A non-water-soluble asphalt release agent, a preparation method and application thereof

Abstract

The application provides a non-water-soluble asphalt separating agent and a preparation method and application thereof, and relates to the technical field of asphalt ductility separating agents. The asphalt separating agent is prepared from raw materials including the following components in mass fractions: vaseline 65-75 parts, silicon grease 10-15 parts, metal stearate 9-15 parts, hardening agent 2-8 parts, and surfactant 1-5 parts. The asphalt separating agent prepared by the application can replace traditional separating agents, solves the problems of inconvenient use, easy sliding, uneven brushing and poor adhesion of traditional asphalt low-temperature ductility separating agents, and has a simple preparation method.

Description

Technical Field

[0001] This invention relates to the field of asphalt ductility release agent technology, and in particular to a non-water-soluble asphalt release agent, its preparation method, and its application. Background Technology

[0002] In the asphalt ductility test, the heated asphalt sample needs to be poured into a specific mold and placed in a constant temperature water bath for 85–95 minutes. The bottom and side molds are removed before the ductility test. Therefore, to prevent the asphalt from sticking to the mold, a release agent needs to be applied to the inside of the bottom and side molds. Current methods use a mixture of two parts glycerol and one part talc (by weight) as the release agent. However, glycerol and talc are organic liquid and inorganic solid, respectively, and are incompatible systems with a density difference. They need to be thoroughly stirred before use to suspend the talc in the glycerol. Insufficient stirring will result in uneven dispersion of the talc, affecting the release effect. Furthermore, repeated application is required during the coating process to ensure uniform application of the release agent. Furthermore, because ordinary release agents contain a large proportion of glycerol, they are in a fluid state at room temperature, resulting in poor adhesion between the release agent and the mold. This is especially true for vertical side molds, where some of the release agent will slide and drip after application, causing it to peel off from the side mold and adhere to the asphalt sample, affecting the determination of test results. Additionally, traditional release agents contain large amounts of glycerol and talc. Glycerol is a water-soluble component, while talc is a water-insoluble component. When the mold coated with the release agent is placed in water, the glycerol in the release agent will dissolve into the constant temperature water bath. Since glycerol has a high viscosity, it will adhere to the surface of the water bath, while the talc will deposit at the bottom, causing inconvenience to the operation of the constant temperature water bath.

[0003] Currently, most of the asphalt release agents disclosed in the literature are applied to the field of asphalt mixtures, with the aim of preventing asphalt mixtures from sticking to mechanical equipment during construction. Since the mechanical equipment moves forward continuously, requiring constant spraying of release agent on the contact surface, the contact between the asphalt mixture and the equipment is brief, ranging from tens of seconds to several minutes. To facilitate spraying, the release agents used for asphalt mixtures are all in liquid form. The asphalt release agent disclosed in Chinese Patent Publication No. CN117551390A is prepared by reacting water, glycerin, vegetable oil, dimethyl silicone oil, and sodium polyoxyethylene ether sulfonate surfactant. Although it has a good release effect, it contains vegetable oil and water. Vegetable oil has a certain compatibility with asphalt, which can lead to a decrease in asphalt performance. However, the asphalt content in asphalt mixtures is only 5%-8%, so the impact on asphalt mixtures is small. But as a release agent for asphalt ductility testing, its liquid form will flow when applied to the mold surface, affecting the release effect. Moreover, the vegetable oil in it can enter the hot asphalt, affecting the accuracy of the test data. In addition, it contains water. When testing asphalt ductility, the temperature of the asphalt sample is higher than 130°C, which will cause the water in the release agent to evaporate, causing the asphalt to stick to the mold or form cavities inside the asphalt, affecting the test results. Chinese patent CN105111936A discloses an asphalt release agent made from glycerol, vegetable oil, water, preservatives, and fragrances through reaction and shear emulsification. It has advantages such as water solubility, good stability, and good release effect. Its principle is based on the dissolving effect of the vegetable oil it contains on asphalt, forming a sliding surface that achieves the release effect. However, when used as an asphalt ductility release agent, the vegetable oil it contains has a certain compatibility with asphalt, which can affect the accuracy of asphalt ductility measurement. Furthermore, the release agent is water-soluble, while asphalt ductility measurement requires a constant-temperature water bath, which can cause the release agent to be lost, affecting the asphalt ductility measurement. Summary of the Invention

[0004] In view of this, the present invention prepares a novel non-water-soluble release agent to replace the traditional asphalt ductility release agent, which solves the shortcomings of the traditional asphalt ductility release agent, such as inconvenience in use, easy slippage, uneven application and poor adhesion, and the preparation method is simple.

[0005] One of the objectives of this invention is to provide a non-water-soluble asphalt release agent.

[0006] The second objective of this invention is to provide a method for preparing the non-water-soluble asphalt release agent.

[0007] A third objective of this invention is to provide an application of this non-water-soluble asphalt release agent.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0009] In a first aspect, the present invention provides a non-water-soluble asphalt release agent, which is prepared from raw materials comprising the following parts by weight: 65-75 parts petrolatum, 10-15 parts silicone grease, 9-15 parts metal stearate, 2-8 parts hardener, and 1-5 parts surfactant.

[0010] In some embodiments, the stearate metal salt is one or both of sodium stearate and potassium stearate, and its effective ingredient content is not less than 99%.

[0011] In some embodiments, the hardener is microcrystalline wax with a softening point of 80–90°C. Its addition to the release agent improves the high-temperature performance of the release agent and allows the release agent to soften and flow when the asphalt sample is poured into the mold due to the high temperature of the sample. This allows the release agent to fill the mold with the flow of the sample, thus providing better release.

[0012] In some embodiments, the surfactant is a nonionic surfactant OP-10.

[0013] Typical but non-restrictive weights of Vaseline are, for example, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, and 75 parts.

[0014] Typical, but not limiting, parts by weight of silicone grease are, for example, 10, 11, 12, 13, 14, or 15 parts.

[0015] Typical, but not limiting, parts by mass of metal stearate salts are, for example, 9, 10, 11, 12, 13, 14, or 15 parts.

[0016] Typical, but not limiting, parts by weight of the hardener are, for example, 2, 3, 4, 5, 6, 7, or 8 parts.

[0017] Typical, but not limiting, parts by mass of surfactants are, for example, 1, 2, 3, 4, or 5 parts.

[0018] Secondly, the present invention provides a method for preparing the above-mentioned asphalt release agent, comprising the following steps:

[0019] (1) According to the mass fraction of raw materials, first place the petrolatum and metal stearate in a constant temperature to melt the metal stearate, and then mechanically stir to make the melted metal stearate evenly dispersed in the petrolatum;

[0020] (2) Add surfactant and hardener in the order of raw material mass parts, continue stirring, add silicone grease in the order of raw material mass parts, and continue stirring to obtain non-water-soluble asphalt release agent.

[0021] In some embodiments, in step (1), constant temperature melting is carried out in an oven at a temperature of 100-120°C for a time of 40-60 minutes.

[0022] In some embodiments, in step (1), the temperature of mechanical stirring is 110-130°C, the speed of mechanical stirring is 200-500 r / min, and the time of mechanical stirring is 10-30 min.

[0023] In some implementations, in step (2), the stirring time is continued for 30 to 40 minutes.

[0024] Thirdly, the present invention provides an application of the above-mentioned asphalt release agent in the determination of asphalt ductility.

[0025] Specifically, the asphalt release agent is applied to the inside of the bottom and side molds of the test mold.

[0026] Beneficial effects:

[0027] The present invention first premixes petrolatum and metal stearate in an oven, using high temperature to melt the solid metal stearate, and then uses mechanical stirring to evenly disperse the melted metal stearate in petrolatum. Since metal stearate is solid at room temperature while petrolatum is semi-solid, the addition of metal stearate increases the viscosity of petrolatum, causing it to solidify to a certain extent and overcoming the drawback of petrolatum's tendency to flow easily at room temperature. Simultaneously, the semi-solid nature of petrolatum provides flow and lubrication, resulting in good workability of the release agent at room temperature. Furthermore, its longer molecular chains provide good extensibility, ensuring easy sampling and application, as well as uniformity and continuity during application. Metal stearate also acts as an adhesive; when evenly dispersed in petrolatum, the molecular chains intertwine, increasing the viscosity of the release agent and forming a continuous network on the mold surface. This ensures the release agent adheres firmly to the mold surface, preventing it from slipping after application. Meanwhile, because stearic acid has a short molecular chain, its molecular chains have a certain degree of sliding, and with the help of the lubricating effect of petrolatum, the release agent can be evenly applied to the mold surface, thereby forming a dense release layer and ensuring the continuity of the coating effect.

[0028] Then, the surfactant and hardener are added sequentially. The addition of the surfactant promotes the dispersion of the hardener and improves the compatibility between the stearate metal salt and the hardener, preventing stratification after mixing and affecting the isolation effect. It also increases the lubricity between the molecular chains of the hardener and the stearate metal salt. When the hardener is added to the release agent, the microcrystalline wax quickly dissolves and disperses into the release agent. The long molecular chains of the microcrystalline wax unfold and intertwine under mechanical stirring, further intertwining with the molecular chains of the stearate metal salt. This forms a network structure with longer molecular chains and higher temperature resistance in the release agent, further curing the release agent and improving its temperature resistance. Simultaneously, the adhesive effect of the stearate metal salt increases adhesion to the mold, preventing the release agent on the mold surface from slipping off at high temperatures and affecting the isolation effect. Furthermore, mixing the hardener with petrolatum and the stearate metal salt further increases the viscosity of the release agent, and the lubricity of petrolatum increases the continuity and uniformity of the release agent application during brushing, solving the problems of poor flowability and adhesion inherent in the hardener itself. Furthermore, microcrystalline wax is used as a hardener. Since microcrystalline wax is a non-water-soluble component, when its molecular chains intertwine with the stearate metal salt molecular chains, it can reduce the water solubility of the stearate metal salt. Finally, the addition of silicone grease enhances the waterproofness of the release agent. Silicone grease contains a large amount of organosilicon oil, which is a strongly hydrophobic material. When added to the release agent, it is evenly dispersed in the release agent under mechanical stirring, forming hydrophobic regions within the release agent. Working together with microcrystalline wax, it prevents the stearate in the release agent from dissolving in water, giving the release agent good hydrophobicity. Being a non-water-soluble component, silicone grease also has a lubricating effect, working together with petrolatum to enhance the lubricity of the release agent.

[0029] Therefore, the asphalt release agent prepared by this invention can replace the traditional release agent, solving the shortcomings of traditional asphalt low-temperature ductility release agents, such as inconvenience in use, easy slippage, uneven application, and poor adhesion. Moreover, the preparation method is simple.

[0030] The present invention has been described in detail above; however, the above embodiments are merely illustrative in nature and are not intended to limit the invention. Furthermore, this document is not limited to the foregoing prior art or the invention itself, or to any theory described in the following embodiments. Detailed Implementation

[0031] The present invention will be further described below with reference to the embodiments. It should be noted that the following embodiments are provided for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0032] Unless otherwise specified, the raw materials, reagents, and methods used in the embodiments are all conventional raw materials, reagents, and methods in the art.

[0033] Vaseline, silicone grease (waterproof silicone grease), sodium stearate, and potassium stearate are from Sinopharm Group;

[0034] OP-10 is from Tianjin Kaixin Chemical Industry Co., Ltd., with a purity >99%.

[0035] The microcrystalline wax comes from Xinsheng Beeswax Factory in Dongguang County.

[0036] Example 1

[0037] A non-water-soluble asphalt release agent, by weight, is composed of: 67 parts petrolatum, 15 parts silicone grease, 11 parts sodium stearate, 5 parts microcrystalline wax, and 2 parts OP-10.

[0038] The preparation method of this asphalt release agent includes the following steps:

[0039] (1) Place petrolatum and sodium stearate in an oven at 110°C for 50 minutes to completely melt the sodium stearate; then stir at 120°C and 400 r / min for 25 minutes.

[0040] (2) Add OP-10 and microcrystalline wax in the order of weight, continue stirring for 30 minutes, then add silicone grease and continue stirring for 30 minutes to obtain the product.

[0041] Example 2

[0042] A non-water-soluble asphalt release agent, by mass parts, is composed of: 65 parts petrolatum, 10 parts silicone grease, 14 parts potassium stearate, 7 parts microcrystalline wax, and 4 parts OP-10.

[0043] The preparation method of this asphalt release agent is the same as in Example 1.

[0044] Example 3

[0045] A non-water-soluble asphalt release agent, by mass parts, is composed of: 69 parts petrolatum, 11 parts silicone grease, 9 parts sodium stearate, 8 parts microcrystalline wax, and 3 parts OP-10.

[0046] The preparation method of this asphalt release agent is the same as in Example 1.

[0047] Example 4

[0048] A non-water-soluble asphalt release agent, by mass parts, is composed of: 65 parts petrolatum, 13 parts silicone grease, 15 parts potassium stearate, 6 parts microcrystalline wax, and 1 part OP-10.

[0049] The preparation method of this asphalt release agent is the same as in Example 1.

[0050] Example 5

[0051] A non-water-soluble asphalt release agent, by mass parts, is composed of: 71 parts petrolatum, 10 parts silicone grease, 12 parts sodium stearate, 2 parts microcrystalline wax, and 5 parts OP-10.

[0052] The preparation method of this asphalt release agent is the same as in Example 1.

[0053] Example 6

[0054] A non-water-soluble asphalt release agent, by weight, is composed of: 75 parts petrolatum, 10 parts silicone grease, 11 parts sodium stearate, 2 parts microcrystalline wax, and 2 parts OP-10.

[0055] The preparation method of this asphalt release agent is the same as in Example 1.

[0056] Comparative Example 1

[0057] The separating agent was prepared by using glycerol and talc, with a mass ratio of glycerol to talc of 2:1.

[0058] Comparative Example 2

[0059] The preparation method for this comparative example is the same as that in Example 1, except that sodium stearate is not added.

[0060] Comparative Example 3

[0061] The preparation method for this comparative example is the same as that in Example 1, except that microcrystalline wax is not added.

[0062] Comparative Example 4

[0063] The preparation method for this comparative example is the same as that in Example 1, except that OP-10 is not added.

[0064] Comparative Example 5

[0065] The preparation method of this comparative example is the same as that of Example 1, the main difference being that OP-10 and microcrystalline wax are not added.

[0066] Comparative Example 6

[0067] The preparation method of this comparative example is the same as that of Example 1, the main difference being that OP-10 and sodium stearate are not added.

[0068] Comparative Example 7

[0069] The preparation method for this comparative example is the same as that in Example 1, the main difference being that no silicone grease is added.

[0070] Comparative Example 8

[0071] The preparation method of this comparative example is the same as that of Example 1, the main difference being that silicone grease and sodium stearate are not added.

[0072] Performance testing

[0073] (1) Observe the appearance of the release agent at 20℃.

[0074] (2) Adhesion (wall adhesion) is determined by the following method.

[0075] Select the side mold for asphalt ductility testing, weigh it, and record its weight as m1g; then apply asphalt release agent to the side mold of the ductility mold, weigh it, and record it as m2g; place the side mold coated with asphalt release agent in a 30℃ constant temperature oven for 60min, remove the side mold and measure its mass, record it as m3g, calculate the release agent residue rate N according to the following formula; heat the base asphalt to 130℃ and apply it to the side containing the release agent. After the asphalt cools to room temperature, peel the asphalt on the side mold surface from the mold and observe whether there is asphalt sample residue on the surface, thereby characterizing the adhesion between the release agent and the mold.

[0076]

[0077] The asphalt release agents prepared in the examples and comparative examples were tested according to the above-described testing methods, and the test data are shown in the table below.

[0078] (3) Coating continuity and uniformity test.

[0079] Place the bottom mold of the asphalt ductility test mold on a horizontal table. Take a certain amount of asphalt release agent, heat it to a fluid state, and use a brush to apply the hot release agent to the mold surface. Repeat this process 3 times. After cooling, observe whether the distribution of the release agent on the mold surface is uniform and continuous.

[0080] (4) Asphalt ductility performance test.

[0081] According to the standard method for determining matrix ductility JTG T0605-2011, the prepared release agent was used as the release agent for asphalt ductility determination. The ductility of the matrix asphalt was measured, and the data characterization was used to determine whether the prepared release agent had an adverse effect on the ductility of asphalt.

[0082] (5) Water solubility determination

[0083] Select a clean, constant-weight culture dish, denoted as M1g. Place 10g of the release agent on the coated culture dish, add distilled water to cover the dish, and let it stand at 10℃ for 120 minutes. Slowly pour out the distilled water from the culture dish, then place the dish containing the release agent in a vacuum oven at 60℃ to dry. After drying, measure the weight of the culture dish, denoted as M2g. Calculate the water solubility S of the release agent using the following formula:

[0084]

[0085] Table 1. Detection data from Examples 1-6

[0086]

[0087] Table 2. Detection data of comparative examples 1-8

[0088]

[0089] Note: - indicates that the test cannot be performed.

[0090] The comparison of the test results of the examples and comparative examples shows that the non-water-soluble asphalt release agent prepared by the present invention utilizes the synergistic and interrelated effects among the components of petrolatum, silicone grease, metal stearate, hardener, and surfactant (for example, compared with Comparative Example 5, Comparative Examples 3, 4, and Example 1 demonstrate the synergistic effect of OP-10 and microcrystalline wax; compared with Comparative Example 6, Comparative Examples 2, 4, and Example 1 demonstrate the synergistic effect of OP-10 and stearate; compared with Comparative Example 8, Comparative Examples 2, 7, and Example 1 demonstrate that silicone grease solves the water solubility problem of sodium stearate). This solves the shortcomings of traditional asphalt ductility release agents, such as inconvenience in use, easy slippage, uneven application, and poor adhesion. Moreover, the preparation method is simple, achieving a replacement for traditional asphalt ductility release agents. Furthermore, the data fluctuations in the asphalt ductility performance measurements are all within the error range, so there will be no negative impact on the asphalt ductility.

[0091] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and substance defined by the claims of the present invention; and such modifications or substitutions are still within the scope defined by the claims of the present invention.

Claims

1. A non-water-soluble asphalt release agent, characterized in that, It is prepared from the following raw materials in parts by weight: 65-75 parts petrolatum, 10-15 parts silicone grease, 9-15 parts metal stearate, 2-8 parts hardener, and 1-5 parts surfactant. The preparation method of the non-water-soluble asphalt release agent includes the following steps: (1) According to the mass fraction of raw materials, first place petrolatum and metal stearate in an oven at 100-120℃ for 40-60 minutes to melt the metal stearate. Then, mechanically stir at 110-130℃ and 200-500r / min for 10-30 minutes to evenly disperse the melted metal stearate in petrolatum. (2) Add surfactant and hardener in the order of raw material mass parts, continue stirring for 30-40 minutes, add silicone grease in the order of raw material mass parts, and continue stirring for 30-40 minutes to obtain non-water-soluble asphalt release agent.

2. The non-water-soluble asphalt release agent according to claim 1, characterized in that, The stearate metal salt is selected from one or both of sodium stearate and potassium stearate.

3. The non-water-soluble asphalt release agent according to claim 1, characterized in that, The hardener is microcrystalline wax with a softening point of 80–90°C.

4. The non-water-soluble asphalt release agent according to claim 1, characterized in that, The surfactant is a nonionic surfactant, OP-10.

5. A method for preparing the non-water-soluble asphalt release agent according to any one of claims 1-4, characterized in that, The steps include the following: (1) According to the mass fraction of raw materials, first place petrolatum and metal stearate in an oven at 100-120℃ for 40-60 minutes to melt the metal stearate. Then, mechanically stir at 110-130℃ and 200-500r / min for 10-30 minutes to evenly disperse the melted metal stearate in petrolatum. (2) Add surfactant and hardener in the order of raw material mass parts, continue stirring for 30-40 minutes, add silicone grease in the order of raw material mass parts, and continue stirring for 30-40 minutes to obtain non-water-soluble asphalt release agent.

6. The application of the non-water-soluble asphalt release agent according to any one of claims 1-4 in the determination of asphalt ductility.

7. The application according to claim 6, characterized in that, The non-water-soluble asphalt release agent is applied to the inside of the bottom and side molds of the test mold.

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