Polymers with Improved Processability for Pipe Applications

Patent metadata

Field	Value
Publication number	US-2016115264-A1
Application number	US-201414522991-A
Country	US
Kind code	A1
Filing date	Oct 24, 2014
Priority date	Oct 24, 2014
Publication date	Apr 28, 2016
Grant date	—

Abstract

A crosslinked metallocene-catalyzed polyethylene copolymer having a higher molecular weight (HMW) component and lower molecular weight (LMW) component wherein the HMW component is present in an amount of from about 10 wt. % to about 30 wt. % and wherein the LMW component is present in an amount of from about 70 wt. % to about 90 wt. %.

First claim

What is claimed is:

1 . A crosslinked metallocene-catalyzed polyethylene copolymer having a higher molecular weight (HMW) component and lower molecular weight (LMW) component wherein the HMW component is present in an amount of from about 10 wt. % to about 30 wt. % and wherein the LMW component is present in an amount of from about 70 wt. % to about 90 wt. %.

2 . The copolymer of claim 1 which when tested in accordance with ASTM D1238 under a force of 21.6 kg has a high load melt index of from about 6 g/10 min to about 25 g/10 min.

3 . The copolymer of claim 1 which when tested in accordance with ASTM D638 and/or ISO 527 has a Young's modulus of from about 120 kpsi to about 190 kpsi.

4 . The copolymer of claim 1 having a viscous relaxation time of from about 0.5 s to about 8 s.

5 . The copolymer of claim 1 having an η 0 (eta_0) of from about 5.0×10 4 Pa-s to about 8.0×10 5 Pa-s.

6 . The copolymer of claim 1 having an η 100 (eta_100) of from about 1,000 Pa-s to about 4,000 Pa-s.

7 . The copolymer of claim 1 which when tested in accordance with ASTM D638 and/or ISO 527 has a percent elongation at break of from about 450% to about 800%.

8 . The copolymer of claim 1 which when tested in accordance with ASTM D638 and/or ISO 527 has a percent elongation at yield of from about 8.0% to about 20%.

9 . The copolymer of claim 1 which when tested in accordance with ASTM D638 and/or ISO 527 has a tensile strength at break of from about 3,500 psi to about 6,000 psi.

10 . The copolymer of claim 1 which when tested in accordance with ASTM D638 and/or ISO 527 has a tensile strength at yield of from about 2,600 psi to about 3,000 psi.

11 . The copolymer of claim 1 which when tested in accordance with ASTM D3895 has an oxidative induction time of greater than about 100 min.

12 . The copolymer of claim 1 which when tested in accordance with ASTM D3895 has an oxidative induction temperature of greater than about 220° C.

13 . The copolymer of claim 1 having gels present in an amount of less than about 300/sq. ft., wherein the gels have a size greater than about 200 microns.

14 . The copolymer of claim 1 which when tested in accordance with ASTM F2231 has a Charpy impact energy of from about 0.9 J to about 3.0 J.

15 . The copolymer of claim 1 which when tested in accordance with ASTM F2231 has a Charpy temperature of from about −35° C. to about −10° C.

16 . The copolymer of claim 1 which when tested in accordance with ASTM D638 has a tensile natural draw ratio of from about 380% to about 500%.

17 . The copolymer of claim 1 which when tested in accordance with ASTM F1473 has a resistance to slow crack growth of greater than about 500 h, wherein the resistance to slow crack growth is defined as the PENT failure time.

18 . The copolymer of claim 1 which when tested in accordance with ISO 13477 has a S4 critical temperature of from about −30° C. to about −10° C. for a 2″DR11 pipe.

19 . The copolymer of claim 1 which when tested in accordance with ISO 13477 has a S4 critical pressure of about greater than about 12 bar as determined at 0° C. for a 2″DR11 pipe.

20 . A pipe formed from the copolymer of claim 1 .

Assignees

• Chevron Phillips Chemical Co

Inventors

• Rohatgi Vivek
• Inn Yongwoo
• Sukhadia Ashish M
• Yang Qing
• Deslauriers Paul J

Classifications

• C08F4/65916

  supported on a carrier, e.g. silica, MgCl2, polymer · 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

• C08F210/16 Primary

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08L2203/18

  used for pipes · CPC title

• C08F2810/10

  including a reactive processing step which leads, inter alia, to morphological and/or rheological modifications, e.g. visbreaking · CPC title