Thermoplastic polyolefin composition

Abstract

Composition comprising a polypropylene matrix (M-PP), at least one elastomeric copolymer (EP), a high density polyethylene (HDPE) being bimodal or multimodal, and a filler (F).

1 . Composition (C) comprising
 (a) at least 36 wt.-% of a polypropylene matrix (M-PP),   (b) at least 6 wt.-% of elastomeric copolymer(s) (EP) comprising units derived from
 (i) ethylene, 
 (ii) at least one C3 to C20 α-olefin, and 
 (iii) optionally a non-conjugated diene; 
   (c) 6 to 27 wt.-% of a high density polyethylene (HDPE) being bimodal or multimodal, and   (d) at least 5 wt.-% of an inorganic filler (F).   
     
     
         2 . Composition (C) according to  claim 1 , wherein
 (a) the elastomeric copolymer(s) (EP), the high density polyethylene (HDPE) and the filler (F) are dispersed in said polypropylene matrix (M-PP) and/or   (b) the xylene soluble (XS) content in the composition (C) is at least 12 wt.-% based on the total composition (C).   
     
     
         3 . Composition (C) according to  claim 1 , wherein the composition (C) comprises
 (a) 36 to 81 wt.-% of the polypropylene matrix (M-PP),   (b) 6 to 72 wt.-% of elastomeric copolymer(s) (EP),   (c) 7 to 27 wt.-% of the high density polyethylene (HDPE), and   (d) 5 to 20 wt.-% of the inorganic filler (F).   
     
     
         4 . Composition (C) according to  claim 1 , wherein the composition (C) comprises an elastomeric copolymer (EP1) and an elastomeric copolymer (EP2),
 (a) said elastomeric copolymer (EP2) has a higher ethylene content than the elastomeric copolymer (EP1) and   (b) said elastomeric copolymer (EP1) is present within the composition (C) from 4 to 36 wt.-% and said elastomeric copolymer (EP2) is present within the composition (C) from 2 to 36 wt.-%.   
     
     
         5 . Composition (C) according to according to  claim 1 , wherein
 (a) the amount of units derived from ethylene within the elastomeric copolymer (EP1) is in the range of 20 to 70 wt.-% and/or   (b) the amount of units derived from ethylene within the elastomeric copolymer (EP2) is more than 50 wt.-%.   
     
     
         6 . Composition (C) according to according to  claim 1 , wherein the weight ratio of the high density polyethylene (HDPE) and the sum of the elastomeric copolymers (EP) is from 1:10 to 2:1. 
     
     
         7 . Composition (C) according to according to  claim 1 , wherein
 (a) the polypropylene matrix (M-PP) is a propylene homopolymer and/or   (b) the elastomeric copolymer(s) (EP) are an ethylene propylene rubber (EPR) and/or an ethylene propylene diene monomer polymer (EPDM).   
     
     
         8 . Composition (C) according to according to  claim 1 , wherein the high density polyethylene (HDPE)
 (a) has a melt flow rate MFR 2  (190° C.) measured according to ISO 1133 of 0.1 to 7.0 g/10 min and/or   (b) has a melt flow rate ratio FRR (MFR 21  (190° C.)/MFR 2  (190° C.)) of 20 to 150 and/or   (c) comprises a fraction (A) and a fraction (B),
 (i) said fraction (A) has a lower weight average molecular weight M w  measured according to ISO 16014 and/or a lower melt flow rate MFR 2  (190° C.) measured according to ISO 1133 as said fraction (B), and 
 (ii) the weight ratio between the fraction (A) and the fraction (B) ranges from 70:30 to 30:70. 
   
     
     
         9 . Composition (C) according to according to  claim 1 , wherein
 (a) said fraction (A) has
 (i) weight average molecular weight M w  measured according to ISO 16014 from 10,000 to 50,000 g/mol and/or 
 (ii) a melt flow rate MFR 2  (190° C.) measured according to ISO 1133 from 50 to 1,000 g/10 min, and/or 
 (iii) a density measured according to ISO 1183-187 from 950 to 980 kg/m 3 , 
   and   (b) said fraction (B) has
 (i) a weight average molecular weight M w  measured according to ISO 16014 from 75,000 to 500,000 g/mol, and/or 
 (ii) a melt flow rate MFR 2  (190° C.) measured according to ISO 1133 from 0.01 to 1.00 g/10 min, and/or 
 (iii) a density measured according to ISO 1183-187 from 920 to 950 kg/m 3 . 
   
     
     
         10 . Composition (MB) comprising:
 (a) an elastomeric copolymer (EP) comprising units derived from
 (i) ethylene, 
 (ii) at least one C3 to C20 α-olefin, and 
 (iii) optionally a non-conjugated diene; 
   and   (b) a high density polyethylene (HDPE) being bimodal or multimodal,   wherein
 (i) the elastomeric copolymer (EP) and the high density polyethylene (HDPE) together constitute at least 85 wt.-% of the composition (MB), 
 and 
 (ii) the weight ratio of the high density polyethylene (HDPE) and the elastomeric copolymer is from 60:40 to 20:80. 
   
     
     
         11 . Composition (MB) according to  claim 10 , wherein the elastomeric copolymer (EP) is the elastomeric copolymer (EP2) as defined in any one of the preceding  claims 1  to  9  and the high density polyethylene (HDPE) is further defined by any one of the preceding  claims 1  to  9 . 
     
     
         12 . Use of a composition (MB) according to  claim 10  to improve the impact resistance of a heterophasic polypropylene, the improvement is defined by
   1.2<[(HECO+MB)/HECO] 
 wherein 
 HECO+MB is the impact resistance measured according to ISO 294-1 at −40° C. of a heterophasic polypropylene as to which the composition (MB) as defined in  claim 10  or  11  is mixed and 
 HECO is the impact resistance measured according to ISO 294-1 at −40° C. of same heterophasic polypropylene as used in HECO+MB, but without any addition of the composition (MB) as defined in  claim 10  or  11 . 
 
     
     
         13 . Process for the preparation of a composition (C) as defined in  claim 1 , wherein
 (a) a heterophasic polypropylene (H-PP) comprising
 (i) a polypropylene matrix (M-PP) as defined in any one of the  claims 1  to  9  and 
 (ii) an elastomeric copolymer (EP), preferably an elastomeric copolymer (EP1), as defined in any one of the  claims 1  to  9  and being dispersed in said matrix (M-PP); 
   (b) a composition (MB) as defined in any one of the  claims 10  to  12 ; and   (c) an inorganic filler (F) are mixed, preferably melt mixed, together.   
     
     
         14 . Process according to  claim 13 , wherein
 (a) 40 to 90 wt.-% of the heterophasic polypropylene (H-PP);   (b) 5 to 45 wt.-% of the composition (MB); and   (c) 5 to 20 wt.-% of the inorganic filler (F)   are mixed, preferably melt mixed, together.   
     
     
         15 . Article comprising a composition (C) according to  claim 1 .