A method of producing a polyurethane or polyisocyanurate foam is provided which involves the use of a specific combination of hydrofluoroolefin blowing agents and cell nucleators. The resulting foams have excellent long term thermal insulating performance and have reduced thickness in comparison to conventional thermal insulating boards. The rigid polyurethane and polyisocyanurate boards may be used to insulate refrigeration bodies, such as those employed in vehicles comprising refrigeration units, and cold storage containers.

The present invention provides a flame-retardant styrene polymer composition comprising an organic bromine compound, zinc stearate and calcium stearate, the use for preparing styrene polymer films or foams and a process for recycling of styrene polymer-containing scrap.

Provided are a flame retardant composition for expandable styrene resin with which an extrusion-foamed molded article having excellent flame retardancy and excellent heat resistance can be produced; a styrene-based resin composition; and an extrusion-foamed molded article of the styrene-based resin composition. The flame retardant composition for expandable styrene resin of the present invention comprises at least B1) tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether), (C) a zinc-modified hydrotalcite, and (D) a phosphoric acid ester-based compound, the component (B1) being contained in an amount of 10 to 98 mass % based on the total amount of the component (B1) and the component (D).

A crosslinked olefin-based thermoplastic elastomer expanded bead including a base polymer having an olefin-based thermoplastic elastomer and a brominated bisphenol-based flame retardant having a chemical structure represented by formula (1). A difference Tm.sub.TPO-T.sub.FR is −5° C. to 40° C., where Tm.sub.TPO is a melting point of the olefin-based thermoplastic elastomer and T.sub.FR is the lower of a glass transition temperature T.sub.gFR and a melting point Tm.sub.FR of the brominated bisphenol-based flame retardant. A xylene insoluble content is 5 mass % to 80 mass %. R.sup.1 and R.sup.3 in the formula (1) are monovalent substituents, R.sup.2 is a divalent substituent, and n is an integer from 1 to 6:

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An article with at least two extruded thermoplastic polymer foam pieces that fit together to form a length of foam having a generally annular cross section, each piece having a concave surface such that the concave surfaces adjoin to form an internal edge defining a hole within the generally annular cross section; wherein each piece has a density less than 36 kilograms per cubic meter, a product of density times average cell size that is less than 17 millimeters*kilogram per cubic meter, and a thermal conductivity of 35 milliwatts per meter*Kelvin or less.

Reversibly cross-linkable foam is provided. The reversibly cross-linked foam includes a first polymeric material, at least one reversibly cross-linkable monomer polymerized with the first polymeric material, and at least one blowing agent. The reversibly cross-linkable co-polymeric foam is thermally stable at temperatures of at least 10 degrees higher than otherwise identical polymeric foam that does not include the reversibly cross-linkable agent polymerized with the first polymeric material.

A process is described for producing PU foams, especially rigid PU foams, based on foamable reaction mixtures containing polyisocyanates, compounds having reactive hydrogen atoms, blowing agents, foam stabilizers, and possibly further additives, wherein specific perfluoropolyethers are additionally used.

A polyolefin composition is foamed by a process in which a nucleator is used, and the nucleator comprises 80% or more of unagglomerated fluororesin particles and/or agglomerates of fluororesin particles in which both the unagglomerated particles and the agglomerates are less than 1 μm in size.

A polyolefin composition is foamed by a process in which a nucleator is used, and the nucleator comprises 80% or more of unagglomerated fluororesin particles and/or agglomerates of fluororesin particles in which both the unagglomerated particles and the agglomerates are less than 1 μm in size.

The flame-retardant urethane resin composition contains a polyisocyanate compound, a polyol compound, a trimerization catalyst, a blowing agent, and an additive, wherein the additives include red phosphorus and a filler, and the filler has an aspect ratio of 5 to 50, an average particle diameter of 0.1 μm or larger, but smaller than 15 μm, and a melting point of 750° C. or higher.