| abstract |
The invention relates to crosslinkable or crosslinked silicone compositions capable of being used to form a water-repellent and release coating for a flexible support made of paper or of polymer, in particular that is heat-sensitive. These compositions are of the type of those comprising crosslinking polyorganosiloxanes (POSs) bearing =Si-H units and unsaturated, preferably =Si-Vi, vinyl-containing POSs, capable of reacting with the crosslinker by polyaddition, in the presence of platinum in order to form the crosslinked release coating on the flexible support. The targeted objective is to enable the coating composition to crosslink instantaneously in order to produce, on all types of flexible supports (paper, e.g. glassine, or polymer, e.g. polyester such as polyethylene terephthalate PET), a crosslinked silicone coating endowed, in particular, on leaving the coating machine, with excellent attachment (adhesion) and mechanical strength or cohesion - "Rub-off" - properties. In order to achieve this objective, the invention proposes the use, per 100 parts by weight of silicone base, of 1 to 40 parts by weight of an additive comprising from 1 or 5 to 80% by weight of particulate filler, preferably nanoscale filler, in a silicone oil capable of reacting with the crosslinker. The supports and the high-speed coating processes are targeted. Applications: silicone release coatings obtained by crosslinking/polyaddition for flexible supports. |