Polypropylene composition with low shrinkage at wide application temperature range
AssigneeBorealis AG
InventorsMarkus Gahleitner, Klaus Bernreitner, Jingbo Wang
Life of this patent
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Abstract
The present application relates to a polypropylene composition having a melt flow rate MFR.2 (230° C.) measured according to ISO 1133 in the range of 5 to 50 g/10 min, to a composition comprising the polypropylene composition and one or more additive(s) in an amount of up to 4 wt.-%, based on the total weight of the composition, to a process for the preparation of the polypropylene composition and an article comprising the polypropylene composition as well as the use of the polypropylene composition for decreasing the brittle-to-ductile transition temperature.
Claims13
A polypropylene composition having a melt flow rate MFR2 (230° C.) measured according to ISO 1133 in the range of 5 to 50 g/10 min, the polypropylene composition comprising:
- (a) 55 to 75 wt. %, based on the total weight of the polypropylene composition, of a crystalline fraction (CF) as determined in the CRYSTEX QC method, the crystalline fraction (CF) having
- i) a melting temperature (Tm) measured by differential scanning calorimetry (DSC) between 147° C. and 162° C., and
- ii) an ethylene content of 1 wt. %, based on the total weight of the crystalline fraction (CF);
- and
- (b) 25 to 45 wt. %, based on the total weight of the polypropylene composition, of a soluble fraction (SF) as determined in a CRYSTEX QC method, the soluble fraction (SF) having
- i) an intrinsic viscosity (IV) in the range of 1.0 to 2.0 dl/g, and
- ii) an ethylene content in the range of 18 to 30 wt. %, based on the total weight of the soluble fraction (SF),
- wherein said polypropylene composition has a ratio of intrinsic viscosity of the soluble fraction (IV(SF)) to intrinsic viscosity of the crystalline fraction (IV(CF)) [(IV(SF))/(IV(CF))] in the range from 0.8 to 1.1, and
- wherein the polypropylene composition is polymerized in the presence of a single-site catalyst consisting of racemic anti-dimethylsilanediyl[2-methyl-4-(4-tert-butylphenyl)-inden-1-yl] [2-methyl-4-(4-tert-butylphenyl)-5-methoxy-6-tert-butyl-inden-1-yl]zirconium dichloride and methylaluminoxane (MAO) as cocatalyst.
Dependencies are inferred from the claim text.