GB1190486A - Bituminous Compositions - Google Patents

Abstract

1,190,486. Bitumen and addition polymer composition. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 6 May, 1968 [8 May, 1967], No. 21355/68. Headings C3N and C3P. A composition comprises 50-95% wt. lowasphaltene bituminous distillation or precipitation residue (a), and 5-50% wt. thermoplastic polymer (b). Bitumen (a) has n-heptaneasphaltene content <2% wt., preferably <0 1%; PEN (25‹ C.) <2000, preferably <500; and softening point <80‹ C., e.g. 25- 60‹ C.; the penetration index of exemplified bitumens is given. Polymer (b) has M.W.> 10,000, preferably 50,000, solubility parameter 7À8-8À8; and crystallinity (25‹ C.)<60%; it may be amorphous; (b) may have been formed by polymerization of olefinically unsaturated monomers; it may be e.g. polyisobutylene, polyisoprene, polybutadiene, or the copolymers ethylene/propylene, styrene/butadiene, ethylene/vinyl - acetate, ethylene/ethyl - acrylate, or ethylene/n-butyl-acrylate; or it may be an A-B-A block copolymer, A being similar or dissimilar monovinyl-substituted aromatic hydrocarbon blocks, e.g. of styrene and B a conjugated polymer block, e.g. of isoprene or butadiene. A may have M.W. 7500-100,000, and B M.W. 25,000-1,000,000. The composition may be prepared by stirring into molten bitumen (b) copolymer, (a) as a finely-dispersed solid or as a solution in benzene or toluene; the solvent may be evaporated afterwards. Additionally present may be glass fibre, asbestos fibre, talcum, sand, or soot. Parameters.-The penetration, softening point, penetration index, and adhesive properties of many compositions are given. The composition may be used as adhesive for rubber roofing sheets. Contrasting examples of (a), (b), and compositions made therefrom are also given.