Release coating compositions having improved release force profiles
View Patent ↗A composition containing (A) a compound having at least one aliphatic unsaturation; (B) a cyclic organohydrogen-silicon crosslinking compound containing at least one silicon-bonded hydrogen atom (Sift) per molecule, prepared by a platinum catalyzed coupling reaction of a methylhydrogen cyclosiloxane, with a reactant containing aliphatic unsaturation, hydroxy functionalities, or a mixture of both; and (B1) a linear or branched acyclic organohydrogensilicon Crosslinking compound containing at least one silicon-bonded hydrogen atom per molecule. The composition can be used to prepare release coating compositions by adding (C) a platinum group metal-containing catalyst. Release coating compositions containing Components (B) and (B1) have better cure, better adhesion, and lower release forces, than release coating compositions containing only Component (B).
1. A composition comprising:
(A) a compound having at least one aliphatic unsaturation;
(B) a cyclic organohydrogensilicon crosslinking compound containing at least one silicon-bonded hydrogen atom (SiH) per molecule, prepared by a platinum catalyzed coupling reaction of a methylhydrogen cyclosiloxane, with a reactant containing aliphatic unsaturation, hydroxy functionalities, or a mixture of both,
wherein 5-70 percent of the SiH bonds in the cyclic organohydrogensilicon crosslinking compound are replaced or converted to functional groups by adding to the coupling reaction at least one functional compound selected from the group consisting of allylglycidyl ether, vinylcyclohexylepoxide, and compounds containing propargyloxy and hexynyloxy groups; and
(B1) a linear organohydrogensilicon crosslinking compound containing at least one silicon-bonded hydrogen atom per molecule.
2. A composition according to claim 1 wherein the functional compound is allylglycidyl ether, or vinylcyclohexylepoxide.
3. A composition according to claim 2 wherein the cyclic organohydrogensilicon crosslinking compound has the structure:
and where 10-25 percent of the SiH groups has been replaced with propylglycidylether groups, x is 1-5, d is about 8, and Me is methyl.
4. A release coating composition comprising:
(A) a compound having at least one aliphatic unsaturation;
(B) a cyclic organohydrogensilicon crosslinking compound containing at least one silicon-bonded hydrogen atom (SiH) per molecule, prepared by a platinum catalyzed coupling reaction of a methylhydrogen cyclosiloxane, with a reactant containing aliphatic unsaturation, hydroxy functionalities, or a mixture of both;
wherein 5-70 percent of the SiH bonds in the cyclic organohydrogensilicon crosslinking compound are replaced or converted to functional groups by adding to the coupling reaction at least one functional compound selected from the group consisting of allylglycidyl ether, vinylcyclohexylepoxide, and compounds containing propargyloxy and hexynyloxy groups;
(B1) a linear organohydrogensilicon crosslinking compound containing at least one silicon-bonded hydrogen atom per molecule; and
(C) a platinum group metal-containing catalyst.
5. A release coating composition according to claim 4 wherein the functional compound is allylglycidyl ether or vinylcyclohexylepoxide.
6. A release coating composition according to claim 5 wherein the cyclic organohydrogensilicon crosslinking compound has the structure:
and where 10-25 percent of the SiH groups has been replaced with propylglycidylether groups, x is 1-5, d is about 8, and Me is methyl.
7. A release coating composition according to claim 4 wherein the composition further comprises one or more components selected from the group consisting of an inhibitor, a bath life extender, a release modifier, and a solvent.