# US 7,745,518 B2 · Asphalt binder for porous pavements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,745,518 B2 - Document ID: US7745518B2 - Status: Granted - Kind: B2 - Application number: 12/092,524 - Filed: 2006-10-16 - Published: 2009-07-16 - Granted: 2010-06-29 - Earliest claimed: 2005-11-04 - Assignees: Kraton Polymers U.S. LLC - Inventors: Erik Jan Scholten - Web page: https://patentgrep.com/patent/US7745518B2 ## CPC - C08L 95/00: Compositions of bituminous materials, e.g. asphalt, tar, pitch - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract An asphalt binder is provided, comprising 85 to 97.5 parts by weight of a bitumen and 16 to 2.5 parts by weigh of a polymer composition, wherein the polymer composition comprises: (i) from 2 to 8, preferably from 3 to 6 parts by weight of a styrenic block copolymer having at least two blocks of monovinylaromatic hydrocarbon (A) and at least one block of a conjugated diene (B), wherein the block copolymer composition has a vinyl content of at least 25% by weight, preferably from 25 to 40% by weight, based on the total diene content; (ii) from 0 to 5, preferably from 1 to 3 parts by weight of a styrenic diblock copolymer having one block of monovinylaromatic hydrocarbon (A) and one block of a conjugated diene (B); and (iii) from 0.5 to 3, preferably from 1 to 2.5 parts by weight of an ethylene-vinyl acetate copolymer, wherein the weight ratio of (i)+(ii):(iii) is from 2:1 to 6:1, preferably from 3:1 to 4:1. In addition, an asphalt mix is provided comprising 2 to 8 parts by weight of the asphalt binder of the present invention and 98 to 92 parts by weight of gap-graded aggregate or open-graded aggregate material. Furthermore, a porous pavement is claimed, produced from the open or gap-graded mixes, by compacting the asphalt mix mentioned above. ## Claims ### Claim 1 An asphalt binder comprising 85 to 97.5 parts by weight of a bitumen and 16 to 2.5 parts by weigh of a polymer composition, wherein the polymer composition comprises: (i) from 2 to 8 parts by weight of a styrenic block copolymer having at least two blocks of monovinylaromatic hydrocarbon (A) and at least one block of a conjugated diene (B), wherein the block copolymer composition has a vinyl content of at least 25% by weight, by weight, based on the total diene content; (ii) from 1 to 5 part by weight, of a styrenic diblock copolymer having one block of monovinylaromatic hydrocarbon (A) and one block of a conjugated diene (B); and (iii) from 0.5 to 3 parts by weight of an ethylene-vinyl acetate copolymer, wherein the weight ratio of (i)+(ii):(iii) is from 2:1 to 6:1. ### Claim 2 (depends on 1) An asphalt binder as claimed in claim 1, wherein the bitumen has a PEN value below about 300 dmm as measured by ASTM Method D5 (at 25° C.). ### Claim 3 (depends on 2) An asphalt binder as claimed in claim 2, wherein the bitumen has a PEN value in the range of from 25 to 300 dmm. ### Claim 4 (depends on 1) An asphalt binder as claimed in claim 1, wherein component (i) is a block copolymer having an apparent molecular weight in the range of from 100 to 500 kg/mol. ### Claim 5 (depends on 4) An asphalt binder as claimed in claim 4, wherein component (i) has a bound styrene content of within the range of 20 to 40% mass; an apparent molecular weight in the range of 120 to 200 kg/mole, and a vinyl polybutadiene content of at least 35%. ### Claim 6 (depends on 1) An asphalt binder as claimed in claim 1, wherein component (ii) is a styrenic diblock copolymer, with optionally no more than 30% triblock copolymer contained therein, based on styrene and butadiene and having an apparent molecular weight in the range of from 75 to 225 kg/mole. ### Claim 7 (depends on 6) An asphalt binder as claimed in claim 6, wherein component (ii) is a clear linear diblock copolymer based on styrene and butadiene, with a bound styrene content of within the range of 30 and 32% mass, and a diblock content of about 78%. ### Claim 8 (depends on 1) An asphalt binder as claimed in claim 1, wherein Component (iii) is an ethylene-vinyl acetate copolymer having a melt flow index of from 0.3 to 33 g/10 minutes (ASTM D1238), and a vinyl acetate content in the range of from 20 to 50% wt, based on the copolymer. ### Claim 9 (depends on 8) An asphalt binder as claimed in claim 8, wherein component (iii) has a vinyl acetate content of about 24% wt and a melt index of about 1.8 g/10 minutes (ASTM D1238). ### Claim 10 (depends on 1) An asphalt binder as claimed in claim 1, wherein the asphalt binder exhibits a PEN value in the range of 10 to 100 dmm (ASTM method D5, at 25° C.). ### Claim 11 (depends on 1, 92, 98) An asphalt mix comprising 2 to 8 parts by weight of the asphalt binder of claims 1 and 98 to 92 parts by weight of gap-graded aggregate or open-graded aggregate material. ### Claim 12 (depends on 11) An asphalt mix according to claim 11, comprising porphyry aggregate. ### Claim 13 (depends on 1) A porous pavement produced from the asphalt mix of claim 1, by compacting this asphalt mix. ### Claim 14 (depends on 3) An asphalt binder as claimed in claim 3, wherein the styrenic block copolymer is from 3 to 6 parts by weight of the composition, the styrenic diblock copolymer is from 1 to 3 parts by weight of the composition, ethylene-vinyl acetate copolymer is from 1 to 2.5 parts by weight of the composition, and the weight ratio of (i)+(ii):(iii) is from 3:1 to 4:1. ### Claim 15 (depends on 3) An asphalt binder as claimed in claim 3, wherein the bitumen has a PEN value in the range of from 30 to 250 dmm. ### Claim 16 (depends on 15) An asphalt binder as claimed in claim 15, wherein the bitumen has a PEN value in the range of from 40 to 200 dmm. ### Claim 17 (depends on 5) An asphalt binder as claimed in claim 5, wherein component (i) has a bound styrene content of within the range of 28.5 to 32.5% mass and an apparent molecular weight in the range of 138 to 162 kg/mole. ### Claim 18 (depends on 6) An asphalt binder as claimed in claim 6, wherein the styrenic diblock copolymer has an apparent molecular weight in the range of from 100 to 200 kg/mole. ### Claim 19 (depends on 10) An asphalt binder as claimed in claim 10, wherein the asphalt binder exhibits a PEN value in the range of from 20 to 75 dmm (ASTM method D5, at 25° C.