WACKER^® CATALYST C 05

WACKER^® CATALYST C 05 is dissolved in a reactive silicone polymer, which is incorporated into the cured rubber during the curing process. Combined with DEHESIVE® silicone polymers, it is excellently suited for providing various substrates, such as paper and films, with a silicone coating that exhibits release properties towards tacky products used in technical, health, hygiene and food sectors.

Processing:

WACKER^® CATALYST C 05 must be added to the mixture of DEHESIVE®, CRA® modifier and crosslinker. During addition, stirring should be as rapid as possible to avoid local over-concentrations of the platinum catalyst, which cause premature curing indicated by formation of gel particles ranging in color from brown to black. It is also important that the platinum catalyst is always added as the last component to the homogeneous mixture of polymer and crosslinker.

Its relatively low platinum content means that WACKER^® CATALYST C 05 is ideally suited for the use in automated mixing and metering equipment. Furthermore, problems with gelation are easier to keep under control when WACKER^® CATALYST C 05 is employed. Before switching from concentrated to diluted catalysts and vice versa, lab tests must be carried out to make sure that this will have no effect on the release values.

WACKER^® CATALYST C 05 contains a considerable amount of a reactive silicone polymer as solvent for the platinum complex. This must be taken into account when WACKER^® CATALYST C 05 is used in formulations containing CRA® modifier (e.g. when increasing or decreasing the amount of WACKER^® CATALYST C 05 in the formulation). The release force for the cured silicone coating will remain constant as long as the percentage of CRA® modifier does not change.

Suitable materials for mixing vessels, stirrers, pumps, tubes, filters, etc. are stainless steel, polyethylene, polypropylene, Teflon and other fluorine polymers, as well as products coated or lined with these materials. If good catalyst activity is to be maintained, it is essential to avoid deactivation of the platinum catalyst. This may occur as a result of contact with the abovementioned equipment, with the ambient air, with unsuitable rolls in the coating equipment, with the customer's additives, or even with the substrate to be coated. If heavy metals (e.g. lead, copper, zinc, iron, chromium or tin) or sulfurous, nitrogenous or phosphorous organic compounds are present in any of the above materials, curing may be impaired or even prevented.