The present invention relates to a curable rubber composition comprising at least one halobutyl rubber, at least one curing agent, which is suitable for curing the at least one halobutyl rubber and which comprises at least one of
sulfur, amines, phenolic resins, hydroquinones and peroxides, and at least one
lignin-based filler F1, which is different from
carbon black, and which has an STSA surface area of up to 200 m² / g, wherein the curable rubber composition comprises no or less than 0.45 phr 2,2'- dibenzothiazolyl disulfide (MBTS), and wherein the total amount of any organic constituents of the curable rubber composition, which are suitable to retard the t90
curing time, including 2,2'-dibenzothiazolyl disulfide, and which are different from the at least one curing agent and the at least one halobutyl rubber and the at least one
lignin-based filler F1, is less than 1.85 phr, a kit-of-parts comprising the rubber composition in spatially separated form, a cured rubber composition obtainable from said curable rubber composition, a use of the aforementioned compositions for manufacturing articles, parts and / or components, thereby obtained articles, parts and / or components, and a process for preparing said article, part and / or component.