Crosslinked compositions, method of making them, and articles comprising them

Patent metadata

Field	Value
Publication number	US-9040601-B2
Application number	US-201213532276-A
Country	US
Kind code	B2
Filing date	Jun 25, 2012
Priority date	May 30, 2008
Publication date	May 26, 2015
Grant date	May 26, 2015

Abstract

The present invention relates to a composition comprising at least one propylene-based polymer comprising less than 0.1 wt. % diene-derived units based on the weight of the propylene-based polymer, an antioxidant, and a co-agent. The composition can be at least partially crosslinked by electron beam irradiation in a dose of less than 200 kGy, and may be further formed into articles including fibers, yarns, films, and nonwovens, among others. The propylene-based polymer of the present invention may be a polymer blend formed by forming a reactor blend from of two or more polymers produced in two or more reactors.

First claim

What is claimed is:

1. A method for making a crosslinked composition comprising the step of crosslinking the composition using electron beam radiation having an electron beam dose of about 200 kGy or less, the composition comprising:
i) one or more propylene-based polymers each comprising from about 75 wt. % to about 99 wt. % propylene-derived units, and from about 1 wt. % to about 25 wt. % ethylene and/or C 4 -C 20 α-olefin-derived units;
wherein at least one of the one or more propylene-based polymers is a polymer blend formed by forming a reactor blend of a first polymer formed in a first reactor and a second polymer formed in a second reactor, the first polymer comprising from about 75 wt. % to about 99 wt. % propylene-derived units, from about 1 wt. % to about 25 wt. % ethylene and/or C 4 -C 20 α-olefin-derived units, and less than 0.1 wt. % diene-derived units, based on the weight of the first polymer; and the second polymer comprising from about 75 wt. % to about 99 wt. % propylene-derived units, from about 1 wt. % to about 25 wt. % ethylene and/or C 4 -C 20 α-olefin-derived units, and less than 0.1 wt. % diene-derived units, based on the weight of the second polymer;

ii) at least one of a multifunctional acrylate, multifunctional methacrylate, functionalized polybutadiene resin, functionalized cyanurate, and allyl isocyanurate; and
iii) at least one of a hindered phenol, phosphite, and hindered amine;
wherein each propylene-based polymer in the composition comprises less than 0.1 wt. % diene derived units, based on the weight of that propylene-based polymer.

2. The method of claim 1 , wherein the electron beam dose is about 100 kGy or less.

3. The method of claim 1 , wherein the electron beam dose is of from about 40 kGy to about 60 kGy.

4. The method of claim 1 , wherein each propylene-based polymer comprises less than 0.01 wt. % diene-derived units based on the weight of that propylene-based polymer.

5. The method of claim 1 , wherein each propylene-based polymer comprises 0 wt. % diene-derived units based on the weight of that propylene-based polymer.

6. The method of claim 1 , wherein at least one of the one or more propylene-based polymers comprises from about 5 wt. % to about 25 wt. % units derived from ethylene, butene, hexene, and/or octane based on the weight of that one of the propylene-based polymers.

7. The method of claim 1 , wherein at least one of the first polymer and the second polymer has a heat of fusion from about 0.5 J/g to about 80 J/g.

8. The method of claim 1 , wherein at least one of the first polymer and the second polymer has a triad tacticity of three propylene units, as determined by 13 C NMR, of 75% or greater.

9. The method of claim 1 , wherein the first polymer comprises from about 12 wt. % to about 20 wt. % ethylene-derived units based on the weight of the first polymer.

10. The method of claim 1 , wherein the second polymer comprises from about 3 wt. % to about 10 wt. % ethylene-derived units based on the weight of the second polymer.

11. The method of claim 1 , wherein the polymer blend comprises from about 10 wt. % to about 18 wt. % ethylene-derived units based on the weight of the polymer blend.

12. The method of claim 1 , wherein the at least one of multifunctional acrylate, multifunctional methacrylate, functionalized polybutadiene resin, functionalized cyanurate, and allyl isocyanurate is present in an amount of from about 0.1 wt. % to 15 wt. % based on the weight of the composition.

13. The method of claim 1 , wherein the at least one of hindered phenol, phosphite, and hindered amine is present in an amount of from about 0.1 wt. % to 5 wt. % based on the weight of the composition.

14. The method of claim 1 , wherein the composition further comprises at least one of a secondary elastomer and a polyolefinic thermoplastic resin.

15. The method of claim 14 , wherein the polyolefinic thermoplastic resin comprises at least one of an isotactic polypropylene, a random copolymer, and an impact copolymer.

16. An article comprising a crosslinked composition made by the method of claim 1 .

17. The article of claim 16 comprising film or nonwoven fiber.

18. A composition comprising:
i) a polymer blend formed by forming a reactor blend of a first polymer formed in a first reactor and a second polymer differing in olefin content from the first polymer and formed in a second reactor, the first polymer comprising from about 75 wt. % to about 99 wt. % propylene-derived units, from about 1 wt. % to about 25 wt. % ethylene and/or C 4 -C 20 α-olefin-derived units, and less than 0.05 wt. % diene-derived units based on the weight of the first polymer; and the second polymer comprising from about 75 wt. % to about 99 wt. % propylene-derived units, from about 1 wt. % to about 25 wt. % ethylene and/or C 4 -C 20 α-olefin-derived units, and less than 0.05 wt. % diene-derived units based on the weight of the second polymer;
ii) at least one of a multifunctional acrylate, multifunctional methacrylate, functionalized polybutadiene resin, functionalized cyanurate, and allyl isocyanurate; and
iii) at least one of a hindered phenol, phosphite, and hindered amine.

19. The composition of claim 18 , wherein the polymer blend comprises 0 wt. % diene-derived units based on the weight of the polymer blend.

20. The composition of claim 18 , wherein the composition is subjected to electron beam radiation having an electron beam dose of about 100 kGy or less.

21. The composition of claim 20 having greater than 40% xylene insolubles as measured according to ASTM-D 5492.

22. A crosslinked composition, comprising:
i) one or more propylene-based polymers each comprising from about 75 wt. % to about 99 wt. % propylene-derived units, from about 1 wt. % to about 25 wt. % ethylene and/or C 4 -C 20 α-olefin-derived units;
wherein at least one of the one or more propylene-based polymers is a polymer blend formed by forming a reactor blend of a first polymer formed in a first reactor and a second polymer formed in a second reactor, the first polymer comprising from about 75 wt. % to about 99 wt. % propylene-derived units, from about 1 wt. % to about 25 wt. % ethylene and/or C 4 -C 20 α-olefin-derived units, and less than 0.1 wt. % diene-derived units, based on the weight of the first polymer; and the second polymer comprising from about 75 wt. % to about 99 wt. % propylene-derived units, from about 1 wt. % to about 25 wt. % ethylene and/or C 4 -C 20 α-olefin-derived units, and less than 0.1 wt. % diene-derived units, based on the weight of the second polymer;

ii) at least one of a multifunctional acrylate, multifunctional methacrylate, functionalized polybutadiene resin, functionalized cyanurate, and allyl isocyanurate;
iii) at least one of a hindered phenol, phosphite, and hindered amine; and
iv) a polyolefinic thermoplastic resin,
wherein the crosslinked composition has greater than 40% xylene insolubles as measured according to ASTM-D 5492; and
wherein each propylene-based polymer in the composition comprises less than 0.1 wt. % diene derived units, based on the weight of that propylene-based polymer.

23. The crosslinked composition of claim 22 , wherein each propylene-based polymer comprises 0 wt. % diene-derived units based on the weight of the propylene-based polymer.

24. An article comprising the crosslinked composition of claim 22 .

Assignees

• Jacob Sunny
• Exxonmobil Chem Patents Inc

Inventors

• Jacob Sunny

Classifications

• C08L23/10

  Homopolymers or copolymers of propene · CPC title

• C08L23/145 Primary

  with monomers having two or more carbon-to-carbon double bonds · CPC title

• C08L2312/06

  by radiation · CPC title

• C08L2205/02

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

• C08L2205/03

  containing three or more polymers in a blend · CPC title