Bio-based polyurethane prepolymer, bio-based waterproof coating and preparation method of bio-based polyurethane prepolymer and bio-based waterproof coating

Abstract

The invention discloses a bio-based polyurethane prepolymer, a bio-based waterproof coating and a preparation method thereof, and the preparation method comprises the following steps: preparation of a first component: introducing dried bio-based polyol and bio-based polyisocyanate into a reaction packed column with a length-diameter ratio greater than 100, and reacting in a flowing process to generate the bio-based polyurethane prepolymer, a material flowing out of the reaction packed column is used as a first component; the reaction packed column comprises a column body with a reaction chamber and a plurality of solid catalysts filled in the reaction chamber, and each solid catalyst comprises a carrier and a first catalyst which is loaded on the carrier and is used for catalyzing reaction; the solid catalyst is movably arranged relative to the reaction chamber and is limited in the reaction chamber; preparation of a second component: mixing bio-based polyol and a second auxiliary agent to obtain the second component; the bio-based waterproof coating prepared by the method has excellent inter-batch quality stability and can be stored for a long time.

Description

Technical Field

[0001] The present invention relates to the field of waterproof coatings, in particular to bio-based waterproof coatings, and specifically to a bio-based polyurethane prepolymer, a bio-based waterproof coating and a preparation method thereof. Background Art

[0002] Reactive waterproof coatings are one of the important branches of building waterproof materials, including epoxy resin waterproof coatings, polyurethane waterproof coatings, polymethyl methacrylate waterproof coatings, etc. Among them, polyurethane waterproof coatings are the most widely used one, because of their outstanding cost-effectiveness. According to their composition and curing mechanism, polyurethane waterproof coatings can be divided into single-component polyurethane waterproof coatings and multi-component polyurethane waterproof coatings (such as two-component polyurethane waterproof coatings). Among them, single-component polyurethane waterproof coatings mainly rely on water vapor in the air to cure (mainly based on the reaction of isocyanate groups (-NCO) with water vapor for curing), so environmental factors are important factors affecting their film quality and performance; multi-component polyurethane waterproof coatings usually include isocyanate components and compounds containing hydroxyl groups (OH and other active groups), which are mainly cured and cross-linked to form films through isocyanate components and compounds containing OH and other active groups (such as polyols, chain extenders, etc.). Since the reaction activity of NCO and active groups such as OH is much greater than the reaction activity of NCO and water vapor, the curing and film-forming process of two-component polyurethane waterproof coatings is less affected by the environment and has better film quality. However, it has been found in practice that the polyurethane waterproof coating prepared by the above method has a large quality difference between batches. In addition, with the continuous improvement of environmental protection requirements, bio-based polyurethane waterproof coating products have appeared, but the materials used, especially polyols and isocyanates, are not all bio-based materials. Only some bio-based raw materials are available, and the sources are limited and difficult to obtain.

[0003] It should be noted that the information disclosed in the above background technology section is only used to understand the background of the present application, so the background technology section of the present invention may contain background information about the problem or environment of the present invention, but not necessarily describe the prior art. Therefore, the content contained in the background technology section is not an admission of the applicant to the prior art. Summary of the invention

[0004] The purpose of the present invention is to overcome one or more deficiencies in the prior art and to provide an improved method for preparing a two-component bio-based waterproof coating and a two-component bio-based waterproof coating made therefrom. The two-component bio-based waterproof coating made by the method has excellent batch-to-batch quality stability and can be stored for a long time.

[0005] The invention also provides a method for preparing a bio-based polyurethane prepolymer.

[0006] In order to achieve the above object, a technical solution adopted by the present invention is:

[0007] A method for preparing a two-component bio-based waterproof coating, the preparation method comprising:

[0008] (1) Preparation of the first component

[0009] Passing a dried bio-based polyol having a hydroxyl value of less than or equal to 160 mgKOH / g, a bio-based polyisocyanate, and a selective first auxiliary agent into a reaction filling column with an aspect ratio greater than 100, reacting to generate a bio-based polyurethane prepolymer during the flow process, and using the material flowing out of the reaction filling column as the first component;

[0010] The reaction filling column comprises a column body formed with a reaction chamber, and a plurality of solid catalysts filled in the reaction chamber, wherein the solid catalyst comprises a carrier and a first catalyst supported on the carrier and used to catalyze the reaction; the solid catalyst is movably arranged relative to the reaction chamber and is confined in the reaction chamber;

[0011] (2) Preparation of the second component

[0012] The bio-based polyol and the second auxiliary agent are mixed as the second component, wherein the second auxiliary agent includes a second catalyst and a cross-linking agent.

[0013] According to some preferred aspects of the present invention, the radial dimension of the reaction chamber varies along its length direction.

[0014] Furthermore, the change has a periodic pattern.

[0015] According to some preferred aspects of the present invention, the maximum radial dimension of the reaction chamber is L1 and the minimum is L2, the radial dimension of the solid catalyst is Φ, and satisfies the following conditions: L2<m×Φ<L1<(m+1.5)×Φ, where m is a positive integer.

[0016] According to some preferred aspects of the present invention, a plurality of arc-shaped protrusions are formed on the inner wall of the reaction chamber.

[0017] Furthermore, the plurality of arc-shaped protrusions are respectively formed on the upper side and the lower side of the inner wall of the reaction chamber and are symmetrically arranged in pairs.

[0018] According to some preferred aspects of the present invention, on each side, the distance between any two adjacent arc-shaped protrusions gradually increases from outside to inside in the radial direction, and a part of the distance is smaller than the radial dimension of the solid catalyst.

[0019] In some embodiments of the present invention, the multiple arc-shaped protrusions separate the reaction chamber into a first chamber and a second chamber connected to the first chamber, the first chamber and the second chamber each have at least one, and the volume of the second chamber is greater than the volume of the first chamber.

[0020] In some embodiments of the present invention, the carrier is a porous material having a diameter of 0.4-4.5 mm and a pore size of 0.05-400 μm.

[0021] In some embodiments of the present invention, the material of the carrier is silica with a porous structure.

[0022] In some embodiments of the present invention, the temperature in the reaction filling column is controlled to be 70-100° C., and the reaction residence time is 10-30 min.

[0023] In some embodiments of the present invention, the length-to-diameter ratio of the reaction filling column is 100-8000.

[0024] According to some preferred aspects of the present invention, the total loading amount of the first catalyst is 0.05%-1.0%, further 0.2%-0.5%, of the total mass of the bio-based polyol and the bio-based polyisocyanate in the reaction chamber.

[0025] In some embodiments of the present invention, the solid catalyst is formed by loading the first catalyst on the carrier by impregnation.

[0026] In some embodiments of the present invention, the bio-based polyol has a hydroxyl value of 10-155 mgKOH / g and a molecular weight of 1000-8000 g / mol.

[0027] In some embodiments of the present invention, the bio-based polyol is a combination of one or more selected from castor oil, modified castor oil hydroxyl-terminated resin, hydroxyl-terminated soybean oil, modified soybean oil hydroxyl-terminated resin, and modified palm oil hydroxyl-terminated resin. These bio-based polyols have good biodegradability and renewability, which helps to reduce the environmental burden of materials.

[0028] In some embodiments of the present invention, the two-component bio-based waterproof coating comprises a first component and a second component, and the mass ratio of the first component to the second component is 1:0.8-1.2;

[0029] In parts by weight, the first component comprises:

[0030] Bio-based polyol 63-72 parts

[0031] Bio-based polyisocyanate 27-37 parts

[0032] The first auxiliary agent 0-1 part;

[0033] The first auxiliary agent includes a defoaming agent;

[0034] In parts by weight, the second component comprises:

[0035] Bio-based polyol 30-60 parts

[0036] Crosslinking agent 0.5-5 parts

[0037] The second catalyst is 0.01-0.2 parts.

[0038] Furthermore, the second auxiliary agent also includes fillers, pigments, dispersants, anti-sagging agents, water removers, antifungal agents, defoamers and flame retardants;

[0039] In parts by weight, the second component comprises:

[0040]

[0041]

[0042] In some embodiments of the present invention, the first catalyst and the second catalyst are independently selected from a combination of one or more of an organic bismuth catalyst, an organic zinc catalyst, and an organic tin catalyst.

[0043] In some embodiments of the present invention, the crosslinking agent is a diol and / or a diamine; further, the crosslinking agent includes one or more selected from ethylene glycol, dihydroxyethyl hydroquinone, 1,4-butanediol, diethyltoluene diamine, 3,3'-dichloro-4,4'-diaminophenylmethane, 1,4-butanediol-2-sulfonate sodium, dihydroxymethylpropionic acid, hexanediol, decanediol, trimethylolpropane, castor oil, modified castor oil, hydroxyl-modified soybean oil, and hydroxyl-modified palm oil.

[0044] In some embodiments of the present invention, the filler is one or a combination of calcium carbonate, kaolin, talc, and white carbon black.

[0045] In some embodiments of the present invention, the pigment is a combination of one or more selected from shell powder, calcium powder, glass beads, bio-based pigment BioBlack TX, and Valley Blue VBL007, which gives the material good color and hiding power.

[0046] In some embodiments of the present invention, the anti-sagging agent is a combination of one or more selected from fumed silica, nano calcium carbonate, modified bentonite, hydrogenated castor oil, and polyamide wax to improve the construction performance and leveling of the material. Preferably, nano calcium carbonate and hydrogenated castor oil are used.

[0047] In some embodiments of the present invention, the dehydrating agent is a combination of one or more selected from calcium oxide, magnesium oxide, p-toluenesulfonyl isocyanate, and molecular sieves.

[0048] In some embodiments of the present invention, the antifungal agent is one or a combination of nano zinc oxide and nano silver, which imparts good antifungal properties to the material.

[0049] In some embodiments of the present invention, the defoaming agent is a combination of one or more selected from acrylates, polysiloxane solutions, modified polysiloxane solutions, and polysiloxane containing hydrophobic particles.

[0050] In some embodiments of the present invention, the flame retardant is one or a combination of several selected from aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, antimony trioxide, zinc borate, barium metaborate, and antimony oxide-silicon oxide composite.

[0051] According to some preferred aspects of the present invention, the bio-based polyisocyanate is prepared by the following method:

[0052] React 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl chloride with sodium azide to generate a compound represented by formula (I);

[0053]

[0054] Further, the reaction is carried out at 20-40° C. in an organic solvent; further, the organic solvent may be acetone or the like;

[0055] The compound represented by formula (I) is reacted with azelaic acid to generate a bio-based polyisocyanate represented by formula (II); wherein the azelaic acid is prepared by ozone decomposition of biomass acid;

[0056]

[0057] Furthermore, the reaction is carried out at 60-80° C. in the presence of 4-dimethylaminopyridine in an organic solvent; further, the organic solvent may be acetonitrile or the like.

[0058] Furthermore, the azelaic acid can be prepared by ozonolysis of biomass acid. The method of preparing azelaic acid by ozonolysis of biomass acid can be carried out with reference to the prior art, or azelaic acid from bio-based sources can be directly purchased.

[0059] Furthermore, the biomass acid may be oleic acid.

[0060] The method for preparing bio-based polyisocyanate of the present invention is simple to operate and has a high yield. Azelaic acid has a wide source and can be prepared by ozone decomposition of biomass acid, thus overcoming the defect that existing biomass polyisocyanate is not easy to obtain.

[0061] Another technical solution provided by the present invention is: a two-component bio-based waterproof coating made by the preparation method of the above-mentioned two-component bio-based waterproof coating.

[0062] Another technical solution provided by the present invention is a method for preparing a bio-based polyurethane prepolymer, the method comprising: introducing a dried bio-based polyol having a hydroxyl value of less than or equal to 160 mgKOH / g and a bio-based polyisocyanate into a reaction filling column with an aspect ratio greater than 100, and reacting to generate a bio-based polyurethane prepolymer during the flow process; wherein the reaction filling column comprises a column body forming a reaction chamber, and a plurality of solid catalysts filled in the reaction chamber, the solid catalyst comprising a carrier and a first catalyst loaded on the carrier and used to catalyze the reaction; the solid catalyst is movably arranged relative to the reaction chamber and is confined in the reaction chamber.

[0063] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0064] The present invention is based on the problem that the polyurethane waterproof coating prepared in the prior art has large quality differences between batches when used. After a large number of experimental studies, the inventors of the present invention believe that this is caused by the existing use of a reactor to react polyols and isocyanates. First, after the added catalyst is added to the reactor, the dispersion efficiency may be low by stirring, resulting in a more intense local reaction, while the reaction of the part without the catalyst is slower. The dispersion of each batch of reactions may be different, resulting in different structures and molecular weights of each batch of polyurethane prepolymers, and obvious quality differences. Second, the added catalyst remains in the polyurethane prepolymer, making it difficult to separate it. Therefore, the catalyst usually remains in the product, causing the catalyst to work during storage, causing the isocyanate group to further react with the carbamate, changing the structure and molecular weight of the polyurethane prepolymer, thereby causing significant differences in the structure and molecular weight of the polyurethane prepolymer between batches, resulting in unstable quality of the waterproof coating; thirdly, the reaction between the isocyanate group and the hydroxyl group is an exothermic process, and it is difficult for the existing conventional reactor to timely conduct the heat released by the internal reaction through the reactor wall, resulting in heat concentration, which in turn causes different reaction degrees in different areas, resulting in large differences in the quality and viscosity of the polyurethane prepolymer obtained in each batch;

[0065] Based on the above findings, the present invention innovatively proposes a new type of reaction filling column for the reaction of polyisocyanate and polyol. By controlling the aspect ratio, the reaction raw materials can react to generate polyurethane prepolymers during the process, especially the catalyst required for the reaction is loaded on the carrier in a loaded manner, and the solid catalyst formed after the catalyst is loaded is movably arranged in the reaction filling column, that is, the solid catalyst can move freely at a local position in the reaction chamber, and then in the contact process with the reaction raw materials, the two can not only maximize the contact, the contact area is large, and the reaction materials use the flow impact to drive the solid catalyst to move and rotate freely during the process, which increases the disturbance of the fluid, further improves the mixing uniformity of polyisocyanate and polyol, and improves the reaction balance; at the same time, because the reaction filling column with a large aspect ratio can provide more contact area with the flowing reaction mixture, the heat will not be concentrated, and it can be more easily dispersed, thereby avoiding the problem of reaction imbalance caused by heat concentration; in addition, after the catalyst of the present invention is loaded and fixed, it will not flow out with the outflow of the polyurethane prepolymer, not only can it be reused, but also avoids a series of problems caused by the catalyst remaining in the polyurethane prepolymer.

[0066] Therefore, the present invention solves the problem that the polyurethane waterproof coating prepared in the prior art has large quality differences between batches when used. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 Schematic diagram of the structure of the column body of the reaction filling column in an embodiment of the present invention;

[0068] Figure 2 This is one of the structural schematic diagrams of the reaction filling column (solid catalyst is filled in a single row) used in the embodiments of the present invention;

[0069] Figure 3 This is the second structural schematic diagram of the reaction filling column (solid catalyst is double-row filled) used in the embodiment of the present invention;

[0070] Figure 4 This is the third structural schematic diagram of the reaction filling column (solid catalyst is filled in three rows) used in the embodiment of the present invention;

[0071] Figure 5 This is a schematic diagram of the structure of a production device used in preparing the first component in the preparation process of a two-component bio-based waterproof coating in an embodiment of the present invention;

[0072] In the accompanying drawings: 100, reaction filling column; 110, column body; 111, reaction chamber; 1111, first chamber; 1112, second chamber; 112, arc-shaped protrusion; 120, solid catalyst; 200, bio-based polyol storage tank; 300, bio-based polyisocyanate storage tank; 400, drying channel; 500, auxiliary agent storage bin; 600, first component storage tank. DETAILED DESCRIPTION

[0073] The present invention provides a method for preparing a two-component bio-based waterproof coating with relatively stable quality between batches, so as to reduce and / or eliminate the negative impact caused by operation and reaction equipment during the preparation process.

[0074] The improved two-component bio-based waterproof coating method comprises:

[0075] (1) Preparation of the first component

[0076] Passing a dried bio-based polyol having a hydroxyl value of less than or equal to 160 mgKOH / g, a bio-based polyisocyanate, and a selective first auxiliary agent into a reaction filling column with an aspect ratio greater than 100, reacting to generate a bio-based polyurethane prepolymer during the flow process, and using the material flowing out of the reaction filling column as the first component;

[0077] The reaction filling column comprises a column body formed with a reaction chamber, and a plurality of solid catalysts filled in the reaction chamber, wherein the solid catalyst comprises a carrier and a first catalyst supported on the carrier and used to catalyze the reaction; the solid catalyst is movably arranged relative to the reaction chamber and is confined in the reaction chamber;

[0078] (2) Preparation of the second component

[0079] The bio-based polyol and the second auxiliary agent are mixed as the second component, wherein the second auxiliary agent includes a second catalyst and a cross-linking agent.

[0080] Combine the following Figures 1 to 5 The above preparation method of the present invention is further described. Figures 1 to 4 The structural schematic diagram of the reaction filling column used in the present invention is given as an example. Figure 5 Schematic diagram of the structure of the production device used to prepare the first component in the preparation process of a two-component bio-based waterproof coating.

[0081] The reaction filling column 100 includes a column body 110 formed with a reaction chamber 111, and a plurality of solid catalysts 120 filled in the reaction chamber 111, wherein the solid catalyst 120 includes a carrier and a first catalyst loaded on the carrier and used for catalytic reaction; the solid catalyst 120 is movably arranged relative to the reaction chamber 111 and is confined in the reaction chamber 111.

[0082] The radial dimension of the reaction chamber 111 varies in its length direction, and the variation has a periodic law, such as Figure 1 As shown, the radial dimension of the reaction chamber 111 in its own length direction first decreases and then increases, decreases and then increases, and repeats this cycle. This change can change the local flow rate of the reaction material passing through, and the different flow rates at various positions will aggravate the fluidity differences of the reaction materials, thereby producing a mutual disturbance effect, which can increase the mixing uniformity between the reaction materials such as bio-based polyols and bio-based polyisocyanates, improve the reaction efficiency and reaction balance, and can quickly disperse and transfer heat outward through the chamber wall during the disturbance and mutual circulation process, thereby avoiding the concentration of heat in local positions.

[0083] Furthermore, the maximum radial dimension of the reaction chamber 111 is L1 and the minimum radial dimension is L2, the radial dimension of the solid catalyst 120 is Φ, and the following conditions are satisfied: L2<m×Φ<L1<(m+1.5)×Φ, where m is a positive integer, see Figure 1 and 2 As shown, such a configuration can prevent the solid catalyst 120 from circulating in a large range and be limited to a specific spatial position. On the one hand, it can prevent the solid catalyst from being aggregated together; on the other hand, it is conducive to evenly distributing the filled solid catalyst along the length direction of the reaction chamber 111, thereby improving the catalytic uniformity and stability.

[0084] In practice, the value of m is determined according to the arrangement of the solid catalyst, for example, see Figure 2 As shown, the solid catalyst 120 is filled in a single row, and m is 1; if Figure 3 As shown, the solid catalyst 120 is filled in double rows, and m is 2; if Figure 4 As shown, the solid catalyst 120 is filled in three rows, and m is 3 at this time, and so on; such an arrangement is more conducive to uniform dispersion of the catalyst.

[0085] Further, a plurality of arc-shaped protrusions 112 are formed on the inner wall of the reaction chamber 111. The aforementioned plurality of arc-shaped protrusions 112 are respectively formed on the upper side and the lower side of the inner wall of the reaction chamber 111 and are symmetrically arranged in pairs; on each side, the distance between any two adjacent arc-shaped protrusions 112 gradually increases from the outside to the inside along the radial direction, and some of the distances are smaller than the radial dimension of the solid catalyst 120. Figure 1As shown, the above-mentioned multiple arc-shaped protrusions 112 separate the reaction chamber 111 into a first chamber 1111 and a second chamber 1112 connected to the first chamber 1111. The first chamber 1111 and the second chamber 1112 each have at least one, and the volume of the second chamber 1112 is greater than the volume of the first chamber 1111. The arrangement of the above-mentioned arc-shaped protrusions 112 realizes that the radial dimension of the reaction chamber 111 changes in its own length direction, and the arc-shaped protrusions 112 can further increase the contact area and improve the heat dissipation efficiency on the one hand, and on the other hand, can change the direction of fluid flow and increase the turbulence effect, that is, can further improve the uniformity of dispersion and mixing; in addition, the arrangement of the above-mentioned arc-shaped protrusions 112 can also increase the probability of the solid catalyst 120 being driven to move or rotate in the reaction material, thereby effectively ensuring the uniformity of the dispersion of the solid catalyst, improving the catalytic effect, and improving the reaction balance.

[0086] Furthermore, in order to prevent the solid catalyst from being taken out of the reaction chamber 111 under certain special circumstances, filter screens (not shown) can be respectively provided at the inlet and outlet of the reaction chamber 111 to prevent the solid catalyst 120 from leaving the reaction chamber 111. Meanwhile, the aspect ratio of the reaction filling column 100 can be 100-8000.

[0087] Furthermore, the carrier is a porous material with a diameter of 0.4-4.5 mm and a pore size of 0.05-400 μm. The material of the carrier is silica with a porous structure. The total loading amount of the first catalyst is 0.05%-1.0% of the total mass of the bio-based polyol and the bio-based polyisocyanate in the reaction chamber, for example, it can be 0.2%-0.5%; the solid catalyst is formed by loading the first catalyst on the carrier by impregnation, and the first catalyst is a combination of one or more selected from organic bismuth catalysts, organic zinc catalysts, and organic tin catalysts.

[0088] Specifically, the preparation method of the solid catalyst is: drying the porous material in a blast drying oven, taking it out and placing it in a drying tower to cool to room temperature, preparing ethanol and ethyl acetate into a mixed solution, adding a measured amount of catalyst and the dried porous material, fully stirring, filtering, and then placing it in a blast drying oven to dry to obtain a solid catalyst.

[0089] Furthermore, the temperature in the reaction column 100 is controlled to be 70-100° C., and the reaction residence time is 10-30 minutes. In the present invention, a temperature control device, such as some heat exchangers, can be used to control the temperature in the reaction column.

[0090] Furthermore, the two-component bio-based waterproof coating includes a first component and a second component, and the mass ratio of the first component to the second component is 1:0.8-1.2; in parts by weight, the first component includes: 63-72 parts of bio-based polyol, 27-37 parts of bio-based polyisocyanate, and 0-1 part of a first auxiliary agent; the first auxiliary agent includes a defoaming agent; in parts by weight, the second component includes: 30-60 parts of bio-based polyol, 0.5-5 parts of a cross-linking agent, and 0.01-0.2 parts of a second catalyst.

[0091] Furthermore, the second auxiliary agent also includes fillers, pigments, dispersants, anti-sagging agents, water removers, antifungal agents, defoamers and flame retardants; in terms of weight, the second component includes: 30-60 parts of bio-based polyols, 15-29 parts of fillers, 10-16 parts of pigments, 2-8 parts of dispersants, 1-5 parts of anti-sagging agents, 0.5-5 parts of cross-linking agents, 0.01-0.2 parts of second catalysts, 0.1-2 parts of water removers, 1-4 parts of antifungal agents, 0.1-1 parts of defoamers, and 2-6 parts of flame retardants.

[0092] See also Figure 5 As shown, the production device used in the preparation process of the two-component bio-based waterproof coating for preparing the first component includes a reaction filling column 100, a bio-based polyol storage tank 200, a bio-based polyisocyanate storage tank 300, a drying channel 400, an auxiliary agent storage bin 500, and a first component storage tank 600; wherein the bio-based polyol storage tank 200, the drying channel 400, the reaction filling column 100, and the first component storage tank 600 are sequentially connected, the bio-based polyisocyanate storage tank 300 and the auxiliary agent storage bin 500 are respectively connected to the reaction filling column 100, and the auxiliary agent storage bin 500 can be used to add a defoaming agent;

[0093] When preparing the second component, all the raw materials need to be mixed evenly.

[0094] Furthermore, the drying channel 400 involved in the preparation process of the two-component bio-based waterproof coating mainly controls the moisture content of the bio-based polyol. For example, the moisture content is preferably controlled below 500 ppm. A circulation tube can be provided, and a fixed desiccant (silica gel, montmorillonite, anhydrous calcium chloride, etc.) can be filled in the circulation tube so that the bio-based polyol is dehydrated by the desiccant during the circulation process. Of course, other methods can also be used to remove the moisture contained in the bio-based polyol, which will not be described in detail here.

[0095] Furthermore, before the preparation begins, each device may be prepared for dehydration, for example, by heating and drying. For channels, inert gases such as nitrogen may be introduced in advance to replace the water-containing air inside.

[0096] The above scheme is further described below in conjunction with specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions adopted in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0097] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared by conventional methods in the art.

[0098] In the following, the bio-based polyisocyanate used is prepared according to the following method: 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl chloride and sodium azide are reacted in a molar ratio of 1:1.2 at room temperature in acetone to generate an intermediate; then the intermediate is reacted with azelaic acid in a molar ratio of 2.4:1 at 70°C in the presence of 4-dimethylaminopyridine in acetonitrile to generate a bio-based polyisocyanate, and the product is separated and purified by thin film distillation separation technology at a separation pressure of 100 Pa and a temperature of 130°C to obtain a purified bio-based polyisocyanate.

[0099] In the following, the solid catalyst is prepared by the following method: the porous material is dried in a 120°C air drying oven for 3 hours, taken out and placed in a drying tower to cool to room temperature, ethanol and ethyl acetate are mixed in a 1:1 ratio, a measured amount of catalyst and the dried porous material are added, stirred thoroughly for 1 hour, filtered, and then placed in a 120°C air drying oven to dry for 3 hours to obtain a solid catalyst.

[0100] Example 1

[0101] This example provides a method for preparing a two-component bio-based waterproof coating and a two-component bio-based waterproof coating prepared by the method. Figure 2 The reaction column shown is packed with Figure 5 The device shown prepares the first component and the above production process;

[0102] Among them, the formula content of the two-component bio-based waterproof coating is shown in Table 1;

[0103] Table 1

[0104]

[0105] The maximum radial dimension L1 of the reaction chamber is 4 mm, the minimum radial dimension L2 is 2.5 mm, and the length is 10 m;

[0106] The first catalyst in the solid catalyst is dibutyltin dilaurate, purchased from Jiangsu Mingtai New Materials Co., Ltd., brand T-12; the carrier is silica, the average diameter of the carrier is Φ3mm, purchased from Qingdao Xinchanglai Silica Gel Co., Ltd., brand FNG-C series (customizable size); the total loading amount of the first catalyst is 0.5% of the total mass of the bio-based polyol and the bio-based polyisocyanate in the reaction chamber;

[0107] The temperature in the reaction column was controlled to be 85°C and the reaction residence time was 10 minutes;

[0108] The second component is prepared by mixing the raw materials uniformly;

[0109] The feed mass ratio of the first component to the second component is 1:1.

[0110] Example 2

[0111] This example provides a method for preparing a two-component bio-based waterproof coating and a two-component bio-based waterproof coating prepared by the method. Figure 3 The reaction column shown is packed with Figure 5 The device shown prepares the first component and the above production process;

[0112] Among them, the formula content of the two-component bio-based waterproof coating is shown in Table 2;

[0113] Table 2

[0114]

[0115]

[0116] The maximum radial dimension L1 of the reaction chamber is 5 mm, the minimum radial dimension L2 is 3.5 mm, and the length is 10 m;

[0117] The first catalyst in the solid catalyst is dibutyltin dilaurate, purchased from Jiangsu Mingtai New Materials Co., Ltd., brand T-12; the carrier is silica, the average diameter of the carrier is Φ2 mm, purchased from Qingdao Xinchanglai Silica Gel Co., Ltd., brand FNG-C series; the total loading amount of the first catalyst is 0.4% of the total mass of the bio-based polyol and the bio-based polyisocyanate in the reaction chamber;

[0118] The temperature in the reaction column was controlled to be 70°C and the reaction residence time was 25 minutes;

[0119] The second component is prepared by mixing the raw materials uniformly;

[0120] The feed mass ratio of the first component to the second component is 1:1.

[0121] Example 3

[0122] This example provides a method for preparing a two-component bio-based waterproof coating and a two-component bio-based waterproof coating prepared by the method. Figure 4 The reaction column shown is packed with Figure 5 The device shown prepares the first component and the above production process;

[0123] Among them, the formula content of the two-component bio-based waterproof coating is shown in Table 3;

[0124] Table 3

[0125]

[0126]

[0127] The maximum radial dimension L1 of the reaction chamber is 5 mm, the minimum radial dimension L2 is 4 mm, and the length is 10 m;

[0128] The first catalyst in the solid catalyst is dibutyltin dilaurate, purchased from Jiangsu Mingtai New Materials Co., Ltd., brand T-12; the carrier is silica, the average diameter of the carrier is Φ1.5mm, purchased from Qingdao Xinchanglai Silica Gel Co., Ltd., brand FNG-C series; the total loading amount of the first catalyst is 0.03% of the total mass of the bio-based polyol and the bio-based polyisocyanate in the reaction chamber;

[0129] The temperature in the reaction column was controlled to be 100°C and the reaction residence time was 30 minutes;

[0130] The second component is prepared by mixing the raw materials uniformly;

[0131] The feed mass ratio of the first component to the second component is 1:1.

[0132] Comparative Example 1

[0133] This example provides a two-component bio-based waterproof coating, which uses a traditional kettle preparation method and has the same formula as Example 1.

[0134] Preparation process: add polyol to the reaction kettle, introduce nitrogen protection, heat to 80°C, add isocyanate, stir and mix at 70-90°C for 2 hours, then cool to 60°C, add the first catalyst and the first auxiliary agent (i.e., defoamer), stir for 25 minutes, and obtain the first component;

[0135] The second component is prepared by mixing the raw materials uniformly;

[0136] The feed mass ratio of the first component to the second component is 1:1.

[0137] Performance Testing

[0138] The two-component bio-based waterproof coatings prepared in the above Examples 1-3 and Comparative Example 1 were subjected to the following performance tests, and the performance test results are shown in Table 4. The viscosity was tested using an NDJ-1s digital rotational viscometer, and the tensile strength and elongation at break were tested in accordance with GB / T 16777-2008.

[0139] Table 4

[0140]

[0141]

[0142] It can be seen from Table 4 that the two-component bio-based waterproof coating of the present invention performs better in storage stability and has better stability.

[0143] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

[0144] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. A method for preparing a two-component bio-based waterproof coating, characterized in that: The preparation method comprises: (1) Preparation of the first component Passing a dried bio-based polyol having a hydroxyl value of less than or equal to 160 mgKOH / g, a bio-based polyisocyanate, and a selective first auxiliary agent into a reaction filling column with an aspect ratio greater than 100, reacting to generate a bio-based polyurethane prepolymer during the flow process, and using the material flowing out of the reaction filling column as the first component; The reaction filling column comprises a column body formed with a reaction chamber, and a plurality of solid catalysts filled in the reaction chamber, wherein the solid catalyst comprises a carrier and a first catalyst supported on the carrier and used to catalyze the reaction; the solid catalyst is movably arranged relative to the reaction chamber and is confined in the reaction chamber; (2) Preparation of the second component The bio-based polyol and the second auxiliary agent are mixed as the second component, wherein the second auxiliary agent includes a second catalyst and a cross-linking agent.

2. The method for preparing a two-component bio-based waterproof coating according to claim 1, characterized in that: The radial dimension of the reaction chamber varies along its length direction.

3. The method for preparing a two-component bio-based waterproof coating according to claim 2, characterized in that: The changes have a periodic pattern.

4. The method for preparing a two-component bio-based waterproof coating according to claim 2, characterized in that: The maximum radial dimension of the reaction chamber is L1 and the minimum radial dimension is L2. The radial dimension of the solid catalyst is Φ and satisfies the following condition: L2<m×Φ<L1<(m+1.5)×Φ, where m is a positive integer.

5. The method for preparing a two-component bio-based waterproof coating according to claim 2, characterized in that: A plurality of arc-shaped protrusions are formed on the inner wall of the reaction chamber.

6. The method for preparing a two-component bio-based waterproof coating according to claim 5, characterized in that: The multiple arc-shaped protrusions are respectively formed on the upper side and the lower side of the inner wall of the reaction chamber and are symmetrically arranged in pairs; and / or, on each side, the distance between any two adjacent arc-shaped protrusions gradually increases from the outside to the inside along the radial direction, and some of the distances are smaller than the radial dimension of the solid catalyst.

7. The method for preparing a two-component bio-based waterproof coating according to claim 5, characterized in that: The multiple arc-shaped protrusions divide the reaction chamber into a first chamber and a second chamber connected to the first chamber. The first chamber and the second chamber each have at least one, and the volume of the second chamber is greater than that of the first chamber.

8. The method for preparing a two-component bio-based waterproof coating according to claim 1, characterized in that: The carrier is a porous material having a diameter of 0.4-4.5 mm and a pore size of 0.05-400 μm; and / or the carrier is made of silicon dioxide with a porous structure.

9. The method for preparing a two-component bio-based waterproof coating according to claim 1, characterized in that: The temperature in the reaction filling column is controlled to be 70-100° C., and the reaction residence time is 10-30 min; and / or the aspect ratio of the reaction filling column is 100-8000.

10. The method for preparing a two-component bio-based waterproof coating according to claim 1, characterized in that: The total loading amount of the first catalyst is 0.05%-1.0%, further 0.2%-0.5%, of the total mass of the bio-based polyol and the bio-based polyisocyanate in the reaction chamber; and / or, the solid catalyst is formed by loading the first catalyst on the carrier by impregnation; and / or, the hydroxyl value of the bio-based polyol is 10-155 mgKOH / g and the molecular weight is 1000-8000 g / mol.

11. The method for preparing a two-component bio-based waterproof coating according to claim 1, characterized in that: The two-component bio-based waterproof coating comprises a first component and a second component, wherein the mass ratio of the first component to the second component is 1:0.8-1.2; In parts by weight, the first component comprises: Bio-based polyol 63-72 parts Bio-based polyisocyanate 27-37 parts The first auxiliary agent 0-1 part; The first auxiliary agent includes a defoaming agent; In parts by weight, the second component comprises: Bio-based polyol 30-50 parts Crosslinking agent 0.5-5 parts The second catalyst is 0.01-0.2 parts.

12. The method for preparing a two-component bio-based waterproof coating according to claim 11, characterized in that: The second auxiliary agent also includes fillers, pigments, dispersants, anti-sagging agents, water removers, antifungal agents, defoamers and flame retardants; In parts by weight, the second component comprises:

13. The method for preparing a two-component bio-based waterproof coating according to any one of claims 1 to 12, characterized in that: The bio-based polyol is a combination of one or more selected from castor oil, modified castor oil terminal hydroxyl resin, terminal hydroxyl soybean oil, modified soybean oil terminal hydroxyl resin, and modified palm oil terminal hydroxyl resin; and / or the first catalyst and the second catalyst are independently selected from a combination of one or more selected from an organic bismuth catalyst, an organic zinc catalyst, and an organic tin catalyst; and / or the cross-linking agent includes one or more selected from ethylene glycol, dihydroxyethyl hydroquinone ether, 1,4-butanediol, diethyltoluenediamine, 3,3'-dichloro-4,4'-diaminophenylmethane, 1,4-butanediol-2-sodium sulfonate, dihydroxymethylpropionic acid, hexanediol, decanediol, trimethylolpropane, castor oil, modified castor oil, hydroxyl-modified soybean oil, and hydroxyl-modified palm oil.

14. The method for preparing a two-component bio-based waterproof coating according to claim 1, characterized in that: The bio-based polyisocyanate is prepared by the following method: React 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl chloride with sodium azide to generate a compound represented by formula (I); The compound represented by formula (I) is reacted with azelaic acid to generate a bio-based polyisocyanate represented by formula (II); wherein the azelaic acid is prepared by ozone decomposition of biomass acid; 15. A two-component bio-based waterproof coating made by the preparation method of the two-component bio-based waterproof coating according to any one of claims 1 to 14.

16. A method for preparing a bio-based polyurethane prepolymer, characterized in that: The preparation method of the bio-based polyurethane prepolymer comprises: introducing a dried bio-based polyol and a bio-based polyisocyanate having a hydroxyl value of less than or equal to 160 mgKOH / g into a reaction filling column with an aspect ratio greater than 100, and reacting to generate a bio-based polyurethane prepolymer during the flow process; wherein the reaction filling column comprises a column body formed with a reaction chamber, and a plurality of solid catalysts filled in the reaction chamber, wherein the solid catalyst comprises a carrier and a first catalyst loaded on the carrier and used to catalyze the reaction; and the solid catalyst is movably arranged relative to the reaction chamber and is confined in the reaction chamber.

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