RU2424262C2 - Modified asphalt binders and compositions of asphalt road surface - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to a method to produce compositions of modified asphalt binder, which includes the following: mixing of an asphalt binder, an unsaturated polymer and a phosphorus pentasulfide to produce a modified asphalt composition, in which amount of polymer makes from around 0.5 to around 10 weight parts per 100 weight parts of the asphalt binder, the amount of phosphorus pentasulfide makes from around 0.001 to around 10 weight parts per 100 weight parts of the asphalt binder, when selecting the specified amounts that ensure elastic recovery of the composition of modified asphalt binder by more than 72.5% at 25°C, at the same time the unsaturated polymer and phosphorus pentasulfide are added directly to the asphalt binder without previous mixing of the unsaturated polymer and phosphorus pentasulfide. The invention represents a composition of the modified asphalt binder produced according to the method of invention and an asphalt composition for road surfaces.

EFFECT: production of a composition of the modified asphalt binder.

10 cl, 1 dwg, 6 tbl, 51 ex

Description

This application claims the benefits of provisional applications US No. 60/755666, 60/755670, 60/755668, 60/755667, filed December 29, 2005, and provisional application US No. 60/813950, filed June 15, 2006.

Technical field

One or more embodiments of the present invention relate to modified asphalt binder compositions that result from the use of phosphorus pentasulfide and polymer, as well as to asphalt pavement compositions obtained using these binder compositions.

State of the art

For a long time, asphalt paving compositions, which include a mixture of asphalt binder and aggregate, have been used in the manufacture of pavements. A long-standing technological problem associated with these pavements was their behavior at extreme temperatures. That is, at high temperatures, road surfaces become soft; and at low temperatures, road surfaces are fragile.

For decades, additives have been used to alleviate the problems experienced at extreme temperatures. For example, polymers were added to asphalt binder compositions. US Pat. No. 4,145,322 teaches polymer-modified bitumen compositions that include elastomers (e.g., polyisoprene, butyl rubber, BSK rubber) that can be used to improve the mechanical properties of bitumen, in particular elastomeric properties. And the use of specific block copolymers of styrene and diene monomer in these bituminous compositions allows one to obtain compositions having desirable mechanical properties, even at low temperatures.

Similarly, JP 51-149312 (1976) reports modified asphalt compositions that include a phosphorus compound such as phosphorus pentoxide, polyphosphoric acid or phosphorus pentasulfide. It is believed that these phosphorus compounds can modify asphalt because they bind to asphalt in asphalt, further strengthening the gel structure. In order to eliminate dispersibility and handling problems associated with these phosphorus compounds, the phosphorus compounds are mixed with petroleum compositions and a mixture is added to the asphalt composition. Oil compositions are characterized by a flash point of 150 ° C or more, and include 0.5–40% of asphaltenes. Phosphorus compounds may be included in the oil composition in an amount in the range of 0.5 to 50 weight percent, and the amount of phosphorus compound added to the modified asphalt may be in the range of 0.2 to 5.0 weight percent.

US Pat. No. 6,569,351 teaches polymer-modified asphalt compositions obtained by combining an accelerator-gelling agent with polymer and asphalt and curing the polymer-modified asphalt at a temperature in the range of 200 ° F. (93.3 ° C.) to 500 ° F. (260.0 ° C). The accelerator-gelling agent additives include 2-75% accelerator, 25-88% process oil and 0.5-10% clay. The accelerator may include sulfur, 4,4'-dithiodimorpholine, thiazole derivatives, dithiocarbonates, phosphorus pentasulfide, phosphorus pentoxide, zinc stearate, ammonium stearate, sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminum oxide, or a combination of these or other vulcanizing or accelerating agents. The accelerator-gelling agent additive can be added to concentrates containing approximately 1-25% of the polymer.

US Pat. No. 5,990,206 teaches a mixture of a polymer and a phosphorus compound (modifier composition) for use in asphalt compositions. The polymer may include rubber-based polymers (modifier) and / or resin-based polymer (modifier). Phosphorus compounds may include phosphoric anhydride (P ₂ O ₅ ), polyphosphoric acid, phosphoric acid, phosphorus oxytrichloride (POCl ₃ ), phosphorus trichloride (PCl ₃ ) and phosphorus pentasulfide (P ₂ S ₅ ). The mixture may contain from about 0.1 to about 10% (wt.) Phosphorus compounds, and asphalt compositions containing from 0.1 to 30% (wt.) Polymer / phosphorus compound (modifier composition) mixtures can be obtained. It seems that the inorganic phosphorus compound in the asphalt acts as a crosslinker between the rubber-based and / or resin-based modifier and the higher-order network (asphaltene) and is suitable for strengthening the gel structure in the asphalt.

The drawing is a block diagram showing a specific embodiment of the present invention.

SUMMARY OF THE INVENTION

One or more embodiments of the present invention provide a method for producing a modified asphalt binder composition, the method comprising mixing asphalt, an unsaturated polymer and phosphorus pentasulfide to obtain a modified asphalt composition.

One or more embodiments of the present invention also provide a method for producing a modified asphalt binder composition, the method comprising mixing the asphalt binder, polymer and phosphorus pentasulfide to obtain a modified asphalt composition, where the mass ratio between polymer and phosphorus pentasulfide is at least 0, 5: 1 and less than 8: 1.

One or more embodiments of the present invention further provides a method for preparing a modified asphalt binder composition, the method comprising introducing a polymer of pentasulfide into an asphalt binder and introducing phosphorus pentasulfide into the asphalt binder, wherein said step of introducing phosphorus pentasulfide into the asphalt comprises adding a phosphorus pentasulfide composition that includes less than than 5% (wt.) hydrocarbon material.

One or more embodiments of the present invention further provides a method for producing a modified asphalt binder composition, the method comprising obtaining a phosphorus pentasulfide-binder concentrate by combining and mixing phosphorus pentasulfide and an asphalt binder, where the phosphorus binder pentasulfide concentrate comprises more than 0.5 mass parts of phosphorus pentasulfide per 100 mass parts of asphalt, obtaining a polymer-binder concentrate by combining and remeshivaniya polymer and asphalt binder, where the polymer-binder concentrate includes greater than 5 parts by weight polymer per 100 parts by weight of asphalt, and combining and mixing the phosphorus pentasulfide concentrate-binder concentrate with the polymer-binder to produce a modified asphalt binder composition.

One or more embodiments of the present invention also provide a modified asphalt binder composition comprising a combination or reaction product of asphalt, phosphorus pentasulfide and an unsaturated polymer.

One or more embodiments of the present invention also provide a modified asphalt binder composition obtained by a method comprising combining and mixing asphalt, phosphorus pentasulfide and a polymer, wherein the weight ratio between polymer and phosphorus pentasulfide is at least 0.5: 1 or less than 8: 1.

One or more embodiments of the present invention further provides an asphalt composition that comprises a reaction product between asphalt, an unsaturated polymer, a phosphorus source and a sulfur source, where the phosphorus source and the sulfur source form reactive crosslinking between the components of the asphalt and the unsaturated polymer.

Detailed Disclosure of Invention

One or more embodiments of the present invention provide a method for producing a modified asphalt binder composition that is suitable for use in the preparation of asphalt paving compositions. In one or more embodiments, a modified asphalt binder composition can be prepared by combining and mixing an asphalt binder, a polymer, and phosphorus pentasulfide. The modified asphalt binder composition may be combined with aggregate to form an asphalt pavement composition. In specific embodiments, an asphalt pavement composition may be formed to form pavements.

The term “asphalt binder” is used as understood by specialists in the relevant field of technology, and is consistent with the meaning given in AASHTO M320. In the case of combining an asphalt binder with aggregate, the term "composition of asphalt pavement" is used. As used herein, the terms “asphalt” and “asphalt binder” can be used synonymously. The asphalt binder material can be obtained from any source of asphalt, such as natural asphalt, mountain asphalt obtained from tar sand, or petroleum asphalt obtained from oil refining. Asphalt binder can be selected from those currently classified in accordance with AASHTO M320 and ASTM D-6373, including asphalt binders classified by performance. In other embodiments, asphalt binders may include a mixture of various asphalts that do not meet the definition of any particular classification. This includes blown petroleum asphalt, vacuum distillation asphalt, asphalt obtained by blowing fuel oil with water vapor, asphalt diluted with oil distillate, or asphalt for the impregnation of roofing materials. Alternatively, you can choose gilsonite, natural or synthetic, used individually or in a mixture with petroleum asphalt. Mixtures of synthetic asphalt suitable for use in the present invention are described, for example, in US patent No. 4437896. In one or more embodiments, asphalt includes petroleum derived asphalt and asphalt oil. These compositions may include asphaltenes, resins, cyclic compounds and saturated hydrocarbons. The percentage of these ingredients in the total composition of the asphalt binder can be varied based on the source of asphalt.

Asphaltenes include black amorphous solids containing, in addition to carbon and hydrogen, a certain amount of nitrogen, sulfur and oxygen. Trace elements such as nickel and vanadium may also be present. In general, highly polar aromatic materials having a number average molecular weight in the range of from about 2000 to about 5000 g / mol are considered as asphaltenes, and they can comprise from about 5 to about 25% by weight of the asphalt.

Resins (polar aromatics) include dark-colored hard and semi-solid, very sticky fractions having a relatively high molecular weight and are present in maltes. They may include dispersants for asphaltene peptizers, and the ratio between the amounts of resins and asphaltenes to some extent determines the sol- or gel-type nature of the asphalts. Resins separated from bitumen may have a number average molecular weight in the range of from about 0.8 to about 2 kg / mol, but there is a wide molecular distribution. This component may comprise from about 15 to about 25% by weight of asphalts.

Cyclic compounds (naphthenic aromatics) include compounds having the lowest molecular weight in bitumen and represent the bulk of the dispersion medium for peptized asphaltenes. They can comprise from about 45 to about 60% (wt.) Of the total asphalt binder and can be dark viscous liquids. They may include compounds containing aromatic and naphthenic aromatic nuclei with substituents in the side chain, and may have molecular weights in the range of 0.5 to about 9 kg / mol.

Saturated hydrocarbons mainly include straight and branched chain aliphatic hydrocarbons present in bitumen, together with alkyl naphthenes and some alkyl aromatics. The average molecular weight range may be approximately the same as for cyclic compounds, and the components may include waxy and non-waxy saturated hydrocarbons. This fraction may comprise from about 5 to about 20% by weight of asphalts.

In these or other embodiments, asphalt binders may include bitumen that is found in nature or can be obtained from oil refining. Asphalts may contain very high molecular weight hydrocarbons called asphaltenes, which may be soluble in carbon disulfide, pyridine, aromatic hydrocarbons, chlorinated hydrocarbons and THF. Asphalts or bituminous materials may be solids, semi-solids or liquids.

In one or more embodiments, asphalt binders before modification (that is, before combining with an unsaturated polymer or P ₂ S ₅ ) can be characterized by a PG of at least PG 64-22, in other embodiments of at least , PG 52-28 and in other embodiments, at least PG 52-34. It should be noted that each of these examples of asphalt binders demonstrates a temperature range of operational characteristics from 86 ° C. Despite the possibility of selecting these asphalt binders in desired and specific embodiments, the practice of the present invention allows the use of an asphalt binder base having a lower temperature range, since this lower temperature range can be increased in the framework of the practice of the present invention. For example, PG 64-16, PG 58-22, or PG 52-28 can be modified to increase their temperature range. As those skilled in the art should understand, PG refers to the performance specifications for Super Pave (PG) binders developed in the United States as a result of a study sponsored by the American Association of Road and transport officials (AASHTO M320).

In one or more embodiments, the polymers can be characterized by a glass transition temperature (Tg) less than 20 ° C, in other embodiments less than 0 ° C, in other embodiments less than -20 ° C, in other embodiments less than -35 ° C and in other embodiments ranging from about -90 ° C to about -20 ° C, as measured by DSC analysis.

In one or more embodiments, the polymer used is an unsaturated polymer. In one or more embodiments, unsaturated polymers include hydrocarbon-based polymers that are characterized by a degree or level of unsaturation that can be quantified based on the number of double bonds (non-conjugated double bonds, either in the main chain or in the side groups), based on the total the number of carbon atoms in the polymer (including carbon atoms of the side groups). For example, in one or more embodiments, unsaturated polymers include at least 5 double bonds, in other embodiments of at least 7 double bonds, in other embodiments of at least 12 double bonds, and in other embodiments at least 16 double bonds per 100 carbon atoms in the polymer. In these or other embodiments, unsaturated polymers include from about 7 to about 25 double bonds, in other embodiments from about 10 to about 20 double bonds, and in other embodiments from about 12 to about 18 double bonds per 100 carbon atoms.

Unsaturated polymers include those polymers that include unsaturation in the main chain, in side groups, or both in the main chain and in side groups (i.e., non-conjugated double bonds). For example, the monomer units of the polymer formed by the 1,2-polymerization mechanism of 1,3-butadiene, or the monomer units of the polymer formed by the 3,4-polymerization mechanism of isoprene, are vinyl lateral units. The number of lateral non-conjugated double bonds can be characterized on the basis of the percentage of vinyl in the monomer units containing unsaturation. For example, a polymer having a 30% vinyl content is called a polymer in which 30% of the unsaturated monomer units are non-conjugated double bonds of the side groups. In one or more embodiments, unsaturated polymers used in the practice of the present invention include zero or only negligible vinyl levels. In other embodiments, unsaturated polymers include low vinyl content (eg, from 1 to about 10%); in other embodiments, they include an average level of vinyl content (for example, from 11 to 40%); and in other embodiments, they include a high level of vinyl content (for example, greater than 40%).

In one or more embodiments, unsaturated polymers may also include monomer units that do not include non-conjugated double bonds. For example, monomer units resulting from the polymerization of a comonomer, such as styrene, do not include non-conjugated double bonds. In one or more embodiments, unsaturated polymers may include from about 0% to about 55% of the monomer units (i.e., when calculated per mole), in other embodiments, from about 3% to about 50% of the monomer units, and in other embodiments from about 10 to about 45% of the monomer units formed from the monomer, which does not result in non-conjugated double bonds (e.g. styrene).

In one or more embodiments, unsaturated polymers can be characterized by a melt index (ASTM D-1238; 2.16 kg load at 190 ° C.) less than 1000 dg / min, in other embodiments less than 500 dg / min, in other embodiments sales of less than 50 dg / min, in other embodiments less than 20 dg / min, in other embodiments less than 10 dg / min and in other embodiments less than 1 dg / min. In these or other embodiments, unsaturated polymers can have a melt index in the range of 3 to 15 dg / min, and in other embodiments, 4 to 12 dg / min.

In one or more embodiments, unsaturated polymers can be characterized by a number average molecular weight (M _n ) in the range of from about 10 to about 1000 kg / mol, in other embodiments, from about 40 to about 500 kg / mol, and in other embodiments, from about 80 up to about 200 kg / mol. In these or other embodiments, unsaturated polymers can also be characterized by a weight average molecular weight (M _w ) in the range of about 10 to about 4000 kg / mol, in other embodiments, from about 40 to about 2000 kg / mol, and in other embodiments, from about 80 to about 800 kg / mol. In one or more embodiments, unsaturated polymers can be characterized by a molecular weight distribution in the range of about 1.1 to about 5, in other embodiments, from about 1.5 to about 4.5, and in other embodiments, from about 1.8 to approximately 4.0. Molecular weight can be determined by gel permeation chromatography (GPC) with calibration using polystyrene standards and fitting for Mark-Houwink constants for the polymer in question.

Unsaturated hydrocarbon-based polymers can be linear, branched polymers or polymers obtained by a coupling reaction. Types of hydrocarbon polymers can include both natural and synthetic polymers. Suitable synthetic polymers may include polydienes or polydiene copolymers with a non-diene comonomer (e.g., styrene). The copolymers may include block and random copolymers. The polymers obtained by the coupling reaction may include linear polymers obtained by the coupling reaction (for example, polymers obtained by the coupling reaction and having two rays), or radial polymers obtained by the coupling reaction (for example, obtained by the coupling reaction and having three rays or a combination reaction obtained and having four rays, a combination reaction obtained and five rays, a combination reaction obtained and six rays and the like). Examples of polydienes include polybutadiene and polyisoprene. Examples of copolymers may include random styrene-butadiene rubber, styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, random styrene-isoprene copolymer, styrene-isoprene block copolymer, styrene-isoprene-butadiene block copolymer -isoprene-butadiene copolymer, styrene-isoprene-styrene block copolymer and chloroprene rubber. In one or more embodiments, the polymer may include a high copolymer block copolymer described in International Application No. PCT / US2005 / 028343. In one or more embodiments, unsaturated polymers include linear or radial block copolymers, where the block copolymers include styrene end blocks. For example, in the case of a radial polymer obtained by a coupling reaction and having three beams, each of the three radial beams of the polymer will include end styrene blocks. In these or other embodiments, internal radial ray segments include polydiene blocks, such as polybutadiene blocks. In these or other embodiments, the styrene level in these block copolymers may range from 10% to 50% (wt.), In other embodiments from 15% to 45% (wt.), And in other embodiments from 20 % to 40% (wt.).

In one or more embodiments, the polymer may include a polymer obtained by anionic polymerization. In other embodiments, the polymer can be prepared by coordination catalysis, such as using coordination systems based on cobalt, based on nickel, or based on lanthanides.

In one or more embodiments, the polymer may include a polydiene and / or a polydiene copolymer having a polar group. These polar groups can be located in the side groups in relation to the main chain of the polymer and / or in the end group of the main chain of the polymer. In one or more embodiments, the polar group may include a carbonyl group, such as a carboxylic acid group or an anhydride group, a hydroxyl group, an amino group, an amido group, a carbamate group, a silicon-containing, a metal-containing group, a phosphorus-containing group, and the like.

In one or more embodiments, the polymer in the asphalt composition may be incorporated in several forms. For example, the polymer can be added as chips, as a crushed polymer, as granules, as a molten polymer, or as a liquid polymer.

In one or more embodiments, phosphorus pentasulfide includes those compounds described by the empirical formulas P ₂ S ₅ or P ₄ S ₁₀ , both of which are used by those skilled in the art as synonyms. In one or more embodiments, phosphorus pentasulfide derivatives include those described by the formula

or their derivatives enriched in phosphorus. These phosphorus-enriched derivatives appear to be obtained when the sulfur atom, which is bound to the phosphorus atom by a double bond, is lost. In one or more embodiments, the concentration of phosphorus in the phosphorus pentasulfide compositions is at least 27.85 weight percent, in other embodiments, is in the range of from about 27.87 to about 28.3 weight percent, and in other embodiments, from about 28.90 to about 28.00 weight percent. Phosphorus pentasulfide is commercially available from sources such as ICL Performance Products, L. P.

In one or more embodiments, the phosphorus pentasulfide that is used in the present invention is used in its solid form, such as solid particles. In one embodiment, phosphorus pentasulfide can be characterized as having a particle size (i.e., average diameter) of less than 20 mm, in other embodiments less than 2 mm, in other embodiments less than 0.2 mm and in other embodiments less less than 0.02 mm; in these or other embodiments, the particle size may be larger than 0.001 mm, in other embodiments greater than 0.009 mm, and in other embodiments greater than 0.01 mm. In these or other embodiments, the average particle size of the phosphorus pentasulfide may range from about 0.03 to about 1.00 mm, in other embodiments from about 0.05 to about 0.95 mm, in other embodiments from about 0 , 06 to about 0.90 mm, and in other embodiments, from about 0.07 to about 0.085 mm. In these or other embodiments, at least 30%, in other embodiments of at least 50%, and in other embodiments of at least 70%, of the phosphorus pentasulfide particles fall in the range of from about 0.03 to about 1.00 mm, and in other embodiments, from about 0.05 to about 0.95 mm, in other embodiments, from about 0.06 to about 0.90 mm, and in other embodiments, from about 0.07 to approximately 0.085 mm.

The phosphorus pentasulfide used in the present invention can be relatively pure. In one or more embodiments, phosphorus pentasulfide comprises less than 10 weight percent, in other embodiments less than 5 weight percent, in other embodiments less than 2 weight percent, and in other embodiments less than 0.5 weight percent, impurities. In addition, in one or more embodiments, phosphorus pentasulfide introduced into the asphalt to mix with it is in its pure form. In one or more embodiments, phosphorus pentasulfide in its pure form is called solid particles that contain less than 5 weight percent, in other embodiments, less than 2 weight percent, in other embodiments, less than 0.5 weight percent, in other embodiments less than 0.1 weight percent and in other embodiments, less than 0.05 weight percent, organic or hydrocarbon substances or impurities.

In one or more embodiments, phosphorus pentasulfide can be used without modification. In other embodiments, phosphorus pentasulfide includes those materials that have not reacted or have not undergone any reaction or preliminary reaction to modify the solubility of phosphorus pentasulfide in the asphalt composition. For example, it has been found that predominantly phosphorus pentasulfide can be used without reacting it with a compound having a hydroxyl group capable of binding to phosphorus pentasulfide. In one or more embodiments, phosphorus pentasulfides can be used without first reacting phosphorus pentasulfides with polyalkylene oxide.

The modified asphalt binder compositions of the present invention may also include those other ingredients or components that are commonly used in industry. For example, compositions may include adhesion enhancing compounds.

In other embodiments, hardeners may be added to the modified asphalt binder composition of this embodiment, if desired. Hardeners may include phenolic resins and elemental sulfur. One example is a bismaleimide hardener. Usual amounts may be used in the practice of this invention. In one or more embodiments, the need for a hardener, in particular sulfur, is eliminated. In other words, the asphalt binder compositions of the present invention can be prepared without the addition of a hardener and / or a sulfur-containing hardener other than phosphorus pentasulfide.

The asphalt binder compositions of the present invention may include from about 0.1 to about 10 parts by weight, in other embodiments from about 0.2 to about 6 parts by weight, and in other embodiments from about 0.5 to about 4 parts by weight, polymer per 100 mass parts of asphalt binder. In these or other embodiments, the asphalt binder compositions of the present invention may include less than 5 parts by mass, in other embodiments, less than 4 parts by mass, in other embodiments, less than 3 parts by mass, in other embodiments, less than 2.5 parts by mass in other embodiments, less than 2 parts by mass, in other embodiments, less than 1.8 parts by mass, in other embodiments, less than 1.5 parts by mass, polymer per 100 parts by mass of asphalt binder. In these or other embodiments, the asphalt binder compositions include at least 0.1 parts by weight, in other embodiments, at least 0.5 parts by weight, in other embodiments, at least 0.7 parts by weight in other embodiments of at least 1.0 mass parts and in other embodiments of at least 1.2 mass parts, polymer per 100 mass parts of asphalt binder.

The asphalt binder compositions of the present invention may include from about 0.001 to about 10, in other embodiments from about 0.05 to about 5, and in other embodiments from about 0.01 to about 1 part by weight of phosphorus pentasulfide per 100 parts by weight of asphalt binder.

In one or more embodiments, the weight ratio between the unsaturated polymer and phosphorus pentasulfide in the modified asphalt binder composition may be at least 0.5: 1, in other embodiments, at least 0.7: 1, in other embodiments the implementation of at least 1: 1, in other embodiments, the implementation of at least 1.3: 1, in other embodiments, the implementation of at least 1.5: 1, in other embodiments, the implementation of at least 1 , 8: 1, and in other embodiments, at least 2.0: 1. In these or other embodiments, the weight ratio between the unsaturated polymer and phosphorus pentasulfide is less than 8: 1, in other embodiments less than 7: 1, in other embodiments less than 6: 1, in other embodiments less than 5: 1 in other embodiments less than 4: 1 and in other embodiments less than 3: 1.

In those embodiments that use a hardener, the asphalt compositions of the present invention may include from about 0.1 to about 10, in other embodiments from about 0.2 to about 6, and in other embodiments from about 0.5 to about 4 mass parts of hardener per 100 mass parts of asphalt. In these or other embodiments, less than 3 parts may be used in the preparation of asphalt binder compositions of the present invention, in other embodiments less than 1 part, in other embodiments less than 0.5 parts, in other embodiments less than 0.25 parts in other embodiments, less than 0.1 parts and in other embodiments less than 0.01 parts by weight of a hardener (eg, free sulfur or elemental sulfur) per 100 parts by weight of asphalt binder.

In one or more embodiments, phosphorus pentasulfide can be used without resorting to polyphosphoric acid or a derivative thereof. In certain embodiments, less than 1 mass part is used in the practice of the invention, in other embodiments less than 0.1 mass parts, in other embodiments less than 0.05 mass parts and in other embodiments less than 0.01 mass parts, polyphosphoric acid or its derivative per 100 mass parts of asphalt. In one or more embodiments, no polyphosphoric acid is used in asphalt compositions and is not added to asphalt compositions. In one or more embodiments, the asphalt compositions of this invention are free of polyphosphoric acid or its reaction products with one or more ingredients of the asphalt composition.

In one or more embodiments, the asphalt compositions of the present invention may comprise less than 1%, in other embodiments less than 0.5%, in other embodiments less than 0.1% and in other embodiments less than 0.05% ( wt.), organophosphorus compounds. In these or other embodiments, the asphalt compositions of the present invention are substantially free of organophosphorus compounds, wherein substantially freedom of content is that amount of the organophosphorus compound that does not have a significant effect on the composition, or less than this. Organophosphorus compounds include those described in US Pat. Nos. 5,990,206 and 6,024,788, which are incorporated herein by reference.

In one or more embodiments, the modified asphalt binder compositions of the present invention can be obtained by combining an asphalt binder with a desired amount of polymer (e.g., an unsaturated polymer) and phosphorus pentasulfide at a desired temperature. In one embodiment, the polymer and phosphorus pentasulfide may be added to the molten asphalt binder at temperatures greater than about 120 ° C, or in other embodiments ranging from about 140 ° C to about 210 ° C. In one or more embodiments, phosphorus pentasulfide, polymer, and asphalt can be mixed or mixed after or during their combination. After this, stirring can be continued for a duration of from about 25 to about 400 minutes at a temperature in the range of from about 145 ° C to about 205 ° C (or in other embodiments, from about 160 ° C to about 193 ° C). In one or more embodiments, in order to disperse the polymer rapidly in asphalt, the mixture of asphalt binder, polymer, and phosphorus pentasulfide can be sheared. Shear action can be carried out, for example, in a high shear mill, such as that produced by Siefer. In other embodiments, when time is of less importance, simple low shear mixing can be used. In one or more embodiments, the resulting modified asphalt binder composition is a homogeneous mixture, which is a mixture in which less than 1% by weight of polymer is separated from the asphalt at 2 ° C, as defined in ASTM D- 7173.

In one or more embodiments, it may be advantageous to add phosphorus pentasulfide to the asphalt binder composition together (i.e., simultaneously) with the polymer. In other words, phosphorus pentasulfide does not need to be premixed with an asphalt binder before the polymer is added. Similarly, the polymer does not need to be premixed with the asphalt binder composition before the addition of phosphorus pentasulfide.

In one or more embodiments, phosphorus pentasulfide and the polymer can be added directly to the asphalt binder (e.g., molten asphalt binder) without pre-mixing the phosphorus pentasulfide and the unsaturated polymer with each other. Phosphorus pentasulfide and the polymer can be added to the asphalt binder simultaneously or sequentially. In one or more embodiments in which phosphorus pentasulfide and a polymer are added to the same binder composition, phosphorus pentasulfide can be added first, followed by polymer. In other embodiments, a polymer may be added first to the asphalt binder, followed by phosphorus pentasulfide.

In still other embodiments, phosphorus pentasulfide and an unsaturated polymer can be separately combined and mixed with separate asphalt binder compositions, and then the individual binder compositions can then be combined and mixed. For example, phosphorus pentasulfide can be added to the first asphalt binder composition to form a first masterbatch binder composition. Similarly, the polymer can be added to the second asphalt binder composition to form a binder composition of the second masterbatch. After this, the compositions of the first and second masterbatch mixtures can be combined and mixed with each other to obtain a modified asphalt binder composition according to the present invention.

In one or more embodiments, the present invention provides a method in which a phosphorus pentasulfide concentrate and an asphalt binder are combined and mixed with a polymer concentrate and an asphalt binder. This method advantageously allows for efficient transportation and / or storage of phosphorus pentasulfide compositions and / or polymer and asphalt binder compositions. In other words, it has been advantageously found that, if the polymer, phosphorus pentasulfide and the asphalt binder are not combined and combined, higher concentrations of phosphorus pentasulfide and / or polymer in the asphalt binder composition can be achieved, provided that the phosphorus pentasulfide and the unsaturated polymer are introduced and mix into separate binder concentrates. Mostly, the concentrates can be delivered to a large number of regional points, where they can be combined and mixed with each other, and / or they can be mainly diluted with additional asphalt binder in regional points.

In one or more embodiments, the phosphorus pentasulfide-binder concentrate may include more than 0.5 parts by weight, in other embodiments more than 2.0 parts by weight, in other embodiments more than 5.0 parts by weight, and in other embodiments more than 8.0 parts by weight phosphorus pentasulfide per 100 parts by weight of asphalt. In these or other embodiments, the phosphorus pentasulfide-binder concentrate may comprise up to 10 parts by weight and in other embodiments up to 12 parts by weight of phosphorus pentasulfide per 100 parts by weight of asphalt binder. Specialists in the relevant field of technology should understand that the upper levels of phosphorus pentasulfide, which can be added to the asphalt binder, are determined by the ability to process and process asphalt (for example, pumpability, in accordance with AASHTO T316).

Similarly, a polymer-binder concentrate may include more than 5 parts by mass, in other embodiments more than 10 parts by mass, in other embodiments more than 15 parts by mass, and in other embodiments more than 18 parts by mass, polymer per 100 parts by mass parts of asphalt. In these or other embodiments, the polymer binder concentrate may comprise up to 20 parts by weight, in other embodiments up to 25 parts by weight, and in other embodiments, up to 30 parts by weight of polymer per 100 parts by weight of asphalt binder. Specialists in the relevant field of technology should understand that the upper levels of polymer that can be added to the asphalt binder are determined by the ability to process and process asphalt (for example, pumpability in accordance with AASHTO T316). Other factors that may affect the upper limit of polymer concentration include polymer molecular weight, polymer macrostructure, and asphalt characteristics.

In one or more embodiments, the asphalt used to produce the phosphorus-binder pentasulfide concentrate may exhibit characteristics different from those of the asphalt used to produce the polymer-binder concentrate. For example, in one embodiment, the asphalt used to make the polymer binder concentrate may be softer asphalt than that used to produce the phosphorus pentasulfide binder concentrate. This may be advantageous since higher polymer loads can be added to softer asphalt, which will thus enable transport and / or storage of more polymer with less asphalt. In addition, as a result of the preparation of a phosphorus pentasulfide-binder concentrate and a polymer-binder concentrate using various asphalts, after mixing, the desired properties can be achieved. For example, a phosphorus-binder pentasulfide concentrate can be prepared using relatively hard asphalt, which, when mixed with a polymer-binder concentrate made using relatively soft asphalt, can provide intermediate hardness for the asphalt binders used to make the concentrates.

One particular embodiment of the method of the present invention is shown in the drawing. At the installation for the manufacture of modified asphalt binder 12 are a container 22 for storing phosphorus pentasulfide, a container 24 for storing an asphalt binder and a container 26 for storing unsaturated polymer. The phosphorus pentasulfide concentrate 28-binder can be obtained by combining and mixing phosphorus pentasulfide and an asphalt binder. The combining and mixing step can be carried out by adding phosphorus pentasulfide particles to an asphalt binder composition maintained at a temperature in the range of from about 120 ° C to about 205 ° C. Similarly, the unsaturated polymer binder concentrate 30 can be obtained by combining and mixing an unsaturated polymer and an asphalt binder. Combining and mixing the unsaturated polymer and the binder can be accomplished by adding granules of the unsaturated polymer to the molten asphalt binder composition, maintained at a temperature in the range of from about 120 ° C to about 205 ° C. After that, the corresponding concentrates of asphalt binders (that is, concentrate 28 and concentrate 30) can be delivered to the unloading point 14. The concentrates can be delivered using heated or insulated cargo containers. Mostly, when using insulated cargo containers, these concentrates can be delivered to the unloading point 14, located at a distance reaching up to and exceeding 1000 miles (1609 km) from the installation for the manufacture of modified asphalt binder 12.

At discharge point 14, the phosphorus pentasulfide-binder concentrate and the unsaturated polymer-binder concentrate can be combined and mixed. This combination and mixing can be carried out at temperatures in the range of from about 145 ° C to about 170 ° C. In addition, the concentrates, before or after combining and mixing them, can be diluted using an additional amount of asphalt binder, which can be stored at discharge point 14 in container 32. After that, the modified binder 34, which is diluted to the desired level of phosphorus pentasulfide obtained in this case, and / or unsaturated polymer, can be transported to a hot mixer 16. Transportation of this modified asphalt binder composition can be carried out in heated or insulated cargo containers, and delivery can be carried out in a hot mixer 16, located at a distance reaching up to and exceeding 300 miles (483 km).

In the hot mixer 16, the modified binder composition can be combined and mixed with aggregate 36 to form a pavement composition 38. Methods for combining and mixing the aggregate and modified binder composition are known in the art and include batch mixing and continuous mixing. In one or more embodiments, the aggregate and the modified asphalt binder are combined and mixed by first preheating the modified asphalt binder to a temperature in the range of from about 120 ° C to about 200 ° C. Immediately after receiving the pavement composition 38, the pavement composition can be transported to a work site (e.g., subgrade) on which the pavement is lined (18). The transportation of the composition of the road surface can be carried out in a heated or insulated cargo container.

Modified asphalt binder compositions obtained in accordance with the present invention can be used to produce asphalt paving compositions. These pavement compositions may include a modified asphalt binder, aggregate, and other optional ingredients that may be added to the pavement composition, as is known in the art. In the practice of this implementation option, you can use the usual placeholder, which is used in road construction. The aggregate may include rock fragments, stones, slag, rubble, gravel, sand, silica, or mixtures of one or more of these aggregates. Specific examples of aggregates include marble, limestone, basalt, dolomite, sandstone, granite, quartzite, steelmaking slag, and mixtures of two or more of these aggregates.

Aggregates are typically characterized by a wide particle size distribution ranging from submicron particles (e.g. dust) to masses with golf ball sizes up to 63 mm in diameter. The best particle size distribution changes when moving from one application to another application.

In addition to aggregate and modified asphalt binder, the paving compositions of the present invention may also include other components or ingredients that can be used in the preparation of asphalt paving compositions. These additional components or ingredients may include fibers, release agents, and fillers. Other examples include calcium hydroxide, grinding dust, cellulosic fibers, propylene-based fibers, and mixtures of two or more of these components.

The asphalt pavement compositions of the present invention can be prepared using standard equipment and techniques. In one or more embodiments, the aggregate is mixed with a modified asphalt binder until a substantially homogeneous asphalt pavement is obtained. For example, the aggregate can be continuously mixed with a modified asphalt binder to form an asphalt pavement composition in a standard mixer. In one or more embodiments, the practice of the present invention substantially eliminates the need for processing aggregate before producing asphalt concrete.

Upon receipt of the composition of the asphalt pavement in the General case, from about 1 weight percent to about 10 weight percent of the modified asphalt and from about 90 weight percent to about 99 weight percent of aggregate are mixed (based on the total weight of the asphalt pavement composition). In other embodiments, paving compositions comprise from about 2 to about 8 weight percent modified asphalt.

Compositions of asphalt binders, as well as compositions of asphalt pavement obtained in accordance with the present invention, demonstrate the presence of several beneficial properties. In one or more embodiments, the compositions can advantageously be stored at elevated temperatures without adversely affecting the temperature of the separation of the polymer and the asphalt binder.

Compositions of asphalt pavement obtained in accordance with the present invention are particularly advantageous in the manufacture of pavements. These pavements may include the following, but are not limited to only this: carriageway, runways, sidewalks, tracks, tracks for golf carts with golfers on the playground, waterproof linings for ponds, landfill coverings and bridge decks. In addition, the modified asphalt binder compositions of the present invention are advantageous in the preparation of compositions other than pavement compositions. For example, modified asphalt compositions may be suitable for use in roofing applications.

In order to demonstrate the practice of the present invention, the following examples were obtained and tested. However, examples should not be construed as limiting the scope of the invention. To determine the invention, the claims should be used.

EXAMPLES

Samples 1-6

Asphalt binder compositions were prepared using the following method. In a container in the form of a tin container with a volume of 1 quart (1.14 L) was added 500 grams of asphalt binder, pre-heated to 163 ° C. Asphalt binder was obtained from BP (Whiting, Indiana) and was characterized by PG 64-22 in accordance with AASHTO M320. When using a 1.14 L tin capacity heater, the asphalt binder was heated to 190 ° C and scrolled in a Silverson high shear mixer, during which phosphorus pentasulfide particles were added by directly adding particles to the asphalt binder and unsaturated polymer pellets by directly adding granules to asphalt binder. Shear effect on the sample in the container was provided for 30 minutes. The lid was loosely placed on the container, and the container was placed in an oven set at 163 ° C for 18 hours. After removing the container from the oven and removing the lid, the entire available foam layer was removed. After that, the sample was mixed and poured onto a grid with 20 mesh cells, and the sifted material was used to obtain samples for testing.

The amount of modifier (e.g., phosphorus pentasulfide and unsaturated polymer) added to each sample is shown in Table I. A portion of each sample was taken from which various test samples were needed for each standardized test used. The test methods used in all of these examples are presented in table I.

The unsaturated polymer used in this set of samples was a radial polymer, which was characterized by the presence of approximately 16.5% vinyl, 90% was a polymer obtained by the combination reaction and having four beams, included approximately 30% block styrene, had a main peak of maximum molecular weight (M _p ) of about 53 kg / mol and was characterized by the value of M _p after the coupling reaction, equal to approximately 228 kg / mol; this polymer was obtained under the trade name 161-B ™ (LCY; China).

The amounts of unsaturated polymer and phosphorus pentasulfide are shown in Table I in parts by weight per 100 parts by weight of asphalt (pha).

TABLE 1 Samples Test method one 2 3 four 5 6 Modifier (parts per 100 parts of asphalt) Unsaturated polymer - 1.25 - 1.25 1.25 1.25 Phosphorus pentasulfide - - 0.5 - - 0.5 Polyphosphoric acid - - - - 0.5 - Sulfur - - - 0.1 - - Performance Analysis Initial Failure Temperature in DSR (Dynamic Shear Plastometer) (° C) AASHTOT315 65.5 69.0 70.6 71.6 72.5 78.7 Failure temperature for RTFO (moving thin film in the oven) in DSR (° C) AASHTOT240 / T315 65.6 69.0 69.6 71.5 73.1 77,2 Phase angle at 76 ° С, ° AASHTOT315 89.0 87.4 87.5 79.4 85.1 69.7 Hardness (MPa) AASHTOT313 210 228 205 195 210 166 The value of m (the rate of change of the coefficient of elasticity over time) AASHTOT313 0.329 0,304 0.326 0.332 0,309 0.345 Binder grade PG (° C) AASHTO M320 64-22 64-22 64-22 70-22 70-22 76-22 Estimated actual mark (° C) Not applicable 65-24 69-22 69-24 71-25 72-22 77-26 PG Interval (° C) Not applicable 89 91 93 96 94 103 Elastic recovery at 25 ° C (%) AASHTO T301 24.0 44.0 34.0 72.5 48.5 87.5 Separation ¹ (° C) ASTMD-7173 0.3 0.5 0.3 0.3 1,6 0.8 Softening Point (° C) AASHTO T53 48.1 52,2 54.7 55.3 55.6 65.8 1 - “Separation” characterizes the difference in softening temperatures in the “separation test” for the asphalt binder; "Separation test" is carried out in accordance with standard ASTM D7173; "Separation test" characterizes the tendency of the polymer to separate from the polymer-modified asphalt binder under static heating conditions.

The estimated PG brand is a measure of the temperature range for the temperature range of the performance of an asphalt binder. Adding numbers to each other forms the temperature range PG. The larger the number, the greater will be the temperature range of performance, on which the asphalt binder will demonstrate performance.

The asphalt binder of sample 1, which is a pure asphalt binder, shows performance in the range of 89 ° C. Sample 2, which includes a saturated polymer, shows an improvement of 2 ° C as an increase from 89 ° C to 91 ° C. Compared to the base asphalt, sample 3, which includes phosphorus pentasulfide, shows a slight improvement in the temperature range of PG by 4 ° C. Compared to the pure binder, sample 4, which includes the unsaturated polymer and sulfur, shows an improvement of 7 ° C as 96 ° C. Sample 5, which includes an unsaturated polymer and polyphosphoric acid, shows an improvement of 5 ° C. Compared to the asphalt base, sample 6, which corresponds to the present invention, unexpectedly demonstrates a temperature improvement of 14 ° C in the form of a temperature range of PG 103 ° C. In addition, the elastic recovery (also called elongation reduction) of sample 6, which is 87.5%, is exceptionally high, which implies the presence of a highly elastic polymer asphalt binder, which is usually achieved only at higher levels of polymer loading. The softening temperature, as well as an estimate of the high temperature PG equal to 77 ° C, suggests that the modified asphalt binder is technologically suitable for use with high temperature. In conclusion, the phase angle for sample 6 was 69.7, which indicates a strong elastic structure formed in an asphalt binder.

Examples 7-13

Additional modified asphalt compositions were obtained by using methods similar to those proposed for previous samples, but in the case of comparative samples (samples 11, 12 and 13), samples were obtained using saturated polymers. Table II presents the amount of each modifier used in each sample, as well as the results of the performance analysis conducted for each sample.

The unsaturated polymer used in sample 8 was a radial polymer, which was characterized by the presence of approximately 16.5% vinyl, 90% was a polymer obtained by the combination reaction and having four beams, included approximately 30% block styrene, had a main peak of maximum molecular mass (M _p ) of about 53 kg / mol and was characterized by the value of M _p after the coupling reaction, equal to approximately 228 kg / mol; this polymer was obtained under the trade name 161-B ™ (LCY; China); this polymer in the tables was designated as radial polymer.

The unsaturated polymer used in sample 9 was a linear polymer obtained by the coupling reaction and having two beams, which was characterized by the presence of approximately 13% vinyl, 92% was a polymer obtained by the coupling reaction and having two beams, included approximately 30% block styrene, had a main peak of maximum molecular weight (M _p ) of about 60 kg / mol and was characterized by a M _p value after the coupling reaction of approximately 106 kg / mol; this polymer was obtained under the trade name 6302 ™ (LCY; China); this polymer in the tables was designated as a high molecular weight polymer.

The unsaturated polymer used in sample 10 was a linear polymer obtained by the coupling reaction and having two beams, which was characterized by the presence of approximately 13% vinyl, 25% was a polymer obtained by the coupling reaction and having two beams, included approximately 30% block styrene, had a major peak maximum molecular weight (M _p ) of about 50 kg / mol and was characterized by a M _p value after the coupling reaction of approximately 90 kg / mol; this polymer was obtained under the trade name 6320 ™ (LCY; China); this polymer in the tables was designated as medium molecular weight polymer.

The saturated polymer used in sample 11 was a hydrogenated styrene-butadiene-styrene block copolymer (CE / B-C), which was obtained under the trade name KRATON ™ G1652.

The saturated polymer used in sample 12 was ethylene-propylene-diene rubber (EPDM), which was obtained under the trade name EP35 (JSR; Japan) and which had a Tg value of approximately −51 ° C, a degree of crystallinity of 0%, a viscosity of Mooney (ML _{1 + 4} at 10 ° C) 91.6, a Mn value of approximately 72 kg / mol, a Mn value of approximately 214 kg / mol, and an MMP (molecular weight distribution) of approximately 2.94 , an ethylene content of approximately 52%, and a diene content of equal m about 5.9%; it should be noted that this polymer is not completely saturated.

The saturated polymer used in sample 13 was ethylene vinyl acetate polymer (EVA), which was prepared under the trade name ELVAX ™ 460 (DuPont).

TABLE II Samples 7 8 9 10 eleven 12 13 Modifier (parts per 100 parts of asphalt) Phosphorus pentasulfide - 0.5 0.5 0.5 0.5 0.5 0.5 Unsaturated polymer Radial polymer - 1,5 - - - - - High molecular weight polymer - - 1,5 - - - - Medium molecular polymer - - - 1,5 - - - High grade polymer S-E / B-S - - - - 1,5 - - EPDM - - - - - 1,5 - EVA - - - - - - 1,5 Performance Analysis Initial fracture temperature in DSR (° C) 65.5 80.6 77.8 75.1 74.1 73.3 74.0 Destruction temperature for RTFO in DSR (° C) 65.6 77.6 77.7 76.3 73.9 73.6 74,4 Phase angle at 76 ° C, ° 89.0 67.3 71.6 81.0 86.4 86.7 84.0 Elastic recovery at 25 ° C (%) 24.0 87.5 87.5 83.5 52.0 38.5 41.5 Separation (° C) 0.3 0.5 0.3 0.3 1,1 0.3 0.4 Softening Point (° C) 48.1 69,4 64,2 57.5 55.8 56.1 56.9

Sample 7 from table II is the same pure asphalt binder used in sample 1 from table I. Samples 8-10 include unsaturated polymers, and data from testing modified asphalt binders indicate that these are unsaturated polymers provide binders that are more resilient (phase angle and resilient recovery) in comparison with what was expected for these polymer loads. Unexpectedly, this indicates that the combination of an unsaturated polymer and phosphorus pentasulfide results in a highly elastic asphalt binder. In addition, with regard to the fracture temperature for RTFO in DSR (aging), compared to pure asphalt binder, high temperature performance specimens comprising an unsaturated polymer show improvements in the range of 10.7 ° C to 12 ° C. In addition to this, samples 8, 9 and 10 provided high elastic recovery values; indeed, in each case there was an excess of 80%. On the other hand, the use of saturated polymers (or a polymer characterized by a low level of unsaturation) led to a slight improvement in elasticity compared to pure asphalt (there was some improvement in high-temperature hardness by 8.3 ° C-8.8 ° C). In general, the data in Table II suggest a synergistic effect between phosphorus pentasulfide, an unsaturated polymer, and an asphalt binder, which unexpectedly results in an improved resilient asphalt binder.

Examples 14-23

Several modified asphalt compositions were prepared using methods similar to those used for the above samples, except that the weight ratio between the unsaturated polymer and phosphorus pentasulfide for all samples was varied while maintaining 1.25 mass parts of polymer per 100 mass parts of asphalt. The unsaturated polymer used was a radial polymer, which was characterized by the presence of approximately 16.5% vinyl, 90% was a polymer obtained by the coupling reaction and having four beams, included approximately 30% block styrene, had a main molecular weight peak (M _p ) of about 53 kg / mol and the value of M _p after the coupling reaction, equal to approximately 228 kg / mol; this polymer was obtained under the trade name 161-B ™ (LCY; China). Table III presents the mass ratio between the polymer and phosphorus pentasulfide, as well as the test results for each sample.

TABLE III Samples fourteen fifteen 16 17 eighteen 19 twenty 21 22 23 Modifier (parts per 100 parts of asphalt) Polymer: phosphorus pentasulfide 12.5: 1 9: 1 5: 1 3.1: 1 2.5: 1 2.1: 1 1.8: 1 1.6: 1 1: 1 1: 2 Performance Analysis DSR Initial Failure Temperature (° C) 70.6 72.7 73.0 76.7 78.7 81.0 83.1 83.5 79.8 86.5 Failure temperature for RTFO in DSR (° C) 71.2 71.9 72.3 74.8 77,2 78.8 80,4 80.8 77,2 84.3 Phase angle at 76 ° С, ° 81.8 78,4 75.3 71.6 69.7 66.5 65.6 65.9 81.2 76.6 Elastic recovery at 25 ° C (%) 69.0 72.5 78.0 83.5 87.5 89.0 88.0 88.0 38.5 41.5 Softening Point (° C) 53.9 56.7 57.5 61.9 65.8 69.7 72.5 72,2 60.8 67.8 Separation (° C) 0.3 0.3 0.5 0.5 0.8 0.5 0.5 0.5 0.8 0.3

The data from table III demonstrate the unexpected effect of changing the ratio between the amounts of polymer and phosphorus pentasulfide. As the ratio decreases, the elastic recovery for the modified binder increases, reaching a maximum in the 1.8: 1 region. Then, as the ratio continued to decrease, the elastic recovery began to decrease. In addition, the phase angle decreases monotonically to a ratio of 1.8: 1, and then increases below this ratio.

Samples 24-33

By a method similar to that used for samples 14-23, additional modified asphalt compositions were prepared and the weight ratio between the unsaturated polymer and phosphorus pentasulfide was varied while maintaining 1.25 parts by weight of polymer per 100 parts by weight of asphalt. These samples differ from samples 14-23 in the used unsaturated polymer, which was a linear polymer obtained by the combination reaction and having two beams, which was characterized by the presence of approximately 13% vinyl, 25% was a polymer obtained by the combination reaction and having two beams, included approximately 30% block styrene, had a major peak maximum molecular weight (M _p ) of about 50 kg / mol, and had a M _p value after the coupling reaction of about 90 kg / mol; this polymer was obtained under the trade name 6320 ™ (LCY; China).

Table IV presents the mass ratio between the polymer and phosphorus pentasulfide, as well as the test results for each sample.

TABLE IV Samples 24 25 26 27 28 29th thirty 31 32 33 Modifier (parts per 100 parts of asphalt) Polymer: phosphorus pentasulfide 12-5: 1 9: 1 5: 1 3.1: 1 2.5: 1 2.1: 1 1.8: 1 1.6: 1 1: 1 1: 2 Performance Analysis DSR Initial Failure Temperature (° C) 69,4 69.9 70.9 73.3 74.7 77,2 78,4 80.2 81.7 87.2 Failure Temperature for RTFO in DSR (° C) 69,4 69,4 70.7 73.0 73,2 76.1 78,2 78.8 80.3 85.7 Phase angle at 76 ° C, ° 86.3 86.0 85.5 83.7 81.7 78.0 75,5 73.1 76.7 73.8 Elastic recovery at 25 ° C (%) 64.0 66.5 71.5 74.5 81.5 83.5 84.5 83.0 45.0 40.5 Softening point, ° C 52,5 53.6 55.0 56.7 57.2 60.8 61.7 62.8 64,4 68.9 Separation (° C) 0.5 0.3 0.3 0.3 0.5 0.3 0.3 0.3 0.3 0.5

As in the case of the data from table III, the data from table IV indicate that as the ratio decreased, the elastic recovery increased, reaching a maximum at 1.8: 1. Similarly, unexpectedly, elastic recovery began to decrease below this ratio. The phase angle followed the pattern of decreasing the phase angle while decreasing the ratio down to 1.6: 1, and after that it increased.

Samples 34-45

Additional modified asphalt compositions were prepared using methods similar to those used for the previously described samples, except that they compared the effectiveness of phosphorus pentasulfide and other compounds. The nature of the various compounds is presented in Table V together with the test results for each sample.

The unsaturated polymer used was a radial polymer, which was characterized by the presence of approximately 16.5% vinyl, 90% was a polymer obtained by the coupling reaction and having four beams, included approximately 30% block styrene, had a main peak of maximum molecular weight (M _p ) about 53 kg / mol and was characterized by the value of M _p after the coupling reaction, equal to approximately 228 kg / mol; this polymer was obtained under the trade name 161-B ™ (LCY; China).

TABLE V Samples 34 35 36 37 38 39 40 41 42 43 44 45 Modifier (parts per 100 parts of asphalt) Polymer 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 Additive P ₂ S ₅ 0.5 - - - - - - - - - - - Zns - 0.5 - - - - - - - - - - Al ₂ S ₃ - - 0.5 - - - - - - - - - FeS - - - 0.5 - - - - - - - - Sb ₂ s ₃ - - - - 0.5 - - - - - - - MoS ₂ - - - - - 0.5 - - - - - - Sb ₂ s ₅ - - - - - - 0.5 - - - - - SeS ₂ - - - - - - - 0.5 - - - - P ₂ O ₅ - - - - - - - - 0.5 - - - H ₃ PO ₄ - - - - - - - - - 0.5 - - PCl ₃ - - - - - - - - - - 0.5 - POCl ₃ - - - - - - - - - - - 0.5 Performance Analysis Failure Temperature for RTFO in DSR (° C) 78.1 70.6 70.6 70.9 70.6 69.0 71.6 71.8 73.6 74.1 70.6 70.5 Elastic recovery at 25 ° C (%) 87.5 49.0 65.0 49.5 50,5 45.0 67.0 44.0 56.0 62.0 51.0 51.0 Softening point, ° C 63.3 51.9 53.3 51.9 52,2 51.7 53.3 51.1 56.9 55.6 55.8 56.4

The data in Table V indicate that the unexpected result of comparing many other compounds with phosphorus pentasulfide is that phosphorus pentasulfide is naturally characterized by the highest stiffness according to the measurement of the fracture temperature in DSR after RTFOT (tests for a moving thin film in an oven). In addition, phosphorus pentasulfide yielded a significantly higher value of elastic recovery. In conclusion, phosphorus pentasulfide resulted in the highest softening point.

Samples 46-51

Additional samples were obtained using techniques similar to those given previously. In this series of samples, the polymer loading was varied per 100 mass parts of asphalt. Table VI presents the amount of polymer in each sample, together with the results of the test that was conducted.

In samples 46 and 49, the unsaturated polymer was a radial polymer, which was characterized by the presence of approximately 16.5% vinyl, 90% was a polymer obtained by the combination reaction and having four beams, included approximately 30% block styrene, had a main peak of maximum molecular weight (M _p ) about 53 kg / mol and was characterized by the value of M _p after the coupling reaction, equal to approximately 228 kg / mol; this polymer was obtained under the trade name 161-B ™ (LCY; China) and designated as radial polymer.

In samples 47 and 50, the unsaturated polymer was a linear polymer obtained by the combination reaction and having two beams, which was characterized by the presence of approximately 13% vinyl, 92% was a polymer obtained by the combination reaction and having two beams, included approximately 30% block styrene had a major peak molecular weight (M _p ) of about 60 kg / mol and was characterized by a M _p value after the coupling reaction of approximately 106 kg / mol; this polymer was obtained under the trade name 6302 ™ (LCY; China); this polymer is indicated in the tables as a high molecular weight polymer.

In samples 48 and 51, the unsaturated polymer was a linear polymer obtained by the combination reaction and having two beams, which was characterized by the presence of approximately 13% vinyl, 25% was a polymer obtained by the combination reaction and having two beams, included approximately 30% block styrene had a main peak of maximum molecular weight (M _p ) of about 50 kg / mol and was characterized by a M _p value after the coupling reaction of approximately 90 kg / mol; this polymer was obtained under the trade name 6320 ™ (LCY; China); this polymer is indicated in the tables as a medium molecular weight polymer.

TABLE VI Samples 46 47 48 49 fifty 51 Modifier (parts per 100 parts of asphalt) Polymer Radial polymer four - - 1,5 - - High molecular weight polymer - four - - 1,5 - Medium molecular polymer - - four - - 1,5 Phosphorus pentasulfide - - - 0.5 0.5 0.5 Sulfur 0.1 0.1 0.1 - - - Performance Analysis DSR Initial Failure Temperature (° C) 81.6 80.7 76,4 80.6 77.8 75.1 Failure Temperature for RTFO in DSR (° C) 77,2 76.6 74.0 77.6 77.7 76.3 Phase angle at 76 ° C, ° 64.7 66.3 72,2 67.3 71.6 81.0 Elastic recovery at 25 ° C (%) 91.0 88.5 84.5 87.5 87.5 83.5

Table VI shows that 4 parts of polymer per 100 parts by weight of asphalt, together with sulfur as an accelerator, give results very close to those obtained using 1.5 parts by weight of polymer per 100 parts by weight of asphalt using phosphorus pentasulfide. It is significant that the results achieved for the respective samples were essentially similar for each of the performance criteria. This is advantageous because the present invention makes it possible to obtain comparable performance with much reduced polymer loading.

Without the desire to be bound by any particular theory or reaction mechanism, it can be said that it appears that modified asphalt binder compositions from one or more embodiments of the present invention may include reactive crosslinking between the components of the asphalt binder and the unsaturated polymer. It is believed that these reactive crosslinking may include phosphorus and sulfur atoms, which form a bridge between hydrocarbon-based ingredients in an asphalt binder, such as asphaltenes, and / or polymer chains. In one or more embodiments, reactive crosslinking may include phosphorus groups attached to the carbon atoms of the ingredients of the asphalt binder and / or polymer. In these or other embodiments, crosslinking may include phosphorus-sulfur-phosphorus groups attached to carbon atoms of an asphalt binder and / or polymer. For example, reactive crosslinking may include a bridge represented by a carbon-phosphorus-sulfur-phosphorus-carbon combination, where the carbon atoms are part of the corresponding ingredients of the asphalt binder and / or polymer. It appears that phosphorus-carbon bonds are reactive, which indicates their susceptibility to attack by other reactive substances, such as nucleophiles. Since nucleophiles in asphalt binders are readily available, it seems that in the modified asphalt binders of the present invention there may be a dynamic situation in which reactive crosslinking can be attacked to form phosphorus and sulfur-containing bonds with various ingredients of the asphalt binder or maybe even with an unsaturated polymer. It seems that phosphorus-sulfur crosslinking can be obtained using compounds that can provide both a sulfur source and a phosphorus source in a particular molecular arrangement. One such compound that these sources can provide and which, as it was unexpectedly discovered, together with the polymer allows the preparation of unique modified asphalt binder compositions, is phosphorus pentasulfide.

In one or more embodiments of the present invention, an advantage that has been unexpectedly achieved is the possibility of obtaining compositions that are technologically suitable for use and modified asphalt binders with a relatively low polymer loading based on the weight of the asphalt binder. For example, in one or more embodiments, modified asphalt binder compositions obtained using phosphorus pentasulfide and less than 2.5 mass parts of polymer, in other embodiments less than 2.0 mass parts, in other embodiments less than 1.8 mass parts and in other embodiments less than 1.5 mass parts, of a polymer, exhibit a phase angle at 76 ° C less than 80 °, in other embodiments less than 77 °, in other embodiments less than 75 °, in other embodiments max implementing smaller than 72 ° and in other embodiments less than 70 °, determined according to AASHTO T315 instrument. Similarly, in one or more embodiments of the composition, modified asphalt binders obtained using phosphorus pentasulfide and less than 2.5 parts by weight of polymer, in other embodiments, less than 2.0 parts by weight, in other embodiments less than 1, 8 parts by weight and in other embodiments of less than 1.5 parts by weight of the polymer, demonstrate elongation recovery (also called elastic recovery) at 25 ° C greater than 75%, in other embodiments, the pain her than 77%, in other embodiments greater than 80%, in other embodiments greater than 83% and in other embodiments greater than 85%, determined according to AASHTO T301 instrument.

For the specialist in the relevant field of technology will be apparent and various modifications and variations that do not deviate from the scope and essence of the present invention. This invention should not be appropriately limited in the form of illustrative embodiments proposed herein.

Claims (10)

1. A method of obtaining a composition of a modified asphalt binder, which includes:
mixing the asphalt binder, unsaturated polymer and phosphorus pentasulfide to obtain a modified asphalt composition in which the amount of polymer is from about 0.5 to about 10 parts by weight per 100 parts by weight asphalt binder, the amount of phosphorus pentasulfide is from about 0.001 to about 10 parts by weight per 100 parts by weight asphalt binder, in the selection of the above amounts, providing elastic recovery of the modified asphalt binder composition more than 72.5% at 25 ° C, while the unsaturated polymer and phosphorus pentasulfide are added directly to the asphalt binder without preliminary mixing the unsaturated polymer and phosphorus pentasulfide. 2. The method according to claim 1, in which the polymer includes a block copolymer comprising at least one block comprising units resulting from the polymerization of a conjugated diene monomer, and at least one unit including units formed in polymerization of a vinyl aromatic monomer, and in which phosphorus pentasulfide is added to the asphalt binder in the form of solid particles of phosphorus pentasulfide. 3. The method according to claim 1, wherein the unsaturated polymer is a linear polymer, wherein the amount of polymer is less than 5 parts by weight. per 100 parts by weight asphalt binder, and the amount of phosphorus pentasulfide is from about 0.05 to about 5 parts by weight per 100 parts by weight asphalt binder. 4. The method according to claim 1, wherein the unsaturated polymer is a radial polymer, wherein the amount of polymer is less than 5 parts by weight. per 100 parts by weight asphalt binder, and the amount of phosphorus pentasulfide is from about 0.05 to about 5 parts by weight per 100 parts by weight asphalt binder. 5. The method according to claim 1, in which the unsaturated polymer is added directly to the first asphalt binder, and phosphorus pentasulfide is added directly to the second asphalt binder, then the first and second asphalt binder is mixed to obtain a modified asphalt binder composition, or in which the unsaturated polymer and pentasulfide phosphorus is added directly to one asphalt binder and mixed to obtain a modified asphalt binder composition, or in which a pentas phosphorus lphide in pure form is added to the asphalt binder as phosphorus pentasulfide, while sulfur-containing hardeners other than phosphorus pentasulfide are not used in the mixing step to obtain a modified asphalt binder composition. 6. The method according to claim 1, in which the mixing stage includes a shear action, which results in a modified asphalt composition, which is a homogeneous mixture. 7. The method according to claim 1, in which the mass ratio between the polymer and phosphorus pentasulfide is at least 1.3: 1 and less than 5: 1, the modified asphalt binder composition comprises less than 2.5 parts by weight. polymer per 100 parts by weight an asphalt binder, an unsaturated polymer includes at least 7 non-conjugated double bonds per 100 carbon atoms in the polymer, and said step of introducing phosphorus pentasulfide into the asphalt binder involves adding a phosphorus pentasulfide composition that comprises less than 2 wt.% impurities. 8. A method of obtaining a modified asphalt binder composition, which includes:
preparation of a phosphorus pentasulfide-asphalt binder concentrate by combining and mixing phosphorus pentasulfide and an asphalt binder, in which a phosphorus pentasulfide-asphalt binder concentrate comprises more than 0.5 and up to 10 parts by weight phosphorus pentasulfide per 100 parts by weight asphalt binder;
the preparation of an unsaturated polymer-asphalt binder concentrate by combining and mixing an unsaturated polymer and an asphalt binder, where the unsaturated polymer-asphalt binder concentrate comprises more than 5 and up to 10 parts by weight polymer per 100 parts by weight asphalt binder; and
combining and mixing the phosphorus pentasulfide-asphalt binder concentrate with the concentrate, an unsaturated polymer-asphalt binder, and optionally diluting the resulting mixture with additional asphalt binder to obtain a modified asphalt binder composition. 9. The composition of the modified asphalt binder for road surfaces, obtained according to one of claims 1 to 8. 10. An asphalt composition for paving, which contains the reaction product between the asphalt binder, obtained according to one of claims 1 to 8, where the phosphorus source and the sulfur source form reactive crosslinking between the components of the asphalt and the unsaturated polymer, in which the phosphorus source and the sulfur source are phosphorus pentasulfide.