Asphalt rubber modifier and preparation method thereof, waterproof coating composition, waterproof coating and preparation method and application thereof

Abstract

The invention relates to the field of building waterproofing, and discloses an asphalt rubber modifier and a preparation method thereof, a waterproof coating composition, a waterproof coating and a preparation method and application of the waterproof coating. The method for preparing the asphalt rubber modifier comprises the following steps: (1) carrying out first contact on vegetable asphalt and vegetable fat to obtain an intermediate I; and (2) carrying out second contact on a styrene-butadiene-styrene block copolymer, butadiene styrene rubber and the intermediate I to obtain the asphalt rubber modifier. When the green rubber modifier is used for preparing the environment-friendly non-curing rubber asphalt waterproof coating for low-temperature construction, the compatibility and dispersity of a styrene-butadiene-styrene block copolymer and butadiene styrene rubber in asphalt can be improved, so that unmelted particles are eliminated, and the product performance and aging resistance are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building waterproofing, in particular to an asphalt rubber modifier and a preparation method thereof, a waterproof coating composition, and a waterproof coating and a preparation method and application thereof. BACKGROUND

[0002] Non-cured rubber asphalt waterproof coating is a functional waterproof material prepared by adding various types of elastomers, plastics and other modified materials to asphalt as a base material. Its core advantages are as follows: (1) permanent creep characteristics: it remains viscous and gel-like after long-term contact with air, and always has plastic flow ability after construction, which can continuously adapt to the slight deformation of the base; (2) super strong adhesion and base surface adaptability: it can be directly constructed on a wet base surface, and shows excellent adhesion to various materials such as concrete, metal and wood, and even can form effective adhesion with foreign matters such as dust and water droplets on the surface of the base; (3) high elasticity and deformation resistance: the material has excellent flexibility, and the elongation rate can reach more than 500%, and when the base cracks, the coating can extend with it without being damaged, which significantly improves the crack resistance of the waterproof system; (4) self-repairing sealing mechanism: if the waterproof layer is damaged during construction, the material can automatically fill the cracks due to its viscous flow property, and the waterproof integrity can be maintained without additional repair; (5) compatibility of composite waterproof system: it can be used with various waterproof materials such as elastomer modified asphalt waterproof roll material and polymer sheet material, and a multi-layer waterproof barrier can be constructed by the "coating + roll material" composite process, which greatly enhances the reliability of the waterproof system.

[0003] Such materials have unique performance combinations and exhibit significant technical advantages in roofing, underground and municipal engineering fields, and are particularly suitable for complex structure, frequent deformation or high difficulty of repair waterproof scenarios.

[0004] However, the compatibility of asphalt and modified materials is poor, making it difficult for the liquefied residue to be uniformly mixed with rubber powder (modifier). This incompatibility can easily cause phase separation in the external additive. Generally, high temperature is used to mix asphalt with SBS (styrene-butadiene-styrene block copolymer) and SBR (styrene-butadiene rubber, divided into emulsion polymerized SBR and solution polymerized SBR). The core of "compatibility" is to uniformly disperse the high molecular elastomer (SBS / SBR) in the asphalt matrix to form a stable "asphalt-elastomer" blend system (rather than stratification or agglomeration). At the same time, non-cured asphalt rubber waterproof coating itself is viscous and gel-like, with strong adhesion and cohesion, making it difficult to be directly applied. Therefore, hot melt construction is adopted, and the construction temperature is usually 160-180℃, and the hot melt temperature reaches 160-200℃ or even higher. In this process, a large amount of energy is consumed, and the asphalt base material is easily oxidized and degraded at a temperature above 180℃, resulting in a decrease in material viscosity, a decrease in adhesion, and the generation of a large amount of harmful gas, which causes irreversible harm to the human body and the environment.

[0005] Therefore, it is urgent to develop an environment-friendly and low-temperature construction non-solidified asphalt rubber waterproof coating. SUMMARY

[0006] The present application aims to overcome the defects of poor compatibility and dispersibility of the modified material with asphalt and high construction temperature in the existing non-solidified asphalt rubber waterproof coating.

[0007] To achieve the above-mentioned purpose, the first aspect of the present application provides a method for preparing an asphalt rubber modifier, which comprises: (1) first contacting plant asphalt and vegetable fat to obtain intermediate I; (2) second contacting styrene-butadiene-styrene block copolymer, styrene-butadiene rubber and the intermediate I to obtain the asphalt rubber modifier; The content of the plant asphalt is 75-90wt% and the content of the vegetable fat is 10-20wt% based on the total mass of the material A; the content of the styrene-butadiene-styrene block copolymer is 2-5wt% and the content of the styrene-butadiene rubber is 2-5wt% based on the total mass of the material A; the total mass of the material A is the sum of the mass of the plant asphalt, the mass of the vegetable fat, the mass of the styrene-butadiene-styrene block copolymer and the mass of the styrene-butadiene rubber.

[0008] The second aspect of the present application provides an asphalt rubber modifier prepared by the method of the first aspect.

[0009] The third aspect of the present application provides a composition for waterproof coating, which comprises asphalt rubber modifier, asphalt, temperature control agent and calcium powder; The content of the asphalt rubber modifier is 30-50wt%, the content of the asphalt is 25-40wt%, the content of the temperature control agent is 2-4wt% and the content of the calcium powder is 25-35wt% based on the total weight of the composition; The asphalt rubber modifier is the asphalt rubber modifier of the second aspect. The fourth aspect of the present application provides a method for preparing waterproof coating, which applies each component in the composition of the third aspect, comprising: S1: first mixing asphalt rubber modifier and the asphalt to obtain mixture I; S2: second mixing the mixture I and the temperature control agent to obtain mixture II; S3: third mixing the mixture II and the calcium powder to obtain the waterproof coating.

[0010] The fifth aspect of the present application provides an environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating prepared by the method of the fourth aspect.

[0011] The sixth aspect of the present application provides the application of the environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating of the fifth aspect in the field of building waterproofing.

[0012] Compared with the prior art, the present application has at least the following technical effects: (1) The asphalt rubber modifier of the present application uses environmentally friendly plant waste residue and waste oil (plant asphalt) and plant-based raw materials (plant oil) as raw materials, has excellent low-temperature performance and super-long elongation performance, and has good flowability at about 100℃. At the same time, waste utilization can be achieved.

[0013] (2) The present application swells the asphalt modifier (styrene-butadiene-styrene block copolymer and styrene-butadiene rubber) which is difficult to swell in the plant asphalt and the plant oil to prepare the asphalt rubber modifier, and then uses the asphalt rubber modifier, the asphalt, the temperature control agent, and the calcium powder to prepare the environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating. The environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating meets the requirements of the non-curing rubber asphalt waterproof coating standard, compared with the production of traditional non-curing asphalt waterproof coating, the product abnormalities caused by the difficulty of the asphalt modifier to dissolve in the asphalt are reduced, and due to the preparation of the asphalt rubber modifier first, the asphalt modifier is more easily dispersed in the asphalt, improving the product performance and aging resistance.

[0014] (3) The construction temperature of the traditional non-curing asphalt waterproof coating is high, the asphalt base material is prone to oxidative degradation for a long time at above 180℃, resulting in a decrease in material viscosity and a decrease in adhesion, and a large amount of harmful gas is generated from the asphalt, causing irreversible harm to the human body and the environment. In view of this, the hot melting temperature of the environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating provided by the present application is 120-140℃, and the construction temperature is 100-120℃. In the preferred case, energy consumption is reduced, production cost is reduced, material performance is better, and the volatilization amount of harmful gases such as benzopyrene and polycyclic aromatic hydrocarbons can be reduced by more than 50%, avoiding the pungent odor and smoke pollution during construction.

[0015] (4) The traditional non-curing asphalt waterproof coating is constructed at 160-200℃, and the high-temperature asphalt steam is easy to cause fire hazards, and the risk of scalding when the construction personnel contact the hot melting material is high; but the environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating provided by the present application can be constructed at a low temperature of less than 120℃, which significantly reduces the safety management pressure of the construction site. At the same time, construction in a low-temperature environment can prolong the service life of heating equipment such as melting kettles and spray guns, avoid problems such as aging of equipment seals and coking of pipelines caused by high temperature, and reduce equipment maintenance costs. DETAILED DESCRIPTION

[0016] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not critical to the invention. Any numeric range recited is intended to include all values from the lower value to the upper value, inclusive of both values, and to sub-ranges falling within the specified range. In this context, individual points within a range should not be dismissed from the scope of the range. For numeric ranges, the endpoints between ranges, the endpoints between ranges and individual points, and individual points can be combined to create one or more new numeric ranges, which should be considered as being specifically disclosed herein.

[0017] As previously mentioned, the first aspect of the present application provides a method for preparing an asphalt rubber modifier, the method comprising: (1) performing a first contacting of a vegetable asphalt and a vegetable oil to obtain an intermediate I; (2) performing a second contacting of a styrene-butadiene-styrene block copolymer, a styrene-butadiene rubber, and the intermediate I to obtain the asphalt rubber modifier; The content of the vegetable asphalt is 75-90 wt%, the content of the vegetable oil is 10-20 wt%, the content of the styrene-butadiene-styrene block copolymer is 2-5 wt%, and the content of the styrene-butadiene rubber is 2-5 wt%, based on the total mass of the material A, and the total mass of the material A is the sum of the mass of the vegetable asphalt, the vegetable oil, the styrene-butadiene-styrene block copolymer, and the styrene-butadiene rubber.

[0018] Preferably, the content molar ratio of styrene structural units to butadiene structural units in the styrene-butadiene-styrene block copolymer is 3:7 to 2:3, and the weight average molecular weight is 100000 g / mol-150000 g / mol.

[0019] Preferably, the softening point of the vegetable asphalt is 40-60 °C, and the elongation is 150-300 mm.

[0020] Preferably, the styrene-butadiene rubber contains 15-35 wt% styrene structural units and 50-90 wt% butadiene structural units, based on the total weight of the styrene-butadiene rubber.

[0021] Preferably, the number average molecular weight of the styrene-butadiene rubber is 200,000 g / mol-300,000 g / mol, and the molecular weight distribution is 1.8-2.5.

[0022] In other embodiments, the number average molecular weight of the styrene-butadiene rubber is 500,000 g / mol-2,500,000 g / mol, and the molecular weight distribution is 1.8-2.5.

[0023] According to a preferred embodiment, the vegetable oil is an esterification reaction product of palm oil and or soybean oil.

[0024] According to a preferred embodiment, the content of lead, cadmium and arsenic in the plant oil is less than or equal to 0.1 mg / kg, and the content of mercury is less than or equal to 0.01 mg / kg.

[0025] According to a specific embodiment, in step (1), the method further comprises: first melting the plant pitch and the plant oil, and then performing the first contacting; and the melting temperature is 100-140°C.

[0026] Preferably, in step (1), the first contacting is performed under the conditions of a temperature of 100-140°C and a time of 10-40 min.

[0027] According to a specific embodiment, in step (1), the first contacting is performed under the conditions of a stirring speed of 250-350 rpm.

[0028] Preferably, in step (2), the second contacting is performed under the conditions of a temperature of 120-180°C and a time of 1-4 h.

[0029] According to a specific embodiment, in step (2), the second contacting is performed under the conditions of a stirring speed of 400-600 rpm.

[0030] As described above, the second aspect of the present application provides a pitch-rubber modifier prepared by the method of the first aspect.

[0031] As described above, the third aspect of the present application provides a composition for waterproof coating, which comprises a pitch-rubber modifier, pitch, a temperature control agent and calcium powder. The content of the pitch-rubber modifier is 30-50 wt%, the content of the pitch is 25-40 wt%, the content of the temperature control agent is 2-4 wt%, and the content of the calcium powder is 25-35 wt%, based on the total weight of the composition. The pitch-rubber modifier is the pitch-rubber modifier of the second aspect.

[0032] According to a preferred embodiment, the pitch is 70# pitch.

[0033] Preferably, the average particle diameter of the calcium powder is 2-10 μm.

[0034] Preferably, the temperature control agent is selected from one of polyethylene wax, oxidized polyethylene wax and polypropylene wax.

[0035] As described above, the fourth aspect of the present application provides a method for preparing waterproof coating, which comprises using the components in the composition of the third aspect. S1: first mixing asphalt rubber modifier and the asphalt to obtain mixture I; S2: second mixing the mixture I and the temperature control agent to obtain mixture II; S3: third mixing the mixture II and the calcium powder to obtain the waterproof coating.

[0036] Preferably, in step S1, the conditions of the first mixing include: time of 20-60 min, temperature of 120-130℃, stirring speed of 200-600 rpm.

[0037] According to a specific embodiment, in step S1, the method further comprises: first melting the asphalt rubber modifier and the asphalt, and then performing the first mixing; the melting temperature is 100-140℃.

[0038] Preferably, in step S2, the conditions of the second mixing include: time of 20-60 min, temperature of 120-130℃, stirring speed of 200-600 rpm.

[0039] Preferably, in step S3, the conditions of the third mixing include: time of 30-90 min, temperature of 120-130℃, stirring speed of 300-900 rpm.

[0040] As described above, the fifth aspect of the present application provides an environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating prepared by the method of the third aspect.

[0041] As described above, the sixth aspect of the present application provides the application of the environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating of the fifth aspect in the field of building waterproofing.

[0042] The present application will be described in detail through examples as follows.

[0043] In the following examples, the reagents and raw materials involved are commercially available, and the reagents are all analytical pure products.

[0044] In the following examples, the room temperature refers to 25±2℃.

[0045] Plant asphalt I: purchased from Hubei Chengfeng Chemical Co., Ltd., softening point of 56℃, ductility of 280mm.

[0046] Plant asphalt II: purchased from Hebei Oujia Lubricating Oil Co., Ltd., softening point of 80℃, ductility of 120mm.

[0047] Vegetable oil: purchased from Suzhou Fengbei Biological Technology Co., Ltd., product number 1031D.

[0048] 70# asphalt: purchased from Maoming Petrochemical Company, model 70#.

[0049] Styrene-butadiene-styrene block copolymer (SBS elastomer): purchased from LG Company in Korea, product number SBS501, the content molar ratio of styrene structural unit to butadiene structural unit in the styrene-butadiene-styrene block copolymer is 31:69, and the weight average molecular weight is 120000 g / mol.

[0050] Styrene-butadiene rubber I (SBR rubber I): purchased from Shandong Haifang Rubber Technology Co., Ltd., product number XY-F023, solid content is 80wt%, the styrene-butadiene rubber I contains 17.2-28wt% styrene structural unit and 72-82.8wt% butadiene structural unit based on the total weight of the styrene-butadiene rubber I, the number average molecular weight of the styrene-butadiene rubber I is 200-300 thousand g / mol, and the molecular weight distribution is 1.8-2.5.

[0051] Styrene-butadiene rubber II (SBR rubber II): purchased from Sinopec Shanghai Gaoqiao Petrochemical Co., Ltd., product number T2003, solid content is 92wt%, the styrene-butadiene rubber II contains 23-27.6wt% styrene structural unit and 72.4-77wt% butadiene structural unit based on the total weight of the styrene-butadiene rubber II, the number average molecular weight of the styrene-butadiene rubber II is 100-150 thousand g / mol, and the molecular weight distribution is 1.2-1.8.

[0052] Oxidized polyethylene wax: purchased from Suzhou Freetree New Material Technology Co., Ltd., product number FT-Y4135.

[0053] Polyethylene wax: purchased from Suzhou Freetree New Material Technology Co., Ltd., product number FT-4108.

[0054] Polypropylene wax: purchased from Nanjing Tian Poetry New Material Technology Co., Ltd., product number PPW-0901.

[0055] 1500 mesh calcium powder purchased from Jiangxi Guangyuan Chemical Industry Co., Ltd., product number GY-516.

[0056] Digital viscometer purchased from Brookfield Company, model TDV2T.

[0057] Preparation Example 1 The asphalt rubber modifier was prepared according to the formulation and process parameters in Table 1, and the specific method was as follows: (1) After hot melting, the vegetable asphalt and vegetable fat were contacted for the first time to obtain intermediate I; (2) styrene-butadiene-styrene block copolymer, styrene-butadiene rubber and the intermediate I are subjected to a second contact to obtain an asphalt rubber modifier.

[0058] Preparation Example 2 This preparation example is performed according to the method of Preparation Example 1, except that: In step (2), the mass of styrene-butadiene-styrene block copolymer and styrene-butadiene rubber is adjusted; The remaining steps are the same as those of Preparation Example 1 to obtain an asphalt rubber modifier.

[0059] Preparation Example 3 This preparation example is performed according to the method of Preparation Example 1, except that: In step (1), the mass of plant asphalt is adjusted; In step (2), the mass of styrene-butadiene-styrene block copolymer and styrene-butadiene rubber is adjusted; The remaining steps are the same as those of Preparation Example 1 to obtain an asphalt rubber modifier.

[0060] Preparation Example 4 This preparation example is performed according to the method of Preparation Example 1, except that: In step (1), plant asphalt I is replaced by an equal mass of plant asphalt II; The remaining steps are the same as those of Preparation Example 1 to obtain an asphalt rubber modifier.

[0061] Preparation Example 5 This preparation example is performed according to the method of Preparation Example 1, except that: In step (2), styrene-butadiene rubber I is replaced by an equal mass of styrene-butadiene rubber II; The remaining steps are the same as those of Preparation Example 1 to obtain an asphalt rubber modifier.

[0062] Comparative Preparation Example 1 This comparative preparation example is performed according to the method of Preparation Example 1, except that: In step (1), the mass of plant asphalt is adjusted; In step (2), the mass of styrene-butadiene-styrene block copolymer and styrene-butadiene rubber is adjusted; The remaining steps are the same as those of Preparation Example 1 to obtain an asphalt rubber modifier.

[0063] Comparative Preparation Example 2 This preparation example is performed according to the method of Preparation Example 1, except that: In step (1), the mass of plant asphalt is adjusted; In step (2), the mass of styrene-butadiene-styrene block copolymer and styrene-butadiene rubber is adjusted; The remaining steps are the same as those in Preparation Example 1 to obtain the asphalt rubber modifier.

[0064] Comparative Preparation Example 3 This comparative preparation example is performed according to the method of Preparation Example 1, except that: In step (1), the mass of the vegetable asphalt is adjusted; In step (2), the mass of the styrene-butadiene-styrene block copolymer is adjusted; The remaining steps are the same as those in Preparation Example 1 to obtain the asphalt rubber modifier.

[0065] Comparative Preparation Example 4 This comparative preparation example is performed according to the method of Preparation Example 1, except that: In step (1), the mass of the vegetable asphalt and the mass of the vegetable oil are adjusted; The remaining steps are the same as those in Preparation Example 1 to obtain the asphalt rubber modifier.

[0066] Table 1

[0067] Table 1 (continued)

[0068] Example 1 The formula and process parameters in the method for preparing the environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating according to the present application are shown in Table 2, and the preparation method is specifically as follows: S1: After the asphalt rubber modifier and the asphalt are hot melted, first mixing is performed to obtain a mixture I; S2: The mixture I and the temperature control agent are second mixed to obtain a mixture II; S3: The mixture II and the calcium powder are third mixed to obtain the environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating.

[0069] The remaining examples are performed according to the method similar to that in Example 1, except that the formula and process parameters are different, and specific reference can be made to Table 2.

[0070] Table 2

[0071] Example 6 This example is performed according to the method of Example 1, except that: In step (1), the asphalt rubber modifier-1 is replaced by an equal mass of asphalt rubber modifier-4; The remaining steps are the same as in Example 1 to obtain the environment-friendly low-temperature construction non-curing rubber asphalt waterproof coating.

[0072] Example 7 This example is performed according to the method of Example 1, except that: In step (1), the asphalt rubber modifier-1 is replaced with equal mass of asphalt rubber modifier-5; The remaining steps are the same as in Example 1 to obtain the environment-friendly low-temperature construction non-curing rubber asphalt waterproof coating.

[0073] Comparative Example 1 This comparative example is performed according to the method of Example 1, except that: In step (1), the asphalt rubber modifier-1 is replaced with equal mass of asphalt rubber modifier-DZ1; The remaining steps are the same as in Example 1 to obtain the environment-friendly low-temperature construction non-curing rubber asphalt waterproof coating.

[0074] Comparative Example 2 This comparative example is performed according to the method of Example 1, except that: In step (1), the asphalt rubber modifier-1 is replaced with equal mass of asphalt rubber modifier-DZ2; The remaining steps are the same as in Example 1 to obtain the environment-friendly low-temperature construction non-curing rubber asphalt waterproof coating.

[0075] Comparative Example 3 This comparative example is performed according to the method of Example 1, except that: In step (1), the asphalt rubber modifier-1 is replaced with equal mass of asphalt rubber modifier-DZ3; The remaining steps are the same as in Example 1 to obtain the environment-friendly low-temperature construction non-curing rubber asphalt waterproof coating.

[0076] Comparative Example 4 This comparative example is performed according to the method of Example 1, except that: In step (1), the asphalt rubber modifier-1 is replaced with equal mass of asphalt rubber modifier-DZ4; The remaining steps are the same as in Example 1 to obtain the environment-friendly low-temperature construction non-curing rubber asphalt waterproof coating.

[0077] Test Example 1 Viscosity at 120℃ (mpa.s): tested using a digital viscometer. The specific test method is as follows: using a digital viscometer, the test temperature is controlled at 120±1℃, and a 27# rotor is used. Start the machine, remove the rotor, and adjust the viscometer level. Set the test temperature to 120℃. Pour the test material into an aluminum tube and place it in the heating jacket for 10 min. Install the rotor, immerse the rotor into the sample to be tested and continue to heat for 10 min, pay attention to keep the machine head and heating jacket in vertical axis alignment, and ensure that the rotor is in the center of the aluminum tube. Adjust the speed during the test to control the torque between 20%-80%, and the test time is 10 min. After the test is completed, read the viscosity value.

[0078] Extensibility (mm): tested according to the method of 7.7 of JC / T 2428-2017 Non-cured rubber asphalt waterproof coating.

[0079] Heat resistance (℃): tested according to the method of 7.9 of JC / T 2428-2017 Non-cured rubber asphalt waterproof coating.

[0080] Construction smoothness: prepare samples according to the formula and process parameters in the method of the present application, pour the sample on the surface of the concrete substrate when the temperature of the sample is reduced to 100-120℃, then use a tooth-shaped scraper (tooth depth 1.5-2.0 mm) for scraping, and investigate whether the scraping process is smooth.

[0081] The environmental-friendly low-temperature construction non-cured rubber asphalt waterproof coating obtained in each example is tested for performance using the above test methods, and the test results are shown in Table 3.

[0082] Table 3

[0083] As can be seen from the results in Table 3, the viscosity of the environmental-friendly low-temperature construction non-cured rubber asphalt waterproof coating provided by the present application at 120℃ does not affect the construction smoothness, while the viscosity of the coating is affected by the formula and raw materials, so the formula, process and raw materials provided by the present application have excellent compatibility. At the same time, plant asphalt and vegetable oil are used, and from the data in Table 3, the viscosity of the environmental-friendly low-temperature construction non-cured rubber asphalt waterproof coating is 700-2000 mpa.s, the heat resistance is ≥65℃, and it can be constructed smoothly at 100℃, so it has the advantages of environmental protection, energy saving and less harm to human body.

[0084] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that each technical feature is combined in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A process for preparing a bitumen rubber modifier, characterized in that, The method comprises: (1) performing first contact of plant pitch and vegetable oil to obtain intermediate I; (2) performing second contact of styrene-butadiene-styrene block copolymer, styrene-butadiene rubber and the intermediate I to obtain the pitch rubber modifier; The content of the plant pitch is 75-90wt% and the content of the vegetable oil is 10-20wt% based on the total mass of the material A; the content of the styrene-butadiene-styrene block copolymer is 2-5wt% and the content of the styrene-butadiene rubber is 2-5wt% based on the total mass of the material A; the total mass of the material A is the sum of the mass of the plant pitch, the vegetable oil, the styrene-butadiene-styrene block copolymer and the styrene-butadiene rubber.

2. The method of claim 1, wherein, The molar ratio of the content of styrene structural unit to butadiene structural unit in the styrene-butadiene-styrene block copolymer is 3:7 to 2:3, and the weight average molecular weight is 100000 g / mol-150000 g / mol; And / or, the softening point of the plant pitch is 40-60℃ and the elongation is 150-300mm.

3. The method according to claim 1 or 2, characterized in that, The styrene-butadiene rubber contains 15-35wt% styrene structural unit and 50-90wt% butadiene structural unit based on the total weight of the styrene-butadiene rubber; And / or, the number average molecular weight of the styrene-butadiene rubber is 200000 g / mol-300000 g / mol and the molecular weight distribution is 1.8-2.5; And / or, the vegetable oil is an esterification reaction product obtained after esterification reaction of palm oil and / or soybean oil.

4. The method according to claim 1 or 2, characterized in that, In step (1), the first contact is performed at a temperature of 100-140℃ for 10-40min; And / or, in step (2), the second contact is performed at a temperature of 120-180℃ for 1-4h.

5. The pitch rubber modifier prepared by the method of any one of claims 1-4.

6. A composition for a water repellent coating, characterized by, The composition comprises the pitch rubber modifier, pitch, temperature control agent and calcium powder; The content of the pitch rubber modifier is 30-50wt%, the content of the pitch is 25-40wt%, the content of the temperature control agent is 2-4wt% and the content of the calcium powder is 25-35wt% based on the total weight of the composition; The pitch rubber modifier is the pitch rubber modifier of claim 5.

7. The composition of claim 6, wherein, The temperature control agent is selected from at least one of polyethylene wax, oxidized polyethylene wax and polypropylene wax; And / or, the pitch is 70# pitch.

8. A method of preparing a water repellent coating, characterized by, The method applies the components in the composition of claim 6 or 7, comprising: S1: performing first mixing of pitch rubber modifier and pitch to obtain mixture I; S2: performing second mixing of the mixture I and temperature control agent to obtain mixture II; S3: performing third mixing of the mixture II and calcium powder to obtain the waterproof coating.

9. The environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating prepared by the method of claim 8.

10. The application of the environmentally friendly low-temperature construction non-curing rubber asphalt waterproof coating of claim 9 in the field of building waterproofing.

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