The present invention is concerned with expanded beads that are olefin-based thermoplastic elastomer expanded beads containing a coloring agent, wherein an apparent density of the expanded beads is 40 to 300 g/L, and an average surface layer membrane thickness (a) is 3 to 25 μm, and a molded article thereof, and is able to provide expanded beads capable of producing an expanded beads molded article which is excellent in in-mold moldability and excellent in tensile characteristics and an expanded beads molded article using the expanded beads.

Heat-expandable microspheres which have a blowing agent encapsulated efficiently therein so as to prevent the blowing agent from escaping out of the microspheres during storage at high temperature, a process for producing the same, and applications thereof. The process for producing heat-expandable microspheres containing a thermoplastic resin shell and a thermally vaporizable blowing agent encapsulated therein includes preparing an aqueous suspension in which oil droplets of an oily mixture containing the blowing agent and a polymerizable component are dispersed in an aqueous dispersion medium and fine particles of an inorganic compound and a monomer (A) and/or a monomer (B) described below are contained in the aqueous dispersion medium; and polymerizing the polymerizable component, wherein Monomer (A): Polymerizable unsaturated monomer having a total sulfuric acid value ranging from more than 0% to 35%; and Monomer (B): Polymerizable unsaturated monomer with a total phosphoric acid ranging from more than 0% to 50%.

The hollow microballoons for CMP polishing pad of the invention are formed of at least one resin selected from the group consisting of a melamine resin, a urea resin and an amide resin and have an average particle size of 1 to 100 μm. According to the invention, there can be provided hollow microballoons for CMP polishing pad, which, when used in CMP polishing pad, exhibit excellent polishing characteristics, and can stably produce CMP polishing pad even in production of CMP polishing pad.

The present disclosure relates to a preparation method of a super absorbent polymer. More specifically, it relates to a preparation method of a super absorbent polymer with improved permeability and anti-caking efficiency while having a high absorption rate by adding an additive having a specific structure to the hydrogel polymer polymerized in the presence of an encapsulated foaming agent, followed by coarse pulverization.

A thermally expandable sheet according to the present invention includes a stress buffer layer provided on one surface of a base material and having an elastic property, a thermal expansion layer provided on the stress buffer layer and containing a first thermally expandable material that expands according to heat and a first binder, and a cover layer provided on the thermal expansion layer and having an elastic property.

The present disclosure relates to thermoplastic polymeric microspheres comprising a thermoplastic polymer shell surrounding a hollow core, in which the thermoplastic polymer shell comprises a homopolymer or copolymer of a monomer of Formula 1

##STR00001## wherein: each of A1 to A11 are independently selected from H and C1 to C4 alkyl, in which each C1-4 alkyl group can optionally be substituted with one or more substituents selected from halogen, hydroxy and C1-4 alkoxy; X is a linking group selected from —O—, —NR″—, —S—, —OC(O)—, —NR″C(O)—, —SC(O)—, —C(O)O—, —C(O)NR″—, and —C(O)S—; and R″ is H or C1-2 alkyl optionally substituted with one or more substituents selected from halogen and hydroxy.

The invention relates to low density fluoropolymer foam, and preferably polyvinylidene fluoride (PVDF) foam, such as that made with KYNAR PVDF resins, and articles made of the foam. The foam is produced by adding microspheres containing blowing agents to the polymer and processing it through an extruder. The microspheres consist of a hard shell containing a physical blowing agent. The shell softens at elevated temperatures and allows the expansion of the blowing agent, and microsphere to create larger voids within the polymer matrix. By proper control of the polymer composition, viscosity, processing temperature, blowing agent selection, loading ratio, and finishing conditions, useful articles such as foamed PVDF pipe, tube, profiles, film, wire jacketing and other articles can be produced. The microspheres may be added to the fluoropolymer matrix by several means, including as part of a masterbatch with a compatible polymer carrier.

Embodiments relate to a porous polyurethane polishing pad for use in a chemical mechanical planarization and a process for preparing the same. It is possible to control the size and distribution of pores in the porous polyurethane polishing pad by using thermally expanded microcapsules and an inert gas as a gas phase foaming agent, whereby the polishing performance thereof can be adjusted.

A method of manufacturing a fluid control device includes extruding a polymer melt into a chamber defined by an outer surface of a support structure and a disintegrable metallic tubular member disposed at the support structure, the polymer melt comprising a high heat polymer and a foaming agent, the high heat polymer having a heat deflection temperature of about 100° C. to about 300° C. measured at 1.82 MPa in accordance with ASTM D648-18; sealing the chamber; and foaming the high heat polymer to produce a porous filtration medium in a compacted shape.

A molded article of polyolefin-based resin expanded beads having excellent appearance and further suppressed color unevenness is provided.

Polyolefin-based resin expanded beads obtained by expanding polyolefin-based resin particles including one or two or more metal borates selected from zinc borate and magnesium borate, wherein the particles of the metal borate has an arithmetic average particle diameter based on the number of 1 μm or more, and a number rate of the particles of the metal borate having a particle diameter of 5 μm or more is 20% or less. A method for producing polyolefin-based resin expanded beads by releasing expandable polyolefin-based resin particles containing one or two or more metal borates selected from zinc borate and magnesium borate and a physical blowing agent dispersed in an aqueous medium in a closed vessel together with the aqueous medium from the closed vessel to a low pressure region than an inside of the closed vessel to expand the expandable polyolefin-based resin particles, the method comprising: using a metal borate having an arithmetic average particle diameter based on the number of 1 μm or more and a number rate of the particles having a particle diameter of 5 μm or more of 20% or less as the metal borate.