An environment-friendly latent curing agent, a preparation method thereof, an environment-friendly polyurethane waterproof coating raw material composition, an environment-friendly polyurethane waterproof coating and a preparation method thereof

Abstract

The present application relates to the technical field of building waterproof coating, and discloses an environmentally-friendly latent curing agent, a preparation method thereof, an environmentally-friendly polyurethane waterproof coating raw material composition, an environmentally-friendly polyurethane waterproof coating and a preparation method thereof. The method for preparing the environmentally-friendly latent curing agent comprises the following steps: (1) in the presence of a solvent, first mixing an aldehyde compound and an amine compound to obtain an intermediate I; the aldehyde compound is a combination of aldehyde compound I and aldehyde compound II with a molar ratio of 1-2.5:1; the aldehyde compound I is benzaldehyde and / or isobutyraldehyde, and the aldehyde compound II is nonanal and / or decanal; (2) carrying out a dehydration condensation reaction on the intermediate I to obtain the environmentally-friendly latent curing agent. The environmentally-friendly polyurethane waterproof coating prepared by the present application has better environmental protection performance and good mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of building waterproof coating technology, specifically to an environmentally friendly latent curing agent and its preparation method, an environmentally friendly polyurethane waterproof coating raw material composition, and an environmentally friendly polyurethane waterproof coating and its preparation method. Background Technology

[0002] Currently, polyurethane is widely used in various aspects of life. For example, polyurethane adhesives have good low-temperature resistance, oil and wear resistance, and the adhesive film is tough, impact-resistant, and has strong adhesion. Rigid polyurethane, after the addition of flame retardants, can withstand high temperatures and is flame-retardant, and is widely used as a fireproof material. Polyurethane boards have good thermal insulation properties and can be used as thermal insulation materials for building exterior walls, which can effectively reduce the thickness of building exterior walls. Moreover, polyurethane materials have excellent anti-aging properties and will not easily crack.

[0003] Currently, polyurethane materials can be divided into two-component polyurethane and one-component polyurethane. Two-component polyurethane consists of a hydroxyl-terminated polyol and a -NCO-terminated compound. Crosslinking these two components yields two-component polyurethane. Its advantages include adjustable performance and fast curing speed, but its disadvantage is the instability of the actual product's performance. One-component polyurethane, abbreviated as SPU, is produced by directly reacting an -NCO-terminated polyurethane prepolymer with water in the air to extend its chain or crosslink it. Compared to two-component polyurethane, SPU has the advantages of stable performance and simpler operation.

[0004] There are two curing modes for single-component polyurethane: moisture curing and latent curing. Moisture curing involves placing the polyurethane prepolymer directly in the air, where it reacts with moisture to form urea bonds. These urea bonds then react with the prepolymer to form polyurethane. Although this method is simple, it generates CO2 during the reaction, which affects performance. Latent curing, on the other hand, avoids the generation of CO2 because the latent curing agent preferentially reacts with water in a humid environment. The product then reacts with the -NCO groups of the prepolymer to cure or crosslink and obtain the polyurethane prepolymer.

[0005] There are two types of polyurethane latent curing agents commonly used: imines and oxazolidines. Both of these will hydrolyze upon contact with water vapor, releasing reactive substances (alkanolamines or amines) and end-capping substances (aldehydes or ketones). The reactive substances react with the -NCO groups in the single-component polyurethane waterproof coating to cure the product, while the end-capping substances are released into the environment. It is precisely because of this release that the chemical toxicity of the end-capping substances themselves can cause varying degrees of harm to the human body and the environment. The volatilization of these substances contributes to a certain VOC emission value and produces an irritating odor, which is particularly detrimental to the health of construction workers in relatively enclosed construction spaces.

[0006] Furthermore, most single-component polyurethane waterproof coatings currently sold in the domestic market are solvent-based. Adding organic solvents to these coatings helps reduce viscosity and improve application performance; however, as the amount of organic solvent added increases, the VOC content of the coating also rises, failing to meet increasingly stringent environmental protection requirements. Another type of single-component polyurethane waterproof coating does not contain latent curing agents. Although its VOC content is very low, this type of coating has poor application performance, resulting in severe blistering after application and failing to meet actual waterproofing requirements.

[0007] Therefore, developing a new type of environmentally friendly single-component polyurethane waterproof coating is of great significance. Summary of the Invention

[0008] The purpose of this invention is to provide an environmentally friendly polyurethane waterproof coating that has low VOC content, does not foam during construction, and has excellent mechanical properties.

[0009] To achieve the above objectives, a first aspect of the present invention provides a method for preparing an environmentally friendly latent curing agent, the method comprising: (1) In the presence of a solvent, an aldehyde compound and an amine compound are first mixed to obtain intermediate I; The molar ratio of the aldehyde compound (calculated as an aldehyde group) to the amine compound (calculated as a primary amino group) is 1-1.1:1; the aldehyde compound is a combination of aldehyde compound I and aldehyde compound II with a molar ratio of 1-2.5:1; aldehyde compound I is benzaldehyde and / or isobutyraldehyde, and aldehyde compound II is nonanal and / or decanal; (2) The intermediate I is subjected to a dehydration condensation reaction to obtain the environmentally friendly latent curing agent.

[0010] A second aspect of the present invention provides an environmentally friendly latent curing agent prepared by the method described in the first aspect above.

[0011] A third aspect of the present invention provides an environmentally friendly polyurethane waterproof coating raw material composition, the composition comprising a main agent and an auxiliary agent, wherein the main agent includes polyether diol, polyether triol, diisocyanate, adsorbent and latent curing agent; Relative to 100 parts by weight of the polyether diol, the content of the polyether triol is 35-65 parts by weight, the content of the diisocyanate is 20-30 parts by weight, the content of the adsorbent is 8-12 parts by weight, and the content of the latent curing agent is 3-8 parts by weight. The latent curing agent is the environmentally friendly latent curing agent described in the second aspect above.

[0012] A fourth aspect of the present invention provides a method for preparing an environmentally friendly polyurethane waterproof coating, the method comprising using the components of the composition described in the third aspect above, the method comprising: S1. Polyether diol, polyether triol and some additives are mixed in contact to obtain mixture I; S2. Mix the diisocyanate with the dehydrated mixture I to obtain mixture II; S3. Stir the latent curing agent with the mixture II to obtain mixture III; S4. Mix the remaining additives with the mixture III to obtain the environmentally friendly polyurethane waterproof coating.

[0013] The fifth aspect of the present invention provides an environmentally friendly polyurethane waterproof coating prepared by the method described in the fourth aspect above.

[0014] Through the above technical solution, the present invention has at least the following beneficial technical effects: (1) The environmentally friendly latent curing agent provided by the present invention is used in polyurethane waterproof coatings. It has a suitable unsealing speed, does not affect the curing speed of the waterproof coating, and has low volatility.

[0015] (2) The environmentally friendly polyurethane waterproof coating provided by the present invention can achieve excellent results with no obvious irritating odor and low VOC emission value through the synergistic effect of specially prepared environmentally friendly latent curing agent, adsorbent, deodorizer and filler.

[0016] (3) The environmentally friendly polyurethane waterproof coating provided by the present invention can effectively prevent bubbling during construction in high temperature and high humidity environments, and also has excellent mechanical properties. Detailed Implementation

[0017] 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.

[0018] As mentioned above, the first aspect of the present invention provides a method for preparing an environmentally friendly latent curing agent, the method comprising: (1) In the presence of a solvent, an aldehyde compound and an amine compound are first mixed to obtain intermediate I; The molar ratio of the aldehyde compound (calculated as an aldehyde group) to the amine compound (calculated as a primary amino group) is 1-1.1:1; the aldehyde compound is a combination of aldehyde compound I and aldehyde compound II with a molar ratio of 1-2.5:1; aldehyde compound I is benzaldehyde and / or isobutyraldehyde, and aldehyde compound II is nonanal and / or decanal; (2) The intermediate I is subjected to a dehydration condensation reaction to obtain the environmentally friendly latent curing agent.

[0019] In this invention, the meaning of "the amount of the aldehyde compound calculated as aldehyde group and the amount of the amine compound calculated as primary amino group" is as follows: the amount of the aldehyde compound is calculated based on the amount of aldehyde group (-CHO) in the aldehyde compound; the amount of the amine compound is calculated based on the amount of primary amino group (-NH2) in the amine compound.

[0020] According to a preferred embodiment, aldehyde compound I is a combination of benzaldehyde and isobutyraldehyde in a molar ratio of 1:1-5, and aldehyde compound II is a combination of nonanal and decanal in a molar ratio of 1:1-3. The inventors of this invention have discovered that, in this preferred embodiment, the environmentally friendly polyurethane waterproof coating provided by this invention has lower VOC emissions and a more suitable desealing speed.

[0021] According to one specific implementation, the conditions for the first mixing include: a temperature of 25-45°C, a time of 1-3 hours, and a rotation speed of 150-200 rpm.

[0022] According to one specific embodiment, the conditions for the dehydration condensation reaction include a temperature of 120-130°C.

[0023] Preferably, the solvent is toluene and / or xylene.

[0024] Preferably, the amount of solvent used is 5-10 wt%, based on the total mass of the solvent, the aldehyde compound, and the amine compound.

[0025] Preferably, the amine compound is a diamine compound.

[0026] More preferably, the amine compound is selected from at least one of ethylenediamine, hexamethylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 2-methylpentanediamine, diethylamine, dibutylamine, and isophoronediamine.

[0027] According to one specific embodiment, in the first mixture, based on the total mass of the solvent, the aldehyde compound, and the amine compound, 0.2-1 wt% of a catalyst may also be added, preferably toluenesulfonic acid.

[0028] The present invention does not have any special requirements on the time of the dehydration condensation reaction. Those skilled in the art only need to ensure that all the water in the reaction system is removed. For example, the time of the dehydration condensation reaction is 1-5 hours.

[0029] According to a specific embodiment, after the dehydration condensation reaction is completed, the preproduct obtained after the dehydration condensation reaction is subjected to vacuum distillation to obtain the environmentally friendly latent curing agent; preferably, the conditions for vacuum distillation include: temperature of 130-140℃, pressure of -0.02MPa to 0.05MPa, and time of 0.5-1h.

[0030] According to a preferred embodiment, the method for preparing the environmentally friendly latent curing agent includes the following steps: (1) At 25-45℃, amine compounds, solvents and catalysts are added to a round-bottom flask and stirred for 5-10 min. Then, aldehyde compounds are added dropwise to the round-bottom flask. After the addition is complete, stirring is continued for 1-3 h to obtain intermediate I. (2) Raise the temperature to 120-130℃, keep it under reflux, and carry out the dehydration condensation reaction. After 1-5 hours, the outflow of water reaches the theoretical outflow (the molar ratio of theoretical outflow to mixed aldehyde is 1:0.8-1); then carry out vacuum distillation at 130-140℃ and -0.02 to 0.05 MPa for 0.5-1 hours to obtain the environmentally friendly latent curing agent.

[0031] As previously stated, the second aspect of the present invention provides an environmentally friendly latent curing agent prepared by the method described in the first aspect.

[0032] As mentioned above, the third aspect of the present invention provides an environmentally friendly polyurethane waterproof coating raw material composition, which consists of a main agent and an auxiliary agent, wherein the main agent includes polyether diol, polyether triol, diisocyanate, adsorbent and latent curing agent; Relative to 100 parts by weight of the polyether diol, the content of the polyether triol is 35-65 parts by weight, the content of the diisocyanate is 20-30 parts by weight, the content of the adsorbent is 8-12 parts by weight, and the content of the latent curing agent is 3-8 parts by weight. The latent curing agent is the environmentally friendly latent curing agent described in the second aspect above.

[0033] According to one specific embodiment, the diisocyanate is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

[0034] According to one specific embodiment, the adsorbent is selected from at least one of alumina, zinc oxide, magnesium oxide, molecular sieve, activated clay, and activated carbon.

[0035] According to one specific embodiment, the additives include a plasticizer, a deodorizer, and a filler; relative to 100 parts by weight of the polyether diol, the content of the plasticizer is 90-120 parts by weight, the content of the deodorizer is 2-5 parts by weight, and the content of the filler is 130-200 parts by weight.

[0036] Preferably, the plasticizer is selected from at least one of vegetable oil-based, trioctyl phosphate, citrate, and chlorinated paraffin.

[0037] Preferably, the deodorizing agent is selected from at least one of N-acetylglycine, N-acetylanine, glycine methyl ester, and alanine ethyl ester.

[0038] Preferably, the filler is selected from at least one of nano-calcium carbonate, talc, fumed silica, heavy calcium carbonate, kaolin, wollastonite powder, mica powder, titanium dioxide, and carbon black.

[0039] According to one specific embodiment, the additive further includes a hydrolysis accelerator and a catalyst; the content of the hydrolysis accelerator is 0.2-1 parts by weight relative to 100 parts by weight of the polyether diol, and the content of the catalyst is 0.2-0.8 parts by weight.

[0040] Preferably, the hydrolysis accelerator is selected from at least one of benzoic acid, salicylic acid, acetic acid, p-toluenesulfonic acid, and citric acid.

[0041] Preferably, the catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, triethylamine, dimethylethanolamine, N,N-dimethylbenzylamine, and bismuth isooctanoate.

[0042] As previously described, the fourth aspect of this invention provides a method for preparing an environmentally friendly polyurethane waterproof coating, the method comprising using the components of the composition described in the third aspect above, the method comprising: S1. Polyether diol, polyether triol and some additives are mixed in contact to obtain mixture I; S2. Mix the diisocyanate with the dehydrated mixture I to obtain mixture II; S3. Stir the latent curing agent with the mixture II to obtain mixture III; S4. Mix the remaining additives with the mixture III to obtain the environmentally friendly polyurethane waterproof coating.

[0043] According to one specific embodiment, a method for preparing an environmentally friendly polyurethane waterproof coating includes the following steps: 1) Under the conditions of temperature of 20-40℃ and rotation speed of 1000-2000rpm, polyether diol, polyether triol, plasticizer, adsorbent, deodorizer and filler are contact mixed for 20-40min to obtain mixture I; 2) Dehydrate the mixture I at 100-110℃ and -0.08 to -0.1MPa for 2-3 hours; 3) At 70-80℃, diisocyanate, catalyst (1 / 4 to 1 / 2 of the formulation amount) are mixed with the mixture I, the temperature is increased by 5-10℃, and the mixture is stirred and mixed for 3-4 hours to obtain mixture II; 4) Keeping the temperature constant, stir the environmentally friendly latent curing agent with the mixture II for 0.5-1 hour to obtain mixture III; 5) At 50-60℃, the catalyst (remaining amount) and hydrolysis accelerator are mixed with the mixture III for 0.5-1h, and after cooling, the environmentally friendly polyurethane waterproof coating is obtained.

[0044] As previously stated, the fifth aspect of the present invention provides an environmentally friendly polyurethane waterproof coating prepared by the method described in the fourth aspect.

[0045] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, all instruments and raw materials used are commercially available products.

[0046] The following examples include some of the raw materials used and their sources: Polyether diol: Functionality 2, number average molecular weight 2000, grade DL-2000D, purchased from Shandong Lanxing Dongda Co., Ltd. Polyether triol: functionality 3, number average molecular weight 5000, grade EP330N, purchased from Shandong Lanxing Dongda Co., Ltd.

[0047] The following preparation examples illustrate the preparation of the environmentally friendly latent curing agent provided by the present invention, specifically: Preparation Example 1 (1) At 40°C, 2 mol of ethylenediamine, 0.35 mol of toluene and 0.007 mol of toluenesulfonic acid were added to a round-bottom flask and stirred for 10 min. Then, a mixed aldehyde (a mixture of 1 mol of benzaldehyde, 1.1 mol of isobutyraldehyde, 1 mol of nonanal and 1 mol of decanal) was added dropwise to the round-bottom flask. After the addition was completed, stirring was continued for 2 h to obtain intermediate I. (2) Raise the temperature to 120°C, keep reflux, and carry out dehydration condensation reaction. After 1.5h, the outflow of water reaches the theoretical outflow (the molar ratio of theoretical outflow to mixed aldehyde is 1:1); then carry out vacuum distillation at 130°C and -0.02MPa for 1h to obtain the environmentally friendly latent curing agent-I.

[0048] Preparation Example 2 (1) At 30°C, 2 mol of m-phenylenediamine, 0.5 mol of xylene and 0.007 mol of toluenesulfonic acid were added to a round-bottom flask and stirred for 10 min. Then, a mixed aldehyde (a mixture of 0.5 mol of benzaldehyde, 1.6 mol of isobutyraldehyde, 1 mol of nonanal and 1 mol of decanal) was added dropwise to the round-bottom flask. After the addition was completed, stirring was continued for 2.5 h to obtain intermediate I. (2) Raise the temperature to 130°C, keep reflux, and carry out dehydration condensation reaction. After 2 hours, the outflow of water reaches the theoretical outflow (the molar ratio of theoretical outflow to mixed aldehyde is 1:1). Then, carry out vacuum distillation at 140°C and -0.02MPa for 0.5 hours to obtain the environmentally friendly latent curing agent-II.

[0049] Preparation Example 3 This preparation example was carried out using a method similar to that of Preparation Example 1, except that in step (1), the composition of the mixed aldehyde was adjusted to be a mixture of 0.3 mol benzaldehyde, 1.8 mol isobutyraldehyde, 0.4 mol nonanal, and 1.6 mol decanal. The remaining operations were the same as in Preparation Example 1, and the environmentally friendly latent curing agent-III was obtained.

[0050] Preparation Example 4 This preparation example was carried out using a method similar to that of Preparation Example 1, except that in step (1), the composition of the mixed aldehyde was adjusted to be a mixture of 2.1 mol benzaldehyde and 2 mol nonanal. The remaining operations were the same as in Preparation Example 1, and the environmentally friendly latent curing agent-IV was prepared.

[0051] Comparative Preparation Example 1 This comparative preparation example was carried out using a method similar to that of Preparation Example 1, except that in step (1), the composition of the mixed aldehyde was adjusted to be a mixture of 2.5 mol benzaldehyde, 0.6 mol isobutyraldehyde, 0.5 mol nonanal, and 0.5 mol decanal. The remaining operations were the same as in Preparation Example 1, and the environmentally friendly latent curing agent-DI was prepared.

[0052] Comparative Preparation Example 2 This comparative preparation example was prepared using a method similar to that of Preparation Example 1. The difference was that in step (1), the amount of ethylenediamine was adjusted to 3 mol, and the remaining operations were the same as in Preparation Example 1, to prepare the environmentally friendly latent curing agent-DII.

[0053] Comparative preparation example 3 This comparative preparation example was prepared using a method similar to that of Preparation Example 4. The difference was that in step (1), benzaldehyde was replaced with an equal amount of formaldehyde and nonanaldehyde was replaced with an equal amount of pentaldehyde. The remaining operations were the same as in Preparation Example 1, and the environmentally friendly latent curing agent-DIII was prepared.

[0054] The embodiments of the present invention are used to illustrate the preparation of environmentally friendly polyurethane waterproof coatings. Unless otherwise specified, the amounts of raw materials used in the following examples are all parts by weight, and each part by weight represents 10g.

[0055] Example 1 1) At a temperature of 30℃ and a rotation speed of 1500rpm, polyether diol, polyether triol, plasticizer, adsorbent, deodorizer and filler were mixed for 40min to obtain mixture I. 2) The mixture I was placed at 100℃ and -0.1MPa for 3 hours to dehydrate; 3) At 70°C, diisocyanate, catalyst (1 / 3 of the formulation amount) are mixed with the mixture I, the temperature is adjusted to 80°C, and mixing is continued for 3 hours to obtain mixture II; 4) Keeping the temperature constant, mix the environmentally friendly latent curing agent with the mixture II for 0.5 hours to obtain mixture III; 5) Adjust the temperature to 50°C, mix the catalyst (remaining amount) and hydrolysis accelerator with the mixture III for 1 hour, and then cool to obtain the environmentally friendly polyurethane waterproof coating.

[0056] The specific types and amounts of substances used in this embodiment are shown in Table 1.

[0057] Unless otherwise specified, Example 2 is carried out in accordance with the method of Example 1, except that the types of substances, amounts and process parameters used in the example are not exactly the same, as detailed in Table 1.

[0058] Table 1

[0059] Example 3 This embodiment uses a method similar to that of Example 1, except that an equal part by weight of environmentally friendly latent curing agent-III is used instead of environmentally friendly latent curing agent-I in Example 1. The remaining operations are the same as in Example 1, and environmentally friendly polyurethane waterproof coating-III is prepared.

[0060] Example 4 This embodiment uses a method similar to that of Example 1, except that an equal part by weight of environmentally friendly latent curing agent-IV is used instead of environmentally friendly latent curing agent-I in Example 1. The remaining operations are the same as in Example 1, and environmentally friendly polyurethane waterproof coating-IV is prepared.

[0061] Comparative Example 1 This comparative example was conducted using a method similar to that of Example 1, except that an equal part by weight of environmentally friendly latent curing agent-DI was used instead of environmentally friendly latent curing agent-I in Example 1. The remaining operations were the same as in Example 1, and environmentally friendly polyurethane waterproof coating-DI was prepared.

[0062] Comparative Example 2 This comparative example was conducted using a method similar to that of Example 1. The difference was that an equal part by weight of environmentally friendly latent curing agent-DII was used instead of environmentally friendly latent curing agent-I in Example 1. The remaining operations were the same as in Example 1, and environmentally friendly polyurethane waterproof coating-DII was prepared.

[0063] Comparative Example 3 This comparative example was conducted using a method similar to that of Example 1, except that an equal part by weight of environmentally friendly latent curing agent-DIII was used to replace environmentally friendly latent curing agent-I in Example 1. The remaining operations were the same as in Example 1, and environmentally friendly polyurethane waterproof coating-DIII was prepared.

[0064] Comparative Example 4 This comparative example was prepared using a method similar to that of Example 1, except that no environmentally friendly latent curing agent was added. The remaining operations were the same as in Example 1, and an environmentally friendly polyurethane waterproof coating-DIV was obtained.

[0065] Test case This test example is used to illustrate the performance testing of the environmentally friendly polyurethane waterproof coatings prepared in the above embodiments and comparative examples.

[0066] Among them, the construction odor test: 200g of the waterproof coating sample prepared above was scraped onto a 30cm×50cm glass plate, and then transferred to a closed fume hood for curing. It was cured for 24h at a temperature of (23±2)℃ and a humidity of (50±10)%. Afterwards, the air odor inside the fume hood was smelled.

[0067] Thick coating foaming property: Tested according to JC / T 2435-2018 standard.

[0068] Surface drying time, complete drying time, tensile strength, elongation at break, tear strength, bond strength, volatile organic compound content, and impermeability were tested according to the method in GB / T 19250-2013.

[0069] The specific test results are shown in Table 2.

[0070] Table 2

[0071] As can be seen from the results in Table 2, the environmentally friendly polyurethane waterproof coating provided by this invention has better environmental performance, and at the same time also has good mechanical properties and bonding strength.

[0072] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing an environmentally friendly latent curing agent, characterized in that, The method includes: (1) In the presence of a solvent, an aldehyde compound and an amine compound are first mixed to obtain intermediate I; The molar ratio of the aldehyde compound (calculated as an aldehyde group) to the amine compound (calculated as a primary amino group) is 1-1.1:1; the aldehyde compound is a combination of aldehyde compound I and aldehyde compound II with a molar ratio of 1-2.5:1; aldehyde compound I is a combination of benzaldehyde and isobutyraldehyde with a molar ratio of 1:1-5, and aldehyde compound II is a combination of nonanal and decanal with a molar ratio of 1:1-3; (2) The intermediate I is subjected to a dehydration condensation reaction to obtain the environmentally friendly latent curing agent.

2. The method according to claim 1, wherein, The conditions for the first mixing include: a temperature of 25-45℃, a time of 1-3 hours, and a rotation speed of 150-200 rpm; And / or, the conditions for the dehydration condensation reaction include: a temperature of 120-130°C.

3. The method according to claim 1 or 2, wherein, The solvent is toluene and / or xylene; And / or, the amine compound is a diamine compound.

4. The method according to claim 3, wherein, The amine compound is selected from at least one of ethylenediamine, hexamethylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 2-methylpentanediamine, and isophoronediamine.

5. An environmentally friendly latent curing agent prepared by the method according to any one of claims 1-4.

6. An environmentally friendly polyurethane waterproof coating raw material composition, characterized in that, The composition consists of a main agent and an auxiliary agent, wherein the main agent includes polyether diol, polyether triol, diisocyanate, adsorbent and latent curing agent; Relative to 100 parts by weight of the polyether diol, the content of the polyether triol is 35-65 parts by weight, the content of the diisocyanate is 20-30 parts by weight, the content of the adsorbent is 8-12 parts by weight, and the content of the latent curing agent is 3-8 parts by weight. The latent curing agent is the environmentally friendly latent curing agent described in claim 5.

7. The composition according to claim 6, wherein, The diisocyanate is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate; And / or, the adsorbent is selected from at least one of alumina, zinc oxide, magnesium oxide, molecular sieve, activated clay and activated carbon.

8. The composition according to claim 6 or 7, wherein, The additives include plasticizers, deodorizers, and fillers; relative to 100 parts by weight of the polyether diol, the content of the plasticizer is 90-120 parts by weight, the content of the deodorizer is 2-5 parts by weight, and the content of the filler is 130-200 parts by weight. And / or, the plasticizer is selected from at least one of vegetable oil-based plasticizers, trioctyl phosphate, citrate, and chlorinated paraffin; And / or, the deodorizing agent is selected from at least one of N-acetylglycine, N-acetylanine, glycine methyl ester and alanine ethyl ester.

9. A method for preparing an environmentally friendly polyurethane waterproof coating, characterized in that, This method is performed using any of the components in the composition according to any one of claims 6-8, and the method includes: S1. Polyether diol, polyether triol and some additives are mixed in contact to obtain mixture I; S2. Mix the diisocyanate with the dehydrated mixture I to obtain mixture II; S3. Stir the latent curing agent with the mixture II to obtain mixture III; S4. Mix the remaining additives with the mixture III to obtain the environmentally friendly polyurethane waterproof coating.

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