| The products of the Catalyst 500 series are diluted solutions of a highly reactive platinum complex in different media. Evonik Hanse GmbH offers two different complexes: the divinyl tetramethyl disiloxaneplatinum(0)-complex and the methyl vinyl cyclosiloxane-platinum(0)-complex. The media offered include Polymer VS, divinyl tetramethyl disiloxane (DVS) and methyl vinyl cyclosiloxane (MVC). Application: The platinum complexes are highly efficient even in very small quantities so that typically, only 10 to 20 ppm of platinum are used in formulations. Increasing the concentration leads to higher crosslinking rates and thus to shorter pot lives. It should be observed that the complexes react sensitively to a number of substances (e. g. sulphur, heavy metal and amino compounds, some PU and PVC types). Contact with such substances shall be avoided both while producing the formulation and while the product cures. If the application imperatively requires for such a contact (e. g. curing in a PU mold), the catalyst loss can be compensated by an increased feedstock concentration of up to approx. 100 ppm. Especially the products Catalyst 517 and 520 are suited for this purpose because they prevent uncontrolled increase of the crosslinking rate due to the inhibiting media DVS and MVC. Information provided by Evonik |
