Extrusion isolation of blends of rubber and asphalt
First Claim
1. A process for blending elastomeric latices and asphalt comprising feeding an aqueous emulsion of elastomeric latex selected from the group consisting of chloroprene polymer latexes, polyisoprene latexes, polystyrene/butadiene latexes, and polybutadiene latexes containing 15 to 70 weight percent elastomer, and asphalt in the form of a melt or in the form of an emulsion containing 20-70 weight percent asphalt to a screw extruder having a flow restriction to apply a back pressure sufficient that water present in the aqueous emulsion is forced out of a vent provided in the extruder upstream from said flow restriction to apply back pressure, feeding asphalt and elastomer through said restriction and recovering the thus formed blend of 5 to 98 weight percent asphalt and 2 to 95 weight percent elastomer from said extruder.
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Accused Products
Abstract
Blends of asphalt emulsions or melts and aqueous elastomeric latices are prepared using a screw type extruder adapted to provide sufficient back pressure within the screw flights of the extruder to express the water from the blend through a vent provided in the extruder.
14 Citations
13 Claims
- 1. A process for blending elastomeric latices and asphalt comprising feeding an aqueous emulsion of elastomeric latex selected from the group consisting of chloroprene polymer latexes, polyisoprene latexes, polystyrene/butadiene latexes, and polybutadiene latexes containing 15 to 70 weight percent elastomer, and asphalt in the form of a melt or in the form of an emulsion containing 20-70 weight percent asphalt to a screw extruder having a flow restriction to apply a back pressure sufficient that water present in the aqueous emulsion is forced out of a vent provided in the extruder upstream from said flow restriction to apply back pressure, feeding asphalt and elastomer through said restriction and recovering the thus formed blend of 5 to 98 weight percent asphalt and 2 to 95 weight percent elastomer from said extruder.
Specification