Abstract: A polyolefin-based resin pre-expanded particle includes a polyolefin-based resin; an organic phosphorus-containing compound being nitrogen-free; and a hindered amine having an OR group substituted directly on an N-atom where R is a saturated or unsaturated hydrocarbyl group, wherein the organic phosphorus-containing compound is at least one selected from the group consisting of alkyl phosphonic acid, an ester of the alkyl phosphonic acid, aryl phosphonic acid, an ester of the aryl phosphonic acid, a cyclic phosphonate, and a cyclic bisphosphonate, the polyolefin-based resin pre-expanded particle comprises from 1.0% by weight to 10% by weight of the organic phosphorus-containing compound and from 0.1% by weight to 5.0% by weight of the hindered amine, and the weight ratio of the organic phosphorus-containing compound to the hindered amine is from 1.0 to 20.

Abstract: A polyolefin-based resin pre-expanded particle includes a polyolefin-based resin; an organic phosphorus-containing compound being nitrogen-free; and a hindered amine having an OR group substituted directly on an N-atom where R is a saturated or unsaturated hydrocarbyl group, wherein the organic phosphorus-containing compound is at least one selected from the group consisting of alkyl phosphonic acid, an ester of the alkyl phosphonic acid, aryl phosphonic acid, an ester of the aryl phosphonic acid, a cyclic phosphonate, and a cyclic bisphosphonate, the polyolefin-based resin pre-expanded particle comprises from 1.0% by weight to 10% by weight of the organic phosphorus-containing compound and from 0.1% by weight to 5.0% by weight of the hindered amine, and the weight ratio of the organic phosphorus-containing compound to the hindered amine is from 1.0 to 20.

Abstract: Molded article prepared by in-mold forming of pre-expanded polyolefin particles, wherein the pre-expanded poly-olefin particles contain carbon black and powdered activated carbon. The invention is also directed to pre-expanded polyolefin particles containing carbon black and powdered activated carbon and a process for producing pre-expanded polyolefin product.

Abstract: A pre-expanded polyolefin particle containing powdered activated carbon (PAC) and a pre-expanded polyolefin particle containing PAC and a sterically hindered amine ether flame retardant, as well as processes for preparing pre-expanded polyolefin particles. A process for producing the pre-expanded polyolefin includes providing polyolefin polymer granules containing powdered activated carbon; impregnating the polyolefin polymer granules with a volatile blowing agent in an aqueous suspension at a pressure of 5 to 50 bar and at temperatures of 100 to 170° C.; and decompression to atmospheric pressure.