A bio-based polyurethane prepolymer, a bio-based waterproof coating and a preparation method thereof

Abstract

The application discloses a kind of bio-based polyurethane prepolymer, bio-based waterproof coating and preparation method thereof, preparation method includes: the preparation of first component: the dried bio-based polyol is passed into the reaction packed column with greater than 100 of length-diameter ratio with bio-based polyisocyanate, bio-based polyurethane prepolymer is generated in the process of flowing reaction, and the material from the reaction packed column is used as first component;Reaction packed column includes the column body formed with reaction chamber, a plurality of solid catalysts packed in reaction chamber, solid catalyst includes carrier and first catalyst for catalyzing reaction and is supported on carrier;Solid catalyst is movably arranged relative to reaction chamber and is limited in reaction chamber;The preparation of second component: bio-based polyol, second auxiliary agent are mixed, as second component;Bio-based waterproof coating prepared by the method has excellent batch quality stability and can be stored for a long time.

Description

Technical Field

[0001] This invention relates to the field of waterproof coatings, and more particularly to bio-based waterproof coatings, specifically to a bio-based polyurethane prepolymer, a bio-based waterproof coating, and a method for preparing the same. Background Technology

[0002] Reactive waterproof coatings are an important branch of building waterproofing materials, including epoxy resin waterproof coatings, polyurethane waterproof coatings, and polymethyl methacrylate waterproof coatings. Among them, polyurethane waterproof coatings are the most widely used due to their outstanding cost-effectiveness. 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) based on their composition and curing mechanism. Single-component polyurethane waterproof coatings mainly rely on moisture in the air for curing (primarily based on the reaction between isocyanate groups (-NCO) and moisture). Therefore, environmental factors are a significant factor affecting their film-forming quality and performance. Multi-component polyurethane waterproof coatings typically include isocyanate components and compounds containing hydroxyl groups (OH and other active groups). They mainly form a film through cross-linking and curing via isocyanate components and compounds containing OH and other active groups (such as polyols and chain extenders). Since the reactivity of NCO with OH and other active groups is much greater than that of NCO with moisture, the curing process of two-component polyurethane waterproof coatings is less affected by the environment, resulting in better film-forming quality. However, current practice has revealed significant batch-to-batch quality variations in polyurethane waterproof coatings prepared using the above method. Furthermore, with increasingly stringent environmental regulations, bio-based polyurethane waterproof coatings have emerged; however, the materials used, particularly polyols and isocyanates, are not entirely bio-based, but only partially bio-based, and their sources are limited and difficult to obtain.

[0003] It should be noted that the information disclosed in the background section above is only for understanding the background of this application. Therefore, the background section of this invention may include background information about the problems or environment of this invention, and is not necessarily a description of the prior art. Thus, the content included in the background section does not constitute an admission of the prior art by the applicant. Summary of the Invention

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

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

[0006] To achieve the above objectives, the present invention employs the following technical solution:

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

[0008] (1) Preparation of the first component

[0009] A dried bio-based polyol with a hydroxyl value of less than or equal to 160 mg KOH / g, a bio-based polyisocyanate, and a selective first auxiliary agent are fed into a reaction-packed column with an aspect ratio greater than 100. During the flow process, a bio-based polyurethane prepolymer is generated, and the material flowing out of the reaction-packed column is used as the first component.

[0010] The reaction-packed column includes a column body forming a reaction chamber, a plurality of solid catalysts filled in the reaction chamber, the solid catalysts including a support and a first catalyst supported on the support and used to catalyze the reaction; the solid catalysts are movably disposed relative to the reaction chamber and confined within the reaction chamber;

[0011] (2) Preparation of the second component

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

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

[0014] Furthermore, the changes exhibit a periodic pattern.

[0015] According to some preferred aspects of the present invention, the radial dimension of the reaction chamber is at most L1 and at least L2, and 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.

[0016] According to some preferred aspects of the 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 and lower sides of the inner wall of the reaction chamber and are arranged symmetrically in pairs.

[0018] According to some preferred aspects of the invention, on each side, the distance between any two adjacent arcuate protrusions gradually increases radially from the outside to the inside, and has a portion of the distance smaller than the radial dimension of the solid catalyst.

[0019] In some embodiments of the present invention, the plurality of arc-shaped protrusions divide the reaction chamber into a first chamber and a second chamber communicating with the first chamber, wherein 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 with 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 carrier is made of silicon dioxide with a porous structure.

[0022] In some embodiments of the present invention, the temperature inside the reaction 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 aspect ratio of the reaction-filled column is 100-8000.

[0024] According to some preferred aspects of the invention, the total loading 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, more specifically 0.2%-0.5%.

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

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

[0027] In some embodiments of the present invention, the bio-based polyol is selected from one or more combinations of 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, wherein the mass ratio of the first component to the second component is 1:0.8-1.2.

[0029] The first component comprises, by weight parts:

[0030] 63-72 parts of bio-based polyols

[0031] 27-37 parts of bio-based polyisocyanate

[0032] First adjuvant: 0-1 part;

[0033] The first additive includes an antifoaming agent;

[0034] The second component comprises, by weight parts:

[0035] 30-60 parts of bio-based polyols

[0036] Crosslinking agent 0.5-5 parts

[0037] 0.01-0.2 parts of the second catalyst.

[0038] Furthermore, the second additive also includes fillers, pigments, dispersants, anti-sagging agents, dehydrating agents, antifungal agents, defoamers, and flame retardants;

[0039] The second component comprises, by weight parts:

[0040]

[0041]

[0042] In some embodiments of the present invention, the first catalyst and the second catalyst are independently selected from one or more combinations of organobismuth catalysts, organozinc catalysts, and organotin catalysts.

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

[0044] In some embodiments of the present invention, the filler is one or a combination of several selected from calcium carbonate, kaolin, talc, and silica.

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

[0046] In some embodiments of the present invention, the anti-sagging agent is selected from one or more combinations of fumed silica, nano-calcium carbonate, modified bentonite, hydrogenated castor oil, and polyamide wax to improve the workability and leveling properties 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 one or more selected from calcium oxide, magnesium oxide, p-toluenesulfonyl isocyanate, and molecular sieve.

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

[0049] In some embodiments of the present invention, the defoamer is one or more combinations selected from acrylates, polysiloxane solutions, modified polysiloxane solutions, and polysiloxanes 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] 1,1-Dimethyl-2,2,2-trichloroethoxycarbonyl chloride was reacted with sodium azide to produce the compound shown in formula (Ⅰ);

[0053]

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

[0055] The compound shown in formula (I) is reacted with azelaic acid to generate the bio-based polyisocyanate shown in formula (II); wherein the azelaic acid is produced by the 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; even further, the organic solvent may be acetonitrile, etc.

[0058] Furthermore, the azelaic acid can be produced by the ozone decomposition of biomass acid. Methods for producing azelaic acid by the ozone decomposition of biomass acid can refer to existing technologies, or bio-based azelaic acid can be directly purchased.

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

[0060] The method for preparing bio-based polyisocyanates described in this invention is simple to operate, has a high yield, utilizes azelaic acid which is widely available and can be produced by ozone decomposition of biomass acids, overcoming the drawback of existing biomass polyisocyanates being difficult to obtain.

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

[0062] Another technical solution provided by the present invention: a method for preparing a bio-based polyurethane prepolymer, the method comprising: passing a dried bio-based polyol with a hydroxyl value less than or equal to 160 mg KOH / g and a bio-based polyisocyanate together into a reaction-packed column with an aspect ratio greater than 100, and reacting to generate a bio-based polyurethane prepolymer during the flow process; wherein, the reaction-packed column comprises a column body forming a reaction chamber, a plurality of solid catalysts filled in the reaction chamber, the solid catalyst comprising a support and a first catalyst supported on the support and used to catalyze the reaction; the solid catalyst is movably disposed relative to the reaction chamber and confined within 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] This invention addresses the problem of significant batch-to-batch quality variations in polyurethane waterproof coatings prepared using existing technologies. Through extensive experimental research, the inventors believe this is due to the use of reaction vessels for the reaction of polyols and isocyanates. Firstly, the addition of catalyst to the reaction vessel, relying on stirring, may result in low dispersion efficiency, leading to more vigorous localized reactions and slower reactions in uncatalyzed areas. This can cause variations in dispersion between batches, resulting in differences in the structure and molecular weight of the polyurethane prepolymer and significant quality differences. Secondly, the added catalyst may remain in the polyurethane prepolymer, making it difficult to separate. Therefore, the catalyst usually remains in the product, causing it to continue to act during storage. This allows the isocyanate groups to react further with the urethane, altering the structure and molecular weight of the polyurethane prepolymer. Consequently, the structure and molecular weight of the polyurethane prepolymer vary significantly between batches, resulting in unstable quality of the waterproof coating. Thirdly, the reaction between the isocyanate groups and the hydroxyl groups is an exothermic process. Existing conventional reactors cannot effectively remove the heat released from the internal reaction through the reactor wall in a timely manner, causing heat concentration. This leads to different reaction degrees in different areas, resulting in significant differences in the quality and viscosity of the polyurethane prepolymer obtained from each batch.

[0065] Based on the above findings, this invention innovatively proposes a novel reaction packing column for the reaction of polyisocyanates and polyols. By controlling its aspect ratio, the reactants can react to form polyurethane prepolymers during the process. In particular, the catalyst required for the reaction is loaded onto a support, and the solid catalyst formed after loading is dynamically arranged in the reaction packing column. This allows the solid catalyst to move freely in local locations within the reaction chamber, maximizing contact area with the reactants. Furthermore, the flow impact of the reactants during the process drives the solid catalyst to move and rotate freely, increasing fluid turbulence and further improving the mixing uniformity of polyisocyanates and polyols, thus enhancing reaction equilibrium. Simultaneously, the reaction packing column with a large aspect ratio provides a larger contact area with the flowing reaction mixture, preventing heat concentration and allowing for easier dispersion, thereby avoiding the problem of reaction imbalance caused by heat concentration. In addition, the catalyst of this invention, once fixed by loading, will not flow out with the polyurethane prepolymer, making it reusable and avoiding a series of problems caused by catalyst remaining in the polyurethane prepolymer.

[0066] Therefore, the present invention solves the problem of large batch-to-batch quality differences in polyurethane waterproof coatings prepared in the prior art. Attached Figure Description

[0067] Figure 1 This is a schematic diagram of the structure of the column body of the reaction-filled column in an embodiment of the present invention;

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

[0069] Figure 3 This is a second schematic diagram of the structure of the reaction packed column (the solid catalyst is packed in two rows) used in the embodiments of the present invention;

[0070] Figure 4 This is the third schematic diagram of the structure of the reaction packed column (the solid catalyst is packed in three rows) used in the embodiments of the present invention;

[0071] Figure 5 This is a schematic diagram of the production apparatus used to prepare the first component in the preparation process of the two-component bio-based waterproof coating in this embodiment of the invention.

[0072] In the attached figures: 100, reaction packed 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 chamber; 600, first component storage tank. Detailed Implementation

[0073] This invention provides a method for preparing a two-component bio-based waterproof coating that can achieve relatively stable quality between batches, thereby reducing and / or eliminating negative impacts caused by operation and reaction equipment during the preparation process.

[0074] The improved method for two-component bio-based waterproof coatings includes:

[0075] (1) Preparation of the first component

[0076] A dried bio-based polyol with a hydroxyl value of less than or equal to 160 mg KOH / g, a bio-based polyisocyanate, and a selective first auxiliary agent are fed into a reaction-packed column with an aspect ratio greater than 100. During the flow process, a bio-based polyurethane prepolymer is generated, and the material flowing out of the reaction-packed column is used as the first component.

[0077] The reaction-packed column includes a column body forming a reaction chamber, a plurality of solid catalysts filled in the reaction chamber, the solid catalysts including a support and a first catalyst supported on the support and used to catalyze the reaction; the solid catalysts are movably disposed relative to the reaction chamber and confined within the reaction chamber;

[0078] (2) Preparation of the second component

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

[0080] The following is combined with Figures 1 to 5 The preparation method of the present invention will be further described below. Figures 1 to 4 An exemplary schematic diagram of the reactive packed column used in this invention is provided. Figure 5 A schematic diagram of the production equipment used to prepare the first component in the preparation process of a two-component bio-based waterproof coating.

[0081] The reaction packed column 100 includes a column body 110 forming a reaction chamber 111, and a plurality of solid catalysts 120 filled in the reaction chamber 111. The solid catalyst 120 includes a support and a first catalyst supported on the support and used for catalyzing the reaction. The solid catalyst 120 is movably disposed relative to the reaction chamber 111 and is confined within the reaction chamber 111.

[0082] The radial dimension of reaction chamber 111 varies along its length, and this variation follows a periodic pattern, such as... Figure 1 As shown, the radial dimension of the reaction chamber 111 first decreases and then increases along its length, then decreases and then increases again, repeating this cycle. This change alters the local flow velocity of the reactants, and the different flow velocities at various locations exacerbate the differences in the fluidity of the reactants, thereby creating a mutual disturbance effect. This can increase the mixing uniformity between reactants such as bio-based polyols and bio-based polyisocyanates, improve reaction efficiency and reaction equilibrium, and allow heat to be quickly dispersed and transferred outward through the chamber wall during the disturbance and mutual flow process, preventing heat from concentrating in local locations.

[0083] Furthermore, the radial dimension of the reaction chamber 111 is at most L1 and at least L2, and the radial dimension of the solid catalyst 120 is Φ, satisfying the following condition: L2 < m × Φ < L1 < (m + 1.5) × Φ, where m is a positive integer. See [link to relevant documentation]. Figure 1 and 2 As shown, this arrangement prevents the solid catalyst 120 from flowing over a wide area and confines it to a specific spatial location. On the one hand, it avoids the solid catalyst from agglomerating together; on the other hand, it facilitates the uniform distribution of the filled solid catalyst along the length of the reaction chamber 111, thereby improving catalytic uniformity and stability.

[0084] In practice, the value of m is determined according to the setup method of the solid catalyst, for example, see [reference needed]. Figure 2 As shown, solid catalyst 120 is filled in a single row, in which case m is 1; if as... Figure 3 As shown, solid catalyst 120 is filled in two rows, in which case m is 2; if as... Figure 4 As shown, the solid catalyst 120 is filled in three rows, so m is 3, and so on; this arrangement is more conducive to the uniform dispersion of the catalyst.

[0085] Furthermore, a plurality of arc-shaped protrusions 112 are formed on the inner wall of the reaction chamber 111. These arc-shaped protrusions 112 are respectively formed on the upper and lower sides 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 radially from the outside to the inside, and some of these distances are smaller than the radial dimension of the solid catalyst 120. See also... Figure 1As shown, the aforementioned multiple arc-shaped protrusions 112 divide the reaction chamber 111 into a first chamber 1111 and a second chamber 1112 communicating with the first chamber 1111. The first chamber 1111 and the second chamber 1112 each have at least one member, and the volume of the second chamber 1112 is larger than the volume of the first chamber 1111. The arrangement of the arc-shaped protrusions 112 allows the radial dimension of the reaction chamber 111 to vary along its length. Furthermore, the arc-shaped protrusions 112 can further increase the contact area and improve heat dissipation efficiency. On the other hand, they can change the direction of fluid flow, increasing the turbulence effect, which further improves the uniformity of dispersion and mixing. In addition, the arrangement of the arc-shaped protrusions 112 can increase the probability of the solid catalyst 120 being driven to move or rotate in the reactants, thereby effectively ensuring the uniformity of solid catalyst dispersion, improving the catalytic effect, and enhancing reaction equilibrium.

[0086] Furthermore, in order to prevent the solid catalyst from being carried out of the reaction chamber 111 under certain special circumstances, filters (not shown) can be installed at the inlet and outlet of the reaction chamber 111 respectively, thereby preventing the solid catalyst 120 from leaving the reaction chamber 111. Meanwhile, the length-to-diameter ratio of the reaction packing column 100 can be 100-8000.

[0087] Furthermore, the support is a porous material with a diameter of 0.4-4.5 mm and a pore size of 0.05-400 μm. The support material is silica with a porous structure. The total loading of the first catalyst is 0.05%-1.0% of the total mass of bio-based polyols and bio-based polyisocyanates in the reaction chamber, for example, 0.2%-0.5%. The solid catalyst is formed by loading the first catalyst onto the support by impregnation. The first catalyst is one or more combinations selected from organobismuth catalysts, organozinc catalysts, and organotin catalysts.

[0088] Specifically, the solid catalyst is prepared by drying the porous material in a forced-air drying oven, taking it out and placing it in a drying tower to cool to room temperature, preparing a mixed solution of ethanol and ethyl acetate, adding a measured amount of catalyst and the dried porous material, stirring thoroughly, filtering, and then placing it in a forced-air drying oven to dry, thereby obtaining the solid catalyst.

[0089] Furthermore, the temperature inside the reaction column 100 is controlled at 70-100°C, and the reaction residence time is 10-30 minutes. In this invention, temperature control devices, such as heat exchangers, can be used to regulate the temperature inside the reaction column.

[0090] Furthermore, the two-component bio-based waterproof coating includes a first component and a second component, with the mass ratio of the first component to the second component being 1:0.8-1.2. By weight, the first component includes: 63-72 parts of bio-based polyol, 27-37 parts of bio-based polyisocyanate, and 0-1 parts of the first additive, which includes an antifoaming agent. By weight, the second component includes: 30-60 parts of bio-based polyol, 0.5-5 parts of crosslinking agent, and 0.01-0.2 parts of the second catalyst.

[0091] Furthermore, the second auxiliary agent also includes fillers, pigments, dispersants, anti-sagging agents, dehydrating agents, antifungal agents, defoamers, and flame retardants; by weight, the second component includes: 30-60 parts of bio-based polyol, 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 crosslinking agents, 0.01-0.2 parts of a second catalyst, 0.1-2 parts of dehydrating agents, 1-4 parts of antifungal agents, 0.1-1 parts of defoamers, and 2-6 parts of flame retardants.

[0092] See Figure 5 As shown, the production apparatus used in the preparation of the first component of the two-component bio-based waterproof coating includes a reaction-filled column 100, a bio-based polyol storage tank 200, a bio-based polyisocyanate storage tank 300, a drying channel 400, an auxiliary agent storage chamber 500, and a first component storage tank 600. The bio-based polyol storage tank 200, drying channel 400, reaction-filled column 100, and first component storage tank 600 are sequentially connected. The bio-based polyisocyanate storage tank 300 and auxiliary agent storage chamber 500 are respectively connected to the reaction-filled column 100. The auxiliary agent storage chamber 500 can be used to add defoamers.

[0093] The second component is prepared by simply mixing all the raw materials evenly.

[0094] Furthermore, the drying channel 400 involved in the preparation process of the two-component bio-based waterproof coating mainly functions to control the water content of the bio-based polyol. For example, it is preferable to control the water content to below 500 ppm. A flow tube can be set up and filled with a fixed desiccant (silica gel, montmorillonite, anhydrous calcium chloride, etc.) so that the bio-based polyol is dehydrated by the desiccant during the flow process. Of course, other methods can also be used to remove the water contained in the bio-based polyol, which will not be elaborated here.

[0095] Furthermore, before the preparation begins, dehydration preparations can be carried out on each piece of equipment, such as by heating and drying. For channels, inert gases such as nitrogen can be introduced in advance to replace the water-containing air inside.

[0096] The above-mentioned solution will be further described below with reference to 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 used 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] The bio-based polyisocyanate used below was prepared according to the following method: 1,1-dimethyl-2,2,2-trichloroethoxycarbonyl chloride and sodium azide were reacted in acetone at room temperature at a molar ratio of 1:1.2 to generate an intermediate; then, the intermediate was reacted with azelaic acid at a molar ratio of 2.4:1 in acetonitrile at 70°C in the presence of 4-dimethylaminopyridine to generate the bio-based polyisocyanate. The product was separated and purified by thin-film distillation at a pressure of 100 Pa and a temperature of 130°C to obtain the purified bio-based polyisocyanate.

[0099] The solid catalyst was prepared as follows: the porous material was dried in a 120°C forced-air drying oven for 3 hours, then removed and placed in a drying tower to cool to room temperature. A mixed solution of ethanol and ethyl acetate was prepared at a mass ratio of 1:1. The measured amount of catalyst and the dried porous material were added, and the mixture was stirred thoroughly for 1 hour. The mixture was then filtered and placed in a 120°C forced-air drying oven for 3 hours to obtain the solid catalyst.

[0100] Example 1

[0101] This example provides a method for preparing a two-component bio-based waterproof coating and the resulting two-component bio-based waterproof coating, using the above-mentioned... Figure 2 The reaction packed column shown Figure 5 The apparatus shown illustrates the preparation of the first component and the aforementioned production process.

[0102] The formulation content of the two-component bio-based waterproof coating is shown in Table 1.

[0103] Table 1

[0104]

[0105] The reaction chamber has a maximum radial dimension L1 of 4 mm, a minimum radial dimension L2 of 2.5 mm, and a length of 10 m.

[0106] The first catalyst in the solid catalyst is dibutyltin dilaurate, purchased from Jiangsu Mingtai New Material Co., Ltd., grade T-12; the support is silica, with an average diameter Φ of 3mm, purchased from Qingdao Xinchanglai Silica Gel Co., Ltd., grade FNG-C series (custom sizes available); the total loading of the first catalyst is 0.5% of the total mass of bio-based polyol and bio-based polyisocyanate in the reaction chamber;

[0107] The temperature inside the reaction column was controlled at 85℃, and the reaction residence time was 10 min.

[0108] The second component is prepared by mixing all the raw materials evenly.

[0109] The 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 the resulting two-component bio-based waterproof coating, using the above-mentioned... Figure 3 The reaction packed column shown Figure 5 The apparatus shown illustrates the preparation of the first component and the aforementioned production process.

[0112] The formulation content of the two-component bio-based waterproof coating is shown in Table 2.

[0113] Table 2

[0114]

[0115]

[0116] The reaction chamber has a maximum radial dimension L1 of 5 mm, a minimum radial dimension L2 of 3.5 mm, and a length of 10 m.

[0117] The first catalyst in the solid catalyst is dibutyltin dilaurate, purchased from Jiangsu Mingtai New Material Co., Ltd., grade T-12; the support is silica, with an average diameter Φ of 2 mm, purchased from Qingdao Xinchanglai Silica Gel Co., Ltd., grade FNG-C series; the total loading of the first catalyst is 0.4% of the total mass of bio-based polyol and bio-based polyisocyanate in the reaction chamber;

[0118] The temperature inside the reaction column was controlled at 70℃, and the reaction residence time was 25 min.

[0119] The second component is prepared by mixing all the raw materials evenly.

[0120] The 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 the resulting two-component bio-based waterproof coating, using the above-mentioned... Figure 4 The reaction packed column shown Figure 5 The apparatus shown illustrates the preparation of the first component and the aforementioned production process.

[0123] The formulation content of the two-component bio-based waterproof coating is shown in Table 3.

[0124] Table 3

[0125]

[0126]

[0127] The reaction chamber has a maximum radial dimension L1 of 5 mm, a minimum radial dimension L2 of 4 mm, and a length of 10 m.

[0128] The first catalyst in the solid catalyst is dibutyltin dilaurate, purchased from Jiangsu Mingtai New Material Co., Ltd., grade T-12; the support is silica, with an average diameter Φ of 1.5 mm, purchased from Qingdao Xinchanglai Silica Gel Co., Ltd., grade FNG-C series; the total loading of the first catalyst is 0.03% of the total mass of bio-based polyol and bio-based polyisocyanate in the reaction chamber;

[0129] The temperature inside the reaction column was controlled at 100℃, and the reaction residence time was 30 min.

[0130] The second component is prepared by mixing all the raw materials evenly.

[0131] The 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 autoclave preparation method and has the same formulation as in Example 1.

[0134] Preparation process: Add polyol to the reaction vessel, purge with nitrogen for 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 another 25 minutes to obtain the first component;

[0135] The second component is prepared by mixing all the raw materials evenly.

[0136] The 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 Examples 1-3 and Comparative Example 1 were subjected to the following performance tests, and the results are shown in Table 4. Viscosity was tested using an NDJ-1s digital rotational viscometer, and tensile strength and elongation at break were tested according to GB / T 16777-2008.

[0139] Table 4

[0140]

[0141]

[0142] As shown in Table 4, the two-component bio-based waterproof coating of the present invention exhibits superior storage stability and better overall stability.

[0143] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

[0144] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. A method for preparing a two-component bio-based waterproof coating, characterized in that, The preparation method includes: (1) Preparation of the first component A dried bio-based polyol with a hydroxyl value of less than or equal to 160 mg KOH / g, a bio-based polyisocyanate, and a selective first auxiliary agent are fed into a reaction-packed column with an aspect ratio greater than 100. During the flow process, a bio-based polyurethane prepolymer is generated, and the material flowing out of the reaction-packed column is used as the first component. The reaction-packed column includes a column body forming a reaction chamber, a plurality of solid catalysts filled in the reaction chamber, the solid catalysts including a support and a first catalyst supported on the support and used to catalyze the reaction; the solid catalysts are movably disposed relative to the reaction chamber and confined within the reaction chamber; The radial dimension of the reaction chamber varies along its length, and this variation follows a periodic pattern. (2) Preparation of the second component A bio-based polyol and a second auxiliary agent are mixed as a second component, wherein the second auxiliary agent includes a second catalyst and a crosslinking agent.

2. The method for preparing the two-component bio-based waterproof coating according to claim 1, characterized in that, The reaction chamber has a maximum radial dimension of L1 and a minimum of L2. The solid catalyst has a radial dimension of Φ and satisfies the following condition: L2<m×Φ<L1<(m+1.5)×Φ, where m is a positive integer.

3. The method for preparing the two-component bio-based waterproof coating according to claim 1, characterized in that, Multiple arc-shaped protrusions are formed on the inner wall of the reaction chamber.

4. The method for preparing the two-component bio-based waterproof coating according to claim 3, characterized in that, The plurality of arc-shaped protrusions are respectively formed on the upper and lower sides of the inner wall of the reaction chamber and are arranged symmetrically in pairs; and / or, on each side, the distance between any two adjacent arc-shaped protrusions gradually increases from the outside to the inside in the radial direction, and has a portion of the distance smaller than the radial dimension of the solid catalyst.

5. The method for preparing the two-component bio-based waterproof coating according to claim 3, characterized in that, The plurality of arc-shaped protrusions divide the reaction chamber into a first chamber and a second chamber communicating with 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.

6. The method for preparing the two-component bio-based waterproof coating according to claim 1, characterized in that, The carrier is a porous material with 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.

7. The method for preparing the two-component bio-based waterproof coating according to claim 1, characterized in that, The temperature inside the reaction column is controlled at 70-100℃, and the reaction residence time is 10-30 min; and / or, the aspect ratio of the reaction column is 100-8000.

8. The method for preparing the two-component bio-based waterproof coating according to claim 1, characterized in that, The total loading 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.

9. The method for preparing the two-component bio-based waterproof coating according to claim 8, characterized in that, The total loading of the first catalyst is 0.2%-0.5% of the total mass of the bio-based polyol and the bio-based polyisocyanate in the reaction chamber.

10. The method for preparing the two-component bio-based waterproof coating according to claim 1, characterized in that, The solid catalyst is formed by loading the first catalyst onto the support by impregnation; and / or, the bio-based polyol has a hydroxyl value of 10-155 mgKOH / g and a molecular weight of 1000-8000 g / mol.

11. The method for preparing the two-component bio-based waterproof coating according to claim 1, characterized in that, The two-component bio-based waterproof coating includes 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. The first component comprises, by weight parts: 63-72 parts of bio-based polyols 27-37 parts of bio-based polyisocyanate First adjuvant: 0-1 part; The first additive includes an antifoaming agent; The second component comprises, by weight parts: 30-50 parts of bio-based polyols Crosslinking agent 0.5-5 parts 0.01-0.2 parts of the second catalyst.

12. The method for preparing the two-component bio-based waterproof coating according to claim 11, characterized in that, The second type of additive also includes fillers, pigments, dispersants, anti-sagging agents, dehydrating agents, antifungal agents, defoamers, and flame retardants; The second component comprises, by weight parts: 30-50 parts of bio-based polyols 15-29 parts of filler 10-16 parts of pigment 2-8 parts of dispersant 1-5 parts of anti-sagging agent Crosslinking agent 0.5-5 parts Second catalyst 0.01-0.2 parts 0.1-2 parts of desiccant 1-4 parts of antifungal agent Defoamer 0.1-1 part 2-6 parts flame retardant.

13. The method for preparing the two-component bio-based waterproof coating according to any one of claims 1-12, characterized in that, The bio-based polyol is selected from one or more of 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; and / or, the first catalyst and the second catalyst are independently selected from one or more of organobismuth catalysts, organozinc catalysts, and organotin catalysts; and / or, the crosslinking agent includes one or more of ethylene glycol, hydroquinone dihydroxyethyl ether, 1,4-butanediol, diethyltoluenediamine, 3,3'-dichloro-4,4'-diaminophenylmethane, sodium 1,4-butanediol-2-sulfonate, dimethylolpropionic acid, hexanediol, decanediol, trimethylolpropane, castor oil, modified castor oil, hydroxyl-modified soybean oil, and hydroxyl-containing 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 using the following method: 1,1-Dimethyl-2,2,2-trichloroethoxycarbonyl chloride was reacted with sodium azide to produce the compound shown in formula (Ⅰ); ； The compound shown in formula (I) is reacted with azelaic acid to produce the bio-based polyisocyanate shown in formula (II); wherein the azelaic acid is produced by the ozone decomposition of biomass acid; 。 15. A two-component bio-based waterproof coating prepared by the preparation method of the two-component bio-based waterproof coating according to any one of claims 1-14.

16. A method for preparing a bio-based polyurethane prepolymer, characterized in that, The method for preparing the bio-based polyurethane prepolymer includes: passing a dried bio-based polyol with a hydroxyl value less than or equal to 160 mg KOH / g and a bio-based polyisocyanate together into a reaction-packed column with an aspect ratio greater than 100, and reacting during the flow to generate a bio-based polyurethane prepolymer; wherein, the reaction-packed column includes a column body forming a reaction chamber, a plurality of solid catalysts filled in the reaction chamber, the solid catalysts including a support and a first catalyst supported on the support and used to catalyze the reaction; the solid catalysts are movably disposed relative to the reaction chamber and confined within the reaction chamber, the radial dimension of the reaction chamber varies along its own length direction, and the variation has a periodic pattern.

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