Method for producing expanded or expandable polyolefin particles
AssigneeBASF SE
InventorFrank Braun
Life of this patent
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Abstract
The invention relates to a process for the production of expanded or expandable polyolefin beads by impregnating polyolefin granules with a volatile blowing agent in suspension under pressure. As suspension aid, use is made of a mixture of a water-insoluble inorganic compound and a surfactant, and the impregnation is carried out in the presence of a surface-active polymer carrying carboxyl or carboxylate groups.
Claims8
A process for the production of expanded polyolefin beads by impregnating polyolefin granules with a volatile blowing agent in aqueous suspension in the presence of at least 0.5% by weight, based on the polyolefin granules, of a water-insoluble inorganic compound in combination with a surfactant as suspension aid at elevated temperature under pressure followed by decompression, which comprises carrying out the impregnation in the presence of a polymer containing carboxyl or carboxylate groups.
A process for the production of expandable polyolefin beads by impregnating polyolefin granules with a volatile blowing agent in aqueous suspension in the presence of at least 0.5% by weight, based on the polyolefin granules, of a water-insoluble inorganic compound in combination with a surfactant as suspension aid at elevated temperature under pressure, and then cooling the beads, followed by decompression, which comprises carrying out the impregnation in the presence of a polymer containing carboxyl or carboxylate groups.
Dependencies are inferred from the claim text.