Asphalt composition

Abstract

The present invention relates to an asphalt composition comprising asphalt and a polyester resin composition, wherein the polyester resin composition comprises a polyester resin and a hydrocarbon compound (i). The polyester resin contains structural units derived from an alcohol component and structural units derived from a carboxylic acid component, and the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids. The polyester resin composition has a glass transition temperature between -70°C and 30°C and is present in the asphalt composition in an amount of 0.5 parts by mass or more and 25 parts by mass or less per 100 parts by mass of asphalt.

Description

[Technical Field]

[0001] The present invention relates to an asphalt composition. [Background technology]

[0002] Asphalt pavement, which uses asphalt mixtures, is used to pave roads, parking lots, freight yards, sidewalks, etc., and is relatively easy to lay, allowing pavements to be laid simply while minimizing traffic disruptions and paving construction time. Asphalt pavement forms a road surface containing an asphalt mixture containing aggregate bound by asphalt, giving the paved road appropriate hardness and durability.

[0003] Patent Document 1 (JP 2021-076005 A) discloses an asphalt composition that exhibits excellent rut resistance on pavement surfaces after construction and high resistance to peeling, particularly under alkaline conditions. This asphalt composition contains asphalt and a polyester, and the polyester has structural units derived from a carboxylic acid component containing at least one selected from alkylsuccinic acids and alkenylsuccinic acids. Summary of the Invention

[0004] The present invention provides an asphalt composition comprising asphalt and a polyester resin composition, the polyester resin composition comprises a polyester resin and a hydrocarbon-based compound (i), the polyester resin contains a structural unit derived from an alcohol component and a structural unit derived from a carboxylic acid component, the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids, the polyester resin composition has a glass transition temperature between -70°C and 30°C, The asphalt composition, wherein the polyester resin composition is present in an amount of ≧0.5 parts by weight and ≦25 parts by weight per 100 parts by weight of asphalt. DETAILED DESCRIPTION OF THE INVENTION

[0005] Asphalt pavement requires surface strength that is not affected by weather conditions. For example, in tropical climates, asphalt pavements are repeatedly exposed to high temperatures due to sunlight during the day and heavy rain. With conventional asphalt pavement technology, when a pavement surface exposed to heavy rain is reheated, water seeps into the gaps between the aggregate and asphalt, causing thermal expansion, which can significantly reduce the adhesive strength between the aggregate and asphalt. Patent Document 1 discloses an asphalt composition that exhibits high resistance to peeling even under alkaline conditions. However, in an environment where cycles of heating and cooling are repeated in the presence of water, the adhesive strength between the aggregate and asphalt may not be sufficiently maintained. The present invention relates to an asphalt composition used to form an asphalt pavement that has peeling resistance (hereinafter simply referred to as peeling resistance) that can promote adhesion strength between aggregate and asphalt even when exposed to multiple heating and cooling cycles in the presence of water, and high rutting resistance under waterlogged conditions.

[0006] The present invention relates to the following [1] and [2]. [1] An asphalt composition comprising asphalt and a polyester resin composition, the polyester resin composition comprises a polyester resin and a hydrocarbon-based compound (i), the polyester resin contains a structural unit derived from an alcohol component and a structural unit derived from a carboxylic acid component, the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids, The polyester resin composition has a glass transition temperature between −70° C. and 30° C., 1. An asphalt composition, wherein the polyester resin composition is present in an amount of ≧0.5 parts by weight and ≦25 parts by weight per 100 parts by weight of asphalt. [2] An asphalt modifier comprising a polyester resin and a hydrocarbon compound (i), the polyester resin contains a structural unit derived from an alcohol component and a structural unit derived from a carboxylic acid component, and the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids; An asphalt modifier having a glass transition temperature comprised between -70°C and 30°C.

[0007] [Asphalt composition] The asphalt composition of the present invention is an asphalt composition comprising asphalt and a polyester resin composition, the polyester resin composition comprises a polyester resin and a hydrocarbon-based compound (i), the polyester resin contains a structural unit derived from an alcohol component and a structural unit derived from a carboxylic acid component, the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids, The polyester resin composition has a glass transition temperature between −70° C. and 30° C., The content of the polyester resin composition is ≧0.5 parts by mass and ≦25 parts by mass relative to 100 parts by mass of asphalt.

[0008] The present invention discloses an asphalt composition used to form an asphalt pavement that has peeling resistance (hereinafter simply referred to as peeling resistance) that can promote the bond strength between aggregate and asphalt even after multiple heating and cooling cycles in the presence of water.

[0009] The present inventors have discovered that the above problems can be solved by using an asphalt composition containing a specific amount of a polyester resin composition produced from a specific polyester resin and a hydrocarbon compound (i) and having a specific glass transition point. The reason why the present invention has such an effect has not yet been clarified, but can be explained as follows. When an asphalt pavement is subjected to cycles of heating and cooling in the presence of water, water penetrates into the gaps between the aggregate and the coating formed by the asphalt. The expansion and contraction of water due to temperature changes widens the gaps, making the asphalt coating more susceptible to peeling. In contrast, the following is expected with asphalt pavements using the asphalt composition of the present invention. Hydrocarbon compound (i), a hydrophobic compound in the polyester resin composition, first penetrates into the gaps between the aggregate and the asphalt coating. Next, the polyester resin, which contains structural units derived from at least one succinic acid compound selected from the group consisting of alkylsuccinic acid and alkenylsuccinic acid, and has a low glass transition temperature that has a high affinity with hydrocarbon compound (i), resulting in high molecular chain mobility even at room temperature, is attracted to hydrocarbon compound (i) that has migrated to the interface between the aggregate and asphalt, and is presumed to fill the gaps between the aggregate and asphalt that have formed due to the thermal expansion of water. That is, it can be interpreted as follows: Even if gaps occur between the aggregate and the asphalt membrane due to external forces, the hydrocarbon compound (i) attracts the highly mobile polyester resin with a predetermined low glass transition point, filling the gaps, so that the adhesive strength between the aggregate and asphalt is maintained even when exposed to multiple heating and cooling cycles in the presence of water. Therefore, as a result of maintaining the adhesive strength between the aggregate and asphalt, the strength of the entire pavement surface is improved, and high durability performance such as rutting resistance is obtained.

[0010] The definitions of various terms used in this specification are shown below. In the polyester resin, a "structural unit derived from an alcohol component" means a structure in which a hydrogen atom is removed from a hydroxy group of an alcohol component, and a "structural unit derived from a carboxylic acid component" means a structure in which a hydroxy group is removed from a carboxy group of a carboxylic acid component. The term "carboxylic acid component" encompasses not only the carboxylic acid itself, but also anhydrides that decompose to produce an acid during the reaction, and alkyl esters of carboxylic acids (for example, alkyl groups having 1 to 3 carbon atoms). When the carboxylic acid component is an alkyl ester of carboxylic acid, the number of carbon atoms in the alkyl group that is the alcohol residue of the ester is not included in the number of carbon atoms of the carboxylic acid. Bisphenol A is 2,2-bis(4-hydroxyphenyl)propane.

[0011] {asphalt} The asphalt compositions of the present invention contain petroleum / bitumen-based materials. Various types of bitumen can be used in the present invention, including straight / unmodified asphalt and modified asphalt, which are bituminous materials for surface paving. Straight asphalt is the residual bitumen material obtained by subjecting crude oil to atmospheric distillation or vacuum distillation. Modified asphalts include blown asphalt, polymer-modified asphalt modified with polymeric materials such as thermoplastic elastomers and thermoplastic resins (hereinafter also referred to as "polymer-modified asphalt"). Blown asphalt refers to asphalt obtained by heating a mixture of straight asphalt and heavy oil and then blowing air into it to oxidize it. The asphalt is preferably selected from straight asphalt and polymer-modified asphalt, with polymer-modified asphalt being more preferred from the viewpoint of durability of the asphalt pavement, and straight asphalt being more preferred from the viewpoint of versatility.

[0012] <<Thermoplastic elastomer>> Examples of the thermoplastic elastomer in the polymer-modified asphalt include styrene / butadiene block copolymers, styrene / butadiene / styrene block copolymers, styrene / butadiene random copolymers, styrene / isoprene block copolymers, styrene / isoprene / styrene block copolymers, styrene / isoprene random copolymers, ethylene / vinyl acetate copolymers, ethylene / acrylic acid ester copolymers, styrene / ethylene / butylene / styrene copolymers, styrene / ethylene / propylene / styrene copolymers, polyurethane-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, isobutylene / isoprene copolymers, polyisoprene, polychloroprene, synthetic rubbers other than those mentioned above, and at least one selected from natural rubber.

[0013] Among these, from the viewpoint of durability of asphalt pavement, the thermoplastic elastomer is preferably at least one selected from styrene / butadiene block copolymer, styrene / butadiene / styrene block copolymer, styrene / butadiene random copolymer, SI, styrene / isoprene / styrene block copolymer, styrene / isoprene random copolymer, and ethylene / acrylic acid ester copolymer, more preferably at least one selected from styrene / butadiene block copolymer, styrene / butadiene / styrene block copolymer, styrene / butadiene random copolymer, styrene / isoprene block copolymer, styrene / isoprene / styrene block copolymer, and styrene / isoprene random copolymer, and even more preferably at least one selected from styrene / butadiene random copolymer and styrene / butadiene / styrene block copolymer. From the viewpoint of the durability of the asphalt pavement, the content of the thermoplastic elastomer in the polymer modified asphalt is preferably ≧0.1 mass%, more preferably ≧0.5 mass%, even more preferably ≧1 mass%, and preferably ≦30 mass%, more preferably ≦15 mass%, even more preferably ≦5 mass%.

[0014] The total content of straight asphalt and polymer-modified asphalt in the asphalt composition is preferably ≧60% by mass, more preferably ≧65% by mass, and even more preferably ≧70% by mass from the viewpoint of asphalt mixing performance, and is preferably ≦99.5% by mass, more preferably ≦99% by mass, and even more preferably ≦98% by mass from the viewpoint of storage stability.

[0015] {Polyester resin composition} The asphalt composition of the present invention contains a polyester resin composition. The polyester resin composition contains a polyester resin and a hydrocarbon-based compound (i), the polyester resin contains a structural unit derived from an alcohol component and a structural unit derived from a carboxylic acid component, the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids, The polyester resin composition has a glass transition temperature comprised between -70°C and 30°C. The polyester resin and the hydrocarbon compound (i) will be described below.

[0016] <<Polyester Resin>> The polyester resin contains structural units derived from an alcohol component and structural units derived from a carboxylic acid component, and the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids. The alcohol component, the carboxylic acid component, and the physical properties of the polyester resin will be described below.

[0017] <Alcohol content> Examples of the alcohol component include aliphatic diols, aromatic diols, trihydric or higher polyhydric alcohols, polyalkylene glycols, etc. These alcohol components can be used alone or in combination of two or more alcohols.

[0018] The aliphatic diols include chain aliphatic diols and alicyclic diols. The chain aliphatic diols are preferably linear or branched chain aliphatic diols having a carbon number between 2 and 12, more preferably linear or branched chain aliphatic diols having a carbon number between 2 and 8. Specific examples of the chain aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,10-decanediol, and 1,12-dodecanediol. Examples of alicyclic diols include hydrogenated bisphenol A (2,2-bis(4-hydroxycyclohexyl)propane), alkylene oxide adducts of hydrogenated bisphenol A, cyclohexanediol, and cyclohexanedimethanol.

[0019] Examples of aromatic diols include bisphenol A and alkylene oxide adducts of bisphenol A. Examples of alkylene oxide adducts of bisphenol A include alkylene oxide adducts of bisphenol A represented by the following formula (I).

[0020] [ka]

[0021] [In the formula, OR 1 and R 1 O is alkylene oxide and R 1 is an alkylene group having 2 or 3 carbon atoms, x and y are positive numbers indicating the average number of moles of alkylene oxide added, and the sum of x and y is preferably ≧1, more preferably ≧1.5, and is preferably ≦16, more preferably ≦8, and even more preferably ≦4.

[0022] Examples of the alkylene oxide adduct of bisphenol A represented by formula (I) include a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A. These alkylene oxide adducts of bisphenol A can be used alone or in combination of two or more kinds.

[0023] The trihydric or higher polyhydric alcohol is preferably a trihydric alcohol, and examples of the trihydric or higher polyhydric alcohol include glycerin, pentaerythritol, trimethylolpropane, and sorbitol.

[0024] Examples of polyalkylene glycols include homopolymers such as polyethylene glycol, polypropylene glycol, and polybutylene glycol, as well as copolymers of two or more selected from ethylene glycol, propylene glycol, and butylene glycol, and are preferably homopolymers, and more preferably polypropylene glycol. From the viewpoint of improving affinity with asphalt and improving peeling resistance, the number average molecular weight of the polyalkylene glycol is preferably ≧100, more preferably ≧200, even more preferably ≧250, and is preferably ≦2000, more preferably ≦1000, even more preferably ≦800.

[0025] The alcohol component may further contain a monohydric aliphatic alcohol from the viewpoint of adjusting physical properties. Examples of the monohydric aliphatic alcohol include lauryl alcohol, myristyl alcohol, palmityl alcohol, and stearyl alcohol. These monohydric aliphatic alcohols may be used alone or in combination of two or more alcohols.

[0026] The alcohol component contains at least one selected from the group consisting of chain aliphatic diols and polyalkylene glycols, from the viewpoint of further improving peel resistance. The chain aliphatic diol is preferably ethylene glycol, 1,2-propanediol, 1,4-butanediol, or 1,6-hexanediol. The polyalkylene glycol is preferably polypropylene glycol. From the same viewpoint as above, the total content of the chain aliphatic diol and polyalkylene glycol in the alcohol component is preferably ≧50 mol%, more preferably ≧70 mol%, even more preferably ≧80 mol%, still more preferably ≧90 mol%, and even more preferably ≦100 mol%.

[0027] <Carboxylic acid component> From the viewpoint of peel resistance, the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids.

[0028] (succinic acid compounds) From the viewpoint of further improving peel resistance, the number of carbon atoms in the alkyl group in the alkylsuccinic acid and the alkenyl group in the alkenylsuccinic acid is preferably ≧9, more preferably ≧10, and preferably ≦19, more preferably ≦15, and even more preferably ≦13. The alkyl and alkenyl groups may be linear or branched, but are preferably branched. The branched structure may be present in any part of the alkyl and alkenyl groups. Therefore, the polyester resin preferably contains a structural unit derived from a branched alkenyl succinic acid. The alkylsuccinic acid and alkenylsuccinic acid are preferably mixtures containing two or more types. The "type" here refers to the alkyl or alkenyl group, and alkyl or alkenyl groups with different carbon chain lengths or structural isomers are treated as different types of alkylsuccinic acid or alkenylsuccinic acid. When the alkylsuccinic acid and / or alkenylsuccinic acid is a mixture containing two or more types, the number of carbon atoms in the alkyl group in the alkylsuccinic acid and the number of carbon atoms in the alkenyl group in the alkenylsuccinic acid is the average number of carbon atoms in the alkyl group in the alkylsuccinic acid and the alkenyl group in the alkenylsuccinic acid contained in the carboxylic acid component.

[0029] From the viewpoint of improving peel resistance, the alkyl succinic acid is preferably a mixture containing two or more alkyl succinic acids having a carbon number of preferably ≥ 9, more preferably ≥ 10, and a branched-chain alkyl group of preferably ≤ 19, more preferably ≤ 14, and even more preferably ≤ 12. Also, the alkenyl succinic acid is preferably a mixture containing two or more alkenyl succinic acids having a branched-chain alkenyl group of preferably ≥ 9, more preferably ≥ 10, and a branched-chain alkenyl group of preferably ≤ 19, more preferably ≤ 15, and even more preferably ≤ 13.

[0030] The alkylsuccinic acid and alkenylsuccinic acid are preferably those obtained from a compound having an alkylene group (alkylene compound) and at least one selected from maleic acid, fumaric acid, and acid anhydrides thereof.

[0031] The alkylene compound is a compound having a carbon number of preferably ≥ 9, more preferably ≥ 10, and preferably ≤ 19, more preferably ≤ 14, and specifically, those obtained from ethylene, propylene, isobutylene, normal butylene, etc., such as trimers and tetramers thereof, are preferred. As a suitable raw material for efficient synthesis of alkylene compounds, propylene tetramer, which has a low molecular weight, is preferred.

[0032] Alkyl succinic acids and alkenyl succinic acids can be obtained by any production method. For example, they can be obtained by mixing an alkylene compound with at least one selected from maleic acid, fumaric acid, and their acid anhydrides, followed by heating, to utilize an ene reaction (see, for example, JP 48-23405 A, JP 48-23404 A, and U.S. Pat. No. 3,374,285). Among maleic acid, fumaric acid, and their acid anhydrides, maleic anhydride is preferred due to its excellent reactivity. Suitable catalysts for use in the synthesis of alkylene compounds include liquid phosphoric acid, solid phosphoric acid, tungsten, and boron trifluoride complexes. From the viewpoint of easily controlling the number of structural isomers and improving rut resistance, a method of adjusting the alkylene compound by distillation after random polymerization is preferred.

[0033] The carboxylic acid component may further contain a component other than the succinic acid compound. Examples of the carboxylic acid component other than the succinic acid compound include aliphatic dicarboxylic acids other than the succinic acid compounds, aromatic dicarboxylic acids, and polycarboxylic acids having a valence of 3 to 6. These carboxylic acid components other than the succinic acid compounds may be used alone or in combination of two or more acids.

[0034] Examples of the aliphatic dicarboxylic acid other than the succinic acid compound include aliphatic dicarboxylic acids having a main chain carbon number of preferably ≧4, and preferably ≦10, more preferably ≦8, and more preferably ≦6, such as fumaric acid, maleic acid, oxalic acid, malonic acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, anhydrides thereof, and alkyl esters thereof (for example, alkyl groups having a carbon number of ≧1 and ≦3).

[0035] Examples of aromatic dicarboxylic acids include phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, anhydrides thereof, and alkyl esters thereof (for example, alkyl groups having a carbon number of ≧1 and ≦3).

[0036] The trivalent or more and hexavalent polycarboxylic acid is preferably a trivalent carboxylic acid. Examples of the trivalent or more and hexavalent polycarboxylic acid include trimellitic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, and acid anhydrides thereof.

[0037] The carboxylic acid component may further contain a monovalent aliphatic carboxylic acid from the viewpoint of adjusting the physical properties of the polyester resin, such as the glass transition point, acid value, hydroxyl value, number average molecular weight, and weight average molecular weight. Examples of the monovalent aliphatic carboxylic acid include monovalent aliphatic carboxylic acids having a carbon number of ≧12 and ≦20, such as lauric acid, myristic acid, palmitic acid, stearic acid, and alkyl esters of these acids (having a carbon number of ≧1 and ≦3). These monovalent aliphatic carboxylic acids may be used alone or in combination of two or more kinds.

[0038] From the viewpoint of further improving peel resistance, the total content of succinic acid compounds in the carboxylic acid component is preferably ≧50 mol%, more preferably ≧70 mol%, even more preferably ≧80 mol%, still more preferably ≧90 mol%, and even more preferably ≦100 mol%.

[0039] <Molar ratio of structural units derived from carboxylic acid components to structural units derived from alcohol components> The molar ratio of structural units derived from carboxylic acid components to structural units derived from alcohol components [carboxylic acid component / alcohol component] is preferably ≧0.7, more preferably ≧0.8, even more preferably ≧0.85, and is preferably ≦1.3, more preferably ≦1.2, even more preferably ≦1.0.

[0040] <Physical properties of polyester resin> From the viewpoint of improving peel resistance, the glass transition point (Tg) of the polyester resin is preferably ≧−70°C, more preferably ≧−60°C, even more preferably ≧−55°C, and preferably ≦30°C, more preferably ≦10°C, even more preferably ≦0°C. From the same viewpoint, the acid value of the polyester resin is preferably ≧0 mgKOH / g, more preferably ≧1 mgKOH / g, even more preferably ≧2 mgKOH / g, and preferably ≦20 mgKOH / g, more preferably ≦15 mgKOH / g, even more preferably ≦13 mgKOH / g. From the same viewpoint, the hydroxyl value of the polyester resin is preferably ≧5 mgKOH / g, more preferably ≧10 mgKOH / g, even more preferably ≧13 mgKOH / g, and preferably ≦40 mgKOH / g, more preferably ≦30 mgKOH / g, even more preferably ≦25 mgKOH / g. From the same viewpoint, the sum of the acid value and hydroxyl value of the polyester resin is preferably ≧5 mgKOH / g, more preferably ≧10 mgKOH / g, even more preferably ≧13 mgKOH / g, and preferably ≦40 mgKOH / g, more preferably ≦30 mgKOH / g, even more preferably ≦25 mgKOH / g. From the same viewpoint, the number average molecular weight (Mn) of the polyester resin is preferably ≧500, more preferably ≧1,000, even more preferably ≧1,500, and preferably ≦10,000, more preferably ≦7,000, even more preferably ≦5,000. From the same viewpoint, the weight average molecular weight (Mw) of the polyester resin is preferably ≧2,000, more preferably ≧5,000, even more preferably ≧8,000, and preferably ≦100,000, more preferably ≦80,000, even more preferably ≦50,000.

[0041] The glass transition point, acid value, hydroxyl value, number average molecular weight and weight average molecular weight of the polyester resin can be measured in the same manner as in the examples, except that the measurement is performed on the polyester resin alone.

[0042] The glass transition temperature of the polyester resin can be calculated from the glass transition temperatures of the alcohol component and the carboxylic acid component, which are the polymerization monomers constituting the polyester resin, using the following Gordon-Taylor equation: The Gordon-Taylor equation is used to calculate the glass transition temperature of a mixed system such as a polymer-plasticizer system. 1 / Tg=(W1 / Tg1)+(W2 / Tg2) W1+W2=1 In the Gordon-Taylor equation, Tg is the glass transition temperature of the polymer-plasticizer mixture, Tg1 is the glass transition temperature of the polymer, and Tg2 is the glass transition temperature of the plasticizer. The unit of temperature is K. Furthermore, W1 represents the mass ratio of the polymer, and W2 represents the mass ratio of the plasticizer. As the glass transition temperature of the homopolymer of each polymerizable monomer in the Gordon-Taylor equation, for example, the value described in Polymer Handbook Third Edition (Wiley-Interscience 1989) can be used.

[0043] The acid value and hydroxyl value of the polyester resin can be calculated from the charge ratio of the alcohol component and the carboxylic acid component when producing the polyester resin. The glass transition temperature, acid value, hydroxyl value, number average molecular weight and weight average molecular weight of the polyester resin can be adjusted by the raw material monomer composition, molecular weight, catalyst amount or reaction conditions.

[0044] The polyester resin may be modified to such an extent that its properties are not substantially impaired. Specific examples of modified polyester resins include polyester resins grafted or blocked with phenol, urethane, epoxy, or the like, by methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, etc. A preferred modified polyester resin is a urethane-modified polyester resin obtained by urethane-extending a polyester resin with a polyisocyanate compound.

[0045] <<Hydrocarbon compounds (i)>> Examples of the hydrocarbon compound (i) include hydrocarbon compounds consisting only of carbon atoms and hydrogen atoms, such as saturated hydrocarbon compounds such as alkanes, and unsaturated hydrocarbon compounds such as alkenes. Alkenes are also called olefins. From the viewpoint of improving peel resistance, the hydrocarbon compound (i) preferably has a carbon number of ≧9, more preferably ≧10, and preferably ≦18, more preferably ≦14. Specific examples of preferred hydrocarbon compounds (i) include those obtained from ethylene, propylene, isobutylene, normal butylene, etc., such as trimers and tetramers thereof. Among these, the hydrocarbon compound (i) is most preferably propylene tetramer. From the viewpoint of improving peel resistance, the hydrocarbon compound (i) is preferably a mixture containing two or more types. Here, the term "type" refers to hydrocarbon compounds (i) with different carbon chain lengths or structural isomers, which are treated as different types of hydrocarbon compounds (i). When the hydrocarbon compound (i) is a mixture containing two or more types, the number of carbon atoms in the hydrocarbon compound (i) is the average number of carbon atoms in the hydrocarbon compound (i) contained in the carboxylic acid component.

[0046] From a similar viewpoint, the ratio of the number of carbon atoms of the succinic acid compound in the carboxylic acid component of the polyester resin to the number of carbon atoms of the hydrocarbon compound (i) [number of carbon atoms of the succinic acid compound / number of carbon atoms of the hydrocarbon compound (i)] is preferably close to 1, specifically, preferably ≧0.65, more preferably ≧0.75, and also preferably ≦1.4, more preferably ≦1.5.

[0047] <Physical properties of hydrocarbon compound (i)> From the same viewpoint, the number average molecular weight (Mn) of the hydrocarbon compound (i) is preferably ≧100, more preferably ≧110, even more preferably ≧120, and preferably ≦300, more preferably ≦280, even more preferably ≦250.

[0048] <<Content of polyester resin and hydrocarbon compound (i)>> From a similar viewpoint, the content of the polyester resin is preferably ≧99.5 mass%, more preferably ≧99.65 mass%, even more preferably ≧99.6 mass%, and preferably ≦99.9 mass%, more preferably ≦99.88 mass%, even more preferably ≦99.85 mass%, based on 100 mass% of the polyester resin composition.

[0049] From the same viewpoint, the content of the hydrocarbon compound (i) is preferably ≧0.1 mass%, more preferably ≧0.12 mass%, even more preferably ≧0.15 mass%, and preferably ≦0.5 mass%, more preferably ≦0.45 mass%, even more preferably ≦0.4 mass%, based on 100 mass% of the polyester resin composition.

[0050] From a similar viewpoint, the total content of the succinic acid compound-derived structural units and the hydrocarbon compound (i) in the polyester resin is, relative to 100% by mass of the polyester resin composition, preferably ≧30% by mass, more preferably ≧31% by mass, even more preferably ≧32% by mass, and is preferably ≦90% by mass, more preferably ≦85% by mass, even more preferably ≦80% by mass. The total content of the succinic acid compound-derived structural unit and the hydrocarbon compound (i) in the polyester resin can be calculated from the charge ratio of the alcohol component, the carboxylic acid component, and the hydrocarbon compound (i).

[0051] <<Physical Properties of Polyester Resin Composition>> To further improve peel resistance: The glass transition temperature (Tg) of the polyester resin composition is between -70°C and 30°C, preferably ≧-65°C, more preferably ≧-60°C, even more preferably ≧-55°C, and preferably ≦25°C, more preferably ≦10°C, even more preferably ≦0°C. From the viewpoint of improving the affinity with asphalt and thereby improving the peel resistance, the acid value of the polyester resin composition is preferably ≧0 mgKOH / g, more preferably ≧1 mgKOH / g, even more preferably ≧2 mgKOH / g, and preferably ≦20 mgKOH / g, more preferably ≦15 mgKOH / g, even more preferably ≦13 mgKOH / g. From the same viewpoint, the hydroxyl value of the polyester resin composition is preferably ≧5 mgKOH / g, more preferably ≧10 mgKOH / g, even more preferably ≧13 mgKOH / g, and preferably ≦40 mgKOH / g, more preferably ≦30 mgKOH / g, even more preferably ≦25 mgKOH / g. From the same viewpoint, the sum of the acid value and the hydroxyl value of the polyester resin composition is preferably ≧5 mgKOH / g, more preferably ≧10 mgKOH / g, even more preferably ≧13 mgKOH / g, and preferably ≦40 mgKOH / g, more preferably ≦30 mgKOH / g, even more preferably ≦25 mgKOH / g. From the same viewpoint, the number average molecular weight (Mn) of the polyester resin composition is preferably ≧500, more preferably ≧1,000, even more preferably ≧1,500, and preferably ≦10,000, more preferably ≦7,000, even more preferably ≦5,000. From the same viewpoint, the weight average molecular weight (Mw) of the polyester resin composition is preferably ≧2,000, more preferably ≧5,000, even more preferably ≧8,000, and preferably ≦100,000, more preferably ≦80,000, even more preferably ≦50,000.

[0052] The glass transition point, acid value, hydroxyl value, number average molecular weight and weight average molecular weight of the polyester resin composition can be measured by the methods described in the examples.

[0053] <Content of Polyester Resin Composition> From the viewpoint of storage stability, the content of the polyester resin in the asphalt composition is between 0.5 and 25 parts by mass, preferably ≧1 mass%, more preferably ≧1.5 mass%, even more preferably ≧2 mass%, and preferably ≦22 mass%, more preferably ≦20 mass%, even more preferably ≦15 mass%.

[0054] <Method of producing polyester resin composition> The method for producing the polyester resin composition contained in the asphalt composition of the present invention is not particularly limited. For example, it can be produced by polycondensing the alcohol component and the carboxylic acid component described above in the presence of the hydrocarbon compound (i). Alternatively, the polyester resin may be obtained by polycondensing the alcohol component and the carboxylic acid component described above, and then mixing the polyester resin with the hydrocarbon compound (i). The amounts of the alcohol component and the carboxylic acid to be blended are such that the molar ratio of the structural units derived from the carboxylic acid component to the structural units derived from the alcohol component [carboxylic acid component / alcohol component] falls within the above-mentioned numerical range. From the viewpoint of reactivity, the temperature of the polycondensation reaction is preferably ≧160°C, more preferably ≧180°C, even more preferably ≧190°C, and preferably ≦260°C, more preferably ≦250°C, even more preferably ≦240°C.

[0055] In view of the reaction rate, an esterification catalyst can be used in the polycondensation reaction. Examples of the esterification catalyst include tin(II) compounds that do not have a Sn-C bond, such as tin(II) di(2-ethylhexanoate). The amount of the esterification catalyst used is preferably ≥ 0.01 parts by mass, more preferably ≥ 0.1 parts by mass, even more preferably ≥ 0.2 parts by mass, and preferably ≤ 1.5 parts by mass, more preferably ≤ 1.0 part by mass, even more preferably ≤ 0.6 parts by mass, relative to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. In addition to the esterification catalyst, a co-catalyst can be used in the polycondensation reaction. Examples of the co-catalyst include pyrogallol compounds such as gallic acid. The amount of the co-catalyst used is preferably ≥ 0.001 parts by mass, more preferably ≥ 0.005 parts by mass, even more preferably ≥ 0.01 parts by mass, and preferably ≤ 0.15 parts by mass, more preferably ≤ 0.10 parts by mass, even more preferably ≤ 0.05 parts by mass, per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component.

[0056] [Method for producing asphalt composition] The asphalt composition of the present invention can be produced by mixing asphalt with the polyester resin composition. Specifically, the asphalt is heated and melted, the polyester resin composition is added, and the mixture is stirred in a commonly used mixer until the polyester resin composition is uniformly dispersed in the asphalt, thereby obtaining the asphalt composition. Commonly used mixers include a homomixer, a dissolver, a paddle mixer, a ribbon mixer, a screw mixer, a planetary mixer, a vacuum countercurrent mixer, a roll mill, and a twin-screw extruder.

[0057] The mixing temperature of the asphalt and the polyester resin composition is preferably ≧140°C, more preferably ≧150°C, and is also preferably 190°C, more preferably 180°C, and even more preferably 170°C, from the viewpoint of uniformly dispersing the polyester resin composition in the asphalt. The mixing time for mixing the asphalt and the polyester resin composition is preferably ≥ 1 minute, more preferably ≥ 10 minutes, and even more preferably ≥ 30 minutes, from the viewpoint of uniformly dispersing the polyester resin composition in the asphalt. To prevent thermal degradation of the asphalt composition, the mixing time is preferably ≤ 48 hours, more preferably ≤ 30 hours, and even more preferably ≤ 24 hours. The asphalt composition of the present invention is a binder composition in an asphalt mixture, and can be used, for example, to form an asphalt mixture by adding aggregate to the asphalt composition, and then to form an asphalt pavement for paving roads.

[0058] [Asphalt mixture] An asphalt mixture, which is a suitable example of the use of the asphalt composition, will be described below: The asphalt mixture contains aggregate and the asphalt composition, i.e., the asphalt mixture contains at least aggregate, asphalt, and the polyester resin composition.

[0059] {aggregate} Any type of aggregate can be used, such as crushed stone, boulders, gravel, sand, recycled asphalt aggregate, ceramics, etc. Coarse aggregate with a particle size of ≥ 2.36 mm and fine aggregate with a particle size of ≤ 2.36 mm can be used. Preferably, the aggregate is a combination of coarse aggregate and fine aggregate. From the viewpoint of durability of the asphalt pavement, the content of aggregate in the asphalt mixture is preferably ≧85 mass%, more preferably ≧90 mass%, more preferably ≧92 mass%, and preferably ≦98 mass%, more preferably ≦97 mass%, and even more preferably ≦96 mass%, based on 100 mass% of the asphalt mixture.

[0060] {Additives} In addition to the aggregate, asphalt, and polyester resin composition described above, various additives conventionally used in asphalt mixtures, such as film-forming agents, thickeners, and emulsifiers, may be added to the asphalt mixture as needed. The total content of these additives is preferably ≦50 mass %, more preferably ≦25 mass %, and even more preferably ≦5 mass %, based on 100 mass % of the asphalt mixture.

[0061] [Asphalt mixture manufacturing method] There are no particular limitations on the method for producing an asphalt mixture, and any production method may be used. Typically, an asphalt mixture can be produced by mixing aggregate with an asphalt composition. Specifically, a method can be used in which the above-mentioned asphalt composition is added to heated aggregate and mixed.

[0062] To ensure uniform and homogeneous mixing of the materials, the temperature of the heated aggregate is preferably ≥ 130°C, more preferably ≥ 150°C, even more preferably ≥ 160°C, and to prevent thermal degradation of the asphalt, it is preferably ≤ 230°C, more preferably ≤ 200°C, even more preferably ≤ 170°C.

[0063] For uniformity and homogeneity of the material mixture, the mixing temperature of the aggregate and the asphalt composition is preferably ≧130°C, more preferably ≧150°C, and even more preferably ≧160°C, and for preventing thermal degradation of the asphalt, the temperature is preferably ≦230°C, more preferably ≦200°C, and even more preferably ≦170°C. The mixing time of the aggregate and the asphalt composition is not particularly limited, but is preferably ≧30 seconds, more preferably ≧1 minute, even more preferably ≧2 minutes, and is preferably ≦2 hours, more preferably ≦1 hour, even more preferably ≦30 minutes.

[0064] The method for producing an asphalt mixture preferably includes a step of mixing aggregate and an asphalt composition, and then maintaining the resulting asphalt mixture at the above-mentioned mixing temperature or at a temperature equal to or higher than the mixing temperature. In the step of holding the asphalt mixture, the mixture may be further mixed. The retention time is preferably ≧0.5 hours, more preferably ≧1 hour, and even more preferably ≧1.5 hours, and the upper limit of the time is not particularly limited, but is, for example, about 48 hours.

[0065] [Road paving method] The asphalt mixture is suitable for road paving, and as described above, an asphalt mixture obtained by adding aggregate to an asphalt composition is used for road paving. The road paving method includes the steps of applying the asphalt mixture to a road to form an asphalt pavement layer. Specifically, the road paving method includes the steps of mixing the asphalt composition with heated aggregate to obtain an asphalt mixture (Step 1), and applying the asphalt mixture obtained in Step 1 to a road to form an asphalt pavement layer (Step 2). The asphalt pavement layer is preferably a base layer or a surface layer.

[0066] [Asphalt modifier] The asphalt modifier of the present invention comprises a polyester resin and a hydrocarbon compound (i), the polyester resin contains a structural unit derived from an alcohol component and a structural unit derived from a carboxylic acid component, and the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids; It has a glass transition temperature comprised between -70°C and 30°C.

[0067] The asphalt modifier of the present invention can be used to prepare an asphalt composition by mixing it with asphalt in an amount of ≥ 0.5 parts by mass and ≤ 25 parts by mass per 100 parts by mass of asphalt. Aggregate is added to the obtained asphalt composition to form an asphalt mixture, which can then be used for paving. The asphalt modifier of the present invention can be suitably used as a modifier to be blended into asphalt mixtures containing aggregate. From the viewpoint of improving peeling resistance, the glass transition temperature (Tg) of the asphalt modifier is between -70°C and 30°C, preferably ≧-65°C, more preferably ≧-60°C, even more preferably ≧-55°C, and preferably ≦25°C, more preferably ≦10°C, even more preferably ≦0°C. The preferred embodiments of the polyester resin and hydrocarbon compound (i) constituting the asphalt modifier are the same as those for the asphalt composition described above.

[0068] In relation to the above-described embodiment, the present invention further discloses the following asphalt composition. [Example]

[0069] [Measurement method]

[0070] (1) Method for measuring the acid value and hydroxyl value of a polyester resin composition or polyester resin The acid value and hydroxyl value of the polyester resin composition or polyester resin were measured according to the method of JIS K0070: 1992. However, the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K0070: 1992 to a mixed solvent of acetone and toluene (acetone:toluene = 1:1 (volume ratio)).

[0071] (2) Measurement method of glass transition temperature The glass transition point of the polyester resin composition or polyester resin was measured using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.) by weighing 0.01 to 0.02 g of a sample into an aluminum pan, heating it to 200°C, and then cooling it to -80°C at a rate of 10°C / min. Measurements were then taken while the temperature was raised to 150°C at a rate of 10°C / min. The glass transition point was determined as the temperature at the intersection of an extension of the baseline below the maximum endothermic peak temperature and a tangent line showing the maximum slope from the rising part of the peak to the peak apex.

[0072] (5) Method for measuring the number average molecular weight and weight average molecular weight of a polyester resin composition or polyester resin The molecular weight distribution was measured by gel permeation chromatography (GPC) according to the following method, and the number average molecular weight (Mn) and weight average molecular weight (Mw) of the polyester resin composition or polyester resin were determined. (i) Preparation of sample solution The sample was dissolved in tetrahydrofuran at 60° C. to a concentration of 0.5 g / 100 mL. Next, at room temperature, this solution was filtered using a PTFE-type membrane filter with a pore size of 0.2 μm ("DISMIC-25JP", manufactured by Toyo Roshi Kaisha, Ltd.) to remove insoluble components, and a sample solution was obtained. (ii) Molecular weight measurement The following measurement equipment and analytical column were used, and tetrahydrofuran was used as the eluent at a flow rate of 1 mL per minute. The column was stabilized in a thermostatic bath at 40°C. 100 μL of the sample solution obtained in (i) above was injected into the column and the measurement was performed. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. Measuring device: "HLC-8320GPC" (Tosoh Corporation) Analytical column: "GMHXL" + "G3000HXL" (manufactured by Tosoh Corporation) The calibration curve is based on several types of monodisperse polystyrene "A-500" (5.0 × 10 2 ), "A-1000" (1.01 x 10 3 ), "A-2500" (2.63 x 10 3 ), "A-5000" (5.97 x 10 3 ), "F-1" (1.02 x 10 3 ), "F-2" (1.81 x 10 4 ), "F-4" (3.97 x 10 4 ), "F-10" (9.64 x 10 4 ), "F-20" (1.90 x 10 5 ), "F-40" (4.27 x 10 5 ), "F-80" (7.06 x 10 5 ), "F-128" (1.09 x 10 6 ) (all manufactured by Tosoh Corporation) were used as standard samples. The numbers in parentheses indicate molecular weights.

[0073] Production Example 1 (Production of Polyester Resin Composition E-1) The alcohol component, carboxylic acid component, hydrocarbon compound (i), and esterification catalyst shown in Table 1 were placed in a 10-liter four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, and the mixture was kept at 180°C under a nitrogen atmosphere for 1 hour, and then heated at 10°C per hour to 220°C over 4 hours. After reaching 220°C, the temperature and pressure were maintained at 8.0 kPa until the target acid value was reached, yielding polyester resin composition E-1. The results of the physical property measurements are shown in Table 1.

[0074] Production Examples 2 to 7 and 10 (Production of Polyester Resin Compositions E-2, E-3, E-4, E-5, E-6, E-7, and C-1) Polyester resins E-2, E-3, E-4, E-5, E-6, E-7, and C-3 were obtained in the same manner as in Production Example 1, except that the alcohol component, carboxylic acid component, hydrocarbon compound (i), and esterification catalyst shown in Table 1 were used. The results of the physical property measurements are shown in Table 1.

[0075] Production Examples 8 and 9 (Production of Polyester Resins C-1 and C-2) Polyester resins C-1 and C-2 were obtained in the same manner as in Production Example 1, except that the alcohol component, carboxylic acid component, and esterification catalyst shown in Table 1 were used. The results of the physical property measurements are shown in Table 1.

[0076] [Table 1]

[0077] The ingredients and notes in the table are as follows: *1: Polypropylene glycol PPG-450I, manufactured by Kao Specialties Americas, average molecular weight: 482 *2: Polyoxypropylene adduct of bisphenol A, average number of moles added: 2.2 mol, molecular weight 350 *3: Polyoxyethylene adduct of bisphenol A, average number of moles added: 2.2 mol, molecular weight 325 *4: Alkenyl succinic acid, average molecular weight: 256, content of components with alkenyl moiety having 12 carbon atoms: 70% to 85% *5: Propylene tetramer, average molecular weight: 160 to 180, content of carbon atoms: 70% to 85% *6: Tegokat 129 (manufactured by TIB Chemicals) *7: Molar amount (molar ratio) per 100 moles of alcohol component *8: The content of hydrocarbon compound (i) was calculated by the ratio of the amount (g) of hydrocarbon compound (i) to the total amount (g) of alcohol component, carboxylic acid component, and hydrocarbon compound (i) [(amount of hydrocarbon compound (i)) / (total amount of alcohol component, carboxylic acid component, and hydrocarbon compound (i)]. *9: The total content of structural units derived from hydrocarbon compound (i) + alkenyl succinic acid is The total amount (g) of the hydrocarbon compound (i) and alkenyl succinic anhydride charged relative to the total amount (g) of the alcohol component, carboxylic acid component, and hydrocarbon compound (i) [(total amount of the hydrocarbon compound (i) and alkenyl succinic anhydride charged) / (total amount of the alcohol component, carboxylic acid component, and hydrocarbon compound (i) charged)] was calculated.

[0078] Example 1 400 g of straight asphalt (Performance Grade (PG) 64-22, manufactured by Associated Asphalt) heated to 165°C was weighed into a 500 mL paint can, and 20 g (5 parts by mass per 100 parts by mass of asphalt) of the polyester resin composition E-1 obtained in Production Example 1 was added thereto. The can was then capped to prevent the asphalt from oxidizing, and the mixture was stirred at 165°C and a stirring speed of 400 rpm for 1 hour to prepare asphalt composition AS-1. Next, using the obtained asphalt composition AS-1, the following aggregates and asphalt composition were mixed in a tabletop mixer (Hobart 5-Quart Mixer, manufactured by Hobart) at 165°C for 1 minute based on AASHTO R30-02. The mixture was then kept at 165°C for 2 hours ± 5 minutes in a ventilated oven to prepare an asphalt mixture (hot-mix asphalt). Specifically, using the following aggregate composition, asphalt composition AS-1 was blended so that the hot-mix asphalt contained 5.6% straight asphalt, resulting in asphalt mixture M-1.

[0079] (aggregate) The aggregate used was manufactured by Blythe Construction Co., Ltd. The 2600g aggregate contained 650g of gravel (coarse aggregate), 1690g of screenings (fine aggregate), and 260g of pit sand (fine aggregate). The mass percentage of each component was as follows: Passed mass%: 〔gravel〕 Sieve size 9.50mm: 90.4% by mass Sieve size 8.00mm: 73.3% by mass Sieve size 4.75mm: 24.8% by mass Sieve size 2.80mm: 3.9% by mass Sieve size 1.00mm: 1.2% by mass Sieve size 0.50mm: 0.8% by mass [Screenings] Sieve size 9.50mm: 100.0% by mass Sieve size 8.00mm: 99.9% by mass Sieve size 4.75mm: 98.2% by mass Sieve size 2.80mm: 77.4% by mass Sieve size 1.00mm: 36.8% by mass Sieve size 0.50mm: 22.1% by mass [Mountain sand] Sieve size 9.50mm: 100.0% by mass Sieve size 8.00mm: 100.0% by mass Sieve size 4.75mm: 98.0% by mass Sieve size 2.80mm: 94.2% by mass Sieve size 1.00mm: 70.6% by mass Sieve size 0.50mm: 33.6% by mass

[0080] [evaluation] [Evaluation of peeling resistance: Boiling water test] The prepared asphalt mixture M-1 was cooled in a loosened state to 85°C or higher and 95°C or lower. Approximately 1000 mL of distilled water was placed in a 2000 mL glass beaker and heated to 85°C or higher using a heat source. Approximately 250 g of asphalt mixture M-1 was weighed out and added to the hot water in the glass beaker, and the mixture was held for 10 minutes ± 15 seconds. The mass (g) of the weighed road paving asphalt mixture M-1 was designated x. Thereafter, the glass beaker was removed from the heat source, the free asphalt floating on the surface of the water was removed, and the underwater asphalt mixture for road paving was allowed to cool to room temperature. The water in the glass beaker was removed by decantation, 1000 mL of fresh cold water was added, and the mixture was left to stand for 10 minutes. The water in the glass beaker was again removed by decantation, and the remaining asphalt mixture was placed on a paper towel and dried for 24 hours while blowing air with a fan. The dried asphalt mixture was heated to between 85°C and 95°C, and the process of holding in hot water, decanting, and drying was repeated two more times. This means that the process was carried out three times in total. Note that heating to between 85°C and 95°C was limited to within one hour to prevent oxidation of the asphalt. After the final 24-hour drying, the mass of the road paving asphalt mixture M-1 was measured. The mass (g) of the road paving asphalt mixture M-1 after 24-hour drying was designated as y. The mass loss (%) was calculated using the following formula (1) to evaluate the peeling resistance of the asphalt composition. The smaller the mass loss (%), the higher the peeling resistance can be evaluated. Formula (1): Mass loss (%)=100×(xy) / x The results are shown in Table 2.

[0081] [Evaluation of rutting resistance: Hamburg Wheel Tracking Testing] Based on AASHTO T 324, Hamburg Wheel Tracking Testing was conducted to evaluate rutting resistance. Using the prepared asphalt mixture M-1, four asphalt specimens with a diameter of 150 mm, a height of 60 mm, and a void ratio of 7.0±1.0 mass% were made using a gyratory compactor (G2 Gyratory Compactor, manufactured by Pine Test Equipment) at 165°C. In accordance with AASHTO T 324, the ends of the two specimens were cut so that there was a 7.5 mm gap between them, and they were then set in a mold. Using a wheel tracking tester, the asphalt specimens were immersed in water at a temperature of 50°C, and the maximum amount of rutting was measured after the wheels had traveled 20,000 times under a load of 705±4.5 N. The maximum rutting amount in the wheel tracking test is an index of the rutting resistance, or durability, of an asphalt pavement, and the smaller the maximum rutting amount, the higher the durability can be evaluated. The results are shown in Table 2.

[0082] Examples 2 to 4 Asphalt mixtures were obtained in the same manner as in Example 1, except that the blending amount of polyester resin composition E-1 was changed to 8 g (2 parts by mass per 100 parts by mass of asphalt), 40 g (10 parts by mass per 100 parts by mass of asphalt), and 80 g (10 parts by mass per 100 parts by mass of asphalt), respectively. Then, mass loss (%) in the boiling water test and maximum rutting amount in the Hamburg Wheel Tracking Test were measured in the same manner as in Example 1. The results are shown in Table 2.

[0083] Examples 5 to 10, Comparative Examples 2 to 4 Asphalt mixtures were obtained in the same manner as in Example 1, except that polyester resin composition E-1 in Example 1 was replaced with the polyester resin compositions or polyester resins E-2 to E-7, and C-1 to C-3 obtained in Production Examples 2 to 10, respectively. Mass loss (%) in the boiling water test and maximum rutting depth in the Hamburg Wheel Tracking Test were then measured in the same manner as in Example 1. The results are shown in Table 2.

[0084] Example 11 An asphalt mixture was obtained in the same manner as in Example 1, except that 20 g of polyester resin composition E-1 was replaced with a combination of 10 g of polyester resin composition E-1 and 10 g of polyester resin C-1 (5 parts by mass per 100 parts by mass of asphalt). Then, in the same manner as in Example 1, the mass loss (%) in the boiling water test and the maximum rutting depth in the Hamburg Wheel Tracking Test were measured. The results are shown in Table 2.

[0085] Comparative Example 1 An asphalt mixture was obtained in the same manner as in Example 1, except that the polyester resin composition E-1 was not blended. Then, the mass loss (%) in the boiling water test and the maximum rutting amount in the Hamburg Wheel Tracking Test were measured. The results are shown in Table 2.

[0086] [Table 2]

[0087] The notes in the table are as follows: *1: Content (parts by mass) per 100 parts by mass of asphalt

[0088] Table 2 shows that the asphalt compositions of Examples 1 to 11, which used specific polyester resin compositions, gave asphalt specimens that exhibited superior peel resistance compared to the asphalt compositions of Comparative Examples.

Claims

1. An asphalt composition comprising asphalt and a polyester resin composition, the polyester resin composition contains a polyester resin and a hydrocarbon-based compound (i), the polyester resin contains a structural unit derived from an alcohol component and a structural unit derived from a carboxylic acid component, the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids, The polyester resin composition has a glass transition temperature between −70° C. and 30° C., An asphalt composition, wherein the polyester resin composition is present in an amount of ≧0.5 parts by weight and ≦25 parts by weight per 100 parts by weight of asphalt.

2. The asphalt composition according to claim 1, wherein the succinic acid compound is at least one succinic acid compound selected from the group consisting of alkylsuccinic acids having an alkyl group with 9 to 19 carbon atoms and alkenylsuccinic acids having an alkenyl group with 9 to 19 carbon atoms.

3. The asphalt composition according to claim 1, wherein the content of the hydrocarbon compound (i) in the polyester resin composition is ≧0.1 mass% and ≦0.5 mass%.

4. 2. The asphalt composition according to claim 1, wherein the hydrocarbon-based compound (i) comprises a hydrocarbon-based compound (i) having a carbon number of ≥ 9 and ≤ 18, and the asphalt composition is for road paving.

5. 2. The asphalt composition of claim 1, wherein the polyester resin is a polyester resin having a weight average molecular weight of ≥ 2,000 and ≤ 100,000.

6. An asphalt modifier comprising a polyester resin and a hydrocarbon compound (i), the polyester resin contains a structural unit derived from an alcohol component and a structural unit derived from a carboxylic acid component, and the carboxylic acid component contains at least one succinic acid compound selected from the group consisting of alkylsuccinic acids and alkenylsuccinic acids; An asphalt modifier having a glass transition temperature comprised between -70°C and 30°C.

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