Propylene-based polymer article

• US 20080032079A1
• Filed: 07/24/2007
• Published: 02/07/2008
• Est. Priority Date: 08/02/2006
• Status: Active Grant

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: Sahnoune, Abdelhadi, Jacob, Sunny
• Granted Patent: US 8,202,467 B2
• Time in Patent Office: Days
• US Class Current: 428/36.8
• CPC Class Codes: B29C 2035/0877 using electron radiation, e.g. beta-rays
• CPC Class Codes: B29C 2791/001 Shaping in several steps
• CPC Class Codes: B29C 48/00 Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor extrusion blow-moulding B29C49/04
• CPC Class Codes: B29C 48/022 characterised by the choice of material
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/10 flexible, e.g. blown foils
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B29K 2301/10 Thermosetting resins
• CPC Class Codes: B29L 2023/22 Tubes or pipes, i.e. rigid bent tubes not for use as pipe couplings B29L2023/004
• CPC Class Codes: B29L 2031/753 Medical equipment; Accessories therefor bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008
• CPC Class Codes: Y10T 428/1386 Natural or synthetic rubber or rubber-like compound containing

Abstract

A method for extruding transparent and/or translucent article is provided. In one embodiment, the method comprises providing a propylene-based polymer comprising propylene derived units and one or more dienes, the propylene-based polymer having a triad tacticity of from 50% to 99% and a heat of fusion of less than 80 J/g, extruding the propylene-based polymer in the absence of processing oil into an article; and then crosslinking the extruded article.

Claims

1. A method for extruding a transparent or translucent article, comprising:

providing a propylene-based polymer comprising propylene derived units and, optionally, one or more dienes, the propylene-based polymer having a triad tacticity of from 50% to 99% and a heat of fusion of less than 80 J/g,

extruding the propylene-based polymer in the absence of processing oil into an article; and

then

crosslinking the extruded article.

2. The method of claim 1, wherein the extruded article is crosslinked using one or more peroxides, one or more free radical generating agents, or electron-beam irradiation.

3. The method of claim 1, wherein the extruded article is crosslinked using electron-beam irradiation.

4. The method of claim 1, wherein the extruded article has a haze value of less than 50%.

5. The method of claim 1, wherein the propylene-based polymer has a melting point of about 100°

C. or less.

6. The method of claim 1, wherein the propylene-based polymer has a heat of fusion from about 1 J/g to about 70 J/g.

7. The method of claim 1, wherein the propylene-based polymer has a triad tacticity from about 60% to about 97%.

8. The method of claim 1, wherein the propylene-based polymer further comprises units derived from an alpha-olefin other than the propylene derived units and/or the one or more dienes.

9. The method of claim 8, wherein the propylene-based polymer comprises units derived from ethylene, butene, hexene and/or octene.

10. The method of claim 9, wherein the propylene-based polymer comprises from about 5 wt % to about 40 wt % of units derived from ethylene and/or butene.

11. The method of claim 9, wherein the propylene-based polymer comprises from about 5 wt % to about 40 wt % of units derived from ethylene and/or hexene.

12. The method of claim 1, wherein the propylene-based polymer comprises from 0.5 to 4 wt % of ENB.

13. The method of claim 1, wherein the extruded article is tubing.

17. The method of claim 1, further comprising blending the propylene-based polymer with an ethylene-propylene copolymer and/or an ethylene-propylene-diene terpolymer prior to extrusion.

18. The method of claim 1, further comprising blending the propylene-based polymer with a co-agent prior to extrusion.

19. The method of claim 17, further comprising blending the propylene-based polymer with a co-agent prior to extrusion.

22. The method of claim 17, wherein the extruded article is tubing.

23. The method of claim 18, wherein the extruded article is tubing.

14. A method for extruding transparent or translucent tubing, comprising:

blending a propylene-based polymer comprising propylene derived units and one or more dienes, the propylene-based polymer having a triad tacticity of from 50% to 99% and a heat of fusion of less than 80 J/g; and

one or more polyolefinic thermoplastic components to provide a blend, wherein the blend contains no processing oil;

extruding the blend into tubing; and

then

crosslinking the extruded tubing.

15. The method of claim 14, wherein the one or more polyolefinic thermoplastic components comprises isotactic polypropylene, random copolymer, and impact copolymer.

20. The method of claim 14, wherein the blend further comprises an ethylene-propylene copolymer and/or an ethylene-propylene-diene terpolymer.

21. The method of claim 14, wherein the blend further comprises a co-agent.

16. A tube comprising:

a propylene-based polymer comprising propylene derived units and one or more dienes, the propylene-based polymer having a triad tacticity of from 50% to 99% and a heat of fusion of less than 80 J/g; and

optionally one or more polyolefinic thermoplastic components, wherein the tube comprises substantially no processing oil.

24. The tube of claim 16, further comprising an ethylene-propylene copolymer and/or an ethylene-propylene-diene terpolymer.

25. The tube of claim 16, further comprising a co-agent.

26. The tube of claim 24, further comprising a co-agent.