EP4466312A1 - Clear binder composition, and uses thereof for road surfacing and development surfacing - Google Patents

Abstract

The present disclosure relates to the field of transport infrastructures and urban planning and development infrastructures, in particular clear or colored surfacing containing clear binders. More particularly, the present disclosure relates to a clear binder composition comprising one or more ethylene and alkyl acrylate copolymers having a melt flow rate greater than 2.5 g/10 min and a melting temperature greater than 85°C.

Description

CLEAR BINDER COMPOSITION AND ITS APPLICATIONS FOR ROAD AND LANDSCAPE SURFACES

FIELD OF THE INVENTION

The present invention relates to the field of transport and urban development infrastructures, in particular clear or colored coatings with clear binders. More particularly, the present invention relates to a clear binder composition comprising one or more copolymers of ethylene and alkyl acrylate having a melt index greater than 2.5 g/10min and a melting temperature greater than 85° vs. The use of such copolymers allows the application of coatings at lowered temperatures while giving them good resistance to permanent deformation at the temperatures of use.

TECHNOLOGICAL BACKGROUND

Conventional bituminous binders, used in road construction, are black in color and are therefore difficult to color. This inability to color bituminous binders is explained by the black color of asphaltenes which are compounds intrinsically present in bitumens.

Coatings based on clear binders make it possible to produce mixes whose color is that of the granular materials which constitute them or possibly a colored color by adding pigments. Users of urban roads (pedestrians, cyclists, motorists) are particularly sensitive to the color of the surfaces on which they travel. Color provides an essential aspect for the harmonious integration of pavements into their environment, but also facilitates their readability. In addition to the aesthetic advantages provided by clear binders, these products are also appreciated for certain specific uses: in paving of tunnels or underpasses, they save lighting and improve visibility, and therefore safety; in the wearing course of engineering structures, they make it possible to reduce the temperature reached by the covering exposed to the sun and thus to limit the thermal stresses on the deck of the structure; finally, in urban areas, they make it possible to limit the surface temperature of the coating and thus contribute to the fight against urban heat islands.

Clear or colored coatings are based on the use of synthetic coating binders with the same characteristics as conventional bitumens but without having the black color. These synthetic binders, made from components of petroleum origin, do not contain asphaltenes and thus have a clear, translucent, transparent appearance in a thin film. The clear binders of the prior art generally consist of a mixture of petroleum oils, petroleum hydrocarbon resins and polymers. However, the clear binders known to those skilled in the art must be heated to temperatures between 150° C. and 200° C. in order to mix them with solid mineral particles also heated in this same temperature range. Manufacturing at these temperatures allows good fluidity of the composition and workability suitable for mechanized or manual application on site. However, the coating applied on site is generally at a temperature above 140-150°C, which results in significant smoke emissions. By lowering the manufacturing temperature, and therefore the application temperature, of these clear coatings, significant workability problems are observed. Indeed, the use of elastomers of the poly(styrene-b-butadiene-b-styrene) (SBS) or styrene-ethylene-butylene-styrene (SEBS) type in the binders of the prior art leads to a filamentous character of the binders when the temperature drops below 120-130°C and the coating is handled. This filamentous nature makes the application of clear binders impossible at lower temperature given the rapid decrease in the temperature of the coating during application on site. The filamentous character means that the binder becomes more viscous and forms threads between the solid mineral particles when the composition is handled. This stringy state makes manual application impossible and may compromise the durability of the coating in the sense that the cohesion of the coating may be disturbed due to insufficient compaction or placement of the coating. One method for reducing the stringiness of coatings with clear synthetic binders consists in reducing the elastomer content in the composition of the binder. However, this method leads to a resistance to permanent deformation which is strongly impacted. The coatings resulting from this method are then no longer suitable for use over a wide traffic and temperature window.

Patent application EP1481023 describes a clear binder composition which comprises from 0.05 to 3% by weight of an amide-type additive which makes it possible to reduce the handling temperature of the clear coating. However, this patent application mentions the use of polymers such as SBS or styrene-isoprene-styrene (SIS) elastomers. The filamentous nature at a temperature below 120-130°C is therefore not eliminated despite the decrease in the dynamic viscosity of the binder.

Patent application WO 2017/076814 describes a synthetic binder composition for the production of clear coatings which comprises a solvent-extracted petroleum oil, a petroleum resin, an SEBS elastomer having a styrene content of 25-35% and a copolymer of ethylene and ethyl acrylate (EEA) having an ethyl acrylate (EA) content of 10-25% and a melt index (MFR or MFI) of 0.5 g/10mm to 2.5 g/10mm. This patent application specifies that the SEBS content denoted y (% by mass) is characterized by -0.6x + 3.1 < y < -0.5x + 6.1 and 0 < y < 2.8 where x is the content (% by weight) of EEA copolymer. The copolymers of ethylene and ethyl acrylate described in application WO 2017/076814 have a melt index between 0.5 and 2.5 g/10min. The use of polymers with such a low melt index does not make it possible to obtain dynamic viscosity values at 150 or 180°C low enough to consider an application of clear coatings at low temperature (temperature below 140-150°C ).

There is therefore a need for the provision of compositions of clear binders whose workability, characterized by the dynamic viscosity of the binder and the absence of filamentous character, is suitable for application at lowered temperature while ensuring good resistance to traffic. coatings prepared from such compositions.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a clear binder composition comprising a plasticizer, a structuring agent and one or more copolymers of ethylene and alkyl acrylate having a melt index greater than 2.5 g/10min as measured according to method IS01 133-1 (2011) and a melting temperature greater than or equal to 85°C as measured according to method ISO 11357-3 (2018).

The present invention also relates to road and landscaping products comprising solid particles and such a composition.

Finally, the present invention relates to the use of a copolymer of ethylene and alkyl acrylate having a melt index greater than 2.5 g/10 min as measured according to the method IS01 133-1 (201 1 ) and a melting temperature greater than or equal to 85°C as measured according to the ISO 11357-3 (2018) method to lower the manufacturing and/or application temperature of hot mixes, warm mixes and asphalts sunk.

Other aspects of the invention are as described below and in the claims.

DETAILED DESCRIPTION OF THE INVENTION

The inventors have developed a binder composition meeting the needs expressed. Surprisingly, it has been demonstrated that the use of a copolymer of ethylene and alkyl acrylate having a melt index greater than 2.5 g/10min and a melting temperature greater than or equal to 85°C in a clear binder composition makes it possible to obtain a clear binder having improved physico-mechanical properties, in particular from the point of view of dynamic viscosity between 100 and 200°C and resistance to permanent deformation. Such compositions exhibit workability suitable for application at lowered temperature while guaranteeing good resistance of the coating produced from such compositions to permanent deformation over its service temperature range.

The clear binder composition developed by the inventors comprises: (a) a plasticizing agent, (b) a structuring agent,

(c) one or more copolymers of ethylene and alkyl acrylate having a melt index greater than 2.5 g/10min and a melting temperature greater than or equal to 85°C.

The term “clear binder composition” refers to a binder composition that is generally colorless or light in color (e.g. white or beige). Thus, the composition is suitable for the preparation of clear coatings or colorable coatings.

The binder composition may further comprise additives commonly used in road engineering, in particular coloring agents.

The binder composition is typically free of asphaltene. More generally, the binder composition is typically free of bitumen.

The clear binder composition generally comprises, by weight relative to the total weight of the composition:

(a) from 25 to 85% by weight, preferably from 50 to 70% by weight of a plasticizer,

(b) from 10 to 70% by weight, preferably from 20 to 40% by weight of a structuring agent,

(c) from 1 to 20% by weight, preferably from 4 to 12% by weight of one or more copolymers of ethylene and alkyl acrylate having a melt index greater than 2.5 g/10min and a melting temperature greater than or equal to 85°C, and

(d) from 0 to 10% by weight, preferably from 0.3 to 3% by weight of additives commonly used in road engineering.

The components entering into the binder composition can be as described below.

Plasticizer

The term “plasticizing agent” denotes a chemical constituent making it possible to thin and reduce the viscosity and the modulus of the binder composition. It is typically an oil. A wide range of so-called lubricating oils can be used in the binder composition according to the invention. Such oils are well known to those skilled in the art.

Typically it is a synthetic petroleum oil. An example of a synthetic petroleum oil suitable for the implementation of the present invention is a petroleum oil resulting from a solvent extraction process of crude oil (commonly designated by the acronym RAE for “Residual Aromatic Extracts”). The oil obtained is rich in aromatic and naphthenic compounds. The extraction solvent is typically phenol, N-methylpyrrolidone and furfural. In some embodiments, the plasticizer is a furfural-extracted RAE oil containing a total aromatic content of at least 20% by weight, for example 20-30% by weight. Other examples of oils which can be used as a plasticizer include, without being limiting, synthetic petroleum oils obtained from the treatment of crude oil distillates, synthetic oils such as poly(alpha olefins), oils of vegetable origin obtained from plants and/or plants directly or after chemical modification such as triglycerides, polyol esters of fatty acids, oligomerized/polymerized triglycerides.

Structuring agent

The term “structuring agent” denotes any chemical constituent conferring satisfactory mechanical properties and cohesiveness on the binder composition. The structuring agents useful for the preparation of clear binder compositions are well known to those skilled in the art.

In certain embodiments, the structuring agent is a hydrocarbon petroleum resin, for example resulting from the copolymerization of aromatic petroleum cuts. An example of this type of resin is a hydrocarbon resin obtained by copolymerization of an aromatic petroleum cut rich in C9 monomers. Such a cut comes from the thermal cracking of naphtha. This aromatic petroleum cut rich in C9 monomer is rich in compounds such as vinyltoluenes, dicyclopentadienes, indene, methylstyrene, styrene and methylindenes.

Other examples of resins that can be used as structuring agent include, without being limiting, resins derived from C5 aliphatic petroleum cuts, resins derived from C5/C9 petroleum cuts, resins of plant origin (obtained from plants and/or plants) such as rosin esters or polyterpene resins or terpene/phenol resins.

Copolymers of ethylene and alkyl acrylate

The copolymer(s) of ethylene and alkyl acrylate that are useful in the context of the present invention have a melt index greater than 2.5 g/10min as measured according to the ISO1133-1 (2011) method ( 190°C/2.16Kg) and a melting temperature greater than or equal to 85°C as measured according to the ISO 11357-3 (2018) method.

Typically, the melt index (MFI) of the copolymers of ethylene and alkyl acrylate useful in the context of the present invention is greater than 2.5 and less than or equal to 700 g/10min, preferably it varies from 6 to 320 g/10 min, even more preferably from 7 to 200 g/10 min.

The copolymers of ethylene and alkyl acrylate useful in the context of the present invention typically comprise from 1 to 40% by weight, preferably from 10 to 35% by weight, even more preferably from 15 to 30% by weight of alkyl acrylate based on the total weight of the copolymer. The alkyl acrylate typically includes alkyl groups containing 1 to 8 carbon atoms. Examples of alkyl acrylate useful in the context of the present invention include methyl acrylate, ethyl acrylate, butyl acrylate or mixtures thereof.

Typically, the melting temperature of the copolymers of ethylene and alkyl acrylate useful in the context of the present invention is below 110°C. Preferably, the melting point of the copolymers of ethylene and alkyl acrylate useful within the scope of the present invention is greater than or equal to 90° C., even more preferably greater than or equal to 95 <C.

The copolymers of ethylene and of alkyl acrylate which are useful in the context of the present invention are prepared by a process of continuous radical copolymerization at high pressure in a tubular reactor (called “tubular copolymerization process”). Tubular copolymerization processes are well known to those skilled in the art. For example, the copolymers of ethylene and of alkyl acrylate which are useful in the context of the present invention can be prepared by a method as described in WO 2003/051630. The copolymers of ethylene and alkyl acrylate useful in the context of the present invention are distinguished from the copolymers of ethylene and alkyl acrylate prepared by a process of radical copolymerization at high pressure in an autoclave reactor (known as "autoclave copolymerization process").

Additives

The additives can be any additive or mixtures thereof commonly used in road engineering. Examples of additives include but are not limited to waxes, adhesion promoters, coloring agents or workability additives.

Raincoats

Waxes can make it possible to further improve the hot dynamic viscosity of binder compositions without impacting the rheological properties at the temperatures of use of clear coatings. The waxes reduce the dynamic viscosity of the binder composition when hot and bring an increase in cohesion to the composition during cooling.

Examples of waxes useful in the context of the present invention include, without limitation, vegetable waxes (e.g. hydrogenated castor oil), synthetic waxes from the Fischer-Tropsch process, microcrystalline petroleum waxes, petroleum waxes of the slack wax, polyethylene waxes, waxes resulting from the copolymerization of ethylene and vinyl acetate, etc...

The waxes can be added, either in the binder composition or during the manufacture of the mix or the mastic asphalt mixed with the solid mineral particles (fillers, sands and aggregates). Membership dopes

The adhesion dopes make it possible to improve the reciprocal affinity between the binder composition and the aggregates and ensure their durability.

Examples of dopes useful in the context of the present invention include, without limitation, nitrogenous surfactant compounds derived from fatty acids (amines, amidoamines, imidazolines), fatty acids or polymerized fatty acids, phosphate esters, d organosilanes, etc.

Coloring agents

The coloring agents can be inorganic pigments or organic dyes. The pigments are selected according to the shade, the color desired for the coating. For example, metal oxides such as iron oxides, chromium oxides, cobalt oxides, titanium oxides can be used to obtain the colors red, yellow, gray, green, blue or white.

The coloring agents can be added, either in the binder composition or during the manufacture of the mix or the mastic asphalt mixed with the solid mineral particles (fillers, sands and aggregates). The coloring agents can also be added in an emulsion comprising the binder composition.

Workability Additives

Workability additives make it possible to improve the workability of compositions intended for the preparation of road and landscaping products. Workability additives may be as described in EP 3 612 597 A1.

In certain embodiments, the compositions of the present invention comprise a synthetic petroleum oil RAE as a plasticizer and a hydrocarbon petroleum resin resulting from the copolymerization of aromatic petroleum cuts rich in C9 monomers as a structuring agent.

The compositions of the present invention can be prepared by a process comprising the following steps:

(a) heating the plasticizer at a temperature ranging from 140 to 200°C, for example for 10 to 30 min;

(b) adding the structuring agent, preferably gradually, mixing and heating at a temperature ranging from 140 to 200°C, for example for 30 to 120 min; (c) adding the copolymer of ethylene and butyl acrylate, mixing and heating at a temperature ranging from 140 to 200° C., for example for 60 to 120 min;

(d) addition of any additives, mixing and heating at a temperature ranging from 140 to 200° C., for example for 5 to 20 min.

The present invention also relates to such a method.

The steps of the process can be carried out in the order presented or the order of these steps can be different.

The compositions of the present invention can be used as a substitute for bitumen-based binders for the preparation of a wide variety of road and landscaping products. In the following, by misuse of language, the road and landscaping products obtained may be referred to collectively as “bituminous products” or individually by usual names referring to the presence of bitumen. It is clear that in such "bituminous products", the bitumen traditionally used is replaced by a composition according to the present invention. Such bituminous products are then light in color or can be colored. The compositions of the present invention can be used for the preparation of asphalt mixes (hot mix asphalt, warm mix asphalt) and mastic asphalt. The low dynamic viscosity of the binder compositions of the present invention makes it possible to prepare and apply these products at temperatures lower than those used in the traditional preparation and application processes. It has been particularly demonstrated that the use of a copolymer of ethylene and alkyl acrylate as described above makes it possible to lower the temperature of manufacture and/or implementation of hot mixes, warm mixes and mastic asphalts. The present invention also relates to such a use.

The compositions of the present invention can also be used for the preparation of binder emulsions useful for the preparation of surface dressings, cold poured bituminous materials, emulsion bituminous concretes and grave emulsion. The low dynamic viscosity of the binder compositions of the present invention can make it possible to facilitate emulsification, particularly by allowing better shear and/or a lower heating temperature.

The present invention also relates to road and landscaping products prepared using the compositions of the present invention. Such road and landscaping products (bituminous products) are well known in road engineering and can be prepared by conventional techniques. For example, some of the aforementioned road and landscaping products may be prepared according to methods such as described in WO 2011/151387, EP 0 384 094, EP 0 524 031, EP 0 781 887, EP 0 552 574, FR 2 732 239 or EP 1 668 184. Road and landscaping products typically meet standards EN 13108-6 (12/2006), EN 12970 (12/2000), EN 13108-1 (02/2007), EN 13108-2 (12/2006), EN 13108-3 (12/2006), EN 13108-4 (12/2006), EN 13969 (09/2005), EN 13108-5 (12/2006), EN 13108 -7 (12/2006) and EN 13108-9 (10/2016).

In the description given below of the road and landscaping products (or bituminous products), it is understood that the term "binder", when the latter is used, designates the binder composition of the present invention.

The term "road and landscaping products" as used here or "bituminous product" as used here by abuse of language designates a product comprising a binder composition according to the present invention and solid particles, in particular particles mineral solids.

The term "solid particles" designates any solid particles that can be used for the production of road and landscaping products according to the invention, in particular for road construction and urban landscaping in clear coatings. Examples of solid particles include solid mineral particles such as natural mineral aggregates (gravel, sand, fines), for example from quarries or gravel pits, products from the recycling of clear coatings such as clear coated aggregates, for example example resulting from the recycling of materials recovered during the repair of clear coatings or surpluses from clear asphalt plants, manufacturing scrap, aggregates from the recycling of road materials including concrete, slag, in particular slag, shales, in particular bauxite or corundum, rubber crumbs, for example from tire recycling, artificial aggregates of any origin and aggregates from, for example, household waste incineration bottom ash (MIOM), as well as mixtures thereof in all proportions.

The solid particles, in particular the solid mineral particles, for example natural mineral aggregates, typically comprise elements smaller than 0.063 mm (filler or fines), sand whose elements are between 0.063 mm and 2 mm and gravel or aggregates , whose elements have dimensions between 2 mm and 6 mm and greater than 6 mm.

The size of solid particles, in particular solid mineral particles, for example mineral aggregates, is measured by the tests described in standard NF EN 933-2 (07/2020). The "solid mineral particles" are also designated by the terms "mineral fraction 0/D". This 0/D mineral fraction can be separated into two particle sizes: the 0/d mineral fraction and the d/D mineral fraction. The finest elements (the mineral fraction 0/d) are those included in the range between 0 and a maximum diameter which can be set between 2 and 6 mm (from 0/2 to 0/6), advantageously between 2 and 4mm. 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. Hot or warm coated

Hot mixes are typically obtained by hot mixing of solid particles as described above (typically a mixture of fines, sand and aggregates having the specific features described above) and a binder composition as described above. above, typically in an asphalt plant. The mixture is then spread and compacted.

The hot mixes prepared using a binder composition according to the present invention can be manufactured at a manufacturing temperature below 170° C., preferably below 160° C., even more preferably at a temperature ranging from 140 at 155°C (mixing or coating temperature). The mixture can then be spread at an application temperature below 140-145°C, preferably below 130°C (eg for example around 100°C, 110°C or 120°C). Advantageously, the working time can be extended without negatively impacting the compactability and workability of the product.

Warm mixes are mixes applied at temperatures approximately 30 to 50°C lower than the temperatures used for hot mixes.

The hot or warm mixes of the invention can be manufactured in any mix plant.

Hot or warm mixes generally comprise from 4 to 10% by weight of the binder composition, advantageously from 4.5 to 6.5% by weight relative to the total weight of the formulated product (that is to say by relative to the total weight of the mixture comprising the binder composition and the solid particles).

Hot or warm bituminous mixes are typically used to produce layers and/or coatings for road construction and/or civil engineering. They are typically used to make wearing courses. Hot or warm bituminous mixes can be used in particular to produce wearing layers such as thin bituminous concrete (BBM), semi-grained bituminous concrete (BBSG), very thin bituminous concrete (BBTM), ultra-thin bituminous concrete (BBUM ), flexible bituminous concretes (BBS), pervious bituminous concretes (BBDr) or high modulus bituminous concretes (BBME).

Hot or warm bituminous mixes can be used for the manufacture of storable mixes. sunk

Cast asphalts designate products obtained by hot casting of a mixture comprising a binder composition, fines, sand, gravel and optionally natural asphalt powder. In mastic asphalts, the interstitial voids that may be present in the mixes are filled with sand, fines and binder. Asphalts Poured can be very particularly used to prepare surfacings for roads, sidewalks or other urban developments or else to prepare waterproofing layers for structures and buildings.

Mastic asphalts prepared using a binder composition according to the present invention can be manufactured at a manufacturing temperature below 200°C, preferably below 180°C, even more preferably at a temperature below 160°C. C (mixing or coating temperature). The mixture can then be cast at a processing temperature below 180°C, for example ranging from 120°C to 180°C.

Mastic asphalts generally comprise from 5 to 12% by weight of the binder composition, advantageously from 7 to 9% by weight relative to the total weight of the formulated product (that is to say relative to the total weight of the mixture comprising binder composition and solid particles).

Binder emulsions and bituminous products prepared using such emulsions

Binder emulsions are commonly used for various road applications, where they can be spread in the presence of aggregates to produce surface dressings.

Binder emulsions can also be mixed with aggregates to obtain cold mixes, either just before laying (Cold Poured Bituminous Materials and recycling in place), or in asphalt mixing plants (storable mixes, Grave-Emulsion, Concrete Bituminous to Emulsion).

Binder emulsions are obtained by dispersing binder droplets in an aqueous phase. The binder droplets are stabilized in the continuous phase by surfactant compounds which can be anionic, non-ionic, amphoteric or cationic. The binder emulsions used in the road industry are mainly cationic in nature. These emulsions are defined and characterized according to different standards and specifications. The European standard EN 13808: 2013 defines the technical specifications for cationic bitumen emulsions used in road construction, road infrastructure maintenance, airports and other surfacings. This European standard applies to bitumen emulsions, fluxed bitumen emulsions, polymer modified bitumen emulsions and polymer modified fluxed bitumen emulsions, which also include latex modified bitumen emulsions.

The binder emulsions according to the present invention comprise a binder composition according to the invention, water and a surfactant, preferably a cationic surfactant. Surfactants useful for the preparation of binder emulsions are well known to those skilled in the art. Surface dressings

Surface wear coatings are surface coatings as described in the guide "Superficial Wear Coatings", Institute of Roads, Streets and Infrastructures for Mobility, Cerema, September 2017. Typically, a surface wear coating denotes a layer consisting of superimposed layers of a binder in the form of an emulsion and of solid particles, in particular solid mineral particles. It is typically obtained by spraying a binder then by spreading solid mineral particles on this binder, in one or more layers. The whole is then compacted.

The total content of binder in a surface wear coating is adapted according to the structure of the coating (single- or two-layer, type of gravelling), the nature of the binder and the size of the solid mineral particles, in particular aggregates, following for example the recommendations of the guide "Superficial Wear Coatings", Institute of Roads, Streets and Infrastructures for Mobility, Cerema, September 2017.

Emulsion bituminous concretes (BBE) and gravel emulsions (GE)

Gravel-emulsion (GE) are used for base courses, binder courses and reprofiling, bituminous emulsion concrete (BBE) for wearing courses.

These products, also called emulsion coated, are cold coated from a mixture of solid particles, in particular solid mineral particles including aggregates, an emulsion binder, typically a cationic emulsion, and additives. The aggregates can be used without prior drying and heating or undergo partial hot pre-lacquering. It may sometimes be necessary to heat the mix obtained after its manufacture, during its implementation.

This technique, known as the "cold" technique, has the significant environmental advantage of not producing smoke emissions.

Gravel-emulsion (GE) and bituminous emulsion concrete (BBE) are as described in the guide "Plant-made emulsion mixes", Institute of Roads, Streets and Infrastructures for Mobility, Cerema , 2020

The binder used for the synthesis of emulsion bituminous concretes is in the form of an emulsion binder. The total residual anhydrous binder content of the cold mix is typically 3 to 7 ppc (part percent by weight), advantageously 3.5 to 5.5 ppc, based on the weight of the solid particles.

In the cold mix, the residual binder content is between 3.5% and 5.5%, advantageously from 4.5 to 5.5%, by weight relative to the total weight of the dry mineral fraction for the bituminous concretes in emulsion or advantageously from 3.5% to 4.5%, by weight relative to the total weight of the dry mineral fraction for a gravel-emulsion. Emulsion bituminous concretes can be used for the manufacture of storable mixes.

Cold Poured Bituminous Materials (MBCF)

Cold-poured bituminous materials are asphalt mixes for a surface layer consisting of solid particles, such as solid mineral particles, for example aggregates, undried coated with binder emulsion and poured in place continuously by means of equipment specific.

Cold Cast Bituminous Materials (MBCF) are as described in the “Cold Cast Bituminous Materials” guide, Institute of Roads, Streets and Mobility Infrastructure, Cerema, 2017.

After its implementation and breaking of the emulsion, this very thin cold poured coating (generally 6 to 13 mm thick per layer) must reach its final consistency (rise in cohesion) very quickly.

The binder used for the manufacture of cold poured bituminous materials is in the form of an emulsion binder. In this emulsion, the binder content advantageously varies from 50 to 75% by weight of binder, relative to the total weight of the emulsion, more advantageously from 55 to 70% by weight, even more advantageously from 60 to 65% by weight .

The total residual anhydrous binder content of the cold poured bituminous material is typically 5.5 to 9 pph (part percent by weight), preferably 6 to 8 pph, based on the weight of the solid particles.

EXAMPLES

1 . Methods

1.1. Preparation of a binder composition according to the invention

A binder composition according to the invention (Example 1) comprises the following constituents:

- 58.9% by mass of an RAE oil characterized by a content of 27% in aromatic compounds, 22% in naphthenic compounds and 51% in paraffinic compounds as a plasticizing agent;

- 34.6% by weight of a petroleum hydrocarbon resin derived from C9 monomers as a structuring agent;

- 6.5% by mass relative to the total mass of oil and resin of a copolymer of ethylene and butyl acrylate having a melt index greater than 2.5 g/10min and a higher melting temperature at 85°C. The composition of Example 1 is prepared according to the following process:

(i) heating the RAE oil, for example to 170°C;

(ii) progressive addition of the resin to the oil and mixing, for example for 1 h to 2 h at 170° C. with a stirring speed of 300 rpm;

(iii) addition of the copolymer of ethylene and butyl acrylate to the oil/resin mixture and mixing, for example for 1 h to 2 h at 170° C. with a stirring speed of 650 rpm;

(iv) if necessary, addition of an adhesive agent in liquid form then mixing, for example for 15 minutes at 170°C.

1.2. Melt index of copolymers of ethylene and alkyl acrylate

The melt index is measured according to the method described in standard ISO1 133-1 (201 1). The copolymers are evaluated at a temperature of 190° C. and under a load of 2.16 kg.

1.3. Determination of needle penetration (NF EN 1426 - January 2018)

This test method allows the determination of the consistency of bitumens, bituminous binders and hydrocarbon binders. The penetration of a reference needle into a conditioned test sample is measured. The operating conditions which apply to penetrabilities up to approximately 330 x 0.1 mm must be: temperature of 25°C, applied load of 100 g and duration of application of the load of 5 seconds.

1.4. Determination of the softening point - Ball and Ring method (NF EN 1427 - January 2018)

This test method allows the determination of the softening point of bitumens, bituminous binders and bituminous binders, in the temperature range of 28°C to 150°C. Two horizontal discs of bitumen, cast in shouldered brass rings, are to be heated in a liquid bath with a controlled rate of temperature rise, while each supports a steel ball. The noted softening point must correspond to the average of the temperatures at which the two discs soften sufficiently to allow each ball, wrapped in bituminous binder, to descend a height of (25.0 ± 0.4) mm.

1.5. Determination of the dynamic viscosity of bituminous binders using a rotating viscometer (NF EN 13302 - June 2018)

This test method allows the determination of the dynamic viscosity of different modified and non-modified bituminous binders and bituminous binders by means of a viscometer with rotating spindle (coaxial viscometer). The torque applied to a rotating spindle (eg a cylinder) in a particular container, which contains the sample to be measured, accounts for the relative resistance of the spindle to rotation and provides a measure of the dynamic viscosity of the sample. The tests are carried out from 100 to 180°C by applying, for each test temperature, a similar shear rate between the different samples.

1.6. Creep-recouyrance test under repeated stresses: MSCR test (NF EN 16659 - February 2016)

This test method is used to determine the existence of an elastic response of bitumens, bituminous binders and bituminous binders under creep-recovery in shear at two stress levels, at a specified temperature. The existence of this elastic response is determined by measuring the recovery percentage and the irreversible compliance of the binder. Irreversible creep compliance has been shown to be an indicator of the resistance of binders to permanent deformation under repeated stresses.

The test must be carried out at 50°C, 60°C, 70°C or 80°C as appropriate. Other test temperatures may be used for comparison. The sample preparation and apparatus are in accordance with EN 14770, with a geometry of parallel plates of 25 mm and an air gap adjustment of 1 mm. The sample is subjected to constant stress for 1 second, followed by recovery for 9 seconds. Ten creep-recovery cycles are performed at a creep stress of 0.100 kPa, followed by another 10 cycles at a creep stress of 3.200 kPa

1.7. Evaluation of the filamentous aspect of binder compositions

A hot mix is first prepared using the binder composition. For this, the mixture below is made at a temperature of 150°C from a total mass of asphalt of 500 g:

- 2/6 Lazard aggregates: 56.50% by weight;

- Sand 0/4 La Nerthe: 36.30% by mass;

- Additive filler (limestone filler): 1.40% by mass;

- Composition of binder: 5.80% by mass.

The mix is then placed in an oven at 120° C. for 30 minutes. After 30 minutes, the temperature of the mix is checked so that the mixture is indeed at 120° C., then the mix is handled using a spatula. The operator visualizes whether filaments are observed during handling of the asphalt. If only one filament is observed, the binder is rated as filamentary in appearance. 2. Examples

In the following examples, the copolymers of ethylene and alkyl acrylate shown in Table 1 below were evaluated.

¹ supplied by SK Functional Polymer; Table 1: Copolymers of ethylene and alkyl acrylate

The EBA1 and EMA3 copolymers are useful copolymers of ethylene and alkyl acrylate in the context of the present invention.

EBA2 and EMA4 copolymers are copolymers of ethylene and alkyl acrylate presented for comparison.

2.1. Demonstration of the importance of the melting temperature of the copolymer

The following binder compositions were fabricated and characterized in order to demonstrate the importance of the melting temperature of the copolymer on the performance of the binder compositions on the criterion of resistance to permanent deformation (Table 2).

Table 2: Performance of binder compositions

The INV1 binder composition is a composition according to the invention: the copolymer used is an EBA copolymer having an MFI of 175 g/10min and a melting temperature of 102°C. The COMP1 binder composition is not a composition according to the invention: the melting point of the EBA is 75°C, therefore less than 85°C.

Despite an equivalent composition of EBAI and TEBA2 (copolymer of ethylene and butyl acrylate with a butyl acrylate content of 28% and an MFI of 175 g/10min), EBAI presents a significantly higher melting temperature than TEBA2. This is explained by the nature of the processes for preparing these copolymers. EBA 1 is prepared using a tubular copolymerization process, thus generating high heterogeneity and therefore a high melting temperature, whereas TEBA2 is prepared using an autoclave copolymerization process, generating a homogeneous copolymer with a low melting temperature. The characterization results of the INV1 and COMF1 binder compositions show that the heterogeneity of the copolymer is essential in order to obtain a high ball-ring temperature value and a good resistance to permanent deformation at 60°C as indicated by the high value of recovery of the composition INV1 and the low irreversible compliance of the composition INV1. 2.2. Demonstration of the importance of the melt index of the copolymer

The following binder compositions were manufactured and characterized in order to demonstrate the importance of the melt index of the copolymer on the reduction in the dynamic viscosity of the composition and therefore on its ability to be applied at lower temperature without influencing the workability of the product at application (Table 3).

Table 3: Performance of binder compositions The INV2 binder composition is a composition according to the invention: the copolymer used is an EMA copolymer having an MFI of 7 g/10min and a melting point of 97°C. The binder composition COMP2 is not a composition according to the invention: the melt index of the EMA is 2 g/10min, therefore less than 2.5 g/m ² . Despite the similar methyl acrylate content between TEMA3 and TEMA4, TEMA3 exhibits a higher melt index than TEMA4. The characterization results of the compositions INV2 and COMP2 show that a high melt index is essential to obtain a lower dynamic viscosity value. Indeed, at 100° C., the binder composition INV2 exhibits a dynamic viscosity lowered by 1000 mPa.s compared with the binder composition COMP2.

The examples of the INV3 and INV1 binder compositions according to the invention make it possible to demonstrate that a preferred mode of the invention consists in selecting copolymers whose melt index is substantially high (Table 4).

Table 4: Performance of binder compositions

Indeed, the results of the INV3 and INV1 binder compositions demonstrate that at the same consistency (values close to penetrability), the use of EBAI, which has a high fluidity index (175 g/10 min for EBA1 against 7 g/ 10min for EMA3) makes it possible to obtain a significantly lower dynamic viscosity at 100°C while maintaining equivalent irreversible compliance between the two binders.

Claims

1 . Clear binder composition comprising: (a) a plasticizing agent, (b) a structuring agent, (c) one or more copolymers of ethylene and alkyl acrylate having a melt index greater than 2.5 g/10min as measured according to the ISO1133-1 (201 1) method and a melting temperature greater than or equal to 85°C as measured according to the ISO 11357-3 (2018) method. 2. Binder composition according to claim 1, in which the structuring agent is a hydrocarbon-based petroleum resin or a resin of vegetable origin, preferably a hydrocarbon-based petroleum resin resulting from the copolymerization of aromatic petroleum cuts rich in C9 monomers. 3. Binder composition according to claim 1 or 2 in which the plasticizer is a synthetic petroleum oil or an oil of vegetable origin, preferably a petroleum oil resulting from a solvent extraction process (RAE). 4. Binder composition according to one of the preceding claims, in which the copolymer of ethylene and alkyl acrylate comprises from 1 to 40% by weight of alkyl acrylate relative to the total weight of the copolymer. 5. Binder composition according to one of the preceding claims, in which the alkyl acrylate is methyl acrylate, ethyl acrylate, butyl acrylate or mixtures thereof. 6. Binder composition according to one of the preceding claims further comprising one or more additives commonly used in road engineering. 7. Binder composition according to claim 6 wherein the additive comprises at least one coloring agent. 8. Road and landscaping product comprising solid particles and a binder composition according to one of the preceding claims. 9. Product according to claim 8 chosen from hot mixes, warm mixes, mastic asphalts, surface dressings, cold poured bituminous materials, emulsion bituminous concretes and serious emulsions. 10. Use of a copolymer of ethylene and alkyl acrylate having a melt index greater than 2.5 g/10min as measured according to the ISO1133-1 (2011) method and a melting temperature greater than or equal to at 85°C as measured according to the ISO 11357-3 (2018) method to lower the manufacturing and/or application temperature of hot mixes, warm mixes and mastic asphalts.