American Colloid Company

Arakawa Kagaku Kogyo Kabushiki Kaisha

Arakawa Chemical Industries, Ltd.

Shozo Tanioku

Takayasu Touda

Muneharu Mikita

Muneharu Makita

Jun-ichi Maeno

Kiyoshi Sato

Tsunemitsu Matsuda

Nobuyuki Oshima

Daisaku Suga

Kenji Takeuchi

The present invention provides an NMR diagnosis assisting sheet characterized in that the sheet comprises a molded body of a water-absorbing resin, the water-absorbing resin forming a uniform matrix phase wherein the molecules of the resin are interlocked with one another, and water absorbed by the resin is uniformly dispersed as chemically and/or physically bonded to the resin.

Sheet for assisting in NMR diagnosis

This invention provides a process for preparing a water-absorbing resin which comprises the steps of mixing powder of an inorganic inactive substance with a water-absorbing resin having carboxylate-containing monomer units, and adding water and a high molecular-weight cross-linking agent to the mixture to perform cross-linking reaction and evaporation of water, the cross-linking agent being selected from a specified copolymer (1) and a specified mixture of copolymers (2), and also provides a water-absorbing resin prepared by the process. The process of the invention gives water-absorbing resins improved not only in water-absorbing ability, rate of water absorption, gel strength after water absorption and unlikelihood of affording a wetty feeling after water absorption but also in capability of retaining water under pressure.

Process for preparing water-absorbing resin

A process for preparing a solid, water absorbing, cross-linked polyacrylate resin including combining potassium acrylate and a polyvinyl monomer, such as N,N-methylene bisacrylamide, with water in an amount of 55 to 80 combined weight percent of potassium acrylate and polyvinyl monomer based on the total weight of potassium acrylate, polyvinyl monomer and water to form a monomer mixture, and adding a polymerization initiator to the monomer mixture to initiate polymerization of the monomer mixture. The monomer mixture then is polymerized without external heating by utilizing the exothermic heat of reaction as substantially the only non-ambient energy source to drive water away from said polyacrylate resin to form the cross-linked polyacrylate resin having a water content sufficiently low (i.e. 15% or less) to be powdered, such as by pulverization, without an intermediate drying step.

Process for preparing dry solid water absorbing polyacrylate resin

A process is disclosed for preparing a solid, water absorbing, cross-linked polyacrylate resin including combining potassium acrylate and a polyvinyl monomer, such as N,N-methylene bisacrylamide, with water in an amount of 55 to 80 combined weight percent of potassium acrylate and polyvinyl monomer based on the total weight of potassium acrylate, polyvinyl monomer and water to form a monomer mixture, and adding a polymerization initiator to the monomer mixture to initiate polymerization of the monomer mixture. The monomer mixture then is polymerized without external heating by utilizing the exothermic heat of reaction as substantially the only non-ambient energy source to drive water away from said polyacrylate resin to form the cross-linked polyacrylate resin having a water content sufficiently low (i.e. 15% or less) to be powdered, such as by pulverization, without an intermediate drying step.

Process for preparing dry solid polyacrylate water absorbing resin

A method for easily, inexpensively and efficiently producing an improved water-absorbent resin having a high water absorbency and a high water absorption rate and capable of forming a gel having a high gel strength and nonstickiness, in which water-absorbent resin particles which contain water and a crosslinking agent and are in the semi-swollen state are agitated at an elevated temperature in the presence of an inert inorganic powder to conduct the crosslinking of the resin, while removing water, the water-absorbent resin containing a monomer units having a carboxyl group in the form of free acid or a metal salt.

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Nara, Japan

Shozo Tanioku