Water-based hybrid polyurea weather-resistant finish paint as well as preparation method and application thereof

Abstract

The invention discloses a water-based hybrid polyurea weather-resistant finish paint and a preparation method and application thereof.The water-based hybrid polyurea weather-resistant finish paint is prepared from polyisocyanate, an active emulsifier, an alkali metal salt water solution, pigment and auxiliaries, and the active emulsifier, the auxiliaries and the pigment are dispersed and ground to obtain a component A; stirring polyisocyanate to obtain a component B; an alkali metal salt water solution is stirred to obtain a component C, the component A and the component B are mixed and added into the component C to be dispersed at a high speed, and the water-based hybrid polyurea weather-resistant finish paint is prepared and used for surface construction of steel and concrete structures in the corrosive atmospheric environment, a first water-based hybrid polyurea heavy anti-corrosion coating of 140-240 micrometers is sprayed, brushed or roller-coated, and a second water-based hybrid polyurea heavy anti-corrosion coating of 140-240 micrometers is sprayed, brushed or roller-coated to obtain the water-based hybrid polyurea weather-resistant finish paint. And then the second water-based hybridized polyurea weather-resistant finish paint is 80-120 microns and has excellent adhesive force, mechanical strength, chemical resistance, corrosion resistance and weather resistance.

Description

Technical Field

[0001] The invention relates to the technical field of weather-resistant topcoats, and in particular to a water-based hybrid polyurea weather-resistant topcoat and a preparation method and application thereof. Background Art

[0002] Weathering topcoat is a special coating designed to provide long-term protection and beautification, especially for buildings, structures and objects exposed to outdoor environments. Weathering topcoat has excellent weather resistance: it can resist the erosion of harsh outdoor environments for a long time, and is not easy to fade, crack and fall off; good decorative properties: it usually has excellent gloss and fullness, which can enhance the overall visual effect of the coated object; strong adhesion: it has good adhesion to a variety of substrates (such as metal, wood, concrete, etc.), ensuring that the coating is not easy to peel off; protective performance: it has good resistance to chemical corrosion, water resistance, and oil resistance, and can protect the substrate from damage by the external environment.

[0003] Acrylic weather-resistant topcoat: With acrylic resin as the main film-forming substance, it has excellent weather resistance, decorative and protective properties. It is widely used in the fields of construction, furniture, transportation, etc., providing customers with an integrated solution of beauty, durability and anti-aging; Water-based weather-resistant waterproof anti-corrosion topcoat: It adopts advanced water-based technology and abandons the harmful volatiles in traditional solvent-based coatings, and has excellent environmental protection, weather resistance and anti-corrosion properties. It can form a dense protective film on the surface of various substrates, effectively isolating the erosion of moisture, oxygen and corrosive substances; Durable polyester topcoat: It is made of polyester synthetic raw materials with good durability and chemical resistance, and has excellent weather resistance and mechanical properties. It is usually used in the preparation of high-durability coil coatings, which can meet the needs of long-term outdoor use; Fluorocarbon weather-resistant topcoat: With fluororesin as the main film-forming substance, it has excellent outdoor durability and chemical resistance. It is particularly suitable for the outdoor architectural color board market with high weather resistance requirements.

[0004] Compared with ordinary anticorrosive coatings, heavy-duty anticorrosive coatings can be used in relatively harsh corrosive environments, and their durability is longer, reaching 15 years or even more than 25 years. Even in acid, alkali, salt and solvent media and under certain temperature conditions, they can be used for more than 5 years. The dry film thickness of ordinary anticorrosive coatings is usually 100-200μm, while the dry film thickness of weather-resistant topcoats is more than 200-400μm, and even up to 2000μm. Weather-resistant topcoats are the most technically representative, influential and promising type of anticorrosive coatings.

[0005] The development of low-VOC high-performance water-based and solvent-free weather-resistant topcoats has become one of the current research hotspots.

[0006] At present, water-based inorganic zinc silicate, water-based epoxy, water-based polyurethane, water-based fluorocarbon coatings and other products have been successfully developed. However, water-based heavy-duty anti-corrosion coatings are prone to flash corrosion, and their chemical resistance, corrosion resistance and mechanical properties are relatively poor. They are not suitable for severe corrosive environments and still need further improvement. Solvent-free epoxy coatings have excellent mechanical properties, chemical resistance and corrosion resistance, and a solid content of up to 100%, but they usually have a high viscosity and a short application period, and many products contain benzyl alcohol, which is considered a source of volatile organic compounds according to the new regulations.

[0007] Weathering topcoat is a coating with excellent weathering resistance, which can resist the erosion of natural factors such as ultraviolet rays, wind and rain, temperature changes, etc., so as to maintain the gloss, integrity and performance of the coating. Weathering topcoat is widely used in various buildings, structures and objects that need to be exposed to outdoor environments for a long time, such as: Construction field: used for coating of building exterior walls, roofs, doors and windows, etc., to provide long-term protection and beautification effect; Transportation field: used for coating of traffic facilities such as bridges, road guardrails, traffic signs, etc., to improve their durability and safety; Industrial field: used for coating of industrial equipment, storage tanks, pipelines and other facilities to prevent them from aging and damage due to corrosion; Furniture field: used for coating of outdoor furniture, such as garden tables and chairs, balcony railings, etc., to provide beautiful and durable protection.

[0008] In addition, the single function of heavy-duty anti-corrosion coatings can no longer meet the huge demand of the modern coatings industry, and it is imperative to diversify the functions of heavy-duty anti-corrosion coatings, such as high-temperature anti-corrosion coatings, conductive anti-corrosion coatings, intumescent fire-retardant coatings, self-healing anti-corrosion coatings, nano-composite coatings, fouling release coatings, and primer-and-surface all-in-one coatings.

[0009] Therefore, it is necessary to develop a green, high-performance weather-resistant topcoat that is suitable for durable decorative protection of surfaces such as steel and concrete in corrosive atmospheres, including petrochemicals, marine engineering, ships and warships, infrastructure, energy transportation, mining and smelting, water treatment facilities, food and medicine, papermaking and printing, OEM, construction and other fields, in order to extend the service life of industrial facilities, reduce energy loss and VOC emissions, and ensure that they meet strict environmental protection requirements.

[0010] Organic-inorganic hybrid polymers are new materials that have attracted much attention in recent years because they can chemically bond organic polymers and inorganic materials in a special structure and use their inherent properties to obtain unusual performance combinations. In general, the properties of organic-inorganic hybrid polymers are usually far superior to non-hybrid materials. For example, hybrid polyurea has higher chemical resistance, radiation resistance and thermal stability than epoxy or polyurethane.

[0011] "Sol-gel" is the most effective method for synthesizing organic-inorganic hybrid polymers, which is chemically related to the polycondensation reaction of organic molecules. When the sol gels into wet gel, the nanoparticles aggregate and form an inorganic skeleton. Thereafter, under different drying conditions, two different structures of aerogel or xerogel are formed. Xerogels can be functionalized to connect active groups on the surface of the gel. Hybrid polymers are formed by the reaction of organic gels with corresponding components.

[0012] "Joint polycondensation" is an innovative synthesis method that is more technically advantageous than "sol-gel". Its characteristics are: since both organic and inorganic substances contain active groups, organic and inorganic components can be polymerized simultaneously in their active mixtures to obtain the most homogeneous interpenetrating network. By changing the chemical composition and ratio of organic and inorganic, the physical and chemical properties of the final organic-inorganic hybrid polymer can be regulated in a wide range. The nanocomposite materials developed in this way have great application potential as heavy-duty anticorrosive coatings.

[0013] Weathering topcoat is a coating with excellent weathering resistance, designed to protect buildings, equipment, etc. from erosion and damage by the natural environment. Weathering topcoat occupies an important position in the coatings industry with its excellent performance and wide application fields. In the future, with the continuous advancement of science and technology and changes in market demand, weathering topcoat will continue to develop in the direction of environmental protection, high performance, multi-function and intelligence. Summary of the invention

[0014] Technical issues solved:

[0015] The purpose of the present invention is to overcome the technical problems existing in the prior art in terms of weather resistance stability. Although the weather-resistant topcoat has excellent weather resistance, its performance may gradually decline under long-term exposure to extreme climatic conditions, leading to problems such as coating aging, cracking, and falling off; in terms of construction performance, some weather-resistant topcoats may have defects such as slow drying speed, sagging, and shrinkage during construction; in terms of environmental protection performance, some weather-resistant topcoats may contain harmful substances such as volatile organic compounds (VOCs), causing pollution to the environment. The present application provides a water-based hybrid polyurea weather-resistant topcoat and a preparation method and application thereof.

[0016] Technical solution:

[0017] To achieve the above objectives, this application is implemented through the following technical solutions:

[0018] A water-based hybrid polyurea weather-resistant topcoat, wherein the raw materials of the water-based hybrid polyurea weather-resistant topcoat are, according to the weight ratio, 37-43 parts of polyisocyanate, 19-27 parts of active emulsifier, 13-26 parts of alkali metal salt aqueous solution, 0.5-18 parts of pigment, and 0.5-3 parts of auxiliary agent; the polyisocyanate is one or more of aliphatic diisocyanate, aliphatic diisocyanate dimer, aliphatic diisocyanate trimer, aliphatic diisocyanate oligomer derivative, alicyclic diisocyanate, alicyclic diisocyanate dimer, alicyclic diisocyanate trimer, and alicyclic diisocyanate oligomer derivative.

[0019] Preferably, the raw materials of the water-based hybrid polyurea weather-resistant topcoat are calculated by weight: 38 to 42 parts of polyisocyanate, 21 to 24 parts of active emulsifier, 17 to 23 parts of alkali metal salt aqueous solution, 1 to 16 parts of pigment, and 1 to 2 parts of additive.

[0020] Preferably, the polyisocyanate is solvent-free isophorone diisocyanate IPDI, 4,4'-dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI, hexamethylene diisocyanate dimer, hexamethylene diisocyanate trimer, a derivative of isophorone diisocyanate IPDI, a derivative of 4,4'-dicyclohexylmethane diisocyanate HMDI, a derivative of hexamethylene diisocyanate HDI, a derivative of hexamethylene diisocyanate dimer or a derivative of hexamethylene diisocyanate trimer.

[0021] Preferably, the reactive emulsifier is a reactive epoxy compound, and the reactive epoxy compound is a hydrogenated bisphenol A epoxy resin and / or an epoxy reactive diluent.

[0022] Preferably, the alkali metal salt aqueous solution is a silicate aqueous solution and / or a borate aqueous solution.

[0023] Preferably, the pigment is an inorganic pigment and / or an organic pigment.

[0024] Preferably, the auxiliary agent is one or more of a catalyst, a rheological agent, a leveling agent, and a light stabilizer.

[0025] A method for preparing any of the above-mentioned water-based hybrid polyurea weather-resistant topcoats comprises the following steps:

[0026] Step 1: Disperse and grind the active emulsifier, additives and pigment to a particle size of ≤10 μm to obtain component A;

[0027] Step 2: Stir the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B;

[0028] Step 3: Stir the alkali metal salt aqueous solution at a speed of 300-500 r / min for 20-30 min to obtain component C;

[0029] Step 4: Mix component A and component B at a speed of 300-500 r / min for 1-2 minutes, adjust the stirring speed to 200-300 r / min, add component C at a uniform speed, add it within 0.5-1 minute, and disperse it at a high speed of 500-1000 r / min for 3-5 minutes to prepare a water-based hybrid polyurea weather-resistant topcoat.

[0030] The present application also discloses the use of any of the above-mentioned water-based hybrid polyurea weather-resistant topcoats in the durable decorative protection of steel and concrete surfaces in a corrosive atmospheric environment.

[0031] Principle explanation: "Sol-gel" is the most effective method for synthesizing organic-inorganic hybrid polymers. It is chemically related to the condensation reaction of organic molecules. When the sol gel enters the wet gel, the nanoparticles aggregate and form an inorganic skeleton. Subsequently, under different drying conditions, two aerogels or dry gels with different structures are formed. The dry gel can be functionalized to connect the active groups on the surface of the gel. The hybrid polymer is formed by the reaction of the organic gel with the corresponding components. The "combined condensation" of this application is an innovative synthesis method. Compared with "sol-gel", it has more technical advantages. The characteristics of "combined condensation" are: since both organic and inorganic substances contain active groups, the organic and inorganic components can be polymerized simultaneously in their active mixture to obtain the most homogeneous interpenetrating network. By changing the organic and inorganic chemical compositions and their proportions, the physical and chemical properties of the final organic-inorganic hybrid polymer can be regulated over a wide range. The nanocomposite materials thus developed have great application potential as weather-resistant topcoats.

[0032] Beneficial effects:

[0033] The present application provides a water-based hybrid polyurea weather-resistant topcoat and a preparation method and application thereof, which have the following beneficial effects:

[0034] 1. The water-based hybrid polyurea weather-resistant topcoat of the present application is obtained by the "joint polycondensation" reaction of polyisocyanate and active emulsifier in the presence of an alkali metal salt aqueous solution, and a dense molecular structure and nano-scale closed barrier are generated in situ, so that the water-based hybrid polyurea weather-resistant topcoat provided by the present application integrates the advantages of organic-inorganic composite materials, and has excellent adhesion and mechanical strength, chemical resistance, corrosion resistance and weather resistance;

[0035] 2. The water-based hybrid polyurea weather-resistant topcoat of this application is a non-hazardous chemical with zero VOC emissions, which is safe, environmentally friendly, non-toxic and odorless;

[0036] 3. The water-based hybrid polyurea weather-resistant topcoat of this application has good construction performance and can be sprayed, brushed or rolled on surfaces such as steel and concrete, in a single or double-layer system, saving labor and time;

[0037] 4. The water-based hybrid polyurea weather-resistant topcoat of this application is suitable for use in corrosive atmospheric environments, especially in extreme conditions and areas requiring corrosion resistance and wear resistance, including petrochemicals, marine engineering, ships and vessels, infrastructure, energy transportation, mining and smelting, water treatment facilities, food and medicine, papermaking and printing, OEM, construction and other fields, as a topcoat or single-layer system;

[0038] 5. The water-based hybrid polyurea weather-resistant topcoat of the present application is a room temperature curing system with a curing temperature range of 10°C to 60°C; the viscosity range of the water-based hybrid polyurea weather-resistant topcoat is controlled between 70-110 KU, and the applicable period is 40-80 minutes; the solid content of the water-based hybrid polyurea weather-resistant topcoat is required to reach 85-95%, and it is convenient to construct by spraying, brushing or roller coating, the curing temperature can be as low as 10°C, and the maximum relative humidity is 85%; it is used for surface construction of steel and concrete structures in corrosive atmospheric environments by spraying, brushing or roller coating the first coat of water-based hybrid polyurea heavy anti-corrosion coating 140-240 microns, and then the second coat of water-based hybrid polyurea weather-resistant topcoat 80-120 microns, which meets / exceeds HG / T 5059-2016 "Anti-corrosion Coatings for Offshore Oil Platforms" and GB / T50393-2017 "Technical Standards for Anti-corrosion Engineering of Steel Petroleum Storage Tanks". DETAILED DESCRIPTION

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0040] Water-based hybrid polyurea weather-resistant topcoat contains polyisocyanate, active emulsifier and alkali metal salt aqueous solution, which determine the adhesion, mechanical strength, chemical resistance, corrosion resistance, weather resistance and workability of the coating.

[0041] The polyisocyanate is one or more of aliphatic diisocyanate, dimer of aliphatic diisocyanate, trimer of aliphatic diisocyanate, oligomer derivative of aliphatic diisocyanate, alicyclic diisocyanate, dimer of alicyclic diisocyanate, trimer of alicyclic diisocyanate, oligomer derivative of alicyclic diisocyanate.

[0042] Preferably, the polyisocyanate is solvent-free isophorone diisocyanate IPDI, 4,4'-dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI, hexamethylene diisocyanate dimer, hexamethylene diisocyanate trimer, a derivative of isophorone diisocyanate IPDI, a derivative of 4,4'-dicyclohexylmethane diisocyanate HMDI, a derivative of hexamethylene diisocyanate HDI, a derivative of hexamethylene diisocyanate dimer or a derivative of hexamethylene diisocyanate trimer.

[0043] Typical aliphatic diisocyanates are Desmodur 3600 (Covestro), Desmodur 3900 (Covestro), Tolonate HDT-LV2 (Vencorex), Coronate HXLV (Tosoh), Wannate HT-500 (Wanhua), Wannate HT-600 (Wanhua), and Desmodur 3400 (Covestro).

[0044] Typical alicyclic diisocyanates are Vestanat IPDI (Evonik), Desmodur I (Covestro), Basonat I (BASF), Wannate IPDI (Wanhua), Vestanat H 12 MDI (Evonik), Desmodur W (Covestro), Wannate HMDI (Wanhua).

[0045] Hydrogenated bisphenol A epoxy resins include Eponex Resin 1510 (Hexion), EP-4080E (Adeka), ST-3000

[0046] (Kukdo), Epalloy 5000 (CVC), XY518 (Anhui Xinyuan Technology) or more.

[0047] Epoxy reactive diluents include Heloxy Modifier 8 (Hexion), Araldite DY-E (Huntsman), Epodil

[0048] 748 (Evonik), Erisys GE 8 (CVC) or more.

[0049] The silicate aqueous solution and / or borate aqueous solution is specifically C30 water-based curing agent (Beijing Haiyan Technology) and / or C31

[0050] Water-based curing agent (Beijing Haiyan Technology).

[0051] The pigment is an inorganic pigment and / or an organic pigment, specifically one or more of titanium dioxide, carbon black, phthalocyanine green, phthalocyanine blue, quinoline yellow and quinacridone red.

[0052] The catalyst is one or more of primary amino alcohol (AMP-Ultra PC, Angus), organic metal compound (Dabco Catalyst T-12, Evonik), inorganic salt (FeCl3, AlCl3, ZnCl2).

[0053] The rheological agent was a polyamide wax (Crayvallac Optima, Arkema).

[0054] The leveling agent is silicone.

[0055] The light stabilizer was a hindered amine light stabilizer (Tinuvin 292, BASF).

[0056] Embodiment 1:

[0057] A water-based hybrid polyurea weather-resistant topcoat, wherein the raw materials of the water-based hybrid polyurea weather-resistant topcoat are, according to the weight ratio, 43.4 parts of polyisocyanate, 26.1 parts of active emulsifier, 13.0 parts of alkali metal salt aqueous solution, 16 parts of pigment, and 1.5 parts of auxiliary agent. The active emulsifier is hydrogenated bisphenol A epoxy resin Eponex Resin 1510 and epoxy active diluent Heloxy Modifier 8; the rheological agent in the auxiliary agent is polyamide wax Crayvallac Optima, the leveling agent is silicone, the light stabilizer is hindered amine light stabilizer Tinuvin 292, the catalyst is an organic metal compound Dabco Catalyst T-12, the pigment is titanium dioxide, the alkali metal salt aqueous solution is C30 water-based curing agent and / or C31 water-based curing agent, and the polyisocyanate is aliphatic diisocyanate Wannate HT-500 and / or alicyclic diisocyanate Wannate IPDI.

[0058] A method for preparing a water-based hybrid polyurea weather-resistant topcoat comprises the following steps:

[0059] Step 1: Grind the active emulsifier, additives and pigments with a high-speed disperser or sand mill to a particle size of ≤10 μm to obtain component A;

[0060] Step 2: Stir the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B;

[0061] Step 3: Stir the alkali metal salt aqueous solution at a speed of 300-500 r / min for 20-30 min to obtain component C;

[0062] Step 4: Mix component A and component B at a speed of 300-500 r / min for 1-2 minutes, adjust the stirring speed to 200-300 r / min, add component C at a uniform speed, add it within 0.5-1 minute, and disperse it at a high speed of 500-1000 r / min for 3-5 minutes to prepare a water-based hybrid polyurea weather-resistant topcoat.

[0063] The water-based hybrid polyurea weather-resistant topcoat is used in the wear-resistant and anti-corrosion coating on the surfaces of steel, concrete and the like in a corrosive atmospheric environment. The first coat of water-based hybrid polyurea heavy anti-corrosion coating is 140-240 microns, and the second coat of water-based hybrid polyurea weather-resistant topcoat is 80-120 microns. The curing temperature range is 10° C. to 60° C., the maximum relative humidity is 85%, the viscosity range of the water-based hybrid polyurea weather-resistant topcoat is controlled between 70-110 KU, the applicable period is 80 minutes, and it is easy to construct, such as airless spraying, brushing or roller coating.

[0064] The preparation method of the first water-based hybrid polyurea heavy anti-corrosion coating is as follows:

[0065] Step 1: According to the weight ratio, 45 parts of polyisocyanate, 35.6 parts of active emulsifier, 18 parts of alkali metal salt aqueous solution, and 1.4 parts of auxiliary agent are mixed, and the active emulsifier and auxiliary agent are dispersed and ground to a particle size of ≤10 μm to obtain component A of heavy-duty anticorrosive coating;

[0066] Step 2: Mix the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B of the heavy-duty anticorrosive coating;

[0067] Step 3: Stir the alkali metal salt aqueous solution at a speed of 300-500 r / min for 20-30 min to obtain the heavy anti-corrosion coating component C;

[0068] Step 4: Stir component A and component B at 300-500r / min for 1-2min, adjust the stirring speed to 200-300r / min, add component C at a uniform speed within 0.5-1 minute, and disperse at high speed at 500-1000r / min for 3-5 minutes to obtain a water-based hybrid polyurea heavy-duty anti-corrosion coating.

[0069] Embodiment 2:

[0070] A water-based hybrid polyurea weather-resistant topcoat, wherein the raw materials of the water-based hybrid polyurea weather-resistant topcoat are, according to the weight ratio, 41.6 parts of polyisocyanate, 24.0 parts of active emulsifier, 16.9 parts of alkali metal salt aqueous solution, 16 parts of pigment, and 1.5 parts of auxiliary agent. The active emulsifier is hydrogenated bisphenol A epoxy resin Eponex Resin 1510 and epoxy active diluent Heloxy Modifier 8; the rheological agent in the auxiliary agent is polyamide wax Crayvallac Optima, the leveling agent is silicone, the light stabilizer is hindered amine light stabilizer Tinuvin 292, the catalyst is an organic metal compound Dabco Catalyst T-12, the pigment is titanium dioxide, the alkali metal salt aqueous solution is C30 water-based curing agent and / or C31 water-based curing agent, and the polyisocyanate is aliphatic diisocyanate Wannate HT-500 and / or alicyclic diisocyanate Wannate IPDI.

[0071] A method for preparing a water-based hybrid polyurea weather-resistant topcoat comprises the following steps:

[0072] Step 1: Grind the active emulsifier, additives and pigments with a high-speed disperser or sand mill to a particle size of ≤10 μm to obtain component A;

[0073] Step 2: Stir the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B;

[0074] Step 3: Stir the alkali metal salt aqueous solution at a speed of 300-500 r / min for 20-30 min to obtain component C;

[0075] Step 4: Mix component A and component B at a speed of 300-500 r / min for 1-2 minutes, adjust the stirring speed to 200-300 r / min, add component C at a uniform speed, add it within 0.5-1 minute, and disperse it at a high speed of 500-1000 r / min for 3-5 minutes to prepare a water-based hybrid polyurea weather-resistant topcoat.

[0076] The water-based hybrid polyurea weather-resistant topcoat is used in the wear-resistant and anti-corrosion coating on the surfaces of steel, concrete and the like in a corrosive atmospheric environment. The first coat of water-based hybrid polyurea heavy anti-corrosion coating is 140-240 microns, and the second coat of water-based hybrid polyurea weather-resistant topcoat is 80-120 microns. The curing temperature range is 10° C. to 60° C., the maximum relative humidity is 85%, the viscosity range of the water-based hybrid polyurea weather-resistant topcoat is controlled between 70-110 KU, the applicable period is 70 minutes, and it is easy to construct, such as airless spraying, brushing or roller coating.

[0077] The preparation method of the water-based hybrid polyurea heavy-duty anti-corrosion coating is shown in Example 1.

[0078] Embodiment 3:

[0079] A water-based hybrid polyurea weather-resistant topcoat, wherein the raw materials of the water-based hybrid polyurea weather-resistant topcoat are, according to the weight ratio, 39.9 parts of polyisocyanate, 22.6 parts of active emulsifier, 20.0 parts of alkali metal salt aqueous solution, 16 parts of pigment, and 1.5 parts of auxiliary agent. The active emulsifier is hydrogenated bisphenol A epoxy resin Eponex Resin 1510 and epoxy active diluent Heloxy Modifier 8; the rheological agent in the auxiliary agent is polyamide wax Crayvallac Optima, the leveling agent is silicone, the light stabilizer is hindered amine light stabilizer Tinuvin 292, the catalyst is an organic metal compound Dabco Catalyst T-12, the pigment is titanium dioxide, the alkali metal salt aqueous solution is C30 water-based curing agent and / or C31 water-based curing agent, and the polyisocyanate is aliphatic diisocyanate Wannate HT-500 and / or alicyclic diisocyanate Wannate IPDI.

[0080] A method for preparing a water-based hybrid polyurea weather-resistant topcoat comprises the following steps:

[0081] Step 1: Grind the active emulsifier, additives and pigments with a high-speed disperser or sand mill to a particle size of ≤10 μm to obtain component A;

[0082] Step 2: Stir the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B;

[0083] Step 3: Stir the alkali metal salt aqueous solution at a speed of 300-500 r / min for 20-30 min to obtain component C;

[0084] Step 4: Mix component A and component B at a speed of 300-500 r / min for 1-2 minutes, adjust the stirring speed to 200-300 r / min, add component C at a uniform speed, add it within 0.5-1 minute, and disperse it at a high speed of 500-1000 r / min for 3-5 minutes to prepare a water-based hybrid polyurea weather-resistant topcoat.

[0085] The water-based hybrid polyurea weather-resistant topcoat is used in the wear-resistant and anti-corrosion coating on the surfaces of steel, concrete and the like in a corrosive atmospheric environment. The first coat of water-based hybrid polyurea heavy anti-corrosion coating is 140-240 microns, and the second coat of water-based hybrid polyurea weather-resistant topcoat is 80-120 microns. The curing temperature range is 10° C. to 60° C., the maximum relative humidity is 85%, the viscosity range of the water-based hybrid polyurea weather-resistant topcoat is controlled between 70-110 KU, the applicable period is 60 minutes, and it is easy to construct, such as airless spraying, brushing or roller coating.

[0086] The preparation method of the water-based hybrid polyurea heavy-duty anti-corrosion coating is shown in Example 1.

[0087] Embodiment 4:

[0088] A water-based hybrid polyurea weather-resistant topcoat, wherein the raw materials of the water-based hybrid polyurea weather-resistant topcoat are, according to the weight ratio, 38.3 parts of polyisocyanate, 21.2 parts of active emulsifier, 23.0 parts of alkali metal salt aqueous solution, 16 parts of pigment, and 1.5 parts of auxiliary agent. The active emulsifier is hydrogenated bisphenol A epoxy resin Eponex Resin 1510 and epoxy active diluent Heloxy Modifier 8; the rheological agent in the auxiliary agent is polyamide wax Crayvallac Optima, the leveling agent is silicone, the light stabilizer is hindered amine light stabilizer Tinuvin 292, the catalyst is an organic metal compound Dabco Catalyst T-12, the pigment is titanium dioxide, the alkali metal salt aqueous solution is C30 water-based curing agent and / or C31 water-based curing agent, and the polyisocyanate is aliphatic diisocyanate Wannate HT-500 and / or alicyclic diisocyanate Wannate IPDI.

[0089] A method for preparing a water-based hybrid polyurea weather-resistant topcoat comprises the following steps:

[0090] Step 1: Grind the active emulsifier, additives and pigments with a high-speed disperser or sand mill to a particle size of ≤10 μm to obtain component A;

[0091] Step 2: Stir the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B;

[0092] Step 3: Stir the alkali metal salt aqueous solution at a speed of 300-500 r / min for 20-30 min to obtain component C;

[0093] Step 4: Mix component A and component B at a speed of 300-500 r / min for 1-2 minutes, adjust the stirring speed to 200-300 r / min, add component C at a uniform speed within 0.5-1 minute, and disperse at a high speed of 500-1000 r / min for 3-5 minutes to prepare a water-based hybrid polyurea weather-resistant topcoat.

[0094] The water-based hybrid polyurea weather-resistant topcoat is used in the wear-resistant and anti-corrosion coating on the surfaces of steel, concrete and the like in a corrosive atmospheric environment. The first coat of water-based hybrid polyurea heavy anti-corrosion coating is 140-240 microns, and the second coat of water-based hybrid polyurea weather-resistant topcoat is 80-120 microns. The curing temperature range is 10° C. to 60° C., the maximum relative humidity is 85%, the viscosity range of the water-based hybrid polyurea weather-resistant topcoat is controlled between 70-110 KU, the applicable period is 50 minutes, and it is easy to construct, such as airless spraying, brushing or roller coating.

[0095] The preparation method of the water-based hybrid polyurea heavy-duty anti-corrosion coating is shown in Example 1.

[0096] Embodiment 5:

[0097] A water-based hybrid polyurea weather-resistant topcoat, wherein the raw materials of the water-based hybrid polyurea weather-resistant topcoat are, according to the weight ratio, 36.9 parts of polyisocyanate, 19.8 parts of active emulsifier, 25.8 parts of alkali metal salt aqueous solution, 16 parts of pigment, and 1.5 parts of auxiliary agent. The active emulsifier is hydrogenated bisphenol A epoxy resin Eponex Resin 1510 and epoxy active diluent Heloxy Modifier 8; the rheological agent in the auxiliary agent is polyamide wax Crayvallac Optima, the leveling agent is silicone, the light stabilizer is hindered amine light stabilizer Tinuvin 292, the catalyst is an organic metal compound Dabco Catalyst T-12, the pigment is titanium dioxide, the alkali metal salt aqueous solution is C30 water-based curing agent and / or C31 water-based curing agent, and the polyisocyanate is aliphatic diisocyanate Wannate HT-500 and / or alicyclic diisocyanate Wannate IPDI.

[0098] A method for preparing a water-based hybrid polyurea weather-resistant topcoat comprises the following steps:

[0099] Step 1: Grind the active emulsifier, additives and pigments with a high-speed disperser or sand mill to a particle size of ≤10 μm to obtain component A;

[0100] Step 2: Stir the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B;

[0101] Step 3: Stir the alkali metal salt aqueous solution at a speed of 300-500 r / min for 20-30 min to obtain component C;

[0102] Step 4: Mix component A and component B at a speed of 300-500 r / min for 1-2 minutes, adjust the stirring speed to 200-300 r / min, add component C at a uniform speed, add it within 0.5-1 minute, and disperse it at a high speed of 500-1000 r / min for 3-5 minutes to prepare a water-based hybrid polyurea weather-resistant topcoat.

[0103] The water-based hybrid polyurea weather-resistant topcoat is used in the wear-resistant and anti-corrosion coating on the surfaces of steel, concrete, etc. in a corrosive atmospheric environment. The first layer of water-based hybrid polyurea heavy anti-corrosion coating is 140-240 microns, and the second layer of water-based hybrid polyurea weather-resistant topcoat is 80-120 microns; the curing temperature range is 10° C. to 60° C., the maximum relative humidity is 85%, the viscosity range of the water-based hybrid polyurea weather-resistant topcoat is controlled between 70-110 KU, the applicable period is 40 minutes, and it is easy to construct, such as airless spraying, brushing or roller coating.

[0104] The preparation method of the water-based hybrid polyurea heavy-duty anti-corrosion coating is shown in Example 1.

[0105] The compositions, physical parameters and paint film properties of the waterborne hybrid polyurea weather-resistant topcoats provided in Examples 1 to 5 are shown in Table 1.

[0106] Table 1: Composition and properties of waterborne hybrid polyurea weathering topcoat

[0107]

[0108]

[0109] Comparison between waterborne hybrid polyurea and polyurethane:

[0110]

[0111] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the water-based hybrid polyurea weather-resistant topcoat of the present invention is obtained by the "combined polycondensation" reaction of polyisocyanate and active emulsifier in the presence of an alkali metal salt aqueous solution, and a dense molecular structure and nano-scale closed barrier are generated in situ, integrating the advantages of organic-inorganic composite materials, and having excellent adhesion and mechanical strength, chemical resistance, corrosion resistance and weather resistance, good construction performance, zero VOC emissions, environmentally friendly and safe, non-toxic and odorless, and can be sprayed, brushed or rolled on surfaces such as steel and concrete, a single-layer or double-layer system, saving labor and time, and is suitable for use in corrosive atmospheric environments, including petrochemicals, marine engineering, ships and warships, infrastructure, energy and transportation, mining and smelting, water treatment facilities, food and medicine, papermaking and printing, OEM, construction and other fields.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A water-based hybrid polyurea weather-resistant topcoat, characterized in that: The raw materials of the water-based hybrid polyurea weather-resistant topcoat are calculated by weight: 37 to 43 parts of polyisocyanate, 19 to 27 parts of active emulsifier, 13 to 26 parts of alkali metal salt aqueous solution, 0.5 to 18 parts of pigment, and 0.5 to 3 parts of additives; the polyisocyanate is one or more of aliphatic diisocyanate, aliphatic diisocyanate dimer, aliphatic diisocyanate trimer, aliphatic diisocyanate oligomer derivative, alicyclic diisocyanate, alicyclic diisocyanate dimer, alicyclic diisocyanate trimer, and alicyclic diisocyanate oligomer derivative.

2. The water-based hybrid polyurea weather-resistant topcoat according to claim 1, characterized in that: The raw materials of the water-based hybrid polyurea weather-resistant topcoat are calculated by weight: 38-42 parts of polyisocyanate, 21-24 parts of active emulsifier, 17-23 parts of alkali metal salt aqueous solution, 1-16 parts of pigment, and 1-2 parts of auxiliary agent.

3. The water-based hybrid polyurea weather-resistant topcoat according to claim 1, characterized in that: The polyisocyanate is solvent-free isophorone diisocyanate IPDI, 4,4'-dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI, hexamethylene diisocyanate dimer, hexamethylene diisocyanate trimer, a derivative of isophorone diisocyanate IPDI, a derivative of 4,4'-dicyclohexylmethane diisocyanate HMDI, a derivative of hexamethylene diisocyanate HDI, a derivative of hexamethylene diisocyanate dimer or a derivative of hexamethylene diisocyanate trimer.

4. The water-based hybrid polyurea weather-resistant topcoat according to claim 1, characterized in that: The active emulsifier is an active epoxy compound, and the active epoxy compound is hydrogenated bisphenol A epoxy resin and / or epoxy active diluent.

5. The water-based hybrid polyurea weather-resistant topcoat according to claim 1, characterized in that: The alkali metal salt aqueous solution is a silicate aqueous solution and / or a borate aqueous solution.

6. The water-based hybrid polyurea weather-resistant topcoat according to claim 1, characterized in that: The pigment is an inorganic pigment and / or an organic pigment.

7. The water-based hybrid polyurea weather-resistant topcoat according to claim 1, characterized in that: The auxiliary agent is one or more of a catalyst, a rheological agent, a leveling agent, and a light stabilizer.

8. A method for preparing the waterborne hybrid polyurea weather-resistant topcoat according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Disperse and grind the active emulsifier, additives and pigment to a particle size of ≤10 μm to obtain component A; Step 2: Stir the polyisocyanate at a speed of 300-500 r / min for 10-20 min to obtain component B; Step 3: Stir the alkali metal salt aqueous solution at a speed of 300-500 r / min for 20-30 min to obtain component C; Step 4: Mix component A and component B at a speed of 300-500 r / min for 1-2 minutes, adjust the stirring speed to 200-300 r / min, add component C at a uniform speed, add it within 0.5-1 minute, and disperse it at a high speed of 500-1000 r / min for 3-5 minutes to prepare a water-based hybrid polyurea weather-resistant topcoat.

9. Use of the water-based hybrid polyurea weather-resistant topcoat according to any one of claims 1 to 7 for durable decorative protection of steel and concrete surfaces in a corrosive atmospheric environment, characterized in that: The first coat of water-based hybrid polyurea heavy-duty anti-corrosion coating is 140-240 microns, and the second coat of water-based hybrid polyurea weather-resistant topcoat is 80-120 microns.

Images