Bitumen emulsion containing polyaluminum compounds
View Patent ↗The invention relates to an additive for a bitumen emulsion, which is a specific mixture of alkoxyiated compounds with low and high amounts of alkylene oxide units, in combination with a polyaluminum compound. Using this additive it is possible to prepare an aqueous slow-setting bitumen emulsion-aggregate mix suitable for cold paving of roads, parking places, sidewalks, and the like.
1. An additive for a bitumen emulsion comprising
i) a polyaluminum compound;
ii) an alkoxylated amine having the formula:
where R is a hydrocarbyl group having from 10 to 24 carbon atoms; n=0-3; each AO is independently ethyleneoxy or propyleneoxy, Y is a hydrocarbyl group having 1-24 carbon atoms, or a group (AO) x H; and the sum of all x in (I) is 0.5-10; and
iii) an alkoxylated compound having the formula:
where R′ is a hydrocarbyl group from 8 to 24 carbon atoms; X is N, C(═O)O or O; s=0-3; p=0 or 1; provided that when X is N, then p is 1 and when X is C(═O)O or O, then p is 0; and Z is a hydrocarbyl group having 1-24 carbon atoms, or a group
where each AO independently is ethyleneoxy or propyleneoxy, and the sum of all y in (II) is from 12 to 200; or castor oil that has been alkoxylated 12 to 200 moles of ethylene oxide and/or propylene oxide per mole of castor oil (III).
2. The additive according to claim 1 , wherein the sum of all x in formula (I) is from 0.5 to 5.
3. The additive according to claim 1 , wherein the sum of all y in formula (II) is from 14 to 100.
4. The additive according to claim 1 , wherein the AO in formula (I) is ethyleneoxy.
5. The additive according to claim 1 , wherein the AO in formula (I) is propyleneoxy.
6. The additive according to claim 1 , wherein at least 50% of the total number of AO-units in formula (II) or castor oil (III) is ethyleneoxy units.
7. The additive according to claim 1 , wherein the AO in formula (II) is ethyleneoxy.
8. The additive according to claim 1 , wherein the weight ratio of the alkoxylated amine to the alkoxylated compound is 1:25 to 4:1, and wherein the weight ratio of the polyaluminum compound to the sum of the alkoxylated amine and the alkoxylated compound is 1:30 to 1:2.
9. A bitumen-in-water emulsion comprising the additive according to claim 1 , bitumen and water.
10. The bitumen emulsion according to claim 9 , comprising
50-75% (w/w) bitumen;
0.002-1.5% (w/w) of the polyaluminum compound;
0.05-3% (w/w) of the total of the alkoxylated amine and the alkoxylated compound;
0-20% (w/w) of other conventional components; and with the balance being water.
11. The bitumen emulsion according to claim 9 , having a pH below 8.
12. The bitumen emulsion according to claim 9 , wherein X in formula (II) is N and p is 1.
13. The bitumen emulsion according to claim 9 , wherein Z is the group:
14. The bitumen emulsion according to claim 9 , wherein X in formula (II) is O, p is 0 and s is 0.
15. A process for the manufacture of an aqueous bitumen-aggregate mix comprising the steps of:
a) providing the bitumen emulsion according to claim 9 ; and
b) mixing said emulsion with an aggregate.
16. An aqueous bitumen-aggregate mix comprising 2-40% by weight of the bitumen emulsion according to claim 9 ; and
60-98% by weight of an aggregate.
17. A method for paving a surface of a road, a sidewalk, a parking lot or an airport runway comprising the step of:
spreading the bitumen-aggregate mix according to claim 16 on the surface, or
spreading the bitumen emulsion according to claim 9 on a surface at least partially covered by an aggregate.
18. The additive of claim 1 , wherein the polyaluminum compound is polyaluminum chloride.
19. The bitumen emulsion of claim 10 , wherein the polyaluminum compound is polyaluminum chloride.