# US 5,708,061 A · In-situ stabilized compositions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,061 A - Document ID: US5708061A - Status: Granted - Kind: A - Application number: 08/477,499 - Filed: 1995-06-07 - Granted: 1998-01-13 - Earliest claimed: 1991-09-30 - Assignees: The University of Toronto Innovations Foundation - Inventors: Simon Hesp; Zhizhong Liang; Raymond T. Woodhams - Web page: https://patentgrep.com/patent/US5708061A ## CPC - C08L 95/00: Compositions of bituminous materials, e.g. asphalt, tar, pitch - C08L 95/005: {Aqueous compositions, e.g. emulsions} - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract Insoluble particulate materials, which may be in solid or liquid form, are dispersed in a continuous non-aqueous phase and the dispersion rendered stable and resistant to phase separation by an in-situ stabilization procedure involving the formation of chemical bonds among the stabilizer components and to dispersed phases to form a network surrounding the particles which is compatible with the continuous phase. The invention has particular application for the formation of stabilized polyolefin-modified bitumen compositions for paving and other applications. ## Claims ### Claim 1 A stable bituminous composition, comprising: a continuous bituminous phase, a dispersed particulate phase of olefinic polymer insoluble in said bituminous phase, a steric stabilizer in the form of an envelope surrounding and anchored to each particle in said particulate phase and comprising a cross-linked structure compatible with said bituminous phase to maintain dispersed particles of said olefinic polymer spaced from each other in said bituminous phase, so as to inhibit separation of said particulate phase from said bituminous phase by progressive coalescence of dispersed particles. ### Claim 2 (depends on 1) The composition of claim 1 wherein said bitumen comprises an asphalt and said olefinic polymer comprises a homopolymer or copolymer of ethylene. ### Claim 3 (depends on 2) The composition of claim 2 wherein said steric stabilizer comprises polydiene compatible with said asphalt and anchored to each said particle of polymeric material. ### Claim 4 A composition for forming a stable dispersion of particulate olefinic polymer in a continuous bituminous phase, comprising a pro-steric stabilizer dissolved in a bituminous-compatible component, said pro-steric stabilizer comprising a bitumen-compatible stabilizer segment bonded to an olefinic polymer-compatible stabilizer segment different from the bitumen-compatible stabilizer segment. ### Claim 5 A method of forming a stable bituminous composition, which comprises: dispersing an olefinic polymer in a continuous bituminous phase in which said olefinic polymer is insoluble at an elevated temperature above the fusion temperature of the olefinic polymer to form a dispersion containing small particles of said olefinic polymer in the presence of steric stabilizer-forming components comprising a first individual component for anchoring to said olefinic polymer particles and a second individual component different from said first individual component soluble in said bituminous phase, and effecting chemical bonding between said steric stabilizer forming components and bonding to said olefinic polymer particles to form a steric stabilizer in the form of an envelope surrounding and anchored to each olefinic polymer particle and comprising a cross-linked structure compatible with the bituminous phase to maintain said olefinic polymer particles spaced apart from each other in said bituminous phase. ### Claim 6 (depends on 5) The method of claim 5 wherein said olefinic polymer dispersed in said bitumen is a homopolymer or copolymer of ethylene having a melting point which permits dispersion of said olefinic polymer as molten droplets in bitumen at a temperature of about 120.degree. to about 190.degree. C. ### Claim 7 (depends on 6) The method of claim 6 wherein said steric stabilization forming components comprise a polydiene, as said second individual component, bound of an olefinic polymer compatible with said homopolymer or copolymer of ethylene, as said first individual component. ### Claim 8 A method of forming a bituminous composition, which comprises: dissolving a functionalized diene in bitumen, dispersing a functionalized olefinic polymer in said bitumen, reacting said functionalized olefinic polymer and said functionalized diene so as to bind one end of said olefinic polymer to said diene by interaction of the functional groups, and dispersing an olefinic polymer in said bitumen to form a stable bituminous composition in which the functionalized olefinic polymer is anchored to the olefinic polymer particles dispersed in the bitumen to maintain the dispersed olefinic polymer particles spaced from each other in the bitumen, so as to inhibit separation of the olefinic polymer particles from the bitumen by progressive coalescence of dispersed olefinic polymer particles. ### Claim 9 (depends on 8) The method of claim 8 wherein said functionalized diene is an amine-terminated polybutadiene and said functionalized olefinic polymer is a carboxylated olefinic polymer. ### Claim 10 (depends on 9) The method of claim 9 wherein unfunctionalized polybutadiene also is dissolved in said bitumen and said unfunctionalized polybutadiene is subjected to partial cross-linking with said functionalized polybutadiene and itself. ### Claim 11 (depends on 10) The method of claim 10 wherein said partial cross-linking is initiated by a free-radical initiator. ### Claim 12 (depends on 11) The method of claim 11 wherein said free-radical initiator is sulfur, with or without sulfur accelerators. ### Claim 13 (depends on 12) The method of claim 12 wherein carboxylated polyethylene, liquid unfunctionalized polybutadiene, amine-terminated polybutadiene and elemental sulfur are dispersed in bitumen at a temperature of about 100.degree. to about 250.degree. C. by stirring until a homogenous composition is formed. ### Claim 14 (depends on 13) The method of claim 13 wherein said homogenous composition is formed in about 0.5 to about 2.5 hours. ### Claim 15 (depends on 8) The method of claim 8, wherein said olefinic polymer dispersed in said bitumen is a polyethylene having a melting point of about 115.degree. to about 130.degree. C. and said dispersing step is effected at a temperature of about 120.degree. to about 190.degree. C. and above the melting point of the polyethylene to form liquid droplets of said polyethylene in said bitumen. ### Claim 16 (depends on 15) The method of claim 15 wherein additional bitumen is added to said bituminous composition. ### Claim 17 (depends on 1) The composition of claim 1 wherein said steric stabilizer comprises a first individual component comprising an olefinic polymer anchored to said particulate phase and a second individual component comprising a polydiene soluble in said bituminous phase and bonded to said first component. ### Claim 18 (depends on 17) The composition of claim 17 wherein said first and second components are bonded by interaction of functional groups provided on said components. ### Claim 19 (depends on 18) The composition of claim 18 wherein the functionalized olefinic polymer is a carboxylated polyethylene and the functionalized polydiene is an amino-terminated diene. ### Claim 20 (depends on 1) The composition of claim 1 wherein said dispersed particulate phase comprises about 0.1 to about 10 wt. % of the continuous bituminous phase. ### Claim 21 (depends on 17) The composition of claim 17 wherein the first individual component comprises about 0.1 to about 5 wt. % of the continuous bituminous phase and the second individual component comprises about 0.1 to 3 wt. % of the continuous bituminous phase. ### Claim 22 (depends on 21) The composition of claim 21 wherein said first individual component is present in an amount of about 0.3 to about 1 wt. % and said second individual component is present in an amount of about 0.2 to about 1 wt. %. ### Claim 23 (depends on 21) The composition of claim 21 wherein said dispersed particulate phase comprises about 0.1 to about 10 wt. % of the continuous bituminous phase. ### Claim 24 (depends on 23) The composition of claim 23 wherein said dispersed particulate phase is present in an amount of about 1 to about 5 wt. %. ### Claim 25 (depends on 19) The composition of claim 19 wherein liquid polybutadiene also is present in the composition. ### Claim 26 (depends on 25) The composition of claim 25 wherein said liquid polybutadiene is present in an amount of about 0.1 to about 10 wt. % of the continuous bituminous phase. ### Claim 27 (depends on 26) The composition of claim 26 wherein said amount is from about 0.4 to about 6 wt. %. ### Claim 28 (depends on 4) The composition of claim 4 wherein said bitumen-compatible stabilizer segment is a functionalized polydiene and said olefinic polymer-compatible segment is a functionalized polyolefin and said segments are bonded by interaction of the functional groups. ### Claim 29 (depends on 20) The composition of claim 20 wherein said functionalized olefinic polymer is a carboxylated polyethylene and said functionalized polydiene is an amino-terminated diene. ### Claim 30 (depends on 6) The method of claim 6 wherein said homopolymer and/or copolymer of ethylene comprises polyethylene having a fusion temperature of about 115.degree. to about 130.degree. C. ### Claim 31 (depends on 7) The method of claim 7 wherein said polydiene comprises a homopolymer or copolymer of butadiene, said olefinic polymer comprises a homopolymer or copolymer of ethylene and said bonding of said components is effected by interaction between amine termination on said butadiene polymer and carboxyl termination on said ethylene polymer. ### Claim 32 (depends on 5) The method of claim 5 wherein additional bitumen is added to the bituminous composition. ### Claim 33 (depends on 13) The method of claim 13, wherein said unfunctionalized polybutadiene has a molecular weight of about 500 to about 45,000 and is soluble in bitumen.