FOAMED POLYPROPYLENE BEADS, A METHOD FOR PRODUCING FOAMED POLYPROPYLENE BEADS, MOLDED ARTICLES OBTAINED FROM FOAMED POLYPROPYLENE BEADS, AND A METHOD FOR PRODUCING SUCH MOLDED ARTICLES Russian patent published in 2023 - IPC C08J9/16 C08J9/232 C08L23/12 C08K3/26 C08K5/00 

FIELD: chemistry technology.

SUBSTANCE: group of inventions relates to foamed polypropylene beads, a method for manufacturing foamed polypropylene beads, moulded products obtained from foamed polypropylene beads, and a method for manufacturing such moulded products. Foamed polypropylene beads for the manufacture of moulded articles are described containing a polypropylene composition (K) having: a) a melt flow index MFR₂ determined in accordance with ISO 1133 at 230°C and a load of 2.16 kg, 1.5 to 15.0 g/10 min, b) melting point Tm, determined by differential scanning calorimetry in accordance with ISO 11357, from 135 to 158°C, and c) loss tangent tanδ at an angular frequency of 0.1 rad/s when measuring dynamic viscoelastic characteristics at 200°C from 2.00 to 4.00, while the polypropylene composition (K) comprises more than 90.0 wt.%, based on the total weight of the polypropylene composition (K), long-chain branched propylene copolymer (s-PP), including up to 8.0 wt.% comonomer or comonomers selected from ethylene and C₄ -C₁₀ alpha-olefins, and an active foam nucleator. A polypropylene composition (K) is used to obtain foamed polypropylene beads having a density of 25 to 150 g/dm³ and a content of closed cells greater than or equal to 80%, and the use of foamed polypropylene beads containing composition (K) to obtain moulded products. having a density of 25 to 150 g/dm³ and the content of closed cells greater than or equal to 80%.

EFFECT: provision of foamed polypropylene beads having an advantageous low content of open cells and good density, suitable for obtaining moulded products by means of a moulding process in a steam chamber at a pressure equal to or less than 0.4 MPa (4 bar), with a short steam treatment time.

17 cl, 4 tbl, 8 ex