Polyurethane waterproof coating and preparation method thereof

Abstract

The invention provides a polyurethane waterproof coating and a preparation method thereof. The preparation method comprises the following steps: providing a liquid filler, a solid filler and polyurethane resin; dehydrating the solid filler to obtain a dehydrated solid filler; adding the dehydrated solid filler, the liquid filler and the polyurethane resin into a production kettle, and stirring; and sequentially adding the solvent and the functional additive into the production kettle, stirring, and defoaming to obtain the polyurethane waterproof coating. According to the preparation method disclosed by the invention, the liquid filler with extremely low water content is not subjected to dehydration operation, and only the solid filler with relatively high water content is dehydrated, so that the dehydration energy consumption is reduced, the production efficiency is improved, and preset dehydration parameters can be set according to the physical and chemical characteristics of the fixed filler so as to obtain a better dehydration effect.

Description

Technical Field

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

[0002] Polyurethane waterproof coating is a high-performance reactive polymer waterproof coating. The "hard phase-soft phase" separation microstructure formed after the reaction of isocyanate with water vapor or polyol resin and curing makes polyurethane waterproof coating have both high tensile strength and excellent elongation. Compared with other waterproof coatings, it has excellent mechanical properties, crack resistance and excellent comprehensive performance. Polyurethane waterproof coating is widely used in the fields of engineering construction waterproofing and civil construction waterproofing.

[0003] One-component polyurethane waterproof coatings are composed of raw materials such as polyols, liquid fillers, solid fillers, isocyanates, functional additives, solvents, etc. Since polyurethane waterproof coatings have very strict requirements on moisture during the production process, all moisture in the raw materials must be removed before the isocyanate reaction.

[0004] The current production process is the reaction method: after the polyol, liquid filler and solid filler are mixed in the production kettle, they are dehydrated in a vacuum and high temperature environment. After the moisture content reaches the requirement, isocyanate is added for a preliminary reaction. After the preliminary reaction is completed, catalysts, functional additives and other raw materials are added for subsequent reactions. After completing the multi-step polymerization chemical reaction, the single-component polyurethane waterproof coating is obtained through the degassing process and the packaging process.

[0005] However, liquid fillers and polyols have low moisture contents, and only solid fillers have high moisture contents. In the prior art, polyols, liquid fillers, solid fillers and other raw materials are premixed and then dehydrated together during dehydration treatment. This causes liquid raw materials that do not need to be dehydrated to also participate in the heating and dehydration process, resulting in energy waste and high energy consumption. Summary of the invention

[0006] The present application provides a method for preparing a polyurethane waterproof coating, wherein the method only dehydrates solid fillers with a high water content, thereby reducing dehydration energy consumption and improving production efficiency.

[0007] In order to achieve the above objectives, this application adopts the following technical solutions:

[0008] In the first aspect, the present application provides a method for preparing a polyurethane waterproof coating, comprising: providing a liquid filler, a solid filler and a polyurethane resin; dehydrating the solid filler to obtain a dehydrated solid filler; adding the dehydrated solid filler, the liquid filler and the polyurethane resin to a production kettle and stirring them; adding a solvent and a functional additive to the production kettle in sequence, stirring and degassing, to obtain a polyurethane waterproof coating.

[0009] As an optional implementation, the step of dehydrating the solid filler also includes: adding the solid filler into a drying vessel, and dehydrating the solid filler according to preset dehydration parameters; when the moisture content of the solid filler is less than a preset moisture content threshold, obtaining a dehydrated solid filler; filling the drying vessel with nitrogen, and storing the dehydrated solid filler at a preset temperature.

[0010] As an optional embodiment, the step of dehydrating the solid filler according to preset dehydration parameters also includes: setting the dehydration temperature of the drying vessel to be greater than or equal to 100°C and less than or equal to 200°C; setting the drying time of the drying vessel to be greater than or equal to 2h and less than or equal to 4h.

[0011] As an optional implementation, the preset moisture content threshold is set to be less than or equal to 0.04%.

[0012] As an optional implementation manner, the preset temperature is set to be less than or equal to 70°C.

[0013] As an optional embodiment, the step of adding dehydrated solid filler, liquid filler and polyurethane resin into the production kettle and stirring also includes: respectively metering the polyurethane resin and the liquid filler and injecting them into the production kettle; starting the stirring system of the production kettle and mixing and stirring according to a first stirring parameter; injecting the dehydrated solid filler into the production kettle and mixing and stirring according to a second stirring parameter.

[0014] As an optional embodiment, the step of performing mixing and stirring according to the first stirring parameter also includes: starting the frame stirring system, and setting the stirring speed to be greater than or equal to 15 r / min and less than or equal to 25 r / min, and setting the stirring time to be greater than or equal to 10 min and less than or equal to 20 min; starting the paddle stirring system, and setting the stirring speed to be greater than or equal to 200 r / min and less than or equal to 400 r / min, and setting the stirring time to be greater than or equal to 10 min and less than or equal to 20 min.

[0015] As an optional embodiment, the step of performing mixed stirring according to setting the second stirring parameters also includes: starting the frame stirring system, and setting the stirring speed to be greater than or equal to 15 r / min and less than or equal to 60 r / min, and setting the stirring time to be greater than or equal to 0.5 min and less than or equal to 2 min; starting the paddle stirring system, and setting the stirring speed to be greater than or equal to 500 r / min and less than or equal to 800 r / min, and setting the stirring time to be greater than or equal to 0.5 min and less than or equal to 2 min.

[0016] As an optional embodiment, the steps of adding the solvent and the functional additive to the production kettle in sequence, and stirring and degassing also include: adjusting the stirring speed of the paddle stirring system to be greater than or equal to 900 r / min and less than or equal to 1200 r / min, and setting the stirring time to be greater than or equal to 2 h and less than or equal to 4 h; adjusting the stirring speed of the frame stirring system to be greater than or equal to 15 r / min and less than or equal to 60 r / min, and setting the stirring time to be greater than or equal to 2 h and less than or equal to 3 h.

[0017] In a second aspect, the present application provides a polyurethane waterproof coating, which is made according to any of the above-mentioned preparation methods.

[0018] The preparation method of the polyurethane waterproof coating provided by the present application does not perform dehydration operation on the liquid filler with extremely low water content, and only dehydrates the solid filler with higher water content, thereby reducing dehydration energy consumption and improving production efficiency. In addition, since the fixed filler is dehydrated separately in the drying container, the preset dehydration parameters can be set according to the physical and chemical properties of the fixed filler to achieve a better dehydration effect. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0020] Figure 1 This is a flow chart of a method for preparing a polyurethane waterproof coating in one embodiment of the present application;

[0021] Figure 2 This is a schematic diagram of a production device for a polyurethane waterproof coating in one embodiment of the present application.

[0022] Description of reference numerals:

[0023] 200. Production kettle; 210. Stirring system; 300. Drying vessel; 400. Measuring vessel; 500. First vacuum system; 600. Second vacuum system. DETAILED DESCRIPTION

[0024] One-component polyurethane waterproof coatings are composed of raw materials such as polyols, liquid fillers, solid fillers, isocyanates, functional additives, solvents, etc. Since polyurethane waterproof coatings have very strict requirements on moisture during the production process, all moisture in the raw materials must be removed before the isocyanate reaction.

[0025] The current production process is the reaction method: after the polyol, liquid filler and solid filler are mixed in the production kettle, they are dehydrated in a vacuum and high temperature environment. After the moisture content reaches the requirement, isocyanate is added for a preliminary reaction. After the preliminary reaction is completed, catalysts, functional additives and other raw materials are added for subsequent reactions. After completing the multi-step polymerization chemical reaction, the single-component polyurethane waterproof coating is obtained through the degassing process and the packaging process.

[0026] However, liquid fillers and polyols have low moisture contents, and only solid fillers have high moisture contents. In the prior art, polyols, liquid fillers, solid fillers and other raw materials are premixed and then dehydrated together during dehydration treatment. This causes liquid raw materials that do not need to be dehydrated to also participate in the heating and dehydration process, resulting in energy waste and high energy consumption.

[0027] The present application provides a method for preparing a polyurethane waterproof coating. In the preparation method, liquid fillers with extremely low water content are not dehydrated, and only solid fillers with higher water content are dehydrated, thereby reducing dehydration energy consumption and improving production efficiency.

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0029] See also Figure 1 The present application provides a method for preparing a polyurethane waterproof coating, which can be achieved by the following steps:

[0030] Step S110: providing liquid filler, solid filler and polyurethane resin.

[0031] Step S120: dehydrating the solid filler to obtain a dehydrated solid filler.

[0032] Step S130, adding dehydrated solid filler, liquid filler and polyurethane resin into the production kettle and stirring.

[0033] Step S140, adding the solvent and the functional additive into the production kettle in sequence, stirring and degassing, to obtain the polyurethane waterproof coating.

[0034] In step S110, the liquid filler may be chlorinated paraffin, and the solid filler may be a combination of heavy calcium carbonate and talc.

[0035] In the traditional one-component polyurethane waterproof coating production process, polyol and isocyanate undergo a chemical reaction in the production kettle to initially form a polyurethane prepolymer, which serves as the basic skeleton of the polyurethane waterproof coating. However, the isocyanate monomer poses certain risks to operators and the environment.

[0036] In this embodiment, polyurethane resin is directly used to replace the polyol and isocyanate skeleton in the traditional production process and formulation, thereby avoiding the multi-step chemical reaction process and the use of highly dangerous isocyanate monomers in the production process, which will effectively avoid the harm of isocyanate monomers to operators and the environment and be safer.

[0037] In some specific embodiments, the polyurethane resin may be PU resin 1 or PU resin 2. PU resin 1 has a higher content of hard segments represented by isocyanate, and its resin terminal -NCO group content is 4.5-6.0%; PU resin 2 has a higher content of soft segments represented by polyether polyol, and its resin terminal -NCO group content is 3.0-4.5%.

[0038] In step S120, the solid filler has a high moisture content, and the solid filler is dehydrated separately, while the liquid filler with extremely low moisture content is not dehydrated, thereby simplifying the dehydration process, reducing energy consumption and improving efficiency.

[0039] In step S130, the dehydrated solid filler, liquid filler and polyurethane resin that have been dehydrated are added to the production kettle and stirred, mixed and dispersed to form a uniform coating.

[0040] In step S140, the solvent may be solvent oil in step S150. The functional auxiliary agent may be a combination of a catalyst and a defoaming agent.

[0041] It should be noted that the specific components or component combinations of the above-mentioned liquid filler, solid filler, solvent and functional additive are only one embodiment, and those skilled in the art can also use other components or component combinations in the prior art.

[0042] In the traditional process, raw materials such as polyols, liquid fillers, and solid fillers are premixed and then dehydrated together. Since the liquid fillers with lower water content are dehydrated together, the energy consumption for dehydration is high, which is not conducive to reducing costs and improving production efficiency.

[0043] In the preparation method of this embodiment, since the liquid filler with extremely low water content is not dehydrated, only the solid filler with higher water content is dehydrated, which reduces the dehydration energy consumption and improves the production efficiency. In addition, since the fixed filler is dehydrated separately in the drying container, the preset dehydration parameters can be set according to the physical and chemical properties of the fixed filler, which can achieve a better dehydration effect without affecting the physical and chemical stability of the liquid filler and other components.

[0044] Furthermore, the step of dehydrating the solid filler may also include: adding the solid filler into a drying vessel, and dehydrating the solid filler according to preset dehydration parameters; when the moisture content of the solid filler is less than a preset moisture content threshold, obtaining a dehydrated solid filler; filling the drying vessel with nitrogen, and storing the dehydrated solid filler at a preset temperature.

[0045] As described above, in the conventional process, raw materials such as polyols, liquid fillers, and solid fillers are premixed and then dehydrated together. This dehydration method has many components and cannot optimize the dehydration parameters according to a certain component, resulting in poor dehydration effect. In this embodiment, since the fixed filler is dehydrated separately in the drying vessel, the preset dehydration parameters can be set according to the physical and chemical properties of the fixed filler to achieve a better dehydration effect.

[0046] In some specific embodiments, the preset moisture content threshold may also be set to be less than or equal to 0.04%, such as 0.04%, 0.03%, 0.02%, etc. When it is detected that the moisture content of the solid filler is less than the preset moisture content threshold, the dehydration of the solid filler is considered to be completed.

[0047] After dehydration, the dehydrated solid filler is properly stored, so as to prevent the dehydrated solid filler from getting damp and to control the temperature so that it meets the temperature for the next step of use.

[0048] Specifically, after drying is completed, nitrogen is introduced into the drying vessel to prevent the dehydrated solid filler from contacting with moisture in the air and preventing moisture from returning. The temperature in the drying vessel is controlled to maintain the temperature of the dehydrated solid filler at a temperature required for the next step of use.

[0049] Furthermore, the step of dehydrating the solid filler according to the preset dehydration parameters also includes: setting the dehydration temperature of the drying vessel to be greater than or equal to 100° C. and less than or equal to 200° C., such as 100° C., 150° C., 200° C., etc. Setting the drying time of the drying vessel to be greater than or equal to 2 hours and less than or equal to 4 hours, such as 2 hours, 3 hours, 4 hours, etc.

[0050] Further, the preset temperature is set to be less than or equal to 70°C, such as 70°C, 65°C, 60°C, etc.

[0051] In some embodiments, the step of adding dehydrated solid filler, liquid filler and polyurethane resin into the production kettle and stirring also includes: respectively metering the polyurethane resin and the liquid filler and injecting them into the production kettle; starting the stirring system of the production kettle and mixing and stirring according to a first stirring parameter; injecting the dehydrated solid filler into the production kettle and mixing and stirring according to a second stirring parameter.

[0052] In this embodiment, the polyurethane resin and the liquid filler are respectively measured and injected into the production kettle, the stirring system of the production kettle is started, the polyurethane resin and the liquid filler are stirred, mixed and dispersed, and then the dehydrated solid filler is injected into the production kettle, and the polyurethane resin, liquid filler and dehydrated solid filler are mixed and stirred.

[0053] In this embodiment, the polyurethane resin, liquid filler and dehydrated solid filler are mixed and stirred in batches. This helps to obtain a better stirring effect. Secondly, adding and stirring in batches can make the nucleation and growth process of the product more uniform and orderly, which helps to obtain a product with uniform particle size distribution and good crystallinity, and improve the physical properties of the product.

[0054] Furthermore, the step of performing mixed stirring according to the first stirring parameter also includes: starting the frame stirring system, and setting the stirring speed to be greater than or equal to 15 r / min and less than or equal to 25 r / min, and setting the stirring time to be greater than or equal to 10 min and less than or equal to 20 min; starting the paddle stirring system, and setting the stirring speed to be greater than or equal to 200 r / min and less than or equal to 400 r / min, and setting the stirring time to be greater than or equal to 10 min and less than or equal to 20 min.

[0055] In this embodiment, the stirring system of the production kettle may include a frame stirring system and a paddle stirring system. The frame stirring system is a device used to stir high-viscosity liquids and high-concentration slurries. The paddle stirring system is suitable for materials with low viscosity and good fluidity, and can quickly promote the flow of liquids to achieve mixing. It can also be used to mix liquids containing suspended solids and debris.

[0056] When stirring the polyurethane resin and the liquid filler, first use a frame stirring system to stir them. The frame stirring system can stir high-viscosity liquids and can achieve rapid fusion of the polyurethane resin and the liquid filler. Then use a paddle stirring system to stir them quickly to form a uniform colloid.

[0057] In some specific embodiments, when stirring with a frame stirring system, the stirring speed of the frame stirring system is set to be greater than or equal to 15 r / min and less than or equal to 25 r / min, for example, 15 r / min, 20 r / min, 25 r / min, etc. The stirring time is set to be greater than or equal to 10 min and less than or equal to 20 min, for example, 10 min, 15 min, 20 min, etc.

[0058] In some specific embodiments, when stirring with a paddle stirring system, the stirring speed of the paddle stirring system is set to be greater than or equal to 200 r / min and less than or equal to 400 r / min, such as 200 r / min, 300 r / min, 400 r / min, etc. The stirring time is set to be greater than or equal to 10 min and less than or equal to 20 min, such as 10 min, 15 min, 20 min, etc.

[0059] Furthermore, the step of mixing and stirring according to the second stirring parameter setting also includes: starting the frame stirring system, and setting the stirring speed to be greater than or equal to 15 r / min and less than or equal to 60 r / min, and setting the stirring time to be greater than or equal to 0.5 h and less than or equal to 2 h. Starting the paddle stirring system, and setting the stirring speed to be greater than or equal to 500 r / min and less than or equal to 800 r / min, and setting the stirring time to be greater than or equal to 0.5 h and less than or equal to 2 h.

[0060] After adding the dehydrated solid filler, firstly use a frame stirring system to stir, which can achieve rapid fusion of the polyurethane resin, liquid filler and dehydrated solid filler, and then use a paddle stirring system to stir quickly to form a uniform colloid.

[0061] In some specific embodiments, when stirring with a frame stirring system, the stirring speed of the frame stirring system is set to be greater than or equal to 15 r / min and less than or equal to 60 r / min, for example, 15 r / min, 25 r / min, 30 r / min, 45 r / min, 50 r / min, 60 r / min, etc. The stirring time is set to be greater than or equal to 0.5 h and less than or equal to 2 h, for example, 0.5 h, 1 h, 1.5 h, 2 h, etc.

[0062] In some specific embodiments, when stirring with a paddle stirring system, the stirring speed of the paddle stirring system is set to be greater than or equal to 500 r / min and less than or equal to 800 r / min, for example, 500 r / min, 600 r / min, 700 r / min, 800 r / min, etc. The stirring time is set to be greater than or equal to 0.5 h and less than or equal to 2 h, for example, 0.5 h, 1 h, 1.5 h, 2 h, etc.

[0063] In some embodiments, the steps of adding the solvent and the functional additive to the production kettle in sequence and stirring and degassing may also include: adjusting the stirring speed of the paddle stirring system to be greater than or equal to 900 r / min and less than or equal to 1200 r / min, and setting the stirring time to be greater than or equal to 2 h and less than or equal to 4 h; adjusting the stirring speed of the frame stirring system to be greater than or equal to 15 r / min and less than or equal to 60 r / min, and setting the stirring time to be greater than or equal to 2 h and less than or equal to 3 h.

[0064] In this embodiment, the solvent and the functional additive are added to the production kettle in sequence, and stirred by a paddle stirring system to allow the solvent and the functional additive to fuse and react, thereby finally forming a polyurethane waterproof coating.

[0065] In some specific embodiments, the stirring speed of the paddle stirring system can be adjusted to 900r / min, 1000r / min, 1100r / min, 1200r / min, etc. The stirring time can be set to be greater than or equal to 2h, 3h, 4h, etc. The working temperature in the production kettle is maintained at 40°C, 45°C, 50°C, etc.

[0066] After the polyurethane waterproof coating is formed, air or other gases are easily mixed in to form bubbles during the previous stirring operation. The presence of bubbles in the coating will lead to problems such as uneven coating, decreased bonding strength, and unstable material properties. Therefore, liquid stirring and degassing is a key step to ensure product quality and performance.

[0067] In this embodiment, a frame stirring system is used to degas the formed polyurethane waterproof coating. The frame stirring system can generate a strong shear force on the coating when stirring, breaking the surface tension of the bubbles and breaking large bubbles into small bubbles. The frame stirring system simultaneously promotes the flow of liquid during the stirring process to form a circular flow pattern, and this flow drives the bubbles to move together. Under the stirring action, the gas molecules in the bubbles are more likely to exchange and diffuse with other molecules in the liquid, so that the gas in the bubbles gradually dissolves into the liquid or escapes from the liquid, thereby achieving the purpose of degassing.

[0068] In some specific embodiments, the stirring speed of the frame stirring system can be adjusted to 15 r / min, 20 r / min, 30 r / min, 45 r / min, 60 r / min, etc. The stirring time can be set to be greater than or equal to 2 h, 2.5 h, 3 h, etc.

[0069] After degassing is completed, the stirring system is turned off, dry nitrogen is filled into the kettle to normal pressure, and the coating is filled into the packaging barrel through the discharge pipeline at the bottom of the production kettle to complete the preparation of the single-component polyurethane waterproof coating.

[0070] See also Figure 2 The present application also provides a production device for preparing a polyurethane waterproof coating, and the production device may also include a production kettle 200, a drying vessel 300 and a measuring vessel 400.

[0071] A stirring system 210 is provided in the production kettle 200, and the stirring system 210 can stir the materials in the production kettle 200. The stirring system 210 includes a frame stirring system 210 and a paddle stirring system 210. A discharge pipeline is provided at the bottom of the production kettle 200, and the material discharge and packaging operation is performed after the coating production is completed.

[0072] The drying vessel 300 is used for drying solid fillers and has a heating function, and the heating method can be electric heating, heat-conducting oil, high-pressure steam, etc.

[0073] The drying vessel 300 also has a weighing function. A weighing module can be installed on the drying vessel 300 to measure the required solid filler according to the recipe requirements.

[0074] The drying vessel 300 can also be connected to the production kettle 200 through a connecting pipe so that the dehydrated solid filler in the drying vessel 300 can be transported to the production kettle 200 .

[0075] In some specific embodiments, the drying vessel 300 may be disposed above the production kettle 200, and the dehydrated solid filler is transported to the production kettle 200 by gravity.

[0076] In some other specific embodiments, the production kettle 200 may be further equipped with a first vacuum system 500 , which maintains a negative pressure in the production kettle 200 , thereby causing the dehydrated solid filler to be transported to the production kettle 200 under the effect of the negative pressure.

[0077] In addition, since the materials need to be stirred in the production kettle 200, the first vacuum system 500 can be turned on during stirring to maintain a negative pressure in the production kettle 200, thereby removing dissolved gas and mixed gas.

[0078] The drying vessel 300 is equipped with a second vacuum system 600, and the first vacuum system 500 can maintain a negative pressure in the drying vessel 300. When the solid filler is dried in the drying vessel 300, the first vacuum system 500 can be started, which firstly increases the pressure difference between the water vapor pressure on the surface and inside of the solid filler and the external pressure, and strengthens the driving force for the water to diffuse from the inside of the solid filler to the surface and evaporate from the surface to the external environment, thereby accelerating the migration and evaporation of the water. Secondly, since the saturated vapor pressure of the liquid is related to the temperature, the water gas pressure is reduced in a vacuum environment, and the boiling point of the water is also reduced, which makes it easier to reduce the drying temperature.

[0079] In some specific embodiments, the drying vessel 300 may be any one of a double-cone rotary vacuum dryer, a single-cone vacuum spiral belt dryer, a vacuum rake dryer, and a hollow paddle vacuum dryer.

[0080] In addition, the present application also provides a polyurethane waterproof coating, which can be made by the preparation method in any of the above embodiments.

[0081] The preparation method of the polyurethane waterproof coating of the present application is further described below through the specific examples in Table 1.

[0082] Table 1 Process parameters in various embodiments

[0083]

[0084] The product performance of each embodiment and the comparative example is compared in Table 2 below. The product performance of each embodiment and the comparative example is tested according to the GB / T 19250-2013 "Polyurethane Waterproof Coating" testing standard. The typical values ​​of the product performance are shown in the following table:

[0085] Table 2 Comparison of product performance of each embodiment and comparative example

[0086]

[0087] Examples 1 to 8 in Table 2 correspond to Examples 1 to 8 in Table 1. The comparative example is synthesized by a conventional chemical method, wherein polyether polyol is mixed with a liquid filler and a solid filler for dehydration, and after the dehydration process is completed, functional additives such as isocyanate and a catalyst are added for polymerization reaction to obtain a polyurethane waterproof coating.

[0088] It can be seen from Table 2 that the one-component polyurethane waterproof coating of the embodiment of the present application not only has product performance that meets the standard requirements of GB / T19250-2013, but also has better product performance than the control example (traditional process).

[0089] The embodiment of the present application takes polyurethane resin as the core and physical dispersion as the center, and the polyurethane waterproof coating produced has better indicators than the waterproof coating synthesized by traditional chemical methods. In addition, since only the solid filler with high water content is dried and dehydrated independently, the liquid filler with extremely low water content is not dehydrated, thereby simplifying the dehydration process and reducing energy consumption by 50%.

[0090] In addition, the embodiment of the present application uses polyurethane resin as the basic skeleton of the coating, avoiding the use of isocyanate monomers, which will effectively avoid the harm of isocyanate monomers to operators and the environment, making it safer. The polyurethane coating product produced in the embodiment of the present application has a 2.1% increase in solid content and a 11% decrease in volatile organic compounds compared to the product produced by the traditional process, making the product more environmentally friendly.

[0091] It should be noted that the phrases "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include certain features, structures or characteristics, but not every embodiment may include the certain features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing certain features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments, whether explicitly or not explicitly described.

[0092] In general, terms should be understood, at least in part, by the context in which they are used. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, depending, at least in part, on the context. Similarly, terms such as "a," "an," or "the" may also be understood to convey singular usage or to convey plural usage, depending, at least in part, on the context.

[0093] It should be easily understood that the terms “on,” “above,” and “over” in this application should be interpreted in the broadest manner, so that “on” means not only “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” includes not only the meaning of “above something” or “over,” but also may include the meaning of “above something” or “over” with no intervening features or layers therebetween (i.e., directly on something).

[0094] In addition, spatially relative terms, such as "below," "below," "beneath," "above," "above," etc., may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90° or at other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a polyurethane waterproof coating, characterized in that: include: Provide liquid fillers, solid fillers and polyurethane resins; Dehydrating the solid filler to obtain a dehydrated solid filler; Adding the dehydrated solid filler, the liquid filler and the polyurethane resin into a production kettle and stirring; The solvent and the functional additive are sequentially added into the production kettle, and stirred and degassed to obtain the polyurethane waterproof coating.

2. The preparation method according to claim 1, characterized in that: The step of dehydrating the solid filler further comprises: Adding the solid filler into a drying vessel, and dehydrating the solid filler according to preset dehydration parameters; When the moisture content of the solid filler is less than a preset moisture content threshold, the dehydrated solid filler is obtained; The drying vessel is filled with nitrogen, and the dehydrated solid filler is stored at a preset temperature.

3. The preparation method according to claim 2, characterized in that: The step of dehydrating the solid filler according to the preset dehydration parameters also includes: The dehydration temperature of the drying vessel is set to be greater than or equal to 100° C. and less than or equal to 200° C.; The drying time of the drying container is set to be greater than or equal to 2 hours and less than or equal to 4 hours.

4. The preparation method according to claim 2, characterized in that: The preset moisture content threshold is set to be less than or equal to 0.04%.

5. The preparation method according to claim 2, characterized in that: The preset temperature is set to be less than or equal to 70°C.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The step of adding the dehydrated solid filler, the liquid filler and the polyurethane resin into the production kettle and stirring them also includes: The polyurethane resin and the liquid filler are respectively measured and injected into the production kettle; Starting the stirring system of the production kettle to perform mixing and stirring according to the first stirring parameter; The dehydrated solid filler is injected into the production kettle, and mixed and stirred according to the second stirring parameter.

7. The preparation method according to claim 6, characterized in that: The step of mixing and stirring according to the first stirring parameter also includes: Start the frame stirring system, and set the stirring speed to be greater than or equal to 15 r / min and less than or equal to 25 r / min, and the stirring time to be greater than or equal to 10 min and less than or equal to 20 min; Start the paddle stirring system, and set the stirring speed to be greater than or equal to 200 r / min and less than or equal to 400 r / min, and the stirring time to be greater than or equal to 10 min and less than or equal to 20 min.

8. The preparation method according to claim 6, characterized in that: The step of mixing and stirring according to the set second stirring parameter also includes: Start the frame stirring system, and set the stirring speed to be greater than or equal to 15 r / min and less than or equal to 60 r / min, and the stirring time to be greater than or equal to 0.5 min and less than or equal to 2 min; Start the paddle stirring system, and set the stirring speed to be greater than or equal to 500 r / min and less than or equal to 800 r / min, and the stirring time to be greater than or equal to 0.5 min and less than or equal to 2 min.

9. The preparation method according to any one of claims 1 to 5, characterized in that: The step of sequentially adding the solvent and the functional additive into the production kettle and stirring and degassing also includes: The stirring speed of the paddle stirring system is adjusted to be greater than or equal to 900 r / min and less than or equal to 1200 r / min, and the stirring time is set to be greater than or equal to 2 h and less than or equal to 4 h; The stirring speed of the frame stirring system is adjusted to be greater than or equal to 15 r / min and less than or equal to 60 r / min, and the stirring time is set to be greater than or equal to 2 h and less than or equal to 3 h.

10. A polyurethane waterproof coating, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 9.

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