Propylene copolymer composition
A propylene copolymer composition which comprises —a random copolymer of propylene (A), —a random copolymer of propylene (B), and —optional additive(s), suitable for pressure pipe applications.
1. A propylene copolymer composition comprising: a polypropylene composition (a) comprising a multimodal polypropylene (a) comprising:
(A) a random copolymer of propylene having:
an MFR 2 of 0.01 to 0.5 g/10 min (ISO 1133, 2.16 kg load, 230° C.),
one or more comonomer(s) selected from ethylene or C4-C10 alpha olefins and having a comonomer content of 5.8 to 7.3 mol %;
(B) a random copolymer of propylene having:
an MFR 2 of 0.1 to 15 g/10 min (ISO 1133, 2.16 kg load, 230° C.),
one or more comonomer selected from ethylene or C4-C10 alpha olefins;
wherein the random copolymer of propylene (A) has a lower MFR 2 and higher comonomer content than the random copolymer of propylene (B);
(C) optional β-nucleating agent; and
(E) optional further additives other than the optional β-nucleating agent (C);
wherein the propylene copolymer composition has an MFR 2 of 0.15 to 0.30 g/10 min and a comonomer content of 2.8 to 9.9 mol %.
2. The propylene copolymer composition according to claim 1 , wherein the propylene copolymer composition comprises a polypropylene composition (a) comprising a multimodal polypropylene (a) which comprises, based on the combined amount of the component (A) and the component (B),
45 65 wt % of the random copolymer of propylene (A); and
35 to 55 wt % of the random copolymer of propylene (B).
3. The propylene copolymer composition according to claim 1 , wherein the propylene copolymer composition comprises a polypropylene composition (a) which comprises (C) β-nucleating agent.
4. The propylene copolymer composition according to claim 1 , wherein:
the propylene copolymer composition has an amount of β-modification (B) of at least 0.6 when defined by the following formula:
B
=
I
β
(
300
)
I
α
(
110
)
+
I
α
(
040
)
+
I
α
(
130
)
+
I
β
(
300
)
wherein I β (300) is the intensity of β(300) peak, I α (110) is the intensity of α(110) peak, I α (040) is the intensity of α(040) peak and I α (130) is the intensity of α(130) peak obtained after subtracting the amorphous halo.
5. The propylene copolymer composition according to claim 1 , wherein the amount of β-nucleating agent product (C) is of from 0.0001 to 2.0 wt %, based on the amount of the propylene copolymer composition the ß-nucleating agents (C) selected from N,N′-dicyclohexyl-2,6-naphthalene dicarboxamide, 5,12-dihydro-quino(2,3-b)acridine-7,14-dione, quino(2,3-b)acridine-6,7,13,14(5H,12H)-tetrone, salts of dicarboxylic acids with at least 7 carbon atoms with metals of group II of the periodic table, and mixtures thereof.
6. The propylene copolymer composition according to claim 1 , wherein the random copolymer of propylene (A) has
an MFR 2 (ISO 1133, 2.16 kg load, 230° C.) of 0.02 to 0.1 g/10 min.
7. The propylene copolymer composition according to claim 1 , wherein the random copolymer of propylene (B) has one or more, in any order of the following properties:
an MFR 2 (ISO 1133, 2.16 kg load, 230° C.) of 0.3 to 10 g/10 min, and/or
the comonomer content of 1.5 to 11 mol %.
8. The propylene copolymer composition according to claim 1 , having one or more of the following properties:
comonomer content of 3.4 to 8.3 mol %, and/or
a Notched Charpy impact of >1 kJ/m 2 when measured at 0° C. according to ISO 179.
9. The propylene copolymer composition according to claim 1 , wherein the comonomer of random copolymer of propylene (A) and the comonomer of random copolymer of propylene (B) is ethylene.
10. An article comprising the propylene composition according to claim 1 .
11. The article according to claim 10 which is a pipe or pipe fitting.
12. The article according to claim 11 , wherein the pipe is for pressure pipe applications.