Seitetsu Kagaku Co., Ltd.

Shigeji Obayashi

Morio Nakamura

Takushi Yamamoto

Hitoshi Tanaka

Yuji Sakamoto

Masato Fujikake

Shinichi Takemori

Kanji Ueda

Yasuhiro Shimada

Thoru Okabe

Koichi Fujiki

Tetsurou Motooka

Kosaku Yamada

Haruhiko Iwatsubo

Motomu Hirakawa

Toshikazu Nakanishi

A water retention material with water-absorbency which comprises finely divided particles of water-absorbent resin having a water absorption capacity of 2 to 50-fold and a particle size of 100.mu. or finer and a hydrophobic material such as a thermoplastic resin, elastomer, sealant, paint or adhesive.

Water retention material with water-absorbency

A water-absorbent resin composition having superior gel stability which comprises a water-absorbent resin, at least one oxygen-containing reducing inorganic salt and, optionally, at least one organic antioxidant.

Water-absorbent resin composition

A water-absorbent resin having excellent physical properties can be produced by a process wherein an aqueous solution containing an .alpha.,.beta.-unsaturated carboxylic acid and an alkali metal salt thereof in a total amount of 25% by weight or more is subjected to polymerization with a radical polymerization initiator in a petroleum-based hydrocarbon solvent in the presence or absence of a crosslinking agent, characterized by using, as a surfactant, a polyglycerine--fatty acid ester having an HLB of 2 to 16 and represented by the general formula ##STR1## (wherein R is an acyl group or hydrogen atom and n is an integer of 0 to 8).

Process for producing a water-absorbent resin

A water-absorbent resin having an appropriate particle size and a narrow particle size distribution can be obtained by adding a powdered inorganic material in a proportion of 0.000005-0.2 part by weight to 1 part by weight of a water-absorbent resin containing therein a carboxylate as a component of the polymer with agitation in an inert solvent in the presence of 0.1-5.0 parts by weight of water and 0.005-0.2 part by weight of a surfactant and then removing water and the inert solvent by distillation.

Process for granulating a water-absorbent resin employing (a) water (b)

A water-absorbent resin usable as a suitable water absorbent in sanitary materials and other fields can be produced by subjecting an aqueous solution of an .alpha.,.beta.-unsaturated carboxylic acid and of an alkali metal salt thereof to polymerization with a radical polymerization initiator in a petroleum-based hydrocarbon solvent in the presence or absence of a crosslinking agent and, in this polymerization, using a saccharose-fatty acid ester as a protective colloid agent.

Water-swellable elastomer composition consisting essentially of a homogeneous mixture of an elastomer, a water-absorbent resin and a water-soluble resin. Said composition exhibits a high degree of swelling and a high swelling rate when it is soaked in water. Also, said composition retains swellability even when it is put in contact with water for a long period of time.

Water-swellable elastomer composition

Water-absorbent resins having improved water-absorbency, water-absorption rate and water-dispersibility can be produced by crosslinking a water-absorbent resin comprising a carboxylate as a constituent of the resin with a crosslinking agent having at least two functional groups in the presence of water in a proportion of 0.01 to 1.3 parts by weight per part by weight of the resin in an inert solvent.

Water-absorbent resin having improved water-absorbency and improved

An alkali metal acrylate polymer obtained by suspending an aqueous solution of acrylic acid and an alkali metal acrylate in an alicyclic or aliphatic hydrocarbon solvent containing a surfactant having an HLB value of 8-12 and subjecting the suspension to inverse suspension polymerization in the presence of a water-soluble radical polymerization initiator has a much higher water-absorbency and particularly salt solution-absorbency than known ones. If said polymer is crosslinked with a crosslinking agent, its stability in the fluid-absorbed state for a long period of time is improved and the absorption rate when absorbing water is also improved.

Alkali metal acrylate or ammonium acrylate polymer excellent in salt

Catalyst for removing nitrogen oxides, whose activity is lowered by poisoning with sulfur oxides, is contacted with an ammonia gas at a temperature of 200.degree. to 500.degree. C, whereby the sulfur oxides are liberated from the catalyst, and the catalyst is regenerated. Concentration of the ammonia gas to be used in the regeneration treatment must be at least 1% by volume and preferably 5 to 50% by volume of ammonia is used in a mixture with other inert diluting gas. The regenerated catalyst is given an activity as high as that before the poisoning without bringing about any damage and cracking to the catalyst.

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Akashi, Japan

Shigeji Obayashi