UPGRADED RECYLED POLYPROPYLENE RICH POLYOLEFIN MATERIAL
A polypropylene-polyethylene composition obtainable by blending a) 80 to 97 wt.-% of a blend (A) comprising A-1) polypropylene and A-2) polyethylene, wherein the weight ratio of polypropylene to polyethylene is from 9:1 to 13:7, and wherein blend (A) is a recycled material, which is recovered from waste plastic derived from post-consumer and/or post-industrial waste; and b) 3 to 20 wt.-% of a compatibilizer (B) being a heterophasic random copolymer comprising a random polypropylene copolymer matrix phase and an elastomer phase dispersed therein, whereby the heterophasic random copolymer has—a xylene insoluble content XCI of 65 to 88 wt.-% (ISO 16152, led, 25° C.), —a xylene soluble content XCS of 12 to 35 wt.-% (ISO 16152, led, 25° C.), the XCS fraction having an intrinsic viscosity (measured in decalin according to DIN ISO 1628/1 at 135° C.) of 1.2 dl/g to less than 3.0 dl/g, and—a flexural modulus of from 300 to 600 MPa (ISO 178, measured on injection moulded specimens, 23° C.); and wherein, the ratio of MFR 2 (blend (A))/MFR 2 (compatibilizer(B)) (ISO1133, 2.16 kg load), is in the range of from 1.5 to 3.5 g/10 min.
1 : A polypropylene-polyethylene composition obtainable by blending:
a) 80 to 97 wt. % of a blend (A), comprising
A-1) polypropylene and
A-2) polyethylene,
wherein the weight ratio of polypropylene to polyethylene is from 9:1 to 13:7, and
wherein blend (A) is a recycled material, which is recovered from a waste plastic material derived from post-consumer and/or post-industrial waste; and
b) 3 to 20 wt. % of a compatibilizer (B) being a heterophasic random copolymer comprising a random polypropylene copolymer matrix phase and an elastomer phase dispersed therein, whereby
the heterophasic random copolymer has:
a xylene insolubles content (XCI) of from 65 to 88 wt. % (ISO 16152, 1 ed, 25° C.), and
a xylene soluble content XCS of 12 to 35 wt. % (ISO 16152, 1 ed, 25° C.), the XCS fraction having an intrinsic viscosity (measured in decalin according to DIN ISO 1628/1 at 135° C.) of 1.2 dl/g to less than 3.0 dl/g, and
a flexural modulus of from 300 to 600 MPa (ISO 178, measured on injection moulded specimens, 23° C.);
wherein the ratio of MFR 2 (blend (A))/MFR 2 (compatibilizer(B)) (ISO1133, 2.16 kg load), is in the range 1.5 to 3.5 g/10 min; and
wherein xylene insoluble content (XCI) and xylene soluble content (XCS) add up to 100 wt. %.
2 : The polypropylene-polyethylene composition according to claim 1 , having a tensile modulus of at least 1000 MPa (measured according to ISO 527-2 using injection moulded specimens as described in EN ISO 1873-2 (dog bone shape, 4 mm thickness)).
3 : The polypropylene-polyethylene composition according to claim 1 , whereby the compatibilizer (B) has a tensile strain at break (MD) of at least 500%.
4 : The polypropylene-polyethylene composition according to claim 1 , whereby the compatibilizer (B) has:
(i) a content of units derived from ethylene in the xylene insoluble (XCI) fraction of 2.0 to 6.0 wt. % and/or
(ii) a content of units derived from ethylene in the xylene soluble (XCS) fraction of 25.0 to 38.0 wt. %.
5 : The polypropylene-polyethylene composition according to claim 1 , whereby the compatibilizer (B) has an MFR 2 (ISO1133; 2.16 kg; 230° C.) of 5 to 15 g/10 min.
6 : The polypropylene-polyethylene composition according to claim 1 , whereby the compatibilizer (B) has:
a total content of units derived from ethylene of 5.0 to 10.0 wt. % and/or
the xylene soluble fraction (XCS) of compatibilizer (B) has an intrinsic viscosity (measured in decalin according to DIN ISO 1628/1 at 135° C.) of from 1.3 to less than 2.2 dl/g.
7 : The polypropylene-polyethylene composition according to claim 1 , whereby the compatibilizer (B) has a flexural modulus of 400 to 550 MPa (ISO 178, measured on injection-moulded specimens, 23° C.).
8 : The polypropylene-polyethylene composition according to claim 1 , having a notched Charpy impact strength (1eA) (non-instrumented, ISO 179-1 at +23° C.) of at least 6.0 kJ/m 2 and/or having a notched Charpy impact strength (1eA) (non-instrumented, ISO 179-1 at −30° C.) of at least 4.0 kJ/m 2 and/or a tensile strain at break (ISO 527-1,2) of at least 20%.
9 : The polypropylene-polyethylene composition according to claim 1 , whereby the ratio of the tensile modulus of the final polypropylene-polyethylene composition versus the tensile modulus of blend (A) is at least 0.95.
10 : The polypropylene-polyethylene composition according to claim 1 , whereby blend (A) has a content of limonene as determined by solid phase micro-extraction (HS-SPME-GC-MS) of from 1 ppm to below 100 ppm.
11 : The polypropylene-polyethylene composition according to claim 1 , whereby blend (A):
(i) contains less than 1.5 wt. % polystyrene; and/or
(ii) contains less than 3.5 wt. % talc; and/or
(iii) contains less than 1.0 wt. % polyamide.
12 : An article comprising at least 95 wt. % of the polypropylene-polyethylene composition of claim 1 with respect to the total weight of the article.
13 : A process for the manufacture of a polypropylene-polyethylene composition according to claim 1 , wherein the process comprises the steps of:
a) providing blend (A) comprising polypropylene and polyethylene in a ratio of 9:1 to 13:7 in an amount of 80 to 97 wt. % based on the total weight of the polypropylene-polyethylene composition,
b) providing a compatibilizer (B) being a heterophasic random copolymer comprising a random polypropylene copolymer matrix phase and an elastomer phase dispersed therein in an amount from 3 to 20 wt. %, based on the total weight of the polyolefin composition, wherein the heterophasic random copolymer has:
a xylene insoluble content (XCI) of 65 to 88 wt. % (ISO 16152, 1 ed, 25° C.), and
a xylene soluble content (XCS) of 12 to 35 wt. % (ISO 16152, 1 ed, 25° C.), the XCS fraction having an intrinsic viscosity (measured in decalin according to DIN ISO 1628/1 at 135° C.) of 1.2 dl/g to less than 3.0 dl/g,
whereby, the ratio of MFR 2 (blend (A))/MFR 2 (compatibilizer(B)) (ISO1133, 2.16 kg load), is in the range 1.5 to 3.5 g/10 min,
c) melting and mixing the blend of blend (A) and the compatibilizer (B), to obtain a polypropylene-polyethylene composition, and
d) optionally cooling down the said polypropylene-polyethylene composition and pelletizing the resulting material.
14 - 15 . (canceled)