Biaxially oriented pipe

Patent metadata

Field	Value
Publication number	US-12066145-B2
Application number	US-202017762409-A
Country	US
Kind code	B2
Filing date	Sep 23, 2020
Priority date	Sep 24, 2019
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

The invention relates to a biaxially oriented pipe made of a polymer composition comprising a propylene-based polymer, wherein the propylene-based polymer comprises a random copolymer of propylene and a comonomer which is ethylene and/or an a-olefin having 4 to 10 carbon atoms, wherein the propylene-based polymer has a comonomer content of 0.5 to 3.8 wt % based on the propylene-based polymer.

First claim

The invention claimed is:

1. A biaxially oriented pipe made of a polymer composition comprising a propylene-based polymer, wherein the propylene-based polymer comprises a random copolymer of propylene and a comonomer which is ethylene and/or an α-olefin having 4 to 10 carbon atoms, wherein the propylene-based polymer has a comonomer content of 0.1 to 3.8 wt % based on the propylene-based polymer, wherein the pipe has a time to failure of at least 100 hours according to ISO 1167-1 determined at a stress level of 20 MPa and a temperature of 20° C.

2. The pipe according to claim 1 , wherein the comonomer content of the propylene-based polymer is 0.5 to 3.5 wt %.

3. The pipe according to claim 1 , wherein the propylene-based polymer is a propylene-ethylene copolymer.

4. The pipe according to claim 1 , wherein the propylene-based polymer has a melt flow index of 0.1 to 10.0 g/10 min measured according to ISO1133-1:2011 (230° C./2.16 kg).

5. The pipe according to claim 1 , wherein the amount of the propylene-based polymer with respect to the total amount of polymers in the polymer composition is at least 95 wt %.

6. The pipe according to claim 1 , wherein the polymer composition further comprises 0 to 5 wt % of additives and 0 to 40 wt % of fillers.

7. The pipe according to claim 1 , wherein the pipe is made by a process comprising the steps of:
a) forming a polymer composition into a tube, and
b) stretching the tube of step a) in the axial direction and in the peripheral direction to obtain the biaxially oriented pipe,
wherein step b) is performed at a drawing temperature of 140 to 160° C. and at an axial draw ratio of 1.1 to 5.0 and an average hoop draw ratio of 1.1 to 3.0.

8. The pipe according to claim 1 , wherein the random copolymer comprises
A) a low comonomer random copolymer of propylene and a comonomer which is ethylene and/or an α-olefin having 4 to 10 carbon atoms, wherein the low comonomer random copolymer has a comonomer content of less than 3.8 wt % based on the low comonomer random copolymer and/or
B) a high comonomer random copolymer of propylene and a comonomer which is ethylene and/or an α-olefin having 4 to 10 carbon atoms, wherein the high comonomer random copolymer has a comonomer content of at least 3.8 wt % based on the high comonomer random copolymer and
the propylene-based polymer optionally comprises
C) a propylene homopolymer.

9. The pipe according to claim 8 , wherein the total amount of A), B) and C) is at least 95 wt % based on the propylene-based polymer.

10. The pipe according to claim 8 , wherein the comonomer content of the low comonomer random copolymers is at least 0.1 wt % based on said random polymer.

11. The pipe according to claim 8 , wherein the comonomer content of the high comonomer random copolymers is 3.8 to 10.0 wt % based on said random copolymer.

12. The pipe according to claim 8 , wherein the propylene-based polymer consists of A).

13. The pipe according to claim 8 , wherein the propylene-based polymer consists of A) and B) or
the propylene-based polymer consists of A) and C) or
the propylene-based polymer consists of A), B) and C).

14. The pipe according to claim 8 , wherein the propylene-based polymer consists of B) and C).

15. The pipe according to claim 1 , wherein the comonomer content of the propylene-based polymer is 0.1 to 3.5 wt %.

16. The pipe according to claim 1 , wherein the comonomer content of the propylene-based polymer is 0.1 to 3.4 wt %.

17. The pipe according to claim 1 , wherein the comonomer content of the propylene-based polymer is 0.1 to 3.0 wt %.

18. The pipe according to claim 1 , wherein the comonomer content of the propylene-based polymer is 0.1 to 2.5 wt %.

19. The pipe according to claim 1 , wherein the comonomer content of the propylene-based polymer is 0.1 to 2.0 wt %.

Assignees

• Sabic Global Technologies Bv

Inventors

• Taraiya Ajay Kumar
• Soliman Maria
• Degenhart Peter
• Boerakker Mark Johannes
• Steenbakkers-Menting Henrica Norberta Alberta Maria

Classifications

• B29L2023/22

  Tubes or pipes, i.e. rigid (bent tubes not for use as pipe couplings B29L2023/004) · CPC title

• B29K2023/16

  EPM, i.e. ethylene-propylene copolymers; EPDM, i.e. ethylene-propylene-diene copolymers; EPT, i.e. ethylene-propylene terpolymers · CPC title

• B29C55/26 Primary

  biaxial · CPC title

• B29C55/005 Primary

  characterised by the choice of materials · CPC title

• B29K2023/14

  Copolymers of polypropylene (B29K2023/16 takes precedence) · CPC title