Low filled polypropylene composition with balanced property profile

Patent metadata

Field	Value
Publication number	US-9701826-B2
Application number	US-201214240260-A
Country	US
Kind code	B2
Filing date	Aug 22, 2012
Priority date	Aug 25, 2011
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

The present invention relates to a polyolefin composition comprising (a) a heterophasic propylene copolymer, wherein the xylene cold soluble fraction of the heterophasic propylene copolymer has an intrinsic viscosity of lower than 2.0 dl/g, (b) a high density polyethylene having a density of at least 940 kg/m 3 , (c) a linear low density polyethylene, and (d) an inorganic filler, wherein the polyolefin composition has a MFR 2 (230° C.) of at least 20 g/10 min.

First claim

The invention claimed is:

1. A polyolefin composition (PO) comprising:
(a) a heterophasic propylene copolymer (HECO) comprising:
(a1) a polypropylene (PP), and
(a2) an elastomeric propylene copolymer (E),

wherein the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (HECO) has an intrinsic viscosity of lower than 2.0 dl/g measured according to DIN ISO 1628/1 (in Decalin at 135° C.),
(b) a high density polyethylene (HDPE) having a density of at least 940 kg/m 3 measured according to ISO 1183-1-method A,
(c) a second polyethylene (PE2) having a density of below 940 kg/m 3 measured according to ISO 1183-1-method A which is
(i) a low density polyethylene (LDPE), or
(ii) a linear low density polyethylene (LLDPE),

(d) an inorganic filler (F),
wherein the polyolefin composition (PO) has a melt flow rate MFR 2 (230° C.) of at least 20 g/10 min measured according to ISO 1133 (230° C., 2.16 kg load).

2. The polyolefin composition (PO) according to claim 1 , wherein the heterophasic propylene copolymer (HECO):
(a) has a melt flow rate MFR 2 (230° C.) in the range of 30 to 100 g/10 min measured according to ISO 1133 (230° C., 2.16 kg load), and/or
(b) comprises the elastomeric propylene copolymer (E) in an amount of 10 to 35 wt. %, and/or
(c) is comprised in the polyolefin composition in an amount of 50 to 90 wt. % based on the total weight of the polyolefin composition (PO), and/or
(d) has a comonomer content of 5.0 to 25.0 wt. % based on the total weight of the heterophasic propylene copolymer (HECO).

3. The polyolefin composition (PO) according to claim 1 , wherein elastomeric propylene copolymer (E)
(a) is bimodal or multimodal, and/or
(b) has an intrinsic viscosity (IV) of lower than 2.0 dl/g, measured as the intrinsic viscosity (IV) of the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (HECO) according to DIN ISO 1628/1 (in Decalin at 135° C.), and/or
(c) has a comonomer content of 30 to 70 wt. % based on the total weight of the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (HECO).

4. The polyolefin composition (PO) according to claim 1 , wherein:
(a) the weight ratio [(HDPE)/(PE2)] of the high density polyethylene (HDPE) to the second polyethylene (PE2) is 2:1 to 1:4; and/or
(b) the weight ratio [(E)/(HDPE)] of the elastomeric propylene copolymer (E) to the high density polyethylene (HDPE) is 4:1 to 1:2; and/or
(c) the polyolefin composition (PO) comprises the high density polyethylene (HDPE) in an amount of 5 to 25 wt. %; and/or
(d) the polyolefin composition (PO) comprises the second polyethylene (PE2) in an amount of 5 to 25 wt. %.

5. The polyolefin composition (PO) according to claim 1 , wherein the polypropylene (PP) is a random propylene copolymer (R-PP).

6. The polyolefin composition according to claim 1 , wherein the polyolefin composition (PO) comprises the inorganic filler (F) in an amount of up to 20 wt. % based on the total weight of the polyolefin composition (PO).

7. The polyolefin composition (PO) according to claim 6 , wherein the inorganic filler (F) has a cutoff particle size d95 [mass percent] of equal or below 20 μm measured according to 13317-3 (Sedigraph).

8. The polyolefin composition (PO) according to claim 1 , wherein the high density polyethylene (HDPE) has a density of at least 945 kg/m 3 measured according to ISO 1183-1-method A.

9. The polyolefin composition (PO) according to claim 1 , wherein the second polyethylene (PE2):
(a) has a melt flow rate MFR 2 (190° C.) in the range of 0.5 to 30 g/10 min measured according to ISO 1133 (190° C., 2.16 kg load), and/or
(b) is an ethylene copolymer.

10. The polyolefin composition (PO) according to claim 1 provided in an article.

11. The polyolefin composition according to claim 10 , wherein the article is an automotive article.

12. The polyolefin composition (PO) according to claim 11 , wherein the automotive article is a bumper.

Assignees

• Grein Christelle
• Tranninger Cornelia
• Grestenberger Georg
• Tranninger Michael
• Borealis Ag

Inventors

• Grein Christelle
• Tranninger Cornelia
• Grestenberger Georg
• Tranninger Michael

Classifications

• C08L23/10 Primary

  Homopolymers or copolymers of propene · CPC title

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title

• C08L23/142 Primary

  at least partially crystalline copolymers of propene with other olefins · CPC title

• C08L23/06

  Polyethylene · CPC title

• C08L23/14 Primary

  Copolymers of propene (C08L23/16 takes precedence) · CPC title