Disclosed are water-absorbent resin particles comprising a crosslinked polymer comprising a monomer unit derived from a water-soluble ethylenically unsaturated monomer, wherein an initial swelling force as measured according to a swelling force test conducted by a predetermined method is 8 N or more, and further, a ratio of the particles having a particle diameter of more than 250 μm and 850 μm or less is 70% by mass or more and a ratio of the particles having a particle diameter of 250 μm or less is 20% by mass or less, with respect to the total amount of the water-absorbent resin particles.

The present invention generally relates to methods for resolving water and oil emulsions in the produced fluid of an oil production system comprising adding a structured copolymer reverse emulsion breaker to the produced fluid of the crude oil production system in an amount effective for resolving an oil-in-water emulsion. In particular, these methods for resolving an oil-in-water emulsion can be used in separation processes where the oil and solids in the produced fluid are separated from the produced water in the produced fluid.

Disclosed are water-absorbent resin particles including: a crosslinked polymer having a structural unit derived from an ethylenically unsaturated monomer including at least one compound selected from the group consisting of (meth)acrylic acid and a salt thereof, in which a proportion of (meth)acrylic acid and a salt thereof is 70 to 100 mol % with respect to a total amount of monomer units in the crosslinked polymer, and in a moisture retention test performed under reduced pressure, a moisture retention rate after 6 hours is 55% by mass or more, and a water retention capacity for a physiological saline solution is 32 to 70 g/g.

Water absorbent polymers and a process for their preparation are disclosed. The process for preparing water absorbent polymers comprises preparing a slurry with relatively high amounts of polymer particles (in the range of 40 to 55 wt % of the total mass of the slurry) having water absorbed therein. The slurry is then directly spray dried to obtain water absorbent polymers.

Water absorbent polymers and a process for their preparation are disclosed. The process for preparing water absorbent polymers comprises preparing a slurry with relatively high amounts of polymer particles (in the range of 40 to 55 wt % of the total mass of the slurry) having water absorbed therein. The slurry is then directly spray dried to obtain water absorbent polymers.

Provided are: a water-absorbent resin which, when used as an absorbent material, retains a high water-absorption performance, increases the diffusivity of a to-be-absorbed liquid and makes it possible to effectively decrease the amount of re-wet; and an absorbent article formed using an absorbent material including the water-absorbent resin. The water-absorbent resin according to the present invention is a water-absorbent resin obtained by polymerizing a water-soluble ethylenically monomer in the presence of an internal-crosslinking agent and thereafter post-crosslinking the polymer with a post-crosslinking agent, characterized in that when subjected to a liquid flow test, the water-absorbent resin has an effective absorbent material index (K) indicated by equation (I) of 250 or greater.

Effective absorbent material index (K)=[(the amount of liquid flow) (g)]×[(artificial-urine absorption ratio) (g/g)]  (I)

An inverse emulsion copolymer composition comprises (A) an aqueous phase comprising a cross-linked hydrophilic polyelectrolyte copolymer (A′) obtained by the free radical copolymerisation of: (i) at least one anionic ethylenically unsaturated monomer bearing a negatively charged group and one polymerisable C═C double bond, or at least one cationic ethylenically unsaturated monomer bearing a positively charged group and one polymerisable C═C double bond, and (ii) at least one non-ionic ethylenically unsaturated cross-linking monomer bearing at least two polymerisable C═C double bonds, and (iii) optionally, one or more hydrophilic non-ionic ethylenically unsaturated monomers bearing one polymerisable C═C double bond, (B) an oil phase comprising a carrier oil (C), (D) (i) at least one water-in-oil emulsifying surfactant, and (D) (ii) at least one oil-in-water emulsifying surfactant; characterised in that the carrier oil component (C) of the oil phase comprises from 75% to 100%, by weight of the said carrier oil component (C), of farnesane (2, 6, 10-trimethyldodecane). The compositions are effective for use as thickeners for thickening aqueous solutions, including solutions which contain dissolved salts. The compositions also show excellent thickening in acidic solutions than counterpart compositions containing paraffinic oils.

The invention relates to a method for preparing a dry cationic hydrogel polymer product. The method comprises polymerisation of a reaction mixture comprising ethylenically unsaturated monomers in presence of water and initiator(s) by radical polymerisation and obtaining a hydrogel polymer. The hydrogel polymer is comminuted by chopping or shredding, and dried, whereby a dry hydrogel polymer product in powder form is obtained. At least one cationic reverse phase emulsion polymer is added to the hydro polymer at the comminuting step. The invention relates also to a dry cationic hydrogel polymer composition prepared by the method and its use.

The invention relates to a method for preparing a dry cationic hydrogel polymer product. The method comprises polymerisation of a reaction mixture comprising ethylenically unsaturated monomers in presence of water and initiator(s) by radical polymerisation and obtaining a hydrogel polymer. The hydrogel polymer is comminuted by chopping or shredding, and dried, whereby a dry hydrogel polymer product in powder form is obtained. At least one cationic reverse phase emulsion polymer is added to the hydro polymer at the comminuting step. The invention relates also to a dry cationic hydrogel polymer composition prepared by the method and its use.

A High Internal Phase Emulsion (HIPE) foam having cellulose nanoparticles.