High flow automotive exterior compounds with excellent surface appearance

Abstract

The present invention is directed to propylene composition applicable for high flow automotive exterior compounds with excellent surface appearance, said composition comprising a modified polypropylene composition and an inorganic filler.

Claims

1. A composition comprising a modified polypropylene composition and an inorganic filler, wherein the modified polypropylene composition is obtained by treatment of a polypropylene composition with a peroxide (PO), the polypropylene composition comprising: (a) a heterophasic composition, comprising: (a1) a (semi)crystalline polypropylene, and (a2) an elastomeric ethylene/propylene copolymer dispersed in the (semi)crystalline polypropylene, (b) a plastomer being a copolymer of ethylene and at least one C4 to C20 α-olefin, and (c) optionally a high flow polypropylene, the high flow polypropylene having a higher melt flow rate MFR.sub.2 (230° C.), measured according to ISO 1133, than the (semi)crystalline polypropylene, wherein the modified polypropylene composition has: (i) a melt flow rate MFR.sub.2 (230° C.) measured according to ISO 1133 above 32 g/10 min, and (ii) an intrinsic viscosity determined according to DIN ISO 1628/1 (in Decalin at 135° C.) of the xylene soluble fraction below 2.30 dl/g and (iii) an intrinsic viscosity determined according to DIN ISO 1628/1 (in Decalin at 135° C.) of the xylene insoluble fraction below 1.05 dl/g.

2. The composition according to claim 1, wherein the plastomer is a copolymer of ethylene and 1-butene or 1-octene.

3. The composition according to claim 1, wherein the weight ratio of the heterophasic composition and the plastomer in the polypropylene composition is in the range of 0.1 to 10.0.

4. The composition according to claim 1, wherein the polypropylene composition comprises 3 to 15 wt.-%, based on the overall weight of the polypropylene composition, of the high flow polypropylene having a higher melt flow rate MFR.sub.2 (230° C.), measured according to ISO 1133, than the (semi)crystalline polypropylene.

5. The composition according to claim 1, comprising: (a) 45 to 95 wt.-% of the modified polypropylene composition, and (b) 5 to 30 wt.-% of the inorganic filler (F), based on the overall weight of the composition (C).

6. The composition according to claim 1, wherein the heterophasic composition has: (a) a comonomer content, based on the total weight of the heterophasic composition (HECO), in the range of 3 to 20 wt.-%, and/or (b) a xylene soluble fraction in the range of 10 to 35 wt.-%, and/or (c) a melt flow rate MFR.sub.2 (230° C.) measured according to ISO 1133 from 40 to 100 g/10 min.

7. The composition according to claim 1, wherein the xylene soluble fraction of the heterophasic composition has: (a) an intrinsic viscosity determined according to DIN ISO 1628/1 (in Decalin at 135° C.) in the range of 1.5 to 4.5 dl/g, and (b) a comonomer content, based on the total weight of the xylene soluble fraction of the heterophasic composition, in the range of 25 to 55 wt.-%.

8. The composition according to claim 1, wherein the plastomer has (a) a melt flow rate MFR (190° C.) measured according to ISO 1133 from 0.05 to 5.0 g/10 min, (b) a comonomer content, based on the total weight of the plastomer, in the range of 5 to 25 mol-%, and (c) a density equal or below 0.880 g/cm.sup.3.

9. The composition according to claim 1, wherein the inorganic filler is talc.

10. An injection moulded automotive article comprising a composition comprising: a modified polypropylene composition and an inorganic filler, wherein the modified polypropylene composition is obtained by treatment of a polypropylene composition with a peroxide (PO), the polypropylene composition comprising: (a) a heterophasic composition, comprising: (a1) a (semi)crystalline polypropylene, and (a2) an elastomeric ethylene/propylene copolymer dispersed in the (semi)crystalline polypropylene, (b) a plastomer being a copolymer of ethylene and at least one C4 to C20 α-olefin, and (c) optionally a high flow polypropylene, the high flow polypropylene having a higher melt flow rate MFR.sub.2 (230° C.), measured according to ISO 1133, than the (semi)crystalline polypropylene, wherein the modified polypropylene composition has: (i) a melt flow rate MFR.sub.2 (230° C.) measured according to ISO 1133 above 32 g/10 min, and (ii) an intrinsic viscosity determined according to DIN ISO 1628/1 (in Decalin at 135° C.) of the xylene soluble fraction below 2.30 dl/g and (iii) an intrinsic viscosity determined according to DIN ISO 1628/1 (in Decalin at 135° C.) of the xylene insoluble fraction below 1.05 dl/g.

11. A process for the preparation of the composition according to claim 1, wherein (a) (a1) the polypropylene composition comprising the heterophasic composition, the plastomer and optionally the high flow polypropylene is extruded in an extruder in the presence of the peroxide to obtain the modified polypropylene composition, and (b1) the modified polypropylene composition is melt blended with the inorganic filler, or (b) the polypropylene composition comprising the heterophasic composition, the plastomer, optionally the high flow polypropylene, and the inorganic filler are extruded in an extruder in the presence of the peroxide.

12. The process of claim 11, wherein the peroxide reduces tigerskin in the polypropylene composition.

13. The process according to claim 12, wherein the reduction of tigerskin is characterized by a mean square error values equal to or below 30 for a gray scale image of the polypropylene composition.

Description

EXAMPLES

1. Definitions/Measuring Methods

(1) 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.

(2) Quantification of Microstructure by NMR Spectroscopy

(3) Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the polymers. Quantitative .sup.13C {.sup.1H} NMR spectra were recorded in the solution-state using a Bruker Advance 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 rotatary 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.

(4) Quantitative .sup.13C {.sup.1H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals using proprietary computer programs. 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).

(5) With characteristic signals corresponding to 2,1 erythro regio defects observed (as described in L. Resconi, L. Cavallo, A. Fait, F. Piemontesi, Chem. Rev. 2000, 100 (4), 1253, in Cheng, H. N., Macromolecules 1984, 17, 1950, and in W-J. Wang and S. Zhu, Macromolecules 2000, 33 1157) the correction for the influence of the regio defects on determined properties was required. Characteristic signals corresponding to other types of regio defects were not observed.

(6) 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.

(7) For systems where only isolated ethylene in PPEPP sequences was observed the method of Wang et. al. was modified to reduce the influence of non-zero integrals of sites that are known to not be 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(Sββ+Sβγ+Sβδ+0.5(Sαβ+Sαγ))

(8) Through the use of this set of sites the corresponding integral equation becomes:
E=0.5(I.sub.H+I.sub.G+0.5(I.sub.C+I.sub.D))

(9) 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.

(10) The mole percent comonomer incorporation was calculated from the mole fraction:
E[mol %]=100*fE

(11) The weight percent comonomer incorporation was calculated from the mole fraction:
E[wt %]=100*(fE*28.06)/((fE*28.06)+((1−fE)*42.08))

(12) The comonomer sequence distribution at the triad level was determined using the analysis method of Kakugo et al. (Kakugo, M., Naito, Y., Mizunuma, K., Miyatake, T. Macromolecules 15 (1982) 1150). This method was chosen for its robust nature and integration regions slightly adjusted to increase applicability to a wider range of comonomer contents.

(13) Calculation of ethylene content of the ethylene/propylene copolymer (EPR):

(14) $\frac{C\left(P\right)-w\left(A\right)\mathrm{xC}\left(A\right)}{w\left(B\right)}=C\left(B\right)$

(15) wherein w(A) is the weight fraction [in wt.-%] of the (semi)crystalline polypropylene (PP1), w(B) is the weight fraction [in wt.-%] of the ethylene/propylene copolymer (EPR), C(A) is the comonomer content [in mol-%] of the (semi)crystalline polypropylene (PP1), C(P) is the comonomer content [in mol-%] of the heterophasic composition (HECO), C(B) is the calculated comonomer content [in mol-%] of the ethylene/propylene copolymer (EPR).

(16) Quantification of Comonomer Content in Plastomer by NMR Spectroscopy

(17) Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the polymers. Quantitative .sup.13C {.sup.1H} NMR spectra recorded in the molten-state using a Bruker Advance III 500 NMR spectrometer operating at 500.13 and 125.76 MHz for .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 7 mm magic-angle spinning (MAS) probehead at 150° C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was packed into a 7 mm outer diameter zirconia MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity needed for rapid identification and accurate quantification [Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382; Parkinson, M., Klimke, K., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2007; 208:2128; Castignolles, P., Graf, R., Parkinson, M., Wilhelm, M., Gaborieau, M., Polymer 50 (2009) 2373]. Standard single-pulse excitation was employed utilising the transient NOE at short recycle delays of 3 s [Pollard, M., Klimke, K., Graf, R., Spiess, H. W., Wilhelm, M., Sperber, O., Piel, C., Kaminsky, W., Macromolecules 2004; 37:813; Klimke, K., Parkinson, M., Piel, C., Kaminsky, W., Spiess, H. W., Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382] and the RS-HEPT decoupling scheme[Filip, X., Tripon, C., Filip, C., J. Mag. Resn. 2005, 176, 239, Griffin, J. M., Tripon, C., Samoson, A., Filip, C., and Brown, S. P., Mag. Res. in Chem. 2007 45, S1, S198]. A total of 1024 (1k) transients were acquired per spectrum. This setup was chosen due its high sensitivity towards low comonomer contents. Quantitative .sup.13C {.sup.1H} NMR spectra were processed, integrated and quantitative properties determined using custom spectral analysis automation programs. All chemical shifts are internally referenced to the bulk methylene signal (δ+) at 30.00 ppm [J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201].

(18) Characteristic signals corresponding to the incorporation of comonomers were observed [J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, C29, 201] and all contents calculated with respect to all other monomers present in the polymer.

(19) [For further information see Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225 and Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128]

(20) Comonomer content in plastomer (PL) was measured in a known manner based on Fourier transform infrared spectroscopy (FTIR) calibrated with .sup.13C-NMR, using Nicolet Magna 550 IR spectrometer together with Nicolet Omnic FTIR software. Films having a thickness of about 250 μm were compression molded from the samples. Similar films were made from calibration samples having a known content of the comonomer. The comonomer content was determined from the spectrum from the wave number range of from 1430 to 1100 cm.sup.−1. The absorbance is measured as the height of the peak by selecting the so-called short or long base line or both. The short base line is drawn in about 1410-1320 cm.sup.−1 through the minimum points and the long base line about between 1410 and 1220 cm.sup.−1. Calibrations need to be done specifically for each base line type. Also, the comonomer content of the unknown sample needs to be within the range of the comonomer contents of the calibration samples.

(21) MFR.sub.2 (230° C.) is measured according to ISO 1133 (230° C., 2.16 kg load).

(22) MFR.sub.2 (190° C.) is measured according to ISO 1133 (190° C., 2.16 kg load).

(23) The xylene cold solubles (XCS, wt.-%): Content of xylene cold solubles (XCS) is determined at 25° C. according to ISO 16152; first edition; 2005-07-01.

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

(25) Density is measured according to ISO 1183-187. Sample preparation is done by compression moulding in accordance with ISO 1872-2:2007.

(26) Flexural Modulus and Flexural Strength were determined in 3-point-bending at 23° C. according to ISO 178 on 80×10×4 mm.sup.3 test bars injection moulded in line with EN ISO 1873-2.

(27) The tensile modulus and tensile strain at break were measured according to ISO 527-2 (cross head speed=1 mm/min; test speed 50 mm/min at 23° C.) using injection molded specimens as described in EN ISO 1873-2 (dog bone shape, 4 mm thickness). The measurement is done after 96 h conditioning time of the specimen.

(28) Izod notched impact strength is determined according to ISO 180/1A at 23° C. and at −20° C. by using injection moulded test specimens as described in EN ISO 1873-2 (80×10×4 mm).

(29) Heat deflection temperature was measured according to ISO 75-2: Methods A and B.

(30) Shrinkage: The shrinkage is determined on centre gated, injection moulded circular disks (diameter 180 mm, thickness 3 mm, having a flow angle of 355° and a cut out of 5°). Two specimens are moulded applying two different holding pressure times (10 s and 20 s respectively). The melt temperature at the gate is 260° C., and the average flow front velocity in the mould 100 mm/s. Tool temperature: 40° C., back pressure: 600 bar.

(31) After conditioning the specimen at room temperature for 96 hours the dimensional changes radial and tangential to the flow direction are measured for both disks. The average of respective values from both disks are reported as final results.

(32) Flow Marks

(33) 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.

(34) 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.

(35) This method consists of two aspects:

(36) 1. Image Recording:

(37) 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.

(38) 2. Image Analysis:

(39) 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.

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

(41) For this evaluation plaques 440×148×2.8 mm with grain VW K50 and a filmgate of 1.4 mm were used and were produced with different filling times of 1.5, 3 and 6 sec respectively.

(42) Further conditions:

(43) Melt temperature: 240° C.

(44) Mould temperature 30° C.

(45) Dynamic pressure: 10 bar hydraulic

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

(47) The Particle Size median (D.sub.50) and top cut (D.sub.95) are calculated from the particle size distribution determined by laser diffraction according to ISO 13320-1:1999.

2. Examples

(48) Preparation of HECO

(49) Catalyst

(50) First, 0.1 mol of MgCl.sub.2×3 EtOH was suspended under inert conditions in 250 ml of decane in a reactor at atmospheric pressure. The solution was cooled to the temperature of −15° C. and 300 ml of cold TiCl.sub.4 was added while maintaining the temperature at said level. Then, the temperature of the slurry was increased slowly to 20° C. At this temperature, 0.02 mol of dioctylphthalate (DOP) was added to the slurry. After the addition of the phthalate, the temperature was raised to 135° C. during 90 minutes and the slurry was allowed to stand for 60 minutes. Then, another 300 ml of TiCl.sub.4 was added and the temperature was kept at 135° C. for 120 minutes. After this, the catalyst was filtered from the liquid and washed six times with 300 ml heptane at 80° C. Then, the solid catalyst component was filtered and dried. Catalyst and its preparation concept is described in general e.g. in patent publications EP 491566, EP 591224 and EP 586390.

(51) The catalyst was further modified (VCH modification of the catalyst).

(52) 35 ml of mineral oil (Paraffinum Liquidum PL68) was added to a 125 ml stainless steel reactor followed by 0.82 g of triethyl aluminium (TEAL) and 0.33 g of dicyclopentyl dimethoxy silane (donor D) under inert conditions at room temperature. After 10 minutes 5.0 g of the catalyst prepared above (Ti content 1.4 wt.-%) was added and after additionally 20 minutes 5.0 g of vinylcyclohexane (VCH) was added. The temperature was increased to 60° C. during 30 minutes and was kept there 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 200 ppm weight.

(53) TABLE-US-00001 TABLE 1 Polymerization of HECO HECO Prepoly Residence time [h] 0.17 Temperature [° C.] 30 Co/ED ratio [mol/mol] 5.01 Co/TC ratio [mol/mol] 200 Loop (R1) Residence time [h] 0.34 Temperature [° C.] 80 H.sub.2/C.sub.3 ratio [mol/kmol] 7 MFR [g/10 min] 162 XCS [wt %] 2.0 C2 content [wt %] 0 split [wt %] 34 1.sup.st GPR (R2) Residence time [h] 1.20 Temperature [° C.] 95 Pressure [bar] 15 H.sub.2/C.sub.3 ratio [mol/kmol] 84 MFR [g/10 min] 159 XCS [wt %] 2.9 C2 content [wt %] 0 split [wt %] 45 2.sup.nd GPR (R3) Residence time [h] 0.21 Temperature [° C.] 85 Pressure [bar] 14 C.sub.2/C.sub.3 ratio [mol/kmol] 600 H.sub.2/C.sub.2 ratio [mol/kmol] 170 MFR [g/10 min] 66 XCS [wt %] 19.8 C2 content [wt %] 12.80 split [wt %] 21

(54) The HECO was mixed in a twin-screw extruder with 1.00 wt.-% Talc 3.1 (CAS-no. 14807-96-6, trade name Talc HM 2 supplied by IMI), 0.25 wt.-% Dimodan HPL 80/BB, 0.1 wt.-% of a blend of 67% tris(2,4-ditert-butylphenyl)phosphite and 33% pentaerythritol tetrakis[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionate] (trade name Irganox B 215 FF) supplied by BASF AG and 0.05 wt.-% Calciumstearate (CAS-no. 1592-23-0) supplied by Croda Polymer Additives.

(55) Preparation of the Composition (C)

Example CE1 (Comparative)

(56) 56.7 wt.-% of HECO, 6.0 wt.-% of the propylene homopolymer HL508FB by Borealis, 20.0 wt.-% of the ethylene-octene copolymer Engage XLT by Dow, 13.0 wt.-% of Talc (Jetfine 3CA by Imerys), 3.0 wt.-% of a masterbatch of 70 wt % of linear density polyethylene (LDPE) and 30 wt % carbon black, 0.3 wt.-% of the UV-stabilizer masterbatch Cyasorb UV-3808PP5 by Cytec, 0.1 wt.-% of Pentaerythrityl-tetrakis(3-(3′,5′-di-tert. butyl-4-hydroxyphenyl)-propionate (Songnox 1010FFby Songwon), 0.1 wt.-% of Tris (2,4-di-t-butylphenyl) phosphite (Kinox-68-G by HPL Additives), 0.3 wt.-% of Oleamide 9-octadecenamide by Croda, 0.2 wt.-% of antistatic agent Dimodan HP FF by Danisco and 0.3 wt.-% of Calciumstearate by Faci were melt blended on a co-rotating twin screw extruder. The polymer melt mixture was discharged and pelletized.

Example IE1 (Inventive)

(57) To a mixture of 56.5 wt.-% of HECO, 6.0 wt.-% of the propylene homopolymer HL508FB by Borealis and 20.0 wt.-% of the ethylene-octene copolymer Engage XLT by Dow, 0.2 wt.-% of a masterbatch of 5 wt.-% 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane with polypropylene were dosed in the main hopper of a twin screw extruder Mega Compounder ZSK 18 (screw length 40 D) with a temperature profile 20/190/220/225/230/230/210/200° C. and a screw speed of 300 rpm. The polymer melt mixture was melt blended with 13.0 wt.-% of Talc (Jetfine 3CA by Imerys), 3.0 wt.-% of a masterbatch of 70 wt % of linear density polyethylene (LDPE) and 30 wt % carbon black, 0.3 wt.-% of the UV-stabilizer masterbatch Cyasorb UV-3808PP5 by Cytec, 0.1 wt.-% of Pentaerythrityl-tetrakis(3-(3′,5′-di-tert. butyl-4-hydroxyphenyl)-propionate (Songnox 1010FFby Songwon), 0.1 wt.-% of Tris (2,4-di-t-butylphenyl) phosphite (Kinox-68-G by HPL Additives), 0.3 wt.-% of Oleamide 9-octadecenamide by Croda, 0.2 wt.-% of antistatic agent Dimodan HP FF by Danisco and 0.3 wt.-% of Calciumstearate by Faci on a co-rotating twin screw extruder, discharged and pelletized.

Example IE2 (Inventive)

(58) IE2 was prepared analogously to IE1 with the difference that 56.3 wt.-% of the HECO and 0.4 wt.-% of the masterbatch of 5 wt.-% 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane with polypropylene were applied.

Example CE2 (Comparative)

(59) CE2 was prepared analogously to CE1 with the difference that the ethylene-octene copolymer Queo 2M137 by Borealis was applied instead of Engage XLT by Dow.

Example IE3 (Inventive)

(60) IE3 was prepared analogously to IE1 with the difference that the ethylene-octene copolymer Queo 2M137 by Borealis was applied instead of Engage XLT by Dow.

Example IE4 (Inventive)

(61) IE4 was prepared analogously to IE1 with the difference that difference that 56.3 wt.-% of the HECO and 0.4 wt.-% of the masterbatch of 5 wt.-% 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane with polypropylene were applied and the ethylene-octene copolymer Queo 2M137 by Borealis was applied instead of Engage XLT by Dow.

Example CE3 (Comparative)

(62) CE3 was prepared analogously to CE1 with the difference that the ethylene-octene copolymer Queo 2M138 by Borealis was applied instead of Engage XLT by Dow.

Example IE5 (Inventive)

(63) IE5 was prepared analogously to IE1 with the difference that difference that 56.3 wt.-% of the HECO and 0.4 wt.-% of the masterbatch of 5 wt.-% 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane with polypropylene were applied and the ethylene-octene copolymer Queo 2M138 by Borealis was applied instead of Engage XLT by Dow.

Example CE4 (Comparative)

(64) CE4 was prepared analogously to CE1 with the difference that 64.0 wt.-% of the HECO, 19.0 wt.-% of the ethylene-butene copolymer Engage 7487 HM by Dow instead of Engage XLT by Dow and 3.0 wt.-% of pigments were applied. The propylene homopolymer HL508FB by Borealis was not applied according to CE4.

Example IE6 (Inventive)

(65) IE6 was prepared analogously to IE1 with the difference that 63.6 wt.-% of the HECO, 19.0 wt.-% of the ethylene-butene copolymer Engage 7487 HM by Dow instead of Engage XLT by Dow, 0.6 wt.-% of the masterbatch of 5 wt.-% 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane with polypropylene and 4.2 wt.-% of pigments were applied. The propylene homopolymer HL508FB by Borealis was not applied according to IE6.

(66) TABLE-US-00002 TABLE 2 Composition of comparative and inventive examples CE1 IE1 IE2 CE2 IE3 IE4 CE3 IE5 CE4 IE6 HECO [wt.-%] 56.7 56.5 56.3 56.7 56.5 56.3 56.7 56.3 64.0 63.4 HPP [wt.-%] 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 — — PL1 [wt.-%] 20.0 20.0 20.0 — — — — — — — PL2 [wt.-%] — — — 20.0 20.0 20.0 — — — — PL3 [wt.-%] — — — — — — 20.0 20.0 — — PL4 [wt.-%] — — — — — — — — 19.0 19.0 Talc [wt.-%] 13.0 13.0 13.0 13.0 13.0 13.0 13.0 13.0 13.0 13.0 Pigments [wt.-%] 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 AD [wt.-%] 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 POX PP [wt.-%] — 0.2 0.4 — 0.2 0.4 — 0.4 — 0.60 HPP is the commercial propylene homopolymer HL508FB by Borealis having a melt flow rate MFR.sub.2 (230° C.) of 800 g/10 min. PL1 is the commercial ethylene-octene copolymer Engage XLT by Dow having a density of 0.875 g/cm.sup.3, a melt flow rate MFR.sub.2 (190° C.) of 0.5 g/10 min and an 1-octene content of 14.5 mol-%. PL2 is the commercial ethylene-octene copolymer Queo 2M137 by Borealis having a density of 0.870 g/cm.sup.3, a melt flow rate MFR.sub.2 (190° C.) of 1.0 g/10 min and an 1-octene content of 9.9 mol-%. PL3 is the commercial ethylene-octene copolymer Queo 2M138 by Borealis having a density of 0.868 g/cm.sup.3, a melt flow rate MFR.sub.2 (190° C.) of 0.5 g/10 min and an 1-octene content of 11.0 mol-%. PL4 is the commercial ethylene-butene copolymer Engage HM 7487 by Dow having a density of 0.860 g/cm.sup.3, a melt flow rate MFR.sub.2 (190° C.) of 0.5 g/10 min and an 1-butene content of 19.1 mol-%. Talc is the commercial Talc Jetfine 3CA by Imerys having a d50 (Sedigraph 5100) of 1.0 μm and d95 (Sedigraph 5100) of 3.3 μm Pigments is a masterbatch of 70 wt % of linear density polyethylene (LDPE) and 30 wt % carbon black, with MFR (190°/21.6 kg) of 15 g/10 min. AD 0.3 wt.-% of the UV-stabilizer masterbatch Cyasorb UV-3808PP5 by Cytec, 0.1 wt.-% of Pentaerythrityl-tetrakis(3-(3′,5′-di-tert. butyl-4-hydroxyphenyl)-propionate (Songnox 1010FFby Songwon), 0.1 wt.-% of Tris (2,4-di-t-butylphenyl) phosphite (Kinox-68-G by HPL Additives), 0.3 wt.-% of Oleamide 9-octadecenamide by Croda, 0.2 wt.-% of antistatic agent Dimodan HP FF by Danisco and 0.3 wt.-% of Calciumstearate by Faci PDX PP is a masterbatch of 5 wt.-% 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane with polypropylene.

(67) TABLE-US-00003 TABLE 3 Properties of comparative and inventive examples CE1 IE1 IE2 CE2 IE3 IE4 CE3 IE5 CE4 IE6 XCS (total) [wt.-%] 31.1 31.1 31.1 31.1 31.1 31.1 31.1 31.1 nd nd MFR.sub.2 [g/10 min] 32.1 35.2 38.4 35.5 38.8 44.6 32.4 41.1 21.5 34.1 C2 (XCS).sup.1) [mol-%] 59 nd 59 59 nd nd nd 59 nd nd IV (XCS).sup.1) [dl/g] 2.30 2.28 2.22 2.20 2.18 2.15 2.13 2.08 2.30 2.21 IV (XCI).sup.1) [dl/g] 1.05 1.03 0.99 1.05 1.03 1.01 1.05 1.02 1.08 1.03 IV (XCS)/IV(XCI).sup.1) [−] 2.19 2.21 2.24 2.09 2.11 2.12 2.03 2.04 2.12 2.14 IV total.sup.1) [dl/g] 1.34 1.32 1.28 1.33 1.30 1.30 1.31 1.28 1.37 1.31 Density [g/cm.sup.3] 0.977 0.977 0.977 0.962 0.964 0.962 0.963 0.964 nd nd Flexural modulus [MPa] 1463 1436 1392 1511 1482 1469 1495 1442 1609 1469 Flexural strength 23.3 22.8 22.3 nd 24.7 24.3 24.3 23.4 24.5 23.0 Tensile modulus [MPa] 1464 1453 1411 1519 1503 1486 1483 1435 nd nd Tensile stress at yield [kJ/m.sup.2] 16.8 16.5 16.0 18.1 17.8 17.3 17.7 16.7 nd nd Tensile stress at break [kJ/m.sup.2] 40.6 31.7 21.3 21.7 14.8 9.7 26.4 11.9 nd nd Heat deflection temperature A (1.80 MPa) [° C.] 50.7 50.6 50.4 50.8 50.7 50.1 50.7 50.2 — — Heat deflection temperature B (0.45 MPa) [° C.] — — — — — — — — 94.1 89.1 Izod impact strength, notched (+23° C.) [kJ/m.sup.2] 29.4 23.1 21.3 45.6 24.1 15.3 36.0 14.8 16.5 10.5 Izod impact strength, notched (−20° C.) [kJ/m.sup.2] 7.4 6.9 6.7 5.4 5.1 4.8 5.8 5.5 5.7 5.2 Mould average shrinkage (disk) [%] 1.11 1.12 1.18 1.14 1.06 1.08 1.01 1.07 nd nd MSE 1.5 s [−] 8.5 5.4 4.8 11.1 6.6 3.7 10.7 3.1 57.5 6.4 MSE 3 s [−] 4.0 3.0 3.0 5.0 4.0 3.0 5.0 3.0 55.0 5.0 MSE 6 s [−] 4.0 5.0 4.0 3.0 3.0 3.5 4.0 3.8 45.0 3.0 .sup.1)Values determined from compositions not containing talc