MODIFIED BITUMINOUS BINDER EMULSION
The invention relates to a process for the preparation of a bituminous binder emulsion for making layers and/or coatings for road construction and/or civil engineering, comprising mixing a dispersing aqueous phase and a bituminous binder comprising an initial bitumen in the presence of at least one emulsifying agent, and obtaining a bituminous binder emulsion comprising a final bitumen with a decreased penetration grade, wherein at least 0.5% by weight of an oxidizing agent, which is neither dioxygen nor ozone, is mixed with the dispersing aqueous phase or the bituminous binder before or during the mixing step, or is added in the mixture after said mixing step has been initiated. The invention also relates to a composition for preparing a modified emulsion and its use for making tack coats having a trackless finish.
1 - 14 . (canceled)
15 . A process for the preparation of a bituminous binder emulsion for making layers and/or coatings for road construction and/or civil engineering, comprising:
a) mixing a dispersing aqueous phase and a bituminous binder comprising an initial bitumen in the presence of at least one emulsifying agent,
b) obtaining a bituminous binder emulsion comprising a final bitumen, characterized in that:
at least one oxidizing agent, which is neither dioxygen nor ozone, is mixed with in the dispersing aqueous phase or the bituminous binder before or during mixing step a), or is added in the mixture after mixing step a) has been initiated and before step b), and said at least one oxidizing agent is present in an amount of at least 0.5% by weight, relative to the emulsion total weight,
the penetration grade of the final bitumen is decreased by at least one grade as defined in the EN-12591 standard as compared to the initial bitumen.
16 . The process of claim 1 , wherein the at least one oxidizing agent is a peroxide.
17 . The process of claim 2 , wherein said peroxide is hydrogen peroxide or a salt thereof.
18 . The process of claim 1 , wherein the at least one oxidizing agent is added as an aqueous solution.
19 . The process of claim 1 , wherein the at least one oxidizing agent is added in the dispersing aqueous phase comprising said at least one emulsifying agent, and then the dispersing aqueous phase is mixed with the bituminous binder.
20 . The process of claim 1 , wherein the at least one oxidizing agent is added to a bituminous binder emulsion obtained after step a), and before step b).
21 . The process of claim 1 , wherein the at least one oxidizing agent is added in the bituminous binder before mixing step a), and mixing step a) is initiated before the initial bitumen penetration grade has been decreased by more than one grade as defined in the EN-12591 standard.
22 . The process of claim 1 , wherein the at least one oxidizing agent is present in an amount ranging from 0.5 to 20% by weight, relative to the emulsion total weight.
23 . The process of claim 1 , wherein the bituminous binder is present in an amount ranging from 10 to 80% by weight, relative to the emulsion total weight.
24 . The process of claim 1 , wherein the bituminous binder contains a bitumen that represents from 25 to 100% of the bituminous binder total weight.
25 . The process of claim 24 , wherein the bituminous binder contains a bitumen that represents from 65 to 90% of the bituminous binder total weight.
26 . The process of claim 1 , wherein the emulsifying agent is present in an amount ranging from 0.05 to 5% by weight, relative to the emulsion total weight.
27 . The process of claim 1 , wherein the layers and/or coatings for road construction and/or civil engineering are trackless tack coats.
28 . The process of claim 1 , wherein the emulsion is a cationic emulsion.
29 . A bituminous binder composition for making layers and/or coatings for road construction and/or civil engineering, comprising a dispersing aqueous phase, at least one emulsifying agent, a bituminous binder and at least one oxidizing agent that is neither dioxygen nor ozone.
30 . A process for improving the trackless nature of a bituminous binder emulsion comprising a dispersing aqueous phase, at least one emulsifying agent and a bituminous binder, comprising the use of a use of an oxidizing agent that is neither dioxygen nor ozone.