Cross-linked polyethylene pipe

Patent metadata

Field	Value
Publication number	US-10082228-B2
Application number	US-200913127036-A
Country	US
Kind code	B2
Filing date	Oct 30, 2009
Priority date	Oct 31, 2008
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

A cross-linked polyethylene pipe comprising an ethylene polymer with a density of at least 948 kg/m3 obtained by polymerization with a single-site catalyst and having a shear thinning index SHI2.7/210 of less than 10; and wherein said pipe has a pressure test at 4.8 MPa and 95° C. of at least 500 h and at 12.4 MPa and 20° C. of at least 500 h.

First claim

What is claimed is:

1. A cross-linked polyethylene pipe comprising a multimodal ethylene homopolymer with a density of at least 950 kg/m 3 obtained by polymerization with a single-site catalyst only and comprising:
a shear thinning index SHI 2.7/210 of less than 10;
an ash content of less than 250 ppm, and
wherein said pipe comprises a pressure test performance at 4.8 MPa and 95° C. of at least 500 h and at 12.4 MPa and 20° C. of at least 500 h,
wherein said multimodal ethylene homopolymer is not cross-linked with silane,
wherein the multimodal ethylene homopolymer consists of a bimodal ethylene homopolymer, and
wherein the multimodal ethylene homopolymer is the only olefinic material in the cross-linked polyethylene pipe.

2. The cross-linked polyethylene pipe as claimed in claim 1 , wherein the density of the bimodal ethylene homopolymer is in the range of more than 950 kg/m 3 to 958 kg/m 3 .

3. The cross-linked polyethylene pipe as claimed in claim 1 , wherein the bimodal ethylene homopolymer comprises an SHI 2.7/210 of less than 5.

4. The cross-linked polyethylene pipe as claimed in claim 1 , wherein the bimodal ethylene homopolymer comprises an MFR 21 of 2 to 10 g/10 min.

5. The cross-linked polyethylene pipe as claimed in claim 1 comprising a cross-linking degree of at least 60%.

6. The cross-linked polyethylene pipe as claimed in claim 1 comprising a pressure test performance at 4.8 MPa and 95° C. of at least 750 h and at 12.4 MPa and 20° C. of at least 700 h.

7. The cross-linked polyethylene pipe as claimed in claim 1 , wherein the bimodal ethylene homopolymer is made in a multistage process.

8. The cross-linked polyethylene pipe as claimed in claim 1 , wherein the bimodal ethylene homopolymer is cross-linked by irradiation.

Assignees

• Pakkanen Anneli
• Palmloef Magnus
• Oderkerk Jeroen
• Borealis Ag

Inventors

• Pakkanen Anneli
• Palmlöf Magnus
• Oderkerk Jeroen

Classifications

• F16L9/12 Primary

  of plastics with or without reinforcement (F16L9/16 - F16L9/22 take precedence) · CPC title

• F16L11/04

  made of rubber or flexible plastics · CPC title

• Y10T428/139

  Open-ended, self-supporting conduit, cylinder, or tube-type article · CPC title

• C08F10/02

  Ethene · CPC title

• C08L23/06

  Polyethylene · CPC title