INTERFACE AGENTS FOR THE PREPARATION OF COLD ROAD SURFACINGS

Abstract

The invention relates to the manufacture of a bituminous product type mix or surface dressing which includes bringing into contact, at a temperature below 110° C., mineral particles with an emulsion (i) derived from emulsification of a hydrocarbon binder in an aqueous phase at a mixing temperature above the contacting temperature, and (ii) which includes an additive which: forms a homogeneous mixture with the hydrocarbon binder at the mixing temperature; is not compatible with the hydrocarbon binder at the contacting temperature; is used at a content above its solubility in the aqueous medium of the emulsion at the contacting temperature.

Claims

1.-10. (canceled)

11. A method for manufacturing a bituminous product comprising: a step (E1) of forming an emulsion comprising a hydrocarbon binder, an additive and an aqueous medium, wherein forming the emulsion comprises introducing the hydrocarbon binder including the additive into the aqueous medium at a mixing temperature T1; and then a step (E2) of contacting mineral particles with the emulsion at a contacting temperature T2 to form the bituminous product, the contacting temperature T2 being lower than the mixing temperature T1, the contacting temperature T2 being below 110° C.; wherein: the additive forms a homogeneous mixture with the hydrocarbon binder at the mixing temperature T1, the additive is insoluble or soluble at a rate of 5% by weight or less in the hydrocarbon binder at the contacting temperature T2, and a content of the additive in the emulsion is greater than a solubility of the additive in the aqueous medium at the contacting temperature T2.

12. The method of claim 11, wherein the additive comprises a volatile compound, and further comprises evaporating the additive from the bituminous product.

13. The method of claim 11, wherein the additive comprises a compound having the following formula (I):
R.sup.1—X—R—Y—R.sup.2  (I) where: R.sup.1 is a methyl R.sup.2, identical or different to R.sup.1, is a C.sub.1-C.sub.11, preferably C.sub.1-C.sub.9, hydrocarbon chain, linear or branched; each of —X— and —Y—, identical or different, is a —O—(C═O)— group; or a —C(═O)—O— group; or a —NR′—C(═O)— group; or a —C(═O)—NR′— group with R′ representing a hydrogen atom or instead a C.sub.1-C.sub.4 alkyl radical; and —R— is a C.sub.1-C.sub.10 divalent hydrocarbon chain, linear or branched, and optionally interrupted by one or more oxygen atoms.

14. The method of claim 13, wherein the additive comprises a compound or a mixture of compounds having the formula (I).

15. The method of claim 13, wherein the additive comprises a dimethyl compound having the following formula (Ia):
CH.sub.3—X—R—Y—CH.sub.3  (Ia) where —X—, —Y—, and —R— have the significations given in claim 13.

16. The method of claim 15, wherein the additive comprises a compound or a mixture of compounds having the formula (Ia) selected from dimethyl adipate, dimethyl glutarate, and dimethyl succinate.

17. The method of claim 15, wherein the additive A is a compound of formula (Ia), where the R group is selected from the following groups: the R.sub.MG group of formula —CH(CH.sub.3)—CH.sub.2—CH.sub.2—, the R.sub.ES group of formula —CH(C.sub.2H.sub.5)—CH.sub.2—, and mixtures thereof.

18. The method of claim 17, wherein the additive is a compound of formula (Ia), wherein X and Y are esters.

19. The method of claim 11, wherein the additive (A) is an interfacing agent at contacting temperature T2, and further comprises expulsing at least one part of said additive outside of hydrocarbon binder of the emulsion to be placed at an interface between the aqueous medium and the hydrocarbon binder.

20. An emulsion, comprising: a hydrocarbon binder, an additive (A), and an aqueous medium, wherein at least one part of the additive (A) is present at the interface between globules of the hydrocarbon binder and the aqueous phase.

21. The emulsion of claim 20, wherein the additive comprises a compound having the following formula (I):
R.sup.1—X—R—Y—R.sup.2  (I) where: R.sup.1 is a methyl R.sup.2, identical or different to R.sup.1, is a C.sub.1-C.sub.11, preferably C.sub.1-C.sub.9, hydrocarbon chain, linear or branched; each of —X— and —Y—, identical or different, is a —O—(C═O)— group; or a —C(═O)—O— group; or a —NR′—C(═O)— group; or a —C(═O)—NR′— group with R′ representing a hydrogen atom or instead a C.sub.1-C.sub.4 alkyl radical; and —R— is a C.sub.1-C.sub.10 divalent hydrocarbon chain, linear or branched, and optionally interrupted by one or more oxygen atoms.

Description

[0114] It is possible to use as compounds of formula (II) compounds in which R is such as defined in one of the following embodiments, or a mixture of compound(s) according to these embodiments: [0115] Embodiment 1: R is a radical of formula —(CH.sub.2).sub.r—, where r is an average number comprised between 2 and 8 included. In particular, R is a radical of formula —(CH.sub.2).sub.r—, where r is an average number comprised between 2 and 4 included. [0116] Preferably, R is selected such that the compound may be a mixture of derivative of adipate (r=4), derivative of glutarate (r=3), and derivative of succinate (r=2). [0117] Embodiment 2: R is a branched C.sub.3-C.sub.10 alkanediyl radical. R may notably be a C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, C.sub.8, C.sub.9 group, or a mixture. It is preferably a C.sub.4 group. [0118] The R group is preferably selected from the following groups: [0119] the R.sub.MG group of formula —CH(CH.sub.3)—CH.sub.2—CH.sub.2—, [0120] the R.sub.ES group of formula —CH(C.sub.2H.sub.5)—CH.sub.2—, and [0121] mixtures thereof. [0122] Such mixtures, as well as appropriate methods for obtaining them are notably described in the documents WO 2007/101929; WO 2007/141404; WO 2008/009792; WO 2008/062058. [0123] Embodiment 3: R is a C.sub.2-C.sub.8, advantageously C.sub.2-C.sub.4, alkenediyl radical, linear or branched. [0124] The R group is preferably selected from the following groups: [0125] the group of formula —CH═CH—, the double bond being of Z configuration [0126] the group of formula —CH═CH—, the double bond being of E configuration [0127] the group of formula —CH(CH.sub.2)—CH.sub.2—, and [0128] mixtures thereof. [0129] Embodiment 4: R is a —(OE/OP).sub.n- radical where OE/OP are alkoxy groups, preferably selected from ethoxy, propoxy groups and ethoxy/propoxy mixtures and n an average number comprised between 1 and 5 included and with a total number of carbons of 10 in the R group.

[0130] Notably in the aforesaid embodiments 1 to 4, X and Y are advantageously esters, preferably esters of diacids (where: —X—═—O—C(═O)—; and Y═—C(═O)—O—) or esters of diols (where: —X—═—C(═O)—O— and Y═—O—C(═O)—)

[0131] Advantageously, when a compound of formula (II) according to the invention is used, this compound (II) is selected from: [0132] diisobutyl adipate, diisobutyl glutarate or diisobutyl succinate, and mixtures thereof, such as for example: [0133] a mixture including, by weight compared to the total weight of the mixture (measurable by gas phase chromatography): 5 to 29% by weight of diisobutyl adipate; 50 to 72% by weight of diisobutyl glutarate; and 10 to 32% by weight of diisobutyl succinate. [0134] the solvent sold by Solvay under the denomination Rhodiasolv® DIB (as an example, a mixture 1:1 by weight of INNROAD® Boost and Rhodiasolv® DIB is compatible hot with the bitumen and solubilises it at a rate of less than 4% at ambient temperature after three days). [0135] diethyl adipate, diethyl glutarate or diethyl succinate, and mixtures thereof, such as for example: [0136] a mixture including, by weight compared to the total weight of the mixture (measurable by gas phase chromatography): 4 to 26% by weight of diethyl adipate; 52 to 77% by weight of diethyl glutarate; and 12 to 32% by weight of diethyl succinate. [0137] the additive available from Solvay under the name INNROAD® Protect

Bituminous Products Accessible According to the Invention

[0138] The bituminous product that the method of the invention makes it possible to prepare include all bituminous products that can be produced at low temperature and notably cold, that is to say all bituminous products of type coated at low temperature according to the present description, including cold mixes and surface dressings and moderate temperature mixes and surface dressings.

[0139] The bituminous products accessible according to the invention include in particular dressings in emulsion and cold mixes notably of cold poured bituminous materials type, bituminous concretes in emulsion and storable mixes in emulsion, which are described in greater detail hereafter.

Surface Dressings

[0140] A surface dressing is typically a course constituted of superimposed states of a hydrocarbon binder and solid mineral particles. It is typically obtained by spraying a hydrocarbon binder then by spreading on this binder solid mineral particles, in one or more layers. The whole is next compacted.

[0141] The solid mineral particles used in a surface dressing advantageously belong to the following granular (d/D) classes: 4/6.3, 6.3/10, 10/14.

[0142] The total hydrocarbon binder content in a surface dressing will be adapted as a function of the structure of the surface dressing (mono- or bi-course, type of chippings), the nature of the binder, climatic conditions and the dimension of the aggregates, following for example the recommendations of the document “Enduits superficiels d'usure—Guide technique, mai 1995”.

[0143] The hydrocarbon binder employed for the manufacture of a surface dressing may be a pure bitumen or a bitumen modified by polymers, such as described previously.

[0144] The hydrocarbon binder is a binder in emulsion. In this embodiment, the hydrocarbon binder advantageously includes, compared to the total weight of hydrocarbon binder, 0.1 to 10% by weight of said compound of formula (I), more advantageously 0.5 to 8% by weight, even more advantageously 1 to 6% by weight.

Mixes:

[0145] Cold Poured Bituminous Materials

[0146] Cold poured bituminous materials are mixes for surface courses constituted of non-dried aggregates mixed in an emulsion of bitumen and poured in place continuously by means of specific equipment.

[0147] After application and breakage of the emulsion, this surfacing, cold poured at very low thickness (generally from 6 to 13 mm of thickness per course), has to reach its definitive consistency (rise in cohesion) very quickly. The additives used according to the invention can favourably influence this parameter.

[0148] For a cold poured bituminous material, the droplets of bitumen initially separated confer on the system a fluid character and an easy placement using specific machines for cold-poured bituminous materials. The system is then viscous. The characteristic time during which this state lasts is called the workability time. Secondly, the droplets of bitumen coalesce and form a gel. When all the droplets of bitumen are grouped together, it is considered that the emulsion has broken (breakage time). The system is then viscoelastic. The system tends thereafter to contract so as to reduce the contact surface between the water and the bitumen (cohesion time). This process follows a kinetic that will depend on the electrostatic repulsions between droplets and thus the nature of the bitumen and the emulsifier. The kinetic of the coalescence reaction between droplets of bitumen, linked at least in part to the physics-chemistry of the interfaces, conditions the speed of the rise in cohesion of the cold poured bituminous material, which can result in a sensitivity or not of the material to ageing conditions at young age.

[0149] Bituminous Concretes in Emulsion

[0150] Bituminous concretes in emulsion are asphalt mixes produced from aggregates and a hydrocarbon binder in emulsion. The aggregates may be used without prior drying and heating or undergo partial hot pre-lacquering. It may sometimes be necessary to reheat the product after its manufacture, during its application.

[0151] The hydrocarbon binder employed for the synthesis of bituminous concretes in emulsion is in the form of a binder in emulsion. The total content of hydrocarbon binder in said emulsion is typically 2 to 8 ppc (parts percent by weight), advantageously 3 to 7 ppc, more advantageously 3.5 to 5.5 ppc, compared to the weight of solid mineral particles. This binder content corresponds to the quantity of binder introduced as such (added binder) plus the quantity of binder recovered from aggregates of mixes forming part of the solid mineral fraction.

[0152] The hydrocarbon binder in an emulsion used for the confection of a bituminous concrete in emulsion advantageously includes, compared to the total weight of the hydrocarbon binder, 1 to 25% by weight of said compound of formula (I), more advantageously 2 to 15% by weight, even more advantageously 2 to 10% by weight, even more advantageously 3 to 10% by weight.

[0153] The bituminous concretes obtained according to the invention in emulsion may be used for the manufacture of storable mixes.

[0154] In this embodiment, the hydrocarbon binder advantageously includes, compared to the total weight of hydrocarbon binder, 10 to 30% by weight of said compound of formula (I), more advantageously 15 to 25% by weight, even more advantageously 17 to 22% by weight.