TH41392A - A polyolefin compound with a highly balanced combination of stiffness and impact strength. - Google Patents

Abstract

DC60 (15/12/42) Polyolefin compounds consist of (percentage by weight): (A) 40 to 60% of a broad molecular weight distribution of propylene polymer (component A) with a polydispersity index of 5 to 15 and a melt flow rate of 80 to 200 g/10 min (according to ASTM-D 1238, condition L); and (B) 40 to 60% of a partially xylene-insoluble olefin polymer (component B) containing at least 65% by weight of ethylene; the IVs/IVA ratio between the intrinsic viscosities (IVs) of the xylene-soluble portion of the compound. The polyolefin mixture was prepared at room temperature with a limiting viscosity (IVA) of component (A) ranging from 2 to 2.5, both measured in tetrahydronaphthalene at 135 °C. The mixture has applications in automotive-related fields. The polyolefin mixture consists of (percentage by weight): (A) 40 to 60% of a broad molecular weight distribution of propylene polymer (component A) with a polydispersity index ranging from 5 to 15 and a melt flow rate ranging from 80 to 200 g/10 min (according to ASTM-D 1238, L conditions); and (B) 40 to 60% of a partially xylene-insoluble olefin polymer (component B) containing at least 65% by weight of ethylene; The IVs/IVA ratio between the intrinsic viscosity (IVs) of the xylene-soluble fraction of the polyolefin mixture at room temperature and the intrinsic viscosity (IVA) of component (A) ranges from 2 to 2.5. Both intrinsic viscosity values were measured in diatrahydronephthalene at 135 °C. Such mixtures have applications in areas related to the automotive industry.

Claims (8)

1) Polyphenolic mixtures consist of (percentage by weight): (A) 40 to 60% of a broad molecular weight distribution of propylene polymer (component A) with a polydispersity index of 5 to 15 and a melt flow rate of 80 to 200 g/10 min (according to ASTM-D 1238, condition L); and (B) 40 to 60% of a partially xylene-insoluble olefin polymer (component B) containing at least 65% by weight of ethylene; the IVs/IVA ratio between the intrinsic viscosities (IVs) of the xylene-soluble portion of the mixture. The polyolefin mixture was prepared at room temperature, and the limiting viscosity (IVA) of component (A) ranged from 2 to 2.5, with the optimal range being from 2.1 to 2.4. Both limiting viscosity values were measured in hydronaphthalene at 135 °C. 2) The polyolefin mixture of claim 1 shall be supplemented with 0.5 to 3 parts by weight in the sum of components (A) and (B) of mineral filler. 3) The polyolefin mixture of claim 2 has a melt flow rate of 5 to 20 g/10 min. 4) Polyolefin mixture of claim 2 where component (A) has a melt flow rate of 80 to 150 g/10 min. 5) Polyolefin mixture of claim No. 2, where component (B) is poly(ethylene-co-propylene). 6) Procedure for the preparation of polyolefin mixtures of Patent 1, where monomers are polymerized in the presence of a stereopice catalyst fixed on an active magnesium halide in at least three consecutive steps, where components (A) and (B) are prepared in separate, consecutive steps, the work in each step in which the polymers are formed and the catalyst is applied immediately before the preceding step. 7) The component is manufactured by blending the polyolefin of claim 1. 8) The bumper is manufactured from the polyolefin composite of claim number 1.