A spray-drying type polyurethane waterproof coating and its preparation method

Abstract

The present invention discloses a spray-drying type polyurethane waterproof coating and its preparation method, which includes component A and component B. Component A contains polyurethane prepolymer and additive A; Component B contains active plasticizer, chain extender, flame-retardant plasticizer, active mineral filler, catalyst, additive B and water remover; When components A and B are mixed, additives A and B react rapidly to form a small molecule polyurea anti-sagging agent, which solves the problem of sagging on vertical surfaces of the product without increasing the viscosity of the product, and realizes solvent-free of the product in cooperation with the powder activation technology; By cooperating with the catalyst and the chain extender, the polyurethane waterproof coating can be dried rapidly, meeting the requirements of large-area mechanical spraying construction and shortening the construction period; The preparation method involved in the present invention is simple, without dehydration treatment, with low energy consumption and high production efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of waterproof coatings, and particularly relates to a spray-drying polyurethane waterproof coating and a preparation method thereof. Background Art

[0002] At present, there are mainly two categories of waterproof materials on the market: one is polymer cement-based waterproof coatings, which are composed of emulsions synthesized from various water-based polymers and high-quality cement mixed with various additives, but the products have low elongation, poor water resistance, and no elasticity. The other is polyurethane waterproof coatings. Such materials have large elongation, high resilience, are resistant to water immersion and corrosion by various chemical substances, and have been popular in the market since they were introduced in the 1980s. However, most of the polyurethane waterproof coating products do not have the anti-sagging function. At present, the technology adopted in China to solve the anti-sagging problem is to add fumed silica, bentonite, and nano-calcium carbonate to the coating, but this results in a relatively high viscosity of the product, and a large amount of organic solvents need to be added to reduce the construction viscosity. Organic solvents not only pollute the environment and endanger the health of workers, but also are prone to cause fires. In recent years, anti-sagging additives containing polyurea structures have emerged on the market. Although the anti-sagging effect is obvious, the products also contain a large amount of organic solvents and are expensive; in addition, the existing polyurethane waterproof coatings dry and form slowly. To achieve a designed waterproof coating thickness of 1.5 mm, multiple construction passes are required, which seriously affects the construction efficiency.

[0003] To address the above technical challenges, Chinese invention patent CN104559734B discloses a two-component chemically reactive thixotropic polyurethane waterproof coating. In the B component of this invention, there is a special amine-based reactive agent that can react with the prepolymer in the A component. Under the action of a specific inhibitor, a polyurea compound is formed within 5 - 10 minutes after the two components are mixed. This compound can form a large number of hydrogen bonds with the polyurethane prepolymer, thus endowing the two-component polyurethane waterproof coating with good thixotropy. However, since the reaction between the prepolymer and the special amine generates a high-molecular polyurea structure, it will sharply increase the static viscosity of the system, causing the system viscosity to increase dozens of times instantaneously. Therefore, organic solvents need to be added to the product to reduce the mixing and construction viscosities. In addition, since the mixing reaction time of the two components exceeds 5 minutes, if the product is constructed by mechanical spraying while mixing, there will still be a sagging problem when directly sprayed on vertical surfaces. Chinese invention patent CN114410210B discloses a two-component anti-sagging polyurethane waterproof coating. In this technical solution, an organic thixotropic agent is added to the A component containing isocyanate, and an inorganic thixotropic agent is added to the B component without isocyanate. When the A component and the B component are mixed, under the synergistic action of the organic-inorganic thixotropic agents, a three-dimensional thixotropic network with structures such as "line-surface" or "line-line" is rapidly formed, thus endowing the coating with good thixotropy and making the coating have excellent anti-sagging effect. However, this product needs to add a large amount of organic solvents to reduce the construction viscosity, and there are also problems of environmental pollution caused by organic solvents and harm to workers' health. The product is not environmentally friendly. In addition, this product has a long drying and forming time and cannot meet the requirements of rapid construction in waterproof projects.

[0004] Therefore, developing a solvent-free polyurethane waterproof coating to solve the environmental pollution and harm to workers' health caused by organic solvents, while greatly reducing the drying and forming time of polyurethane waterproof coatings, adopting a spraying construction method, and thus greatly improving the construction efficiency to meet the current fast-paced construction requirements, obviously has positive practical significance. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a polyurethane waterproof coating that can be spray-constructed, rapidly cured, does not flow on vertical surfaces, and is solvent-free, so as to improve the construction efficiency, enhance the quality of waterproof projects, and protect the environment to cope with increasingly complex waterproof working conditions.

[0006] To achieve the above invention purpose, the technical solution adopted by the present invention is: a spray-drying type polyurethane waterproof coating, which is composed of an A component and a B component by mass parts;

[0007] The A component mainly includes the following components:

[0008] Polyether polyol 60 - 80 parts;

[0009] 17 - 38 parts of isocyanate monomer;

[0010] 0.5 - 3 parts of additive A;

[0011] The component B mainly includes the following components:

[0012]

[0013] The waterproof coating does not contain organic solvents.

[0014] The purpose of the present invention is to provide a spray - quick - drying polyurethane waterproof coating. By adding special additives A and B to the component A and component B respectively, before the mixing of the component A and component B, both additive A and B are in liquid state and can reduce the viscosity of the system. The reaction activity of additive A in component A is higher than that of the isocyanate monomer, and the reaction activity of additive B in component B is higher than that of the chain extender. When the component A and component B are mixed, additive A and additive B preferentially and rapidly undergo chemical cross - linking to generate small - molecule substances containing polyurea characteristic groups These small - molecule substances provide thixotropy for the polyurethane waterproof coating, producing an anti - sagging effect, enabling the polyurethane waterproof coating not to flow during the construction on slopes and vertical surfaces, and ensuring the flatness of the coating film surface and the uniformity of the thickness. Compared with the traditional high - molecular polyurea structure, the advantage of the small - molecule substances generated by the present invention is that they produce an anti - sagging effect without increasing the viscosity of the system. The reaction of additive A and B is completed within 1 - 20 seconds at the moment of mixing. When mechanical spraying construction is adopted, it is possible to mix and spray simultaneously without sagging. By selecting a specific combination of chain extender and trace catalyst to improve the curing speed, the product can achieve surface drying within a few minutes and complete drying within 30 minutes. Thus, the product can achieve a certain thickness at one time, and the next process can be carried out after the product is completely dry, thereby greatly improving the construction efficiency and saving the construction period. By using surface - modified active mineral fillers, the problems of significant increase in system viscosity caused by mineral fillers and powder sedimentation can be greatly improved. The present invention controls the moisture content of the materials by adding a water remover, eliminating the need for a dehydration process, thereby saving energy consumption and improving production efficiency.

[0015] The waterproof coating of the present invention is constructed by spraying and can achieve surface drying within 1 - 10 minutes and complete drying within 30 minutes.

[0016] Preferably, the isocyanate monomer is toluene diisocyanate or isophorone diisocyanate. When the product is applied to non - exposed projects, toluene diisocyanate is used as the isocyanate monomer. When the product is applied to exposed projects, isophorone diisocyanate is used as the isocyanate monomer.

[0017] Preferably, the auxiliary agent A is selected from one or more of diphenylmethane diisocyanate (MDI), polyphenyl polymethylene polyisocyanate (PAPI), liquefied diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate. When the product is applied to non-exposed projects, the auxiliary agent A is selected from one of diphenylmethane diisocyanate (MDI), polyphenyl polymethylene polyisocyanate (PAPI), liquefied diphenylmethane diisocyanate, and xylylene diisocyanate. When the product is applied to exposed projects, the auxiliary agent A is selected from one of hexamethylene diisocyanate and 4,4'-dicyclohexylmethane diisocyanate.

[0018] Preferably, the auxiliary agent B is a binary primary amine (H2N-R-NH2), a tertiary primary amine or a mixture of both, wherein R is an aliphatic or aromatic alkane structure, polyether structure, polyester structure, or an aliphatic-aromatic blend structure.

[0019] Preferably, the active plasticizer is selected from one or more of polyethylene glycol (PEG), polypropylene glycol (PPG), and polytetrahydrofuran glycol (PTMEG), and its functionality is 2-3. Preferably, the hydroxyl value of the active plasticizer is between 20 and 200 KOHmg / g, and more preferably, the hydroxyl value is 20-58 KOHmg / g.

[0020] Preferably, the chain extender is a sterically hindered amine chain extender, and the sterically hindered amine chain extender is preferably selected from one or more of dimethylthiotoluenediamine, 4,4'-bis(alkylamino)-diphenylmethane, N,N'-dialkylbenzene diamine, 4,4'-bis(alkylamino)-dicyclohexylmethane, and polyaspartate prepared by the Micheal addition reaction of dialkyl maleate and aliphatic primary diamine.

[0021] Preferably, the active mineral filler is selected from one or more of talc, kaolin, mica powder, and calcium carbonate activated by chemical coating method. The chemical coating method is a prior art, which refers to a method of modifying the surface of inorganic particles through silane coupling agents, alkyl fatty acids, phthalate esters, etc. The mineral powder includes but is not limited to calcined kaolin, talc, mica powder, and calcium carbonate. The modified mineral powder has a low oil absorption value, can better reduce the system viscosity compared with unactivated mineral fillers, is not easy to agglomerate and precipitate after being added to the polyurethane system, and improves the leveling.

[0022] Preferably, the catalyst is an organotin catalyst or an organobismuth catalyst.

[0023] Preferably, the flame retardant plasticizer is selected from one or more of chlorinated paraffin, trioctyl phosphate, tolyldiphenyl phosphate, diphenylisodecyl phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate, tris(2-chloropropyl) phosphate, and tris(2-chloroethyl) phosphate.

[0024]

[0025] Preferably, the water remover is selected from one or more of calcium oxide, magnesium oxide, and vinylalkoxysilane coupling agent.

[0026] The present invention also claims protection for a preparation method of a spray-fast-drying polyurethane waterproof coating, which includes the following steps:

[0027] The two-component waterproof coating consists of component A and component B;

[0028] The manufacturing method of component A includes the following steps: adding polyether polyol with a water content lower than 0.05% into a reaction kettle, introducing nitrogen for protection, heating the materials to above 80°C, adding isocyanate monomer, stirring and mixing at 70-90°C for 2-3 hours, then cooling to 60°C, and adding additive A.

[0029] Continue to stir for 10-30 min to obtain component A.

[0030] The manufacturing method of component B includes the following steps: adding active plasticizer, flame retardant plasticizer, chain extender, and additive B into a reaction kettle, introducing nitrogen for protection, heating the materials to 70-90°C, adding active mineral filler, keeping the materials at a constant temperature of 70-90°C, and performing high-speed shear dispersion for at least 30 min. Transfer the materials to another reaction kettle through a grinding pump, without heating or cooling. After measuring the water content with a moisture meter, add the corresponding water remover, stir and mix for 10-30 min, add a catalyst, and stir and mix for 10-30 min to obtain component B.

[0031] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0032] The present invention has developed a new type of fast-drying polyurethane waterproof coating. The production raw materials do not need to be heated and dehydrated, the manufacturing energy consumption is low, the production efficiency is high, the product has the characteristics of being solvent-free, anti-sagging, rapid forming, and can be thick-coated at one time. The product is safe, environmentally friendly, and has high construction efficiency, and can meet the design requirements of various waterproof projects to the greatest extent.

[0033] ​The present invention is further described below in conjunction with the examples. However, the present invention is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to the different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with embodiments:

[0035] Example 1

[0036] This embodiment provides a spray-on quick-drying polyurethane waterproof coating, comprising component A and component B, wherein the mixing ratio of component A to component B is 1:1;

[0037] In parts by weight, the raw materials of component A include 80 parts of polyether diol (brand name DL-1000, Bluestar Dongda Chemical), 19.5 parts of toluene diisocyanate (brand name T-80, Yantai Wanhua Chemical), and 0.5 parts of diphenylmethane diisocyanate (brand name MI-50, Yantai Wanhua Chemical);

[0038] The raw materials of component B include 30 parts of polyether polyol (brand name EP-3600, Bluestar Dongda Chemical), 5 parts of N,N'-dialkylphenylenediamine (brand name Wanalink 6200, Wanhua Chemical), 17.49 parts of trioctyl phosphate (brand name TOP, Zhejiang Wansheng Co., Ltd.), 46.5 parts of active fine calcium carbonate (brand name carb 5T, Omya), 0.01 parts of dibutyltin dilaurate (brand name T-12, Jiangsu Mingtai New Materials), 0.5 parts of binary polyetheramine (brand name CAD230, Yangzhou Chenhua), and 0.5 parts of vinyl trimethoxysilane (brand name WD-21, Wuhan University Silicone).

[0039] The preparation method specifically comprises:

[0040] Preparation of component A: add 80 parts of DL-1000 polyether polyol to a reaction kettle, introduce nitrogen protection, heat the material to 80°C, add 19.5 parts of T-80, stir and mix at 70-90°C for 2 hours, then cool to 60°C, add 0.5 parts of MI-50, and stir for 25 minutes to obtain the component A;

[0041] Preparation of component B: Add 30 parts of EP-3600, 17.49 parts of TOP and 5 parts of Wanalink 6200 chain extender to the reactor, introduce nitrogen protection, heat the material to 90-100°C, add 46.5 parts of carb 5T active calcium powder, keep the temperature at 90-100°C and high-speed shear dispersion for 30 minutes, and transport the material to another reactor through a grinding pump without heating or cooling.

[0042] After measuring the moisture content with a moisture meter, add the corresponding 0.5 parts of WD-21 water remover, stir and mix for 20 min, add 0.01 part of T-12, 0.5 part of CAD-230, and stir and mix for 20 min to obtain the component B.

[0043] Example 2

[0044] This example provides a spray-drying polyurethane waterproof coating, including component A and component B, and the mixing ratio of component A and component B is 1:1;

[0045] By weight, the raw materials of component A include 70 parts of polyether diol (brand DL-2000, Bluestar Dongda Chemical), 28 parts of isophorone diisocyanate (brand IPDI, Yantai Wanhua Chemical), and 2 parts of 4,4'-dicyclohexylmethane diisocyanate (brand HMDI, Yantai Wanhua Chemical);

[0046] The raw materials of component B include 25 parts of polyether polyol (brand EP-3600, Bluestar Dongda Chemical), 6 parts of polyaspartate (brand F220, Zhuhai Feiyang Chemical), 25.47 parts of chlorinated paraffin (brand No. 42, Jiangsu Suxing New Materials), 41 parts of active fine calcium carbonate (brand RP5, Guangxi Kelong Powder), 0.03 part of stannous octoate (brand T-9, Jiangsu Yak Chemical), 1.5 parts of trietheramine (brand CAT403, Yangzhou Chenhua), and 1 part of fine magnesium oxide (brand MS-180, Hebei Meishen Technology).

[0047] The preparation method is the same as that of Example 1.

[0048] Example 3

[0049] This example provides a spray-drying polyurethane waterproof coating, including component A and component B, and the mixing ratio of component A and component B is 1:1;

[0050] By weight, the raw materials of component A include 60 parts of polytetrahydrofuran diol (brand PTMEG, basf), 37 parts of polyphenyl polymethylene polyisocyanate (brand PM-200, Yantai Wanhua Chemical), and 3 parts of diphenylmethane-4,4'-diisocyanate (brand MI, Yantai Wanhua Chemical);

[0051] The raw materials of component B include 15 parts of polyether polyol (brand name MN-3050, Bluestar Dongda Chemical), 10 parts of dimethylthiotoluene diamine (brand name E-300, Yabao Chemical), 29.95 parts of diethyl ethyl phosphate (brand name DEEP, Yangzhou Chenhua), 41 parts of activated talc (brand name CSP-1C, Jiangsu Qunxin Powder), 0.05 parts of dibutyltin neodecanoate (brand name FT-13A, Suzhou Feite New Materials), 2 parts of ternary polyetheramine (brand name CAT403, Yangzhou Chenhua), and 2 parts of fine calcium oxide (brand name JYQ-02, Changshu Hongyu Calcide).

[0052] The preparation method is the same as that of Example 1.

[0053] Comparative Example 1

[0054] This embodiment provides a polyurethane waterproof coating, including component A and component B, and the mixing ratio of component A to component B is 1:1;

[0055] In parts by weight, the raw materials of component A include 80 parts of polyether diol (brand name DL-1000, Bluestar Dongda Chemical) and 20 parts of toluene diisocyanate (brand name T-80, Yantai Wanhua Chemical);

[0056] The raw materials of component B include 30 parts of polyether polyol (brand name EP-3600, Bluestar Dongda Chemical), 5 parts of N,N'-dialkylphenylenediamine (brand name Wanalink 6200, Wanhua Chemical), 17.49 parts of trioctyl phosphate (brand name TOP, Zhejiang Wansheng Co., Ltd.), 46.5 parts of active fine calcium carbonate (brand name carb 5T, Omya), 0.01 parts of dibutyltin dilaurate (brand name T-12, Jiangsu Mingtai New Materials) and 1 part of fine calcium oxide (brand name JYQ-02, Changshu Hongyu Calcification).

[0057] The preparation method is the same as that of Example 1.

[0058] Comparative Example 2

[0059] This embodiment provides a polyurethane waterproof coating, including component A and component B, and the mixing ratio of component A to component B is 1:1;

[0060] In parts by weight, the raw materials of component A include 80 parts of polyether diol (brand name DL-1000, Bluestar Dongda Chemical) and 20 parts of toluene diisocyanate (brand name T-80, Yantai Wanhua Chemical);

[0061] The raw materials of component B include 30 parts of polyether polyol (brand name EP-3600, Bluestar Dongda Chemical), 5 parts of N,N'-dialkylphenylenediamine (brand name Wanalink 6200, Wanhua Chemical), 17.49 parts of trioctyl phosphate (brand name TOP, Zhejiang Wansheng Co., Ltd.), 46.5 parts of fine calcium carbonate (brand name LD-600, Lida Powder), 0.01 parts of dibutyltin dilaurate (brand name T-12, Jiangsu Mingtai New Materials), 1 part of fine calcium oxide (brand name JYQ-02, Changshu Hongyu Calcification), and 30 parts of organic solvent.

[0062] The preparation method is the same as that of Example 1.

[0063] The surface drying time, actual drying time and anti-sagging property of the embodiment and the comparative example were tested according to the standard T / CECS10302-2023 "Anti-sagging polyurethane waterproof coating". The test results are shown in Table 1.

[0064] Table 1

[0065]

[0066] From the comparison between Example 1 and Comparative Examples 1 and 2, it can be seen that when the main components of the two are the same, the anti-sagging performance of the comparative example without adding additives A and B cannot meet the standard. From the comparison between Comparative Examples 1 and 2, it can be seen that when the mineral filler is not activated, the viscosity of component B will increase greatly, resulting in the need to add organic solvents in actual use to reduce the viscosity of the ingredients and construction.

[0067] The test results show that the quick-drying polyurethane waterproof coating of the present invention has excellent anti-sagging effect and can be quickly cured and formed (the product is surface dry within 3 to 12 minutes and is completely dry within 11 to 23 minutes), which meets the requirements of most waterproof engineering designs.

[0068] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A spray-drying type polyurethane waterproof coating, characterized in that, It consists of component A and component B by mass parts; Component A mainly includes the following components: Polyether polyol 60 - 80 parts; Isocyanate monomer 17 - 38 parts; Auxiliary A 0.5 - 3 parts; Component B mainly includes the following components: Active plasticizer 10 - 30 parts; Chain extender 2 - 10 parts; Flame retardant plasticizer 10 - 30 parts; Active mineral filler 30 - 50 parts; Catalyst 0.01 - 0.05 parts; Auxiliary B 0.5 - 2 parts; Water scavenger 0.1 - 2 parts; The waterproof coating does not contain organic solvents; Auxiliary A is selected from one or more of polyphenyl polymethylene polyisocyanate, liquefied diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate; The auxiliary agent B is , or a mixture of both, wherein R is an aliphatic or aromatic alkane structure, polyether structure, polyester structure, or an aliphatic and aromatic blend structure; The preparation method of the above spray-drying polyurethane waterproof coating includes the following steps: The waterproof coating consists of component A and component B; The manufacturing method of component A includes the following steps: Add polyether polyol to the reaction kettle, introduce nitrogen for protection, heat the material to above 80 °C, add isocyanate monomer, stir and mix at 70 - 90 °C for 2 - 3 hours, then cool down to 60 °C, add auxiliary A, and continue to stir for 10 - 30 min to obtain component A; The manufacturing method of component B includes the following steps: Add active plasticizer, chain extender and auxiliary B to the reaction kettle, introduce nitrogen for protection, heat the material to 70 - 90 °C, add active mineral filler, keep the material at a constant temperature of 70 - 90 °C, and disperse by high-speed shearing for at least 30 min. Transfer the material to another reaction kettle through a grinding pump, without heating or cooling. After measuring the moisture content by a moisture meter, add the corresponding water scavenger, stir and mix for 10 - 30 min, add the catalyst, and stir and mix for 10 - 30 min to obtain component B; The chain extender is a sterically hindered amine chain extender.

2. The spray-drying type polyurethane waterproof coating according to claim 1, characterized in that: The active plasticizer is selected from one or more of polyethylene oxide polyol, polypropylene oxide polyol, polytetrahydrofuran polyol, and its functionality is 2 - 3.

3. The spray-drying type polyurethane waterproof coating according to claim 2, characterized in that: The hydroxyl value of the active plasticizer is between 20 and 200 KOHmg / g.

4. The spray-drying type polyurethane waterproof coating according to claim 1, characterized in that: The isocyanate monomer is toluene diisocyanate and / or isophorone diisocyanate.

5. The spray-drying type polyurethane waterproof coating according to claim 1, characterized in that: The active mineral filler is selected from one or more of talc powder, kaolin, mica powder, calcium carbonate, and wollastonite activated by chemical coating method.

6. The spray-drying type polyurethane waterproof coating according to claim 1, characterized in that: The catalyst is an organotin catalyst or an organic bismuth catalyst.

7. The spray-drying polyurethane waterproof coating according to claim 1, wherein: The flame retardant plasticizer is selected from one or more of chlorinated paraffin, trioctyl phosphate, tolyldiphenyl phosphate, diphenylisodecyl phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate, tris(2-chloropropyl) phosphate, and tris(2-chloroethyl) phosphate.

8. The spray-drying type polyurethane waterproof coating according to claim 1, characterized in that: The chain extender is selected from one or more of dimethylthiotoluenediamine, 4,4'-bis(alkylamino)-diphenylmethane, N,N'-dialkylbenzene diamine, 4,4'-bis(alkylamino)-dicyclohexylmethane, and polyaspartate prepared by Michael addition reaction of dialkyl maleate and aliphatic primary diamine.

9. The spray-drying type polyurethane waterproof coating according to claim 1, characterized in that: The water remover is selected from one or more of calcium oxide, magnesium oxide, and vinyl alkoxysilane coupling agent.

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