Low energy surface bonding system containing a primer with long open time

• US 8,080,609 B2
• Filed: 10/29/2009
• Issued: 12/20/2011
• Est. Priority Date: 10/29/2008
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Schmatloch, Stefan
• Primary Examiner(s): NILAND, PATRICK DENNIS
• Application Number:
  US12/608,366
• Publication Number:
  US 20100105829A1
• Time in Patent Office: 782 Days
• Field of Search: 156/329, 156/331.4, 156/331.5, 156/331.7, 427/372.2, 427/385.5, 428/423.1, 524/588, 524/589, 524/590, 524/906
• US Class Current: 524/588
• 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 18/2027 having two nitrogen atoms in the ring
• CPC Class Codes: C08G 18/289 containing silicon
• CPC Class Codes: C08G 18/3206 aliphatic
• CPC Class Codes: C08G 18/3296 being in latent form
• CPC Class Codes: C08G 18/4829 Polyethers containing at least three hydroxy groups C08G18/4833 - C08G18/5096 take precedence
• CPC Class Codes: C08G 18/724 Combination of aromatic polyisocyanates with (cyclo)aliphatic polyisocyanates
• CPC Class Codes: C08G 18/755 and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate
• CPC Class Codes: C08G 18/7671 containing only one alkylene bisphenyl group
• CPC Class Codes: C08G 18/776 phosphorus
• CPC Class Codes: C08G 18/8025 Masked aliphatic or cycloaliphatic polyisocyanates
• CPC Class Codes: C08G 18/809 containing silicon
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08L 2666/20 Macromolecular compounds having nitrogen in the main chain according to C08L75/00 - C08L79/00; Derivatives thereof
• CPC Class Codes: C08L 33/08 Homopolymers or copolymers of acrylic acid esters
• CPC Class Codes: C09J 175/04 Polyurethanes
• CPC Class Codes: Y10S 524/906 Multipackage compositions
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]

Abstract

The invention is a composition comprising

a) one or more prepolymers having on average three or more aliphatic isocyanate groups and further containing alkoxysilane groups; b) one or more aromatic polyisocyanates; c) one or more compounds having at least one heterocyclic ring which hydrolyzes when exposed to moisture to form at least one isocyanate reactive group; d) one or more solvents; and e) one or more amine and/or organometallic polyurethane catalysts; wherein the ratio of aromatic isocyanate groups to aliphatic isocyanate groups in the composition is from about 0.5:1.0 to about 1.5:1.0, preferably about 0.9:1.0 to about 1.5:1.0, and the equivalent ratio of isocyanate groups to isocyanate reactive groups derivable from the one or more compounds having at least one hydrolyzable heterocylic ring is from about 0.8:1.0 to about 5.3:1.0, and most preferably about 1.5:1.0 to about 1.7:1.0.

Claims

1. A composition comprising

a) one or more prepolymers having on average three or more aliphatic isocyanate groups and further containing alkoxysilane groups;

b) one or more aromatic polyisocyanates;

c) one or more compounds having at least one heterocyclic ring which hydrolyzes when exposed to moisture to form at least one isocyanate reactive group;

d) one or more solvents;

e) one or more amine or organometallic polyurethane catalysts;

wherein the ratio of aromatic isocyanate groups to aliphatic isocyanate groups is from about 0.5;

1.0 to about 1.5;

1.0 and the equivalent ratio of isocyanate groups to isocyanate reactive groups derivable from the one or more compounds having at least one hydrolyzable heterocylic ring is from about 0.8;

1.0 to about 5.3;

1.0.

2. A composition according to claim 1 wherein the ratio of aromatic isocyanate groups to aliphatic isocyanate groups is from about 0.9:

1.0 to about 1.5;

1.0 and the equivalent ratio of isocyanate groups to isocyanate reactive groups derivable from the one or more compounds having at least one hydrolyzable heterocylic ring is from about 1.5;

1.0 to about 1.7;

1.0.

3. A composition according to claim 1 wherein the composition further comprises a film forming resin.

4. A composition according to claim 1 wherein b) the one or more aromatic polyisocyanates comprises one or more of polyisocyanates, polymeric polyisocyanates, or adducts of polyisocyanates with compounds having two or more isocyanate reactive groups.

5. A composition according to claim 4 wherein b) the one or more aromatic polyisocyanates comprises i) one or more of polyisocyanates or polymeric polyisocyanates and ii) one or more adducts of polyisocyanates with compounds having one or more isocyanate reactive groups which further contain alkoxysilane groups.

6. A composition according to claim 4 wherein the one or more adducts of polyisocyanates with compounds having one or more isocyanate reactive groups comprise the reaction product of a phosphorus containing polyisocyanate and an aminoalkylsilane containing one or more isocyanate reactive groups.

7. A composition according to claim 1 wherein the one or more compounds having at least one heterocyclic ring which hydrolyzes when exposed to moisture comprises one or more compounds containing one of more of azole groups.

8. A composition according to claim 7 wherein the one or more compounds having at least one heterocyclic ring which hydrolyzes when exposed to moisture comprises one or more compounds containing one of more of oxazolidine groups.

9. A composition according to claim 7 wherein the one or more compounds having at least one heterocyclic ring which hydrolyzes when exposed to moisture comprises one or more compounds containing one or more bis oxazolidine groups.

10. A composition according to claim 1 wherein the weight percentage of alkoxy silane groups in the composition is from about 1.0 to about 10 percent by weight based on the weight of composition.

11. A composition according to claim 1 wherein the composition further comprises one or more reinforcing fillers.

12. A composition according to claim 1 which comprises

a) from about 1 to 90 percent by weight of one or more prepolymers having on average three or more aliphatic isocyanate groups and further containing alkoxysilane groups;

b) from about 1 to about 30 percent by weight of one or more aromatic polyisocyanates;

c) from about 1 to about 10 percent by weight of one or more compounds having at least one heterocyclic ring which hydrolyzes when exposed to moisture to form at least one isocyanate reactive group;

d) from about 35 to about 85 percent by weight of one or more solvents;

e) from about 1 to about 5 percent by weight of one or more amine or organometallic polyurethane catalysts;

f) from about 0 to about 8 percent by weight of one or more film forming resins;

g) from about 0 to about 20 percent by weight of one or more pigments;

wherein the percentages are based on the total weight of the composition.

13. A composition according to claim 12 wherein component b) comprises i) from about 3 to about 15 percent by weight of i) one or more comprises one or more of polyisocyanates or polymeric polyisocyanates and from about 1 to about 7 percent by weight of ii) one or more adducts of polyisocyanates with compounds having two or more isocyanate reactive groups which further contain alkoxysilane groups.

14. A system for bonding two substrates together which comprises a composition according to claim 1 and an adhesive having one or more functional groups selected from acrylic, methacrylic, isocyanate, siloxy or mixtures thereof.

15. A method of priming a surface to enhance the bond of a polyisocyanate functional adhesive to the surface which comprises contacting a composition according to claim 1 with the surface and allowing the solvent to evaporate.

16. A method of bonding two substrates together which comprises

a) applying a composition according to claim 1 to the surface of one or more of the substrates and allowing the solvent to evaporate away;

b) applying an isocyanate functional adhesive to the surfaces of the two or more substrates to which the composition was applied according to step a);

c) contacting the two or more substrates together with the adhesive disposed between the substrates; and

d) allowing the adhesive to cure so as to bond the two or more substrates together.

17. A method according to claim 16 wherein the time between the application of the primer and application of the adhesive is from about 20 second to about 1 year.

18. A method according to claim 17 wherein after step a) one or more of the substrates are moved to another location for performance of step b).

19. An article comprising a substrate having deposited thereon the composition of claim 1.

20. An article comprising a substrate having deposited thereon the composition of claim 1 without the solvent.