| 主权项 |
1. Process for improving the water repellency of a substrate by treating it with an emulsion having a Volatile Organic Content according to ASTM 5095 below 50 g/l which includes water, at least one surfactant, and a siloxane copolymer obtained by the process of
Reacting (i) 1-octene (ii) a cyclic siloxane having the formula: wherein R is methyl; and c is between 4 and 6,
in the presence of a platinum catalyst so as to form a cyclic copolymer having the formula: where R′ is octenyl, a is less than 3 and b is equal to or greater than 2, a+b=c; Removing the unreacted alkene and volatile cyclic siloxanes from the reaction mixture and where the molar ratio alkene:cyclic siloxanes is ≧1.5, wherein the substrate comprises at least one of regular concrete, high strength concrete, stamped concrete, high performance concrete, self consolidating concrete, shotcrete, cellular concrete, lightweight aerated concrete, variable density concrete, foamed concrete, lightweight or ultra-lightweight concrete, rapid strength concrete, pre-stressed concrete or reinforced concrete for use in pavements, highways/roadways, bridges/overpasses, parking structures, stadiums, precast structures, tilt up structures, drainage pipes, tunnels or reservoir structures, concrete masonry units, concrete blocks, split faced blocks, natural stone or bricks for use on building facades or foundations. |
