Polypropylene-based adhesive compositions

1. An adhesive composition comprising:

a. a first propylene-based copolymer component comprising propylene and at least one comonomer wherein the first propylene-based copolymer component has a propylene content of greater than 50 mol % and a weight average molecular weight of 100,000 or less; and

b. a second propylene-based copolymer component comprising propylene and at least one comonomer wherein the second propylene-based copolymer component has a propylene content of greater than 50 mol %, a comonomer content of at least 2 mol % greater than the comonomer content of the first propylene-based copolymer component, and a weight average molecular weight of 100,000 or less;

wherein the first propylene-based copolymer has a heat of fusion of between about 1 and about 120 J/g and wherein the second propylene-based copolymer has a heat of fusion of between about 1 and about 100 J/g;

wherein the at least one comonomer of the first propylene-based copolymer component and the second propylene-based copolymer component is ethylene; and

wherein the second propylene-based polymer component has a viscosity of 1,500 mPa·sec or more at 190° C.

2. The adhesive composition of claim 1 , wherein the comonomer content of the second propylene-based copolymer component is at least 4 mol % greater than the comonomer content of the first propylene-based copolymer component.

3. The adhesive composition of claim 1 , wherein the difference in comonomer content between the first propylene-based copolymer component and the second propylene-based copolymer component is about 2 mol % to about 16 mol %.

4. The adhesive composition of claim 1 , wherein the comonomer content of the first propylene-based copolymer component is greater than 1 mol % and the comonomer content of the second propylene-based copolymer component is greater than 5 mol %.

5. The adhesive composition of claim 1 , wherein the weight content ratio of the first propylene-based copolymer component to second propylene-based copolymer component is greater than 3:1 in the adhesive composition.

6. The adhesive composition of claim 1 , wherein the weight content ratio of the first propylene-based copolymer component to second propylene-based copolymer component is between about 4:1 to about 1:4 and wherein the first propylene-based copolymer component and second propylene-based copolymer component comprise at least 50 wt % of the adhesive composition.

7. The adhesive composition of claim 1 , wherein the first propylene-based copolymer component and the second propylene-based copolymer component have a difference in heat of fusion of at least 20 J/g.

8. The adhesive composition of claim 1 , wherein the first propylene-based copolymer component and the second propylene-based copolymer component have a difference in heat of fusion of at least 30 J/g.

9. The adhesive composition of claim 1 , further comprising at least one tackifier resin component.

10. The adhesive composition of claim 1 , further comprising at least one functionalized component.

11. The adhesive composition of claim 1 , further comprising at least one block copolymer.

12. The adhesive composition of claim 1 , further comprising at least one ester copolymer.

13. The adhesive composition of claim 1 , wherein the adhesive composition comprises from 1 wt % to 50 wt % of the first propylene-based copolymer and from 1 wt % to 50 wt % of the second propylene-based copolymer component.

14. The adhesive composition of claim 1 , wherein the adhesive composition comprises from 1 wt % to 70 wt % of the first propylene-based copolymer and from 1 wt % to 70 wt % of the second propylene-based copolymer component and from 10 wt % to 50 wt % tackifier resin component.

15. The adhesive composition of claim 1 , wherein the set time is less than 3 seconds and the fiber tear is greater than 80%.

16. The adhesive composition of claim 1 , wherein the first propylene-based copolymer component and second propylene-based copolymer component have an MFR of greater than 500 dg/min.

17. The adhesive composition of claim 1 , wherein each of the first propylene-based copolymer component and second propylene-based copolymer component have a Brookfield Viscosity of greater than 500 mPa·sec (as measured by ASTM D 3236 at 190° C.).

18. The adhesive composition of claim 1 , wherein the first propylene-based copolymer component has a heat of fusion of greater than 30 J/g and the second propylene-based copolymer component has a heat of fusion of less than 20 J/g.

19. The adhesive composition of claim 1 , wherein the first propylene-based copolymer component has a comonomer content of from 1 mol % to 14 mol % and the second propylene-based copolymer component has a comonomer content of from 14 mol % to 50 mol %.

20. An adhesive composition comprising:

a. a first propylene-based copolymer component comprising propylene and at least one comonomer wherein the first propylene-based copolymer component has a propylene content of greater than 50 mol % and a weight average molecular weight of 100,000 or less; and

b. a second propylene-based copolymer component comprising propylene and at least one comonomer wherein the second propylene-based copolymer component has a propylene content of greater than 50 mol %, a heat of fusion of at least 10 J/g less than the heat of fusion of the first propylene-based copolymer component, a comonomer content of at least 2 mol % greater than the comonomer content of the first propylene-based copolymer component, and a weight average molecular weight of less than 100,000 or less;

wherein the first propylene-based copolymer has a heat of fusion of between about 1 and about 120 J/g and wherein the second propylene-based copolymer has a heat of fusion of between about 1 and about 100 J/g;

wherein the at least one comonomer of the first propylene-based copolymer component and the second propylene-based copolymer component is ethylene; and

wherein the second propylene-based polymer component has a viscosity of 1,500 mPa·sec or more at 190° C.

21. A hot melt adhesive composition comprising:

a. from 1 wt % to 70 wt % of a first propylene-based copolymer component comprising propylene and at least one comonomer wherein the first propylene-based copolymer component has a propylene content of greater than 50 mol %, a comonomer content of less than 14 mol %, a heat of fusion of greater than 30 J/g, and a Brookfield viscosity of greater than 500 mPa·sec at 190° C.;

b. from 1 wt % to 70 wt % of a second propylene-based copolymer component comprising propylene and at least one comonomer wherein the second propylene-based copolymer component has a propylene content of greater than 50 mol %, a comonomer content of greater than 14 mol % and at least 2 mol % greater than the comonomer content of the first propylene-based copolymer component, a heat of fusion that is at least 10 J/g less than the first propylene-based polymer component, and a Brookfield viscosity of greater than 500 mPa·sec at 190° C.;

c. from 1 wt % to 80 wt % of a tackifier resin component; and

d. from 1 wt % to 20 wt % of a wax;

wherein the first propylene-based copolymer has a heat of fusion of between about 1 and about 120 J/g and wherein the second propylene-based copolymer has a heat of fusion of between about 1 and about 100 J/g;

wherein the at least one comonomer of the first propylene-based copolymer component and the second propylene-based copolymer component is ethylene; and

wherein the second propylene-based polymer component has a viscosity of 1,500 mPa·sec or more at 190° C.

22. The adhesive composition of claim 1 , further comprising (c) a functional component, wherein the functional component is present in the amount of less than 15 wt %.

23. The adhesive composition of claim 20 , further comprising (c) a functional component, wherein the functional component is present in the amount of less than 15 wt %.

24. The adhesive composition of claim 21 , further comprising (e) a functional component, wherein the functional component is present in the amount of less than 15 wt %.