Silylated polyurethanes and methods for preparing thereof
The present invention discloses silylated polyurethanes obtainable by reacting at least one polyols, at least one polyisocyanates, at least one silicon-containing heterocycle of the general formula (I): wherein R 1 is hydrogen; R 2 and R 3 are same or different and are, independently from one another, selected from a linear or branched, substituted or unsubstituted C 1 -C 20 alkyl or C 6 -C 18 aryl residue which may be interrupted by at least one heteroatom; R 4 is selected from a linear or branched, substituted or unsubstituted C 1 -C 20 alkylene residue which may be interrupted by at least one heteroatom; R 5 and R 6 are same or different and are, independently from one another, selected from the group consisting of hydrogen, a linear or branched, substituted or unsubstituted C 1 -C 20 alkyl or C 6 -C 18 aryl which may be interrupted by at least one heteroatom, and a C 4 -C 8 cycloalkyl, or R 5 and R 6 may form a ring, preferably a 4- to 8-membered alkyl ring; and n is 0, 1 or 2, their preparation methods, curable compositions comprising the silylated polyurethanes, and their use as adhesive, sealant, spray foam and/or coating.
1. A silylated polyurethane that is the reaction product of:
a) at least one polyol having a number average molecular weight of from 1000 to 50,000 g/mol;
b) at least one polyisocyanate; and
c) at least one silicon-containing heterocycle of the general formula (I)
wherein R 1 is hydrogen;
R 2 and R 3 are same or different and are, independently from one another, selected from a linear or branched, substituted or unsubstituted C 1 -C 20 alkyl or C 6 -C 18 aryl residue which may be interrupted by at least one heteroatom;
R 4 is selected from a linear or branched, substituted or unsubstituted C 1 -C 20 alkylene residue which may be interrupted by at least one heteroatom;
R 5 and R 6 are same or different and are, independently from one another, selected from the group consisting of hydrogen, a linear or branched, substituted or unsubstituted C 1 -C 20 alkyl or C 6 -C 18 aryl which may be interrupted by at least one heteroatom, a C 4 -C 8 cycloalkyl, or R 5 and R 6 may form a ring; and
n is 0, 1 or 2.
2. The silylated polyurethane according to claim 1 , wherein the silicon-containing heterocycle of the general formula (I) is the product of a one-step reaction of at least one epoxide compound of the general formula (II)
wherein R 5 and R 6 are the same as defined for the general formula (I) above, and
at least one aminoalkoxysilane having a primary amino group in the presence of a catalyst.
3. The silylated polyurethane according to claim 2 , wherein the aminoalkoxysilane has the general formula (III)
wherein R 1 to R 4 are the same as defined for the general formula (I); and n is 0, 1, 2 or 3.
4. The silylated polyurethane according to claim 1 , wherein n in general formula (III) is 3.
5. The silylated polyurethane according to claim 1 , wherein the polyol is a polyether polyol.
6. The silylated polyurethane according to claim 1 , wherein n in the general formula (I) is 2.
7. The silylated polyurethane according to claim 1 , wherein R 3 is selected from a C 1 -C 8 alkyl residue.
8. Cured reaction products of the silylated polyurethane according to claim 1 .
9. A curable composition comprising the silylated polyurethane according to claim 1 .
10. A curable composition comprising the silylated polyurethane according to claim 1 and further comprising at least one component selected from plasticizers, stabilizers, antioxidants, fillers, reactive diluents, drying agents, adhesion promoters, UV stabilizers, rheological agents, solvents and mixtures thereof.
11. An adhesive, sealant, foam and/or coating comprising the curable composition according to claim 10 .
12. A method for preparing a silylated polyurethane by reacting:
a) at least one polyol having a number average molecular weight of from 1000 to 50,000 g/mol;
b) at least one polyisocyanate; and
c) at least one silicon-containing heterocycle of the general formula (I)
wherein R 1 is hydrogen;
R 2 and R 3 are same or different and are, independently from one another, selected from a linear or branched, substituted or unsubstituted C 1 -C 20 alkyl or C 6 -C 18 aryl residue which may be interrupted by at least one heteroatom;
R 4 is selected from a linear or branched, substituted or unsubstituted C 1 -C 20 alkylene residue which may be interrupted by at least one heteroatom;
R 5 and R 6 are same or different and are, independently from one another, selected from the group consisting of hydrogen, a linear or branched, substituted or unsubstituted C 1 -C 20 alkyl or C 6 -C 18 aryl which may be interrupted by at least one heteroatom, and a C 4 -C 8 cycloalkyl, or R 5 and R 6 may form a ring; and
n is 0, 1 or 2.
13. The method of claim 12 , wherein the polyisocyanate is a diisocyanate.
14. The method of claim 12 , wherein R 5 and R 6 form a 4- to 8-membered alkyl ring.
15. The method of claim 12 , wherein n is 2.
16. The method of claim 12 , wherein R 3 is selected from methyl, ethyl or n-propyl.
17. The method of claim 12 , wherein the silylated polyurethane is prepared by:
(a) reacting the at least one polyol having a number average molecular weight of from 1000 to 50,000 g/mol with the at least one polyisocyanate, with a stoichiometric excess of the NCO group of the polyisocyanate(s) with respect to the OH group of the polyol(s) to form a NCO-terminated polyurethane prepolymer; and
(b) reacting said NCO-terminated polyurethane prepolymer with the at least one silicon-containing heterocycle of the general formula (I)
18. The silylated polyurethane according to claim 17 , wherein a molar ratio of the NCO group of the polyisocyanate(s) to the OH group of the polyol(s) is from 1.01 to 2.0.
19. The method of claim 12 wherein the silylated polyurethane is prepared by:
(a) reacting the at least one polyisocyanate with the at least one silicon-containing heterocycle of the general formula (I)
with a stoichiometric excess of the NCO group of the polyisocyanate(s) with respect to the amino group of the silicon-containing heterocycle(s) of the general formula (I); and
(b) reacting the reaction product obtained in step (a) with the at least one polyol having a number average molecular weight of from 1000 to 50,000 g/mol.
20. The silylated polyurethane according to claim 19 , wherein a molar ratio of the NCO group of the polyisocyanate(s) to the amino group of the silicon-containing heterocycle(s) of the general formula (I) is from 1.1 to 3.0.