Waterproof coating based on epoxy resin and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and discloses a waterproof coating based on epoxy resin and a preparation method thereof.The waterproof coating is formed by mixing epoxy resin serving as a base material with auxiliary materials such as a modified kaolin adding component, and the modified kaolin adding component is prepared by modifying the surface of kaolin with a macromolecular modifier. The macromolecular modifier has an organic fluorine and organic silicon block alternate connection structure, and can participate in the subsequent curing process of epoxy resin, so that the macromolecular modifier is mutually connected with an epoxy resin molecular chain, the interface problem between kaolin and an epoxy resin base material is further improved, kaolin can fully exert the self-enhancement advantage, and the service life of kaolin is prolonged. Furthermore, a coating formed after the coating is cured has good impact toughness, organic fluorine and organic silicon in a macromolecular modifier structure have extremely low surface energy, a super-hydrophobic layer can be formed on the surface of the coating, the coating is endowed with a super-hydrophobic effect, and the waterproof performance of the coating is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to an epoxy resin-based waterproof coating and a preparation method thereof. Background Art

[0002] Waterproof coating is a kind of coating specially used to prevent water penetration, usually composed of resin, filler and additives. After mixing, reacting and curing, these ingredients can form a dense waterproof layer on the surface of the substrate, effectively blocking the penetration of water and other harmful substances. Waterproof coating has the advantages of convenient construction, strong adaptability and good waterproof effect, so it has been widely used in construction projects.

[0003] As an important resin material, epoxy resin has become an important component in coatings due to its excellent aging resistance, freeze-thaw resistance and corrosion resistance. Epoxy resin coatings are mainly composed of epoxy resin, and by adding additives such as dispersants and curing agents, they form a solid body with a three-dimensional network structure after reaction and curing. This structure makes epoxy resin coatings have excellent bonding properties and durability.

[0004] However, since epoxy resin is very brittle after curing and has poor toughness, and in actual performance, its waterproof performance is also relatively general and cannot prevent the penetration of water, as a waterproof coating, epoxy resin still has certain limitations in use at this stage. Therefore, it is of great significance to improve the functionality of epoxy resin. Summary of the invention

[0005] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides an epoxy resin-based waterproof coating and a preparation method thereof.

[0006] (II) Technical solution A method for preparing a waterproof coating based on epoxy resin, wherein the waterproof coating is prepared by using the following raw materials measured in parts by weight: Epoxy resin 45-48 parts; Modified kaolin added component 2-3.5 parts; Thixotropic agent 0.5-1.5 parts; 0.5-1 part of leveling agent; Dispersant 6-8 parts; Defoaming agent 0.5-1 part; 15-25 parts of curing agent; 3-5 parts of curing accelerator; The preparation method comprises the following steps: The first step is to weigh each raw material according to the weight and set aside; Step 2: Add epoxy resin, thixotropic agent, leveling agent, and dispersant into a stirring kettle. Set the stirring rate to 300 - 500 r / min. After mechanical stirring evenly, add the modified kaolin additive component into the stirring kettle. Adjust the stirring rate to 800 - 1000 r / min and stir for 40 - 60 min. Then continue to add defoaming agent and stir for 20 - 30 min. After that, let it stand for 1 - 2 h to form a precursor material. Step 3: Add curing agent and curing accelerator into the precursor material, stir evenly, and store at room temperature.

[0007] As a further aspect of the present invention, the epoxy resin is at least one of bisphenol A epoxy resin or bisphenol F epoxy resin.

[0008] As a further aspect of the present invention, the preparation method of the modified kaolin additive component is as follows: Step S1: Halogenation modification of kaolin Disperse kaolin in an ethanol aqueous solution. Then add a halogenated silane coupling agent into the formed dispersion liquid. Heat up to 60 - 70 °C and continuously stir and react for 6 - 9 h. After that, cool down and discharge the material. After washing and vacuum drying treatment, halogenated modified kaolin can be obtained. Step S2: Preparation of modified kaolin additive component Add halogenated modified kaolin into N,N - dimethylformamide and ultrasonicate to form a uniform dispersion liquid. Then add a macromolecular modifier into the dispersion liquid, and at the same time add a deacidifying agent triethylamine. After adding, raise the temperature to 70 - 80 °C and continuously keep warm for 8 - 12 h. Cool down and discharge the material, and centrifuge to obtain a solid material, thus obtaining the modified kaolin additive component.

[0009] As a further aspect of the present invention, in step S1, the halogenated silane coupling agent is selected from any one of 3 - chloropropyltrimethoxysilane, 3 - chloropropyltriethoxysilane, or 3 - bromopropyltrimethoxysilane.

[0010] As a further aspect of the present invention, in step S2, the preparation method of the macromolecular modifier is as follows: Add 1,5 - bis(epoxypropoxypropyl) - 3 - phenyl - 1,1,3,5,5 - pentamethyltrisiloxane into toluene solvent. After mechanical stirring to form a uniform solution, add a diamine bridging agent into the solution, and introduce nitrogen for protection. Then control the heating rate to 3 - 5 °C / min and raise the temperature to 80 - 90 °C. Continuously keep warm and stir for 12 - 18 h. Then remove nitrogen, stop heating, collect the product, and through a purification treatment process, the macromolecular modifier can be obtained.

[0011] As a further solution of the present invention, the diamine bridging agent is 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane.

[0012] As a further solution of the present invention, the molar ratio of 1,5-bis(epoxypropoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane to the diamine bridging agent is 1:1 - 1.2.

[0013] In the above technical solution, first, the kaolin is surface-modified with a silane coupling agent containing a halogen group to form a halogenated modified kaolin with halogen substituents on the surface.

[0014] Next, using 1,5-bis(epoxypropoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane as a linker, a continuous ring-opening addition reaction is carried out with the diamine bridging agent. By controlling the dosage ratio of the two, a macromolecular modifier with an alternating connection structure of organofluorine and organosilicon blocks and an active amino substituent at the end of the structure can be prepared.

[0015] Finally, through the substitution reaction of the halogen substituents of the halogenated modified kaolin with the active amino groups at the end of the macromolecular modifier structure, the macromolecular modifier is modified on the surface of the kaolin to obtain a modified kaolin additive component.

[0016] As a further solution of the present invention, the thixotropic agent is fumed silica; the leveling agent is at least one of BYK-310 or BYK-315N; the dispersant is at least one of glycerol diglycidyl ether or 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate; the defoaming agent is any one of BYK-052N or BYK-085; the curing agent is any one of amine curing agents; the curing accelerator is any one of imidazole curing accelerators.

[0017] A waterproof coating based on epoxy resin is prepared by using the above preparation method.

[0018] (III) Beneficial technical effects The present invention prepares a modified kaolin additive component by modifying the surface of kaolin with a macromolecular modifier. The macromolecular modifier has an alternating connection structure of organic fluorine and organosilicon blocks, and a large number of active hydroxyl groups generated by ring-opening reaction are contained in the structure. These active hydroxyl groups can participate in the subsequent curing process of epoxy resin, thereby forming an intertwined and entangled three-dimensional network structure with the epoxy resin molecular chain. On the one hand, it can effectively improve the interfacial problem between kaolin and epoxy resin base material, enabling kaolin to fully exert its own strengthening advantages, and then making the coating formed after the coating is cured have good impact toughness. Moreover, the uniform dispersion of kaolin in the coating can utilize its own layered structure to prevent the infiltration of moisture, thereby improving the waterproof effect of the coating. On the other hand, the organic fluorine and organosilicon in the structure of the macromolecular modifier have extremely low surface energy, which can form a superhydrophobic layer on the surface of the coating, endowing the coating with superhydrophobic effect, thereby further improving the waterproof performance of the coating. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 It is an infrared analysis test chart of the macromolecular modifier. Detailed Embodiments

[0021] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below. Preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present invention more thorough and comprehensive.

[0022] Preparation Example 1, Preparation of Modified Kaolin Additive Component: Step S1, Halogenation Modification of Kaolin Disperse 1.8 g of kaolin in an ethanol aqueous solution, then add 3.5 g of 3-chloropropyltriethoxysilane to the formed dispersion, heat up to 65 °C, continuously stir and react for 8 h, then cool and discharge, and after washing and vacuum drying treatment, halogenated modified kaolin can be obtained; Step S2, Preparation of Macromolecular Modifier 0.3 g of 1,5-bis(glycidoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane is added to a toluene solvent, and mechanically stirred to form a uniform solution. Then, 0.35 g of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane is added to the solution, and nitrogen is introduced for protection. Then, the heating rate is controlled to be 5°C / min, and the temperature is raised to 85°C. After continuous stirring and heat preservation for 16 hours, the nitrogen is removed, the heating is stopped, the product is collected, and a macromolecular modifier is obtained through a purification process. Figure 1 This is the infrared analysis test image of the macromolecular modifier, where 3397cm -1 and 3355cm -1 The characteristic absorption peak at 3239cm is the NH characteristic absorption peak. -1 The characteristic absorption peak at 1392cm is the characteristic absorption peak of hydroxyl group, the characteristic absorption peak at 3000-3100cm is the characteristic absorption peak of CH of benzene ring skeleton, -1 The characteristic absorption peak at 1071cm is the CF characteristic absorption peak. -1 The characteristic absorption peak that appears at is the Si-O characteristic absorption peak.

[0023] Step S3: preparing modified kaolin additive components 1.5 g of halogenated modified kaolin was added to N,N-dimethylformamide, and ultrasonicated to form a uniform dispersion. Then 2.5 g of macromolecular modifier was added to the dispersion, and 0.5 g of acid binding agent triethylamine was added at the same time. After the addition, the temperature was raised to 75°C and kept warm for 9 hours. The material was cooled and discharged, and the solid material was centrifuged to obtain a modified kaolin additive component.

[0024] Example 1, a waterproof coating based on epoxy resin, is made of the following raw materials measured in parts by weight: 45 parts of E44 epoxy resin; 2 parts of modified kaolin additive component; 0.5 parts of fumed silica; Leveling agent BYK-310 0.5 parts; Dispersant: 6 parts of glycerol diglycidyl ether; Defoaming agent BYK-052N 0.5 parts; 15 parts of curing agent; 3 parts of curing accelerator; The preparation method of the waterproof coating comprises the following steps: The first step is to weigh each raw material according to the weight and set aside; Step 2: Add E44 epoxy resin, fumed silica, leveling agent BYK-310, and glycerol diglycidyl ether to the stirring kettle, set the stirring rate to 300r / min, and stir evenly mechanically. Then add the modified kaolin additive to the stirring kettle, adjust the stirring rate to 800r / min, stir for 60min, and then continue to add defoaming agent BYK-052N. After stirring for 20min, let it stand for 1h to form a precursor material. Step 3: Add the curing agent and curing accelerator to the precursor, stir evenly, and store at room temperature.

[0025] The preparation method of the modified kaolin additive component is shown in Preparation Example 1; the curing agent is polyetheramine; the curing accelerator is imidazole, and the rest are the same.

[0026] Example 2, a waterproof coating based on epoxy resin, is made of the following raw materials measured in parts by weight: 46 parts of E44 epoxy resin; 3.2 parts of modified kaolin additive; 1 part of fumed silica; Leveling agent BYK-315N 0.6 parts; Dispersant: 8 parts of glycerol diglycidyl ether; Defoamer BYK-085 0.8 parts; 20 parts of curing agent; 4 parts of curing accelerator; The preparation method of the waterproof coating comprises the following steps: The first step is to weigh each raw material according to the weight and set aside; Step 2: Add E44 epoxy resin, fumed silica, leveling agent BYK-315N, and glycerol diglycidyl ether to the stirring kettle, set the stirring rate to 400r / min, and stir evenly mechanically. Then add the modified kaolin additive component to the stirring kettle, adjust the stirring rate to 1000r / min, stir for 50min, and then continue to add defoaming agent BYK-085. After stirring for 30min, let it stand for 2h to form a precursor material. Step 3: Add the curing agent and curing accelerator to the precursor, stir evenly, and store at room temperature.

[0027] Example 3, a waterproof coating based on epoxy resin, is made of the following raw materials measured in parts by weight: 48 parts of E44 epoxy resin; 3.5 parts of modified kaolin additive; 1.5 parts of fumed silica; Leveling agent BYK-315N 1 part; 8 parts of dispersant glycerol diglycidyl ether; 1 part of defoamer BYK-085; 25 parts of curing agent; 5 parts of curing accelerator; The preparation method of the waterproof coating includes the following steps: First step, weigh each raw material according to the weight parts and set aside; Second step, add E44 type epoxy resin, fumed silica, leveling agent BYK-315N, and glycerol diglycidyl ether into a stirring kettle, set the stirring rate to 500 r / min, stir mechanically until evenly mixed, then add the modified kaolin additive component into the stirring kettle, adjust the stirring rate to 1000 r / min, stir for 40 min, then continue to add defoamer BYK-085, stir for 30 min, and then let it stand for 2 h to form a precursor; Third step, add the curing agent and curing accelerator into the precursor, stir evenly, and store at room temperature.

[0028] Comparative Example 1, a waterproof coating based on epoxy resin, is made of the following raw materials measured by weight parts: 46 parts of E44 type epoxy resin; 3.2 parts of kaolin; 1 part of fumed silica; 0.6 part of leveling agent BYK-315N; 8 parts of dispersant glycerol diglycidyl ether; 0.8 part of defoamer BYK-085; 20 parts of curing agent; 4 parts of curing accelerator; The preparation method of the waterproof coating includes the following steps: First step, weigh each raw material according to the weight parts and set aside; Second step, add E44 type epoxy resin, fumed silica, leveling agent BYK-315N, and glycerol diglycidyl ether into a stirring kettle, set the stirring rate to 400 r / min, stir mechanically until evenly mixed, then add kaolin into the stirring kettle, adjust the stirring rate to 1000 r / min, stir for 50 min, then continue to add defoamer BYK-085, stir for 30 min, and then let it stand for 2 h to form a precursor; Third step, add the curing agent and curing accelerator into the precursor, stir evenly, and store at room temperature.

[0029] Comparative Example 2, a waterproof coating based on epoxy resin, is made of the following raw materials measured by weight parts: 46 parts of E44 type epoxy resin; 1 part of fumed silica; 0.6 part of leveling agent BYK-315N; 8 parts of dispersant glycerol diglycidyl ether; 0.8 part of defoaming agent BYK-085; 20 parts of curing agent; 4 parts of curing accelerator; The preparation method of the waterproof coating includes the following steps: First step, weigh each raw material according to the weight parts and set aside; Second step, add E44 type epoxy resin, fumed silica, leveling agent BYK-315N, and glycerol diglycidyl ether into a stirring kettle, set the stirring rate to 400 r / min, stir evenly mechanically, then continue to add defoaming agent BYK-085, stir for 30 min, and then stand for 2 h to form a precursor; Third step, add the curing agent and the curing accelerator into the precursor, stir evenly, and store at room temperature.

[0030] Test Example 1, make the coatings prepared in the examples and comparative examples into coatings, and conduct the following performance tests: According to the standard GB / T 1732-2020, conduct an impact performance test; Use a TC-A3 type automatic contact angle measuring instrument to test the water contact angle of the coating; The test results are recorded in Table 1: Table 1 - Test Results

[0031] The test results show that the coating formed after curing the coating prepared with the modified kaolin additive component in Preparation Example 1 of the present invention significantly has stronger impact performance, and the water contact angle is greater than 150°, having a superhydrophobic effect, which can effectively prevent the penetration of moisture and has a good waterproof effect.

[0032] When using unmodified kaolin as an additive, it can be clearly seen that the impact strength of the coating significantly decreases, which is due to the interfacial problem between kaolin and epoxy resin, resulting in its inability to be evenly dispersed and difficult to fully exert its own advantages.

[0033] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0034] Enlightened by the ideal embodiments of the present invention, through the above description, relevant personnel can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A method for preparing a waterproof coating based on epoxy resin, characterized in that: The waterproof coating is made of the following raw materials measured in parts by weight: Epoxy resin 45-48 parts; Modified kaolin added component 2-3.5 parts; Thixotropic agent 0.5-1.5 parts; 0.5-1 part of leveling agent; Dispersant 6-8 parts; Defoaming agent 0.5-1 part; 15-25 parts of curing agent; 3-5 parts of curing accelerator; The preparation method comprises the following steps: The first step is to weigh each raw material according to the weight and set aside; Step 2: Add epoxy resin, thixotropic agent, leveling agent and dispersant to the stirring kettle, set the stirring rate to 300-500r / min, and after mechanical stirring, add the modified kaolin additive component to the stirring kettle, adjust the stirring rate to 800-1000r / min, stir for 40-60min, then continue to add defoamer, stir for 20-30min, and let stand for 1-2h to form a precursor; Step 3: Add the curing agent and curing accelerator to the precursor, stir evenly, and store at room temperature.

2. The method for preparing a waterproof coating based on epoxy resin according to claim 1, characterized in that: The epoxy resin is at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

3. The method for preparing a waterproof coating based on epoxy resin according to claim 1, characterized in that: The preparation method of the modified kaolin additive component is as follows: Step S1: halogenation modification of kaolin The halogenated modified kaolin can be prepared by using a halogenated silane coupling agent to modify the surface of kaolin; Step S2: preparing modified kaolin additives The modified kaolin additive component can be prepared by further surface treating the halogenated modified kaolin using a macromolecular modifier.

4. The method for preparing a waterproof coating based on epoxy resin according to claim 3, characterized in that: In the step S1, the halogenated silane coupling agent is selected from any one of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane or 3-bromopropyltrimethoxysilane.

5. The method for preparing a waterproof coating based on epoxy resin according to claim 3, characterized in that: In step S2, the preparation method of the macromolecular modifier is as follows: 1,5-bis(glycidoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane is added to a toluene solvent, and mechanically stirred to form a uniform solution. Then, a diamine bridging agent is added to the solution, and nitrogen is introduced for protection. Then, the heating rate is controlled to be 3-5°C / min, and the temperature is raised to 80-90°C. After continuous stirring and heat preservation for 12-18 hours, the nitrogen is removed, the heating is stopped, the product is collected, and a macromolecular modifier is obtained through a purification process.

6. The method for preparing a waterproof coating based on epoxy resin according to claim 5, characterized in that: The diamine bridging agent is 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane.

7. The method for preparing a waterproof coating based on epoxy resin according to claim 5, characterized in that: The molar ratio of the 1,5-bis(glycidoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane to the diamine bridging agent is 1:1-1.

2.

8. The method for preparing a waterproof coating based on epoxy resin according to claim 1, characterized in that: The thixotropic agent is fumed silica; the leveling agent is at least one of BYK-310 and BYK-315N; the dispersant is at least one of glycerol diglycidyl ether and 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate; the defoaming agent is any one of BYK-052N and BYK-085; the curing agent is any one of amine curing agents; and the curing accelerator is any one of imidazole curing accelerators.

9. A waterproof coating based on epoxy resin, characterized in that: The method is prepared according to any one of claims 1 to 8.

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