Roofing composition and resulting product
AssigneeButler-Schoenke Roofing Specialties, Inc.
InventorWilliam Emil Schoenke
Life of this patent
Estimating the term…
Abstract
A roofing composition for producing a roofing membrane having good bond strength, resistance to cracking, tensile strength and hardness, comprising 5-40% of asphalt and 60-95% of a block copolymer of the A-B-A type in which each end block A is formed from a vinyl aromatic monomer and midblock B is a hydrogenated polydiene or a polymer of the ethylene/propylene or ethylene/butylene type. A white top coating may be applied over the membrane without staining being visible through the top coating. Optionally the composition may also contain nonstaining carbon black, extender pigments, synthetic or natural resins to vary membrane film properties, and conventional additives, such as stabilizers and fire retardants.
Claims13
In a fluid, curable roofing composition which is free from terminally-reactive diolefin polymer and from a curing or vulcanization agent and which comprises an intimate admixture of elastomer and asphalt, the improvement wherein:
- (a) the elastomer is in the form of a midblock B of an A-B-A block copolymer wherein each end block A is a polymer block of a polymerized vinyl aromatic monomer and the midblock B is a polymer block of polymerized aliphatic hydrocarbon monomer, the polymerized aliphatic hydrocarbon monomer having at most a proportion of olefinic unsaturation which is significantly less than that of a polydiene or of a polymerized mixture of dienes,
- (b) the block copolymer is in solution in a solvent,
- (c) the asphalt has a softening point of from about 100.degree. to about 175.degree. F.,
- (d) the weight percent of A-B-A block copolymer is from about 60 to about 95 percent and
- (e) the weight percent of asphalt is from about 40 to about 5 percent, the respective weight percents being based on the total amount of A-B-A block copolymer and asphalt in the roofing composition.
Dependencies are inferred from the claim text.