An organosilicon-modified exterior wall waterproof coating and its preparation method

Abstract

The present application specifically discloses a silicone-modified exterior wall waterproof coating and a preparation method thereof. A silicone-modified exterior wall waterproof coating comprises raw materials in the following weight parts: The waterproof coating comprises raw materials in the following weight parts: 90-120 parts of amino siloxane, 90-120 parts of vinyl siloxane, 50-80 parts of mercaptoethanol, 3-5 parts of dendritic molecular nano-silicon composite material, 100-120 parts of alcohol solvent, and 350-450 parts of water. The present application has the advantages of improving the tensile property and wear resistance of the exterior wall waterproof coating for buildings.

Description

Technical Field

[0001] The present invention relates to the technical field of building waterproof materials, and in particular to a silicone-modified exterior wall waterproof coating and a preparation method thereof. Background Art

[0002] With the continuous emergence of building waterproof engineering technologies and their waterproof materials, exterior wall waterproof coatings for buildings are widely used in the field of building exterior wall waterproofing due to their advantages of simple use and remarkable effects.

[0003] Since the exterior walls of buildings are exposed to wind, sun, rain and other elements all year round, there will be problems such as easy peeling, discoloration, and aging of the exterior wall coatings. Therefore, the performance and quality requirements for exterior wall waterproof coatings for buildings are also getting higher and higher.

[0004] The current exterior wall coatings for buildings generally have a general waterproof effect, and due to their poor tensile resistance and wear resistance, as the service time of the building exterior wall increases, the waterproof coating formed by the exterior wall waterproof coating is easily damaged, making its waterproof performance deteriorate. Summary of the Invention

[0005] In order to improve the tensile resistance and wear resistance of the waterproof layer formed by the exterior wall waterproof coating, the present application provides a silicone-modified exterior wall waterproof coating and a preparation method thereof.

[0006] In the first aspect, the present application provides a silicone-modified exterior wall waterproof coating, adopting the following technical solution:

[0007] A silicone-modified exterior wall waterproof coating, comprising the following raw materials in parts by weight: 90 - 120 parts of amino siloxane, 90 - 120 parts of vinyl siloxane, 50 - 80 parts of mercaptoethanol, 3 - 5 parts of dendritic molecular nano-silicon composite material, 100 - 120 parts of alcohol solvent, and 350 - 450 parts of water.

[0008] First, the amino silicone and vinyl silicone can react in the system, thereby improving the flexibility and rotatability of the silicone backbone and enhancing the shrinkage of the silicone backbone. Secondly, by introducing the dendritic molecular nano-silicon composite material, a stable three-dimensional network structure is generated in the system. This three-dimensional network structure can cooperate with the above-mentioned silicone backbone with excellent rotatability, enabling a higher degree of molecularization and density in the coating system, improving the tensile properties of the waterproof coating. Moreover, there is an elastic cavity structure in the three-dimensional network structure formed by the dendritic molecular nano-silicon composite material, which can further buffer the damage of external environmental forces to the coating. At the same time, the nano-silicon is also evenly loaded on this three-dimensional network structure, thus being evenly dispersed in the coating system to improve the wear resistance of the waterproof coating. Finally, the amino group in the amino silicone can react with the mercapto group in mercaptoethanol to form a urea group, introducing C-S bonds and C-N bonds into the reaction system, thereby further enhancing the tensile strength and wear resistance of the hydrophobic film formed by the waterproof agent on the exterior wall surface, and avoiding the decline in waterproof performance of the coating due to wall weathering, cracking, etc. on the wall surface.

[0009] Preferably, the alcohol solvent includes at least one of methanol and ethanol.

[0010] Preferably, based on the dendritic molecular nano-silicon composite material, the dendritic molecular nano-silicon composite material comprises the following raw materials in parts by weight: 3 - 5 parts of nano-silicon, 5 - 9 parts of oleic acid polyethylene glycol active ester, 1 - 2 parts of dendritic molecule, 10 - 20 parts of organic solvent, 0.5 - 1 part of N-hydroxysuccinimide, and 0.5 - 2 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0011] Preferably, the organic solvent includes at least one of N-methylpyrrolidone and ethanol.

[0012] Preferably, the dendritic molecular nano-silicon composite material is prepared by a method comprising the following steps:

[0013] S1: Mix and disperse the nano-silicon and the oleic acid polyethylene glycol active ester to obtain a first suspension; mix and disperse the dendritic molecule and the organic solution to obtain a second suspension.

[0014] S2: Mix and stir the N-hydroxysuccinimide, the 1-ethyl-(3-dimethylaminopropyl)carbodiimide and the second suspension to obtain an activated mixture.

[0015] S3: Mix, heat and stir the activated mixture and the first suspension, and the obtained product is purified and dried to obtain the dendritic molecular nano-silicon composite material.

[0016] The first suspension is prepared by mixing nano-silicon with oleic acid polyethylene glycol active ester. On the one hand, the agglomeration of nano-silicon particles is reduced, and its dispersion uniformity in the reaction system is improved, which is beneficial to obtaining a product with uniform and stable performance. On the other hand, the encapsulation of nano-silicon by oleic acid polyethylene glycol active ester and its activation effect on dendritic molecules can improve the binding effect between nano-silicon and dendritic molecules, and a dendritic molecule nano-silicon composite material with a regular and ordered three-dimensional network structure is prepared; the cooperation of the second suspension and the first suspension can graft as much nano-silicon as possible onto the surface of dendritic molecules, improve the ductility of the three-dimensional structure formed by the dendritic molecule structure in the coating system, and improve the tensile strength and wear resistance of the waterproof layer formed by the coating.

[0017] Preferably, in S1, the first suspension is obtained after dispersing for 3 - 5 minutes, and the second suspension is obtained after dispersing for 4 - 6 minutes; the stirring time in S2 is 10 - 15 minutes; the heating temperature in S3 is 60 - 80 °C, and the stirring time is 8 - 12 hours.

[0018] Under the preparation preconditions of the above raw materials, the obtained dendritic molecule nano-silicon composite material has a more significant improvement effect on the tensile performance and wear resistance of the waterproof layer formed by the coating.

[0019] Preferably, the particle size of the nano-silicon is 0.5 - 4 nm.

[0020] By selecting nano-silicon materials with appropriate particle sizes, nano-silicon can be combined with dendritic molecules to a great extent, and nano-silicon can be evenly dispersed in the coating system, which is beneficial to improving the tensile strength and wear resistance of the waterproof layer formed by the coating.

[0021] Preferably, the dendritic molecule includes any one or a mixture of two of PAMAM dendritic molecules and aryl ether dendrimers.

[0022] Preferably, the amino-siloxane includes at least one of ammonia-terminated polydimethylsiloxane and 3-aminopropylmethyldimethoxysilane.

[0023] Preferably, the amino-siloxane includes 3-aminopropylmethyldimethoxysilane.

[0024] Preferably, the vinyl-siloxane includes at least one of vinyltriacetoxysilane and vinyltriisopropenyloxysilane.

[0025] Preferably, the vinyl-siloxane includes vinyltriacetoxysilane.

[0026] Through the cooperation of amino-modified siloxane and vinyl-siloxane, the flexibility of the siloxane main chain is significantly improved, and the tensile performance of the waterproof layer formed by the coating is improved.

[0027] In a second aspect, the present application provides a method for preparing an organosilicon-modified exterior wall waterproof coating, adopting the following technical solution:

[0028] A method for preparing an organosilicon-modified exterior wall waterproof coating includes the following steps:

[0029] Step 1: Mix the amino siloxane, the vinyl siloxane, the mercaptoethanol and the alcohol solvent to obtain a siloxane mixture;

[0030] Step 2: Add the water droplets to the siloxane mixture and heat to obtain an intermediate product;

[0031] Step 3: Mix the dendritic molecular nano-silicon composite material with the intermediate product, heat and stir to obtain the organosilicon-modified exterior wall waterproof coating.

[0032] Preferably, the dropping time during the process of adding the water droplets to the siloxane mixture is 10 - 15 min.

[0033] Preferably, the heating temperature in Step 2 is 60 - 70 °C and the heating time is 1 - 2 h; the heating temperature in Step 3 is 40 - 50 °C and the heating time is 2 - 3 h. Specific Embodiments

[0034] For better understanding and implementation, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0036] Unless otherwise specified, all numerical values expressing amounts of ingredients, reaction conditions, etc. used in the specification and claims are understood to be modified by the term "about". Therefore, unless there is a contrary indication, the numerical parameters set forth herein are approximate values that can vary depending on the desired properties to be obtained.

[0037] As used herein, "and / or" refers to one or all of the recited elements.

[0038] As used herein, "comprising" and "including" cover the case where only the recited elements are present and the case where there are other unrecited elements in addition to the recited elements.

[0039] All percentages in the present invention are weight percentages unless otherwise specified.

[0040] Unless otherwise specified, the terms "a", "one kind", "one" and "the" as used in this specification are intended to include "at least one kind" or "one kind or more kinds". For example, "a component" refers to one kind or more kinds of components, so more than one kind of component may be considered and may be adopted or used in the implementation of the described embodiments.

[0041] Example

[0042] Example 1

[0043] 1. Preparation of Dendrimer Nanoscale Silicon Composite

[0044] The dendrimer nanoscale silicon composite comprises raw materials with the following weights:

[0045] 4 g of nanoscale silicon, 8 g of oleic acid polyethylene glycol active ester, 1.5 g of PAMAM dendrimer, 20 g of N-methylpyrrolidone, 0.5 g of N-hydroxysuccinimide, and 2 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0046] The dendrimer nanoscale silicon composite is prepared by the following steps:

[0047] S1: Mix the nanoscale silicon with the oleic acid polyethylene glycol active ester and ultrasonically disperse for 4 min to obtain a first suspension; mix the PAMAM dendrimer with N-methylpyrrolidone and ultrasonically disperse for 4 min to obtain a second suspension;

[0048] S2: Mix N-hydroxysuccinimide, 1-ethyl-(3-dimethylaminopropyl)carbodiimide with the second suspension and stir for 15 min to obtain an activated mixture;

[0049] S3: Mix the activated mixture with the first suspension, heat and stir at 80 °C for 8 h, and purify and dry the obtained product to obtain the dendrimer nanoscale silicon composite.

[0050] 2. Preparation of Organosilicon-Modified Exterior Wall Waterproof Coating

[0051] The organosilicon-modified exterior wall waterproof coating comprises raw materials in the following parts by weight:

[0052] 100 g of 3-aminopropylmethyldimethoxysilane, 110 g of vinyltriacetoxysilane, 65 g of mercaptoethanol, 4 g of dendrimer nanoscale silicon composite, 110 g of ethanol, and 400 g of deionized water.

[0053] The organosilicon-modified exterior wall waterproof coating is prepared by the following steps:

[0054] Step 1, mix 3-aminopropylmethyldimethoxysilane, vinyltriacetoxysilane, mercaptoethanol with ethanol to obtain a siloxane mixture;

[0055] Step 2: Add water droplets to the silicone mixture and heat at 65 °C for 2 h to obtain an intermediate product;

[0056] Step 3: Mix the dendritic molecule nanosilicon composite material with the intermediate product and heat at 45 °C for 2 h to obtain an organosilicon-modified exterior wall waterproof coating.

[0057] Example 2

[0058] 1. Preparation of dendritic molecule nanosilicon composite material

[0059] The dendritic molecule nanosilicon composite material comprises raw materials with the following weights:

[0060] 3 g of nanosilicon, 5 g of oleic acid polyethylene glycol active ester, 2 g of PAMAM dendritic molecule, 10 g of ethanol, 0.8 g of N-hydroxysuccinimide, and 1.2 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0061] The dendritic molecule nanosilicon composite material is prepared by the following steps:

[0062] S1: Mix nanosilicon with oleic acid polyethylene glycol active ester and ultrasonically disperse for 3 min to obtain a first suspension; mix PAMAM dendritic molecule with ethanol and ultrasonically disperse for 6 min to obtain a second suspension;

[0063] S2: Mix N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide with the second suspension and stir for 12 min to obtain an activated mixture;

[0064] S3: Mix the activated mixture with the first suspension, heat and stir at 70 °C for 12 h, and purify and dry the obtained product to obtain the dendritic molecule nanosilicon composite material.

[0065] 2. Preparation of organosilicon-modified exterior wall waterproof coating

[0066] The organosilicon-modified exterior wall waterproof coating comprises raw materials with the following parts by weight:

[0067] 90 g of amino-terminated polydimethylsiloxane, 120 g of vinyltriisopropenyloxysilane, 80 g of mercaptoethanol, 3 g of dendritic molecule nanosilicon composite material, 120 g of methanol, and 350 g of deionized water.

[0068] The organosilicon-modified exterior wall waterproof coating is prepared by the following steps:

[0069] Step 1: Mix amino-terminated polydimethylsiloxane, vinyltriisopropenyloxysilane, mercaptoethanol, and methanol to obtain a silicone mixture;

[0070] Step 2: Add water droplets to the silicone mixture and heat at 60 °C for 1.5 h to obtain an intermediate product;

[0071] Step 3: Mix the dendritic molecular nano-silicon composite material with the intermediate product and heat at 40 °C for 3 h to obtain an organosilicon-modified exterior wall waterproof coating.

[0072] Example 3

[0073] 1. Preparation of dendritic molecular nano-silicon composite material

[0074] The dendritic molecular nano-silicon composite material comprises raw materials with the following weights:

[0075] 5 g of nano-silicon, 9 g of oleic acid polyethylene glycol active ester, 1 g of aryl ether dendritic molecule, 15 g of N-methylpyrrolidone, 1 g of N-hydroxysuccinimide, and 0.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0076] The dendritic molecular nano-silicon composite material is prepared by the following steps:

[0077] S1: Mix nano-silicon with oleic acid polyethylene glycol active ester and ultrasonically disperse for 5 min to obtain a first suspension; mix the aryl ether dendritic molecule with N-methylpyrrolidone and ultrasonically disperse for 5 min to obtain a second suspension;

[0078] S2: Mix N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide with the second suspension and stir for 10 min to obtain an activated mixture;

[0079] S3: Mix the activated mixture with the first suspension, heat and stir at 60 °C for 10 h, and purify and dry the obtained product to obtain the dendritic molecular nano-silicon composite material.

[0080] 2. Preparation of organosilicon-modified exterior wall waterproof coating

[0081] The organosilicon-modified exterior wall waterproof coating comprises raw materials in the following parts by weight:

[0082] 120 g of 3-aminopropylmethyldimethoxysilane, 90 g of vinyltriisopropenyloxysilane, 50 g of mercaptoethanol, 5 g of dendritic molecular nano-silicon composite material, 100 g of ethanol, and 450 g of deionized water.

[0083] The organosilicon-modified exterior wall waterproof coating is prepared by the following steps:

[0084] Step 1: Mix 3-aminopropylmethyldimethoxysilane, vinyltriisopropenyloxysilane, mercaptoethanol with ethanol to obtain a silicone mixture;

[0085] Step 2: Add water droplets to the silicone mixture and heat at 70 °C for 1 h to obtain an intermediate product;

[0086] Step 3: Mix the dendritic molecular nanosilicon composite material with the intermediate product and heat at 50 °C for 2.5 h to obtain an organosilicon-modified exterior wall waterproof coating.

[0087] Example 4

[0088] 1. Preparation of dendritic molecular nanosilicon composite material

[0089] The dendritic molecular nanosilicon composite material comprises raw materials with the following weights:

[0090] 5 g of nanosilicon, 8 g of oleic acid polyethylene glycol active ester, 1 g of aryl ether dendrimer, 1 g of PAMAM dendrimer, 15 g of N-methylpyrrolidone, 1 g of N-hydroxysuccinimide, and 2 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0091] The dendritic molecular nanosilicon composite material is prepared by the following steps:

[0092] S1: Mix nanosilicon with oleic acid polyethylene glycol active ester and ultrasonically disperse for 5 min to obtain a first suspension; mix aryl ether dendrimer, PAMAM dendrimer with N-methylpyrrolidone and ultrasonically disperse for 6 min to obtain a second suspension;

[0093] S2: Mix N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide with the second suspension and stir for 10 min to obtain an activated mixture;

[0094] S3: Mix the activated mixture with the first suspension, heat and stir at 80 °C for 10 h, and purify and dry the obtained product to obtain the dendritic molecular nanosilicon composite material.

[0095] 2. Preparation of organosilicon-modified exterior wall waterproof coating

[0096] The organosilicon-modified exterior wall waterproof coating comprises raw materials in the following parts by weight:

[0097] 100 g of 3-aminopropylmethyldimethoxysilane, 110 g of vinyltriacetoxysilane, 70 g of mercaptoethanol, 4 g of dendritic molecular nanosilicon composite material, 110 g of ethanol, and 400 g of deionized water.

[0098] The organosilicon-modified exterior wall waterproof coating is prepared by the following steps:

[0099] Step 1: Mix 3-aminopropylmethyldimethoxysilane, vinyltriacetoxysilane, mercaptoethanol with ethanol to obtain a silicone mixture;

[0100] Step 2: Add water droplets into the silicone mixture and heat at 70 °C for 2 h to obtain an intermediate product;

[0101] Step 3: Mix the dendritic molecular nanosilicon composite material with the intermediate product and heat at 50 °C for 2 h to obtain an organosilicon-modified exterior wall waterproof coating.

[0102] Example 5

[0103] The difference between this example and Example 1 is that equal weight of oleic acid is used instead of oleic acid polyethylene glycol active ester in the process of preparing the dendritic molecular nanosilicon composite material; the rest is the same as Example 1.

[0104] Example 6

[0105] The difference between this example and Example 1 is that oleic acid polyethylene glycol active ester is not used in the process of preparing the dendritic molecular nanosilicon composite material; the rest is the same as Example 1.

[0106] Example 7

[0107] The difference between this example and Example 1 is that the process of preparing the dendritic molecular nanosilicon composite material adopts the following steps:

[0108] S1: Mix nanosilicon, oleic acid polyethylene glycol active ester, dendritic molecule, and organic solution to obtain a suspension;

[0109] S2: Mix N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide with the suspension, stir for 15 min to obtain an activated mixture, heat and stir the activated mixture at 80 °C for 8 h, and purify and dry the obtained product to obtain the dendritic molecular nanosilicon composite material;

[0110] The rest is the same as Example 1.

[0111] Example 8

[0112] The difference between this example and Example 1 is that the heating temperature in S3 during the process of preparing the dendritic molecular nanosilicon composite material is 50 °C and the heating time is 14 h; the rest is the same as Example 1.

[0113] Example 9

[0114] The difference between this example and Example 1 is that the heating temperature in S3 during the process of preparing the dendritic molecular nanosilicon composite material is 100 °C and the heating time is 6 h; the rest is the same as Example 1.

[0115] Example 10

[0116] This embodiment is different from Embodiment 1 in that the heating temperature in Step 2 during the preparation of the silicone-modified exterior wall waterproof coating is 100°C; the rest is the same as Embodiment 1.

[0117] Embodiment 11

[0118] This embodiment is different from Embodiment 1 in that the heating temperature in Step 3 during the preparation of the silicone-modified exterior wall waterproof coating is 80°C; the rest is the same as Embodiment 1.

[0119] Comparative Example 1

[0120] This comparative example is different from Embodiment 1 in that dendritic molecular nanosilicon composite materials are not used during the preparation of the silicone-modified exterior wall waterproof coating; the rest is the same as Embodiment 1.

[0121] Comparative Example 2

[0122] This comparative example is different from Embodiment 1 in that a mixture of equal weights of nanosilicon and dendritic molecules is used to replace the dendritic molecular nanosilicon composite material during the preparation of the silicone-modified exterior wall waterproof coating, where the nanosilicon is 1 g and the dendritic molecules are 0.5 g; the rest is the same as Embodiment 1.

[0123] Comparative Example 3

[0124] This comparative example is different from Embodiment 1 in that mercaptoethanol is not used during the preparation of the silicone-modified exterior wall waterproof coating; the rest is the same as Embodiment 1.

[0125] Testing Method

[0126] I. Mechanical Property Testing

[0127] The exterior wall waterproof coatings of Embodiments 1-11 and Comparative Examples 1-3 were subjected to mechanical property testing. The testing method was based on the testing method described for reactive products in GB / T16777-2008 "Test Methods for Building Waterproof Coatings". The coating thickness was set according to the film requirements of 1.0 ± 0.2 mm in JG / T375-2012 "Acrylic High-Elastic Waterproof Coating for Metal Roofs" standard, and the performance detection of the set items was carried out with reference to the performance indicators of ASTM D6694. Each embodiment and comparative example was tested. The reference standards for each test index are shown in Table 1, and the test results are shown in Table 2.

[0128] Table 1

[0129] Serial number Item Technical index 1 Tensile strength / MPa ≥1.03 2 Elongation at break / % ≥100 3 Retention rate of tensile strength after artificial weathering treatment / % ≥80 4 Elongation at break after artificial weathering treatment / % ≥100

[0130] II. Abrasion Resistance Testing

[0131] The wear resistance of the exterior wall waterproof coatings of Examples 1-11 and Comparative Examples 1-3 was tested. The test method was based on GB / T 1768-2006. Each example and comparative example was tested, and the test results are shown in Table 2.

[0132] Table 2

[0133]

[0134] Combined with Examples 1-4, Comparative Examples 1-3 and Tables 1-2, it can be seen that the composite material formed by nano-silicon and dendritic molecules can act together with the silicone main chain, mercaptoethanol, etc. in the coating to significantly improve the tensile strength and wear resistance of the coating. This is because the dendritic molecule nano-silicon composite material can evenly disperse nano-silicon in the coating system, and a stable three-dimensional network structure is formed in the coating system. Cooperating with the silicone main chain in the coating system can not only further improve the tensile strength and wear resistance of the coating, but also form a water-repellent layer formed by the oriented arrangement of a large number of end groups -CH3 on the surface of the three-dimensional network structure, and the persistence is strong, thereby improving the waterproof performance of the coating.

[0135] Combined with Examples 1, 5-6 and Tables 1-2, it can be seen that when oleic acid polyglycol active ester is not used or oleic acid is used instead of oleic acid polyglycol active ester during the preparation of dendritic molecules, the tensile strength and wear resistance of the coating decrease. This is because when preparing the dendritic molecule nano-silicon composite material, oleic acid polyglycol active ester can not only effectively encapsulate nano-silicon to avoid the agglomeration of nano-silicon, but also activate the carboxyl functional groups on the dendritic molecules, improving the binding degree of the encapsulated nano-silicon and dendritic molecules. Therefore, the binding effect of nano-silicon and dendritic molecules can be improved.

[0136] Combined with Examples 1, 7 and Tables 1-2, it can be seen that when the composite materials for preparing dendritic molecule nano-silicon are directly mixed together for preparation, nano-silicon and dendritic molecules are prone to agglomeration effects, which is not conducive to the full reaction of the two to form an orderly and regular three-dimensional network structure, and is not conducive to the improvement of the tensile properties of the coating.

[0137] Combined with Examples 1, 8-9 and Tables 1-2, it can be seen that when the heating temperature in S3 is too high or too low, it is not conducive to the formation of an orderly and regular three-dimensional network structure of the dendritic molecule nano-silicon composite material, and is not conducive to the improvement of the tensile strength and wear resistance of the coating.

[0138] Combined with Examples 1, 10-11 and Tables 1-2, it can be seen that when the temperature in Step 2 or Step 3 is too high, the cooperative effect of each component in the coating is weakened, which is not conducive to the improvement of the tensile strength and wear resistance of the coating.

[0139] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A silicone-modified exterior wall waterproof coating, characterized in that: It includes raw materials in the following parts by weight: 90 - 120 parts of amino silicone, 90 - 120 parts of vinyl silicone, 50 - 80 parts of mercaptoethanol, 3 - 5 parts of dendritic molecular nano - silicon composite material, 100 - 120 parts of alcohol solvent, and 350 - 450 parts of water; The dendritic molecular nano - silicon composite material is prepared by a method including the following steps: S1: Mix and disperse nano - silicon and oleic acid polyethylene glycol active ester to obtain a first suspension; mix and disperse dendritic molecules and organic solvent to obtain a second suspension; S2: Mix and stir N - hydroxysuccinimide, 1 - ethyl - (3 - dimethylaminopropyl) carbodiimide with the second suspension to obtain an activated mixture; S3: Mix the activated mixture with the first suspension, heat and stir, and the obtained product is purified and dried to obtain the dendritic molecular nano - silicon composite material.

2. The silicone-modified exterior wall waterproof coating according to claim 1, characterized in that: Based on the dendritic molecular nano - silicon composite material, it includes raw materials in the following parts by weight: 3 - 5 parts of the nano - silicon, 5 - 9 parts of the oleic acid polyethylene glycol active ester, 1 - 2 parts of the dendritic molecules, 10 - 20 parts of the organic solvent, 0.5 - 1 part of the N - hydroxysuccinimide, and 0.5 - 2 parts of the 1 - ethyl - (3 - dimethylaminopropyl) carbodiimide.

3. An organosilicon-modified exterior wall waterproof coating according to claim 1, characterized in that: In S1, the first suspension is obtained after dispersing for 3 - 5 min, and the second suspension is obtained after dispersing for 4 - 6 min; the stirring time in S2 is 10 - 15 min; the heating temperature in S3 is 60 - 80 °C, and the stirring time is 8 - 12 h.

4. The silicone-modified exterior wall waterproof coating according to claim 1, wherein: The particle size of the nano - silicon is 0.5 - 4 nm.

5. An organosilicon-modified exterior wall waterproof coating according to claim 1, characterized in that: The dendritic molecules include any one or a mixture of two of PAMAM dendritic molecules and aryl ether dendritic molecules.

6. The silicone-modified exterior wall waterproof coating according to claim 1, characterized in that: The amino silicone includes at least one of ammonia - terminated polydimethylsiloxane and 3 - aminopropylmethyldimethoxysilane.

7. An organosilicon-modified exterior wall waterproof coating according to claim 1, characterized in that: The vinyl silicone includes at least one of vinyltriacetoxysilane and vinyltriisopropenyloxysilane.

8. The preparation method of the silicone-modified exterior wall waterproof coating according to any one of claims 1-7, characterized in that: It includes the following steps: Step 1, mix the amino silicone, the vinyl silicone, the mercaptoethanol and the alcohol solvent to obtain a silicone mixture; Step 2, add the water drop - by - drop to the silicone mixture and heat to obtain an intermediate product; Step 3, mix the dendritic molecular nano - silicon composite material with the intermediate product, heat and stir to obtain the organosilicon - modified exterior wall waterproof coating.

9. The preparation method of the silicone-modified exterior wall waterproof coating according to claim 8, characterized in that: The heating temperature in Step 2 is 60 - 70 °C, and the heating time is 1 - 2 h; the heating temperature in Step 3 is 40 - 50 °C, and the heating time is 2 - 3 h.

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