Nippon Gohsei Kagaku Kogyo Kabushiki Kaisha

Nippon Gohsei Kagaku Kabushiki

Susumu Kondo

Tetsuo Moriya

Hiroshi Aoyama

Tomiji Itou

Shinji Sanuki

A process for preparing a porous and water-absorbent resin which includes dispersing an aqueous solution containing at least one .alpha.,.beta.-unsaturated carboxylic acid monomer, its alkali metal salt or its ammonium salt in a hydrophobic organic solvent, and conducting a reversed phase suspension polymerization by using a water-soluble radical polymerization initiator, while distilling away the hydrophobic organic solvent together with water. A porous and water-absorbent resin having excellent absorbency and a remarkably improved rate of water absorption can be easily and efficiently obtained on an industrial scale.

Process for preparing porous and water-absorbent resin

A process for preparing particles of a high water-absorbent resin which comprises mixing a powder of a high water-absorbent resin having a water content of 10 to 60% by weight with a powder of water-soluble high molecular weight compound and drying the mixture. The obtained particles according to the present invention are suitable for use of sanitary goods, water-retaining agents or soil conditioner in the fields of agriculture and horticulture and other various uses.

Process for preparing particles of high water-absorbent resin

A process for preparing particles of a high water-absorbent resin which comprises mixing a powder of a high water-absorbent resin with a solution of a sorbitan surfactant having an HLB of 2.1 to 5.0 dissolved in an organic solvent, volatilizing the organic solvent from the mixture to give a resin powder with a content of the organic solvent of not more than 5% by weight, adding water to the mixture to adjust a water content in the resin powder to 25 to 60% by weight, adding an inorganic powder to the resin powder, and drying the resulting mixture. The particles of the high water-absorbent resin obtained according to the present invention are suitable for use of sanitary goods, water-retaining agents or soil conditioner in the fields of agriculture and horgiculture and other various uses.

A process is provided for the production of a highly water-absorbing resin comprising a polymer obtained by polymerizing a monomer composition mainly composed of an ethylenically unsaturated monocarboxylic acid and/or an alkali metal salt thereof. The process comprises incorporating an oil-soluble polyfunctional epoxy compound having a solubility in 100 g of water at 20.degree. C. of not more than 0.3 g into the polymer by adding 0.0005-3 parts by weight of the oil-soluble polyfunctional epoxy compound to 100 parts by weight of the polymer or the monomer composition to be subjected to polymerization and thereby causing crosslinking.

Process for producing highly water-absorbing resins from diepoxides and

In a process for producing a highly water-absorbent resin comprising subjecting a mixture of (meth)acrylic acid with a water-soluble salt thereof as a monomer to reversed phase suspension polymerization in a hydrophobic solvent in the presence of a dispersing agent, improvements that at least a portion of said monomer is fed sequentially with the progress of polymerization reaction and at least a portion of said dispersing agent is fed sequentially with the progress of polymerization. The resulting resin is useful as a highly water-soluble resin component of sanitary products, or as a humectant/desiccant, a rheology modifier and so on.

Process for production of highly water-absorbent resin

Polymerization of acrylic or methacrylic acid and a water-soluble acrylic or methacrylic acid salt in the presence of a carboxyl group-containing polyvinyl alcohol resin gives highly water-absorbing resins with the water absorbency, water absorption rate, water insolubility and other characteristics well balanced therein.

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Kyoto, Japan

Susumu Kondo