Waterproofing membrane composition, process for manufacturing said composition and uses thereof

A waterproofing membrane composition comprising active membrane compounds containing:

• polyvinyl butyral (PVB);
• polymer modified bitumen, where the polymer of the polymer modified bitumen forms a polymeric matrix wherein bitumen and PVB are retained;
• and
• at least one compatibilizing agent selected from the group consisting of
• a succinate mixed ester of benzyl and of branched nonyl or decyl;
• a bis(ethoxylated alkyl) succinate;
• and
• a composition comprising aliphatic polycarboxylic acid esters of formula:
• R′—X—[O—C(O)—R]n
• wherein
• R is selected from the group consisting of epoxidized oleic, epoxidized linoleic, and epoxidized linolenic acid and mixtures thereof, or R is R1 being a tetrahydrofurfuryl group, or a substituted tetrahydrofurfuryl group, or R is R2 being an alkoxylated alkyl group, or a substituted alkoxylated alkyl group, different from R1;
• R′ is a methyl group when R is selected from the group consisting of epoxidized oleic, linoleic, and linolenic acid and mixtures thereof, X is —CH2— and n is 1;
• or R′ is Y—OC(O)-group wherein Y is R1 being a tetrahydrofurfuryl group, or a substituted tetrahydrofurfuryl group, or Y is R2 being an alkoxylated alkyl group, or a substituted alkoxylated alkyl group, different from R1;
• X is an alkylene group or an hydroxyl-substituted alkylene group comprising from 1 to 4 carbon atoms;
• and
• n is 1 or 2,
• or a mixture thereof.