use of a trapping material.

Method for producing particulate water-absorbing agent composed principally of water-absorbing resin

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Himeji, Japan

Kozo Nogi