An epoxy-based waterproof coating and a preparation method thereof

Abstract

This invention relates to the field of coating technology and discloses a waterproof coating based on epoxy resin and its preparation method. The waterproof coating is formed by mixing epoxy resin as the base material with modified kaolin and other auxiliary materials. The modified kaolin is obtained by modifying the surface of kaolin with a macromolecular modifier. The macromolecular modifier has an alternating block structure of organofluorine and organosilicon, which can participate in the subsequent curing process of epoxy resin, thereby forming an interlink with the epoxy resin molecular chain. This improves the interface between kaolin and epoxy resin, allowing kaolin to fully exert its reinforcing advantages. As a result, the coating formed after curing has good impact toughness. The organofluorine and organosilicon in the macromolecular modifier structure have extremely low surface energy, which can form a superhydrophobic layer on the coating surface, giving the coating a superhydrophobic effect, thereby further improving the waterproof performance of the coating.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a waterproof coating based on epoxy resin and its preparation method. Background Technology

[0002] Waterproof coatings are specifically designed to prevent moisture penetration and are typically composed of resins, fillers, and additives. After mixing, reacting, and curing, these components form a dense, waterproof layer on the substrate surface, effectively blocking the penetration of moisture and other harmful substances. Waterproof coatings offer advantages such as easy application, strong adaptability, and excellent waterproofing performance, and are therefore widely used in construction projects.

[0003] Epoxy resin, as an important resin material, is a key component in coatings due to its excellent aging resistance, freeze-thaw resistance, and corrosion resistance. Epoxy resin coatings use epoxy resin as the main component, and with the addition of dispersants and curing agents, they form a solidified body with a three-dimensional network structure after reaction and curing. This structure gives epoxy resin coatings excellent adhesion and durability.

[0004] However, epoxy resin is brittle and has poor toughness after curing. In practice, its waterproof performance is also relatively poor, and it cannot prevent water penetration. As a waterproof coating, epoxy resin still has certain limitations in its application. Therefore, improving the functionality of epoxy resin is of great significance. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides an epoxy resin-based waterproof coating and its preparation method.

[0007] (II) Technical Solution

[0008] A method for preparing an epoxy resin-based waterproof coating, wherein the waterproof coating is made from the following raw materials measured in parts by weight:

[0009] 45-48 parts epoxy resin;

[0010] Add 2-3.5 parts of modified kaolin components;

[0011] Thixotropic agent 0.5-1.5 parts;

[0012] Leveling agent 0.5-1 part;

[0013] 6-8 parts dispersant;

[0014] 0.5-1 part defoamer;

[0015] 15-25 parts of curing agent;

[0016] 3-5 parts of curing accelerator;

[0017] The preparation method includes the following steps:

[0018] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0019] The second step involves adding epoxy resin, thixotropic agent, leveling agent, and dispersant to a mixing tank, setting the stirring speed to 300-500 r / min, and mechanically stirring until homogeneous. Then, the modified kaolin additive is added to the mixing tank, and the stirring speed is adjusted to 800-1000 r / min. The mixture is stirred for 40-60 minutes, followed by the addition of defoamer. After stirring for 20-30 minutes, the mixture is allowed to stand for 1-2 hours to form the precursor material.

[0020] The third step is to add the curing agent and curing accelerator to the precursor, stir well, and store at room temperature.

[0021] As a further aspect of the present invention, the epoxy resin is at least one of bisphenol A type epoxy resin or bisphenol F type epoxy resin.

[0022] As a further aspect of the present invention, the preparation method of the modified kaolin additive is as follows:

[0023] Step S1: Kaolin Halogenation Modification

[0024] Kaolin is dispersed in an aqueous ethanol solution, and then a halosilane coupling agent is added to the resulting dispersion. The temperature is raised to 60-70℃, and the reaction is stirred continuously for 6-9 hours. After cooling, the material is discharged, washed, and vacuum dried to obtain halomodified kaolin.

[0025] Step S2: Preparation of modified kaolin additives

[0026] Halogenated modified kaolin was added to N,N-dimethylformamide and sonicated until a uniform dispersion was formed. Then, a macromolecular modifier was added to the dispersion, along with the acid-binding agent triethylamine. After the addition was complete, the temperature was raised to 70-80℃ and kept at that temperature for 8-12 hours. The mixture was then cooled and discharged, and the solid material was centrifuged to obtain the modified kaolin additive.

[0027] As a further aspect of the present invention, in step S1, the halosilane coupling agent is selected from any one of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, or 3-bromopropyltrimethoxysilane.

[0028] As a further aspect of the present invention, the preparation method of the macromolecular modifier in step S2 is as follows:

[0029] 1,5-Bis(epoxypropoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane was added to toluene solvent and mechanically stirred until a homogeneous solution was formed. Then, a diamine bridging agent was added to the solution, and nitrogen gas was introduced for protection. The temperature was then raised to 80-90°C at a controlled heating rate of 3-5°C / min. The temperature was maintained and stirred for 12-18 hours. After that, the nitrogen gas was removed, the heating was stopped, the product was collected, and the macromolecular modifier was obtained through purification.

[0030] As a further embodiment of the present invention, the diamine bridging agent is 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane.

[0031] As a further aspect of the present invention, the molar ratio of 1,5-bis(epoxypropoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane and the diamine bridging agent is 1:1-1.2.

[0032] In the above technical solution, kaolin is first surface modified with a silane coupling agent containing halogen groups to form halogenated modified kaolin with halogen substituents on its surface.

[0033] 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 a diamine bridging agent. By controlling the ratio of the two, a macromolecular modifier with an alternating linking structure of organofluorine and organosilicon blocks and an active amino substituent at the end of the structure can be obtained.

[0034] Finally, the halogen substituents of the halogenated kaolinite were substituted with the active amino groups at the structural ends of the macromolecular modifier to modify the surface of the kaolinite, thus obtaining the modified kaolinite additive.

[0035] As a further embodiment 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-epoxycyclohexyl carboxylate; the defoamer is any one of BYK-052N or BYK-085; the curing agent is any one of amine curing agents; and the curing accelerator is any one of imidazole curing accelerators.

[0036] A waterproof coating based on epoxy resin is prepared using the above-described preparation method.

[0037] (iii) Beneficial technical effects

[0038] This invention modifies kaolin by modifying its surface with a macromolecular modifier to obtain a modified kaolin additive. The macromolecular modifier has an alternating block structure of organofluorine and organosilicon, and contains a large number of active hydroxyl groups generated by ring-opening reactions. These active hydroxyl groups can participate in the subsequent curing process of epoxy resin, forming an interwoven three-dimensional network structure with the epoxy resin molecular chains. On the one hand, this effectively improves the interface problem between kaolin and the epoxy resin matrix, allowing kaolin to fully utilize its reinforcing advantages, resulting in a coating with good impact toughness after curing. Furthermore, the uniform dispersion of kaolin in the coating, utilizing its layered structure, prevents water penetration, thereby improving the coating's waterproofing effect. On the other hand, the organofluorine and organosilicon in the macromolecular modifier structure have extremely low surface energy, forming a superhydrophobic layer on the coating surface, giving the coating a superhydrophobic effect, further improving its waterproofing performance. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is an infrared analysis test image of a macromolecular modifier. Detailed Implementation

[0041] To facilitate understanding of the present invention, a more complete description will be provided below. Preferred embodiments of the invention are given below. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0042] Preparation Example 1: Preparation of Modified Kaolin Additives:

[0043] Step S1: Kaolin Halogenation Modification

[0044] 1.8g of kaolin was dispersed in an ethanol aqueous solution, and then 3.5g of 3-chloropropyltriethoxysilane was added to the dispersion. The mixture was heated to 65°C and stirred continuously for 8 hours. After cooling, the mixture was discharged, washed, and vacuum dried to obtain halogenated modified kaolin.

[0045] Step S2: Preparation of macromolecular modifiers

[0046] 0.3 g of 1,5-bis(epoxypropoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane was added to toluene solvent and mechanically stirred until a homogeneous solution was formed. Then, 0.35 g of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane was added to the solution. Nitrogen gas was introduced for protection, and the temperature was raised to 85°C at a controlled heating rate of 5°C / min. The temperature was maintained and stirred for 16 h. After that, the nitrogen gas was removed, the heating was stopped, the product was collected, and the macromolecular modifier was obtained through purification.

[0047] Figure 1 This is the infrared analysis spectrum of the macromolecular modifier, where 3397 cm⁻¹... -1 and 3355cm -1 The characteristic absorption peak appearing at 3239 cm⁻¹ is the characteristic absorption peak of NH. -1 The characteristic absorption peak at 3000-3100 is the characteristic absorption peak of hydroxyl group, and the characteristic absorption peak at 1392 cm⁻¹ is the characteristic absorption peak of CH in the benzene ring skeleton. -1 The characteristic absorption peak appearing at 1071 cm⁻¹ is the characteristic absorption peak of CF. -1 The characteristic absorption peak appearing at this point is a characteristic absorption peak of Si-O.

[0048] Step S3: Preparation of modified kaolin additives

[0049] 1.5g of halogenated modified kaolin was added to N,N-dimethylformamide and sonicated until a uniform dispersion was formed. Then, 2.5g of macromolecular modifier was added to the dispersion, along with 0.5g of acid-binding agent triethylamine. After the addition was complete, the temperature was raised to 75℃ and kept at that temperature for 9 hours. The mixture was then cooled and discharged, and the solid material was centrifuged to obtain the modified kaolin additive component.

[0050] Example 1: An epoxy resin-based waterproof coating, made from the following raw materials measured in parts by weight:

[0051] 45 parts of E44 type epoxy resin;

[0052] Two parts of modified kaolin additive;

[0053] 0.5 parts of fumed silica;

[0054] Leveling agent BYK-310 0.5 parts;

[0055] Dispersant: 6 parts of glycerol diglycidyl ether;

[0056] 0.5 parts of defoamer BYK-052N;

[0057] 15 parts of curing agent;

[0058] 3 parts curing accelerator;

[0059] The preparation method of the waterproof coating includes the following steps:

[0060] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0061] Step 2: Add E44 epoxy resin, fumed silica, leveling agent BYK-310, and glyceryl diglycidyl ether to a mixing tank. Set the stirring speed to 300 r / min and stir mechanically until homogeneous. Then add the modified kaolin additive to the mixing tank and adjust the stirring speed to 800 r / min. Stir for 60 min. Next, add defoamer BYK-052N and stir for 20 min. Let stand for 1 h to form the precursor material.

[0062] The third step is to add the curing agent and curing accelerator to the precursor, stir well, and store at room temperature.

[0063] The preparation method of the modified kaolin additive is shown in Preparation Example 1; the curing agent is polyetheramine; the curing accelerator is imidazole, and the same applies to the following.

[0064] Example 2: An epoxy resin-based waterproof coating, made from the following raw materials measured in parts by weight:

[0065] 46 parts of E44 type epoxy resin;

[0066] 3.2 parts of modified kaolin additive;

[0067] 1 part of fumed silica;

[0068] Leveling agent BYK-315N 0.6 parts;

[0069] Dispersant: 8 parts of glycerol diglycidyl ether;

[0070] Defoamer BYK-085 0.8 parts;

[0071] 20 parts of curing agent;

[0072] 4 parts curing accelerator;

[0073] The preparation method of the waterproof coating includes the following steps:

[0074] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0075] Step 2: Add E44 epoxy resin, fumed silica, leveling agent BYK-315N, and glyceryl diglycidyl ether to a mixing tank. Set the stirring speed to 400 r / min and stir mechanically until homogeneous. Then add the modified kaolin additive to the mixing tank and adjust the stirring speed to 1000 r / min. Stir for 50 min, then add defoamer BYK-085 and stir for 30 min. Let stand for 2 h to form the precursor material.

[0076] The third step is to add the curing agent and curing accelerator to the precursor, stir well, and store at room temperature.

[0077] Example 3: An epoxy resin-based waterproof coating, made from the following raw materials measured in parts by weight:

[0078] 48 parts of E44 type epoxy resin;

[0079] 3.5 parts of modified kaolin additives;

[0080] 1.5 parts of fumed silica;

[0081] Leveling agent BYK-315N 1 part;

[0082] Dispersant: 8 parts of glycerol diglycidyl ether;

[0083] 1 part of defoamer BYK-085;

[0084] 25 parts of curing agent;

[0085] 5 parts of curing accelerator;

[0086] The preparation method of the waterproof coating includes the following steps:

[0087] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0088] Step 2: Add E44 epoxy resin, fumed silica, leveling agent BYK-315N, and glyceryl diglycidyl ether to a mixing tank. Set the stirring speed to 500 r / min and stir mechanically until homogeneous. Then add the modified kaolin additive to the mixing tank and adjust the stirring speed to 1000 r / min. Stir for 40 min. Next, add defoamer BYK-085 and stir for 30 min. Let stand for 2 h to form the precursor material.

[0089] The third step is to add the curing agent and curing accelerator to the precursor, stir well, and store at room temperature.

[0090] Comparative Example 1: An epoxy resin-based waterproof coating, made from the following raw materials measured in parts by weight:

[0091] 46 parts of E44 type epoxy resin;

[0092] 3.2 parts of kaolin;

[0093] 1 part of fumed silica;

[0094] Leveling agent BYK-315N 0.6 parts;

[0095] Dispersant: 8 parts of glycerol diglycidyl ether;

[0096] Defoamer BYK-085 0.8 parts;

[0097] 20 parts of curing agent;

[0098] 4 parts curing accelerator;

[0099] The preparation method of the waterproof coating includes the following steps:

[0100] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0101] Step 2: Add E44 epoxy resin, fumed silica, leveling agent BYK-315N, and glyceryl diglycidyl ether to a mixing tank. Set the stirring speed to 400 r / min and stir mechanically until homogeneous. Then add kaolin to the mixing tank and adjust the stirring speed to 1000 r / min. Stir for 50 min. Next, add defoamer BYK-085 and stir for 30 min. Let stand for 2 h to form the precursor material.

[0102] The third step is to add the curing agent and curing accelerator to the precursor, stir well, and store at room temperature.

[0103] Comparative Example 2, an epoxy resin-based waterproof coating, is made from the following raw materials measured in parts by weight:

[0104] 46 parts of E44 type epoxy resin;

[0105] 1 part of fumed silica;

[0106] Leveling agent BYK-315N 0.6 parts;

[0107] Dispersant: 8 parts of glycerol diglycidyl ether;

[0108] Defoamer BYK-085 0.8 parts;

[0109] 20 parts of curing agent;

[0110] 4 parts curing accelerator;

[0111] The preparation method of the waterproof coating includes the following steps:

[0112] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0113] The second step involves adding E44 epoxy resin, fumed silica, leveling agent BYK-315N, and glyceryl diglycidyl ether to a mixing tank. The stirring speed is set to 400 r / min. After mechanically stirring until uniform, defoamer BYK-085 is added. After stirring for 30 minutes, the mixture is allowed to stand for 2 hours to form a precursor material.

[0114] The third step is to add the curing agent and curing accelerator to the precursor, stir well, and store at room temperature.

[0115] Test Example 1: The coatings prepared in the Examples and Comparative Examples were used to make coatings, and the following performance tests were conducted:

[0116] Impact performance testing was conducted according to standard GB / T 1732-2020;

[0117] The water contact angle of the coating was tested using a TC-A3 automatic contact angle measuring instrument.

[0118] The test results are recorded in Table 1:

[0119] Table 1 - Test Results

[0120]

[0121] Test results show that the coating prepared by using the modified kaolin additive component in Preparation Example 1 of the present invention as an additive has significantly stronger impact resistance after curing, and the water contact angle is greater than 150°, exhibiting superhydrophobic effect, which can effectively prevent water penetration and has good waterproof effect.

[0122] When using unmodified kaolin as an additive, it is evident that the impact strength of the coating decreases significantly. This is due to the interfacial issues between kaolin and epoxy resin, which prevents it from being evenly dispersed and thus hinders the full realization of its advantages.

[0123] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0124] Based on the preferred embodiments of the present invention, and through the above description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing an epoxy resin-based waterproof coating, characterized in that, The waterproof coating is made from the following raw materials measured in parts by weight: 45-48 parts epoxy resin; Add 2-3.5 parts of modified kaolin components; Thixotropic agent 0.5-1.5 parts; Leveling agent 0.5-1 part; 6-8 parts dispersant; 0.5-1 part defoamer; 15-25 parts of curing agent; 3-5 parts of curing accelerator; The preparation method includes the following steps: Step 1: Weigh out each ingredient according to the specified weight proportions and set aside. The second step involves adding epoxy resin, thixotropic agent, leveling agent, and dispersant to a mixing tank, setting the stirring speed to 300-500 r / min, and mechanically stirring until homogeneous. Then, the modified kaolin additive is added to the mixing tank, and the stirring speed is adjusted to 800-1000 r / min. The mixture is stirred for 40-60 minutes, followed by the addition of defoamer. After stirring for 20-30 minutes, the mixture is allowed to stand for 1-2 hours to form the precursor material. The third step is to add the curing agent and curing accelerator to the precursor, stir well, and store at room temperature. The preparation method of the modified kaolin additive is as follows: Step S1: Kaolin Halogenation Modification Halogenated modified kaolin can be prepared by surface modification of kaolin using a halosilane coupling agent. Step S2: Preparation of modified kaolin additives Modified kaolin additives can be obtained by further surface treatment of halogenated modified kaolin using macromolecular modifiers. The preparation method of the macromolecular modifier is as follows: 1,5-Bis(glycidoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane was added to toluene solvent and mechanically stirred until a homogeneous solution was formed. Then, a diamine bridging agent was added to the solution, and nitrogen gas was introduced for protection. The temperature was then raised to 80-90℃ at a controlled heating rate of 3-5℃ / min. The temperature was maintained and stirred for 12-18 hours. After that, the nitrogen gas was removed, the heating was stopped, the product was collected, and the macromolecular modifier was obtained through purification. The diamine bridging agent is 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane; The molar ratio of 1,5-bis(epoxypropoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane and the diamine bridging agent is 1:1-1.

2.

2. The method for preparing an epoxy resin-based waterproof coating according to claim 1, characterized in that, The epoxy resin is at least one of bisphenol A type epoxy resin or bisphenol F type epoxy resin.

3. The method for preparing an epoxy resin-based waterproof coating according to claim 1, characterized in that, In step S1, the halosilane coupling agent is selected from any one of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, or 3-bromopropyltrimethoxysilane.

4. The method for preparing an epoxy resin-based waterproof coating according to claim 1, characterized in that, 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-epoxycyclohexyl carboxylate; the defoamer is either BYK-052N or BYK-085; the curing agent is any one of amine curing agents; and the curing accelerator is any one of imidazole curing accelerators.

5. A waterproof coating based on epoxy resin, characterized in that, It is prepared by the preparation method described in any one of claims 1-4.

Images