MOISTURE CURABLE HOT MELT SEALANTS FOR GLASS CONSTRUCTIONS

• US 20040180155A1
• Filed: 03/13/2003
• Published: 09/16/2004
• Est. Priority Date: 03/13/2003
• Status: Active Grant

• Current Assignee: HB Fuller Company
• Original Assignee: H.B. Fuller Licensing & Financing, Inc.
• Inventors: Acevedo, Margarita, Nguyen-Misra, Mai T.
• Granted Patent: US 6,803,412 B2
• Time in Patent Office: Days
• US Class Current: 428/34
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/2825 having at least 6 carbon atoms
• CPC Class Codes: C08G 18/289 containing silicon
• CPC Class Codes: C08G 18/307 Atmospheric humidity
• CPC Class Codes: C09J 175/06 from polyesters

Abstract

A moisture curable hot melt sealant composition that includes polyurethane prepolymer having at least one of isocyanate functional groups and silane functional groups, reactive plasticizer capable of reacting with at least one of the polyurethane prepolymer and itself, and thermoplastic polymer.

Claims

1. A moisture curable hot melt sealant composition comprising:

polyurethane prepolymer comprising isocyanate functional groups, silane functional groups, or a combination thereof;

reactive plasticizer capable of reacting with at least one of said polyurethane prepolymer and itself; and

thermoplastic polymer.

2. The sealant composition of claim 1, wherein said polyurethane prepolymer comprises silane functional groups.

3. The sealant composition of claim 1, wherein said polyurethane prepolymer comprises isocyanate functional groups.

4. The sealant composition of claim 1, wherein said polyurethane prepolymer comprises the reaction product of

polyester polyol;

polyisocyanate;

monofunctional alcohol having from 12 to 20 carbon atoms; and

hydrogen active organofunctional silane.

5. The sealant composition of claim 4, wherein said hydrogen active organofunctional silane comprises amino-alkoxysilane, mercapto-alkoxysilane, or a combination thereof.

6. The sealant composition of claim 4, wherein said hydrogen active organofunctional silane comprises N-methyl-3-amino-2-methylpropyltrimethoxysilane, N-ethyl-3-amino-2-methylpropyltrimethoxysilane, N-ethyl-3-amino-2-methylpropyldiethoxysilane, N-ethyl-3-amino-2-methylpropyltriethoxysilane, N-ethyl-3-amino-2-methylpropylmethyldimethoxysilane, N-butyl-3-amino-2-methylpropyltrimethoxysilane, 3-(N-methyl-3-amino-1-methyl-1-ethoxy) propyltrimethoxysilane, N-ethyl-4-amino-3,3-dimethylbutyldimethoxymethylsilane, N-ethyl-4-amino-3,3-dimethylbutyltrimethoxysilane, bis-(3-trimethoxysilyl-2-methylpropyl)amine, N-(3′

-trimethoxysilylpropyl)-3-amino-2-methylpropyltrimethoxysilane, N-(n-butyl)aminopropyltrimethoxysilane, or a combination thereof.

7. The sealant composition of claim 4, wherein said monofunctional alcohol has from 12 to 16 carbon atoms.

8. The sealant composition of claim 1, wherein said reactive plasticizer comprises silyl-terminated polyether.

9. The sealant composition of claim 1, wherein said reactive plasticizer comprises alkoxysilyl reactive groups.

10. The sealant composition of claim 1, wherein said reactive plasticizer is selected from the group consisting of aldimines, ketimines, oxazolidines, dioxolanes, and combinations thereof

11. The sealant composition of claim 1, wherein said reactive plasticizer has a molecular weight of from about 300 g/mole to about 10,000 g/mole.

12. The sealant composition of claim 1, wherein said reactive plasticizer has a molecular weight of from about 500 g/mole to about 6,000 g/mole.

13. The sealant composition of claim 1, comprising

from about 5% by weight to about 50% by weight said polyurethane prepolymer,

from no greater than 20% by weight said reactive plasticizer, and

from about 5% by weight to about 80% by weight said thermoplastic polymer.

14. The sealant composition of claim 1, comprising

from about 10% by weight to about 40% by weight said polyurethane prepolymer,

from about 2% by weight to about 15% by weight said reactive plasticizer, and

from about 10% by weight to about 70% by weight said thermoplastic polymer.

15. The sealant composition of claim 1, comprising

from about 15% by weight to about 35% by weight said polyurethane prepolymer,

from about 3% by weight to about 10% by weight said reactive plasticizer, and

from about 15% by weight to about 60% by weight said thermoplastic polymer.

16. The sealant composition of claim 1, wherein said composition exhibits an initial lap shear of at least 10 psi.

17. The sealant composition of claim 1, wherein said composition exhibits an open time of at least 60 seconds.

18. The sealant composition of claim 1, wherein said composition exhibits a softening temperature of no greater than 50°

C.

19. The sealant composition of claim 1, wherein said sealant composition exhibits a glass transition temperature of less than −

5°

C.

20. The sealant composition of claim 1, wherein said sealant composition exhibits a glass transition temperature of less than −

25°

C.

21. The sealant composition of claim 1, wherein said composition exhibits a viscosity of from about 150,000 centipoise to about 400,000 centipoise at 230°

F.

22. The sealant composition of claim 1, wherein said composition exhibits a lap shear of at least 80 psi after three weeks at 23°

C. and 50% relative humidity.

23. The sealant composition of claim 1, wherein said composition, after cure, exhibits an elongation of at least 200%.

24. The sealant composition of claim 1, wherein said composition, after cure, exhibits a tensile strength of at least 100 psi.

25. The sealant composition of claim 1, wherein said composition, after cure, exhibits a modulus at 100% elongation of no greater than 300 psi.

26. The sealant composition of claim 1, wherein said composition, when in the form of a cured 60 mil film, exhibits a moisture vapor transmission rate no greater than 10 g/m²/day.

27. The sealant composition of claim 1 further comprising tackifying agent.

28. The sealant composition of claim 1 further comprising non-reactive plasticizer.

29. The sealant composition of claim 1 further comprising silane adhesion promoter.

30. The sealant composition of claim 1, wherein said thermoplastic polymer comprises ethylene vinyl acetate.

31. The sealant composition of claim 1, wherein said thermoplastic polymer is selected from the group consisting of polyolefins, polyalphaolefins, polyesters, polyacrylates, polymethacrylates, polyacrylamides, polyacrylonitriles, polyimides, polyamides, copolymers of vinyl alcohol and ethylenically unsaturated monomers, polyvinyl chloride, polysiloxanes, polyurethanes, polystyrene, and combinations thereof.

32. The sealant composition of claim 1, wherein said thermoplastic polymer comprises thermoplastic elastomer selected from the group consisting of polyetheramide copolymers, styrene-butadiene copolymers, styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, styrene-ethylene-butylene-styrene copolymers, styrene-ethylene-propylene-styrene copolymers, butyl rubber, polyisobutylene, isobutylene-isoprene copolymers, and combinations thereof.

33. A multipane glass assembly comprising:

a first glass pane;

a second glass pane;

a spacer; and

a sealant composition comprising the reaction product of a moisture curable hot melt sealant composition comprising

polyurethane prepolymer comprising isocyanate functional groups, silane functional groups, or a combination thereof;

reactive plasticizer capable of reacting with at least one of said polyurethane prepolymer and itself; and

thermoplastic polymer,

said first glass pane and said second glass pane bonded to said spacer through said sealant composition.

34. A multipane glass assembly comprising:

an insulating glass unit comprising

a first glass pane;

a second glass pane;

a spacer; and

a first sealant composition, said first glass pane being bonded to a first surface of said spacer through said first sealant composition, said second glass pane being bonded to a second surface of said spacer through said first sealant composition;

a frame; and

a second sealant composition, said insulating glass unit being bonded to said frame through said second sealant composition, said second sealant composition comprising a moisture cured sealant composition comprising the reaction product of

polyurethane prepolymer comprising isocyanate functional groups, silane functional groups, or a combination thereof;

reactive plasticizer capable of reacting with at least one of said polyurethane prepolymer and itself; and

thermoplastic polymer.

35. A polyurethane prepolymer comprising the reaction product of

polyester polyol;

polyisocyanate; and

monofunctional alkyl alcohol having from 12 to 16 carbon atoms.

36. The polyurethane prepolymer of claim 35, wherein the reactants further comprise hydrogen active organofunctional silane.

37. The prepolymer of claim 35, wherein said polyol is amorphous.

38. The prepolymer of claim 35, wherein said polyol has a glass transition temperature less than 0°

C.

39. The prepolymer of claim 35, wherein said polyol is hydrophobic.

40. A moisture curable hot melt sealant composition comprising:

moisture curable polymer;

reactive plasticizer capable of reacting with at least one of said moisture curable polymer and itself; and

thermoplastic polymer.