Pressure sensitive bituminous compositions
AssigneeTamko Asphalt Products, Inc.
InventorGrant D. Mitchell
Life of this patent
Estimating the term…
Abstract
A pressure sensitive bituminous composition having improved tack and adhesiveness, comprising: (1) from about 50% to about 87% of a bituminous component; from about 1 to about 15% of a thermoplastic block copolymer, M.sub.1, of the A-B-A type, preferably styrene-butadiene-styrene; (3) from about 1% to about 10% of a block copolymer, M.sub.2, of the A-B type, preferably styrene-butadiene; and (4) from about 5% to about 50% of a fumed silica. The fumed silica is an active ingredient which absorbs excess oil and improves the tack and adhesiveness of the final composition.
Claims23
A pressure sensitive bituminous composition having improved adhesiveness and tack comprising:
- a) from about 50% to about 87% by weight of a bituminous component having a penetration rate between about 250 and about 450 (0.1 mm) at 25.degree. C. and a total aromatic content from about 45% to about 75% by weight of the bituminous component;
- b) from about 1% to about 15% by weight of a first block copolymer M.sub.1 of the A-B-A type in which the two A blocks are the same or different thermoplastic non-elastomeric polymer blocks prepared by polymerization of one or more monoalkenyl aromatics and in which the polymer block B is an elastomeric polymer block prepared either by polymerization of one or more conjugated alkadienes with one or more monovinyl aromatics;
- c) from about 1% to about 10% by weight of a second block copolymer M.sub.2 of the A-B type in which block A represents a thermoplastic polymer block prepared by polymerization of one or more alkenyl aromatics and block B represents an elastomeric polymer block prepared either by polymerization of one or more conjugated alkadienes or by copolymerization of one or more conjugated alkadienes with one or more monovinyl aromatics, such that the percentage of said first block copolymer M.sub.1 and said second block copolymer M.sub.2 in combination is at least about 3%;
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- d) from about 5% to about 50% by weight of a fumed silica.
A pressure sensitive bituminous composition having improved adhesive properties comprising:
- a) about 65.25% by weight of a bituminous component having a penetration rate between 250 and 450 (0.1 mm at 25.degree. C. and a total aromatic content from 45% to 75% by weight of the bituminous component;
- b) about 7.5% by weight of a first block copolymer, M.sub.1, of the A-B-A type with polystyrene end blocks A and a rubbery polybutadiene midblock B;
- c) about 2.25% by weight of a second block copolymer, M.sub.2, of the A-B type with a polystyrene end block A and a polybutadiene midblock B;
- d) 25.0% by weight of a fumed silica having an average particle size less than or equal to about 0.1 microns in diameter.
Dependencies are inferred from the claim text.