Cellulose is dissolved in an ionic liquid without derivatization, and is regenerated in a range of structural forms without requiring the use of harmful or volatile organic solvents. Cellulose solubility and the solution properties can be controlled by the selection of the ionic liquid constituents, with small cations and halide or pseudohalide anions favoring solution.

Dissolution and processing of cellulose using ionic liquids

In a production process for a water-absorbent resin, comprising the steps of: blending a liquid material and a water-absorbent resin; and heating the resultant mixture in order to produce a modified water-absorbent resin, the present invention is to provide: a method for uniformly and efficiently treating a water-absorbent resin favorably in view of industry, and as a result, a good-balanced water-absorbent resin having various excellent properties, such absorption capacity without a load, absorption capacity under a load, and single-layer absorption capacity under a load in contact with an aqueous liquid. The production process comprises the step of spray-blending a water-absorbent resin (A) and a liquid material (B) with a blending apparatus equipped with a spray nozzle (C), wherein the liquid material (B) is sprayed from the spray nozzle (C) and its spray pattern is a circular and hollow cone shape or a double-convex-lens and elliptic cone shape. In addition, the production process comprises the step of heat-treating a water-absorbent resin under an atmosphere having a dew point of not higher than 60° C. and a temperature of not lower than 90° C., wherein the water-absorbent resin is obtained after a drying step following a pulverization step.

Water-absorbent resin and production process therefor

The particulate water absorbent has a cross-linking structure therein, and contains (i) a particulate water absorbent resin having a cross-linking structure on a surface therof and (ii) not less than 0.001 mass % and less than 10 mass % of an organic acid multivalent metal salt whose molecule contains not less than seven carbon atoms. Futher, the particulate water absorbent contains 90 mass % of particles, whose particle diameter is not less than 106µm and 850µm, with respect to the particulate water absorbent.

Particulate water absorbent containing water absorbent resin as a main component

The present invention provides a production process by which a water-absorbent resin of excellent quality can be obtained at a low cost by reasonable steps in aqueous solution polymerization. The process for producing a water-absorbent resin comprises the step of polymerizing an aqueous solution of water-absorbent resin-forming monomers including acrylic acid and/or its sodium salt as major components, wherein: (1) the aqueous solution has a monomer component concentration of not less than 45 weight %; (2) the polymerization is carried out while water is evaporated so that the ratio (concentration ratio) between a solid component concentration in a hydropolymer as formed by the polymerization and a solid component concentration in the aqueous monomer solution will not be less than 1.10; and (3) the solid component concentration in the hydropolymer as formed by the polymerization is not more than 80 weight %.

Water-absorbent resin, hydropolymer, process for producing them, and uses of them

Recent advances in additive-enhanced polymer electrolyte membrane properties in fuel cell applications: An overview

PROBLEM TO BE SOLVED: To provide a method for producing a water-absorbing resin powder excellent in particle size distribution and physical properties, preventing their adhesion and coagulation in their production process, also excellent in energy efficiency, drying efficiency and productivity. SOLUTION: The method for producing the water-absorbing resin powder comprises heating for drying a water-containing gel state cross linked polymer obtained by polymerizing an aqueous monomer solution containing a cross linking agent and then crushing, and is characterized by having 200-600 μm range mean particle diameter of the water-absorbing resin particles after crushing and ≤15 wt.% ratio of particles having 150-850 μm diameter, and compulsorily cooling the dried polymer after the heat-drying before the crushing or at the crushing. COPYRIGHT: (C)2002,JPO

Water-absorbing resin powder and method for producing the same

PROBLEM TO BE SOLVED: To obtain the subject polymer large in absorption speed, easy in dryness and small in load on grinding by mixing a monomer aqueous solution containing a water-soluble ethylenically unsaturated monomer with a gas and subsequently polymerizing the monomer in the bubble-dispersed state SOLUTION: This method for producing a hydrophilic polymer comprises mixing an aqueous monomer solution containing a water-soluble ethylenically unsaturated monomer such as (meth)acrylic acid with a gas such as an inert gas in a liquid state, preferably introducing the solution and the gas into a mixing region having an uneven surface and/or containing a filler to mix both the components or jetting either one of the aqueous monomer solution and the gas into the flow of the other from a nozzle in parallel to the flow to mix both the components, preferably adding a surfactant to the bubble-dispersed monomer aqueous solution, and subsequently polymerizing the monomer in the bubble-dispersed state, thus producing the objective polymer useful for uses requiring water absorption and water retention, such as the field of sanitary materials, eg sanitary articles or paper diapers, the fields of agriculture and horticulture, the field of foods, eg food freshness-holding materials, and the field of industrial materials, eg dew-preventing materials and cooling materials

Production of hydrophilic polymer

PROBLEM TO BE SOLVED: To provide a water absorbent composition superior in water absorption speed, permeation speed of a gel layer, permeation speed under pressure of the gel layer and absorption ratio under pressure to respective components, and water absorbent compositions which can show excellent absorption characteristics even with increased wt.% (resin concentrations) of a water absorbing resin when used in a hygienic medium and the like. SOLUTION: In the water absorbent composition comprising at least water absorbing resin particles having anionic dissociable groups and water swelling resin particles having cationic groups, 45-90 mol% anionic dissociable groups are neutralized, and the weight ratio (α) of the anionic dissociable group- containing water absorbing resin particles to the total weight of the anionic dissociable group-containing water absorbing resin particles and the cationic group-containing water swelling resin particles is at least 0.8, and the absorption ratio under pressure (P) of the water absorbent compositions is at least 20 g/g.

Water-absorbent composition

PROBLEM TO BE SOLVED: To obtain the subject composition simultaneously satisfiable water absorption rate, water absorption ratio under pressure, gel strength of a swollen gel, etc., by adding a post crosslinking agent to a blended material of a specific primary particle with a specific pelletizing particle and post crosslinking a vicinity of the surface. SOLUTION: This composition is obtained by adding (B) a post crosslinking agent to (A) a blended material of (i) a primary particle obtained by copolymerizing a monomer containing an acrylic acid (salt) with 0.06-0.5 mol.% of inner crosslinking agent with (ii) a pelletizing particle of a crosslinked fine particle obtained by copolymerizing a monomer containing an acrylic acid (salt) with 0.06-0.5 mol.% of inner crosslinking agent. Specifically, a partially neutralized crosslinking polyacrylic acid (salt) obtained by copolymerizing a multifuctional monomer having >=2 pieces of polymerizable unsaturated double bond per a molecule in an amount of 0.06-0.5 mol.% based on a mol number of the acrylic acid (salt) with the acrylic acid (salt) and is used as a starting raw material and the one is used as a blended state with the primary particles and the pelletizing particles to obtain the objective composition.

Water absorptive polymer composition and its production

PURPOSE:To easily obtain a water-absorptive agent which is hard to move and drop off when it is compounded with cellulose fibers and thus expected to have a synergistic effect on the water-absorptive function. CONSTITUTION:The surface of water-absorptive particles having a carboxyl group is treated with a cross-linking agent having two or more functional groups which are able to form a covalent bond by reaction with the carboxyl group to cross-link a part of the carboxyl group and, after that, the particles are mixed with a cationic high molecular compound having 2000 or more weight average molecular weight and able to form an ionic bond by reaction with the carboxyl group.

信幸原田

Papers

Water-absorbing resin powder and method for producing the same

Production of hydrophilic polymer

Water-absorbent composition

Water absorptive polymer composition and its production

Manufacture of water-absorptive agent

信幸 原田

Papers

Water-absorbing resin powder and method for producing the same

Production of hydrophilic polymer

Water-absorbent composition

Water absorptive polymer composition and its production

Manufacture of water-absorptive agent

信幸原田