“…Typical additives for butyl sealants are alkylphenol–formaldehyde resins (APFRs); gum rosin; hydrocarbon resins; low-molecular-weight polyisobutylene [ 67 ], paraffinic oil [ 68 ], C5 resin [ 69 ], high-molecular-weight polyisobutylene, silane-modified poly-alfa-olefin [ 70 ], butyl rubber, butadiene-styrene, and butadiene–nitrile rubbers, acrylic polymers, among other oligomers, polymers, and mixtures thereof, as well as natural and precipitated calcium carbonate silica [ 71 ], montmorillonites [ 71 ], sepiolite [ 72 ], carbon black [ 68 ], titanium dioxide [ 69 ], fumed silica, and halloysite [ 73 ]. Therefore, there is a large base of additives for HMA formulations, including organic and inorganic materials; however, usually, each one has a specific role, such as rheology or tackiness modifier, extender, pigment, etc.…”