Polyurea coating, method for its production and floor coating

Abstract

This application relates to a polyurea coating, its preparation method, and a floor coating. The polyurea coating comprises component A and component R; by weight, component A comprises: 15-25 parts of aromatic isocyanate, 20-32 parts of aliphatic isocyanate, and 45-53 parts of polyol; by weight, component R comprises: 10-18 parts of amine chain extender and 15-35 parts of modified amino-hydroxy chain extender; the modified amino-hydroxy chain extender contains a β-hydroxycarbamate structure in its chemical structure. The polyurea coating has a low cost and can achieve high hardness while maintaining a long operating time.

Description

Technical Field

[0001] This application relates to the field of coating technology, and in particular to a polyurea coating, a method for preparing the same, and a floor coating. Background Technology

[0002] Traditional flooring materials such as epoxy flooring and cement mortar-based inorganic flooring are mostly rigid materials, which are prone to deformation and cracking, wear and tear, and noise due to their hardness. Elastic flooring, primarily based on polyurethane and polyurethane urea systems, balances load-bearing capacity and comfort, offering unique advantages in applications such as warehouses, factories, schools, hospitals, and commercial spaces. Currently, there are two main types of elastic polyurethane coatings on the market: one is a two-component solvent-free polyurethane coating that reacts modified bio-based polyol resins with isocyanates; the other is a polyurea coating that reacts with amine chain extenders and isocyanates.

[0003] While commercially available two-component solvent-free elastic polyurethane coatings have advantages such as long working time, good leveling properties, high strength after complete curing, and good abrasion resistance, they also have other drawbacks: firstly, their early curing process is easily affected by the competition between isocyanate and environmental moisture, making them highly sensitive to temperature and humidity, difficult to control in terms of appearance, and subject to many environmental limitations during construction; secondly, they also have problems such as slow curing speed and insufficient elasticity.

[0004] Polyurea self-leveling coatings do not rely on spraying equipment and have low sensitivity to environmental moisture, easily adjustable elasticity, and good weather resistance, making them promising solutions to some of the challenges in the field of elastic polyurethane flooring. Traditional polyurea flooring coatings are mainly based on the aspartic polyurea system, which is a reaction between polyaspartic ester and aliphatic isocyanate. However, the main resin raw materials are expensive, limiting their application, and there is also the problem of not being able to balance hardness and elasticity. Another method uses other secondary amine chain extenders to react with isocyanates, which can achieve higher hardness, but the initial reaction activity is high, and the material handling cycle is short, which is not conducive to industrial implementation. Summary of the Invention

[0005] Based on this, this application provides a low-cost polyurea coating, a preparation method thereof, and a floor coating that can achieve good elasticity while also having a long operating time and high hardness.

[0006] A first aspect of this application provides a polyurea coating comprising component A and component R;

[0007] Component A, by weight, comprises:

[0008] 15 to 25 parts of aromatic isocyanate,

[0009] 20 to 32 parts of aliphatic isocyanate, and

[0010] 45-53 parts of polyols;

[0011] The R component comprises, by weight:

[0012] 10 to 18 parts of amine chain extender, and

[0013] 15 to 35 parts of modified amino-hydroxy chain extender;

[0014] The modified amino-hydroxy chain extender contains a β-hydroxycarbamate structure in its chemical structure.

[0015] In one embodiment, the modified amino-hydroxy chain extender is prepared from raw materials comprising a five-membered cyclic carbonate compound and a primary amine compound;

[0016] Optionally, the five-membered cyclic carbonate compound includes one or more of propylene carbonate, ethylene carbonate, and glycerol carbonate;

[0017] Optionally, the primary amine compounds include one or more of aromatic primary amine compounds and alicyclic primary amine compounds; further, the primary amine compounds include one or more of 4,4'-methylenebis(2-chloroaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 3,5-dimethylthiotoluenediamine, 4,4'-diaminodiphenylmethane, toluenediamine, and isophoronediamine;

[0018] Optionally, the mass ratio of the five-membered cyclic carbonate compound to the primary amine compound is (0.3~1.3):1, and more preferably (0.8~1.3):1;

[0019] Optionally, the raw material may further include polyether polyols;

[0020] Further optionally, the mass ratio of the polyether polyol to the primary amine compound is (0.8~1.3):1;

[0021] Further optionally, the number average molecular weight of the polyether polyol is 2000~8000, and even more preferably 4000~6000;

[0022] Optionally, the modified amino-hydroxy chain extender has an average molecular weight of 500-1000, and optionally 600-800.

[0023] In one embodiment, component A includes one or more of the following features:

[0024] (1) The aromatic isocyanate includes one or more of 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 2,6-toluene diisocyanate;

[0025] (2) The aliphatic isocyanate includes one or more of hexamethylene diisocyanate (HDI), hexamethylene diisocyanate-based polyisocyanate (HDI polymer), isophorone diisocyanate (IPDI) and dicyclohexylmethane diisocyanate (HMDI), and optionally includes one or more of hexamethylene diisocyanate-based polyisocyanate and dicyclohexylmethane diisocyanate (HMDI);

[0026] (3) The polyols include one or more of polyoxypropylene ether polyols, polyoxyethylene ether polyols, polyoxypropylene polyoxyethylene polyols, and polytetrahydrofuran ether diols;

[0027] (4) The number average molecular weight of the polyol is 500~8000, and can be selected as 1000~6000.

[0028] In one embodiment, component A further includes 5 to 10 parts by weight of a first plasticizer;

[0029] Optionally, the first plasticizer includes one or more of acetylated tributyl citrate, dioctyl terephthalate, chlorinated paraffin, propylene carbonate, dioctyl phthalate, and epoxidized soybean oil.

[0030] In one embodiment, the amine chain extender in the R component includes one or more of 3,5-diethyltoluenediamine, 3,5-dimethylthiotoluenediamine, 4,4'-bis(sec-butylamino)-diphenylmethane, 4,4'-methylenebis(2-chloroaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and polyaspartic acid resin.

[0031] In one embodiment, the R component further includes one or more of the following: inorganic filler, second plasticizer, defoamer, dispersant, antisettling agent, silane coupling agent, and antioxidant;

[0032] Optionally, the R component, in parts by weight, comprises:

[0033] 41 to 51 parts of inorganic filler

[0034] 10 to 15 parts of the second plasticizer,

[0035] Defoamer 0.1 to 0.5 parts,

[0036] Dispersant 0.1 to 0.5 parts,

[0037] Anti-settling agent 0.1 to 2 parts,

[0038] 0.5 to 1 part of silane coupling agent, and

[0039] Antioxidant 0.1 to 0.5 parts;

[0040] Optionally, the particle size of the inorganic filler is ≥400 mesh;

[0041] Optionally, the inorganic filler includes one or more of calcium carbonate, talc, barium sulfate, kaolin, carbon black, and titanium dioxide;

[0042] Optionally, the second plasticizer includes one or more of acetylated tributyl citrate, dioctyl terephthalate, chlorinated paraffin, propylene carbonate, dioctyl phthalate, and epoxidized soybean oil;

[0043] Optionally, the defoamer includes one or more of the following: silicone-based defoamers, polyolefin-silicone composite defoamers, and polyether-based defoamers;

[0044] Optionally, the dispersant includes one or more of the following: polymeric dispersants containing hydroxyl and / or carboxyl groups, polycarboxylate dispersants, and polyacrylate dispersants;

[0045] Optionally, the antisettling agent includes one or more of fumed silica, hydrogenated castor oil, bentonite, and hydroxyethyl cellulose;

[0046] Optionally, the silane coupling agent includes one or more of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-(phenylamino)propyltrimethoxysilane;

[0047] Optionally, the antioxidant includes hindered phenolic antioxidants, and may further include one or more of the following: octadecyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate, isooctyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid.

[0048] A second aspect of this application provides a method for preparing a polyurea coating, comprising the following steps:

[0049] Component A is prepared by prepolymerization of aromatic isocyanates, aliphatic isocyanates and polyols;

[0050] Component R is prepared by mixing an amine chain extender and a modified amino-hydroxy chain extender;

[0051] The modified amino-hydroxy chain extender contains a β-hydroxycarbamate structure in its chemical structure.

[0052] In one embodiment, the method for preparing the polyurea coating includes one or more of the following features:

[0053] (1) The preparation method of the modified amino-hydroxy chain extender includes the following steps:

[0054] A five-membered cyclic carbonate compound is reacted with a primary amine compound to form the β-hydroxycarbamate structure.

[0055] Optionally, the first reaction is carried out in the presence of a catalyst, said catalyst comprising one or more of 1,4-diazabicyclo[2.2.2]octane (DABCO), N-methylmorpholine (NMM), and 4-dimethylaminopyridine (DMAP);

[0056] Further optionally, the mass ratio of the catalyst to the primary amine compound is (0.008~0.012):1;

[0057] Optionally, the conditions for the first reaction include: a temperature of 115℃~130℃ and a time of 2h~5h;

[0058] Optionally, after the first reaction is completed, a step of adding a polyether polyol to carry out a second reaction is also included;

[0059] Further optionally, the conditions for the second reaction include: a temperature of 100℃~110℃ and a time of 0.5h~3h;

[0060] (2) The temperature of the prepolymerization reaction is 75℃~90℃.

[0061] A third aspect of this application provides a floor coating formed by curing a polyurea coating prepared using the polyurea coating described in the first aspect or the preparation method described in the second aspect.

[0062] In one embodiment, the floor coating includes one or more of the following features:

[0063] (1) The mass ratio of component A to component R is (0.8~1.3):1;

[0064] (2) The isocyanate index of components A and R is 1.04~1.1;

[0065] (3) The curing method is natural curing.

[0066] This application uses a combination of aromatic and aliphatic isocyanates as the isocyanate component in component A, and introduces a modified amino-hydroxy chain extender containing a β-hydroxycarbamate structure into component R. This enables the resulting polyurea coating to achieve high hardness and elongation at break, while also possessing a long working time and rapid curing performance. Furthermore, the raw materials for preparing the modified amino-hydroxy chain extender containing the β-hydroxycarbamate structure are low-cost, and the overall solution has a significant cost advantage compared to traditional coatings such as polyaspartic acid ester-based polyurea systems. In this composition, the aromatic isocyanates and aliphatic polyisocyanates in component A can be prepolymerized with polyols to obtain high-performance polyurethane prepolymers. While maintaining good flowability due to low viscosity, these prepolymers effectively improve the hardness of polyurea materials, resulting in greater compressive strength and abrasion resistance. Component R employs a modified amino-hydroxy chain extender containing a β-hydroxycarbamate structure. On one hand, the β-hydroxycarbamate structure creates a significant steric hindrance effect, making the modified amino-hydroxy chain extender a stable liquid at room temperature. Furthermore, it exhibits a lower reaction rate compared to traditional chain extenders such as aromatic primary amines and polyaspartic acid esters. On the other hand, it offers higher hardness and a faster late-stage reaction rate compared to secondary amine chain extenders. Using this modified amino-hydroxy chain extender in conjunction with traditional amine chain extenders can significantly reduce the early-stage reactivity of the system in high-hardness systems, extending the material's operating period.

[0067] Specifically, the beneficial effects of this application are as follows:

[0068] (1) Compared with the traditional aromatic self-leveling polyurea system, this application uses a modified amino-hydroxy chain extender to achieve a higher hardness and a longer working time at room temperature. This overcomes the contradiction of insufficient working time in polyurea systems composed of aromatic diamine and aromatic modified isocyanate when achieving high hardness. It can meet the leveling requirements of large-area coating and ensure rapid curing of coating, significantly improving the construction adaptability.

[0069] (2) The polyurea coating of this application has excellent workability and outstanding elastic properties. Compared with traditional flooring systems such as aspartic acid ester polyurea, the coating formed has higher tensile strength, tear strength and elongation at break, and the material hardness and toughness have a wide range of adjustable properties, making it more versatile.

[0070] (3) Compared with traditional flooring systems such as polyurea based on aspartic acid esters, the polyurea coating of this application does not rely on polyaspartic acid ester resin, and the raw material cost of the modified amino-hydroxy chain extender is relatively lower, resulting in better economic benefits. Detailed Implementation

[0071] The following detailed description, in conjunction with specific embodiments, illustrates the polyurea coating, its preparation method, and the floor coating of this application. This application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0072] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0073] In this article, "one or more" refers to any one, two or more of the listed items.

[0074] In this application, terms such as "first aspect," "second aspect," "third aspect," and "fourth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0075] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0076] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0077] Unless otherwise specified, the percentage content mentioned in this application refers to mass percentage for solid-liquid mixtures and solid-phase-solid mixtures, and volume percentage for liquid-phase-liquid mixtures.

[0078] Unless otherwise specified, all percentage concentrations mentioned in this application refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0079] Unless otherwise specified, the temperature parameters in this application may be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows for temperature fluctuations within the precision range controlled by the instrument.

[0080] In this application, room temperature generally refers to 4℃~30℃, and preferably 20±5℃.

[0081] Some embodiments of this application provide a polyurea coating, comprising component A and component R;

[0082] Component A, by weight, comprises:

[0083] 15 to 25 parts of aromatic isocyanate,

[0084] 20 to 32 parts of aliphatic isocyanate, and

[0085] 45-53 parts of polyols;

[0086] The R component comprises, by weight:

[0087] 10 to 18 parts of amine chain extender, and

[0088] 15 to 35 parts of modified amino-hydroxy chain extender;

[0089] The modified amino-hydroxy chain extender contains a β-hydroxycarbamate structure in its chemical structure.

[0090] Specifically, in component A, the amount of aromatic isocyanate by weight includes, but is not limited to, 15 parts, 17 parts, 20 parts, 22 parts, 25 parts, or any combination thereof.

[0091] Specifically, in component A, the weight parts of aliphatic isocyanate include, but are not limited to: 20 parts, 24 parts, 25 parts, 27 parts, 30 parts, 32 parts, or any combination thereof.

[0092] Specifically, in component A, the weight parts of the polyol include, but are not limited to: 45 parts, 48 ​​parts, 50 parts, 51 parts, 53 parts, or any range between the two mentioned above.

[0093] Specifically, in component R, the weight parts of the amine chain extender include, but are not limited to, 10 parts, 13 parts, 17 parts, 18 parts, or any range between the two mentioned above.

[0094] Specifically, in component R, the modified amino-hydroxy chain extender is present in parts by weight including but not limited to: 15 parts, 17 parts, 20 parts, 23 parts, 25 parts, 26 parts, 28 parts, 30 parts, 33 parts, 35 parts, or any combination thereof.

[0095] In some embodiments, the modified amino-hydroxy chain extender is prepared from raw materials comprising a five-membered cyclic carbonate compound and a primary amine compound.

[0096] Without limitation, nucleophilic ring-opening reactions can occur between five-membered cyclic carbonate compounds and primary amine compounds, partially hydroxyalkylating and capping the primary amine compounds, disrupting their structural symmetry, and giving the product a β-hydroxycarbamate structure.

[0097] Furthermore, the five-membered cyclic carbonate compound includes one or more of propylene carbonate, ethylene carbonate, and glycerol carbonate.

[0098] Furthermore, the primary amine compounds include one or more of aromatic primary amine compounds and alicyclic primary amine compounds. The presence of aromatic and alicyclic groups is more conducive to the formation of steric hindrance effects, thereby increasing the operating time.

[0099] Furthermore, the primary amine compounds include one or more of 4,4'-methylenebis(2-chloroaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and 3,5-dimethylthiotoluenediamine.

[0100] Without limitation, taking propylene carbonate and 4,4'-methylenebis(2-chloroaniline) as examples, the modified amino-hydroxy chain extender includes at least the components shown in the following structural formulas:

[0101] .

[0102] Further, the mass ratio of the five-membered cyclic carbonate compound to the primary amine compound is (0.3~1.3):1. By reasonably controlling this mass ratio, the obtained modified chain extender enables polyurea floor coatings to achieve higher hardness and strength while extending the working period and improving initial flowability, which is beneficial for improving coating application. Specifically, this mass ratio includes, but is not limited to: 0.3:1, 0.5:1, 0.8:1, 1:1, 1.3:1, or any range between the foregoing. Further, the mass ratio of the five-membered cyclic carbonate compound to the primary amine compound is (0.8~1.3):1.

[0103] In some embodiments, the raw material further includes polyether polyols. Polyether polyols can act as environmental media modifiers to promote later-stage reactions, and are also used to adjust the molecular weight and viscosity of modified chain extenders to improve low-temperature storage stability.

[0104] Further, the mass ratio of the polyether polyol to the primary amine compound is (0.8~1.3):1. Specifically, this mass ratio includes, but is not limited to: 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, or any range between the two aforementioned.

[0105] Further, the molecular weight of the polyether polyol is 2000-8000. Specifically, the molecular weight of the polyether polyol includes, but is not limited to: 2000, 3000, 4000, 4800, 5000, 6000, 7000, 8000, or any range between the foregoing. Even further, the molecular weight of the polyether polyol is 4000-6000.

[0106] In some embodiments, the modified amino-hydroxyl chain extender has an average molecular weight of 500-1000. Specifically, the average molecular weight of the modified amino-hydroxyl chain extender includes, but is not limited to, 500, 600, 700, 750, 800, 900, 1000, or any range between the foregoing. Further, the average molecular weight of the modified amino-hydroxyl chain extender is 600-800.

[0107] In some embodiments, the aromatic isocyanate in component A includes one or more of 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, and 2,6-toluene diisocyanate.

[0108] In some embodiments, the aliphatic isocyanate in component A includes one or more of hexamethylene diisocyanate (HDI), hexamethylene diisocyanate-based polyisocyanate (HDI polymer), isophorone diisocyanate (IPDI), and dicyclohexylmethane diisocyanate (HMDI), optionally including one or more of hexamethylene diisocyanate-based polyisocyanate and dicyclohexylmethane diisocyanate (HMDI).

[0109] In some embodiments, the polyol in component A includes one or more of polyoxypropylene ether polyol, polyoxyethylene ether polyol, polyoxypropylene polyoxyethylene polyol, and polytetrahydrofuran ether diol.

[0110] In some embodiments, the polyol in component A has a molecular weight of 500-8000. Specifically, the molecular weight of the polyol includes, but is not limited to: 500, 1000, 2000, 3000, 4000, 4800, 5000, 6000, 7000, 8000, or any range between the foregoing. Further, the molecular weight of the polyol is 1000-6000.

[0111] In some embodiments, component A further comprises 5 to 10 parts by weight of a first plasticizer. Specifically, the weight of the first plasticizer includes, but is not limited to, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, or any range between the foregoing.

[0112] Furthermore, the first plasticizer includes one or more of acetylated tributyl citrate, dioctyl terephthalate, chlorinated paraffin, propylene carbonate, dioctyl phthalate, and epoxidized soybean oil.

[0113] In some embodiments, the amine chain extender in component R includes aromatic amine chain extenders, such as one or more of aromatic secondary amines and aromatic primary amines. Specifically, the amine chain extender includes one or more of 3,5-diethyltoluenediamine, 3,5-dimethylthiotoluenediamine, 4,4'-bis(sec-butylamino)-diphenylmethane, 4,4'-methylenebis(2-chloroaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and polyaspartic acid resin.

[0114] In addition, appropriate additives may be introduced into the R component as needed for practical applications. Without limitation, the additives may include, for example, one or more of the following: inorganic fillers, secondary plasticizers, defoamers, dispersants, anti-settling agents, silane coupling agents, and antioxidants.

[0115] In some embodiments, the R component, by weight, comprises:

[0116] 41 to 51 parts of inorganic filler

[0117] 10 to 15 parts of the second plasticizer,

[0118] Defoamer 0.1 to 0.5 parts,

[0119] Dispersant 0.1 to 0.5 parts,

[0120] Anti-settling agent 0.1 to 2 parts,

[0121] 0.5 to 1 part of silane coupling agent, and

[0122] Antioxidant 0.1 to 0.5 parts.

[0123] As an example, the inorganic filler has a particle size of ≥400 mesh.

[0124] As an example, the inorganic filler includes one or more of calcium carbonate, talc, barium sulfate, kaolin, carbon black, and titanium dioxide.

[0125] As an example, the second plasticizer includes one or more of acetylated tributyl citrate, dioctyl terephthalate, chlorinated paraffin, propylene carbonate, dioctyl phthalate, and epoxidized soybean oil.

[0126] As an example, the defoamer includes one or more of silicone-based defoamers, polyolefin-silicone composite defoamers, and polyether-based defoamers. As an example, the dispersant includes one or more of polymeric dispersants containing hydroxyl and / or carboxyl groups (pigment and filler affinity groups), polycarboxylate dispersants, and polyacrylate dispersants.

[0127] As an example, the antisettling agent is a powder that readily forms hydrogen bonds with the resin system, including one or more of fumed silica, hydrogenated castor oil, bentonite, and hydroxyethyl cellulose.

[0128] As an example, the silane coupling agent includes one or more of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-(phenylamino)propyltrimethoxysilane.

[0129] As an example, the antioxidant includes hindered phenolic antioxidants, and may further optionally include one or more of the following: octadecyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate, isooctyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid.

[0130] Other embodiments of this application provide a method for preparing a polyurea coating, comprising the following steps:

[0131] Component A is prepared by prepolymerization of aromatic isocyanates, aliphatic isocyanates and polyols;

[0132] Component R is prepared by mixing an amine chain extender and a modified amino-hydroxy chain extender;

[0133] The modified amino-hydroxy chain extender contains a β-hydroxycarbamate structure in its chemical structure.

[0134] Understandably, the polyurea coating prepared by the method described above has the same technical solution and advantages as the polyurea coatings mentioned above, and will not be repeated here.

[0135] In some embodiments, the prepolymerization reaction temperature is 75°C to 90°C. Specifically, the prepolymerization reaction temperature includes, but is not limited to, 75°C, 80°C, 85°C, 90°C, or any range between the two. Without limitation, the prepolymerization reaction time is 3 h to 5 h. Specifically, the prepolymerization reaction time includes, but is not limited to, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, or any range between the two.

[0136] Without limitation, the preparation of component A may include the addition of a first plasticizer after the prepolymerization reaction is completed.

[0137] In some embodiments, the preparation method of the modified amino-hydroxy chain extender includes the following steps:

[0138] A five-membered cyclic carbonate compound is reacted with a primary amine compound to form the β-hydroxycarbamate structure.

[0139] Furthermore, the first reaction is carried out in the presence of a catalyst, which includes one or more of 1,4-diazabicyclo[2.2.2]octane (DABCO), N-methylmorpholine (NMM), and 4-dimethylaminopyridine (DMAP).

[0140] Further, the mass ratio of the catalyst to the primary amine compound is (0.008~0.012):1. Specifically, this mass ratio includes, but is not limited to: 0.008:1, 0.009:1, 0.01:1, 0.011:1, 0.012:1, or any range between the two aforementioned.

[0141] Furthermore, the conditions for the first reaction include: a temperature of 115℃ to 130℃ and a time of 2h to 5h. Specifically, the temperature includes, but is not limited to: 115℃, 118℃, 120℃, 125℃, 130℃ or any two of the foregoing; the time includes, but is not limited to: 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h or any two of the foregoing.

[0142] In some embodiments, after the first reaction is completed, a second reaction is carried out by adding a polyether polyol.

[0143] Furthermore, the conditions for the second reaction include: a temperature of 100℃~110℃ and a time of 0.5h~3h. Specifically, the temperature includes, but is not limited to: 100℃, 105℃, 110℃ or any two of the foregoing; the time includes, but is not limited to: 0.5h, 1h, 1.5h, 2h, 2.5h, 3h or any two of the foregoing.

[0144] Without limitation, the preparation of component R, including the mixing process, also includes the step of adding auxiliary agents.

[0145] In other embodiments of this application, a floor coating is provided, which is formed by curing a polyurea coating prepared by the polyurea coating method described above or prepared by the method described above.

[0146] In some embodiments, the mass ratio of component A to component R is (0.8~1.3):1. Specifically, this mass ratio includes, but is not limited to: 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, or any range between the two aforementioned.

[0147] In some embodiments, the isocyanate index (R value) of component A and component R is 1.04 to 1.1. Understandably, the "isocyanate index R value" refers to the ratio of the number of moles of -NCO in component A to the number of moles of active hydrogen in component R. Specifically, the isocyanate index of component A and component R includes, but is not limited to, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.1, or a range between any two of the foregoing.

[0148] In some embodiments, the curing method is natural curing. Understandably, "natural curing" means that after the polyurea coating is applied, no additional processing is performed, allowing the coating to cure naturally in the environment to form a floor coating.

[0149] Without limitation, the polyurea coating can be applied by methods such as scraping or troweling.

[0150] For experimental parameters not specified in the following specific embodiments, please refer to the guidelines given in this application document first, or refer to experimental manuals or other experimental methods known in the art, or refer to the experimental conditions recommended by the manufacturer.

[0151] The raw materials and reagents involved in the following specific embodiments can be obtained commercially or prepared by those skilled in the art using known methods.

[0152] The abbreviations, sources, and names of the raw materials involved in this application are summarized in Table 1 below:

[0153] Table 1

[0154]

[0155]

[0156]

[0157]

[0158]

[0159]

[0160] Example 1

[0161] This embodiment provides an elastic polyurea floor coating, comprising component A and component R.

[0162] Component A, by mass parts, includes:

[0163] Aromatic isocyanates (8.5 parts TDI-80 and 6.5 parts MDI-50), totaling 15 parts.

[0164] Aliphatic isocyanate (HT-300) 32 parts,

[0165] A total of 48 parts of polyether polyols (19.5 parts F3128, 8.5 parts C2010D, and 20 parts C2020).

[0166] Plasticizer (DOTP) 5 parts.

[0167] Component R, by mass parts, includes:

[0168] 10 parts of amine chain extender (E-300)

[0169] Modified amino-hydroxy chain extender (self-made, labeled R1) 35 parts,

[0170] Inorganic filler (calcium carbonate) 41 parts,

[0171] Plasticizer (DOP) 10 parts,

[0172] Defoamer (BYK-088) 0.2 parts,

[0173] Dispersant (BYK-W-969) 0.3 parts,

[0174] Anti-settling agent (bentonite) 2 parts,

[0175] 1 part of silane coupling agent (KH550),

[0176] Antioxidant (1010) 0.5 parts.

[0177] The preparation method of modified amino-hydroxy chain extender R1 in component R is as follows:

[0178] 32 parts of type II-MOCA were melted and then 0.4 parts of DABCO were added. The mixture was stirred under nitrogen protection to homogenize the system. Then, 25.6 parts of propylene carbonate were added in batches and reacted at 118°C for 3 hours. The temperature was then lowered to 110°C, and 42 parts of WANOLF3135 were added. The mixture was reacted at 110°C for another hour to obtain modified amino-hydroxy chain extender R1, which has an average functionality of 2 and an average molecular weight of 700.

[0179] The preparation method of the above-mentioned elastic polyurea floor coating is as follows:

[0180] (1) WANOL C2010D, WANOL C2020 and WANOL F3128 after dehydration were added to a reactor and heated to 60°C; then TDI-80, MDI-50 and HT-300 were added and reacted at 80°C for 4 hours, then cooled to 65°C and DOP was added, and the mixture was stirred for 10 minutes to obtain component A with an NCO% of 10.7%;

[0181] (2) E300, modified amino-hydroxy chain extender R1, DOTP, BYK-088, BYK-969, KH550, calcium carbonate, bentonite, and antioxidant 1010 are mixed evenly to obtain component R;

[0182] (3) Mix component A and component R at a mass ratio of 0.8:1, with an R value of 1.05. Cast the mixture into a mold and leave it at room temperature for 7 days to obtain sample #1.

[0183] Example 2

[0184] This embodiment provides an elastic polyurea floor coating, comprising component A and component R.

[0185] Component A, by mass parts, includes:

[0186] Aromatic isocyanates (10 parts TDI-80 and 7 parts MDI-50, totaling 17 parts),

[0187] Aliphatic isocyanate (HT-600) 24 parts,

[0188] A total of 53 polyols (23 parts F3128, 10 parts C2010D, and 20 parts PTMEG 2000) were used.

[0189] Plasticizer (ATBC) 6 parts.

[0190] Component R, by mass parts, includes:

[0191] Amine chain extender (E300) totaling 18 parts,

[0192] Modified amino-hydroxy chain extender (self-made, labeled R2) 26 parts,

[0193] Inorganic filler (talc powder) 42 parts,

[0194] Plasticizer (DOTP) 12 parts,

[0195] Defoamer (BYK-088) 0.1 parts,

[0196] Dispersant (BY-9066) 0.1 parts,

[0197] Anti-settling agent (fumed silica) 0.8 parts,

[0198] 0.6 parts of silane coupling agent (KH560),

[0199] Antioxidant (1135) 0.4 parts.

[0200] The preparation method of modified amino-hydroxy chain extender R2 in component R includes the following steps:

[0201] After melting 33 parts of type II-MOCA, 0.3 g of DABCO was added, and the system was homogenized by stirring under nitrogen protection. Then, 35.7 parts of propylene carbonate were added in batches, and the reaction was carried out at 115℃ for 5 h. Then, the temperature was lowered to 110℃, 31 parts of WANOLC2140 were added, and the reaction was continued at 110℃ for 0.5 h to obtain modified amino-hydroxy chain extender R1, which has an average functionality of 2 and an average molecular weight of 750.

[0202] The preparation method of the above-mentioned elastic polyurea floor coating is as follows:

[0203] (1) WANOL C2010D, WANOL F3128 and PTMEG-2000 after dehydration were added to a reactor and heated to 60°C; then TDI-80, MDI-50 and HT-600 were added and reacted at 80°C for 5 h, the temperature was lowered to 65°C and ATBC was added, and the mixture was stirred for 10 min to obtain component A with an NCO% of 10.4%;

[0204] (2) E300, modified amino-hydroxy chain extender R2, DOTP, BYK-088, BY-9066, KH560, talc, fumed silica and antioxidant 1135 are mixed evenly to obtain component R;

[0205] (3) Mix component A and component R in a 1:1 mass ratio, with R value of 1.04. Cast the mixture into a mold and leave it at room temperature for 7 days to obtain sample #2.

[0206] Example 3

[0207] This embodiment provides an elastic polyurea floor coating, comprising component A and component R.

[0208] Component A, by mass parts, includes:

[0209] Aromatic isocyanates (8 parts TDI-80 and 12 parts MDI-50, totaling 20 parts)

[0210] Aliphatic isocyanate (HT-300) 25 parts,

[0211] A total of 45 parts of polyols (13 parts F3135, 12 parts C2010D, and 20 parts PTMEG-2000).

[0212] Plasticizer (DOTP) 10 parts.

[0213] Component R, by mass parts, includes:

[0214] Amine chain extender (E300) totaling 16 parts,

[0215] Modified amino-hydroxy chain extender (self-made, labeled R3) 24 parts,

[0216] Inorganic filler (talc) 46.5 parts,

[0217] Plasticizer (ATBC) 11 parts,

[0218] Defoamer (Silok 4016) 0.3 parts,

[0219] Dispersant (BY-9066) 0.2 parts,

[0220] Anti-settling agent (bentonite) 1 part,

[0221] 0.7 parts of silane coupling agent (KH550),

[0222] Antioxidant (1010) 0.3 parts.

[0223] The preparation method of modified amino-hydroxy chain extender R3 in component R includes the following steps:

[0224] After melting 30 parts of type II-MOCA, 0.3 parts of N-methylmorpholine were added, and the system was homogenized by stirring under nitrogen protection. Then, 39 parts of propylene carbonate were added in batches, and the reaction was carried out at 120°C for 2 hours. Then, the temperature was lowered to 110°C, 30.7 parts of WANOLF3135 were added, and the reaction was continued at 110°C for 3 hours to obtain modified amino-hydroxy chain extender R3, which has an average functionality of 2 and an average molecular weight of 800.

[0225] The preparation method of the above-mentioned elastic polyurea floor coating is as follows:

[0226] (1) WANOL F3135, WANOL C2010D and PTMEG-2000 after dehydration were added to a reactor and heated to 60°C; then TDI-80, MDI-50 and HT-300 were added and reacted at 80°C for 3.5 h, the temperature was lowered to 65°C and ATBC was added, and the mixture was stirred for 10 min to obtain component A with an NCO% of 10.7%;

[0227] (2) E300, modified amino-hydroxy chain extender R3, ATBC, Silok 4016, BY-9066, KH550, talc, bentonite and antioxidant 1010 are mixed evenly to obtain component R;

[0228] (3) Mix component A and component R at a mass ratio of 0.9:1, with an R value of 1.09. Cast the mixture into a mold and leave it at room temperature for 7 days to obtain sample #3.

[0229] Example 4

[0230] This embodiment provides an elastic polyurea floor coating, comprising component A and component R.

[0231] Component A, by mass parts, includes:

[0232] Aromatic isocyanate (MDI-50) in total, 20 parts.

[0233] Aliphatic isocyanate (HMDI) 20 parts,

[0234] A total of 51 polyols (20 parts F3135, 15 parts C2020, and 16 parts PTMEG 1000).

[0235] Plasticizer (DOP) 9 parts.

[0236] Component R, by mass parts, includes:

[0237] Amine chain extender (E300) totaling 17 parts,

[0238] Modified amino-hydroxy chain extender (R2) 28 parts,

[0239] 42 parts of inorganic filler (barium sulfate),

[0240] Plasticizer (ATBC) 11 parts,

[0241] Defoamer (Silok 4016) 0.2 parts,

[0242] Dispersant (BYK-W-961) 0.2 parts,

[0243] Anti-settling agent (fumed silica) 0.9 parts,

[0244] 0.5 parts of silane coupling agent (KH560),

[0245] Antioxidant (1076) 0.2 parts.

[0246] Among them, the self-made modified amino-hydroxy chain extender in component R is R2, and the preparation method is the same as in Example 2.

[0247] The preparation method of the above-mentioned elastic polyurea floor coating is as follows:

[0248] (1) WANOL C2020, WANOL F3135 and PTMEG-1000 after dehydration were added to a reactor and heated to 60°C; then MDI-50 and HMDI were added and reacted at 80°C for 3 hours, then cooled to 65°C and DOP was added, and the mixture was stirred for 10 minutes to obtain component A with an NCO% of 10.6%;

[0249] (2) E300, modified amino-hydroxy chain extender R2, ATBC, Silok 4016, BYK-961, KH560, talc, fumed silica and antioxidant 1076 are mixed evenly to obtain component R;

[0250] (3) Mix component A and component R in a 1:1 mass ratio, with R value of 1.08. Cast the mixture into a mold and leave it at room temperature for 7 days to obtain sample #4.

[0251] Example 5

[0252] This embodiment provides an elastic polyurea floor coating, comprising component A and component R.

[0253] Component A, by mass parts, includes:

[0254] Aromatic isocyanates (12 parts TDI-80 and 13 parts MDI-50), totaling 25 parts.

[0255] Aliphatic isocyanate (HT-600) 20 parts,

[0256] A total of 50 parts of polyols (21 parts F3128, 20 parts C2020, and 9 parts PTMEG-1000).

[0257] 5 parts of plasticizer (ATBC).

[0258] Component R, by mass parts, includes:

[0259] Amine chain extender (13 parts E300 and 5 parts WANALINK 6200), totaling 17 parts.

[0260] Modified amino-hydroxy chain extender (self-made, labeled R4) 15 parts,

[0261] Inorganic filler (calcium carbonate) 51 parts,

[0262] Plasticizer (DOTP) 15 parts,

[0263] Defoamer (BYK-088) 0.5 parts,

[0264] Dispersant (BYK-W-961) 0.5 parts,

[0265] Anti-settling agent (BYK-410) 0.1 parts,

[0266] 0.8 parts of silane coupling agent (KH560),

[0267] Antioxidant (1076) 0.1 parts.

[0268] The preparation method of the self-made modified amino-hydroxy chain extender R4 in component R includes the following steps:

[0269] 40 parts of type II-MOCA were melted and then 0.32 parts of DABCO were added. The mixture was stirred under nitrogen protection to homogenize the system. Then, 27.6 parts of glyceryl carbonate were added in batches and reacted at 125°C for 3 hours. The temperature was then lowered to 100°C, and 32 parts of WANOLF3128 were added. The mixture was reacted at 100°C for another hour to obtain modified amino-hydroxy chain extender R1, which has an average functionality of 2 and an average molecular weight of 600.

[0270] The preparation method of the above-mentioned elastic polyurea floor coating is as follows:

[0271] (1) PTMEG-1000, WANOL C2020, and WANOL F3128 after dehydration were added to a reactor and heated to 60°C; then TDI-80, MDI-50, and HT-600 were added and reacted at 80°C for 3.5 h. The temperature was then lowered to 65°C and ATBC was added. The mixture was stirred and mixed for 10 min to obtain component A, with an NCO% of 7.2%.

[0272] (2) E300, WANALINK 6200, modified amino-hydroxy chain extender R3, DOTP, BYK-088, BYK-961, KH560, talc, attapulgite, and antioxidant 1076 are mixed evenly to obtain component R;

[0273] (3) Mix component A and component R at a mass ratio of 1.3:1, with R value of 1.10. Cast the mixture into a mold and leave it at room temperature for 7 days to obtain test piece #5.

[0274] Example 6

[0275] This embodiment provides an elastic polyurea floor coating, whose components and preparation method are the same as in Example 5, the main difference being that the modified amino-hydroxy chain extender used is replaced by R5 instead of R4. Test piece #6 was prepared.

[0276] The preparation method of the modified amino-hydroxy chain extender R5 is as follows:

[0277] 40 parts of type II-MOCA were melted and then 0.3 parts of DABCO were added. The mixture was stirred under nitrogen protection to homogenize the system. Then, 12 parts of propylene carbonate were added in batches and reacted at 130°C for 2.5 h. The temperature was then lowered to 105°C, and 47.7 parts of WANOLC2020 were added. The mixture was reacted at 105°C for another 1.5 h to obtain the modified amino-hydroxy chain extender R5, which has an average functionality of 2 and an average molecular weight of 600.

[0278] Example 7

[0279] This embodiment provides an elastic polyurea floor coating, whose components and preparation method are the same as in Example 4, the main difference being that the modified amino-hydroxy chain extender used is replaced by R6 instead of R2. Test piece #7 was obtained.

[0280] The preparation method of modified amino-hydroxy chain extender R6 is as follows:

[0281] 42 parts of M-CDEA were melted and 0.5 parts of N-methylmorpholine were added. The mixture was stirred under nitrogen protection to homogenize the system. Then, 25 parts of propylene carbonate were added in batches and reacted at 120°C for 4 hours. The temperature was then lowered to 100°C, and 32.5 parts of WANOLC2140 were added. The mixture was reacted at 100°C for another hour to obtain the modified amino-hydroxy chain extender R6, which has an average functionality of 2 and an average molecular weight of 750.

[0282] Example 8

[0283] This embodiment provides an elastic polyurea floor coating, whose components and preparation method are the same as in Example 5, the main difference being that the modified amino-hydroxy chain extender used is replaced by R7 instead of R4. Test piece #8 was obtained.

[0284] The modified amino-hydroxy chain extender R7 does not use polyether polyols in its raw material, and its preparation method is as follows:

[0285] 45 parts of type II MOCA were melted and then 0.4 parts of DABCO were added. The mixture was stirred under nitrogen protection to homogenize the system. Then, 54.6 parts of propylene carbonate were added in batches and reacted at 125°C for 4 hours to obtain modified amino-hydroxy chain extender R7, which has an average functionality of 2 and an average molecular weight of 570.

[0286] Example 9

[0287] This embodiment provides an elastic polyurea floor coating, whose components and preparation method are the same as in Example 4, with the same NCO component A. The main difference is that the aliphatic isocyanate in component A is replaced with isophorone diisocyanate. That is:

[0288] Component A, by mass parts, includes:

[0289] A total of 18 parts of aromatic isocyanate (MDI-50) were contained.

[0290] Isophorone diisocyanate (IPDI) 19 parts,

[0291] A total of 53 polyols (19 parts F3135, 15 parts C2020, and 19 parts PTMEG 1000) were used.

[0292] Plasticizer (DOP) 9 parts.

[0293] Test piece #9 was prepared.

[0294] Example 10

[0295] This embodiment provides an elastic polyurea floor coating, whose components and preparation method are the same as in Embodiment 2. The main difference is that inorganic fillers, plasticizers, defoamers, dispersants, anti-settling agents, silane coupling agents, and antioxidants are not used in component R. Test piece #10 was prepared.

[0296] Comparative Example 1

[0297] This comparative example is a polyurea floor coating, whose components and preparation method are the same as in Example 1, the main difference being that WANALINK 6200 is used instead of the modified amino-hydroxyl chain extender in component R. Sample #11 was prepared.

[0298] Component R, by mass parts, includes

[0299] Amine chain extender (E300) 8 parts,

[0300] 19 copies of WANALINK 6200 (homemade, marked R1)

[0301] Inorganic filler (calcium carbonate), 54 parts.

[0302] Plasticizer (DOP) 15 parts,

[0303] Defoamer (BYK-088) 0.2 parts,

[0304] Dispersant (BYK-969) 0.3 parts,

[0305] Anti-settling agent (bentonite) 2 parts,

[0306] 1 part of silane coupling agent (KH550),

[0307] Antioxidant (1010) 0.5 parts.

[0308] Comparative Example 2

[0309] This comparative example is a polyurea floor coating, whose components and preparation method are the same as in Example 2, the main difference being that polyaspartic acid ester is used in component R instead of the modified amino-hydroxyl chain extender. Test piece #12 was prepared.

[0310] Component R, by mass parts, includes:

[0311] Amine chain extender (E300) 18 parts,

[0312] Polyaspartic acid ester (F420) 20 parts,

[0313] Inorganic filler (talc) 48 parts,

[0314] Plasticizer (DOTP) 12 parts,

[0315] Defoamer (BYK-088) 0.1 parts,

[0316] Dispersant (BY-9066) 0.1 parts,

[0317] Anti-settling agent (fumed silica) 0.8 parts,

[0318] 0.6 parts of silane coupling agent (KH560),

[0319] Antioxidant (1135) 0.4 parts.

[0320] Comparative Example 3

[0321] This comparative example is a polyurea floor coating, whose components and preparation method are the same as in Example 3. The main difference is that 12 parts of type II-MOCA and 12 parts of WANOL F3135 are used to replace 24 parts of modified amino-hydroxy chain extender, that is, no reaction is carried out to obtain the β-hydroxycarbamate structure. Test piece #13 was prepared.

[0322] Comparative Example 4

[0323] This comparative example is a polyurea floor coating, whose components and preparation method are the same as in Example 3, with the same NCO component A. The main difference is that component A does not use aliphatic isocyanate, but instead uses aromatic isocyanate. That is:

[0324] Component A, by mass parts, includes:

[0325] Aromatic isocyanates (8 parts TDI-80 and 28 parts MDI-50), totaling 36 parts.

[0326] A total of 55 parts of polyols (21 parts F3135, 16 parts C2020, and 18 parts PTMEG 1000).

[0327] Plasticizer (DOP) 9 parts.

[0328] Test piece #14 was prepared.

[0329] Test case

[0330] Test method:

[0331] (1) Coating appearance: The coating appearance of the floor coating prepared in accordance with the standard GB / T 22374-2018 "Floor Coating Materials" is tested.

[0332] (2) Initial flowability: The initial flowability of the floor coating prepared in accordance with the standard GB / T 22374-2018 "Floor Coating Materials" is tested.

[0333] (3) Operation period: After mixing and stirring component A and component R for 1 minute, pour the mixture into a film. Use a scraper to gently scrape the film. The shortest time that the film cannot be restored within 30 seconds or the film is drawn into a string or scratches is the operation period.

[0334] (4) Hardness: The hardness of the floor coating film prepared is tested in accordance with the standard GB / T 22374-2018 "Floor Coating Materials". Specifically, it is carried out in accordance with GB / T 2411-2008, using a type D Shore hardness tester.

[0335] (5) Abrasion resistance: The abrasion resistance of the floor coating film prepared according to the standard GB / T 22374-2018 "Floor Coating Materials" is tested.

[0336] (6) Tensile properties: Applicable to elastic floor coating materials, the tensile strength and elongation at break of the floor coating film prepared according to the standard GB / T 22374-2018 "Floor Coating Materials" are tested.

[0337] (7) Scratch resistance: Applicable to smooth floor coating materials, the initial gloss and gloss after scratching of the prepared floor coating are tested according to the standard GB / T 22374-2018 "Floor Coating Materials". For elastic floor coatings, the steel wool fiber mentioned in the scratch test in the standard is replaced with 400# industrial scouring pad.

[0338] The test results are shown in Tables 2 and 3 below.

[0339] Table 2

[0340]

[0341] Table 3

[0342]

[0343] The two-component elastic polyurea floor coating of this application, through the use of sterically hindered modified amino-hydroxy chain extenders and the combination of aromatic isocyanates and aliphatic polyisocyanates, can achieve a balance of high hardness, long working life, and good elasticity and wear resistance. Moreover, the cost is lower than that of polyaspartic acid ester polyurea system, and the performance is easy to adjust, making it suitable for more scenarios.

[0344] As shown in Examples 1-9, the obtained polyurea floor coatings have a good appearance, a hardness of over 50 Shore D, high tensile strength (>10 MPa), and scratch resistance, as well as good elasticity and good leveling properties. More importantly, conventional aromatic amine chain extenders (such as 3,5-dimethylthiotoluene diamine, 4,4'-bis(sec-butylamino)-diphenylmethane) or polyaspartic acid esters react quickly with isocyanates, while the polyurea floor coatings shown in Examples 1-9, even with a high NCO% (NCO%>10) in component A, can still achieve an operating time of ≥27 min.

[0345] Comparative Example 1, component R, did not use modified amino-hydroxy chain extenders, but only aromatic amine chain extenders E300 and WANALINK 6200. The reaction rate was too fast, with an operating period of only 18 minutes, and the hardness was only 40D and the tensile strength was only 8.4 MPa. It could not have good strength and hardness at the same time as high elasticity.

[0346] Comparative Example 2 uses a polyaspartic acid ester system for component R. Due to the fast-drying properties of polyaspartic acid ester, the working period is too short (17 min), and the wear resistance is relatively low, which is not conducive to floor construction.

[0347] Comparative Example 3 uses unmodified 4,4'-methylenebis(2-chloroaniline) and polyether polyol as component R. Compared with the modified amino-hydroxy chain extender, although it also has amino and hydroxyl groups, it has an actual elongation at break of only 90.5% due to the absence of β-hydroxycarbamate structure. It also has insufficient elasticity, abrasion resistance and scratch resistance, and has blistering and more pinholes.

[0348] Comparative Example 4, in which aliphatic isocyanates were not used in component A, had a longer working period, but its hardness and tensile strength were significantly reduced, and its scratch resistance was also poor.

[0349] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0350] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A polyurea coating, characterized in that, Includes component A and component R; Component A, by weight, comprises: 15 to 25 parts of aromatic isocyanate, 20 to 32 parts of aliphatic isocyanate, and 45-53 parts of polyols; The R component comprises, by weight: 10 to 18 parts of amine chain extender, and 15 to 35 parts of modified amino-hydroxy chain extender; The modified amino-hydroxy chain extender contains a β-hydroxycarbamate structure in its chemical structure.

2. The polyurea coating according to claim 1, characterized in that, The modified amino-hydroxy chain extender is prepared from raw materials including five-membered cyclic carbonate compounds and primary amine compounds; Optionally, the five-membered cyclic carbonate compound includes one or more of propylene carbonate, ethylene carbonate, and glycerol carbonate; Optionally, the primary amine compound includes one or more of aromatic primary amine compounds and alicyclic primary amine compounds; more preferably, the primary amine compound includes one or more of 4,4'-methylenebis(2-chloroaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 3,5-dimethylthiotoluenediamine, 4,4'-diaminodiphenylmethane, toluenediamine, and isophoronediamine; Optionally, the mass ratio of the five-membered cyclic carbonate compound to the primary amine compound is (0.3~1.3):1, and more preferably (0.8~1.3):1; Optionally, the raw material may further include polyether polyols; Further optionally, the mass ratio of the polyether polyol to the primary amine compound is (0.8~1.3):1; Further optionally, the number average molecular weight of the polyether polyol is 2000~8000, and even more preferably 4000~6000; Optionally, the modified amino-hydroxy chain extender has an average molecular weight of 500-1000, and optionally 600-800.

3. The polyurea coating according to claim 1 or 2, characterized in that, Component A includes one or more of the following characteristics: (1) The aromatic isocyanate includes one or more of 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 2,6-toluene diisocyanate; (2) The aliphatic isocyanate includes one or more of hexamethylene diisocyanate, hexamethylene diisocyanate-based polyisocyanate, isophorone diisocyanate and dicyclohexylmethane diisocyanate, and optionally includes one or more of hexamethylene diisocyanate-based polyisocyanate and dicyclohexylmethane diisocyanate. (3) The polyols include one or more of polyoxypropylene ether polyols, polyoxyethylene ether polyols, polyoxypropylene polyoxyethylene polyols, and polytetrahydrofuran ether diols; (4) The number average molecular weight of the polyol is 500~8000, and can be selected as 1000~6000.

4. The polyurea coating according to claim 1 or 2, characterized in that, By weight, component A further includes 5 to 10 parts of a first plasticizer; Optionally, the first plasticizer includes one or more of acetylated tributyl citrate, dioctyl terephthalate, chlorinated paraffin, propylene carbonate, dioctyl phthalate, and epoxidized soybean oil.

5. The polyurea coating according to claim 1 or 2, characterized in that, In the R component, the amine chain extender includes one or more of 3,5-diethyltoluenediamine, 3,5-dimethylthiotoluenediamine, 4,4'-bis(sec-butylamino)-diphenylmethane, 4,4'-methylenebis(2-chloroaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and polyaspartic acid resin.

6. The polyurea coating according to claim 1 or 2, characterized in that, The R component further includes one or more of the following: inorganic filler, second plasticizer, defoamer, dispersant, antisettling agent, silane coupling agent, and antioxidant; Optionally, the R component, in parts by weight, comprises: 41 to 51 parts of inorganic filler 10 to 15 parts of the second plasticizer, Defoamer 0.1 to 0.5 parts, Dispersant 0.1 to 0.5 parts, Anti-settling agent 0.1 to 2 parts, 0.5 to 1 part of silane coupling agent, and Antioxidant 0.1 to 0.5 parts; Optionally, the particle size of the inorganic filler is ≥400 mesh; Optionally, the inorganic filler includes one or more of calcium carbonate, talc, barium sulfate, kaolin, carbon black, and titanium dioxide; Optionally, the second plasticizer includes one or more of acetylated tributyl citrate, dioctyl terephthalate, chlorinated paraffin, propylene carbonate, dioctyl phthalate, and epoxidized soybean oil; Optionally, the defoamer includes one or more of the following: silicone-based defoamers, polyolefin-silicone composite defoamers, and polyether-based defoamers; Optionally, the dispersant includes one or more of the following: polymeric dispersants containing hydroxyl and / or carboxyl groups, polycarboxylate dispersants, and polyacrylate dispersants; Optionally, the antisettling agent includes one or more of fumed silica, hydrogenated castor oil, bentonite, and hydroxyethyl cellulose; Optionally, the silane coupling agent includes one or more of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-(phenylamino)propyltrimethoxysilane; Optionally, the antioxidant includes hindered phenolic antioxidants, and may further include one or more of the following: octadecyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate, isooctyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid.

7. A method for preparing a polyurea coating, characterized in that, Includes the following steps: Component A is prepared by prepolymerization of aromatic isocyanates, aliphatic isocyanates and polyols; Component R is prepared by mixing an amine chain extender and a modified amino-hydroxy chain extender; The modified amino-hydroxy chain extender contains a β-hydroxycarbamate structure in its chemical structure.

8. The method for preparing polyurea coating according to claim 7, characterized in that, Includes one or more of the following features: (1) The preparation method of the modified amino-hydroxy chain extender includes the following steps: A five-membered cyclic carbonate compound is reacted with a primary amine compound to form the β-hydroxycarbamate structure. Optionally, the first reaction is carried out in the presence of a catalyst, said catalyst comprising one or more of 1,4-diazabicyclo[2.2.2]octane, N-methylmorpholine, and 4-dimethylaminopyridine; Further optionally, the mass ratio of the catalyst to the primary amine compound is (0.008~0.012):1; Optionally, the conditions for the first reaction include: a temperature of 115℃~130℃ and a time of 2h~5h; Optionally, after the first reaction is completed, a step of adding a polyether polyol to carry out a second reaction is also included; Further optionally, the conditions for the second reaction include: a temperature of 100℃~110℃ and a time of 0.5h~3h; (2) The temperature of the prepolymerization reaction is 75℃~90℃.

9. A floor coating, characterized in that, The polyurea coating prepared by any one of claims 1 to 6 or by any one of claims 7 to 8 is cured to form a polyurea coating.

10. The floor coating according to claim 9, characterized in that, Includes one or more of the following characteristics: (1) The mass ratio of component A to component R is (0.8~1.3):1; (2) The isocyanate index of components A and R is 1.04~1.1; (3) The curing method is natural curing.

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