Composition containing anti-misting component of reduced molecular weight and viscosity
The invention relates to compositions comprising (I) a silicone-based coating component susceptible to misting under mist-producing conditions; and (II) an anti-misting amount of at least one branched polysiloxane of reduced molecular weight and viscosity. The invention also relates to a process for coating a substrate with the above coating formulation, as well as hardened silicone-based coatings or films produced by subjecting the coated substrate to one or more curing steps.
1 . A composition comprising:
(I) a silicone-based coating component susceptible to misting under mist-producing conditions; and
(II) an anti-misting amount of a branched polysiloxane composition of reduced molecular weight and viscosity which comprises at least one member selected from the group consisting of:
i) branched fragmented pplyorganosiloxane, the polysiloxane resulting from reacting under hydrosilylation reaction conditions a mixture comprising:
a) at least one compound containing on average at least two unsaturated sites per molecule, and
b) at least one polyorganosiloxane containing on average at least two silylhydride functional groups per molecule,
provided, that at least one of (a) and/or (b) is fragmented by shearing prior to and/or during the hydrosilylation reaction and/or the polyorganosiloxane resulting from the hydrosilylation reaction is fragmented by shearing to provide the branched fragmented polyorganosiloxane;
ii) branched fragmented polyorganosiloxane, the polysiloxane resulting from equilibrating under equilibration conditions at least two polyoganosiloxanes selected from the group consisting of cyclic, linear and branched polyorganosiloxanes, provided, that at least one polyorganosiloxane is fragmented by shearing prior to and/or during equilibrating and/or the polyorganosiloxane resulting from equilibration is fragmented by shearing to provide the branched fragmented polyorganosiloxane; and,
iii) branched fragmented polyorganosiloxane, the polysiloxane resulting from copolymerization under condensation conditions of at least one polyorganosiloxane containing at least two functional groups, provided, that at least one polyorganosiloxane is fragmented by shearing prior to and/or during copolymerization and/or the polyorganosiloxane resulting from copolymerization is fragmented by shearing to provide the branched fragmented polyorganosiloxane.
2 . The composition of claim 1 wherein compound (a) is at least one polyorganosiloxane containing on average at least two unsaturated sites per molecule.
3 . The composition of claim 1 wherein branched fragmented polyorganosiloxane iii) results from copolymerization under condensation conditions of at least one polyorganosiloxane containing at least two functional groups and at least one compound with at least two functional groups, provided, that at least one polyorganosiloxane and/or compound is fragmented by shearing prior to and/or during copolymerization and/or the copolymerized polyorganosiloxane is fragmented by shearing to provide the branched fragmented polyorganosiloxane.
4 . The composition of claim 1 wherein at least one of compound (a) or polyorganosiloxane (b) contains at least six functional groups per molecule.
5 . The composition of claim 3 wherein at least one of the polyorganosiloxane or compound contains at least six functional groups per molecule.
6 . The composition of claim 1 wherein at least one of compound (a) or polyorganosiloxane (b) has more functional groups than the other and is present in a molar amount equal to or lower than the molar amount of the other.
7 . The composition of claim 3 wherein at least one of the polyorganosiloxane or compound has more functional groups than the other and is present in a molar amount equal to or lower than the molar amount of the other.
8 . The composition of claim 1 wherein the unsaturated sites of (a) are in a molar ratio to silylhydride functional groups of (b) within a range of about (6-s):1 or about 1 :(1+t) where s represents a number equal to or greater than 0 and less than 5, and t represents a number greater than 0 and equal to or less than 5.
9 . The composition of claim 3 wherein the functional groups of the polyorganosiloxane are in a molar ratio to the functional groups of the compound within a range of about (6-s):1 or about 1(1+t) where s represents a number equal to or greater than 0 and less than 5, and t represents a number greater than 0 and equal to or less than 5.
10 . The composition of claim 1 wherein the unsaturated sites of (a) are in a molar ratio to silylhydride functional groups of (b) within a range according to a formula (4.6-s):1 or 1:(1+s) where s represents a number greater than 0 and less than 3.6.
11 . The composition of claim 3 wherein the functional groups of polyorganosiloxane are in a molar ratio to the functional groups of the compound within a range according to a formula (4.6-s):1 or 1:(1+s) where s represents a number greater than 0 and less than 3.6.
12 . The composition of claim 1 wherein the unsaturated sites of (a) are in a molar ratio to silylhydride functional groups of (b) within a range according to a formula (4.25-s):1 or 1:(1+t) where s represents a number equal to or greater than 0 and less than 3.25, and t represents a number greater than 0 and equal to or less than 3.25.
13 . The composition of claim 3 wherein the functional groups of polyorganosiloxane are in a molar ratio to the functional groups of the compound within a range according to a formula (4.25-s):1 or 1:(1+t) where s represents a number equal to or greater than 0 and less than 3.25, and t represents a number greater than 0 and equal to or less than 3.25.
14 . The composition of claim 1 wherein the unsaturated sites of (a) are in a molar ratio to silylhydride functional groups of (b) within a range according to a formula (4.6-s):1 where s represents a number greater than 0 and less than 3.6.
15 . The composition of claim 3 wherein the functional groups of polyorganosiloxane are in a molar ratio to the functional groups of the compound within a range according to a formula (4.6-s):1 where s represents a number greater than 0 and less than 3.6.
16 . The composition of claim 1 wherein the unsaturated sites of (a) are in a molar ratio to silylhydride functional groups of (b) within a range of about 4.5:1 to about 2:1.
17 . The composition of claim 3 wherein the functional groups of polyorganosiloxane are in a molar ratio to the functional groups of the compound within a range of about 4.5:1 to about 2:1.
18 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 1 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
19 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 2 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
20 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 3 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
21 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 4 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
22 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 5 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
23 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 6 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
24 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 7 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
25 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 8 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
26 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 9 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
27 . A coating process comprising applying to a substrate under mist-producing conditions the composition of claim 10 , the composition exhibiting reduced misting when subjected to said mist-producing conditions as compared to the same composition lacking an anti-misting amount of branched polysiloxane composition of reduced molecular weight and viscosity.
28 . A hardened silicone-based coating or film produced by subjecting a substrate coated with the composition of claim 1 to one or more curing steps.