Reactive hot melt adhesive
View Patent ↗High green strength reactive hot melt adhesives are prepared using silane-functional liquid polymers. The adhesive are formulated using a silane-reactive polymer or, alternatively, a non-silane-reactive polymer together with a compatible tackifier.
1. A moisture curable hot melt adhesive composition prepared from a mixture comprising:
a silane-functional liquid polymer that is liquid at room temperature, represented by:
X—Si(C x H 2x+1 ) n (OC y H 2y+1 ) 3−n ,
wherein n=0, 1 or 2; x and y are, independently, integral numbers from 1 to 12 and X is a group that links to a silane-functional polymer backbone; and the polymer backbone is selected from polyolefin, polyacrylate, polyurethane, polyether and acrylate modified polyether; and
a silane-reactive polymer comprising silane reactive groups selected from the group consisting of carboxylic acid, amine, thiol and hydroxyl.
2. The adhesive composition of claim 1 wherein the mixture further comprises an adhesion promoter.
3. The adhesive composition of claim 2 wherein the mixture further comprises a catalyst.
4. The adhesive composition of claim 1 wherein the mixture comprises 20 to 80% by weight based on the weight of the adhesive composition of silane-functional liquid polymer, 5 to 70% by weight based on the weight of the adhesive composition of silane-reactive polymer, 0.01 to 10% by weight based on the weight of the adhesive composition of an adhesion promoter, 0.05 to 5% by weight based on the weight of the adhesive composition of a catalyst, and 0-70% by weight of adhesive composition of a tackifier.
5. The adhesive composition of claim 4 wherein the silane-reactive polymer is a solid.
6. The adhesive composition of claim 5 wherein the silane-reactive polymer is an acrylic polymer.
7. The adhesive composition of claim 1 wherein the mixture comprises 35 to 55% by weight based on the weight of the adhesive composition of silane-functional liquid polymer, the silane functional polymer backbone comprises polypropylene oxide, 20 to 40% by weight based on the weight of the adhesive composition of silane-reactive polymer comprising a solid acrylic polymer with acid functionality, 20-40% by weight based on the weight of the adhesive composition of tackifier, 0.2-3% by weight based on the weight of the adhesive composition of adhesion promoter, and 0.05-5% by weight based on the weight of the adhesive composition of catalyst.
8. A moisture curable hot melt adhesive composition prepared from a mixture comprising a silane-functional liquid polymer that is liquid at room temperature, represented by:
X—Si(C x H 2x+1 ) n (OC y H 2y+1 ) 3−n ,
wherein n=0, 1 or 2; x and y are, independently, integral numbers from 1 to 12 and X is a group that links to a silane-functional polymer backbone; and the polymer backbone is selected from polyolefin, polyacrylate, polyurethane, polyether and acrylate modified polyether;
a non-silane-reactive polymer; and
from about 10% to about 50% by weight based on the weight of the adhesive composition of a compatibilizing tackifier.
9. The adhesive composition of claim 1 wherein the silane-functional liquid polymer comprises an acrylate modified polyether backbone and the silane-reactive polymer is an acrylic polymer having silane reactive groups selected from the group consisting of carboxylic acid; hydroxyl and combinations thereof.
10. The adhesive composition of claim 1 wherein the hot melt adhesive in a solid form thereof has a phase separated morphology.
11. The adhesive composition of claim 1 providing isocyanate free moisture cure.
12. Cured reaction products of the adhesive composition of claim 1 .
13. The adhesive composition of claim 1 or 8 which has a viscosity of less than 100,000 cP at 140° C.
14. The adhesive composition of claim 8 wherein the non-silane-reactive polymer is an acrylic polymer.
15. The adhesive composition of claim 14 wherein the mixture comprises about 20% to about 40% by weight based on the weight of the adhesive composition of a compatibilizing tackifier.
16. The adhesive composition of claim 8 wherein the non-silane-reactive polymer comprises an acrylic polymer.
17. The hot melt adhesive composition of claim 8 providing isocyanate free moisture cure.
18. The adhesive composition of claim 17 wherein a solid form thereof has a phase separated morphology.
19. Cured reaction products of the adhesive composition of claim 8 .