A tasteless asphalt additive, tasteless asphalt and a preparation method thereof

Abstract

The application discloses a kind of odorless asphalt additives, odorless asphalt and preparation method thereof.The odorless asphalt additives of the application includes the following components by weight: auxiliary odorless agent 1-5 parts;Modified slow-release odorless microcapsule 1-5 parts;Dispersing agent 1-10 parts;The modified slow-release odorless microcapsule includes shell material and core material, wherein the shell material is silicon dioxide;The core material is selected from one or more of aldehydes, esters, alcohols, terpenes.The odorless asphalt of the application includes the following components by weight: base asphalt 100-500 parts;Odorless asphalt additive 5-30 parts;Odorless asphalt additive further, base asphalt is heated to molten state, odorless asphalt additive is added under stirring condition, and odorless asphalt is obtained after mixing uniformly.The application uses modified slow-release odorless microcapsule as odorless asphalt additive, and the content of irritating gas in asphalt fume is effectively reduced through the slow-release effect of microcapsule, which has good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of environmentally friendly asphalt, specifically relating to a odor-neutralizing asphalt additive, odor-neutralizing asphalt, and its preparation method. Background Technology

[0002] With the accelerating pace of urban modernization, urban roads, a central component of municipal construction, are constantly expanding. Asphalt pavement, due to its excellent mechanical properties, smooth and wear-resistant surface, comfortable driving experience, and good construction and workability, has become the main structural form of high-grade pavements. However, the hot-mix hot-laying process used in asphalt pavement construction releases large amounts of asphalt fumes under high-temperature conditions. These fumes severely disrupt the ecological balance, pollute the surrounding environment, and harm human health. Research has found that asphalt fumes are composed of hydrocarbons and hydrocarbon derivatives of different properties and molecular weights, with particle sizes concentrated around 1 μm. They are mainly polycyclic aromatic hydrocarbons (PAHs), nitrogen-containing compounds, and sulfur-containing compounds, including strong carcinogens such as carbazole and benzo[a]pyrene, as well as gases with irritating odors such as ammonia, hydrogen sulfide, sulfur dioxide, and thiophene. In recent years, my country has increasingly emphasized energy conservation, emission reduction, and green development, making the future introduction of policies restricting asphalt fume emissions an inevitable trend. Therefore, conducting relevant research on the treatment of asphalt fumes is essential.

[0003] Currently reported methods for treating asphalt fumes mainly involve external devices: these devices are installed at the exhaust stacks of asphalt construction equipment to efficiently remove toxic, harmful, and irritating gases from the fumes. However, this method only addresses fumes generated by non-mobile equipment during asphalt mixing plant construction; it cannot handle the unorganized fumes generated during asphalt mixture transportation and paving. Furthermore, these fume purification devices are typically expensive and have high operating costs, hindering their widespread adoption. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a odor-neutralizing asphalt additive, odor-neutralizing asphalt, and a method for preparing the same. This invention uses modified slow-release odor-neutralizing microcapsules as the odor-neutralizing asphalt additive. Through the slow-release effect of the microcapsules, the odor-neutralizing asphalt effectively reduces the content of irritating gases in asphalt fumes, showing promising application prospects.

[0005] The odor-neutralizing asphalt additive of the present invention comprises the following components by weight:

[0006] 1-5 parts of auxiliary deodorizing agent;

[0007] Modified sustained-release deodorizing microcapsules, 1-5 parts;

[0008] Dispersant 1-10 parts.

[0009] Furthermore, the mass ratio of the auxiliary deodorizing agent to the modified sustained-release deodorizing microcapsules is 1:1.

[0010] Furthermore, the auxiliary deodorizing agent is selected from one or more of the following: solid aldehydes with a boiling point greater than 250°C, amide compounds with a boiling point greater than 250°C, and antioxidants with a boiling point greater than 300°C.

[0011] Furthermore, the solid aldehydes with a boiling point greater than 250°C are selected from one or more of N,N-diethyl-4-aminobenzaldehyde, 3-methoxy-4-hydroxybenzaldehyde, and 3,4-methylenedioxybenzaldehyde.

[0012] Furthermore, the amide compound with a boiling point greater than 250°C is selected from one or more of 4,4'-methylenebis(N-phenylmaleimide), NN-diethylmaleimide, N-phenylmaleimide, succinimide 6-(maleimino)hexanoate, tris(2-maleiminoethyl)amine, and N-(2-hydroxyethyl)maleimide.

[0013] Furthermore, the antioxidant with a boiling point greater than 300°C is an ester antioxidant and / or a carboxylic acid antioxidant.

[0014] Furthermore, the ester antioxidant with a boiling point greater than 300°C is selected from one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate isooctyl ester, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0015] Furthermore, the carboxylic acid antioxidant with a boiling point greater than 300°C is selected from one or more of 3,5-di-tert-butyl-4-hydroxybenzoic acid, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylic acid, 3-(3,5-dimethyl-4-hydroxyphenyl)acrylic acid, 3-(3,5-dimethoxy-4-hydroxyphenyl)acrylic acid, and 3-(3-methoxy-4-hydroxyphenyl)acrylic acid.

[0016] Furthermore, the modified sustained-release deodorizing microcapsule includes a shell material and a core material, wherein the shell material is silicon dioxide.

[0017] Furthermore, the core material is selected from one or more of aldehydes, esters, alcohols, and terpenes.

[0018] Furthermore, the aldehydes are selected from aromatic aldehydes with a boiling point greater than 230°C and terpenoid aldehydes with a boiling point greater than 170°C; the aromatic aldehydes with a boiling point greater than 230°C include cinnamaldehyde, p-methoxybenzaldehyde, and 2-methyl-3-(3,4-methylenedioxyphenyl)propanal; the terpenoid aldehydes with a boiling point greater than 170°C include one or more of citral, citronellol, and hydroxycitronellol.

[0019] Furthermore, the esters are selected from benzoic acid esters with a boiling point greater than 210°C and terpene alcohol esters with a boiling point greater than 190°C; the benzoic acid esters with a boiling point greater than 210°C are selected from one or more of ethyl benzoate, isobutyl benzoate, isoamyl benzoate, and benzyl benzoate; the terpene alcohol esters with a boiling point greater than 190°C include one or more of geraniol acetate, linalool isobutyrate, citronellol acetate, or citronellol isobutyrate.

[0020] Furthermore, the alcohols are selected from aromatic alcohols with a boiling point greater than 200°C and terpene alcohols with a boiling point greater than 160°C; the aromatic alcohols with a boiling point greater than 200°C are selected from one or more of benzyl alcohol and β-phenylethanol; the terpene alcohols with a boiling point greater than 160°C are selected from one or more of geraniol, nerol, ionol, and myrceneol.

[0021] Furthermore, the terpenes are cyclic terpenes with a boiling point greater than 150°C, specifically selected from one or more of α-terpinene, α-phellandrene, α-pinene, β-caryophyllene, and thujone.

[0022] Furthermore, the mass ratio of the shell material to the core material of the modified sustained-release deodorizing microcapsule is 1:(0.5-2).

[0023] Furthermore, the modified sustained-release deodorizing microcapsules have a nanostructure with a particle size of 300-800 nm.

[0024] Furthermore, the preparation method of the modified sustained-release deodorizing microcapsules includes the following steps:

[0025] S1: After mixing the core material raw materials in equal mass ratio, add surfactant and distilled water and stir for a period of time to obtain a homogeneous emulsion;

[0026] S2: A sol is prepared by mixing tetraethyl orthosilicate, distilled water and ethanol and stirring for a period of time.

[0027] S3: Add the sol obtained in S2 to the emulsion obtained in S1, and add ammonia water to adjust the pH of the system to 9-10. Stir for a period of time until the reaction system turns grayish-white, then turn off the stirring and age at a constant temperature for a period of time. Filter, wash and freeze-dry the bottom solid powder to obtain sustained-release deodorizing microcapsules.

[0028] S4: Add the sustained-release deodorizing microcapsules obtained in S3 to deionized water, adjust the pH of the system to 9-10 using ammonia, then add γ-aminopropyltriethoxysilane, stir for a period of time, wash, filter and freeze-dry the solid powder in the system to obtain the modified sustained-release deodorizing microcapsules. The entire reaction process is carried out under nitrogen protection.

[0029] Furthermore, in step S1, the stirring temperature is 40-65℃, the stirring speed is 600-800rpm, and the stirring time is 2-4h.

[0030] Furthermore, the emulsifier in step S1 is a cationic surfactant, preferably hexadecyltrimethylammonium bromide.

[0031] Furthermore, in step S1, the mass ratio of distilled water to core material mixture is (5-10):1, and the mass ratio of emulsifier to core material mixture is (0.1-0.5):1.

[0032] Furthermore, the stirring time in step S2 is 3-5 hours, the stirring speed is 300-600 rpm, and the stirring temperature is 40-60℃.

[0033] Furthermore, in step S2, the mass ratio of tetraethyl orthosilicate to distilled water is 1:(0.5-2), and the mass ratio of distilled water to ethanol is 1:(0.5-2).

[0034] Furthermore, in step S3, the stirring temperature is 40-65℃, the stirring speed is 300-600rpm, and the stirring time is 2-4h.

[0035] Furthermore, the mass ratio of the sol to the emulsion in step S3 is 1:(0.1-10).

[0036] Furthermore, the stirring time in step S4 is 2-4 hours, the stirring speed is 100-200 rpm, and the stirring temperature is 60-80℃.

[0037] Furthermore, in step S4, the mass ratio of the sustained-release deodorizing microcapsule to γ-aminopropyltriethoxysilane is (2-5):1.

[0038] Furthermore, the pH of the solution in step S4 is 9-10.

[0039] Furthermore, the dispersant is one of dodecyl dimethyl betaine and 1-hydroxyethyl-carboxymethyl-alkyl imidazoline.

[0040] The preparation method of the odor-neutralizing asphalt additive of the present invention includes the following steps: mixing an auxiliary odor-neutralizing agent and a dispersant; after the auxiliary odor-neutralizing agent has completely dissolved, adding modified slow-release odor-neutralizing microcapsules; and mixing evenly to obtain the odor-neutralizing asphalt additive.

[0041] This invention also provides an odor-neutralizing asphalt, comprising the following components by weight:

[0042] 100-500 parts of base bitumen;

[0043] Odor-neutralizing asphalt additive: 1-30 parts;

[0044] Furthermore, the base asphalt is heated to a molten state, and then an odor-neutralizing asphalt additive is added under stirring conditions. After mixing evenly, odor-neutralizing asphalt is obtained.

[0045] The base asphalt is commercially available No. 50, No. 70 and No. 90 road asphalt, preferably No. 70 Grade A asphalt.

[0046] Compared with the prior art, the present invention has the following advantages:

[0047] (1) In the odor-neutralizing asphalt additive of the present invention, the core material of the modified slow-release odor-neutralizing microcapsule and the auxiliary odor-neutralizing agent can react chemically with the lighter components in the asphalt (such as sulfides, benzene series compounds, etc.) to generate compounds with larger molecular weight, stronger stability and higher boiling point. They are not easy to escape at high temperature, which effectively reduces the content of irritating gases in the flue gas released by asphalt during high-temperature construction.

[0048] (2) The odor-neutralizing asphalt additive of the present invention can react with the free radicals generated by asphalt under high temperature conditions, reduce the small molecular weight gaseous hydrocarbons generated by the free radical reaction, and reduce the risk of smog to a certain extent.

[0049] (3) The odor-neutralizing asphalt additive of the present invention, the odor-neutralizing asphalt, the modified slow-release odor-neutralizing microcapsules added can slowly release the core material - odor-neutralizing active components after the asphalt is added, so as to achieve the purpose of long-term odor neutralization and odor suppression. The modified slow-release odor-neutralizing microcapsules have a nanostructure, and the shell material is silica with a porous structure and a large amount of amino groups on the surface. It has good compatibility with asphalt, can effectively improve the high temperature stability of asphalt materials, optimize their road performance, and extend the service life of asphalt pavement. Attached Figure Description

[0050] Figure 1 This is an electron microscope image of the modified sustained-release deodorizing microcapsule described in Example 1 of the present invention. Detailed Implementation

[0051] To further illustrate the relevant features and technical means of the present invention, the present invention will be clearly and thoroughly described below in conjunction with embodiments. The microcapsules of the present invention were morphologically tested using a ZEISS Supra 55 scanning electron microscope with an accelerating voltage of 20KV. Since the microcapsule wall material is non-conductive, the samples needed to be sputter-coated with gold before testing. The sulfides in the odor-neutralizing asphalt flue gas of the present invention were tested using gas chromatography according to the national standard GBT14678-1993, "Determination of Hydrogen Sulfide, Methanethiol, Dimethyl Sulfide and Dimethyl Disulfide in Air Quality," using an Agilent 7890 gas chromatograph. The matrix asphalt used was Sinopec Donghai brand Grade 70 A asphalt.

[0052] Example 1

[0053] S1: The core material mixture is prepared by mixing cinnamaldehyde, citral, ethyl benzoate, geraniol acetate, benzyl alcohol, geraniol and α-terpinene in a certain mass ratio and stirring at 400 rpm for 30 min at 50°C.

[0054] S2: Add hexadecyltrimethylammonium bromide and distilled water to the above core material mixture, and continue stirring at 800 rpm for 4 hours at 50°C to form a homogeneous emulsion. The mass ratio of the core material mixture, hexadecyltrimethylammonium bromide and distilled water is 5:1:34.

[0055] S3: Take tetraethyl orthosilicate, distilled water and ethanol and stir at 400 rpm for 4 hours at 50℃ to obtain a sol. The mass ratio of tetraethyl orthosilicate, distilled water and ethanol is 1:1:2.

[0056] S4: The prepared sol is added dropwise to the emulsion obtained in S2. The mass ratio of the sol to the core material mixture is 1:2. At the same time, ammonia water is added dropwise to adjust the pH of the system to 9. The mixture is stirred at 400 rpm for 3 hours at 50°C. Then the stirring is turned off and the mixture is aged at 50°C for 12 hours. After centrifugation and freeze-drying, sustained-release deodorizing microcapsules are obtained.

[0057] S5: Add the sustained-release deodorizing microcapsules prepared in S4 to deionized water, adjust the pH of the system to 10 using ammonia, then add γ-aminopropyltriethoxysilane, and stir for 2 hours at 70°C and 200 rpm. After stirring, wash, filter and freeze dry to obtain the modified sustained-release deodorizing microcapsules. The reaction process is carried out under nitrogen protection throughout, and the mass ratio of sustained-release deodorizing microcapsules to γ-aminopropyltriethoxysilane is 2:1.

[0058] S6: The active components of the auxiliary deodorizing agent, N,N-diethyl-4-aminobenzaldehyde, 4,4'-methylenebis(N-phenylmaleimide), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate isooctyl ester, and 3,5-di-tert-butyl-4-hydroxybenzoic acid, are mixed in equal proportions and dispersed in 1-hydroxyethyl-carboxymethyl-alkylimidazoline. The mixture is stirred at 400 rpm at room temperature until all the solids are dissolved. Then, the modified slow-release deodorizing microcapsules prepared in S5 are added, and stirring is continued for 1 hour to obtain the deodorizing asphalt additive. The mass ratio of the modified slow-release deodorizing microcapsules, the auxiliary deodorizing agent, and 1-hydroxyethyl-carboxymethyl-alkylimidazoline is 1:1:2.

[0059] Furthermore, heat 100 parts of No. 70 Grade A base asphalt to 143°C, add 8 parts of odor-neutralizing asphalt additive at 500 rpm, and stir for 2 hours to obtain odor-neutralizing asphalt.

[0060] Example 2

[0061] Except that the mass ratio of sol to emulsion is 1:1, the other steps are the same as in Example 1.

[0062] Example 3

[0063] Except that the mass ratio of sol to emulsion is 1:4, the other steps are the same as in Example 1.

[0064] Example 4

[0065] Except that the amount of base bitumen used is changed to 200 parts, the rest of the steps are the same as in Example 1.

[0066] Example 5

[0067] Except that the dispersant is dodecyl dimethyl betaine, the other steps are the same as in Example 1.

[0068] Example 6

[0069] Except for the core material solution, which is a mixture of p-methoxybenzaldehyde, citronellal, isobutyl benzoate, linaloyl isobutyrate, benzyl alcohol, nerol, and α-phellandrene in equal proportions, the rest is the same as in Example 1.

[0070] Example 7

[0071] Except for the auxiliary deodorizing agent, which is a mixture of 3-methoxy-4-hydroxybenzaldehyde, NN-diethylmaleimide, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] in equal proportions, the rest is the same as in Example 6.

[0072] Example 8

[0073] Except that the core material solution is a mixture of 2-methyl-3-(3,4-methylenedioxyphenyl)propionaldehyde, hydroxycitronellol, benzyl benzoate, citronellol acetate, β-phenylethanol, ionol, and α-pinene in equal proportions, and the auxiliary deodorizing agent is a mixture of 3,4-methylenedioxybenzaldehyde, tris(2-maleimide ethyl)amine, isooctyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 3-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylic acid in equal proportions, the rest is the same as in Example 1.

[0074] Example 9

[0075] Except that the mass ratio of the modified sustained-release deodorizing microcapsules, the auxiliary deodorizing agent, and 1-hydroxyethyl-carboxymethyl-alkylimidazoline is 3:3:2, the rest is the same as in Example 8.

[0076] Example 10

[0077] Except that the mass ratio of the modified sustained-release deodorizing microcapsules, the auxiliary deodorizing agent, and 1-hydroxyethyl-carboxymethyl-alkylimidazoline is 1:1:6, the rest is the same as in Example 8.

[0078] Comparative Example 1

[0079] S1: The deodorizing agent mixture is prepared by mixing cinnamaldehyde, citral, ethyl benzoate, geraniol acetate, benzyl alcohol, geraniol and α-terpinene in a certain mass ratio and stirring at 400 rpm for 30 min at 50°C.

[0080] S2: The active components of the auxiliary deodorizing agent, N,N-diethyl-4-aminobenzaldehyde, 4,4'-methylenebis(N-phenylmaleimide), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate isooctyl ester, and 3,5-di-tert-butyl-4-hydroxybenzoic acid, are mixed in equal proportions and dispersed in 1-hydroxyethyl-carboxymethyl-alkylimidazoline. After the solid is completely dissolved, the deodorizing agent mixture prepared in S1 is added, and stirring is continued for 1 hour to obtain the deodorizing asphalt additive. The mass ratio of the deodorizing agent mixture, the auxiliary deodorizing agent, and 1-hydroxyethyl-carboxymethyl-alkylimidazoline is 0.5:1:2.

[0081] Furthermore, 100 parts of base asphalt are heated to 143°C, and 7 parts of odor-neutralizing asphalt additive are added at 500 rpm. Stirring for 2 hours will yield odor-neutralizing asphalt.

[0082] Comparative Example 2

[0083] S1: The core material mixture is prepared by mixing cinnamaldehyde, citral, ethyl benzoate, geraniol acetate, benzyl alcohol, geraniol and α-terpinene in equal proportions and stirring at 400 rpm for 30 min at 50°C.

[0084] S2: Add hexadecyltrimethylammonium bromide and distilled water to the above core material mixture, and continue stirring at 800 rpm for 4 hours at 50°C to form a homogeneous emulsion. The mass ratio of the core material mixture, hexadecyltrimethylammonium bromide and distilled water is 5:1:34.

[0085] S3: Take tetraethyl orthosilicate, distilled water and ethanol and stir at 400 rpm for 4 hours at 50℃ to obtain a sol. The mass ratio of tetraethyl orthosilicate, distilled water and ethanol is 1:1:2.

[0086] S4: The prepared sol is added dropwise to the emulsion obtained in S2. The mass ratio of sol to core material mixture is 4:1. At the same time, ammonia water is added dropwise to adjust the pH of the system to 9. The mixture is stirred at 400 rpm for 3 hours at 50°C. Then the stirring is turned off and the mixture is aged at 50°C for 12 hours. After centrifugation and freeze-drying, sustained-release deodorizing microcapsules are obtained.

[0087] S5: Add the sustained-release deodorizing microcapsules prepared in S4 to deionized water, adjust the pH of the system to 10 using ammonia, then add γ-aminopropyltriethoxysilane, and stir for 2 hours at 70°C and 200 rpm. After stirring, wash, filter and freeze dry to obtain the modified sustained-release deodorizing microcapsules. The reaction process is carried out under nitrogen protection throughout. The mass ratio of sustained-release deodorizing microcapsules, γ-aminopropyltriethoxysilane and deionized water is 2:1:30.

[0088] S6: The odor-neutralizing asphalt additive is prepared by mixing the dispersant 1-hydroxyethyl-carboxymethyl-alkylimidazoline with the modified sustained-release odor-neutralizing microcapsules prepared in S5 at room temperature and stirring at 400 rpm for 1 hour. The mass ratio of the modified sustained-release odor-neutralizing microcapsules to 1-hydroxyethyl-carboxymethyl-alkylimidazoline is 1:2.

[0089] Furthermore, 100 parts of base asphalt are heated to 143°C, and 6 parts of odor-neutralizing asphalt additive are added at 500 rpm. Stirring for 2 hours will yield odor-neutralizing asphalt.

[0090] Comparative Example 3

[0091] S1: The core material mixture is prepared by mixing cinnamaldehyde, citral, ethyl benzoate, geraniol acetate, benzyl alcohol, geraniol and α-terpinene in equal proportions and stirring at 400 rpm for 30 min at 50°C.

[0092] S2: Add hexadecyltrimethylammonium bromide and distilled water to the above core material mixture, and continue stirring at 800 rpm for 4 hours at 50°C to form a homogeneous emulsion. The mass ratio of the core material mixture, hexadecyltrimethylammonium bromide and distilled water is 5:1:34.

[0093] S3: Take tetraethyl orthosilicate, distilled water and ethanol and stir at 400 rpm for 4 hours at 50℃ to obtain a sol. The mass ratio of tetraethyl orthosilicate, distilled water and ethanol is 1:1:2.

[0094] S4: The prepared sol is added dropwise to the emulsion obtained in S2. The mass ratio of sol to core material mixture is 4:1. At the same time, ammonia water is added dropwise to adjust the pH of the system to 9. The mixture is stirred at 400 rpm for 3 hours at 50°C. Then the stirring is turned off and the mixture is aged at 50°C for 12 hours. After centrifugation and freeze-drying, sustained-release deodorizing microcapsules are obtained.

[0095] S5: The active components of the auxiliary deodorizing agent, N,N-diethyl-4-aminobenzaldehyde, 4,4'-methylenebis(N-phenylmaleimide), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate isooctyl ester, and 3,5-di-tert-butyl-4-hydroxybenzoic acid, are mixed in equal proportions and dispersed in 1-hydroxyethyl-carboxymethyl-alkylimidazoline. The mixture is stirred at 400 rpm at room temperature. After all the solids are dissolved, the slow-release deodorizing microcapsules prepared in S4 are added, and stirring is continued for 1 hour to obtain the long-lasting deodorizing asphalt additive. The mass ratio of the slow-release deodorizing microcapsules, the auxiliary deodorizing agent, and 1-hydroxyethyl-carboxymethyl-alkylimidazoline is 1:1:2.

[0096] Heat 100 parts of base asphalt to 143°C, add 8 parts of odor-neutralizing asphalt additive at 500 rpm, and stir for 2 hours to obtain odor-neutralizing asphalt.

[0097] Comparative Example 4:

[0098] S1: The core material mixture is prepared by mixing cinnamaldehyde, citral, ethyl benzoate, geraniol acetate, benzyl alcohol, geraniol and α-terpinene in equal proportions and stirring at 400 rpm for 30 min at 50°C.

[0099] S2: Add hexadecyltrimethylammonium bromide and distilled water to the above core material mixture, and continue stirring at 800 rpm for 4 hours at 50°C to form a homogeneous emulsion. The mass ratio of the core material mixture, hexadecyltrimethylammonium bromide and distilled water is 5:1:34.

[0100] S3: Take tetraethyl orthosilicate, distilled water and ethanol and stir at 400 rpm for 4 hours at 50℃ to obtain a sol. The mass ratio of tetraethyl orthosilicate, distilled water and ethanol is 1:1:2.

[0101] S4: The prepared sol is added dropwise to the emulsion obtained in S2. The mass ratio of sol to core material mixture is 4:1. At the same time, ammonia water is added dropwise to adjust the pH of the system to 9. The mixture is stirred at 400 rpm for 3 hours at 50°C. Then the stirring is turned off and the mixture is aged at 50°C for 12 hours. After centrifugation and freeze-drying, sustained-release deodorizing microcapsules are obtained.

[0102] S5: Add the sustained-release deodorizing microcapsules prepared in S4 to deionized water, adjust the pH of the system to 10 using ammonia, then add γ-aminopropyltriethoxysilane, and stir for 2 hours at 70°C and 200 rpm. After stirring, wash, filter and freeze dry to obtain the modified sustained-release deodorizing microcapsules. The reaction process is carried out under nitrogen protection throughout. The mass ratio of sustained-release deodorizing microcapsules, γ-aminopropyltriethoxysilane and deionized water is 2:1:30.

[0103] S6: An auxiliary deodorizing agent prepared by mixing N,N-diethyl-4-aminobenzaldehyde, 4,4'-methylenebis(N-phenylmaleimide), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate isooctyl ester, and 3,5-di-tert-butyl-4-hydroxybenzoic acid in equal proportions can be mixed with modified slow-release deodorizing microcapsules to obtain a deodorizing asphalt additive, wherein the mass ratio of modified slow-release deodorizing microcapsules to auxiliary deodorizing agent is 1:1;

[0104] Furthermore, heat 100 parts of base asphalt to 143°C, add 4 parts of odor-neutralizing asphalt additive at 500 rpm, and stir for 2 hours to obtain odor-neutralizing asphalt.

[0105] Test case

[0106] Sulfides are the main cause of the pungent odor in asphalt fumes. Odorless asphalt was prepared using Sinopec Donghai brand No. 70 Grade A asphalt. Examples 1-10 and Comparative Examples 1-4 were thermally stored at 143°C for 0, 7, and 30 days, respectively. Then, equal masses of the stored asphalt samples were transferred to a sealed container, and fumes were enriched at 163°C for 4 hours. After enrichment, the gas in the sealed container was collected, and the sulfide content was tested using gas chromatography. The data are shown in Table 1 below.

[0107] Table 1 Gas Chromatography Sulfide Test Data

[0108]

[0109] The conventional properties of asphalt were tested, and the data obtained are shown in Table 2 below.

[0110] Table 2. Test data for conventional properties of asphalt

[0111] .

Claims

1. A neutralizing asphalt additive, characterized in that... The following components are included in parts by weight: 1-5 parts of auxiliary deodorizing agent; Modified sustained-release deodorizing microcapsules, 1-5 parts; 1-10 parts of dispersant; The mass ratio of the auxiliary deodorizing agent to the modified sustained-release deodorizing microcapsules is 1:1; The auxiliary deodorizing agent is selected from one or more of the following: solid aldehydes with a boiling point greater than 250°C, amide compounds with a boiling point greater than 250°C, and antioxidants with a boiling point greater than 300°C. The solid aldehydes with a boiling point greater than 250°C are selected from one or more of N,N-diethyl-4-aminobenzaldehyde, 3-methoxy-4-hydroxybenzaldehyde, and 3,4-methylenedioxybenzaldehyde. The amide compounds with boiling points greater than 250°C are selected from one or more of 4,4'-methylenebis(N-phenylmaleimide), NN-diethylmaleimide, N-phenylmaleimide, succinimide 6-(maleimideo)hexanoate, tris(2-maleimideoethyl)amine, and N-(2-hydroxyethyl)maleimide. The antioxidant with a boiling point greater than 300°C is an ester antioxidant and / or a carboxylic acid antioxidant; The modified sustained-release deodorizing microcapsule comprises a shell material and a core material, wherein the shell material is silicon dioxide and the core material is selected from one or more of aldehydes, esters, alcohols, and terpenes; The aldehydes are selected from aromatic aldehydes with a boiling point greater than 230°C and / or terpene aldehydes with a boiling point greater than 170°C. The esters are selected from benzoic acid esters with a boiling point greater than 210°C and / or terpene alcohol esters with a boiling point greater than 190°C. The alcohols are selected from aromatic alcohols with a boiling point greater than 200°C and / or terpene alcohols with a boiling point greater than 160°C. The terpenes are cyclic terpenes with a boiling point greater than 150℃.

2. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The ester antioxidants are selected from one or more of the following: β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate isooctyl ester, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

3. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The carboxylic acid antioxidant is selected from one or more of 3,5-di-tert-butyl-4-hydroxybenzoic acid, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylic acid, 3-(3,5-dimethyl-4-hydroxyphenyl)acrylic acid, 3-(3,5-dimethoxy-4-hydroxyphenyl)acrylic acid, and 3-(3-methoxy-4-hydroxyphenyl)acrylic acid.

4. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The aromatic aldehyde with a boiling point greater than 230°C is selected from one or more of cinnamaldehyde, p-methoxybenzaldehyde, and 2-methyl-3-(3,4-methylenedioxyphenyl)propanal; the terpene aldehyde with a boiling point greater than 170°C is selected from one or more of citral, citronellol, and hydroxycitronellol.

5. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The benzoic acid ester with a boiling point greater than 210°C is selected from one or more of ethyl benzoate, isobutyl benzoate, isoamyl benzoate, and benzyl benzoate; the terpene alcohol ester with a boiling point greater than 190°C is selected from one or more of geraniol acetate, linalool isobutyrate, citronellol acetate, or citronellol isobutyrate.

6. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The aromatic alcohol with a boiling point greater than 200°C is selected from one or more of benzyl alcohol and β-phenylethanol; the terpene alcohol with a boiling point greater than 160°C is selected from one or more of geraniol, nerol, ionol, and myrceneol.

7. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The terpenes are selected from one or more of α-terpinene, α-phellandrene, α-pinene, β-caryophyllene, and thujone.

8. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The mass ratio of the shell material to the core material of the modified sustained-release deodorizing microcapsule is 1:(0.5~2).

9. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The modified sustained-release deodorizing microcapsules have a nanostructure with a particle size of 300-800 nm.

10. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The preparation method of the modified sustained-release deodorizing microcapsules includes the following steps: S1: Mix the core material raw materials in equal mass ratio, add hexadecyltrimethylammonium bromide and distilled water and stir for a period of time to obtain a homogeneous emulsion; S2: A sol is prepared by mixing tetraethyl orthosilicate, distilled water and ethanol and stirring for a period of time. S3: Add the sol obtained in S2 to the emulsion obtained in S1, and add ammonia water to adjust the pH of the system to 9-10. Stir for a period of time until the reaction system turns grayish-white, then turn off the stirring and age at a constant temperature for a period of time. Filter, wash and freeze-dry the bottom solid powder to obtain sustained-release deodorizing microcapsules. S4: Add the sustained-release deodorizing microcapsules obtained in S3 to deionized water, adjust the pH of the system to 9-10 using ammonia, then add γ-aminopropyltriethoxysilane, stir for a period of time, wash, filter and freeze-dry the solid powder in the system to obtain the modified sustained-release deodorizing microcapsules. The entire reaction process is carried out under nitrogen protection.

11. The odor-neutralizing asphalt additive according to claim 10, characterized in that: The stirring temperature in step S1 is 40-65℃, the stirring speed is 600-800rpm, and the stirring time is 2-4h.

12. The odor-neutralizing asphalt additive according to claim 10, characterized in that: In step S1, the mass ratio of distilled water to core material mixture is (5-10):1, and the mass ratio of emulsifier to core material mixture is (0.1-0.5):

1.

13. The odor-neutralizing asphalt additive according to claim 10, characterized in that: The stirring time in step S2 is 3-5 hours, the stirring speed is 300-600 rpm, and the stirring temperature is 40-60℃.

14. The odor-neutralizing asphalt additive according to claim 10, characterized in that: In step S2, the mass ratio of tetraethyl orthosilicate to distilled water is 1:0.5-2, and the mass ratio of distilled water to ethanol is 1:0.5-2.

15. The odor-neutralizing asphalt additive according to claim 10, characterized in that: The stirring temperature in step S3 is 40-65℃, the stirring speed is 300-600rpm, and the stirring time is 2-4h.

16. The odor-neutralizing asphalt additive according to claim 10, characterized in that: The mass ratio of sol to emulsion in step S3 is 1:(0.1-10).

17. The odor-neutralizing asphalt additive according to claim 10, characterized in that: The stirring time in step S4 is 2-4 hours, the stirring speed is 100-200 rpm, and the stirring temperature is 60-80℃.

18. The odor-neutralizing asphalt additive according to claim 10, characterized in that: The mass ratio of the sustained-release deodorizing microcapsules to γ-aminopropyltriethoxysilane in step S4 is (2-5):

1.

19. The odor-neutralizing asphalt additive according to claim 1, characterized in that: The dispersant is dodecyl dimethyl betaine and / or 1-hydroxyethyl-carboxymethyl-alkyl imidazoline.

20. A method for preparing the odor-neutralizing asphalt additive according to any one of claims 1 to 19, characterized in that... The process includes the following: mixing auxiliary deodorizing agent and dispersant, and after the auxiliary deodorizing agent has completely dissolved, adding modified slow-release deodorizing microcapsules and mixing evenly to obtain deodorizing asphalt additive.

21. A neutral-odor asphalt composition comprising, by weight: 100-500 parts of base asphalt; and 5-30 parts of the neutral-odor asphalt additive as described in any one of claims 1 to 19.

22. The odor-neutralizing asphalt composition according to claim 21, characterized in that: The base asphalt is one of No. 50, No. 70 and No. 90 road asphalt.

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