FR3044675A1 - THERMORETICULATED BITUMEN-POLYMER COMPOSITION AND PROCESS FOR PREPARING THE SAME - Google Patents

Abstract

A process for the preparation of a thermocoated bitumen-polymer composition comprising: a) the preparation of a thermo-cured bitumen-polymer composition (BPa) comprising at least one heat-curable bitumen-polymer base and the additive of general formula (I) R1- ( Wherein R1 is a linear or branched hydrocarbon chain, saturated or unsaturated comprising from 4 to 68 carbon atoms, and z an integer ranging from 1 to 4; b) the hot mix of the bitumen-thermo-polymer-polymer composition; (BPa) with at least one bitumen base. Bitumen-polymer composition obtained by this process and its uses, in particular for the manufacture of asphalt.

Description

THERMORETICULATED BITUMEN-POLYMER COMPOSITION AND METHOD THEREOF

OF PREPARATION

TECHNICAL AREA

The subject of the present invention is a process for the preparation of a thermocure-polymer bitumen-polymer composition. This composition may be stored and / or cold-transported in an intermediate state and then converted into a storage-stable composition, preferably heat-storage and ready for application with satisfactory elastic properties.

The subject of the present invention is also a process for the preparation of bituminous mixes comprising mixing the aggregates with this storage-stable, heat-storage thermocure bitumen-polymer composition, preferably in hot storage and ready for application.

STATE OF THE ART

For many years, bitumen-polymer compositions crosslinked with sulfur-containing agents are used in the road sector and mainly for the manufacture of road pavements. These sulfur-crosslinked bitumen-polymer compositions have improved mechanical and rheological properties compared with conventional bitumen compositions, in particular they have elastic properties greater than these.

However, as with all existing road bitumens, these bitumen-polymer compositions are stored and transported hot, in bulk, in tanker trucks or by boats at high temperatures of the order of 120 ° C to 200 ° C.

The storage and transport of hot bitumen has certain disadvantages. On the one hand, the transport of hot bitumen in liquid form is considered dangerous and it is very framed from a regulatory point of view. This mode of transport presents no particular difficulties when the equipment and the transport infrastructures are in good condition. Otherwise, it can become problematic: if the tanker is not sufficiently insulated, the bitumen may become viscous during a trip too long. Delivery distances for bitumen are therefore limited. On the other hand, the maintenance of bitumen at high temperatures in tanks or tank trucks consumes energy. In addition, maintaining the temperature of the bitumen for a given period can affect the properties of the bitumen, in particular due to aging phenomena and thus change the final performance of the asphalt.

In addition, it is known that the sulfur-crosslinked bitumen-polymer compositions have disadvantages because during the crosslinking step, there is formation of hydrogen sulphide, which is a toxic gas. By way of example, the application WO2008 / 137394 describes a process for preparing a polymer-modified bituminous binder composition in the absence of crosslinking agents by heating a bitumen at a temperature of 160 ° C to 220 ° C. C, adding a block copolymer composition and stirring to form a homogeneous mixture. The block copolymer compositions used comprise one or more block copolymers having at least one monovinylaromatic block, at least one polybutadiene block having a vinyl content of less than 15 mol percent and at least one polybutadiene block having a vinyl content of more than 25 percent by mole. These bitumen-polymer compositions are crosslinked in the absence of crosslinking agent such as sulfur, but however do not overcome the drawbacks of transport and storage of hot bitumen. Therefore, to overcome the problems of transport and storage of hot bitumen, transport and storage solutions in cold conditioning have been developed. This mode of transportation of cold-packaged bitumen represents only a small fraction of the quantities transported worldwide, but it corresponds to very real needs for geographical regions of difficult and expensive access by traditional means of transport. By way of example, mention may be made of the transport of bitumen at ambient temperature in metal drums. This means is increasingly questionable from an environmental point of view because the cold bitumen stored in the barrels must be reheated before use as a road binder. However, this operation is difficult to implement for this type of packaging and the drums are a waste after use. On the other hand, the storage of cold bitumen in drums leads to losses because the bitumen is very viscous, and part of the product remains on the walls of the drum during the transfer of the bitumen to the tanks of the production units. As for handling and transporting bituminous products in these drums, they may be difficult and dangerous if specialized drum handling equipment is not available at the carriers or where the bitumen is used. In addition, the barrels used to transport the bitumen are not recovered again to transport the bitumen and therefore generate additional waste to be reprocessed.

The packaging of bituminous products in paper or thermoplastic bags, such as polypropylene or polyethylene, has been the subject of recent developments. For example, the US patent application 2011/0290695 describes a system for dispensing and packaging bituminous products in block form. Each block of bitumen is surrounded by a film of bituminous composition consisting of about 10 to 30% by weight of natural bitumen and about 5 to 25% by weight of a polymer of synthetic rubber and copolymers. The bituminous composition film is melted with the bituminous product and is fully compatible with the molten bitumen.

However, it has been found that bituminous products packaged in the form of paper bags or of thermoplastic material can flow during their handling, storage and transport, because the bags or films made of thermoplastic material can be pierced, increasing the risk of deformation. and leakage, especially when the outside temperature is high. When the bags or films of thermoplastic material are pierced, the bitumen flows and the bags or blocks surrounded by thermoplastic film stick together. The handling of the bags or blocks surrounded by thermoplastic material film thus deteriorated becomes impossible, which renders them unusable.

Despite the recent development of bituminous product packaging, there is still a need to find a storage solution and transport of road bitumen and cold bituminous materials to overcome the drawbacks mentioned above.

In particular, the object of the present invention is to provide a bitumen-polymer composition that does not generate a toxic and transportable and / or cold-storable product that is improved.

Another object of the invention is to provide a bitumen-polymer composition for easy handling of road bitumen during handling operations.

Another objective of the invention is to propose an ecological and economical process for transporting road bitumen and to avoid the use of additional means for maintaining the temperature of said bitumen during transport and / or storage.

This objective has been achieved by the addition of an acidic compound in the bitumen-thermo-cured polymer base.

However, the addition of acidic compounds in a heat-curable bitumen-polymer base does not always have any effect on the properties of the composition, in particular on its properties of use, and in particular the elastic properties of the thermocure-polymer bitumen-polymer compositions. .

Another object of the invention has been to provide a bituminous polymer-polymer composition storable and transportable cold and having elastic properties comparable to those thermoreiculated bitumen-polymer compositions having no acidic compounds.

An object of the present invention is to provide a thermo-cured bitumen-polymer composition and a process for preparing this composition, such that the elastic properties of the thermoreiculated bitumen-polymer compositions obtained are comparable to those of the thermoreically-cured bitumen-polymer compositions without acid compound.

In particular, the object of the present invention is to provide a composition of bitumen / thermally-cured polymer which in an intermediate state is storable and / or cold-transportable and a method for restoring the elastic properties, in particular the springback, of these compositions thermo-polymerised bitumen-polymer.

OBJECT OF THE INVENTION The subject of the invention is a process for the preparation of a thermocomposed bitumen-polymer composition comprising: a) the preparation of a thermo-cured bitumen-polymer composition (BPa) comprising at least one heat-curable bitumen-polymer base and an additive of general formula (I) R1- (COOH) z in which R1 is a linear or branched, saturated or unsaturated hydrocarbon-based chain comprising from 4 to 68 carbon atoms, and z an integer ranging from 1 to 4, b) hot mixing the bitumen-thermo-polymer-polymer composition (BPa) with at least one bitumen base to obtain a composition (BPb).

According to a preferred embodiment, the method comprises at least one step of storage and / or cold transport of the composition (BPa) between steps a) and b).

According to a still preferred embodiment, the composition (BPa) is stored and / or transported in the form of bitumen bars.

According to a preferred embodiment, step b) of the process comprises the steps of: i) heating the bitumen-thermo-polymer-polymer composition (BPa) at a temperature of between 100 ° C. and 200 ° C. and stirring up to obtaining a homogeneous mixture, ii) adding at least one bitumen base simultaneously or after step i)

According to a still preferred embodiment, the bitumen base added in step ii) is preheated to a temperature of between 100 ° C. and 200 ° C.

According to a preferred embodiment, the additive (I) is a diacid of the general formula HOOC-CwH2w-COOH in which w is an integer ranging from 4 to 22.

According to a still more preferred embodiment, the additive (I) is a diacid chosen from the group consisting of adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, 1,2-dodecanedioic acid and tetradecanedioic acid.

According to a preferred embodiment, the thermo-polymerized bitumen-polymer composition (BPa) comprises from 0.1% to 5% by weight of the additive (I) relative to the total weight of the bitumen-polymer-thermo-polymer (BPa) composition. .

According to a preferred embodiment, the polymer is an elastomer based on a monovinyl aromatic hydrocarbon monomer and butadiene.

According to a still more preferred embodiment, the polymer is an elastomer chosen from thermally crosslinkable block copolymers of formula S-B1-B2, in which S represents a monovinyl aromatic hydrocarbon block having a peak molecular weight of 10,000 to 25,000, B1. is a polybutadiene block having a vinyl content of not more than 15 mole percent, B2 is a polybutadiene block having a vinyl content greater than or equal to 25 mole percent, B1 / B2 mass ratio is greater than or equal to at 1: 1, and wherein the S-B1-B2 block copolymer has a peak molecular weight of 40,000 to 200,000; the elastomer may further comprise at least one thermally crosslinkable block copolymer having the formula (S-B1-B2) nX wherein each S represents a monovinyl aromatic hydrocarbon block having a peak molecular weight of 10,000 to 25,000, each B1 is a polybutadiene block having a vinyl content of less than or equal to 15 mole percent, each B2 is a polybutadiene block having a vinyl content greater than or equal to 25 mole percent, n is an integer ranging from 2 to 6 and X is the residue of a coupling agent, wherein the mass ratio B1 / B2 is greater than or equal to 1: 1, and the block copolymer (S-B1-B2) nX has a peak molecular weight which is 1.5 to 6.0 times the peak molecular weight of the S-B1-B2 block copolymer.

According to a preferred embodiment, the composition (BPa) has a polymer content ranging from 1 to 30% by weight of polymer relative to the total weight of the composition (BPa), preferably from 3 to 20%, more preferably from 5 to 15%.

According to a preferred embodiment, the bitumen-thermo-polymer-polymer composition (BPb) has an additive content (I) less than or equal to 1.1% by weight relative to the total mass of the composition (BPb).

According to a preferred embodiment, the thermo-polymerized bitumen-polymer composition (BPb) has a polymer content of less than or equal to 5% by weight relative to the total mass of the composition (BPb). The subject of the invention is also a thermocured polymer bitumen composition obtained by the process as described above.

According to a preferred embodiment, the composition has an elastic return measured at 25 ° C according to standard NF EN 13398 of at least 70% with respect to the elastic return of the uncrosslinked bitumen-polymer base, measured under the same conditions. The invention also relates to the use of the composition as defined above, for the manufacture of bituminous mixes. The invention also relates to a process for manufacturing bituminous mixes comprising at least one bitumen-thermo-polymer-polymer composition as defined above and aggregates, this process comprising at least the steps of: - heating the aggregates to a temperature ranging from 100.degree. C. to 180.degree. C., preferably from 120.degree. C. to 160.degree. C., mixing the aggregates with the bitumen-thermo-polymer-polymer composition, obtaining mixes.

According to a preferred embodiment, the method comprises a storage step, preferably a hot storage step, of the bitumen-polymer thermo-crosslinked composition as defined above obtained in step b) of the process according to the invention. , before the heating steps of aggregates and mixing.

DETAILED DESCRIPTION

The objectives that the applicant has set has been achieved thanks to the development of a bitumen-polymer thermo-cured composition resulting from the mixing and heating of the bitumen-thermo-polymer-polymer base with a compound of general formula (I) R1- (COOH) z in which R 1 is a linear or branched, saturated or unsaturated hydrocarbon-based chain comprising from 4 to 68 carbon atoms, and z an integer ranging from 1 to 4, with at least one bitumen base.

These objectives have been achieved thanks to the development of a process comprising: on the one hand the preparation of a thermo-cured bitumen-polymer composition (BPa) comprising the additive of general formula (I) defined above, this composition being storable and / or transportable cold, • on the other hand the hot mix of the bitumen-polymer thermoreticulated composition (BPa) with at least one bitumen base.

This process makes it possible to transform a sterilizable and / or cold transportable bitumen-polymer composition (BPa) into a thermoreistulated bitumen-polymer composition (BPb) which is stable in storage, preferably stable to hot storage and ready for application, by dilution with at least one bitumen base, such that the elastic properties of said thermo-polymerized bitumen-polymer composition (BPb) are comparable to the elastic properties of a bitumen-polymer base or of a conventional thermore-cured bitumen-polymer composition that does not include additive (I).

By bitumen-polymer composition is meant a bituminous composition consisting of one or more bitumen bases and comprising one or more polymers. Preferably, the bitumen-polymer composition is intended for road application. Advantageously, the bitumen-polymer composition is used as a road binder to manufacture mixes, in combination with aggregates according to any known method. Bituminous mixes are used as materials for the construction and maintenance of pavement bodies and their pavement, as well as for the realization of all road works. For example, superficial coatings, hot mixes, cold mixes, cold-cast asphalts, deep emulsions, base, binding, hooking and rolling layers, and other combinations of coatings can be mentioned. a bituminous binder and road aggregate having particular properties, such as anti-omerant layers, draining mixes, or asphalts (mixture between a binder and granules of the sand type).

The term "conventional bitumen-polymer composition" means a bitumen-polymer composition comprising no additive (I) or which has not been obtained by heating a bitumen-polymer composition comprising an additive (I).

The preparation of the thermoreiculated bitumen-polymer composition (BPa) storable and / or transportable cold

According to the invention, a heat-transferable and / or cold-transportable bitumen-polymer composition (BPa) is prepared by contacting at least: a bitumen base, a thermocrosslinkable polymer, a compound of general formula (I): Wherein R 1 is a linear or branched hydrocarbon chain, saturated or unsaturated having from 4 to 68 carbon atoms, and z an integer ranging from 1 to 4.

Preferably, a heat-transferable and / or cold-transportable bitumen-polymer composition (BPa) is prepared by: contacting at least one bitumen base and a thermally crosslinkable polymer, and then adding to the mixture previously obtained a compound of general formula (I): R1- (COOH) z wherein R1 is a linear or branched, saturated or unsaturated hydrocarbon chain comprising from 4 to 68 carbon atoms, and z an integer ranging from 1 to 4.

Among the bitumen bases that may be used according to the invention, mention may first be made of bitumens of natural origin, those contained in deposits of natural bitumen, natural asphalt or bituminous sands and bitumens originating from the refining of crude oil. . The bitumen bases according to the invention are advantageously chosen from bitumen bases originating from the refining of crude oil. The bitumen bases may be chosen from bitumen bases or mixtures of bitumen bases from the refining of crude oil, in particular bitumen bases containing asphaltenes. The bitumen bases can be obtained by conventional processes for the manufacture of bitumen bases in a refinery, in particular by direct distillation and / or vacuum distillation of the oil. These bitumen bases may optionally be visbroken and / or deasphalted and / or rectified in air. The various bitumen bases obtained by the refining processes can be combined with each other to obtain the best technical compromise. The bitumen base can also be a bitumen base for recycling. The bitumen bases may be bitumen bases of hard grade or soft grade. The bitumen bases according to the invention have a penetrability, measured at 25 ° C. according to the EN 1426 standard, between 5 and 300 1/10 mm, preferably between 10 and 100 1/10 mm, more preferably between 30 and 100 1 / 10 mm.

In a well-known manner, the so-called "needle penetration" measurement is carried out by means of a standardized test NF EN 1426 at 25 ° C. (P25). This characteristic of penetrability is expressed in tenths of a millimeter (dmm or 1/10 mm). The needle penetration, measured at 25 ° C, according to the standardized test NF EN 1426, represents the measurement of the penetration into a sample of bitumen, after a time of 5 seconds, of a needle whose weight with its support is 100 g. The NF EN 1426 standard replaces the homologated NF T 66-004 standard of December 1986 with effect from December 20, 1999 (decision of the Chief Executive Officer of AFNOR dated November 20, 1999).

The polymer included in the bitumen-polymer composition according to the invention is a thermocurable elastomer for known bitumen, preferably chosen elastomers made from styrene monomers and butadiene monomers allowing crosslinking without a crosslinking agent as described in WO2007 / 058994 and WO2008 / 137394 and also by the applicant in the patent application WO2011 / 013073.

According to a particular embodiment of the invention, the elastomer is a tri-block copolymer or a mixture of tri-block copolymers.

According to a preferred embodiment of the invention the elastomer is a copolymer based on a monovinyl aromatic hydrocarbon monomer, such as for example styrene, and butadiene.

The elastomer is preferably chosen from thermally crosslinkable block copolymers of formula S-B1-B2, in which S represents a monovinyl aromatic hydrocarbon block having a peak molecular weight of 10,000 to 25,000, B1 is a polybutadiene block having a vinyl content. less than or equal to 15 mole percent, B2 is a polybutadiene block having a vinyl content of greater than or equal to 25 mole percent. The elastomer may further comprise at least one thermally crosslinkable block copolymer having the formula (S-B1-B2) nX wherein each S represents a monovinyl aromatic hydrocarbon block having a peak molecular weight of 10,000 to 25,000, each B1 is a polybutadiene block having a vinyl content of less than or equal to 15 mole percent, each B2 is a polybutadiene block having a vinyl content greater than or equal to 25 mole percent, n is an integer ranging from 2 to 6 and X is the residue of a coupling agent.

Very advantageously, according to this embodiment, the elastomer is chosen from thermally crosslinkable block copolymers of formula S-B1-B2, in which S represents a monovinyl aromatic hydrocarbon block having a peak molecular weight of 10,000 to 25,000, B1 is a polybutadiene block having a vinyl content of 15 mol% or less, B2 is a polybutadiene block having a vinyl content of 25 mol% or more, and the B1 / B2 weight ratio is greater than or equal to 1: 1, and wherein the S-B1-B2 block terpolymer has a peak molecular weight of from about 40,000 to about 200,000. The elastomer may further comprise at least one thermally crosslinkable block copolymer having the formula ( S-B1-B2) nX wherein each S represents a monovinyl aromatic hydrocarbon block having a peak molecular weight of 10,000 to 25,000, each B1 represents a polybutadiene block having a lower vinyl content. less than or equal to 15 mole percent, each B2 represents a polybutadiene block having a vinyl content greater than or equal to 25 mole percent, n is an integer from 2 to 6, and X is the residue of a coupling agent, the mass ratio B1 / B2 is greater than or equal to 1: 1, and the block copolymer (S-B1-B2) nX has a peak molecular weight which is 1.5 to 6.0 times the peak molecular weight of the S-B1-B2 block copolymer.

The monovinylaromatic hydrocarbon groups designated S can be any monovinylaromatic hydrocarbon compound known for use in the preparation of block copolymers such as: styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2, 4-dimethylstyrene, alpha-methylstyrene, vinylnaphthalene, vinyltoluene and vinylxylene or mixtures thereof. The preferred monovinyl aromatic hydrocarbon compound according to the present invention is styrene, which is used as a substantially pure monomer or as a major component in mixtures with minor proportions of another structurally related vinyl aromatic monomer, such as Γο methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene, alpha-methylstyrene, vinylnaphthalene, vinyltoluene and vinylxylene, ie in proportions of at most 10% in weight. The use of substantially pure styrene is particularly preferred in the present invention.

The polybutadiene blocks B1, B2 used in the above-mentioned block copolymers are based on substantially pure butadiene monomer or comprising minor proportions, up to 10% by weight, of structurally related conjugated dienes. Preferably, the polybutadiene is purely constituted from butadiene monomer.

With regard to the block copolymers of the present invention, the term "molecular weight" refers to the true molecular weight in g / mol of the block copolymer. The molecular weights mentioned in the specification and claims can be measured by gel permeation chromatography (GPC) using polystyrene standards, for example as taught by ASTM 3536. GPC is a well-known process in which polymers are separated according to their molecular mass, the largest molecule being eluted first. The chromatograph is calibrated using polystyrene standards of various molecular weights available commercially. The molecular weight of the polymers measured by GPC is a molecular weight equivalent of styrene. The styrene equivalent molecular weight can be converted to a true molecular weight when the styrene content of the polymer and the vinyl content of the diene blocks are known. The detector used is preferably a combination of ultraviolet light and a refractive index detector. Molecular weights are measured at the peak of the GPC peak, converted to true molecular weights, and are commonly referred to as peak molecular weights.

The peak molecular weight of each monovinyl aromatic hydrocarbon block, especially polystyrene, is from about 10,000 to about 25,000, preferably from about 12,000 to about 20,000. According to a preferred variant, the peak molecular weight of styrenic blocks range from about 14,000 to about 18,000.

Each block copolymer of the formula S-B1-B2 used in the present invention has a peak molecular weight of about 40,000 to about 200,000, preferably about 65,000 to about 160,000, more preferably about 75,000. 000 to about 150,000, and still more preferably from about 75,000 to 130,000.

The peak molecular weight of the block copolymers of formula (S-B1-B2) nX depends on the peak molecular weight of the block copolymer of formula S-B1-B2 used. More specifically, the peak molecular weight of the (S-B1-B2) nX copolymers is from about 1.5 to about 6.0 times the peak molecular weight of the S-B1-B2 block copolymer. Preferably, the peak molecular weight of the nX (S-B1-B2) block copolymers is from about 1.8 to about 5.0 times the peak molecular weight of the S-B1-B2 block copolymer.

The combined molecular weight of the two butadiene blocks (B1 and B2) is from about 25,000 to about 190,000. The two butadiene blocks (B1 and B2) are present in a weight ratio B1 / B2 greater than or equal to 1: 1. In other words, B1 is present in an amount (% by weight) greater than or equal to 50% of the total of segment B1-B2 and B2 is present in an amount (% by weight) less than or equal to 50% of the total of segment B1-B2.

When 1,3-butadiene is polymerized via a 1,2-addition mechanism, the result is a pendant vinyl group relative to the polymer backbone. As noted above, polybutadiene is present in blocks or segments that contain different levels of vinyl. This vinyl content makes it possible to characterize the polymer.

With respect to the polybutadiene block B1, it is preferred that there be at most about 15 mole percent vinyl in the B1 block. Preferably, the vinyl content in the B1 block should be about 5 percent. in moles to about 15 mole percent of the fused polybutadiene units. Given the known anionic polymerization processes of butadiene, typically from about 7 to about 15 mole percent of the polybutadiene units have the 1,2-addition configuration.

With respect to the polybutadiene block B2, it is preferred that there be at least 25 mole percent of vinyl in the B2 block. Preferably, the vinyl content in the B2 block is from about 25 mole percent to about 80 mole percent of the fused polybutadiene units, more preferably about 40 mole percent to about 75 mole percent of the polybutadiene units. have a 1,2-addition configuration, and even more preferably from about 50 to about 65 mole percent of the polybutadiene units have a 1,2-addition configuration.

The monovinyl aromatic hydrocarbon monomer content of the copolymer (preferably the styrene content) is from about 10% to about 40% by weight, based on the total weight of the S-B1-B2 block copolymer and optionally (S-B-1). -B2) n. Preferably, the monovinyl aromatic hydrocarbon content (advantageously styrene) of the S-B1-B2 block copolymers, and optionally (S-B1-B2) nX, is from about 18% to about 35% by weight, more preferably from from about 19% to about 32% by weight, based on the total weight of the copolymer.

In a preferred embodiment of the invention, the elastomer comprises a block copolymer of the formula S-B1-B2 alone.

In another preferred embodiment, S-B1-B2 is used in combination with a block copolymer of formula (S-B1-B2) nX wherein each S is a monovinyl aromatic hydrocarbon block, preferably styrene, each B1 is a polybutadiene block having a vinyl content of less than or equal to 15 mole percent, each B2 is a polybutadiene block having a vinyl content greater than or equal to 25 mole percent, n is an integer ranging from 2 to And X is the residue of a coupling agent. When the block copolymers of formula (S-B1-B2) nX are used, preferably n is an integer from 2 to 4, more preferably n = 2.

Advantageously, the block copolymers of the invention are in a substantially non-hydrogenated form. When the block copolymer composition comprises such a mixture, the weight ratio of the S-B1-B2 / (S-B1-B2) nX block copolymer is greater than or equal to about 1: 1. In a particularly preferred embodiment, the ratio is from about 1: 1 to about 10: 1, with the preferred ratio being from about 1: 1 to about 4: 1.

The weight average molecular weight of the elastomer is advantageously between 10,000 and 600,000 daltons, preferably between 30,000 and 400,000 daltons.

The block copolymers used in the invention are described in WO2008 / 137394. A process for their preparation is described in US-3,231,635; U.S. 3,251,905; U.S. 3,390,207; U.S. 3,598,887; US 4,219,627; EP0413294; EP0387671; EP 0636654 and WO 94/22931.

According to one particular embodiment of the invention, the thermo-crosslinked bitumen-polymer composition comprises from 1% to 30% by weight, preferably from 3% to 20% by weight, more preferably from 5% to 15% by weight of polymer with respect to the total mass of said composition.

The additive compound has the following general formula (I): R '- (COOH) z (I) in which R 1 is a linear or branched, saturated or unsaturated hydrocarbon-based chain containing from 4 to 68 carbon atoms, preferably from 4 to 54 carbon atoms, more preferably 4 to 36 carbon atoms and z an integer ranging from 1 to 4, preferably from 2 to 4, more preferably equal to 2.

The chemical additives of formula (Γ) may advantageously be monoacids (z = 1), diacids (z = 2), triacids (z = 3) or tetracides (z = 4). The preferred chemical additives are diacids with z = 2. The R 1 group is preferably a linear and saturated hydrocarbon chain of formula CwH 2w with w an integer ranging from 4 to 22, preferably from 4 to 12.

The chemical additives have, in particular, the general formula HOOC-CwH2W-COOH where w is an integer ranging from 4 to 22, preferably from 4 to 12. These chemical additives correspond to the preceding formula (I) in which z = 2 and R1 = CwH2w

The preferred diacids are: - adipic acid or 1,6-hexanedioic acid with w = 4 - pimelic acid or 1,7-heptanedioic acid with w = 5 - suberic acid or acid 1,8- octanedioic acid with w = 6 - azelaic acid or 1,9-nonanedioic acid with w = 7 - sebacic acid or 1,10-decanedioic acid with w = 8 - undecanedioic acid with w = 9 - acid 1,2-dodecanedioic acid with w = 10 - tetradecanedioic acid with w = 12.

Advantageously, the diacid (I) is sebacic acid.

The diacids may also be diacid dimers of unsaturated fatty acid (s), that is to say dimers formed from at least one unsaturated fatty acid, for example from a single fatty acid unsaturated or from two different unsaturated fatty acids. The diacid dimers of unsaturated fatty acid (s) are conventionally obtained by intermolecular dimerization reaction of at least one unsaturated fatty acid (reaction of Diels Aid for example). Preferably, only one type of unsaturated fatty acid is dimerized. They are derived in particular from the dimerization of an unsaturated fatty acid, especially of C 1 to C 34, in particular C 12 to C 22, in particular C 16 to C 20, and more particularly C 18. A preferred fatty acid dimer is obtained by dimerization of linoleic acid, which can then be partially or fully hydrogenated. Another preferred fatty acid dimer has the formula HOOC- (CH 2) 7 -CH = CH- (CH 2) 7 -COOH. Another preferred fatty acid dimer is obtained by dimerization of methyl linoleate. In the same way, it is possible to find triacids of fatty acids and tetracides of fatty acids, obtained respectively by trimerization and tetramerization of at least one fatty acid.

According to a particular embodiment of the invention, the bitumen-polymer thermoreticulated composition (BPa) comprises from 0.1% to 5% by weight, preferably from 0.5% to 4% by weight, more preferably 1% 2.5% by weight of the additive (I) relative to the total mass of the bitumen-polymer composition (BPa).

According to a particular embodiment of the invention, the bitumen-polymer thermoreticulated composition (BPa) comprising an additive of formula (I) may also further comprise other additives such as adhesiveness dopes and / or surfactants. ; waxes of animal, vegetable or hydrocarbon origin; paraffins such as polymethylene paraffins and polyethylene paraffins; fluxes such as oils based on animal and / or vegetable fats or hydrocarbon oils of petroleum origin; resins of vegetable origin such as rosins; anti-foam additives; detergent and / or anti-corrosion additives; lubricant additives or anti-wear agent; crystallization modifying additives; additives inhibiting paraffin deposits; pour point depressant additives; the modifiers of low temperature rheology; antioxidants; metal passivators; acid neutralizers; additives to lower the mixing temperature of asphalt and asphalt; additives for improving the adhesion of bituminous binders to fillers and aggregates such as polyisobutylene succinimides; acids such as polyphosphoric acid or diacids, in particular fatty diacids; vulcanization accelerators such as zinc-2-mercaptobenzothiazole, zinc dibutyldithiocarbamate, tetramethylthiuram monosulphide.

The additives other than the additive of formula (I) are used in amounts well known to those skilled in the art, depending on the nature of the additive, depending on the bitumen base and expected properties.

According to another particular embodiment of the invention, the thermo-polymerized bitumen-polymer composition (BPa) comprising an additive of formula (I) may also further comprise an olefinic polymer adjuvant. The olefin polymer adjuvant is preferably selected from the group consisting of (a) ethylene / glycidyl (meth) acrylate copolymers; (b) ethylene / monomer A / monomer B terpolymers and (c) copolymers resulting from the grafting of a monomer B onto a polymer substrate. (a) The ethylene / glycidyl (meth) acrylate copolymers are advantageously chosen from random or block copolymers, preferably random copolymers of ethylene and a monomer chosen from glycidyl acrylate and glycidyl methacrylate, comprising from 50% to 99.7% by weight, preferably from 60% to 95% by weight, more preferably 60% to 90% by weight of ethylene. (b) The terpolymers are advantageously chosen from random or sequential terpolymers, preferably random, of ethylene, a monomer A and a monomer B.

The monomer A is selected from vinyl acetate and C1-C6 alkyl acrylates or methacrylates.

Monomer B is selected from glycidyl acrylate and glycidyl methacrylate.

The ethylene / monomer A / monomer B terpolymers comprise from 0.5% to 40% by weight, preferably from 5% to 35% by weight, more preferably from 10% to 30% by weight of units derived from monomer A and from From 0.5% to 15% by weight, preferably from 2.5% to 15% by weight of units derived from monomer B, the remainder being formed from units derived from ethylene. (c) The copolymers result from the grafting of a B monomer selected from glycidyl acrylate and glycidyl methacrylate onto a polymeric substrate. The polymer substrate consists of a polymer chosen from polyethylenes, in particular low density polyethylenes, polypropylenes, statistical or sequential copolymers, preferably random copolymers of ethylene and vinyl acetate, and statistical or block copolymers, preferably statistical copolymers. of ethylene and C 1 -C 6 alkyl acrylate or methacrylate comprising from 40% to 99.7% by weight, preferably from 50% to 99% by weight of ethylene. Said graft copolymers comprise from 0.5% to 15% by weight, preferably from 2.5% to 15% by weight of grafted units derived from monomer B. The olefinic polymer adjuvant is preferably chosen from terpolymers ( b) ethylene / monomer A / monomer B described above.

Advantageously, the olefinic polymer adjuvant is chosen from among the random terpolymers of ethylene, a monomer A chosen from C1-C6 alkyl acrylates or methacrylates and a monomer B chosen from glycidyl acrylate and glycidyl methacrylate, comprising from 0.5% to 40% by weight, preferably from 5% to 35% by weight, more preferably from 10% to 30% by weight of units derived from monomer A and 0.5% by weight at 15% by weight, preferably from 2.5% to 15% by weight of units derived from monomer B, the remainder being formed from units derived from ethylene.

According to a particular embodiment of the invention, the bitumen-polymer composition (BPa) further comprises from 0.05% to 15% by weight, preferably from 0.1% to 10% by weight, more preferably from 0% to From 5% to 6% by weight of the olefinic polymer adjuvant relative to the total weight of the bitumen-polymer composition (BPa).

The thermo-cured bitumen-polymer composition (BPa) is prepared by hot mixing the components. It is carried out at manufacturing temperatures of between 100 ° C. and 200 ° C., preferably between 140 ° C. and 200 ° C., more preferably between 140 ° C. and 170 ° C., and with stirring for a period of at least 10 ° C. minutes, preferably between 30 minutes and 10 hours, more preferably between 1 hour and 6 hours. The term "manufacturing temperature" means the heating temperature of the bitumen base before mixing as well as the mixing temperature. The temperature and the duration of the heating vary according to the quantity of bitumen used and are defined by the standard NF EN 12594.

The thermo-polymerized bitumen-polymer composition (BPa) is transportable and / or cold-storable, said thermo-cured bitumen-polymer composition (BPa) being transported and / or stored in divided form.

Transportable and / or cold-storable means transport and / or storage at a temperature below 100 ° C. The temperature is preferably between 20 ° C and 90 ° C, preferably between 20 ° C and 80 ° C, more preferably between 20 ° C and 70 ° C.

By split form, it is meant that the composition is packaged in separate unitary units for handling by an individual or a machine, unlike a composition prepared and stored hot in a tank, a metal drum or a reactor.

According to a preferred embodiment, the bitumen-polymer thermoreticulated composition (BPa) is packaged in the form of bitumen bars.

According to another embodiment, the bitumen-thermo-polymerized polymer composition could be in the form of granules or particles.

According to a particular embodiment of the invention, the bitumen-polymer thermoreticulated composition (BPa) according to the invention is in the form of bread (s) bitumen.

The bitumen cake according to the invention preferably has a volume of between 1000 cm3 and 50000 cm3, preferably between 5000 cm3 and 30000 cm3, more preferably between 10000 cm3 and 25000 cm3, even more preferably between 14000 cm3 and 25000 cm3. .

When the bitumen roll is handled manually by a person, the mass of bitumen bread can vary from 1 to 20 kg, and from 20 to 50 kg in the case of handling by two people. When handling is carried out by mechanical equipment, the mass of bitumen bread can vary from 50 to 1000 kg.

The bitumen cake is made from a thermo-cured bitumen-polymer composition (BPa) as described above according to any known method, for example according to the manufacturing method described in the document US2011 / 0290695.

Advantageously, the bitumen roll is packaged with a hot-melt film according to any known method, preferably a polypropylene film, polyethylene or a mixture of polyethylene and polypropylene. The thermo-cured bitumen-polymer composition (BPa) packaged in bitumen roll packaged with a hot-melt film has the advantage of being ready for use, that is to say that it can be directly heated as described herein. below in step i) of the process according to the invention. The hot-melt material that melts with the thermo-cured bitumen-polymer composition (BPa) does not affect the properties of said composition. Alternatively, the bitumen cake may also be packaged in a silicone carton according to any known method. In particular, the bitumen cake is packaged in a silicone cardboard by hot casting the bitumen-polymer thermo-cured composition comprising an additive in a carton whose wall of the inner face is silicone and then cooled, the dimensions of the cardboard being adapted to the weight and / or the volume of bitumen bread desired.

In this variant, when the bitumen roll is packaged in a silicone carton, prior to step i) of the process of the invention, the bitumen cake is removed from the silicone carton.

When the bread of thermo-cured bitumen-polymer composition (BPa) according to the invention is packaged with a hot-melt film or is packaged in a carton, the applicant has demonstrated that the deterioration of said hot melt film or said carton during transport and / or cold storage of said bitumen cake did not cause the creep of the bitumen. Therefore, the bitumen rolls according to the invention retain their original shape and do not stick to each other during their transport and / or cold storage even if the hot melt film or cardboard is damaged. The absence of creep of the bitumen-polymer polymer composition in the form of bread during its transport and / or cold storage is due to the presence of at least one chemical additive of formula (I) within the bitumen composition. thermocrosslinked polymer.

According to another embodiment, the bitumen-polymer thermoreticulated composition (BPa) according to the invention is in the form of granules.

The bitumen granules are obtained by shaping the thermo-polymerized polymer bitumen composition (BPa) as described above according to any known method, for example according to the manufacturing method described in the document US Pat. No. 3,026,568, the document WO 2009 / 153324 or the document WO 2012/168380. In a known manner, the shaping of the granules can be carried out by dripping, in particular using a drum. Other techniques can be used in the process for manufacturing bitumen granules, in particular molding, extrusion ... According to this variant, advantageously, the bitumen granules further comprise at least one anti-caking agent, preferably of mineral or organic origin. According to this variant, advantageously, the bitumen granules are covered on at least a portion of their surface with an anti-caking agent, preferably over their entire surface.

These granules once formed have a high load resistance. These properties have the consequence that the bitumen granules thus formulated can be stored and / or transported without sticking together, agglomerate, without deformation, and retain their consistency even at high ambient temperature (50 ° C).

The preparation of the storage-stable heat-curable bitumen-polymer composition (BPb), preferably in hot storage and ready for application

The process for the preparation of a storage stable, preferably heat-storage stable and ready-to-use heat-storage polymer bitumen-polymer composition (BPb), in particular in the form of road bitumen, is carried out using a bitumen composition thermocrosslinked polymer (BPa) comprising the additive of general formula (I).

For the purposes of the invention, the term "storage stable, preferably stable to hot stacking and ready for application" that the bitumen-polymer composition (BPb) can be stored, preferably stored hot, without damage to its components. mechanical and elastic properties before being used, for example for the manufacture of asphalt.

According to a first variant, the bitumen-polymer composition (BPb) obtained in step b) of its preparation process is stored, preferably stored under heat, then is then used, for example for the manufacture of mixes.

Preferably, the bitumen-polymer composition (BPb) is stored, preferably stored under heat, for a period of between 1 h and 4 weeks, preferably between 1 h and 2 weeks, more preferably between 1 h and 72 h.

According to a second variant, the bitumen-polymer composition (BPb) obtained in step b) of its preparation process is directly used, for example for the manufacture of mixes, without having been previously stored.

According to a preferred embodiment of the invention, the bitumen-polymer thermoreticulated composition (BPa) has been stored and / or transported, in solid form, divided, in particular in the form of bitumen bars, between its manufacture and its implementation. It is used in the preparation of a storage stable, preferably heat storage stable, thermoreiculated polymer bitumen polymer (BPb), ready for application.

The method comprises at least one step of hot mixing the bitumen-polymer thermoreticulated composition (BPa) with at least one bitumen base.

This process comprises the steps of: i) heating a thermo-polymerized bitumen-polymer composition (BPa) at a temperature of between 100 ° C. and 200 ° C. and stirring until a homogeneous mixture is obtained, ii) addition of at least one bitumen base, simultaneously or after step i), iii) obtaining a storage-stable, preferably heat-storage stable, heat-storage bitumen-polymer composition (BPb), ready for application.

The amount of bitumen base added in step ii) is controlled so as to obtain a non-crosslinked bitumen-polymer composition (BPb) having satisfactory elastic and mechanical properties. In particular, it is adjusted to achieve levels of additive (Γ) and polymer that are exposed below.

Preferably, the bitumen-thermo-polymer-polymer composition (BPb) has an additive content (I) less than or equal to 1.1% by weight relative to the total mass of the composition (BPb), preferably less than or equal to 1 %.

Preferably, the thermo-polymerized bitumen-polymer composition (BPb) has a polymer content of less than or equal to 5% by weight relative to the total weight of the composition (BPb), preferably from 3 to 5%.

Advantageously, the bitumen-thermo-polymer-polymer composition (BPb) has an additive content (I) less than or equal to 1.1% and a polymer content of less than or equal to 5% by weight relative to the total mass of the composition (BPB).

According to one embodiment, the thermo-polymerized bitumen-polymer composition (BPb) has an additive content (I) of less than or equal to 1% and a polymer content of less than or equal to 5% by weight relative to the total mass of the composition (BPb).

According to another embodiment, the bitumen-polymer thermoreticulated composition (BPb) has an additive content (I) of less than or equal to 1.1% and a polymer content ranging from 3 to 5% by weight relative to the total mass of the composition (BPb).

In a very preferential manner, the bitumen-thermo-polymer-polymer composition (BPb) has an additive content (I) of less than or equal to 1% and a polymer content ranging from 3 to 5% by weight relative to the total mass of the composition (BPb).

It has been found that the thermo-polymerized bitumen-polymer composition (BPb) has very satisfactory elastic properties, in particular an elastic return measured at 25 ° C. according to standard NF EN 13398 greater than or equal to 70%.

According to one embodiment of the invention, the temperature and duration of the heating of step i) can vary according to the amount of bitumen used and are defined by the standard NF EN 12594.

Preferably, the heating of step i) is between 120 ° C and 200 ° C, more preferably between 140 ° C and 200 ° C, even more preferably between 140 ° C and 170 ° C.

Preferably, the stirring of step i) is carried out for a period of at least 15 minutes, more preferably between 15 minutes and 10 hours, even more preferably between 15 minutes and 6 hours.

According to one embodiment of the invention, the bitumen base added to step ii) of the process according to the invention is preheated to a temperature of between 100 ° C. and 200 ° C.

Preferably, the bitumen base added in step ii) is heated to a temperature of between 120 ° C. and 200 ° C., more preferably between 140 ° C. and 200 ° C., and even more preferably between 140 ° C. and 170 ° C. .

Advantageously, the bitumen base added in step ii) is heated to the same heating temperature of step i) or at a temperature different from the heating temperature of the heating temperature of step i).

The bitumen base added in step ii) can have the same grade or a different grade of the bitumen base constituting the composition (BPa).

Depending on the grade of the composition (BPb) expected, the skilled person will be able to choose the grade (s) of bitumen bases and the amounts of bitumen bases to be added in step ii) according to their rank.

As illustrated in the experimental part, the addition of an additive (I) in a bitumen-thermo-polymer-polymer base can degrade the elastic properties of the bitumen-polymer thermo-cured composition (BPa) compared to the starting bitumen-thermo-polymer-polymer base. The composition and the method of the invention allow the restoration of the elastic properties of a bitumen-thermo-polymerized polymer composition with respect to the starting bitumen-thermo-polymerated polymer base. In particular, the recovery of at least 70% of the elastic recovery of the storage stable, preferably heat-stable and ready-to-apply heat-storage bitumen-polymer composition (BPb) relative to the bitumen-thermo-polymer-polymer base is observed. to a conventional thermoreiculated bitumen-polymer composition used as raw material, preferably at least 80%.

In a well-known manner, the so-called "elastic return" measurement is carried out by means of a standardized test NF EN 13398 at 25 ° C (R25). This elastic return characteristic is expressed in percent (%). The elastic return, measured at 25 ° C, according to the standardized test NF EN 13398, represents the measurement of the capacity of a sample of bitumen to recover its initial shape after stretching, after a time of 30 minutes with a distance stretching applied 20 cm.

Asphalt mix production

Another object of the invention relates to the use of the bitumen-polymer thermocure composition for the manufacture of bituminous mixes.

Bituminous mixes are used as materials for the construction and maintenance of pavement bodies and their pavement, as well as for the realization of all road works. For example, superficial coatings, hot mixes, cold mixes, cold-cast asphalts, deep emulsions, base, binding, hooking and rolling layers, and other combinations of coatings can be mentioned. an asphalt binder and road aggregate having particular properties, such as anti-omerant layers, draining asphalts, or asphalts (a mixture of bituminous binder and sand-like aggregates).

Another subject of the invention also relates to a process for manufacturing bituminous mixes comprising at least the bitumen-thermo-polymer-polymer composition as defined above and aggregates, this process comprising at least the steps of: heating the aggregates with a temperature ranging from 100 ° C. to 180 ° C., preferably from 120 ° C. to 160 ° C., mixing the aggregates with the bitumen-thermo-polymer-polymer composition as defined above, obtaining mixes.

According to one embodiment of the invention, the process for manufacturing bituminous mixes comprises a step of storage, preferably a hot storage step, of the bitumen-thermo-polymerized polymer composition obtained in step b) of the process such as as defined above prior to the heating steps of the aggregates and mixing.

According to another embodiment of the invention, the thermocured bitumen-polymer composition obtained in step b) of the process as defined above is directly used in the step of mixing with the aggregates without a storage step, preferably without a hot storage step.

Preferably, the step of mixing the aggregates and the bitumen-polymer composition (BPb) is carried out with stirring, then the stirring is maintained for not more than 5 minutes, preferably not more than 1 minute to allow obtaining a homogeneous mixture.

The various embodiments, variants, preferences and advantages described above may be taken separately or in combination.

Examples The invention is illustrated by the following non-limiting examples. The rheological and mechanical characteristics of the bitumens referred to in these examples are measured as shown in Table 1.

Table 1

P bit of bitumen?

Raw materials: - a 70/100 grade bitumen base, rated Bi, having a penetrability P25 of 82 1/10 mm and a TBA of 46 ° C and commercially available from the TOTAL group under the trademark AZALT®; an elastomer, denoted SBB, comprising a mixture of block terpolymer styrene-B1-B2 and copolymer (styrene-B1-B2) nX with: B1 is a polybutadiene block having a vinyl content of less than or equal to 15 mole percent and B2 is a polybutadiene block having a vinyl content greater than or equal to 25 mole percent, the ratio of B1 / B2 is greater than or equal to 1: 1, n is an integer ranging from 2 to 6, X is the a coupling agent residue, the block copolymer (styrene-B1-B2) nX has a peak molecular weight which is 1.5 to 6.0 times the peak molecular weight of the styrene-B1-B2 block copolymer, wherein the styrene-B1-B2 / (styrene-B1-B2) mass ratio nX is greater than or equal to 1: 1. The vinyl group content of the mixture is 20.2% by weight relative to the total mass of the polymer blend. The weight average molecular weight of the mixture is 235,000 Daltons. This elastomer is available from Kraton.

an additive, sebacic acid commercially available from Copci-metamine.

The percentages by weight percentage used for each bitumen as well as their rheological and mechanical properties are indicated in Table 2 below.

Table 2

n.d .: not determinable

The preparation of the control bitumen base B2 was carried out by introducing into a reactor maintained at 190 ° C. and with stirring using a Silverson® for 2 hours, the bitumen base Bi and 8% by weight of SBB with respect to the total mass of the control bitumen base B2. The contents are then transferred to another reactor with stirring at 300 to 400 rpm while decreasing the temperature of the reactor contents from 190 ° C to 165 ° C for 2 hours.

The preparation of the bitumen base B3 was carried out by introducing into a reactor maintained at 190 ° C. and under stirring using a Silverson® for 2 hours, the base bitumen Bi and 8% by weight of SBB with respect to the total mass of bitumen base B3. The contents are then transferred to another reactor with stirring between 300 and 400 rpm while reducing the temperature of the reactor contents from 190 ° C. to 165 ° C. for 2 h and then 1.5% by weight of sebacic acid per second. relative to the total mass of the bitumen base B3 is added to the mixture. The mixture is stirred for about 1 hour at 165 ° C to obtain a homogeneous final appearance.

Bitumen bars P2 and P3 are respectively prepared from bitumens B2 and B3 according to the following method.

A mass of about 0.5 kg of bitumen is cast at 160 ° C in a rectangular steel mold covered with a polyethylene / polypropylene hot melt film. The mold is then cooled to room temperature and then demolded.

Creep test

A qualitative creep test is carried out beforehand. The bitumen bars P2 and P3 thus obtained are placed in incubators at different temperatures and under a load of 3.65 kg (+/- 50 g) to simulate the stacking of the loaves on each other during their transport. and / or their storage. Indeed, it is estimated that 5 loaves are stacked vertically on a pallet during the transport and / or storage of bitumen bars. Therefore, the load of 3.65 kg (+/- 50 g) corresponding to the load applied to a block of 500 g is approximately equivalent to the load applied to a block of 25 kg in a pallet containing 40 blocks and having a mass total of about 1000 kg.

The mathematical formula for calculating the load for a block of 25 kg within a pallet of 40 blocks is P = [(M * g) / S] / n where M is the load or about 1000 kg, where g is the gravitational constant of 9.81 m s-2, S being the surface of the pallet is 1.21 m2 and n being the number of blocks in the pallet is 40.

The blocks are first placed in an oven at a temperature of 40 ° C. If no creep is observed after a certain time, at most after 3 weeks, new loaves are molded and placed at an oven temperature of 50 ° C for at least 7 days. This operation is repeated by increasing the temperature from 10 ° C to a maximum temperature of 80 ° C if no creep is observed, or up to the temperature where a large creep breads is observed if said temperature is below 80 ° C. Creep results visually in deformation of the loaves and flow of the bitumen.

Table 3 below lists the results of the creep test obtained for P2 and P3 bitumen breads.

Table 3

+++: no creep observed after 15 days ++: no creep observed after 7 days +: creep observed after 3 days: significant creep in less than 2 hours * np: irrelevant; the creep test was not performed at this temperature since creep is observed at lower temperatures.

P3 bitumen bread does not flow under conventional storage and / or transport conditions. However, as shown in Table 1, the elastic properties and in particular the elastic return of the bitumen-polymer composition B3 making it possible to obtain P3 are degraded with respect to the bitumen-polymer composition B2 making it possible to obtain P2.

Restoring the elastic properties of P3

A thermo-C4 thermo-polymerized bitumen-polymer composition with restored elastic properties, in particular with a restored elastic return, was obtained from the bitumen cake P3 according to the process described below.

A bitumen cake is placed in a melter and heated to about 170 ° C with stirring and simultaneously heating the bitumen bread bitumen base Bi preheated to a temperature of about 170 ° C is added. The mixture thus obtained is mixed for 1 h until a homogeneous mixture is obtained.

The mixture thus obtained can be subsequently used for the manufacture of asphalt.

Table 4 below lists the various experimental conditions of the process for restoring the elastic properties of the bitumen-polymer compositions according to the invention and their mechanical and rheological properties.

Table 4

(*)% by mass with respect to the mass of B2 or B3 (**)% by mass with respect to the mass of B2 or B3 n.d.: not determinable

It is observed that the dilution of a bitumen-thermo-polymer-polymer composition comprising an additive in the form of bread P3 makes it possible to restore the elastic properties, in particular the elastic return of the bitumen-polymer composition C4 obtained from P3 while maintaining good properties. mechanical aspects with regard to the respective elastic and mechanical properties of the control thermo-controlled bitumen-polymer composition B2.

More particularly, it is observed that the bitumen-polymer composition C4 covers at least 70% of the springback with respect to the thermo-controlled bitumen-control polymer composition B2.

Claims (18)

A process for the preparation of a thermocure-polymer bitumen-polymer composition comprising: a) the preparation of a thermo-cured bitumen-polymer composition (BPa) comprising at least one heat-curable bitumen-polymer base and an additive of general formula (I) R ' Wherein R 1 is a linear or branched hydrocarbon chain, saturated or unsaturated comprising from 4 to 68 carbon atoms, and z an integer ranging from 1 to 4; b) the hot mix of the bitumen-polymer thermo-cured composition (BPa) with at least one bitumen base to obtain a composition (BPb). 2. Method according to claim 1 comprising at least one step of storage and / or cold transport of the composition (BPa) between steps a) and b). 3. The method of claim 2, wherein the composition (BPa) is stored and / or transported in the form of bitumen bars. 4. Method according to any one of claims 1 to 3, wherein step b) of the process comprises the steps of: i) heating the bitumen-polymer thermoreticulated composition (BPa) at a temperature between 100 ° C and 200 ° C and stirring until a homogeneous mixture is obtained, ii) adding at least one bitumen base simultaneously or after step i). 5. The method of claim 4, wherein the bitumen base added in step ii) is preheated to a temperature of between 100 ° C and 200 ° C. 6. Process according to any one of the preceding claims, in which the additive (I) is a diacid of the general formula HOOC-CwH2W-COOH in which w is an integer ranging from 4 to 22. 7. The method of claim 6, wherein the additive (I) is a diacid selected from the group consisting of adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, 1,2-dodecanedioic acid and tetradecanedioic acid. 8. Process according to any one of claims 1 to 7, wherein the bitumen-polymer thermally-cured composition (BPa) comprises from 0.1% to 5% by weight of the additive (I) relative to the total mass of the bitumen-polymer thermoreticulated composition (BPa). 9. Process according to any one of claims 1 to 8, wherein the polymer is an elastomer based on a monovinyl aromatic hydrocarbon monomer and butadiene. The process according to claim 9, wherein the polymer is an elastomer selected from thermally crosslinkable block copolymers of formula S-B1-B2, wherein S represents a monovinyl aromatic hydrocarbon block having a peak molecular weight of 10,000 to 25,000. , B1 is a polybutadiene block having a vinyl content of not more than 15 mole percent, B2 is a polybutadiene block having a vinyl content of 25 mole or more, the B1 / B2 mass ratio is greater than or 1: 1, and wherein the S-B1-B2 block copolymer has a peak molecular weight of 40,000 to 200,000; the elastomer may further comprise at least one thermally crosslinkable block copolymer having the formula (S-B1-B2) nX wherein each S represents a monovinyl aromatic hydrocarbon block having a peak molecular weight of 10,000 to 25,000, each B1 is a polybutadiene block having a vinyl content of less than or equal to 15 mole percent, each B2 is a polybutadiene block having a vinyl content greater than or equal to 25 mole percent, n is an integer ranging from 2 to 6 and X is the residue of a coupling agent, wherein the mass ratio B1 / B2 is greater than or equal to 1: 1, and the block copolymer (S-B1-B2) nX has a peak molecular weight which is 1.5 to 6.0 times the peak molecular weight of the S-B1-B2 block copolymer. 11. A method according to any one of claims 1 to 10, wherein the composition (BPa) has a polymer content ranging from 1 to 30% by weight of polymer relative to the total weight of the composition (BPa), preferably from 3 to 20%, more preferably from 5 to 15%. 12. Method according to any one of claims 1 to 11, wherein the bitumen-thermo-polymer composition polymer (BPb) has an additive content (I) less than or equal to 1.1% by weight relative to the total mass of the composition (BPb). 13. Process according to any one of Claims 1 to 12, in which the bitumen-polymer-thermo-polymer composition (BPb) has a polymer content of less than or equal to 5% by mass relative to the total mass of the composition (BPb). . 14. Thermocured polymer bitumen composition obtained by the process according to any one of Claims 1 to 13. 15. The composition of claim 14 which has a springback measured at 25 ° C according to standard NF EN 13398 of at least 70% relative to the elastic return of the uncrosslinked bitumen-polymer base, measured under the same conditions. 16. Use of the composition according to claim 14 or 15, for the manufacture of bituminous mixes. 17. A process for manufacturing bituminous mixes comprising at least one thermocoated bitumen-polymer composition according to claim 14 or 15 and aggregates, said method comprising at least the steps of: - heating the aggregates at a temperature ranging from 100 ° C to 180 ° C ° C, preferably from 120 ° C to 160 ° C, - mixing the aggregates with the bitumen-thermo-polymer composition polymer according to claim 14 or 15, - obtaining asphalt. 18. A process according to claim 17, comprising a storage step, preferably a hot storage step, of the thermocoated bitumen-polymer composition according to claim 14 or 15 obtained in step b) of the process according to any one of Claims 1 to 13 before the steps of heating the aggregates and mixing.