Water-insoluble asphalt separant as well as preparation method and application thereof

Abstract

The invention provides a water-insoluble asphalt separant as well as a preparation method and application thereof, and relates to the technical field of asphalt ductility separants. The asphalt separant is prepared from the following raw materials in parts by mass: 65-75 parts of vaseline, 10-15 parts of silicone grease, 9-15 parts of stearic acid metal salt, 2-8 parts of a hardening agent and 1-5 parts of a surfactant. The prepared asphalt separant can replace a traditional separant, the defects that a traditional asphalt low-temperature ductility separant is inconvenient to use, prone to sliding off, uneven in brushing and poor in adhesion are overcome, and the preparation method is simple.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt ductility release agents, and in particular to a water-insoluble asphalt release agent and a preparation method and application thereof. Background Art

[0002] During the asphalt ductility measurement process, the heated asphalt sample needs to be poured into a specific mold and placed in a constant temperature water bath for 85 to 95 minutes. The bottom mold and side molds must be removed before the measurement to perform the ductility measurement. Therefore, in order to prevent the asphalt from sticking to the mold, an isolation agent needs to be applied to the inner side of the bottom mold and the side mold. In the existing measurement method, a mixture of two parts of glycerin and one part of talcum powder (by weight) is used as an isolation agent. However, glycerin and talcum powder are respectively organic liquids and inorganic solids. The two are incompatible systems and have a density difference. They need to be fully stirred before use so that the talcum powder is suspended in the glycerin. If the stirring is not sufficient, the talcum powder cannot be evenly dispersed, affecting the isolation effect. At the same time, during the brushing process, it is necessary to brush repeatedly to ensure the uniformity of the brushing of the isolation agent. In addition, since the proportion of glycerin in common release agents is relatively large, the release agents are in a flowing state at room temperature, resulting in poor adhesion between the release agent and the mold. Especially for the vertical side mold, part of the release agent will slide down and drip after the release agent is applied, causing the release agent to peel off from the side mold, causing the side mold to adhere to the asphalt sample, affecting the determination of the test results. At the same time, traditional release agents contain a large amount of glycerin and talcum powder. Glycerin is a water-soluble component, and talcum powder is a non-water-soluble component. When the mold coated with the release agent is placed in water, the glycerin in the release agent will dissolve into the constant temperature water bath, and the glycerin has a high viscosity, and then it will adhere to the surface of the constant temperature water bath, while the talcum powder will be deposited at the bottom of the water bath, which brings inconvenience to the operation of the constant temperature water bath.

[0003] At present, most of the asphalt isolation agents disclosed in the literature are used in the field of asphalt mixtures, and their purpose is to prevent the asphalt mixture from sticking to mechanical equipment during the construction process. Since the operation of mechanical equipment is constantly moving forward, it is necessary to continuously spray isolation agents on the contact surface between the two. Therefore, the contact between the asphalt mixture and the mechanical equipment is short-term, from tens of seconds to several minutes. In order to facilitate spraying, the isolation agents used in the asphalt mixture are all in liquid state. The asphalt isolation agent disclosed in the Chinese patent with publication number CN117551390A is prepared by reaction of water, glycerin, vegetable oil, dimethyl silicone oil and sodium polyoxyethylene ether sulfonate surfactant. Although it has a good isolation effect, it contains vegetable oil and water. Vegetable oil has a certain compatibility with asphalt, which will lead to a decrease in asphalt performance. However, the content of asphalt in the asphalt mixture is only 5%-8%, so the impact on the asphalt mixture is small. However, as an isolation agent for asphalt ductility measurement, the liquid isolation agent is applied to the mold surface and will flow, affecting the isolation effect. The vegetable oil therein will enter the hot asphalt, affecting the accuracy of the measurement data. In addition, it contains water inside. When measuring the ductility of asphalt, the temperature of the asphalt sample is higher than 130°C, which will cause the volatilization of the water in the isolation agent, causing the asphalt to adhere to the mold or form a cavity inside the asphalt, affecting the measurement result. The asphalt isolation agent disclosed in the Chinese patent with publication number CN105111936A uses propylene glycol, vegetable oil, water, preservatives and fragrances as raw materials, and is prepared by reaction and shear emulsification. It has the advantages of being soluble in water, having good stability and good isolation effect. The principle is to use the vegetable oil contained in it to dissolve the asphalt and form a sliding surface, thereby achieving the isolation effect. However, when it is used as an asphalt ductility isolation agent, the vegetable oil it contains has a certain compatibility with asphalt, which will affect the accuracy of the asphalt ductility measurement. In addition, the isolation agent can be soluble in water, and the asphalt ductility measurement needs to be placed in a constant temperature water bath, which will cause the loss of the isolation agent and affect the asphalt ductility measurement. Summary of the invention

[0004] In view of this, the present invention prepares a new type of non-water-soluble isolation agent to replace the traditional asphalt ductility isolation agent, thereby solving the shortcomings of the traditional asphalt ductility isolation agent such as inconvenient use, easy slipping, uneven coating and poor adhesion, and the preparation method is simple.

[0005] One of the purposes of the present invention is to provide a water-insoluble asphalt release agent.

[0006] The second purpose of the present invention is to provide a method for preparing the non-water-soluble asphalt isolation agent.

[0007] The third purpose of the present invention is to provide an application of the non-water-soluble asphalt isolation agent.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

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

[0010] In some embodiments, the metal stearate is one or both of sodium stearate and potassium stearate, and the content of active ingredients thereof is not less than 99%.

[0011] In some embodiments, the hardener is microcrystalline wax, and its softening point is 80-90° C. When added to the release agent, it can not only improve the high temperature performance of the release agent, but also make the release agent soften and flow due to the high temperature sample when the asphalt sample is poured into the mold, and fill the mold with the flow of the sample, thereby playing a better isolation role.

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

[0013] Typical but non-limiting mass fractions of petrolatum are, for example, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75 parts.

[0014] Typical but non-limiting weight fractions of silicone grease are, for example, 10, 11, 12, 13, 14, or 15 parts by weight.

[0015] Typical but non-limiting weight fractions of metal stearate are, for example, 9, 10, 11, 12, 13, 14, 15 parts.

[0016] Typical but non-limiting weight fractions of the hardener are, for example, 2, 3, 4, 5, 6, 7, 8 parts.

[0017] Typical but non-limiting weight fractions of surfactant are, for example, 1, 2, 3, 4, or 5 parts.

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

[0019] (1) placing vaseline and metal stearate at a constant temperature according to the mass fraction of the raw materials to melt the metal stearate, and then mechanically stirring to uniformly disperse the melted metal stearate in the vaseline;

[0020] (2) Add a surfactant and a hardener in order according to the mass fraction of the raw materials, continue stirring, and then add silicone grease in order according to the mass fraction of the raw materials, continue stirring to obtain a water-insoluble asphalt release agent.

[0021] In some embodiments, in step (1), constant temperature melting is performed in an oven, the temperature of the constant temperature melting is 100 to 120° C., and the time of the constant temperature melting is 40 to 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 embodiments, in step (2), the stirring is continued for 30 to 40 minutes.

[0024] In a third aspect, the present invention provides an application of the above-mentioned asphalt isolation agent in the determination of asphalt ductility.

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

[0026] Beneficial effects:

[0027] The invention firstly premixes vaseline and stearic acid metal salt in an oven, melts the solid stearic acid metal salt by high temperature, and then uniformly disperses the melted stearic acid metal salt in the vaseline by mechanical stirring. Since metal stearate is solid at room temperature, while vaseline is semi-solid, the addition of metal stearate can increase the viscosity of vaseline and solidify it to a certain extent, thus solving the shortcoming of vaseline being easy to flow at room temperature. Meanwhile, semi-solid vaseline has the functions of flowing and lubricating, which makes the release agent have good workability at room temperature, and has a relatively long molecular chain, which makes the release agent have good extensibility, thus ensuring that the release agent is easy to sample and apply, and also ensuring the uniformity and continuity of the application during the use of the release agent. Metal stearate has an adhesive effect. When metal stearate is evenly dispersed in vaseline, the molecular chains of the metal stearate are entangled with each other, thus increasing the viscosity of the release agent, so that the release agent forms a continuous network on the mold surface, thus ensuring that the release agent can firmly adhere to the mold surface and preventing the release agent from slipping after application. At the same time, since the molecular chain of stearic acid is relatively short, there is a certain degree of sliding between its molecular chains, and with the help of the lubricating effect of vaseline, the release agent can be evenly coated on the mold surface, thus forming a dense isolation layer to ensure the continuity of the coating effect.

[0028] Then add surfactant and hardener successively.The addition of surfactant can promote the dispersion of hardener, and improve the compatibility between metal stearate and hardener, prevent the two from stratification after mixing, affect isolation effect, and can increase the lubricity between the molecular chain of hardener and the molecular chain of metal stearate simultaneously.When hardener is added in isolation agent, microcrystalline wax can dissolve and be dispersed in isolation agent quickly, the molecular long chain in microcrystalline wax is launched, and is intertwined with each other under the effect of mechanical stirring, and is further intertwined with the molecular chain of metal stearate, forms the network structure with longer molecular chain and higher temperature resistance in isolation agent, makes isolation agent further solidify, improves the temperature resistance of isolation agent, utilizes the bonding effect of metal stearate simultaneously, can increase the adhesion between mold, prevent the isolation agent on mold surface from slipping when temperature is high, affect isolation effect, simultaneously hardener is mixed with vaseline, metal stearate, can further increase the viscosity of isolation agent, and utilizes the lubricity of vaseline, increases the continuity and uniformity of isolation agent brushing in brushing process, solves the problem of poor fluidity and poor adhesion brought by hardener itself. In addition, microcrystalline wax is used as a hardener. Since microcrystalline wax is a non-water-soluble component, when its molecular chain is entangled with the molecular chain of metal stearate, the water solubility of metal stearate can be reduced. Finally, the addition of silicone grease can improve the waterproofness of the release agent. Silicone grease contains a large amount of organic silicone oil inside, which is a strong hydrophobic material. When it is added to the release agent, it is evenly dispersed in the release agent under the action of mechanical stirring, forming a hydrophobic area in the release agent, and working together with microcrystalline wax, it can prevent the stearate in the release agent from dissolving in water, and can give the release agent good hydrophobicity. It is a non-water-soluble component. At the same time, silicone grease also has a lubricating effect, and works together with vaseline to improve the lubricity of the release agent.

[0029] Therefore, the asphalt isolation agent prepared by the present invention can replace the traditional isolation agent, solve the shortcomings of the traditional asphalt low-temperature ductility isolation agent, such as inconvenient use, easy slipping, uneven coating and poor adhesion, and the preparation method is simple.

[0030] The present invention has been described in detail above, but the above embodiments are only illustrative in nature and are not intended to limit the present invention. In addition, this article is not limited by any theory described in the above prior art or invention content or the following examples. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with examples. It should be noted that the following examples are provided for illustrative purposes only and do not constitute a limitation on the scope of protection claimed for the present invention.

[0032] Unless otherwise specified, the raw materials, reagents, methods, etc. used in the examples are conventional raw materials, reagents, methods in the art.

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

[0034] OP-10 was from Tianjin Kaixin Chemical Industry Co., Ltd., purity >99%;

[0035] Microcrystalline wax comes from Dongguang County Xinsheng Beeswax Factory.

[0036] Example 1

[0037] A water-insoluble asphalt release agent comprises, by weight, 67 parts of vaseline, 15 parts of silicone grease, 11 parts of sodium stearate, 5 parts of microcrystalline wax and 2 parts of OP-10.

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

[0039] (1) Vaseline and sodium stearate were placed in an oven at 110° C. for 50 minutes according to weight, and the temperature was kept constant to allow the sodium stearate to completely melt; and then stirred at 120° C. and a stirring speed of 400 r / min for 25 minutes.

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

[0041] Example 2

[0042] A water-insoluble asphalt release agent comprises, by weight, 65 parts of vaseline, 10 parts of silicone grease, 14 parts of potassium stearate, 7 parts of microcrystalline wax and 4 parts of OP-10.

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

[0044] Example 3

[0045] A water-insoluble asphalt release agent comprises, by weight, 69 parts of vaseline, 11 parts of silicone grease, 9 parts of sodium stearate, 8 parts of microcrystalline wax and 3 parts of OP-10.

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

[0047] Example 4

[0048] A water-insoluble asphalt release agent comprises, by weight, 65 parts of vaseline, 13 parts of silicone grease, 15 parts of potassium stearate, 6 parts of microcrystalline wax and 1 part of OP-10.

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

[0050] Example 5

[0051] A water-insoluble asphalt release agent comprises, by weight, 71 parts of vaseline, 10 parts of silicone grease, 12 parts of sodium stearate, 2 parts of microcrystalline wax and 5 parts of OP-10.

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

[0053] Example 6

[0054] A water-insoluble asphalt release agent comprises, by weight, 75 parts of vaseline, 10 parts of silicone grease, 11 parts of sodium stearate, 2 parts of microcrystalline wax and 2 parts of OP-10.

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

[0056] Comparative Example 1

[0057] The isolation agent is prepared by using glycerin and talcum powder, and the mass ratio of glycerin to talcum powder is 2:1.

[0058] Comparative Example 2

[0059] The preparation method of this comparative example is the same as that of Example 1, the main difference being that sodium stearate is not added.

[0060] Comparative Example 3

[0061] The preparation method of this comparative example is the same as that of Example 1, the main difference being that no microcrystalline wax is added.

[0062] Comparative Example 4

[0063] The preparation method of this comparative example is the same as that of Example 1, the main difference being 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 of this comparative example is the same as that of 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°C.

[0074] (2) Adhesion (sticking to the wall) was measured by the following method.

[0075] Select the side mold for asphalt ductility measurement and weigh it, recorded as m1g; then apply asphalt isolation agent on the side mold of the ductility mold and weigh it, recorded as m2g; place the side mold coated with asphalt isolation agent in a constant temperature oven at 30℃ for 60min, take out the side mold and measure its mass, recorded as m3g, and calculate the isolation agent residual rate N according to the following formula; and heat the matrix asphalt to 130℃ and apply it to the side containing the isolation agent. After the asphalt is cooled to room temperature, peel off the asphalt on the surface of the side mold and the mold, and observe whether there is any asphalt sample remaining on the surface to characterize the adhesion between the isolation agent and the mold.

[0076]

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

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

[0079] Place the bottom mold of the asphalt ductility measurement mold on a horizontal table, take a certain amount of asphalt isolation agent, heat it to a fluid state, use a brush to apply the heat isolation agent to the mold surface, repeat 3 times, and observe whether the isolation agent distribution on the mold surface is uniform and continuous after cooling.

[0080] (4) Asphalt ductility performance test.

[0081] According to the standard method for matrix ductility determination JTG T0605-2011, the prepared isolation agent is used as an isolation agent for asphalt ductility determination, and the ductility of the matrix asphalt is measured. Through data characterization, it can be determined whether the prepared isolation agent has an adverse effect on the ductility of asphalt.

[0082] (5) Water solubility determination

[0083] Select a clean, constant-weight culture dish, recorded as M1g, take 10g of the isolation agent and place it on the dish, add distilled water to cover the dish, and place it in a 10°C environment for 120 minutes, slowly pour out the distilled water in the dish, and then place the dish in a vacuum oven at 60°C. After drying the water, measure the weight of the dish, recorded as M2g, and calculate the water solubility S of the isolation agent according to the following formula:

[0084]

[0085] Table 1 Test data of Examples 1 to 6

[0086]

[0087] Table 2 Comparative Examples 1 to 8 Test Data

[0088]

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

[0090] By comparing the test results of the embodiments with those of the comparative examples, it can be seen that the water-insoluble asphalt isolation agent prepared by the present invention solves the shortcomings of the traditional asphalt ductility isolation agent, such as inconvenient use, easy slipping, uneven coating and poor adhesion, by utilizing the synergistic and interrelated effects among vaseline, silicone grease, metal stearate, hardener and surfactant components (such as comparative examples 3, 4 and Example 1 compared with comparative example 5, it can be proved that OP-10 and microcrystalline wax are synergistic; comparative examples 2, 4 and Example 1 compared with comparative example 6, it can be proved that OP-10 and stearate are synergistic; comparative examples 2, 7 and Example 1 compared with comparative example 8, it can be proved that silicone grease solves the water solubility of sodium stearate), and the preparation method is simple, and the traditional asphalt ductility isolation agent can be replaced. Moreover, through the measurement of the asphalt ductility performance, the data fluctuations are all within the error range, so there will be no negative impact on the asphalt ductility.

[0091] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents, without departing from the spirit and essence of the claims of the present invention; and these modifications or replacements are still within the scope defined by the claims of the present invention.

Claims

1. A water-insoluble asphalt release agent, characterized in that: The invention is prepared from the following raw materials in parts by weight: 65-75 parts of vaseline, 10-15 parts of silicone grease, 9-15 parts of metal stearate, 2-8 parts of hardener and 1-5 parts of surfactant.

2. The water-insoluble asphalt release agent according to claim 1, characterized in that: The metal stearate is one or two selected from sodium stearate and potassium stearate.

3. The water-insoluble asphalt release agent according to claim 1, characterized in that: The hardener is microcrystalline wax, and its softening point is 80-90°C.

4. The water-insoluble asphalt release agent according to claim 1, characterized in that: The surfactant is the nonionic surfactant OP-10.

5. A method for preparing the water-insoluble asphalt release agent according to any one of claims 1 to 4, characterized in that: The steps include: (1) placing vaseline and metal stearate at a constant temperature according to the mass fraction of the raw materials to melt the metal stearate, and then mechanically stirring to uniformly disperse the melted metal stearate in the vaseline; (2) Add a surfactant and a hardener in order according to the mass fraction of the raw materials, continue stirring, and then add silicone grease in order according to the mass fraction of the raw materials, continue stirring to obtain a water-insoluble asphalt release agent.

6. The preparation method according to claim 5, characterized in that: In step (1), constant temperature melting is carried out in an oven, the temperature of the constant temperature melting is 100-120° C., and the time of the constant temperature melting is 40-60 minutes.

7. The preparation method according to claim 5, characterized in that: 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.

8. The preparation method according to claim 5, characterized in that: In step (2), the stirring time is continued for 30 to 40 minutes.

9. Use of the water-insoluble asphalt release agent described in any one of claims 1 to 4 or the water-insoluble asphalt release agent prepared by the preparation method described in any one of claims 5 to 8 in the determination of asphalt ductility.

10. The use according to claim 9, characterized in that: The non-water-soluble asphalt release agent is applied to the inner sides of the bottom mold and the side mold of the test mold.

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