Asphalt smell suppressing composition, asphalt composition, asphalt smell composition, method for suppressing asphalt smell, method for screening asphalt smell suppressing composition

Abstract

To provide a composition capable of achieving both suppression effect of asphalt odor and its persistence.SOLUTION: A composition for suppressing asphalt smell contains at least one of the following components (A), (B), and (C). (A): Alcohols represented by formula (1) (B): At least one type of rosin selected from rosin, polymerized rosin, disproportionated rosin, and hydrogenated rosin, esterified with carbon 1 to 8 alkyl or carbon 1 to 8 alkenyl polyalcohol ester compounds (C): Specific fragrance components.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for suppressing asphalt odor, an asphalt composition, an asphalt odor composition, a method for suppressing asphalt odor, and a method for screening a composition for suppressing asphalt odor. [Background technology]

[0002] Generally, various offensive odors are generated during the heating process in asphalt composition (sometimes referred to as asphalt mixture) manufacturing plants. In particular, asphalt mixture manufacturing plants produce asphalt mixtures by heating and mixing recycled aggregates (prepared by crushing aggregates such as gravel and asphalt) with fillers such as stone powder at temperatures ranging from 150 to 200°C, and sometimes even up to 280°C. During this process, the asphalt heated to high temperatures emits sulfur-based components such as hydrocarbons and hydrogen sulfide, as well as offensive odor components such as aldehydes and carboxylic acids. Furthermore, the odors generated by the recycled aggregate and the odors of rubber and thermoplastic elastomer degradation products contained in modified asphalt are compounded, further increasing the odor. Thus, with the increasing ratio of recycled aggregate and the widespread use of modified asphalt in the asphalt heating process, it has become increasingly important to address odors not only for workers due to the offensive odors during production and construction, but also for neighboring residents, facilities, and the natural environment.

[0003] Several proposals have been made to suppress the odor caused by asphalt. For example, Patent Document 1 describes a method of masking (blocking) the odor by mixing a liquid fragrance additive containing a fragrance or the like into asphalt to suppress the odor. Patent Document 2 describes an asphalt deodorizing composition comprising a fragrance that is stable even at high temperatures (boiling point of 200°C or higher at normal pressure) and a fragrance-retaining substrate such as silica gel. Patent Document 3 proposes a method of effectively reducing the unpleasant odor of asphalt by blending specific fragrance components such as dihydromyrcenol or allyl amyl glycolate. Patent Document 4 also proposes a method of suppressing the thermal decomposition and oxidative degradation of asphalt using an antioxidant with a melting point of 60 to 200°C. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-342908 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-137922 [Patent Document 3] Japanese Patent Application Publication No. 2019-162346 [Patent Document 4] Japanese Patent Publication No. 2020-199237 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the liquid fragrance additive described in Patent Document 1 is highly volatile, and when added to asphalt heated to a high temperature of 100°C or higher, the fragrance components volatilize in a short period of time, often resulting in the deodorizing or masking effect not being sufficiently sustained. Therefore, there are many challenges in obtaining a sufficiently sustained masking effect by adding a fragrance additive to asphalt in advance and then heating it.

[0006] The asphalt deodorizing composition described in Patent Document 2 uses a fragrance with a boiling point of 200°C or higher at normal pressure, which means that the masking effect lasts even at high temperatures, but it is poorly volatile and may not be able to sufficiently deodorize or mask the odor of asphalt. Furthermore, the asphalt deodorizing composition described in Patent Document 2 has a limit to the amount of fragrance that can be held in a holding substrate such as silica gel, so it is necessary to use a large amount of holding substrate, which makes it less convenient to handle and raises concerns about increased manufacturing and operating costs, as well as a decrease in the performance of asphalt.

[0007] Furthermore, there are concerns that there are limits to the asphalt odor masking and deodorizing effects of the two specific aroma components described in Patent Document 3. While the antioxidant described in Patent Document 4 is expected to be effective against deterioration odors caused by radical decomposition, there are issues with resolving asphalt odors caused by deterioration and decomposition without oxidation, and the malodor itself that occurs when heated at high temperatures.

[0008] Furthermore, none of the conventional technologies have clarified the odorous components that cause the asphalt odor, and there has been a demand for a fundamental technology to combat asphalt odor that clarifies the cause of the odor.

[0009] The object of the present invention is to identify the substance that causes the odor generated when asphalt is heated, to provide a composition for suppressing asphalt odor that has an excellent effect of suppressing asphalt odor and has an excellent durability of the suppression effect, and to provide a method for suppressing asphalt odor. [Means for solving the problem]

[0010] The present invention has been made in consideration of the above circumstances, and includes the following aspects.

[0011] A composition for suppressing asphalt odor that suppresses the odor generated when asphalt is heated.

[0012] An asphalt odor composition containing at least one of a compound represented by the following general formula (2) and a compound represented by the following general formula (3):

[0013] [ka]

[0014] (In formula (2), R 1 ~R 5 R each independently represents a hydrogen atom, a hydroxyl group, or a monovalent hydrocarbon group having 1 to 3 carbon atoms. 1 and R 2 may be bonded to each other to form a benzene ring.

[0015] [ka]

[0016] (In formula (3), R 6 ~R 9 R each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms. 6 and R 7 may be bonded to each other to form a benzene ring. [Effects of the Invention]

[0017] According to the present invention, the substances that cause the odor generated when asphalt is heated have been identified, and it is possible to provide a composition for suppressing asphalt odor that effectively suppresses the odor of asphalt and a method for suppressing asphalt odor. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 shows a comparison of gas chromatograms of Test Example 5 with a uniform scale. [Figure 2] FIG. 2 is a total ion chromatogram of the blank in Test Example 7. [Figure 3] FIG. 3 is a total ion chromatogram of Example 7 in Test Example 7. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments for carrying out the present invention will be described in detail. In the present invention, deodorizing, deodorizing, masking, and odor suppressing effects refer to chemical deodorizing and / or deodorizing and / or masking effects and / or odor suppressing effects, and sensory deodorizing and / or deodorizing and / or masking effects and / or odor suppressing effects. It is essential to exhibit at least one of these effects, and it is more desirable to exhibit multiple effects. These multiple effects may be expressed as deodorizing effect, deodorizing effect, masking effect, or odor suppressing effect, but it should be clearly stated in advance that these are not limited to these effects. In the following description, the "odor generated when asphalt is heated" may be referred to as "asphalt odor," "asphalt odor," or "unpleasant asphalt odor."

[0020] <Asphalt odor suppressing composition> The composition for suppressing asphalt odor according to this embodiment is characterized by suppressing odors that are generated when asphalt is heated. As mentioned above, asphalt is heated to high temperatures of at least 100°C and as high as 280°C, so it is essential that the composition for suppressing asphalt odor remain stable at these high temperatures and exhibit a sustained and excellent asphalt odor suppression effect. The components of the composition for suppressing asphalt odor according to this embodiment that satisfy these requirements will be described in detail below.

[0021] The composition for suppressing asphalt odor according to this embodiment preferably contains at least one of the following components (A) to (C).

[0022] (Component (A)) Alcohols represented by general formula (1):

[0023] [ka]

[0024] In the formula, X represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxyl group, and Y represents a hydrogen atom or a hydroxyl group, provided that when X represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, Y represents a hydroxyl group. Component (A) has an amphiphilic structure that combines the hydrophobicity of the p-menthane skeleton with hydroxyl groups, which allows it to efficiently suppress asphalt odor through hydrophobic-hydrophobic packing and hydrogen bonding with the asphalt odor components, and it also allows the gradual release of the aroma components of component (C), making it possible to sustain the asphalt odor suppression effect.

[0025] This component is not particularly limited, but specific examples include menthol, menthoxypropanediol, p-menthane-3,8-diol, menthoxyethanol, menthoxypropanol, etc. As for the alcohols represented by general formula (1), those having multiple hydroxyl groups are particularly suitable in terms of both thermal stability and durability of the deodorizing effect, and specifically, menthoxypropanediol and p-menthane-3,8-diol are particularly preferred.

[0026] There are no particular limitations on the amount of this component added, but it is preferably 0.1 to 50 mass %, more preferably 0.5 to 40 mass %, and even more preferably 1.0 to 30 mass % in the asphalt odor suppressing composition.

[0027] (Component (B)) Component (B) is a C1-C8 alkyl or C1-C8 alkenyl polyalcohol ester compound of at least one type of rosin selected from rosin, polymerized rosin, disproportionated rosin, and hydrogenated rosin. The number of repeating units of the polyalcohol ester is preferably 1-6. Component (B) has a characteristic amphiphilic structure similar to that of component (A), and contributes to the suppression of asphalt odor and the sustained release of component (C), making it possible to sustain the asphalt odor suppression effect.

[0028] This component is not particularly limited, but specific examples include hydrogenated methyl rosinate, hydrogenated rosin glycerin ester, and hydrogenated pentaerythrityl rosinate. These are odorless components with excellent thermal stability and are effective in masking the asphalt odor generated at high temperatures. In particular, hydrogenated methyl rosinate is more preferably used in terms of compatibility with other deodorizing fragrance components and cost.

[0029] There are no particular limitations on the amount of this component added, but it is preferably 1 to 90 mass %, more preferably 5 to 85 mass %, and even more preferably 10 to 80 mass % of the asphalt odor suppressing composition.

[0030] (Component (C)) Component (C) is at least one fragrance component selected from the following: Methyl dihydrojasmonate, gamma-undecalactone, isobornyl acetate, menthone, isopulegol, L-citronellal, citronellyl acetate, citronellyl nitrile, L-dihydrocitronellal, dihydrocitronellol, geraniol, farnesol, dihydrofarnesol, dihydrofarnesal, trans-2-decenal, trans-4-decenal, cis-4-decenal, 9-decenal, trans-2-decenal, 8-mercapto-p-menthan-3-one (RINGONOL®), lemongrass oil, lime oil, patchouli oil, vetiver oil, peppermint oil, cornmint oil, rosemary oil, bergamot oil, grapefruit oil, orange oil, dipropylene glycol, benzyl benzoate, triethyl citrate

[0031] The above-mentioned components are representative aroma components that can efficiently reduce the odor of asphalt, and among these, citronellyl nitrile, 8-mercapto-p-menthan-3-one (RINGONOL, a registered trademark of Takasago International Corporation), lemongrass oil, lime oil, patchouli oil, and vetiver oil are particularly preferred.

[0032] Component (C) is capable of sensorially masking the asphalt odor, but is known as a fragrance component with a characteristic scent or a faint fragrance component, and since the fragrance component may be perceived as an unpleasant odor, it is desirable to adjust the amount of component (C) in the asphalt odor suppression composition so that the fragrance component is faint.

[0033] The amount of component (C) is not particularly limited, but as mentioned above, it is preferable that the composition for suppressing asphalt odor have a light fragrance. Therefore, for example, the amount in the composition for suppressing asphalt odor preferably does not exceed 80% by mass, and specifically, it is preferably 10 to 75% by mass, more preferably 15 to 70% by mass, and even more preferably 25 to 65% by mass. Alternatively, it is possible to make the fragrance even lighter by increasing the proportion of lightly scented fragrance materials such as dipropylene glycol, benzyl benzoate, and triethyl citrate listed as component (C).

[0034] The composition for suppressing asphalt odor according to this embodiment preferably contains one or more of the above components (A) to (C), and preferably contains two or more from the viewpoint of enhancing the odor suppressing effect. When two or more types are contained, it is preferable to contain at least one of component (A) and component (B) and component (C). In this embodiment, the ratio of at least one of component (A) and component (B) to component (C) is preferably such that the total amount of at least one of component (A) and component (B) is 5 to 70 parts by mass, more preferably 10 to 60 parts by mass, per 100 parts by mass of component (C).

[0035] The asphalt odor suppressing composition according to this embodiment may contain optional components other than the above components (A) to (C). The optional components include fragrance components other than component (C), such as various synthetic fragrances, natural fragrances, natural essential oils, and plant extracts that are commonly used in this field. Examples of optional components include, but are not limited to, the natural essential oils, natural fragrances, and synthetic fragrances described in "Japan Patent Office Gazette, Collection of Well-Known and Commonly Used Techniques (Fragrances), Part I: General Fragrances," pp. 23-250, published January 29, 1999" and "Japan Patent Office Gazette, Collection of Well-Known and Commonly Used Techniques (Fragrances), Part III: Fragrances for Cosmetics," pp. 48-62, published June 15, 2001."

[0036] (Other additives that can be used in combination) The asphalt odor suppressing composition according to this embodiment can be mixed with any additive component depending on the purpose and application. For example, it can be used by impregnating a solid component such as silica gel or zeolite. It can also be used by dissolving or diluting it in a polyhydric alcohol such as ester oil or polyethylene glycol, or a surfactant such as polyglyceryl ester.

[0037] <Asphalt composition and method for suppressing asphalt odor> The asphalt composition according to this embodiment contains the asphalt odor suppressing composition according to this embodiment. This allows for effective and continuous suppression of odors generated when asphalt is heated. The asphalt composition according to this embodiment preferably contains asphalt or an asphalt mixture in addition to the asphalt odor suppressing composition according to this embodiment.

[0038] The method for suppressing asphalt odor according to the first embodiment of the present invention includes adding the composition for suppressing asphalt odor according to the present embodiment to asphalt or an asphalt mixture, thereby effectively and continuously suppressing odors generated when asphalt is heated.

[0039] The amount of the asphalt odor suppressing composition according to this embodiment that is used relative to the asphalt or asphalt mixture is not particularly limited, but is preferably 0.0001 to 5.0 mass %, more preferably 0.0005 to 2.0 mass %, relative to the molten asphalt component. A concentration of 0.0001 mass % or more is preferred because it can fully exert its deodorizing and odor-preventing effects. The upper limit concentration may vary depending on the balance of components (A) to (C), but a concentration of 5.0 mass % or less is preferred from the viewpoints of avoiding an unpleasant odor from the deodorizing fragrance itself and maintaining cost benefits.

[0040] The type of asphalt is not particularly limited, but examples include straight asphalt, blown asphalt, modified asphalt with the addition of rubber or polymer, and light-colored (bleached) asphalt. Examples of asphalt mixtures include mixtures containing the above-mentioned asphalt, aggregates such as crushed stone and sand, and / or recycled aggregates made by crushing and classifying removed asphalt pavement slabs, and stone powder.

[0041] Furthermore, a method for suppressing asphalt odor according to a second embodiment of the present invention includes adding the asphalt odor suppressing composition according to the present embodiment to a space in which heated asphalt or an asphalt mixture is produced. The asphalt or asphalt mixture production space includes asphalt or asphalt mixture production spaces, whether internal or external, such as asphalt mixing mixers, asphalt metering tanks, asphalt storage tanks, heated dryers, and exhaust stacks. By adding the asphalt odor suppressing composition to such a production space, the asphalt odor in such a space can be effectively and continuously suppressed. The heating temperature of the asphalt or asphalt mixture is preferably 100 to 280°C, as this is the temperature range in which odors are likely to be generated.

[0042] The amount of the asphalt odor suppressing composition according to this embodiment that is used in the production space is not particularly limited, and an amount that sufficiently reduces the asphalt odor in the production space can be selected. The asphalt odor suppressing composition according to this embodiment can be added to the production space by spraying it into the space.

[0043] <Key components of asphalt odor, asphalt odor composition> According to the present invention, the components that are the main cause of asphalt odor have been identified. The unpleasant odor of asphalt preferably contains at least one of a compound represented by the following general formula (2) and a compound represented by formula (3) as a key component. The following compounds are easy to reproduce the asphalt odor. Therefore, by including the following compounds, an asphalt odor composition with excellent reproducibility can be obtained. The asphalt odor composition according to this embodiment contains at least one of a compound represented by the following general formula (2) and a compound represented by formula (3).

[0044] [ka]

[0045] In formula (2), R 1 ~R 5 R each independently represents a hydrogen atom, a hydroxyl group, or a monovalent hydrocarbon group having 1 to 3 carbon atoms. 1 and R 2 may be bonded to each other to form a benzene ring.

[0046] [ka]

[0047] In formula (3), R 6 ~R 9 R each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms. 6 and R 7 may be bonded to each other to form a benzene ring.

[0048] Specific examples of the compound of general formula (2) include, but are not limited to, phenol, o-cresol, m-cresol, p-cresol, 2-ethylphenol, 3-ethylphenol, 4-ethylphenol, 2-vinylphenol, 3-vinylphenol, 4-vinylphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2-isopropenylphenol, 3-isopropenylphenol, 4-isopropenylphenol, 2-allylphenol, 3-allylphenol, chavicol, 2-(1-propenyl)phenol, 3-(1-propenyl)phenol, 4-(1-propenyl)phenol, 2,3-dimethylphenol, and 3,4-dimethylphenol. phenol, 3,5-dimethylphenol, 2,4-dimethylphenol, 2,5-dimethylphenol, 2,6-dimethylphenol, 2,3,4-trimethylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, 2,4,5-trimethylphenol, 2,4,6-trimethylphenol, 3,4,5-trimethylphenol, 2,3,4,5-tetramethylphenol, 2,3,4,6-tetramethylphenol, 2,3,5,6-tetramethylphenol, 2,3,4,5,6-pentamethylphenol, 2,3-diethylphenol, 3,4-diethylphenol, 3,5-diethylphenol, 4-diethylphenol, 2,5-diethylphenol, 2,6-diethylphenol, 2,4,6-triethylphenol, 2,3,4,5,6-Pentaethylphenol, 3-methyl-4-isopropylphenol, thymol, 2-isopropyl-4-methylphenol, 4-isopropyl-2-methylphenol, carvacrol, catechol, resorcinol, hydroquinone, 3-methylcatechol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, methylhydroquinone, 3-ethylcatechol, 4-ethylcatechol, 2-ethylresorcinol, 4-ethylresorcinol, 5-ethylresorcinol, 2-ethylha Hydroquinone, 3-vinylcatechol, 4-vinylcatechol, 2-vinylresorcinol, 4-vinylresorcinol, 5-vinylresorcinol, 2-vinylhydroquinone, 3-propylcatechol, 4-propylcatechol, 2-propylresorcinol, 4-propylresorcinol, 5-propylresorcinol, 3-isopropylcatechol, 4-isopropylcatechol, 2-isopropylresorcinol, 4-isopropylresorcinol, 2-isopropylhydroquinone, 4-isopropenylcatechol, 2-Isopropenylresorcinol, 5-Isopropenylresorcinol, 3-Allylcatechol, 4-Allylcatechol, 2-Allylresorcinol, 4-Allylresorcinol, 5-Allylresorcinol, 2-Allylhydroquinone, 3-(1-propenyl)catechol, 2-(1-propenyl)resorcinol, 5-(1-propenyl)resorcinol, 2,4-Dimethylresorcinol, 4,5-Dimethylresorcinol, 4,6-Dimethylresorcinol, 2,3-Dimethylhydroquinone, 2,5-Dimethylhydroquinone Examples of the hydroxybenzoates include 1,2,3,4,5-trimethylresorcinol, 2,6-dimethylhydroquinone, 2,4,5-trimethylresorcinol, trimethylhydroquinone, tetramethylhydroquinone, pyrogallol, phloroglucinol, 1,2,3,4,5-pentahydroxybenzene, hexahydroxybenzene, 1-naphthol, 2-methyl-1-naphthol, 4-methyl-1-naphthol, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, and 2-methyl-1,4-dihydroxynaphthalene.

[0049] From the viewpoint of excellent reproducibility of asphalt odor, in formula (2), R 1 ~R 5 At least one, more preferably at least two, of the above groups is a monovalent hydrocarbon group having 1 to 3 carbon atoms, and the remainder is preferably a hydrogen atom or a hydroxyl group. The monovalent hydrocarbon group having 1 to 3 carbon atoms is preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group, an ethyl group, an n-propyl group, or an iso-propyl group, and particularly preferably a methyl group.

[0050] Compounds of formula (2) that are particularly effective in reproducing the asphalt odor are 2,3-dimethylphenol, 3,4-dimethylphenol, and 3,5-dimethylphenol.

[0051] Specific examples of the compound of general formula (3) include thiophene, 2-methylthiophene, 3-methylthiophene, 2-vinylthiophene, 3-vinylthiophene, 2-ethylthiophene, 3-ethylthiophene, 2-propylthiophene, 3-propylthiophene, 2-allylthiophene, 3-allylthiophene, 2-(1-propenyl)thiophene, 2-isopropylthiophene, 3-isopropylthiophene, 2-isopropenylthiophene, 3-isopropenylthiophene, 2,3-dimethylthiophene, 2,4 -Dimethylthiophene, 2,5-dimethylthiophene, 3,4-dimethylthiophene, 2,3-diethylthiophene, 2,4-diethylthiophene, 2,5-diethylthiophene, 3,4-diethylthiophene, 2,3-divinylthiophene, 2,4-divinylthiophene, 2,5-divinylthiophene, 3,4-divinylthiophene, 2,5-dipropylthiophene, 3,4-dipropylthiophene, 2,5-diisopropylthiophene, 2-methyl-5-propylthiophene, 2-methyl-5-allylthiophene , 2-methyl-5-isopropylthiophene, 2-ethyl-3-methylthiophene, 2-ethyl-4-methylthiophene, 2-ethyl-5-methylthiophene, 2-ethyl-3-propylthiophene, 2-ethyl-5-propylthiophene, 3-ethyl-2-methylthiophene, 3-ethyl-4-methylthiophene, 4-ethyl-2-methylthiophene, 2-vinyl-3-methylthiophene, 2-vinyl-4-methylthiophene, 2-vinyl-5-methylthiophene, 2-vinyl-5-propylthiophene, 3-vinyl 2-methylthiophene, 2,3,4-trimethylthiophene, 2,3,5-trimethylthiophene, 2,3,5-triethylthiophene, 2-ethyl-3,5-dimethylthiophene, 3-ethyl-2,5-dimethylthiophene, 5-ethyl-2,3-dimethylthiophene, 2,3,4,5-tetramethylthiophene, 2,3,4,5-tetrapropylthiophene, benzothiophene, 2-methylbenzothiophene, 3-methylbenzothiophene, 2-ethylbenzothiophene, 3-ethylbenzothiophene, 2,Examples of the benzothiophene include 3-dimethylbenzothiophene, 2-vinylbenzothiophene, 3-vinylbenzothiophene, 2-propylbenzothiophene, 2-(1-propenyl)benzothiophene, 3-(1-propenyl)benzothiophene, 2-allylbenzothiophene, 3-allylbenzothiophene, 3-propenylbenzothiophene, 2-isopropylbenzothiophene, 3-isopropylbenzothiophene, 2-isopropenylbenzothiophene, 3-isopropenylbenzothiophene, 2,3-dimethylbenzothiophene, 3,5-dimethylbenzothiophene, 2,3-diethylbenzothiophene, 3-methyl-2-propylbenzothiophene, 3-ethyl-2-methylbenzothiophene, and 3-vinyl-2-methylbenzothiophene.

[0052] From the viewpoint of excellent reproducibility of asphalt odor, in formula (3), R 6 ~R 9 At least one of R is preferably a monovalent hydrocarbon group having 1 to 3 carbon atoms, and the remainder is a hydrogen atom, or 8 or R 9 is preferably a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R 6 and R 7 and preferably bond to each other to form a benzene ring. As the monovalent hydrocarbon group having 1 to 3 carbon atoms, an alkyl group having 1 to 3 carbon atoms is preferred, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group is more preferred, and a methyl group or an ethyl group is particularly preferred.

[0053] In particular, the compounds of formula (3) that are remarkably effective in reproducing the asphalt odor are 2-ethylthiophene, 3-ethylthiophene, 2-methylbenzothiophene, and 3-methylbenzothiophene.

[0054] The asphalt odor composition according to this embodiment may contain at least one of the compound represented by the general formula (2) and the compound represented by formula (3), or may contain both compounds, but it is preferable to contain both compounds from the viewpoint of asphalt odor reproducibility.

[0055] When the asphalt odor composition according to this embodiment contains both compounds, the molar ratio of the compound represented by formula (2) to the compound represented by formula (3) is preferably 95:5 to 5:95, more preferably 70:30 to 30:70.

[0056] <Method for screening compositions for suppressing asphalt odor> The screening method for asphalt odor suppressing compositions according to this embodiment includes using the asphalt odor composition according to this embodiment. The asphalt odor composition according to this embodiment is excellent in reproducing the asphalt odor, and is therefore effective for screening whether or not a composition for suppressing asphalt odor has an asphalt odor suppressing effect.

[0057] Based on the above, the present specification discloses the following: [1] A composition for suppressing asphalt odor that suppresses the odor generated when asphalt is heated. [2] The composition for suppressing asphalt odor according to [1], which contains at least one of the following components (A), (B), and (C): Component (A): Alcohols represented by the following general formula (1):

[0058] [ka]

[0059] (In the formula, X represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxyl group, and Y represents a hydrogen atom or a hydroxyl group. However, when X represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, Y represents a hydroxyl group.) Ingredient (B): C1-C8 alkyl or C1-C8 alkenyl polyalcohol ester compounds of at least one type of rosin selected from rosin, polymerized rosin, disproportionated rosin, and hydrogenated rosin Ingredients (C): At least one aroma component selected from the following: Methyl dihydrojasmonate, gamma-undecalactone, isobornyl acetate, menthone, isopulegol, L-citronellal, citronellyl acetate, citronellyl nitrile, L-dihydrocitronellal, dihydrocitronellol, geraniol, farnesol, dihydrofarnesol, dihydrofarnesal, trans-2-decenal, trans-4-decenal, cis-4-decenal, 9-decenal, trans-2-decenal, 8-mercapto-p-menthan-3-one (RINGONOL®), lemongrass oil, lime oil, patchouli oil, vetiver oil, peppermint oil, cornmint oil, rosemary oil, bergamot oil, grapefruit oil, orange oil, dipropylene glycol, benzyl benzoate, triethyl citrate [3] The composition for suppressing asphalt odor according to [1] or [2], wherein the odor generated when the asphalt is heated contains at least one of a compound represented by the following general formula (2) and a compound represented by the following general formula (3):

[0060] [ka]

[0061] (In formula (2), R 1 ~R 5 R each independently represents a hydrogen atom, a hydroxyl group, or a monovalent hydrocarbon group having 1 to 3 carbon atoms. 1 and R 2 may be bonded to each other to form a benzene ring.

[0062] [ka]

[0063] (In formula (3), R 6 ~R 9 R each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms. 6 and R 7 may be bonded to each other to form a benzene ring. [4] An asphalt composition comprising the composition for suppressing asphalt odor according to any one of [1] to [3]. [5] A method for suppressing the odor of asphalt, comprising adding the composition for suppressing asphalt odor described in any one of [1] to [3] to a space for producing asphalt or an asphalt mixture heated at 100°C to 280°C. [6] A method for suppressing asphalt odor, comprising adding the composition for suppressing asphalt odor according to any one of [1] to [3] in an amount of 0.0001 to 5.0 mass % to a molten asphalt component. [7] An asphalt odor composition containing at least one of a compound represented by the following general formula (2) and a compound represented by the following general formula (3):

[0064] [ka]

[0065] (In formula (2), R 1 ~R 5 R each independently represents a hydrogen atom, a hydroxyl group, or a monovalent hydrocarbon group having 1 to 3 carbon atoms. 1 and R 2 may be bonded to each other to form a benzene ring.

[0066] [ka]

[0067] (In formula (3), R 6 ~R 9 R each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms. 6 and R 7 may be bonded to each other to form a benzene ring. [8] A method for screening compositions for suppressing asphalt odor, comprising using the asphalt odor composition described in [7]. [Example]

[0068] The present invention will be explained in more detail below by way of test examples and examples, but the present invention is not limited to these.

[0069] <1. Preparation of asphalt odor composition> [Test Example 1] Test Method) (i) Comparative Example 1: Preparation of Asphalt Odor Composition 1 Approximately 170 g of an equimolar mixture of 2-methylpentane, a linear alkane having 6 to 15 carbon atoms, and 1,2,4-trimethylbenzene was prepared and used as asphalt odor composition 1 (AS odor 1). (ii) Examples 1 to 6: Preparation of asphalt odor compositions 2 to 7 Asphalt odor composition 1 (AS odor 1) is 100 mol%, and 3,4-dimethylphenol, 3,5-dimethylphenol, 3-ethylthiophene, 2-methylbenzothiophene, and 3-methylbenzothiophene were added to AS odor 1 (approximately 10 g) in the molar ratios shown in Table 2, and heated to dissolve as needed to prepare asphalt odor compositions 2 to 7 (AS odors 2 to 7). (iii) Verification of odor similarity of asphalt odor composition 10 g of straight asphalt (Idemitsu Kosan Co., Ltd., Lot #MR07B10Y) was heated and melted at 170°C, and the odor generated was scored as 5. The odor similarity to asphalt odor compositions 1 to 7 was evaluated by a panel of 10 experts.

[0070] The odor similarity was judged according to the evaluation criteria in Table 1 below, and the average score was calculated. The results are shown in Table 2.

[0071] [Table 1]

[0072] [Table 2]

[0073] As is clear from Table 2, the results of Examples 1 to 3 show that the inclusion of either the compound represented by general formula (2) or the compound represented by general formula (3) improved the asphalt odor similarity. Furthermore, the results of Examples 4 to 6 show that the combined use of two or more compounds selected from the compound represented by general formula (2) and the compound represented by general formula (3) allows the preparation of an asphalt odor composition with extremely high reproducibility.

[0074] <2. Odor suppression effect of aroma components on simulated asphalt odor> [Test Example 2] The asphalt odor suppressing effect of the aromatic components shown in Table 4 on the asphalt odor composition 7 prepared in Example 6 above was examined. Test Method) (i) A 10% benzyl benzoate solution was prepared of the asphalt odor composition 7 prepared in Example 6. Also, a 10% dipropylene glycol solution of the aroma components shown in Table 4 below was prepared. (ii) A piece of filter paper (3 × 3 cm) was placed in a 150 mL beaker. (iii) The filter paper was impregnated with the AS odor 7 solution (10 μL) and fragrance solution (10 μL) prepared in (i). (iv) The beaker was covered with aluminum foil and allowed to stand for 30 minutes. (v) At the time of sensory evaluation, the lid was opened and the sensory evaluation was carried out by 10 expert panelists according to the evaluation criteria in Table 3 below.

[0075] [Table 3]

[0076] The average results of the asphalt odor suppression test for aroma compounds are shown in Table 4. As is clear from Table 4, aroma compounds with a score of more than 2 but less than 3 had a mild asphalt odor suppression effect, aroma compounds with a score of more than 1 but less than 2 had a clear asphalt odor suppression effect, and aroma compounds with a score of 1 or less had a significant asphalt odor suppression effect.

[0077] [Table 4]

[0078] <3. Preparation of asphalt odor suppression composition and odor suppression test for simulated asphalt odor> [Test Example 3] Six asphalt odor suppressing compositions (Examples 7 to 12) and a comparative blended fragrance (Comparative Example 2) shown in Tables 5 to 11 were prepared, and an odor suppression test for asphalt odor composition 7 prepared in Example 6 was carried out in the same manner as in Test Example 2 to verify the odor suppression (masking) effect. In addition, the pleasantness / unpleasantness of the odor was verified by measuring whether the odor was harmonized.

[0079] [Table 5]

[0080] [Table 6]

[0081] [Table 7]

[0082] [Table 8]

[0083] [Table 9]

[0084] [Table 10]

[0085] [Table 11]

[0086] The odor suppression (masking) effect and the evaluation criteria for the pleasantness or unpleasantness of the odor are shown in Tables 12 and 13 below.

[0087] [Table 12]

[0088] [Table 13]

[0089] The test results are shown in Table 14 as average values.

[0090] [Table 14]

[0091] As is clear from Table 14, the asphalt odor suppressing compositions of Examples 7 to 12 exhibited excellent effects in terms of both odor suppression effect and comfort level, confirming their excellent asphalt odor suppression effect.

[0092] <4. Verification of odor suppression effect against actual asphalt odor> [Test Example 4] 50 g of straight asphalt was weighed into a stainless steel container. The container was heated on a hot plate set to 180°C in a draft chamber, and the asphalt odor was confirmed. Then, 0.005 mass%, 0.01 mass%, and 0.015 mass% (50, 100, and 150 ppm) of odor suppressant were added and mixed with a stainless steel spoon. The odor was confirmed and evaluated immediately after addition and 30 minutes after addition. The odor control agents used in the test were the three asphalt odor control compositions of Examples 7 to 9, and the commercially available deodorant Ecosorb (Comparative Example 3). As a control, a test was also run with no odor control agent added (hereinafter referred to as blank).

[0093] The odor of asphalt was evaluated by a sensory test in which six evaluators smelled the odor after adding the odor suppressant. The evaluation was carried out based on the asphalt odor suppression effect and the pleasantness / unpleasantness of the odor (improvement effect). The odor suppression effect on asphalt odor was evaluated at 0 (when no asphalt odor was detected at all (completely masked)) and 5 (when blank (no masking at all when no deodorant was added)) with 0 being the score, with intervals of 0.5 between the two scores. The pleasantness or unpleasantness of the odor was evaluated based on whether the odor was harmonized or not, with -1 representing unpleasant and completely ineffective, and 1 representing very harmonious and effective, with the scores in 0.1 increments between these. The results are shown in Table 15 as average values.

[0094] [Table 15]

[0095] The asphalt odor suppressing compositions of Examples 7 to 9 exhibited excellent asphalt odor suppression effects and the effect of modifying the asphalt odor to a pleasant fragrance both when heated at high temperatures immediately after the asphalt mixture was prepared and 30 minutes later, and were found to have excellent effects in both immediate and long-lasting action. Furthermore, they were also found to exhibit superior asphalt odor suppression effects and improved comfort and unpleasantness compared to commercially available deodorizers. Furthermore, it was confirmed that the asphalt odor suppressing composition exhibited a sufficient deodorizing effect even when added in an amount of 0.005 mass % (50 ppm).

[0096] [Test Example 5] 1. Method Coarse aggregate, fine aggregate, and stone powder were placed in an iron container and heated to 170°C and kept warm. This was then placed in a small mixer and mixed for 1 minute 30 seconds. After mixing, straight asphalt heated to 160°C and odor suppressant were added, and the mixture was mixed for another 1 minute 30 seconds while heating to produce an asphalt mixture. The prepared asphalt mixture was mixed while maintained at 160°C, and the generated odorous gas was collected in a sampling bag. The odorous gas was collected in a Tenax collection tube and analyzed and compared using a thermal desorption gas chromatograph mass spectrometer (ATD-GC / MS). The amount of odor inhibitor added was 100 mg / kg (100 mass ppm) relative to the weight of asphalt in the asphalt mixture. The odor control agents used were the asphalt odor control composition of Example 7 and the commercially available deodorant (Ecosorb) of Comparative Example 3, and a blank was also run as a control.

[0097] 2.Results Figure 1 shows gas chromatograms of all three samples, scaled to a unified scale with the largest detected peak set to 100%. As shown in Figure 1, the peaks detected in Example 7 were clearly reduced compared to the blank and Comparative Example 3.

[0098] [Test Example 6] 1. Method At the asphalt mixture plant, preheated coarse aggregate and fine aggregate were fed from the aggregate measuring tank into a mixer. Next, stone powder was fed from the stone powder measuring tank into the mixer, and the aggregate and stone powder were mixed. Next, straight asphalt was added to the mixer from the asphalt measuring tank. The odor inhibitor was added to the asphalt when it was measured. The aggregate, stone powder, and asphalt were mixed to produce an asphalt mixture. The concentration of the odor inhibitor added was 100 mg / kg of asphalt weight. The odor control agents used were the asphalt odor control composition of Example 7 and the commercially available deodorant (Ecosorb) of Comparative Example 3. A blank was also run as a control.

[0099] The asphalt odor was evaluated by a sensory test in which the asphalt mixture discharged from the mixer was collected with a shovel and placed on a flat surface, and the odor was smelled by eight evaluators. The evaluation covered the degree to which the asphalt odor was perceived (hereinafter referred to as As sensation), odor intensity, and pleasantness / unpleasantness. The smell of asphalt was evaluated as 0: no asphalt smell, 1: asphalt smell, with 0.1 intervals between the two. Odor intensity was measured using a six-level odor intensity scale ranging from 0 to 5 (0: no odor, 1: barely detectable odor (detection threshold), 2: weak odor that is recognizable (recognition threshold), 3: easily detectable odor, 4: strong odor, 5: intense odor). The pleasantness / unpleasantness scale is a measure of the pleasantness / unpleasantness of an odor, and the evaluation index is as follows: With an odor that is neither pleasant nor unpleasant as the midpoint, there are 9 levels, with 4 levels in the unpleasant direction and 4 levels in the pleasant direction (-4: extremely unpleasant, -3: very unpleasant, -2: unpleasant, -1: slightly unpleasant, 0: neither pleasant nor unpleasant, +1: slightly pleasant, +2: pleasant, +3: very pleasant, +4: extremely pleasant). The results are shown in Table 16 as average values.

[0100] 2.Results As shown in Table 16, the addition of the asphalt odor suppressing composition of Example 7 reduced the As odor sensation and odor intensity, and improved the comfort level.

[0101] [Table 16]

[0102] [Test Example 7] 2.0 g of each sample of the asphalt mixture treated with the asphalt odor suppressing composition of Example 7 obtained in Test Example 6 above and the asphalt mixture (blank) without any odor suppressant added were placed in a 20 mL vial, heated to 160°C with aluminum beads for 3 hours, and headspace gas was collected in MonoTrap DCC18 and RCC18. After ultrasonic extraction with diethyl ether, the mixture was concentrated in a nitrogen stream. The resulting odor concentrates were compared using GCxGC / TOFMS analysis. The results are shown in Table 17 below and Figures 2 and 3.

[0103] [Table 17]

[0104] As is clear from Table 17 and Figures 2 and 3, the total ion peaks derived from the asphalt treated with the asphalt odor suppressing composition of Example 7 were attenuated compared to the blank sample, and it was confirmed that the total peak area was reduced by approximately 80%.

Claims

1. A composition for suppressing asphalt odor that suppresses the odor generated when asphalt is heated.

2. 2. The composition for suppressing asphalt odor according to claim 1, comprising at least one of the following components (A), (B), and (C): Component (A): Alcohols represented by the following general formula (1): 【Chemistry 1】 (In the formula, X represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxyl group, and Y represents a hydrogen atom or a hydroxyl group. However, when X represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, Y represents a hydroxyl group.) Ingredient (B): C1-C8 alkyl or C1-C8 alkenyl polyalcohol ester compounds of at least one type of rosin selected from rosin, polymerized rosin, disproportionated rosin and hydrogenated rosin Component (C): At least one aroma component selected from the following: Methyl dihydrojasmonate, γ-undecalactone, isobornyl acetate, menthone, isopulegol, L-citronellal, citronellyl acetate, citronellyl nitrile, L-dihydrocitronellal, dihydrocitronellol, geraniol, farnesol, dihydrofarnesol, dihydrofarnesal, trans-2-decenal, trans-4-decenal, cis-4-decenal, 9-decenal, trans-2-decenal, 8-mercapto-p-menthan-3-one (RINGONOL®), lemongrass oil, lime oil, patchouli oil, vetiver oil, peppermint oil, cornmint oil, rosemary oil, bergamot oil, grapefruit oil, orange oil, dipropylene glycol, benzyl benzoate, triethyl citrate

3. The composition for suppressing asphalt odor according to claim 1, wherein the odor generated when the asphalt is heated contains at least one of a compound represented by the following general formula (2) and a compound represented by the following general formula (3): 【Chemistry 2】 (In formula (2), R １ ~R ５ R each independently represents a hydrogen atom, a hydroxyl group, or a monovalent hydrocarbon group having 1 to 3 carbon atoms. １ and R ２ may be bonded to each other to form a benzene ring.) 【Transformation 3】 (In formula (3), R ６ ~R ９ R each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms. ６ and R ７ may be bonded to each other to form a benzene ring.)

4. An asphalt composition comprising the asphalt odor suppressing composition according to any one of claims 1 to 3.

5. A method for suppressing asphalt odor, comprising adding the asphalt odor suppressing composition according to any one of claims 1 to 3 to a space for producing asphalt or an asphalt mixture heated at 100°C to 280°C.

6. A method for suppressing asphalt odor, comprising adding the asphalt odor suppressing composition according to any one of claims 1 to 3 in an amount of 0.0001 to 5.0 mass % to a molten asphalt component.

7. An asphalt odor composition containing at least one of a compound represented by the following general formula (2) and a compound represented by the following general formula (3): 【Chemistry 4】 (In formula (2), R １ ~R ５ R each independently represents a hydrogen atom, a hydroxyl group, or a monovalent hydrocarbon group having 1 to 3 carbon atoms. １ and R ２ may be bonded to each other to form a benzene ring.) 【Transformation 5】 (In formula (3), R ６ ~R ９ R each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms. ６ and R ７ may be bonded to each other to form a benzene ring.)

8. A method for screening compositions for suppressing asphalt odor, comprising using the asphalt odor composition according to claim 7.

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