Laminating adhesive, laminate including the same, and method of making a laminate

1. A method of making a laminate, said method comprising:

a) preparing an adhesive composition, said preparing comprising combining

a first part comprising

(meth)acrylate functional, polyisocyanate prepolymer, and

polyisocyanate monomer,

said first part comprising at least 10% by weight

isocyanate functional groups,

a second part comprising polyol, and

optionally, a third part,

at least one of said first part, said second part and said optional third part comprising photoinitiator;

b) coating a first flexible substrate with said adhesive composition;

c) exposing the adhesive composition to radiation to partially cure said adhesive composition; and

d) contacting said adhesive composition with a second flexible substrate.

2. The method of claim 1 , wherein said first part comprises at least 15% by weight said polyisocyanate monomer.

3. The method of claim 1 , wherein said first part comprises at least 30% by weight said polyisocyanate monomer.

4. The method of claim 1 , wherein said exposing occurs prior to contacting said adhesive composition with said second flexible substrate.

5. The method of claim 1 , wherein said exposing occurs after contacting said adhesive composition with said second flexible substrate.

6. The method of claim 1 , wherein said adhesive composition exhibits a viscosity of from 250 centipoise to 5000 centipoise at a temperature from 65° F. to 170° F.

7. The method of claim 1 , wherein said coating comprises coating said adhesive composition at a coating weight of from 0.5 pounds per 3000 square feet to 4 pounds per 3000 square feet.

8. The method of claim 1 , wherein said adhesive composition exhibits a lap shear strength of at least 25 g/in 2 after exposure to said radiation.

9. The method of claim 1 , wherein said adhesive composition exhibits a lap shear strength of at least 100 g/in 2 after exposure to said radiation.

10. The method of claim 1 , wherein said adhesive composition comprises

from 5% by weight to 70% by weight said (meth)acrylate functional, polyisocyanate prepolymer;

at least 7% by weight said polyisocyanate monomer;

from 30% by weight to 95% by weight said polyol; and

from 0.2% by weight to 10% by weight said photoinitiator.

11. The method of claim 1 , wherein said first part of said adhesive composition comprises

from 40% by weight to 90% by weight said (meth)acrylate functional, polyisocyanate prepolymer, and

from 10% by weight to 60% by weight said polyisocyanate monomer.

12. The method of claim 1 , wherein said first part of said adhesive composition comprises from 10% by weight to about 20% by weight isocyanate functional groups.

13. The method of claim 1 , wherein said first part comprises from about 0.5% by weight to about 20% by weight radiation polymerizable groups.

14. The method of claim 1 , wherein said first part comprises from about 1% by weight to about 10% by weight radiation polymerizable groups.

15. The method of claim 1 , wherein the first part and the second part are combined in amounts such that the stoichiometric ratio of isocyanate (NCO) to hydroxyl group (OH) (NCO:OH) is from about 1:1 to about 2:1.

16. The method of claim 1 , wherein said (meth)acrylate polyisocyanate prepolymer comprises the reaction product of

a) an isocyanate polyurethane prepolymer comprising the reaction product of

i) polyol and

ii) isocyanate; and

b) hydroxy functional (meth)acrylate.

17. The method of claim 16 , wherein said hydroxy functional acrylate comprises hydroxyalkyl(meth)acrylate.

18. The method of claim 16 , wherein said hydroxy functional acrylate comprises hydroxyethyl acrylate.

19. The method of claim 1 , wherein said polyol comprises polyester polyol, polyether polyol, or a mixture thereof.

20. The method of claim 1 , wherein said polyol has a functionality of at least 2.

21. The method of claim 1 , wherein said polyol has a functionality of no greater than 3.

22. The method of claim 1 , wherein said adhesive composition comprises from 20% by weight to 95% by weight said polyol.

23. The method of claim 1 , wherein said adhesive composition comprises from 30% by weight to 70% by weight said polyol.

24. The method of claim 1 , wherein said adhesive composition comprises from 30% by weight to 70% by weight said (meth)acrylate functional, polyisocyanate prepolymer.

25. The method of claim 1 , wherein said adhesive composition comprises from 20% by weight to 60% by weight said (meth)acrylate functional, polyisocyanate prepolymer.

26. The method of claim 1 , wherein said photoinitiator is selected from the group consisting of dialkoxy acetophenones, hydroxyalkyl phenyl ketones, benzoin ethers, benzoin acetals, acyl phosphine oxides, and combinations thereof.

27. The method of claim 1 , wherein said photoinitiator comprises a hydroxyl functional photoinitiator.

28. The method of claim 1 , wherein at least one of said first and second flexible substrates is a polymer film.

29. The method of claim 1 , wherein at least one of said first and second flexible substrates is a metallized polymer film.

30. The method of claim 1 , wherein at least one of said first flexible substrate and said second flexible substrate comprises polyethylene terephthalate, polypropylene, polyethylene, metallized polypropylene, metalized polyethylene terephthalate, Nylon, and metal foil.

31. A method of making a laminate, said method comprising:

a) coating a first flexible substrate with a composition comprising

(meth)acrylate functional, polyisocyanate prepolymer,

at least 7% by weight polyisocyanate monomer,

polyol, and

photoinitiator;

b) exposing said adhesive composition to radiation to partially cure said adhesive composition; and

c) contacting said adhesive composition with a second flexible substrate.

32. A method of making a laminate, said method comprising:

a) preparing an adhesive composition, said preparing comprising combining

a first part comprising

(meth)acrylate functional, polyisocyanate prepolymer, and

at least 15% by weight polyisocyanate monomer,

a second part comprising polyol, and

optionally, a third part,

at least one of said first part, said second part and said optional third part comprising photoinitiator;

b) coating a first flexible substrate with said adhesive composition

c) exposing said composition to radiation to partially cure said composition; and

d) contacting said adhesive composition with a second flexible substrate.

33. A method of making a laminate, said method comprising:

a) preparing an adhesive composition, said preparing comprising combining

(meth)acrylate functional, polyisocyanate prepolymer,

polyisocyanate monomer,

the combination of said prepolymer and said monomer comprising

at least 10% by weight isocyanate functional groups based on the combined weight of said prepolymer and said polyisocyanate monomer,

polyol, and

photoinitiator;

b) coating a first flexible substrate with said adhesive composition;

c) exposing the adhesive composition to radiation to partially cure said adhesive composition; and

d) contacting said adhesive composition with a second flexible substrate.

34. A laminate comprising:

an adhesive composition comprising the reaction product of

(meth)acrylate functional, polyisocyanate prepolymer,

polyisocyanate monomer,

the combination of said prepolymer and said monomer comprising at least 10% by weight isocyanate functional groups based on the combined weight of said prepolymer and said polyisocyanate monomer,

polyol, and

photoinitiator;

a first flexible substrate; and

a second flexible substrate,

said first flexible substrate being bonded to said flexible substrate through said adhesive composition.

35. A laminate comprising:

an adhesive composition comprising the reaction product of

a (meth)acrylate functional, polyisocyanate prepolymer,

polyisocyanate monomer,

polyol, and

photoinitiator,

a first flexible substrate; and

a second flexible substrate,

said first flexible substrate being bonded to said second flexible substrate through said adhesive composition,

said adhesive composition exhibiting a destructive peel to at least one of said first and second substrates.

36. A package comprising:

a) a food article; and

b) the laminate of claim 34 at least partially surrounding said food article.