Batches of cross-linking agents, containing marking substances, novel cross-linkable rubber mixtures, method for the production thereof, and use of same

A crosslinking agent masterbatch configured to provide inline detectable dispersion of the masterbatch within a polymer product during production of the polymer product from the masterbatch, the masterbatch comprising:

• at least a first polymer selected from the group consisting of:
• natural rubber (NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene-isobutyiene rubber (IIR), polychloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), hydrogenated acrylonitrile-butadiene rubber (HNBR), carboxylated acrylonitrile-butadiene rubber (XNBR), hydrogenated carboxylated acrylonitrile-butadiene rubber (HXNBR), ethylene-propylene-diene rubber (EPOM), ethylene-propylene rubber (EPM), fluor( )rubber (FKM), perfluorinated fluoro rubber (FFKM), acrylate-ethylene rubber (AEM), acrylate rubber (ACM), ethylenemethylene-acrylate rubber (EMA), chlorinated polyethylene, chiorosulfonated polyethylene, ethylene-vinyl acetate rubber (EV A), ethylene-epichlorchydrin rubber (ECO), epichlorohydrin rubber (CO), and/or polyurethane rubber (PU);
• at least one pulverulent marker substance dispersed within the first polymer and configured to be inline detectable within the polymer product during processing of the masterbatch with at least one additional polymer to produce the polymer product, wherein the pulverulent marker substance is solid at temperatures of less than 130° C., has a density greater than 2 g/cm3 and is configured to be detectable by ultrasound analysis when dispersed in the polymer for inline determination of dispersion of the marker substance within the polymer, wherein the marker substance is selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, compounds of the transition groups of the periodic table of the elements, compounds of the rare earths, heavy metal powders, coated metal powders and/or compounds of these, lead compounds, inorganic bismuth compounds, metal carbides, and/or minerals selected from the group of antimonite, apatite, albite, almandine, anhydrite, aragonite, argentite, anglesite, arsenopyrite, baryte, bauxite, galena, cassisterite, cerussite, chicanite, celestine, dolomite, feldspar, fluorite, graphite, mica, ilmenite, kaolin, corundum, cryollite, corrundum, magnetite, molybdenite, muscovite, montmorilonite, monazite, magensite, pyrite, quartz, rutile, scheelite, sperrylite, strontianite, tantalite, topaz, uraninite, vanadinite, bismuth, bismuthinite, wolframite, wollastonite, willemite, wulfenite, cinnabar, and/or zircon;
• and
• at least one crosslinking agent selected from the group consisting of sulfur, peroxides, metal oxides, dithiocarbamates, thiurams, thiourea s, mercapto accelerators, sulfenamides, thiophoaphate accelerators, dithiophosphate accelerators, and/or guanidines.