Heterophasic propylene copolymer with low extractables

Patent metadata

Field	Value
Publication number	US-9944780-B2
Application number	US-201515127444-A
Country	US
Kind code	B2
Filing date	Apr 1, 2015
Priority date	Apr 4, 2014
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

Heterophasic propylene copolymer comprising a propylene-C 4 to C 12 α-olefin copolymer as a matrix in which an ethylene-propylene rubber is dispersed, said heterophasic propylene copolymer has good mechanical properties and low extractables.

First claim

The invention claimed is:

1. Heterophasic propylene copolymer (RAHECO) comprising
(i) a matrix (M) being a propylene-C 4 to C 12 α-olefin copolymer (C-PP), said propylene-C 4 to C 12 α-olefin copolymer (C-PP) comprises units derivable from
(i.1) propylene and
(i.2) at least one C 4 to C 12 α-olefin; and

(ii) an elastomeric propylene copolymer (EC) dispersed in said matrix (M), said elastomeric propylene copolymer (EC) comprises units derivable from
(ii.1) propylene and
(ii.2) ethylene and optionally at least one C 4 to C 12 α-olefin;

wherein said heterophasic propylene copolymer (RAHECO) has
(a) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 2.5 to 200.0 g/10 min;
(b) a total comonomer content in the range of 12.0 to 35.0 wt.-%;
(c) a xylene cold soluble (XCS) fraction determined according to ISO 16152 (25° C.) in an amount of 10.0 to 40.0 wt.-%;
(d) a total comonomer content of the xylene soluble (XCS) fraction in the range of 50.0 to 90.0 wt.-%
wherein said heterophasic propylene copolymer (RAHECO) fulfills
(e) the in-equation (I)

C
⁢

⁢
2
⁢

(
total
)

Cx
⁡

(
total
)

>
1.0

(
I
)

 wherein
C2(total) is the ethylene content [in wt.-%] of the heterophasic propylene copolymer (RAHECO);
Cx(total) is the C 4 to C 12 α-olefin content [in wt.-%] of the heterophasic propylene copolymer (RAHECO)

wherein said heterophasic propylene copolymer (RAHECO) comprises a xylene cold in-soluble (XCI) fraction, having one or more of:
(f) a total comonomer content [in wt.-%] based on the weight of the xylene cold in-soluble (XCI) fraction in the range of 3.0 to 12.0 wt.-%;
(g) an ethylene content [in wt.-%] based on the total weight of the xylene cold in-soluble (XCI) fraction in the range of 2.0 to 11.0 wt.-%;
(h) a C 4 to C 12 α-olefin content [in wt.-%] based on the total weight of the xylene cold in-soluble (XCI) fraction in the range of 0.5 to 6.0 wt.-%;
(i) fulfills the in-equation (II)

C
⁢

⁢
2
⁢

(
XCI
)

Cx
⁡

(
XCI
)

>
1.0

(
II
)

wherein
C2(XCI) is the ethylene content [in wt.-%] of the xylene cold in-soluble (XCI) fraction of the heterophasic propylene copolymer (RAHECO);
Cx(XCI) is the C 4 to C 12 α-olefin content [in wt.-%] of the xylene cold in-soluble (XCI) fraction of the heterophasic propylene copolymer (RAHECO); or combinations thereof.

2. Heterophasic propylene copolymer (RAHECO) according to claim 1 , wherein one or more of the following is fulfilled:
(a) the ethylene content of the total heterophasic propylene copolymer (RAHECO) is in the range of 12.0 to 33.0 wt.-%, based on the weight of the heterophasic propylene copolymer (RAHECO);
(b) the C 4 to C 12 α-olefin content of the total heterophasic propylene copolymer (RAHECO) is in the range of 0.5 to 6.0 wt.-%, based on the weight of the heterophasic propylene copolymer (RAHECO); or combinations thereof.

3. Heterophasic propylene copolymer (RAHECO) according to claim 1 , wherein one or more of the following is fulfilled:
(a) the propylene-C 4 to C 12 α-olefin copolymer (C-PP) is a propylene-1-hexene copolymer (C 6 -PP);
(b) the elastomeric propylene copolymer (EC) is an ethylene-propylene rubber (EPR); or a combination thereof.

4. Heterophasic propylene copolymer (RAHECO) according to claim 1 , wherein the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (RAHECO) has an intrinsic viscosity (IV) determined according to DIN ISO 1628/1 (in Decalin at 135° C.) of at least 1.2 dl/g.

5. Heterophasic propylene copolymer (RAHECO) according to claim 1 fulfilling one or more of:
(a) the in-equation (III)

C
⁡

(
XCS
)

C
⁡

(
total
)

≥
1.5

(
III
)

 wherein
C(XCS) is the total comonomer content [in wt.-%] of the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (RAHECO);
C(total) is the total comonomer content [in wt.-%] of the total heterophasic propylene copolymer (RAHECO);

(b) the in-equation (IV)

C
⁢

⁢
2
⁢

(
XCS
)

C
⁢

⁢
2
⁢

Assignees

• Borealis Ag

Inventors

• Wang Jingbo
• Doshev Petar
• Gahleitner Markus
• Leskinen Pauli

Classifications

• C08L2203/10

  used for bottles · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L2310/00

  Masterbatches · CPC title

• C08L2207/02

  Heterophasic composition · CPC title

• C08L23/14 Primary

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