Nippon Shokubai Co., Ltd.

Ykk Corporation

Matsushita Electric Industrial Co., Ltd.

Kawasaki Jukogyo Kabushiki Kaisha

Satoshi Matsumoto

Kunihiko Ishizaki

Shinichi Fujino

Syuji Kanzaki

Kozo Nogi

Sumio Okuda

Yorimichi Dairoku

Makoto Matsumoto

Shigeyoshi Takazawa

Kenji Kadonaga

Yoshifumi Adachi

Masatoshi Nakamura

Narito Shibaike

Yusuke Watanabe

Hirofumi Shibata

Reiko Nakatsuru

Seiji Kato

Toshihiro Takaai

Kazumasa Konishi

Koji Honda

Chi-yuan Huang

Kazushi Torii

Kazuhiko Sakamoto

Shigeru Sakamoto

Ryo Tanaka

Sayaka Machida

Kazuki Kimura

Kenji Yuki

Toshiyuki Tsubone

Yoshitake Ishii

Masahiro Kusayama

Shin-Ichi Fujino

Yota Katsukawa

Takeshi Watanabe

Chih Hung Lin

Yuki Kabeya

Satoshi Kikuya

Ryota Wakabayashi

Shigeyoshi Takasawa

Akira Soeda

Yoshihiro Shobo

Toyofumi Sakai

Mai Sato

Masashi Ono

Takashi Miyamoto

Shin-ya Katsube

Tsuyoshi Yorino

Youhei Kaetsu

Tomoyuki Arake

Yoshitaka Awazu

Eri Nagasawa

Ryuta Kondo

Satoshi Imabayashi

Hiroki Hayashi

Naoki Katakura

Sumito Kumagai

Kenta Matsubara

Kanako Tsuru

Ke Jyun Wu

Keijiro Kunimoto

Shin-ichi Fujino

Yuichi Kurimoto

Yoshitsugu Nishiyama

Masahumi Inoue

Koji Shibata

Yuki Miura

The present invention addresses the problem of providing; a water absorbent resin powder having a reduced amount of fine powder generated and a reduced amount of fine powder recovered; and a production method for the water absorbent resin. The production method of the present invention includes a drying step and a fine powder granulation step. The drying step is for obtaining a dried polymer by drying a particulate water-containing gel crosslinked polymer which is obtained using an acid group-containing unsaturated monomer as a main component. The fine powder granulation step is for obtaining a fine powder granulated product by adding a binder and an adhesion control agent to a fine powder made of a water absorbent resin. In this production method, the obtained fine powder granulated product is recovered in the drying step or in any step before the drying step.

Water-absorbent resin powder and production method thereof

The present invention addresses the problem of reducing the undried residue when recycling a fine powder of water-absorbing resin. The present invention is a method for producing a water-absorbing resin, wherein: a fine powder recycling step includes vi-1) a granulation step for obtaining a granulated gel, vi-2) a granulated gel addition step, and vi-3) a gel mixing step; the solids content of the granulated gel in the granulated gel addition step is 50-90% by mass; and the temperature of the granulated gel and the temperature of the water-containing gel-like crosslinked polymer is 50-100° C.

Method for producing water-absorbent resin

A polyacrylic acid (salt), or a polyacrylic acid (salt)-based water-absorbing resin, contains a tracer for detecting various troubles in the water-absorbing resin during the period from the production of the water-absorbing resin to the use and discard thereof by a consumer. The polyacrylic acid (salt)-based water-absorbing resin has a stable carbon isotope ratio, as determined by accelerator mass spectrometry, of less than &#x2212;20&#x2030; and a radioactive carbon content of 1.0&#xd7;10or more. The polyacrylic acid (salt)-based water-absorbing resin has: a CRC of 10 [g/g] or more; an AAP of 20 [g/g] or more; an Ext of 35 wt. % or less; a content of residual monomers of 1,000 ppm or less; a PSD in which the proportion of particles having a particle diameter of 150 &#x3bc;m or larger but less than 850 &#x3bc;m is 90 wt. % or more; and an FSR of 0.15 [g/g/s] or more.

Polyacrylic acid (salt), polyacrylic acid (salt)-based water-absorbing resin, and process for producing same

Disclosed are a polyacrylate (salt) and a polyacrylate (salt) water-absorbent resin containing a tracer which can be verified back to the manufacturing process of the water-absorbent resin when dealing with various problems with the water-absorbent resin which can occur from the manufacturing process of the water-resistant resin, during the use thereof by a consumer, up until the disposal thereof. The disclosed polyacrylate (salt) and the polyacrylate (salt) water-absorbent resin have a carbon stable isotope ratio (&#x3b4;C) of at least &#x2212;20&#x2030; when measured by accelerator mass spectrometry.

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

The disclosed process for continuously producing a water-absorbing resin comprising a plurality of joined continuous steps; a polymerization step of polymerizing an aqueous unsaturated monomer solution, a drying step of drying a particulated water-containing gel-like crosslinked polymer obtained in a finely crushing step during the polymerization or after the polymerization, a pulverizing step after the drying, a classification step after the drying, and a surface treatment step for the water-absorbing resin powder after the classification step. In the process, with some of the above steps kept running, the other steps are interrupted, and subsequently all the steps are restarted.

Process for producing water-absorbing resin

A method for producing a polyacrylic acid (salt)-based water absorbent resin, sequentially including the steps of: storing or producing acrylic acid; mixing acrylic acid containing a polymerization inhibitor with water, a crosslinking agent, and optionally, a basic composition, and/or neutralizing them, to prepare an aqueous monomer solution; polymerizing the aqueous monomer solution; drying an obtained water-containing gel-like crosslinked polymer; and optionally carrying out surface crosslinking, wherein the acrylic acid containing the polymerization inhibitor has a water content of not higher than 1,000 ppm (by mass; the same applies hereinafter), and/or the aqueous monomer solution has a formic acid content of 1 to 700 ppm, relative to the monomer.

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

An air cleaner mounted on a motorcycle for purifying an engine intake air includes a lower casing forming a cleaner main body, a covering for covering an upward region of the lower casing, a cleaner element disposed inside the lower casing and positioned below a mating interface between the lower casing and the covering, and a partition wall formed in the lower casing for supporting the cleaner element and forming a part of a wall of a clean chamber.

Air cleaner for motorcycle

Provided is a method for producing a polyacrylic acid (salt)-based water absorbent resin, which is a convenient production method for a water absorbent resin for an absorbent suitable for practical use, the water absorbent resin having a reduced amount of residual monomers. Disclosed is a method for producing a polyacrylic acid (salt)-based water absorbent resin, the method comprising a polymerization step of polymerizing an aqueous monomer solution containing acrylic acid (salt) as a main component; a drying step of drying a water-containing gel-like crosslinked polymer obtained in the polymerization step; a surface crosslinking step of surface crosslinking the water absorbent resin under drying or the water absorbent resin which has been dried; and a packaging step of packaging the surface crosslinked water absorbent resin, wherein an iron content in the aqueous monomer solution in the polymerization step is 2 ppm (relative to the monomer(s)) or less, a moisture content of the water absorbent resin in the packaging step is 1% by weight or more, and the method further comprises, after the packaging step, a storage step of storing the packaged water absorbent resin for 3 days or longer.

Polyacrylic acid (salt)-based water absorbent resin, and method for production thereof

The present invention provides a method for producing, by adding an additive and/or gas bubbles to a monomer with high efficiency, a polyacrylic acid (salt)-based water-absorbing resin having high physical properties while high productivity is maintained. The step of preparing an aqueous monomer solution includes the steps of: preparing an aqueous solution; and adding a water-insoluble additive and/or gas bubbles. A retention time from when the water-insoluble additive and/or the gas bubbles is/are added to when polymerization starts is 1 second to 60 seconds.

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

To provide a method for producing a water-absorbing resin by which problems caused by addition of a particulate additive or water-absorbing resin fine powder can be prevented and a water-absorbing resin having high physical properties can be stably and efficiently obtained. A method for producing a polyacrylic acid (salt)-based water-absorbing resin, the method including: an aqueous monomer solution preparation step for preparing an aqueous solution containing a monomer having an acrylic acid (salt) as a main component; a polymerization step for polymerizing the monomer to obtain a hydrogel-forming crosslinked polymer; and a drying step for drying the hydrogel-forming crosslinked polymer to obtain a dry polymer, wherein the method further includes an adding step for adding a particulate additive to the aqueous monomer solution and/or the hydrogel-forming crosslinked polymer, and in the adding step, an oxygen concentration in an ambient atmosphere of the particulate additive is set to 5% by volume or less.

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

A method for producing polyacrylic acid (salt)-based water-absorbing resin includes a step of polymerizing an acrylic acid (salt)-based aqueous monomer solution, the polymerization step involving use of a polymerization reaction apparatus including a polymerization reaction unit covered with a casing, the polymerization step involving a polymerization reaction under internal pressure of the polymerization reaction unit, the internal pressure being slightly reduced and having a pressure reduction level of more than 0 kPa and not more than 10 kPa relative to the ambient pressure at the periphery of the polymerization reaction unit.

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 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

An object of the present invention is to provide a simple method for improving and stabilizing the physical properties (for example, liquid permeability) of a water absorbent resin, without requiring investment in expensive facilities or modification of raw materials. In particular, the object is to provide a method which is useful in the large-scale production of a water absorbent resin. The method for producing polyacrylic acid (salt)-based water absorbent resin of the present invention includes, in order, a step in which an acrylic acid (salt)-based monomer aqueous solution is polymerized, a step in which the water-containing gel-like crosslinked polymer obtained in the polymerization step is dried, a step in which the dried polymer obtained in the drying step is pulverized, and a classification step which takes place after the drying step or after the pulverizing step, wherein, at the time of providing the dried polymer to the roll mill used in the pulverizing step, the dried polymer is provided in a dispersed state in the axial direction of the roll of the roll mill.

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

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Hyogo, Japan

Satoshi Matsumoto