Waterproof coating and its preparation method and application

Abstract

The present application discloses a waterproof coating, its preparation method, and application. The waterproof coating comprises the following raw material components in parts by weight: 20 to 75 parts of diisocyanate; 100 to 500 parts of bio-based polyol; 100 to 300 parts of plasticizer; and 15 to 60 parts of latent curing agent. The diisocyanate and the bio-based polyol are reacted to form an isocyanate-terminated polyurethane prepolymer, wherein the molar ratio of the isocyanate groups in the diisocyanate to the hydroxyl groups in the bio-based polyol is 1.5:1 to 2.5:1, and after the diisocyanate and the bio-based polyol react to form the isocyanate-terminated polyurethane prepolymer, the molar ratio of the remaining isocyanate groups to the active hydrogen after hydrolysis of the latent curing agent is 1:1 to 1:2. Compared with existing waterproof coatings, the waterproof coating has superior water resistance, acid and alkali resistance, and heat aging resistance, while reducing the use of petrochemical products.

Description

Technical Field

[0001] The present application belongs to the technical field of waterproof coatings, and in particular relates to a waterproof coating and a preparation method and application thereof. Background Art

[0002] Polyurethane waterproof coating is a reaction-curing coating characterized by high strength, high elongation, and excellent water resistance. It is made by mixing an isocyanate-containing prepolymer, produced through the addition polymerization of isocyanates and polyethers, with catalysts, additives, and fillers.

[0003] Composite waterproofing processes represented by coatings and membranes have become a common process in the field of building / road and bridge waterproofing. However, after traditional solvent-based polyurethane waterproof coatings are compounded with asphalt waterproof membranes, the residual unvolatile solvent will cause the waterproof membrane to swell and reduce the physical properties of the asphalt membrane. At the same time, the migration of plasticizers in polyurethane coatings will cause the adhesion between the coating and the asphalt membrane to be weak, easy to fall off, and affect the waterproofing effect. Summary of the Invention

[0004] The embodiments of the present application provide a waterproof coating, a preparation method thereof, and an application thereof, which has more excellent water resistance, acid and alkali resistance, and heat aging resistance than existing waterproof coatings, and at the same time reduces the use of petrochemical products.

[0005] In a first aspect, a waterproof coating is provided, comprising the following raw material components in parts by weight: 20 to 75 parts of diisocyanate; 100 to 500 parts of bio-based polyol; 100 to 300 parts of plasticizer; and 15 to 60 parts of latent curing agent. The diisocyanate and the bio-based polyol are used to react to form an isocyanate group-terminated polyurethane prepolymer, wherein the molar ratio of the isocyanate groups in the diisocyanate to the hydroxyl groups in the bio-based polyol is 1.5:1 to 2.5:1, and after the diisocyanate and the bio-based polyol react to form the isocyanate group-terminated polyurethane prepolymer, the molar ratio of the remaining amount of the isocyanate groups to the active hydrogen after hydrolysis of the latent curing agent is 1:1 to 1:2.

[0006] In the present application, the waterproof coating uses bio-based polyols to generate isocyanate group-terminated polyurethane prepolymers. At the same time, the molar ratio of isocyanate groups to hydroxyl groups in the bio-based polyols and the molar ratio of the residual amount of isocyanate groups to the active hydrogen after hydrolysis of the latent curing agent are controlled, so that the waterproof coating of the present application can not only ensure the bonding effect between the waterproof coating and the asphalt roll, but also has excellent water resistance, acid and alkali resistance, and heat aging resistance.

[0007] In a first possible implementation, the bio-based polyol satisfies at least one of the following conditions: (1) the hydroxyl value of the bio-based polyol is 30 mg KOH / g to 120 mg KOH / g; (2) the functionality of the bio-based polyol is 2 to 5; and (3) the viscosity of the bio-based polyol at 25° C. is 300 cp to 7000 cp.

[0008] In combination with the above possible implementation methods, the plasticizer includes a bio-based reactive plasticizer and a conventional plasticizer, and the mass ratio of the bio-based reactive plasticizer to the conventional plasticizer is 1.5:1 to 14:1. Preferably, the bio-based reactive plasticizer includes one or more of epoxidized soybean oil, epoxidized fatty acid methyl ester and epoxidized linseed oil, and the conventional plasticizer includes one or more of chlorinated paraffins, citrates, phthalates and trioctyl phosphate.

[0009] This application controls the mass ratio of bio-based reactive plasticizers and ordinary plasticizers in the plasticizer, thereby ensuring the construction viscosity of the solvent-free polyurethane waterproof coating, solving the problem of plasticizer migration in the waterproof coating, and ensuring the bonding effect between the polyurethane waterproof coating and the asphalt membrane.

[0010] In combination with the above possible implementation methods, the plasticizer includes a bio-based reactive plasticizer, and the raw material components may further include 0.1 to 0.5 parts of a catalyst, and the mass ratio of the catalyst to the bio-based polyol is 1:200 to 1:5000. The catalyst is used to catalyze the cross-linking reaction of the isocyanate group-terminated polyurethane prepolymer, the latent curing agent and the bio-based reactive plasticizer. Preferably, the catalyst includes one or more of dibutyltin dilaurate, stannous octoate, lead isooctanoate and bismuth isooctanoate.

[0011] In combination with the above possible implementation methods, the raw material components may further include 0.1 to 0.5 parts of a latent curing agent hydrolysis accelerator, and the mass ratio of the latent curing agent hydrolysis accelerator to the latent curing agent is 1:30 to 1:450.

[0012] In combination with the above possible implementation methods, the diisocyanate includes one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate and toluene diisocyanate; and / or, the latent curing agent includes one or more of aldehyde imine latent curing agents, ketimine latent curing agents and oxazolidine latent curing agents.

[0013] In combination with the above possible implementation methods, the raw material components may further include additives, which include, by weight: filler, 100 to 500 parts; pigment, 5 to 10 parts; dispersant, 0.5 to 1 part; defoaming agent, 1 to 3 parts.

[0014] In combination with the above possible implementation methods, the filler includes one or more of nano calcium carbonate, talc, fumed silica, barium sulfate, heavy calcium carbonate, light calcium carbonate and kaolin. Preferably, the particle size of the filler is 800 mesh to 3000 mesh; and / or, the pigment includes one or more of carbon black, red iron oxide, titanium dioxide, yellow iron oxide and composite emerald green; and / or, the dispersant includes a nonionic dispersant and / or an anionic dispersant; and / or, the defoamer includes a silicone defoamer and / or a mineral oil defoamer.

[0015] In a second aspect, a method for preparing a waterproof coating comprises: stirring, mixing and dehydrating 100 to 500 parts of a bio-based polyol and 100 to 300 parts of a plasticizer to obtain a first mixture; adding 20 to 75 parts of a diisocyanate to the first mixture to react to obtain a second mixture; and adding 15 to 60 parts of a latent curing agent to the second mixture to react to obtain a waterproof coating.

[0016] A first possible implementation method is to stir, mix and dehydrate 100 to 500 parts of bio-based polyol and 100 to 300 parts of plasticizer to obtain a first mixture, wherein the bio-based polyol and additive are stirred and heated to 102° C. to 108° C., and then dehydrated for 2 to 4 hours; and / or, stir, mix and dehydrate 100 to 500 parts of bio-based polyol and 100 to 300 parts of plasticizer to obtain a first mixture, and additives may be added before mixing; and / or, add 20 to 75 parts of diisocyanate to the first mixture to react to obtain a second mixture, cool the first mixture to 75 to 80° C., add diisocyanate, and then adjust the temperature to 78 to 82° C. to react for 2 to 4 hours.

[0017] In combination with the above possible implementation methods, the steps of adding 15 to 60 parts of a latent curing agent to the second mixture for mixed reaction to obtain a waterproof coating include: controlling the temperature of the second mixture to 73°C to 77°C, adding a catalyst, and reacting for 0.5h to 2h to obtain a third mixture; controlling the temperature of the third mixture at 73°C to 77°C, adding a latent curing agent, and continuing the reaction for 0.5 to 2h to obtain a fourth mixture; controlling the temperature of the fourth mixture to 65°C to 70°C, adding a latent curing agent hydrolysis accelerator, and reacting for 20min to 50min to obtain a fifth mixture; controlling the temperature of the fifth mixture to 63°C to 67°C, vacuum degassing for 10min to 20min, and discharging under protective gas protection to obtain a waterproof coating.

[0018] In a third aspect, a composite waterproof layer comprises an asphalt waterproof roll and a waterproof coating layer formed by the waterproof coating of the first aspect and / or a waterproof coating layer formed by the waterproof coating prepared by the preparation method of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is a schematic diagram of the curing principle of a waterproof coating using an aldimine latent curing agent according to an embodiment of the present application.

[0021] Figure 2 This is a schematic diagram of the curing principle of a waterproof coating using a ketimine latent curing agent according to an embodiment of the present application.

[0022] Figure 3 This is a schematic diagram of the curing principle of a waterproof coating using an oxazolidine latent curing agent according to an embodiment of the present application.

[0023] Figure 4 This is a schematic diagram of the curing principle of a waterproof coating using an oxazolidine latent curing agent according to another embodiment of the present application. DETAILED DESCRIPTION

[0024] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0025] For simplicity, this application only explicitly discloses certain numerical ranges. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, although not explicitly stated, each point or individual value between the endpoints of a range is included in the range. Thus, each point or individual value may serve as its own lower limit or upper limit and be combined with any other point or individual value, or with other lower limits or upper limits, to form an unspecified range.

[0026] The above invention content of this application is not intended to describe every disclosed embodiment or every implementation in this application. The following description illustrates exemplary embodiments in more detail. In many places throughout the application, guidance is provided through a series of examples, which can be used in various combinations. In each example, the enumeration is only as a representative group and should not be interpreted as exhaustive. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0028] Polyurethane waterproof coatings are made by mixing isocyanate-containing prepolymers generated through the addition polymerization of isocyanates and polyethers, along with catalysts, additives, and fillers. Polyurethane waterproof coatings are reaction-curing coatings characterized by high strength, high elongation, and excellent water resistance. Polyurethane waterproof coatings are commonly made from petrochemical raw materials. Due to fluctuations in crude oil prices and the growing awareness of green environmental protection, the bio-based materials industry, such as bio-based polyols and bio-based plasticizers, is expected to accelerate further, and the industry's development momentum is expected to remain positive.

[0029] Composite waterproofing processes, typically using coatings and membranes, have become a common practice in the construction, road, and bridge waterproofing industries. However, after laminating traditional solvent-based polyurethane waterproofing coatings with asphalt waterproofing membranes, residual unvolatile solvent can cause the membrane to swell, degrading its physical properties. Furthermore, migration of plasticizers in the polyurethane coating can lead to weak adhesion between the coating and the asphalt membrane, causing it to easily fall off and compromise its waterproofing effectiveness. Furthermore, new regulations require polyurethane waterproofing coatings to maintain an 80% bond strength after immersion in water. Existing polyurethane waterproofing coatings struggle to meet this requirement on unprimed cementitious surfaces.

[0030] In view of the above technical problems, the embodiments of the present application provide a waterproof coating that has better water resistance, acid and alkali resistance, and heat aging resistance than existing waterproof coatings, while reducing the use of petrochemical products.

[0031] The following first introduces the waterproof coating provided in the embodiments of the present application.

[0032] According to the present application, the waterproof coating includes the following raw material components in parts by weight: diisocyanate, 20 parts to 75 parts; bio-based polyol, 100 parts to 500 parts; plasticizer, 100 parts to 300 parts; latent curing agent, 15 parts to 60 parts; diisocyanate and bio-based polyol are used to react to form an isocyanate group-terminated polyurethane prepolymer, wherein the molar ratio of the isocyanate group (-NCO) in the diisocyanate to the hydroxyl group (-OH) in the bio-based polyol is 1.5:1 to 2.5:1, for example, The molar ratio can be 1.5:1, 1.8:1, 2:1, 2.2:1, 2.5:1, or any combination of the above values. After the diisocyanate reacts with the bio-based polyol to form the isocyanate group-terminated polyurethane prepolymer, the molar ratio of the remaining isocyanate group (-NCO) to the active hydrogen (α-H) after hydrolysis of the latent curing agent is 1:1 to 1:2. For example, the molar ratio can be 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, or any combination of the above values.

[0033] The inventors discovered that by using bio-based polyols to generate isocyanate group-terminated polyurethane prepolymers, and at the same time controlling the molar ratio of isocyanate groups to hydroxyl groups in the bio-based polyols, as well as the molar ratio of the remaining amount of isocyanate groups to the active hydrogen after hydrolysis of the latent curing agent, the waterproof coating of the present application can not only ensure the bonding effect between the waterproof coating and the asphalt roll, but also improve the water-immersion bonding strength retention rate of the polyurethane waterproof coating, which can ensure that the water-immersion bonding strength retention rate is higher than 80%, and has excellent water resistance, acid and alkali resistance, and heat aging resistance.

[0034] In some specific embodiments, the bio-based polyol satisfies at least one of the following conditions: (1) the hydroxyl value of the bio-based polyol is 30 mg KOH / g to 120 mg KOH / g, for example, 30 mg KOH / g, 40 mg KOH / g, 50 mg KOH / g, 60 mg KOH / g, 70 mg KOH / g, 80 mg KOH / g, 100 mg KOH / g, 120 mg KOH / g, or any combination thereof; (2) the functionality of the bio-based polyol is 2 to 5, for example, 2, 3, 4, or 5; (3) the viscosity of the bio-based polyol at 25° C. is 300 cp to 7000 cp, for example, 300 cp, 500 cp, 800 cp, 1000 cp, 2000 cp, 3000 cp, 4000 cp, 5000 cp, 6000 cp, 7000 cp, or any combination thereof.

[0035] In some specific embodiments, the plasticizer includes a bio-based reactive plasticizer and a conventional plasticizer, and the mass ratio of the bio-based reactive plasticizer to the conventional plasticizer is 1.5:1 to 14:1. For example, it can be 1.5:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 14:1, or any combination range of the above values. Preferably, the bio-based reactive plasticizer includes one or more of epoxidized soybean oil, epoxy fatty acid methyl ester and epoxy linseed oil, and the conventional plasticizer includes one or more of chlorinated paraffins, citrates, phthalates and trioctyl phosphate.

[0036] In the above specific embodiments, the present application controls the mass ratio of the bio-based reactive plasticizer and the ordinary plasticizer in the plasticizer, thereby ensuring the construction viscosity of the solvent-free polyurethane waterproof coating and solving the problem of plasticizer migration in the waterproof coating, thereby ensuring the bonding effect between the polyurethane waterproof coating and the asphalt roll. This solves the problem that the existing solvent-free polyurethane waterproof coating generally adds small molecule plasticizers to control the product viscosity and ensure the construction performance, but the small molecule plasticizers are expensive and have poor plasticizing effects, resulting in low product performance, and the product performance can only be controlled by further increasing costs.

[0037] In some specific embodiments, the plasticizer includes a bio-based reactive plasticizer, and the raw material components may further include 0.1 to 0.5 parts of a catalyst, for example, 0.1, 0.2, 0.3, 0.4, 0.5, or any combination range of the above values. The mass ratio of the catalyst to the bio-based polyol is 1:200 to 1:5000, for example, 1:200, 1:500, 1:800, 1:1000, 1:2000, 1:3000, 1:4000, 1:5000, or any combination range of the above values. The catalyst is used to catalyze the cross-linking reaction of the isocyanate group-terminated polyurethane prepolymer, the latent curing agent and the bio-based reactive plasticizer. Preferably, the catalyst includes one or more of dibutyltin dilaurate, stannous octoate, lead isooctanoate and bismuth isooctanoate.

[0038] In some specific embodiments, the raw material components may further include 0.1 to 0.5 parts of a latent curing agent hydrolysis accelerator, for example, 0.1, 0.2, 0.3, 0.4, 0.5, or any combination thereof, and the mass ratio of the latent curing agent hydrolysis accelerator to the latent curing agent is 1:30 to 1:450, for example, 1:30, 1:50, 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450, or any combination thereof.

[0039] In some specific embodiments, the diisocyanate includes one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate and toluene diisocyanate; and / or, the latent curing agent includes one or more of aldehyde imine latent curing agents, ketimine latent curing agents and oxazolidine latent curing agents.

[0040] In some specific embodiments, the raw material components may further include additives, which include, by weight: filler, 100 to 500 parts; pigment, 5 to 10 parts; dispersant, 0.5 to 1 part; defoaming agent, 1 to 3 parts.

[0041] In some specific embodiments, the filler includes one or more of nano calcium carbonate, talc, fumed silica, barium sulfate, heavy calcium carbonate (heavy calcium), light calcium carbonate (light calcium) and kaolin. Preferably, the particle size of the filler is 800 mesh to 3000 mesh, for example, it can be 800 mesh, 1000 mesh, 1500 mesh, 2000 mesh, 2500 mesh, 3000 mesh, or any combination range of the above values; and / or, the pigment includes one or more of carbon black, red iron oxide, titanium dioxide, yellow iron oxide and composite emerald green; and / or, the dispersant includes a nonionic dispersant and / or an anionic dispersant; and / or, the defoamer includes a silicone defoamer and / or a mineral oil defoamer.

[0042] In a second aspect, a method for preparing a waterproof coating comprises: stirring and mixing 100 to 500 parts of a bio-based polyol and 100 to 300 parts of a plasticizer, and dehydrating the mixture to obtain a first mixture; adding 20 to 75 parts of a diisocyanate to the first mixture to react to obtain a second mixture, wherein the diisocyanate reacts with the bio-based polyol to generate an isocyanate group-terminated polyurethane prepolymer; adding 15 to 60 parts of a latent curing agent to the second mixture, and mixing and reacting to obtain a waterproof coating. The specific mechanism is as follows: Figures 1 to 4 As shown in the figure, the chemical formula where R is located represents a bio-based reactive plasticizer containing an epoxy group, the chemical formula where R1 is located represents an isocyanate group-terminated polyurethane prepolymer obtained by reacting a bio-based polyol with an isocyanate, and R2, R3, and R4 are all selected from C1-C6 alkyl, C6-C 10 Any one of an aromatic group and a C3-C6 cycloalkyl group. An isocyanate-terminated polyurethane prepolymer, a bio-based reactive plasticizer, and a latent curing agent undergo crosslinking in the presence of water to produce a polyurethane and a volatile organic compound (VOC). Specifically, after the waterproof coating of the present application is applied, water vapor in the air reacts with the latent curing agent, causing the latent curing agent to hydrolyze, and the aldehyde or ketone substance serving as the blocking agent volatilizes. The substance containing active hydrogen acts as a chain extender and participates in the chain extension reaction between the NCO group and the epoxy group, thereby curing the coating to form a film.

[0043] In some specific embodiments, 100 to 500 parts of bio-based polyol and 100 to 300 parts of plasticizer are stirred, mixed and dehydrated to obtain a first mixture. In the step, the bio-based polyol and the additive are stirred and heated to 102° C. to 108° C., for example, 102° C., 103° C., 104° C., 105° C., 106° C., 107° C., 108° C., or any combination range of the above values, and then dehydrated for 2 h to 4 h, for example, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, or any combination range of the above values; and / or, 100 to 500 parts of bio-based polyol and 100 to 300 parts of plasticizer are stirred, mixed and dehydrated. In the step of obtaining the first mixture, additives may be added before mixing; and / or, in the step of adding 20 to 75 parts of diisocyanate to the first mixture to react and obtain the second mixture, the first mixture is cooled to 75°C to 80°C, for example, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, or any combination range of the above values, and the diisocyanate is added and then the temperature is adjusted to 78°C to 82°C, for example, 78°C, 79°C, 80°C, 81°C, 82°C, or any combination range of the above values, and the reaction is carried out for 2h to 4h, for example, 2h, 2.5h, 3h, 3.5h, 4h, or any combination range of the above values.

[0044] In some specific embodiments, the step of adding 15 to 60 parts of a latent curing agent to the second mixture and mixing to obtain a waterproof coating includes: controlling the temperature of the second mixture to 73° C. to 77° C., for example, 73° C., 74° C., 75° C., 76° C., 77° C., or any combination range of the above values, adding a catalyst, and reacting for 0.5 h to 2 h to obtain a third mixture, for example, 0.5 h, 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, or any combination range of the above values; controlling the temperature of the third mixture at 73° C. to 77° C., for example, 73° C., 74° C., 75° C., 76° C., 77° C., or any combination range of the above values, adding a latent curing agent, and continuing the reaction for 0.5 h to 2 h, for example, 0.5 h, 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, or any combination range of the above values, Obtain a fourth mixture; control the temperature of the fourth mixture to 65°C to 70°C, for example, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, or any combination range of the above values, add a latent curing agent hydrolysis accelerator, and react for 20min to 50min, for example, 20min, 25min, 30min, 35min, 40min, 45min, 50min, or any combination range of the above values ​​to obtain a fifth mixture; control the temperature of the fifth mixture to 63°C to 67°C, for example, 63°C, 64°C, 65°C, 66°C, 67°C, or any combination range of the above values, vacuum degassing for 10 to 20min, for example, 10min, 12min, 14min, 16min, 18min, 20min, or any combination range of the above values, and discharge the material under the protection of protective gas to obtain a waterproof coating.

[0045] In a third aspect, a composite waterproof layer comprises an asphalt waterproof membrane and a waterproof coating layer formed by the waterproof coating of the first aspect and / or a waterproof coating layer formed by the waterproof coating prepared by the preparation method of the second aspect. The composite waterproof layer of the present application effectively solves the problem of residual solvent causing swelling of the asphalt membrane, thereby ensuring the physical properties of the composite waterproof layer.

[0046] In this document, the term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0047] It should be understood that in the embodiments of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should also be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0048] Example

[0049] The following examples describe the present disclosure in more detail, and these examples are for illustrative purposes only.

[0050] Because various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art, unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by mass, and all raw materials used in the examples are commercially available or prepared according to conventional methods and used directly without further treatment, and the instruments used in the examples are commercially available.

[0051] In the following examples, the sources and models of some raw materials are as follows: Bio-based polyols: ECOPROL H2700, etc. Polyether diol: DL-2000D, Shandong Bluestar Dongda Co., Ltd.; trifunctional polyether polyol: EP330N, Shandong Bluestar Dongda Co., Ltd. Fillers: 800-mesh heavy calcium carbonate, 1250-mesh talc. Pigments: carbon black, composite emerald green. Conventional plasticizers: 52# chlorinated paraffin, acetyl tributyl citrate. Bio-based reactive plasticizer: epoxidized soybean oil. Catalyst: dibutyltin dilaurate (T12 organotin catalyst). Dispersant: DisuperS18, purchased from Guangzhou Core New Materials Technology Co., Ltd. Defoamer: BYK-052N. Latent curing agent: Latent curing agent YRLH-1106 (containing two active hydrogen functionalities, molecular weight 250), Guangzhou Yourun Synthetic Materials Co., Ltd. Latent curing agent hydrolysis accelerator: Accelerator B, Shandong Zhihuapu New Materials Co., Ltd.

[0052] In this application The hydroxyl value of ECOPROL H2700 is 56 mg KOH / g, the functionality is 2, and the viscosity at 25°C is 1360 cp; the hydroxyl value of ECOPROL H2700 is 42 mg KOH / g, the functionality is 2, and the viscosity at 25°C is 3100 cp; The hydroxyl value of ECOPROL H1000 is 37 mg KOH / g, the functionality is 2, and the viscosity at 25°C is 3860 cp; the hydroxyl value of ECOPROL H1000 is 112 mg KOH / g, the functionality is 2, and the viscosity at 25°C is 500 cp; the hydroxyl value of HM-1070 is 81 mg KOH / g, the functionality is 4, and the viscosity at 25°C is 2250 cp; The hydroxyl value of HM-140 is 28 mg KOH / g, the functionality is 2, and the viscosity is 8600 cp at 25°C. The hydroxyl value of HM-140 is 110 mg KOH / g, the functionality is 6, and the viscosity is 1400 cp at 25°C. The hydroxyl value of polyether diol DL-2000D is 56 mg KOH / g, the functionality is 2, and the viscosity is 400 cp at 25°C. The trifunctional polyether polyol EP330N has a hydroxyl value of 35 mg KOH / g, the functionality is 3, and the viscosity is 900 cp at 25°C.

[0053] The molecular weight of the polyol in this embodiment can be calculated by the following formula: molecular weight = 56.1 × 1000 × f / (hydroxyl value + acid value), where 56.1 is the molecular weight of KOH and f is the functionality.

[0054] Example 1

[0055] A waterproof coating comprising the following raw material components in parts by weight: 180 parts D-2000, 140 parts of ECOPROL H2700, 100 parts of 52# chlorinated paraffin, 200 parts of epoxidized soybean oil, 0.8 parts of DisuperS18, 2 parts of BYK-052N, 280 parts of 800 mesh heavy calcium carbonate, 170 parts of 1250 mesh talc, 0.8 parts of carbon black, 7 parts of composite emerald green, 45 parts of toluene diisocyanate (TDI), 0.4 parts of T12, 35 parts of latent curing agent YRLH-1106 and 0.4 parts of accelerator B.

[0056] In this embodiment, the molar ratio of isocyanate groups in the diisocyanate to hydroxyl groups in the bio-based polyol is 1.82:1. After the diisocyanate reacts with the bio-based polyol to form an isocyanate-terminated polyurethane prepolymer, the molar ratio of the remaining isocyanate groups to the active hydrogen after hydrolysis of the latent curing agent is 1:1.201. The mass ratio of the catalyst to the bio-based polyol is 1:800, and the mass ratio of the latent curing agent hydrolysis accelerator to the latent curing agent is 1:87.5.

[0057] The waterproof coating is prepared by the following method:

[0058] Add bio-based polyol to the reaction vessel ECOPROL H2700, plasticizer 52# chlorinated paraffin and epoxidized soybean oil, pigments and fillers (a mixture of heavy calcium and talc as well as carbon black and composite emerald green), dispersant DisuperS18, and defoamer BYK-052N were stirred and heated to 105°C ± 3°C, and dehydrated under a vacuum degree of -0.1 MPa for 2 hours to obtain a first mixture.

[0059] After dehydration, the first mixture was cooled to 75° C. to 80° C., diisocyanate was added, and then the temperature was raised to 80° C.±2° C. and reacted for 3 h to obtain a second mixture.

[0060] The temperature of the second mixture was controlled to 75° C.±2° C., a catalyst was added, and the mixture was reacted for 1 h to obtain a third mixture.

[0061] The temperature of the third mixture was controlled at 75° C.±2° C., a latent curing agent was added, and the reaction was continued for 1 hour to obtain a fourth mixture.

[0062] The fourth mixture was cooled to 65° C. to 70° C., a latent curing agent hydrolysis accelerator was added, and the mixture was reacted for 20 minutes to obtain a fifth mixture.

[0063] The fifth mixture was cooled to 65°C ± 2°C, vacuum degassed for 10 minutes, and discharged under nitrogen protection to obtain a waterproof coating.

[0064] Example 2

[0065] The preparation process of the waterproof coating of Example 2 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0066] Example 3

[0067] The preparation process of the waterproof coating of Example 3 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0068] Example 4

[0069] The preparation process of the waterproof coating of Example 4 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0070] Example 5

[0071] The preparation process of the waterproof coating of Example 5 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0072] Example 6

[0073] The preparation process of the waterproof coating of Example 6 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0074] Example 7

[0075] The preparation process of the waterproof coating of Example 7 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0076] Example 8

[0077] The preparation process of the waterproof coating of Example 8 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0078] Example 9

[0079] The preparation process of the waterproof coating of Example 9 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0080] Example 10

[0081] The preparation process of the waterproof coating of Example 10 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0082] Example 11

[0083] The preparation process of the waterproof coating of Example 11 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0084] Example 12

[0085] The preparation process of the waterproof coating of Example 12 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0086] Example 13

[0087] The preparation process of the waterproof coating of Example 13 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0088] Example 14

[0089] The preparation process of the waterproof coating of Example 14 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 1 and Table 3.

[0090] Comparative Example 1

[0091] The preparation process of the waterproof coating of Comparative Example 1 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 2 and Table 3.

[0092] Comparative Example 2

[0093] The preparation process of the waterproof coating of Comparative Example 2 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 2 and Table 3.

[0094] Comparative Example 3

[0095] The preparation process of the waterproof coating of Comparative Example 3 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 2 and Table 3.

[0096] Comparative Example 4

[0097] The preparation process of the waterproof coating of Comparative Example 4 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 2 and Table 3.

[0098] Comparative Example 5

[0099] The preparation process of the waterproof coating of Comparative Example 5 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 2 and Table 3.

[0100] Comparative Example 6

[0101] The preparation process of the waterproof coating of Comparative Example 6 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 2 and Table 3.

[0102] Comparative Example 7

[0103] The preparation process of the waterproof coating of Comparative Example 7 is the same as that of Example 1, except for the material selection and addition amount. The addition amount of each material is shown in Table 2 and Table 3.

[0104]

[0105]

[0106] Table 2 Raw material ingredients list of comparative examples 1-7

[0107]

[0108] Table 3 Parameters of Examples 1-14 and Comparative Examples 1-7

[0109]

[0110]

[0111]

[0112] Test section

[0113] The elongation at break, tensile strength, tear strength, and VOC content of the waterproof coatings prepared in Examples 1-14 and Comparative Examples 1-7 were tested using the test methods of GB / T 16777-2008, GB / T 19250-2013, and GB 55030-2022. The test results are shown in Table 4.

[0114] Table 4 Test results of waterproof coatings of Examples 1-14 and Comparative Examples 1-7

[0115]

[0116]

[0117] The performance data in Table 4 show that the present application controls the molar ratio of isocyanate groups to hydroxyl groups in bio-based polyols, the molar ratio of the remaining amount of isocyanate groups to the active hydrogen after hydrolysis of the latent curing agent, and the mass ratio of the bio-based reactive plasticizer to the ordinary plasticizer. The waterproof coating obtained by the synergistic effect of multiple factors has excellent mechanical strength, as well as good water-immersion adhesion strength retention and strength retention after acid, alkali, and heat treatment.

[0118] Among them, based on the performance data of Example 1 using bio-based polyols, Comparative Example 1 using conventional polyether polyols, and Comparative Examples 6-9, the present application controls the molar ratio of isocyanate groups to hydroxyl groups in the bio-based polyols, the molar ratio of the remaining amount of isocyanate groups to the active hydrogen after hydrolysis of the latent curing agent, and the mass ratio of the bio-based reactive plasticizer to the ordinary plasticizer. Under the synergistic effect of the two, the strength retention rate of the waterproof coating of Example 1 after acid, alkali, and heat treatment is significantly higher than that of Comparative Example 1, and the comprehensive performance of the waterproof coating of Example 1 is also significantly higher than that of the waterproof coating of Comparative Examples 4-7. From the performance data of Examples 1, 11, 12, and Comparative Examples 2-3, it can be seen that by controlling the molar ratio of isocyanate groups to hydroxyl groups in the bio-based polyols, the molar ratio of the remaining amount of isocyanate groups to the active hydrogen after hydrolysis of the latent curing agent, and the mass ratio of the bio-based reactive plasticizer to the ordinary plasticizer in the present application, the synergistic effect of the three can ensure the mechanical properties of the waterproof coating while ensuring the water-immersion bonding strength of the waterproof coating, and the finished product has a lower viscosity and is easy to apply. For example, when only conventional plasticizers are used, the water-immersion bonding strength retention rate obviously does not meet the requirements (Comparative Examples 2 and 3); when only bio-based reactive plasticizers are used, the elongation at break of the coating decreases (Example 11); the mass ratio of bio-based reactive plasticizers to conventional curing agents is reduced, and the water-immersion bonding strength retention rate and mechanical properties are both poor (Example 12). In addition, it can be seen from the performance data of Examples 1, 13, and 14 that the special selection of hydroxyl value, viscosity, and functionality of bio-based polyols in this application can further improve the comprehensive performance of the waterproof coating.

[0119] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A waterproof coating, characterized in that: The raw material components include the following parts by weight: Diisocyanate, 20 to 75 parts; Bio-based polyol, 100-500 parts; Plasticizer, 100~300 parts; Latent curing agent, 15 to 60 parts; The diisocyanate and the bio-based polyol are used to react to form an isocyanate group-terminated polyurethane prepolymer, wherein the molar ratio of the isocyanate groups in the diisocyanate to the hydroxyl groups in the bio-based polyol is 1.5:1 to 2.5:1, and after the diisocyanate and the bio-based polyol react to form the isocyanate group-terminated polyurethane prepolymer, the molar ratio of the remaining isocyanate groups to the active hydrogen after hydrolysis of the latent curing agent is 1:1 to 1:2; The plasticizer includes a bio-based reactive plasticizer and a common plasticizer, the mass ratio of the bio-based reactive plasticizer to the common plasticizer is 1.5:1 to 14:1, the bio-based reactive plasticizer includes one or more of epoxidized soybean oil, epoxidized fatty acid methyl ester and epoxidized linseed oil, and the common plasticizer includes one or more of chlorinated paraffins, citrates, phthalates and trioctyl phosphate.

2. The waterproof coating according to claim 1, characterized in that The bio-based polyol satisfies at least one of the following conditions: (1) The hydroxyl value of the bio-based polyol is 30 mg KOH / g to 120 mg KOH / g; (2) The functionality of the bio-based polyol is 2 to 5; (3) The viscosity of the bio-based polyol at 25° C. is 300 cp~7000 cp.

3. The waterproof coating according to claim 1, characterized in that The plasticizer includes a bio-based reactive plasticizer, and the raw material components also include 0.1 to 0.5 parts of a catalyst, the mass ratio of the catalyst to the bio-based polyol is 1:200 to 1:5000, and the catalyst is used to catalyze the cross-linking reaction of the isocyanate group-terminated polyurethane prepolymer, the latent curing agent and the bio-based reactive plasticizer.

4. The waterproof coating according to claim 3, characterized in that: The catalyst includes one or more of dibutyltin dilaurate, stannous octoate, lead isooctanoate and bismuth isooctanoate.

5. The waterproof coating according to claim 1, characterized in that: The raw material components also include 0.1 to 0.5 parts of a latent curing agent hydrolysis accelerator, and the mass ratio of the latent curing agent hydrolysis accelerator to the latent curing agent is 1:30 to 1:

450.

6. The waterproof coating according to claim 1, characterized in that: The diisocyanate includes one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate and toluene diisocyanate; And / or, the latent curing agent includes one or more of an aldimine latent curing agent, a ketimine latent curing agent and an oxazolidine latent curing agent.

7. The waterproof coating according to any one of claims 1 to 5, characterized in that: The raw material components also include additives, which include, by weight: Filler, 100~500 parts; Pigment, 5 to 10 parts; Dispersant, 0.5 to 1 part; Defoaming agent, 1 to 3 parts.

8. The waterproof coating according to claim 7, characterized in that: The filler includes one or more of nano calcium carbonate, talc, fumed silica, barium sulfate, heavy calcium carbonate, light calcium carbonate and kaolin; And / or, the pigment includes one or more of carbon black, red iron oxide, titanium dioxide, yellow iron oxide and composite emerald green; and / or, the dispersant comprises a nonionic dispersant and / or an anionic dispersant; And / or, the defoaming agent includes a silicone defoaming agent and / or a mineral oil defoaming agent.

9. The waterproof coating according to claim 8, characterized in that: The particle size of the filler is 800 mesh to 3000 mesh.

10. A method for preparing a waterproof coating according to any one of claims 1 to 9, characterized in that: include: 100 to 500 parts of bio-based polyol and 100 to 300 parts of plasticizer are stirred, mixed, and dehydrated to obtain a first mixture; Adding 20 to 75 parts of diisocyanate to the first mixture to react to obtain a second mixture; 15 to 60 parts of a latent curing agent are added to the second mixture for mixed reaction to obtain the waterproof coating.

11. The preparation method according to claim 10, characterized in that: In the step of obtaining a first mixture by stirring and mixing 100 to 500 parts of a bio-based polyol and 100 to 300 parts of a plasticizer, the mixture is dehydrated, wherein the bio-based polyol and the additive are stirred and heated to 102° C. to 108° C., and then dehydrated for 2 h to 4 h; and / or, in the step of mixing and dehydrating 100 to 500 parts of bio-based polyol and 100 to 300 parts of plasticizer to obtain a first mixture, adding additives before mixing; And / or, in the step of adding 20 to 75 parts of diisocyanate to the first mixture to react and obtain the second mixture, the first mixture is cooled to 75° C. to 80° C., the diisocyanate is added, and then the temperature is adjusted to 78° C. to 82° C. and reacted for 2 h to 4 h.

12. The preparation method according to claim 10, characterized in that The step of adding 15 to 60 parts of a latent curing agent to the second mixture for mixed reaction to obtain the waterproof coating comprises: controlling the temperature of the second mixture to 73° C. to 77° C., adding a catalyst, and reacting for 0.5 h to 2 h to obtain a third mixture; Controlling the temperature of the third mixture at 73° C. to 77° C., adding a latent curing agent, and continuing the reaction for 0.5 to 2 hours to obtain a fourth mixture; controlling the temperature of the fourth mixture to 65° C. to 70° C., adding a latent curing agent hydrolysis accelerator, and reacting for 20 min to 50 min to obtain a fifth mixture; The temperature of the fifth mixture is controlled to 63° C. to 67° C., vacuum degassing is performed for 10 min to 20 min, and the mixture is discharged under the protection of protective gas to obtain the waterproof coating.

13. A composite waterproof layer, characterized in that: The invention comprises an asphalt waterproofing coil and a waterproof coating layer formed by the waterproof coating according to any one of claims 1 to 9 and / or a waterproof coating layer formed by the waterproof coating prepared by the preparation method according to any one of claims 10 to 12.

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