Provided is a method of preparing a superabsorbent polymer, in which an interpenetrating polymer network (IPN) is formed on the surface of the superabsorbent polymer during formation of a surface-crosslinked layer of the superabsorbent polymer, thereby improving physical properties of the superabsorbent polymer.

The present disclosure is drawn to a composite particulate build material, including 92 wt % to 99.5 wt % polymeric particles having an average size from 10 μm to 150 μm and an average aspect ratio of less than 2:1. The composite particulate build material further includes from 0.5 wt % to 8 wt % reinforcing particles having an average size of 0.1 μm to 20 μm and an average aspect ratio of 3:1 to 100:1 applied to a surface of the polymeric particles.

A method includes producing recycled products from a plurality of used absorbent articles, each including a top sheet, a back sheet and an absorbent body including absorbent body materials, by recovering a plurality of structural members from the plurality of used absorbent articles. At least one of the top sheet and the back sheet includes a film. The method includes: separating the plurality of used absorbent articles into a plurality of the films and the absorbent body materials; sorting the plurality of films into a plurality of types of recyclable films according to the filler contents of the plurality of films; and forming a plurality of types of recycled resin pellets from the plurality of types of recyclable films.

[Problem to be solved] To provide a water-soluble film capable of which is excellent in water solubility and less likely to cause problems such as breakage of packaging material during storage and transportation by controlling the crystal long period structure of the PVA molecule and, for example, the degree of phase separation state between PVA and other components in the water-soluble film.

[Problem to be solved] To provide a water-soluble film excellent in high-speed heat-sealing property while maintaining excellent solubility in water, and a package using the same.

[Solution] A water-soluble film of the present invention is a water-soluble film containing a polyvinyl alcohol resin, wherein after conditioning the water-soluble film at a temperature of 20° C. and a relative humidity of 60% for 24 hours, a first melting temperature Tm.sub.1 obtained from a melting curve when the temperature of the water-soluble film is raised to 200° C. at 500° C./sec and a second melting temperature Tm.sub.2 obtained from a melting curve when the temperature of the water-soluble film is cooled to 0° C. at 100° C./sec after a temperature rise and the temperature of the water-soluble film is again raised to 200° C. at 100° C./sec satisfy relationships of the following formulas (1) and (2).

105° C.≤Tm.sub.1≤165° C.  (1)

Tm.sub.2−Tm.sub.1≥20° C.  (2)

[Problem to be solved] To provide a water-soluble film having good transparency and good releasability from a support with less surfactant content.

[Solution] A water-soluble film containing a polyvinyl alcohol resin and surfactant, wherein a content of the surfactant is 0.005 to 1 parts by mass with respect to 100 parts by mass of the polyvinyl alcohol resin, and a ratio S(0)/S(32) of an abundance amount S(0) of the surfactant on at least one surface of the water-soluble film to an abundance amount S(32) of the surfactant on a cross-section surface at a depth of 32 nm from the at least one surface of the water-soluble film, measured by a count number of fragment ions derived from the surfactant detected by time-of-flight secondary ion mass spectrometry on the at least one surface of the water-soluble film, is in the range of 100 to 500.

Described herein is a method for producing photochromic contact lenses, in particular, photochromic silicone hydrogel contact lenses. The method comprises a step of cast molding of a lens-forming composition including an iniferter to form an unprocessed contact lens having iniferter moieties covalently incorporated into its polymer matrix and a step of iniferter-induced graft-polymerization of a photochromic vinylic monomer to the polymer matrix only in its central region which is circular and concentric with the central axis of the unprocessed contact lens. The obtained photochromic contact lens has a central pupillary region that only can undergo a reversible color change upon exposure to UV/HEVL-radiation.

[Problem to be solved] To provide a water-soluble film that is excellent in high-speed printability and moisture resistance.

[Solution] A water-soluble film containing a polyvinyl alcohol resin, wherein the water-soluble film has a surface on at least one side in which an abundance ratio of carbon-oxygen single bond (C—O) in all carbon element bonds obtained by X-ray photoelectron spectroscopy is in the range of 75 to 85%.

The invention provides a novel hydrophilic polymer and rubber polymer microparticles blend coating formulation and compositions thereof for rubber gloves to improve wet donning properties for easy application. More particularly, the invention relates to a novel hydrophilic polymer and rubber polymer microparticles blend coating formulation and compositions thereof, and their use on gloves to form hydrophilic and flexible coatings with durable lubricity. The gloves of the invention exhibit good donnability, tensile strength, elongation to break, and stress at 500% elongation.

An AHP is disclosed having a topsheet, a backsheet joined with the topsheet, an absorbent core, disposed between the topsheet and the backsheet, and a poly(acrylic acid)-based superabsorbent polymer (SAP), partly derived from recycled resources. The SAP exhibits defined Saline Flow Conductivity and Absorption Against Pressure values. Methods for making the aforementioned AHP are also disclosed.