Thank you Tom1953!
I do not need Rhenosin C10 anymore- we solved the problem in another way. We are located in Vienna (Austria). I am a chemist (had nothing to do with rubber just a few months ago...) and new in this business, therefore my question.
We used Rhenosin C10 as softener and homogenizing agent. Now it is not available anymore. Does someone know an acceptable replacement? It should not contain aromatic hydrocarbons.