Silane modified polymers with improved characteristics for adhesive compositions
Disclosed are silane modified copolymers that are moisture curable; curable adhesive compositions comprising the silane modified copolymers; and methods of making the silane modified copolymers.
1. A silane modified copolymer that is the reaction product of an aminosilane and an isocyanate functional copolymer, wherein the isocyanate functional copolymer is the reaction product of a polyether polyol having a number average molecular weight greater than 6000 and an amine based diol containing secondary hydroxyl groups and a cycloaliphatic diisocyanate.
2. The silane modified copolymer of claim 1 wherein said aminosilane comprises at least one secondary amine function and alkoxy functional groups attached to at least one silicon atom.
3. The silane modified copolymer of claim 1 wherein said aminosilane is bipodal and comprises at least one secondary amine function and alkoxy functional groups attached to its silicon atoms.
4. The silane modified copolymer of claim 1 wherein said amine based diol containing secondary hydroxyl groups has a number average molecular weight of less than 6,000, and at least one tertiary amine group.
5. The silane modified copolymer of claim 1 wherein said amine based diol containing secondary hydroxyl groups is present in a positive amount of less than 50 wt. % based on a total combined weight of said amine-based diol polyether polyol.
6. The silane modified copolymer of claim 1 wherein said polyether polyol is present in an amount of greater than 50 wt. % based on a total combined weight of said amine-based diol and said polyether polyol.
7. A composition comprising the silane modified copolymer of claim 1 and further comprising an isocyanate functional reaction product of a polyether polyol having a molecular weight greater than 6000 and a cycloaliphatic diisocyanate.
8. A composition comprising the silane modified copolymer of claim 1 and further comprising an isocyanate functional reaction product of a polyether polyol having a molecular weight greater than 6000 and a cycloaliphatic diisocyanate, and an isocyanate functional reaction product of an amine based diol containing secondary hydroxyl groups and a cycloaliphatic diisocyanate.
9. An adhesive composition comprising the silane modified copolymer of claim 1 .
10. A moisture curable adhesive composition comprising the silane modified copolymer of claim 1 and a silane modified polymer having a structure different from the silane modified copolymer.
11. A moisture curable adhesive composition comprising the silane modified copolymer of claim 1 and a hydrolysable siloxane oligomer.
12. A method of forming an adhesive comprising the steps of:
a) forming a mixture of different isocyanate terminated prepolymers by reacting a mixture of an amine based diol containing secondary hydroxyl groups, a polyether polyol having a number average molecular weight greater than 6000 and a cycloaliphatic diisocyanate, optionally in the presence of a urethane catalyst; and
b) reacting the mixture of different urethane terminated prepolymers of step a) with at least one aminosilane, thereby forming an adhesive additive comprising silane terminated copolymers.
13. The method according to claim 12 wherein step a) comprises providing as the amine based diol containing secondary hydroxyl groups an amine-based polyether polyol having a number average molecular weight of less than 6,000, at least one tertiary amine group and a functionality of 2 or greater.
14. The method according to claim 12 wherein step a) comprises providing the amine based diol containing secondary hydroxyl groups in a positive amount of less than 50 wt. % based on a total combined weight of the amine based diol containing secondary hydroxyl groups and the polyether polyol having a molecular weight greater than 6000.
15. The method as recited in claim 12 wherein the amino silane is step b) is bipodal.