Polymer composition for crosslinked articles

Patent metadata

Field	Value
Publication number	US-9562631-B2
Application number	US-201013322287-A
Country	US
Kind code	B2
Filing date	May 20, 2010
Priority date	May 26, 2009
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

The invention is directed to a use of a polymer composition comprising an ethylene polymer for producing a crosslinked article, a process for producing a crosslinked article and to a crosslinked article comprising a crosslinked polymer composition which comprises a crosslinked ethylene polymer.

First claim

The invention claimed is:

1. A process for the preparation of a crosslinked article comprising:
(I) polymerising ethylene optionally together with one or more comonomer(s) in the presence of a Ziegler-Natta catalyst as the sole catalyst, so as to form an ethylene polymer which is an ethylene homopolymer or a copolymer of ethylene with one or more C4-12 alpha-olefin comonomers containing carbon-carbon double bonds in an amount of more than 0.5 carbon-carbon bonds/1000 carbon atoms measured by FTIR, wherein said polymerisation is carried out without using any polyunsaturated comonomers;
(II) making a polymer composition comprising at least 50 wt % of said ethylene polymer, wherein said polymer composition has a crosslinkability expressed as a gel content of at least 80 wt % when measured from a disc sample of the crosslinked ethylene polymer (ASTM D 2765-01, Method A, decaline extraction);
(III) forming an article consisting of said polymer composition of step (II);
(IV) crosslinking the article obtained from step (III).

2. The process according to claim 1 , wherein the article is crosslinked by irradiation or by using a free radical generating agent.

3. A crosslinked article which is obtained by the process as defined in claim 1 .

4. A crosslinked article comprising a crosslinked polymer composition, said polymer composition comprising, before cross-linking, at least 50 wt % of an ethylene polymer, wherein the ethylene polymer is obtained by polymerising ethylene optionally together with one or more comonomer(s) in the presence of a Ziegler-Natta catalyst as the sole catalyst, wherein said polymerisation is carried out without using any polyunsaturated comonomers; wherein the ethylene polymer is an ethylene homopolymer or a copolymer of ethylene with one or more C4-12 alpha-olefin comonomers and contains carbon-carbon double bonds in an amount of more than 0.5 carbon-carbon double bonds/1000 carbon atoms measured by FTIR; and wherein the polymer composition has a crosslinkability expressed as a gel content of at least 80 wt % when measured from a disc sample of the crosslinked polymer composition (ASTM D 2765-01, Method A, decaline extraction).

5. The crosslinked article according to claim 4 , wherein the ethylene polymer prior to crosslinking contains at least 0.2 vinyl groups per chain, when measured according to “Amount of Unsaturation” as described under “Determination methods”.

6. The crosslinked article according to claim 4 , wherein the polymer composition has at least one of the following properties:
(i) has prior crosslinking a number average molecular weight (Mn) of at least 7000 g/mol,
(ii) is crosslinked by irradiation and the ethylene polymer has prior crosslinking an MFR 2 of from 0.01 to 5.0 g/10 min, or is crosslinked using a free radical generating agent and the ethylene polymer has prior crosslinking an MFR 2 of from 0.01 to 5.0 g/10 min,
(iii) a volatile organic compounds (VOC) of less than 15, and fumes produced at given temperature (FOG) of less than 15, when measured as defined under “Determination methods”, or
(iv) has a maximum torque (Torque max, dNm,) of at least 5.0 dNm, when measured according to Monsanto test using a disc sample consisting of the Polymer composition as described in “Gel content and torque” under “Determination methods”.

7. The crosslinked article of claim 4 wherein the article is crosslinked using free radical generating agent.

8. The crosslinked article of claim 4 wherein the article is crosslinked by irradiation.

9. The process according to claim 1 , wherein the ethylene polymer contains at least 0.2 vinyl groups per chain when determined according to “Amount of Unsaturation” as described under “Determination Methods”.

10. The process according to claim 1 , wherein the ethylene polymer is selected from:
elastomers (POE), plastomers (POP) or a very low density ethylene copolymers (VLDPE) which cover the density range of from 855 to 909 kg/m 3 ,
linear low density ethylene copolymers (LLDPE) having a density of from 910 to 930 kg/m 3 ,
medium density ethylene copolymers (MDPE) having a density of from 931 to 945 kg/m 3 , or
high density polyethylenes (HDPE) which are selected form ethylene homo- or copolymers and have a density of more than 946 kg/m 3 .

11. The process according to claim 1 , wherein the ethylene polymer has at least one of the following properties:
(i) is unimodal or multimodal with respect to molecular weight distribution (MWD),
(ii) has an MFR 2 of from 0.01 to 200.0 g/10 min,
(iii) has an MFR 21 of less than 50.0 g/10 min,
(iv) has a number average molecular weight (Mn) of at least 7000 g/mol, or
(v) has a weight average molecular weight (Mw) of at least 35 000 g/mol.

Assignees

• Ek Carl-Gustaf
• Palmlöf Magnus
• Prades Floran
• Borealis Ag

Inventors

• Ek Carl-Gustaf
• Palmlöf Magnus
• Prades Floran

Classifications

• C08L23/0815

  with aliphatic 1-olefins containing one carbon-to-carbon double bond · CPC title

• C08L23/06

  Polyethylene · CPC title

• C08F220/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title

• C08K5/14

  Peroxides · CPC title