High flowable heterophasic polypropylene

Abstract

Heterophasic polypropylene resin having an MFR (2.16 kg, 230 DEG C) of more than 40 g / 10 min, determined according to ISO 1133 comprising a propylene homo- or copolymer matrix (A) and an ethylene-propylene rubber phase (B) dispersed within the matrix, wherein the heterophasic polypropylene resin has a fraction insoluble in p-xylene at 25 DEG C (XCU) with an intrinsic viscosity of 1.2 dl / g or less, determined according to DIN EN ISO 1628-1 and -3, the fraction insoluble in p-xylene at 25 DEG C (XCU) being composed of propylene monomer units in an amount of at least 95 wt.-%, and a fraction soluble in p-xylene at 25 DEG C (XCS), having an intrinsic viscosity of 2.0 to 3.5 dl / g, determined according to DIN EN ISO 1628-1 and -3 and being composed of propylene monomer units in an amount of 50 wt. -% or more, and having a glass transition temperature Tg as measured by DSC according to ISO 6721-7 at a compression moulded sample consisting of the XCS fraction in the range of - 42 to - 30 DEG C.

Description

technical field [0001] The present invention relates to high flow heterophasic polypropylene resins comprising a propylene homopolymer or copolymer matrix (A) and an ethylene-propylene rubber phase (B) dispersed in the matrix. Background technique [0002] Known commercial polypropylenes are inter alia isotactic, semi-crystalline, thermoplastic polymer materials. One of the main application areas of polypropylene is injection molded thin-walled products. Typical examples include plastic cups, pickets and small containers mainly used for food packaging. To be suitable for thin wall injection molding, the polypropylene should exhibit excellent processability / flow, usually expressed as a high melt flow rate (MFR), ie low average molecular weight. However, these polypropylenes exhibit brittleness under impact loads, especially at low temperatures. [0003] EP 1 354 901 and EP 1 659 151 have taught adding large amounts of impact modifiers, such as elastomeric ethylene-propylen...

AI Technical Summary

Problems solved by technology

However, visbreaking is not an advisable technical solution as it has a negative effect on the stiffness especially of molded articles and leads to the presence of impurities in the film or molded article in the form of volatiles

Images