Pressure-sensitive adhesive compositions and constructions
View Patent ↗The present invention is directed to pressure-sensitive adhesive compositions and pressure-sensitive adhesive constructions fabricated using the pressure-sensitive adhesive compositions. The pressure-sensitive adhesive compositions comprise about 10 to about 40% of a styrene-isoprene block copolymer, about 5 to about 30% of a styrene-butadiene block copolymer, about 30 to about 65% of an aromatically modified tackifying resin, about 8 to about 30% of a plasticizing oil and optionally about 0.2 to about 2% of an antioxidant, wherein the percentages are based on the total weight of the composition.
1. A pressure-sensitive adhesive composition comprising:
a) about 10 to about 40 wt. % of a styrene-isoprene block copolymer having a styrene content of from about 14% to about 20% by weight;
b) about 5 to about 30 wt. % of a styrene-butadiene block copolymer;
c) about 30 to about 65 wt. % of an aromatically modified tackifying resin; and,
d) about 8 to about 30 wt. % of a plasticizing oil.
2. The adhesive composition of claim 1 further comprising about 0.2 to about 2.0 wt. % of an antioxidant.
3. The adhesive composition of claim 2 wherein said antioxidant comprises a pre-blended antioxidant in a resin carrier.
4. The adhesive composition of claim 1 wherein said styrene-isoprene block copolymer comprises from about 13 to about 27 wt. % of said composition.
5. The adhesive composition of claim 4 wherein said styrene-isoprene block copolymer comprises about 5 to about 80% by weight styrene-isoprene diblock component.
6. The adhesive composition of claim 4 wherein said styrene-isoprene block copolymer comprises about 40 to about 60% by weight styrene-isoprene diblock component.
7. The adhesive composition of claim 1 wherein said styrene-butadiene block copolymer comprises from about 8 to about 25 wt. % of said composition.
8. The adhesive composition of claim 7 wherein said styrene-butadiene block copolymer comprises from about 20 to about 35 wt. % bound styrene.
9. The adhesive composition of claim 8 wherein said styrene-butadiene block copolymer comprises from about 15 to about 20 wt. % block styrene.
10. The adhesive composition of claim 1 wherein said styrene-butadiene block copolymer comprises from about 10 to about 18 wt. % of said composition.
11. The adhesive composition of claim 10 wherein said styrene-butadiene block copolymer comprises from about 20 to about 35 wt. % bound styrene.
12. The adhesive composition of claim 11 wherein said styrene-butadiene block copolymer comprises from about 15 to about 20 wt. % block styrene.
13. The adhesive composition of claim 12 further comprising about 0.2 to about 2.0 wt. % of an antioxidant.
14. The adhesive composition of claim 1 wherein said aromatically modified tackifying resin has a softening point above about 85° C.
15. The adhesive composition of claim 14 wherein said aromatically modified tackifying resin comprises about 6 to about 35% by weight aromatic content.
16. The adhesive composition of claim 14 wherein said aromatically modified tackifying resin has a softening point above about 90° C.
17. The adhesive composition of claim 1 wherein said aromatically modified tackifying resin comprises about 6 to about 35% by weight aromatic content.
18. The adhesive composition of claim 1 wherein said aromatically modified tackifying resin has a softening point above about 90° C.
19. The adhesive composition of claim 1 wherein said aromatically modified tackifying resin comprises about 40 to about 52 wt. % of said composition.
20. The adhesive composition of claim 19 wherein said aromatically modified tackifying resin comprises about 6 to about 35% by weight aromatic content.
21. The adhesive composition of claim 19 wherein said aromatically modified tackifying resin has a softening point above about 85° C.
22. The adhesive composition of claim 21 further comprising about 0.2 to about 2.0 wt. % of an antioxidant.
23. The adhesive composition of claim 1 wherein said plasticizing oil comprises about 16 to about 22 wt. % of said composition.
24. The adhesive composition of claim 1 wherein said composition expresses a single glass transition temperature.
25. The adhesive composition of claim 1 wherein said adhesive composition has a tangent δ value of greater than 0.5 at all temperatures in the range of about −20° C. to about 100° C.
26. The adhesive composition of claim 1 wherein said composition has a composite midblock glass transition temperature of about 258 Kelvin to about 288 Kelvin.
27. The adhesive composition of claim 26 wherein said composition has a composite midblock glass transition temperature of about 263 Kelvin to about 283 Kelvin.
28. The adhesive composition of claim 26 wherein said composition has a composite midblock glass transition temperature of about 268 Kelvin to about 282 Kelvin.
29. The adhesive composition of claim 1 wherein said composition has a loop tack adhesion value to high density polyethylene greater than about 0.5 psi at 35° F.
30. The adhesive composition of claim 1 wherein said composition has a loop tack adhesion value to high density polyethylene greater than about 2.5 psi at 70° F.
31. The adhesive composition of claim 1 wherein said composition has a loop tack adhesion value to corrugated paperboard greater than about 0.3 psi at 35° F.
32. The adhesive composition of claim 1 wherein said composition has a loop tack adhesion value to corrugated paperboard greater than about 1.5 psi at 70° F.
33. A pressure-sensitive adhesive composition comprising:
a) about 10 to about 40 wt. % of a styrene-isoprene block copolymer having about 5 to about 80% by weight styrene-isoprene diblock component having a styrene content of from about 14% to about 20% by weight;
b) about 5 to about 30 wt. % of a styrene-butadiene block copolymer having from about 20 to about 35 wt. % bound styrene and about 15 to about 20 wt. % block styrene;
c) about 30 to about 65 wt. % of an aromatically modified tackifying resin having between about 6 to about 35% aromatic content and a softening point above about 85° C.; and
d) about 8 to about 30 wt. % of a plasticizing oil,
wherein said composition expresses a single glass transition temperature and has a tangent δ value of greater than about 0.5 for all temperatures in the range of about −20° C. to about 100° C.
34. The adhesive composition according to claim 33 wherein said styrene-isoprene block copolymer comprises about 13 to about 27 wt. % of said composition.
35. The adhesive composition according to claim 33 wherein said styrene-isoprene block copolymer comprises about 14 to about 22 wt. % of said composition.
36. The adhesive composition according to claim 33 wherein said styrene-butadiene block copolymer comprises about 8 to about 25 wt. %of said composition.
37. The adhesive composition according to claim 33 wherein said styrene-butadiene block copolymer comprises about 10 to about 18 wt. % of said composition.
38. The adhesive composition according to claim 33 wherein said aromatically modified tackifying resin comprises about 40 to about 52 wt. % of said composition.
39. The adhesive composition according to claim 33 wherein said aromatically modified tackifying resin comprises about 45 to about 52 wt. % of said composition.
40. The adhesive composition according to claim 33 wherein said composition has a composite midblock glass transition temperature of about 258 Kelvin to about 288 Kelvin.
41. The adhesive composition according to claim 40 wherein said composition has a composite midblock glass transition temperature of about 263 Kelvin to about 283 Kelvin.
42. The adhesive composition according to claim 40 wherein said composition has a composite midblock glass transition temperature of about 268 Kelvin to about 282 Kelvin.
43. The adhesive composition according to claim 33 further comprising about 0.2 to about 2.0 wt. % of an antioxidant.
44. A pressure-sensitive adhesive construction comprising:
a) a face stock; and
b) a pressure-sensitive adhesive layer coated on at least one surface of said face stock, said pressure-sensitive adhesive comprising:
i) about 10 to about 40 wt. % of a styrene-isoprene block copolymer having a styrene content of from about 14% to about 20% by weight;
ii) about 5 to about 30 wt. % of a styrene-butadiene block copolymer;
iii) about 30 to about 65 wt. % of an aromatically modified tackifying resin; and,
iv) about 8 to about 30 wt. % of a plasticizing oil.
45. The pressure-sensitive adhesive construction of claim 44 further comprising a release layer in contact with said pressure-sensitive adhesive layer.
46. The pressure-sensitive adhesive construction of claim 44 wherein said styrene-isoprene block copolymer comprises about 40 to about 60 wt. % by weight styrene-isoprene diblock component.
47. The pressure-sensitive adhesive construction of claim 44 wherein said aromatically modified tackifying resin has a softening point of greater than about 85° C.
48. The pressure-sensitive adhesive construction of claim 44 wherein said aromatically modified tackifying resin has a softening point of greater than about 90° C.
49. The pressure-sensitive adhesive construction of claim 44 wherein said aromatically modified tackifying resin has between from about 6% to about 35% by weight aromatic content.
50. The pressure-sensitive adhesive construction of claim 44 wherein said pressure-sensitive adhesive comprises:
i) about 10 to about 40 wt. % of a styrene-isoprene block copolymer having about 5 to about 80% by weight styrene-isoprene diblock component;
ii) about 5 to about 30 wt. % of a styrene-butadiene block copolymer having from about 20 to about 35 wt. % bound styrene and about 15 to about 20 wt. % block styrene;
iii) about 30 to about 65 wt. % of an aromatically modified tackifying resin having between about 6 to about 35% aromatic content and a softening point above about 85° C.;
iv) about 8 to about 30 wt. % of a plasticizing oil, and
v) about 0.2 to about 2.0 wt. % of an antioxidant,
wherein said pressure-sensitive adhesive expresses a single glass transition temperature and has a tangent δ value of greater than about 0.5 for all temperatures in the range of about −20° C. to about 100° C.
51. The pressure-sensitive adhesive construction of claim 50 further comprising a release layer in contact with said pressure-sensitive adhesive layer.
52. The pressure-sensitive adhesive construction of claim 50 wherein said styrene-isoprene block copolymer comprises about 40 to about 60% by weight styrene-isoprene diblock component.
53. The pressure-sensitive adhesive construction of claim 50 wherein said styrene-isoprene block copolymer comprises about 50 to about 58% by weight styrene-isoprene diblock component.
54. The pressure-sensitive adhesive construction of claim 50 wherein said aromatically modified tackifying resin has a softening point of greater than about 85° C.
55. The pressure-sensitive adhesive construction of claim 50 wherein said aromatically modified tackifying resin has a softening point of greater than about 90° C.