Abstract: A method for producing a water-absorbent resin including the step of subjecting a water-soluble ethylenically unsaturated monomer to a reversed phase suspension polymerization in a petroleum hydrocarbon dispersion medium in the presence of a radical polymerization initiator and a dispersion stabilizer, wherein the method is characterized by the use of an ether-ester type nonionic surfactant as the dispersion stabilizer, and a water-absorbent resin obtained by the method, wherein the water-absorbent resin has a water-retention capacity of saline solution of 25 g/g or more, a water-absorption rate of saline solution of 50 seconds or less, and a flow index under moisture absorption of 70% or more. According to the method of the present invention, a water-absorbent resin having high water-retention capacity, excellent water-absorption rate, and further having excellent flowability under moisture absorption can be produced.

Abstract: The invention relates to a process for operating a mixing kneader, comprising one or more shafts on whose surfaces are disposed kneading bars and which are surrounded by a casing, comprising the following steps: (a) supplying reactants at an addition site in the mixing kneader, (b) converting the reactants in an exothermic reaction, the reaction at first forming a coherent kneadable intermediate, (c) tearing and dividing the coherent kneadable intermediate to form a product, the exothermic reaction optionally continuing during the tearing and division, (d) withdrawing the product at a withdrawal site in the mixing kneader, wherein at least one of the shafts and/or the casing is heated to a temperature above 20° C. during the operation of the mixing kneader.

Abstract: 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 %.

Abstract: The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution in a surrounding heated gas phase and flowing the gas cocurrent through the polymerization chamber, which comprises thermal postcrosslinking in the presence of steam.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets, wherein the particle surface is coated at least partly with at least one polymer and/or wax.

Abstract: An apparatus (2) includes a neutralization tank (3), a pump (4), a heat exchanger (6), a line mixer (8), a polymerizer (10), a first pipe (12), a second pipe (14), a third pipe (16), a fourth pipe (18), and a fifth pipe (20). Continuously supplied into the neutralization tank (3) are a monomer aqueous solution and a basic aqueous solution, so as to prepare a mixture solution. The mixture solution is circulated through the first pipe (12), the pump (4), the second pipe (14), the heat exchanger (6), and the third pipe (16). The mixture solution is supplied to the polymerizer through the fourth pipe (18).

Abstract: In a process for producing water-absorbing polymeric particles which comprises generating droplets comprising monomers, polymerizing the monomers in a heated gas phase surrounding the droplets and flowing the gas through the polymerization reactor, the temperature of the gas leaving the polymerization reactor is closed-loop controlled.

Abstract: A process for producing water-absorbing polymeric particles by a suspension polymerization with recycling of the hydrophobic solvent, the hydrophobic solvent comprising branched saturated aliphatic hydrocarbons.

Abstract: A process for producing water-absorbing polymer particles by neutralizing the monomer and cooling it by means of an indirect heat exchanger, wherein the specific cooling performance of the heat exchanger is less than 10 W/m2.

Abstract: A process for preparing water-absorbing polymer beads by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets, the initiator being added to the monomer solution from 0.5 to 60 seconds before the droplets are generated.

Abstract: The present invention provides a process for producing water-absorbing resin particles which possess a high water retention capacity (absorbing capacity), a high water-absorbing capacity under pressure, and a high gel strength and a small amount of water-soluble substance and is favorably usable in sanitary materials; water-absorbing resin particles obtained by the process; and absorbent materials and absorbent articles made by using the particles. More specifically, the water-absorbing resin particles are produced by a process for producing water-absorbing resin particles, comprising a step of a post-crosslinking reaction by adding a post-crosslinking agent in at least two stages to a water-absorbing resin particle precursor obtained by polymerization of a water-soluble ethylenic unsaturated monomer to carry out the post-crosslinking reaction.

Abstract: A process for producing water-absorbing polymeric particles comprises conducting the polymerization in at least two parallel continuous polymerization reactors under substantially identical conditions and further processing the reaction products conjointly in at least one process step.

Abstract: The present invention provides a process for the preparation of polymer which comprises the steps of i) feeding an aqueous mixture comprising a monoethylenically unsaturated monomer or a mixture of monoethylenically unsaturated monomers and an initiator into the top of a reactor ii) polymerizing the monoethylenically unsaturated monomer to form a gel-like aqueous mixture comprising the polymer, iii) squeezing the gel-like aqueous mixture comprising the polymer out of the bottom of the reactor using inert gas, wherein the reactor is either a vertical fully conical reactor having an angle (alpha) between top diameter (d1) of the reactor and inner wall of the reactor of smaller than 90° but larger than 45° or is made up of 2 to 5 connected vertical fully conical parts, which are on top of one another, each having an angle between top diameter of the part and inner wall of the part of smaller than 90° but larger than 45°.

Abstract: The present invention relates to a method for manufacturing super-absorbent polymers, comprising providing a reaction mixture which comprises at least a first monomer and a second monomer and a radical-forming polymerization initiator, and subsequently causing the monomers to polymerize under the influence of an energy source, wherein radical formation occurs and the polymerization is started, wherein the first monomer is neutralized with an inorganic base before polymerization, in addition to the manufactured super-absorbent polymers. The invention further relates to a method for applying a coating of super-absorbent polymers to a carrier.

Abstract: A method for mixing a water-absorbent resin and a surface cross-linking agent-containing solution to repress aggregates is equipped. The water-absorbent resin and the surface cross-linking agent-containing solution is mixed with a plow-shaped mixing device which is equipped with an inner wall formed of material manifesting an interfacial contact angle of not less than 60° to water and possessing a temperature of heat distortion of not lower than 70° C., a plow-shaped stirring vane and a disintegrating blade.

Abstract: A polyamphoteric superabsorbent copolymer made up of polymerizerable acid monomer and of polymerizable base monomer and optionally a supplemental monomer. In particular, the invention includes a radiation curable coating composition that comprises from about 20 weight % to about 80 weight % of polymerizerable acid monomer and from about 20 weight % to about 80 weight of polymerizable base monomer; and from 0 weight % to about 50 weight % of supplemental monomer. On exposure to radiation the coating composition forms a polyamphoteric superabsorbent copolymer. The radiation curable coating composition may be used with suitable substrates.

Abstract: Processes for chemically-modifying the surface of an emulsion polymer particle are provided which include providing an aqueous emulsion polymer, a monomer at a level of at least 0.5% by weight based on the weight of the emulsion polymer and a, surface-modifying chemical capable of bonding with the monomer, under conditions where there is no substantial polymerization of the monomer, and then reducing the level of the monomer by at least 50%.

Abstract: The present invention provides: a water-absorbent resin powder, which includes no fine metallic foreign substance, and in which the deterioration is suppressed; its production process; and uses. The present invention production process for a water-absorbent resin powder comprises the steps of: polymerizing an unsaturated monomer; and drying the resultant crosslinked hydrogel polymer, wherein the water-absorbent resin powder has a crosslinked structure and a mass-average particle diameter of 300 to 600 &mgr;m wherein the ratio of fine particles having particle diameters of not larger than 150 &mgr;m is less than 10 mass % of the water-absorbent resin powder, with the production process being characterized by further comprising a magnetic-flux irradiation step of passing a magnetic field having a magnetic flux density of not less than 0.05 Wb/m2 through the water-absorbent resin powder after the drying step in the production process.

Abstract: A continuous manufacturing method of a water-absorbent polymer by continuously performing a polymerization of a hydrophilic monomer using a solution containing a hydrophilic monomer, includes at least one of the following steps (A) to (D): (A) introducing an inert gas into the solution in a continuous manner before subjecting the solution to a polymerization reaction, and subsequently removing the inert gas from the solution; (B) supplying the solution to a polymerization process, and washing out the solution with water supplied before, at, or after a timing of supplying the solution to the polymerization process; (C) detecting reaction temperatures of a polymerization reaction in non-contact manner at a plurality of points different distances away from a point where a solution is supplied; and (D) supplying water to a water-containing gel and/or transport means when transporting the water-containing gel of the water-absorbent polymer obtained in or after the polymerization reaction.

Abstract: Described herein is a pentaalkyldisiloxane containing polymeric surfactant prepared by the copolymerization of an alkoxypolyoxyalkylenyl acrylate and an acrylate containing a pentaalkyldisiloxane group. A method for preparing beaded polyethylene glycol-based resins in silicone oil in the presence of a polymeric surfactant containing a pentaalkyldisiloxane group is also described. The average bead size can be controlled by varying the stirring rate, the polymerization temperature, the amount of surfactant, the type of solvent, and the amount of solvent. The surfactant does not interfere with the polymerization and can be removed together with residual silicone oil by a simple washing procedure. The resins can be used, for example, as a support for solid phase organic synthesis, as a chromatographic resin, as a resin for solid phase MAS-NMR spectroscopy, and as a carrier for drug molecules, various reagents, or scavengers.

Abstract: A composite of a substrate having an application of superabsorbent polymer. The composite is made by applying, directly onto the substrate, an application of a polymer that will, upon being subjected to radiation, convert to a superabsorbent polymer. The substrate with applied polymer is subjected to radiation, such as being heated at a sufficient temperature for a sufficient time, to obtain the composite of substrate with superabsorbent polymer adhered to it.

Abstract: Improved crosslinked ionic polymers or salts thereof having a soluble polymer fraction of less than about 15 wt %, and methods for making the same. The polymers are useful as bioadhesives, thickeners, emulsifiers, suspending aids, and pharmaceutical controlled release excipients.

Abstract: Coatable ink-receptive compositions and coated substrates are provided. The compositions contain a pigment dispersed in a binder composed of an ethylene vinyl acetate emulsion polymer and at least one water soluble, cationic polymer, such as polydiallyldimethylammonium chloride and copolymers of a quaternary amino acrylate or methacrylate and a hydroxy-lower alkyl acrylate or methacrylate. Papers, films, labels and similar products, coated with an ink-receptive composition, are also provided.

Abstract: A process for producing water-absorbent resins having an average particle diameter of 100 to 600 .mu.m and a particle diameter distribution of 0.35 or less by polymerizing an aqueous solution of a water-soluble ethylenically unsaturated monomer, pulverizing and sieving the polymer so obtained, and crosslinking the surface of the polymer powder.

Abstract: The acrylic copolymer and the acrylic resin particles of the invention have a recurring unit derived from a nitrogen-containing acrylic monomer having, in its molecule, at least one CH.sub.2 .dbd.CR.sup.1 --CO-- group (R.sup.1 is a hydrogen atom, methyl or ethyl) and at least one --N.sup.+ R.sup.2.sub.3.X.sup.- group (R.sup.2 is H--, an alkyl group of 1 to 5 carbon atoms or an alkylol group of 1 to 5 carbon atoms, and X is a halogen atom) and a recurring unit derived from an acrylic monomer represented by the formula CH.sub.2 .dbd.CR.sup.3 --CO--Q wherein R.sup.3 is H--, CH.sub.3 -- or C.sub.2 H.sub.5 --, and Q is --NH.sub.2, --NH--R.sup.4 --OH (R.sup.4 is an alkylene group of 1 to 5 carbon atoms) or --R.sup.5 (R.sup.5 is H-- or an alkoxy group of 1 to 20 carbon atoms), and further have a crosslinked structure. The ink-jet recording medium of the invention contains the acrylic resin particles in its ink-receiving layer. The acrylic resin particles have good water resistance though they are hydrophilic.

Abstract: Methods and compositions for encapsulated polymeric gels swollen with nonaqueous reactive materials are provided. The methods include gel synthesis, swelling of a gel precursor with a first nonaqueous reactive material, and encapsulation of the swollen gel with a second nonaqueous reactive material. Gels precursors may be synthesized from crosslinking polymers, or alternatively, may be formed by crosslinking and polymerizing a monomer starting material. An accelerator may be utilized to facilitate swelling of the gel precursor with the first nonaqueous reactive material. Foams and composites may also be swollen with the first nonaqueous reactive material. The swollen gel is then contacted with a second nonaqueous reactive material such that an encapsulation layer is formed thereby. The encapsulated gels may be stored for subsequent use.

Abstract: A method for preparing water-absorbent resins (D) by radically polymerizing a water soluble monomer (A), or a water-soluble monomer (A) and a polysaccharide (B) in the presence of a crosslinking agent (C) and water, wherein the polymerization is conducted under the existence of a thiol compound (E). Water-absorbent resins obtained in the method of the present invention provide high absorption while providing safety with very little amount of a water-soluble component.

Abstract: A process for preparing an absorbent resin includes the steps of: preparing a first crosslinking agent (A) including at least two polymerizable unsaturated bonds; preparing a second crosslinking agent (B) including at least two polymerizable unsaturated bonds and hydroxyl groups; preparing a crosslinking agent including (A) and (B) with a ratio of (A) to (B) ranging from 95/5 to 50/50; and polymerizing a hydrophilic unsaturated monomer having at least one carboxyl group using the crosslinking agent. The crosslinking agent includes a crosslinking agent which includes a main component at least 90 percent by weight, the main component being an ester having at least two polymerizable unsaturated bonds, wherein the ester is composed of a polyhydroxy alcohol (C) having not more than six carbon atoms and at least three hydroxy groups, and an unsaturated carboxylic acid (D); and a molecular weight ratio of the main component to a standard compound (E) is in the range of from 0.7/1 to less than 1.

Abstract: The present invention provides new non-spherical microparticles. The microparticles are a hemisphere or a half elliptic sphere having a big opening at the central portion, say bowl-shape microparticles, and a water uptake of from 80 to 140 ml/100 g, which can be produced by suspension polymerization of polymerizable monomers in the presence of crosslinking agents and hydrophobic liquids in water. The microparticle of the present invention has an excellent extending ability, adhesiveness and water uptake. The new bowl-shape microparticles having the big opening at the center can be easily produced according to the present invention, and the size and shape can be easily controlled.

Abstract: Disclosed are a polymer emulsion prepared by neutralizing a seed polymer with an acid or a salt or by quaternizing it with a quaternizing agent and a method of preparing the polymer emulsion. The surfaces of the emulsion grains are very densely cationated. The seed polymer is formed by polymerizing a monomer of formula (I) or a mixture of the monomer (I) and copolymerizable ethylenic unsaturated monomer(s) (II) and a seed latex of a carboxyl-modified synthetic rubber latex or synthetic resin emulsion. ##STR1## R.sub.1 is H or CH.sub.3 ; R.sub.2 is a 2-5C alkylene; R.sub.3 and R.sub.4 each are H or a 1-5C alkyl; A is--COO--or--CONH--; and R.sub.1, R.sub.3 and R.sub.4 are so selected that the monomer is hardly soluble or insoluble in water. As a consequence of being very densely cationated by post-modification, the cationic polymer emulsion is useful in various fields as binders, fixers or other additives.

Abstract: An insect bait station comprising a first compartment with a hydrated macel containing at least one species of entomopathogen and a second compartment containing a hydrated water retentive compound layer which acts as a water-reservoir for the entomopathogen.

Abstract: Polycarbophil or crosslinked acrylic acid polymer is prepared in a solvent selected from acetone, alkyl acetates, and mixtures thereof, in the presence of an effective amount of divinyl glycol crosslinker, and in the presence of an effective amount of a suitable initiator allowing for polymerization to proceed at a temperature below 100.degree. C. at atmospheric pressure. The polymer produced has average particle size of less than 10 microns without grinding, its viscosity is greater than about 20,000 cPs when measured in water at 1% concentration, and it adheres to mucous membranes. By preparing the polymer in a non-aqueous solvent, the need for aqueous washing is avoided and the subsequent and enormous swelling of the polymer is avoided which means that prolonged and excessive drying inherent in the known processes is avoided.

Abstract: Disclosed are a polymer gel in which a phase transition occurs due to a stimulus, a method of manufacturing such a polymer gel, and an actuator which employs such a polymer gel. The polymer gel which is formed by polymerizing monomers at a temperature equal to or less than a phase transition temperature of the resultant polymer gel and separating and/or classifying the polymer gel into fractions according to its size at a temperature equal to or greater than the phase transition temperature thereof. Alternatively, the polymer gel is separated and/or classified into fractions by adding a low molecular weight compound that can dissolve and swell the polymer gel to separate the polymer gel into fractions based upon a difference in dissolving rate or swelling rate. Alternatively separation and/or classification of the polymer gel is performed by a combination of the above-described two methods. In consequence, the resultant polymer gel has an average particle size ranging from 0.1 .mu.m to 100 .mu.

Abstract: Finely divided, gel-like, water-swellable copolymers are prepared by copolymerizing(a) 100 parts by weight of water-soluble, monoethylenically unsaturated monomers,(b) from 0.01 to 5 parts by weight of monomers containing two or more ethylenically unsaturated double bonds and(c) from 0 to 20 parts by weight of water-insoluble, monoethylenically unsaturated monomersin 20-80% strength by weight aqueous solution in the presence of a polymerization initiator and from 0.1 to 10% by weight, based on the monomers used in the copolymerization, of a surfactant, by a process in which the monomers are copolymerized in the presence of initially from 0 to 50% by weight of the amount of surfactant to a conversion of not less than 60%, the remaining amount of surfactant is then added to the reaction mixture and the copolymerization is completed and the resulting gel particles dried.

Abstract: Improved water absorbent polymers can be prepared by agglomerating acrylic acid gel polymer fines with small quantities of difunctional epoxides.

Abstract: The invention relates to filaments and fibers of acrylonitrile polymers, which contain 10 to 30% by weight of carboxyl groups, their use and processes for their production. The filaments and fibers exhibit, in the dry state, tensile strengths of more than 10 cN/tex and knot strengths of more than 6 cN/tex and can be processed on customary machinery and are suitable for the production of shaped structures of high water retention. The polymeric raw materials required for the spinning are produced by hydrolysis of acrylonitrile polymers using aqueous dilute acids in a heterogeneous phase system.

Abstract: The present invention is a method for the production of a water absorbent resin, which comprises preparing a monomer component possessing an ability to form a cross-linked structure and convert itself into a hydrated gel polymer during the course of aqueous solution polymerization, possessing an acid group-containing monomer content of at least 50 mol %, and having 10 to 50 mol % of said acid group-containing monomer neutralized and subjecting said monomer component to aqueous solution polymerization within a reaction vessel having a plurality of rotary shafts each fitted with stirring blades.

Abstract: A method for reconstituting superabsorbent polymer fines which comprises the following steps: wetting the superabsorbent polymer fines with an aqueous solution sufficient to form an amorphous gel of the fines, grinding the gel, and drying the ground gel product; wherein the improvement is characterized by the addition of an aqueous solution containing a persulfate salt.

Abstract: A copolymer of recurring units of at least one .alpha.,.beta.-unsaturated monomer and recurring units of at least one copolymerizable comonomer comprising, in its preferred embodiment from about 20 to about 80 percent pendant carboxylic acid units and from about 80 to about 20 percent pendant carboxylate salt units, is blended with a heterocyclic carbonate to produce a water-absorbing composition upon curing. The composition is particularly suitable for fiber formation.

Abstract: There is provided a process for preparing a water absorptive composite material, which comprises the combination of the following steps:(A) applying an aqueous solution of polymerizable monomers comprising as a main component acrylic acid, of which 20% or more of the carboxyl groups have been neutralized to its alkali metal salt or ammonium salt, to a prefabricated fibrous substrate;(B) polymerizing the polymerizable monomers applied to said fibrous substrate to form a composite of a polymer derived from said polymerizable monomers and said fibrous substrate; and(C) irradiating ultraviolet rays onto said composite with its water content being 0.01 to 40 parts by weight per 1 part by weight of said polymer to obtain a water absorptive composite having a lower content of unpolymerized monomers than said composite.

Abstract: Aqueous solution of alkali or ammonium acrylate is applied to a prefabricated fibrous substrate, and the acrylate is subjected to polymerization in two steps, namely the first step in which the acrylate is polymerized by means of a radical polymerization initiator and the second step which is subsequent to the first step and in which the unpolymerized acrylate is polymerized by means of heat treatment at 100.degree.-250.degree. C.

Abstract: A water-in-oil suspension polymerization process of the type comprising a process for preparing a water-insoluble polymer capable of absorbing water, aqueous salt solutions and blood, which utilizes as the suspending agent a cellulose ester or ether protective colloid, the improvement which comprises using as the protective colloid an oil-soluble, water-insoluble, polymeric surfactant instead of the cellulose derivatives, in an amount sufficient to stabilize the emulsion, said polymeric surfactant having the formula: ##STR1## wherein x is a whole number greater than about 5, the mole ratio of a:b is from 3:1 to 1:3, provided the HLB number is maintained at less than about 14, R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from the group consisting of hydrogen, alkyl (C.sub.1-16), aryl (C.sub.6-12), alkaryl (C.sub.7-12), and R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are such that the surfactant is oil-soluble and water-insoluble.

Abstract: An osmotic capsule is disclosed for delivering a beneficial agent formulation to an environment of use. The osmotic capsule comprises an outer semipermeable wall surrounding and laminating an inner capsule wall formed of a different polymeric composition than the outer wall. The walls define an interior space containing the beneficial agent formulation. A passageway through the walls connects the exterior of the osmotic capsule with the interior of the osmotic capsule.