Polyolefin composition with improved surface appearance

Abstract

The present invention is directed to a heterophasic polypropylene composition (HECO1) and the use thereof to reduce the amount of flow marks of an injection moulded polyolefin composition. Further, the present invention is directed to a polyolefin composition (C) comprising a polyolefin (PO), said heterophasic polypropylene composition (HECO1) and optionally a filler as well as an article comprising said polyolefin composition (C).

Claims

1. A heterophasic polypropylene composition (HECO1), comprising: i) a matrix (M) comprising a first propylene polymer (PP1) and a second propylene polymer (PP2), and ii) an elastomeric propylene copolymer (EPR) being a copolymer of propylene and ethylene and/or a C.sub.4 to C.sub.8 -olefin dispersed within the matrix (M), wherein the ratio MFR(PP1)/MFR(PP2) is above 10,000, wherein MFR(PP1) is the melt flow rate MFR (230 C., 2.16 kg) in [g/10 min] determined according to ISO 1133 of the first propylene polymer (PP1) and MFR(PP2) is the melt flow rate MFR (230 C., 2.16 kg) in [g/10 min] determined according to ISO 1133 of the second propylene polymer (PP2).

2. The heterophasic polypropylene composition (HECO1) according to claim 1, wherein the second propylene polymer (PP2) has a melt flow rate MFR (230 C., 2.16 kg) determined according to ISO 1133 equal or below 10.0 g/10 min.

3. A heterophasic polypropylene composition (HECO1), comprising: i) a matrix (M) comprising a first propylene polymer (PP1) and a second propylene polymer (PP2), wherein the second propylene copolymer has a melt flow rate MFR (230 C., 2.16 kg) determined according to ISO 1133 of equal or below 0.05 g/10 min, and ii) an elastomeric propylene copolymer (EPR) dispersed within the matrix (M), wherein the ratio MFR(PP1)/MFR(PP2) is above 61, wherein MFR(PP1) is the melt flow rate MFR (230 C., 2.16 kg) in [g/10 min] determined according to ISO 1133 of the first propylene polymer (PP1) and MFR(PP2) is the melt flow rate MFR (230 C., 2.16 kg) in [g/10 min] determined according to ISO 1133 of the second propylene polymer (PP2).

4. The heterophasic polypropylene composition (HECO1) according to claim 1, wherein the first propylene polymer (PP1) has a melt flow rate MFR (230 C., 2.16 kg) determined according to ISO 1133 equal or above 100 g/10 min.

5. The heterophasic polypropylene composition (HECO1) according to claim 1, wherein the matrix (M) comprises the first propylene polymer (PP1) and the second propylene polymer (PP2) in a weight ratio of 99:1 to 80:20.

6. The heterophasic polypropylene composition (HECO1) according to claim 1, having a xylene soluble fraction (XCS) in the range of 10.0 to 50.0 wt. %.

7. The heterophasic polypropylene composition (HECO1) according to claim 6, wherein the comonomer content of the xylene soluble fraction (XCS) is in the range of 20.0 to 65.0 mol %.

8. The heterophasic polypropylene composition (HECO1) according to claim 1, comprising the matrix (M) and the elastomeric propylene copolymer (EPR) in a weight ratio of 70:30 to 30:70.

9. The heterophasic polypropylene composition (HECO1) according to claim 1, wherein the elastomeric propylene copolymer (EPR) comprises: i) a first elastomeric propylene copolymer (EPR1), and ii) a second elastomeric propylene copolymer (EPR2), wherein the ratio C(EPR2)/C(EPR1) is in the range of 1.1 to 10.0, wherein C(EPR2) is the comonomer content in [mol %] of the second elastomeric propylene copolymer (EPR2) and (EPR1) is the comonomer content in [mol %] of the first elastomeric propylene copolymer (EPR1).

10. The heterophasic polypropylene composition (HECO1) according to claim 1, having a melt flow rate MFR (230 C., 2.16 kg) determined according to ISO 1133 equal or below 10.0 g/10 min.

11. The heterophasic polypropylene composition (HECO1) according to claim 1, wherein said heterophasic polypropylene composition (HECO1) a) is free of phthalic acid esters as well as their respective decomposition products and b) has 2,1 regio defects of less than 0.4% determined by .sup.13C-NMR spectroscopy.

12. A polyolefin composition (C), comprising: i) a polyolefin (PO), ii) the heterophasic polypropylene composition (HECO1) according to claim 1, and iii) optionally an inorganic filler (F).

13. The polyolefin composition (C) according to claim 12, comprising 5.0 to 30.0 wt. % of the heterophasic polypropylene composition (HECO1), based on the overall weight of the polypropylene composition (C).

14. A polyolefin composition (C) according to claim 12, wherein the polyolefin (PO) is a polypropylene being different than the heterophasic polypropylene composition (HECO1).

15. An injection moulded article, comprising the polyolefin composition (C) according to claim 14.

Description

EXAMPLES

(1) 1. Measuring Methods

(2) The following definitions of terms and determination methods apply for the above general description of the invention as well as to the below examples unless otherwise defined.

(3) Calculation of comonomer content of the first elastomeric propylene copolymer fraction, i.e. the polymer fraction produced in the third reactor (R3), of the heterophasic propylene copolymer (HECO1):

(4) $\frac{C\left(\mathrm{PP}\right)-w\left(\mathrm{PP}12\right)C\left(\mathrm{PP}12\right)}{w\left(\mathrm{PP}3\right)}=C\left(\mathrm{PP}3\right)$
wherein w(PP12) is the weight fraction of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), w(PP3) is the weight fraction of the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the third reactor (R3), C(PP12) is the comonomer content [in mol-%] of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), C(PP) is the comonomer content [in mol-%] of the first and second propylene polymer fractions and the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the first, second and third reactor (R1+R2+R3), C(PP3) is the calculated comonomer content [in mol-%] of the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the third reactor (R3).

(5) Calculation of comonomer content of the second elastomeric propylene copolymer fraction, i.e. the polymer fraction produced in the fourth reactor (R4), of the heterophasic propylene copolymer (HECO1):

(6) $\frac{C\left(\mathrm{PP}\right)-w\left(\mathrm{PP}123\right)C\left(\mathrm{PP}123\right)}{w\left(\mathrm{PP}4\right)}=C\left(\mathrm{PP}4\right)$ wherein w(PP123) is the weight fraction] of the first and second propylene polymer fractions and the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the first, second and third reactor (R1+R2+R3), w(PP4) is the weight fraction of second elastomeric propylene copolymer fraction, i.e. the polymer produced in the fourth reactor (R4), C(PP123) is the comonomer content [in mol-%] of the first and second propylene polymer fractions and the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the first, second and third reactor (R1+R2+R3), C(PP) is the comonomer content [in mol-%] of the first and second propylene polymer fractions and the first and second elastomeric propylene copolymer fractions, i.e. the polymer produced in the first, second, third and fourth reactor (R1+R2+R3), C(PP4) is the calculated comonomer content [in mol-%] of the second elastomeric propylene copolymer fraction, i.e. the polymer produced in the fourth reactor (R4).

(7) Calculation of the xylene cold soluble (XCS) content of the elastomeric propylene copolymer fraction, i.e. the polymer fraction produced in the third and fourth reactor (R3+R4), of the heterophasic propylene copolymer (HECO1):

(8) $\frac{\mathrm{XS}\left(\mathrm{HECO}\right)-w\left(\mathrm{PP}12\right)\mathrm{XS}\left(\mathrm{PP}12\right)}{w\left(E\right)}=\mathrm{XS}\left(E\right)$
wherein w(PP12) is the weight fraction of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), w(E) is the weight fraction of the elastomeric propylene copolymer fraction, i.e. the polymer produced in the third and fourth reactor (R3+R4) XS(PP12) is the xylene cold soluble (XCS) content [in wt.-%] of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), XS(HECO) is the xylene cold soluble (XCS) content [in wt.-%] of the first and second propylene polymer fractions and the elastomeric propylene copolymer fraction, i.e. polymer produced in the first, second, third and fourth (R1+R2+R3+R4), XS(E) is the calculated xylene cold soluble (XCS) content [in wt.-%] of the elastomeric propylene copolymer fraction, i.e. the polymer produced in the third and fourth reactor (R3+R4).

(9) Calculation of the xylene cold soluble (XCS) content of the first elastomeric propylene copolymer fraction, i.e. the polymer fraction produced in the third reactor (R3), of the heterophasic propylene copolymer (HECO1):

(10) $\frac{\mathrm{XS}\left(\mathrm{PP}\right)-w\left(\mathrm{PP}12\right)\mathrm{XS}\left(\mathrm{PP}12\right)}{w\left(\mathrm{PP}3\right)}=\mathrm{XS}\left(\mathrm{PP}3\right)$
wherein w(PP12) is the weight fraction of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), w(PP3) is the weight fraction of the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the third reactor (R3) XS(PP12) is the xylene cold soluble (XCS) content [in wt.-%] of the first and second elastomeric propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), XS(PP) is the xylene cold soluble (XCS) content [in wt.-%] of the first and second propylene polymer fraction and the first elastomeric propylene copolymer fraction, i.e. polymer produced in the first, second and third reactor (R1+R2+R3), XS(PP3) is the calculated xylene cold soluble (XCS) content [in wt.-%] of the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the third reactor (R3).

(11) Calculation of the xylene cold soluble (XCS) content of the second elastomeric propylene copolymer fraction, i.e. the polymer fraction produced in the fourth reactor (R4), of the heterophasic propylene copolymer (HECO1):

(12) $\frac{\mathrm{XS}\left(\mathrm{PP}\right)-w\left(\mathrm{PP}123\right)\mathrm{XS}\left(\mathrm{PP}123\right)}{w\left(\mathrm{PP}4\right)}=\mathrm{XS}\left(\mathrm{PP}4\right)$
wherein w(PP123) is the weight fraction of the first and second propylene polymer fractions and the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the first, second and third reactor (R1+R2+R3), w(PP4) is the weight fraction of the second propylene copolymer fraction, i.e. the polymer produced in the fourth reactor (R4) XS(PP123) is the xylene cold soluble (XCS) content [in wt.-%] of the first and second propylene polymer fractions and the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the first, second and third reactor (R1+R2+R3), XS(PP) is the xylene cold soluble (XCS) content [in wt.-%] of the first and second propylene polymer fractions and the first and second elastomeric propylene copolymer fractions, i.e. polymer produced in the first, second reactor and third reactor (R1+R2+R3+R4), XS(PP4) is the calculated xylene cold soluble (XCS) content [in wt.-%] of the second elastomeric propylene copolymer fraction, i.e. the polymer produced in the fourth reactor (R4).

(13) Calculation of melt flow rate MFR.sub.2 (230 C.) of the second propylene polymer fraction, i.e. the polymer fraction produced in the second reactor (R2), of the heterophasic propylene copolymer (HECO1):

(14) $\mathrm{MFR}\left(\mathrm{PP}2\right)={10}^{\left[\frac{\log \left(\mathrm{MFR}\left(\mathrm{PP}\right)\right)-w\left(\mathrm{PP}1\right)\log \left(\mathrm{MFR}\left(\mathrm{PP}1\right)\right)}{w\left(\mathrm{PP}2\right)}\right]}$
wherein w(PP1) is the weight fraction of the first propylene polymer fraction, i.e. the polymer produced in the first reactor (R1), w(PP2) is the weight fraction of the first second propylene polymer fraction, i.e. the polymer produced in the second reactor (R2), MFR(PP1) is the melt flow rate MFR.sub.2 (230 C.) [in g/10 min] of the first propylene polymer fraction, i.e. the polymer produced in the first reactor (R1), MFR(PP) is the melt flow rate MFR.sub.2 (230 C.) [in g/10 min] of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), MFR(PP2) is the calculated melt flow rate MFR.sub.2 (230 C.) [in g/10 min] of the first propylene polymer fraction, i.e. the polymer produced in the second reactor (R2).

(15) Calculation of the intrinsic viscosity of the xylene soluble fraction of the first elastomeric propylene copolymer fraction, i.e. the polymer fraction produced in the third reactor (R3), of the heterophasic propylene copolymer (HECO):

(16) $\frac{\mathrm{IV}\left(\mathrm{PP}\right)-\frac{\mathrm{XCS}\left(\mathrm{PP}12\right)}{100}\mathrm{IV}\left(\mathrm{PP}12\right)}{\frac{\mathrm{XCS}\left(\mathrm{PP}3\right)}{100}}=\mathrm{IV}\left(\mathrm{PP}3\right)$
wherein XCS(PP12) is the xylene soluble fraction [in wt.-%] of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), XCS(PP3) is the xylene soluble fraction [in wt.-%] of the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the third reactor (R3), IV(PP12) is the intrinsic viscosity [in dl/g] of the xylene soluble fraction of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), IV(PP) is the intrinsic viscosity [in dl/g] of the xylene soluble fraction of the first and second propylene polymer fractions and the first elastomeric propylene copolymer fraction, i.e. polymer produced in the first, second and third reactor (R1+R2+R3), IV(PP3) is the calculated intrinsic viscosity [in dl/g] of the xylene soluble fraction of the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the third reactor (R3).

(17) Calculation of the intrinsic viscosity of the xylene soluble fraction of the second elastomeric propylene copolymer fraction, i.e. the polymer fraction produced in the fourth reactor (R4), of the heterophasic propylene copolymer (HECO1):

(18) $\frac{\mathrm{IV}\left(\mathrm{PP}\right)-\frac{\mathrm{XCS}\left(\mathrm{PP}123\right)}{100}\mathrm{IV}\left(\mathrm{PP}123\right)}{\frac{\mathrm{XCS}\left(\mathrm{PP}4\right)}{100}}=\mathrm{IV}\left(\mathrm{PP}4\right)$
wherein XCS(PP123) is the xylene soluble fraction [in wt.-%] of the first and second propylene polymer fractions and the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the first, second and third reactor (R1+R2+R3), XCS(PP4) is the xylene soluble fraction [in wt.-%] of second elastomeric propylene copolymer fraction, i.e. the polymer produced in the fourth reactor (R4), IV(PP123) is the intrinsic viscosity [in dl/g] of the xylene soluble fraction of the first and second propylene polymer fractions and the first elastomeric propylene copolymer fraction, i.e. the polymer produced in the first, second and third reactor (R1+R2+R3), IV(PP) is the intrinsic viscosity [in dl/g] of the xylene soluble fraction of the first and second propylene polymer fractions and the first and second elastomeric propylene copolymer fractions, i.e. polymer produced in the first, second, third and fourth reactor (R1+R2+R3+R4), IV(PP4) is the calculated intrinsic viscosity [in dug] of the xylene soluble fraction of the second elastomeric propylene copolymer fraction, i.e. the polymer produced in the fourth reactor (R4).

(19) Calculation of comonomer content of the elastomeric propylene copolymer fraction, i.e. the polymer fraction produced in the third and fourth reactor (R3+R4), of the heterophasic propylene copolymer (HECO1):

(20) 0$\frac{C\left(\mathrm{HECO}\right)-w\left(\mathrm{PP}12\right)C\left(\mathrm{PP}12\right)}{w\left(E\right)}=C\left(E\right)$
wherein w(PP12) is the weight fraction of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), w(E) is the weight fraction of the elastomeric propylene copolymer fraction, i.e. the polymer produced in the third and fourth reactor (R3+R4) C(PP12) is the comonomer content [in mol-%] of the first and second propylene polymer fractions, i.e. the polymer produced in the first and second reactor (R1+R2), C(HECO) is the comonomer content [in mol-%] of the first and second propylene polymer fractions and the elastomeric propylene copolymer, i.e. polymer produced in the first, second, third and fourth (R1+R2+R3+R4), C(E) is the calculated comonomer content [in mol-%] of the elastomeric propylene copolymer fraction, i.e. the polymer produced in the third and fourth reactor (R3+R4). MFR.sub.2 (230 C.) is measured according to ISO 1133 (230 C., 2.16 kg load).
Determination of Comonomer Content

(21) Quantitative infrared (IR) spectroscopy was used to quantify the ethylene content of the poly(ethylene-co-propene) copolymers through calibration to a primary method. Calibration was facilitated through the use of a set of in-house non-commercial calibration standards of known ethylene contents determined by quantitative .sup.13C solution-state nuclear magnetic resonance (NMR) spectroscopy. The calibration procedure was undertaken in the conventional manner well documented in the literature. The calibration set consisted of 38 calibration standards with ethylene contents ranging 0.2-75.0 wt % produced at either pilot or full scale under a variety of conditions. The calibration set was selected to reflect the typical variety of copolymers encountered by the final quantitative IR spectroscopy method. Quantitative IR spectra were recorded in the solid-state using a Bruker Vertex 70 FTIR spectrometer. Spectra were recorded on 2525 mm square films of 300 um thickness prepared by compression moulding at 180-210 C. and 4-6 mPa. For samples with very high ethylene contents (>50 mol %) 100 um thick films were used. Standard transmission FTIR spectroscopy was employed using a spectral range of 5000-500 cm.sup.1, an aperture of 6 mm, a spectral resolution of 2 cm.sup.1, 16 background scans, 16 spectrum scans, an interferogram zero filling factor of 64 and Blackmann-Harris 3-term apodisation. Quantitative analysis was undertaken using the total area of the CH.sub.2 rocking deformations at 730 and 720 cm.sup.1 (A.sub.Q) corresponding to (CH.sub.2).sub.>2 structural units (integration method G, limits 762 and 694 cm.sup.1). The quantitative band was normalised to the area of the CH band at 4323 cm.sup.1 (A.sub.R) corresponding to CH structural units (integration method G, limits 4650, 4007 cm.sup.1). The ethylene content in units of weight percent was then predicted from the normalised absorption (A.sub.Q/A.sub.R) using a quadratic calibration curve. The calibration curve having previously been constructed by ordinary least squares (OLS) regression of the normalised absorptions and primary comonomer contents measured on the calibration set. Quantitative .sup.13C {.sup.1H} NMR spectra were recorded in the solution-state using a Bruker Avance III 400 NMR spectrometer operating at 400.15 and 100.62 MHz for .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 10 mm extended temperature probehead at 125 C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was dissolved in 3 ml of 1,2-tetrachloroethane-d.sub.2 (TCE-d.sub.2) along with chromium (III) acetylacetonate (Cr(acac).sub.3) resulting in a 65 mM solution of relaxation agent in solvent (Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475). To ensure a homogenous solution, after initial sample preparation in a heat block, the NMR tube was further heated in a rotatory oven for at least 1 hour. Upon insertion into the magnet the tube was spun at 10 Hz. This setup was chosen primarily for the high resolution and quantitatively needed for accurate ethylene content quantification. Standard single-pulse excitation was employed without NOE, using an optimised tip angle, 1 s recycle delay and a bi-level WALTZ16 decoupling scheme (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225, Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128). A total of 6144 (6k) transients were acquired per spectra. Quantitative .sup.13C {.sup.1H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm using the chemical shift of the solvent. This approach allowed comparable referencing even when this structural unit was not present. Characteristic signals corresponding to the incorporation of ethylene were observed (Cheng, H. N., Macromolecules 17 (1984), 1950) and the comonomer fraction calculated as the fraction of ethylene in the polymer with respect to all monomer in the polymer: fE=(E/(P+E) The comonomer fraction was quantified using the method of Wang et. al. (Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157) through integration of multiple signals across the whole spectral region in the .sup.13C {.sup.1H} spectra. This method was chosen for its robust nature and ability to account for the presence of regio-defects when needed. Integral regions were slightly adjusted to increase applicability across the whole range of encountered comonomer contents. For systems with very low ethylene content where only isolated ethylene in PPEPP sequences were observed the method of Wang et. al. was modified reducing the influence of integration of sites that are no longer present. This approach reduced the overestimation of ethylene content for such systems and was achieved by reduction of the number of sites used to determine the absolute ethylene content to
E=0.5(S+S+S+0.5(S+S))
Through the use of this set of sites the corresponding integral equation becomes
E=0.5(I.sub.H+I.sub.G0.5(I.sub.C+I.sub.D))
using the same notation used in the article of Wang et. al. (Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157). Equations used for absolute propylene content were not modified. The mole percent comonomer incorporation was calculated from the mole fraction: E [mol %]=100*fE. The weight percent comonomer incorporation was calculated from the mole fraction: E [wt %]=100*(fE*28.06)/((fE*28.06)+((1fE)*42.08))
Number Average Molecular Weight (M.sub.n), Weight Average Molecular Weight (M.sub.w) and Molecular Weight Distribution (MWD)

(22) Molecular weight averages (Mw, Mn), and the molecular weight distribution (MWD), i.e. the Mw/Mn (wherein Mn is the number average molecular weight and Mw is the weight average molecular weight), were determined by Gel Permeation Chromatography (GPC) according to ISO 16014-4:2003 and ASTM D 6474-99. A PolymerChar GPC instrument, equipped with infrared (IR) detector was used with 3 Olexis and 1 Olexis Guard columns from Polymer Laboratories and 1,2,4-trichlorobenzene (TCB, stabilized with 250 mg/L 2,6-Di tert butyl-4-methyl-phenol) as solvent at 160 C. and at a constant flow rate of 1 mL/min 200 L. of sample solution were injected per analysis. The column set was calibrated using universal calibration (according to ISO 16014-2:2003) with at least 15 narrow MWD polystyrene (PS) standards in the range of 0.5 kg/mol to 11 500 kg/mol. Mark Houwink constants for PS, PE and PP used are as described per ASTM D 6474-99. All samples were prepared by dissolving 5.0-9.0 mg of polymer in 8 mL (at 160 C.) of stabilized TCB (same as mobile phase) for 2.5 hours for PP or 3 hours for PE at max. 160 C. under continuous gentle shaking in the autosampler of the GPC instrument.

(23) Intrinsic viscosity is measured according to DIN ISO 1628/1, October 1999 (in Decalin at 135 C.).

(24) The xylene solubles (XCS, wt.-%): Content of xylene cold solubles (XCS) is determined at 25 C. according ISO 16152; first edition; 2005-07-01. The part which remains insoluble is the xylene cold insoluble (XCI) fraction.

(25) Flexural Modulus was measured according to ISO 178 using injection molded test specimen as described in EN ISO 1873-2 with dimensions of 80104 mm.sup.3 at 23 C. at least 96 h after demoulding. Crosshead speed was 2 mm/min for determining the flexural modulus.
Charpy Notched Impact Strength (CNIS) is measured according to ISO 179-1/1 eA/DIN 53453 at 23 C. and 20 C., using injection molded bar test specimens of 80104 mm.sup.3 prepared in accordance with ISO 294-1:1996.
Flow Marks

(26) The tendency to show flow marks was examined with a method as described below. This method is described in detail in WO 2010/149529, which is incorporated herein in its entirety.

(27) An optical measurement system, as described by Sybille Frank et al. in PPS 25 Intern. Conf. Polym. Proc. Soc 2009 or Proceedings of the SPIE, Volume 6831, pp 68130T-68130T-8 (2008) was used for characterizing the surface quality.

(28) This method consists of two aspects:

(29) 1. Image recording:

(30) The basic principle of the measurement system is to illuminate the plates with a defined light source (LED) in a closed environment and to record an image with a CCD-camera system. A schematic setup is given in FIG. 1.

(31) 2. Image Analysis:

(32) The specimen is floodlit from one side and the upwards reflected portion of the light is deflected via two mirrors to a CCD-sensor. The such created grey value image is analyzed in lines. From the recorded deviations of grey values the mean square error (MSE) is calculated allowing a quantification of surface quality, i.e. the larger the MSE value the more pronounced is the surface defect.

(33) Generally, for one and the same material, the tendency to flow marks increases when the injection speed is increased.

(34) For this evaluation plaques 4401482.8 mm with grain VW K50 and a Hot_I gate of 2.8 mm were used. The plaques were produced with filling time of 1.5 sec (filling rate 300 mm/sec).

(35) Further Conditions:

(36) Melt temperature: 240 C.

(37) Mould temperature 30 C.

(38) Dynamic pressure: 10 bar hydraulic

(39) The smaller the MSE value is at a certain filling time, the smaller is the tendency for flow marks.

2. Examples

(40) A. Preparation of the Heterophasic Polypropylene Composition (HECO1) Preparation of the Catalyst

(41) Used Chemicals:

(42) 20% solution in toluene of butyl ethyl magnesium (Mg(Bu)(Et), BEM), provided by Chemtura

(43) 2-ethylhexanol, provided by Amphochem

(44) 3-Butoxy-2-propanol(DOWANOL PnB), provided by Dow

(45) bis(2-ethylhexyl)citraconate, provided by SynphaBase

(46) TiCl.sub.4, provided by Millenium Chemicals

(47) Toluene, provided by Aspokem

(48) Viscoplex 1-254, provided by Evonik

(49) Heptane, provided by Chevron

(50) Preparation of a Mg Alkoxy Compound

(51) Mg alkoxide solution was prepared by adding, with stirring (70 rpm), into 11 kg of a 20 wt-% solution in toluene of butyl ethyl magnesium (Mg(Bu)(Et)), a mixture of 4.7 kg of 2-ethylhexanol and 1.2 kg of butoxypropanol in a 20 l stainless steel reactor. During the addition the reactor contents were maintained below 45 C. After addition was completed, mixing (70 rpm) of the reaction mixture was continued at 60 C. for 30 minutes. After cooling to room temperature 2.3 kg g of the donor bis(2-ethylhexyl)citraconate was added to the Mg-alkoxide solution keeping temperature below 25 C. Mixing was continued for 15 minutes under stirring (70 rpm).

(52) Preparation of Solid Catalyst Component

(53) 20.3 kg of TiCL and 1.1 kg of toluene were added into a 20 l stainless steel reactor. Under 350 rpm mixing and keeping the temperature at 0 C., 14.5 kg of the Mg alkoxy compound prepared in example 1 was added during 1.5 hours. 1.7 l of Viscoplex 1-254 and 7.5 kg of heptane were added and after 1 hour mixing at 0 C. the temperature of the formed emulsion was raised to 90 C. within 1 hour. After 30 minutes mixing was stopped catalyst droplets were solidified and the formed catalyst particles were allowed to settle. After settling (1 hour), the supernatant liquid was siphoned away. Then the catalyst particles were washed with 45 kg of toluene at 90 C. for 20 minutes followed by two heptane washes (30 kg, 15 min). During the first heptane wash the temperature was decreased to 50 C. and during the second wash to room temperature.

(54) VCH Modification of the Catalyst

(55) 35 ml of mineral oil (Paraffinum Liquidum PL68) was added to a 125 ml stainless steel reactor followed by 1.139 g of triethyl aluminium (TEAL) and 0.985 g of dicyclopentyl dimethoxy silane (donor D) under inert conditions at room temperature. After 10 minutes 5.0 g of the catalyst prepared as described above (Ti content 4.14 wt %) was added and after additionally 20 minutes 5.0 g of vinylcyclohexane (VCH) was added. The temperature was increased to 60 C. within 30 minutes and was kept at 60 C. for 20 hours. Finally, the temperature was decreased to 20 C. and the concentration of unreacted VCH in the oil/catalyst mixture was analysed and was found to be 700 ppm weight.

(56) Preparation of the Heterophasic Polypropylene Compositions (HECO1)

(57) The heterophasic polypropylene compositions (HECO1) were prepared in a sequential process comprising a loop (bulk) reactor and two or three gas phase reactors. The reaction conditions are summarized in Tables 1 and 2.

(58) TABLE-US-00001 TABLE 1 Preparation and properties of the comparative and inventive heterophasic polypropylenes (HECO1) HECO1 Prepoly HECO1a HECO1b HECO1c HECO1d TEAL/Ti [mol/mol] 250 250 250 250 TEAL/donor [mol/mol] 10 10 10 10 Temperature [ C.] 30 30 30 30 Loop (Bulk) (R1) Temperature [ C.] 80 80 80 80 MFR [g/10 min] 140 550 550 400 Split [%] 44 43 54 52 1.sup.st GPR (R2) Temperature [ C.] 80 80 Pressure [kPa] 2600 2600 MFR GPR1 [g/10 min] 14 0.01 calc MFR GPR1 [g/10 min] 55 250 final Split [%] 29 2 2.sup.nd GPR (R3) Temperature [ C.] 80 80 80 80 C2 (XCS) [mol %] 37.9 23.8 51.0 51.0 IV (XCS) [dl/g] 6.7 7.7 9.3 8.8 Split [%] 17 57 46 46 3.sup.rd GPR (R4) Temperature [ C.] 80 C2 (XCS) [mol %] 37.9 calc IV (XCS) [dl/g] 6.7 calc Split [%] 10 MFR final [g/10 min] 6.30 0.25 3.15 2.34 XCS final [wt %] 22.0 33.2 32.2 33.4 C2 (XCS) [mol %] 37.9 23.7 51.0 51.0 final IV (XCS) [dl/g] 6.7 7.7 9.3 8.8 final Flexural [MPa] 1030 742 699 699 Modulus Charpy NIS [kJ/m.sup.2] 45 89 70 70 +23 C. Charpy NIS [kJ/m.sup.2] 6.3 2.6 15.1 15.1 -20 C.

(59) TABLE-US-00002 TABLE 2 Preparation and properties of the comparative and inventive heterophasic polypropylenes (HECO1) HECO1 Prepoly HECO1e HECO1f HECO1g TEAL/Ti [mol/mol] 250 250 250 TEAL/donor [mol/mol] 10 10 10 Temperature [ C.] 30 30 30 Loop (Bulk) (R1) Temperature [ C.] 80 80 80 MFR [g/10 min] 400 550 550 Split [%] 51 53 53 1.sup.st GPR (R2) Temperature [ C.] 80 80 80 Pressure [kPa] 2600 2600 2600 MFR GPR1 calc [g/10 min] 0.01 0.01 0.01 MFR GPR1 final [g/10 min] 250 350 350 Split [%] 2 2 2 2.sup.nd GPR (R3) Temperature [ C.] 80 80 80 C2 (XCS) [mol %] 33.3 27.3 27.3 IV (XCS) [dl/g] 8.1 7.7 7.7 Split [%] 23 30 16 3.sup.rd GPR (R4) Temperature [ C.] 80 80 80 C2 (XCS) calc [mol %] 60.0 69.2 69.2 IV (XCS) calc [dl/g] 9.8 10.5 10.5 Split [%] 24 15 29 MFR final [g/10 min] 1.64 1.64 1.58 XCS final [wt %] 36.4 28.6 28.6 C2 (XCS) final [mol %] 48.0 42.4 46.7 IV (XCS) final [dl/g] 8.9 9.5 8.1 Flexural Modulus [MPa] 705 714 689 Charpy NIS +23 C. [kJ/m.sup.2] 73 77 66 Charpy NIS -20 C. [kJ/m.sup.2] 13.6 10.8 18.1

(60) The heterophasic polypropylene compositions (HECO1) were pelletized on a co-rotating twin screw extruder with 0.2 wt.-% Irganox B225 by BASF and 0.05 wt.-% calcium stearate.

(61) B. Preparation of the Polyolefin Composition (C)

(62) Used Materials

(63) HECO2 is the commercial heterophasic polypropylene E050 AE by Borealis having a melt flow rate of 11.0 g/10 min, an ethylene content of 18.3 mol-%, a xylene soluble fraction (XCS) of 32.0 wt.-%, an ethylene content of the xylene soluble fraction (XCS) of 47.9 mol-% and an intrinsic viscosity (IV) of the xylene soluble fraction (XCS) of 2.5 dl/g. Talc is the commercial Talc Steamic T1 CA of Imerys.

Example CE1 (comparative)

(64) 15.0 wt.-% of HECO1a, 15.0 wt.-% of Talc and balance of HECO2 were melt blended on a co-rotating twin screw extruder. The polymer melt mixture was discharged and pelletized.

Examples CE2, CE3 (Comparative) and IE1 to IE4 (Inventive)

(65) 13.5 wt.-% of the respective HECO1, 13.0 wt.-% of Talc and balance of HECO2 were melt blended on a co-rotating twin screw extruder. The polymer melt mixture was discharged and pelletized.

(66) The properties of the comparative and inventive compositions are summarized in Table 3.

(67) TABLE-US-00003 TABLE 3 Properties of the comparative and inventive compositions Flexural Charpy NIS Charpy NIS MFR Modulus +23 C. 20 C. MSE 1.5 s HECO1 [g/10 min] [MPa] [kJ/m.sup.2] [kJ/m.sup.2] [] CE1 HECO1a 9.5 1728 41.2 6.5 10.0 CE2 HECO1b 6.9 1688 35.0 5.1 6.3 CE3 HECO1c 9.4 1618 48.0 8.0 8.4 IE1 HECO1d 9.0 1618 48.0 8.0 5.8 IE2 HECO1e 8.3 1626 46.0 7.6 4.6 IE3 HECO1f 8.3 1642 43.0 7.0 4.2 IE4 HECO1g 8.5 1601 51.0 8.6 5.8