A high-strength and high-weather-resistant elastic coating and its preparation method and application

Abstract

The present invention provides a high-strength and high-weather-resistant elastic coating and a preparation method and application thereof, and relates to the technical field of coatings. The present invention uses a difunctional terminal hydroxyl long-chain substance, a difunctional active hydrogen short-chain substance and an aliphatic diisocyanate as raw materials to prepare a linear difunctional aliphatic isocyanate prepolymer, wherein the difunctional terminal hydroxyl long-chain substance includes a difunctional terminal hydroxyl high cohesive energy long-chain substance, so that the molecular main chain of the linear difunctional aliphatic isocyanate prepolymer is a high cohesive energy main chain, and maintains high elasticity, high strength and high weather resistance, and the tensile strength of the coating is high. The difunctional active hydrogen short-chain substance acts as a short-chain chain extender, which greatly increases the secondary force on the molecular chain, greatly improves the molecular strength of the linear difunctional aliphatic isocyanate prepolymer, and then greatly improves the strength of the coating. The linear difunctional aliphatic isocyanate prepolymer uses an aliphatic isocyanate in the main chain, so that the prepolymer itself has good weather resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a high-strength and high-weather-resistant elastic coating, a preparation method thereof, and an application thereof. Background Art

[0002] Existing one-component polyisocyanate coatings include one-component polyurethane coatings and one-component polyurea coatings. Most of them are based on aromatic polyisocyanates, with terminal hydroxyl low-energy ether as the main chain back bond (ethylene oxide ether, propylene oxide ether, butylene oxide ether, and mixtures thereof) and aromatic polyisocyanate prepolymers as the base glue, mixed with other materials.

[0003] Aromatic polyisocyanate polymers are the main chain film-forming substances of polyurethane coatings, polyurethane urea coatings and polyurea coatings. For example, the polyurethane waterproof coatings of Chinese patents CN102807812A, CN104877542A and CN105315878A all use aromatic polyisocyanates as film-forming substances. The above coatings can solve the problems of coating blistering, root barrier or single-component solvent-free. However, since the above coatings all use low cohesive energy main chain aromatic polyisocyanates, their tensile strength is relatively low and they are not weather-resistant.

[0004] Chinese patent CN110387187A discloses a one-component polyurethane waterproof coating, comprising at least one polyurethane prepolymer formed by a polyol component and toluene diisocyanate (TDI), and at least one aldimine-type latent curing agent, wherein the polyol component comprises 50-90wt% of a triol and 10-50wt% of a diol. The coating can solve the problems of thick coating without bubbling and general building roofing exposed waterproof maintenance market. However, the trifunctional branched aromatic isocyanate in the polyurethane prepolymer has a high degree of crosslinking after curing, resulting in low tear strength of the coating; it uses a polyether with relatively low cohesive energy as the main chain of the elastomer, and this type of polyether provides Polyurethane materials are flexible, but due to the low cohesive energy and insufficient strength of the main chain segments; the polyether used is extremely hydrophilic. Under the conditions of long-term rain and immersion in water, the oxidized ethylene ether and / or oxidized propylene ether polymer segments with flexible segments will swell under immersion conditions, causing the elastomer to deteriorate and affecting its durability under immersion water and long-term rain and high temperature conditions; and, because the cohesive energy of the above-mentioned polyether main chain itself is very low, the elastomer main chain does not have the essential characteristics of high strength, and it is difficult to resist the damage of mechanical forces such as strong winds, people trampling, vehicles running over, stress concentration of buildings, settlement, impact of foreign objects in the air, rain erosion, hail, snow, frost and freezing.

[0005] Chinese patent CN111349380A discloses an aromatic single-component polyurea coating, including polycarbonate diol, dimer acid polyester diol and terminal hydroxyl liquid rubber and one or two of MDI (diphenylmethane diisocyanate) and TDI to make a prepolymer and an "imide-type" curing agent substance. However, the above-mentioned coating uses monomer MDI alone, and a long-chain MDI-terminated prepolymer, which has poor stability with the "imine" curing agent, and the terminal NCO of the MDI prepolymer does not have weather resistance after curing, and the chemical composition of the imine substance is not clearly disclosed.

[0006] Chinese patent CN109401581A discloses a one-component aromatic polyurea coating, including aromatic isocyanate monomers (TDI, MDI, tetramethyl metaxylene diisocyanate TMXDI, polymethylene polyphenyl polyisocyanate PAPI, naphthyl diisocyanate NDI), polyester polyols, polyether polyols, polytetramethylene glycol, butylene glycol, pentanediol, ketimine, organic tin catalyst and solvent oil, in addition, it also includes low molecular weight diols or triols (including trimethylolpropane). However, the stability of the ketimine curing agent in the system is poor, resulting in poor storage stability of the coating, and the use of ordinary polyether polyols causes poor oxidation resistance of the coating, and the end NCO of the prepolymer synthesized by using the aromatic isocyanate monomers PAPI, MDI, and NDI alone does not have good stability with the latent curing agent, and its weather resistance is poor, and the outdoor use of the coating is limited.

[0007] Chinese patent CN111454650A discloses a one-component polyurea coating, which is made of liquefied MDI, low cohesive energy polyether (trifunctional group, such as 330N polyether, 551C polyether), polyester polyol, isocyanate prepolymer composed of amine chain extender, and latent curing agent oxazolidine. However, it uses ordinary low cohesive energy polyether as the main chain, the oxidation resistance is not high enough, its weather resistance is limited, and the stability of aromatic trifunctional prepolymer and oxazolidine is poor.

[0008] Chinese patent CN106497371A discloses a one-component polyurea coating, which uses an amine chain extender (such as diethylenetriamine, carbazole diamine, diacetyl hexamethylenediamine), cyclohexanone and amino polyether end-capping reaction, and then mixes with polyisocyanate prepolymer to prepare a one-component polyurea, which has anti-corrosion properties. However, the above coating is difficult to apply to long-term weather resistance and oxidation resistance, and the oxypropylene ether in the amino polyether segment as the main chain does not have good water resistance and oxidation resistance, and the strength of the coating is low.

[0009] Chinese patent CN102101967A discloses a one-component polyurea polyurethane coating, wherein amino polyether is chemically blocked and isocyanate prepolymer is blocked, and the double-blocked materials are mixed to obtain a one-component polyurea polyurethane coating. However, the main chain is a simple oxypropylene ether with low cohesive energy, and the strength of the above coating is relatively low.

[0010] Chinese patent CN110527066A discloses an environmentally friendly high urea bond fast curing single-component polyurea material, which uses amino polyether as the main material. However, its oxidized propylene ether segment as the main chain has poor oxidation resistance and strong hydrophilicity, resulting in poor weather resistance of the coating. In addition, the industrial production, storage and use of the blocked isocyanate prepolymer are not operational and practical, and are actually difficult to achieve under the solvent-free conditions.

[0011] Chinese patent CN106590376A discloses an anti-sagging single-component polyurea coating to solve the problem of rheological properties of coatings. However, based on the use of polyoxypropylene ether as the main chain, it has fundamental defects in water resistance, oxidation resistance and strength, and the highly branched urea-based thixotropic agent has too many urea groups per unit mass. It is a solid material, and the mixing process and actual viscosity are difficult to meet the processing requirements, and it is not industrially operable.

[0012] Chinese patent CN104903371A discloses a relatively large molecular weight ester-based aldimine substance having more than 12 carbon atoms and containing an ester group. This aldimine having a long carbon chain and containing an electron-donating ester group is mixed with oxazolidine to achieve the purpose of reducing the viscosity of the system, and a branched aliphatic polyisocyanate prepolymer having an average functional group of 1.7-3.0 is mixed with it to form a single-component coating to achieve the purpose of low viscosity and low solvent; however, the patent preferably uses polyoxypropylene diol and triol with an average molecular weight of 500-6000 g / mol, particularly preferably in the range of 1000-4000 g / mol, and polyoxypropylene diol and triol terminated with ethylene oxide in the specification, which causes the main chain of the aliphatic prepolymer to be not a linear structure, but a difunctional and trifunctional aliphatic branched mixed prepolymer, and the future elastomer has poor tear resistance; further, the main chain is a low cohesive energy Back of polyoxypropylene. bond is the main molecular chain, and its final elastomer tensile strength is relatively low. In actual use, it is difficult to reach more than 10MPa, and it is even more difficult to reach the required tensile strength of more than 20MPa; further, the aldimine with more than 12 carbon atoms and containing an ester group hydrolyzes relatively slowly, and the by-product molecules after hydrolysis are ester-based aldehydes with more than 12 carbon atoms and a large molecular weight. They slowly evaporate into the air and remain in the elastomer film for a considerable time, similar to an oil or plasticizer. In the presence of inorganic fillers, it causes swelling when soaked in water, which also causes the elastomer strength to decay, and its water-immersion durability is limited.

[0013] Chinese patent CN115433508A discloses an aromatic high-strength weather-resistant one-component elastic coating. Although this one-component coating has high strength and good weather resistance, in some areas with strong ultraviolet rays, due to the aromatic characteristics of its elastomer main chain, the color still changes to a certain extent after long-term use, that is, the probability of color difference change ΔE being higher than 3 still exists.

[0014] Chinese patent CN117106366A discloses a one-component polyurea coating, wherein the high-dose silane sealant is actually a polyacrylate containing a silane group, which is a macromolecule with a large molecular weight and contains multiple hydroxyl groups in the molecule, causing gelation or direct curing after being added to an isocyanate prepolymer. Further, the diluent contains ethanol and isopropanol monofunctional hydroxyl groups, which react directly with the isocyanate in the system, resulting in the final product being sticky or difficult to cure. The specification further describes that "heating releases NCO, which reacts with diol to form a urea bond, thereby obtaining a polyurea product", but in the actual process, the NCO group reacts with the diol to form a urea bond, and it is difficult to obtain the polyurea product.

[0015] In order to achieve ultra-long durability (at least 10 years) and weather resistance (especially color difference ΔE not exceeding 3) under outdoor natural conditions, outdoor coatings need to meet the following requirements: (1) High strength, requiring the minimum tensile strength of the coating to be above 10MPa for ordinary civil engineering, and greater than 15MPa for water conservancy projects, and greater than 20MPa for impact and abrasion resistance; outdoor high-strength coatings have good resistance to damage from other mechanical forces such as strong winds, rain, hail, impact of frozen and thawed ice, impact of seawater, impact of high-speed water in ditches, ponds, reservoirs and dams, vibration of the base layer, trampling of people and vehicle rolling, heavy vehicle rolling, and deep water pressure; (2) High weather resistance, being able to resist the combined effects of moisture, oxidation, light aging, and temperature difference at the same time, being actually exposed to the sun for at least 10 years under outdoor natural conditions, and having a color difference ΔE not higher than 3, basically maintaining the original color. However, current coatings are difficult to meet the above requirements of high strength and high weather resistance and color difference. Summary of the invention

[0016] In view of this, the object of the present invention is to provide a high-strength and high-weather-resistant elastic coating and a preparation method and application thereof. The high-strength and high-weather-resistant elastic coating provided by the present invention has high strength and high weather resistance (after 2000 hours of ultraviolet irradiation, the color change color difference ΔE is less than 3).

[0017] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0018] The present invention provides a high-strength and high-weather-resistant elastic coating, the preparation raw materials of which include a linear bifunctional aliphatic isocyanate prepolymer and a latent curing agent;

[0019] The linear bifunctional aliphatic isocyanate prepolymer is obtained by adding a bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate;

[0020] The latent curing agent is one or more of bicyclic oxazolidine and polyaldimine; the bicyclic oxazolidine is an oxazolidine containing two five-membered rings; the polyaldimine is a substance containing two and / or three aldimine groups, obtained by dehydration after addition of C3-C10 aldehyde and polyamine;

[0021] The mass of the latent curing agent is 2-45% of the mass of the total film-forming material, and the total film-forming material includes a preparation raw material containing an isocyanate group and a latent curing agent; the preparation raw material containing an isocyanate group includes a linear bifunctional aliphatic isocyanate prepolymer;

[0022] The ratio of the amount of the aliphatic diisocyanate to the total amount of the two-functional terminal hydroxyl long-chain substance and the two-functional active hydrogen short-chain substance is (1.2-2.5): 1;

[0023] The two-functional active hydrogen short-chain substance includes one or more of a two-functional diol short-chain substance and / or a two-functional secondary amine short-chain substance;

[0024] The molecular weight of the bifunctional diol short-chain substance is <500 g / mol, and the molecular weight of the bifunctional secondary amine short-chain substance is ≤900 g / mol;

[0025] The bifunctional hydroxyl-terminated long-chain substance includes a bifunctional hydroxyl-terminated high cohesive energy long-chain substance; the molecular weight of the bifunctional hydroxyl-terminated long-chain substance is 500-5000 g / mol;

[0026] The content of hydrogen bond donor in the linear bifunctional aliphatic isocyanate prepolymer is greater than 1 mol / kg; the content of hydrogen bond donor is the ratio of the total amount of hydroxyl and secondary amine groups in the bifunctional terminal hydroxyl long-chain substance and the bifunctional active hydrogen short-chain substance to the mass of the linear bifunctional aliphatic isocyanate prepolymer;

[0027] The molar ratio of the two-functional active hydrogen short-chain substance to the two-functional terminal hydroxyl long-chain substance is greater than 0 and less than 15.

[0028] Preferably, the bifunctional hydroxyl-terminated long-chain substance further comprises a bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance; the mass ratio of the bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance to the bifunctional hydroxyl-terminated high cohesive energy long-chain substance in the bifunctional hydroxyl-terminated long-chain substance is less than 5;

[0029] The bifunctional hydroxyl-terminated high cohesive energy long-chain substance includes one or more of hydroxyl-terminated polyester, hydroxyl-terminated polytetrahydrofuran ether, hydroxyl-terminated polymethyltetrahydrofuran ether and bifunctional hydroxyl-terminated polymer polyether; the bifunctional hydroxyl-terminated polymer polyether includes hydroxyl-terminated polyoxypropylene ether containing styrene and / or acrylonitrile oligomer;

[0030] The two-functional group terminal hydroxyl low cohesive energy polyether long chain material includes one or more of two-functional group terminal hydroxyl polyoxypropylene ether, two-functional group terminal hydroxyl polyoxyethylene ether, two-functional group terminal hydroxyl polyoxyethylene propylene ether and two-functional group terminal hydroxyl polyoxybutylene ether;

[0031] The residues other than the hydroxyl group and the secondary amine group in the two-functional group active hydrogen short-chain substance are hydrocarbon segments, or hydrocarbon segments containing benzene ring groups and / or heteroatoms; the heteroatoms include one or more of oxygen, nitrogen and sulfur;

[0032] The aliphatic diisocyanate includes one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, meta-xylylene diisocyanate, para-xylylene diisocyanate, o-xylylene diisocyanate, cyclohexyl dimethylene diisocyanate, tetramethyl meta-xylylene diisocyanate, pentamethylene diisocyanate, trimethyl hexamethylene diisocyanate and tetramethylene diisocyanate.

[0033] Preferably, the raw materials for preparing the high-strength and high-weather-resistant elastic coating further include aliphatic adducts;

[0034] The aliphatic adducts include adducts of oligomers of diisocyanates and monofunctional active hydrogen substances;

[0035] The oligomer of diisocyanate includes one or more of dimers and trimers of hexamethylene diisocyanate and / or isophorone diisocyanate, or at least two of dimers, trimers and tetramers;

[0036] The monofunctional active hydrogen substance includes one or more of a monofunctional hydroxyl substance, a monofunctional thiol substance and a monofunctional secondary amine substance;

[0037] The mass ratio of the aliphatic adduct to the linear bifunctional aliphatic isocyanate prepolymer is (0-0.5):1;

[0038] The functionality of the aliphatic adduct is 1.95 to 2.05;

[0039] The aliphatic adduct is used in the form of an aliphatic adduct or an aliphatic adduct-viscosity reducer mixture, wherein the mass fraction of the viscosity reducer in the aliphatic adduct-viscosity reducer mixture is 0.1 to 90%;

[0040] The isocyanate group-containing preparation raw materials include aliphatic adducts.

[0041] Preferably, the raw materials for preparing the high-strength and high-weather-resistant elastic coating further include urea-based adducts;

[0042] The mass ratio of the urea adduct to the linear bifunctional aliphatic isocyanate prepolymer is (0-0.5):1;

[0043] The urea-based adduct is obtained by the addition reaction of a linear diamine chain extender and an aliphatic diisocyanate;

[0044] The urea-based adduct is used in the form of a urea-based adduct or a urea-based adduct-viscosity reducer mixture, wherein the mass fraction of the viscosity reducer in the urea-based adduct-viscosity reducer mixture is 2 to 90%;

[0045] The isocyanate group-containing preparation raw materials include urea adducts.

[0046] Preferably, the raw materials for preparing the high-strength and high-weather-resistant elastic coating further include aromatic terminal diisocyanate linear adducts;

[0047] The aromatic terminal diisocyanate linear adduct is obtained by reacting an aromatic diisocyanate monomer with a difunctional terminal hydroxyl substance;

[0048] The molar ratio of the aromatic diisocyanate monomer to the difunctional terminal hydroxyl substance is (1.9-2.05):1;

[0049] The number average molecular weight of the bifunctional hydroxyl-terminated substance is not greater than 4000; the bifunctional hydroxyl-terminated substance includes hydroxyl-terminated polyether and / or hydroxyl-terminated polyester;

[0050] The ratio of the aromatic terminal diisocyanate linear adduct to the linear bifunctional aliphatic isocyanate prepolymer is (0-0.5):1.

[0051] Preferably, the raw materials for preparing the high-strength and high-weather-resistant elastic coating also include auxiliary materials, and the auxiliary materials include one or more of viscosity reducers, wetting agents, defoaming agents, leveling agents, coupling agents, antioxidants, light stabilizers, anti-aquatic agents, fillers, pigments, thixotropic agents, flame retardants, hydrolysis accelerators and catalysts.

[0052] The present invention provides a method for preparing the high-strength and high-weather-resistant elastic coating described in the above technical solution, comprising the following steps:

[0053] (1) A bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate are mixed and subjected to an addition reaction to obtain a linear bifunctional aliphatic isocyanate prepolymer;

[0054] (2) The linear bifunctional aliphatic isocyanate prepolymer and the latent curing agent are mixed under dry conditions to obtain a high-strength and high-weather-resistant elastic coating.

[0055] Preferably, step (2) is replaced by: mixing one or more of the linear bifunctional aliphatic isocyanate prepolymer, urea adduct, aliphatic adduct, aromatic terminal diisocyanate linear adduct and auxiliary materials, and then adding a latent curing agent to mix, so as to obtain a high-strength and high-weatherability one-component coating.

[0056] The present invention also provides a method for preparing the high-strength and high-weather-resistant elastic coating described in the above technical scheme, comprising the following steps: mixing a two-functional group terminal hydroxyl long-chain substance, a two-functional group active hydrogen short-chain substance and auxiliary materials, then adding an aliphatic diisocyanate to mix and carry out an addition reaction, then adding one or more of a urea adduct, an aliphatic adduct and an aromatic terminal diisocyanate linear adduct to mix, and finally adding a latent curing agent to mix to obtain a high-strength and high-weather-resistant single-component coating.

[0057] The present invention also provides the use of the high-strength and high-weather-resistant elastic coating described in the above technical solution or the high-strength and high-weather-resistant elastic coating obtained by the preparation method described in the above technical solution in waterproofing, protection, anti-corrosion, flooring, coating or sealing and bonding;

[0058] The application industries include water conservancy, new energy, transportation, railways, bridges, construction, municipal administration, light industry, electricity, electronics, machinery, vehicles, marine engineering, underground, communications, chemicals, sewage, seawater desalination, wind energy, photovoltaics, nuclear energy, hydropower, aerospace, mining, shipbuilding or metallurgy.

[0059] The present invention uses a difunctional terminal hydroxyl long-chain substance, a difunctional active hydrogen short-chain substance and an aliphatic diisocyanate as raw materials to prepare a linear difunctional aliphatic isocyanate prepolymer, wherein the difunctional terminal hydroxyl long-chain substance includes a difunctional terminal hydroxyl high cohesive energy long-chain substance, so that the molecular main chain of the linear difunctional aliphatic isocyanate prepolymer is a high cohesive energy main chain, and maintains high elasticity, high strength and high weather resistance, and the tensile strength of the coating formed by the coating is high. The difunctional active hydrogen short-chain substance is used as a short-chain chain extender, which greatly increases the secondary force on the molecular chain, greatly improves the molecular strength of the linear difunctional aliphatic isocyanate prepolymer, and then greatly improves the tensile strength of the coating. The linear difunctional aliphatic isocyanate prepolymer uses an aliphatic isocyanate in the main chain, so that the prepolymer itself has good weather resistance, and under the action of light irradiation, the color difference changes less, and ΔE is less than 3.

[0060] The present invention uses one or more of bicyclic oxazolidine and polyaldimine (obtained by dehydration after addition of C3-C10 aldehyde and polyamine) as latent curing agent, so that linear bifunctional aliphatic isocyanate prepolymer can be cured in order, and carbon dioxide bubbles and defects caused by water are eliminated. The latent curing agent used is hydrolyzed preferentially before the isocyanate group is hydrolyzed, and urea group and uret group are formed at the cross-linking curing point, so that the coating film formed by the coating has good curing morphology, high strength and high tensile strength. In addition, the polyaldimine has a small number of carbon atoms, its hydrolysis speed is fast, and its detached molecules are easy to be dispersed at a fast speed.

[0061] The linear isocyanates used in the present invention are all aliphatic polyisocyanates, which improve the weather resistance of the coating, and especially ensure that the color difference changes less under light irradiation, and ΔE is less than 3.

[0062] The invention adds urea-based adducts into the coating to increase the secondary strength of the coating and further improve the tensile strength of the coating film.

[0063] The invention adds aliphatic adducts into the coating to further improve the weather resistance of the coating film.

[0064] The invention adds aromatic terminal diisocyanate linear adducts into the coating, thereby improving the coating film strength and reducing the coating cost.

[0065] The present invention adds auxiliary materials (functional additives) to the coating to improve some properties of the coating. For example, adding fillers can reduce the production cost of the coating; adding pigments facilitates the adjustment of the required color of the coating; adding wetting agents facilitates the compatibility of pigments and fillers with linear two-functional aliphatic isocyanate prepolymers and the wetting properties of the coating and the base layer; adding coupling agents facilitates the increase of the adhesion between the coating and the base layer; adding antioxidants can improve the anti-oxidation properties of the coating; adding light absorbers and stabilizers facilitates the stability of the coating in absorbing ultraviolet rays and photolysis; adding thixotropic agents facilitates the improvement of the rheological properties of the coating; adding flame retardants improves the flame retardant properties of the coating; adding anti-aquatic organisms additives facilitates the coating to have the ability to resist the erosion of aquatic organisms when it is immersed in water for a long time. DETAILED DESCRIPTION

[0066] The present invention provides a high-strength and high-weather-resistant elastic coating, the preparation raw materials of which include a linear bifunctional aliphatic isocyanate prepolymer and a latent curing agent;

[0067] The linear bifunctional aliphatic isocyanate prepolymer is obtained by adding a bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate;

[0068] The latent curing agent is one or more of bicyclic oxazolidine and polyaldimine; the bicyclic oxazolidine is an oxazolidine containing two five-membered rings; the polyaldimine is a substance containing two and / or three aldimine groups, obtained by dehydration after addition of C3-C10 aldehyde and polyamine;

[0069] The mass of the latent curing agent is 2-45% of the mass of the total film-forming material, and the total film-forming material includes a preparation raw material containing an isocyanate group and a latent curing agent; the preparation raw material containing an isocyanate group includes a linear bifunctional aliphatic isocyanate prepolymer;

[0070] The ratio of the amount of the aliphatic diisocyanate to the total amount of the two-functional terminal hydroxyl long-chain substance and the two-functional active hydrogen short-chain substance is (1.2-2.5): 1;

[0071] The two-functional active hydrogen short-chain substance includes one or more of a two-functional diol short-chain substance and / or a two-functional secondary amine short-chain substance;

[0072] The molecular weight of the bifunctional diol short-chain substance is <500 g / mol, and the molecular weight of the bifunctional secondary amine short-chain substance is ≤900 g / mol;

[0073] The bifunctional hydroxyl-terminated long-chain substance includes a bifunctional hydroxyl-terminated high cohesive energy long-chain substance; the molecular weight of the bifunctional hydroxyl-terminated long-chain substance is 500-5000 g / mol;

[0074] The content of hydrogen bond donor in the linear bifunctional aliphatic isocyanate prepolymer is greater than 1 mol / kg; the content of hydrogen bond donor is the ratio of the total amount of hydroxyl and secondary amine groups in the bifunctional terminal hydroxyl long-chain substance and the bifunctional active hydrogen short-chain substance to the mass of the linear bifunctional aliphatic isocyanate prepolymer;

[0075] The molar ratio of the two-functional active hydrogen short-chain substance to the two-functional terminal hydroxyl long-chain substance is greater than 0 and less than 15.

[0076] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0077] In the present invention, the viscosity (Brookfield rotation viscosity) of the high-strength resistant one-component elastic coating is preferably 2000-30000 cPs, more preferably 2000-20000 cPs, further preferably 2000-12000 cPs, and the viscosity is preferably the viscosity at 20°C.

[0078] The raw materials for preparing the high-strength and high-weather-resistant elastic coating provided by the present invention include a linear bifunctional aliphatic isocyanate prepolymer. In the present invention, the linear bifunctional aliphatic isocyanate prepolymer is obtained by adding a bifunctional terminal hydroxyl long-chain substance (denoted as L), a bifunctional active hydrogen short-chain substance (denoted as S) and an aliphatic diisocyanate (denoted as F).

[0079] In the present invention, the molecular weight of the bifunctional diol short-chain substance is <500 g / mol, preferably greater than 60 g / mol and not higher than 400 g / mol; the molecular weight of the bifunctional secondary amine short-chain substance is ≤900 g / mol.

[0080] In the present invention, the molecular weight of the bifunctional hydroxyl-terminated long-chain substance is 500-5000 g / mol, preferably 1000-4000 g / mol.

[0081] In the present invention, the molar ratio of the difunctional active hydrogen short-chain substance to the difunctional terminal hydroxyl long-chain substance (S / L molar ratio) is greater than 0 and less than 15, preferably (0-8):1 and not 0, more preferably (0.5-5):1. In the present invention, the activity of the difunctional active hydrogen short-chain substance is higher than that of the difunctional terminal hydroxyl long-chain substance, and the difunctional active hydrogen short-chain substance reacts with the aliphatic diisocyanate preferentially over the difunctional terminal hydroxyl long-chain substance.

[0082] In the present invention, the viscosity reducer is a substance with a relatively low molecular weight that does not react with isocyanate, amine substances and latent curing agent and plays a role in reducing viscosity, preferably including a diluent and / or a plasticizer, and more preferably including one or more of an ester viscosity reducer, a hydrocarbon viscosity reducer, an ether viscosity reducer, a ketone viscosity reducer, an ether ester viscosity reducer, an aldehyde viscosity reducer, an amide viscosity reducer, dimethyl sulfoxide, a chlorinated paraffin viscosity reducer and a silicone viscosity reducer.

[0083] In the present invention, the ester viscosity reducer preferably includes ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, heptyl acetate, octyl acetate, isooctyl acetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, amyl propionate, isoamyl propionate, hexyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, methyl isobutyrate, ethyl isobutyrate, propyl isobutyrate, isopropyl isobutyrate, isobutyl isobutyrate, amyl isobutyrate, methyl valerate, ethyl valerate, methyl isovalerate, ethyl isovalerate , methyl hexanoate, ethyl hexanoate, dimethyl malonate, diethyl malonate, diethyl oxalate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, hexyl formate, heptyl formate, propylene glycol diacetate, alkylbenzene sulfonate, phthalate, alkyl phosphite and alkyl phosphate; the phthalate preferably includes one or more of dimethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, diisooctyl phthalate, didecyl phthalate, dinonyl phthalate, diisononyl phthalate and vegetable oils and fats.

[0084] In the present invention, the hydrocarbon viscosity reducer preferably includes one or more of cyclohexane, methylcyclohexane, heptane, octane, benzene, toluene, xylene, trimethylbenzene, diisopropylnaphthalene, solvent oil, biphenyls, ethylbenzene, isopropylbenzene, butylbenzene, D30 and D40, and naphtha; the solvent oil preferably includes one or more of 100# solvent oil, 120# solvent oil, 140# solvent oil, 160# solvent oil, diisopropylnaphthalene, aromatic oils, paraffin oil and white oil (mineral oil).

[0085] In the present invention, the ether viscosity reducer preferably includes one or more of dipropyl ether, diisopropyl ether, diisobutyl ether, dibutyl ether, n-pentyl ether, diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether and dioxane, tetrahydrofuran ether, cyclohexyl ether, dicyclopentyl ether and polymethoxy dimethyl ether.

[0086] In the present invention, the ketone viscosity reducer preferably includes one or more of acetone, butanone, pentanone, methyl isobutyl ketone, hexanone, heptanone, methyl isoheptanone and octanone, nonanone, decanone, cyclohexanone, cyclopentanone, methyl cyclopentanone, ethyl cyclopentanone, methyl cyclohexanone and ethyl cyclohexanone.

[0087] In the present invention, the aldehyde viscosity reducer preferably includes one or more of isopropyl aldehyde, propionaldehyde, butyraldehyde, isobutyl aldehyde, valeraldehyde, isovaleraldehyde, hexanal, heptaldehyde and isooctyl aldehyde.

[0088] In the present invention, the amide viscosity reducer preferably includes one or more of N-methylpyrrolidone (NMP), N-ethylpyrrolidone, N,N-dimethylformamide (DMF) and N,N-dimethylaniline.

[0089] In the present invention, the ether ester viscosity reducer preferably includes one or more of ethylene glycol ethyl ether acetate, ethylene glycol methyl ether acetate, ethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, ethylene glycol methyl ether methacrylate and diethylene glycol methyl ether acrylate.

[0090] In the present invention, the plasticizer preferably includes one or more of phthalates, alkyl sulfonate phenyl esters, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB), dipropylene glycol dibenzoate (DPGDB), polyol benzoates (DEGBD), terephthalates, isophthalates, aliphatic dibasic acid esters, epoxy esters, Mesamoll (trade name, from LANXESS), phosphates and polyphosphates, and citrates.

[0091] In the present invention, the organosilicon viscosity reducer preferably includes one or more of silicone oil substances and dimethylsiloxane ring bodies, and the dimethylsiloxane ring body preferably includes one or more of D2, D3 and D4.

[0092] In the present invention, the viscosity reducer is used to reduce the viscosity. The viscosity reducer does not react with the active substances (such as isocyanate groups and latent curing agents) in the high-strength and high-weather-resistant elastic coating, and is in a free state in the coating. The present invention does not specifically limit the amount of the viscosity reducer, which preferably accounts for less than 60% of the total mass of the high-strength and high-weather-resistant elastic coating, more preferably <40%, and further preferably <20%; it can ensure that the viscosity of the high-strength and high-weather-resistant elastic coating is 2000~30000cPs (Brookfield viscosity).

[0093] In the present invention, the content of hydrogen bond donor in the linear difunctional aliphatic isocyanate prepolymer is greater than 1 mol / kg, preferably 1.05-6 mol / kg, more preferably 1.2-6 mol / kg; the content of hydrogen bond donor is the ratio of the total amount of hydroxyl groups and secondary amino groups in difunctional terminal hydroxyl long-chain substances and difunctional active hydrogen short-chain substances to the mass of the linear difunctional aliphatic isocyanate prepolymer; the hydrogen atoms in the hydroxyl groups and secondary amino groups in the preparation raw materials are respectively converted into corresponding hydrogen bond donors in the finally formed linear difunctional aliphatic isocyanate prepolymer and exist in the urethane group (-OCONH-) and the uret group (-NCONH-). Theoretically, the higher the hydrogen bond donor content of the linear difunctional aliphatic isocyanate prepolymer, the greater the interaction between molecules; however, if the hydrogen bond donor content is too high, its viscosity will increase sharply, and the activity of the terminal -NCO group in the linear difunctional isocyanate prepolymer will also increase, and its stability for coexistence with latent curing agents will be reduced to a certain extent. Therefore, a reasonable hydrogen bond donor content should have both high cohesion and workability and storage stability of the coating system. The present invention maintains the above ratio as a reasonable ratio, so that the coating has high strength and high weather resistance.

[0094] In the present invention, the bifunctional hydroxyl-terminated long-chain substance preferably includes a bifunctional hydroxyl-terminated high cohesive energy long-chain substance, or a mixture of a bifunctional hydroxyl-terminated high cohesive energy long-chain substance and a bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance; the mass ratio of the bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance to the bifunctional hydroxyl-terminated high cohesive energy long-chain substance in the mixture is preferably <5, more preferably <3.

[0095] Since the difunctional group-terminated hydroxyl long-chain substances include difunctional group-terminated hydroxyl high cohesive energy long-chain substances, the viscosity of the prepolymer is often very high. Adding difunctional group-terminated hydroxyl low cohesive energy polyether long-chain substances makes a great contribution to reducing the viscosity. On the other hand, adding too much difunctional group-terminated hydroxyl low cohesive energy long-chain substances will reduce the strength of the final coating film. The present invention controls the mass ratio of difunctional group-terminated hydroxyl low cohesive energy polyether long-chain substances to difunctional group-terminated hydroxyl high cohesive energy long-chain substances to be less than 5, and the addition amount of difunctional group-terminated hydroxyl low cohesive energy long-chain substances is reasonable. Under the condition of not affecting the strength, the effect of reducing the viscosity is achieved. When the difunctional group-terminated hydroxyl low cohesive energy long-chain substance is not added, the viscosity of the system is high, and more viscosity reducers need to be added to achieve the purpose of reducing the viscosity of the system.

[0096] In the present invention, the bifunctional hydroxyl-terminated high cohesive energy long-chain substance preferably includes one or more of hydroxyl-terminated polyester, hydroxyl-terminated polytetrahydrofuran ether, hydroxyl-terminated polymethyltetrahydrofuran ether and bifunctional hydroxyl-terminated polymer polyether. In the present invention, the bifunctional hydroxyl-terminated polymer polyether preferably includes hydroxyl-terminated polyoxypropylene ether containing styrene and / or acrylonitrile oligomers, and the content of styrene and / or acrylonitrile oligomers in the bifunctional hydroxyl-terminated polymer polyether is preferably more than 30%. In theory, the higher the polymer content, the higher the mechanical properties; it is well known that the polymer polyether contains styrene and / or acrylonitrile oligomers. The present invention does not specifically limit the source of the bifunctional hydroxyl-terminated long-chain substance, and it can be prepared using commercial products well known to those skilled in the art or preparation methods well known to those skilled in the art.

[0097] In the present invention, the two-functional group-terminated hydroxyl-low cohesive energy polyether long-chain substance preferably includes one or more of two-functional group-terminated hydroxyl-polyoxypropylene ether, two-functional group-terminated hydroxyl-polyoxyethylene ether, two-functional group-terminated hydroxyl-polyoxyethylene propylene ether and two-functional group-terminated hydroxyl-polyoxybutylene ether; the two-functional group-terminated hydroxyl-polyoxybutylene ether preferably includes two-functional group-terminated hydroxyl-polyoxy 1,2-butyl ether and / or two-functional group-terminated hydroxyl-polyoxy 2,3-butyl ether.

[0098] In the present invention, the viscosity of the bifunctional hydroxyl-terminated high cohesive energy long-chain substance is relatively high. The present invention can reduce the viscosity of the bifunctional hydroxyl-terminated high cohesive energy long-chain substance by using the bifunctional hydroxyl-terminated high cohesive energy long-chain substance in combination with the bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance, and simultaneously connect the bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance into the main chain segment. However, if only the bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance is used, the strength of the coating body is reduced. Therefore, the bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance cannot be used entirely, but the bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance and the bifunctional hydroxyl-terminated high cohesive energy long-chain substance are used in combination.

[0099] In the present invention, the two-functional group active hydrogen short-chain substance includes one or more of a two-functional group diol short-chain substance and / or a two-functional group secondary amine short-chain substance. In the present invention, the residues other than hydroxyl and secondary amine in the two-functional group active hydrogen short-chain substance are preferably hydrocarbon segments, or hydrocarbon segments containing benzene ring groups and / or heteroatoms; the heteroatoms preferably include one or more of oxygen, nitrogen and sulfur; the groups formed by the heteroatoms preferably include one or more of ether groups, ester groups, tertiary amino groups, carbonyl groups and urethane groups.

[0100] In the present invention, the bifunctional diol short-chain substances preferably include ethylene glycol, propylene glycol, 2-ethyl-1,3-propanediol, 2-methyl-1,3-propanediol, butylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, pentanediol, neopentyl glycol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, hexanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-2-butyl-1,3-propanediol, trimethyl hexanediol, cyclohexanedimethanol, heptanediol, neopentyl glycol, octanediol, nonanediol, decanediol, undecanediol, hydrogenated bisphenol A, dipropylene glycol (D PG), tripropylene glycol (TPG), diethylene glycol, triethylene glycol, cyclohexanedimethyl glycol, terminal dihydroxy polyether oligomer, xylene glycol, hydroquinone dihydroxyethyl ether, resorcinol di(2-hydroxyethyl) ether, HQEE, HQEE-L, HER, HER-L, hydroquinone bis-β-hydroxyethyl ether, resorcinol di(2-hydroxyethyl) ether, 3-hydroxyethyloxyethyl-1-hydroxyethylphenylene diether and 4-hydroxyethyloxyethyl-1-hydroxyethylphenylene diether. The HQEE, HQEE-L, HER and HER-L are preferably purchased from Suzhou Xiangyuan New Materials Co., Ltd.

[0101] In the present invention, the bifunctional secondary amine short-chain substance preferably includes one or more of 4,4'-di-sec-butylaminodiphenylmethane and bifunctional aspartic acid esters, and the bifunctional aspartic acid esters preferably include the adduct of maleate and dibasic aliphatic primary amines or commercially available bifunctional secondary amine short-chain substances; the maleate preferably includes one or more of dimethyl maleate, diethyl maleate, dipropyl maleate and dibutyl maleate; the dibasic aliphatic primary amines preferably include ethylenediamine, butanediamine, pentamethylenediamine, 2-methylpentamethylenediamine, hexamethylenediamine, trimethylhexamethylenediamine, isophoronediamine (IPDA), xylene diamine (XDA), 4,4'-diaminodicyclohexylmethane (H 12 MDA), 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane, 3(4),8(9)-bis(aminomethyl)-tricyclo[5.2.1.0 2,6] one or more of decane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane and difunctional amino polyether; the diphenylenediamine preferably includes one or more of metaphenylenediamine, paraphenylenediamine and o-phenylenediamine, diethyltoluenediamine and dimethylthiotoluenediamine; the molecular weight of the difunctional amino polyether is preferably ≤600g / mol, and the difunctional amino polyether preferably includes one or more of polyether D230, polyether D600 and polyether D400. In the present invention, the preparation method of the adduct of maleate and dibasic aliphatic primary amine preferably includes the following steps: mixing maleate and dibasic primary amine, performing addition reaction, and obtaining the adduct of maleate and dibasic primary amine. In the present invention, the molar ratio of maleate to dibasic aliphatic primary amine is preferably 2:1. The present invention has no special limitation on the preparation method of the difunctional aspartic acid ester, and the preparation method well known to those skilled in the art can be used. In the present invention, the commercially available difunctional secondary amine short-chain substances preferably include Desmophen® NH1420, Desmophen® NH1422, Desmophen® NH1520, and Desmophen® NH 1220.

[0102] In the present invention, the aliphatic diisocyanate preferably includes hexamethylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (H 12 One or more of the group consisting of MDI, methylcyclohexane diisocyanate (HTDI), meta-xylylene diisocyanate (XDI), para-xylylene diisocyanate, o-xylylene diisocyanate, cyclohexyl dimethylene diisocyanate, tetramethyl meta-xylylene diisocyanate (TMXDI), pentamethylene diisocyanate, 2-methyl pentamethylene diisocyanate, trimethyl hexamethylene diisocyanate and tetramethylene diisocyanate.

[0103] In the present invention, the ratio of the amount of the aliphatic diisocyanate to the total amount of the two-functional terminal hydroxyl long-chain substance and the two-functional active hydrogen short-chain substance (i.e., the F / (L+S) molar ratio) is (1.2-2.5):1, preferably (1.4-1.95):1. When the molar ratio of the NCO group to the active hydrogen group of the aliphatic diisocyanate is less than 1.2:1 (such as (0.95-1.2):1), the obtained linear two-functional aliphatic isocyanate prepolymer has a very high viscosity during the synthesis process, and even gels or directly solidifies.

[0104] In the present invention, the latent curing agent is one or more of a bicyclic oxazolidine and a polyaldimine; the bicyclic oxazolidine is an oxazolidine containing two five-membered rings, preferably including one or more of a bicyclic oxazolidine containing two aliphatic urethane groups, a bicyclic oxazolidine containing a carbonate group and an aromatic polyurethane-based bisoxazolidine.

[0105] In the present invention, the bicyclic oxazolidine containing two aliphatic urethane groups is preferably a commercially available product or a self-made bicyclic oxazolidine containing two aliphatic urethane groups; the commercially available bicyclic oxazolidine containing two aliphatic urethane groups preferably includes one or more of Incorez ® OZ4, Incoreze ® CF, Incorez ® EH, Incorez ® K, Incorez ® NC, Incorez ® HP, Desmofen ® hardner OZ and Desmofen ® VSLP 2949, and the Incorez ® OZ4, Incoreze ® CF, Incorez ® EH, Incorez ® K, Incorez ® NC and Incorez ® HP are preferably purchased from ICL; the Desmofen ® hardner OZ and Desmofen ® VSLP2949 are preferably purchased from Allnex.

[0106] In the present invention, the bicyclic oxazolidine containing two aliphatic urethane groups is preferably obtained by an addition reaction between a mono-oxazolidine containing a hydroxyl group and an aliphatic diisocyanate compound. In the present invention, the mono-oxazolidine containing a hydroxyl group preferably includes 2-isopropyl-3-hydroxyethyl-1,3-oxazolidine and / or 2-(1'-ethyl-pentyl)-3-hydroxyethyl-1,3-oxazolidine. In the present invention, the aliphatic diisocyanate compound preferably includes a monomer and / or a prepolymer of an aliphatic diisocyanate; the monomer of the aliphatic diisocyanate preferably includes hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), meta-xylyl diisocyanate (XDI), hydrogenated diphenylmethane diisocyanate (HDI), and hydrogenated diphenylmethane diisocyanate (HDI). 12One or more of tetramethyl meta-xylylene diisocyanate (MDI), tetramethyl meta-xylylene diisocyanate (TMXDI), hydrogenated meta-xylylene diisocyanate (HXDI), methyl cyclohexyl diisocyanate, pentamethylene diisocyanate and methyl pentamethylene diisocyanate. The present invention has no special restrictions on the preparation conditions of the bicyclic oxazolidine containing two aliphatic urethane groups. The preparation conditions of the bicyclic oxazolidine containing two aliphatic urethane groups can be prepared by the addition reaction of a mono-oxazolidine containing a hydroxyl group and an aliphatic diisocyanate compound well known to those skilled in the art. Specifically, the temperature of the addition reaction is preferably 80-120° C., and the catalyst used in the addition reaction preferably includes a metal organic catalyst, more preferably one or more of organic tin, organic bismuth, organic zinc and organic zirconium; during the addition reaction, two moles of the mono-oxazolidine containing a hydroxyl group react with one mole of the aliphatic diisocyanate compound to obtain the bicyclic oxazolidine containing two aliphatic urethane groups; the mass content of -NCO groups in the bicyclic oxazolidine product containing two aliphatic urethane groups is tested to be zero, indicating that the reaction is complete.

[0107] In the present invention, the bicyclic oxazolidine containing a carbonate group preferably includes Incorez ® LV (produced by ICL, UK).

[0108] In the present invention, the aromatic polyurethane-based bisoxazolidine is preferably obtained by addition reaction of a monooxazolidine containing a hydroxyl group and an aromatic diisocyanate; the monooxazolidine containing a hydroxyl group preferably includes 2-isopropyl-3-hydroxyethyl-1,3-oxazolidine and / or 2-(1'-ethylpentyl)-3-hydroxyethyl-1,3-oxazolidine; the aromatic diisocyanate preferably includes a monomer or prepolymer of an aromatic diisocyanate, and the monomer of the aromatic diisocyanate preferably includes one or two of toluene diisocyanate (TDI) and / or diphenylmethane diisocyanate (MDI). The present invention does not specifically limit the preparation conditions of the aromatic polyurethane-based bisoxazolidine, and the preparation conditions of the aromatic polyurethane-based bisoxazolidine from a monooxazolidine containing a hydroxyl group and an aromatic diisocyanate well known to those skilled in the art can be used. In the present invention, the hydroxyl group in the mono-oxazolidine containing hydroxyl group is preferably a primary hydroxyl group, and the mono-oxazolidine containing hydroxyl group reacts faster with the aromatic -NCO group. The addition reaction temperature is preferably 50-80°C, and the mass content of the tested -NCO group is zero, indicating that the reaction is complete.

[0109] In the present invention, the polyaldimine is a substance containing two and / or three aldimine groups (—CH═N—). In the present invention, the polyaldimine is preferably a polyaldimine without ester aldehyde.

[0110] In the present invention, the polyaldimine is preferably a commercially available polyaldimine or self-made; the commercially available polyaldimine preferably includes one or more of A-139 (a dialdehyde imine produced by Evonik, an adduct obtained by addition dehydration of isobutylaldehyde and isophorone diamine), SJK-Hard-302, 302 (aldimine, a dehydrated adduct of benzaldehyde and hexamethylenediamine) produced by Jinzhao Environmental Protection Company, Incorez® BH (an adduct of diamino ether and benzaldehyde) and Dytek® Aaldimine.

[0111] In the present invention, the polyaldimine is preferably obtained by dehydration after addition of C3~C10 aldehyde and polyvalent primary amine. In the present invention, the C3~C10 aldehyde preferably includes one or more of isobutylaldehyde, isovaleraldehyde, pivalaldehyde, 2-ethylhexanal, benzaldehyde and substituted benzaldehyde; the substituent in the substituted benzaldehyde preferably includes alkyl or alkoxy. In the present invention, the diprimary amine preferably includes one or more of propylenediamine, butanediamine, pentamethylenediamine, methylpentamethylenediamine, hexamethylenediamine, trimethylhexamethylenediamine, isophoronediamine, dicyclohexylmethanediamine, methylcyclohexyldiamine, xylylenediamine, hydrogenated xylylenediamine, tetramethyl-m-xylylenediamine and difunctional amino-terminated polyether; the ternary primary amine preferably includes a trifunctional substance of amino-terminated polyether. In the present invention, the number average molecular weight of the amino-terminated polyether is preferably 200-5000, more preferably 200-2000, and further preferably 230-600. The amino-terminated polyether preferably includes diamino-terminated polyether and / or triamino-terminated polyether, and more preferably is formed by aldehyde addition dehydration of one or more of Hunsman's D230, D400, D600 and T403. The present invention has no special restrictions on the aldehyde addition dehydration reaction, and the preparation conditions familiar to those skilled in the art can be adopted, such as the reaction temperature is 50-110°C, the volatile water is removed by vacuum, the volatile aldehyde is cooled and refluxed, and the chromatographic test after the reaction shows that the main latent curing agent content and the active hydrogen amine substances disappear, and the design expected value is reached.

[0112] In the present invention, the polyaldimine preferably includes N,N'-bis(2-methylpropylene)-tetramethylene-1,4-diamine, N,N'-bis(2-methylpropylene)-pentamethylene-1,5-diamine, N,N'-bis(2-methylpropylene)-methylpentamethylenediamine, N,N'-bis(2-methylpropylene)-hexamethylene-1,6-diamine, N,N'-bis(2-methylpropylene)-trimethylhexamethylene-1,6-diamine, N,N'-bis(2-methylpropylene)-isophoronediamine, N,N'-bis(2-methylpropylene)-dicyclohexylmethanediamine, N,N'-bis(2-methylpropylene)-m-xylenediamine, N,N'-bis(2-methylpropylene)-hydrogenated m-xylenediamine, One or more of amine, N,N'-bis(2-methylpropylene)-tetramethyl-m-xylene diamine, addition dehydration product of amino polyether and isobutyraldehyde and addition dehydration product of trifunctional amino polyether and isobutyraldehyde; the number average molecular weight of the amino polyether is preferably 200-2000, more preferably 500-1000; the addition dehydration product of the amino polyether and isobutyraldehyde preferably includes N,N'-bis(2-methylpropylene)-polyoxypropylene diamine; the number average molecular weight of the trifunctional amino polyether is preferably 300-5000, more preferably 300-3000; the addition dehydration product of the trifunctional amino polyether and isobutyraldehyde preferably includes N,N',N''-tri(2-methylpropylene)-polyoxypropylene triamine.

[0113] In the present invention, 2-ethylhexanal is subjected to addition dehydration with a polyamine to form aldimine, and the residue after the oxygen atom of 2-ethylhexanal is removed (2-ethylhexylene, i.e., CH3CH2CH2CH2CH(C2H5)CH=) is connected to the nitrogen atom from which two hydrogen atoms are removed in the polyamine to form a plurality of aldimine groups -CH=N-. In the present invention, the polyaldehyde imine preferably includes N,N'-bis(2-ethylhexylene)-tetramethylene-1,4-diamine, N,N'-bis(2-ethylhexylene)-pentamethylene-1,5-diamine, N,N'-bis(2-ethylhexylene)-hexamethylene-1,6-diamine, N,N'-bis(2-ethylhexylene)-trimethylhexamethylene-1,6-diamine, N,N'-bis(2-ethylhexylene)-isophorone diamine, N,N'-bis(2-ethylhexylene)-dicyclohexylmethane diamine, N,N'-bis(2-ethylhexylene)-m-xylenediamine, N,N'-bis(2-ethylhexylene)-hydrogenated m-xylenediamine, N,N'-bis(2-ethylhexylene)-tetramethylm-xylenediamine, bifunctional One or more of the addition dehydration products of amino polyether and 2-ethylhexanal and the addition dehydration products of trifunctional amino polyether and 2-ethylhexanal; the number average molecular weight of the amino polyether is preferably 200-2000 g / mol, more preferably 230-1000 g / mol; the addition dehydration product of the amino polyether and 2-ethylhexanal preferably includes N,N'-bis(2-ethylhexylene)-polyoxypropylene diamine; the number average molecular weight of the trifunctional amino polyether is preferably 300-5000 g / mol, more preferably 300-3000 g / mol; the addition dehydration product of the trifunctional amino polyether and 2-ethylhexanal preferably includes N,N',N''-tri(2-ethylhexylene)-polyoxypropylene triamine.

[0114] In the present invention, the aldimine formed by the addition dehydration of benzaldehyde and polyamines, and the dehydrated addition product of aldehyde having a substituted group on the benzene ring of benzaldehyde and polyamines; the residual group after removing one oxygen atom from benzaldehyde (phenyl methylene, i.e. C6H5CH=), which is connected with the nitrogen atom after removing two hydrogen atoms from the amino group of the polyamines, forms a plurality of aromatic aldimine groups C6H5-CH=N-. In the present invention, the polyaldehyde imine preferably includes N,N'-bis(phenylmethylene)-tetramethylene-1,4-diamine, N,N'-bis(phenylmethylene)-pentamethylene-1,5-diamine, N,N'-bis(phenylmethylene)-methylpentamethylene-1,5-diamine, N,N'-bis(phenylmethylene)-hexamethylene-1,6-diamine, N,N'-bis(phenylmethylene)-trimethylhexamethylene-1,6-diamine, N,N'-bis(phenylmethylene)-isophoronediamine, N,N'-bis(phenylmethylene)-dicyclohexylmethanediamine, N,N'-bis(phenylmethylene)-m-xylenediamine, N,N'-bis(phenylmethylene)-hydrogenated m-xylenediamine, N,N'-bis(phenylmethylene)-m ... -bis(phenylmethylene)-tetramethyl-meta-xylene diamine, one or more of the addition dehydration products of difunctional amino polyether and benzaldehyde and the addition dehydration products of trifunctional amino polyether and benzaldehyde; the number average molecular weight of the amino polyether is preferably 200-2000, more preferably 230-1000; the addition dehydration product of the amino polyether and benzaldehyde preferably includes N,N'-bis(phenylmethylene)-polyoxypropylene diamine; the number average molecular weight of the trifunctional amino polyether is preferably 300-5000, more preferably 300-3000; the addition dehydration product of the trifunctional amino polyether and benzaldehyde preferably includes N,N',N''-tri(phenylmethylene)-polyoxypropylene triamine.

[0115] In the present invention, the raw materials for preparing the high-strength and high-weather-resistant elastic coating preferably also include aliphatic adducts; the aliphatic adducts preferably include adducts of diisocyanate oligomers and monofunctional active hydrogen substances. In the present invention, the mass ratio of the aliphatic adduct to the linear two-functional aliphatic isocyanate prepolymer is (0-0.5):1, more preferably (0.03-0.4):1, and further preferably (0.1-0.3):1. In the present invention, the functionality of the aliphatic adduct is preferably 1.95-2.05, more preferably 2.

[0116] In the present invention, the oligomer of diisocyanate includes one or more of dimers and trimers of hexamethylene diisocyanate and / or isophorone diisocyanate, or at least two of dimers, trimers and tetramers; the oligomer of diisocyanate preferably includes one or more of Desmodur® N100, Desmodur® N75, Desmodur® N3200, Desmodur® N3300, Desmodur® N3400, Desmodur® N3500, Desmodur® N3600, Desmodur® N3700, Desmodur® N3800, Desmodur® N3900 and Desmodur® 4470, preferably purchased from Covestro;. In the present invention, the average functionality (—NCO) of the oligomer of diisocyanate is preferably 2.4 to 3.5, and more preferably 3.

[0117] In the present invention, the monofunctional active hydrogen substance preferably includes one or more of a monofunctional hydroxyl substance, a monofunctional thiol substance and a monofunctional secondary amine substance. In the present invention, the monofunctional hydroxyl substance preferably includes one or more of an alkyl alcohol, an aromatic alcohol, a phenol and a monofunctional active hydrogen petroleum resin, and more preferably includes one or more of an alkyl alcohol and an aromatic alcohol; the alkyl alcohol preferably includes one or more of isopropanol, isobutyl alcohol, amyl alcohol, isopentanol, 2-ethylhexanol, heptanol, octanol, isooctyl alcohol, nonanol and decanol; the aromatic alcohol preferably includes benzyl alcohol; the phenol preferably includes one or two of phenol and cardanol; the monofunctional active hydrogen petroleum resin preferably includes one or more of LA100, LA300, LS500 and LA700, purchased from Rutger Company.

[0118] In the present invention, the monofunctional thiol substance preferably includes alkyl mercaptan and / or aromatic mercaptan; the alkyl mercaptan preferably includes one or more of ethanethiol, propanethiol, butanethiol, 2-methyl-2-propanethiol, 2-methylbutanethiol, 2-methyl-2-butanethiol, pentanethiol, 2-methyl-2-pentanethiol, hexanethiol, 2-ethylhexanethiol, octanthiol, heptanethiol and nonanethiol; the aromatic mercaptan preferably includes one or more of benzenethiol, 2-methylthiophenol, 3-methylthiophenol, 4-methylthiophenol and 2-ethylthiophenol.

[0119] In the present invention, the monofunctional secondary amine substance preferably includes one or more of alkylamines, aromatic amines, azacycloalkanes, piperazines and pyrroles, and more preferably includes N-ethylmethylamine, diethylamine, N-tert-butylethylamine, diisopropylamine, N-methylisopropylamine, N-ethylisopropylamine, di-n-propylamine, N-isopropylpropylamine, di-n-butylamine, azotidine, N-isopropyl-1-n-butylamine, N-methylbutylamine, N-methyl-tert-butylamine, N-methylisobutylamine, N-ethylbutylamine, N-propylbutylamine, N-tert-butyl-1-n-butylamine, di-tert-amylamine, dipentylamine, pyrrolidine, N-methylpentylamine, N-methylisopentylamine, N-cyclopentyl-n-propylamine (N-cyclopentylisopropylamine), N-ethyl-3-methyl-1-butylamine, N-allylcyclopentylamine, N-butyl-1-pentylamine, dihexylamine, azacyclohexane, N-methylhexylamine, N-ethylhexylamine, N-isopropylcyclohexylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine, N-tert-butylcyclohexylamine, N-benzylcyclohexylamine, dicyclohexyl Amine, N-cyclopropylcyclohexylamine, N-(2-heptyl)cyclohexylamine, diheptylamine, N-methylheptylamine, N-ethylheptylamine, dioctylamine, N-methyloctylamine, N-ethyloctylamine, tert-amyl-tert-octylamine, diisooctylamine, N-methylaniline, N-ethylaniline, N-isopropylaniline, N-butylaniline, N-pentylaniline, N-methylbenzylamine, N-ethylbenzylamine, N-isopropylbenzylamine, N-cyclopropylbenzylamine, N-propylbenzylamine, N-butylbenzylamine, N-(cyclohexylmethyl)benzylamine, N-methyl-1-naphthylamine, N- One or more of ethylnaphthylamine, N-phenyl-1-naphthylamine, N-ethylpiperazine, N-methylpiperazine, 1-propylpiperazine, N-isopropylpiperazine, 1-butylpiperazine, 1-isobutylpiperazine, 1-cyclopentylpiperazine, 1-hexylpiperazine, 1-cyclohexylpiperazine, 1-N-heptylpiperazine, 1-cyclopropylpiperazine, pyrrole, 3-methylpyrrole, 2-methyl-1H-pyrrole, 2-ethylpyrrole, 2,4-dimethyl-3-ethylpyrrole, 3,4-diethylpyrrole, 3-tert-butylpyrrolidine and 2-butylpyrrolidine.

[0120] In the present invention, during the addition reaction of the diisocyanate oligomer with the monofunctional active hydrogen substance, the monofunctional active hydrogen substance reacts with the diisocyanate oligomer according to one active hydrogen group and one -NCO group to obtain an adduct of an aliphatic polyisocyanate having an average -NCO functionality of about 2.0; the molar ratio of the diisocyanate oligomer to the monofunctional active hydrogen substance is preferably determined according to the average functionality of the diisocyanate oligomer. For example, when the diisocyanate oligomer having an average functionality of 2.5 is subjected to an addition reaction with the monofunctional active hydrogen substance, the molar ratio of the diisocyanate oligomer to the monofunctional active hydrogen substance is preferably determined according to the average functionality of the diisocyanate oligomer. The molar ratio of the diisocyanate oligomer with an average functionality of 3.5 and the monofunctional active hydrogen substance are 2.5:0.5; the diisocyanate oligomer with an average functionality of 3.5 and the monofunctional active hydrogen substance are 3.5:1.5; the diisocyanate oligomer with an average functionality of 2.9 and the monofunctional active hydrogen substance are 2.9:0.9; the molar ratios of the diisocyanate oligomers with other average functionalities and the monofunctional active hydrogen substance are similar and will not be described in detail here.

[0121] In the present invention, the aliphatic adduct is preferably used in the form of an aliphatic adduct or an aliphatic adduct-viscosity reducer mixture, and the mass fraction of the viscosity reducer in the aliphatic adduct-viscosity reducer mixture is preferably 0.1 to 90%, more preferably 10 to 50%, and further preferably 20 to 30%. In the present invention, the optional types of the viscosity reducer are preferably the same as the aforementioned viscosity reducer, which will not be repeated here.

[0122] The addition of aliphatic adducts increases the weather resistance of the coating and its adhesion to the substrate.

[0123] In the present invention, the raw materials for preparing the high-strength and high-weather-resistant elastic coating preferably further include a urea-based adduct; the mass ratio of the urea-based adduct to the linear bifunctional aliphatic isocyanate prepolymer is preferably (0-0.5):1, more preferably (0.03-0.3):1. In the present invention, the addition of the urea-based adduct further increases the hydrogen bond donor content of the isocyanate in the coating, which greatly contributes to improving the strength of the coating after curing.

[0124] In the present invention, the urea adduct is preferably obtained by addition reaction of a linear diamine chain extender and an aliphatic diisocyanate; the molar ratio of the linear diamine chain extender to the aliphatic diisocyanate is preferably 1:(1.9-2.1), more preferably 1:2. In the present invention, the number average molecular weight of the linear diamine chain extender is preferably 58-1000, more preferably 100-500; the residues other than the amine groups in the linear diamine chain extender are preferably hydrocarbon segments, or hydrocarbon segments containing benzene ring groups and / or heteroatoms; the heteroatoms preferably include one or more of oxygen, nitrogen and sulfur. In the present invention, the linear diamine chain extender preferably includes one or more of terminal amino chain extenders, aspartic acid esters and amino polyethers, and more preferably includes diethyltoluenediamine (DETDA), dimethylthiotoluenediamine (DMTDA), butanediamine, pentamethylenediamine, hexamethylenediamine, trimethylhexamethylenediamine, isophoronediamine (IPDA), meta-xylylenediamine, cyclohexyldimethylamine, bis(4-aminocyclohexyl)methane (H 12 MDA), 3,6-dioxaoctane-1,8-diamine, 4,7-dioxadecane-1,10-diamine, 4-aminomethyl-1,8-octanediamine, bis(4-amino-3-methyl-cyclohexyl)methane, bicyclo(2,2,1)heptanedimethylamine, tricyclo(5,2,1,0 2,6 ) one or more of decyl dimethylamine, amino-terminated propylene oxide ether, 4,4'-diamino, 3,3'-dichloro-diphenylmethane (MOCA), 2,4-diamino-3,5-dimethylthiochlorobenzene and N,N'-dibutylaminophenylmethane; the molecular weight of the amino-terminated propylene oxide ether is preferably <1000g / mol, more preferably 200~600g / mol. In the present invention, the optional types of the aliphatic diisocyanate are the same as the aforementioned aliphatic diisocyanate, which will not be repeated here. In the present invention, the molar ratio of the aliphatic diisocyanate to the linear diamine chain extender is preferably 2:1.

[0125] In the present invention, the urea adduct is used in the form of a urea adduct or a urea adduct-viscosity reducer mixture, and the mass fraction of the viscosity reducer in the urea adduct-viscosity reducer mixture is 2 to 90%, more preferably 10 to 50%, and further preferably 20 to 30%. In the present invention, the optional types of the viscosity reducer are preferably the same as the aforementioned viscosity reducer, which will not be repeated here.

[0126] In the present invention, the raw materials for preparing the high-strength and high-weather-resistant elastic coating preferably also include aromatic terminal diisocyanate linear adducts; the aromatic terminal diisocyanate linear adducts are preferably obtained by reacting aromatic diisocyanate monomers with difunctional terminal hydroxyl substances; the molar ratio of the aromatic diisocyanate monomers to the difunctional terminal hydroxyl substances is preferably (1.9~2.05):1, more preferably (1.95~2):1. In the present invention, the number average molecular weight of the bifunctional terminal hydroxyl substance is preferably not more than 4000, more preferably 1000-3000; the bifunctional terminal hydroxyl substance preferably includes terminal hydroxyl polyether and / or terminal hydroxyl polyester; the terminal hydroxyl polyether preferably includes one or more of terminal hydroxyl polytetrahydrofuran ether, terminal hydroxyl polymethyltetrahydrofuran ether, terminal hydroxyl polyoxyethylene ether, terminal hydroxyl polyoxypropylene ether and terminal hydroxyl oxybutylene ether; the terminal hydroxyl polyester preferably includes one or more of terminal hydroxyl polycaprolactone, terminal hydroxyl polycarbonate, terminal hydroxyl adipate and terminal hydroxyl polyphthalate, terminal hydroxyl dimer acid ester. In the present invention, the mass ratio of the aromatic terminal diisocyanate linear adduct to the linear bifunctional aliphatic isocyanate prepolymer is preferably (0-0.5):1, more preferably (0.01-0.3):1, and further preferably (0.1-0.2):1. In the present invention, the aromatic diisocyanate monomer preferably includes toluene diisocyanate, or a mixture of toluene diisocyanate and diphenylmethane diisocyanate, wherein the amount of toluene diisocyanate in the mixture is higher than 50%.

[0127] In the present invention, the mass of the latent curing agent is 2-45% of the mass of the total film-forming material, preferably 5-30%, and more preferably 10-20%; the total film-forming material includes a preparation raw material containing an isocyanate group and a latent curing agent; the preparation raw material containing an isocyanate group includes a linear bifunctional aliphatic isocyanate prepolymer; when the preparation raw material of the coating also includes one or more of an aliphatic adduct, a urea adduct and an aromatic terminal diisocyanate linear adduct, the preparation raw material containing an isocyanate group also includes one or more of an aliphatic adduct, a urea adduct and an aromatic diisocyanate linear adduct.

[0128] In the present invention, the raw materials for preparing the high-strength and high-weather-resistant elastic coating preferably also include auxiliary materials, and the auxiliary materials preferably include one or more of a viscosity reducer, a wetting agent, a defoaming agent, a leveling agent, a coupling agent, an antioxidant, a light stabilizer, an anti-aquatic agent, a filler, a pigment, a thixotropic agent, a flame retardant, a hydrolysis accelerator and a catalyst.

[0129] In the present invention, the hydrolysis promoter preferably includes organic acid and / or organic anhydride, more preferably includes benzoic acid, phthalic acid, maleic acid, adipic acid, lauric acid, oleic acid, palmitic acid, stearic acid, dimer acid, phthalic anhydride, hydrogenated phthalic anhydride, salicylic acid, oxalic acid, maleic anhydride, adipic anhydride, methyl hydrogenated phthalic anhydride, malonic acid, succinic acid, glutaric acid, methyl hexahydrophthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, modified methyl tetrahydrophthalic anhydride and nadic anhydride. One or more. In the present invention, the role of the hydrolysis promoter is to accelerate the preferential hydrolysis of the latent curing agent. In the present invention, the mass ratio of the hydrolysis promoter to the latent curing agent is preferably (0~0.8):1, more preferably (0.01~0.6):1, and further preferably (0.1~0.5):1.

[0130] In the present invention, the latent curing agent preferentially hydrolyzes and consumes more than 30% of the highly active -NCO groups in the system, so that dense carbon dioxide aggregation and the formation of coating bubbles can be avoided. More preferably, more than 60% of the -NCO groups in the system are cross-linked by the latent curing agent reaction, and further preferably more than 80% of the NCO groups are cross-linked by the latent curing agent reaction, and most preferably 90-100% of the -NCO groups are cross-linked by the latent curing agent reaction. In the present invention, when all -NCO groups in the system react with all the amino groups and secondary amino groups of the latent hydrolysis, all the cross-linking points are urea groups and uret groups, and almost no NCO cross-linking points are lost; after curing, the number of hydrogen bond donors per unit mass of the coating layer reaches the maximum value, which can not only be applied thickly at one time without bubbles, but also has the best mechanical properties.

[0131] In the present invention, the catalyst preferably includes a metal organic catalyst, more preferably includes one or more of organic tin, organic bismuth, organic zinc and organic zirconium; the mass ratio of the catalyst to the total film-forming material is preferably (0.01-3):100, more preferably (0.1-2):100, and further preferably (0.5-1):100. In the present invention, when the latent curing agent is hydrolyzed to produce secondary amino groups, amino groups and hydroxyl groups, the amino groups and secondary amino groups react preferentially with -NCO groups. When the molar ratio of -NCO groups to amino secondary amino groups is 1:1, the amino secondary amino groups react with all -NCO groups, some hydroxyl groups may react, and some hydroxyl groups do not participate in the reaction; when the catalyst is present and the total amount of amino groups and secondary amino groups after the latent curing agent is hydrolyzed is lower than the number of -NCO groups, the catalyst can promote the cross-linking reaction between the hydroxyl groups produced by hydrolysis and the -NCO groups.

[0132] In the present invention, the optional types of the viscosity reducer are preferably the same as the aforementioned viscosity reducer, which will not be described in detail herein.

[0133] In the present invention, the filler preferably includes an inorganic filler and / or an organic filler; the inorganic filler powder preferably includes one or more of calcium carbonate, barium sulfate, silica powder, quartz powder, porcelain powder, ceramic powder, glass powder, garnet powder, kaolin, cement clinker, talcum powder, lithopone and alumina; the organic filler preferably includes polyvinyl chloride and / or chlorinated polyethylene; the mass ratio of the filler to the linear bifunctional aliphatic isocyanate prepolymer is preferably (0~50):100, more preferably (0~30):100, further preferably (0.1~20):100. Adding fillers can reduce costs and help increase mechanical properties.

[0134] In the present invention, the pigment preferably includes one or more of titanium dioxide, zinc dioxide, barium dioxide, carbon black, phthalocyanine pigments, iron oxide red, iron oxide yellow, iron oxide black, chrome yellow and organic pigments; the mass ratio of the pigment to the linear bifunctional aliphatic isocyanate prepolymer is preferably (0-30):100, more preferably (1-20):100, and further preferably (3-15):100.

[0135] In the present invention, the stabilizer preferably includes p-toluenesulfonyl isocyanate (PTSI) and / or an acyl chloride stabilizer, the acyl chloride stabilizer preferably includes one or more of formyl chloride, acetyl chloride and benzoyl chloride, and the stabilizer more preferably includes PTSI and formyl chloride, acetyl chloride, benzoyl chloride; the mass ratio of the stabilizer to the linear bifunctional aliphatic isocyanate prepolymer is preferably (0-2):100, more preferably (0.01-1):100. In the present invention, adding a stabilizer to the high-strength and high-weather-resistant elastic coating can improve the stability of the coating system and extend its storage period.

[0136] In the present invention, the thixotropic agent includes one or more of white carbon black, carbon black, amide thixotropic agent and urea-based thixotropic agent; the mass ratio of the thixotropic agent to the linear two-functional isocyanate prepolymer is preferably (0-20): 100, more preferably (0.1-5): 100. In the present invention, adding a thixotropic agent to the high-strength and high-weather-resistant elastic coating can improve the rheological properties of the coating and assist in improving the strength.

[0137] In the present invention, the coupling agent preferably includes one or more of epoxysiloxane, isocyanatesiloxane, titanate and acrylatesiloxane; the mass ratio of the coupling agent to the linear two-functional aliphatic isocyanate prepolymer is preferably (0.2-3): 100, more preferably (0.5-2): 100. In the present invention, adding a coupling agent to the high-strength and high-weather-resistant elastic coating can increase the adhesion between the coating and the substrate.

[0138] In the present invention, the anti-aquatic organism additive preferably includes one or more of capsaicin, sulfonamide compounds and cuprous compounds; the mass ratio of the anti-aquatic organism additive to the linear bifunctional aliphatic isocyanate prepolymer is preferably (0-1.5):1, more preferably (0.01-1):1. The present invention adds an anti-aquatic organism additive to the high-strength and high-weather-resistant elastic coating, which is beneficial to prevent aquatic organisms from attaching to the coating surface when the coating is used in a water environment, improves corrosion resistance, and prevents aquatic organisms from lying on the surface of the hull in the water and affecting the activities of the ship.

[0139] In the present invention, the defoamer preferably includes an organosilicon defoamer; the mass ratio of the defoamer to the linear difunctional isocyanate prepolymer is preferably (0-0.5): 100, more preferably (0.1-0.5): 100. In the present invention, adding a defoamer to the high-strength and high-weather-resistant elastic coating can improve the physical defoaming process of the coating and prevent the generation of physical air bubbles in the coating film after construction.

[0140] In the present invention, the leveling agent preferably includes one or more of an acrylic leveling agent, a silicone leveling agent and a fluorocarbon leveling agent; the mass ratio of the leveling agent to the linear two-functional aliphatic isocyanate prepolymer is preferably (0-1): 100, more preferably (0.1-0.5): 100. In the present invention, adding a leveling agent to the high-strength and high-weather-resistant elastic coating is beneficial to the construction and automatic leveling of the coating, and a good coating appearance is obtained.

[0141] In the present invention, the antioxidant preferably includes an organic phenol antioxidant and / or a phosphite antioxidant; the weight ratio of the antioxidant to the linear difunctional aliphatic isocyanate prepolymer is preferably (0-5):100, more preferably (0.1-2):100. In the present invention, adding an antioxidant to the high-strength and high-weather-resistant elastic coating can increase the ability of the cured coating film to resist oxidation in the air.

[0142] In the present invention, the anti-ultraviolet agent is preferably an ultraviolet absorber and / or a light stabilizer, and more preferably comprises Tinuvin 123 and / or Tinuvin 292; the mass ratio of the anti-ultraviolet agent to the linear two-functional aliphatic isocyanate prepolymer is preferably (0-0.5): 100. In the present invention, an anti-ultraviolet agent is added to the high-strength and high-weather-resistant elastic coating so that the coating film has the ability to resist ultraviolet rays under sunlight after curing.

[0143] In the present invention, the total content of the viscosity reducer in the high-strength and high-weather-resistant elastic coating is preferably 0-60wt%, more preferably 1-50wt%, and further preferably 5-30wt%.

[0144] The present invention provides a method for preparing the high-strength and high-weather-resistant elastic coating described in the above technical solution, comprising the following steps:

[0145] (1) A bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate are mixed and subjected to an addition reaction to obtain a linear bifunctional aliphatic isocyanate prepolymer;

[0146] (2) The linear bifunctional aliphatic isocyanate prepolymer and the latent curing agent are mixed under dry conditions to obtain a high-strength and high-weather-resistant elastic coating.

[0147] The invention mixes a bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate for addition reaction to obtain a linear bifunctional aliphatic isocyanate prepolymer.

[0148] In the present invention, the addition reaction preferably obtains one linear difunctional aliphatic isocyanate prepolymer or a mixture of a plurality of linear difunctional aliphatic isocyanate prepolymers.

[0149] In the present invention, the mixing is preferably heating the difunctional terminal hydroxyl long-chain substance and the difunctional active hydrogen short-chain substance to remove water, and then adding the aliphatic diisocyanate and mixing. In the present invention, the heating dehydration is preferably vacuum heating dehydration, the temperature of the heating dehydration is preferably 100~120℃, more preferably 105~115℃, and further preferably 110℃, the vacuum degree of the vacuum heating dehydration is preferably -0.09~-0.098MPa, more preferably -0.095MPa, and an azeotrope is preferably added during the heating dehydration process, and the azeotrope preferably includes toluene, xylene or methylcyclohexane; the ratio of the mass of the azeotrope to the total mass of the two-functional terminal hydroxyl long-chain substance and the two-functional active hydrogen short-chain substance is preferably (1~3):100, more preferably (1.5~2.5):100, and further preferably 2:100; the present invention has no special limitation on the time of the heating dehydration, and the heating dehydration is performed until the total water content of the two-functional terminal hydroxyl long-chain substance and the two-functional active hydrogen short-chain substance is preferably <300ppm.

[0150] In the present invention, the addition reaction is preferably carried out under dry conditions, and the dry conditions preferably include vacuum conditions or dry inert gas protection conditions, and the vacuum degree of the vacuum condition is preferably -0.09~-0.095MPa; the inert gas preferably includes argon, helium or nitrogen; the dry inert gas protection condition is preferably evacuated and then filled with dry inert gas; the water content of the dry condition is preferably <300ppm. In the present invention, the temperature of the addition reaction is preferably 80~125℃, more preferably 100~120℃; the time of the addition reaction is preferably 2~8h, more preferably 4~6h; the addition reaction is preferably carried out under air-tight conditions. In a specific embodiment of the present invention, it is preferred to test the -NCO content in the aliphatic mixed prepolymer to determine the time of the addition reaction, and stop the addition reaction when the test value of the -NCO content differs from the theoretical design value by no more than 3%. In the present invention, the mass content of -NCO groups in the linear difunctional aliphatic isocyanate prepolymer is preferably 2-10%, more preferably 3-7%.

[0151] In the present invention, the linear difunctional aliphatic isocyanate prepolymer is preferably prepared in the presence of auxiliary materials, so as to facilitate the removal of moisture in advance; the specific steps are preferably: mixing one or more of the auxiliary materials, a difunctional hydroxyl-terminated long-chain substance and a difunctional active hydrogen short-chain substance, heating and vacuum dehydration, then adding aliphatic diisocyanate to mix and carry out addition reaction to obtain a prepolymer-pigment-viscosity reducer mixture, adding one or more of urea adducts, aliphatic adducts and aromatic diisocyanate linear adducts or not adding urea adducts, aliphatic adducts and aromatic diisocyanate linear adducts, and finally adding a latent curing agent to obtain a high-strength and high-weatherability elastic coating. In the present invention, the mass ratio of the viscosity reducer to the difunctional hydroxyl-terminated long-chain substance is preferably (0-20):100, more preferably (5-10):100. In the present invention, the heating dehydration is preferably vacuum heating dehydration, the heating dehydration temperature is preferably 100-120°C, more preferably 105-115°C, and further preferably 110°C, the vacuum degree of the vacuum heating dehydration is preferably -0.09-0.098MPa, more preferably -0.095MPa, and the heating dehydration time is preferably 1-3h, more preferably 2h. In the present invention, the temperature of the addition reaction is preferably 80-125°C, more preferably 90-120°C; the time of the addition reaction is preferably 2-8h, more preferably 2-5h; the addition reaction is preferably carried out in an airtight condition.

[0152] In the present invention, it is preferred to synthesize one or more linear difunctional aliphatic isocyanate prepolymers first, and then use them after mixing the linear difunctional aliphatic isocyanate prepolymers.

[0153] After obtaining the linear bifunctional aliphatic isocyanate prepolymer, the present invention mixes the linear bifunctional aliphatic isocyanate prepolymer and a latent curing agent under dry conditions to obtain a high-strength and high-weather-resistant elastic coating.

[0154] In the present invention, when the preparation raw materials also include one or more of a linear difunctional aliphatic isocyanate prepolymer, a urea-based adduct, an aliphatic adduct, an aromatic terminal diisocyanate linear adduct and auxiliary materials, the linear difunctional aliphatic isocyanate prepolymer and the latent curing agent are mixed under dry conditions and replaced by: the linear difunctional aliphatic isocyanate prepolymer, the urea-based adduct, the aliphatic adduct, the aromatic terminal diisocyanate linear adduct and one or more of the auxiliary materials are mixed, and then the latent curing agent is added and mixed to obtain a high-strength and high-weatherability one-component coating.

[0155] The present invention also provides a method for preparing the high-strength and high-weather-resistant elastic coating described in the above technical solution, comprising the following steps: mixing a two-functional group terminal hydroxyl long-chain substance, a two-functional group active hydrogen short-chain substance and an auxiliary material, then adding an aliphatic diisocyanate to mix for addition reaction, then adding one or more of a urea adduct, an aliphatic adduct and an aromatic terminal diisocyanate linear adduct to mix, and finally adding a latent curing agent to mix to obtain a high-strength and high-weather-resistant single-component coating. In the present invention, the two-functional group terminal hydroxyl long-chain substance, the two-functional group active hydrogen short-chain substance and the auxiliary material are preferably dried before use. In the present invention, the preparation conditions of the high-strength and high-weather-resistant elastic coating are the same as those of the aforementioned high-strength and high-weather-resistant elastic coating, and will not be repeated here.

[0156] The present invention provides the application of the high-strength and high-weather-resistant elastic coating described in the above technical scheme or the high-strength and high-weather-resistant elastic coating obtained by the preparation method described in the above technical scheme in waterproofing, protection, anti-corrosion, flooring, coating or sealing and bonding; the application industries preferably include hydraulic engineering, new energy, transportation, railways, bridges, construction, municipal administration, light industry, electricity, electronics, machinery, vehicles, marine engineering, underground, communications, chemical industry, sewage, seawater desalination, wind energy, photovoltaics, nuclear energy, hydropower, aerospace, mining, shipbuilding or metallurgy.

[0157] In order to further illustrate the present invention, the high-strength and high-weather-resistant elastic coating and its preparation method and application are described in detail below in conjunction with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0158] In the following examples and comparative examples, unless otherwise specified, the test was carried out under standard test conditions of (23+ / -2)°C and (50+ / -5)% relative humidity, the vacuum degree of the container or the air-tight container was in a range of -0.09 to -0.095 MPa, and the raw materials and synthetic intermediates were as follows:

[0159] Hydroxyl-terminated diol polyester, 2200A from Yueyang Juren Company, average molecular weight about 2000 g / mol;

[0160] Hydroxyl-terminated polytetramethylene oxide, BASF's polyTHF ® 2000, average molecular weight about 2000 g / mol; polyTHF ® 1000, average molecular weight 1000 g / mol.

[0161] Hydroxyl-terminated polyoxypropylene ether PPG, DL-2000 from Dongda Company, average molecular weight about 2000 g / mol;

[0162] Two-functional hydroxyl-terminated polymer polyether (polymer with a content of more than 35%, containing styrene and acrylonitrile), trade name LTCP-245, provided by Lingtong Chemical Technology Co., Ltd.;

[0163] Dipropylene glycol, DPG, Dow Chemical;

[0164] 1,4-Butanediol, BDO, Shanxi Sanwei;

[0165] Isophorone diamine, IPDA, BASF;

[0166] Isophorone diisocyanate, IPDI, Covestro;

[0167] Dicyclohexylmethane diisocyanate, H 12 MDI, Wanhua Chemical;

[0168] Bicyclic oxazolidine, trade name Desmofen ® Hardner OZ, based on the adduct of 2-isopropyl-3-hydroxyethyl 1,3-oxazolidine and hexamethylene diisocyanate, Allnex (formerly Bayer) bicyclic oxazolidine latent curing agent; it is an oxazolidine with two five-membered rings containing an urethane group;

[0169] Bicyclic oxazolidine, trade name Desmofen ® hardner VP LS 2959, produced by Allnex (formerly Bayer).

[0170] Trade name A-139 aldimine, Evonik (Degussa), based on the addition dehydration product of isobutyraldehyde and isophorone diamine;

[0171] Trade name: 302 aldimine, a dehydrated adduct of benzaldehyde and hexamethylenediamine, provided by Guangzhou Jinzhao Environmental Protection Materials Co., Ltd.

[0172] HDI oligomer, trade name Demodur ® N100, provided by Covestro;

[0173] Isooctyl alcohol, produced by Hualu Group Corporation;

[0174] Aspartic acid ester, trade name Desmofen ® NH 1420, Covestro.

[0175] PMA propylene glycol methyl ether acetate, Dow Chemical;

[0176] Butanone, MEK, purchased from the market;

[0177] Barium sulfate, ultrafine powder, purchased from the market; quartz powder, ultrafine powder, purchased from the market; titanium dioxide (rutile type), ultrafine powder, purchased from the market; calcium oxide, ultrafine powder, purchased from the market; gas silica white, Wacker, Germany.

[0178] DuPont titanium dioxide 706.

[0179] All molecular weights in the present invention are number average molecular weights.

[0180] EFCA 2722, additive from BASF.

[0181] MHTPA methylhexahydrophthalic anhydride, Puyang Huicheng Company.

[0182] IPDI, a Covestro company;

[0183] TDI, Cangzhou Dahua Company;

[0184] MDI50, Wanhua Chemical Company;

[0185] HDI, Covestro;

[0186] DMF, NN dimethylformamide, purchased from the market.

[0187] H 12 MDA, Wanhua Chemical Company.

[0188] NMP, N-methylpyrrolidone, purchased from the market.

[0189] BiCAT® 8108 Catalyst, Shepherd Lead Chemicals.

[0190] KH 560 epoxy silane coupling agent, purchased from the market.

[0191] Example 1

[0192] Preparation of polyaldimine AlM-001 (dehydration addition product of benzaldehyde and isophoronediamine IPDA)

[0193] 220 parts of benzaldehyde, 169 parts of isophorone diamine and 60 parts of toluene were mixed, and the mixture was subjected to a thermal reaction at 80°C for 6 hours under a vacuum pressure of -0.090 to -0.095 MPa for complete dehydration. The toluene solution was refluxed, and after GC testing, the elution peak of isophorone diamine disappeared, thereby obtaining AIM-001 aldimine latent curing agent.

[0194] Example 2

[0195] Preparation of aliphatic adduct ADT-001

[0196] 52 parts of Desmodur ® N100 and 13.5 parts of dry isooctyl alcohol were mixed under dry, air-tight vacuum conditions, 55 parts of PMA were added, and the mixture was reacted at 110°C for 4 hours to obtain aliphatic adduct ADT-001.

[0197] Example 3

[0198] Preparation of Linear Bifunctional Aromatic Prepolymer ADT-002

[0199] Under vacuum conditions, 200 parts of polyTHF ® 2000, 34 parts of TDI and 20 parts of PMA were added and reacted at 75°C for 3 hours to obtain the linear bifunctional aromatic prepolymer ADT-002.

[0200] Example 4

[0201] Preparation of urea adduct U-01

[0202] Using 16.9 parts (WT) of dry IPDA, 45 parts of IPDI and 69 parts of PMA, IPDA was added dropwise to the IPDI / PMA solution in an airtight environment at 20-30°C. After stirring evenly at 500-1100 r / min, the mixture was reacted for 0.3 h to obtain the urea adduct U-01.

[0203] Example 5

[0204] Preparation of linear bifunctional aliphatic isocyanate prepolymer PU-101 (abbreviated as PU-101)

[0205] In terms of mass, 100 parts of dry 2200A terminal hydroxyl polyester, 0.1 parts of benzoyl chloride, 43 parts of dry DMF, and 50 parts of dicyclohexylmethane diisocyanate were used, and 4.5 parts of melted dry butanediol were added dropwise. The mixture was isolated from air and reacted at 110°C for 6 hours to obtain a linear bifunctional aliphatic isocyanate prepolymer PU-101.

[0206] Example 6

[0207] Preparation of linear bifunctional aliphatic isocyanate prepolymer PU-102 (abbreviated as PU-102)

[0208] By mass, 100 parts of PTMEG (polyTHF ® 2000, BASF), 7 parts of DPG, 10 parts of Desmofen ® NH1420, 40 parts of PMA, 60 parts of dicyclohexylmethane diisocyanate, and 0.1 parts of benzoyl chloride were mixed evenly in an airtight condition and reacted at 110°C for 6 hours to obtain a linear bifunctional aliphatic isocyanate prepolymer PU-102.

[0209] Example 7

[0210] Preparation of linear bifunctional aliphatic isocyanate prepolymer PU-103 (abbreviated as PU-103)

[0211] In terms of mass, 100 parts of dried DL-2000 terminal hydroxyl oxide propylene ether, 100 parts of dried melted (70°C) PolyTHF® 2000, 139 parts of dicyclohexylmethane diisocyanate, 2 parts of dried NMP, 2 parts of DMF, and 100 parts of PMA are first stirred evenly below 70°C, and then 15 parts of dried BDO butanediol are added dropwise at 110°C in three times. The reaction is carried out for 7 hours to obtain a linear two-functional aliphatic isocyanate prepolymer PU-103.

[0212] Example 8

[0213] Preparation of linear bifunctional aliphatic isocyanate prepolymer PU-104 (abbreviated as PU-104)

[0214] In terms of mass, 100 parts of dry polyTHF ® 2000, 25 parts of dry PMA, and 10 parts of DMF were used, and 45 parts of IPDI were added. The mixture was stirred evenly, and then 21 parts of dicyclohexylmethane diisocyanate were added. The mixture was mixed evenly. Then, 10 parts of melted BDO butanediol were added dropwise at 110°C in two batches. The mixture was reacted for 6 hours to obtain a linear bifunctional aliphatic isocyanate prepolymer PU-104.

[0215] Example 9

[0216] Preparation of precursor QU-105

[0217] In parts by mass, 100 parts of linear two-functional hydroxyl-terminated polymer polyether LTCP-245, 15 parts of DPG, 2 parts of dry barium sulfate ultrafine powder, 3 parts of dry silicon powder, 2 parts of fumed silica white carbon black, 2 parts of rutile titanium dioxide, 0.1 parts of acetylene carbon black, 1 part of EFCA 2722, and 15 parts of xylene are mixed evenly, dehydrated at 105°C and vacuum degree of -0.090MPa for 2h, filled with dry nitrogen, and then 70 parts of dicyclohexylmethane diisocyanate and 15 parts of dry butanone are added, and the reaction is carried out at 115°C for 5h to obtain the precursor QU-105.

[0218] Example 10

[0219] In parts by mass, 60 parts of PU-101, 8 parts of butyl acetate, 5 parts of butanone, 5 parts of dry barium sulfate, 1 part of fumed silica V15, 3 parts of dry DuPont titanium dioxide 706, 0.1 part of carbon black, 1 part of additive EFCA 2722, 2 parts of KH560 coupling agent, 6 parts of Desmofen® hardner OZ, and 0.05 parts of Bicat® 8108 were added and stirred evenly in an airtight manner to obtain a high-strength and high-weather-resistant elastic coating SJK-001.

[0220] Embodiment 11

[0221] In parts by mass, 60 parts of PU-101 are added with 5 parts of butyl acetate, 5 parts of butanone, 5 parts of dry barium sulfate, 1 part of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 parts of carbon black, 1 part of auxiliary agent EFCA 2722, 2 parts of KH560 coupling agent, and 6.9 parts of aldimine A-139. The mixture is isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-002.

[0222] Example 12

[0223] In parts by mass, 60 parts of PU-101 were added with 5 parts of butyl acetate, 5 parts of butanone, 5 parts of dry barium sulfate, 1 part of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 parts of carbon black, 1 part of additive EFCA 2722, 2 parts of KH560 coupling agent, 4 parts of aldimine A-139, and 3 parts of Desmofen® hardner OZ. The mixture was isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-003.

[0224] Example 13

[0225] In terms of mass, 60 parts of PU-102 are added with 5 parts of PMA, 5 parts of butanone, 5 parts of dry barium sulfate, 2 parts of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 parts of carbon black, 1 part of auxiliary agent EFCA 2722, 2 parts of KH560 coupling agent, 3 parts of A-139, and 4.5 parts of polyaldehyde imine AlM-001. The mixture is isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-004.

[0226] Embodiment 14

[0227] In terms of mass, 60 parts of PU-102 were added with 5 parts of PMA, 8 parts of butanone, 5 parts of dry barium sulfate, 2 parts of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 parts of carbon black, 1 part of additive EFCA 2722, 2 parts of KH560 coupling agent, 6.0 parts of A-139, and 1.5 parts of Desmofen® hardner OZ. The mixture was isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-005.

[0228] Embodiment 15

[0229] In terms of mass, 60 parts of PU-103, 5 parts of PMA, 3 parts of butanone, 5 parts of dry barium sulfate, 1 part of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 part of carbon black, 1 part of additive EFCA 2722, 2 parts of KH560 coupling agent, and 8.5 parts of aldimine A139 were added, and the mixture was isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-006.

[0230] Example 16

[0231] In parts by mass, 60 parts of PU-103, 5 parts of PMA, 3 parts of butanone, 5 parts of dry barium sulfate, 1 part of white carbon black V15, 3 parts of dry titanium dioxide DuPont 706, 0.1 parts of carbon black, 1 part of additive EFCA 2722, 2 parts of KH560 coupling agent, 5.5 parts of aldimine A-139, 2.5 parts of Desmofen® hardner OZ, and 0.05 parts of BiCAT®8108 catalyst were added, and the mixture was isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-007.

[0232] Embodiment 17

[0233] In terms of mass, 60 parts of PU-104 were added with 5 parts of PMA, 5 parts of butanone, 5 parts of dry barium sulfate, 1 part of white carbon black V15, 3 parts of dry titanium dioxide DuPont 706, 0.1 parts of carbon black, 1 part of additive EFCA 2722, 2 parts of KH560 coupling agent, 2 parts of Desmofen® hardner OZ, and 6.5 parts of aldimine A-139. The mixture was isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-008.

[0234] Embodiment 18

[0235] In terms of mass, 60 parts of QU-105 were added with 5 parts of PMA, 3 parts of butanone, 1.5 parts of KH560 coupling agent, 5 parts of A-139 aldimine, and 1.8 parts of Desmofen® hardner OZ. The mixture was stirred evenly in an air-tight environment to obtain a high-strength and high-weather-resistant elastic coating SJK-009.

[0236] Embodiment 19

[0237] In terms of mass, 60 parts of PU-102 were added with 5 parts of PMA, 5 parts of butanone, 5 parts of dry barium sulfate, 1 part of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 parts of carbon black, 1 part of auxiliary agent EFCA 2722, 2 parts of KH560 coupling agent, and 3 parts of urea adduct U-01. After stirring evenly, 6 parts of aldimine A-139 and 2.0 parts of Desmofen® hardner OZ were added. The mixture was isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-010.

[0238] Embodiment 20

[0239] In parts by mass, 60 parts of PU-102 were added with 5 parts of PMA, 5 parts of butanone, 5 parts of dry barium sulfate, 1 part of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 part of carbon black, 1 part of auxiliary agent EFCA 2722, 2 parts of KH560 coupling agent, and 3 parts of aliphatic adduct ADT-001 prepared in Example 2. After stirring evenly, 2 parts of Desmofen® hardner OZ and 5.8 parts of aldimine A-139 were added, and the mixture was isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-011.

[0240] Embodiment 21

[0241] In parts by mass, 60 parts of PU-102 were added with 5 parts of PMA, 5 parts of butanone, 5 parts of dry barium sulfate, 1 part of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 parts of carbon black, 1 part of auxiliary agent EFCA 2722, 2 parts of KH560 coupling agent, and 2 parts of linear bifunctional aromatic prepolymer ADT-002 prepared in Example 3. After stirring evenly, 2.0 parts of Desmofen® hardnerOZ and 5.0 parts of aldimine A-139 were added, and the mixture was isolated from air and stirred evenly to obtain a high-strength and high-weather-resistant elastic coating SJK-012.

[0242] Comparative Example 1

[0243] In terms of mass, 100 parts of polyTHF ® 2000, 15 parts of DPG, 48 parts of TDI, 15 parts of PMA, and 0.3 parts of benzoyl chloride were added, and the mixture was reacted at 90°C for 3 hours to obtain an aromatic prepolymer. 60 parts of the aromatic prepolymer were added with 5 parts of PMA, 5 parts of butanone, 5 parts of dry barium sulfate, 3 parts of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 parts of carbon black, 1 part of auxiliary agent EFCA 2722, and 2 parts of KH560 coupling agent, and stirred evenly, and then 7.0 parts of Desmofen ® hardner OZ and 3 parts of polyaldehyde imine A-139 were added, and the mixture was isolated from air and stirred evenly to obtain coating DSJK-01.

[0244] Comparative Example 2

[0245] By weight, 100 parts of polyTHF ® 2000, 13.1 parts of H 12 MDI, 11.2 parts IPDI, add 12 parts PMA, react at 110℃ for 5h to obtain aliphatic prepolymer. Take 60 parts of the aliphatic prepolymer, add 5 parts PMA, 5 parts butanone, 5 parts dry barium sulfate, 1 part white carbon black V15, 3 parts dry titanium dioxide 706, 0.1 parts carbon black, 1 part auxiliary agent EFCA 2722, 2 parts KH560 coupling agent, stir evenly, add 2.3 parts aldimine A-139, 3 parts Desmofen ®hardner VP LS 2959, isolate air and stir evenly to obtain coating DSJK-02.

[0246] Comparative Example 3

[0247] In terms of mass fractions, 100 parts of DL-2000, 9.8 parts of tripropylene glycol, 0.2 parts of benzoyl chloride, 48 parts of diphenylmethane diisocyanate MDI 50 (Wanhua Chemical), and 15 parts of dry PMA were added, and the reaction was carried out at 80°C for 3 hours to obtain an aromatic prepolymer. 60 parts of the aromatic prepolymer were added with 8 parts of PMA, 8 parts of butanone, 5 parts of dry barium sulfate, 3 parts of white carbon black V15, 3 parts of dry titanium dioxide 706, 0.1 parts of carbon black, 1 part of auxiliary agent EFCA 2722, and 2 parts of KH560 coupling agent, and stirred evenly, and then 4 parts of polyaldehyde imine A-139 and 5 parts of Desmofen ® hardner VP LS 2959, as well as 0.5 parts of MHTPA were added, and the mixture was isolated from air and stirred evenly to obtain the coating DSJK-03.

[0248] Test Case

[0249] The coatings prepared in each embodiment and each comparative example were coated on a PE plate under standard test conditions of (23±2)°C and (50±5)% relative humidity. The coating thickness was 1.5 mm. The coating was turned over on the 5th day and continued to be cured for 9 days. According to the conditions of JC / T2435-2018, the tensile properties were tested and the coating was irradiated in a QUVA box for 2000 hours. The surface color change ΔE before and after irradiation was observed. The results are shown in Table 1.

[0250] Table 1 Performance test results of the one-component coatings prepared in various embodiments and comparative examples

[0251]

[0252] It can be seen from Table 1 that the tensile strength of the high-strength and high-weather-resistant elastic coatings SJK-001 to SJK-012 prepared in the examples is 10 MPa or above, and after 2000h of ultraviolet irradiation in the QUVA box, the color change ΔE before and after irradiation is 0.9~2.8, which is less than 3; however, in Comparative Example 1, since the main chain adopts an aromatic prepolymer, although the tensile strength is relatively high, exceeding 10MPa, after 2000h of QUVA ultraviolet irradiation, the color change ΔE is as high as 3.8, and there is a certain slight powdering phenomenon on the surface. Comparative Example 2 adopts an aliphatic prepolymer, but no chain extender is used, and the prepolymer hydrogen bond donor content is less than 1.0 mol / kg. Although the color change is small, its tensile strength is only 6.5MPa, which does not meet the high strength requirement of 10MPa; Comparative Example 3 all uses low cohesive energy long-chain terminal hydroxyl polyoxypropylene ether as the main chain, and uses aromatic isocyanate. Although there is a terminal hydroxyl chain extender, the tensile strength is only 5.8MPa, and the color change ΔE is as high as 4.5 or more. After QUVA ultraviolet irradiation, the surface cracks and powders seriously.

[0253] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-strength and high-weather-resistant elastic coating, the raw materials for preparation include a linear bifunctional aliphatic isocyanate prepolymer and a latent curing agent; The linear bifunctional aliphatic isocyanate prepolymer is obtained by adding a bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate; The latent curing agent is one or more of bicyclic oxazolidine and polyaldimine; the bicyclic oxazolidine is an oxazolidine containing two five-membered rings; the polyaldimine is a substance containing two and / or three aldimine groups, obtained by dehydration after addition of C3-C10 aldehyde and polyamine; The mass of the latent curing agent is 2-45% of the mass of the total film-forming material, and the total film-forming material includes a preparation raw material containing an isocyanate group and a latent curing agent; the preparation raw material containing an isocyanate group includes a linear bifunctional aliphatic isocyanate prepolymer; The ratio of the amount of the aliphatic diisocyanate to the total amount of the two-functional terminal hydroxyl long-chain substance and the two-functional active hydrogen short-chain substance is (1.2-1.95): 1; The two-functional active hydrogen short-chain substance includes one or more of a two-functional diol short-chain substance and / or a two-functional secondary amine short-chain substance; The molecular weight of the bifunctional diol short-chain substance is <500 g / mol, and the molecular weight of the bifunctional secondary amine short-chain substance is ≤900 g / mol; The bifunctional hydroxyl-terminated long-chain substance includes a bifunctional hydroxyl-terminated high cohesive energy long-chain substance; the molecular weight of the bifunctional hydroxyl-terminated long-chain substance is 500-5000 g / mol; The content of hydrogen bond donor in the linear bifunctional aliphatic isocyanate prepolymer is 1.05-6 mol / kg; the content of hydrogen bond donor is the ratio of the total amount of hydroxyl and secondary amine groups in the bifunctional terminal hydroxyl long-chain substance and the bifunctional active hydrogen short-chain substance to the mass of the linear bifunctional aliphatic isocyanate prepolymer; The molar ratio of the two-functional active hydrogen short-chain substance to the two-functional terminal hydroxyl long-chain substance is (0-8):1 and is not 0; The bifunctional hydroxyl-terminated long-chain substance also includes a bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance; the mass ratio of the bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance to the bifunctional hydroxyl-terminated high cohesive energy long-chain substance in the bifunctional hydroxyl-terminated long-chain substance is less than 5; The bifunctional hydroxyl-terminated high cohesive energy long-chain substance includes one or more of hydroxyl-terminated polyester, hydroxyl-terminated polytetrahydrofuran ether, hydroxyl-terminated polymethyltetrahydrofuran ether and bifunctional hydroxyl-terminated polymer polyether; the bifunctional hydroxyl-terminated polymer polyether includes LTCP-245; The bifunctional hydroxyl-terminated low cohesive energy polyether long-chain substance includes one or more of bifunctional hydroxyl-terminated polyoxypropylene ether, bifunctional hydroxyl-terminated polyoxyethylene ether and bifunctional hydroxyl-terminated polyoxyethylene propylene ether.

2. The high-strength and high-weather-resistant elastic coating according to claim 1, characterized in that: The residues other than the hydroxyl group and the secondary amine group in the two-functional group active hydrogen short-chain substance are hydrocarbon segments, or hydrocarbon segments containing benzene ring groups and / or heteroatoms; the heteroatoms include one or more of oxygen, nitrogen and sulfur; The aliphatic diisocyanate includes one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, meta-xylylene diisocyanate, para-xylylene diisocyanate, o-xylylene diisocyanate, cyclohexyl dimethylene diisocyanate, pentamethylene diisocyanate, trimethylhexamethylene diisocyanate and tetramethylene diisocyanate.

3. The high-strength and high-weather-resistant elastic coating according to claim 1 or 2, characterized in that: The raw materials for preparing the high-strength and high-weather-resistant elastic coating also include aliphatic adducts; The aliphatic adducts include adducts of oligomers of diisocyanates and monofunctional active hydrogen substances; The oligomer of diisocyanate includes one or more of dimers and trimers of hexamethylene diisocyanate and / or isophorone diisocyanate, or at least two of dimers, trimers and tetramers; The monofunctional active hydrogen substance includes one or more of a monofunctional hydroxyl substance, a monofunctional thiol substance and a monofunctional secondary amine substance; The mass ratio of the aliphatic adduct to the linear bifunctional aliphatic isocyanate prepolymer is (0-0.5):1; The functionality of the aliphatic adduct is 1.95 to 2.05; The aliphatic adduct is used in the form of an aliphatic adduct or an aliphatic adduct-viscosity reducer mixture, wherein the mass fraction of the viscosity reducer in the aliphatic adduct-viscosity reducer mixture is 0.1 to 90%; The isocyanate group-containing preparation raw materials include aliphatic adducts.

4. The high-strength and high-weather-resistant elastic coating according to claim 3, characterized in that: The raw materials for preparing the high-strength and high-weather-resistant elastic coating also include urea-based adducts; The mass ratio of the urea adduct to the linear bifunctional aliphatic isocyanate prepolymer is (0-0.5):1; The urea-based adduct is obtained by the addition reaction of a linear diamine chain extender and an aliphatic diisocyanate; The urea-based adduct is used in the form of a urea-based adduct or a urea-based adduct-viscosity reducer mixture, wherein the mass fraction of the viscosity reducer in the urea-based adduct-viscosity reducer mixture is 2 to 90%; The isocyanate group-containing preparation raw materials include urea adducts.

5. The high-strength and high-weather-resistant elastic coating according to claim 1 or 2, characterized in that: The raw materials for preparing the high-strength and high-weather-resistant elastic coating also include auxiliary materials, which include one or more of a viscosity reducer, a wetting agent, a defoamer, a leveling agent, a coupling agent, an antioxidant, a light stabilizer, an anti-aquatic agent, a filler, a pigment, a thixotropic agent, a flame retardant, a hydrolysis accelerator and a catalyst.

6. The method for preparing the high-strength and high-weather-resistant elastic coating according to claim 1 or 2, characterized in that: The following steps are involved: (1) A bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate are mixed and subjected to an addition reaction to obtain a linear bifunctional aliphatic isocyanate prepolymer; (2) The linear bifunctional aliphatic isocyanate prepolymer and the latent curing agent are mixed under dry conditions to obtain a high-strength and high-weather-resistant elastic coating.

7. The method for preparing the high-strength and high-weather-resistant elastic coating according to claim 3, characterized in that: The following steps are involved: (1) A bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate are mixed and subjected to an addition reaction to obtain a linear bifunctional aliphatic isocyanate prepolymer; (2) The linear bifunctional aliphatic isocyanate prepolymer and the aliphatic adduct are mixed, and then a latent curing agent is added to obtain a high-strength and high-weatherability one-component coating.

8. The method for preparing the high-strength and high-weather-resistant elastic coating according to claim 4, characterized in that: The following steps are involved: (1) A bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate are mixed and subjected to an addition reaction to obtain a linear bifunctional aliphatic isocyanate prepolymer; (2) The linear bifunctional aliphatic isocyanate prepolymer, the aliphatic adduct and the urea adduct are mixed, and then a latent curing agent is added and mixed to obtain a high-strength and high-weatherability one-component coating.

9. The method for preparing the high-strength and high-weather-resistant elastic coating according to claim 5, characterized in that: The following steps are involved: (1) A bifunctional terminal hydroxyl long-chain substance, a bifunctional active hydrogen short-chain substance and an aliphatic diisocyanate are mixed and subjected to an addition reaction to obtain a linear bifunctional aliphatic isocyanate prepolymer; (2) The linear bifunctional aliphatic isocyanate prepolymer and auxiliary materials are mixed, and then a latent curing agent is added to mix, so as to obtain a high-strength and high-weather-resistant single-component coating.

10. Use of the high-strength and high-weather-resistant elastic coating according to any one of claims 1 to 5 or the high-strength and high-weather-resistant elastic coating obtained by the preparation method according to any one of claims 6 to 9 in waterproofing, protection, anti-corrosion or flooring.

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