Hydroxyl groups-terminated macromonomer grafted on polyurethane

• US 5,908,700 A
• Filed: 06/09/1997
• Issued: 06/01/1999
• Est. Priority Date: 05/10/1995
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Shimizu, Yoshinori, Everaerts, Albert I., Babu, Gaddam N.
• Primary Examiner(s): Sellers, Robert E.
• Application Number:
  US08/871,158
• Time in Patent Office: 722 Days
• Field of Search: 428/423.1, 428/424.7, 428/525, 428/425.1, 428/425.6, 428/425.8, 525/131, 526/322, 526/327, 526/329.5, 526/303.1, 526/307.7, 526/328
• US Class Current: 428/423.1
• CPC Class Codes: C08G 18/12 using two or more compounds having active hydrogen in the first polymerisation step
• CPC Class Codes: C08G 18/289 containing silicon
• CPC Class Codes: C08G 18/307 Atmospheric humidity
• CPC Class Codes: C08G 18/4063 Mixtures of compounds of group C08G18/62 with other macromolecular compounds
• CPC Class Codes: C08G 18/6245 Polymers having terminal groups containing active hydrogen
• CPC Class Codes: C08G 18/6287 Polymers of sulfur containing compounds having carbon-to-carbon double bonds
• CPC Class Codes: C08G 2170/20 Compositions for hot melt adhesives
• CPC Class Codes: C08G 2250/00 Compositions for preparing crystalline polymers
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31583 Nitrile monomer type [polyacrylonitrile, etc.]
• CPC Class Codes: Y10T 428/31591 Next to cellulosic
• CPC Class Codes: Y10T 428/31601 Quartz or glass
• CPC Class Codes: Y10T 428/31605 Next to free metal

Abstract

A moisture-curable, hot melt composition comprising a graft polyurethane prepolymer made by reacting a macromonomer, polyol, polyisocyanate and optional silane reagent is provided. The composition advantageously provides adhesives having initial creep resistance, short set times, and long open times.

Claims

1. A moisture-curable, hot melt composition comprising a graft polyurethane prepolymer having a polyurethane backbone that (1) is terminated by at least one moisture-reactive group and (2) has at least one crystalline macromonomer sidechain grafted thereto, said crystalline macromonomer sidechain derived from a crystalline macromonomer bearing a terminal moiety having two hydroxyl groups and comprising polymerized units of one or more monomers that are free from active hydrogen-containing moieties.

2. A moisture-curable, hot melt composition according to claim 1, wherein said at least one moisture-reactive group is selected from the group consisting of an isocyanate group and a silane group.

3. A moisture-curable, hot melt composition according to claim 1, wherein said graft polyurethane prepolymer comprises the reaction product of at least one polyol, at least one diisocyanate, and at least one crystalline macromonomer, wherein said polyol is crystalline.

4. A moisture-curable, hot melt composition according to claim 1 wherein said polymerized units of said crystalline macromonomer consist essentially of (meth)acrylate monomers.

5. A moisture-curable, hot melt composition according to claim 1 wherein said crystalline macromonomer exhibits a T_m in the range of from about 15°

C. to about 135°

C.

6. A moisture-curable, hot melt composition according to claim 1, wherein said crystalline macromonomer comprises polymerized units of at least one crystalline monomer, at least one low T_g monomer, and at least one high T_g monomer.

7. A moisture-curable, hot melt composition according to claim 6, wherein said crystalline monomer is selected from the group consisting of monofunctional (meth)acrylate esters of non-tertiary alcohols, the alkyl portions of which comprise from about 16 to about 50 carbon atoms, and blends thereof.

8. A moisture-curable, hot melt composition according to claim 6, wherein said low T_g monomer is selected from the group consisting of monofunctional (meth)acrylate esters of non-tertiary alkyl alcohols (the alkyl portions of which comprise 1 to about 15 carbon atoms) which provide a homopolymer having a T_g less than 5°

C., and blends thereof.

9. A moisture-curable, hot melt composition according to claim 6, wherein said high T_g monomer is selected from the group consisting of monofunctional (meth)acrylate esters of non-tertiary alcohols (the alkyl or cycloalkyl portions of which comprise from about 1 to about 15 carbon atoms) which provide a homopolymer having a T_g equal to or greater than 5°

C., acrylamides, and blends thereof.

10. A moisture-curable, hot melt composition according to claim 6, wherein said crystalline monomer is selected from the group consisting of octadecyl (meth)acrylate and behenyl (meth)acrylate.

11. A moisture-curable, hot melt composition according to claim 6, wherein said low T_g monomer is selected from the group consisting of butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate and lauryl acrylate.

12. A moisture-curable, hot melt composition according to claim 6, wherein said high T_g monomer is selected from the group consisting of isobornyl acrylate, N,N-dimethyl acrylamide, and methyl (meth)acrylate.

13. A moisture-curable, hot melt composition according to claim 1, wherein said macromonomer is amorphous.

14. A moisture-curable, hot melt composition according to claim 1 wherein said macromonomer has a theoretical T_g in the range of from about 5°

C. to about 80°

C.

15. A moisture-curable, hot melt composition according to claim 1, wherein said macromonomer comprises polymerized units of at least one low T_g monomer and at least one high T_g monomer.

16. A moisture-curable, hot melt composition according to claim 15, wherein said low T_g monomer is selected from the group consisting of monofunctional (meth)acrylate esters of non-tertiary alkyl alcohols (the alkyl portions of which comprise 1 to about 15 carbon atoms) which provide a homopolymer having a T_g less than 5°

C., and blends thereof.

17. A moisture-curable, hot melt composition according to claim 15 wherein said high T_g monomer is selected from the group consisting of monofuncional (meth)acrylate esters of non-teriary alcohols (the alkyl or cycloalkyl portions of which comprise from about 1 to about 15 carbon atoms) which provide a homopolymer having a T_g equal to or greater than 5°

C., acrylamides, and blends thereof.

18. A moisture-curable, hot melt composition according to claim 15, wherein said low T_g monomer is selected from the group consisting of butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate and lauryl acrylate.

19. A moisture-curable, hot melt composition according to claim 15, wherein said high T_g monomer is selected from the group consisting of isobornyl acrylate, N,N-dimethyl acrylamide, and methyl (meth)acrylate.

20. A moisture-curable, hot melt composition according to claim 1, wherein said composition provides an initial creep resistance less than 1 mm one minute after bond formation.

21. A moisture-curable, hot melt composition according to claim 1, wherein said composition provides a set time less than 60 seconds.

22. A moisture-curable, hot melt composition according to claim 1, wherein said composition provides an open time greater than 5 minutes.

26. Two substrates bonded together using the composition of claim 1.

27. The cured composition of claim 1.

29. A moisture-curable, hot melt composition according to claim 1, wherein said polyurethane backbone comprises crystalline segments derived from a crystalline polyol.

23. A crystalline macromonomer bearing a terminal moiety having two hydroxyl groups and comprising polymerized units of at least one crystalline monomer, at least one high T_g monomer, and optionally at least one low T_g monomer, each monomer being free from active hydrogen-containing moieties.

24. A crystalline macromonomer according to claim 23 wherein said crystalline monomer is selected from the group consisting of monofunctional (meth)acrylate esters of non-tertiary alcohols, the alkyl portions of which comprise from about 16 to about 50 carbon atoms, and blends thereof, said optional low T_g monomer is selected from the group consisting of monofunctional (meth)acrylate esters of non-tertiary alkyl alcohols (the alkyl portions of which comprise 1 to about 15 carbon atoms) which provide a homopolymer having a T_g less than 5°

C., and blends thereof, and said high T_g monomer is selected from the group consisting of monofunctional (meth)acrylate esters of non-tertiary alcohols (the alkyl or cycloalkyl portions of which comprise from about 1 to about 15 carbon atoms) which provide a homopolymer having a T_g equal to or greater than 5°

C., acrylamides, and blends thereof.

25. A crystalline macromonomer according to claim 23 wherein said crystalline monomer is selected from the group consisting of octadecyl (meth)acrylate and behenyl (meth)acrylate;

said optional low T_g monomer is selected from the group consisting of butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate; and

said high T_g monomer is selected from the group consisting of isobornyl acrylate, N,N-dimethyl acrylamide, and methyl (meth)acrylate.

28. A moisture-curable, hot melt composition comprising a graft polyurethane prepolymer having a polyurethane backbone that (1) is terminated by at least one moisture-reactive group and (2) has at least one macromonomer sidechain grafted thereto, said macromonomer sidechain derived from a macromonomer bearing a terminal moiety having two hydroxyl groups and comprising polymerized units of one or more monomers that are free from active hydrogen-containing moieties, wherein said moisture-curable, hot melt composition provides an open time greater than 5 minutes.