EP3615615A1

EP3615615A1 - Interface agents for cold road surfacing preparation

Info

Publication number: EP3615615A1
Application number: EP18718853.7A
Authority: EP
Inventors: Arnaud Bourdette; Frédéric DELFOSSE; Marie-Pierre Labeau; Thomas LEBARBE; Hélène MARTIN; Simon Rousseau; Pierre-Jean MERCIER
Original assignee: Rhodia Operations SAS; Eurovia SA
Current assignee: Rhodia Operations SAS; Eurovia SA
Priority date: 2017-04-27
Filing date: 2018-04-27
Publication date: 2020-03-04
Also published as: WO2018197660A1; CA3061502A1; FR3065732B1; FR3065732A1; CN111386316A; US20210114931A1

Abstract

The invention relates to the manufacture of a coated bituminous product, which comprises bringing mineral particles into contact, at a temperature of less than 110°C, with an emulsion (i) which results from an emulsification of a hydrocarbon-based binder in an aqueous phase at a mixing temperature above the contacting temperature, and (ii) which comprises an additive which: - forms a homogeneous mixture with the hydrocarbon-based binder at the mixing temperature; - is non-compatible with the hydrocarbon-based binder at the contacting temperature; - and is used at a content above the solubility thereof in the aqueous medium of the emulsion at the contacting temperature.

Description

Interface agents for the preparation of cold road surfaces

The present invention relates to the field of bituminous products, in particular useful for the production of road surfacing, based on mineral particles joined together by a hydrocarbon binder according to techniques, wherein the hydrocarbon binder is brought into contact with the mineral particles at low temperatures. temperature, especially according to so-called cold techniques. It relates more specifically to a process for manufacturing low temperature bituminous products using specific additives in the hydrocarbon binder, leading to particularly interesting bituminous products.

In so-called "bituminous" products, mineral particles are bound together by a hydrocarbon binder, which covers all or part of their surface. This hydrocarbon binder is generally a bitumen (bitumen pure or modified by adding in particular polymer (s) or fluxes for example of petroleum or vegetable origin), a vegetable binder (pure or modified) or a synthetic binder of origin oil and may or may not contain a plant part.

Various techniques for the preparation of bituminous products using this type of hydrocarbon binder are known. When the particles are totally (or substantially completely) covered by the binder, it is referred to as a "coating" technique, which leads to a bituminous product called "coated". Alternatively, it is also possible to join particles without necessarily completely coating them, according to techniques in which the particles are deposited on a layer of hydrocarbon binder, the product obtained formed being a "coating" in which the particles are only partly covered. Whether asphalt mixes or coatings, there are two main methods of preparation, according to so-called "hot" and "cold" techniques, respectively.

Hot techniques (which lead to bituminous products of the type coated or "hot" coated) contact aggregates (heated or not) with a hydrocarbon binder raised to a temperature above 1 10 ° C, typically around from 140 to 160 ° C.

Hot bituminous products generally have good qualities in terms of binding aggregates, handling and mechanical properties after implementation and cooling, with properties relatively easy to adapt by adjusting the nature of the binder. However, they have disadvantages in terms of heating costs and, often, environmental impacts. Reason why were developed lower temperature techniques, including so-called "cold" techniques.

The present invention is concerned with these techniques for the preparation of low temperature bituminous products, which include in particular the so-called "cold" techniques.

For the purpose of the present description, for the sake of brevity, the term "coating (total or partial) at low temperature", a process wherein inorganic particles and a binder are contacted at a temperature below 1 10 ° C. and generally less than 100 ° C, typically less than or equal to 90 ° C, and more generally 60 ° C. The bituminous products obtained according to these so-called low temperature coating techniques are either asphalt in the true sense when the coating is total, or coatings when it is partial. These bituminous products will be designated in this description, respectively, by the terms "low temperature hydrocarbon mixes" and "low temperature hydrocarbon coatings" (or more simply "coated (or coated) at low temperature).

Low temperature coating techniques include cold techniques, in particular the technique known as "cold coating", where the coating is carried out without heating, and without drying aggregates, therefore at a temperature close to ambient, typically at temperatures between 5 and 50 ° C depending on the climatic conditions (preferably between 10 and 40 ° C). Low temperature coating techniques that do not meet this definition will be referred to in the present description as "moderate temperature coating" techniques where the contacting of aggregates and bitumen is typically at a temperature, for example between 40 and 110 ° C, typically with preheating of the hydrocarbon binder and / or drying and / or heating of the particles prior to contacting.

Cold coating techniques lead to bituminous products (namely asphalt or coatings) called "cold". The bituminous products obtained by the so-called moderate temperature coating techniques will be referred to as bituminous products (ie coated or coated) known as "moderate temperature". For the purposes of the present description, the use of the term "cold hydrocarbon coating" will be reserved to designate a "hydrocarbon coating made from aggregates, a hydrocarbon binder and optionally dopes and / or additives, whose characteristics allow a coating without drying and heating aggregates ", which corresponds to the definition of NF P 98-149 (Terminology of hydrocarbon mixes). In low temperature coating techniques, both for cold coating and at moderate temperature, the aggregates to be coated are generally brought into contact at low temperature with a hydrocarbon binder in the form of an emulsion and the bituminous material. is obtained by rupture of the emulsion and progressive coalescence of the globules of hydrocarbon binder on all or part of the surface of the particles.

The behavior of the binder after the rupture has a significant impact on the workability of the resulting mixes as well as on the compactibility properties of the mixes and coatings and on the final mechanical properties of the coating obtained. In the low temperature conditions used for the production of temperate or cold mixes, the viscosity of the hydrocarbon binders may in particular have a negative impact on the quality of the coating.

An object of the present invention is to provide a method for improving the quality of bituminous products obtained by coating (total or partial) at low temperature of the aforementioned type. For this purpose, the present invention proposes to incorporate a particular additive in the hydrocarbon binder in low temperature coating techniques, namely a compound that is heat-solubilizable in the hydrocarbon binder, but that is less soluble in the hydrocarbon binder when the low temperature coating, which makes it possible to modify the interface properties between water and bitumen. More specifically, according to a first aspect, the subject of the present invention is a method of manufacturing a bituminous product which comprises a step (E2) of contacting mineral particles with a hydrocarbon binder emulsion carried out at a temperature of setting contact (T2) less than 1 10 ° C,

wherein said emulsion is prepared according to a preliminary emulsification step (E1) in which a hydrocarbon binder comprising an additive (A) is introduced into an aqueous medium (M) and brought to a mixing temperature T1 greater than the setting temperature. T2 contact,

said additive (A):

forming a homogeneous mixture with the hydrocarbon binder at the mixing temperature T1; and - Being a compound not compatible with the hydrocarbon binder at the T2 contact temperature, typically unable to solubilize the hydrocarbon binder more than 5% by weight; and

- being used at a content greater than its solubility in said aqueous medium (M) at the contact temperature T2.

The work which led to the present invention indicates that the use of the additive under the aforementioned conditions makes it possible to advantageously modify the interface between the bitumen particles and the aqueous phase, which is of a nature to optimize the fracture and the coating (partial total) of the particles. In the process of the invention, the additive A is first introduced into the hydrocarbon-based binder at a temperature at least equal to T1, then, in the emulsification step (E1), the aqueous medium (M) is charged with hydrocarbon binder at the temperature T1, the temperature at which said binder is compatible with the additive (A) and forms a homogeneous mixture without phase shift. At the temperature T1, the additive advantageously plays the role of fluxing bitumen.

Next, the emulsion is employed in the step of contacting mineral particles with a hydrocarbon binder emulsion (E2) at a lower contact temperature (T2), where the additive (A) is significantly less compatible with the hydrocarbon binder, which schematically forces the additive to be expelled from the bitumen globules of the emulsion.

The work of the inventors seems to indicate that, under the conditions of the contacting step (E2), and in particular to the extent that it is also used at a content greater than its solubility in water, the additive as well expelled by the hydrocarbon binder is found at least partly "blocked" at the interfaces between the aqueous medium and the hydrocarbon binder given its low compatibility in both media. The additive then passes schematically from the fluxant status of the hydrocarbon binder it provided in step (E1) to that of interface agent. In practice this passage is most often upstream of step (E2): during the decrease in temperature from T1 to T2, the emulsion generally passes through an intermediate temperature where the transition takes place. The contacting temperature T2 to which reference is made in the present description is that of the emulsion at the moment of contacting. In practice, emulsion and aggregates are at the same temperature T2 during the contacting:

When the bituminous product prepared according to step (E2) is an asphalt mix:

the temperature of contacting T2 corresponds generally to the temperature of the aggregates (taking into account the mass effect, the emulsion is brought to their temperature, namely at ambient temperature if the aggregates are not preheated, or alternatively at the temperature at which the aggregates are preheated, typically between 20 and 40 ° C). When the bituminous product prepared according to step (E2) is a coating:

the temperature of contacting T2 corresponds as a rule to the ambient temperature (for a plaster, the asphalt is brought into contact with the ground, and is thus brought to its temperature, before the deposition of aggregates (gravelling). In a particular aspect, the subject of the present invention is the use of additives A of the abovementioned type as an interface agent in a process for the preparation of a bituminous product, in particular intended for the production or repair of a coating. road.

The effect at the interfaces obtained before, during and / or after step (E2) is likely to modify the coalescence phenomena between the globules of hydrocarbon binder. It seems moreover that the modifications that it induces at the interfaces are able to improve the processes of drainage of the water following the rupture of the emulsion.

According to another particular aspect, the subject of the invention is the particular emulsions of the type described above which are used in step (E2) where it seems that at least a part of the additive is at the interface between the globules of bitumen and the aqueous phase.

Preferably, the additive A used according to the invention is a volatile compound, which evaporates out of the prepared bituminous product (after having ensured its dual role of fluxing agent and then interface agent), this evaporation making it possible to obtain a low temperature mix of composition not modified by the additive. The present invention is particularly interesting when the additive employed comprises at least one compound corresponding to the following formula (I):

R ¹ -XRYR ² (I)

or :

R ¹ is a methyl

R ^2, identical or different from R ¹ is a hydrocarbon chain (typically alkyl), linear and branched C _\ -C _\ - _\, preferably C1-C9, more preferably C1-C7, or in CrC ₅ ;

each of -X- and -Y-, identical or different, is -O-C (= O) -; or a group -C (= O) -O-; or a group -NR'-C (= O) -; or a group - C (= O) -NR'- with R 'representing a hydrogen atom or an alkyl radical

-R- is a divalent hydrocarbon chain C1-C1 ₀ , linear or branched, and optionally interrupted by one or more oxygen atoms.

As additive A, it is possible to use according to the invention (i) a single compound corresponding to formula (I) above, namely a single compound of formula CH ₃ -XRY-R ² with groups R ² X, Y and R as defined above; or, alternatively, (ii) a mixture of several compounds of formula CH ₃ -XRYR ² with several types of groups R ² , X, Y and R as defined above.

According to one particular embodiment, a mixture comprising one or more compounds of formula (I) according to the invention with other compounds may be used as additive (A), provided that said mixture meets the criteria required for an additive (A). ) according to the invention in terms of compatibility with the bitumen (at temperature T1 and T2) and the aqueous medium (at temperature T2). Provided that this condition is fulfilled, it is possible for example to use as additive A a mixture comprising at least one compound (I) according to the invention and at least one compound of formula Alk-XRYR ^{2 in} which Alk- denotes a chain hydrocarbon-based (typically alkyl), linear or branched, d-C11, preferably C1-C9 _; and X, Y and R are as defined above for these groups in the compounds of formula (I). Various aspects of the invention and conceivable embodiments of the invention are described in more detail below

Mineral particles

The mineral particles used in step (E2) of the process of the invention are solid particles which can be chosen from all those used for the production of bituminous products, in particular for road construction.

As an example of mineral particles that can be used in step (E2) in the case of the production of an asphalt mix, mention may in particular be made of natural mineral aggregates (chippings, sand, fines) derived from quarries or gravel pits. recycling products such as asphalt aggregates resulting from the recycling of materials recovered during road repairs as well as surplus asphalt plants, manufacturing scrap, shingles (from recycling of roofing membranes) aggregates derived from the recycling of road materials including concretes, slags in particular slags, schists, in particular bauxite or corundum, rubber crumbs derived from the recycling of tires, artificial aggregates of any origin, and from for example household waste incineration slag (MIOM), as well as their mixtures in all proportions.

In step (E2), it is possible to use untreated mineral particles or mineral particles, part of which has been subjected to coating before coating of step (E2). For example, it is possible to use, in step (E2), natural granules, only part of which has previously been coated with a hydrocarbon binder (for example mineral aggregates, all or part of the mineral fraction d / D having been previously subjected to a coating step.

Natural mineral aggregates typically include:

elements less than 0.063 mm (filler or fine) sand whose elements are between 0.063 mm and 2 mm; chippings, the elements of which have dimensions

o between 2 mm and 6 mm;

o greater than 6 mm;

The size of the inorganic aggregates is measured by the tests described in standard NF EN 933-2 (version May 1996). "Asphalt aggregates" means mixtures of aggregates and bituminous binders from asphalt mix milling, crushing of asphalt pavement slabs, asphalt mix pieces, asphalt waste or surplus production of asphalt mixes (production surpluses are materials coated or partially coated in a plant resulting from transitional manufacturing phases). These and other recycling products can reach dimensions up to 31.5 mm.

"Mineral particles" of the type employed in step (E2) are also referred to as "mineral fraction 0 / D". This mineral fraction 0 / D can be separated into two granulometries: the mineral fraction 0 / d and the mineral fraction d / D.

The finer elements (the mineral fraction 0 / d) will be those in the range from 0 to a maximum diameter that can be set between 2 and 6 mm (0/2 to 0/6), preferably between 2 and 4 mm. The other elements (minimum diameter greater than 2, 3, 4, 5 or 6 mm, and approximately up to 31.5 mm) constitute the mineral fraction d / D.

By way of example of mineral particles that can be used in step (E2) in the case of the production of a coating, particular mention may be made of natural mineral aggregates (chippings, sand, fines) coming from quarries or gravel pits. slags, in particular slags, in particular bauxite or corundum, artificial aggregates of any origin and coming for example from household waste incineration slag (MIOM), as well as their mixtures in all proportions.

The hydrocarbon binder and the emulsion prepared in step (E1)

For the purposes of the present description, the term "hydrocarbon-based binder" (also referred to more concisely as "binder") means any hydrocarbon compound of fossil or vegetable origin that can be used for the production of bituminous products, this hydrocarbon-based binder may for example be a bitumen, a vegetable binder or a synthetic binder of petroleum origin, and may, independently of its nature, be pure or modified, in particular by adding dopes or polymer (s).

The binder used according to the present invention may moreover be a soft to hard binder, advantageously of a grade ranging from 10/20 to 160/220. In an interesting way, the binder is a bitumen, pure or modified with polymers. The "polymer" modifying the bitumen referred to herein may be selected from natural or synthetic polymers. It is ^a question, for example ^a polymer of the elastomer family, synthetic or natural, and of indicative and non limiting manner:

random, multi-block or star copolymers of styrene and butadiene or isoprene in all proportions (in particular styrene-butadiene-styrene block copolymers (SBS), styrene-butadiene copolymers (SB, also known as SBR "For styrene-butadiene rubber", styrene-isoprene-styrene (SIS)) or copolymers of the same chemical family (isoprene, natural rubber, ...), optionally crosslinked in situ,

- copolymers ^of vinyl acetate and ^ethylene in all proportions,

copolymers of ethylene and esters of acrylic acid, methacrylic acid or maleic anhydride, copolymers and terpolymers of ethylene and of glycidyl methacrylate and polyolefins.

The bitumen-modifying polymer may be chosen from the recovery polymers, for example "rubber crumb" or other rubber compositions reduced to pieces or in powder form, for example obtained from used tires or other waste materials. base polymers (cables, packaging, agriculture ...) or any other polymer commonly used for bitumen modification such as those mentioned in the Technical Guide written by ^the International Road Association (PIARC) and published by the Laboratory Central of the Bridges and Roads "Use of Modified Bituminous Binders, Special Bitumen and Bitumen with Additives in Road Pavements" (Paris, LCPC, 1999), as well as any mixture in all proportion of these polymers.

Regardless of its exact nature, the binder employed in step (E2) is specifically in the form of an emulsion prepared in step (E1), namely a dispersion of the binder in the aqueous medium (M) which plays the continuous phase role of the emulsion (bitumen emulsion when the binder is a bitumen).

The aqueous phase (M) used in the process of the invention to produce the emulsion of hydrocarbon binder is typically water, but the process is not limited to this single embodiment. Typically, the aqueous phase (M) used in the context of the invention comprises at least 50% by weight of water relative to the total mass of the aqueous phase, and most often at least 80%, or even at least 90% by weight. % by weight of water relative to the total mass of the aqueous phase. Most often, water is substantially the only hydrophilic solvent present in the aqueous phase and is typically between 95 and 100% by weight of all hydrophilic solvents present.

Although this is not systematically required, the emulsion prepared in step (E1) most often contains a surfactant or a mixture of surfactants, which makes it possible in particular to stabilize the emulsion and / or to assist in the dispersion. hydrocarbon binder in the aqueous medium (M). In this context, for a given hydrocarbon-based binder, it is possible to use, during step (E1), any surfactant or emulsifier suitable for the emulsification and stabilization of the dispersion of the targeted hydrocarbon binder, the surfactants of this type well known in the art. self of the skilled person.

During the manufacture of emulsion during step (E1), the binder is typically dispersed in the form of fine droplets (globules) in water for example by a mechanical action, the addition of surfactant that can help this process (the surfactant typically forms a kind of protective film around the droplets, preventing them from clumping together and thus keeping the mixture stable and storing it for a period of time). The amount and type of surfactant added to the mixture determines the storage stability of the emulsion and affects cure time at the time of application.

When a surfactant is employed, it may be positively charged (cationic surfactant), negatively charged (anionic surfactant), or it may be an amphoteric or zwitterionic surfactant, or a nonionic surfactant. These surfactants may be of petroleum, plant and / or animal origin (for example surfactants of vegetable and petroleum origin may be used). The surfactant may be an alkaline soap of fatty acids: sodium or potassium salts of an organic acid (resin for example). The emulsion prepared is then called anionic. On the other hand, the surfactant may be an acidic soap, which is generally obtained by the action of hydrochloric acid on one or two amines. The emulsion is then called cationic. Among the surfactants that are relevant for road application, mention may be made of: surfactants marketed by Akzo NOBEL (Redicote® E9, Redicote® EM 44, Redicote® EM 76), surfactants marketed by CECA (Dinoram® S, Polyram® S, Polyram® L 80), the surfactants marketed by Meadwestvaco (Indulin® R33, Indulin® R66, Indulin® W5). One or more of these surfactants can be used alone or in mixtures. The emulsion formed in step (E1) may be wholly or partly in the form of a foam. Such a foam may for example be formed when the hydrocarbon binder and the aqueous medium are mixed by a method of injecting the aqueous phase (optionally with air) into a binder stream.

The emulsion formed in step (E1) is typically conducted by mixing the hydrocarbon binder brought to the mixing temperature T1 in the aqueous phase generally to a temperature below T1 (the aqueous phase is generally heated prior to emulsification but not up to T1 in most cases). The mixing temperature T1 to which the hydrocarbon binder is brought just before contacting with the aqueous medium (M) is typically greater than 110 ° C. or even 120 ° C. and is generally between 125 and 160 ° C. , especially between 130 and 150 ° C.

The emulsion formed in step (E1) may optionally comprise (in addition to the aqueous phase, bitumen including additive A, and optional surfactants) one or more other additives commonly used in this type of emulsion, in particular those used in the road, such as compositions based on reduced rubber powder ("rubber crumb"), vegetable or petrochemical waxes, or adhesives dopes.

Furthermore, the emulsion of hydrocarbon binder formed in step (E1) may optionally contain a latex, synthetic or natural. By latex is meant a dispersion of polymers (polyisoprene, SBS, SB, SBR, acrylic polymers, etc.), crosslinked or otherwise, in the aqueous phase of the emulsion. This latex is then typically incorporated in the aqueous phase before emulsification or in-line during the manufacture of the emulsion, or even after dispersion of the binder in the aqueous medium (M).

The additive A The nature of the additive A used according to the invention can vary to a very large extent provided that this additive meets the following two criteria in terms of compatibility with the hydrocarbon binder used in the process:

additive A forms a homogeneous mixture, namely without phase separation, with the hydrocarbon-based binder at the mixing temperature T1 of step (E1); and additive A is much less compatible with the hydrocarbon binder at the contacting temperature T2 of step (E2)

It is preferred that the additive A is as least compatible as possible in the hydrocarbon binder at the contacting temperature T2 of step (E2). Typically the hydrocarbon binder is soluble to less than 5% by weight, or even less than 4% by weight, in the additive A at the contact temperature T 2.

The solubility of a bitumen hydrocarbon binder in a given additive can be evaluated by measuring the amount of hydrocarbon binder passed in solution in the additive after 3 days of immersion at room temperature.

Moreover, the additive A is specifically employed in the process of the invention in a content greater than its solubility in said aqueous medium (M) at the T2 contact temperature. By this is meant that the amount of additive A present in the emulsion at the temperature T2 outside the particles of hydrocarbon binder (that is to say, schematically the amount of additive A released by the hydrocarbon binder taking into account the decrease in temperature) is greater than the amount of additive (A) that can solubilize the aqueous medium. For a given additive, knowing its solubility in the aqueous medium and in the hydrocarbon binder (which can be determined experimentally), it is within the skill of the person skilled in the art to adapt the amount of additive A to be used in the process.

According to one possible embodiment, it is possible to carry out the emulsification of step (E1) with both additive A in the bituminous binder and also in an aqueous medium so as to ensure that the additive A will be present beyond its solubility limit in the aqueous medium in step (E1). One possible mode in this context, although of little interest from an economic point of view, consists in carrying out the emulsification of a hydrocarbon binder comprising the additive A solubilized in an aqueous medium saturated with said additive A.

Furthermore, the additive A employed according to the invention is preferably a volatile compound at room temperature, which is preferably rapidly removed from the bituminous products prepared according to the process of the invention. The compounds of formula (I) that can be used according to the invention

As particularly suitable additives A according to the invention, it is possible in particular to use compounds of formula (I) defined above in the present description, namely compounds or mixtures of compounds of formula CH ₃ -XRYR ² , where the groups R ² , -X-, -Y-, and -R- have the abovementioned meanings.

According to the invention, it is possible to use either a single type of compound (I) or, alternatively, a mixture comprising various compounds corresponding to formula (I). In the application, except explicit mention, the concept of compound of formula (I) used in the singular or the plural intends to target both the mode where a single type of compound of the formula (I) is used as that where we put in a mixture of several types of compounds having the formula (I).

The compounds of formula (I) advantageously have a molecular mass of between 130 g / mol and 290 g / mol, more advantageously of between 140 g / mol and 250 g / mol, even more advantageously between 150 g / mol and 200 g. / mol.

In the compounds of formula (I) used according to the invention, the total number of carbon atoms is preferably between 5 and 12. According to one embodiment, the total number of carbon atoms is greater than or equal to 6. Furthermore, it is generally preferred that the total number of carbon atoms is less than or equal to 1 1, for example less than or equal to 10. Thus, for example, the total number of carbon atoms can be between 6 and 1 1, for example between 6 and 8.

The total number of carbon atoms defined in the preceding paragraph is particularly valid when the groups R, R ¹ and R ² are saturated, linear or branched groups.

The R ² group, preferably represents an alkyl, aryl, alkylaryl, or arylalkyl, linear or branched, cyclic or noncyclic, saturated or unsaturated and usually saturated in C _\ -C _\ - _\, typically C1 C9.

The group R 2 may especially be a methyl, ethyl, n-propyl, isopropyl, benzyl, phenyl, n-butyl, isobutyl, n-pentyl, isoamyl, cyclohexyl, hexyl, n-hexyl, heptyl, isooctyl or 2-ethylhexyl group. 2-propylhexyl. At least one of R1, R2 is a methyl radical. Advantageously, (especially for reasons of ease of synthesis) R 1, R ² both represent a methyl radical and the compound of formula (I) is then a dimethyl compound which then corresponds to the following formula (Ia): where the groups -X-, -Y-, and -R- have the aforementioned meanings.

According to a first advantageous variant, a compound of formula (I) according to the invention may for example be a compound of formula (Ia) chosen from dimethyl adipate, dimethyl glutarate, dimethyl succinate, and mixtures thereof.

A suitable mixture according to this variant may for example comprise, by weight relative to the total weight of the mixture (measurable for example by gas chromatography), a mixture of dimethyl adipate (for example from 4 to 22% by weight), by dimethyl glutarate (for example from 55 to 77% by weight), and dimethyl succinate (for example from 12 to 32% by weight).

It is possible for example to use as compound (I) according to the first variant, the solvent marketed by Solvay under the name Rhodiasolv® RPDE.

Advantageously, the additive may be used, available from Solvay under the tradename ^® INNROAD BOOST (hot additive consistent with the bitumen and the bitumen solubilizing up to less than 2% at room temperature after three days).

According to a second possible variant, another compound of formula (I) which can be used, alone or as a mixture with that of the first variant, is a compound of formula (Ia) and the group R is chosen from the following groups:

the group R _M G of formula -CH (CH ₃ ) -CH ₂ -Cl-12,

the group R _E s of formula -CH (C2H ₅ ) -CH ₂ -, and

- their mixtures.

-X- and -Y- are advantageously esters,

preferably diacid esters

(compounds where -X- = -O-C (= O) -; and -Y- = -C (= O) -O-,

that is of formula: CH ₃ -O-C (= O) -RC (= O) -R ² ); or

esters of diols (where -X- = -C (= O) -O- and -Y- = -O-C (= O) - namely of formula: CH ₃ -C (= O) -O-R -O-C (= O) -R ² ). Can be used for example according to this second variant, the solvent marketed by Solvay under the trademark Rhodiasolv ^® IRIS, (which is compatible hot with asphalt and solubilized in the amount of less than 3% at room temperature after three days) In one embodiment As a possible embodiment, the additive A may be a mixture, meeting the criteria required for an additive (A) according to the invention in terms of compatibility with the hydrocarbon binder (at T1 and T2) and with the aqueous medium (at T2). and including:

one or more of the compounds of formula (I) above, in particular compounds of formula (I) according to the first and second variants defined in the above paragraphs; and

one or more compounds corresponding to the following formula (II):

R ¹ -XRYR ² (II)

or :

R ¹ is a linear or branched, C ₂ -C n, preferably C ₂ -C _9, hydrocarbon-based chain _, preferably an alkyl, aryl, alkylaryl or arylalkyl group, linear or branched, cyclic; or not cyclic, saturated or unsaturated and most often saturated, C ₂ -C n, typically C ₂ -C ₉

X-, -Y-, -R-, and R ² have the aforementioned meanings given for the compound of formula (I)

When this type of mixture is used, the compounds of formula (I) are generally in the majority and the mass ratio (I) / (II) of the total mass of compound (s) of formula (I) referred to the total mass of compound (s) of formula (II) is most often greater than or equal to 1, for example greater than or equal to 2.

In the compounds of formula (II) optionally used according to the invention, the total number of carbon atoms is preferably between 7 and 16. According to one embodiment, the total number of carbon atoms is greater than or equal to at 8, or even greater than or equal to 9. Moreover, it is generally preferred that the total number of carbon atoms is less than or equal to 15, for example less than or equal to 14. Thus, for example, the total number of carbon atoms is carbon atom can be between 8 and 15, for example between 8 and 12 or between 10 and 15 or between 10 and 12 or between 12 and 14. The total number of carbon atoms defined in the preceding paragraph is particularly valid when the R, R ¹ and R ² groups are saturated, linear or branched groups, and especially when they are saturated and branched groups. In the compounds of formula (II) optionally used according to the invention, the groups R ¹ and R ² can in particular be chosen from ethyl, n-propyl, isopropyl, benzyl, phenyl, n-butyl and isobutyl groups. -pentyl, isoamyl, cyclohexyl, hexyl, n-hexyl, heptyl, isooctyl, 2-ethylhexyl, 2-propylhexyl. Typically (especially for reasons of ease of synthesis) R ¹ and R ² are identical and are selected from ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isoamyl, in particular ethyl or isobutyl.

Compounds in which R is as defined in one of the following modes or a mixture of compound (s) according to these embodiments can be used as compounds of formula (II):

^■ Mode 1: R is a radical of formula - (CH ₂ ) _r -, where r is an average number between 2 and 8 inclusive. In particular, R is a radical of formula - (CH ₂ ) _r -, where r is an average number between 2 and 4 inclusive.

Preferably, R is chosen so that the compound can be a mixture of adipate derivative (r = 4), glutarate derivative (r = 3), and succinate derivative (r =

2).

^■ Mode 2: R is an alkanediyl radical of C ₃ -C ₁₀ branched. R may especially be a C _3, C ₄ , C ₅ , C ₆ , C ₇ , C ₈ or C _{9 group} , or a mixture. It is preferably a C _{4 group} .

The group R is preferably chosen from the following groups:

the group R _M G of formula -CH (CH ₃ ) -CH ₂ -Cl-12,

the group R _E s of formula -CH (C2H ₅ ) -CH ₂ -, and

- their mixtures.

Such mixtures, as well as suitable methods for obtaining them, are described in particular in documents WO 2007/101929; WO 2007/141404; WO

2008/009792; WO 2008/062058.

^■ Mode 3: R is a linear or branched C ₂ -C ₈ , advantageously C ₂ -C _4, alkenyl radical.

The group R is preferably chosen from the following groups: the group of formula -CH = CH-, the double bond being of Z configuration

the group of formula -CH = CH-, the double bond being of configuration E

the group of formula -CH (CH ₂ ) -CH ₂ -, and

- their mixtures. Mode 4: R is a radical - (OE / OP) _n - where OE / OP are alkoxy groups, preferably chosen from ethoxy, propoxy and ethoxy / propoxy mixtures and n is an average number of between 1 and 5; included and with a total carbon number of 10 in the R group.

In the above-mentioned modes 1 to 4, X and Y are advantageously esters, preferably diacid esters (where: -X- = -O-C (= O) - and Y = -C (= O) - 0-) or diol esters (where: -X- = -C (= O) -O- and Y = -O-C (= O) -)

Advantageously, when a compound of formula (II) according to the invention is used, this compound (II) is chosen from:

^■ diisobutyl adipate, diisobutyl glutarate and diisobutyl succinate, and mixtures thereof, such as:

a mixture comprising, by weight relative to the total weight of the mixture (measurable by Gas Chromatography): from 5 to 29% by weight of diisobutyl adipate; from 50 to 72% by weight of diisobutyl glutarate; and from 10 to 32% by weight of diisobutyl succinate.

the solvent marketed by Solvay under the name Rhodiasolv® DIB (for example, a 1: 1 mixture by weight of INNROAD® Boost and Rhodiasolv® DIB is hot-compatible with the bitumen and solubilizes it to less than 4% at room temperature after three days).

^■ diethyl adipate, diethyl glutarate and diethyl succinate, and mixtures thereof, such as:

a mixture comprising, by weight relative to the total weight of the mixture (measurable by Gas Chromatography): from 4 to 26% by weight of diethyl adipate; from 52 to 77% by weight of diethyl glutarate; and from 12 to 32% by weight of diethyl succinate.

- the additive available from Solvay under the name INNROAD® Protect Accessible bituminous products according to the invention

The bituminous products which the process of the invention makes it possible to prepare include all bituminous products which can be produced at low temperature and in particular at cold temperature, that is to say all bituminous products of the type coated at low temperature according to the present description, including cold mixes and coatings and mixes and coatings at moderate temperature. .

The bituminous products accessible according to the invention include, in particular, emulsion and cold-mix coatings, in particular of the cold-cast bituminous material type, bituminous concretes with emulsion and emulsion-stable mixes, which are described. more in detail below.

coatings

A surface coating is typically a layer of superimposed states of a hydrocarbon binder and mineral solid particles. It is typically obtained by spraying a hydrocarbon binder and then spreading on this binder mineral solid particles in one or more layers. The whole is then compacted.

The mineral solid particles employed in a coating advantageously belong to the following granular classes (d / D): 4 / 6.3, 6.3 / 10, 10/14.

The total content of hydrocarbon binder in a coating will be adapted according to the structure of the coating (mono- or bilayer, type of gravel), the nature of the binder, the climatic conditions and the size of the aggregates, following by example the recommendations of the document "Superficial wear coatings - Technical Guide, May 1995".

The hydrocarbon binder used for the manufacture of a coating may be a pure bitumen or modified with polymers, as described above.

The hydrocarbon binder is an emulsion binder. In this embodiment, the hydrocarbon-based binder advantageously comprises, relative to the total weight of the hydrocarbon-based binder, 0.1 to 10% by weight of said compound of formula (I), more advantageously 0.5 to 8% by weight, and even more advantageously 1 to 10% by weight. at 6% by weight. Covered:

^■ Cold bituminous materials

Cold-rolled bituminous materials are surface coating mixes consisting of undried aggregates coated with bitumen emulsion and continuously cast in place using specific equipment.

After its implementation and rupture of the emulsion, this very low-thickness cold-cast coating (generally 6 to 13 mm thick per layer) must reach its final consistency (cohesion) very rapidly. The additives used according to the invention can have a favorable influence on this parameter.

For a cold-poured bituminous material, the initially separated bitumen droplets give the system a fluid character and easy set-up using specific machines for cold-poured bituminous materials. The system is then viscous. The characteristic time during which this state continues is called the maneuverability time. In a second step, the droplets of bitumen coalesce and form a gel. When all the bitumen droplets are pooled, it is considered that the emulsion has broken (break time). The system is then viscoelastic. The system then tends to contract so as to reduce the contact surface between the water and the bitumen (cohesion time). This process follows a kinetics that will depend on the electrostatic repulsions between droplets and therefore the nature of the bitumen and the emulsifier. The kinetics of the coalescence reaction between the bitumen droplets, linked at least in part to the physico-chemistry of the interfaces, determines the speed of the cohesion increase of the cold-poured bituminous material which can result in a sensitivity or not in the material with maturing conditions at young age

^■ Bituminous concrete with emulsion

Bituminous concretes with emulsion are hydrocarbon mixes made from aggregates and a hydrocarbon emulsion binder. Aggregates can be used without drying and pre-heating or partially pre-lacquered hot. It may sometimes be necessary to warm the product after its manufacture, when it is used.

The hydrocarbon binder used for the synthesis of bituminous concretes in the emulsion is in the form of an emulsion binder. The total content of hydrocarbon binder in said The emulsion is typically 2 to 8 phr (part percent by weight), preferably 3 to 7 phr, more preferably 3.5 to 5.5 phr, based on the weight of the inorganic solid particles. This binder content corresponds to the amount of binder introduced as such (binder) plus the amount of binder recovered from the asphalt aggregates forming part of the solid mineral fraction.

The hydrocarbon binder in an emulsion used for the preparation of an asphalt concrete with emulsion advantageously comprises, relative 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, still more preferably 2 to 10% by weight, still more preferably 3 to 10% by weight.

Bituminous concretes obtained according to the invention to the emulsion can be used for the manufacture of storable mixes.

In this embodiment, the hydrocarbon-based binder advantageously comprises, relative to the total weight of the hydrocarbon-based binder, 10 to 30% by weight of said compound of formula (I), more preferably 15 to 25% by weight, and even more advantageously 17 to 22% by weight. % in weight.

Claims

A method of manufacturing a bituminous product, which comprises a step (E2) of contacting mineral particles with a hydrocarbon binder emulsion carried out at a contact temperature (T2) of less than 1 10 ° C,

wherein said emulsion is derived from a preliminary emulsification step (E1) in which a hydrocarbon binder comprising an additive (A) is introduced into an aqueous medium (M) and brought to a mixing temperature T1 greater than the setting temperature. in contact T2,

where said additive (A):

- form a homogeneous mixture with the hydrocarbon binder at the mixing temperature T1; and

- Is a compound not compatible with the hydrocarbon binder at the T2 contact temperature; and

is used at a content greater than its solubility in said aqueous medium (M) at the T2 contact temperature.

2. Process according to claim 1, wherein the additive A is a volatile compound which evaporates out of the prepared bituminous product.

3. Process according to claim 1 or 2, wherein the additive A comprises a compound corresponding to the following formula (I):

R ¹ -XRYR ² (I)

or :

R ¹ is a methyl

R ² , which is identical to or different from R ¹ , is a linear or branched hydrocarbon-based chain, in C, preferably in d-Cg;

each of -X- and -Y-, identical or different, is -O- (C = O) -; or a group -C (= O) -O-; or a group -NR'-C (= O) -; or a group -C (= 0) - NR'- with R 'representing a hydrogen atom or an alkyl radical

and

-R- is a divalent hydrocarbon chain, C ₁ -C ₁₀ , linear or branched, and optionally interrupted by one or more oxygen atoms.

The process according to claim 3, wherein the additive A is a compound of formula (I) or a mixture of such compounds.

Process according to claim 3 or 4, wherein additive A is a dimethyl compound which corresponds to formula (la) below: where -X-, -Y-, and -R- have the meanings given in claim 3.

Process according to Claim 5, in which additive A is a compound of formula (Ia) chosen from dimethyl adipate, dimethyl glutarate and dimethyl succinate, and mixtures thereof.

The process according to claim 5, wherein the additive A is composed of formula (Ia), wherein: the group R is selected from the following groups:

the group R _M G of formula -CH (CH ₃ ) -CH ₂ -Cl-12,

the group R _E s of formula -CH (C2H ₅ ) -CH ₂ -, and

- their mixtures;

-X- and -Y- are preferably esters.

Use in the method of claim 1, particularly for the production or repair of a road surface, additive A as an interface agent.

Emulsions adapted to the implementation of step (E2) of the process of claim 1, comprising at least a portion of the additive A at the interface between the globules of bitumen and the aqueous phase.

An emulsion according to claim 8, wherein the additive is as defined in one of claims 3 to 6.