Free radical initiator modified hot melt adhesive composition including functionalized polyethylene and propylene-alpha-olefin polymer
View Patent ↗A hot melt adhesive composition that includes a first copolymer that includes the reaction product of a functionalized polyethylene, a propylene-alpha-olefin polymer that includes at least 50 mole % propylene and has a viscosity of no greater than 10,000 centipoise at 190° C., a ratio of z average molecular weight (Mz) to number average molecular weight (Mn) (Mz/Mn) of greater than 20, and a ratio of Mz to weight average molecular weight (Mw) (Mz/Mw) of greater than 3.0, and a free radical initiator.
1. A hot melt adhesive composition comprising:
a first copolymer comprising the reaction product of
a functionalized polyethylene,
a propylene-alpha-olefin polymer comprising at least 50 mole % propylene and having a viscosity of no greater than 10,000 centipoise at 190° C., a ratio of z average molecular weight (Mz) to number average molecular weight (Mn) (Mz/Mn) of greater than 20, and a ratio of Mz to weight average molecular weight (Mw) (Mz/Mw) of greater than 3.0, and
a free radical initiator.
2. The adhesive composition of claim 1 having a viscosity of no greater than 2,000 centipoise at 177° C.
3. The adhesive composition of claim 1 having a viscosity of from about 400 to about 2,000 centipoise at 177° C.
4. The adhesive composition of claim 1 , wherein the adhesive composition exhibits a fiber tearing bond at −29° C. and at +60° C.
5. The adhesive composition of claim 1 , wherein the adhesive composition exhibits at least about 50% fiber tear at −29° C. and at +60° C.
6. The adhesive composition of claim 1 , wherein the first copolymer is formed from of at least 2% by weight of the functionalized polyethylene based on the weight of the first copolymer.
7. The adhesive composition of claim 1 , wherein the first copolymer is formed from at least about 10% by weight of the functionalized polyethylene based on the weight of the first copolymer.
8. The adhesive composition of claim 1 , wherein the first copolymer comprises the reaction product of at least about 2% by weight of maleated polyethylene and at least about 80% by weight of the propylene-alpha-olefin polymer.
9. The adhesive composition of claim 1 , wherein the first copolymer comprises the reaction product of at least about 10% by weight maleated polyethylene and at least about 85% by weight of the propylene-alpha-olefin polymer.
10. The adhesive composition of claim 1 , wherein the adhesive composition is homogeneous after aging for 96 hours at 177° C.
11. The adhesive composition of claim 1 exhibiting a single thermal melt transition temperature when tested using differential scanning calorimetry.
12. The adhesive composition of claim 1 exhibiting an initial Gardner color of no greater than 3.
13. The adhesive composition of claim 1 exhibiting a Gardner color after aging for 72hours at 177° C. of no greater than 5.
14. The adhesive composition of claim 1 , wherein the free radical initiator comprises peroxide.
15. The adhesive composition of claim 1 , wherein the propylene-alpha-olefin polymer comprises ethylene, butene, pentene, hexene, heptene, octene, nonene, decene, dodecene, or a combination thereof.
16. The adhesive composition of claim 1 , wherein the propylene-alpha-olefin polymer comprises at least 25 mole % butene.
17. The adhesive composition of claim 1 further comprising Fischer Tropsch wax, polyethylene wax, polypropylene wax, maleated polypropylene wax, or a combination thereof.
18. The adhesive composition of claim 1 , wherein the functionalized polyethylene comprises maleated polyethylene wax and the composition further comprises Fischer Tropsch wax, polyethylene wax, maleated polypropylene wax, or a combination thereof.
19. The adhesive composition of claim 1 , wherein the functionalized polyethylene comprises maleated polyethylene wax and the composition further comprises Fischer Tropsch wax.
20. The adhesive composition of claim 18 , further comprising an olefin polymer.
21. The adhesive composition of claim 1 further comprising at least about 5% by weight wax.
22. The adhesive composition of claim 1 further comprising at least about 5% by weight wax selected from the group consisting of polyethylene wax, maleated polypropylene wax, and Fischer Tropsch wax.
23. The adhesive composition of claim 1 , wherein the adhesive composition exhibits a set time of less than 15 seconds.
24. The adhesive composition of claim 1 , wherein the adhesive composition exhibits a set time of less than 10 seconds.
25. The adhesive composition of claim 1 , wherein the first copolymer comprises the reaction product of at least about 2% by weight maleated polyethylene and at least about 80% by weight propylene-alpha-olefin polymer, the adhesive composition further comprising at least about 5% by weight wax and having a viscosity no greater than 2,000 centipoise at 177° C.
26. The adhesive composition of claim 1 , exhibiting a Mz/Mn of greater than 18, and a Mz/Mw of from 2.3 to no greater than 6.
27. The adhesive composition of claim 1 , exhibiting a Mz/Mn of at least 27 and a Mz/Mw of from 2.3 to no greater than 4.
28. The adhesive composition of claim 1 further comprising tackifying agent.
29. The adhesive composition of claim 1 further comprising from at least 15% by weight to about 30% by weight tackifying agent.
30. The adhesive composition of claim 1 , wherein the first copolymer is formed from a reaction mixture comprising a polyfunctional acid.
31. The adhesive composition of claim 1 comprising at least about 55% by weight of the copolymer and further comprising a tackifying agent and a wax comprising Fischer Tropsch wax, polyethylene wax, polypropylene wax, maleated polypropylene wax, or a combination thereof.
32. The adhesive composition of claim 1 comprising at least about 70% by weight of the copolymer and further comprising a tackifying agent and a wax comprising Fischer Tropsch wax, polyethylene wax, polypropylene wax, maleated polypropylene wax, or a combination thereof.
33. A method of making a hot melt adhesive composition, the method comprising:
heating a mixture comprising
at least 80% by weight propylene-alpha-olefin polymer comprising at least 50 mole % propylene, the propylene-alpha-olefin polymer having a viscosity of no greater than 10,000 centipoise at 190° C., a ratio of z average molecular weight (Mz) to number average molecular weight (Mn) (Mz/Mn) of greater than 20, and a ratio of Mz to weight average molecular weight (Mw) (Mz/Mw) of greater than 3.0,
functionalized polyethylene, and
a free radical initiator.
34. The method of claim 33 , wherein the functionalized polyethylene comprises functionalized polyethylene wax.
35. The method of claim 33 , wherein the functionalized polyethylene comprises maleated polyethylene wax and the mixture comprises at least about 2% by weight of the maleated polyethylene wax.
36. The method of claim 33 , wherein the hot melt adhesive composition exhibits a fiber tearing bond at −29° C. and at +60° C.
37. The method of claim 33 , wherein the mixture further comprises a polyfunctional acid.
38. A hot melt adhesive composition comprising:
a copolymer comprising the reaction product of
a functionalized polyethylene,
a propylene-alpha-olefin polymer comprising at least 50 mole % propylene, and
a free radical initiator,
the hot melt adhesive composition exhibiting a ratio of z average molecular weight (Mz) to number average molecular weight (Mn) (Mz/Mn) of greater than 18, and a ratio of Mz to weight average molecular weight (Mw) (Mz/Mw) of from 2.3 to no greater than 6.
39. The hot melt adhesive composition of claim 38 , wherein the Mz/Mn is at least 27 and the Mz/Mw is from 2.5 to no greater than 6.
40. The hot melt adhesive composition of claim 38 , wherein the adhesive composition exhibits at least about 50% fiber tear at −29° C. and at +60° C.
41. The hot melt adhesive composition of claim 38 , wherein the functionalized polyethylene comprises functionalized polyethylene wax.
42. The hot melt adhesive composition of claim 1 further comprising filler.