Method for preparing improved asphalt emulsion compositions

• US 5,811,477 A
• Filed: 07/26/1996
• Issued: 09/22/1998
• Est. Priority Date: 03/11/1994
• Status: Expired due to Term

• Current Assignee: Flex Products Incorporated (Sicpa Holding SA)
• Original Assignee: Michael V. Burris
• Inventors: Burris, Bryan B., Burris, Michael V.
• Primary Examiner(s): Szekely, Peter A.
• Application Number:
  US08/687,770
• Time in Patent Office: 788 Days
• Field of Search: 521/40.5, 521/41, 521/44.5, 521/45, 524/59, 524/60, 524/61, 524/68, 524/69, 524/71, 404/32
• US Class Current: 524/60
• CPC Class Codes: C08L 2207/24 recycling of old tyres and caoutchouc and addition of caoutchouc particles
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 2666/08 Homopolymers or copolymers according to C08L7/00 - C08L21/00; Derivatives thereof
• CPC Class Codes: C08L 95/00 Compositions of bituminous materials, e.g. asphalt, tar, pitch
• CPC Class Codes: C08L 95/005 Aqueous compositions, e.g. emulsions

Abstract

A method of preparing an asphalt emulsion composition comprises mixing an aqueous asphalt emulsion, water, latex rubber, and a solids mix composition comprising reclaimed rubber particles passing through a 40 mesh U.S. series sieve and one or more solid addends selected from the group consisting of a rheological agent, gilsonite, carbon black, surface active clay and polymer fibers, and mixtures thereof and wherein the ratio of latex rubber:rubber particles is between about 1:1 and about 1:10, by weight, respectively, and mixing the components at substantially ambient temperature.

Claims

1. A method of preparing an improved asphalt emulsion paving composition comprising:

mixing aggregate, an aqueous asphalt emulsion, water, polymer latex, reclaimed rubber particles passing through a 20 mesh U.S. series sieve and one or more solid addends selected from the group consisting of a rheological agent, gilsonite, carbon black, surface active clay and polymer fibers, and mixtures thereof wherein the ratio of polymer latex;

rubber particles is between about 1;

1 and about 1;

10, by weight, respectively, and mixing the components at substantially ambient temperature.

2. The method of claim 1 including preparing said aqueous asphalt emulsion using gilsonite and asphalt whereby said aqueous asphalt emulsion comprises an asphalt phase comprising a mixture of asphalt and gilsonite in a ratio of asphalt:

gilsonite of between about 99;

1 and about 5;

95, by weight, respectively, and a water phase comprising water and between about 0.05% and about 5%, by weight, of an emulsifying agent, wherein the ratio of asphalt phase;

water phase is between about 3;

1 and about 1;

2, respectively, by weight.

3. The method of claim 2 wherein said aqueous asphalt emulsion is prepared by melting gilsonite, blending asphalt with the melted gilsonite to form a fluid mixture thereof, and blending said fluid mixture with water and an emulsifying agent to form said aqueous asphalt emulsion.

4. The method of claim 3 wherein said emulsifying agent is a cationic, anionic or non-ionic emulsifier.

5. The method of claim 2 wherein said aqueous asphalt emulsion is prepared by mixing gilsonite particles with asphalt at substantially ambient temperature to form a mixture thereof, and blending said mixture with water and an emulsifying agent to form said aqueous asphalt emulsion.

6. The method of claim 5 wherein said emulsifying agent is a cationic, anionic or non-ionic emulsifier.

7. The method of claim 1 wherein said aqueous asphalt emulsion is cationic, anionic or nonionic.

8. The method of claim 7 wherein said aqueous asphalt emulsion includes a surface active clay.

9. The method of claim 1 wherein said aqueous asphalt emulsion includes a surface active clay.

10. The method of claim 9 wherein said surface active clay comprises a bentonite clay.

11. The method of claim 1 wherein said polymer fibers are natural, synthetic or semisynthetic fibers.

12. The method of claim 1 wherein said polymer fibers comprise cellulosic fibers.

13. The method of claim 1 wherein said polymer fibers comprise synthetic polymer fibers.

14. The method of claim 1 wherein said rubber particles comprise reclaimed rubber processed to remove volatiles.

15. The method of claim 14 wherein said rubber particles comprise a mixture of carbon black and ash prepared by treating used rubber tires in the presence of a catalyst to remove substantial amounts of hydrocarbon, oils and metals therefrom.

16. An asphalt emulsion paving composition prepared by the method of claim 15.

17. A paving composition of claim 16 wherein said polymer latex is a latex rubber.

18. The method of claim 1 including adding a thickening agent during said mixing wherein the viscosity of said asphalt emulsion paving composition is between 1500 cp and 20,000 cp at 68°

F.

19. An asphalt emulsion paving composition prepared by the method of claim 18.

20. A paving composition of claim 19 wherein said polymer latex is a latex rubber.

21. The method of claim 1 wherein a portion of said aggregate comprises recycled asphaltic concrete.

22. The method of claim 21 wherein said recycled asphaltic concrete comprises asphaltic concrete particles at least a portion passing a 16 mesh U.S. series sieve.

23. The method of claim 1 wherein said aqueous asphalt emulsion is prepared by mixing sulfur with asphalt and preparing an aqueous emulsion of the mixture.

24. The method of claim 23 wherein said sulfur and said asphalt are mixed above the melting point of sulfur.

25. The method of claim 24 including blending a liquid petroleum hydrocarbon with said asphalt and sulfur mixture, and forming an aqueous emulsion thereof.

26. An asphalt emulsion paving composition prepared according to the method of claim 1 containing a combination of said rubber particles and polymer fibers.

27. A method of claim 1 wherein said polymer latex is a latex rubber.

28. The method of claim 1 wherein at least a portion of the rubber particles will pass through a 40 mesh U.S. series sieve.

29. The method of claim 1 wherein the ratio of polymer latex:

rubber particles is between 1;

2 and 1;

5, by weight, respectively.

30. An asphalt emulsion paving composition prepared according to the method of claim 29.

31. The method of claim 1 wherein said reclaimed rubber particles and said polymer latex are mixed prior to being mixed with said aqueous asphalt emulsion and said aggregate.

32. An asphalt emulsion paving composition prepared according to the method of claim 31.

33. The method of claim 1 wherein said reclaimed rubber particles and said one or more solids addends are blended to form a solids mix composition, and wherein said solids mix composition is mixed with said polymer latex, said aqueous asphalt emulsion and said aggregate to prepare said paving composition.

34. An asphalt emulsion paving composition prepared according to the method of claim 33 wherein the components thereof, excluding said aggregate, comprise:

about 50%-80% aqueous asphalt emulsion,

about 1%-30% water,

about 1%-5% latex rubber, and

about 5%-25% of said solids mix composition, and wherein the ratio of latex rubber;

rubber particles is between about 1;

1 and about 1;

10, respectively,

said amounts being by weight.

35. A composition of claim 34 wherein said solids mix composition comprises rubber particles and polymer fibers.

36. A composition of claim 35 wherein said polymer fibers comprise semisynthetic fibers from recycled newspaper.

37. A composition of claim 35 wherein said polymer fibers comprise synthetic fibers obtained from used rubber tires.

38. A composition of claim 37 wherein said solids mix composition includes between about 0.1% and about 10%, by weight, carbon black.

39. A composition of claim 34 wherein said solids mix composition includes a mixture of carbon black and polymer fibers prepared by treating used rubber tires.

40. A composition of claim 34 wherein said aqueous asphalt emulsion includes sulfur.

41. A composition of claim 40 wherein said aqueous asphalt emulsion comprises an asphalt phase having between about 50% and about 98%, by weight, paving grade asphalt and between about 1% and about 10%, by weight, added sulfur over the amount of any residual sulfur in said asphalt.

42. A composition of claim 41 wherein said asphalt phase includes between about 1% and about 35%, by weight, of a liquid petroleum hydrocarbon having a boiling point above about 200°

F.

43. A composition of claim 34 wherein the ratio of latex rubber and rubber particles is between 1:

2 and 1;

5, by weight, respectively.

44. The method of claim 33 wherein at least a portion of said water is mixed with said reclaimed rubber particles and said one or more solid addends to form said solids mix composition.

45. An asphalt emulsion paving composition prepared according to the method of claim 44.

46. An asphalt emulsion paving composition prepared according to the method of claim 33.

47. The method of claim 1 wherein said reclaimed rubber particles, said one or more solid addends, and said polymer latex are blended to form a solids mix composition, and wherein said solids mix composition is mixed with said aqueous asphalt emulsion and said aggregate to prepare said paving composition.

48. The method of claim 47 wherein at least a portion of said water is mixed with said reclaimed rubber particles, said one or more solid addends and said polymer latex to form said solids mix composition.

49. An asphalt emulsion paving composition prepared according to the method of claim 48.

50. An asphalt emulsion paving composition prepared according to the method of claim 47.

51. An asphalt emulsion paving composition prepared according to the method of claim 1 wherein the components thereof, excluding said aggregate, comprise:

about 50%-80% aqueous asphalt emulsion,

about 1%-30% water,

about 1%-5% latex rubber, and

about 5%-25% of said reclaimed rubber particles and said one or more solid addends,

and wherein the ratio of latex rubber;

rubber particles is between about 1;

1 and about 1;

10, respectively, said amounts being by weight.

52. A composition of claim 51 wherein said one or more solid addends comprises a rheological agent.

53. A composition of claim 51 wherein said one or more solid addends comprises polymer fibers.

54. An asphalt emulsion paving composition prepared according to the method of claim 1.

55. An asphalt emulsion composition prepared by mixing, at substantially ambient temperature:

a major amount of an aqueous asphalt emulsion, polymer latex, rubber particles passing a 40 mesh U.S. series sieve and natural, synthetic or semisynthetic polymer fibers wherein the ratio of polymer latex;

rubber particles is between about 1;

1 and 1;

10, by weight, respectively.

56. A paving composition prepared by mixing the asphalt emulsion composition of claim 55 with aggregate at substantially ambient temperature.

57. A paving composition of claim 56 wherein said polymer latex is a latex rubber.

58. A paving composition of claim 56 comprising between about 5 and about 20 pounds of said aggregate per gallon of said asphalt emulsion composition.

59. A paving composition of claim 56 wherein said asphalt emulsion composition includes carbon black.

60. A paving composition of claim 59 wherein said polymer fibers comprise synthetic fibers and carbon black prepared by treating used rubber tires.

61. A solids mix composition comprising reclaimed rubber particles, at least a major amount of which pass a #20 U.S. series mesh, and latex rubber, wherein the ratio of said latex rubber:

rubber particles is between about 1;

2 and about 1;

5, by weight, respectively, and one or more solid components selected from the group consisting of a rheological agent, gilsonite, carbon black, natural synthetic or semisynthetic fibers, and a surface active clay.

62. A solids mix composition of claim 61 including between about 1% and about 20%, by weight of a rheological or thixotropic agent capable of thickening an aqueous asphalt emulsion composition.

63. A solids mix composition of claim 62 including between about 0.1% and about 10% carbon black, by weight.

64. A solids mix composition of claim 63 including between about 0.1% and about 25% gilsonite, by weight.

65. A solids mix composition of claim 64 including between about 10% and about 75% polymers fibers, by weight.

66. A solids mix composition of claim 64 including between about 0.5% and about 10% surface active clay, by weight.

67. A solids mix composition of claim 66 including between about 15% and about 50% water, by weight.

68. A solids mix composition of claim 61 including between about 0.1% and about 10% carbon black, by weight.

69. A solids mix composition of claim 61 including between about 0.1% and about 25% gilsonite, by weight.

70. A solids mix composition of claim 61 including between about 10% and about 75% polymer fibers, by weight.

71. A solids mix composition of claim 61 including between about 0.5% and about 10% surface active clay, by weight.

72. A solids mix composition of claim 61 including between about 15% and about 50% water, by weight.

73. A solids mix composition of claim 61 wherein at least a portion of said reclaimed rubber particles comprises a mixture of ash and carbon black obtained by heating reclaimed rubber tires above about 300°

F. in the presence of catalysts to separate hydrocarbons, oils, and metals.

74. A method of preparing an improved asphalt emulsion paving composition comprising:

mixing the solids mix composition of claim 61, water, aqueous asphalt emulsion and aggregate at substantially ambient temperature.

75. An asphalt emulsion paving composition prepared according to the method of claim 74.