Fast set moisture curable hot melt adhesive composition and articles including the same
A moisture curable hot melt adhesive composition that includes isocyanate-terminated polyurethane prepolymer that includes the reaction product of a crystalline polyester polyol, a polyether polyol, and diisocyanate, clay, polyester/polyether elastomer, a first thermoplastic polymer selected from the group consisting of ethylene vinyl acetate copolymer, ethylene (alkyl)acrylate copolymer, and combinations thereof, a tackifying agent, and optionally a second thermoplastic polymer selected from the group consisting of thermoplastic polyurethane, thermoplastic polycaprolactone, and combinations thereof.
1. A moisture curable hot melt adhesive composition comprising:
isocyanate-terminated polyurethane prepolymer comprising a reaction product of crystalline polyester polyol exhibiting a crystallization peak temperature of at least 55° C., polyether polyol, and diisocyanate;
clay;
polyester/polyether thermoplastic elastomer;
a first thermoplastic polymer selected from the group consisting of ethylene vinyl acetate copolymer, ethylene (alkyl)acrylate copolymer, and combinations thereof;
a second thermoplastic polymer selected from the group consisting of thermoplastic polyurethane, thermoplastic polycaprolactone, and combinations thereof; and
a first tackifying agent.
2. The moisture curable hot melt adhesive composition of claim 1 comprising
from 10% by weight to 50% by weight isocyanate-terminated polyurethane prepolymer; and
from 1% by weight to 40% by weight clay.
3. The moisture curable hot melt adhesive composition of claim 1 comprising
from 25% by weight to 45% by weight isocyanate-terminated polyurethane prepolymer; and
from 5% by weight to 30% by weight clay.
4. The moisture curable hot melt adhesive composition of claim 1 , wherein the isocyanate-terminated polyurethane prepolymer has an NCO:OH ratio of from 5:1 to 2:1.
5. The moisture curable hot melt adhesive composition of claim 1 , wherein the isocyanate-terminated polyurethane prepolymer has an NCO:OH ratio of from 4:1 to 3:1.
6. The moisture curable hot melt adhesive composition of claim 1 comprising from 10% by weight to 20% by weight clay.
7. The moisture curable hot melt adhesive composition of claim 1 comprising from 5% by weight to 35% by weight tackifying agent.
8. The moisture curable hot melt adhesive composition of claim 1 further comprising a second tackifying agent,
the first tackifying agent comprising an aromatic hydrocarbon resin, and
the second tackifying agent comprising an alpha-methyl styrene tackifying agent.
9. The moisture curable hot melt adhesive composition of claim 1 , wherein the crystalline polyester polyol exhibits a crystallization peak temperature of at least 60° C.
10. The moisture curable hot melt adhesive composition of claim 1 , wherein the crystalline polyester polyol is derived from a diol having at least 2 carbon atoms and a diacid having from 10 to 20 carbon atoms.
11. The moisture curable hot melt adhesive composition of claim 1 , wherein the crystalline polyester polyol is derived from ethylene glycol and a diacid selected from the group consisting of tetradecanedioic acid, dodecanedioic acid, and combinations thereof.
12. The moisture curable hot melt adhesive composition of claim 1 , wherein the second thermoplastic polymer exhibits a melting point of at least 80° C.
13. The moisture curable hot melt adhesive composition of claim 1 , wherein the composition exhibits a Five Minute Overlap Shear Strength of at least 500 Newtons.
14. The moisture curable hot melt adhesive composition of claim 1 , wherein the composition exhibits a Five Minute Overlap Shear Strength of at least 600 Newtons.
15. The moisture curable hot melt adhesive composition of claim 1 , wherein the composition exhibits a High Temperature Overlap Shear Strength of at least 640 Newtons.
16. The moisture curable hot melt adhesive composition of claim 1 , wherein the composition passes the Static Load at 3 Minutes Test Method.
17. The moisture curable hot melt adhesive composition of claim 1 , wherein the composition, upon cooling from melt, exhibits a crystallization transition time of no greater than 215 seconds.
18. The moisture curable hot melt adhesive composition of claim 1 , wherein the composition, upon cooling from melt, exhibits a crystallization transition temperature of at least 45° C.
19. The moisture curable hot melt adhesive composition of claim 1 , wherein the composition exhibits at least 90% transmittance when tested according to the Fogging Test Method.
20. The moisture curable hot melt adhesive composition of claim 1 , wherein the composition exhibits 100% transmittance when tested according to the Fogging Test Method.
21. A moisture curable hot melt adhesive composition comprising:
isocyanate-terminated polyurethane prepolymer comprising the reaction product of a crystalline polyester polyol exhibiting a crystallization peak temperature of at least 55° C., a polyether polyol, and diisocyanate;
clay;
polyester/polyether thermoplastic elastomer;
a thermoplastic polymer selected from the group consisting of ethylene vinyl acetate copolymer, ethylene (alkyl)acrylate copolymer, and combinations thereof; and
a first tackifying agent.
22. An article comprising:
a first substrate;
a second substrate; and
the cured adhesive composition of claim 1 , the first substrate being bonded to the second substrate through the cured adhesive composition.
23. The article of claim 22 , wherein the first substrate comprises polycarbonate, and the second substrate comprises polypropylene.
24. A head lamp comprising:
a polycarbonate substrate;
a polypropylene substrate, and
the cured adhesive composition of claim 1 , the polycarbonate substrate being bonded to the polypropylene substrate through the cured adhesive composition.
25. The moisture curable hot melt adhesive composition of claim 21 , wherein the polyester/polyether thermoplastic elastomer has a melt flow rate no greater than 25 g/10 min when tested at 190° C. using a 2.16 kilogram weight.
26. The moisture curable hot melt adhesive composition of claim 1 , wherein the polyester/polyether thermoplastic elastomer has a melt flow rate no greater than 25 g/10 min when tested at 190° C. using a 2.16 kilogram weight.
27. The moisture curable hot melt adhesive composition of claim 1 , wherein the polyester/polyether thermoplastic elastomer has a melt flow rate no greater than 15 g/10 min when tested at 190° C. using a 2.16 kilogram weight.
28. The moisture curable hot melt adhesive composition of claim 21 further comprising a second tackifying agent,
the first tackifying agent comprising an aromatic hydrocarbon resin, and
the second tackifying agent comprising an alpha-methyl styrene tackifying agent.
29. The moisture curable hot melt adhesive composition of claim 21 comprising from 5% by weight to 30% by weight clay.