Metathesis-curable composition with a reaction control agent
View Patent ↗A composition curable by a metathesis reaction upon mixing its components and comprising an olefin-containing substrate, a metathesis catalyst, and a reaction control agent for slowing the progress of the metathesis reaction. The metathesis catalyst is a ruthenium or osmium carbene complex catalyst having high activity and good air stability. In one embodiment, the catalyst is free of phosphine ligands. The reaction control agent is an organic compound that contains carbon-carbon double and/or triple bonds and one or more Group 14 atoms and is present in an amount effective to slow the progress of the metathesis reaction. In one embodiment, the olefin-containing substrate may comprise one or more oligomers or polymers having a >20 wt. % linear siloxane (Si—O—Si) backbone tethered and/or end-capped with functional olefin groups, such as cycloalkenyl group.
1. A composition capable of undergoing a metathesis reaction upon mixing its components, the components comprising:
an olefin-containing substrate capable of undergoing a metathesis reaction;
a carbene complex catalyst capable of initiating the metathesis reaction in the composition, wherein the catalyst has the structure:
wherein:
M is ruthenium or osmium,
X is an alkylidene ligand with basicity higher than that of tricyclohexylphosphine (PCy 3 ),
Z is oxygen (O) or sulfur (S)
X 2 and X 3 are either the same or different and are any anionic ligand, and
R 4 , R 5 , a, b, c, and d are the same or different and are each a linear, branched, cyclic or polycyclic organic residue optionally containing siloxane groups (Si—O—Si) and optionally containing heteroatoms selected from the group consisting of B, N, O, Si, P, and S; and
at least one reaction control agent for slowing the progress of the metathesis reaction after mixing the composition components and having the structure:
wherein:
G is selected from the group consisting of: L 3 ,
L is a hydrocarbon fragment containing a double or triple bond,
L 1 -L 9 are each independently selected from the group consisting of L, alkyl, aryl, aralkyl or haloalkyl,
A is a Group 14 atom,
n=0-20, and
m=0-20.
2. The composition of claim 1 wherein M is ruthenium; X is 1,3-bis(2,4,6-trimethylphenyl)-imidazol-2-ylidene; X 2 and X 3 are chlorine atoms; Z is oxygen; R 4 is isopropyl, ethyl or methyl; a, b, c, and d are each either hydrogen, ethoxy or methoxy; and R 5 is hydrogen.
3. The composition of claim 1 wherein the X has the structure:
wherein Mes is mesityl and R′ is hydrogen or phenyl.
4. The composition of claim 1 wherein the X has the structure:
wherein Mes is mesityl.
5. The composition of claim 1 wherein the catalyst is free of phosphines.
6. The composition of claim 1 wherein L is a hydrocarbon fragment containing an allyl group, a vinyl group, an ethynyl group or a propargyl group.
7. The composition of claim 1 wherein A is silicon.
8. The composition of claim 1 wherein the at least one reaction control agent includes tetraallyl silane or tetraallyloxysilane.
9. The composition of claim 1 wherein the olefin-containing substrate includes at least one oligomer or polymer having a >20 wt. % linear siloxane (Si—O—Si) backbone functionalized with cycloalkenyl groups capable of undergoing a metathesis reaction.
10. A composition capable of undergoing a metathesis reaction upon mixing of its components, the components comprising:
an olefin-containing substrate comprising at least one oligomer or polymer having a >20 wt. % linear siloxane (Si—O—Si) backbone functionalized with olefin groups capable of undergoing a metathesis reaction, wherein the at least one oligomer or polymer is selected from the group consisting of: a telechelic oligomer or polymer end-capped with the olefin groups, an oligomer or polymer tethered and end-capped with the olefin groups, a tri-functional oligomer or polymer end-capped with the olefin groups, and a quadri-functional oligomer or polymer end-capped with the olefin groups;
a ruthenium carbene complex catalyst capable of initiating the metathesis reaction in the composition, wherein the catalyst has the formula:
wherein:
M is ruthenium or osmium,
X is an alkylidene ligand with basicity higher than that of tricyclohexylphosphine (PCy 3 ),
Z is oxygen (O) or sulfur (S)
X 2 and X 3 are either the same or different and are any anionic ligand, and
R 4 , R 5 , a, b, c, and d are the same or different and are each a linear, branched, cyclic or polycyclic organic residue optionally containing siloxane groups (Si—O—Si) and optionally containing heteroatoms selected from the group consisting of B, N, O, Si, P, and S; and
at least one reaction control agent for slowing the progress of the metathesis reaction after mixing the composition components and having the structure:
wherein:
G is selected from the group consisting of: L 3 ,
L is a hydrocarbon fragment containing an allyl group, a vinyl group, an ethynyl group or a propargyl group,
L 1 -L 9 are each independently selected from the group consisting of L, alkyl, aryl, aralkyl or haloalkyl,
A is a Group 14 atom,
n=0-20, and
m=0-20.
11. The composition of claim 10 wherein the olefin groups are norbomenyl groups or norbornenylethyl groups.
12. The composition of claim 10 wherein the olefin-containing substrate includes polydimethylsiloxane tethered and end-capped with norbornenylethyl groups and having the formula:
where n=5-5000, and m=1-100.
13. The composition of claim 10 wherein the olefin-containing substrate includes telechelic polydimethylsiloxane end-functionalized with norbornenylethyl groups and having the formula:
wherein n=5-5000.
14. The composition of claim 10 wherein M is ruthenium; X is 1,3-bis(2,4,6-trimethylphenyl)-imidazol-2-ylidene; X 2 and X 3 are chlorine atoms; Z is oxygen; R 4 is isopropyl, ethyl or methyl; a, b, c and d are each either hydrogen, ethoxy or methoxy; and R 5 is hydrogen.
15. The composition of claim 10 wherein the X has the structure:
wherein Mes is mesityl and R′ is hydrogen or phenyl.
16. The composition of claim 10 wherein the X has the structure:
wherein Mes is mesityl.
17. The composition of claim 10 wherein the catalyst is free of phosphines.
18. The composition of claim 10 wherein L is a hydrocarbon fragment containing an allyl group, a vinyl group, an ethynyl group or a propargyl group.
19. The composition of claim 10 wherein A is silicon.
20. The composition of claim 10 wherein the at least one reaction control agent includes tetraallyl silane or tetraallyloxysilane.
21. A curable composition comprising:
an olefin-containing substrate comprising at least one oligomer or polymer having a >20 wt. % linear siloxane (Si—O—Si) backbone functionalized with cycloalkenyl groups capable of undergoing a metathesis reaction;
a ruthenium carbene complex catalyst capable of initiating the metathesis reaction in the composition, wherein the catalyst has the structure:
wherein R 4 is isopropyl, ethyl or methyl, and c is hydrogen, methoxy or ethoxy; and
a reaction control agent for slowing the progress of the metathesis reaction, wherein the reaction control agent is tetraallyl silane or tetraallyloxysilane.
22. The composition of claim 21 wherein the cycloalkenyl groups are norbornenyl groups or norbornenylethyl groups.
23. The composition of claim 21 wherein the olefin-containing substrate includes polydimethylsiloxane tethered and end-capped with norbornenylethyl groups and having the formula:
where n=5-5000, and m=1-100.
24. The composition of claim 21 wherein the olefin-containing substrate includes telechelic polydimethylsiloxane end-functionalized with norbornenylethyl groups and having the formula:
wherein n=5-5000.