Enhanced heat stability polypropylene

Patent metadata

Field	Value
Publication number	US-11780939-B2
Application number	US-202016795790-A
Country	US
Kind code	B2
Filing date	Feb 20, 2020
Priority date	Feb 20, 2019
Publication date	Oct 10, 2023
Grant date	Oct 10, 2023

Abstract

A process forming a high MFR polypropylene includes providing a reactor powder polypropylene, the reactor powder polypropylene having a melt flow rate of less than 100 dg/min. The process also includes mixing the reactor powder polypropylene with a free-radical initiator to form a powder/initiator mixture and subjecting the powder/initiator mixture to post-reactor forming. The present disclosure further provides for a vis-broken polypropylene and a polymer article.

First claim

What is claimed is:

1. A process for forming a high melt flow rate (MFR) polypropylene comprising:
providing a reactor powder polypropylene, wherein the reactor powder polypropylene comprises a nucleator comprising talc, and wherein the reactor powder polypropylene has a MFR of less than 100 dg/min as determined by ASTM D1238;
mixing the reactor powder polypropylene with a free-radical initiator to form a powder/initiator mixture; and
subjecting the powder/initiator mixture to post-reactor forming to form discrete particle comprising a vis-broken polypropylene as the high MFR polypropylene, wherein the vis-broken polypropylene has a MFR greater than the MFR of the reactor powder polypropylene and in a range of from 80 dg/min to 150 dg/min.

2. The process of claim 1 , wherein the reactor powder polypropylene is a homopolymer, a random copolymer, or an impact copolymer.

3. The process of claim 1 , wherein the reactor powder polypropylene has a MFR greater than or equal to 10 and less than 100 dg/min as measured by ASTM D1238.

4. The process of claim 1 , wherein the nucleator further comprises silica, a metallic-silicate hydrate, an organic derivative of dibenzylidene sorbitol, a sorbitol acetal, or a combination thereof.

5. The process of claim 1 , wherein the free radical initiator is an organic peroxide.

6. The process of claim 5 , wherein organic peroxide is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane, or 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane.

7. The process of claim 6 , wherein the organic peroxide is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane and no 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane is present.

8. The process of claim 5 , wherein an amount of organic peroxide present in the powder/initiator mixture is between 50 ppm to 1500 ppm.

9. The process of claim 1 , wherein a ratio of MFR of the vis-broken polypropylene to the reactor powder polypropylene is between 1.25:1 to 25:1.

10. The process of claim 9 , wherein the ratio of MFR of the vis-broken polypropylene to the reactor powder polypropylene is between 2.5:1 to 12:1.

11. The process of claim 1 , wherein the powder/initiator mixture is combined with a secondary antioxidant.

12. The process of claim 11 , wherein the secondary antioxidant is a phosphite, hindered amine stabilizer or hydroxylamine.

13. The process of claim 12 , wherein the secondary antioxidant is present in the powder/initiator mixture in an amount between 0.1% to 3 wt %.

14. The process of claim 1 , wherein, following post-reactor forming, a TGA of the high MFR polypropylene at 230° C. has a 2% loss in weight of between 75 minutes and 200 minutes.

15. The process of claim 14 , wherein, following post-reactor forming, the TGA of the high MFR polypropylene at 230° C. has a 3% loss in weight of between 77 minutes and 210 minutes.

16. The process of claim 1 , wherein the post-reaction forming is accomplished by extrusion into pellets, compaction into a fused/physically bonded pellet, prill bead manufacturing, pastillation, or melt atomization.

17. A vis-broken polypropylene obtained by the process of claim 1 .

18. The process of claim 1 further comprising forming the discrete particle into an article.

19. The process of claim 18 , wherein the article is a motor vehicle component, appliance, or filter media.

20. A polymer article formed from the vis-broken polypropylene of claim 1 .

21. The process of claim 1 , wherein the MFR of the high MFR polypropylene is in a range of from about 100 dg/min to 150 dg/min.

22. A process for forming a high melt flow rate (MFR) polypropylene comprising:
providing a reactor powder polypropylene, the reactor powder polypropylene comprising a nucleator and having a MFR of less than 100 dg/min as determined by ASTM D1238;
mixing the reactor powder polypropylene with a free-radical initiator to form a powder/initiator mixture; and
subjecting the powder/initiator mixture to post-reactor forming to form discrete particle comprising a vis-broken polypropylene as the high MFR polypropylene, wherein the vis-broken polypropylene has a MFR greater than the MFR of the reactor powder propylene and in a range of from 80 dg/min to 150 dg/min;
wherein the nucleator is talc and the talc is present in the reactor powder polypropylene in an amount between 500 ppm and 20,000 ppm.

23. The process of claim 22 , wherein the MFR of the high MFR polypropylene is in a range of from about 100 dg/min to 150 dg/min.

24. A process for forming a high melt flow rate (MFR) polypropylene comprising:
providing a reactor powder polypropylene, the reactor powder polypropylene having a MFR of less than 100 dg/min as determined by ASTM D1238;
mixing the reactor powder polypropylene with a free-radical initiator to form a powder/initiator mixture; and
subjecting the powder/initiator mixture to post-reactor forming to form discrete particle comprising a vis-broken polypropylene as the high MFR polypropylene, wherein the vis-broken polypropylene has a MFR greater than the MFR of the reactor powder polypropylene and in a range of from 80 dg/min to 150 dg/min;
wherein the powder/initiator mixture is combined with talc.

25. The process of claim 24 , wherein the MFR of the high MFR polypropylene is in a range of from about 100 dg/min to 150 dg/min.

Assignees

• Fina Technology

Inventors

• Mcleod Michael
• Mcdonald Russell
• Shuler Joseph
• Patkar Mahesh
• Mayhall Marc

Classifications

• C08F10/06 Primary

  Propene · CPC title

• B29B9/12

  characterised by structure or composition · CPC title

• C08K3/34

  Silicon-containing compounds · CPC title

• C08K5/005

  Stabilisers against oxidation, heat, light, ozone · CPC title

• C08K5/14

  Peroxides · CPC title